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Biomedical subjects

A Bernard

Publications and source records attributed to A Bernard.

At least 613 records · Page 34Linked to original sources
PubMed1980

[Actidione-cycloheximide and the route of intestinal absorption of lipids in the rat].

The effect of actidione-cycloheximide on the intestinal absorption of 14C oleic acid was studied on male rats using the ex vivo perfusion technique in control rats and those treated with a protein synthesis inhibitor. With the amounts of lipid infused, the radioactivity recovered in portal blood lipids was the same in treated rats and in controls. However, differences were observed in the appearance of oleic acid in the portal blood during the first 15 min. When protein synthesis was inhibited, absorption occurred earlier via the portal blood. The absorption balance in this type of experiment was considerably lower than normal absorption probably because or surgical stress. In conclusion, when esterification was impaired, oleic acid seemed to be absorbed via the portal blood at the beginning of the experiment like short or medium-chain fatty acids.

Animals↗
PubMed1980

[Biochemical and ultrastructural study of actidione-cycloheximide effect on fat intestinal absorption in the rat (author's transl)].

The biochemical and ultrastructural aspects of intestinall fat absorption and chylomicron formation have been studied in rats treated with actidione-cycloheximide. Rats were prepared with a catheter in the main mesenteric lymph duct. The next day, primor rapeseed oil containing 14C triolein was infused in the duodenum of control rats and actidione-cycloheximide treated rats four hours before experiments. In each case, the quantity of lipids absorbed was determined after six hours, and the lipids present in the mucosa were studied as were those present in the lymph collected throughout the absorption period. Furthermore, the ultrastructural study of the mucosa and the morphological study of the lymph lipoprotein particles were carried out using electron microscopy. Disappearance of intraluminal lipids and mucosal lipids appeared slightly impaired after actidione-cycloheximide treatment, but only a very small proportion of the infused lipids were recovered in the intestinal lymph (0.05% compared to 3% in control rats, Table I). The amount of esterified lipids found in the mucosa, after six hours, was clearly lower (49%) when compared with those of control rats (79%) (Table II). This suggests that, following inhibition of protein synthesis by actidione-cycloheximide, lymph fat absorption was much impaired. An alteration in cellular structure appeared in microscopic observations of treated rat enterocytes (Fig. 2 and 3) compared with the control (Fig. 1). Many whorl formations and autophagic vacuoles were included in these cytotoxic effects during lipid absorption. Treated animal enterocyte lipid particles did not have the organized structure of those in the controls. While lymph particles of control rats revealed a regular progression in size (Fig. 4A, B), lymph particles of treated-rats showed a few large chylomicrons (equal or far larger than in the controls) among small particles (Fig. 4 C, D, E); furthermore, evidence of coalescence might be observed (Fig. 4 F). All these observations emphasize the prevailing role of the different protein structures of the enterocytes during lipid intestinal absorption, particularly for chylomicron organization after long-chain fatty acid uptake.

Animals↗
PubMed1980

Assessment of renal function of workers exposed to inorganic lead, calcium or mercury vapor.

The renal function of workers occupationally exposed to cadmium (n = 148), to mercury vapor (n = 63) or to inorganic lead (n = 25) has been compared with that of workers with no occupational exposure to heavy metals (n = 88). A moderate exposure to lead (Pb-B < 62 microgram/100 ml) does not seem to alter renal function. Excessive exposure to cadmium increases the urinary excretion of both low- and high-molecular-weight proteins and of tubular enzymes. These changes are mainly observed in workers excreting more than 10 microgram Cd/g creatinine or with Cd-B above 1 microgram Cd/100 ml whole blood. Occupational exposure to mercury vapor induces glomerular dysfunction as evidenced by an increased urinary excretion of high-molecular-weight proteins and a slightly increased prevalence of higher beta 2-microglobulin concentration in plasma without concomitant change in urinary beta 2-microglobulin concentration. beta-galactosidase activity in blood and in urine is also increased. The likelihood of these findings is greater in workers with Hg-B and Hg-U exceeding 3 microgram/100 ml whole blood and 50 microgram/g creatinine, respectively. The hypothesis is put forward that the glomerular dysfunction induced by cadmium and mercury might result from an autoimmune mechanism.

Adult↗
PubMed1980

Induction of preterm labor in the rabbit by antiprogesterone.

On the 25th day of pregnancy, 14 New Zealand white rabbits were treated orally with 500 mg of the progesterone (P)-synthesis inhibitor: Isoxazol. This treatment was repeated 12 hours (n = 6) or 24 hours (n = 8) later. An additional group of 6 rabbits received at the same time the solvent, without Isoxazol, to serve as vehicle controls. From day 26 onward all these 20 animals were induced every day with a single i.v. injection of 100 mU oxytocin until they delivered. The 14 Isoxazol rabbits responded to oxytocin on day 27.7 plus or minus 0.2 (Mean plus or minus S.E.), while the vehicle controls failed to respond until day 30.3 plus or minus 0.4 of pregnancy (p smaller than 0.001). Progesterone assays in the uterine vein plasma showed that, in comparison with 14 untreated controls of similar gestational age, plasma P of the 14 Isoxazol rabbits was significantly reduced (p smaller than 0.01). The vehicle controls became inducable when their P was endogenously lowered to the level at which oxytocin readily provokes parturition near term. Neither Isoxazol, nor oxytocin altered the normally low prostaglandin F levels of the uterine vein plasma, indicating that Isoxazol provokes premature inducability in the rabbit through P-withdrawal, rather than through an elevation of PG-levels.

Androstenols↗
PubMed1979

[Electron microscopic study of secretion of chylomicrons in the rat by enterocytes in lymphatic capillary lumen].

Rats were fed on a 20% fat diet; 30 min. or 2 hrs later intestinal jejunal cells were fixed in situ; samples were taken and processed for subsequent study by electron microscopy. Chylomicron secretion was followed from the enterocyte to the lymphatic capillary lumen. Chylomicrons entered the lamina propria through breaks in the basal membrane at intercellular space level. Their penetration into the lymphatic capillary lumen occurred through the open junctions of the endothelial cells normally kept closed by desmosomal formations.

Animals↗
PubMed1979

Isolation and characterisation of a defective measles virus from a subacute sclerosing panencephalitis patient.

A cytopathic measles virus was isolated from a brain biopsy of a subacute sclerosing panencephalitis (SSPE) patient. The agent could be transferred to Vero cells by cocultivation, but the infectivity always remained cell-associated -ie, a defective virus infection. The cell-associated nature of the virus was retained through 25 passages in Vero cells. Intracerebral inoculation of hamsters (2-6 days old) with the cocultured Vero cells gave rise to 100% mortality in 5-7 days. The virus retained its cell-associated nature after passage in hamsters. Electron microscopy of the brain and Vero cocultures showed the presence of virus-like ribonucleoparticles mainly in the nucleus. The presence of viral antigens in the nucleus, cytoplasm, and on the plasma membranes was confirmed by immunofluorescence. Using a combination of immunological and biochemical techniques, it was shown that all the viral proteins were synthesized with the exception of the haemagglutinin. Inclusion of the fusion inhibitor SV4814 (CBZ-D phenylalanine-L-phenylalanine-L-arginine-NO2) in the culture medium led to the elimination of the SSPE infection.

Adult↗
PubMed1979

Renal excretion of proteins and enzymes in workers exposed to cadmium.

The proteinuria rate and the relative clearances of beta 2-microglobulin, orosomucoid, albumin, transferrin and IgG were measured in forty-two workers exposed to cadmium and in seventy-seven control workers. A tubular type proteinuria with an increased excretion of beta 2-microglobulin and often also a glomerular type proteinuria with an increased excretion of orosomucoid, albumin, transferrin and IgG were observed mainly in workers exposed to cadmium for more than 25 years and whose cadmium concentration in blood exceeded 1 microgram Cd/100 ml and that in urine 10 microgram Cd/g creatinine. The glomerular dysfunction was also suggested by an increased plasma level of beta 2-microglobulin and creatinine. Both tubular and glomerular impairments occurred with the same prevalence and were not necessarily associated. The increased release of beta-galactosidase by the kidney suggested that cadmium can damage some epithelial cells.

Adult↗
PubMed1979

Stimulation of the alpha-and beta-adrenergic receptors in human ovarian vasculature in vitro.

The effect of fenoterol and norepinephrine was studied on the vascular resistance of in vitro perfused human ovary. It was found that the beta-adrenergic stimulant fenoterol causes vasodilatation, whereas the alpha-adrenergic stimulant norepinephrine elicits vasoconstriction in the arterial vascular bed of the ovary showing the role of adrenergic mechanism in the regulation of ovarian blood flow. It was supposed that therapeutical administration of beta-mimetic drugs leads to the elevation of ovarian blood flow, which may have special importance in the case of corpus luteum insufficiency.

Adult↗
PubMed1979

Investigations on the lung and kidney function in workers exposed to cadmium.

The kidney seems more sensitive to the chronic effect of cadmium than the lung. Only minor impairments of lung function (mild form of obstructive lung disease) were found after long-term occupational exposure (less than 20 yr) to moderate concentration of cadmium oxide dust and fume. This conclusion, cannot, however be extrapolated to acute or subacute inhalational exposure. The nephrotoxicity of cadmium consists in a tubular dysfunction characterized by an increased excretion of beta 2-microglobulin and giving rise to the classical tubular proteinuria and in a glomerular dysfunction evidenced by an increased excretion of high molecular weight proteins and increased levels of beta 2-microglobulin and creatinine in plasma and giving rise to a glomerular type proteinuria. These renal changes were mainly found in workers whose cadmium concentration at time of the survey exceeded 1 microgram Cd/100 ml in blood and 10 microgram Cd/g creatinine in urine. It should, however, be stressed that higher levels of Cd in blood and in urine are not necessarily associated with the presence of excessive proteinuria. In newly exposed workers, the Cd level in blood increases progressively to a plateau after several weeks. Cadmium level in urine fluctuates more. In workers exposed for several months to an airborne concentration exceeding 200 microgram/m3, Cd concentration in urine seems mainly influenced by recent exposure.

Adult↗
PubMed1979

Human T cell differentiation antigens and correlation of their expression with various markers of T cell maturation.

Two sets of differentiation antigens are demonstrated on human T cells by using 11 heterologous anti-human antisera raised against various normal and malignant T cells. The two antigenic determinants from the first set of differentiation antigens are expressed only on thymus cells and on T lymphoblasts, whereas the two antigenic determinants from the second set are expressed on blood T cells, Sezary cells, T.CLL cells, and thymus cells. Four T cell phenotypes are thus defined; two phenotypes are expressed only by T lymphoblasts, whereas the other two phenotypes are expressed both by normal and malignant T cells. Moreover, a clear-cut relationship exists between the four T cell antigenic phenotypes and two other markers of T cell differentiation: terminal deoxynucleotidyl transferase and peanut agglutinin. Two phenotypes are linked with the presence of TdT, one phenotype is linked with the affinity for PNA, and the fourth phenotype is correlated with the absence of both markers.

Acute Disease↗
PubMed1979

Subsets of malignant lymphomas in children related to the cell phenotype.

We studied the lymphomatous cells of 39 children presenting with the classical features of malignant lymphoma. Twenty-two had T lymphoblasts. We could classify these patients into three subsets: The T lymphoblasts from children group 1 displayed antigen(s) shared by a thymocyte subpopulation, had terminal deoxynucleotidyl transferase (TDT), but no affinity for peanut agglutinin (PNA). The T lymphoblasts from children group 2 lacked the thymocyte antigen(s), had no TDT, but showed affinity for PNA. The T lymphoblasts from children group 3 displayed mature T-cell antigens, had no TDT, and no affinity for PNA. Children from the three groups were similar in terms of clinical presentation, age and sex distribution, and cell morphology; however patients from the three groups might have a different prognosis. Fourteen children had B lymphoblasts that, in half of the cases, had affinity for Helix pomatia agglutinin. Three patients had lymphoblasts lacking specific marker. Two of them had cells displaying an antigen found on common acute lymphoblastic leukemia cells and had TDT.

Adolescent↗