Search PubMed⌕ Search

Biomedical subjects

P Hubert

Publications and source records attributed to P Hubert.

At least 217 records · Page 12Linked to original sources
PubMed1983

Arguments in favour of endocytosis of glycoprotein components of the membranes of parallel fibers by Purkinje cells during the development of the rat cerebellum.

Chloroquine (a drug known to induce a dysfunction of lysosomes) was used to study the behavior of Concanavalin A binding glycoproteins located on the axolemma of parallel fibers in young rat cerebella, and abundant on these membranes at a period preceding synaptogenesis with the dendrites of Purkinje cells. Chloroquine induces in Purkinje cells a large accumulation of grains consisting of membrane whorls in lysosomes. These grains stain for Concanavalin A, and do not stain either for a mitochondrial marker (aspartate aminotransferase mitochondrial isoenzyme) or for a marker of the Purkinje cell internal membrane (PSG). It is suggested that the material accumulating in the Purkinje cells under the effect of chloroquine comes from the parallel fibers. Together with the observation that alpha-D-mannosidase (involved in the degradation of these glycoproteins) is exclusively located inside Purkinje cells, these results provide a firm indication that this material enters the Purkinje cells through pinocytosis. The absence of ATPase activity (ATPase is a glycoprotein plasma membrane marker highly concentrated on parallel fibers) within these grains suggested that not all the components of these membranes are pinocytosed, but that the process is specific for certain molecules. These results are compatible with the ultrastructural observations of others, and support the arguments in favour of the pinocytosis phenomenon being one of the first steps of synapse formation. The observed specificity of pinocytosis for certain molecules suggests that a receptor-mediated recognition of some glycans of glycoproteins is the preliminary event in the establishment of synapses.

Adenosine Triphosphatases↗
PubMed1983

[Retrospective study of 56 congenital diaphragmatic hernias. Prognostic factors, therapeutic deductions].

Fifty-six neonates were treated for congenital diaphragmatic hernia (48 left and 8 right) in our intensive care unit from 1972 to 1980. Because of the high mortality, we studied the factors which could predict the outcome. Early onset of symptoms (before the 2nd hour of life) and low post-ductal shunt (PAO2/FiO2 less then 15) after the 3rd postoperative hour appear to be signs of poor prognosis. Our present attitude is early surgical procedure, controlled ventilation with a FiO2 1 with Pancuronium, prevention of pneumothorax and different use of pulmonary arterial vasodilatators.

Hernia, Diaphragmatic↗
PubMed1982

Lipid composition in liver and brain of genetically obese (ob/ob), heterozygote (ob/+)and normal (+/+) mice.

Lipid composition was studied in liver and brain of normal (+/+), heterozygote (ob/+) and obese (ob/ob) mice. It was found that this genetic defect is expressed differently in the lipid composition of these organs. Cholesterol is increased in liver but strongly decreased in brain of obese animals. Phosphatide fatty acid composition is modified in liver and not in brain. In contrast, phospholipids and total ganglioside sialic acid are affected similarly in both organs. Although clinically normal, heterozygote (ob/+) mice already show an abnormal lipid composition in liver and brain. The potential importance of these results is presented.

Animals↗
PubMed1981

[Occupational risk and technological innovations. Comparison of conventional and nuclear energy systems (fuel, coal and nuclear) (author's transl)].

The objective is to compare the occupational risks associated to the production of electricity through three alternative technologies: fuel, coal and nuclear (Pressurised Water Reactor). A methodology is proposed in order to integrate the operation and construction activities. The data related to a French scenario have been collected and are presented. The results obtained in the case of nuclear technology correspond to the present French program for 1990 and have in this respect a prospective value.

Accidents, Occupational↗
PubMed1980

Metal chelate affinity chromatography. I. Influence of various parameters on the retention of nucleotides and related compounds.

The influence of various parameters, such as pH, ionic strength and temperature, on the retention of different nucleotides and related compounds on copper chelate gels has been investigated in order to understand the respective roles played by the different solute constituents (i.e., heterocyclic bases, sugars and phosphate groups) in the interaction and to define optimal conditions for subsequent application to the fractionation of oligo- and polynucleotides.

Biopolymers↗
PubMed1980

[Contribution to the study of labeled neurohypophysial hormones. Preliminary data on the properties of the macromolecular compound: vasopressin-dextran (author's transl)].

The neuropeptide binding sites at the level of their target cells can be localized by several morphological methods. For one of the neurohypophysial hormones, vasopressin, not all labelling techniques can be applied: radioiodinated vasopressin has no biological activity; only 3Hvasopressin can be used. Immunocytochemical evidence for vasopressin receptors must be supported by complementary data in order to demonstrate the specificity of the binding. A new labelled ligand is prepared: vasopressin-dextran. In vivo, this macromolecular compound has antidiuretic properties equivalent to those of free vasopressin. In vitro, it gives a cross reaction with specific anti-vasopressin antibodies. For the same macromolecular compound, the ratio between the conjugated vasopressin estimated through R.I.A. and that assayed by biological method was 30.

Animals↗
PubMed1980

[Severe blood coagulation disorder as the first sign of a peritoneal hemangio-endothelioma: a new therapeutic approach (author's transl)].

The authors describe a 3 1/2 month old infant with hemangio-endothelioma and a severe blood coagulation disorder. The tumor was inoperable and the severe blood coagulation disorder posed considerable therapeutic problem. After treatment with massive amounts of blood clotting factors, an antifibrinolytic drug and radiotherapy, the child's condition improved.

Blood Coagulation Disorders↗
PubMed1979

Direct evidence for internalization of mitochondrial aspartate aminotransferase into mitoplasts.

Mitochondrial aspartate aminotransferase, an enzyme localized on the inner face of the inner mitochondrial membrane, is released into the intermembrane space upon addition of a "movement effector" (succinate, fumarate, pyruvate, or glutamate) [Waksman, A., & Rendon, A. (1974) Biochimie 56, 907-924]. After removal of the movement effector, 90% of the released enzyme rebound to mitoplasts. Lubrol fractionation showed that this bound activity was associated with the inner membrane. Internalization was demonstrated by using both enzymatic and molecular approaches. It was found that 70% of the reassociated enzyme became inaccessible from the outside of the mitoplast either to a nonpermeating substrate (NADH), to mild protease hydrolysis, or to recognition by a specific antibody. In contrast, in inside-out vesicles, the enzyme remained accessible to NADH, protease, and antibodies. Latency measurements performed at different temperatures on whole intact mitochondria confirmed the existence of reversible intermembrane movement of the enzyme in situ.

Animals↗