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Changes in body temperature after administration of amino acids, peptides, dopamine, neuroleptics and related agents.

Drugs may alter body temperature by acting on any component of the thermoregulatory system. These components include heat production, heat conservation and heat loss effectors and their efferent pathways, thermosensors and their afferent pathways and neurons within the central nervous system that coordinate thermoregulatory effector activities. A thermostat is often thought to be involved although thermoregulation can be explained by models that do not incorporate a thermostat. An action on a particular component can be assessed by determining the effect of a drug on body temperature over a range of environmental temperatures and by observation and measurement of associated changes in effector activities. A scheme for such assessment is presented along with examples of its use. The study of drug-induced changes in body temperature has expanded greatly within the past decade. The primary purpose of this review is to provide a readily available source of information on interactions between certain drugs and the thermoregulatory system. Extensive tables are presented of body temperature changes after administration of amino acids, peptides, dopamine and related agents, phenothiazine neuroleptics and also phenothiazines that lack neuroleptic activity, butyrophenones, diphenylbutylpiperidines such as pimozide and miscellaneous neuroleptics. The information tabulated includes the species used, route of administration and dose of drugs, the environmental temperature at which the experiments were performed, the number of tests, the direction and magnitude of body temperature change and remarks on the presence of special conditions, such as age or lesions, or on the influence of other drugs, such as antagonists, on the response to the primary drug. Most of the cited literature was published since 1965.

Does penicillin kill bacteria?.

The thesis is presented that the bactericidal action of penicillin and of other inhibitors of cell wall peptidoglycan synthesis, such as vancomycin and cycloserine, is secondary or tertiary to their ability inhibit specific reactions in the assembly of an osmotically protective cell wall. Examples are given of the inhibition of these reactions, which results in inhibition of cell growth (bacteriostatic action) in the absence of either cellular lysis or rapid loss of viability. Thus, in some instances, inhibitory concentrations of these drugs are, in effect, sublethal; this is true, for example, for Streptococcus mutans, a species of bacteria that is part of the normal flora of the oropharynx and that can cause subacute bacterial endocarditis. On the other hand, the damaging effects of the subminimal inhibitory concentrations of penicillin G on Streptococcus faecalis, a species with an active autolytic enzyme system, can be uncovered and converted to a lytic (and lethal) response by partial inhibition of fatty acid synthesis with low concentrations of cerulenin. Some theoretical and practical implications of the occurrence and inhibition of these secondary lethal consequences are discussed.

Quantitative changes in regional cerebral blood flow of rats induced by alpha- and beta-adrenergic stimulants.

Cerebral blood flow was measured with the 14C-ethanol technique in 8 regions (frontal, parieto-temporal and occipital cortex, caudate nucleus, thalamus, cerebellum, mesencephalon, and pons) of rats. The highest flow values (83-89.5 ml/100 g/min) were found in cortical areas, whereas pons had the lowest flow (48 ml/100 g/min). Intravenous infusion of noradrenaline or adrenaline markedly reduced rCBF (by 22-48% of control levels) in all regions except thalamus, mesencephalon, and pons. The noradrenaline-induced reduction was blocked, and the effect of adrenaline reversed, after pretreatment with the alpha-receptor antagonist, phentolamine. Isoprenaline infusion markedly augmented rCBF in thalamus, mesencephalon, pons, and also in the caudate nucleus. The response was reduced by the beta-receptor antagonist, propranolol. The experiments show the presence and heterogenous distribution in the cerebrovascular bed of slpha- and beta-adrenoceptors that can be activated by sympathomimetics given systematically. If noradrenaline was allowed to pass the blood-brain barrier after osmotic opening with urea, an increased regional flow was obtained, probably due to a mechanism where the vasodilator effect secondary to activation of cerebral metabolism predominated over the direct vasoconstrictor effect of the amine.

Heat inactivation of Mycobacterium avium-Mycobacterium intracellulare complex organisms in aqueous suspension.

Isolants from swine and from humans representing serotypes 1, 2, 4, 8, and 10 of the Mycobacterium avium-Mycobacterium intracellulare complex were compared for heat tolerance in aqueous suspension. The most heat-resistant isolant found was a serovar 10 isolated from a human. This isolant was examined further to determine the rate of kill at various temperatures and pH's, the effect of meat protein and fat, and the effect of nitrite. Kill rates were not significant at 60 degrees C or below. Decimal reduction values were 4 min or less at 65 degrees C and 1.5 min or less at 70 degrees C. Kill rates were slightly higher at pH values of 6.5 and 7.0 than at 5.5 or 6.0. the water-soluble fraction of wiener emulsion did not alter kill rates, but the saline-soluble fraction protected the organism somewhat. Fat did not affect the survival of the organisms except to eliminate the protective effect of saline extract when the suspension contained 50% fat. The addition of sodium nitrite to the suspension did not alter the heat sensitivity of the organisms.

Microbial oxidation of methane and methanol: purification and properties of a heme-containing aldehyde dehydrogenase from Methylomonas methylovora.

Procedures for the purification of an aldehyde dehydrogenase from extracts of the obligate methylotroph, Methylomonas methylovora are described. The purified enzyme is homogeneous as judged from polyacrylamide gel electrophoresis. In the presence of an artificial electron acceptor (phenazine methosulfate), the purified enzyme catalyzes the oxidation of straight chain aldehydes (C1--C10 tested), aromatic aldehydes (benzaldehyde, salicylaldehyde), glyoxylate, and glyceraldehyde. Biological electron acceptors such as NAD+, NADP+, FAD, FMN, pyridoxal phosphate, and cytochrome c cannot act as electron carriers. The activity of the enzyme is inhibited by sulfhydryl agents [p-chloromercuribenzoate, N-ethylmaleimide and 5,5-dithiobis (2-nitrobenzoic acid)], cuprous chloride, and ferrour nitrate. The molecular weight of the enzyme as estimated by gel filtration is approximately 45000 and the subunit size determined by sodium dodecyl sulfate-gel electrophoresis is approximately 23000. The purified enzyme is light brown and has an absorption peak at 410 nm. Reduction of enzyme with sodium dithionite or aldehyde substrate resulted in the appearance of peaks at 523 nm and 552nm. These results suggest that the enzyme is a hemoprotein. There was no evidence that flavins were present as prosthetic group. The amino acid composition of the enzyme is also presented.

Effect of cholesterol-rich diet on the content of nicotinamide nucleotides, adenine nucleotides and acetyl-CoA in the liver, the vascular wall and the kidney of spontaneously hypertensive rats (SHR).

The liver content of NAD and of adenylic nucleotides of normally fed spontaneously hypertensive rats (SHR) is lower than in normotensive rats. The cholesterol-rich diet does not change the liver NAD level. However it decreases adenine nucleotides and increases the level of acetyl-CoA and of NADP. Normal refeeding after a long-term cholesterol-rich diet induces an increase in the low levels of the coenzymes (moth NAD and adenine nucleotides). The liver coenzyme changes caused by the cholesterol-rich diet and by the normal refeeding of SHR are opposite to those established in normotensive rats. Vascular wall nicotinamide coenzymes in SHR are lower than in ulistar rats. The vascular wall of SHR reacts to the cholesterol-rich diet by a rise in NAD, i.e. conversely to the reaction observed in the liver of SHR and vascular wall of normotensive rats. Normal refeeding induces a further increase in the content of coenzymes. These results show that the effect of cholesterol-rich diet on the coenzyme content in the SHR is opposite to that in normotensive rats. The renal redox-system NAD+-NAD-H is more sensitive to the cholesterol-rich diet than the liver one, and its coenzyme changes indicate a greater reduction state, a reaction pattern which is typical for renal hypoxia. The results suggest that the cholesterol-rich diet influences the metabolism of the liver, the kidney and the vascular wall in a different way and to a different degree. SHR have a specific type of reaction to this cholesterol-rich diet.

Comparative studies on dihydrofolate reductases from Plasmodium falciparum and Aotus trivirgatus.

Dihydrofolate reductase (E.C. 1.5.1.3) from Plasmodium falciparum and from its host, the owl monkey (Aotus trivirgatus), were partially purified and characterized. The molecular weight of the parasite enzyme was estimated to be over 10 times as high as that of the host enzyme. The host enzyme had 2 pH optima whereas the parasite enzyme only one. The activity of the host enzyme was greatly stimulated by KCl and urea, while that of the parasite enzyme was inhibited at high concentrations of such chaotropic agents. Km of the parasite enzyme was significantly higher than that of the host enzyme. The parasite enzyme had much lower Ki for pyrimethamine than the host enzyme. Dihydrofolate reductases isolated from pyrimethamine-resistant and pyrimethamine sensitive strains of P. falciparum were found to be similar.

Disaggregation of brain polysomes after LSD in vivo. Involvement of LSD-induced hyperthermia.

LSD-induced hyperthermia is implicated in the brain-specific disaggregation of polysomes which is induced following intravenous administration of the drug to rabbits. Both LSD-induced hyperthermia and brain polysome disaggregation were found to increase in parallel under conditions which accentuated the effect of the drug on brain protein synthesis. Pretreatment with neurotransmitter receptor blockers or placing the animal at an ambient temperature of 4 degrees C after LSD administration prevented both hyperthermia and brain polysome disaggregation. The administration of apomorphine, which causes hyperthermia in rabbits also caused disaggregation of brain polysomes. Direct elevation of the body temperature to levels similar to that found after LSD was achieved by placing animals at an ambient temperature of 37 degrees C. Under these conditions a brain-specific disaggregation of polysomes resulted which was not due to RNAase activation. After either LSD or direct heating, the brain polysome shift was associated with a relocalization of polyadenylated mRNA from polysomes to monosomes as determined by [3H]polyuridylate hybridization. Since polysome disaggregation was found only in brain, it appears that the brain may be more sensitive to elevations in body temperature compared to other organs.

Ultracytochemical characterization of non-specific acid phosphatase activities in Saccharomyces cerevisiae.

Glutaraldehyde prefixation causes a considerable inactivation of the acid phosphatase of yeast protoplasts in dependence on the duration of aldehyde influence. Lead ions necessary for ultracytochemical demonstration effect a still stronger inhibition of enzymatic activity. Prefixation, however, protects the enzyme from further inhibition by lead. At pH 4.4 in intact cells acid phosphatase activities are mainly localized in the periplasmic space and in vesicles fused with the plasma membrane. The cell wall and cytoplasm usually remain free of reaction products. On the cell surface activities are found in form of globular lead deposits. At pH 5.2 and 6.3 the periplasmic activity appears decreased compared to that at lower pH values and the intracellular activity is increased. The plasma membrane of protoplasts is completely free of precipitates. The intracellular activity sites of protoplasts (cisternae of endoplasmic reticulum and/or Golgi-like system, small vesicles, central vacuole, nuclear envelope) are the same as for intact cells. The occurrence of at least two forms of acid phosphatase in S. cerevisiae id deduced.

Production of hyaluronidase by propionibacteria from different origins.

114 strains of anaerobic and microaerophilic coryneform bacteria from different origins were investigated for production of free extracellular hyaluronidase (hyaluronate glycanohydrolase, EC 3.2.1.36). A quantitative technique was applied measuring the release of N-acetyl-glucosamine groups from purified human potassium hyaluronate. The strains belonged to the following species: Propionibacterium acnes, P. avidum, P. granulosum, P. lymphophilum, the formerly so-called Corynebacterium parvum, P. freudenreichii subsp. freudenreichii and shermanii, P. thoenii, P. acidi-propionici, C. minutissimum, and Arachnia propionica. All together, 59 out of 114 (approximately 51.8%) tested strains showed clearly measurable hyaluronidase activities. P. acnes, the propionibacterium species most frequently found in acne vulgaris lesions, proved to be the most active species tested, 44 out of 64 (approximately 68.8%) P. acnes strains being positive. 5 strains producing hyaluronate glycanohydrolase activities of more than 60 mU/ml in thioglycollate broth cultures could be detected. P. avidum and P. granulosum strains were positive in only 45.0% and 33.3%, respectively, and their mean hyaluronidase activities were significantly lower. Differences in hyaluronidase activities of P. acnes strains isolated from acne vulgaris lesions and strains from normal human skin could not be found. The possible pathogenic role of propionibacteria hyaluronidase in acne vulgaris is discussed.

The pathogenicity of avian mycoplasmas.

Based on literature data and own experiences the author gives an outlook about pathogenicity of avian mycoplasmas. In chickens and turkeys M. gallisepticum and M. synoviae (in addition to it M. meleagridis exclusively in turkeys) are the most important mycoplasmas producing respiratory disease, inflamation of synovial membranes and other lesions. Their pathogenic effect is very much influenced by dose of agent, route of entry of microorganism, age of birds, virulence and tropism of organism as well as associated other mycoplasma or virus or bacterial or fungal infections and conditions of environment. These facts rise difficulties in serological diagnostic and erradication program. Recently ureaplasma infection was also established in chickens and turkeys which can also be associated with respiratory disease. From ducks A. laidlawii, M. anatis and various unclassified strains were isolated, among these M. anatis and unclassified arginine splitting mycoplasma strains proved to be pathogenic. In geese M. gallinarum, A. laidlawii and A. axanthum were detected. A. axanthum showed pathogenicity for goslings and goose embryos. Its effect is exacerbated by associated parvovirus infection.

Effect of intestinal flagellate Spironucleus (Hexamita) muris and of dimetridazole on intestinal microflora in thymus-defficient (nude) mice.

Two groups of the intestinal microflora, the lactobacilli and the coliforms, were examined in thymus-deficient (nude) mice during the development of an experimental infection with the intestinal flagellate Spironucleus (Hexamita) muris and during the treatment with dimetridazole. The observed significant decrease in the number of lactobacilli under infection was probably due to the fact that the protozoan parasite fed on the microbes. Dimetridazole (0.3% in drinking water) did not influence the quantity of the lactobacilli but, owing to its selective killing of anaerobes and the lack of their antagonistic activity, a 100- to 1000-fold rise in the number of coliform microbes was observed. No of the drugs tested (dimetridazole, ornidazole, metronidazole, tinidazole, carbimazole BP and chlormethoxy-acridilamino-diethylamino-propanol-dihydrochliorde) was fully successful in the treatment of experimental spironucleosis in mice (Kunstýr, 1978) and it is suggested that recent reports on the therapeutic success of tinidazole in human giardiasis be treated with caution.

Effect of histamine and stress on the gastric mucosal Ca2+ content during the development of gastric ulcers.

The influence of histamine, its triazole derivative (3-beta-aminoethyl-1,2,4-triazole) and immobilization stress on the gastric mucosal Ca2+ content during the development of gastric ulcers in guinea pigs and rats was investigated. A considerable fall in the concentration of Ca2+ in gastric tissues of guinea pigs after administration of histamine 0.25 mg/kg, down to 80% (8.0 mumol/g), its derivative (1 mg/kg) to 72% (7.2 mucol/g) and stress to 76% (7.6 mumol/g) was recorded by atomic absorption-spectrophotometric techniques, while the calcium level in the controls stood at 9.9 mumole/g. Similar changes (90-65%) were seen in the blood plasma. In rats, the Ca2+-decreasing effects of stress ran closely parallel with increasing ulceration, and depended on the duration of stress. The immobilization of rats evoked a slight rise in the Na+ content of the gastric tissues. After 4 h immobilization, the tissue concentration of Na+ was increased to 116% of control levels. Cimetidine (100 mumol kg-1 more than 50% inhibited the development of gastric ulcers and prevented the change in Ca2+ concentration ions. Thus, the data suggest that Ca2+ ions take part not only in the regulation of secretion, but also in stress tissue dystrophy.

A spin label study of horseradish peroxidase.

The topography of the active sites of native horseradish peroxidase and manganic horseradish peroxidase has been studied with the aid of a spin-labeled analog of benzhydroxamic acid (N-(1-oxyl-2,2,5,5-tetramethylpyrroline-3-carboxy)-p-aminobenzhydroxamic acid). The optical spectra of complexes between the spin-labeled analog of benzhydroxamic acid and Fe3+ or Mn3+ horseradish peroxidase resembled the spectra of the corresponding enzyme complexes with benzhydroxamic acid. Electron spin resonance (ESR) measurement indicated that at pH 7 the nitroxide moiety of the spin-labeled analog of benzhydroxamic acid became strongly immobilized when this label bound to either ferric or manganic horseradish peroxidase. The titration of horseradish peroxidase with the spin-labeled analog of benzhydroxamic acid revealed a single binding site with association constant Ka approximately 4.7 . 10(5) M-1. Since the interaction of ligands (e.g. F-, CN-) and H2O2 with horseradish peroxidase was found to displace the spin label, it was concluded that the spin label did not indeed bind to the active site of horseradish peroxidase. At alkaline pH values, the high spin iron of native horseradish peroxidase is converted to the low spin form and the binding of the spin-labeled analog of benzhydroxamic acid to horseradish peroxidase is completely inhibited. From the changes in the concentration of both bound and free spin label with pH, the pK value of the acid-alkali transition of horseradish peroxidase was found to be 10.5. The 2Tm value of the bound spin label varied inversely with temperature, reaching a value of 68.25 G at 0 degree C and 46.5 G at 52 degrees C. The dipolar interaction between the iron atom and the free radical accounted for a 12% decrease in the ESR signal intensity of the spin label bound to horseradish peroxidase. From this finding, the minimum distance between the iron atom and nitroxide group and hence a lower limit to the depth of the heme pocket of horseradish peroxidase was estimated to be 22 A.

Quantitation of the adherence of an enteropathogenic Escherichia coli to isolated rabbit intestinal brush borders.

Two assays were developed to quantitate the adherence of an Escherichia coli strain (RDEC-1) known to colonize the mucosal surface of the small intestine of rabbits to brush borders isolated from rabbit intestinal epithelial cells. In the first assay, the mean adherence per rabbit brush border was determined by counting the number of organisms adhering to each of 40 brush borders under phase microscopy. The mean adherence of RDEC-1 (11.5 +/- 0.7 per rabbit brush border) was significantly greater than adherence of two nonpathogenic strains: HS (2.7 +/- 0.4 per rabbit brush border) and 640 (0.8 +/- 0.1 per rabbit brush border). A similar distinction between the adherence of RDEC-1 and the control (nonadherent) organisms could be made more rapidly by determining the percentage of the total number of brush borders which had 10 or more adherent organisms; this second assay was used to define the optimum conditions for adherence. Maximum adherence was seen within 15 min. Adherence was temperature dependent, with adherence after 1 min at 37 degrees C being fourfold greater than that at 4 degrees C. The pH optimum for adherence was between 6.5 and 7.0, and adherence was abolished below pH 5.0. With the first, more sensitive assay, the effect of electrolytes and a number of hexoses and hexosamines on adherence was analyzed. RDEC-1 adherence was inhibited at high ionic strengths; however, adherence was not influenced at moderately high concentrations (20 mg/ml) by either d-mannose or l-fucose, in contrast to the case for other reported enteric pathogens. These two quantitative in vitro assays for adherence produce consistent results and have been used to partially characterize the adherence of RDEC-1 to rabbit brush borders.

Is glutamate the transmitter of crustacean motoneurons?

1. Bath-application of L-glutamate to crayfish opener muscle causes depolarization and resistance changes which both increase with falling temperature. At temperatures above 15 degrees C there is usually a resistance increase, at lower temperatures the resistance is decreased. 2. Meso-gamma . gamma'-diaminosuberic acid-dihydrochloride (meso-di-GABA) and dl-diamino-nonanedicarboxylic acid dihydrochloride (C-9) were newly synthesized as potential glutamate blockers. 3. Meso-di-GABA (10(-4) to 10(-3)M) usually caused a significant increase (15 degrees C) or decrease (7 degrees C) of membrane resistance and slight depolarization. Excitatory junction potentials (ejps) were reversibly depressed or blocked while the effects of glutamate were potentiated. The depression or block of neuromuscular transmission was not prevented by picrotoxin or by concanavaline A. 4. C-9 (3 x 10(-4) M) depressed or blocked the effect of applied glutamate with little or no effect on ejps. 5. The results are best explained by assuming that bath-applied glutamate acts mainly on extrasynaptic receptors. Meso-di-GABA is assumed to block synaptic receptors and to activate non-synaptic receptors while C-9 seems to act mainly as a blocker of glutamate action on non-synaptic receptors.

Comparative study of erythromycin, amoxicillin and ampicillin antimicrobial activity against human respiratory tract pathogens.

An in vitro test system was used to compare the antimicrobial activity of erythromycin, amoxicillin and ampicillin against respiratory tract pathogens isolated from man. The minimum inhibitory concentrations (MICs) of fresh clinical isolates of Streptoccus pyogenes, Streptocuccus pneumoniae, Staphylococcus aureus and Haemophilus influenzae to the macrolide and penicillins ranged between 0.01 and 0.9 microgram/ml. The microbes were exposed to each antibiotic for approximately 3 h at 1x,2x and 5x the relevant MIC. Irreversible surface defects and intracellular lesions were resolved by scanning and transmission electron microscopy in all antibiotic-treated bacterial species, irrespective of the antimicrobial used. In each case, inhibition of growth was recorded by turbometric assay; no significant difference was observed among the declining slopes of post-dosing growth curves for either erythromycin-, amoxicillin- or ampicillin-treated pathogens. The experimental observations show that the onset of antimicrobial activity and the bactericidal effectiveness of equipotent concentrations of erythromycin, amoxicillin and ampicillin were comparable in this study. The results complement previous clinical, bacteriologic and ultrastructure studies in vivo and demonstrate the contribution of the combined in vivo/in vitro study design for better understanding of antimicrobial activity in human respiratory tract infections.

Mammalian serum susceptibility of Serratia marcescens: detection of three human serum susceptibility categories.

A total of 65 strains of S. marcescens, including 36 currently employed O- and H-antigen reference strains, were examined for their susceptibility to the bactericidal activity of 80 vol % of fresh human serum. The majority of strains (57 = 87.6%) proved 'delayed serum-sensitive' (DSS); 4 strains (6.2%) were 'promptly serum-sensitive' (PSS), whereas 4 strains (6.2%) resisted (NSS) complement-mediated killing by human serum. Fresh sera obtained from 7 adult human volunteers yielded essentially identical kinetic killing data against representative NSS, DSS and PSS strains of S. marcescens. These observations were interpreted as further justification for the assignment of clinical isolates of S. marcescens to 3 categories of human serum susceptibility: DSS, PSS and NSS. Species differences among fresh sera from sheep, rabbits and guinea pigs, as contrasted with fresh human serum, were noted. In general, PSS strains of S. marcescens were killed in a slightly delayed fashion; DSS strains of S. marcescens were killed in an unpredictable kinetic pattern by sheep and rabbit sera, whereas fresh guinea pig serum entirely failed to kill selected DSS isolates of S. marcescens.

The effect of Toxoplasma cell fractions and mycobacterial immunostimulants against virulent Toxoplasma gondii in mice.

Toxoplasma gondii tachyzoites were disrupted in a Ribi cell fractionator and separated into cell walls and protoplasm by differential centrifugation. These products were used alone or combined with a mycobacterial glycolipid (P3) and injected either as oil-in-water emulsions or incorporated in Freund's incomplete adjuvant. Mice were vaccinated by intravenous or intradermal routes and challenged intraperitoneally with a highly virulent strain of Toxoplasma gondii. A local granuloma formation was induced after i.d. inoculation of Toxoplasma vaccines containing P3 as this glycolipid enabled an adherence of the antigens on the mineral oil droplets. The adjuvant effect of P3 on antibody formation was also observed. Most of the fractions showed a low, but statistically significant prolongation of survival time. Vaccination by the i.v. route with homologous or heterologous antigens, including Trypanosoma cruzi, were not significantly effective, with the exception of a high dose of Toxoplasma protoplasm associated with P3.

[New possibilities in diagnosis and therapy of renal carcinoma (author's transl)].

A brief discussion of the aetiology and epidemiology of renal carcinomas is followed by a description of the clinical features. Attention is drawn to the significance of symptoms emphasizing the importance of early diagnosis. Intravenous urography still remains as the most important diagnostic procedure. It is pointed out that sonography and computer-tomography are now established as newer diagnostic methods, i.e. in distinguishing between cyst and tumor, in renal masses. Therapy, is still based upon surgical treatment. Transperitoneal, radical tumornephrectomy as compared with simple lumbar nephrectomy, has improved 5-year survival rate up to 16% especially in stage III tumors. Extracorporeal surgery for single kidney patients as hyperthermic surgery constitute new surgical methods, but only for specifically equiped urologic clinics. Embolisation of renal cell carcinoma is also used as therapeutic management in largely progressed tumors, and also used, as a preoperative measure, for the reducement of tumor size. Irradiation, before and after surgical treatment, as well as cytostatic therapy, revealed no significant improvement. We have reason to hope that progress in the research of hormonal- and immunotherapy will improve 5-year survival rate, in renal cell carcinoma.

[Biochemical methodology for studying affective disorders].

Defects in brain neurotransmitter function are believed to be involved in the aetiology of mood disorders, and model systems are based on this concept. Abnormalities in synthesis, storage, release, reuptake or catabolism of monamines, GABA, glycine, taurine, peptides and purines may occur. There may also be an endogenous psychotogen--an aberrant metabolite of a transmitter. Models are divided into two groups. 1. Human. Brain, CSF, blood cells (platelets, erythrocytes), plasma and urine have been analysed for neurotransmitters or metabolites. Particular emphasis has been given to serotonin (5-HT) and the catecholamines, dopamine and noradrenaline. 2. Animal. Human mood disorders may be stimulated by drug-induced behavioural changes in animals (hyperactivity, stereotyped behaviour sedation). The above biochemical parameters relating to neuronal function can then be assessed. Brain neuronal pathways can be stimulated in animals with monoamine precursors and MAO inhibitor drugs. This drug-induced hyperactivity can be used to "evaluate" therapeutic techniques such as electroconvulsive therapy (ECT). Model analogues of mood disorder have limited use until human disease aetiology is known, currently the best use of models may be for demonstration and evaluation of particular similarities between human mood disorders and drug-induced alterations of animal behavioural patterns.

[Amineptine, a new antidepressant: pharmacological review (author's transl)].

Amineptine is a tricyclic derivative with a 7-carbon chain of aminoacids. Chemical alterations of the aminoacid chain have revealed its importance in the shaping of the pharmacological effects. The drug is rapidly absorbed. Amineptine is metabolised principally by beta-hydroxylation of the chain. The pharmacological profile at different doses is as follows: a. 0.1 mg/kg: reduction of exploratory behaviour, b. 1 mg/kg: reduction of serum prolactin level, c. 5 mg/kg: potentiation of L-5 HTP, d. 10 mg/kg: antagonism of the effects of reserpine and of tetrabenazine, e. increased activity and social behaviour, EEG alerting effect limited to 1 hour and increase in paradoxical sleep (15 to 20 mg/kg). This pharmacological profile suggests an effect of amineptine upon certain dopamine structures. At synapse, neurobiochemistry confirms a mechanism of inhibition of DA incorporation and inhibition of uptake and/or release of 5 HT. Amineptine is virtually devoid of peripheral activity, particularly anticholinergic Amineptine may be indicated for the treatment of depression where retardation is dominant.

[Place of routine amnioscopy in the screening of fetal distress (author's transl)].

In order to assess the benefits of routine amnioscopy in the screening of fetal distress, the CTG score, the pH of umbilical artery and the Apgar score were determined and compared in two groups of patients: one group had meconium stained amniotic fluid (MSAF), the other (control) had clear amniotic fluid. Although the prepathological and pathological CTG scores were more frequent in the MSAF group, the values of the umbilical artery pH had the same distribution in the two groups. The percentage of acidotic fetuses in the MSAF group is very low (2.9 p. 100) and practically the same as in the control group (2.5 p. 100). The Apgar score distribution at one and five minutes is also the same in the two groups. The distribution of CTG scores in acidotic fetuses is the same in the two groups, but the pre-acidotic fetuses born with meconial fluid have more often a pre-pathological or pathological CTG score. Fetuses with normal or suspect CTG-score and nevertheless acidotic or pre-acidotic pH values at birth are equally present whether the liquid is stained or not. Amnioscopy is therefore of no help even in this situation. In conclusion, the discovery of a MSAF is the manifestation of fetal hypoxia in only 2.9 p. 100 of cases: the detection of this condition is better achieved by CTG recordings than by routine amnioscopy.

NMR of fd coat protein.

The conformations of the major coat protein of a filamentous bacteriophage can be described by nuclear magnetic resonance spectroscopy of the protein and the virus. The NMR experiments involve detection of the 13C and 1H nuclei of the coat protein. Both the 13C and 1H nuclear magnetic resonance (NMR) spectra show that regions of the polypeptide chain have substantially more motion than a typical globular protein. The fd coat protein was purified by gel chromatography of the SDA solubilized virus. Natural abundance 13C NMR spectra at 38 MHz resolve all of the nonprotonated aromatic carbons from the three phenylalanines, two tyrosines, and one tryptophan of the coat protein. The alpha carbons of the coat protein show at least two different classes of relaxation behavior, indicative of substantial variation in the motion of the backbone carbons in contrast to the rigidity of the alpha carbons of globular proteins. The 1H spectrum at 360 MHz shows all of the aromatic carbons and many of the amide protons. Titration of a 1H spectra gives the pKas for the tyrosines.

[Fructose and citric acid content in the sperm of stud males with forms of impotencia generandi].

Fructose and citric acid content was investigated in the sperm of 27 bulls with anamnesis data for "low quality sperm". The bulls were used as breeding males in various stations for artificial insemination. Three forms of Imp. generandi are described and several grades of Oligokinospermia are differentiated. Changes in fructose and citric acid quantity differed in degree in the various forms of Imp. generandi described. Fructose and citric acid value in I and II grade Oligokinospermia were insignificantly lower than the low limit of these indices observed in bulls with normal spermoproduction. Correlation between the changes observed is positive, slight, insignificant or entirely missing. Fructose content is insignificantly lower in cases of III and IV grade Oligokinospermia and in Akinospermia, while citric acid content is reduced only in Akinospermia. The correlation between the changes is positive , high and significant. Fructose reduction in bull's semen below 400.0 mg% and of citric acid below 500.0 mg% in case of negative data for inflammatory changes in vesiculae seminalis is a diagnostic symptom for disfunction of vesiculae seminalis. More considerable changes occur in fructose values.

[Comparative studies on the vaccination of mice with inactivated influenza virus administered by the aerosol technique, by the intranasal or intramuscular route (author's transl)].

NMRI mice were immunized intramuscular, intranasal or by Aerosol, using the ethylethylenimine inactivated and polyethylenglycolconcentrated influenza virus strain A/PR/8/34 (HO/N1). Differences in the immune response resulted from all three routes. Intranasal and intramuscular vaccination were superior to aerosol application. A possible explanation for this could be the fact that relatively small amounts of the inhaled virus antigen developed antigenic activity on the mucous membrane. A single vaccination by the aerosol technique gave significant protection only, if the challenge virus was applied by the same procedure. However no protection was found after intranasal challenge. Intranasal challenge on the third day post vaccination revealed that intramuscular immunization had a significant better protective effect than intranasal immunization. However from the 5th to the 10th day post vaccination this effect reversed and intranasal vaccination became superior. This immunity persisted for the whole period of observation and it was accompained by a higher titer of local antibodies. Similar results were obtained in experiments with aerosol challenge. Here only the intranasal vaccinated mice were completely protected after the 10th day post vaccinationem while intramuscular vaccinated animals were less protected. Sera of intramuscular immunized mice revealed a higher content in antibodies of the Ig M type and less of the Ig G type compared to mice vaccinated by the intranasal route.

Further characterization of "promptly" and "delayed" human serum-sensitive strains of Serratia marcescens.

The kinetics of the bactericidal activity of 80 vol% of fresh human serum against representative 'delayed serum-sensitive' (DSS) and 'promptly serum-sensitive' (PSS) strains of Serratia marcescens were further examined with regard to various chemical and absorption procedures known to affect various components of the alternative and classical pathways of human complement activation. Inulin treatment of fresh human serum failed to diminish serum bactericidal activity against DSS and PSS assay strains. Fresh human serum that had been depleted of properdin (factor P) through absorption with zymosan, was as active as control serum against DSS strains of S. marcescens; however, PSS strains were killed in a 'delayed' fashion. Human serum that had been heat-inactivated at 50 degrees C for minutes (depletion of factor B), no longer killed DSS strains, whereas PSS strains of S. marcescens and the PSS control strain Escherichia coli C were killed in a slightly delayed fashion. Hydrazine-hydrate treatment (inactivation of C3 of the complement system) and exposure of fresh human serum to dithiothreitol completely abolished serum bactericidal activity. Bentonite-absorbed fresh human serum no longer killed DSS strains of S. marcescens; some PSS strains of S. marcescens were killed in a delayed manner, whereas control strain E. coli C was as PSS as before. Addition of Seitz-filtered fresh human serum, that lacked beta-lysin and was deficient in lysozyme, to bentonite-absorbed human serum restored bactericidal activity against DSS and PSS strains of S. marcescens; addition to heat-inactivated or Seitz-filtered, heat-inactivated human serum failed to do so. Therefore, bentonite absorption removed to a heat-labile component from fresh human serum clearly different from beta-lysin and lysozyme. Furthermore, human serum beta-lysin and lysozyme were not required for serum-mediated killing of S. marcescens strains of either serum susceptibility category.

The breakdown of adenine nucleotides in glucose-depleted human red cells.

1) The rate of 2,3-bisphosphoglycerate breakdown is independent of pH value. 2) The adenine nucleotide pattern at alkaline pH values with its characteristic lowering of ATP and the accompanying accumulation of fructose-1,6-bisphosphate is caused by a relative excess of the activity of the hexokinase-phosphofructokinase system as compared wity pyruvate kinase. 3) The breakdown of adenine nucleotides proceeds via AMP mainly through phosphatase and not via AMP deaminase. 4) The constancy of the sum of nucleotides as long as glucose is present is postulated to be due to resynthesis via adenosine kinase which competes successfully with adenosine deaminase. 5) A procedure is given to calculate ATPase activity of glucose-depleted red cells. The results indicate that the ATPase activity is less at lower pH values and declines with time. An ATPase with a high Km for ATP is postulated. 6) During glucose depletion ATP production is mostly derived from the breakdown of 2,3-bisphosphoglycerate and the supply from the pentose phosphate pool both of which proceed at a constant rate. The contribution of pentose phosphate from the breakdown of adenine nucleotides amounts to 40% of the lactate formed at pH 6.8 and is about twice the lactate at pH 8.1.

[Factors responsible for post-operative infection].

Post-operative infection is often due to a combination of several factors. A decrease in immune defence processes represents the first factor. This is seen in situations such as malnutrition (undernourishment or obesity), alcoholism, diabetes, neoplasms, infections and old age. It may also be induced by therapy such as immunodepressants, antimitotic chemotherapy, corticosteroids and radiotherapy. Finally, certain antibiotics have been accused of reducing immune defences. The second factor responsible for infection is bacterial flora. Errors such as broad spectrum antibiotic therapy prescribed in the presence of unexplored fever, or changed repeatedly, are responsible for imbalance in the bacterial flora and the acquisition of resistance to antibiotics. These errors firstly increased the prevalence of infections and, secondly their severity and the difficulty of their treatment. The last factor responsible for infection is rupture of the natural barriers formed by the skin and mucosae. This is related on the one hand to surgery itself and, secondly, to the intensive care techniques surrounding the surgical act: venous catheterization above all, but also bladder catheterization, tracheal intubation, etc.

[Neonatal consequences of cesarean section on the presumably healthy infant].

The authors studied the effects on the child of 196 caesarian sections performed in the absence of foetal distress. The following were noted for each child: the time before the first cry, the Apgar score, pH and the need or not for resuscitation techniques. Each feature was studied in terms of different factors: foetal, obstetric, anaesthetic and surgical. The conclusions were as follows: caesarian section, which remains the best means of preventing obstetric trauma, has its own direct complications which are linked to the conditions in which the operation takes place. These can be reduced to a minimum or even completely suppressed if the caesarian section is performed under ideal conditions: few or no depressant drugs before the operation (the use of diazepam for induction should be abandoned); inclined position of 15 degrees, even of the mother has never suffered from utero-caval syndrome and if possible on a heated mattress; extraction of the infant between the 5th and 15th minutes; finally, and above all, prior labour is desirable whenever obstetric conditions permit.

[The role of renin after betablocking diuretic and vasodilator treatment in essential hypertension (author's transl)].

Ten patients affected by essential moderate or severe hypertension were given five sequential treatments, each for three weeks: 1) placebo, 2) chlorthalidone (Cl) 100 mg daily, 3) Cl 50 mg + oxprenolol slow release (Ox) 160 mg daily, 4) Ox 160 mg and 5) Ox 320 mg daily. Four subjects poor responders (DPB greater than or equal to 110 mmHg) received a later administration of Ox 160 + Cl 50 + hydrallazine (Hydr) 25-100 mg daily. Both groups of patients showed the greatest antihypertensive action with Ox 160 + Cl 50 mg daily. Oxprenolol induced a similar hypotensive effectiveness at 160, as well as 320 mg/day. Relationship between plasma renin activity (PRA) values and antihypertensive response to each treatment takes the following conclusions: 1) Basal PRA levels cannot be a guide for preferential choice of diuretic or betablocking therapy. 2) It is likely that renin activated by Cl and Hydr partially blunts their hypotensive activity. On the contrary, essential hypertension with normal or low PRA does not seem depending on angiogensinogenic factors. 3) Oxprenolol remarkably inhibits the overreninism induced by chlorthalidone and hydrallazine, in such way increasing their antihypertensive action. 4) In the management of essential moderate or severe hypertension is preferable to employ a mild dosage of betablockers and diuretics, rather than use higher doses of a single agent.

Summary of laboratory studies on the antibacterial activity of cefaclor.

Laboratory aspects of cefaclor, a new orally-effective cephalosporin antibiotic, are summarized. On the basis of data from a variety of studies, the useful antibacterial spectrum of cefaclor is shown to include all classes of bacteria that are generally susceptible to cephalothin and cephalexin. Cefaclor has a significant potency advantage over cephalexin against many Enterobacteriaceae, Haemophilus sp. and Streptococcus pneumoniae. Bacteria that are susceptible to cefaclor are killed by concentrations at or near the inhibitory concentration. In vitro enzymatic hydrolysis experiments have shown that cefaclor is a relatively good substrate for several beta-lactamases. Orally administered cefaclor is effective in protection of mice from the lethal effects of intraperitoneal challenges with cefaclor-susceptible bacteria. The chemical instability of cefaclor, test medium composition and inoculum density influence the results of in vitro susceptibility tests with cefaclor. Methods for routine susceptibility testing are described.

Experimental design for the surgical relocation of the ovary into the vaginal fornix.

After translocation into the vaginal vault while attached to a pedicle consisting of the infundibulo-pelvic ligament, the ovary was found to maintain its function in laboratory primates. In the majority of the baboons the ovulatory pattern returned within a few weeks after the surgical procedure. The only significant complication was a transitory, and self-limited, infection which was evident on inspection and on the biopsy specimens, but caused no clinical symptoms. By comparing the surgical outcome in two primate species, namely Papio Cynocephalus and Macaca Arctoides, it could be deduced that the Homo Sapiens would be a more suitable experimental model than either of the laboratory primates used in this research. Because there are potentially effective methods for reducing the likelihood of postoperative infection in the relocated ovary, the experience gained by this new method suggests the possibility that it could be utilized in the future for the purpose of collecting ova for in vitro fertilization in carefully selected, and otherwise untreatable, cases of female sterility.

Abnormalities of the vas deferens and epididymis in cryptorchid boys with congenital rubella.

Cryptorchidism was present in 12% of 316 boys with congenital rubella (CR) followed by The Roosevelt Hospital Rubella Project. Eight of these patients, age 4 through 16 yr, had a recent orchiopexy, 4 on the left, 2 on the right, and 2 bilaterally. The vasoepididymal system was absent or apparently obstructed in 60% of the 10 sides. The epididymis was abnormal in 6 instances and the vas deferens in 5. Sixty-one boys of the entire series had an intravenous pyelogram (IVP) that was significantly abnormal in 18%. The 8 patients described all had a normal IVP except for 2 who had a malrotated kidney on the involved side. In 5 of the 8, a known maternal rubella infection has occurred during the first 8 wk of gestation. As the rubella virus is known to interfere with cellular growth and tissue differentiation in early pregnancy, it apparently altered the developing testis and mesonephric duct system. Similar vasoepididymal abnormalities have been described previously in patients with uncomplicated cryptorchidism, inguinal hernia, kidney defects, cystic fibrosis and male sterility. Their presence should alert the clinician to perform an IVP and also consider a diagnosis of congenital rubella.

Demonstration of two new endogenous "benzodiazepine-like" compounds from brain.

The recent report that purines are competitive inhibitors of specific [3H] diazepam binding to brain membranes has prompted further work concerning the characterization of possible endogenous ligands for the benzodiazepine receptor. In this report, two previously undescribed fractions capable of apparent competitive inhibition of [3H] diazepam binding are reported. Both factors are heat stable and resistant to proteolytic degradation. The larger factor (approximately 700 to 30,000 daltons) is present only in brain and pituitary. The smaller factor (500 to 600 daltons) is found in pituitary, liver, and muscle, but the highest levels are found in brain.

The ribosomal serine proteinase: cathepsin R.

As has been known for several years, thoroughly purified ribosomes contain a firmly bound serine proteinase with an optimum of activity at neutral pH. The present paper shows that the activity is found in free cytoplasmic ribosomes as well as in ribosomes detached from the membranes of the endoplasmic reticulum of rat liver. After ribosome dissociation, the proteinase activity is found only on the 40 S subunits. Recovery of the proteinase in the proteins of whole ribosomes or of 40 S subunits amounts to 44 and 65%, respectively. Ribosomes purified both from plant (Euglena) and bacterial (Acinetobacter) cells contain a serine proteinase having an activity quite comparable to that of rat liver ribosomes. In view of the recommendations of BARRETT et al. ( in REICH, RIFKIN and SHAW (eds).: Proteinases and Biological Control, Cold Spring Harbour Lab., 1975, p. 481), who no longer restrict the name "cathepsin" to acid or even lysosomal proteinases, we propose the name " ccathepsin R" for this ribosomal serine proteinase.

[Effect of almitrine on arterial gases in patients with chronic respiratory insufficiency. Comparison with doxapram. Preliminary results].

We compared the effects of almitrine and doxapram on the arterial blood gases and ventilation of patients with chronic respiratory insufficiency and chronic hypercapnia and hypoxemia. Sixteen long-term in-patients were randomly allocated to one of the following treatment groups: the first group (8 patients) received IV almitrine 0.5 mg/kg and the second group (8 patients) IV doxapram 1 mg/kg by IV perfusion during 30 min. All gave their informed consent. Arterial blood gases and ventilation were measured 10 min and 5 min before treatment, at the 5th, 15th and 25th min of perfusion time, and 5, 10 and 15 min after infusion. There was a marked increase in paO2 in almitrine-treated patients, which was maximum at the 25th min of infusion (+ 14.6 mm Hg, p < 0.001), but only a slight improvement was observed in the doxapram group (+ 3.3 mm Hg, p < 0.05). After almitrine the maximum mean paCO2 decrease was at the 10th min after perfusion (-6.9 mm Hg, p < 0.001); after doxapram the maximum decrease, although highly significant, was much less (-2.8 mm Hg, p < 0.01). Thus, at the presently used and well-tolerated doses, almitrine is much more efficient than doxapram in improving gas exchange in patients with chronic hypoxemia and hypercapnia. However, complementary studies using higher dosage of doxapram are warranted.

[The role of anaerobe adhesion in the colonization of the vaginal mucosa].

Some our previous research works on bacterial adhesion to vaginal cells in the different phases of the menstruum showed that adhesion changes depending on changing environmental conditions. We therefore considered interesting to extend our investigations to anaerobic flora, in the light of recent observations intended to attribute an important role to anaerobic flora in the pathogenesis of vaginitis. The results obtained so far indicate that the maximum adhesion capability is found in the middle of the menstruum. The very low adhesion of bacteria belonging to the Leptothrix genus remains substantially unaltered throughout the menstruum. Low adhesion is also found in sporogenic bacteria, whereas the coccoid ones have a stronger adhesion, particularly about the middle of the menstruum. With lower pH values adhesion of the anaerobic flora is enhanced, whereas in the final phase of the menstruum, with higher pH values, adhesion is reduced. Competition tests evidence a stronger adhesion of coccoid as compared to bacillar types.

[Hemodynamic effects of normovolemic hemodilution].

After reviewing data from the literature concerning the effects of normovolaemic haemodilution on cardiac output and regional flow rates, the authors illustrate these concepts by a personal study involving the haemodynamics of 10 subjects undergoing operation in normovolaemic haemodilution. Removal of blood was compensated simultaneously by modified liquid gelatin in electrolytic solution (Plasmion) until the haematocrit was 0.30. Measurements were performed before haemodilution in patients in a steady state (anaesthetised, intubated, normoventilated), at the end of haemodilution, at the end of the operation, then 4 hours after recovery. There was no variation in blood pressure and heart rate, showing that normovolaemia was maintained. At the end of haemodilution, cardiac index increased from 3.10 to 3.84 l.min-1.m-2 (0.0517 to 0.0638 l.s-1 . m-2) (p < 0.005); stroke volume increased from 70 to 83 ml (p < 0.005); systemic resistance fell from 1585 to 1262 dynes. s.cm-5 (158.5 to 130.4 kPa.s.l-1) (p < 0.005); arterial oxygen content decreased from 191.1 to 152.1 ml.100 ml-1 (8.535 to 6.793 mmol.l-1) (p < 0.005), whilst oxygen transport was unchanged. These various haemodynamic measurements showed no significant changes at the subsequent times when they were measured, values remaining close to those obtained at the end of haemodilution. The results confirm the fact that norvolaemic haemodilution is accompanied by a fall in systemic vascular resistance with an increase in cardiac output. Regional circulations are thus improved. Since oxygen transport is unaffected, the oxygenation of peripheral tissues is ensured normally.

Microelectrophoretic application of antagonists of putative neurotransmitters onto various types of bulbar respiratory neurons.

Seven antagonists of putative neurotransmitters were applied to bulbar respiratory neurons and, for comparison, also to unspecific cells. The antagonists exerted distinct effects when released alone, permitting to draw conclusions about receptor properties of the various cell types. With strychnine, specific antagonist of glycine, excitation prevailed in EI, I and E neurons. With bicuculline, specific antagonist of GABA, excitation preponderated in EI and E cells. About half of the unspecific neurons were activated and the remainder were unresponsive. GDEE (glutamatediethylester), antagonist of glutamate, excited part of the IE neurons and inhibited part of the E units, while the remainder of both types as well as 2 EI cells tested were not affected. With flupentixol, antagonist of dopamine, excitation prevailed in I neurons. About half of the IE and E units remained unaffected, while in the remainder E cells inhibition preponderated over excitation. With yohimbine, an alpha-adrenoceptor blocker, inhibition prevailed in E units. The two EI as well as the majority of the I neurons remained unaffected, with two cells of the latter type being activated. Propranolol, a beta-adrenoceptor blocker, inhibited about half of the E neurons, while the remainder as well as most IE and the 2 EI cells tested were not affected. Cyproheptadine, an antagonist of 5-HT, excited most E neurons. As concerns NE-receptors, those of the alpha-type might be involved in activation of part of the E cells only, whereas all other NE effects (inhibition or activation) are mediated by CNS-specific receptors different from the alpha- and beta-type. 5-HT effects apparently are mediated by two different receptor types.

Relative number and proliferation kinetics of hemopoietic stem cells in the mouse.

A model calculation of the hemopoiesis of the mouse based on known hematologic data leads to the conclusion that approximately 3% of all nucleated bone marrow cells are stem cells (pluripotent plus committed stem cells). By a new 125IUdR labeling technique on radiation chimeras, a relative number of 2%-7% stem cells was determined. In previous studies with test systems for stem cells using colony formation in vivo or in vitro, a relative number of stem cells of at least one order of magnitude lower has been estimated. In this study the stem cells are found to have a turnover time of about 4.3 days in the donor mice. This turnover time remained unchanged even after transfusion of marrow cells into lethally irradiated recipient mice. Radiosensitivity determinations yielded a D0 of 80 rad for stem cells in S-phase and D0 of 185 rad for stem cells distributed throughout the entire cell cycle. The respective extrapolation numbers were 1.23 and 1.14. Experiments using an 3H-TdR suicide technique revealed different cell cycle parameters for bone marrow stem cells seeding to the spleens and to the femurs of lethally irradiated recipients, primarily a shortening of S-phase in cells seeding to femurs. The method described here provides a new approach to hematologic stem cell research.

Rat brain ribonucleases.

Rat brain ribonucleases (RNases) were studied. Three types of RNases with maximum activities at pH 5.0, 7.2 and 9.5 were found. The activity of the pH 7.2 enzyme can be detected only by avoiding the interference of a very active inhibitor with p-chlor-mercuri-benzoic acid (PCMB). The effect of bivalent cations (Ca2+, Mg2+), Na+ and ethylenediamine tetraacetic acid (EDTA) was investigated. The activities studied showed a different subcellular distribution. Changes in RNase activity during postnatal rat brain development were studied. The pH 7.2 and 9.5 enzymes have a similar behavior increasing up to the 15th-20th day and remaining constant thereafter. The pH 5.0 enzyme remains constant from the 5th to the 20th day, decreasing thereafter.

Regulation of nerve terminal calcium channel selectivity by a weak acid site.

The effects of low pH, and of alkaline earth cations, were examined on calcium uptake by pinched-off nerve terminals (synaptosomes). This uptake appears to be mediated by voltage-sensitive Ca channels (J. Physiol. 247:617, 1975). Ca uptake was measured in low (5 mM) or high (77 mM) potassium media. The extra uptake promoted by depolarizing (K-rich) media was almost maximal at pH 7.5, and decreased as the pH was lowered. Data relating depolarization-induced 45Ca uptake to pH fit a titration curve with a pKa approximately 6. Experiments in which Ca concentration and pH were both varied indicated that Ca2+ and H+ compete for a common binding site. Inhibition of depolarization-induced 45Ca uptake by the alkaline earth cations was studied to determine the apparent binding sequence for these cations in the Ca channels: Ca greater than Sr greater than Ba greater than Mg. This sequence resembles that observed for block of Ca channels in other preparations. The apparent binding sequence of the alkaline earth cations and the apparent pKa (approximately 6) of the Ca-binding site indicate that the Ca channel is a "high field strength" system. Protonation of a Ca channel binding site could explain the inhibitory effect of low pH on Ca-dependent neurotransmitter release (cf. Del Castillo et al., J. Cell. Comp. Physiol. 59:35, 1962).

Aldose reductase in diabetic complications of the eye.

Aldose reductase (AR) appears to initiate the cataractous process in galactosemic and diabetic animals. Sugars in excess are converted to polyols by lens AR. In sugar cataracts, polyols accumulate to levels substantial enough to cause a hypertonicity leading to lens fiber swelling. All other changes appear secondary to polyol accumulation and lens swelling. The development of sugar cataracts can be duplicated in organ culture. In culture, the various changes that occur were minimized or did not occur when inhibitors of AR were included in the medium. Moreover, AR inhibitors were shown to effectively delay the onset of sugar cataract development in animals. A defect in the corneal epithelium of diabetics became apparent in vitrectomy. One manifestation of this problem was the delay in the reepithelialization of denuded corneas. In examining this problem experimentally, the epithelium was removed from the corneas of diabetic and normal rats. The regeneration of epithelium in corneas of diabetic rats required a longer period than in the normal. The possibility that AR, active in the epithelium, was involved in this phenomenon was investigated. The corneal epithelium was removed from both eyes of a diabetic rat. One eye was treated topically with the AR inhibitor CP-45,634 while the other served as control. The eye treated with CP-45,635 regenerated epithelium much more quickly than the untreated eye. Other AR inhibitors had similar beneficial effects.

Effect of the frequency of stimulation on the blocker action of propranolol in isolated rat left atria.

The beta-blocking activity of propranolol was studied on the positive inotropic effect of norepinephrine, epinephrine, isoproterenol, dopamine and ethylephrine, in the left atrium driven at different rates. Dose of the antagonist of 10(-8) and 10(-7) M did not block the norepinephrine dose-response curve at 1 and 2.8 Hz, but a shift to the right was observed at 1.6 Hz. Although epinephrine showed a significant increase in its pD2 (p less than 0.001) at the lower stimulation frequency, the blockade increased progressively the higher the rates. On the other hand, propranolol antagonized isoproterenol at all the frequencies tested, in spite of an increase in the maxima at 2.8 Hz. This latter behavior was also true for dopamine and ethylephrine. Both sympathomimetic amines were blocked by propranolol at 1 and 1.6 Hz. The complex effect of propranolol on Ca2+ movements and its effects on cAMP and ATPase seem to be superimposed to the beta-blocking activity. Thus, the various actions on the sympathomimetic amines change according to the agonist considered and the stimulation frequency employed.

Neuroendocrine modulation of calcitonin and parathyroid hormone in man.

Recent evidence suggests that of calcitonin (CT) and parathyroid hormone (PTH) is controlled by factors other than the ambient serum calcium concentration. We studied the effects of infusions of four neuroendocrine modulators upon CT and PTH levels: isoproterenol (beta-adrenergic agonist), methoxamine (alpha adrenergic agonist), prostaglandin E2, and somatostatin. Isoproterenol was a consistent secretagogue for both hormones. Maximal CT increments during isoproterenol infusion in normal subjects were 13 +/- 2 pg/ml (mean +/- SEM, n = 6, P less than 0.001; basal, 26 +/- 5). Maximal increments in PTH were 113 +/- 22 pg/ml (P less than 0.01, n = 6; basal, 430 +/- 11). Infusions of methoxamine increased CT by 13 +/- 5 pg/ml (n = 5, P less than 0.05; basal, 43 +/- 13), but had no effect on PTH. The means of the maximal CT increments during isoproterenol (21 +/- 8 pg/ml) and methoxamine infusion (28 +/- 11 pg/ml) were not statistically different from those achieved by acute elevations of serum calcium levels within the physiological range (41 +/- 23 pg/ml). Infusions of somatostatin and prostaglandin E2 had no or only transient effects on basal or stimulated CT or PTH levels. Our data suggest that adrenergic input modulates CT and PTH secretion in humans independently of changes in serum calcium.

Effect of dopamine agonist (Lergotrile mesylate) therapy on twenty-four hour secretion of prolactin in treated Parkinson's disease.

Plasma PRL was measured at 20-min intervals in six patients with Parkinson's disease under various treatment protocols. In addition, 24-h mean GH levels were measured. The results of these studies showed that two untreated patients with Parkinson's disease had normal 24-h mean PRL levels with the normal increase during sleep. During chronic treatment with L-dopa-carbidopa (Sinemet), the 24-h PRL level was 12.8 +/- 4.9 ng/ml (mean +/- SD) and there was persistence of augmented PRL secretion during sleep. The 24-h mean GH level ranged from 1.5-4.4 ng/ml, with a mean of 2.5 ng/ml. The addition of a dopamine agonist (Lergotrile mesylate) resulted in a significant (P less than 0.01) suppression of the 24-h mean PRL levels and abolition of the normal sleep augmentation after 2 weeks of therapy. This suppression was maintained in one patient who was restudied 4 months after the addition of dopamine agonist therapy to L-dopa-carbidopa. The 24-h mean GH levels did not change significantly after the addition of the dopamine agonist when compared to L-dopa-carbidopa alone. These results suggest a dichotomy between the PRL and GH responses to combined L-dopa-carbidopa and dopamine agonist therapy. In addition, the preservation of normal PRL regulation in the two untreated patients with Parkinson's disease suggests that dopaminergic neurons are not universally affected in this disorder.

Requirements for blastocyst development in vitro.

Four characteristics of culture medium that are important to embryo development and nutrition of the blastocyst have been discussed. An examination of several of the most commonly used media for embryo culture demonstrates many similarities among them. The milliosmolarities of the media range from the hypoosmotic optimums (256 milliosmols) demonstrated in several in vitro studies to the physiologic range (308 to 315 milliosmols). Media between these extremes generally allow good development. Low oxygen concentrations (5%) in the culture environment allow somewhat better development of early cleavage stages, but recent studies suggest the difference between development in 5 and 20% oxygen to be less than originally thought. The media most commonly employed for early embryo culture contain bicarbonate as the buffer, but maintenance of pH is probably not the most crucial role of the CO2-bicarbonate content of the media. Likewise, since 1965 almost all media used to culture embryos have used pyruvate as the primary energy source. This is particularly important when early stages, before blastocyst development, are cultured. The concentration used generally falls within the optimum range of 2.5 to 5.0 X 10(-4)M first reported. Although glucose is not oxidized well by the early cleavage stages, it is an important energy source for all blastocysts. Furthermore, glucose contributes more than any other carbon source, including amino acids, to protein formation. Much is yet to be learned concerning the nutrition of the blastocyst, but our knowledge has increased immensely during the last 15 years. Hopefully our progress will be at least as rapid in the coming decade.

Isolation and characterization of a polynucleotide phosphorylase from Bacillus amyloliquefaciens.

Bacillus amyloliquefaciens BaM-2 produces large amounts of extracellular enzymes, and the synthesis of these proteins appears to be dependent upon abnormal ribonucleic acid metabolism. A polynucleotide phosphorylase (nucleoside diphosphate:polynucleotide nucleotidyl transferase) was identified, purified, and characterized from this strain. The purification scheme involved cell disruption, phase partitioning, differential (NH4)2SO4 solubilities, agarose gel filtration, and diethylaminoethyl-Sephadex chromatography. The purified enzyme demonstrated the reactions characteristic of polynucleotide phosphorylase: polymerization, phosphorolysis, and inorganic phosphate exchange with the beta-phosphate of a nucleotide diphosphate. The enzyme was apparently primer independent and required a divalent cation. The reactions for the synthesis of the homopolyribonucleotides, (A)n and (G)n, were optimized with respect to pH and divalent cation concentration. The enzyme is sensitive to inhibition by phosphate ion and heparin and is partially inhibited by rifamycin SV and synthetic polynucleotides.

Head-to-head association in bovine spermatozoa induced by catecholamines.

Noradrenaline, adrenaline, and isoproterenol induce head-to-head association in bovine spermatozoa in a Tris-HCl-buffered medium. Noradrenaline was the most and isoproterenol the least efficient. This effect was stimulated by Ca2+, Mg2+ and Mn2+, Ca2+ being more efficient than the other two ions. At 2 X 10(-6) M Ca2+, oxidation products of adrenaline dissociated spermatozoa associated by washing; at 2 X 10(-5) M Ca2+, the dissociating effect was transformed into association. The induction of association by adrenaline was blocked by both alpha- and beta-adrenergic blockers at low concentrations (2 X 10(-7) M). Both cAMP and dibutyryl substituted cAMP (db-cAMP) induced association in the Tris-buffered medium at 2 X 10(-6) M Ca2+. Further increase in association was brought about by increasing the Ca2+ concentration to 2 X 10(-5) M. Prolongation of the treatment with cAMP increased association. When combined with cAMP under the same conditions as used in the combination with adrenaline, L-propranolol did not inhibit association induced by cAMP. In an identical experiment, performed in Tyrode solution, L-propranolol inhibited association induced by cAMP. At 2 X 10(-5) M, theophylline, caffeine, and papaverine induced association in the presence of 2 X 10(-5) M Ca2+. The results are compatible with the hypothesis that catecholamines act via receptors and formation of cAMP.

Metabolic changes in Crithidia fasciculata accompanying physiological adaptation to growth in the presence of carbonyl cyanide m-chlorophenylhydrazone.

1. Crithidia fasciculata adapted to growth in the presence of 10(-5) M carbonyl cyanide m-chlorophenylhydrazone (CCCP), an uncoupler of oxidative phosphorylation, maintained adenosine phosphate pools and an adenylate energy charge comparable to those of control cells. 2. CCCP-adapted cells in the presence of the uncoupler respire endogenous substrate at a greater rate than control cells and this effect of CCCP appears readily reversible. 3. CCCP-treated, adapted cells, supporting high endogenous respiration rates, were not responsive to added substrates which significantly stimulated the oxygen utilization of normal C. fasciculata. 4. CCCP-adapted cells, provided with [U-14C]-labeled proline, utilize this substrate at 67% the rate of control cells, but divide the isotopic label between CO2 and protein in a ratio identical to that of normal cells. 5. The transport of alanine and proline by adapted C. fasciculata was severely impaired, while the transport of tyrosine and leucine was unaffected.

Genetic determinants of microbial resistance to antibiotics.

Emergence of antibiotic resistance is related to the ease of mutation, to the extent of exchange of genetic information in bacteria by conjugation, transformation, and transduction, and to the large-scale use of antimicrobial agents in the biosphere. In addition to the development of resistance through chromosomal mutation and exchange of chromosomal genes among organisms, there is a more profound enlargement of the gene pool by the dissemination and amplification of plasmids. Two examples of the exchange of antibiotic resistance are analyzed: the transfer of plasmids from Bacteroides fragilis to Escherichia coli and the emergence of antibiotic-resistant strains of STreptococcus pneumoniae. Plasmids encoding antibiotic resistance in B. fragilis were transferred to E. coli by DNA-mediated transformation and conjugation. The beta-lactamase in the transformants and transconjugants displayed the same substrate specificity and electrophoretic mobility as the donor strain. The plasmid apparently was integrated rapidly into the chromosome of the recipient strain. Multiple antibiotic-resistant strains of S. pneumoniae were analyzed for plasmids, and none were detected. Furthermore, no evidence of linkage between the traits of multiple antibiotic resistance was observed. beta-Lactamase was not detected in the penicillin-resistant strains; therefore, it is likely that the resistance in these strains was chromosomal rather than plasmid-mediated. The range of genetic exchange and the use of Koch's postulates in determining the genetic mechanism of antibiotic resistance are illustrated and discussed.

Teichoic acids of group D streptococci with special reference to strains from pig meningitis (Streptococcus suis).

Immunoelectrophoresis revealed in phenol extracts from S. faecalis and S. faecium a mixture of free and lipid-bound teichoic acids, both reactive with Group D antisera. In phenol extracts from S. suis only lipid-bound teichoic acid, also reactive with Group D antiserum, was seen. This difference probably accounts for the low yield of Group D antigen from S. suis as compared with S. faecalis and S. faecium when heating at pH 2 is used for extraction. When phenol is used good yields are obtained from S. suis as well as from S. faecalis and S. faecium. Lipoteichoic acids from S. faecalis and S. faecium have a backbone structure the same as or similar to that of Group A streptococcal teichoic acid. Lipoteichoic acid from S. suis has a structure differing from that of S. faecalis and S. faecium, e.g., possibly in the attachment of its glucosyl substituents. Precipitation reactions between S. suis lipoteichoic acid and Group D antisera were specifically inhibited by glucose. Reactions between S. bovis phenol extracts and some Group D antisera were also specifically inhibited by glucose, but extracts from S. faecalis and S. faecium were not. This may indicate a monosaccharide glucosyl substituent in teichoic acid from S. suis and S. bovis instead of the di- or trisaccharide previously postulated as the glucosyl substituent in the teichoic acid of S. faecalis.

Studies on the induction of petite mutants in yeast by analogues of berenil. Characterization of three mutants resistant to the compound Hoe 15,030.

Compound Hoe 15,030 is an analogue of berenil which is as effective as berenil in inducing petite mutants in Saccharomyces cerevisiae. Hoe 15,030 has greater stability than berenil in aqueous solution, and is less toxic to yeast at high drug concentrations. Mutants of S. cerevisiae strain J69-1B have been isolated which are resistant to the petite inducing effects of Hoe 15,030. Three mutant strains (HR7, HR8 and HR10) were characterized and each was shown to carry a recessive nuclear mutation determining resistance to Hoe 15,030. The degree of resistance to Hoe 15,030 is different for each mutant, and each was found to be co-ordinately cross-resistant both to berenil and to another analogue of berenil, Hoe 13,548. However, the three mutants show no cross-resistance to other unrelated petite inducing drugs, including ethidium bromide, euflavine and 1-methyl phenyl neutral red. Further studies on the mutants revealed that each strain exhibits characteristic new properties indicative of changes in mitochondrial membrane functions concerned with the replication (and probably also repair) of mitochondrial DNA. Thus, mutant HR7 is hypersensitive to petite induction by the detergent sodium dodecyl sulphate under conditions where the parent J69-1B is unaffected by this agent. Mutant HR8 is even more sensitive to sodium dodecyl sulphate than is HR7, and additionally shows a markedly elevated spontaneous petite frequency. Isolated mitochondria from strains HR8 and HR10 (but not HR7) show resistance to the inhibitory effects of Hoe 15,030 on the replication of mitochondrial DNA in vitro.

[Histologic-histochemical findings in the salivary glands of guinea pigs after sectioning the chorda tympani].

We investigated Gl. submandibularis and Gl. sublingualis of the guinea-pig 1, 2, 5, 7, 14 und 28 days after section of the Chorda tympani with histological-histochemical methods. The innervation pattern of both glands (Gl. submandibularis: aminergic-cholinergic double innervated; Gl. sublingualis: cholinergic innervated) remains unchanged. In the gland cells the following effects were observed: a) Gl. sublingualis. In the first 3 days apocrine and holocrine secretion phenomena are often seen, suggesting a maximal stimulation of the gland parenchyma. They are accompanied with cellular reactions of the interstitial space. In a second phase a new gland cell population appears that uniformly exhibits intracellular accumulation of secretion products. Involution begins from the 14th day on. Secretory cells are dedifferentiated to intercalated duct cells; autophagic processes help to degradate the accumulated secretion granules. b) Gl. submandibularis. Here the effects are less dramatic. The accumulation of the secretory granules starts as soon as 24 h after section of the Chorda and is maximal between the 5th and 8th p. o. day. Involution of the gland begins from the 14th day on. The accumulated secretory granules show high activities of two histochemically demonstrable enzymes, the cholinesterase and the peroxidase.

Airless paint gun injuries: an update.

The airless paint gun delivers paint at pressures approximating 3,000 psi. Paint accidently injected into the skin under this pressure causes a devastating injury which is a result of the paint material, the level of bacterial contamination, and the pressure at which the paint is delivered. The time interval between injury and treatment seems a critical determinant of outcome. Decompression of the closed vascular compartments of the hand must be begun immediately to release the underlying tissue distended by the injected paint. Judicious wound debridement must be performed. Immediate antibiotic treatment is indicated in all patients. Studies seem to indicate that steroids limit the severity of inflammatory response. A regimen of hydrocortisone sodium succinate, 100 mg IV, administered immediately before surgery should be followed by a seven-day tapering course of oral prednisone starting with 40 mg on the first postoperative day. Recent safety measures and consumer warnings through the Consumer Product Safety Commission may reduce the number of airless paint gun injuries.

[Anatomic and histologic studies of a Triatominae subfamily (Heteroptera, Reduviidae). Triatoma infestans' brain and its nerves].

To give a concrete aspect of structure, topography and function of the different nervous systems of the Triatominae, we begin this study with a description of the senso-motor system. As the first part we choose the study of the brain and its nerves. The external form of the brain is conditioned by the anatomy and morphology of the head. The brain is situated in the posterior part of the head beneath and behind the ocelli. It is characterized by the reduction of its longitudinal extension and, by this, the connectives between Syncerebrum and Gnathocerebrum are extremely short, but large, and the third commissure is included in the mass of the mandibular segment of the Gnatocerebrum. The optical masses are of the typical form, also the optical commissure. The Central Corps is volumous and is directly linked with the majority of the centres of the Protocerebrum and Deutocerebrum. The Pedunculated Corps has only one glomerulus that looks like a pedunculated mushroom without any signal of the formation of a calyx, found in ants and other more evoluted insects. Beneath the Central Corps, the extremities of the pedunculus disintegrate and form a number of claviform annexes like in the primitive Machilidae. The Deutocerebrum is characterized by volumous antennal centre, composed by numerous little glomeruli in peripheral situation. The Tritocerebrum is very reduced and has in its anterior part two very short frontal connectives and, by this, the frontal ganglion lies near the Tritocerebrum. The compact mass of the Gnathocerebrum shows its composition by three pairs of ganglions only by observation of series of preparations. With exception of the Lobi optici, 8 pair nerves and 3 impair nerves come from the brain: From the Protocerebrum: the nerves of the ocelli and the nerve of the Corpus allatum. From the Deutocerebrum: the nerves of the antennae and those of the pharynx. From the Tritocerebrum, the nerves of the labrum and, by the frontal ganglion, the Nervus recurrens and the nerve of pharyngeal muscles. From the Gnathocerebrum: the nerves of the amndibulae, maxillae, labium and of the salivary glands.

Cation-sugar cotransport in the melibiose transport system of Escherichia coli.

The entry of Na+ or H+ into cells of Escherichia coli via the melibiose transport system was stimulated by the addition of certain galactosides. The principal cell used in these studies (W3133) was a lactose transport negative strain of E. coli possessing an inducible melibiose transport system. Such cells were grown in the presence of melibiose, washed, and incubated in the presence of 25 microM Na+. The addition of thiomethylgalactoside (TMG) resulted in a fall in Na+ concentration in the incubation medium. No TMG-stimulated Na+ movement was observed in uninduced cells. In an alpha-galactosidase negative derivative of W3133 (RA11) a sugar-stimulated Na+ uptake was observed in melibiose-induced cells on the addition of melibiose, thiodigalactoside, methyl-alpha-galactoside, methyl-beta-galactoside, and galactose, but not lactose. It was inferred from these studies that the substrates of the melibiose system enter the cell on the melibiose carrier associated with the simultaneous entry of Na+ when this cation is present in the incubation medium. Extracellular pH was measured in unbuffered suspensions of induced cells in order to study proton movement across the membrane of cells exposed to different galactosides. In the absence of external Na+ or Li+ the addition of melibiose or methyl-alpha-galactoside resulted in marked alkalinization of the external medium (consistent with H+-sugar cotransport). On the other hand TMG, thiodigalactoside, and methyl-beta-galactoside gave no proton movement under these conditions. When Na+ was present, the addition of TMG or melibiose resulted in acidification of the medium. This observation is consistent with the view that the entry of Na+ with TMG or melibiose carries into the cell a positive charge (Na+) which provides the driving force for the diffusion of protons out of the cell. It is concluded that the melibiose carrier recognition of cations differs with different substrates.

Enhancement of macrophage adenylate cyclase by microtubule disrupting drugs.

The accumulation of cyclic adenosine 3',5'-monophosphate (cAMP) in guinea-pig macrophages exposed to the adenylate cyclase (AC) stimulators prostaglandin E1 (PGE1) and isoproterenol (IP), was markedly enhanced by pretreatment of the cells with colchicine, vinblastine, and podophyllotoxin--agents which prevent microtubule assembly. The same agents did not augment basal cAMP levels. The facilitating effect of the drugs on the response to PGE1 and IP developed both in the absence and presence of a phosphodiesterase (PDE) inhibitor. The same drugs also enhanced the accumulation of cAMP induced by cholera toxin (CT) but the presence of a PDE inhibitor was required for such enhancement to become evident. Pretreatment of macrophages with cytochalasin B, an agent interfering with microfilament function, had no effect on the responsiveness of the cells to AC stimulators. The microtubule stabilizer, deuterium oxide (D2O) partially reversed the colchicine effect. Microtubule disrupting drugs did not block the release of cAMP from the cells into the surrounding medium. Macrophages incubated as monolayers or in suspension showed the same degree of increased responsiveness to stimulators after preexposure to colchicine. Preincubation with the ionophore A23187, which elevates the intracellular concentration of Ca2+, also enhanced the stimulation of AC by PGE1 and IP. Microtubule disrupting agents did not potentiate AC activity in broken cell preparations, whether added to the intact cells before disruption or directly to the enzyme assay mixture, nor did they affect PDE activity of macrophage sonicates. Moderate enhancement of PGE1-induced cAMP formation was also seen in colchicine- and vinblastine-treated lymphocytes. It was concluded that microtubules control the activity of AC by restricting the mobility of membrane receptors. Disruption of microtubules by drugs results in the removal of such restraints and an augmented chance of productive interactions between receptors and catalytic units of AC.

Nonmechanical factors affecting aortocoronary vein graft flow.

To study aortocoronary vein graft flow, hemodynamic measurements were made in 17 patients with 22 grafts while on cardiopulmonary bypass during ventricular fibrillation and sinus rhythm and 15 minutes after termination of cardiopulmonary bypass. When compared with graft flow to the stable working heart, flow to the nonworking heart in sinus rhythm was reduced 50%. When fibrillating, the nonworking heart received 33% more flow than when in sinus rhythm but still significantly less flow than the working heart. All hemodynamic parameters measured, including flow in 12 grafts, remained stable between 15 minutes and 60 minutes following cardiopulmonary bypass. In contrast, heart rate and flow in 10 grafts fell within five minutes after 1 mg of propranolol was given intravenously. Although it was still reduced, heart rate had begun to rise 30 minutes after propranolol, but graft flow did not begin to return toward predrug control levels until over 60 minutes after drug administration. Further reduction in aortocoronary vein graft flow after heart rate had started to increase supports the possibility of a direct propranolol action reducing myocardial oxygen consumption in addition to its bradycardiac effect. This study shows the sensitivity of intraoperative vein graft flow to physiological and pharmacological factors and the need to standardize the technique and timing of flow measurements if their value for predicting long-term graft patency is to be determined.

An ultrastructural examination of the role of cell membrane surface coat material during neurulation.

Data from neural crest cultures indicate that cell surface coat material (CSM) is directly involved in cellular migration and events surrounding differentiation. To investigate whether the CSM also has a morphogenetic role, embryos of the amphibian Ambystoma maculatum were examined ultrastructurally throughout the stages of neurulation. Segments of the neural axis were fixed in glutaraldehyde-containing Alcian blue 8GX, which reportedly enhances preservation of CSM, and were postfixed in OsO4 containing 1 percent lanthanum nitrate, which stains the CSM. The medial groove formed by the appearance of the neural ridges contains a large amount of CSM and numerous vesicles coated with lanthanum-positive material. In contrast, the lateral ridge surfaces are covered by a small amount of uniformly distributed CSM and a paucity of vesicles. As the ridges begin to fold there is a progressive increase in the amount of CSM within the presumptive neural tube region. Further convergence of the neural folds is accompanied by an increase of CSM at their leading edges. As the folds approximate each other, lanthanum-positive material physically bridges the gap. However, as the apposing tissue actually abuts to form the neural tube, no CSM is observed in the remaining interspace. The specific distribution and sequential accumulation of cell CSM during the events of neurulation strongly suggest its direct participation in the morphogenetic process.

Normal and altered phenotypic expression of immunoglobulin genes.

Genetically controlled intraspecific differences between immunoglobulins (allotypes) provide valuable markers for the study of the quantitative expression of allelic and nonallelic alternative forms of immunoglobulins (Igs) during the normal development of rabbits. Heterozygous rabbits are mosaics of cells expressing different Ig-genes since fully differentiated productive cells generally secrete only one of alternative forms of Ig. The proportions of cells that differentiate to produce allelic forms of immunoglobulins during normal development depend on the particular heterozygous genotype. The normal proportions of some markers can be drastically altered if the differentiation of lymphoid cells in the young rabbit occurs in the milieu of antibody specific for one form (allotype suppression). An initiating step in the establishment of persistent allotype suppression is probably the interaction of antiallotype antibody with allotype-bearing receptors on lymphoid cell surfaces, but the mechanism for the maintenance of a state of chronic suppression may well be more complex. Allotype suppression can be viewed as one example of numerous immunological phenomena that reflect specific and finely tuned regulatory mechanisms governing the differentiation and clonal expansion of lymphoid cells destined to secrete immunoglobulins.

The instructional media: an overview.

The advantages of using audiovisual instructional techniques in training programs for nurses were noted and administrative strategies for encouraging the effective use of educational technology were provided. Audiovisual instructional techniques can enhance classroom learning, create opportunity for individualized learning programs, and can serve as an effective tool for monitoring and supervising clinical training. In the classroom situation, audiovisual techniques should be incorporated as a basic instructional tool and not simply used to occasionally supplement traditional learning techniques. The use of these tools can free the teacher for more personalized teaching tasks. Educational technology permits instructors to develop individualized learning programs for their students. Students can progress at their own pace and students can learn to manage their own learning process. Audiovisual tools can be used to monitor student-patient interactions. Supervisors can monitor the work of a larger number of students with these devices. These devices also permit students to reexamine and to judge their own performance. Administrations should not view educational technology as a way to reduce costs. Costs will not decline and may, at least initially, increase. Administrators should purchase equipment to fit the needs of the faculty and the students instead of expecting the faculty to develop programs suited to particular types of equipment. The faculty should be provided with assistance to learn how to operate the new equipment.

The variable fine structure of elastin visualized with Verhoeff's iron hematoxylin.

Verhoeff's iron hematoxylin (VIH) followed by lead citrate (LC) applied to epoxy thin sections stained the dense component of elastic fibers heavily and the peripheral microfibrillar component lightly in guinea pig trachea and mouse testis fixed with a glutaraldehyde-osmium tetroxide sequence. This method stained large fimbriated fibers beneath tracheal epithelium, small fibers and stacked aggregates thereof in the deep lamina propria, cartilage and adventitia of the trachea and large stacked fibers in the fibroelastic band of the trachea. Fibers of the fetus differed from those of the adult, especially in the subepithelial elastic lamina of the trachea. Elastic fibers were intimately associated with fibroblasts and particularly slender fibroblast processes in tracheal stroma and with chondrocytes in tracheal cartilage. Fibroblasts associated with elastic fibers in the tracheal subepithelial lamina propria were often closely bordered by eosinophils, mast cells, or monocytes. Occasional mast cells extended slender processes around elastic fibers in the subepithelial lamina propria. In mouse testis and in many regions of the trachea, small elastic fibers were identified which were below the limits of resolution for the light microscope and were not apparent at the ultrastructural level in routinely stained thin sections.

Biochemical estimation of the basic dye-binding capacity of RNA from rat hepatoma.

Areas of hyperplastic livers that acquire hyperbasophilic properties at advanced stages of carcinogenesis apparently represent the sites of neoplastic trasnformation, and hyperstaining of cytoplasmic RNA with basic dyes also characterizes the cancer cells. Estimations of the RNA content of cell fractions from normal rat liver and solid Novikoff hepatoma provided no evidence that the intense staining of cancer cells could be explained on the basis of an increase in cytoplasmic RNA content. The possibility that cytoplasmic fractions of Novikoff hepatoma show greater affinity for basic dyes than corresponding normal fractions has been examined by means of a test-tube toluidine blue-binding assay. The results revealed that the dye-binding capacity of total cytoplasmic fractions from tumors is 75% higher than normal after Carnoy fixation which retains mostly ribosomal RNA. Assays on fresh ribosomes indicated that tumor ribosomes bind 71% more toluidine blue per mg of RNA than the ribosomal preparation from normal liver. This study thus demonstrates a greater affinity of tumor RNA for basic dyes, and a comparison of biochemical and cytophotometric analyses suggests that an increase in basophilia by a factor OF ABOUT 2 WOULD BE DUE TO A qualitative alteration in robosomal RNA molecules and/or ribosome structure in cnacer cells.

Cortical evoked potentials elicited by real speech words and human sounds.

Averaged evoked potentials were recorded from PZ and left and right temporo-parietal electodes to real speech words and human sounds in 8 right-handed subjects. Stimuli were presented in a "no task" condition where the subject was instructed to listen attentively, and a vigilance condition where the subject responded to a particular word or sound during a run of such stimuli. The vigilance condition produced two classes of stimuli:signals and non-signals. Evoked potentials to physically identical words or sounds were examined when they were "no task", non-signal and signal stimuli. P300 amplitude increased significantly as a function of increasing task demands going from "no task" to non-signal to signal. When a strict statistical criterion for multiple comparisons (Bonferroni test) was applied in looking for asymmetries between hemispheres, only 2 isolated left greater than right differences turned out to be significant. Review of the literature concerning evoked potential correlates of differential hemispheric processing pointed up flaws in design, statistical technique, and inconsistencies in reported findings which suggested that while evoked potentials may sometimes reflect differences in hemispheric functioning, this effect is marginal at best.

A simulation study of the efficacy of stepwise discriminant analysis in the detection and comparison of event related potentials.

Cortical average evoked potentials were simulated by summing five damped sinusoids. The characteristics of these "evoked" responses could be manipulated by changing parameters of the sinusoids. The synthesized signals were mixed with noise processes whose power and band-width were manipulated. Thus data were generated to stimulate a variety of conditions which could conceivably occur in an experiment on evoked potentials. Stepwise discriminant analysis (BMD07M) has been applied to these simulated data in an attempt to determine the degree to which the program identifies, in a sensible manner, the differences we introduced into the synthesized evoked responses. The simulation results indicate that stepwise discriminant analysis can indeed be an efficacious tool in research on evoked potentials. The program does detect differences in evoked potentials. It can be used, with some reservations, to identify the components of an evoked potential which the experimental variables have affected. In a special set of simulations we have attempted to determine the degree to which stepwise discriminant analysis could serve to detect the presence or absence of an evoked potential. These simulations show that the score of an average evoked potential in the data. The implications of this finding to the use of evoked potentials in sensory sensitivity testing were evaluated in studies for the effect on them of stimulus intensity.

Morphological and functional identifications of catfish retinal neurons. II. Morphological identification.

In this study the morphological origins of the responses from the catfish retinal neurons evoked by step inputs were determined by injecting intracellularly a dye, Procion yellow. A method was devised to view the dye-injected neurons in flat mount to study their dendritic expansion; later the same neurons could be sectioned radially to locate the levels of their somata or dendritic expansion. The results of this study show the inherent danger of identifying dye-injected neurons only in a radial or tangential view. Bipolar cells could be identified functionally without any ambiguity by changing widely the stimulus parameters, because the stimulation of their receptive-field center and surround gave rise to responses of opposing polarity. We found no exception to this rule. The neurons in the proximal layers produced a large variety of responses which could not be segregated into two such classes as the amacrine and ganglion cells. In this part II they were classified into three broad categories: neurons giving rise to sustained, transient, and spiking responses. The demarcation among the three types, morphologywise and functionwise, was vague and not well established. The sustained responses were recoreded from the starburst and spaghetti neurons (part I (9)) which correspond to Ramón y Cajal's (2) amacrine cells. The transient responses, whose patterns were largely invariant of the changes in the stimulus parameters, were recorded from a class of neurons with spindle-shaped somata in the INL. We do not know whether they had axons or not, but we will not be surprised if a future study defines them as a class of ganglion cells. Responses with or without spike discharges were recorded from a class of neurons which were identified as ganglion cells. Observations made on a large number of Procion-injected neurons in both flat-mount preparations and radial sections show that finer dendritic arborizations were not seen in the dye-injected neurons although the presence of such branches was proved in the Golgi preparations. Probably this was due to the weak contrast of the Procion-injected cell against the tissue background, rather than the failure of the dye to diffuse into finer branches. We recognize the severe difficulty involved in the traditional approach of identifying a class of neurons based on typical but subjectively selected functional and structural samples. Neurons have to be classified statistically according to their (quantitative) parameters. (cont'd)

Hyperactive behavior and EEG arousal reactions in children.

EEG arousal reactions and parameters of spontaneous EEG activity were studied in two extreme groups of behavior problem children (11 hyperactives and 11 non-hyperactives), selected on the basis of a rating of motor restlessness the core symptom of the "hyperactivity syndrome". The EEG was recorded in three reaction time experiments: a tone light conditioning paradigm and two series with random stimulation. An automatic analysis of EEG parameters was employed to describe the time functions of alpha amplitudes in the single trial. The main findings are: 1. In periods free from stimulation, hyperactive children have higher alpha and beta amplitudes, more alpha waves and a smaller amount of beta waves. This indicates a lower state of EEG arousal in the hyperactives. 2. The amplitude reduction to tone (in the single trial) develops more slowly in the hyperactive group. This group difference increases over the experimental situations. 3. The arousal responses to tone, in terms of the level of maximum amplitude reduction, become comparably weaker in the hyperactives across the experiments. 4. Under all experimental conditions the hyperactives exhibit shorter arousal responses to the light stimulus than the non-hyperactive children. 5. Reaction time performance of the groups is clearly different, hyperactives showing the longer latencies. 6. Although conditional changes in the arousal reactions to both stimuli are reliably demonstrable in all children, the groups show no difference in the corresponding measures. These findings are discussed under the aspects of activation and of attention behavior of the subjects.

Hypertensive crisis, erythrocytosis, and uraemia due to renal-artery stenosis of kidney transplants.

Two patients with kidney transplants had hypertensive encephalopathy and rapidly progressive kidney failure 10 weeks and 18 months postoperatively. In one patient renal failure was associated with erythrocytosis. Absence of proteinuria, despite progressive renal insufficiency in both patients, suggested that these abnormalities were not due to rejection episodes. Subsequently, angiography proved that each of these patients had renal-artery stenosis. Surgical repair of this lesion increased creatinine clearance at least threefold, and the hypertension and erythrocytosis disappeared. Apparent "rejection" episodes in which there is no proteinuria should alert clinicians to the possiblity of renal-artery stenosis of the graft. Restoration of kidney function and amelioration of hypertension may follow revascularisation, even after many months of renal ischaemia producing severe uraemia.

Short-course chemotherapy in pulmonary tuberculosis. A controlled trial by the British Thoracic and Tuberculosis Association.

The results of short courses of chemotherapy using rifampicin plus isoniazid, supplemented for the first two months by streptomycin or ethambutol, in patients with newly diagnosed pulmonary tuberculosis, have been studied. 174 patients with little or no cavitation received six months chemotherapy. 1 (0.6%) failed to convert to culture negative during treatment and 5 (3%) relapsed in the twelve months after the end of treatment. In 177 patients with similar disease, twelve months chemotherapy was 100% effective in rendering the sputum culture negative and in preventing relapse in the six months after the end of treatment. 151 patients with more extensive cavitation received chemotherapy for nine months; this was 100% effective in sputum conversion and in preventing relapse in the nine months after the end of treatment. In 155 patients with similar disease, the eighteen-month regimen was uniformly successful in sputum conversion. The rifampicin plus isoniazed regimen was well tolerated, producing adverse effects which warranted withdrawal from the study in only 3.6% of patients. Comparison of ethambutol with streptomycin as a third drug given for the first eight weeks showed no significant difference in the rate of sputum conbersion nor in the incidence of relapse. Streptomycin produced significant adverse effects in 8% of patients whilst ethambutol caused none. Chemotherapy with rifampicin plus isoniazed for nine months, supplemented initially by ethambutol, is more acceptable than standard chemotherapy for eighteen months, is highly effective in sputum conversion, and has resulted in no relapses over a nine-month follow-up period. Further follow-up is being continued to confirm that relapse does not occur.

A new program for investigating adult human skeletal muscle grown aneurally in tissue culture.

With our new "explant-reexplanting" technique, abundant growth of mature human muscle in long-term tissue culture was achieved,and with the "sandwich" technique several histochemical reactions were obtained on serial cross sections of the cultured fibers. An advanced degree of maturation but lack of differentiation into reciprocally staining fiber-types was demonstrated. For electron-microscopic and electronmicroscopic-histochemical study, a method was developed in which the embedded fibers of greatest potential interest were identified by light microscopy and punched out by our specially-designed hollow drill. This selection procedure is critically important when the goal is to study in cultured diseased human muscle: (1) successive stages of development and (2) certain structural changes that often occur only in some fibers and only in certain regions of those fibers. The electronmicroscopic-histochemical appearance of developing cultured muscle fibers correlated well with the fresh-frozen light microscopic histochemical cross-sections and longitudinal whole preparations of similar fibers.

Histamine release during antigen inhalation in experimental asthma in dogs.

Histamine release after antigen inhalation was studied in 12 dogs sensitive to nematode antigens. In 19 experiments, histamine was detected in arterial plasma after antigen inhalation; its concentration was correlated with changes in airflow resistance of the respiratory system (Rrs) (per cent change above control equals 132.3 plus 250 log histamine concentration). Histamine was released from the lung and was not attributable to the concomitant hypoxia. In 6 dogs given aerosols of dilute antigen and in 4 dogs given aerosols of compound 48/80, Rrs increased significantly, but no histamine was detected. Histamine may have been released close to airway receptors, inducing bronchoconstriction, but in amounts undetectable in arterial plasma. In 6 dogs, administration of 48/80 caused partial depletion of histamine stores but prevented the response to antigen inhalation in only one of 6 dogs tested. The close correlation between arterial histamine concentration and Rrs, the qualitatively similar response to antigen and 48/80 aerosols, and the inhibition of the response to antigen when histamine was depleted completely from the lung tissues suggests that chemical mediators are critically important in antigen-induced airway reactions.

Electron microscopic observations of horseradish peroxidase transported from the caudoputamen to the substantia nigra in the rat: possible involvement of the agranular reticulum.

The intracellular distribution of horeseradish peroxidase (HRP) transported intraaxonally from the caudoputaminal complex to the substantia nigra has been examined with the electron microscope. The reciprocal axonal connections between the caudoputamen and the substantia nigra permitted observation not only of HRP transported retrogradely from axons and axon terminals in the caudoputamen to the cell bodies of origin in the pars compacta of the substantia nigra, but also provided information suggesting that HRP may be transported anterogradely by neurons of the caudoputamen to their terminals, which are especially numerous in the pars reticulata of the substantia nigra. Special attention was focused on observations which might elucidate the manner in which exogenous proteins are compartmentalized and transported intracellularly. It is suggested that the agranular reitculum is involved in the retrograde transport of proteins which are pinocytosed near the axon terminal and ultimately reach lysosomes in the perikaryon. A possible anterograde movement of HRP may also involve the agranular reticulum. The implications such findings have on the use of HRP in neuroanatomical tracing techniques are also discussed.

Pulmonary mycotoxicosis.

Mycotoxicosis is a term used to define a toxic reaction due to the ingestion of toxins produced by fungi. Oral ingestion, however, may not be the sole means of exposure. We have recently observed ten patients who had inhaled massive amounts of fungi, which resulted in an apparent toxic pulmonary reaction. Immunologic studies showed no sensitivity to various fungal antigen preparations and histologic study of the lung showed a multi-focal acute process, with primary involvement of the terminal bronchioles containing large numbers of various spores. Cultures from lung biopsy material revealed at least five fungal organisms. A one to ten year followup indicates that avoidance of massive reexposure to fungal dust is the key to the prevention of recurrent pulmonary mycotoxicosis.

Long-term results with the Björk-Shiley tilting disk valve in aortic valvular disease.

The construction of the Björk-Shiley prosthesis, with its nonoverlapping tilting disk, provides an optimal orifice area in relation to tissue diameter. The transprosthetic forward flow is central and mainly laminar. The resistance to blood flow remains low with increasing cardiac output during exercise, even when the smaller sizes of the prosthesis are used for implantation in narrow aortic roots. Mechanical crushing of erythrocytes is minimized by the nonoverlapping closing mechanism, and the resulting regurgitation is negligible. The in vivo durability of the prosthesis is excellent and thromboembolism does not occur as long as dicoumarol treatment is effective. In aortic valvular disease, an effective unloading of the left ventricle was obtained at rest and during exercise after aortic valve replacement. The resulting hemodynamic improvement correlated with a reduction in cardiomegaly, increase in physical working capacity and relief of distressing symptoms. Clinical improvement was maintained for up to five years.

The distribution of the alpha type of ganglion cells in the cat's retina.

There is a distinct class of large ganglion cell bodies observable in whole-mount preparations of the cat's retina stained with cresyl violet. Measurements of perikaryal size and its variation with eccentricity from the central area support the identification of the large cells with the class of alpha cells previously defined in Golgi-stained preparations. A complete enumeration of alpha cells in one retina yielded a total of 6212. They were encountered in all parts of the retina and had a peak density within the central area ( 200/mm2). The retinal distribution was displayed as a contour map of alpha-cell density. Away from the central area, the lines of iso-density had the form of a 4-pointed star with rather blunt points corresponding to horizontal and vertical ridges of augmented density. Along horizontal, vertical and oblique strips through the central area, alpha-cell density was an approximately constant fraction of total ganglion cell-density. The average value of the fraction was 3.3% from which it has been calculated that the cat's retina may contain as many as 190,000 ganglion cells.

The release of four mediators of immediate hypersensitivity from human leukemic basophils.

The availability of a patient with basophilic leukemia manifesting 75 to 90% mature basophils permitted the use of a cell concentration sufficient to generate and release mediators upon interaction with a calcium ionophore in quantities adequate for their physiocochemical characterization. The mediators were defined in terms of their physicochemical characteristics: slow reacting substance of anaphylaxis (SRS-A) by purification through silicic acid chromatography and inactivation by arylsulfatase; eosinophil chemotactic factor of anaphylaxis (ECF-A) by its gel filtration through Sephadex G-25 and inactivation by subtilisin and not trypsin; and platelet-activating factor (PAF) by its inherent binding to albumin. Both ECF-A and histamine were present in their preformed state, and for histamine it was possible to establish that the concentration per cell was comparable to that of normal human basophils. Dibutyryl cyclic AMP suppressed release of histamine and SRS-A, indicating that their availability was under a control similar to that observed with normal cells subjected to immunologic activation. The demonstration that a suspension of leukemic human basophils contained the preformed mediators, histamine and ECF-A, and generated SRS-A and PAF for release along with histamine and ECF-A, after activation with a calcium ionophore, establishes that a single cell type can serve as a source of the four recognized mediators of immediate-type hypersensitivity.

Suppression of reaginic antibody formation. II. The use of adoptive transfer system for the study of immunological unresponsiveness.

By the use of the adoptive transfer system in syngeneic mice it was demonstrated that: i) spleen cells of animals tolerized by the i.v. injection of DNP8-MgammaG 1 month before adoptive transfer into x-irradiated recipients remained unresponsive when further challenged with the sensitizing antigen (DNP2.3-OA administered i.p. with Al (OH)3); by contrast, a significant response (typical of a secondary response) was obtained in recipients of cells from mice which had received only the sensitized antigen; ii) the anti-hapten IgE secondary response of primed cells was not affected by the presence of cells of tolerized mice when these two types of cells were administered and challenged together in x-irradiated recipients; iii) the transfer of spleen cells or serum of mice, tolerized 20 days before harvesting, into intact syngeneic recipients did not interfere with the normal development of the anti-DNP IgE response of the latter; iv) the anti-hapten responses of tolerized animals receiving spleen cells from normal or primed mice together with the sensitizing antigen resulted, respectively, in a primary or secondary response; (v) the unresponsive state of tolerized cells, achievkd by immunosuppression of the original donors with respect to the haptenic determinant, was maintained even after two serial exposures of the cells to the immunizing antigen in two consecutive adoptive cell transfers into x-irradiated recipients. These findings provide a strong basis for the interpretation that the hapten-specific tolerace induced in mice by treatment with DNP8-MphiG involved the elimination or inactivation of hapten-specific IgE-producing cells or the blockade of the receptors of these cells.

Complement-mediated alteration of antibody specificity in vivo.

The simultaneous injection of heterologous anti-EL4 lymphoma serum and complement results in the rapid disappearance of such antibody from the periphery of non-tumor bearing mice. However, this phenomenon is only observed when a complement source capable of mediating the lysis of EL4 cells sensitized with such heterologous antibody is used. This complement mediated enhancement of anti-tumor antibody absorption was observed in vivo for three strains of mice. Omission of complement or the use of genetically deficient complement sources resulted in no effect on circulating antibody titer when compared to the titer of heterologous anti-tumor antibody observed in the periphery when injected alone. Exogenous complement did not enhance the clearance of heterologous anti-tetanus toxin serum, thereby suggesting that the increased absorption of anti-EL4 in vivo is not related simply to the enhanced clearance of foreign gamma-globulin. Confirmatory evidence of the role of complement in altering anti-tumor antibody specificity in vivo was obtained in a guinea pig tumor model as well. The data suggest that anti-tumor serum shown to be relatively specific for the tumor cell gains additional specificity in the presence of functional complement and consequently manifests avidity for cross-reactive determinants previously thought to be unrelated.

Suppression of the immune response by alpha-fetoprotein on the primary and secondary antibody response.

Mouse amniotic fluid was shown to contain a noncytotoxic inhibitor of primary gammaM and secondary gammaM, gammaG subclass splenic plaque forming cells in vitro to SRBC. The suppressive effect was not abolished by exhaustive dialysis or by absorption of mouse amniotic fluid (MAF) with SRBC. Polyacrylamide gel analysis showed that dialyzed MAF was composed of three major protein components, transferrin, albumin, and alpha-fetoprotein (AFP). The selective removal of each of these patients from MAF by affinity chromatography suggested that AFP was the immunosuppressive substance in MAF. This conclusion was verified by the demonstration that pure AFP suppressed in vitro antibody synthesis in microgram quantities whereas equivalent amounts of normal mouse serum, transferrin, or albumin did not. Dose-response studies showed that the effect of AFP in the isolated form was equivalent to the suppressive effect of comparable amounts of AFP in MAF. gammaA and gammaG plaque-forming cell (PFC) responses were suppressed by a significantly lower concentration of AFP than was the gammaM PFC response. The degree of suppression watration of AFP than was the gammaM PFC response. The degree of suppression was dependent on the time at which AFP was added to the cultures; MAF added to antigen-stimulated cultures up to 24 h after initiation of cultures was immunosuppressive whereas similar additions of MAF at 48 h after initiation or later did not suppress. The duration of exposure of spleen cells to MAF in cultures without antigen necessary to achieve suppression of a subsequent primary immune response was determine-d to be approximately 8 h. The results suggest that AFP may have an immunoregulatry function. This has potentially important implications in the maternal-fetal relationship, the immune capabilities of the fetus and newborn, and in certain malignant and nonmalignant diseases in which AFP is elevated.

Binding properties of avian myeloblastosis virus DNA polymerases to nucleic acid affinity columns.

A new method for the analysis and purification of the RNA-directed DNA polymerase of RNA tumor viruses has been developed. This nucleic acid affinity chromatography system utilizes an immobilized oligo (dT) moiety annealed with poly (A). The alpha and alphabeta DNA polymerases of avain myeloblastosis virus bound effectively to poly (A) oligo (dT)-cellulose. Alpha DNA polymerase did not bind effectively to poly (A) oligo (dT)-cellulose, poly (A)-cellulose, or to cellulose. Alphabeta bound to oligo (dT)-cellulose and cellulose at the same extent (approximately 30%), indicating that this enzyme did not bind specifically to the oligo (DT) moiety only. However, alphabeta bound to poly (A)-cellulose two to three times better than to cellulose itself, showing that alphabeta could bind to poly (A) without a primer. Alphabeta DNA polymerase also bound to poly (C)-cellulose, whereas alpha did not. These data show that the alpha DNA polymerase is defective in binding to nucleic acids if the beta subunit is not present. Data is presented which demonstrates that the alphabeta DNA polymerase bound tighter to poly (A). oligo (DT)-cellulose and to calf thymus DNA-cellulose than the alpha DNA polymerase, suggesting that the beta subunit or, at least part of it is responsible for this tighter binding. In addition, alphabeta DNA polymerase is able to reversibly transcribe avian myeloblastosis virus 70S RNA approximately fivefold faster than alpha DNA polymerase in the presence of Mg2+ and equally efficient in the presence of Mn2+. alpha DNA polymerase transcribed 9S globin m RNA slightly better than alphabeta with either metal ion.

New approach to management of intracranial aneurysms.

In six cases an attempt was made to relieve the tension on intracranial aneurysms by temporarily clamping the internal carotid artery in the neck, so as to increase the expansibility of the artery. This approach was based on the concept (or "A principle") that haemorrhage is caused by the aneurysm having to bear the full force of systolic pulse pressure when atherosclerosis prevents this pressure being taken up by the normally expansile arterial wall. Follow-up has been fairly short, but the preliminary findings in four of the six patients are encouraging. More attention must be paid in the future to the significance of atherosclerosis in the onset of bleeding from intracranial aneurysms and the incidence of postoperative problems. The argument that atherosclerosis permits the transmission of the systolic pulse directly to the aneurysm wall requires further investigation. The earlier pathological signs of atherosclerosis must receive greater attention, and post-mortem study of the walls of arteries in immediate juxtaposition to aneurysms with high-powered magnification is required.

Minor calyces as primary pacemaker sites for ureteral activity in man.

In isolated preparations of human upper-urinary-tract muscle in the organ-bath, calyceal and subcalyceal areas behave differently. Minor calyx preparations invariably exhibit immediate and extremely regular rhythmical contractions, in direct contrast to preparations of major calyx/pelvis which remain completely quiescent. Specimens of ureter do contract spontaneously but only after periods up to 1 hour. Smooth muscle of the minor calyces possesses excitatory alpha-adrenoceptors, as does that of the remainder of the upper urinary tract; but sensitivity of the minor calyx to alpha-adrenoceptor agonists is far greater than that of preparations from any other site. Furthermore, stimulation of intrinsic nerves can modify activity of the isolated minor calyx, whereas no such effect is observed in any area distal to the minor calyces. These physiological and pharmacological properties of the most proximal areas, considered together with the finding of structurally specialised smooth-muscle cells in this area, form the basis of a hypothesis at that minor calyces in multicalyceal kidneys act as a primary pacemaker sites.

Diogenes syndrome. A clinical study of gross neglect in old age.

A study of elderly patients (fourteen men, sixteen women) who were admitted to hospital with acute illness and extreme self-neglect revealed common features which might be called Diogenes syndrome. All had dirty, untidy homes and a filthy personal appearance about which they showed no shame. Hoarding of rubbish (syllogomania) was sometimes seen. All except two lived alone, but poverty and poor housing standards were not a serious problem. All were known to the social-services departments and a third had persistently refused offers of help. An acute presentation with falls or collapse was common, and several physical diagnoses could be made. Multiple deficiency states were found--including iron, folate, vitamin B12, vitamin C, calcium and vitamin D, serum proteins and albumin, water, and potassium. The mortality, especially for women, was high (46%); most of the survivors responded well and were discharged. Half showed no evidence of psychiatric disorder and possessed higher than average intelligence. Many had led successful professional and business lives, with good family backgrounds and upbringing. Personality characteristics showed them to tend to be aloff, suspicious, emotionally labile, aggressive, group-dependent, and reality-distorting individuals. It is suggested that this syndrome may be a reaction late in life to stress in a certain type of personality.

Cytological differentiation of asymptomatic pancreatic islet cell tumours in autopsy material.

In eleven cases thirteen pancreatic islet cell adenomas were found in autopsy material from 1366 adult cases. Ten of the adenomas were solitary, while 3 small adenomas were observed in a single case. Another four possible solitary adenomas were observed, but their identity was uncertain owing to marked fibrosis. All the adenomas contained A-2 (A)-1 cells but no B (B)-1 cells. Nine of them also contained A-1 (D)-1 cells. The majority of cells in the adenomas were A-2 cells or cells which did not stain with any of the techniques used. The 4 possible adenomas contained islet cells (A-1, A-2, B) in different proportions. With one exception the patients with adenomas and possible adenomas were 65 years of age or older, and in some of these cases adenomas or hyperplasias were also found in other endocrine organs. The frequency of gastroduodenal ulcers or scars in the cases with adenoma or possible adenoma did not differ notably from that found in the cases without pancreatic adenomas. Among the cases with pancreatic adenoma and possible adenoma there were 3 patients with maturity onset diabetes mellitus, but otherwise no clinical symptoms of endocrine disturbances were noted.

A reassessment of the distribution of multiple sclerosis. Part one.

When reviewed some 10 years ago, available prevalence studies of multiple sclerosis (MS) seemed to divide the world into three frequency zones for MS: high prevalence at 30 to 60 per 100,000 population; medium at 5 to 15; and low at less than 5 per 100,000. In the last decade the number of the available studies has more than tripled. Their reassessment, including judgments of comparability, still indicates a high-medium-low division of MS frequency world-wide. The risk areas comprise northern Europe, northern United States, much of southern Canada, New Zealand, and probably southern Australia. Prevalence rates in these regions are mostly 30 to 80 per 100,000 population, centering at about 50. Medium frequency is defined as prevalence of 5 to 25, and is mostly 10 to 15. In Europe, the medium frequency zone bounds that of high frequency to the north, east, and south. The European Mediterranean basin is of medium prevalence with a sharp division from the high zone across France and Switzerland. It is likely that this division continues eastward across Austria, north of Hungary, and across the upper Ukraine to the Caspien Sea, but this is not definite. Medium risk areas of Europe thus include surveyed sites of Spain, Italy, Hungary, Jugoslavia, Bulgaria, and central Ukraine, together with southeastern France and southern Switzerland. Though Romania could be high, it is more likely to be of medium prevalence. Turkey measures low, but from incomplete data. From nationwide prevalence and mortality studies, the west coast of Norway and all Scandinavia above latitude 65 degrees north are of medium frequency. Based on hospital data, northwestern USSR is high, and central and southern USSR medium, in MS risk. Other medium risk areas include southern United States, most of Australia, one ethnic group only in South Africs, and possibly Hawaii. Low risk areas are allsurveyed sites of Asia, the Pacific islands, Africa, Latin America, Alaska, and Greenland.

Incidence and description of accelerated ventricular rhythm complicating acute myocardial infarction.

One hundred and nineteen episodes of accelerated ventricular rhythm (less than 125/min) were noted in 37 patinets with acute myocardial infarction during a 1 year period. The incidence was 12.7 per cent. Twenty-seven episodes of fast ventricular tachycardia (less than 125/min) were noted in 16 of these patients. Eighteen patients had anterior myocardial infarction and 19 inferior myocardial infarction. The mechanism of onset of accelerated ventricular rhythm was classified as escape in 65 episodes. Ventricular premature beats were noted close to episodes of accelerated ventricular rhythm in 31 patients and fast ventricular tachycardia in 14 patients. The morphology of accelerated ventricular rhythm was similar to the ventricular premature beats in 27 patients and similar to the fast ventricular tachycardia in 12. In 11 patinets the morphology of ventricular premature beats, accelerated ventricular rhythm and fast ventricular tachycardia were all the same. In six patients the coupling time of the ventricular premature beats and the onset of the accelerated ventricular rhythm were the same. In seven patients the morphology of the accelerated ventricular rhythm and fast ventricular tachycardia were the same, and the rate of the accelerated ventricular rhythm was exactly half that of the fast ventricular tachycardia. There were three deaths due to shock and heart failure. Three episodes of fast ventricular tachycardia progressed to ventricular fibrillation and were successfully cardioverted. It is concluded that accelerated ventricular rhythm and fast ventricular tachycardia were all the same. In six patients the coupling time of the ventricular premature beats and the onset of the accelerated ventricular rhythm were the same. In seven patients the morphology of the accelerated ventricular rhythm and fast ventricular tachycardia were the same, and the rate of the accelerated ventricular rhythm was exactly half that of the fast ventricular tachycardia. There were three deaths due to shock and heart failure. Three episodes of fast ventricular tachycardia progressed to ventricular fibrillation and were successfully cardioverted. It is concluded that accelerated ventricular rhythm is a relatively common complication of both anterior and inferior myocardial infarction. The high incidence of concomitant fast ventricular tachycardia, the frequency of ventricular premature beats with similar morphology and coupling time, and the instances of two arrhythmias having common rate multiples, suggest that at least in some instances accelerated ventricular rhythm may represent an ectopic focus with exit block.

Myocardial conduction defects in association with compression of the umbilical cord. Experimental observations on fetal baboons.

Experiments have been performed in 16 pregnant baboons to study in greater detail the fetal hemodynamics, heart rate, and acid-base changes during occlusion of the umbilical cord. A total of 32 observations were made during which the umbilical cord was completely occluded with the fetus intact in utero; 11 were made after the intravenous administration of atropine, 0.01 to 0.02 mg. per kilogram, to fetus. Various degrees of conduction defects occurred in 17 of 21 observations before atropine. Complete atrioventricular block with extrasystoles was seen six times. Upon release of cord occlusion, there was a rapid recovery of myocardial conduction. Atropine prevented myocardial conduction defects; bradycardia was less and the onset was delayed. These observations suggest that myocardial conduction defects which occur during the course of cord occlusion are due to parasynpathetic stimulation. They could also be due to an increased sensitivity of the fetal myocardium to acetylcholine under hypoxic conditions. No recommendation can be made at the present time with regard to the administration of atropine to the fetus when cord compression is suspected on clinical grounds.

Repeated oral administration of coumaphos in sheep: interactions of coumaphos with bishydroxycoumarin, trichlorfon, and phenobarbital sodium.

Interactions between treatments with coumaphos, bishydroxycoumarin (an anticoagulane), trichlorfon (an organophosphorous compound), and phenobarbital sodium (an inducer of microsomal enzymes) were investigated in sheep. A daily dose of 2 mg of coumaphos/kg of body weight for 6 days did not affect the plasma enzymes or the antiprothrombinemic effect of bishydroxy-coumarin in wethers. The treatment of ewes with an intravenous (IV) injection of trichlorfon, insufficient to produce significant inhibition of erythrocyte acetylcholinesterase (AChE) activity, appeared to produce additive effects with those produced by subsequent treatment with 4 mg of coumaphos/kg/day. In ewes given 40 mg of phenobarbital sodium/kg for 5 days intraperitoneally (IP), the anticholinesterase effect of 4 mg of coumaphos/kg was significantly reduced and signs of toxicity were not present. Treatment with daily doses of 2 mg of coumaphos/kg for 6 days did not modify the anticholinesterase effect of a 2nd series of treatments given 6 weeks later.

Hormonal regulation of the hepatic messenger RNA levels for alpha2u globulin.

The messenger RNA rat alpha2u globulin has been identified and quantitated in a cell-free translational system derived from Krebs II ascites cells. Hepatic tissue of the mature male rats which normally produce alpha2u globulin was also found to contain a high level of alpha2u mRNA. Approximately 1.6 per cent of all poly(A) containing RNA of the adult male rat liver could be accounted for alpha2u messenger activity. Female rats do not produce alpha2u globulin and no alpha2u mRNA activity could be detected in the poly(A) containing RNA fraction obtained from the livers of these animals. However, androgen treatment to spayed female rats was found to induce the parallel appearance to both alpha2u globulin and its corresponding mRNA. Both hypophysectomy and adrenalectomy which are known to reduce the level of alpha2u globulin in the urine of male rats were found also to reduce the hepatic level of alpha2u mRNA. The results indicate that hormonal control of alpha2u globulin synthesis in rat liver is achieved primarily through regulation of its translatable mRNA level and that more than one hormone may participate in this regulation.

Slow axonal transport or proteins; blockade by interruption of contact between cell body and axon.

The influence of ligation and colchicine treatment on the axonal transport of slowly migrating [3H]leucine-labelled proteins was studied in the vagus nerve of the rabbit. Two days after [3H]leucine labelling of the dorsal motor nucleus of the vagus nerve, ligation or local application of 60 mM colchicine immediately blocked the further progression of slowly migrating proteins distal to the site of treatment. Application of 50-100 mug colchicine to the nerve cell bodies 2 days after labelling blocked the transport of slowly migrating proteins within the next 24 h. It is suggested that contact between nerve cell body and the axon is necessary for the maintenance of the slow transport of proteins in these nerves.

Pepstatin, an inhibitor of leukokinin formation and ascitic fluid accumulation.

Ascites fluid accumulation accompanying a mastocytoma or L1210 murine tumor is significantly retarded following the i.p. or s.c. injection of moderate quantities of pepstatin, a known acid protease inhibitor. No effect on cell count was noted by pepstatin treatment. The probable mechanism by which pepstatin acts is by inhigiting the enzymatic formation of chemical mediators known as leukokinins. These are pharmoacologically active peptiedes having potent permeability characteristics previously described by this laboratory. Leukokinins are formed by cathepsin D-like enzymes present in the invading cells and in the ascites fluid acting on a protein substrate, leukokininogen. present in the ascites fluid. Pestatin inhibits the action of these leukokinin-forming enzymes invitro but has no effect on kallikreins (bradykinin-forming enzymes) in vitro. Human ascites fluid from a patient with ovarian carcioma was found to have a paepstatin-inhibited, leukokinin-generating system, as does the mouse. A 'chemical mediator' theory is proposed for ascites fromation which broadens the previously held theory of lymphatic blockage (Holm-Nielsen) and may explain the recent findings of Hirabayashi and Graham of increased plasma-ascites exchange in peritoneal carcionmatosis. Pepstatin inhibition of chemical mediator formation may represent a new therapeutic approach to ascites fluid accumulation in neoplastic disease.

Three variants of concealed bigeminy.

Long electrocardiographic strips were analyzed from five patients who exhibited periods of typical "concealed bigeminy," i. e., recurrent unifocal extrasystoles which were separated from one another by odd numbers of normally conducted sinus beats. However, in each of these patients, there were periods in which one of three different variants of concealed bigeminy was observed. Three patients displayed an "even number" variant; i. e., there were large numbers of consecutive extrasystoles which were separated exclusively or preponderantly by even rather than by odd numbers of sinus beats. One other patient exhibited an "interpolated extrasystole" variant: those interectopic intervals which were initiated by an interpolated extrasystole contained an even number of sinus beats, whereas all other interectopic intervals contained an odd number. In the fifth patient, the distribution of the numbers of sinus beats separating extrasystoles was such as to suggest a periodic fluctuation between the classical forms of concealed bigeminy and concealed trigeminy; i. e., a "combined bigeminy and trigeminy" variant.

Effect of hippocampectomy on sleep patterns in cats.

The study was planned to see if the hippocampus has an influence on fast wave sleep (FWS) as well as on slow wave sleep (SWS). From 8 male cats EEG, EMG and EOG were recorded for 24 h, first under normal conditions, secondly after cortical damage to the dorsal marginal portion of posterior ectosylvian gyrus, and thirdly following hippocampectomy done through the cortical damage. From the records, SWS, FWS and the sleep state (defined as a sequence of SWS or SWS-FWS phases between two successive waking states) were measured in terms of their occurrence, the mean duration and the total time they occupied in the day, night and 24 h. In addition, sleep sequences were classified according to the number of constituent sleep phases. Cortical damage did not affect SWS, FWS, or sleep state with regard to their occurrence, the mean duration, and the total time they occupied in 24 h. Nor did it affect the proportion of short and long sequences. The circadian variation of sleep was clearly retained. Hippocampectomy significantly reduced the total time occupied by sleep state, SWS and FWS, increased the occurrence of sleep state and SWS phase against decreased incidence of FWS phase, and reduced the mean duration of sleep state and SWS phase. Hippocampectomy also significantly increased the occurrence of sleep sequences with only one SWS phase at the cost of sequences with alternating SWS and FWS phases. Following hippocampectomy, the circadian variation of sleep was not only retained, but actually exagerated. The hippocampus in inferred to facilitate the FWS as well as the SWS phase of sleep.

Motor potentials and the timing of muscular activity.

The purpose of this study was to determine whether dominant components of the motor potential recorded from the scalp, were coincident with the rise and fall of muscular activity in single movements and return movements in serial flexion and extension of the elbow. Electroencephalographic recordings obtained from two right-handed subjects through scalp electrodes were averaged by computer and related to EMG, force and displacement of the limb. In the single movements, coincident events in the motor potential indicated the rise and fall of EMG and force. Events in the motor potential of the return movement coincided with the rise of EMG and of force in the first phase, and the rise of EMG in the second phase. Other time relationships were not clear. Relationships between events were clearer in one subject than in the other. This could have been caused by different characteristics in the performance of the task or by problems related to the location of scalp electrodes. The general waveform of the motor potentials and the EMG traces seemed to be related in a few samples of the single movement task, suggesting that other factors than time may also be related between the motor potential and the EMG.

Effects of procaine hydrochloride, diazepam, and diphenylhydantoin on seizure development in cortical and subcortical structures in rats.

Procaine HCl and diphenylhydantoin (DPH) increased the duration and propagation of epileptiform afterdischarges (ADs) produced by electrical stimulation of the amygdala in rats. Procaine and DPH also increased the rate of seizure development (kindling) produced by repeated stimulation of the amygdala. Procaine and to a limited extentDPH would themselves act as convulsants in well kindled subjects. Diazepam, on the other hand, retarded or blocked amygdaloid kindling. Diazepam trigered a high frequency (20-30 c/sec) rhtthm in the amygdala, hippocampus and preoptic area. None of these drugs had any significant effect on potentials evoked in secondary limbic sites by single electrical pulses applied to the amygdala. Also, none of these drugs had any effect on recruiting or post-tetanic potentiation (PTP) in secondary sites produced by amygdala stimulation and none of the drugs had any effect on amygdaloid AD thresholds. The effects of these drugs on the responses evoked by anterior neocortex stimulation were quite different. Diazepam had no effect on any of the characteristics of the discharge or convulsion even at twice the dose levels used for the amygdala group. Procaine and DPH, however, blocked not only the eonvulsion but the AD as well. Eighty percent of the procaine- and DPH-treated rats failed to respond with neocortical AD even at current levels as high as 2000 muA. The few cortically stimulated subjects that did respond with an AD showed a subcortical rather than a neocortical seizure response. DPH had no effect on recruiting or PTP of the transcallosal response. Both procaine and DPH produced a weak but significant increase in the amplitude of the transcallosal evoked potential, while diazepam produce a weak decrement in that response.

EEG correlates of visual-motor practice in man.

Special analysis of EEG signals was performed for 15 subjects engaged in three motor tasks of differing difficulty. A measure of average weighted coherence (C) was computed between the six possible combinations of four scalp areas: Oz, C3, C4 and Fz. In all subjects, regardless of task, scalp recordings over cortical areas known to have relatively dense fiber connections had significantly greater C values. However, the effects of task difficulty and practice were superimposed upon this basic pattern. Thus, the most difficult task (pursuit-rotor tracking) resulted in the highest coherence levels, while the least difficult task (visual tracking only of the pursuit-rotor disk) resulted in the lowest coherence levels. Practice, on the other hand, was associated with a significant decrease in overall level of coherence. This decrease is consistent with an interpretation of reduced task difficulty due to visual-motor learning. The results of the present study suggest that patterns of scalp EEG coherence may reflect some aspects of the underlying pattern of anatomical pathways, as well as the more dynamic properties of task difficulty and visual--motor practice.

Attachment and ingestion of gonococci human neutrophils.

Previous studies have indirectly shown that type 1 gonococci are more resistant to phagocytosis by human neutrophils (PMN) than type 3 gonococci. Using phase contrast, fluorescent, and light microscopy, we directly quantitated PMN-gonococcal interaction, with emphasis on separating ingestion from attachment. PMN monolayers were incubated on slides with type 1 or type 3 gonococcal fluorescent antibody (FA). After methanol fixation, the FA-stained gonococci associated with PMN were cointed. Since the live PMN excludes FA, the FA-stained gonococci represent only extracellular gonococci. Methylene blue was then added to the smae slide to stain both ingested and surface attached gonococci. Using these methods, intracellular and extracellular cell-associated gonococci were quantitated under varying conditions. The numbers of methylene blue-stained cell-associated gonococci that were ingested were: with normal serum, 3.7 plus or minus 4.1 per cent for type 1 and 56.2 plus or minus 3.7 percent for type 3 (P smaller than 0.001); with heat-inactivated serum, 1.0 plus or minus 3.0 per cent for type 1 and 52.6 plus or minus 3.7 per cent for type 3 (P smaller than 0.001); with higher-titer anti-gonococcal antibody serum, 4.8 plus or minus 4.3 percent for type 1 and 64.0 plus or minus 1.6 per cent for type 3 (P smaller than 0.001). Thus, most type 3 organisms were ingested, but most type 1 gonococci were bound on the PMN surface.

Observations on rabbit thymocytes and peripheral T cells. I. Anomalous results in the mixed antiglobulin reaction caused by non-specific adsorption of sheep immunoglobulin.

The "single-stage" mixed antiglobulin reaction (MAR) was carried out with rabbit thymocytes. This test involved treating the cells with either sheep or goat anti-rabbit globulin sera, and subsequently reacting them with indicator erythrocytes coated with rabbit immunoglobulin (Ig) so as to form rosettes. An unexpectedly high number (up to 38%) of thymocytes reacted, although the rosettes were weaker than those given by peripheral B lymphocytes. When blood and lymph node lymphocytes or thymus cells which had already been treated with sheep anti-rabbit globulin serum were subsequently exposed to rabbit anti-sheep Ig serum and then rosetted with indicator cells coated with ox Ig (cross-reacts with sheep Ig) almost 100% reaction was obtained in each of the cell suspensions. This was designated the "two-stage" MAR. The anomalous results, both in the one-stage and two-stage MAR, were abolished by pepsin-treating the sheep anti-rabbit globulin serum; thus indicating that sheep Ig is adsorbed non-specifically via the Fc part of the molecules to the surface of rabbit thymocytes and peripheral T lymphocytes.