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PMID:29590

Utilization of D-amino acids by dadR mutants of Salmonella typhimurium.

Utilization of D-amino acids being substrates of D-amino acid dehydrogenase of Salmonella typhimurium was examined. The experiments were done with wild type strains and the mutants dadA missing the enzyme activity and dadR in which its synthesis is released from catabolite repression. Growth on D-tryptophan, D-histidine and D-methionine used as precursors of the L-amino acids was faster when the respective auxotrophs carried dadR mutations. The dadR mutants grew faster when D-or L-alanine was present as a sole source of nitrogen. Experiments with D-amino acid dehydrogenase in vitro provided evidence that D-tryptophan is its substrate with a very low affinity to the dehydrogenase.

Utilization of D-amino acids by dadR mutants of Salmonella typhimurium. Utilization of D-amino acids being substrates of D-amino acid dehydrogenase of Salmonella typhimurium was examined. The experiments were done with wild type strains and the mutants dadA missing the enzyme activity and dadR in which its synthesis is released from catabolite repression. Growth on D-tryptophan, D-histidine and D-methionine used as precursors of the L-amino acids was faster when the respective auxotrophs carried dadR mutations. The dadR mutants grew faster when D-or L-alanine was present as a sole source of nitrogen. Experiments with D-amino acid dehydrogenase in vitro provided evidence that D-tryptophan is its substrate with a very low affinity to the dehydrogenase.

PMID:29592

Relation of plasma prolactin to clinical response in schizophrenic patients.

It has been suggested that, if dopamine antagonism is a necessary condition for the antischizophrenic action of neuroleptics, the prolactin response, as an index of dopamine blockade, would correlate with clinical response. Morning prolactin and clinical symptomatology were measured in 15 schizophrenic patients before neuroleptic therapy, and after three and six weeks of high-dose butaperazine or loxapine treatment. Prolactin levels were transiently elevated during the unmedicated admission period, probably reflecting a normal stress response. Prolactin increased in all patients during neuroleptic therapy. There was, however, no correlation between magnitude of prolactin changes and clinical response, probably because the prolactin response achieved a maximum at relatively low doses of neuroleptics.

Relation of plasma prolactin to clinical response in schizophrenic patients. It has been suggested that, if dopamine antagonism is a necessary condition for the antischizophrenic action of neuroleptics, the prolactin response, as an index of dopamine blockade, would correlate with clinical response. Morning prolactin and clinical symptomatology were measured in 15 schizophrenic patients before neuroleptic therapy, and after three and six weeks of high-dose butaperazine or loxapine treatment. Prolactin levels were transiently elevated during the unmedicated admission period, probably reflecting a normal stress response. Prolactin increased in all patients during neuroleptic therapy. There was, however, no correlation between magnitude of prolactin changes and clinical response, probably because the prolactin response achieved a maximum at relatively low doses of neuroleptics.

PMID:29593

Monozygotic twins with presumed metachromatic leukodystrophy. Activity of arylsulfatase A in serum of patients and family.

Arylsulfatase A (ASA) activity in urine and serum was assayed on two 21-month-old monozygotic twins with presumed metachromatic leukodystrophy (MLD), their parents, and kin. The patients showed a marked reduction in ASA activity in both urine and serum. The twins' parents and 11 kin, a total of 13 persons, were examined for ASA activity in serum, but it was not possible to delineate heterozygous carriers of MLD by the present study. The assay of ASA activity in serum promises to be useful for diagnosis of MLD.

Monozygotic twins with presumed metachromatic leukodystrophy. Activity of arylsulfatase A in serum of patients and family. Arylsulfatase A (ASA) activity in urine and serum was assayed on two 21-month-old monozygotic twins with presumed metachromatic leukodystrophy (MLD), their parents, and kin. The patients showed a marked reduction in ASA activity in both urine and serum. The twins' parents and 11 kin, a total of 13 persons, were examined for ASA activity in serum, but it was not possible to delineate heterozygous carriers of MLD by the present study. The assay of ASA activity in serum promises to be useful for diagnosis of MLD.

PMID:29597

Behavior therapy and the treatment of flight phobia.

Research since 1960 was reviewed to compare the relative efficacy of behavior therapy and other therapy modalities in the treatment of flight phobias in trained military aircrew, commercial flight crews, and civilian air travellers. Results indicated that treatment programs involving behavior therapy techniques appeared to have a higher success rate than treatment programs not involving these techniques, especially in cases of focal fear with acute onset under stressful conditions. Other conditions for optimal outcome are outlined and hypotheses for a more programmatic research effort discussed.

Behavior therapy and the treatment of flight phobia. Research since 1960 was reviewed to compare the relative efficacy of behavior therapy and other therapy modalities in the treatment of flight phobias in trained military aircrew, commercial flight crews, and civilian air travellers. Results indicated that treatment programs involving behavior therapy techniques appeared to have a higher success rate than treatment programs not involving these techniques, especially in cases of focal fear with acute onset under stressful conditions. Other conditions for optimal outcome are outlined and hypotheses for a more programmatic research effort discussed.

PMID:29601

Purification and properties of gamma-glutamylcyclotransferase from human erythrocytes.

1. GAMMA-Glutamylcyclotransferase was purified 10000-fold from human erythrocytes. 2. The purification steps involved fractionation with (NH4)(2)SO(4) and chromatography on Sephadex G-75, DEAE-cellulose and hydroxyapatite. The purified enzyme was found to be homogeneous on density-gradient polyacrylamide-gel electrophoresis. 3. The maximum reaction rate was observed at pH9.0 and the apparent Km value for gamma-glutamyl-L-alanine was 2.2mM. 4. The molecular weight (25250) of the purified enzyme agreed well with the value (25500) in fresh haemolysates, indicating no apparent structural modification of the enzyme during purification. However, rapid processing of the blood through the initial (NH4)(2)SO(4) and Sephadex-chromatography steps was required to prevent formation of a high-molecular-weight aggregate with substantially lower specific activity. 5. gamma-Glutamylcyclotransferase catalyses the formation of 5-oxoproline from gamma-glutamyl dipeptides. The role of this enzyme in erythrocytes is of particular interest, because gamma-glutamyl-L-cysteine serves as a substrate for both gamma-glutamylcyclotransferase and glutathione synthetase. Thus the cyclotransferase could modulate glutathione synthesis.

Purification and properties of gamma-glutamylcyclotransferase from human erythrocytes. 1. GAMMA-Glutamylcyclotransferase was purified 10000-fold from human erythrocytes. 2. The purification steps involved fractionation with (NH4)(2)SO(4) and chromatography on Sephadex G-75, DEAE-cellulose and hydroxyapatite. The purified enzyme was found to be homogeneous on density-gradient polyacrylamide-gel electrophoresis. 3. The maximum reaction rate was observed at pH9.0 and the apparent Km value for gamma-glutamyl-L-alanine was 2.2mM. 4. The molecular weight (25250) of the purified enzyme agreed well with the value (25500) in fresh haemolysates, indicating no apparent structural modification of the enzyme during purification. However, rapid processing of the blood through the initial (NH4)(2)SO(4) and Sephadex-chromatography steps was required to prevent formation of a high-molecular-weight aggregate with substantially lower specific activity. 5. gamma-Glutamylcyclotransferase catalyses the formation of 5-oxoproline from gamma-glutamyl dipeptides. The role of this enzyme in erythrocytes is of particular interest, because gamma-glutamyl-L-cysteine serves as a substrate for both gamma-glutamylcyclotransferase and glutathione synthetase. Thus the cyclotransferase could modulate glutathione synthesis.

PMID:29602

Purification of rat intestinal maltase/glucoamylase and its anomalous dissociation either by heat or by low pH.

Maltase-glucoamylase, a microvillous membrane ectoenzyme, was solubilized from rat intestinal mucosa by digestion with papain and subsequently purified to homogeneity with an overall yield of 10--20%. An antibody to the purified enzyme formed a single precipitin line in immunodiffusion experiments with an intestinal homogenate. The enzyme was shown to be an acidic glycoprotein (20% sugar by weight) which contained low amounts of cysteine and no sialic acid. At pH3--6, maltase activity was slowly lost, but the enzyme was re-activated by re-adjustment of the pH to neutrality. However, in the presence of sodium dodecyl sulphate, acid pH values inactivated maltase irreversibly, and at the same time converted the enzyme (mol.wt. 500000 approx.) into five new species with apparent molecular weights ranging from 134000 to 480000 as judged by polyacrylamide-gel electrophoresis. The same five fragments were also formed by boiling the enzyme for brief periods in the presence of sodium dodecyl sulphate or urea either with or without reducing agents. The dissociated species were stable on re-electrophoresis, and amino acid analysis showed them to be very similar to each other and to the original enzyme. The bands migrated anomalously on polyacrylamide gels of different concentration, thereby preventing the assignment of precise molecular weights. It is possible that the five species may represent stable aggregates of a common monomer of the enzyme.

Purification of rat intestinal maltase/glucoamylase and its anomalous dissociation either by heat or by low pH. Maltase-glucoamylase, a microvillous membrane ectoenzyme, was solubilized from rat intestinal mucosa by digestion with papain and subsequently purified to homogeneity with an overall yield of 10--20%. An antibody to the purified enzyme formed a single precipitin line in immunodiffusion experiments with an intestinal homogenate. The enzyme was shown to be an acidic glycoprotein (20% sugar by weight) which contained low amounts of cysteine and no sialic acid. At pH3--6, maltase activity was slowly lost, but the enzyme was re-activated by re-adjustment of the pH to neutrality. However, in the presence of sodium dodecyl sulphate, acid pH values inactivated maltase irreversibly, and at the same time converted the enzyme (mol.wt. 500000 approx.) into five new species with apparent molecular weights ranging from 134000 to 480000 as judged by polyacrylamide-gel electrophoresis. The same five fragments were also formed by boiling the enzyme for brief periods in the presence of sodium dodecyl sulphate or urea either with or without reducing agents. The dissociated species were stable on re-electrophoresis, and amino acid analysis showed them to be very similar to each other and to the original enzyme. The bands migrated anomalously on polyacrylamide gels of different concentration, thereby preventing the assignment of precise molecular weights. It is possible that the five species may represent stable aggregates of a common monomer of the enzyme.

PMID:29603

The selective retardation of NADP+-dependent dehydrogenases by immobilized procion red HE-3B.

The capacities of Procion Red HE-3B and Cibacron Blue F3G-A immobilized to Sepharose CL-4B and Matrex 201R for NAD+-, NADP+- and NAD(P)+-dependent dehydrogenases were measured. Procion Red HE-3B columns retarded NADP+-dependent dehydrogenases more effectively than NAD+-dependent dehydrogenases, whilst immobilized Cibacron Blue F3G-A retarded NAD+-dependent dehydrogenases more effectively than NADP+-dependent dehydrogenases. The capacity of procion Red HE-3B-Sepharose CL-4B for five dehydrogenases was highest in the region of 70nmol of immobilized ligand/ml of settled gel. The effects of using poly(ethyleneimine) as a spacer for both porous and pellicular supports were also examined. Four NADP+-dependent dehydrogenases were purified from yeast extract by using Procion Red HE-3B-Sepharose CL-4B. Two NAD+-dependent dehydrogenases were purified from the same source using Cibacron Blue F3G-A-Sepharose CL-4B. These results are discussed in relation to the use of immobilized Procion Red HE-3B to purify dehydrogenases. This immobilized dye's chromatograhic behaviour is compared with that of immobilized nucleotides. The most important feature of immobilized tirazine dyes seems to be their high operational capacities when compared with group-specific nucleotide adsorbents.

The selective retardation of NADP+-dependent dehydrogenases by immobilized procion red HE-3B. The capacities of Procion Red HE-3B and Cibacron Blue F3G-A immobilized to Sepharose CL-4B and Matrex 201R for NAD+-, NADP+- and NAD(P)+-dependent dehydrogenases were measured. Procion Red HE-3B columns retarded NADP+-dependent dehydrogenases more effectively than NAD+-dependent dehydrogenases, whilst immobilized Cibacron Blue F3G-A retarded NAD+-dependent dehydrogenases more effectively than NADP+-dependent dehydrogenases. The capacity of procion Red HE-3B-Sepharose CL-4B for five dehydrogenases was highest in the region of 70nmol of immobilized ligand/ml of settled gel. The effects of using poly(ethyleneimine) as a spacer for both porous and pellicular supports were also examined. Four NADP+-dependent dehydrogenases were purified from yeast extract by using Procion Red HE-3B-Sepharose CL-4B. Two NAD+-dependent dehydrogenases were purified from the same source using Cibacron Blue F3G-A-Sepharose CL-4B. These results are discussed in relation to the use of immobilized Procion Red HE-3B to purify dehydrogenases. This immobilized dye's chromatograhic behaviour is compared with that of immobilized nucleotides. The most important feature of immobilized tirazine dyes seems to be their high operational capacities when compared with group-specific nucleotide adsorbents.

PMID:29604

Malate dehydrogenase of the cytosol. Ionizations of the enzyme-reduced-coenzyme complex and a comparison with lactate dehydrogenase.

1. The pH-dependencies of the binding of NADH and reduced nicotinamide--benzimidazole dinucleotide to pig heart cytoplasmic malate dehydrogenase and lactate dehydrogenase are reported. 2. Two ionizing groups were observed in the binding of both reduced coenzymes to lactate dehydrogenase. One group, with pKa in the range 6.3--6.7, is the active-site histidine residue and its deprotonation weakens binding of reduced coenzyme 3-fold. Binding of both coenzymes is decreased to zero when a second group, of pKa 8.9, deprotonates. This group is not cysteine-165.3. Only one ionization is required to characterize the binding of the two reduced coenzymes to malate dehydrogenase. The group involved appears to be the active-site histidine residue, since its ethoxycarbonylation inhibits the enzyme and abolishes binding of reduced coenzyme. Binding of either reduced coenzyme increases the pKa of the group from 6.4 to 7.4, and deprotonation of the group is accompanied by a 10-fold weakening of coenzyme binding. 4. Two reactive histidine residues were detected per malate dehydrogenase dimer. 5. A mechanism which emphasizes the homology between the two enzymes is presented.

Malate dehydrogenase of the cytosol. Ionizations of the enzyme-reduced-coenzyme complex and a comparison with lactate dehydrogenase. 1. The pH-dependencies of the binding of NADH and reduced nicotinamide--benzimidazole dinucleotide to pig heart cytoplasmic malate dehydrogenase and lactate dehydrogenase are reported. 2. Two ionizing groups were observed in the binding of both reduced coenzymes to lactate dehydrogenase. One group, with pKa in the range 6.3--6.7, is the active-site histidine residue and its deprotonation weakens binding of reduced coenzyme 3-fold. Binding of both coenzymes is decreased to zero when a second group, of pKa 8.9, deprotonates. This group is not cysteine-165.3. Only one ionization is required to characterize the binding of the two reduced coenzymes to malate dehydrogenase. The group involved appears to be the active-site histidine residue, since its ethoxycarbonylation inhibits the enzyme and abolishes binding of reduced coenzyme. Binding of either reduced coenzyme increases the pKa of the group from 6.4 to 7.4, and deprotonation of the group is accompanied by a 10-fold weakening of coenzyme binding. 4. Two reactive histidine residues were detected per malate dehydrogenase dimer. 5. A mechanism which emphasizes the homology between the two enzymes is presented.

PMID:29605

Identification of histidine-122alpha in human haemoglobin as one of the unknown alkaline Bohr groups by hydrogen--tritium exchange.

Human carbonmonoxy- and deoxy-haemoglobins were incubated at 37 degrees C in 3H2O at various pH values to measure the pH-dependent hydrogen--tritium exchange at the C-2 position of the imidazole ring of histidine-122alpha. To obtain the pseudo-first-order rate constants for the exchange, k, the two peptides containing histidine-122alpha were isolated and the amounts of tritium incorporated were determined. The rate constants gave pK values for the histidine of 6.1 in carbonmonoxyhaemoglobin and 6.6 in deoxyhaemoglobin, showing that it contributes about 20% to the total alkaline Bohr effect and about 10% at pH7.4.

Identification of histidine-122alpha in human haemoglobin as one of the unknown alkaline Bohr groups by hydrogen--tritium exchange. Human carbonmonoxy- and deoxy-haemoglobins were incubated at 37 degrees C in 3H2O at various pH values to measure the pH-dependent hydrogen--tritium exchange at the C-2 position of the imidazole ring of histidine-122alpha. To obtain the pseudo-first-order rate constants for the exchange, k, the two peptides containing histidine-122alpha were isolated and the amounts of tritium incorporated were determined. The rate constants gave pK values for the histidine of 6.1 in carbonmonoxyhaemoglobin and 6.6 in deoxyhaemoglobin, showing that it contributes about 20% to the total alkaline Bohr effect and about 10% at pH7.4.

PMID:29606

Sequential deiodination of thyroxine in rat liver homogenate.

Rat liver homogenate was incubated at 37 degrees C with thyroxine, 3,3',5-tri-iodothyronine, 3,3',5'-tri-iodothyronine or 3,3'-di-iodothyronine. The degradation or accumulation of these compounds was measured by specific radioimmunoassays. (1) Production of 3,3',5-tri-iodothyronine from thyroxine was highest at pH 6.0--6.5 and was markedly stimulated by the addition of dithiothreitol and effectively inhibited in the presence of 6-propyl-2-thiouracil. (2) Accumulation of 3,3',5'-tri-iodothyronine on incubation of thyroxine with homogenate was only observed above pH 8.5. Otherwise the product was converted into 3,3'-di-iodothyronine too rapidly to allow its measurement. By measuring 3,3'-di-iodothyronine it was deduced that 5-deiodination of thyroxine was most effective at approx. pH 8.0. Dithiothreitol powerfully stimulated this reaction and 6-propyl-2-thiouracil strongly inhibited. (3) Monodeiodination of the tyrosine ring of 3,3',5-tri-iodothyronine was the slowest reaction, was optimal at pH 8.0 and was less affected by dithiothreitol and 6-propyl-2-thiouracil than the above reactions. (4) 5'-Deiodination of 3,3',5'-tri-iodothyronine was extremely rapid, with a pH optimum probably at about 6.5. Owing to the high reaction rate under the conditions used it was not possible to assess the effects of dithiothreitol and 6-propyl-2-thiouracil.

Sequential deiodination of thyroxine in rat liver homogenate. Rat liver homogenate was incubated at 37 degrees C with thyroxine, 3,3',5-tri-iodothyronine, 3,3',5'-tri-iodothyronine or 3,3'-di-iodothyronine. The degradation or accumulation of these compounds was measured by specific radioimmunoassays. (1) Production of 3,3',5-tri-iodothyronine from thyroxine was highest at pH 6.0--6.5 and was markedly stimulated by the addition of dithiothreitol and effectively inhibited in the presence of 6-propyl-2-thiouracil. (2) Accumulation of 3,3',5'-tri-iodothyronine on incubation of thyroxine with homogenate was only observed above pH 8.5. Otherwise the product was converted into 3,3'-di-iodothyronine too rapidly to allow its measurement. By measuring 3,3'-di-iodothyronine it was deduced that 5-deiodination of thyroxine was most effective at approx. pH 8.0. Dithiothreitol powerfully stimulated this reaction and 6-propyl-2-thiouracil strongly inhibited. (3) Monodeiodination of the tyrosine ring of 3,3',5-tri-iodothyronine was the slowest reaction, was optimal at pH 8.0 and was less affected by dithiothreitol and 6-propyl-2-thiouracil than the above reactions. (4) 5'-Deiodination of 3,3',5'-tri-iodothyronine was extremely rapid, with a pH optimum probably at about 6.5. Owing to the high reaction rate under the conditions used it was not possible to assess the effects of dithiothreitol and 6-propyl-2-thiouracil.

PMID:29607

Factors affecting the activity of guanylate cyclase in lysates of human blood platelets.

1. Under optimal ionic conditions (4 mM-MnCl2) the specific activity of guanylate cyclase in fresh platelet lysates was about 10nmol of cyclic GMP formed/20 min per mg of protein at 30 degrees C. Activity was 15% of optimum with 10mM-MgCl2 and negligible with 4mM-CaCl2. Synergism between MnCl2 and MgCl2 or CaCl2 was observed when [MnCl2] less than or equal to [GPT]. 2. Lower than optimal specific activities were obtained in assays containing large volumes of platelet lysate, owing to the presence of inhibitory factors that could be removed by ultrafiltration. Adenine nucleotides accounted for less than 50% of the inhibitory activity. 3. Preincubation of lysate for 1 h at 30 degrees C increased the specific activity of platelet guanylate cyclase by about 2-fold. 4. Lubrol PX (1%, w/v) stimulated guanylate cyclase activity by 3--5-fold before preincubation and by about 2-fold after preincubation. Triton X-100 was much less effective. 5. Dithiothreitol inhibited the guanylate cyclase activity of untreated, preincubated and Lubrol PX-treated lysates and prevented activation by preincubation provided that it was added beforehand. 6. Oleate stimulated guanylate cyclase activity 3--4-fold and arachidonate 2--3-fold, whereas palmitate was almost inactive. Pretreatment of lysate with indomethacin did not inhibit this effect of arachidonate. Oleate and arachidonate caused marked stimulation of guanylate cyclase in preincubated lysate, but inhibited the enzyme in Lubrol PX-treated lysate. 7. NaN3 (10mM) increased guanylate cyclase activity by up to 7-fold; this effect was both time- and temperature-dependent. NaN3 did not further activate the enzyme in Lubrol PX-treated lysate. 8. The results indicated that preincubation, Lubrol PX, fatty acids and NaN3 activated platelet guanylate cyclase by different mechanisms. 9. Platelet particulate fractions contained no guanylate cyclase activity detectable in the presence or absence of Lubrol PX that could not be accounted for by contaminating soluble enzyme, suggesting that physiological aggregating agents may increase cyclic GMP in intact platelets through the effects of intermediary factors. The activated and inhibited states of the enzyme described in the present paper may be relevant to the actions of these factors.

Factors affecting the activity of guanylate cyclase in lysates of human blood platelets. 1. Under optimal ionic conditions (4 mM-MnCl2) the specific activity of guanylate cyclase in fresh platelet lysates was about 10nmol of cyclic GMP formed/20 min per mg of protein at 30 degrees C. Activity was 15% of optimum with 10mM-MgCl2 and negligible with 4mM-CaCl2. Synergism between MnCl2 and MgCl2 or CaCl2 was observed when [MnCl2] less than or equal to [GPT]. 2. Lower than optimal specific activities were obtained in assays containing large volumes of platelet lysate, owing to the presence of inhibitory factors that could be removed by ultrafiltration. Adenine nucleotides accounted for less than 50% of the inhibitory activity. 3. Preincubation of lysate for 1 h at 30 degrees C increased the specific activity of platelet guanylate cyclase by about 2-fold. 4. Lubrol PX (1%, w/v) stimulated guanylate cyclase activity by 3--5-fold before preincubation and by about 2-fold after preincubation. Triton X-100 was much less effective. 5. Dithiothreitol inhibited the guanylate cyclase activity of untreated, preincubated and Lubrol PX-treated lysates and prevented activation by preincubation provided that it was added beforehand. 6. Oleate stimulated guanylate cyclase activity 3--4-fold and arachidonate 2--3-fold, whereas palmitate was almost inactive. Pretreatment of lysate with indomethacin did not inhibit this effect of arachidonate. Oleate and arachidonate caused marked stimulation of guanylate cyclase in preincubated lysate, but inhibited the enzyme in Lubrol PX-treated lysate. 7. NaN3 (10mM) increased guanylate cyclase activity by up to 7-fold; this effect was both time- and temperature-dependent. NaN3 did not further activate the enzyme in Lubrol PX-treated lysate. 8. The results indicated that preincubation, Lubrol PX, fatty acids and NaN3 activated platelet guanylate cyclase by different mechanisms. 9. Platelet particulate fractions contained no guanylate cyclase activity detectable in the presence or absence of Lubrol PX that could not be accounted for by contaminating soluble enzyme, suggesting that physiological aggregating agents may increase cyclic GMP in intact platelets through the effects of intermediary factors. The activated and inhibited states of the enzyme described in the present paper may be relevant to the actions of these factors.

PMID:29608

Subcellular distribution of glycosidases in human polymorphonuclear leucocytes.

The subcellular distribution of nine glycosidases were studied in fractions of homogenized human polymorphonuclear leucocytes (neutrophils) obtained by isopycnic centrifugation through linear sucrose density gradients. The substrates were 4-methylumbelliferyl glycosides. All nine glycosides were hydrolysed by enzymes in neutrophil cytosol fractions, and by enzymes in at least one granule population. alpha-Glucosidase activity sedimented in sucrose density gradients to a point (p = 1.180 g/ml) just above the specific granules, possibly the 'tertiary' granule population. The peak corresponding to alpha-glucosidase did not co-sediment with, but considerably overlapped, the peak corresponding to lactoferrin, a marker for specific granules (p = 1.187 g/ml). alpha-Galactosidase activity was found primarily in heavy azurophil granules (p = 1.222 g/ml). alpha-Mannosidase activity was found primarily in light azurophil granules (p = 1.206 g/ml), following the distribution of myeloperoxidase, the commonly used azurophil granule marker. beta-Glucosidase activity was concentrated in mitochondrial fractions (p = 1.160 g/ml). All other glycosidases presented complex distributions, with activities not restricted to one granule class. Granule-associated glycosidase activities were increased 2--38 times when measured in the presence of 0.05% Triton X-100, indicating latency of the enzymes within granules.

Subcellular distribution of glycosidases in human polymorphonuclear leucocytes. The subcellular distribution of nine glycosidases were studied in fractions of homogenized human polymorphonuclear leucocytes (neutrophils) obtained by isopycnic centrifugation through linear sucrose density gradients. The substrates were 4-methylumbelliferyl glycosides. All nine glycosides were hydrolysed by enzymes in neutrophil cytosol fractions, and by enzymes in at least one granule population. alpha-Glucosidase activity sedimented in sucrose density gradients to a point (p = 1.180 g/ml) just above the specific granules, possibly the 'tertiary' granule population. The peak corresponding to alpha-glucosidase did not co-sediment with, but considerably overlapped, the peak corresponding to lactoferrin, a marker for specific granules (p = 1.187 g/ml). alpha-Galactosidase activity was found primarily in heavy azurophil granules (p = 1.222 g/ml). alpha-Mannosidase activity was found primarily in light azurophil granules (p = 1.206 g/ml), following the distribution of myeloperoxidase, the commonly used azurophil granule marker. beta-Glucosidase activity was concentrated in mitochondrial fractions (p = 1.160 g/ml). All other glycosidases presented complex distributions, with activities not restricted to one granule class. Granule-associated glycosidase activities were increased 2--38 times when measured in the presence of 0.05% Triton X-100, indicating latency of the enzymes within granules.

PMID:29653

Effect of diuretic, beta-adrenoceptor blocking agent and their combination on elevated blood pressure and serum potassium: a cross-over study.

1. The antihypertensive effect of a new beta-adrenoceptor blocking agent, trimepranol (10--14 mg/twice daily), chlorthalidone (50 mg every second day) and their combination was studied in eighteen patients with mild to moderate essential hypertension. In a controlled randomized cross-over study the drugs were given for 6 week periods. 2. A significant and equal decrease in blood pressure was achieved both with trimepranol and chlorthalidone, whereas their combination was significantly more effective. 3. Trimepranol significantly antagonized the chlorthalidone-induced hypokalemia. 4. The results favor the use of diuretic or diuretic-beta-adrenoceptor blocker combination over beta-adrenoceptor blocker monotherapy in the treatment of mild to moderate hypertension.

Effect of diuretic, beta-adrenoceptor blocking agent and their combination on elevated blood pressure and serum potassium: a cross-over study. 1. The antihypertensive effect of a new beta-adrenoceptor blocking agent, trimepranol (10--14 mg/twice daily), chlorthalidone (50 mg every second day) and their combination was studied in eighteen patients with mild to moderate essential hypertension. In a controlled randomized cross-over study the drugs were given for 6 week periods. 2. A significant and equal decrease in blood pressure was achieved both with trimepranol and chlorthalidone, whereas their combination was significantly more effective. 3. Trimepranol significantly antagonized the chlorthalidone-induced hypokalemia. 4. The results favor the use of diuretic or diuretic-beta-adrenoceptor blocker combination over beta-adrenoceptor blocker monotherapy in the treatment of mild to moderate hypertension.

PMID:29654

Pleuropulmonary lung infection by anaerobic bacteria.

Two patients with severe pleuropulmonary infection caused by non-sporing anaerobic bacteria are described. One had an empyema with foul-smelling pus and developed bacteraemia, and the other developed a lung abscess. Both were successfully treated with antibiotics and drainage, chest surgery being avoided. The successful diagnosis and treatment of these patients involved close liaison between clinical and laboratory staff.

Pleuropulmonary lung infection by anaerobic bacteria. Two patients with severe pleuropulmonary infection caused by non-sporing anaerobic bacteria are described. One had an empyema with foul-smelling pus and developed bacteraemia, and the other developed a lung abscess. Both were successfully treated with antibiotics and drainage, chest surgery being avoided. The successful diagnosis and treatment of these patients involved close liaison between clinical and laboratory staff.

PMID:29656

Continuous measurement of tissue pH in the human fetal scalp.

A method for continuous measurement of scalp tissue pH is described. The tissue pH probe was found to be robust and values for tissue pH were close to those for scalp blood pH. Combining the pH and fetal heart fate (FHR) electrodes in the one mechanical assembly facilitated application to the fetal scalp in early labour but the combined assembly electrode was found to have some disadvantages and manufacture of a separate tissue PH electrode is recommended. Continuous monitoring of scalp tissue pH enables closer study of the physiological basis of changes in fetal acid base status and should prove useful to the obstetrician in management of high risk pregnancies during labour.

Continuous measurement of tissue pH in the human fetal scalp. A method for continuous measurement of scalp tissue pH is described. The tissue pH probe was found to be robust and values for tissue pH were close to those for scalp blood pH. Combining the pH and fetal heart fate (FHR) electrodes in the one mechanical assembly facilitated application to the fetal scalp in early labour but the combined assembly electrode was found to have some disadvantages and manufacture of a separate tissue PH electrode is recommended. Continuous monitoring of scalp tissue pH enables closer study of the physiological basis of changes in fetal acid base status and should prove useful to the obstetrician in management of high risk pregnancies during labour.

PMID:29657

The level and origin of amylase (EC 3.2.1.1) in the digestive tract of chicks receiving trypsin inhibitors in their diet.

1. Amylase (EC 3.2.1.1) activity found in the intestinal tract of chicks posterior to the stomach is of endogenous origin, as amylase in the food is inactivated by the low pH in the stomachs. 2. Ingestion of raw soya-bean diet (RSD) or of heated soya-bean diet (HSD) supplemented with trypsin inhibitors induced higher amylase activites in the lower part of the small intestine and caecum as compared with HSD. 3. Ingestion of RSD after ligation at the end of the duodenum, end of the ileum or one of the cacea, or injection of soya-bean trypsin inhibitor into a aligated caecum, indicated that there is no amylase synthesis by the intestinal tract cells or microflora as a response to the presence of RSD or trypsin inhibitors. 4. It seems that amylase found in the digestive tract of the chick is of pancreatic origin and the RSD or trypsin inhibitors induce higher pancreatic amylase secretion than HSD which (the additiona amylase) accumulates mainly in the caeca.

The level and origin of amylase (EC 3.2.1.1) in the digestive tract of chicks receiving trypsin inhibitors in their diet. 1. Amylase (EC 3.2.1.1) activity found in the intestinal tract of chicks posterior to the stomach is of endogenous origin, as amylase in the food is inactivated by the low pH in the stomachs. 2. Ingestion of raw soya-bean diet (RSD) or of heated soya-bean diet (HSD) supplemented with trypsin inhibitors induced higher amylase activites in the lower part of the small intestine and caecum as compared with HSD. 3. Ingestion of RSD after ligation at the end of the duodenum, end of the ileum or one of the cacea, or injection of soya-bean trypsin inhibitor into a aligated caecum, indicated that there is no amylase synthesis by the intestinal tract cells or microflora as a response to the presence of RSD or trypsin inhibitors. 4. It seems that amylase found in the digestive tract of the chick is of pancreatic origin and the RSD or trypsin inhibitors induce higher pancreatic amylase secretion than HSD which (the additiona amylase) accumulates mainly in the caeca.

PMID:29659

Critical ionization states in the reaction catalyzed by triosephosphate isomerase.

To allow the detailed interpretation of the pH dependences of the steady-state parameters for the reaction catalyzed by triosephosphate isomerase, three kinds of experiments have been performed. First, the value of kcat/Km for enzyme-catalyzed isomerization of the phosphonate analogue of D-glyceraldehyde 3-phosphate (2-hydroxy-4-phosphonobutyraldehyde) has been shown to titrate with an apparent pKa of 7.5, which is close to the phosphonate's second ionization constant. Secondly, the sulfate ester analogue of dihydroxyacetone phosphate (dihydroxyacetone sulfate), which exists only as a monoanion over the pH range of interest, has been shown not to bind detectably to the enzyme. Thirdly, an isotopic discrimination experiment at pH 5.2 has been compared with a similar investigation at pH 7.6. The results together demonstrate that both enzyme and substrate ionizations control the reaction rate in the pH range 5 to 8.

Critical ionization states in the reaction catalyzed by triosephosphate isomerase. To allow the detailed interpretation of the pH dependences of the steady-state parameters for the reaction catalyzed by triosephosphate isomerase, three kinds of experiments have been performed. First, the value of kcat/Km for enzyme-catalyzed isomerization of the phosphonate analogue of D-glyceraldehyde 3-phosphate (2-hydroxy-4-phosphonobutyraldehyde) has been shown to titrate with an apparent pKa of 7.5, which is close to the phosphonate's second ionization constant. Secondly, the sulfate ester analogue of dihydroxyacetone phosphate (dihydroxyacetone sulfate), which exists only as a monoanion over the pH range of interest, has been shown not to bind detectably to the enzyme. Thirdly, an isotopic discrimination experiment at pH 5.2 has been compared with a similar investigation at pH 7.6. The results together demonstrate that both enzyme and substrate ionizations control the reaction rate in the pH range 5 to 8.

PMID:29660

Exchange mechanisms for hydrogen bonding protons of cytidylic and guanylic acids.

The pH dependence of buffer catalysis of exchange of the C-4 amino protons of cyclic cytosine 2',3'-monophosphate (cCMP) and the N-1 proton of cyclic guanosine 2',3'-monophosphate (cGMP) conforms to an exchange mechanism, in which protonation of the nucleobases at C(N-3) AND G(N-7) establishes the important intermediates at neutral to acidic pH. Rate constants for transfer of the G(N-1) proton to H2O, OH-, phosphate, acetate, chloracetate, lactate, and cytosine (N-3) were obtained from 1H nuclear magnetic resonance line width measurements at 360 MHz and were used to estimate the pK or acidity of the exchange site in both the protonated and unprotonated nucleobase. These estimates reveal an increase in acidity of the G(N-1) site corresponding to 2 to 3 pK units as the G(N-7) site is protonated: At neutral pH the G(N-1) site of the protonated purine would be ionized (pK = 6.3). Determinations of phosphate, imidazole, and methylimidazole rate constants for transfer of the amino protons of cCMP provide a more approximate estimate of pK = 7 to 9 for the amino of the protonated pyrimidine. A comparison of the intrinsic amino acidity in the neutral and protonated cytosine is vitiated by the observation that OH- catalyzed exchange in the neutral base is not diffusion limited. This leads to the conclusion that protonation of the nucleobase effects a qualitative increase in the ability of the amino protons to form hydrogen bonds: from very poor in the neutral base to "normal" in the conjugate acid.

Exchange mechanisms for hydrogen bonding protons of cytidylic and guanylic acids. The pH dependence of buffer catalysis of exchange of the C-4 amino protons of cyclic cytosine 2',3'-monophosphate (cCMP) and the N-1 proton of cyclic guanosine 2',3'-monophosphate (cGMP) conforms to an exchange mechanism, in which protonation of the nucleobases at C(N-3) AND G(N-7) establishes the important intermediates at neutral to acidic pH. Rate constants for transfer of the G(N-1) proton to H2O, OH-, phosphate, acetate, chloracetate, lactate, and cytosine (N-3) were obtained from 1H nuclear magnetic resonance line width measurements at 360 MHz and were used to estimate the pK or acidity of the exchange site in both the protonated and unprotonated nucleobase. These estimates reveal an increase in acidity of the G(N-1) site corresponding to 2 to 3 pK units as the G(N-7) site is protonated: At neutral pH the G(N-1) site of the protonated purine would be ionized (pK = 6.3). Determinations of phosphate, imidazole, and methylimidazole rate constants for transfer of the amino protons of cCMP provide a more approximate estimate of pK = 7 to 9 for the amino of the protonated pyrimidine. A comparison of the intrinsic amino acidity in the neutral and protonated cytosine is vitiated by the observation that OH- catalyzed exchange in the neutral base is not diffusion limited. This leads to the conclusion that protonation of the nucleobase effects a qualitative increase in the ability of the amino protons to form hydrogen bonds: from very poor in the neutral base to "normal" in the conjugate acid.

PMID:29661

Refolding transition of alpha-chymotrypsin: pH and salt dependence.

It is well known that alpha-chymotrypsin can exist in two major conformational states, only one of which is active. We have examined the pH (pH 2.0--11.0) and salt (ionic strength 0.01--1.0) dependence of the transition between the active and inactive forms in detail. At low pH (pH 2.0--6.0) the equilibrium is very dependent on salt concentration, with high salt concentrations effectively stabilizing the active conformation. This apparent stabilization is an artifact due to the salt-dependent dimerization of alpha-chymotrypsin, and our data show that only active species form dimers and higher aggregates. At neutral pH (6.0--8.0) dimerization is absent, yet an ionic strength dependence remains. The effects show no lyotropic order and appear to be due to preferential salt binding to the active conformation at one or possibly a few sites. Above pH 6 (pH 6.0--11.0), the pH dependence can be described by a two-ionization mechanism at all ionic strengths. We report values for all seven equilibrium constants in the proposed mechanism at four ionic strengths (mu = 0.01, 0.05, 0.2, and 1.0). The transition is the first "refolding" transition to be studied at high precision, but, even so, certain decisions about the mechanism must await higher experimental precision not available with present methods.

Refolding transition of alpha-chymotrypsin: pH and salt dependence. It is well known that alpha-chymotrypsin can exist in two major conformational states, only one of which is active. We have examined the pH (pH 2.0--11.0) and salt (ionic strength 0.01--1.0) dependence of the transition between the active and inactive forms in detail. At low pH (pH 2.0--6.0) the equilibrium is very dependent on salt concentration, with high salt concentrations effectively stabilizing the active conformation. This apparent stabilization is an artifact due to the salt-dependent dimerization of alpha-chymotrypsin, and our data show that only active species form dimers and higher aggregates. At neutral pH (6.0--8.0) dimerization is absent, yet an ionic strength dependence remains. The effects show no lyotropic order and appear to be due to preferential salt binding to the active conformation at one or possibly a few sites. Above pH 6 (pH 6.0--11.0), the pH dependence can be described by a two-ionization mechanism at all ionic strengths. We report values for all seven equilibrium constants in the proposed mechanism at four ionic strengths (mu = 0.01, 0.05, 0.2, and 1.0). The transition is the first "refolding" transition to be studied at high precision, but, even so, certain decisions about the mechanism must await higher experimental precision not available with present methods.

PMID:29662

Chloride ion binding to human plasma albumin from chlorine-35 quadrupole relaxation.

The 35Cl nuclear magnetic quadrupole relaxation enhancement on binding of chloride ions to human plasma albumin (HPA) has been studied under conditions of variable temperature, pH, ionic strength, protein, and sodium dodecyl sulfate concentration. A small number (less than 10) of chloride ions, most of which are bound to the primary detergent binding sites, contribute a major portion of the relaxation enhancement (greater than 80% at neutral pH). A comparison of the pH dependence of the relaxation rate with the hydrogen ion titration curve, which was determined and analyzed, identified ten lysyl and arginyl residues as being involved in the chloride ion binding. These data, in conjuction with NaDodSO4 titrations at different pH values and the amino acid sequence of HPA, suggests that the high-affinity chloride-binding sites are doubly cationic at neutral pH. An irreversible dimerization at acidic pH and 5 x 10(-5) m HPA was detected. The data also indicate the presence of internal modes of motion in the expanded forms of the HPA molecule, probably an independent reorientation of domains. The rate of exchange of chloride ions was shown to be much higher than the corresponding intrinsic relaxation rate in the temperature range 2--26 degrees C and pH values ranging from 4.0 to 10.5. No indications of protein-protein interaction could be found up to the physiological concentration of ca. 6 x 10(-4)m HPA at either neutral or alkaline pH. The mechanistic basis for HPA's exceptional capacity for binding of inorganic anions was discussed.

Chloride ion binding to human plasma albumin from chlorine-35 quadrupole relaxation. The 35Cl nuclear magnetic quadrupole relaxation enhancement on binding of chloride ions to human plasma albumin (HPA) has been studied under conditions of variable temperature, pH, ionic strength, protein, and sodium dodecyl sulfate concentration. A small number (less than 10) of chloride ions, most of which are bound to the primary detergent binding sites, contribute a major portion of the relaxation enhancement (greater than 80% at neutral pH). A comparison of the pH dependence of the relaxation rate with the hydrogen ion titration curve, which was determined and analyzed, identified ten lysyl and arginyl residues as being involved in the chloride ion binding. These data, in conjuction with NaDodSO4 titrations at different pH values and the amino acid sequence of HPA, suggests that the high-affinity chloride-binding sites are doubly cationic at neutral pH. An irreversible dimerization at acidic pH and 5 x 10(-5) m HPA was detected. The data also indicate the presence of internal modes of motion in the expanded forms of the HPA molecule, probably an independent reorientation of domains. The rate of exchange of chloride ions was shown to be much higher than the corresponding intrinsic relaxation rate in the temperature range 2--26 degrees C and pH values ranging from 4.0 to 10.5. No indications of protein-protein interaction could be found up to the physiological concentration of ca. 6 x 10(-4)m HPA at either neutral or alkaline pH. The mechanistic basis for HPA's exceptional capacity for binding of inorganic anions was discussed.

PMID:29663

Estimation of transmembrane pH gradients from phase equilibria of spin-labeled amines.

Spin-labeled secondary amines have been used to measure transmembrane proton gradients in sonicated liposomes. The electron paramagnetic resonance spectra of these probes show changes in the ratio of membrane associated to free aqueous probe as a function of transmembrane pH gradient. As the pH gradient is increased, inside acidic, the amount of membrane associated probe increases. The results are accounted for by a simple thermodynamic theory.

Estimation of transmembrane pH gradients from phase equilibria of spin-labeled amines. Spin-labeled secondary amines have been used to measure transmembrane proton gradients in sonicated liposomes. The electron paramagnetic resonance spectra of these probes show changes in the ratio of membrane associated to free aqueous probe as a function of transmembrane pH gradient. As the pH gradient is increased, inside acidic, the amount of membrane associated probe increases. The results are accounted for by a simple thermodynamic theory.

PMID:29664

Cytochromes and gastric acid secretion. A reevaluation of mucosal acidification experiments.

Using an improved spectrophotometer, we have reinvestigated the report (Hersey, S.J. (1974) Biochim. Biophys. Acta 344, 157--203) that acidification of the mucosal surface of frog gastric mucosa produces a crossover point between flavoprotein and cytochrome b, thus identifying a site of energy coupling between the cytochrome and H+ transport systems. While we find spectrophotometric changes upon addition of HCl to the mucosal solution, we find similar changes upon addition of NaCl without pH change, but no changes when the pH is lowered by substitution of H+ for Na+ at constant osmolality. We show that osmolality changes, with consequent alteration in tissue light scattering, are responsible for these effects. Further, we can show that the pH changes used do not inhibit acid secretion, and that one cannot do so without osmolality increase. We conclude that the imputed crossover point is not demonstrated, and that models based on its existence must be revised.

Cytochromes and gastric acid secretion. A reevaluation of mucosal acidification experiments. Using an improved spectrophotometer, we have reinvestigated the report (Hersey, S.J. (1974) Biochim. Biophys. Acta 344, 157--203) that acidification of the mucosal surface of frog gastric mucosa produces a crossover point between flavoprotein and cytochrome b, thus identifying a site of energy coupling between the cytochrome and H+ transport systems. While we find spectrophotometric changes upon addition of HCl to the mucosal solution, we find similar changes upon addition of NaCl without pH change, but no changes when the pH is lowered by substitution of H+ for Na+ at constant osmolality. We show that osmolality changes, with consequent alteration in tissue light scattering, are responsible for these effects. Further, we can show that the pH changes used do not inhibit acid secretion, and that one cannot do so without osmolality increase. We conclude that the imputed crossover point is not demonstrated, and that models based on its existence must be revised.

PMID:29665

Comparative studies on the effects of pH and Ca2+ on bilayers of various negatively charged phospholipids and their mixtures with phosphatidylcholine.

(1) The thermotropic behaviour of dimyristoyl phosphatidylglycerol, phosphatidylserine, phosphatidic acid and phosphatidylcholine was investigated by differential scanning calorimetry and freeze-fracture electron microscopy as a function of pH and of Ca2+ concentration. (2) From the thermotropic behaviour as a function of pH, profiles could be constructed from which apparent pK values of the charged groups of the lipids could be determined. (3) Excess Ca2+ induced a shift of the total phase transition in 14 : 0/14 : 0-glycerophosphocholine and 14 : 0/14 : 0-glycerophosphoglycerol mixtures. In 14 : 0/14 : 0-glycerophosphocholine bilayers containing 16 : 0/16 : 0-glycerophosphoglycerol lateral phase separation was induced by Ca2+. (4) Up to molar ratios of 1 : 2 of 14 : 0/14 : 0-glycerophosphoserine to 14 : 0/14: 0-glycerophosphocholine, excess Ca2+ induced lateral phase separation. Addition to mixtures of higher molar ratios caused segregation into different structures: the liposome organization and the stacked lamellae/cylindrical organization. (5) Addition of excess Ca2+ to mixtures of 14 : 0/14 : 0-glycerophosphocholine and 14 : 0/14 : 0-phosphatidic acid caused, independent of the molar ratio, separation into two structural different organizations. (6) The nature of Ca2+-induced changes in bilayers containing negatively charged phospholipids is strongly dependent on the character of the polar headgroup of the negatively charged phospholipid involved.

Comparative studies on the effects of pH and Ca2+ on bilayers of various negatively charged phospholipids and their mixtures with phosphatidylcholine. (1) The thermotropic behaviour of dimyristoyl phosphatidylglycerol, phosphatidylserine, phosphatidic acid and phosphatidylcholine was investigated by differential scanning calorimetry and freeze-fracture electron microscopy as a function of pH and of Ca2+ concentration. (2) From the thermotropic behaviour as a function of pH, profiles could be constructed from which apparent pK values of the charged groups of the lipids could be determined. (3) Excess Ca2+ induced a shift of the total phase transition in 14 : 0/14 : 0-glycerophosphocholine and 14 : 0/14 : 0-glycerophosphoglycerol mixtures. In 14 : 0/14 : 0-glycerophosphocholine bilayers containing 16 : 0/16 : 0-glycerophosphoglycerol lateral phase separation was induced by Ca2+. (4) Up to molar ratios of 1 : 2 of 14 : 0/14 : 0-glycerophosphoserine to 14 : 0/14: 0-glycerophosphocholine, excess Ca2+ induced lateral phase separation. Addition to mixtures of higher molar ratios caused segregation into different structures: the liposome organization and the stacked lamellae/cylindrical organization. (5) Addition of excess Ca2+ to mixtures of 14 : 0/14 : 0-glycerophosphocholine and 14 : 0/14 : 0-phosphatidic acid caused, independent of the molar ratio, separation into two structural different organizations. (6) The nature of Ca2+-induced changes in bilayers containing negatively charged phospholipids is strongly dependent on the character of the polar headgroup of the negatively charged phospholipid involved.

PMID:29667

The hydrolysis of triacylglycerol and diacylglycerol by a rat brain microsomal lipase with an acidic pH optimum.

Lipase activity towards triacylglycerol and diacylglycerol was measured at pH 4.8 using a microsomal preparation from rat brain as the enzyme source. The optimal pH for the hydrolysis of triacylglycerol was 4.8, with only minor lipolytic activity in the alkaline pH range. Diacylglycerol was the major product of triacylglycerol hydrolysis, with only little monoacylglycerol being formed. When diacylglycerol was the starting substrate it was hydrolyzed at a rate 10-fold greater than triacylglycerol, and the product was monoacylglycerol. The enzyme showed positional specificity for the fatty acid moieties located at the primary positions of sn-glycerol. 1,3-Diacylglycerol was hydrolyzed at greater than twice the rate of the corresponding 1,2(2,3)-isomer.

The hydrolysis of triacylglycerol and diacylglycerol by a rat brain microsomal lipase with an acidic pH optimum. Lipase activity towards triacylglycerol and diacylglycerol was measured at pH 4.8 using a microsomal preparation from rat brain as the enzyme source. The optimal pH for the hydrolysis of triacylglycerol was 4.8, with only minor lipolytic activity in the alkaline pH range. Diacylglycerol was the major product of triacylglycerol hydrolysis, with only little monoacylglycerol being formed. When diacylglycerol was the starting substrate it was hydrolyzed at a rate 10-fold greater than triacylglycerol, and the product was monoacylglycerol. The enzyme showed positional specificity for the fatty acid moieties located at the primary positions of sn-glycerol. 1,3-Diacylglycerol was hydrolyzed at greater than twice the rate of the corresponding 1,2(2,3)-isomer.

PMID:29669

Kinetics and mechanism of dissociation of zinc ion from carbonic anhydrase.

The kinetics of dissociation of Zn2+ from the metalloenzyme carbonic anhydrase was measured over a range of pH, temperature, and acetate concentration. The rate of dissociation is extremely slow at neutral pH (t1/2 approximately 3) years, 4 degrees C), but increases in almost direct proportion to the hydrogen ion concentration and is enhanced in the presence of 1,10-phenanthroline or acetate. The thermodynamic stability of the zinc-apoenzyme complex was determined over a range of pH from rate data on binding and dissociation (stability constants 10(9)-10(11) M-1, 25 degrees C). The great stability of the complex and slow exchange of the apoenzyme ligand is attributed, at least in part, to the rigidity of the multidentate protein ligand.

Kinetics and mechanism of dissociation of zinc ion from carbonic anhydrase. The kinetics of dissociation of Zn2+ from the metalloenzyme carbonic anhydrase was measured over a range of pH, temperature, and acetate concentration. The rate of dissociation is extremely slow at neutral pH (t1/2 approximately 3) years, 4 degrees C), but increases in almost direct proportion to the hydrogen ion concentration and is enhanced in the presence of 1,10-phenanthroline or acetate. The thermodynamic stability of the zinc-apoenzyme complex was determined over a range of pH from rate data on binding and dissociation (stability constants 10(9)-10(11) M-1, 25 degrees C). The great stability of the complex and slow exchange of the apoenzyme ligand is attributed, at least in part, to the rigidity of the multidentate protein ligand.

PMID:29672

[Stimulation mechanism of soluble ATPase from chloroplasts (CF1)].

Effects of various compounds on Mg-dependent ATPase activity of chloroplast coupling factor--CF1--were studied. It was shown that the stimulating effect of compounds is increased with the increase in their hydrophobicity. Under given experimental conditions all compounds under study readily accept and donate protons. The maximal efficiency is reached when pH of the medium is close to the pK value of conjugated acid. It is assumed that the stimulating effects of compounds on Mg-dependent chloroplast ATPase consist in the increase of the rate of the limiting step of enzyme induced proton translocation coupled to the catalytic step of ATP hydrolysis.

[Stimulation mechanism of soluble ATPase from chloroplasts (CF1)]. Effects of various compounds on Mg-dependent ATPase activity of chloroplast coupling factor--CF1--were studied. It was shown that the stimulating effect of compounds is increased with the increase in their hydrophobicity. Under given experimental conditions all compounds under study readily accept and donate protons. The maximal efficiency is reached when pH of the medium is close to the pK value of conjugated acid. It is assumed that the stimulating effects of compounds on Mg-dependent chloroplast ATPase consist in the increase of the rate of the limiting step of enzyme induced proton translocation coupled to the catalytic step of ATP hydrolysis.

PMID:29673

[Isolation and properties of bovine kidney aminopeptidase A].

Aminopeptidase A, which specifically hydrolyses N-terminal dicarbonic amino acid residues containing free alpha-amino groups, is isolated from bovine kidney. The enzyme is 500-fold purified and is homogenous under electrophoresis and ultracentrifugation. Aminopeptidase A has pH optimum of 7.5, it is activated with Ca2+ and inactivated with EDTA. Its molecular weight is 53000. The enzyme hydrolyses alpha-L-aspartyl-beta-naphtylamide and splits peptides having N-terminal glycine, lysine, arginine and alanine are hydrolyzed by the enzyme much slower. Aminopeptidase A does not attack alpha-L-alanyl-beta-naphtylamide, leucineamide, insulin, peptides with blocked N-terminal amino acid and peptides which have proline to be the second N-terminal amino acid.

[Isolation and properties of bovine kidney aminopeptidase A]. Aminopeptidase A, which specifically hydrolyses N-terminal dicarbonic amino acid residues containing free alpha-amino groups, is isolated from bovine kidney. The enzyme is 500-fold purified and is homogenous under electrophoresis and ultracentrifugation. Aminopeptidase A has pH optimum of 7.5, it is activated with Ca2+ and inactivated with EDTA. Its molecular weight is 53000. The enzyme hydrolyses alpha-L-aspartyl-beta-naphtylamide and splits peptides having N-terminal glycine, lysine, arginine and alanine are hydrolyzed by the enzyme much slower. Aminopeptidase A does not attack alpha-L-alanyl-beta-naphtylamide, leucineamide, insulin, peptides with blocked N-terminal amino acid and peptides which have proline to be the second N-terminal amino acid.

PMID:29668

[Effect of adsorption on the structure and properties of hemoglobin].

Adsorption spectra of Hb+ and HbO2 adsorbed on silica and monolayers cholesterol supported on silica have been studied. It is shown that immobilization leads to new states of proteins, their properties depending on the nature of support and conditions of adsorption. Adsorption of haemoglobin leads to its inactivation. The rate of inactivation decreases with an increase of surface concentration of haemoglobin and with simultaneous adsorption of inert proteins.

[Effect of adsorption on the structure and properties of hemoglobin]. Adsorption spectra of Hb+ and HbO2 adsorbed on silica and monolayers cholesterol supported on silica have been studied. It is shown that immobilization leads to new states of proteins, their properties depending on the nature of support and conditions of adsorption. Adsorption of haemoglobin leads to its inactivation. The rate of inactivation decreases with an increase of surface concentration of haemoglobin and with simultaneous adsorption of inert proteins.

PMID:29674

[Chemical modification of epsilon-amino lysine groups in horseradish peroxidase. Its effect on catalytic properties and spatial structure of the enzyme].

Effect of chemical modification of horseradish peroxidase lysine epsilon-amino groups by propionic, butyric, valeric, succinic anhydrides and trinitrobenzolsulfonic acid (TNBS) on catalytic properties of the enzyme is investigated. All the preparations of modified peroxidase have 100% peroxidase activity for o-dianizidine at pH 7.0, which indicates the absence of lysine epsilon-amino group in the enzyme active site. pH-dependencies of modified peroxidase relative activity are studied; modification by anhydrides of monobasic acids is not found to result in changes of the relative activity pH-profile, while modification by succinic anhydride widens it. Absorption and circular dichoism spectra of native and modified peroxidase within 260--270 nm are obtained, some changes in the enzyme tertiary structure after its epsilon-amino groups modification are observed. Modification of four epsilon-amino groups by buturic and succinic anhydrides and of three epsilon-amino groups by TNBS is found to increase the regidity of protein surrounding of heme, and modification of six epsilon-amino groups by TNBS results in more unwrapped enzyme structure as compared with its native molecule.

[Chemical modification of epsilon-amino lysine groups in horseradish peroxidase. Its effect on catalytic properties and spatial structure of the enzyme]. Effect of chemical modification of horseradish peroxidase lysine epsilon-amino groups by propionic, butyric, valeric, succinic anhydrides and trinitrobenzolsulfonic acid (TNBS) on catalytic properties of the enzyme is investigated. All the preparations of modified peroxidase have 100% peroxidase activity for o-dianizidine at pH 7.0, which indicates the absence of lysine epsilon-amino group in the enzyme active site. pH-dependencies of modified peroxidase relative activity are studied; modification by anhydrides of monobasic acids is not found to result in changes of the relative activity pH-profile, while modification by succinic anhydride widens it. Absorption and circular dichoism spectra of native and modified peroxidase within 260--270 nm are obtained, some changes in the enzyme tertiary structure after its epsilon-amino groups modification are observed. Modification of four epsilon-amino groups by buturic and succinic anhydrides and of three epsilon-amino groups by TNBS is found to increase the regidity of protein surrounding of heme, and modification of six epsilon-amino groups by TNBS results in more unwrapped enzyme structure as compared with its native molecule.

PMID:29675

[Immobilization of glyceraldehyde-3-phosphate dehydrogenase by non-covalent binding to specific antibodies and Fab-fragments coupled to Sepharose].

Rabbit antibodies to rat skeletal muscle glyceraldehyde-3-phosphate dehydrogenase, as well as monovalent Fab fragments of these antibodies were coupled to CNBr-activated Sepharose 4B. Rat skeletal muscle glyceraldehyde-3-phosphate dehydrogenase was then immobilized on a matrix by non-covalent binding to specific antibodies. Immobilized enzyme retains approximately 90% catalytic activity of the soluble dehydrogenase; pH optimum of activity and the Km value observed are changed as compared to the enzyme in solution. Glyceraldehyde-3-phosphate dehydrogenase immobilized on specific antibodies is shown to undergo adenine nucleotide-induced dissociation into dimers. The immobilized dimeric form of the enzyme thus obtained is catalytically active and capable of reassociating with the dimers of apoglyceraldehyde-3-phosphate dehydrogenase added in solution to the suspension of Sepharose.

[Immobilization of glyceraldehyde-3-phosphate dehydrogenase by non-covalent binding to specific antibodies and Fab-fragments coupled to Sepharose]. Rabbit antibodies to rat skeletal muscle glyceraldehyde-3-phosphate dehydrogenase, as well as monovalent Fab fragments of these antibodies were coupled to CNBr-activated Sepharose 4B. Rat skeletal muscle glyceraldehyde-3-phosphate dehydrogenase was then immobilized on a matrix by non-covalent binding to specific antibodies. Immobilized enzyme retains approximately 90% catalytic activity of the soluble dehydrogenase; pH optimum of activity and the Km value observed are changed as compared to the enzyme in solution. Glyceraldehyde-3-phosphate dehydrogenase immobilized on specific antibodies is shown to undergo adenine nucleotide-induced dissociation into dimers. The immobilized dimeric form of the enzyme thus obtained is catalytically active and capable of reassociating with the dimers of apoglyceraldehyde-3-phosphate dehydrogenase added in solution to the suspension of Sepharose.

PMID:29676

[Glucose-isomerizing enzyme from Actinomyces olivocinereus and its immobilization on aminosilochrome].

Glucose-isomerizing enzyme was isolated from the culture of Actinomyces olivocinereus. It was purified by the chromatography on DEAE-cellulose. The samples of glucose-isomerasing enzyme are homogeneous according to the results of analytical electrophoresis and ultracentrifugation. Glucose-isomerase is more stable than soluble one. The pH-optima of soluble and immobilized enzymes are 8.5 and 7.5, respectively. The temperature optimum of immobilized enzyme, Km, V, and activation energy do not change during immobilization. The immobilized sample has 58% activity of soluble enzyme.

[Glucose-isomerizing enzyme from Actinomyces olivocinereus and its immobilization on aminosilochrome]. Glucose-isomerizing enzyme was isolated from the culture of Actinomyces olivocinereus. It was purified by the chromatography on DEAE-cellulose. The samples of glucose-isomerasing enzyme are homogeneous according to the results of analytical electrophoresis and ultracentrifugation. Glucose-isomerase is more stable than soluble one. The pH-optima of soluble and immobilized enzymes are 8.5 and 7.5, respectively. The temperature optimum of immobilized enzyme, Km, V, and activation energy do not change during immobilization. The immobilized sample has 58% activity of soluble enzyme.

PMID:29677

[Changes in the conformation of myo-inositol residues in triphosphoinositides].

Dependency of optical rotation of di- and triphosphoinositide water solutions on pH is investigated. The inversion of myo-inosite ring in triphosphoinositide molecule is found to take place at pH range corresponding to the transition of phosphomonoesters from monoanionic into dianionic form. Stabilization of optical rotation is observed at pH range, where one monoester phosphate group is in monoanionic form and the other--in dianionic form. Probably, triphosphoinositide is in the conformation (distorted boat) at this pH range. Diphosphoinositide does not change its optical rotation under pH changes of water or organic solutions. A contribution is estimated of free conformational energy into standard free energy of splitting triphosphoinositide phosphate group depending on pH value. It is concluded that low energy phosphate bond becomes high energy bond due to the free electrostatic interaction of dianionic phosphate group with other negatively charged group in sin-clynal conformation.

[Changes in the conformation of myo-inositol residues in triphosphoinositides]. Dependency of optical rotation of di- and triphosphoinositide water solutions on pH is investigated. The inversion of myo-inosite ring in triphosphoinositide molecule is found to take place at pH range corresponding to the transition of phosphomonoesters from monoanionic into dianionic form. Stabilization of optical rotation is observed at pH range, where one monoester phosphate group is in monoanionic form and the other--in dianionic form. Probably, triphosphoinositide is in the conformation (distorted boat) at this pH range. Diphosphoinositide does not change its optical rotation under pH changes of water or organic solutions. A contribution is estimated of free conformational energy into standard free energy of splitting triphosphoinositide phosphate group depending on pH value. It is concluded that low energy phosphate bond becomes high energy bond due to the free electrostatic interaction of dianionic phosphate group with other negatively charged group in sin-clynal conformation.

PMID:29678

Effect of hypoxia on monoamine synthesis in brains of developing rats. III. Various O2 levels.

1-, 4-, 14- and 28-day-old rats were exposed to a hypoxic environment of 5.9, 8.0 or 12.0% O2 during a period of 30 min. In the brain, tyrosine hydroxylase and tryptophan hydroxylase activity was studied in vivo by measuring the accumulation of dihydroxyphenylalanine (DOPA) and 5-hydroxytryptophan (5-HTP), respectively, after inhibition of L-aromatic amino acid decarboxylase with NSD 1015. Tyrosine and tryptophan levels in the brain were measured simultaneously. The brain tyrosine and tryptophan levels were generally not influenced either by age or hypoxic levels. Tyrosine and tryptophan hydroxylase activity decreased to about the same extent during the various hypoxic levels at all ages studied. It is concluded that the first, rate-limiting, step in the synthesis of the monoamine neurotransmittors dopamine (DA), noradrenaline (NA) and 5-hydroxy-tryptophan (5-HT) is affected during moderate as well as severe hypoxia at all stages of development.

Effect of hypoxia on monoamine synthesis in brains of developing rats. III. Various O2 levels. 1-, 4-, 14- and 28-day-old rats were exposed to a hypoxic environment of 5.9, 8.0 or 12.0% O2 during a period of 30 min. In the brain, tyrosine hydroxylase and tryptophan hydroxylase activity was studied in vivo by measuring the accumulation of dihydroxyphenylalanine (DOPA) and 5-hydroxytryptophan (5-HTP), respectively, after inhibition of L-aromatic amino acid decarboxylase with NSD 1015. Tyrosine and tryptophan levels in the brain were measured simultaneously. The brain tyrosine and tryptophan levels were generally not influenced either by age or hypoxic levels. Tyrosine and tryptophan hydroxylase activity decreased to about the same extent during the various hypoxic levels at all ages studied. It is concluded that the first, rate-limiting, step in the synthesis of the monoamine neurotransmittors dopamine (DA), noradrenaline (NA) and 5-hydroxy-tryptophan (5-HT) is affected during moderate as well as severe hypoxia at all stages of development.

PMID:29679

[Mechanisms of changes in the mass of the organs central to immunity during adenovirus carcinogenesis].

The spleen cells transfer from mice CBA at the 25th day of the carcinogenesis latent period induced by adenovirus SA7(S8) to newborn syngeneic animals caused the graft versus host reaction in them. There was splenomegaly and progressive decrease in weight of the recipients' thymus. Analogous alterations of lymphoid organs were noted in the animals infected during the neonatal period by oncogenic adenovirus SA7(C8). Results showed that adenoviral carcinogenesis had some manifestations of autoimmune disease.

[Mechanisms of changes in the mass of the organs central to immunity during adenovirus carcinogenesis]. The spleen cells transfer from mice CBA at the 25th day of the carcinogenesis latent period induced by adenovirus SA7(S8) to newborn syngeneic animals caused the graft versus host reaction in them. There was splenomegaly and progressive decrease in weight of the recipients' thymus. Analogous alterations of lymphoid organs were noted in the animals infected during the neonatal period by oncogenic adenovirus SA7(C8). Results showed that adenoviral carcinogenesis had some manifestations of autoimmune disease.

PMID:29684

Characterization of adrenoceptors mediating positive inotropic responses in the ventricular myocardium of the dog.

1 The pharmacological characteristics of adrenoceptors mediating the positive inotropic action in the dog heart were assessed by the use of blood-perfused papillary muscles and isolated strips of ventricular myocardium.2 On the blood-perfused papillary muscle driven at 2 Hz and in sinus node preparations, phenylephrine induced positive inotropic and chronotropic responses in the same dose range and was much less potent than isoprenaline. The dose-response curve for the chronotropic action of phenylephrine was parallel to that of isoprenaline, whilst the dose-response curve for the inotropic action of phenylephrine was less steep than that of isoprenaline.3 The infusion of pindolol, a beta-adrenoceptor blocking agent, at a rate of 1 mug/min, shifted the isoprenaline dose-response curves to the right, and to the same extent, in both papillary muscle and sinus node preparations. In contrast to isoprenaline, the antagonism of phenylephrine by pindolol was noncompetitive. Phentolamine did not affect the positive inotropic and chronotropic actions of phenylephrine.4 On isolated ventricular strips alpha-adrenoceptor blockade by 10(-6) M phentolamine did not affect dose-response curves to phenylephrine or dopamine. Pindolol shifted the dopamine dose-response curves to the right in a competitive manner and those of phenylephrine in a noncompetitive manner.5 On ventricular strips from reserpine-pretreated dogs phenylephrine and tyramine dose-response curves were shifted markedly to the right and downwards. Desipramine (10(-5) M) which enhanced the action of noradrenaline considerably reduced the myocardial responses of phenylephrine.6 Papaverine (10(-5) M) decreased the threshold concentration of phenylephrine required to stimulate the myocardium and shifted phenylephrine dose-response curves to the left.7 Raising the temperature from 32 degrees C to 37 degrees C shifted phenylephrine dose-response curves to the right; when the temperature was raised from 37 degrees C to 42 degrees C the affinity of the drug was not changed.8 Other alpha-adrenoceptor stimulants, methoxamine and clonidine, decreased the active tension of ventricular strips. The responses to noradrenaline and adrenaline (in the presence of pindolol; 3 x 10(-8) M) were not affected by phentolamine (10(-6) M).9 The results indicate that adrenoceptors mediating positive inotropic responses in the dog ventricle are of the beta-type and that post-synaptic alpha-adrenoceptors are not involved. Phenylephrine acts mainly by releasing noradrenaline from adrenergic nerve endings and partly by a weak direct action on beta-adrenoceptors.

Characterization of adrenoceptors mediating positive inotropic responses in the ventricular myocardium of the dog. 1 The pharmacological characteristics of adrenoceptors mediating the positive inotropic action in the dog heart were assessed by the use of blood-perfused papillary muscles and isolated strips of ventricular myocardium.2 On the blood-perfused papillary muscle driven at 2 Hz and in sinus node preparations, phenylephrine induced positive inotropic and chronotropic responses in the same dose range and was much less potent than isoprenaline. The dose-response curve for the chronotropic action of phenylephrine was parallel to that of isoprenaline, whilst the dose-response curve for the inotropic action of phenylephrine was less steep than that of isoprenaline.3 The infusion of pindolol, a beta-adrenoceptor blocking agent, at a rate of 1 mug/min, shifted the isoprenaline dose-response curves to the right, and to the same extent, in both papillary muscle and sinus node preparations. In contrast to isoprenaline, the antagonism of phenylephrine by pindolol was noncompetitive. Phentolamine did not affect the positive inotropic and chronotropic actions of phenylephrine.4 On isolated ventricular strips alpha-adrenoceptor blockade by 10(-6) M phentolamine did not affect dose-response curves to phenylephrine or dopamine. Pindolol shifted the dopamine dose-response curves to the right in a competitive manner and those of phenylephrine in a noncompetitive manner.5 On ventricular strips from reserpine-pretreated dogs phenylephrine and tyramine dose-response curves were shifted markedly to the right and downwards. Desipramine (10(-5) M) which enhanced the action of noradrenaline considerably reduced the myocardial responses of phenylephrine.6 Papaverine (10(-5) M) decreased the threshold concentration of phenylephrine required to stimulate the myocardium and shifted phenylephrine dose-response curves to the left.7 Raising the temperature from 32 degrees C to 37 degrees C shifted phenylephrine dose-response curves to the right; when the temperature was raised from 37 degrees C to 42 degrees C the affinity of the drug was not changed.8 Other alpha-adrenoceptor stimulants, methoxamine and clonidine, decreased the active tension of ventricular strips. The responses to noradrenaline and adrenaline (in the presence of pindolol; 3 x 10(-8) M) were not affected by phentolamine (10(-6) M).9 The results indicate that adrenoceptors mediating positive inotropic responses in the dog ventricle are of the beta-type and that post-synaptic alpha-adrenoceptors are not involved. Phenylephrine acts mainly by releasing noradrenaline from adrenergic nerve endings and partly by a weak direct action on beta-adrenoceptors.

PMID:29685

Sulphasalazine is a potent inhibitor of prostaglandin 15-hydroxydehydrogenase: possible basis for therapeutic action in ulcerative colitis.

Sulphasalazine is a potent and selective inhibitor in vitro of prostaglandin 15-hydroxydehydrogenase in rabbit colon (ID50 = 50 micrometer) and in several other organs of different species, but does not inhibit prostaglandin delta-13 reductase or microsomal prostaglandin synthesis from arachidonic acid. It is suggested that this action may underly the therapeutic usefulness of sulphasalazine in ulcerative colitis for the prevention of relapse.

Sulphasalazine is a potent inhibitor of prostaglandin 15-hydroxydehydrogenase: possible basis for therapeutic action in ulcerative colitis. Sulphasalazine is a potent and selective inhibitor in vitro of prostaglandin 15-hydroxydehydrogenase in rabbit colon (ID50 = 50 micrometer) and in several other organs of different species, but does not inhibit prostaglandin delta-13 reductase or microsomal prostaglandin synthesis from arachidonic acid. It is suggested that this action may underly the therapeutic usefulness of sulphasalazine in ulcerative colitis for the prevention of relapse.

PMID:29686

Effects of narcotic analgesics on the uptake and release of 5-hydroxytryptamine in rat synaptosomal preparations.

1 The effects of various narcotic analgesics on the uptake and release of labelled 5-hydroxytryptamine (5-HT) in brain and spinal cord synaptosomes were investigated.2 Methadone was most active in inhibiting 5-HT uptake (IC(50) 2.5 x 10(-7) M). Levorphanol also inhibited 5-HT uptake to a large extent (IC(50) 8.8 x 10(-7) M) while dextrophan, pethidine and pentazocine showed much less activity. Etorphine and morphine had virtually no such activity, with IC(50)S higher than 10(-4) and 10(-3) M respectively.3 The same order of potency as ;5-HT releasers' was found when radioactivity was measured in [(3)H]-5-HT preloaded synaptosomal pellets incubated for 20 min with the various narcotics. Methadone, like chlorimipramine, showed a significant effect at a concentration of 10(-7) M while morphine, at a concentration of 10(-4) M, had no effect.4 When 5-HT release was studied by a perfusion technique, which largely prevents reuptake of the released amine, only fenfluramine, an anorectic agent proposed as a 5-HT releaser, significantly increased spontaneous 5-HT release. These data suggest that the apparent 5-HT release induced by various narcotics in traditional incubation techniques may largely depend on their ability to interfere with neurotransmitter reuptake mechanisms.5 The effects of the various narcotics on 5-HT uptake have no relationship to their relative potency as analgesics in the rat. In the light of their poor effectiveness as 5-HT releasers, it can be concluded that mechanisms other than 5-HT uptake inhibition and release are probably involved in the analgesic effects of these compounds in intact animals.

Effects of narcotic analgesics on the uptake and release of 5-hydroxytryptamine in rat synaptosomal preparations. 1 The effects of various narcotic analgesics on the uptake and release of labelled 5-hydroxytryptamine (5-HT) in brain and spinal cord synaptosomes were investigated.2 Methadone was most active in inhibiting 5-HT uptake (IC(50) 2.5 x 10(-7) M). Levorphanol also inhibited 5-HT uptake to a large extent (IC(50) 8.8 x 10(-7) M) while dextrophan, pethidine and pentazocine showed much less activity. Etorphine and morphine had virtually no such activity, with IC(50)S higher than 10(-4) and 10(-3) M respectively.3 The same order of potency as ;5-HT releasers' was found when radioactivity was measured in [(3)H]-5-HT preloaded synaptosomal pellets incubated for 20 min with the various narcotics. Methadone, like chlorimipramine, showed a significant effect at a concentration of 10(-7) M while morphine, at a concentration of 10(-4) M, had no effect.4 When 5-HT release was studied by a perfusion technique, which largely prevents reuptake of the released amine, only fenfluramine, an anorectic agent proposed as a 5-HT releaser, significantly increased spontaneous 5-HT release. These data suggest that the apparent 5-HT release induced by various narcotics in traditional incubation techniques may largely depend on their ability to interfere with neurotransmitter reuptake mechanisms.5 The effects of the various narcotics on 5-HT uptake have no relationship to their relative potency as analgesics in the rat. In the light of their poor effectiveness as 5-HT releasers, it can be concluded that mechanisms other than 5-HT uptake inhibition and release are probably involved in the analgesic effects of these compounds in intact animals.

PMID:29695

The effect of parenteral glutamate treatment on the localization of neurotransmitters in the mediobasal hypothalamus.

The localization of cholinergic, aminergic and amino acid-ergic neurones in the mediobasal hypothalamus has been studied in normal rat brain and in brains where neurones in nucleus arcuatus were destroyed by repeated administration of 2 mg/g body weight monosodium glutamate to newborn animals. In normal animals acetylcholinesterase staining, choline acetyltransferase and aromatic L-amino acid decarboxylase were concentrated in the median eminence and the arcuate nucleus. Glutamate decarboxylase was concentrated at the boundary between the ventromedial and the arcuate nuclei, with lower activity in the arcuate nucleus and very low activity in the median eminence. Nucleus arcuatus contained an intermediate level of high affinity glutamate uptake. In the lesioned animals, there were significant decreases in choline acetyltransferase, acetylcholinesterase staining and glutamate decarboxylase in the median eminence, whereas choline acetyltransferase activity and acetylcholinesterase staining, but not glutamate decarboxylase activity, were decreased in nucleus arcuatus. Aromatic L-amino acid decarboxylase was unchanged in all regions studied. The high affinity uptakes of glutamate, dopamine and noradrenaline, and the endogenous amino acid levels were also unchanged in the treated animals. The results indicate the existence of acetylcholine- and GABA-containing elements in the tuberoinfundibular tract. They further indicate that the dopamine cells in the arcuate nucleus are less sensitive to the toxic effect of glutamate than other cell types, possibly because they contain less glutamate receptors.

The effect of parenteral glutamate treatment on the localization of neurotransmitters in the mediobasal hypothalamus. The localization of cholinergic, aminergic and amino acid-ergic neurones in the mediobasal hypothalamus has been studied in normal rat brain and in brains where neurones in nucleus arcuatus were destroyed by repeated administration of 2 mg/g body weight monosodium glutamate to newborn animals. In normal animals acetylcholinesterase staining, choline acetyltransferase and aromatic L-amino acid decarboxylase were concentrated in the median eminence and the arcuate nucleus. Glutamate decarboxylase was concentrated at the boundary between the ventromedial and the arcuate nuclei, with lower activity in the arcuate nucleus and very low activity in the median eminence. Nucleus arcuatus contained an intermediate level of high affinity glutamate uptake. In the lesioned animals, there were significant decreases in choline acetyltransferase, acetylcholinesterase staining and glutamate decarboxylase in the median eminence, whereas choline acetyltransferase activity and acetylcholinesterase staining, but not glutamate decarboxylase activity, were decreased in nucleus arcuatus. Aromatic L-amino acid decarboxylase was unchanged in all regions studied. The high affinity uptakes of glutamate, dopamine and noradrenaline, and the endogenous amino acid levels were also unchanged in the treated animals. The results indicate the existence of acetylcholine- and GABA-containing elements in the tuberoinfundibular tract. They further indicate that the dopamine cells in the arcuate nucleus are less sensitive to the toxic effect of glutamate than other cell types, possibly because they contain less glutamate receptors.

PMID:29697

SIF cells, cyclic AMP responses, and catecholamines of the guinea pig superior cervical ganglion.

The superior cervical ganglion (SCG) of the guinea pig has been investigated by a multidisciplinary approach. Dopamine (50 micron) produced no increase in cyclic AMP levels above control values of 27.9 pmole/mg protein, but 50 micron isoproterenol produced cyclic AMP levels of 210 pmole/mg protein, indicating the existence of a beta-adrenergic receptor-adenylate cyclase complex. The SIF cells were studied by fluorescence histochemistry, which indicated that two morphological types were present. A few Type I cells of the guinea pig SCG were solitary, but most were present in clusters containing many Type II cells. Immunohistochemical localization of antibodies to dopamine-beta-hydroxylase (DBH) and phenylethanolamine-N-methyltransferase (PNMT) demonstrated that types of SIF cell localize antibodies to DBH but not PNMT, providing strong evidence that norepinephrine is the neurotransmitter for all the SIF cells of the guinea pig SCG. Determination of the ratio of norepinephrine to dopamine confirmed that no other dopamine pools exist in the guinea pig SCG.

SIF cells, cyclic AMP responses, and catecholamines of the guinea pig superior cervical ganglion. The superior cervical ganglion (SCG) of the guinea pig has been investigated by a multidisciplinary approach. Dopamine (50 micron) produced no increase in cyclic AMP levels above control values of 27.9 pmole/mg protein, but 50 micron isoproterenol produced cyclic AMP levels of 210 pmole/mg protein, indicating the existence of a beta-adrenergic receptor-adenylate cyclase complex. The SIF cells were studied by fluorescence histochemistry, which indicated that two morphological types were present. A few Type I cells of the guinea pig SCG were solitary, but most were present in clusters containing many Type II cells. Immunohistochemical localization of antibodies to dopamine-beta-hydroxylase (DBH) and phenylethanolamine-N-methyltransferase (PNMT) demonstrated that types of SIF cell localize antibodies to DBH but not PNMT, providing strong evidence that norepinephrine is the neurotransmitter for all the SIF cells of the guinea pig SCG. Determination of the ratio of norepinephrine to dopamine confirmed that no other dopamine pools exist in the guinea pig SCG.

PMID:29698

Amplitude and rate of decay of post-tetanic potentiation are controlled by different mechanisms.

Evidence is presented that post-tetanic potentiation (PTP) of the cholinergic, fast, Cl- dependent IPSP seen in cell L5 of the abdominal ganglion of Aplysia californica upon eliciting a spoke in cell L10 is due to an increase in spike-evoked transmitter release. The magnitude of the post-tetanic change in spike-evoked release is inversely correlated with the amount of transmitter released by an isolated presynaptic spike. This was found whether the latter was increased by injection of tetraethyl ammonium (TEA) into the soma of L10 or decreased by hyperpolarization of the soma of L10. Neither of these manipulations affected the rate of decay of PTP. The magnitude of PTP was increased and the rate of decay reduced by increasing either the number or frequency of stimuli in the tetanus. Under all conditions PTP decayed with a single exponential time course, asymptotically approaching the unpotentiated magnitude. It is concluded that while both the amplitude and rate of decay of PTP are affected by the frequency and number of stimuli in the tetanus, the underlying mechanism controlling the amplitude of PTP is different from the mechanism controlling the rate of decay of PTP.

Amplitude and rate of decay of post-tetanic potentiation are controlled by different mechanisms. Evidence is presented that post-tetanic potentiation (PTP) of the cholinergic, fast, Cl- dependent IPSP seen in cell L5 of the abdominal ganglion of Aplysia californica upon eliciting a spoke in cell L10 is due to an increase in spike-evoked transmitter release. The magnitude of the post-tetanic change in spike-evoked release is inversely correlated with the amount of transmitter released by an isolated presynaptic spike. This was found whether the latter was increased by injection of tetraethyl ammonium (TEA) into the soma of L10 or decreased by hyperpolarization of the soma of L10. Neither of these manipulations affected the rate of decay of PTP. The magnitude of PTP was increased and the rate of decay reduced by increasing either the number or frequency of stimuli in the tetanus. Under all conditions PTP decayed with a single exponential time course, asymptotically approaching the unpotentiated magnitude. It is concluded that while both the amplitude and rate of decay of PTP are affected by the frequency and number of stimuli in the tetanus, the underlying mechanism controlling the amplitude of PTP is different from the mechanism controlling the rate of decay of PTP.

PMID:29702

Guanyl O6-arylamination and O6-arylation of DNA by the carcinogen N-hydroxy-1-naphthylamine.

The carcinogen N-hydroxy-1-naphthylamine reacted with nucleic acids and protein under slightly acidic conditions (pH 5) to form covalently bound derivatives with 3 to 20 naphthyl residues/1000 monomer units. The level of binding was in the following order: DNA greater than polyguanylic acid greater than denatured DNA and ribosomal RNA greater than serum albumin greater than transfer RNA greater than polyadenylic acid. Reactions with nucleosides and nucleotides were not detected, and the binding of N-hydroxy-1-naphthylamine to DNA was not inhibited by the addition of nucleosides, nucleotides, methionine, or glutathione. The reaction rates were first order with respect to both DNA and N-hydroxy-1-naphthylamine concentrations. Enzymatic hydrolysis of the DNA containing naphthyl residues yielded 3 nucleoside-arylamine adducts. The major adduct was identified by chemical, ultraviolet, nuclear magnetic resonance, and mass spectrometric analyses as N-(deoxyguanosin-O6-yl)-1-naphthylamine. The other two adducts were identified as 2-(deoxyguanosin-O6-yl)-1-naphthylamine and its decomposition product. Direct evidence for acid-dependent arylnitrenium ion formation was obtained by isotope exchange upon solvolysis of N-hydroxy-1-naphthylamine in acidic H2 18O, and carbocation formation was indicated by the formation of the solvolysis products, 1-amino-2-naphthol and 1-amino-4-naphthol. These studies demonstrated the conversion of a carcinogenic N-hydroxy arylamine to electrophilic arylnitrenium ion and carbocation species that display high selectivity toward macromolecules. The roles of these electrophiles and their macromolecular adducts in the initiation of urinary bladder carcinogenesis through formation of promutagenic lesions in DNA are suggested.

Guanyl O6-arylamination and O6-arylation of DNA by the carcinogen N-hydroxy-1-naphthylamine. The carcinogen N-hydroxy-1-naphthylamine reacted with nucleic acids and protein under slightly acidic conditions (pH 5) to form covalently bound derivatives with 3 to 20 naphthyl residues/1000 monomer units. The level of binding was in the following order: DNA greater than polyguanylic acid greater than denatured DNA and ribosomal RNA greater than serum albumin greater than transfer RNA greater than polyadenylic acid. Reactions with nucleosides and nucleotides were not detected, and the binding of N-hydroxy-1-naphthylamine to DNA was not inhibited by the addition of nucleosides, nucleotides, methionine, or glutathione. The reaction rates were first order with respect to both DNA and N-hydroxy-1-naphthylamine concentrations. Enzymatic hydrolysis of the DNA containing naphthyl residues yielded 3 nucleoside-arylamine adducts. The major adduct was identified by chemical, ultraviolet, nuclear magnetic resonance, and mass spectrometric analyses as N-(deoxyguanosin-O6-yl)-1-naphthylamine. The other two adducts were identified as 2-(deoxyguanosin-O6-yl)-1-naphthylamine and its decomposition product. Direct evidence for acid-dependent arylnitrenium ion formation was obtained by isotope exchange upon solvolysis of N-hydroxy-1-naphthylamine in acidic H2 18O, and carbocation formation was indicated by the formation of the solvolysis products, 1-amino-2-naphthol and 1-amino-4-naphthol. These studies demonstrated the conversion of a carcinogenic N-hydroxy arylamine to electrophilic arylnitrenium ion and carbocation species that display high selectivity toward macromolecules. The roles of these electrophiles and their macromolecular adducts in the initiation of urinary bladder carcinogenesis through formation of promutagenic lesions in DNA are suggested.

PMID:29706

Estradiol receptor analysis in human breast cancer tissue by isoelectric focusing in polyacrylamide gel.

Isoelectric focusing in polyacrylamide gel combined with limited proteolysis is a simple and specific method for quantitation of estradiol receptors in breast cancer tissue. At least eight different samples can be analyzed simultaneously on one gel, and the whole procedure, including sample preparation, takes less than 7 hr. In comparison with sucrose gradient centrifugation, isoelectric focusing is more sensitive, possibly due to the short time (1.5 to 2 hr) needed for the analysis. Furthermore, only one incubation with tritium-labeled estradiol is needed for an analysis, which means that a smaller amount of tumor tissue is needed than for most other methods. This fact allows analysis of the estrogen receptor content in tumor material obtained from fine-needle biopsy.

Estradiol receptor analysis in human breast cancer tissue by isoelectric focusing in polyacrylamide gel. Isoelectric focusing in polyacrylamide gel combined with limited proteolysis is a simple and specific method for quantitation of estradiol receptors in breast cancer tissue. At least eight different samples can be analyzed simultaneously on one gel, and the whole procedure, including sample preparation, takes less than 7 hr. In comparison with sucrose gradient centrifugation, isoelectric focusing is more sensitive, possibly due to the short time (1.5 to 2 hr) needed for the analysis. Furthermore, only one incubation with tritium-labeled estradiol is needed for an analysis, which means that a smaller amount of tumor tissue is needed than for most other methods. This fact allows analysis of the estrogen receptor content in tumor material obtained from fine-needle biopsy.

PMID:29708

Calcification of the collagenous axial skeleton of Veretillum cynomorium pall. (Cnidaria: Pennatulacea).

The axial skeletal rod of Veretillium cynomorium consists of a fibrillar collagenous matrix calcified with calcite. The present paper describes ultrastructural and crystallographic details of its organization and deposition. At the inferior end of the rod is a calcification gradient between the noncalcified tip and the rest of the axis. Initial mineral deposits, which are sometimes associated with cell debris, give rise to calcitic nodules which enlarge by the radical growth of several lobes. These nodules fuse and form the core of the axis. Subsequent increase in diameter of the rod involves the radial development of irregular columns of calcite which arise from the peripheral nodules. Mineral surfaces exhibit a distinctive microarchitecture which can be related to the predominantly c-axis parallel growth of the calcite. Particular attention is paid to the relationship between mineral and matrix. The collagen fibrils, embedded in the calcite but never impregnated with it, are not responsible for the initial nucleation of mineral. The crystallographic orientation of the calcite also appears to be independent of these fibrils.

Calcification of the collagenous axial skeleton of Veretillum cynomorium pall. (Cnidaria: Pennatulacea). The axial skeletal rod of Veretillium cynomorium consists of a fibrillar collagenous matrix calcified with calcite. The present paper describes ultrastructural and crystallographic details of its organization and deposition. At the inferior end of the rod is a calcification gradient between the noncalcified tip and the rest of the axis. Initial mineral deposits, which are sometimes associated with cell debris, give rise to calcitic nodules which enlarge by the radical growth of several lobes. These nodules fuse and form the core of the axis. Subsequent increase in diameter of the rod involves the radial development of irregular columns of calcite which arise from the peripheral nodules. Mineral surfaces exhibit a distinctive microarchitecture which can be related to the predominantly c-axis parallel growth of the calcite. Particular attention is paid to the relationship between mineral and matrix. The collagen fibrils, embedded in the calcite but never impregnated with it, are not responsible for the initial nucleation of mineral. The crystallographic orientation of the calcite also appears to be independent of these fibrils.

PMID:29714

[Effects of levophacetoperane, pemoline, fenozolone, and centrophenoxine on catecholamines and serotonin uptake in various parts of the rat brain].

These drugs, except centrophenoxine, inhibit in vitro in a competitive manner, norepinephrin uptake in Rat hypothalamus and cortex, and dopamine uptake in corpus striatum and cortex, at higher concentrations than d.l. amphetamine; this alone inhibits serotonin uptake in hypothalamus.

[Effects of levophacetoperane, pemoline, fenozolone, and centrophenoxine on catecholamines and serotonin uptake in various parts of the rat brain]. These drugs, except centrophenoxine, inhibit in vitro in a competitive manner, norepinephrin uptake in Rat hypothalamus and cortex, and dopamine uptake in corpus striatum and cortex, at higher concentrations than d.l. amphetamine; this alone inhibits serotonin uptake in hypothalamus.

PMID:29715

[Induction of hepatic tyrosine transaminase in rats by phenothiazine derivatives and analogs].

We have showed induction of tyrosine-alpha-ketoglutarate transaminase in hepatic cytosol of Rats (Wistar strain) five hours after intraperitoneal administration of tricyclic compounds (phenothiazine, iminodibenzyl, thioxanthene, thiophenylpyridylamin, dibenzocycloheptadiene, dibenzoxepin derivatives). Chemical structure of these molecules is very important: sulfur atom (phenothiazine, thioxanthene), some substituants like chlorine (chlorpromazine, chlorprothixene) and 2'-dimethylaminopropyl chain (promethazine) increase this inductive effect.

[Induction of hepatic tyrosine transaminase in rats by phenothiazine derivatives and analogs]. We have showed induction of tyrosine-alpha-ketoglutarate transaminase in hepatic cytosol of Rats (Wistar strain) five hours after intraperitoneal administration of tricyclic compounds (phenothiazine, iminodibenzyl, thioxanthene, thiophenylpyridylamin, dibenzocycloheptadiene, dibenzoxepin derivatives). Chemical structure of these molecules is very important: sulfur atom (phenothiazine, thioxanthene), some substituants like chlorine (chlorpromazine, chlorprothixene) and 2'-dimethylaminopropyl chain (promethazine) increase this inductive effect.

PMID:29716

[Mechanism of induction of tyrosine in rat liver by phenothiazine derivatives and related chemical compounds].

Increase of hepatic tyrosine-alpha-ketoglutarate transaminase is observed in Rats (Wistar strain) after intraperitoneal administration of tricyclic compounds (phenothiazin and related structure derivatives). This is an induction process: actinomycine D inhibits this effect. This action is not mediated by glucocorticoids: induction persists in adrenalectomized Rats. The mechanism of action is different too: additive effects are found after simultaneous injection of glucocorticoid and tricyclic drug.

[Mechanism of induction of tyrosine in rat liver by phenothiazine derivatives and related chemical compounds]. Increase of hepatic tyrosine-alpha-ketoglutarate transaminase is observed in Rats (Wistar strain) after intraperitoneal administration of tricyclic compounds (phenothiazin and related structure derivatives). This is an induction process: actinomycine D inhibits this effect. This action is not mediated by glucocorticoids: induction persists in adrenalectomized Rats. The mechanism of action is different too: additive effects are found after simultaneous injection of glucocorticoid and tricyclic drug.

PMID:29720

Kinetics of the reactions of unconjugated and conjugated bilirubins with p-diazobenzenesulfonic acid.

We report the kinetics of the reactions of unconjugated bilirubin and conjugated bilirubin with p-diazobenzene sulfonic acid in aqueous media. Our studies confirm that each reaction proceeds in two steps and that the second step is catalyzed by sulfanilic acid. In the presence of an excess of p-diazobenzenesulfonic acid and in the absence of sulfanilic acid, the reaction for either unconjugated or conjugated bilirubin proceeds in two successive first-order steps, the second step being much the slower. This study emphasizes the first step in the reaction for each species and includes data on the effects of p-diazobenzenesulfonic acid, albumin, benzoate, and caffeine concentrations, pH in the range from 4 to 12, and temperature. Mechanisms proposed for reactions with and without caffeine are used to develop rate equations, and the kinetic data are used to evaluate rate constants, acid dissociation constants for the different bilirubin species, and formation constants for bilirubin-caffeine complex species that are proposed.

Kinetics of the reactions of unconjugated and conjugated bilirubins with p-diazobenzenesulfonic acid. We report the kinetics of the reactions of unconjugated bilirubin and conjugated bilirubin with p-diazobenzene sulfonic acid in aqueous media. Our studies confirm that each reaction proceeds in two steps and that the second step is catalyzed by sulfanilic acid. In the presence of an excess of p-diazobenzenesulfonic acid and in the absence of sulfanilic acid, the reaction for either unconjugated or conjugated bilirubin proceeds in two successive first-order steps, the second step being much the slower. This study emphasizes the first step in the reaction for each species and includes data on the effects of p-diazobenzenesulfonic acid, albumin, benzoate, and caffeine concentrations, pH in the range from 4 to 12, and temperature. Mechanisms proposed for reactions with and without caffeine are used to develop rate equations, and the kinetic data are used to evaluate rate constants, acid dissociation constants for the different bilirubin species, and formation constants for bilirubin-caffeine complex species that are proposed.

PMID:29721

Evaluation of a kinetic method for simultaneous determination of conjugated and unconjugated bilirubin.

This paper describes a fast kinetic method for the simultaneous determination of unconjugated and conjugated bilirugin in the same reaction solution. A stopped-flow mixing system with a stabilized photometer and small computer is used to mix sample and reagent rapidly and to record 250 data points during a 700-ms reaction time, and a regression program is used to resolve these kinetic data into the concentrations of unconjugated and conjugated bilirubin. Data are reported for synthetic single and two-component samples and for serum samples. Kinetic results for synthetic mixtures and serum samples are compared with results obtained by a conventional two-step procedure. Regression equations show good linearity between kinetically determined absorbance changes and concentration, good agreement between taken and found values for total, unconjugated, and conjugated bilirubin for synthetic samples in human serum albumin, and a good correlation between kinetic and equilibrium results for these species in sera. Regression slopes for kinetic vs. equilibrium assay results for total, unconjugated, and conjugated bilirubins in sera were 1.01 +/- 0.05, 1.04 +/- 0.03 and 0.91 +/- 0.04, respectively, with intercepts of 6.6,--2.7, and 3.8 micromol/liter, and standard errors of estimate of 28, 14, and 20 micromol/liter. These data reflect uncertainties in both the kinetic and equilibrium methods.

Evaluation of a kinetic method for simultaneous determination of conjugated and unconjugated bilirubin. This paper describes a fast kinetic method for the simultaneous determination of unconjugated and conjugated bilirugin in the same reaction solution. A stopped-flow mixing system with a stabilized photometer and small computer is used to mix sample and reagent rapidly and to record 250 data points during a 700-ms reaction time, and a regression program is used to resolve these kinetic data into the concentrations of unconjugated and conjugated bilirubin. Data are reported for synthetic single and two-component samples and for serum samples. Kinetic results for synthetic mixtures and serum samples are compared with results obtained by a conventional two-step procedure. Regression equations show good linearity between kinetically determined absorbance changes and concentration, good agreement between taken and found values for total, unconjugated, and conjugated bilirubin for synthetic samples in human serum albumin, and a good correlation between kinetic and equilibrium results for these species in sera. Regression slopes for kinetic vs. equilibrium assay results for total, unconjugated, and conjugated bilirubins in sera were 1.01 +/- 0.05, 1.04 +/- 0.03 and 0.91 +/- 0.04, respectively, with intercepts of 6.6,--2.7, and 3.8 micromol/liter, and standard errors of estimate of 28, 14, and 20 micromol/liter. These data reflect uncertainties in both the kinetic and equilibrium methods.

PMID:29722

Characterization of the principal human prostatic acid phosphatase isoenzyme, purified by affinity chromatography and isoelectric focusing. Part II.

The principal enzyme of human prostatic acid phosphatase [orthophosphoric monoester phosphohydrolase (acid optimum), EC 3.1.3.2], which had been highly purified by affinity chromatography, isoelectric focusing, and gel filtrations, was shown to be homogeneous at pH 5.0 by sedimentation equilibrium analysis. The amino acid composition was determined and the sedimentation coefficient of the native molecule measured. The relative molecular mass was 89,000 at pH 5.0, as measured by analytical ultracentrifugation. The Km-value of the enzyme for p-nitrophenyl phosphate as substrate is 1.8-10(-4) mol/liter. I also examined substrate speificity, different inhibitors, and the effects of pH, temperature, and serum on the enzyme activity.

Characterization of the principal human prostatic acid phosphatase isoenzyme, purified by affinity chromatography and isoelectric focusing. Part II. The principal enzyme of human prostatic acid phosphatase [orthophosphoric monoester phosphohydrolase (acid optimum), EC 3.1.3.2], which had been highly purified by affinity chromatography, isoelectric focusing, and gel filtrations, was shown to be homogeneous at pH 5.0 by sedimentation equilibrium analysis. The amino acid composition was determined and the sedimentation coefficient of the native molecule measured. The relative molecular mass was 89,000 at pH 5.0, as measured by analytical ultracentrifugation. The Km-value of the enzyme for p-nitrophenyl phosphate as substrate is 1.8-10(-4) mol/liter. I also examined substrate speificity, different inhibitors, and the effects of pH, temperature, and serum on the enzyme activity.

PMID:29723

Column-chromatographic separation of isoenzymes of aspartate aminotransferase.

We describe a column-chromatographic method for separating the mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase in human serum. Bed height of the ion exchanger, pH, and salt concentrations in the eluting buffers are shown to be variables affecting the separation of the isoenzymes. Under the optimized conditions selected for this study, a 30% increase in volume was observed in one fraction, associated with changing the salt concentration of the eluting buffer and attributed to a contraction of the DEAE-Sephadex A-50. Elution profiles (enzyme activity vs. fraction number) were examined with highly purified mitochondrial and cytoplasmic isoenzymes of human origin in bovine serum albumin and human serum. Recovery of the enzyme in the eluted fractions averaged 102% (SD, 2.0%) for specimens prepared from the purified isoenzymes and 104% (SD, 10.7%) for 38 human serum specimens. The separation technique showed linearity to catalytic concentrations in excess of 200 U/liter (reaction temperature 30 degrees C) for each isoenzyme. Additional information is presented regarding among-day precision and the effect of specimen dilution.

Column-chromatographic separation of isoenzymes of aspartate aminotransferase. We describe a column-chromatographic method for separating the mitochondrial and cytoplasmic isoenzymes of aspartate aminotransferase in human serum. Bed height of the ion exchanger, pH, and salt concentrations in the eluting buffers are shown to be variables affecting the separation of the isoenzymes. Under the optimized conditions selected for this study, a 30% increase in volume was observed in one fraction, associated with changing the salt concentration of the eluting buffer and attributed to a contraction of the DEAE-Sephadex A-50. Elution profiles (enzyme activity vs. fraction number) were examined with highly purified mitochondrial and cytoplasmic isoenzymes of human origin in bovine serum albumin and human serum. Recovery of the enzyme in the eluted fractions averaged 102% (SD, 2.0%) for specimens prepared from the purified isoenzymes and 104% (SD, 10.7%) for 38 human serum specimens. The separation technique showed linearity to catalytic concentrations in excess of 200 U/liter (reaction temperature 30 degrees C) for each isoenzyme. Additional information is presented regarding among-day precision and the effect of specimen dilution.

PMID:29725

Investigations into the choice of immunogen, ligand, antiserum and assay conditions for the radioimmunoassay of conjugated cholic acid.

Investigations into the choice of immunogen, ligand, antiserum and assay conditions for the radioimmunoassay of conjugated cholic acid have been performed with a view to producing optimal assay conditions. Cholic acid-BSA was found to be the best immunogen to produce antibodies to conjugated cholic acid and the response was of an IgG type. Incorporating a spacer (hexanoic acid) between hapten and carrier protein resulted in a decrease in antiserum titre. Optimal conditions for the assay were found using [125I]histamine-glycocholic acid as ligand with a dilution of antiserum to produce 60% binding of ligand and a pH of 7.4. Using these assay conditions no serum effects were found; extraction of serum prior to assay was therefore unnecessary. The assay was sensitive enough to detect post-prandial increased in serum bile acid concentrations following a liquid test meal; no increase was observed throughout the same time period in a fasting control.

Investigations into the choice of immunogen, ligand, antiserum and assay conditions for the radioimmunoassay of conjugated cholic acid. Investigations into the choice of immunogen, ligand, antiserum and assay conditions for the radioimmunoassay of conjugated cholic acid have been performed with a view to producing optimal assay conditions. Cholic acid-BSA was found to be the best immunogen to produce antibodies to conjugated cholic acid and the response was of an IgG type. Incorporating a spacer (hexanoic acid) between hapten and carrier protein resulted in a decrease in antiserum titre. Optimal conditions for the assay were found using [125I]histamine-glycocholic acid as ligand with a dilution of antiserum to produce 60% binding of ligand and a pH of 7.4. Using these assay conditions no serum effects were found; extraction of serum prior to assay was therefore unnecessary. The assay was sensitive enough to detect post-prandial increased in serum bile acid concentrations following a liquid test meal; no increase was observed throughout the same time period in a fasting control.

PMID:29726

Determination of cystyl-aminopeptidase. Isoenzymes in seminal plasma and serum of different origin.

The "oxytocinase" activity has been determined as the CAP (cystyl-aminopeptidase, EC 3.4.11.3) activity with several substrates. It was demonstrated that serum samples from pregnant women and patients with serious liver disease had increased CAP activities compared with normal serum. It was also shown that seminal plasma had very high CAP activity. The pH optimum for the enzymes from the various sources differed, as did the metal dependence. Furthermore, samples from patients with liver disease had higher CAP activities when assayed in buffers containing amino groups, in contrast to the other samples. Gel chromatography and gel electrophoresis revealed the presence of several isoenzymes. The serum from pregnant women contained an isoenzyme neither present in normal plasma nor in any of the other sources tested. It is possible that this isoenzymes represents the true oxytocinase. CAP and LAP (leucine aminopeptidase) activities were very well correlated in serum from pregnant women and seminal plasma, while the correlation for samples from patients with liver disease was not as good. When care was taken to determine the CAP activity at the right pH and with the appropriate buffer, the risk for interference from other enzymes was minimized in the determination of oxytocinase as CAP activity.

Determination of cystyl-aminopeptidase. Isoenzymes in seminal plasma and serum of different origin. The "oxytocinase" activity has been determined as the CAP (cystyl-aminopeptidase, EC 3.4.11.3) activity with several substrates. It was demonstrated that serum samples from pregnant women and patients with serious liver disease had increased CAP activities compared with normal serum. It was also shown that seminal plasma had very high CAP activity. The pH optimum for the enzymes from the various sources differed, as did the metal dependence. Furthermore, samples from patients with liver disease had higher CAP activities when assayed in buffers containing amino groups, in contrast to the other samples. Gel chromatography and gel electrophoresis revealed the presence of several isoenzymes. The serum from pregnant women contained an isoenzyme neither present in normal plasma nor in any of the other sources tested. It is possible that this isoenzymes represents the true oxytocinase. CAP and LAP (leucine aminopeptidase) activities were very well correlated in serum from pregnant women and seminal plasma, while the correlation for samples from patients with liver disease was not as good. When care was taken to determine the CAP activity at the right pH and with the appropriate buffer, the risk for interference from other enzymes was minimized in the determination of oxytocinase as CAP activity.

PMID:29727

The activity of gamma-glutamyltransferase after bile duct ligation in guinea pig.

The activity of gamma-glutamyltransferase was studied in guinea pig after bile duct ligation. In serum, an abrupt increase in activity up to 10--20 times the normal value was found 3 h after obstruction and the mean activity over the first 3 days following the operation was some 8 times the normal value. In liver, however, a small decline in activity could be demonstrated. The administration of cycloheximide did not influence the acute increase in serum activity. Bile duct ligation caused marked increases in serum bile acid levels which initially paralleled the serum gamma-glutamyltransferase activity. It is suggested that the increased serum activity may arise from the solubilization by bile acids of liver membrane-bound enzyme.

The activity of gamma-glutamyltransferase after bile duct ligation in guinea pig. The activity of gamma-glutamyltransferase was studied in guinea pig after bile duct ligation. In serum, an abrupt increase in activity up to 10--20 times the normal value was found 3 h after obstruction and the mean activity over the first 3 days following the operation was some 8 times the normal value. In liver, however, a small decline in activity could be demonstrated. The administration of cycloheximide did not influence the acute increase in serum activity. Bile duct ligation caused marked increases in serum bile acid levels which initially paralleled the serum gamma-glutamyltransferase activity. It is suggested that the increased serum activity may arise from the solubilization by bile acids of liver membrane-bound enzyme.

PMID:29728

[A new method for determination of cadmium in plasma (author's transl)].

Cadmium can be isolated from plasma by formation of negative charged iodide complexes bound to an anion exchange resin. Elution from the resin gives a cadmium solution with only a few interfering substances in an uniform matrix. Thus an undisturbed determination by flameless atomic absorption spectrometry is achieved. The mean of the natural cadmium level found in plasma was 1.9 +/- 0.8 ng/ml, within the normal range between 1.1 and 3.3 ng/ml.

[A new method for determination of cadmium in plasma (author's transl)]. Cadmium can be isolated from plasma by formation of negative charged iodide complexes bound to an anion exchange resin. Elution from the resin gives a cadmium solution with only a few interfering substances in an uniform matrix. Thus an undisturbed determination by flameless atomic absorption spectrometry is achieved. The mean of the natural cadmium level found in plasma was 1.9 +/- 0.8 ng/ml, within the normal range between 1.1 and 3.3 ng/ml.

PMID:29729

Lactosyl ceramidosis: deficient activity of neutral beta-galactosidase in liver and cultivated fibroblasts?

Neutral beta-galactosidase was partially purified from liver of normal controls, a patient with Niemann-Pick disease type A and the previously described patient with lactosyl ceramidosis using Concanavalin A-Sepharose adsorption and Sephadex G-100 gel filtration. The partially purified fractions were essentially free of galactosyl ceramide beta-galactosidase and GM1 beta-galactosidase activities. The normal and Niemann-Pick fractions were found to hydrolyze lactosyl ceramide, in the presence of sodium taurodeoxycholate, at a pH optimum of 5.6 as well as aryl beta-galactosides and aryl beta-glucosides at pH 6.2. The corresponding fraction from the lactosyl ceramidosis liver contained only 1--4% of the normal activity towards artificial substrates and lactosyl ceramide. Cross-reacting material identical to the normal was demonstrated in this fraction with antiserum raised against purified neutral beta-galactosidase, but no activity was observed in the precipitin line when stained with naphthol AS-LC-beta-galactoside or naphthol AS-LC-beta-glucoside. A similar deficiency of neutral beta-galactosidase activity was demonstrated in cultivated fibroblasts of the patient with lactosyl ceramidosis. Following adsorption on Concanavalin A-Sepharose and anti-GM1 beta-galactosidase antibody-Sepharose conjugates and chromatography on DEAE cellulose, fibroblast lysates from the patient exhibited 3% of normal activity towards 4-methyl-umbelliferyl beta-glucoside at pH 6.2 and 12% of normal activity towards lactosyl ceramide at pH 5.6. These data suggest that neutral beta-galactosidase may have an in vivo role in the cleavage of lactosyl ceramide and that a deficiency of this activity may be related to the lactosyl ceramide accumulation observed in the patient with lactosyl ceramidosis.

Lactosyl ceramidosis: deficient activity of neutral beta-galactosidase in liver and cultivated fibroblasts? Neutral beta-galactosidase was partially purified from liver of normal controls, a patient with Niemann-Pick disease type A and the previously described patient with lactosyl ceramidosis using Concanavalin A-Sepharose adsorption and Sephadex G-100 gel filtration. The partially purified fractions were essentially free of galactosyl ceramide beta-galactosidase and GM1 beta-galactosidase activities. The normal and Niemann-Pick fractions were found to hydrolyze lactosyl ceramide, in the presence of sodium taurodeoxycholate, at a pH optimum of 5.6 as well as aryl beta-galactosides and aryl beta-glucosides at pH 6.2. The corresponding fraction from the lactosyl ceramidosis liver contained only 1--4% of the normal activity towards artificial substrates and lactosyl ceramide. Cross-reacting material identical to the normal was demonstrated in this fraction with antiserum raised against purified neutral beta-galactosidase, but no activity was observed in the precipitin line when stained with naphthol AS-LC-beta-galactoside or naphthol AS-LC-beta-glucoside. A similar deficiency of neutral beta-galactosidase activity was demonstrated in cultivated fibroblasts of the patient with lactosyl ceramidosis. Following adsorption on Concanavalin A-Sepharose and anti-GM1 beta-galactosidase antibody-Sepharose conjugates and chromatography on DEAE cellulose, fibroblast lysates from the patient exhibited 3% of normal activity towards 4-methyl-umbelliferyl beta-glucoside at pH 6.2 and 12% of normal activity towards lactosyl ceramide at pH 5.6. These data suggest that neutral beta-galactosidase may have an in vivo role in the cleavage of lactosyl ceramide and that a deficiency of this activity may be related to the lactosyl ceramide accumulation observed in the patient with lactosyl ceramidosis.

PMID:29730

A simple UV spectrophotometric method for theophylline serum level determination.

A brief, simple and unexpensive UV spectrophotometric method for theophylline serum level determination is described. Charcoal extraction was performed for theophylline isolation from biological fluids. Coefficients of variation and recovery are similar to other parallel methods.

A simple UV spectrophotometric method for theophylline serum level determination. A brief, simple and unexpensive UV spectrophotometric method for theophylline serum level determination is described. Charcoal extraction was performed for theophylline isolation from biological fluids. Coefficients of variation and recovery are similar to other parallel methods.

PMID:29732

Calcium ion as second messenger.

The role of calcium as an intracellular messenger in the activation of eukaryotic cells is discussed. Particular emphasis is devoted to: (1) the interrelationship between cell activation by chemical stimuli and alterations in intracellular calcium metabolism, and (2) the interrelated roles of calcium and the cyclic nucleotides, cyclic AMP and cyclic GMP, in achieving the final integrated, co-ordinated cellular response.

Calcium ion as second messenger. The role of calcium as an intracellular messenger in the activation of eukaryotic cells is discussed. Particular emphasis is devoted to: (1) the interrelationship between cell activation by chemical stimuli and alterations in intracellular calcium metabolism, and (2) the interrelated roles of calcium and the cyclic nucleotides, cyclic AMP and cyclic GMP, in achieving the final integrated, co-ordinated cellular response.

PMID:29733

Evidence for secretion of vasoactive intestinal peptide by tumours of pancreas, adrenal medulla, thyroid and lung: support for the unifying APUD concept.

Levels of vasoactive intestinal polypeptide (VIP) were measured by radioimmunoassay in plasma or tissue from thirty-five patients with watery diarrhoea, and in plasma of twenty-five normal controls. Plasma levels were between 0.6 and 11.0 ng/ml in thirty-one of the thirty-three patients in whom it was measured and too low to measure (less than 200 pg/ml) in the other two. Peptide levels were less than 200 pg/ml in twenty-three of the controls, but higher in the remaining two. All tissues from patients were "rich" in VIP (10 ng to 35 microgram per g). The aetiologic diagnoses included pancreatic islet-cell adenoma or adenocarcinoma, islet-cell hyperplasia, bronchogenic carcinoma, pheochromocytoma, ganglioneuroblastoma, medullary thyroid carcinoma, and retroperitoneal histiocytoma. The findings support the conclusions that: (1) VIP is a likely mediator of the water-diarrhoea syndrome; (2) the syndrome may result from a variety of tumours; (3) this or a related peptide hormone may be secreted by these tumours; and (4) these tumours may have a common embryonic origin.

Evidence for secretion of vasoactive intestinal peptide by tumours of pancreas, adrenal medulla, thyroid and lung: support for the unifying APUD concept. Levels of vasoactive intestinal polypeptide (VIP) were measured by radioimmunoassay in plasma or tissue from thirty-five patients with watery diarrhoea, and in plasma of twenty-five normal controls. Plasma levels were between 0.6 and 11.0 ng/ml in thirty-one of the thirty-three patients in whom it was measured and too low to measure (less than 200 pg/ml) in the other two. Peptide levels were less than 200 pg/ml in twenty-three of the controls, but higher in the remaining two. All tissues from patients were "rich" in VIP (10 ng to 35 microgram per g). The aetiologic diagnoses included pancreatic islet-cell adenoma or adenocarcinoma, islet-cell hyperplasia, bronchogenic carcinoma, pheochromocytoma, ganglioneuroblastoma, medullary thyroid carcinoma, and retroperitoneal histiocytoma. The findings support the conclusions that: (1) VIP is a likely mediator of the water-diarrhoea syndrome; (2) the syndrome may result from a variety of tumours; (3) this or a related peptide hormone may be secreted by these tumours; and (4) these tumours may have a common embryonic origin.

PMID:29734

Neuroendocrine embryology and the APUD concept.

In the Vertebrata the great majority of cells producing hormonal peptides belong to the APUD series and share its distinctive cytochemical and ultrastructural characteristics. According to the concept all members of the series are to be regarded as derivatives of neuroectoderm or of specialized (placodal) ectoderm. For most of the APUD cells this criterion is fulfilled in that their origin from neural tube, neural ridges or neural crest can be considered proven. Complete proof is not yet available for the APUD cells of the gastrointestinal tract and pancreas, and indeed much contrary evidence can be cited. Despite the latter, our embryological studies show: (1) that the hypothalamohypophyseal complex is wholly neuroectodermal; (2)that the chronology of neural crest dispersion is such that this tissue could be responsible for observed APUD cell contributions to the foregut; (3) that placodal ectoderm makes important contributions to pharyngeal pouch endocrine derivatives in birds and mammals; and (4) that the amphibian parathyroid gland is derived from the same layer of neural ectoderm as the hypothalamo-hypophyseal axis. Supporting immunocytochemical studies indicate that peptides belonging to the APUD series are more widely distributed than hitherto recognized and it is concluded: (1) that the whole of peptide endocrinology is neuroendocrinology; and (2) that the APUD cells, with a few cells hitherto regarded as being outside the series, form a third (Endocrine) division of the nervous system to add to the existing Somatic and Autonomic divisions.

Neuroendocrine embryology and the APUD concept. In the Vertebrata the great majority of cells producing hormonal peptides belong to the APUD series and share its distinctive cytochemical and ultrastructural characteristics. According to the concept all members of the series are to be regarded as derivatives of neuroectoderm or of specialized (placodal) ectoderm. For most of the APUD cells this criterion is fulfilled in that their origin from neural tube, neural ridges or neural crest can be considered proven. Complete proof is not yet available for the APUD cells of the gastrointestinal tract and pancreas, and indeed much contrary evidence can be cited. Despite the latter, our embryological studies show: (1) that the hypothalamohypophyseal complex is wholly neuroectodermal; (2)that the chronology of neural crest dispersion is such that this tissue could be responsible for observed APUD cell contributions to the foregut; (3) that placodal ectoderm makes important contributions to pharyngeal pouch endocrine derivatives in birds and mammals; and (4) that the amphibian parathyroid gland is derived from the same layer of neural ectoderm as the hypothalamo-hypophyseal axis. Supporting immunocytochemical studies indicate that peptides belonging to the APUD series are more widely distributed than hitherto recognized and it is concluded: (1) that the whole of peptide endocrinology is neuroendocrinology; and (2) that the APUD cells, with a few cells hitherto regarded as being outside the series, form a third (Endocrine) division of the nervous system to add to the existing Somatic and Autonomic divisions.

PMID:29735

The development of the releasing factor concept.

After four decades of intense and competitive research, three hypothalamic releasing hormones (formerly factors) have recently been isolated and characterized. These are the decapeptide gonadotrophin releasing hormone (GnRH), tripeptide thyrotrophin releasing hormone (TRH), and the tetradecapeptide somatostatin. Some aspects of these hormones are discussed, and GnRH is considered in greater detail to demonstrate the difficulties involved in fulfilling completely the criteria which determine whether a substance can be accepted as a physiological releasing hormone. A substance immunologically similar to GnRH is present in rat hypophysial portal vessel blood, but, while the amount of this substance released into the portal circulation can be increased significantly by electrical stimulation of the preoptic area, no significant changes occur during the oestrous cycle or after long-term castration. This may be due to interference with the normal secretion of GnRH by the trauma and anaesthesia which necessarily accompany exposure of the pituitary stalk. However, the possibility exists that our preconceived notions regarding the changes in plasma levels of releasing hormones under physiological conditions may be incorrect. Thus it seems likely that changes in the rate of secretion of thyrotrophin is effected by throid hormones modulating the responsiveness of the thyrotrophs to a steady input of TRH. Evidence is presented for the existence of a similar mechanism for gonadotrophin secretion, and the role of steroid hormones and the priming effect of GnRH in modulating the responsiveness of the gonadotrophs is considered. The intrinsic connexions of the hypothalamus, the role of the hypothalamic aminergic systems and the autonomy of the hypothalamus with respect to anterior pituitary control present many problems which will prove difficult to solve.

The development of the releasing factor concept. After four decades of intense and competitive research, three hypothalamic releasing hormones (formerly factors) have recently been isolated and characterized. These are the decapeptide gonadotrophin releasing hormone (GnRH), tripeptide thyrotrophin releasing hormone (TRH), and the tetradecapeptide somatostatin. Some aspects of these hormones are discussed, and GnRH is considered in greater detail to demonstrate the difficulties involved in fulfilling completely the criteria which determine whether a substance can be accepted as a physiological releasing hormone. A substance immunologically similar to GnRH is present in rat hypophysial portal vessel blood, but, while the amount of this substance released into the portal circulation can be increased significantly by electrical stimulation of the preoptic area, no significant changes occur during the oestrous cycle or after long-term castration. This may be due to interference with the normal secretion of GnRH by the trauma and anaesthesia which necessarily accompany exposure of the pituitary stalk. However, the possibility exists that our preconceived notions regarding the changes in plasma levels of releasing hormones under physiological conditions may be incorrect. Thus it seems likely that changes in the rate of secretion of thyrotrophin is effected by throid hormones modulating the responsiveness of the thyrotrophs to a steady input of TRH. Evidence is presented for the existence of a similar mechanism for gonadotrophin secretion, and the role of steroid hormones and the priming effect of GnRH in modulating the responsiveness of the gonadotrophs is considered. The intrinsic connexions of the hypothalamus, the role of the hypothalamic aminergic systems and the autonomy of the hypothalamus with respect to anterior pituitary control present many problems which will prove difficult to solve.

PMID:29737

The influence of dialysis fluid composition on the blood pressure response during dialysis.

To elucidate the relative role of osmolar (sodium) and acetate shifts during dialysis, 6 patients with problems of overhydration underwent rapid ultrafiltration for 1 hr (mean weight reduction 2.0 kg), using the 1 m2 RP 6 dialyzer. Ultrafiltration was carried out at the beginning of each of 5 dialysis treatments at weekly intervals. Ultrafiltration was undertaken without dialysis (controls) and with simultaneous dialysis using acetate (40 mmoles/1) or bicarbonate (25 mmoles/1) in the dialysis fluid with dialyzate sodium concentration of 133 and 145 mmoles/1. The systolic blood pressure and mean arterial pressure which were stable with ultrafiltration only fell slightly when a high dialyzate sodium concentration was used and much further when the dialyzate sodium concentration was kept low. These changes were apparently related to the changes in plasma osmolality. Acetate had no effect on blood pressure at the higher sodium concentration, but a slight (insignificant) additive effect when used in the low-sodium dialyzate. Shifts in osmolality (sodium concentration) seem to be more important than the effect of acetate in inducing dialysis-associated hypotension.

The influence of dialysis fluid composition on the blood pressure response during dialysis. To elucidate the relative role of osmolar (sodium) and acetate shifts during dialysis, 6 patients with problems of overhydration underwent rapid ultrafiltration for 1 hr (mean weight reduction 2.0 kg), using the 1 m2 RP 6 dialyzer. Ultrafiltration was carried out at the beginning of each of 5 dialysis treatments at weekly intervals. Ultrafiltration was undertaken without dialysis (controls) and with simultaneous dialysis using acetate (40 mmoles/1) or bicarbonate (25 mmoles/1) in the dialysis fluid with dialyzate sodium concentration of 133 and 145 mmoles/1. The systolic blood pressure and mean arterial pressure which were stable with ultrafiltration only fell slightly when a high dialyzate sodium concentration was used and much further when the dialyzate sodium concentration was kept low. These changes were apparently related to the changes in plasma osmolality. Acetate had no effect on blood pressure at the higher sodium concentration, but a slight (insignificant) additive effect when used in the low-sodium dialyzate. Shifts in osmolality (sodium concentration) seem to be more important than the effect of acetate in inducing dialysis-associated hypotension.

PMID:29738

Drug concentration in saliva.

It is possible to predict plasma concentrations of drugs by measurement in saliva, obviating the need for venipuncture. Using a selection of weakly acidic and basic drugs, we have found this prediction reliable for drugs largely nonionized at normal plasma pH (phenytoin, phenobarbital, antipyrine) but unreliable for ionized drugs (chlorpropramide, tolbutamide, propranolol, meperidine). Deliberate alteration of saliva flow rate and pH using different stimuli have produced twofold changes in saliva drug concentrations. Wide interindividual variability of saliva pH is the likely explanation for the inconstancy of saliva to plasma concentration ratios for ionized drugs.

Drug concentration in saliva. It is possible to predict plasma concentrations of drugs by measurement in saliva, obviating the need for venipuncture. Using a selection of weakly acidic and basic drugs, we have found this prediction reliable for drugs largely nonionized at normal plasma pH (phenytoin, phenobarbital, antipyrine) but unreliable for ionized drugs (chlorpropramide, tolbutamide, propranolol, meperidine). Deliberate alteration of saliva flow rate and pH using different stimuli have produced twofold changes in saliva drug concentrations. Wide interindividual variability of saliva pH is the likely explanation for the inconstancy of saliva to plasma concentration ratios for ionized drugs.

PMID:29739

Interaction of disulfiram with benzodiazepines.

The disposition of chlordiazepoxide (50 mg, intravenously), diazepam (0.143 mg/kg, orally), and oxazepam (0.429 mg/kg, orally) were studied in normal and alcoholic men before and after chronic disulfiram administration. Decreases in the plasma clearance of chlordiazepoxide (54%, p less than 0.05), diazepam (41%, p less than 0.05), and their active N-desmethyl metabolites were observed. Oxazepam has no important active metabolites and its net disposition is minimally altered by disulfiram. Oxazepam disposition is unaffected by age and liver disease. These considerations together with that of the short half-life of oxazepam (median, 6.1 hr) suggest that oxazepam may be the drug of choice if benzodiazepine therapy is used for patients taking disulfiram.

Interaction of disulfiram with benzodiazepines. The disposition of chlordiazepoxide (50 mg, intravenously), diazepam (0.143 mg/kg, orally), and oxazepam (0.429 mg/kg, orally) were studied in normal and alcoholic men before and after chronic disulfiram administration. Decreases in the plasma clearance of chlordiazepoxide (54%, p less than 0.05), diazepam (41%, p less than 0.05), and their active N-desmethyl metabolites were observed. Oxazepam has no important active metabolites and its net disposition is minimally altered by disulfiram. Oxazepam disposition is unaffected by age and liver disease. These considerations together with that of the short half-life of oxazepam (median, 6.1 hr) suggest that oxazepam may be the drug of choice if benzodiazepine therapy is used for patients taking disulfiram.

PMID:29740

(-)-2-Hydroxy-n-cyclopropylmethylmorphinan: radioimmunoassay and phamacokinetic profile.

The pharmacokinetic profile of (-)-2-hydroxy-N-cyclopropylmethylmorphinan (HCMM), a narcotic antagonist and analgesic, has been evaluated in man following administration of 25 to 50 mg of the drug orally and 10 to 15 mg intramuscularly. A specific radioimmunoassay procedure was developed for the determination of HCMM in plasma and urine. The drug had a mean "apparent" elimination half-life in plasma of about 11 hr following both routes of administration. A mean of 47% of the oral dose was excreted in the urine as unconjugated and conjugated HCMM and only 5% of the dose was excreted as intact HCMM. In one subject studied, the plasma levels of conjugated HCMM were as much as 5-fold higher than the levels of unconjugated drug. Although there was considerable intersubject variability following both routes of administration, the overall pharmacokinetic parameters suggest that oral and intramuscular doses are bioequivalent.

(-)-2-Hydroxy-n-cyclopropylmethylmorphinan: radioimmunoassay and phamacokinetic profile. The pharmacokinetic profile of (-)-2-hydroxy-N-cyclopropylmethylmorphinan (HCMM), a narcotic antagonist and analgesic, has been evaluated in man following administration of 25 to 50 mg of the drug orally and 10 to 15 mg intramuscularly. A specific radioimmunoassay procedure was developed for the determination of HCMM in plasma and urine. The drug had a mean "apparent" elimination half-life in plasma of about 11 hr following both routes of administration. A mean of 47% of the oral dose was excreted in the urine as unconjugated and conjugated HCMM and only 5% of the dose was excreted as intact HCMM. In one subject studied, the plasma levels of conjugated HCMM were as much as 5-fold higher than the levels of unconjugated drug. Although there was considerable intersubject variability following both routes of administration, the overall pharmacokinetic parameters suggest that oral and intramuscular doses are bioequivalent.

PMID:29741

Effects of the beta-receptor antagonists propranolol, oxprenolol and labetalol on human vascular smooth-muscle contraction.

1. Spiral strips of human digital arteries have been studied in vitro to investigate whether DL-propranolol, D-propranolol, oxprenolol and labetalol have peripheral vascular effects in man. 2. Labetalol was a potent inhibitor of contractile responses to noradrenaline, but had less effect on responses to 5-hydroxytryptamine and barium chloride. 3. DL-and D-propranolol were equally effective inhibitors of responses to barium chloride. They were only weak antagonists of noradrenaline responses, but stronger, non-competitive antagonists of 5-hydroxytryptamine responses. 4. Oxprenolol was only a weak inhibitor of the responses to both noradrenaline and 5-hydroxytryptamine and had little effect on responses to barium chloride. 5. It is concluded that labetalol has specific alpha-adrenoreceptor-blocking properties, which are probably relevant to its therapeutic action in man. Propranolol has non-specific inhibitory effect on vascular smooth muscle, which might contribute to its hypotensive activity at high concentrations, but oxprenolol has only slight peripheral effects that are probably therapeutically insignificant.

Effects of the beta-receptor antagonists propranolol, oxprenolol and labetalol on human vascular smooth-muscle contraction. 1. Spiral strips of human digital arteries have been studied in vitro to investigate whether DL-propranolol, D-propranolol, oxprenolol and labetalol have peripheral vascular effects in man. 2. Labetalol was a potent inhibitor of contractile responses to noradrenaline, but had less effect on responses to 5-hydroxytryptamine and barium chloride. 3. DL-and D-propranolol were equally effective inhibitors of responses to barium chloride. They were only weak antagonists of noradrenaline responses, but stronger, non-competitive antagonists of 5-hydroxytryptamine responses. 4. Oxprenolol was only a weak inhibitor of the responses to both noradrenaline and 5-hydroxytryptamine and had little effect on responses to barium chloride. 5. It is concluded that labetalol has specific alpha-adrenoreceptor-blocking properties, which are probably relevant to its therapeutic action in man. Propranolol has non-specific inhibitory effect on vascular smooth muscle, which might contribute to its hypotensive activity at high concentrations, but oxprenolol has only slight peripheral effects that are probably therapeutically insignificant.

PMID:29736

Differential blockade of octopamine and dopamine receptors by analogues of clozapine and metoclopramide.

1. Sulpiride, but not procainamide, antagonizes the excitatory effects of (+/-)-octopamine receptors in the Tapes ventricle. Neither compound attenuates dopamine excitation. 2. Clozapine will attenuate the effects of (+/-)-octopamine and (-)-alpha-methyl octopamine at the octopamine receptor but not the excitatory effect of dopamine at dopamine receptors. 3. Clozapine is more potent than its 2-positional isomer HF 2046 in attenuating octopamine excitation. However, HF 2046, unlike clozapine, will attenuate the excitatory effects of dopamine. 4. These data indicate that replacement of the 8-chloro substituent in the clozapine nucleus with a 2-chloro substituent decreases the ability of the compound to blockaed octopamine receptors. However, the 2-chloro-substituted compound (HF 2046) now has the added ability to blockade excitatory dopamine receptors. 5. The greater potency of clozapine than HF 2046 as an octopamine antagonist suggests that it is the 8-chloro-substituted aromatic ring of clozapine which overlaps the aromatic site usually occupied by the octopamine aromatic ring.

Differential blockade of octopamine and dopamine receptors by analogues of clozapine and metoclopramide. 1. Sulpiride, but not procainamide, antagonizes the excitatory effects of (+/-)-octopamine receptors in the Tapes ventricle. Neither compound attenuates dopamine excitation. 2. Clozapine will attenuate the effects of (+/-)-octopamine and (-)-alpha-methyl octopamine at the octopamine receptor but not the excitatory effect of dopamine at dopamine receptors. 3. Clozapine is more potent than its 2-positional isomer HF 2046 in attenuating octopamine excitation. However, HF 2046, unlike clozapine, will attenuate the excitatory effects of dopamine. 4. These data indicate that replacement of the 8-chloro substituent in the clozapine nucleus with a 2-chloro substituent decreases the ability of the compound to blockaed octopamine receptors. However, the 2-chloro-substituted compound (HF 2046) now has the added ability to blockade excitatory dopamine receptors. 5. The greater potency of clozapine than HF 2046 as an octopamine antagonist suggests that it is the 8-chloro-substituted aromatic ring of clozapine which overlaps the aromatic site usually occupied by the octopamine aromatic ring.

PMID:29744

Doxapram hydrochloride in the treatment of acute exacerbation of chronic respiratory failure. A patient with four episodes treated without use of a respirator.

A 51-year-old woman with chronic respiratory failure (status after tuberculosis) was given an infusion of doxapram hydrochloride (1 to 2 mg/kg of body weight per hour) for four episodes of acute exacerbation of her condition. Treatment with the drug prevented worsening of hypercapnia in the four episodes, when administration of 24 percent oxygen had occasioned rises in the arterial carbon dioxide tension of 23, 10, 9, and 7 mm Hg.

Doxapram hydrochloride in the treatment of acute exacerbation of chronic respiratory failure. A patient with four episodes treated without use of a respirator. A 51-year-old woman with chronic respiratory failure (status after tuberculosis) was given an infusion of doxapram hydrochloride (1 to 2 mg/kg of body weight per hour) for four episodes of acute exacerbation of her condition. Treatment with the drug prevented worsening of hypercapnia in the four episodes, when administration of 24 percent oxygen had occasioned rises in the arterial carbon dioxide tension of 23, 10, 9, and 7 mm Hg.

PMID:29748

[Scanning electromicroscopic studies of the surface of teeth. I. After manual treatment with tooth cleansers. II. Tooth cleaning with power-driven instruments].

Scanning electron microscopic examination of tooth surfaces after using manually operated instruments to remove calculus showed distinct lesions on the hard substances of the tooth. The extent of damage depends considerably on the area of the tooth treated (the border between the enamel and the cementum is particularly endangered), the amount of force used, and the length of time required for treatment. Examination of tooth surfaces following application of various types of power-driven scaling instruments revealed that lesions of the hard substances on the tooth are possible. The extent of the damage depends on several different factors, particularly the pressure applied and the area of the tooth treated. The border between the enamel and the cementum is particulary endangered.

[Scanning electromicroscopic studies of the surface of teeth. I. After manual treatment with tooth cleansers. II. Tooth cleaning with power-driven instruments]. Scanning electron microscopic examination of tooth surfaces after using manually operated instruments to remove calculus showed distinct lesions on the hard substances of the tooth. The extent of damage depends considerably on the area of the tooth treated (the border between the enamel and the cementum is particularly endangered), the amount of force used, and the length of time required for treatment. Examination of tooth surfaces following application of various types of power-driven scaling instruments revealed that lesions of the hard substances on the tooth are possible. The extent of the damage depends on several different factors, particularly the pressure applied and the area of the tooth treated. The border between the enamel and the cementum is particulary endangered.

PMID:29749

[In vitro demethylation with a NADPH-generating system containing rat cytosol enzymes].

The author uses during demethylization in vitro two types of NADPH-generating systems: 1) postmitochondrial supernatant, whose disadvantage is that in vivo effects the cause for changes in demethylization could be due both to microsomes and dehydrogenases: 2) imported purified enzymic preparations, which is connected with supplying difficulties. The author proposes the usage of postmicrosomal supernatant (cytosol) from rats' liver to overcome these disadvantages. This fraction is with very good efficiency compared with that of the imported purified enzymes. The isolated cytosol, preserved at -10 degrees keeps its initial activity for a period of three days, but after or six days the diminition of the enzymic activity could be compensated by using simultaneously two substrates-isocytrate and glucose-6-phosphate for demethylizating systems.

[In vitro demethylation with a NADPH-generating system containing rat cytosol enzymes]. The author uses during demethylization in vitro two types of NADPH-generating systems: 1) postmitochondrial supernatant, whose disadvantage is that in vivo effects the cause for changes in demethylization could be due both to microsomes and dehydrogenases: 2) imported purified enzymic preparations, which is connected with supplying difficulties. The author proposes the usage of postmicrosomal supernatant (cytosol) from rats' liver to overcome these disadvantages. This fraction is with very good efficiency compared with that of the imported purified enzymes. The isolated cytosol, preserved at -10 degrees keeps its initial activity for a period of three days, but after or six days the diminition of the enzymic activity could be compensated by using simultaneously two substrates-isocytrate and glucose-6-phosphate for demethylizating systems.

PMID:29750

Premedication for upper gastrointestinal endoscopy: a comparative study of flunitrazepam, diazepam and neuroleptanalgesia.

Flunitrazepam or diazepam with atropine and a combination of phenoperidine, droperidol and cyclizine (neuroleptanalgesia) were compared as premedication in three groups of 25 patients undergoing routine upper gastrointestinal endoscopy. Drug doses were titrated carefully against response and all three regimes were found to be similar in terms of safety, patient co-operation, relaxation and speed of recovery. Neuroleptanalgesia however produced a statistically significant rise in endtidal pCO2 and systolic blood pressure. The benzodiazepines, and in particular flunitrazepam, produced a significantly greater amnesia for the procedure, patients given these drugs being more willing to undergo repeat endoscopy.

Premedication for upper gastrointestinal endoscopy: a comparative study of flunitrazepam, diazepam and neuroleptanalgesia. Flunitrazepam or diazepam with atropine and a combination of phenoperidine, droperidol and cyclizine (neuroleptanalgesia) were compared as premedication in three groups of 25 patients undergoing routine upper gastrointestinal endoscopy. Drug doses were titrated carefully against response and all three regimes were found to be similar in terms of safety, patient co-operation, relaxation and speed of recovery. Neuroleptanalgesia however produced a statistically significant rise in endtidal pCO2 and systolic blood pressure. The benzodiazepines, and in particular flunitrazepam, produced a significantly greater amnesia for the procedure, patients given these drugs being more willing to undergo repeat endoscopy.

PMID:29753

Amino-acid sequence of toxin I from Anemonia sulcata.

Toxin I from Anemonia sulcata, a major component of the sea anemone venom, consists of 46 amino acid residues which are linked by three disulfide bridges. The [14C]carboxymethylated polypeptide was sequenced to position 29 by automated Edman degradation. The remaining sequence was determined from cyanogen bromide peptides and from tryptic peptides of the citraconylated [14C]carboxymethylated toxin. Toxin I is homologous to toxin II from Anemonia sulcata and to anthopleurin A, a toxin from the sea anemone Anthopleura xanthogrammica. These toxins constitute a new class of polypeptide toxins. No significant homologies exist with toxin III from Anemonia sulcata nor with known sequences of neurotoxins or cardiotoxins of various origin.

Amino-acid sequence of toxin I from Anemonia sulcata. Toxin I from Anemonia sulcata, a major component of the sea anemone venom, consists of 46 amino acid residues which are linked by three disulfide bridges. The [14C]carboxymethylated polypeptide was sequenced to position 29 by automated Edman degradation. The remaining sequence was determined from cyanogen bromide peptides and from tryptic peptides of the citraconylated [14C]carboxymethylated toxin. Toxin I is homologous to toxin II from Anemonia sulcata and to anthopleurin A, a toxin from the sea anemone Anthopleura xanthogrammica. These toxins constitute a new class of polypeptide toxins. No significant homologies exist with toxin III from Anemonia sulcata nor with known sequences of neurotoxins or cardiotoxins of various origin.

PMID:29754

The proton pump of cytochrome c oxidase and its stoichiometry.

The operation of cytochrome c oxidase with ascorbate/N,N,N',N'-tetramethyl-p-phenylenediamine as substrate in antimycin-A-inhibited rat liver mitochondria is coupled to proton ejection. Measurements of the initial rate of valinomycin-dependent K+ uptake have shown that nearly 4 K+ are taken up as 2 electrons are transferred from cytochrome c to oxygen. This proves directly that a charge separation of nearly 4 occurs across the inner mitochondrial membrane each time 2 electrons are transferred to oxygen. Measurements of the initial rate of proton movement after addition of the reductant show that about 1.6 protons are released by the mitochondria as 2 electrons are transferred from cytochrome c to oxygen. The data support the suggestion of a proton pump coupled to the operation of cytochrome c oxidase [Wikström, M. F. K. (1977) Nature (Lond.) 266, 271--273].

The proton pump of cytochrome c oxidase and its stoichiometry. The operation of cytochrome c oxidase with ascorbate/N,N,N',N'-tetramethyl-p-phenylenediamine as substrate in antimycin-A-inhibited rat liver mitochondria is coupled to proton ejection. Measurements of the initial rate of valinomycin-dependent K+ uptake have shown that nearly 4 K+ are taken up as 2 electrons are transferred from cytochrome c to oxygen. This proves directly that a charge separation of nearly 4 occurs across the inner mitochondrial membrane each time 2 electrons are transferred to oxygen. Measurements of the initial rate of proton movement after addition of the reductant show that about 1.6 protons are released by the mitochondria as 2 electrons are transferred from cytochrome c to oxygen. The data support the suggestion of a proton pump coupled to the operation of cytochrome c oxidase [Wikström, M. F. K. (1977) Nature (Lond.) 266, 271--273].

PMID:29755

Potassium uniport and ATP synthesis in Halobacterium halobium.

Light-driven potassium ion uptake in Halobacterium halobium is mediated by bacteriorhodopsin. This uptake is charge-balanced by sodium ions and not by proton release. Light-induced shifts in concentrations of divalent cations were found to be negligible. The transient changes in extracellular pH (alkaline overshoot) can be understood by the concomitant processes of ATP synthesis, proton/sodium exchange and potassium uptake. The driving force of potassium ion uptake is the membrane potential, no ATP-dependent potassium transport process is found. Fluorescence measurements indicate a high permeability of the membrane to potassium ions compared to sodium ions. Therefore the potassium ion diffusion potential contributes to the membrane potential (about 30 mV/decade) and thereby influences the ATP level. Sudden enhancement of the diffusion potential by the potassium ionophore monactin leads to the expected transient increase in cellular ATP level. Due to the large size (up to 100-fold) of the potassium ion gradient and its high capacity (intracellular concentration up to 3 M) the potassium ion gradient can well serve the cell as a long term storage form of energy.

Potassium uniport and ATP synthesis in Halobacterium halobium. Light-driven potassium ion uptake in Halobacterium halobium is mediated by bacteriorhodopsin. This uptake is charge-balanced by sodium ions and not by proton release. Light-induced shifts in concentrations of divalent cations were found to be negligible. The transient changes in extracellular pH (alkaline overshoot) can be understood by the concomitant processes of ATP synthesis, proton/sodium exchange and potassium uptake. The driving force of potassium ion uptake is the membrane potential, no ATP-dependent potassium transport process is found. Fluorescence measurements indicate a high permeability of the membrane to potassium ions compared to sodium ions. Therefore the potassium ion diffusion potential contributes to the membrane potential (about 30 mV/decade) and thereby influences the ATP level. Sudden enhancement of the diffusion potential by the potassium ionophore monactin leads to the expected transient increase in cellular ATP level. Due to the large size (up to 100-fold) of the potassium ion gradient and its high capacity (intracellular concentration up to 3 M) the potassium ion gradient can well serve the cell as a long term storage form of energy.

PMID:29757

The glutamine synthetase from Azotobacter vinelandii: purification, characterization, regulation and localization.

The glutamine synthetase (EC 6.3.1.2) from the N2-fixing bacterium Azotobacter vinelandii was purified to homogeneity by heat treatment, ammonium sulfate precipitation and ion-exchange chromatography. The following molecular parameters were determined: molecular weight 640 000, subunit molecular weight 53 000, partial specific volume 0.710 cm3/g, isoelectric point 4.6, amino acid composition. Most of the molecules are composed of 12 identical subunits but active oligomers of other degrees of polymerization, apparently aggregates with 8, 10 and 24 subunits, were also detected to a lesser extent. The enzymatic activity is regulated via adenylylation-deadenylylation cycles: liberation of AMP was detected upon treatment of the adenylylated form with phosphodiesterase along with a change in the catalytic properties. Adenylylation in vivo is specifically induced by high extracellular ammonia levels. The Km values for the Mg2+-dependent formation of glutamine were independent of the degree of adenylylation for glutamate and ATP, but varied for ammonia. Furthermore the catalytic activity is regulated by several nitrogenous feedback inhibitors. The degree of inhibition in some cases was dependent on the substrate concentrations: the sensitivity towards glycine, alanine and serine decreased with a decreasing ammonia level, while the sensitivity towards ADP or AMP increased with a decreasing ATP concentration. Part of the enzyme (about 30%) seems to be attached to the plasma membrane while the main fraction is found in the cytosol.

The glutamine synthetase from Azotobacter vinelandii: purification, characterization, regulation and localization. The glutamine synthetase (EC 6.3.1.2) from the N2-fixing bacterium Azotobacter vinelandii was purified to homogeneity by heat treatment, ammonium sulfate precipitation and ion-exchange chromatography. The following molecular parameters were determined: molecular weight 640 000, subunit molecular weight 53 000, partial specific volume 0.710 cm3/g, isoelectric point 4.6, amino acid composition. Most of the molecules are composed of 12 identical subunits but active oligomers of other degrees of polymerization, apparently aggregates with 8, 10 and 24 subunits, were also detected to a lesser extent. The enzymatic activity is regulated via adenylylation-deadenylylation cycles: liberation of AMP was detected upon treatment of the adenylylated form with phosphodiesterase along with a change in the catalytic properties. Adenylylation in vivo is specifically induced by high extracellular ammonia levels. The Km values for the Mg2+-dependent formation of glutamine were independent of the degree of adenylylation for glutamate and ATP, but varied for ammonia. Furthermore the catalytic activity is regulated by several nitrogenous feedback inhibitors. The degree of inhibition in some cases was dependent on the substrate concentrations: the sensitivity towards glycine, alanine and serine decreased with a decreasing ammonia level, while the sensitivity towards ADP or AMP increased with a decreasing ATP concentration. Part of the enzyme (about 30%) seems to be attached to the plasma membrane while the main fraction is found in the cytosol.

PMID:29758

Benzamides and classical neuroleptics: comparison of their actions using 6 apomorphine-induced effects.

The effects of 6 benzamides and 8 classical neuroleptics were studied on 6 different apomorphine-induced effects. These drugs did not antagonize all the effects in the same way. The differences are discussed according to the two types of dopaminergic receptor hypothesis. Some apomorphine-induced effects (stereotyped behavior, circling behavior, climbing behavior, and increased motor activity) could be related to stimulation of one type of dopaminergic receptor, other effects (hypothermia and decreased activity) to the other type. Pimozide, sulpiride, thioproperazine, GRI 1665 and TER 1546, could block selectively one type of dopaminergic receptor, at least in a given range of doses. Clozapine, chlorpromazine, levomepromazine, and thioridazine, could block selectively the other type of dopaminergic receptor. Haloperidol, metoclopramide, prochlorperazine, sultopride, and tiapride, could block both types of dopaminergic receptors with equal intensity whatever the dose.

Benzamides and classical neuroleptics: comparison of their actions using 6 apomorphine-induced effects. The effects of 6 benzamides and 8 classical neuroleptics were studied on 6 different apomorphine-induced effects. These drugs did not antagonize all the effects in the same way. The differences are discussed according to the two types of dopaminergic receptor hypothesis. Some apomorphine-induced effects (stereotyped behavior, circling behavior, climbing behavior, and increased motor activity) could be related to stimulation of one type of dopaminergic receptor, other effects (hypothermia and decreased activity) to the other type. Pimozide, sulpiride, thioproperazine, GRI 1665 and TER 1546, could block selectively one type of dopaminergic receptor, at least in a given range of doses. Clozapine, chlorpromazine, levomepromazine, and thioridazine, could block selectively the other type of dopaminergic receptor. Haloperidol, metoclopramide, prochlorperazine, sultopride, and tiapride, could block both types of dopaminergic receptors with equal intensity whatever the dose.

PMID:29759

Regional localization of halopemide, a new psychotropic agent, in the rat brain.

Halopemide is a new psychotropic agent, structurally related to the neuroleptics of the butyrophenone type, but with a different phamacological and clinical profile. The concentration of halopemide in the rat brain is about 10 times less than that of R29800, its chemical congener and of spiperone, both typical neuroleptics. In the pituitary gland, however, the levels are the same. The distribution profile of halopemide in rat brain deviates from that of neuroleptics. The highest level of halopemide is found in septal and thalamic areas whereas the neuroleptics are concentrated in the caudate nucleus, the nucleus accumbens and the tuberculum olfactorium. Subcellular distribution experiments show that in the caudate nucleus halopemide is far less particle-bound that are the neuroleptic agents.

Regional localization of halopemide, a new psychotropic agent, in the rat brain. Halopemide is a new psychotropic agent, structurally related to the neuroleptics of the butyrophenone type, but with a different phamacological and clinical profile. The concentration of halopemide in the rat brain is about 10 times less than that of R29800, its chemical congener and of spiperone, both typical neuroleptics. In the pituitary gland, however, the levels are the same. The distribution profile of halopemide in rat brain deviates from that of neuroleptics. The highest level of halopemide is found in septal and thalamic areas whereas the neuroleptics are concentrated in the caudate nucleus, the nucleus accumbens and the tuberculum olfactorium. Subcellular distribution experiments show that in the caudate nucleus halopemide is far less particle-bound that are the neuroleptic agents.

PMID:29761

Mianserin--an analysis of its peripheral autonomic actions.

The autonomic profile of mianserin has been compared with that of yohimbine, phentolamine, phenoxybenzamine and desmethylimipramine. The effects of mianserin on tyramine and noradrenaline pressor responses in the pithed rat were consistent with alpha-adrenoceptor antagonist and uptake blocking properties. In isolated tissue experiments, the selectivity of mianserin for pre- and postsynaptic alpha-adrenoceptors was similar to that of phentolamine. In pitched rats mianserin antagonised the pressor response produced by clonidine and reversed the inhibitory actions of clonidine on cardiac nerve stimulation. In contrast mianserin only caused slight reversal of the inhibitory effects of clonidine on hypogastric nerve stimulation. Uptake blockade itself inhibits hypogastric nerve stimulation and this could counteract any antagonism of the effects of clonidine at the presynaptic alpha-adrenoceptor. The results demonstrate the uptake blocking properties of mianserin and its antagonism at both pre- and postsynaptic alpha-adrenoceptors.

Mianserin--an analysis of its peripheral autonomic actions. The autonomic profile of mianserin has been compared with that of yohimbine, phentolamine, phenoxybenzamine and desmethylimipramine. The effects of mianserin on tyramine and noradrenaline pressor responses in the pithed rat were consistent with alpha-adrenoceptor antagonist and uptake blocking properties. In isolated tissue experiments, the selectivity of mianserin for pre- and postsynaptic alpha-adrenoceptors was similar to that of phentolamine. In pitched rats mianserin antagonised the pressor response produced by clonidine and reversed the inhibitory actions of clonidine on cardiac nerve stimulation. In contrast mianserin only caused slight reversal of the inhibitory effects of clonidine on hypogastric nerve stimulation. Uptake blockade itself inhibits hypogastric nerve stimulation and this could counteract any antagonism of the effects of clonidine at the presynaptic alpha-adrenoceptor. The results demonstrate the uptake blocking properties of mianserin and its antagonism at both pre- and postsynaptic alpha-adrenoceptors.

PMID:29762

Studies on renal dopamine receptors with a new agonist.

SK & F 38393 (2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine) is a new dopamine receptor agonist which selectively increased renal blood flow when administered i.v. to dogs at cumulative doses of 3.3-1333 microgram/kg. Consistent changes in arterial blood pressure heart rate and cardiac output were not observed. The renal response, which was mediated locally in the kidney, was not antagonized by adequate blocking doses of atropine, propranolol, metiamide and/or mepyramine nor by reserpinization or treatment with indomethacin. It was inhibited, however, by the selective peripheral dopamine receptor antagonist, bulbocapnine. Perhaps as a result of its action on renal blood flow, SK & F 38393 produced a diuresis in normally hydrated rats which was characterized by an increased excretion of sodium, potassium and chloride and a increased urinary pH. Compounds of this type may be useful in better defining dopaminergic receptors and in the treatment of disease states where renal ischemia is present.

Studies on renal dopamine receptors with a new agonist. SK & F 38393 (2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine) is a new dopamine receptor agonist which selectively increased renal blood flow when administered i.v. to dogs at cumulative doses of 3.3-1333 microgram/kg. Consistent changes in arterial blood pressure heart rate and cardiac output were not observed. The renal response, which was mediated locally in the kidney, was not antagonized by adequate blocking doses of atropine, propranolol, metiamide and/or mepyramine nor by reserpinization or treatment with indomethacin. It was inhibited, however, by the selective peripheral dopamine receptor antagonist, bulbocapnine. Perhaps as a result of its action on renal blood flow, SK & F 38393 produced a diuresis in normally hydrated rats which was characterized by an increased excretion of sodium, potassium and chloride and a increased urinary pH. Compounds of this type may be useful in better defining dopaminergic receptors and in the treatment of disease states where renal ischemia is present.

PMID:29763

An interaction of histamine H2-receptor antagonists with the noradrenergic system in rat brain.

Intraventricular administration of 50 microgram of burimamide or 250 microgram of either metiamide or cimetidine decreased the NA concentration in rat hypothalamus by nearly 30%. Cimetidine did not significantly influence either DA or DOPAC levels in striatum. Cimetidine and metiamide significantly potentiated locomotor activity of tranylcypromine-treated rats and this effect was antagonized by phentolamine. It is concluded that the three histamine H2-receptor antagonists released NA in rat brain.

An interaction of histamine H2-receptor antagonists with the noradrenergic system in rat brain. Intraventricular administration of 50 microgram of burimamide or 250 microgram of either metiamide or cimetidine decreased the NA concentration in rat hypothalamus by nearly 30%. Cimetidine did not significantly influence either DA or DOPAC levels in striatum. Cimetidine and metiamide significantly potentiated locomotor activity of tranylcypromine-treated rats and this effect was antagonized by phentolamine. It is concluded that the three histamine H2-receptor antagonists released NA in rat brain.

PMID:29764

Differential blockade of bicuculline convulsions by neuroleptics.

Haloperidol, pimozide, sulpiride and metoclopramide blocked bicuculline-induced convulsions in mice. Chlorpromazine and thioridazine exhibited this effect at low doses whereas at higher doses (e.g. 1 mg/kg i.p. chlorpromazine) this activity was no longer apparent. A dose of phenoxybenzamine which was inactive alone (7.5 mg/kg i.p.) completely blocked the anti-bicuculline effect of sulpiride and antagonized that of haloperidol. These data are interpreted as indicating that intact noradrenergic systems are necessary for the anti-bicuculline effect of the neuroleptics.

Differential blockade of bicuculline convulsions by neuroleptics. Haloperidol, pimozide, sulpiride and metoclopramide blocked bicuculline-induced convulsions in mice. Chlorpromazine and thioridazine exhibited this effect at low doses whereas at higher doses (e.g. 1 mg/kg i.p. chlorpromazine) this activity was no longer apparent. A dose of phenoxybenzamine which was inactive alone (7.5 mg/kg i.p.) completely blocked the anti-bicuculline effect of sulpiride and antagonized that of haloperidol. These data are interpreted as indicating that intact noradrenergic systems are necessary for the anti-bicuculline effect of the neuroleptics.

PMID:29766

Neuropharmacological studies on the nigro-striatal and raphe-striatal system in the rat.

The responses of single neostriatal neurones to substantia nigra (SN) and dorsal raphe nucleus (DRN) stimulation and iontophoretic administration of several drugs were studied in urethane-anaesthetised rats. Stimulation of the SN-evoked excitation followed by inhibition in striatal neurones. In some cells only inhibition of firing was evoked indicating that there may be separate nigrostriatal inhibitory and excitatory pathways. DRN stimulation evoked mainly inhibition of striatal cell firing. The activity of most neurones responding to SN and DRN stimulation was depressed by iontophoretically administered dopamine, 5-hydroxytryptamine and GABA and increased by acetylcholine. Studies with antagonist revealed that alpha-flupenthixol reduced responses to dopamine and 5-hydroxytryptamine and inhibition evoked by SN and DRN stimulation. Bicuculline methochloride only reduced responses to GABA. Methysergide selectively reduced responses to 5-hydroxytryptamine and also reduced DRN-but not SN-evoked inhibition. It was concluded that the SN-evoked inhibition was probably mediated by dopamine and DRN-evoked inhibition by 5-hydroxytryptamine.

Neuropharmacological studies on the nigro-striatal and raphe-striatal system in the rat. The responses of single neostriatal neurones to substantia nigra (SN) and dorsal raphe nucleus (DRN) stimulation and iontophoretic administration of several drugs were studied in urethane-anaesthetised rats. Stimulation of the SN-evoked excitation followed by inhibition in striatal neurones. In some cells only inhibition of firing was evoked indicating that there may be separate nigrostriatal inhibitory and excitatory pathways. DRN stimulation evoked mainly inhibition of striatal cell firing. The activity of most neurones responding to SN and DRN stimulation was depressed by iontophoretically administered dopamine, 5-hydroxytryptamine and GABA and increased by acetylcholine. Studies with antagonist revealed that alpha-flupenthixol reduced responses to dopamine and 5-hydroxytryptamine and inhibition evoked by SN and DRN stimulation. Bicuculline methochloride only reduced responses to GABA. Methysergide selectively reduced responses to 5-hydroxytryptamine and also reduced DRN-but not SN-evoked inhibition. It was concluded that the SN-evoked inhibition was probably mediated by dopamine and DRN-evoked inhibition by 5-hydroxytryptamine.

PMID:29768

Sensitivity of lateral cerebellar nucleus to macular stimulation in the rabbit.

Experiments were performed in decerebrate rabbits to determine the sensitivity of the lateral cerebellar nucleus (LCN) to macular stimulation. Twenty-three percent of the neurons recorded extracellularly in the LCN showed steady changes in their discharge rate during 20 degrees tilt in both directions of the medial plane. Most of these neurons exhibited an alpha- and beta-type of response. A few gamma-types, but no delta-types were observed. The units sensitive to tilt were restricted to the caudal half of the LCN. Some of these positionally sensitive neurons responded monosynaptically to ipsilateral labyrinthine stimulation, but many received a polysynaptic input. These units could be activated antidromically by stimulation of the oculomotor nucleus but at a very high intensity suggesting current spread to the nearby brachium conjunctivum fibers. These results exclude a role of the LCN in the disynaptic otolith-ocular reflex.

Sensitivity of lateral cerebellar nucleus to macular stimulation in the rabbit. Experiments were performed in decerebrate rabbits to determine the sensitivity of the lateral cerebellar nucleus (LCN) to macular stimulation. Twenty-three percent of the neurons recorded extracellularly in the LCN showed steady changes in their discharge rate during 20 degrees tilt in both directions of the medial plane. Most of these neurons exhibited an alpha- and beta-type of response. A few gamma-types, but no delta-types were observed. The units sensitive to tilt were restricted to the caudal half of the LCN. Some of these positionally sensitive neurons responded monosynaptically to ipsilateral labyrinthine stimulation, but many received a polysynaptic input. These units could be activated antidromically by stimulation of the oculomotor nucleus but at a very high intensity suggesting current spread to the nearby brachium conjunctivum fibers. These results exclude a role of the LCN in the disynaptic otolith-ocular reflex.

PMID:29769

Ultrastructural differences in mitochondria of skeletal muscle in the prerigor and rigor states.

Loss of cristae and matrix occur in the mitochondria of skeletal muscles prior to any observable changes in myofibrillar proteins during the development of rigor mortis. Care must be observed because ultrastructural changes in mitochondria in some studies may be attributed to a specific trauma, whereas the changes may be due to the lower pH in postmortem muscle.

Ultrastructural differences in mitochondria of skeletal muscle in the prerigor and rigor states. Loss of cristae and matrix occur in the mitochondria of skeletal muscles prior to any observable changes in myofibrillar proteins during the development of rigor mortis. Care must be observed because ultrastructural changes in mitochondria in some studies may be attributed to a specific trauma, whereas the changes may be due to the lower pH in postmortem muscle.

PMID:29770

31P-NMR study on nucleotides and intracellular pH of hereditary spherocytes.

As determined by 31p-NMR spectroscopy, intracellular pH of hereditary spherocytes was lower (pH 6.7-6.9) than that of normal red cells. The level of adenosine diphosphate in hereditary spherocytes was found to be persistently high. The metabolism of nucleotides and other phosphoryl compounds in human red blood cells have been studied in detail by 31p-MNR spectroscopy. However, to our knowledge, there seems to be no report describing the result of 31p-NMR spectroscopy on red blood cells from hereditary spherocytosis.

31P-NMR study on nucleotides and intracellular pH of hereditary spherocytes. As determined by 31p-NMR spectroscopy, intracellular pH of hereditary spherocytes was lower (pH 6.7-6.9) than that of normal red cells. The level of adenosine diphosphate in hereditary spherocytes was found to be persistently high. The metabolism of nucleotides and other phosphoryl compounds in human red blood cells have been studied in detail by 31p-MNR spectroscopy. However, to our knowledge, there seems to be no report describing the result of 31p-NMR spectroscopy on red blood cells from hereditary spherocytosis.

PMID:29771

Effect of adrenaline and adrenergic active drugs on growth hormone secretion in immature cockerels.

In immature cockerels adrenaline administration lowered the levels of plasma growth hormone. Both alpha and beta adrenergic receptor agonists also depressed the circulating growth hormone levels. In the presence of beta blockade, the suppressive effect of adrenaline on growth hormone secretion was not observed.

Effect of adrenaline and adrenergic active drugs on growth hormone secretion in immature cockerels. In immature cockerels adrenaline administration lowered the levels of plasma growth hormone. Both alpha and beta adrenergic receptor agonists also depressed the circulating growth hormone levels. In the presence of beta blockade, the suppressive effect of adrenaline on growth hormone secretion was not observed.

PMID:29775

Behavior therapy in a family context: treating elective mutism.

This paper discusses the necessity of using both behavioral and family approaches in combination, while working with electively mute children. The symptom and its significance within the family system is presented along with a rationale for avoiding the pitfalls of individual approaches with such children. A case history outlining specific behavioral techniques is described in detail with an exploration of the use of reinforcement theory, counter-conditioning, and successive approximations in bringing about change in electively mute children. The need for bringing about changes within the family system so as to maintain the changes that have occurred through use of the behavior techniques is discussed and presented as crucial to the treatment process. The paper takes the position that either approach, by itself, will not be effective in helping electively mute children but that the treatment of choice is a combination of therapeutic techniques.

Behavior therapy in a family context: treating elective mutism. This paper discusses the necessity of using both behavioral and family approaches in combination, while working with electively mute children. The symptom and its significance within the family system is presented along with a rationale for avoiding the pitfalls of individual approaches with such children. A case history outlining specific behavioral techniques is described in detail with an exploration of the use of reinforcement theory, counter-conditioning, and successive approximations in bringing about change in electively mute children. The need for bringing about changes within the family system so as to maintain the changes that have occurred through use of the behavior techniques is discussed and presented as crucial to the treatment process. The paper takes the position that either approach, by itself, will not be effective in helping electively mute children but that the treatment of choice is a combination of therapeutic techniques.

PMID:29777

[Influence of adrenergic-blocking agents on the pain-alleviating effect of narcotic analgesics].

The action of adrenoblocking agents on the dynamics of the pain allaying effect of narcotic analgesics, measured by the magnitude of the pain reaction threshold after irritation of the tail skin with electric current was studies in tests on mice. The beta-adreno-blocking agent (anaprillin or inderal) was found to significantly potentiate and to lengthen the action of morphine, and so did, to a lesser degree, promedol (trimeperedin) and phentanyl, while the alpha-adrenoblocking agent (phentolamine) weakened the analgesic effects of morphine and promedol, without having any essential influence on the effect of phentanyl. Phentolamine does not eliminate the potentiating effect of anapraline on the analgesic action of morphine but is capable to lessen it.

[Influence of adrenergic-blocking agents on the pain-alleviating effect of narcotic analgesics]. The action of adrenoblocking agents on the dynamics of the pain allaying effect of narcotic analgesics, measured by the magnitude of the pain reaction threshold after irritation of the tail skin with electric current was studies in tests on mice. The beta-adreno-blocking agent (anaprillin or inderal) was found to significantly potentiate and to lengthen the action of morphine, and so did, to a lesser degree, promedol (trimeperedin) and phentanyl, while the alpha-adrenoblocking agent (phentolamine) weakened the analgesic effects of morphine and promedol, without having any essential influence on the effect of phentanyl. Phentolamine does not eliminate the potentiating effect of anapraline on the analgesic action of morphine but is capable to lessen it.

PMID:29791

Channels in epithelial cell membranes and junctions.

Epithelia may be classified as "tight" or "leaky," depending on whether there is a significant pathway for transepithelial ion permeation via the junctions and bypassing the cells. The resistance of this paracellular channel may depend partly on structures visible in the electron microscope, partly on wall charge. Permeability determinations in the leaky junctions of gallbladder epithelium, using many different organic cations, suggest that the critical barriers barriers to ion permeation are 5--8 A in radius and bind cations by up to four strongly proton-accepting oxygens. The apical cell membrane of tight epithelia contains a Na+-selective channel that is blocked by amiloride and Ca2+, subject to negative feedback control by the Na+ pump in the basolateral membrane, and somehow promoted by aldosterone. To determine the permeabilities of these two channels (the junctional channel of leaky epithelia, and the Na+ channel of tight epithelia) to water and nonelectrolytes remains a major unsolved problem.

Channels in epithelial cell membranes and junctions. Epithelia may be classified as "tight" or "leaky," depending on whether there is a significant pathway for transepithelial ion permeation via the junctions and bypassing the cells. The resistance of this paracellular channel may depend partly on structures visible in the electron microscope, partly on wall charge. Permeability determinations in the leaky junctions of gallbladder epithelium, using many different organic cations, suggest that the critical barriers barriers to ion permeation are 5--8 A in radius and bind cations by up to four strongly proton-accepting oxygens. The apical cell membrane of tight epithelia contains a Na+-selective channel that is blocked by amiloride and Ca2+, subject to negative feedback control by the Na+ pump in the basolateral membrane, and somehow promoted by aldosterone. To determine the permeabilities of these two channels (the junctional channel of leaky epithelia, and the Na+ channel of tight epithelia) to water and nonelectrolytes remains a major unsolved problem.

PMID:29792

Effects of monitoring high-risk pregnancies and intrapartum FHR monitoring on perinates.

A protocol of chronic antepartum surveillance was initiated at the University of Illinois hospitals in 1973 to assess the impact on perinatal mortality. At the same time, a policy of unselected fetal heart rate (FHR) monitoring was initiated to judge the effect on the intrapartum stillbirth rate. The impact of both programs played a significant role in the decline of perinatal mortality rates for infants weighing more than 1 500 g, from 21.1/1 000 births in 1970--1971 to 14.4/1 000 births in the monitored years 1973 and 1974 (p less than 0.02).

Effects of monitoring high-risk pregnancies and intrapartum FHR monitoring on perinates. A protocol of chronic antepartum surveillance was initiated at the University of Illinois hospitals in 1973 to assess the impact on perinatal mortality. At the same time, a policy of unselected fetal heart rate (FHR) monitoring was initiated to judge the effect on the intrapartum stillbirth rate. The impact of both programs played a significant role in the decline of perinatal mortality rates for infants weighing more than 1 500 g, from 21.1/1 000 births in 1970--1971 to 14.4/1 000 births in the monitored years 1973 and 1974 (p less than 0.02).

PMID:29793

Obstetric aspects of adolescent pregnancy and delivery.

An analysis of 31 years of adolescent pregnancies and deliveries at Novi Sad Medical Facility is presented. Obstetric complications are discussed. The psychological impact of adolescent pregnancy is examined.

Obstetric aspects of adolescent pregnancy and delivery. An analysis of 31 years of adolescent pregnancies and deliveries at Novi Sad Medical Facility is presented. Obstetric complications are discussed. The psychological impact of adolescent pregnancy is examined.

PMID:29794

Carcinoma in situ cervicis uteri: diagnosis, treatment and prognosis.

A total of 252 patients with carcinoma in situ colli uteri were treated at the Women's Clinic at Turku University between 1964 and 1971. Seventy-seven percent of the patients came to the clinic for treatment after they had participated in a mass screening program (cytodiagnosis, colposcopy). Extrafascial hysterectomy was performed most often on women in the older age groups, while most of the younger patients were treated by conization. Patients were followed up for a minimum of 5 years. There was a 1.0% recurrence of invasive carcinoma and a 4.0% recurrence of noninvasive carcinoma. All invasive recurrences occurred after hysterectomy. None of the patients died from complications of carcinoma.

Carcinoma in situ cervicis uteri: diagnosis, treatment and prognosis. A total of 252 patients with carcinoma in situ colli uteri were treated at the Women's Clinic at Turku University between 1964 and 1971. Seventy-seven percent of the patients came to the clinic for treatment after they had participated in a mass screening program (cytodiagnosis, colposcopy). Extrafascial hysterectomy was performed most often on women in the older age groups, while most of the younger patients were treated by conization. Patients were followed up for a minimum of 5 years. There was a 1.0% recurrence of invasive carcinoma and a 4.0% recurrence of noninvasive carcinoma. All invasive recurrences occurred after hysterectomy. None of the patients died from complications of carcinoma.

PMID:29795

Birth interval study in a culturally stable urban population.

Five hundred women were interviewed within 2 days of delivery to examine indigenous birth spacing among the urban and rural population of Ife township. The crude birth interval was between 30 and 40 months due mainly to cultural attitudes towards lactation and sexual abstinence. The women studied possessed considerable knowledge of Western contraceptive methods, but they rejected them. The possible cause of this rejection is examined and solutions to the problem are suggested.

Birth interval study in a culturally stable urban population. Five hundred women were interviewed within 2 days of delivery to examine indigenous birth spacing among the urban and rural population of Ife township. The crude birth interval was between 30 and 40 months due mainly to cultural attitudes towards lactation and sexual abstinence. The women studied possessed considerable knowledge of Western contraceptive methods, but they rejected them. The possible cause of this rejection is examined and solutions to the problem are suggested.

PMID:29796

Metronidazole treatment in pregnancy.

Vaginal trichomoniasis was treated with standard courses of oral metronidazole in 597 pregnant women. In 283 other pregnant women, the infection remained untreated. The incidences of low-birth-weight infants, stillbirths and congenital abnormalities were not affected by metronidazole treatment of trichomoniasis in pregnancy.

Metronidazole treatment in pregnancy. Vaginal trichomoniasis was treated with standard courses of oral metronidazole in 597 pregnant women. In 283 other pregnant women, the infection remained untreated. The incidences of low-birth-weight infants, stillbirths and congenital abnormalities were not affected by metronidazole treatment of trichomoniasis in pregnancy.

PMID:29797

Evaluation of 496 menstrual regulation and abortion patients in Calcutta.

From March to December 1975, 496 patients were studied to compare the safety and effectiveness of menstrual regulation (MR) performed with a Karman hand syringe and first trimester abortion performed with an electric vacuum aspirator. All procedures were done on an outpatient basis. The complication rate for the MR patients was significantly lower than that for the other first trimester abortion patients. Study results indicate that MR with the Karman syringe is a safer, simpler and less costly procedure than first trimester abortion with the electric vacuum aspirator. Further research and study are necessary to determine the effect of the initial and repeat MR procedures on women's menstrual patterns and future pregnancies, including any subsequent prematurity, stillbirths and Rh immunization.

Evaluation of 496 menstrual regulation and abortion patients in Calcutta. From March to December 1975, 496 patients were studied to compare the safety and effectiveness of menstrual regulation (MR) performed with a Karman hand syringe and first trimester abortion performed with an electric vacuum aspirator. All procedures were done on an outpatient basis. The complication rate for the MR patients was significantly lower than that for the other first trimester abortion patients. Study results indicate that MR with the Karman syringe is a safer, simpler and less costly procedure than first trimester abortion with the electric vacuum aspirator. Further research and study are necessary to determine the effect of the initial and repeat MR procedures on women's menstrual patterns and future pregnancies, including any subsequent prematurity, stillbirths and Rh immunization.

PMID:29798

Variable range directional doppler and abdominal ECG for FHR monitoring.

Antepartum nonstress fetal heart rate (FHR) monitoring may become a valuable screening tool for all pregnancies. Two methods proposed for an antepartum FHR monitor are examined: abdominal electrocardiogram (AECG) and variable range directional Doppler (RDD). A good quality (detailed, clearcut baseline) RDD FHR record was obtained in 74/75 (99%) examinations, and a good quality AECG record was obtained i31/75 (41%). Each patient was monitored in the supine, lateral and sitting positions. Considering all positions, 76% of the RDD records and 19% of the AECG records were good. The RDD system was efficacious for routine, clinical antepartum FHR monitoring, but the performance of the AECG was too limited for this purpose.

Variable range directional doppler and abdominal ECG for FHR monitoring. Antepartum nonstress fetal heart rate (FHR) monitoring may become a valuable screening tool for all pregnancies. Two methods proposed for an antepartum FHR monitor are examined: abdominal electrocardiogram (AECG) and variable range directional Doppler (RDD). A good quality (detailed, clearcut baseline) RDD FHR record was obtained in 74/75 (99%) examinations, and a good quality AECG record was obtained i31/75 (41%). Each patient was monitored in the supine, lateral and sitting positions. Considering all positions, 76% of the RDD records and 19% of the AECG records were good. The RDD system was efficacious for routine, clinical antepartum FHR monitoring, but the performance of the AECG was too limited for this purpose.

PMID:29799

Estrogens in food: the almond mystery.

Studies were made of 36 different nuts, grains, fruits and vegetables commonly used as human foods; each of these was fed to a group of ovariectomized rats for 10 days as a sole diet. The estrogenic activities of the foods were estimated by comparing the uterine weights, uterine fluid volumes and the vaginal cornification indices of each group of rats with those of groups fed other foods. Almonds, cashew nuts, peanuts, oats, corn, wheat and apples all showed estrogenic activity. The original sample of almonds showed the greatest estrogenic activity (p less than 0.01) which was confirmed by repetition of the experiment (p less than 0.01), but subsequent studies of other samples of almonds showed no estrogenic activity. Possible reasons for the disparity of the results with different lots of almonds are discussed.

Estrogens in food: the almond mystery. Studies were made of 36 different nuts, grains, fruits and vegetables commonly used as human foods; each of these was fed to a group of ovariectomized rats for 10 days as a sole diet. The estrogenic activities of the foods were estimated by comparing the uterine weights, uterine fluid volumes and the vaginal cornification indices of each group of rats with those of groups fed other foods. Almonds, cashew nuts, peanuts, oats, corn, wheat and apples all showed estrogenic activity. The original sample of almonds showed the greatest estrogenic activity (p less than 0.01) which was confirmed by repetition of the experiment (p less than 0.01), but subsequent studies of other samples of almonds showed no estrogenic activity. Possible reasons for the disparity of the results with different lots of almonds are discussed.

PMID:29800

Asherman's syndrome--a self-limiting disease?

Intrauterine adhesions (Asherman's syndrome) may follow curettage in a recently pregnant uterus. Treatment consisting of dilatation and curettage and possibly the insertion of an intrauterine device usually is started early. The success rate is high. Very few cases of spontaneous recurring menstruation have been reported, and none of them have been based on hysterosalpingographic evidence of adhesions. The pregnancy outcome is generally poor in those cases of assumed spontaneous resolution. We present a case of spontaneous restitution of a functional uterine cavity and normal menstruation following Asherman's syndrome. Subsequent pregnancy was uneventful. A short review of the literature is presented, and the possible self-limiting character of the disease is discussed.

Asherman's syndrome--a self-limiting disease? Intrauterine adhesions (Asherman's syndrome) may follow curettage in a recently pregnant uterus. Treatment consisting of dilatation and curettage and possibly the insertion of an intrauterine device usually is started early. The success rate is high. Very few cases of spontaneous recurring menstruation have been reported, and none of them have been based on hysterosalpingographic evidence of adhesions. The pregnancy outcome is generally poor in those cases of assumed spontaneous resolution. We present a case of spontaneous restitution of a functional uterine cavity and normal menstruation following Asherman's syndrome. Subsequent pregnancy was uneventful. A short review of the literature is presented, and the possible self-limiting character of the disease is discussed.

PMID:29801

Intrapartum maternal and fetal monitoring: the obstetric intensive care unit.

The Obstetric Intensive Care Unit (OBICU) at Bellevue Hospital in New York City has adapted intensive care and coronary care models to the care of patients in labor. During the past 3 years, 519 of the most serious of 2 250 high-risk obstetric patients treated at the hospital were monitored in the OBICU. There were two maternal and six perinatal deaths. The perinatal mortality rate of the very high risk population of the OBICU was 11.6/1 000, compared to 14.7/1 000 for all deliveries performed at the hospital. Our findings indicate that the OBICU system provides the ideal mechanism for the rapid and continuous control of symptoms in very high risk gravidas which is essential for stabilizing the patient, both for prompt delivery and for optimal maternal and fetal survival.

Intrapartum maternal and fetal monitoring: the obstetric intensive care unit. The Obstetric Intensive Care Unit (OBICU) at Bellevue Hospital in New York City has adapted intensive care and coronary care models to the care of patients in labor. During the past 3 years, 519 of the most serious of 2 250 high-risk obstetric patients treated at the hospital were monitored in the OBICU. There were two maternal and six perinatal deaths. The perinatal mortality rate of the very high risk population of the OBICU was 11.6/1 000, compared to 14.7/1 000 for all deliveries performed at the hospital. Our findings indicate that the OBICU system provides the ideal mechanism for the rapid and continuous control of symptoms in very high risk gravidas which is essential for stabilizing the patient, both for prompt delivery and for optimal maternal and fetal survival.

PMID:29802

Inducing labor with oral prostaglandin E2 in Khartoum hospital.

Prostagland-n E2 (PGE2) was administered orally to 109 patients to induce labor. Sixty-five of these patients had an amniotomy prior to PGE2 administration. PGE2 was administered to the remaining. 44, who subsequently underwent amniotomy only after their cervices had reached approximately 6 cm dilation. Labor was successfully induced in 95 patients, but its duration was shorter when amniotomy was immediatedly followed by PGE2 administration. Failed cases were successfully managed with amniotomy and oxytocin infusion. Maternal side effects were minimal. No fetal complications occurred.

Inducing labor with oral prostaglandin E2 in Khartoum hospital. Prostagland-n E2 (PGE2) was administered orally to 109 patients to induce labor. Sixty-five of these patients had an amniotomy prior to PGE2 administration. PGE2 was administered to the remaining. 44, who subsequently underwent amniotomy only after their cervices had reached approximately 6 cm dilation. Labor was successfully induced in 95 patients, but its duration was shorter when amniotomy was immediatedly followed by PGE2 administration. Failed cases were successfully managed with amniotomy and oxytocin infusion. Maternal side effects were minimal. No fetal complications occurred.

PMID:29803

Burst abdomen following cesarean section.

Fifty-one cases of burst abdomen occurred following 1 988 cesarean sections performed at the University of Nigeria Teaching Hospital over a 5-year period. The incidence of this occurrence was 2.6% (2.3% if all laparotomies in both obstetrics and gynecology are combined). The risk was three times as great for "unbooked" patients, who were first seen in labor. Possible etiologic factors and preventive measures are discussed.

Burst abdomen following cesarean section. Fifty-one cases of burst abdomen occurred following 1 988 cesarean sections performed at the University of Nigeria Teaching Hospital over a 5-year period. The incidence of this occurrence was 2.6% (2.3% if all laparotomies in both obstetrics and gynecology are combined). The risk was three times as great for "unbooked" patients, who were first seen in labor. Possible etiologic factors and preventive measures are discussed.