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Biomedical subjects

J Drouet

Publications and source records attributed to J Drouet.

At least 19 recordsLinked to original sources
PubMed1991

Oxygen-induced modifications of benzodiazepine receptors and D2 dopamine receptors in the rat under hyperoxia.

Peripheral-type benzodiazepine Receptors (PBR) in the kidney and Central-type Benzodiazepine Receptors (CBR) in the cerebral cortex were not affected in rats exposed to chronic hyperoxia (85% O2, ATA, 6 days). Nevertheless, cortical CBR showed a significant decrease (29%) after hyperbaric hyperoxia (100% O2, 3.5 ATA, 2 h) in rats at a preconvulsive stage, with no concomitant alteration of kidney PBR. A similar down-regulation of striatal D2 dopamine receptors was noticed (27%)--after hyperbaric hyperoxia--without any modification of cortical PBR. On the contrary, an up regulation of liver PBR was obtained in the same conditions (20%). It is likely that receptors implicated in neurotransmission are particularly down regulated or altered under hyperbaric hyperoxia.

Animals↗
PubMed1985

Production of high specific activity 123I for protein iodination for medical use.

Iodine-123 is produced via xenon-133 by irradiation of a sodium iodide target with 108 MeV deuterons from the synchrocyclotron of IPN. The on-line production method is described. The specific activity of the iodine is determined by neutron activation analysis and by a radioimmunological method. The conditions labelling different proteins (insulin, angiotensin) are given and also the purification method to obtain a product ready for injection to patients.

Angiotensins↗
PubMed1985

[In vitro evaluation and study of the survival of erythrocytes preserved in a saline-adenine-glucose-mannitol medium for 35 days].

The saline-adenine-glucose-mannitol (SAGM) solution for resuspension of red cells was evaluated on 30 blood units tested over 42 days and compared to 5 red cell concentrates collected on the conventional CPD medium. Total and extra-cellular hemoglobin, potassium, pH, ATP and DPG concentrations, osmotic fragility, schizocyte formation, and red cell antigenicity were studied through the storage period. Chromium survival studies of autologous donated red cells were performed in 10 donors. Red cell concentrates resuspended in SAGM solution showed at the 35th day of conservation at 4 degrees C, a mean storage hemolysis of only 0.66%, an ATP concentration of 67% of the initial value, a schizocyte proportion of less than 1.5%, a mean 24 hour posttransfusion viability of 88.33% and a mean red cell T 1/2 survival of 25 days 10 hours. No alteration of common blood group antigens could be found after storage of red cells for 42 days.

Adenine↗
PubMed1985

[Various characteristics of intravenous polyvalent immunoglobulins].

Polyvalent human immunoglobulins for intravenous use (GVP) are obtained by fractionating human plasma with ethanol, according to a method in which traces of pepsin at pH4 eliminate any anticomplementary activity. All the analytical tests have come within official requirements. Results of extended tests concerning specificity, potency, immunoglobulin subclass distribution, biological half-life and opsonic function are presented. Since their official release for clinical use on July 1st, 1983, almost 15,000 therapeutic units of 2.5 g of immunoglobulins have been consumed without any reported major side effects. Multicenter clinical trials are being carried out with adults and children. Available results confirm very good tolerance, and, as expected, effectiveness for well known and codified indications.

Antigens, Bacterial↗
PubMed1985

Blood donors positive for HBsAg and negative for anti-HBc antibody.

From January 1980 to December 1983, 989,907 blood donations were screened for HBsAg. A total of 1,345 was found HBsAg positive; 33 of whom were negative for anti-HBc (2.45%); in 10 cases HBeAg was present at a low level along with HBsAg. 2 of the 33 subjects were lost to follow-up. Late serum samples were available for 28 blood donors, and clinical and biological data only were known for the 3 others. An evolution of HBV markers was observed in each case; anti-HBc antibody became positive in 24 subjects (the 4 remaining subjects had a very short follow-up); HBeAg was positive at a high titer in 18 subjects and seroconversion to anti-HBe was observed in 7 individuals; HBsAg concentration increased in 21 subjects from 2 to 4,000 times and decreased in the 7 others. Seroconversion to anti-HBs was observed in 8 individuals. According to these serological, biological and clinical findings, different outcomes were observed: in 6 subjects too short a follow-up was available to allow appropriate classification, but there was evidence to suggest all probably developed clinical hepatitis; in 6 subjects asymptomatic hepatitis with rapid loss of HBsAg occurred; in 2 subjects asymptomatic hepatitis with the persistence of HBsAg at a low level and seroconversion to anti-HBe occurred; and in 17 subjects clinical hepatitis developed. These observations establish that most of the 33 blood donors were infectious at the time of their blood donation, and that anti-HBc antibody screening must not replace HBsAg screening for blood donations.

Adult↗
PubMed1984

[Parvovirus (serum-parvovirus-like-virus) and Aurillac antigen. A study of 18 cases].

Two cases of parvovirus viraemia were observed in 1972 by screening of blood donors for HBs Ag by counter-electrophoresis. This virus was named "Aurillac" from the town in which the first case originated. In London, a virus found in the same circumstances in 1975, was found identical to the Aurillac Ag. The authors named it "serum parvovirus-like virus" (SPLV) or parvovirus B 19. Since 1972, 16 additional cases have been observed in Paris. Among these 18 cases, 11 were blood donors, 4 were hospital staff and 3 were patients. Second serum samples were available for 13 of the 18 cases. Seroconversion has been detected in all except one, a patient with lymphosarcoma. Antibody could be observed within few days. Anti-Aurillac antibody was found by CEP in 25,3% of blood donors. Examination of antigen positive sera by immune electron microscopy using a late serum sample showed aggregates of spherical particles measuring 20 nm in diameter. The antigen banded in caesium chloride at a density of 1.38. Ten of the 15 healthy adults could be interviewed: 7 appeared symptomless, 1 had a fever up to 39 degrees C for one day, 2 had erythema (as well as 3 subjects who had been in contact with these 2 persons). These cases are discussed and compared to the British literature showing that this virus could provoke the fifth disease or erythema infectiosum and aplastic crisis in chronic hemolytic syndromes. This virus could contaminate clotting factors.

Adolescent↗
PubMed1983

Specific immune responses after booster immunization with tetanus toxoid in man: study of kinetics, family segregation, and linkage to HLA of in vitro lymphocyte proliferative responses and serum-antibody responses.

Kinetics and family transmission of antigen-specific in vitro cell-mediated responses were investigated in 68, and serum-antibody responses to tetanus toxoid (TT) in 73 individuals from a total of 12 families. Proliferative responses to highly purified TT monomer were studied in 6- to 7-day lymphocyte cultures. The effect of booster immunization was detectable 7 (D7) and 30 (D30), but not 120 days (D120) later. The sex of donors was not found to have any influence. A significant influence of the time interval since the last immunization was found for the responses at D7 and D30. Data were correspondingly adjusted for segregation and linkage analyses. Several transmission hypotheses for the data obtained at D7 and D30 were evaluated by likelihood ratio tests. Observations at D30 were compatible with the hypothesis of a control by a dominant genetic determinant for high responses closely linked to the major histocompatibility complex region. No such evidence could be found for D7. After booster immunization, mean antibody levels determined on D7, D30 (peak of response), and D120 were found to be higher than those prior to immunization (D0). The sex of the donors was found to have no influence on antibody responses. The time interval since the last immunization and the age of donors both had a slight influence, and data were correspondingly adjusted for segregation and linkage analyses, which showed no evidence of genetic control of the antibody responses or of linkage to HLA.

Adolescent↗
PubMed1983

Effect of whole-body irradiation on phagocytic activity of rat alveolar macrophages.

The phagocytic activity of rat alveolar macrophages was studied in vitro for up to six weeks after whole-body gamma irradiation (7.5 Gy). Ingestion of fluorescent latex microspheres was evaluated using both microscopic examination and flow cytometric quantitation. After a transient decrease on first day post-irradiation, a slight increase in the phagocytic ability was observed from day 14 to day 28, with a maximum on day 21. From day 35 onwards, phagocytic capacities returned approximately to those of the controls. The percentage of phagocytic cells (cells having ingested one microsphere or more) increased by 75 per cent on day 21 after irradiation and the phagocytic index (percentage of phagocytic cells X the average number of ingested microspheres per cell) increased by 250 per cent while at the same time, the number of recovered alveolar cells decreased by 37 per cent. The augmentation of phagocytic capacities after irradiation was particularly characterized by an increase in the percentage of cells ingesting more than five microspheres. Flow cytometric studies showed a significant increase in mean cell size on day 21 post-irradiation. The augmentation of the phagocytic activity was not found when macrophages from control rats were incubated with serum or alveolar lavage fluid from an irradiated donor. Augmentation of phagocytic capacity was also observed after 8.5 Gy but no effect could be observed after 6.5 Gy.

Animals↗
PubMed1983

[Genetic effect on specific human immune responses to tetanus anatoxin].

Kinetics and family transmission of antigen specific immune responses were investigated before and 7, 30 and 120 days after booster immunization with tetanus toxoid (TT) in 73 individuals from 12 families. The study of TT specific in vitro lymphocyte proliferative response and of TT antibody levels by radioimmunoassay were performed in parallel; the effect of booster immunization was detectable 7 and 30 days later and still 120 days later for antibody response. No influence of the sex of donors was found. Because of the significant influence on the level of responses of the time interval since last immunization, data were correspondingly adjusted for segregation and linkage analysis. Observations at day 30 were compatible with the hypothesis of control by a dominant genetic determinant for high proliferative responses closely linked to the major histocompatibility complex region.

Antibodies, Bacterial↗
PubMed1983

Monoclonal antibodies to HBsAg: a study of their specificities for eight different HBsAg subtypes.

Spleens from high responder Biozzi mice immunized with purified HBsAg of adw2, adw4 and ayw3 subtypes respectively were fused with N5-1 mouse myeloma cells. Over 30 clones with anti-alpha activity were obtained (principally from fusion adw2) as well as numerous clones with restrictive anti-HBs reactivity. The aim of this study was to characterize 9 different monoclonal antibodies with restrictive reactivity in comparison to a monoclonal anti-alpha antibody. Two different techniques were used: immunodiffusion and enzymoimmunoassay. Already known specificities or common reactivity between some subtypes were found, as w4, subdivision of ayw3 subtype, antigenic determinant common to w4 and adr, absence of the same determinant in adw2 and ayw1, the 2 subtypes having the highest capacity to absorb anti-alpha. Other monoclonal antibodies indicated the presence of previously unidentified subtype specificities: one of them recognized all HBsAg with d determinant but also ayw4, another recognized all HBsAg with y determinant but also adr, 2 others recognized determinants present completely or partially (spur formation) in many subtypes, another one recognized ayw4 and adw4 but also adw2. The combination of new tools such as monoclonal antibodies and synthetic peptides should facilitate the analysis of HBsAg.

Animals↗
PubMed1982

Subgranular zone of the dentate gyrus of young rabbits as a secondary matrix. A high-resolution autoradiographic study.

Cell genesis in the subgranular zone of the dentate gyrus of 2-month-old rabbits has been investigated. After incorporation of tritiated thymidine, electron microscopic autoradiography allowed description of the ultrastructure of the cells labelled and the progressive transformation of these cells into granular neurons to be followed. Quantitative evaluation of the time course of this transformation has been performed by light microscope autoradiography using 1-micrometer sections. Precursor cells, labelled initially with 3H-thymidine, were transformed after 5 days into early neuroblasts, these cells in turn giving rise to neurons some 8 days later. At the latest time period examined (42 days), 80% of the labelled cells were neurons; more than 10% remained as precursor cells. It is suspected that the latter may behave as reserve cells. Small numbers of glial cells, astrocytes, and microglia, scattered throughout the hilus of the dentate gyrus and the molecular layer, were found labelled, and it is possible that they arise from a different precusor pool. It is concluded that the subgranular zone functions as a secondary matrix for granule neurons of the dentate gyrus in young rabbits. These late-forming and apparently synaptically uncommitted neurons may be recruited during the development and refinement of postnatal behavioral substrates, by one or other of the dominant afferent systems.

Animals↗
PubMed1981

[Ability of isoelectric focusing to separate antitetanus antibodies in venous blood].

In a previous study, we have showed a great heterogeneity of antitetanus antibodies using polyacrylamide thin layer isoelectrofocusing. In this study, we have improved the resolution of the focused antitetanus antibodies by electrofocusing in sucrose density gradients, which is a suitable procedure for preparative work. After isoelectrofocusing the elution is performed according to any pH variation. For each fraction, we have determined pH, absorbance at 280 nm, protein level by method of Lowry, IgG concentration using immunonephelometric method and antitetanus antibodies concentration by radioimmunoassay. Furthermore, the purity of each fraction is verified by polyacrylamide slab gel isoelectrofocusing. It is concluded that the isoelectric point of antitetanus antibodies is alkaline range between 7.5 and 8.5. This precise knowledge could afford an opportunity for the industrial preparation of antitetanus antibodies.

Absorption↗
PubMed1980

Radioimmunoassay of the myelin basic protein in biological fluids, conditions improving sensitivity and specificity.

The radioimmunoassay (RIA) for myelin basic protein (MBP) in biological fluids was reassessed in order to improve its sensitivity and eliminate some interferences. By using the preincubation technique and the charcoal-dextran-horse serum mixture for the separation step, the detection limit could be lowered to 200 pg/ml for cerebrospinal fluids (CSF), amniotic fluids (AF) and nervous tissue extracts and 600 pg/ml for sera. The RIA could be used directly on CSF, AF and nervous tissue extracts. Sera, however, had to be heated in citrate buffer at 100 degrees C in order to discard interfering material. The present method is 10 to 20 times more sensitive than others previously published. Moreover, it can be applied to amniotic fluid. The biological fluids had to be promptly frozen to avoid degradation of MBP.

Amniotic Fluid↗
PubMed1980

Studies of microsomal glucose-6-phosphatase on liver of irradiated rats.

The activity of microsomal glucose-6-phosphatase (EC 3.1.3.9) on male rat liver was measured 1-9 days after whole-body gamma-irradiation. A marked fall of activity, expressed per whole liver, was observed reaching a minimum on the 4th day following irradiation. The enzyme activity is partially and momentarily restored (on day 7), before a new decrease occurred. Furthermore, when the results are expressed per milligram of microsomal proteins, there was no change. Cysteamine, when injected in vivo, kept up the glucose-6-phosphatase of whole liver. On day 4, a histochemical demonstration of the enzyme in liver cells is in accordance with enzyme measures. These observations suggested that the enzyme quantity was altered during the acute radiation syndrome in the rat.

Animals↗
PubMed1979

Differential radiosensitivity of neurons and neuroglia of the hippocampus in the adult rabbit.

Adult rabbits were subjected to 4.5 Gy of whole-blody or brain alone gamma-irradiation, and their hippocampus was examined with the light and electron microscope. Pycnotic cells were found at the base of the granular layer of the dentate gyrus in the so-called subgranular zone, as soon as 3 h after irradiation, and were cleared up by active phagocytosis after 48 h. Some of these cells appeared as undifferentiated, whereas others were differentiating granule cells, and possibly immature neuroglia. The extent of cell necrosis was contingent upon the age of the animal, the oldest animal studied (27 months) showing only sparse lesion of that type. Astrocytes and microglia were responsible for the phagocytosis of dead cells. Another type of lesion was found in the nuclei of the mature granule cells and consisted of light spots which appeared 1 h after the irradiation and disappeared almost completely after 48 h. Pyramidal cells did not show any of these two lesions. It is concluded that the laterations in the electrical activity of pyrimidal cells, following irradiation, are at least partly due to lesions affecting the dentate gyrus. Radionecrosis in the subgranular zone is related to the presence of immature cells in this region.

Age Factors↗