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Biomedical subjects

A Bernard

Publications and source records attributed to A Bernard.

At least 559 records · Page 31Linked to original sources
PubMed1984

[Intraenterocytic metabolism and blood uptake of caproic and oleic acids in control and actidione-cycloheximide-treated rats].

Intestinal absorption of capric and oleic acids from the intestinal lumen into mesenteric portal vein blood was investigated in control and actidione-cycloheximide-treated rats using the ex vivo vascular perfusion technique. The measurement of 14C-labeled lipids, 14CO2 and 14C-labeled acid-soluble products was simultaneously carried out with blood collected at 5-min intervals for 60 min. The enterocyte catabolism of capric and oleic acids, one of which was preferentially absorbed via the blood, has been interpreted by the different processes of absorption. The greater enterocyte catabolic activity with capric acid, compared to oleic acid, could be related to the slight affinity of FABP Z for this medium-chain fatty acid and also to lack of capric acid esterification; a non-negligible fraction of this fatty acid actually disappeared from the lumen and was catabolized into the enterocyte at an early stage of its absorption. The actidione-cycloheximide treatment affected oleic acid absorption via the blood to a greater degree than that of capric acid. But it modified both intestinal blood absorption and the catabolism of the two fatty acids in the same manner.

Animals↗
PubMed1983

Health surveillance of workers exposed to tetrachloroethylene in dry-cleaning shops.

Behavioral, renal, hepatic and pulmonary tests were applied to 22 subjects exposed to tetrachloroethylene in 6 dry-cleaning shops. The results were compared with those obtained in 33 subjects non-occupationally exposed to organic solvents. The intensity of exposure was monitored by personal environmental monitoring and by urine analysis for trichloroacetic acid and expired air and venous blood analysis for tetrachloroethylene. The time-weighted average exposure to tetrachloroethylene amounted to 21 ppm (range 9 to 38 ppm). The correlation between the concentration of tetrachloroethylene in ambient air sampled with the charcoal tube method and with a passive dosimeter indicates that the latter can correctly estimate the time-weighted average exposure to the solvent. In view of the long biological half-life of tetrachloroethylene, the internal dose may be better estimated by measuring its concentration in blood 16 h after the end of exposure (i.e. before resuming work the next morning). The present study suggests that if the blood concentration of tetrachloroethylene does not exceed 1 mg/l, 16 h after the end of exposure, the time-weighted average exposure is likely to have been below 50 ppm. Exposure to such level for 6 years on the average does not seem to exert any adverse effect on the central nervous system, the liver and the kidney.

Adolescent↗
PubMed1983

Significance of urinary metallothionein in workers exposed to cadmium.

Cadmium in blood (Cd-B) and in urine (Cd-U) and metallothionein (Mt-U) and beta 2-microglobulin in urine (beta 2m-U) were measured in 94 male Cd workers. The results were examined according to the workers' current exposure to cadmium (group C, n = 73, workers currently exposed to Cd; group R, n = 21, Cd workers removed from exposure or retired) and according to their renal status (group N, n = 66, normal beta 2m-U; group I, n = 28, beta 2m-U greater than 200 micrograms/g creatinine). The interrelationships between Mt-U, Cd-U, Cd-B and years of cadmium exposure were examined in the various subgroups. The study of the correlations between these variables demonstrates that Mt-U is directly correlated with Cd-U but not with Cd-B or years of Cd exposure. The association between Cd-U and Mt-U is independent of the status of renal function and the intensity of current exposure to cadmium. Under moderate chronic exposure to cadmium, the fraction of Cd-U which is directly influenced by recent exposure (Cd-B) is small in comparison with that influenced by the cadmium body burden.

Adult↗
PubMed1983

Renal handling of human beta 2-microglobulin in normal and cadmium-poisoned rats.

The renal handling of human beta 2-microglobulin (beta 2-m) was investigated in normal rat and in rat with cadmium-induced renal damage. Cadmium was administered either in drinking water at a concentration of 100 ppm for up to 16 months or by i.p. injection of 1 mg Cd/kg, five times a week for up to 4 months. When renal dysfunction has developed, namely after 2 and 10 months of the i.p. and oral treatment respectively, unlabelled human beta 2-m was injected intravenously and its disappearance in serum and its urinary excretion were studied by means of a sensitive immunoassay. In serum, the level of beta 2-m drops by about 90% during the 10 first min, then declines more slowly with a half life around 20 min. Serum disappearance curves of beta 2-m in normal and cadmium-treated rats did not differ markedly. The amount of beta 2-m recovered in urine during the 4 h following the injection averaged 0.03% of the injected dose in normal rats. It increased on the average to 10% in rats treated i.p. with 1 mg Cd/kg for 3 months. However, in rats given 100 ppm Cd per os for 10 months, this amount averaged only 0.14%. A similar value was observed 5 months later, although at that stage, the critical level of cadmium in kidney cortex had been reached for 6-7 months. These data which were in accordance with the disturbances of the other renal parameters measured in cadmium-treated rats indicate that: 1) human beta 2-m is reabsorbed by rat kidney at a similar rate as by human kidney; 2) if the occurrence of cadmium tubulopathy is concomitant with the saturation of cadmium-binding sites in kidney, its severity depends greatly on the rate at which cadmium reaches the saturated kidneys.

Animals↗
PubMed1983

Gentamicin nephrotoxicity in cadmium, lead and mercury pretreated rats.

The effect of a previous chronic exposure to cadmium, lead or inorganic mercury on the nephrotoxic potential of gentamicin was investigated in female Sprague-Dawley rats. A daily dose of 10 mg gentamicin/kg body weight/day was administered for 21 days to rats having a renal load of 168 micrograms Cd, 35 micrograms Pb or 129 micrograms Hg/g whole kidney. Urine analysis suggests an attenuation of the nephrotoxic potential of gentamicin while a microscopical examination of kidneys indicates a superimposition of the effects of the metals and the antibiotics. The only clear interaction observed consists in a reduction of gentamicin accumulation in the cortex of cadmium-treated animals. It is concluded that none of the metal pretreatments potentiates the nephrotoxic effects of gentamicin.

Amino Acids↗
PubMed1983

Anti-laminin antibodies in workers exposed to mercury vapour.

In 62 male workers exposed to mercury vapour for 5.5 years on average, the results of several renal parameters were not significantly different from those found in a well-matched control group (n = 60). Circulating anti-laminin antibodies were found, however, in 8 workers exposed to mercury vapour but in none of the control workers. These results suggest that occupational exposure to mercury vapour may lead to immune dysfunction in a certain percentage of the exposed population. Whether such a finding is predictive of the occurrence of an immune glomerulonephritis remains to be evaluated.

Antibodies↗
PubMed1983

Canine distemper infection in mice: characterization of a neuro-adapted virus strain and its long-term evolution in the mouse.

The Onderstepoort strain of canine distemper virus (CDV) which has been adapted to newborn Swiss mice was used in a study in weanling mice. Intracerebral inoculation of newborn mice with either the parent or mouse-adapted virus strain led to mortality in 100% of the animals. In weanling mice the parent virus produced less than 10% mortality, whereas the mouse-adapted strain killed approximately 40% of the animals and this was not dose-dependent. Although a meningitis was observed in the surviving mice, the occurrence of viral antigens was less widespread in the brain of weanling mice than in the brain of newborn mice, and could not be detected more than 5 months after infection. In long-term experiments two phenomena were observed. At 4 to 6 months post-infection up to 30% of the mice became obese; however, no viral antigens were detected in the brains. At 13 to 17 months post-infection a number of mice became paralysed and virus antigen could be detected in the brain and lymph glands; however, infectious virus could not be isolated. These observations are discussed in relation to neurological infection and metabolic disease.

Animals↗
PubMed1983

Anti-D47: a monoclonal antibody reacting with the secretory cells of human eccrine sweat glands.

Anti-D47 is a monoclonal antibody reacting with a surface antigen of human cortical thymocytes (different from the T6 antigen). It was prepared by immunization of mice with human thymocytes. The known cross-reactivity of monoclonal antibodies prepared against thymic cells with skin components prompted us to test anti-D47 on human skin as well as animal tissues. No labelling was observed on animal tissues. On human skin, anti-D47 was found to react with the secretory portion of eccrine sweat glands (ESG), i.e. with a cytoplasmic antigen of the secretory cells lining the deep portion of ESG glomeruli. No labelling was observed on apocrine sweat glands or on the excretory portion of ESG. Anti-D47 was also tested on histologically proven extramammary (vulvar) Paget's disease and basal cell epitheliomas: no staining of the neoplastic cells was observed. Anti-D47 appears to be an immunological marker of the secretory cells of human ESG and a new tool for the investigation of human sweat gland pathology.

Animals↗
PubMed1983

Biochemical and electron microscope radioautographic study of intestinal absorption of tritiated palmitic and oleic acids in control and actidione-cycloheximide-treated rats.

Intestinal absorption of tritiated palmitic and oleic acids was investigated in control and actidione-cycloheximide-treated rats. Pancreatic juice was collected and 24 hr later an intestinal loop was cannulated in situ. A 90 mumole-lipid emulsion composed of an equimolar mixture of monopalmitin, palmitic and oleic acids with bile was infused with either 3H-labeled palmitic or oleic acid. After 15 or 30 min biochemical analysis was carried out to follow the uptake and the transfer of the labeled fatty acids. Mucosa was removed for both biochemical analysis of lipid classes and the ultrastructural or radioautographic electron microscope study depending on the radioactive activity. Following actidione-cycloheximide treatment, the uptake of both fatty acids decreased, but the amount of lipids in the mucosa greatly increased, while amount of the reesterification of fatty acids in the mucosa diminished. Consequently the amount of infused palmitic acid which was transferred in 15 min decreased from 36% in the absence of treatment to 4.6% when treatment was used. The corresponding figures for oleic acid are 70% and 20.9%. Unstructured lipids were in the intercellular spaces, indicating that a cytotoxic effect had occurred which produced a defect in the lipoprotein particle organization. The Golgi complex, in the final step of the chylomicron synthesis before exocytosis, showed low level of radioautographic reaction indicating less participation by the complex in lipid transfer. The various processes which were inhibited during long-chain fatty acid absorption from the luminal area to the Golgi complex included fatty acid binding by proteins, enzymatic acylation and esterification, apoprotein participation. This inhibition explains why long-chain fatty acid absorption was greatly impaired. Moreover, our observations compared with those obtained during decanoic acid absorption, particularly our radioautography based observations, emphasize the important role of the Golgi complex which requires intense membrane turnover during lipid absorption.

Animals↗
PubMed1983

Latex immunoassay of urinary albumin.

A new non isotopic immunoassay based on latex particle agglutination has been developed for the determination of albumin in urine. The assay consists in incubating the urine sample for 30 min at 37 degrees C with latex particles coated with a specific antibody, followed by quantification of the resulting agglutination by particle counting or turbidimetry. The stability of antibody-coated particles during incubation is achieved by diluting them just before the assay in a buffer containing bovine serum albumin. The pH of this buffer, the antibody loading and the concentration of latex particles in the incubation mixture were optimized to obtain the maximal specific and minimal nonspecific agglutination. The albumin standard curve ranges from 25 to 800 micrograms/l. Reproducibility tests performed within and between run gave CV's ranging from 8.2 to 11.6%. The recovery of albumin added to 10 urines averaged 95.5%. A correlation coefficient of 0.96 was obtained between latex immunoassay and nephelometry for the determination of albumin in 51 urines.

Adult↗
PubMed1983

[Cervical aortic arch. Apropos of a case].

A new case of left cervical aorta is described, affecting a 12-year-old girl. Haemodynamic, CT scan and radiological investigations are described. The only associated abnormality in the present case was hypoplasia of the left vertebral artery. There were two spicules on the medial surface of the descending aorta, possibly embryonic rests. A review is made of the literature and there is discussion of the contribution of different diagnostic techniques to determination of the embryological origin or the abnormality and its possible treatment.

Aorta, Thoracic↗
PubMed1982

[Fall in the levels of circulating lymphoblasts caused by intravenous administration of the A50 monoclonal antibody in a patient with acute T-cell lymphoblastic leukemia. A step in the demonstration of serotherapy with monoclonal antibodies].

In an 8-year-old boy with acute lymphoblastic leukaemia not previously treated intravenous administration of a single 8 mg dose of a monoclonal antibody that recognizes an epitope restricted to the surface of mature T-cells resulted, within 20 hours, in a fall in circulating lymphoblasts from 200 000 to 70 000. No adverse clinical or biological reaction was detected and no antigenic modulation occurred at lymphoblast surface. This observation constitutes a first step in the complex development of effective serotherapy for malignant diseases, using monoclonal antibodies.

Animals↗
PubMed1982

[Identification of lymphocyte populations producing alpha-interferon by monoclonal antibodies].

Two different leucocyte populations producing alpha-interferon can be defined by monoclonal antibodies. One non glass adherent population produces interferon after induction with Herpes and Sendaï viruses. It is characterized by anti-D44 antibody, defining both some T and NK cells, but not by anti-D66 antibody with selective reactivity for T cells. The other glass adherent population is identified by OKM1 antibody, which defines about 70% of the monocytes, and can be induced only with Sendaï virus.

Antibodies, Monoclonal↗
PubMed1982

Phenomenon of human T cells rosetting with sheep erythrocytes analyzed with monoclonal antibodies. "Modulation" of a partially hidden epitope determining the conditions of interaction between T cells and erythrocytes.

Anti-D66 is a monoclonal antibody able to inhibit E-rosette formation of T cells both at 4 degrees C and at 37 degree C but that does not inhibit T cell rosette formation with neuraminidase or 2-amino-ethylisothiouronium bromide (AET)-pretreated E. As demonstrated by capping experiments, it defines an epitope, D66, that is directly involved in E-rosette formation. D66 is distinct from the epitope defined by 9.6 because 9.6, a previously defined "pan-T" monoclonal antibody, inhibits E(AET) rosette formation and because no cross-blocking occurred between both antibodies fixation. However, 9.6 and D66 are carried by the same molecule, as demonstrated by sequential immunoprecipitation assays performed on two different T cell lines. On the thymocyte surface, also, 9.6 and D66 are most probably carried by the same molecule, as indicated by cocapping and colysostripping experiments. D66 is present at higher densities on thymocytes and activated T cells than on peripheral blood T cells. Investigation of numerous T cell populations, both normal and malignant, showed a straightforward correlation between elevated D66 density and ability to form 37 degrees C stable E-rosettes. Neuraminidase treatment of thymocytes and peripheral blood lymphocytes forming E-rosettes unmasked a large fraction of D66 not readily accessible on their surface. These hidden D66 epitopes appear to be responsible for a surprising observation: the ability of anti-D66 to inhibit E-rosette formation could be totally reversed by fixation on anti-D66 of an antibody to mouse immunoglobulin or an Fab fragment anti-mouse immunoglobulin. This would induce microdisplacement with emergence of hidden D66, as documented by fluorometric studies. Finally, malignant T cells with a differentiative status of mature T cells, but forming no (or low numbers of) E-rosettes, could be induced both to display D66 and to form E-rosettes by neuraminidase treatment.

Animals↗