bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of Active Hexose and Amino Acid Transport by Conjugated Bile Salts in Rat Ileum*
Authors: Caspary W.F. 
Published: March 2008

Abstract. The effect of conjugated trihydroxy bile salts, tauro‐ and glycocholate, and of deoxycholate on tissue uptake and mucosal to serosal transfer of actively transported hex‐oses and amino acids has been examined in rat small intestine in vitro.Conjugated trihydroxy bile salts and deoxycholate markedly inhibited active transport of hexoses and amino acids in the ileum of rat small intestine, whereas in the jejunum, deoxycholate alone was inhibitory. The inhibitory effect of tauro‐ and glycocholate increased with incubation time. It persisted after washing of the tissue and reincubation with hexoses in a bile salt free medium, and could be observed with only 2 × 10‐4 M taurocholate. Taurocholate was able to evoke an increase of transmural potential difference (PD) in the ileum, but did not affect PD in the jejunum. Prein cubation of ileal small intestine with taurocholate depressed subsequent glucose‐induced PD‐increments. In the jejunum, however, taurocholate did not affect PD‐increments induced by D‐glucose.It is concluded that conjugated trihydroxy bile salts have to enter intestinal mucosal epithelial cells to an appreciable extent in order to affect other active, energy‐requiring transport systems in rat small intestine. Previous results showing a failure of conjugated bile salts to inhibit active transport of hexoses and amino acids are explained by the fact that only jejunal transport had been examined.
Isozymes of Aspartate Aminotransferase in Rat Liver during Acute Uraemia
Authors: Maier K. P. , Herz E. , Herz G. , Hoppe‐Seyler G. , Talke H. , Frohlich J. , Schollmeyer P. , Gerok W. 
Published: March 2008

Abstract. Total activity of aspartate‐aminotransferase (GOT; EC 2.6.1.1) and activities of the cytoplasmic (c‐GOT) and mitochondrial (m‐GOT) isozymes were measured in rat liver 24 and 48 h after bilateral nephrectomy.24 h after nephrectomy no significant differences in enzyme activities could be detected between uraemic animals and sham‐operated controls. However 48 h after nephthrectomy the total activity of GOT increased significantly. Fractional tissue extraction revealed an elevation of only the cytoplasmic isozyme (c‐GOT), due to a selective increase of this enzyme fraction. No significant change could be noticed of the mitochondrial isozyme (m‐GOT). These results are discussed with regard to an increased gluconeogenesis in rat liver 48 h after bilateral nephrectomy.
Metabolic Studies on the Pathogenesis of Hangover
Authors: Ylikahri R. H. , Huttunen M. O. , Eriksson C. J. P. , Nikklä E. A. 
Published: March 2008

Abstract. A variety of metabolic parameters were evaluated in 23 healthy male volunteers, after ethanol administration (1.5 g/kg) and correlated to the symptoms of hangover. The degree of intoxication and hangover were estimated using a simple test program according to which 11 subjects had severe and 12 mild hangover. Sequential determinations of blood ethanol, acetaldehyde, glucose, lactate, free fatty acids (FFA), triglycerides (TG) and ketone bodies were made during the 21 hours after administration. Each subject served as his own control by taking part in an identical experimental session but receiving no ethanol.The maximal hangover occurred 12 to 14 hours after the initiation of drinking. At this time almost all of the ethanol and acetaldehyde had been eliminated from the blood. The intensity of the hangover did not correlate with the peak concentrations of ethanol or acetaldehyde in the blood. Marked hypoglycemia regularly followed the administration of ethanol, but the nadir blood glucose values had no correlation with the intensity of hangover. Ethanol induced a significant rise in blood lactate concentration, the extent of which was similar in subjects with mild or severe hangover.During the most intensive hangover plasma FFA level increased when compared to the values observed during the control period. These concentrations were significantly higher in subjects with severe hangover than in those whose hangover was mild. An increase in plasma TG concentration regularly followed ethanol administration but the extent of the rise did not correlate with the degree of intoxication or hangover. Ethanol had a marked antiketogenic effect during the first 8 hours of the experiment after which the concentration of ketone bodies rose rapidly above the control level. Again the changes showed no correlation with the intensity of hangover.The results indicate that the intensity of hangover bears little relation to the changes in the metabolite concentrations measured. This suggests that the symptoms of hangover can not be accounted for by the ethanol‐induced alterations of the major blood metabolite concentrations.
The Effect of Acute Uraemia on Gluconeogenesis in Isolated Perfused Rat Livers
Authors: Fröhlich J. , Schölmerich J. , Hoppe‐Seyler G. , Maier K. P. , Talke H. , Schollmeyer P. , Gerok W. 
Published: March 2008

Abstract. The effect of acute uraemia on glucose and urea formation by isolated perfused livers of fasting rats was investigated.The basal gluconeogenesis following nephrectomy was significantly increased as compared to normal and sham operated controls. Enhanced glucose formation was associated with an increase in both urea synthesis and output of the poorly metabolizable amino acids valine, leucine, and iso‐leucine. In the presence of a mixture of amino acid3 (serine, threonine, lysine, glutamic acid, ornithine, and citrulline) all added at near physiological concentrations, the stimulating effect of uraemia on gluconeogenesis was further enhanced. This was paralleled by an increased formation of urea and an increased uptake of the amino acids. It is concluded that acute uraemia may stimulate glucose synthesis by increased substrate supply. This seems to be achieved by at least two different mechanisms, namely increased protein degradation and accelerated amino acid utilization.
Insignificance of Gluconeogenesis in Human Blood Platelets
Authors: Schrijver J. , Koster J. F. , Hülsmann W. C. 
Published: March 2008

Abstract. Human blood platelets contain no detectable activity of the enzymes fructose diphosphatase (EC 3. 1. 3. 11), phospho‐enolpyruvate carboxykinase (EC 4. 1. 1. 32) and pyruvate carboxylase (EC 6. 4. 1. 1.). Glucose‐6‐phosphatase (EC 3. 1. 3. 9) activity is very low.Phosphofructokinase present in human blood platelets, catalyzes a reaction which can be stimulated by AMP in a platelet homogenate, due to the presence of endogenous ADP and myokinase. These enzymes are responsible for the formation of fructose‐6‐phosphate from fructose‐1, 6‐diphosphate.Pyruvate kinase (EC 2. 7. 1. 40) in human blood platelets belongs to the M‐type, which is not inhibited by ATP, at least not under the conditions applied.The results obtained indicate that gluconeogenesis in human blood platelets is not present in the way which has been established for liver and kidney.
Liver Inclusions in Erythropoietic Protoporphyria
Authors: Wolff K. , Wolff‐Schreiner E. , Gschnait F. 
Published: March 2008

Abstract. Needle‐like inclusions have been found, by electron microscopy, in the livers of two unrelated patients with erythropoietic protoporphyria. Since they have not been noted in other hepatic conditions but do occur in the livers of protoporphyric mice it is suggested that they represent markers for proto‐porphyric liver disease.Paracrystalline inclusions that have been previously described in Wilson's disease and porphyria cutanea tarda were also present in the hepatocytes of one of these patients.
Double Isotope Measurement of Peritoneal Clearance of Iodide and Albumin Loss during Peritoneal Dialysis in Man
Authors: Mariani G. , Bianchi R. , Pilo A. , Palla R. , Toni M. G. , Cazzuola F. 
Published: March 2008

Summary. 131I‐labelled Human Serum Albumin and 125I‐sodium iodide were used to measure protein loss from the peritoneum and peritoneal clearance of iodide in a group of 8 uraemic patients, each one being studied after a different number of dialyses.Both albumin loss and iodide clearance reached a maximum at about the 10th dialytic treatment and then tended towards the initial levels.Protein loss as determined isotopically was markedly lower than indicated by direct radioimmunoassay measurements performed in three cases. Fitting experimental points by a model which assumes direct passage of protein from plasma to peritoneal cavity suggests the presence of a “delay” pool between plasma and the peritoneal cavity itself (extravascular sites adjacent to peritoneum?).The shorter retention time of the dialysis solution in the abdomen (4–8 minutes) seemed to us to cause lower protein losses than reported by authors using longer retention times.
Deoxyribonucleoside Triphosphates in Human Cells: Changes in Disease and Following Exposure to Drugs
Authors: Tattersall M. H. N. , Lavoie A. , Ganeshaguru K. , Tripp E. , Hoffbrand A. V. 
Published: March 2008

Abstract. Deoxyribonucleic acid synthesis requires adequate cellular concentrations of the four deoxyribonucleoside triphosphates. Using a sensitive enzymic assay, we have measured the concentrations (pools) of these compounds in human bone marrow cells and in lymphocytes. The mean concentrations (pmol/106 cells) in normal human bone marrow cells were: deoxyadenosine triphosphate (dATP) 1. 5; deoxyguanosine triphosphate (dGTP) 0.4; thymidine triphosphate (dTTP) 1. 4 and deoxycytidine triphosphate (dCTP) 0.6; and in normal phytohaemagglutinin (PHA)‐stimulated lymphocytes (72 h cultures); dATP 3. 7; dGTP 1. 9; dTTP 9. 4 and dCTP 2. 9. The deoxyribonucleoside triphosphate concentrations were increased approximately threefold in the nucleated marrow cells from patients with leukaemia and myeloproliferative diseases. PHA‐stimulation of lymphocytes caused a marked increase of the deoxyribonucleoside triphosphate concentrations, particularly of dTTP, between 24 and 48 h of culture. In PHA‐stimulated lymphocytes, the antifolate drugs methotrexate, pyrimethamine and trimethoprim, all produced a fall in dTTP and a rise in dATP concentrations within 1 h. These effects could be reversed by folinic acid. 5‐Fluorouracil caused a fall in dTTP and in dCTP but no consistent changes in dATP; hydroxyurea caused a fall in dATP with a rise in dTTP. BCNU caused a significant fall in dATP and dCTP. Dibutyryl cyclic 3′, 5′ adenosine monophosphate and theophylline had no consistent effect on the deoxyribonucleoside triphosphate concentrations. 6‐Mercaptopurine caused a fall in dATP and dGTP, the fall in dATP being marked after 4 h incubation.It is concluded that measurement of the deoxyribonucleoside triphosphates in human cells provides a new method of studying DNA synthesis in human disease states and of analysing the action of antimetabolite drugs on normal and diseased cells.
The Glucose‐Induced Gastrointestinal Stimulation of Insulin Secretion in Man: Relation to Age and to Gastrin Release
Authors: Rehfeld J. F. , Stadil F. 
Published: March 2008

Abstract. An oral 50 g glucose tolerance test and a simple intravenous glucose infusion test were performed in 20 young (20–32 years), 20 middle‐aged (42–55 years), and 20 old (65–81 years) normal subjects. Blood glucose, serum insulin, and serum gastrin concentrations were measured during all tests. The intravenous glucose infusion duplicated the oral blood glucose curve in young, middle‐aged, and half of the old subjects. In the remaining old subjects the intravenous blood glucose curve was below the oral blood glucose curve. Glucose and insulin concentrations were of similar magnitude in all groups, but maximum concentrations were reached later in the old subjects. Glucose per os induced a rapid rise in serum gastrin concentrations of the order of 10 pmol/1 and a subsequent decrease of about 20 pmol/1 in all groups. The intravenous glucose infusion induced no significant changes in serum gastrin concentrations. The non‐glycaemic (i. e. enteral) stimulation of insulin secretion was expressed as the difference between the integrated incremental areas of the oral and intravenous insulin curves in subjects with identical glucose curves during the two tests. This stimulation was of similar magnitude in all age groups, and it was not correlated to variations in gastrin concentrations. However, in the young subjects the enteral stimulation was greater during the first 30 minutes and smaller during the two last hours when compared to the old subjects.The results suggest that: 1. A simple intravenous glucose infusion test can be used to copy the oral blood glucose curve. 2. The size of the enteral stimulation of insulin secretion during the whole test is independent of age. 3. The action of the glucose‐induced enteral stimulation is delayed with age, and closely linked to the dynamics of the glycaemic stimulus. 4. The glucose‐induced gastrin release is probably too small to affect insulin secretion significantly.
Radioimmunoassay of Prostaglandins Fα, E1 and E2 in Human Plasma
Authors: Dray F. , Charbonnel B. , Maclouf J. 
Published: March 2008

Abstract. Antibodies against prostaglandins (PG)F2α, E1 and E2 were obtained in rabbits immunized with respectively PG F2α, PG E1 and PG E2 conjugated to bovine serum albumin by carbodiimide. A radioimmunoassay capable of measuring 7 pg of PG Fα, 2 pg of PG E2 and 14 pg of PG Ej in human peripheral plasma is described. Plasma samples (pH 3, citric acid) are extracted with cyclohexane: ethyl acetate, 1:1 and then chromatographed on silicic acid columns to separate the prostaglandins into three fractions: fraction I, PG A, PG B and some unknown immunoraactive compounds; fraction II, PG E and fraction III PG Fα. The recovery is 80 %± 6. 2. Mean plasma levels iu adults of PG Fa and PG E, expressed in pg/ml: ‐PG Fα 12 ± 2. 8 (n = 25 men), 8 ± 2. 3 (n = 18 women, follicular phase), 7 ± 1. 4 (n = 18 women, luteal phase). ‐PG E1 40. 5 + 7. 6 (n = 13 men), 38 + 17. 1 (n = 10 women). ‐PG E2 4. 5 ± 1 (n = 12 adult subjects).The major characteristics of the method described herein are the following: ‐ a large volume of plasma has to be processed (10 ml or more for PG Fa and PG E1, 5 ml or more for PG E2). ‐ a chromatographic step is necessary to separate the different prostaglandins which makes it possible to circumvent problems of immunological cross reactivity and interference with unknown immunoreactive compounds. ‐ great care has been taken in collection of blood samples, especially to insure complete removal of blood cells namely platelets.
Metabolism of Very Low Density Lipoproteins in Hyperlipidaemia: Studies of Apolipoprotein B Kinetics in Man
Authors: Sigurdsson G. , Nicoll A. , Lewis B. 
Published: March 2008

AbstractThe metabolism of very low density lipoprotein‐B (VLDL‐B) peptide was studied in nineteen subjects with endogenous hypertrigylceridaemia (Types V, IV and lib), three patients with heterozygous familial hyperbetalipoproteinaemia (Type Ila) and eight healthy subjects, by reinjecting autologous radioiodinated VLDL. The kinetics of VLDL‐B peptide were followed. The mean turnover rate of VLDL‐B peptide was significantly higher in the hypertriglyceridaemic group than in the control group but a considerable overlap in turnover rate was found between these groups. The patients with heterozygous familial hyperbetalipoproteinaemia had a normal turnover rate of VLDL‐B peptide. A significant positive correlation was found between the turnover rate of VLDL‐B peptide and VLDL‐triglyceride concentration in the whole series.It is concluded that the underlying defect in endogenous hypertriglyceridaemia is heterogeneous. Overproduction of VLDL is a major determining factor in seme patients whereas a reduced clearance is the determining factor in others.
Triglyceride Metabolism in Acute Starvation: The Role of Secretin and Glucagon
Authors: Stout R.W. , Henry R.W. , Buchanan K.D. 
Published: March 2008

AbstractPlasma lipid and hormone levels have been measured during 72 hours total starvation in nine healthy subjects, to assess the relative importance of hormones and substrates in human triglyceride metabolism. Plasma free fatty acid and glycerol concentrations rose steadily on each day of starvation. Plasma triglyceride concentrations rose on the second and third days, from a control level of 649 ± 67 mg/1 to a maximum of 1001 ± 66 mg/1. Plasma cholesterol concentrations remained unchanged while glucose concentrations fell and insulin did not change. Plasma glucagon (C‐GLI) levels doubled while secretin levels, reported previously, rose threefold. It is suggested that during acute starvation the rise in triglyceride concentration results from the increased availability of free fatty acids, and that elevated secretin and glucagon levels enhance lipolysis and hence provide substrates for triglyceride synthesis.
Fatty Acid Incorporation into Human Adipose Tissue in Hypertrigiyceridaemia*
Authors: Carlson L.A. , Walldius G. 
Published: March 2008

AbstractThe fatty acid and glucose incorporation into glycerides and glycerol release from adipose tissue were determined in a middle‐aged population of 109 men and 41 women. 43 men and 19 women were rrormolipidaemic. The same analysis was also carried out in 13 male and 9 female normolipidaemic students. Needle biopsy specimens of adipose tissue were incubated in vitro in an albumin medium containing 3H‐fatty acids and 14C‐glucose. After two hours of incubation values for fatty acid and glucose incorporation were calculated from the incorporation of 3H‐activity into the fatty acids and 14C‐activity into the glycerol moiety of extracted glycerides. The mean values for fatty acid incorporation were lower in all types of hypertriglyceridaemic subjects (II B, III, IV and V) than in the normolipidaemic control subjects. In the male hypertriglyceridaemic population 36 % had values for fatty acid incorporation below the 5th percentile of the normolipidaemic group and 14 % had values below the lowest normal value. The rate of fatty acid incorporation was negatively correlated with the serum triglyceride concentration. This correlation remained unchanged when partial correlation was performed when the influence of body weight was eliminated. Fatty acid and glucose incorporation correlated positively. Incorporation of glucose behaved in the same way as described above for incorporation of fatty acids. Glycerol and fatty acid release was the same in the normo‐ and hypertriglyceridaemic groups. It is likely that the removal of plasma triglycerides from blood requires hydrolysis of triglycerides to fatty acids and the subsequent removal of the fatty acids. The hypothesis has been formulated that when the former process is normal, a defect of fatty acid removal (a low rate of fatty acid incorporation into glycerides) may be responsible for an impaired removal of plasma triglyceride‐fatty acids. A low rate of fatty acid incorporation may contribute to the development of hypertrigiyceridaemia, according to this hypothesis.
Compensatory Mechanisms for the Severe Anaemia Caused by Haemoglobin Hammersmith
Authors: Gillies I. D. S. , White Y. S. , White J.M. 
Published: March 2008

AbstractA severely anaemic, but asymptomatic patient, who is a heterozygous carrier of haemoglobin Hammersmith (β42 (CD1) phenylalanine ‐ Serine), has been studied to elucidate the mechanisms resulting in physiological compensation for the anaemia. Four factors have been investigated: the oxygen affinity of her blood, the cardiac output at rest and during exercise, the blood gas indices, and pulmonary funtion.It was found that due to the presence of Heinz bodies within the erythrocytes, the level of functional, haemoglobin was considerably less (50 g/1) than that measured by standard methods (87 g/1). In addition a moderate degree of arterial hypoxaemia (arterial oxygen tension = 10.7 JcPa (80.4 mmHg)) was present which could not be explained on the basis of abnormal pulmonary function. Both of these factors would result in tissue hypoxia, but the finding of consistently normal oxygen tensions (‘mixed’ venous oxygen tension = 5.4 kPa (40.3 mmHg)) in blood obtained from the right atrium, suggested that hypoxia was not present. This was explained by a decreased whole blood oxygen affinity (P50 = 4.6 kPa (34.5 mmHg) at pH 7.4) and an increase in the cardiac index (5.3 L.min.‐1m‐2). The latter was the result of an increased stroke volume (125 ‐ 135 ml), the heart rate being normal (63/min.). During moderate exercise, further increases of cardiac output were brought about by a change in heart rate alone. It has been calculated that the decrease in whole blood oxygen per se could not account for adequate tissue oxygenation. This is confirmed by the finding of an increased cardiac output in this patient. It is suggested that in any severe haemolytic anaemia, even if the whole blood oxygen affinity is low, cardiac output is probably increased to achieve complete physiological compensation.
Partial Purification of Human Renin Substrate
Authors: Schiøler V. , Nielsen M. Damkjasr , Kappelgaard A. M. , Giese J. 
Published: March 2008

AbstractA two‐step purification method is described for the preparation of renin substrate from human plasma. Pooled plasma from women on oral contraceptives is used for the purification. The overall yield of renin substrate is 57%, with a twenty‐fold purification. The specific renin substrate content of the preparation, as determined by enzymatic degradation with an excess of human renin, is 2 μg angiotensin I per mg protein. The product has a very low endogenous renin activity and is free from angiotensinase activity. An additional purification step involving affinity chromatography is described. In pilot studies a renin substrate yield of 37% has been achieved, with a hundred‐fold purification. The final product has a specific renin substrate content of 10 μg angiotensin I per mg protein. The preparation contains up to 12 different plasma proteins, nine of which have been identified and guantitated.
Effects of Intravenous Phospholipid on Low Density Lipoprotein Turnover in Man*
Authors: Thompson G. R. , Jadhav A. , Nava M. , Gotto A.M. 
Published: March 2008

AbstractThe mechanism of the rise in plasma low density lipoprotein (LDL) levels following intravenous administration of a triglyceride‐phospholipid emulsion (Intralipid) has been investigated by measuring LDL turnover in eight healthy subjects. The plasma half‐life, and the absolute and fractional catabolic rates of LDL protein (apo‐LDL) were unaffected by intragastric Intralipid, whereas apo‐LDL half‐life was prolonged and its fractional catabolic rate was decreased by intravenous Intralipid. Similar changes were observed after intravenous administration of the egg phospholipid constituent of Intralipid. Accompanying increases in the oleate: linoleate ratio of both high and low density lipoprotein cholesterol esters were secondary to phospholipid exchange between infused and endogenous lecithin. These results suggest that the increased concentration of LDL in plasma following intravenous administration of egg phospholipid‐containing emulsions was due, at least in part, to a decrease in the fractional catabolic rate of apo‐LDL. The data further suggest a possible relationship between apo‐LDL catabolism and the fatty acid composition of LDL.