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Biomedical subjects

E Michel

Publications and source records attributed to E Michel.

At least 91 records · Page 5Linked to original sources
PubMed1989

[The effect of high glucose concentrations on the osmotic and mechanical resistance of human erythrocytes].

Incubation of citrated or heparinized blood samples with 25 or 50 mmoles/l glucose for 1 hour at 37 degrees C results in a decrease in the osmotic and mechanical resistance of red blood cells as well as in an increase in the red blood cell volume measured as increase in haematocrit. Fructose, but not sorbitol or saccharose has effects on red blood cells that are similar to those of glucose. It is discussed that an uptake of glucose into red blood cells with subsequent water influx results in swelling and decreased stability of the cells.

Erythrocyte Volume↗
PubMed1988

Characterization of a biotin-conjugated ovine prolactin ligand.

Ovine prolactin was biotinylated with N-hydroxysuccinimidobiotin. Biotinylation was proportional to the molar ratio of reactants. Gel electrophoresis of the biotinylated derivative revealed little or no change in migration, but isoelectric focusing showed an acidic shift when compared to oPRL. Biotinylated ovine prolactin (B-oPRL) was detected by anti-oPRL antiserum and avidin-fluorescein-isothiocyanate (FITC) on protein blots. Competitive binding assays using 125I-B-oPRL and 125I-oPRL revealed: (a) similar dissociation constants and ID50 values for binding to anti-oPRL antibodies; (b) similar dissociation constants and maximum binding values for binding to liver membrane preparations; and (c) similar dissociation curves for displacement by several pituitary hormones. In contrast, binding of biotinylated oPRL to Nb2 node cells was reduced by approximately 70% and its bioreactivity was only 10% of that of oPRL. Our results indicate that biotinylation of oPRL does not alter its binding characteristics as measured by radioimmunoassay and radioreceptor assay using hepatic lactogenic receptors, but decreases its binding and bioreactivity when measured in Nb2 lymphoma cells. Assuming that N-hydroxysuccinimidobiotin interacts with reactive free amino groups of oPRL, our results suggest that these groups are essential for binding and bioreactivity of the molecule in the Nb2 lymphoma cell system.

Animals↗
PubMed1988

Inhibition of platelet activation by 2-mercaptopropionylglycin in vitro and in vivo.

2-mercaptopropionylglycin (2-MPG), a cell membrane penetrating thiol, was evaluated for its antithrombotic potential using in vitro and in vivo tests. 2-MPG was found to inhibit agonist-induced platelet aggregation and serotonin release as well as prostaglandin/thromboxane synthesis in platelet-rich plasma. Administration of 2-MPG to rats resulted in an inhibition of laser-induced thrombus formation in mesenteric vessels. When plasma was incubated with 2-MPG and then used for determination of various standard coagulation parameters, significant prolongation of the clotting times were observed.

Animals↗
PubMed1988

[Doppler flow velocities in cerebral arteries in relation to intravenous phenobarbital in premature infants weighing between 500 and 1,500 g].

In very premature ventilated infants (GA 25-30 weeks, BW 575-1420 g) values for heart frequency, mean arterial blood pressure and pCO2 were obtained, and also Doppler-sonographic measurements of the right internal carotid artery were performed to assess cerebral haemodynamics, before and 5-10 min after the intravenous injection of 20 mg/kg phenobarbitone (study I/n = 10) or 5 mg/kg phenobarbitone (study II/n = 10). There were no significant changes in any of these parameters. Therefore phenobarbitone does not have seem to have any significant effect on cerebral haemodynamics up to a dosage of 20 mg/kg, so that there is no apparent effect on the risk of cerebral haemorrhage. On the other hand this study confirms that phenobarbitone can be used in very low birth weight preterm infants with this dosage without causing any substantial haemodynamic risk.

Birth Weight↗
PubMed1988

[Sudden infant death in France during the winter of 1986].

From the statistics of the medical causes of deaths and the results of a retrospective survey carried out among the physicians who certified the deaths, an analysis of post-neonatal mortality during winter of 1986 was undertaken in order to know if the relative part of the sudden infant death syndrome (SIDS) had increased during that winter. It appeared that the deaths attributed to SIDS can be distinguished from deaths of other causes for several factors (place of death, former status of the baby). However, the low number of post mortem examinations performed does not allow in all the declared cases to assess SIDS as internationally defined. However, it is shown that sudden mortality was not higher during this special winter and that immunizations were not more frequently related to this cause than to other causes of death.

France↗
PubMed1987

Structure-activity relationship in PAF-acether. 3. Hydrophobic contribution to agonistic activity.

The synthesis of some selected PAF-acether homologues with an alkoxy-chain length from C1 to C20 in position 1 is described. All agonist activities are closely correlated among themselves and with the calculated fatty-chain hydrophobicity. After a discussion on recent published results and comparison with our data, we conclude that the ether oxide function is absolutely essential at the glycerol 1-position for potent agonist activity and that potency correlates well with hydrophobicity parameters. We indicate the importance of steric and configurational constraints.

Animals↗
PubMed1985

Failure of high-dose sustained release luteinizing hormone releasing hormone agonist (buserelin) plus oral testosterone to suppress male fertility.

Previously we have demonstrated that sperm counts of normal young men decreased during constant subcutaneous infusion of the LHRH agonist buserelin (118 or 230 micrograms/d). In order to test whether azoospermia can be achieved with higher doses, seven young men received 450 micrograms buserelin subcutaneously daily for 12 weeks via extracorporeal osmotic minipumps. To avoid symptoms of androgen deficiency, oral supplementation with 80 mg/d testosterone undecanoate (TU) was initiated in week 5 and was increased to 120 mg/d by week 8. Follow-up after treatment lasted for another 12 weeks. In order to evaluate possible psychotropic effects of treatment-related endocrine changes, continuous psychometric testing was performed focusing on personality, emotions and sexuality. After an initial rise, both serum LH and FSH returned to normal. FSH was below normal during the 3rd-5th week following treatment. LHRH stimulation tests performed at the end of treatment showed pituitary desensitization. Serum T (always measured between 0800 and 1300 h at least 12 h after last TU) tended to decrease by week 7 and remained slightly depressed until the end of treatment while libido, potency and emotional well-being remained unchanged. While testicular volumes showed a reduction from week 7 of treatment to week 10 post-treatment, sperm counts decreased only insignificantly from 65 +/- 10 to 44 +/- 14 million per ml in week 12 post-treatment. Severe oligo- or azoospermia was not observed in any of the seven men. It is concluded that full androgen substitution by TU can drastically delay if not abolish the antifertility effect of LHRH-induced pituitary desensitization.

Administration, Oral↗
PubMed1984

Effect of diamide (azodicarboxylic acid-bis-dimethylamide) on arachidonic acid release from human blood platelet phospholipids.

It was found that the thiol-oxidizing agent diamide inhibits the formation of arachidonic acid metabolites in thrombin-stimulated platelets. An inhibition of arachidonic acid release from membrane phospholipids in diamide-treated platelets is concluded since diamide does not diminish the formation of stable metabolites from exogenous arachidonic acid. The role of the cellular thiol-disulfide status for the activities of phospholipases involved in arachidonic acid release is discussed.

Arachidonic Acid↗
PubMed1984

[Professional housekeeping aide for elderly persons. Needs, demand and beneficiaries].

Professional home help services (aide- menag ère) in France is one of the principal means to permit the disabled elderly to remain at home. For this reason, an evaluative study was conducted on existent needs of the inhabitants of one region: Upper-Normandy. The authors considered both demand and effective need among people concerned. At the time of the study (1979), 4.2% of the population 65 and older were beneficiaries of the service. The proportion of those who would have desired the service was then 14.7%--or 3.5 times higher. But the study of effective need provided a very different perspective: it concerned those unable to perform household tasks and also having no possibilities of help from the immediate family. If home assistance were limited to those not bedridden, having restricted ability to perform household tasks, and living alone, it would affect 17% of the elderly and would require 64,000 hours weekly, against 43,000 provided at the time of the survey. If other tasks were included (personal hygiene care, or care of the bedridden or of those unable to go out), the service would affect 24% of the population and would require 153,000 hours weekly. Based on the criteria applied, it appears that 20% of the service goes to those without effective need. Also, almost two-thirds of those needing the service state that they do not want it. The development of home help services in France must be considered in the framework of a global planning process of all services designed to enable the dependent elderly to remain at home.

Aged↗
PubMed1983

[Pelvic inflammatory disease in private practice. An indirect estimation of the importance of the phenomenon in the French population].

A significant increase in the incidence of pelvic inflammatory disease in women aged 15-45 over two decades has been notified by many authors. We have therefore used the data of a survey in private practice in order to evaluate the size of the problem in France taking into consideration that the majority of cases of PID are managed primary primary care systems (G.P. and private specialists). Compared with other pathological problems PID rarely appears in practice (0.6% of contacts with physicians) but the total number of contacts during a year can be estimated at 745 000 in 1975 throughout the country. The highest frequency is observed in the 25-29 age group. There is no difference between professional women and women who have no profession, nor between rural and urban areas. Half of all cases had been notified by general practitioners and the others by gynaecologist/obstetricians. About two-thirds of cases present as acute problems. With this information it is possible to discuss extrapolation to the whole area so as to estimate the prevalence and incidence of PID in France. If a woman has 3 contacts a year with her doctor when she has PID it can be calculated that in 1975 the prevalence was about 2.1% of women aged between 15 and 44 (+/- 0.5). If all acute problems are considered as new cases, the incidence can be estimated at about 1.3% (+/- 0.4) of women aged between 15 and 44.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

[Diabetes in private practice. Data of the INSERM national survey on private practice (1974-1975)].

Data from a national survey of private medicine in France were used to estimate the frequency of diabetes in primary care and to analyse both patient characteristics and therapeutic management. An approach was made to 2012 physicians who were requested to complete a questionnaire for each patient they saw during the course of a single day; 1103 responded and completed more than 20000 questionnaires. An additional investigation looked into the nature of the non responders. Diabetics represent 2,2% of patients in private medicine. Each year about 5,5 million consultations in private practice in France are for diabetes alone or for diabetes in association with other illnesses. 89% of diabetic patients are over 45 years of age and more than 48% older than 65. In most cases (80%), diabetes is associated with other medical problems, half of them being consequences of diabetes (cardio-vascular diseases, ocular and renal diseases). In 85% of cases, diabetics receive their basic care from a general practitioner. Therapeutic management is based mainly on drugs; diet or advice about life style are mentioned in barely one third of cases. Using linkage with social security data, it was possible to make a crude estimate of the number of diabetics in France. It was estimated at about 1 million for 52,6 million inhabitants.

Adult↗
PubMed1982

Radio-labelling of 1-O-alkyl, 2-O-acetyl, sn-glycero-3-phosphorylcholine, 1-O-(9,10-di3H)-octadecyl PAF-acether.

3H-labelling of 1-3H-PAF-aceter was prepared by catalytic reduction of 1-O-(9,10)-octadecenyl-2-O-benzyl-sn-glyceryl-3-phosphorylcholine and then acetylated. 5 mumoles of this dehydro derivative dissolved in methanol was treated during 4 hours with tritium gas (80 Ci) and compressed until 1.1 bar by an automatic tritium transfer unit [1]. The catalyst was removed by filtration over Millex (Millipore) and labile tritium atoms eliminated by rotatory flash evaporation. The chemical purity was checked by 3H scanning and autoradiography. It was finally recovered through preparative thin-layer chromatography and then acetylated. The specific radioactivity was found to be close to 40-50 Ci/mmole.

Isotope Labeling↗