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Biomedical subjects

P Robert

Publications and source records attributed to P Robert.

At least 73 records · Page 4Linked to original sources
PubMed1994

Insecticidal and cytotoxic effects of natural and hemisynthetic destruxins.

The insecticidal and cytotoxic effects of 13 natural and hemisynthetic destruxins have been studied. DE shows insecticidal effects similar to those of DA, while DE and DA are more active than all the other natural compounds and analogues tested. Brominated destruxin is a relatively active analogue displaying particular modalities of cytotoxic effects which reflect a certain originality of its mode of action. The linear molecule resulting from the opening of the DA cycle is not toxic. The most hydrophilic destruxins showing e.g. charged radicals (COO-) appear the least toxic probably because they do not penetrate easily the cellular membranes.

Administration, Oral↗
PubMed1994

[Effect of a diet supplemented with soybean oil or fish oil on the reversibility of docosahexaenoic acid deficiency (22:6w3) in the brain and erythrocytes of rats].

This study was undertaken, to evaluate the effects of dietary supplements containing either soybean oil (19:3w3; ALA), or fish oil (22:6w3; DHA), added to the lactating rat dam diet, on the levels of DHA in brain and erythrocytes of DHA deficient pups. Pregnant rats fed omega 3 deficient diets were divided at parturition into three groups. One group was kept on the same diet fed during pregnancy. The two remaining groups received the above mentioned omega 3 supplements. These feeding regimens were maintained during 18 days. Supplementation of diet with 114 mg DHA/100g diet, increased significantly the concentration of DHA in brain and erythrocytes of the suckling rats. In contrast, the effects of the supplementation with ALA (700 mg/100g diet), were limited to the increase of DHA content in the brain. This increase however, was partial, reaching only 50% of the normal. Results suggest that newborn rat has a limited capacity to convert DHA from ALA, becoming dependent of preformed DHA supply to cover DHA requirements at the cellular level.

Analysis of Variance↗
PubMed1994

Semi-automatic external defibrillation.

Malignant arrhythmia, which is responsible for most of the out-of-hospital cardiac arrests, is ventricular fibrillation (VF). The best treatment of VF is a controlled electric shock on the chest administered in a short delay. The emergency medical technicians (EMTs) qualified to carry out this treatment in Belgium and in districts often succeed in arriving on the spot 8 minutes earlier than the people of the Service Mobile d'Urgence et de Réanimation (SMUR). The delegation of defibrillation to ambulance crew members however implies a specific teaching, training and a medical control. The Brussels experience shows that semi-automatic external defibrillation by EMT-Ds (SAED) is feasible when criteria for applying SAED in the pre-hospital phase are applicable.

Aged↗
PubMed1993

Expression of the human follicle-stimulating hormone receptor in the baculovirus system.

Human follitropin receptor (hFSHR) cDNA was inserted into the genome of Autographa californica nuclear polyhedrosis virus under the control of the polyhedrin promoter. Spodoptera frugiperda (Sf9) insect cells expressed the hFSHR at the membrane level, 2-3 days after infection. Ligand binding analysis demonstrated saturable, high-affinity binding of 125I-labeled recombinant hFSH (Kd = 0.17 nM) as well as binding specificity for both human and equine FSH. Interestingly, a highly purified preparation of equine choriogonadotropin was found to compete with the binding of 125I-rhFSH. Finally, Western-blot analysis, using a monoclonal antipeptide antibody directed to the 178-206 region of the hFSHR, revealed two bands migrating at M(r) 77 and 130 kDa.

Animals↗
PubMed1993

Real-time measurement of the contribution of the muscular activity to the metabolic rate in freely moving rats.

A new real-time ergometric system, ERGORAT, for measuring the energy expenditure due to muscular activity of small mammals is described. The method is based on measuring the vibrations induced by a freely moving rat to a platform on which it is living. Six accelerometers placed on the platform detect all the vibrations produced by the rat. The co-ordinates of the centre of mass of the animal are located by an optoelectronic device. This location and the six accelerations are fed to a microprocessor-based data acquisition and processing system. Using a Lagrangian dynamic model, the values of the mechanical energy transferred to the platform are computed every second. ERGORAT is used as part of an experimental setup allowing the measurement of the energetic balance of lean and obese rats. The results clearly show that the increase in metabolic rate of obese rats during cold exposure can be entirely explained by the cost of their increase in locomotor activity, whereas for lean rats, this cost accounts for only 41.5 per cent of their metabolic increase, the remaining being the contribution of their active brown adipose tissue.

Animals↗
PubMed1993

Biocompatibility and resorbability of a polylactic acid membrane for periodontal guided tissue regeneration.

The biocompatibility and degradation processes of biomembranes made of a mixture of a high molecular weight racemic polylactic acid (PLA50P) with 0, 10, 20 and 30% w/w racemic polylactic acid oligomers (PLA50p) were assessed for morphological changes in subcutaneous abdominal membrane implantations after 15, 21, 30 and 60 d in 45 Wistar rats. These membranes, prepared for periodontal guided tissue regeneration, showed excellent tissue tolerance without an inflammatory reaction. The higher the content in low molecular weight polylactic acid, the higher the degradation rate. At 60 d, the resorption process was almost complete. This process was initiated by outgrowths of short vascular septa, which developed into lobular networks infiltrating the membranes, which were progressively replaced by normal fibrous connective tissue.

Animals↗
PubMed1992

Trimipramine: acute and lasting effects on sleep in healthy and major depressive subjects.

The acute effects of trimipramine on sleep EEG patterns were investigated in six depressed inpatients and six healthy volunteers. The effects of long-term administration were then assessed in depressed patients after 4 weeks of treatment. Sedative effects of the drug were more pronounced in healthy subjects while sleep parameters of depressed patients seemed less sensitive to the drug. Chronic effects tended to correct most of the sleep disturbances seen in depressed subjects with respect to the natural organization of sleep. The major sleep effect of trimipramine concerned REM latency which was lengthened in both groups, independently of the treatment protocol.

Adult↗
PubMed1992

[Disorders of circadian rhythms in depression].

The authors make a synthesis of studies about circadian rhythms in depression and of hypothesis to explain them. They successively study trials on the phases, on the average levels, on the amplitude of rhythms. They conclude the most significant troubles are, shortening of latency on paradoxical sleep for phases, slump of melatonin levels, blunded amplitude of every parameter. Among possible explanations, they present and discuss a trouble of oscillators, a decrease of sensitivity to external synchronizers and a trouble in rhythm coupling.

Adrenocorticotropic Hormone↗
PubMed1991

Effect of cold preservation on lymphocyte adherence in the perfused rat liver.

A study was designed to determine if cold preservation induces an increase in lymphocyte adherence to liver sinusoids on reperfusion. Rat livers were stored at 1 degree C in University of Wisconsin solution for 45 min, 8 hr, or 30 hr, and then reperfused for 90 min at 37 degrees C in an isolated perfused rat liver apparatus. Just prior to reperfusion, isogeneic rat lymphocytes prepared on a Ficoll-Paque gradient were added to the perfusate. In some studies lymphocytes were labeled with a fluorescent lipophilic membrane marker. There was no change in the number of circulating lymphocytes in an anhepatic circuit. When livers were present in the circuit, lymphocytes were lost from the perfusate into the liver in all studies, with the most rapid decrease occurring within 10 min of reperfusion. The length of preservation had a marked and statistically significant effect on the rate of disappearance of lymphocytes from the perfusate. Reduction by 50% of the number of lymphocytes infused did not affect the results when expressed as percent lymphocytes remaining in perfusate. To exclude the possibility that the loss of lymphocytes into the liver was due to a damaged subpopulation of lymphocytes, two livers stored 3 for 45 min were put into the circuit in sequence. The percent reduction in cells due to exposure to a second liver was not significantly different from that observed when cells were exposed only to a single liver. Histological studies showed fluorescence-labeled lymphocytes adherent in sinusoids, and the number of labeled cells was directly related to the length of preservation. Cold preservation induces an increase in lymphocyte adherence in the reperfused liver, which might be important in graft malfunction and rejection.

Animals↗
PubMed1990

Open trial of a calcium antagonist, nimodipine, in acute mania.

Following previous works showing an action of calcium channel blockers in mania, this trial explores the clinical efficiency of another anticalcic agent, nimodipine, which has been selected for its specific action on the CNS. Our design has been a 7-day controlled open trial. We included six inpatients diagnosed according to DSM III-R criteria as having mild to acute mania. Evaluations have been made by clinical scales, electroencephalography, electrocardiography, and extensive biological blood tests. No other medication than nimodipine was allowed excepted i.m. droperidol in case of severe excitement. We used nimodipine at a dose of 360 mg/day. The results showed good clinical efficiency in each of our six inpatients, with an important and significant improvement of scales scores. We noticed an early and significant action on mood without important sedative effect. The treatment has been well tolerated, without biological effects. Further studies are needed, but nimodipine could be an alternative treatment to the neuroleptics with a different type of action, less sedative and more specific on mood.

Acute Disease↗
PubMed1989

Evaluation of fibrosis in the disse space in noncirrhotic alcoholic liver disease.

In 40 alcoholic noncirrhotic patients, we performed a liver biopsy and determined the wedged hepatic vein pressure, the free hepatic vein pressure, and the intrahepatic vein pressure. In 27 of them, the serum concentration of the N-terminal peptide of type III procollagen (PIIIP) and of the laminin P1 fragment was measured. All the liver biopsies were studied by light and transmission electronic microscopy. A score of collagenization of the Disse space (six classes) was performed using transmission electronic microscopy. 37 of the 40 patients had pathological collagenization of the Disse space which was correlated with intrahepatic pressure (p less than 0.01). The lamin P1 blood level in patients (1.38 +/- 0.51 U/ml) was increased, compared to the values of our controls (0.99 +/- 0.10 U/ml, p less than 0.01) and was correlated with the wedge hepatic vein pressure (p less than 0.01). The PIIIP blood level was not significantly increased except when Mallory bodies were found in hepatocytes (p less than 0.05). The laminin P1 blood level seemed to be a good biological marker for detection of liver fibrosis in long-term alcoholic intake.

Adult↗
PubMed1989

Course of psychosis in Algeria and in France: about 342 cases observed from 1975 to 1985.

The aim of this study was to compare the evolution of psychotic patients in Algeria and in France. In 1975, 105 patients were selected in Algeria and 237 in France. Ten years later, in 1985, all these patients were interviewed. In 1985, we investigated for each subject the evolution of the following parameters: sex, age, DSM-III axis 1 and 5, marital status, social welfare work, and treatment variables. Our results indicate that the improvement of the psychosocial adaptation (DSM-III axis 5) is slightly better in Algeria than in France. Medical and social support seems to be quantitatively less important in Algeria.

Adult↗
PubMed1989

[The development of psychoses: results of a clinical survey concerning 383 cases followed during 10 years (1975-1985)].

383 psychotics patients were selected in 1975 according to the french classification (INSERM). These initial population was simultaneously subdivided according 2 types of criteria: Diagnosis criteria (DSM III Axis 1), Psychosocial adaptation criteria (DSM III axis V). For each subjects we investigates in 1985 evolution of following data previously collected in 1975: Diagnosis and psychosocial adaptation, Marital status and presence of social welfare work, Treatment variable (Hospitalization and out patient department care, neuroleptic treatment). Results indicate than: psychosocial adaptation criteria are better than diagnosis criteria for outcome judgment. most of the time there is no correlation between high quantity of care and better outcome, furthermore some time there is a correlation between high quantity of care and negative outcome, We must consider, as one explanation of this fact, that it's the more severe patients who use the higher quantity of care.

Adaptation, Psychological↗
PubMed1989

[Evaluation of exocrine pancreatic function by the haptocorrin degradation test of the duodenal fluid collected by endoscopy].

Two groups of biological methods are commonly used to evaluate the exocrine pancreatic function: tests which require tubes for the collection of duodenal juice and the tubeless tests which are indirect tests of pancreatic function. In this study we have attempted to improve a new test: the test of haptocorrin degradation (THD). This test measures the transfer of labelled cobalamin from haptocorrin to the intrinsic factor which is provoked by the degradation of the haptocorrin by proteases in the duodenal juice. We present the results of this test in 90 patients with chronic pancreatitis. THD was first assayed with basal duodenal juice collected by naso duodenal tubing during secretin cerulein stimulation. In this study the sensitivity and specificity of THD was 0.86 and 0.93, respectively. In the second part of this study we demonstrated that the means of collecting duodenal juice had no effect on the results of THD. Duodenal juice was collected during a secretin cerulein test or during a routine upper gastrointestinal endoscopy after pancreatic stimulation with secretin. The sensitivity and specificity of THD was 0.90 and 0.94, respectively, when duodenal juice was collected during endoscopy. THD was significantly correlated with the NBT-PABA test, steatorrhea, and with the activity of trypsin and chymotrypsin in the duodenal juice. In this study, NBT-PABA was less sensitive than THD for the diagnosis of chronic pancreatitis (sensitivity was 0.70 and 0.89, respectively). The specificity of THD was estimated at 0.94. THD seemed to be a valuable adjunct to test pancreatic function. As upper gastrointestinal endoscopy is usually performed in patients with proved or suspected chronic pancreatitis, THD seems to have a place of choice among the other tests of pancreatic exocrine function. Further evaluation of this test by a multicentric prospective trial is now needed.

Adult↗
PubMed1988

Antidepressant effect of 5-methoxypsoralen: a preliminary report.

5-Methoxypsoralen (5 MOP) administered daily (40 mg at 9 p.m.) was compared with placebo in the treatment of severe depression. The clinical response was evaluated using the Hamilton Depression Rating Scale after 1 week of treatment. Our preliminary data indicate that patients receiving 5 MOP improved significantly after 1 week, whereas patients treated with placebo did not. The stimulating effect of 5 MOP on the melatonin secretion may be involved in this clinical effect.

5-Methoxypsoralen↗