Determination of erythrocyte surface sialic acid residues by a new colorimetric method.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to G Durand.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Hepatocytes isolated from streptozotocin treated Rats bind less asialotransferrin than hepatocytes isolated from normal rats. This decrease is parallel with a decrease in the sialic acid content. Insulin therapy restored simultaneously membrane sialic acid content and asialotransferrin binding capacity.
Explore the source record for details and available documents.
Plasma levels of haloperidol were monitored in children and teenagers suffering from psychotic episodes and/or abnormal movements (tics and Gilles de la Tourette's syndrome). Steady-state concentrations of haloperidol ranged from 0.7 to 19 ng/ml without any apparent relationship with the administered dose (15--285 micrograms/kg/day) and a 15-fold variability was observed for the same daily dosage. On the contrary, a significant (p < 0.02) relationship was found between the age of the patients and the plasma concentrations to dose ratios, lower values being present in younger patients. Side effects too appeared to be related to plasma levels, with a significant increase (p < 0.01) in incidence for concentrations over 6 ng/ml. In most of the cases suffering from tics and Gilles de la Tourette's syndrome, a positive response was associated with plasma levels of 1--4 ng/ml, while no relationship could be established for the psychotic group. The relevance of monitoring plasma drug levels when prescribing haloperidol in pediatrics is discussed.
Mild periodate treatment is mitogenic for T lymphocytes. With murine spleen cells periodate oxidation is effective between C8 and C9 on sialyl acid residues. With human blood lymphocytes this oxidation occurs between C7 and C8 of these residues. In vitro immune response is inhibited by periodate treatment. Activation of an immunosuppressive T lymphocyte population is obtained. Similar results are performed with human blood lymphocytes.
The injection of alpha-chymotrypsin into the posterior chamber of the eye is known to produce an experimental ocular hypertension of long duration in animals. The present study reports the pathological changes which occur in the eye during the first nine months after the ocular injection of alpha-chymotrypsin in rabbits. Six weeks after treatment most of the eyes showed a buphthalmia and an intraocular pressure elevation which varied greatly from animal to animal. The anterior chamber angle of the treated eyes showed a progressive enlargement. Several days after the enzyme injection a transient increase in thickness of the cornea and Descemet membrane was noted. Cupping of the optic disc, characterized by a total disappearance of the optic nerve head fibers and an excavation beginning at margins of the retina appeared after four months and in most cases were present seven months after the treatment. More or less prominent retinal degeneration was also evidenced three months after enzyme injection. The results indicate alpha-chymotrypsin-induced occular hypertension in the rabbit leads after several months to pathological change in the eye analogous to that observed in human glaucoma.
Substituting soya oil for lard considerably reduced hypercholesterolemia in the male rat with induced hypercholesterolemia due to a dietary overlead of cholesterol and sodium deoxycholate. The decrement was more marked when a mixture of 80 p. 100 soya oil + 20 p. 100 sardine oil replaced the lard. This improvement of the hypocholesterolemic effect by adding sardine oil to soya oil was due to the long-chain fatty acids (mainly C20:5 and/or C22:5 n-3 in the fish oil).
In 5 French Alpine goats, omental adipose tissue acetyl-CoA carboxylase, glucose-6-phosphate deshydrogenase, malic enzyme and lipoprotein lipase activities significantly decreased during the third month of gestation, whereas plasma non-esterified fatty acid and triacyglycerol contents increased. This probably reflects an early decreasing rate of adipose tissue anabolism during gestation in the Goat. At the third week of lactation, anabolic activities relative to DNA content of adipose tissue were extremely low, and the tissue weight relative to DNA was lower than during gestation. Metabolic alterations of omental adipose tissue in early lactation do not seem to be related to milk production level. These results could contribute to a better control of the kinetic of body lipid stores during the reproductive cycle in high milk yielding ruminants.
5 French Alpine Goats were studied after normal or premature parturition. Mammary tissue acetyl-C oA carboxylase, glucose-6-phosphate dehydrogenase, malic enzyme and lipoprotein lipase (LPL) activities varied in parallel with milk fat secretion from the 3rd to the 9th week of lactation. Variations of mammary LPL activity and of long chain fatty acid secretion were positively highly correlated during that period. In goats with normal parturition, lipogenic activities seemed to reach a maximum level shortly after parturition. There was a positive correlation between mammary Ll activities and plasma non esterified fatty acid contents, possibly reflecting a relationship between adipose tissue mobilisation and mammary metabolism.
After thymidine-3H injection into pregnant Rat, histoautoradiographic studies showed that adipose cell proliferation in different subcutaneous and visceral sites, was very important in Rat foetuses about 24 h before birth and that lipid accumulation in the labelled cells was very fast during perinatal 48 h.
Explore the source record for details and available documents.
The possibility of producing L-lysine from chemically synthesized DL-lysine has been investigated. Optical resolution of racemic DK-lysine may be achieved by using the stereospecific esterasic activity of trypsin on DL-lysine methyl ester, which gives L-lysine and unchanged D-lysine methyl ester. SL-lysine methyl ester spontaneous hydrolysis may be neglected when operating at pH 5.5 and 30 degrees C. Effect of pH and substrate concentration on hydrolysis rate has been investigated when using as a catalyst either soluble or immobilized trypsin. For this purpose, trypsin was coupled onto an amine porous silica, Spherosil, activated with glutaraldehyde. The optimal pH is 5.8 for soluble trypsin and 6.0 for immobilized trypsin. It was yet possible to lower the parent optimal pH of immobilized trypsin, and thus increase its activity at 5.5, by co-grafting onto Spherosil an aminosilane, for enzyme coupling via glutaraldehyde activation and a positively charged diethyl amino ethyl (DEAE) silane, for decreasing the pH of trypsin microenvironment.
The development of pancreatic tissue (fresh weight, total proteins, RNA and DNA) and of the level of pancreatic enzymes (trypsin, chymotrypsin, lipase and amylase) of the piglet has been followed from birth to the age of 8 weeks in 10 animals at each of 7 stages. There was an increase with age and body weight of the total fresh weight of the exocrine pancreas. From birth until 4 weeks the development of the pancreatic gland was due to hyperplasia; from the 4th week till the 8th week of age, it was due both to hyperplasia and hypertrophy. There was a specific period, at the age of 3--4 weeks, from which total enzymatic activities markedly increased. Furthermore, from the 4th week of age there was a rise in the intake of total dietary proteins, fat and carbohydrates, due to the intake of solid food.
The wet weight evolution and specific and total lipoprotein lipase (LPL) activities of the heart were studied in male rats fed with diets containing 4, 12 or 21 p. 100 lipids from 50 g (3 weeks age) to 400 g body weight (13 weeks of age). The animals were compared at 100, 150, 200 and 400 g. The main results show that:--a lipid-rich diet caused some cardiac hypertrophy beginning at 100 g body weight:--specific LPL activity (activity/g of wet tissue) in the 50-400 g interval was higher when the diet contained more lipids;--when the diet contained 4 p. 100 and 12 p. 100 lipids, specific LPL activity decreased from weaning until a plateau was reached at 200 g body weight. On the other hand, when the diet contained 21 p. 100 lipids, specific LPL activity increased to a maximum in the 150-200 g interval; it then declined rapidly so that at 400 g there were no longer significant differences between the specific LPL cardiac activities of the three groups of animals. The activities thus became independant of the dietary lipid level;--total LPL cardiac activity was higher when the diet contained more lipids, at least up to the 400 g stage. When the diet contained 4 and 12 p. 100 lipids, the activity increased linearly in the 100-400 g interval. When the diet contained 21 p. 100 lipids, it increased very rapidly in the 50-200 g interval then decreased in the 200-400 g interval. In the latter interval, the differences between LPL activities of the three groups were less so that at 400 g there was only significant difference between the extreme high and low lipid groups. Thus, as specific activity, total LPL cardiac activity tended to become independent of dietary lipid level when the animals became adult.
A review of the effects during labour of epidural analgesia on dilatation, expulsion and delivery of the placenta. Uncertainties in knowledge of the precise organisation of uterine innervation and of the intrinsic innervation of the organ render the study of changes in uterine contraction and in cervical resistances difficult. At circulating levels higher than those found in clinical practice, local anaesthetics have a definite oxytocic e-fect, local anaesthetics have a definite oxytoci effect, whilst adrenalin is a powerfult tocolytic. By contrast, the indirect effects related to neurolysis in extradural analgesia are negligeable. Cervico-segmentary resistances are decreased. In practice, there is no increase in the period of dilatation in the absence of any haemodynamic disturbances and if mixtures containing adrenalin are avoided. Expulsion is favourised by muscular relaxation but impaired by the lack of voluntary expulsive effort, hence the choice of a local anaesthetic with the lowest possible motor effect. Delivery of the placenta, which involves only uterine contraction, which is not affected, may be accelerated by oxytocics.
Mouse spleen cells free of erythrocytes were suspended in PBS at a concentration of 2 X 10(7) cells/ml and mixed with an equal volume of sodium periodate in PBS for 10 min. at 4 degrees C to give a final concentration of periodate ranging from 10(-4) M to 5 X 10(-3) M. The cells were then washed and suspended (60 X 10(6) ml) in PBS containing 3H-labelled sodium borohydrate and incubated for 30 min, at 23 degrees C. Following this, the cells were washed and the pellets treated with H2SO4 0.1 N for 60 min. at 80 degrees C. Compounds liberated by such treatment, were identified by chromatography as derivates of sialic acid. The data provide direct evidence that the mitogenic effect of sodium periodate is associated to the oxidation of the sialic acid residues on the lymphocyte membrane.
In the goat the passage from late pregnancy to early lactation is accompanied by a decrease of the epiploon lipoprotein lipase activity and an increase in the epiploon DNA content. The between-goat variations allow us to emphasize a linear relation between the lipoprotein lipase activity decrease and the reduction of the epiploon volume, expressed on a DNA basis. These parameters, used as indicators of the adipose tissue metabolic status, could contribue to the determination of a feeding strategy adapted to high yield milking Ruminants.