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Biomedical subjects

J Michel

Publications and source records attributed to J Michel.

At least 109 records · Page 6Linked to original sources
PubMed1990

Sigma receptors modulate the hypothalamic-pituitary-adrenal (HPA) axis centrally: evidence for a functional interaction with NMDA receptors, in vivo.

The present report investigates the modulation of the hypothalamic-pituitary-adrenal (HPA) axis in the rat by sigma receptors, using a selective ligand, (+) pentazocine, and comparing the effects with (+) SKF 10, 047. Both compounds stimulate ACTH release potently after central and peripheral administration. These effects are centrally mediated, since they did not release ACTH from anterior pituitary primary cultures. The effects are not blocked by naloxone, but are blocked by the NMDA antagonist, CPP, indicating a centrally mediated functional interaction between NMDA and sigma receptors, in vivo.

Adrenocorticotropic Hormone↗
PubMed1990

A randomized study comparing etoposide and vindesine with or without cisplatin as induction therapy for small cell lung cancer. EORTC Lung Cancer Working Party.

We conducted a randomized trial testing etoposide (120 mg/m2 d1-3) + vindesine (3 mg/m2 d1) with or without cisplatin (60 mg/m2 d1) in patients with SCLC. A total of 8 courses were given at 3-week intervals. 221 patients were registered and 201, 95 in the CEV arm and 106 in the EV arm, were eligible for survival analysis. 183 patients were evaluable for response: 74% had an objective response (OR) with CEV versus 55% with EV (p = 0.01). Complete response rates were, respectively, 21% and 13% (NS). In patients with limited disease (LD), OR rates were 72% and 61% (NS), and 76% and 48% in extensive disease (ED) (p = 0.01). There was no statistically significant difference in survival between the two regimens (p = 0.745, log rank test). Median survival for EV and CEV were, respectively, 40 and 45 weeks, and two-year survivals were 11% and 9%; in patients with LD, the corresponding figures were 14% and 16% (NS) and in those with ED, 8% and 3% (NS). Disease extent (LD vs ED), Karnofsky performance status and loss of body weight were significant prognostic factors for survival; age, sex, type of treatment and type of lesion were not. The CEV regimen was not significantly more myelotoxic than EV but was associated with more severe nausea, vomiting and alopecia. In conclusion, the addition of cisplatin to the EV regimen, a combination reported to be easily manageable, was associated with a significantly higher OR rate but survival was not significantly improved.

Adult↗
PubMed1990

Atrial natriuretic peptides in brain nuclei of rats with inherited diabetes insipidus (Brattleboro rats).

The concentration of atrial natriuretic peptides (ANF) was measured radioimmunologically in 18 selected microdissected brain areas of rats with inherited diabetes insipidus (Brattleboro rats) and their control rats (Long-Evans rats). In 7 brain areas known to be involved in the regulation of fluid homeostasis or blood pressure (subfornical organ, organum vasculosum lamina terminalis, periventricular preoptic nucleus, perifornical nucleus, nucleus of the solitary tract, tegmentum pontis, arcuate nucleus) ANF concentration was significantly changed. After restoration of antidiuresis with the V2 receptor agonist 1-desamino-8-D-arginine vasopressin (DDAVP) ANF levels of Brattleboro rats adapted at least partly to those of the control rats in all brain areas except the subfornical organ. Furthermore, ANF was then significantly changed in the supraoptic and paraventricular nuclei of DDAVP-treated diabetes insipidus rats. These data show that the central ANF system is sensitive for changes in electrolyte and fluid homeostasis.

Animals↗
PubMed1990

[Results of emergency aortocoronary venous bypass surgery after failed percutaneous transluminal coronary angioplasty in patients with unstable angina pectoris].

During a 4-year period from January 1985 to December 1988 140 patients underwent percutaneous transluminal coronary angioplasty (PTCA) of the culprit-vessel for unstable angina. Seventeen patients (12%) needed emergency aorta coronary bypass surgery (ACVB) for failed angioplasty. In 15 cases the culprit-vessel was the LAD and in 2 cases a dominant right coronary artery. Only in 2 cases a history of myocardial infarction was present. Twelve patients were in hemodynamic stable condition after arriving in the operating-room. Five patients were hemodynamic unstable, 4 of them were in cardiogenic shock. Four patients died representing an operative mortality rate of 23%. Three patients died from pump failure despite intraaortic balloon counterpulsation in 2 cases. One patient died from cerebral damage 12 day after surgery. All patients who died were in cardiogenic shock preoperatively. Two patients who survived suffered an extensive myocardial infarction. Thus including the patients who died from pump failure the perioperative infarction rate was 30%. From these results it is concluded that emergency ACVB after failed PTCA of the culprit-vessel in patients with unstable angina results in a significant higher mortality and morbidity as compared with patients who had primary surgery for unstable angina. The prognosis of patients after failed PTCA for unstable angina depends on the hemodynamic situation thereafter and becomes worse in patients with cardiogenic shock.

Adult↗
PubMed1989

Adjuvant radiotherapy and chemotherapy in resectable gastric cancer. A randomized trial of the gastro-intestinal tract cancer cooperative group of the EORTC.

One hundred and fifteen patients with curative and palliative surgery for gastric cancer were randomized to receive radiotherapy alone (1) or in combination with short-term (ST) 5-FU (2), long-term (LT) 5-FU (3), ST and LT 5-FU (4). The ST 5-FU was given at a daily dose of 575 mg/m2, every 4-6 h during the first 4 days of treatment before starting irradiation. The LT 5-FU was given at a dosage of 750 mg/m2 every 2 weeks for 18 months or until progression. The median survival times for treatment 1 to 4 was respectively 12, 10, 15 and 18 months. There was a statistically significant overall difference between the four treatments (P = 0.041). However, when the comparisons were adjusted for the most significant prognostic factors, the difference in survival disappeared. Moreover, no difference was found between treatments in terms of time progression. Nevertheless, among 22 patients with residual tumour, the three who were still alive without disease progression (with survivals of 19+, 49+ and 90+ months at the time of this analysis) had been treated with radiotherapy combined with ST and LT 5-FU.

Adenocarcinoma↗
PubMed1988

Relationship between the high-energy phosphate content and various left ventricular functional parameters of the normal and hypertrophied heart after global ischemia and reperfusion.

Using an isolated rat heart preparation (Langendorff perfusion, perfusion pressure 100 cm H2O) the correlation between the high-energy phosphate content and various left ventricular (lv) functional parameters of the hypertrophied heart (spontaneous hypertensive rats lv/body weight ratio 3.6 +/- 0.5 x 10(-3) was determined after normo- (30 min) and hypothermic (25 degrees C, 120 min) cardioplegic arrest and reperfusion, and compared with normal hearts (Wistar rats lv/body weight ratio 2.0 +/- 0.3 x 10(-3). St. Thomas Hospital solution was used as the cardioplegic agent. Before ischemia hypertrophied hearts had a significantly higher developed left ventricular pressure, pressure rate product and dp/dtmax, but a significantly lower ATP and total adenine nucleotide content. Irrespective of the mode and temperature of cardiac arrest there was a strong correlation both for normal and for hypertrophied hearts between the high-energy phosphate content expressed as ATP, total adenine nucleotides or the "energy charge" and the left ventricular functional parameters pressure rate product and dp/dtmax. The correlation coefficient ranged from 0.80 to 0.89 and was highest when the ATP content was plotted against pressure rate product (r = 0.89). There was a different slope for normal and hypertrophied hearts with a steeper decline of the left ventricular function in hypertrophied hearts for any given reduction of the myocardial adenine nucleotide content. Our results indicate that a similar reduction of the ATP or total adenine nucleotide content in both the normal and hypertrophied heart reduces left ventricular function to a greater degree in the hypertrophied heart.

Adenosine Diphosphate↗
PubMed1988

The Israeli Study of Surgical Infections (ISSI): I. Methods for developing a standardized surveillance system for a multicenter study of surgical infections.

The postoperative wound infection experience in 11 Israeli hospitals was investigated with two objectives: (1) to utilize the variability among hospitals for a better understanding of the determinants of these infections, and (2) to present surgeons and infection control teams with information upon which they can take action. This article summarizes the methods that were applied to maximize the uniformity of information obtained from hospitals. (1) The same kind of patients were sampled in every hospital. (2) The data collection system was standardized, and analyzed for errors. The overall error rate was small (2%) but there were potential problem areas, such as missing information on underlying diagnoses (12%). Few errors (1%) were found in the nurses' observations of the wounds. (3) All wound infections were diagnosed in a uniform manner by convening a panel of four specialists at the central Israeli Study of Surgical Infections (ISSI) office. (4) The definition of infection that was finally chosen for this multicenter study had to be broadened to include, in addition to pus, "discharge other than pus," because of the higher reliability among panel members. This definition was also clinically valid in terms of morbidity. (5) The rate of postdischarge infections was estimated and was not found to be related to the discharge policies in the various hospitals.

Data Collection↗
PubMed1988

Effects of guanine nucleotides on N-methyl-D-aspartate receptor-ligand interactions.

Guanine nucleotides have been examined as to their effects on subclass-specific excitatory amino acid receptor-ligand interactions. Guanine nucleotides selectively inhibit L-[3H]glutamate binding to the N-methyl-D-aspartate (NMDA) recognition site while showing a lesser effect on [3H]kainate, [3H]alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate and sodium-dependent L-[3H]glutamate binding. Of the series of guanine nucleotides tested in the inhibition of NMDA-specific L-[3H]glutamate binding, GTP, GDP, 5'-guanylylimidodiphosphate and 5'-guanylylmethylenediphosphate were significantly more potent than GMP, cyclic GMP and guanosine. Scatchard analysis indicates that the GTP inhibition (IC50 = 28 microM) of this NMDA-specific L-[3H]glutamate binding results from a decrease in the affinity of L-glutamate for the NMDA receptor whereas no alteration in the number of binding sites is observed. A kinetic analysis indicates that this decrease in affinity may be attributed to a decrease in association rate whereas no change in dissociation rate is observed. GTP (25 microM) lowers the affinities of both NMDA agonists (NMDA, L-glutamate, L-aspartate, and L-homocysteate) and antagonists (D-2-amino-5-phosphonovalerate, D-2-amino-7-phosphonoheptanoate, and D-2-aminoadipate). Pretreatment of the synaptic plasma membranes with either pertussis or cholera toxin had no significant effect on the GTP inhibition of NMDA-specific L-[3H] glutamate binding. The data suggest that guanine nucleotides can negatively modulate the NMDA receptor; however, the mechanism of this modulation is unclear.

Animals↗
PubMed1987

Embryonal rhabdomyosarcoma of the biliary tree in children: a case report.

Embryonal rhabdomyosarcoma (ERS) in children is a very rare tumor. Jaundice is the capital symptom. Diagnosis can be made by echography, which shows echogenic formations without posterior conic shadows in a dilated biliary duct. The prognosis is bleak in spite of the combination of surgery, radiotherapy and chemotherapy.

Bile Duct Neoplasms↗
PubMed1987

Identification and characterization of an N-methyl-D-aspartate-specific L-[3H]glutamate recognition site in synaptic plasma membranes.

Conditions have been developed for an L-[3H]glutamate binding assay in which 85-95% of the specific binding is to a site that corresponds to the N-methyl-D-aspartate subclass of acidic amino acid receptors. Incubation of synaptic plasma membranes with L-[3H]glutamate in 50 mM Tris/acetate, pH 7.4, for 2-20 min at 2 degrees C results in binding with pharmacological characteristics of the electrophysiologically defined N-methyl-D-aspartate receptor. The fraction of glutamate binding to this subclass of receptors, relative to the total, decreases with both increased time and temperature. This binding is reversible, is concentrated in the synaptic plasma membrane fraction, has a pH optimum of 7.0-7.4, and is linear with respect to tissue protein concentration. The binding is unaffected by 1 mM concentrations of the anions sulfate, chloride, bromide, thiocyanate, phosphate, acetate, nitrate, or carbonate and the monovalent cations potassium or ammonium. However sodium and the divalent cations copper, cobalt, zinc, cadmium, and manganese decrease binding to this N-methyl-D-aspartate site.

Animals↗