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Biomedical subjects

L Robert

Publications and source records attributed to L Robert.

At least 235 records · Page 13Linked to original sources
PubMed1981

Fibronectin-like protein in Porifera: its role in cell aggregation.

Experiments were carried out on a freshwater sponge (Ephydatia mulleri) in order to demonstrate the presence of fibronectin in Porifera. By using antibodies to highly purified human plasma fibronectin, the presence of a similar or identical protein could be demonstrated in the membranes of E. mulleri cells such as epithelial cells, fibroblast-like cells, and choanocytes. The reaction was specific, could be abolished by the addition of excess fibronectin, and was not observed with nonimmune rabbit serum. The immune fluorescent reaction became stronger when the sponge cells were pretreated with acetone and could also be observed, although with a less intense staining, on the intercellular matrix. This shows the predominant presence of a sponge fibronectin-like protein in the cell membranes and also its presence to a lesser extent in the intercellular matrix. When dissociated sponge cells were led to reassociate under the microscope, reassociation could be completely inhibited by anti-human fibronectin antiserum up to a dilution of 1:120 and partially inhibited up to a dilution of 1:240. The reassociation of dissociated sponge cells could also be inhibited by the addition of purified gelatin but not with serum albumin or with a normal, nonimmune rabbit serum. These results clearly indicate that a sponge cell fibronectin-like protein may play an important role as the (or one of the) recognition site(s) of the aggregation factor(s) and can therefore be directly involved in cell association, morphogenesis, and differentiation.

Animals↗
PubMed1981

[A simple method for detection of functional and genetics alpha-1-antitrypsin deficiencies of human serum (author's transl)].

Insoluble elastin immobilised in Agar plates was used as substrate to quantitate the elastase inhibitory capacity of human sera. This technique was found valuable to evaluate the genetic deficiency of alpha-1-antitrypsin (Z phenotypes) and also the functional loss of the elastase inhibitory capacity in smokers. A significant decrease of elastase inhibitory capacity was demonstrated in the sera of smokers between 40 and 80 years of age, as compared to non smokers of the same age. This method may be useful for the evaluation of patients suffering from elastic tissue diseases (emphysema, arteriosclerosis).

Elastin↗
PubMed1981

Studies on elastic tissue of aorta in aortic dissections and Marfan syndrome.

Insoluble elastins were isolated from control and aneurytic aortas by a sequential extraction procedure involving the use of purified collagenase. Marked differences in amino acid analyses and susceptibilities to pancreatic elastase were observed between normal and pathological samples. The incorporation of either 14C-lysine or 14C-glucosamine into proteins of the vessel wall was also studied. In addition, high amounts of elastase-type activity was extractable from pathological aorta specimens which may contribute significantly to the loss of elastic tissue evidenced by ultra-structural studies and confirmed by the biochemical technics. We propose therefore that increased elastase-type protease activity in these pathological aortas does significantly contribute to the weakening of the aortic wall and also may well be the main cause of the rupture of aneurysms observed occasionally.

Adult↗
PubMed1981

Pharmacological studies on elastin peptides (kappa-elastin). Blood clearance, percutaneous penetration and tissue distribution.

Soluble elastin peptides obtained by partial hydrolysis of ligamentum nuchae elastin in 1M KOH in 80 per cent aqueous ethanol (kappa-elastin) were labelled in vitro by incubation with tritiated borohydrate. 3H-labelled kappa-elastin was administered iv and percutaneously and its elimination and organ distribution determined. iv administered kappa-elastin is rapidly eliminated through the kidneys with a first rapid phase (t 1/2 9.9 min) and a second slower phase (t 1/2 169 min). Percutaneously administered elastin peptides penetrate in the dermis and 30 to 40 per cent of the administered label can still be found in the skin 48 hours later. Resorption through the skin is a slow process, with very little or no radioactivity detectable at any time in the blood. Only liver and lung contained significant amounts of radioactivity (4 per cent and 2 per cent of the total dose administered) at 48 hours after administration. Urinary elimination represented about 5 per cent of the administered dose. Histochemical studies performed on the skin of rats treated daily with kappa-elastin (25 mg per day for 4 weeks) showed an increase of elastin-staining material in the dermis. This increase is partly due to a modified staining of collagen bundles, resulting probably from the association of elastin peptides with the collagen bundles. It may also partly be due to an increase of elastin fibers in the dermis through the stimulation of fibroblast activity. These histochemical results confirm the penetration of elastin peptides in the dermis, their association with dermal collagen fibers and also their action on the cellular activity of the dermis.

Administration, Topical↗
PubMed1981

[Mortality: comparison of mortality between a specific industry and the French population (author's transl)].

Mortality statistics are underutilized in France. Authors show that it is possible to use them for small population (125 000). Classical statistical methods are utilized. The interpretation of the results is difficult with regard to the quality of National data. Comparison data conclude that mortality rates are lower within the industry for lung and gastrointestinal disease, suicide, injuries and that three health problems are more prevalent: alcholism, injuries for young men and cancer.

Accidents, Occupational↗
PubMed1980

Loss of fibronectin in human breast cancer.

The distribution of fibronectin was studied in normal human breast tissue and in breast tumors. In normal tissues and in benign tumors, fibronectin was present in basal laminae and on the cellular surfaces of myoepithelial and secretory cells. A partial loss of (pericellular) fibronectin was seen in atypical dystrophies, and a complete disappearance of pericellular and basement membrane-bound fibronectin was observed in invasive adenocarcinoma.

Adenocarcinoma↗