PubMed Health⌕ Search

Biomedical subjects

S Shoshan

Publications and source records attributed to S Shoshan.

At least 55 records · Page 3Linked to original sources
PubMed1981

Wound healing.

Explore the source record for details and available documents.

Animals↗
PubMed1980

Inhibition of collagen breakdown by diphenylhydantoin.

Gingival tissue obtained from diphenylhydantoin-treated patients was cultured in the presence of [14C]proline for 24 h. The radioactive medium was removed and the tissue cultured for three days more. DNA, protein, hydroxyproline, proline and radioactivity determinations in the tissue indicated increased cellular proliferation, increased collagen contents and decreased breakdown of collagen in the affected tissues. The media were assayed for dialyzable and non-dialyzable hydroxyproline contents. It was found that the media in which diphenylhydantoin tissues were cultured contained more than twice as much non-dialyzable hydroxyproline than the controls. It was concluded that diphenylhydantoin brought about a reduction in collagen breakdown thus explaining the accumulation of hydroxylated collagen in the tissue.

Carbon Radioisotopes↗
PubMed1980

Electroconductivity of collagen in vitro and in vivo.

Electrical conductivity was measured on thermally reconstituted collagen fibers in vitro and on isolated rat tail tendon collagen fiber bundles in vivo. The results obtained indicated that collagen per se is not an electroconductor under physiological conditions, but rather a biological insulator.

Animals↗
PubMed1980

Three-dimensional organization of collagen fibres in tendon.

Electron microscopic observations are presented on thin sections of excised chicken breast tendon following the introduction and diffusion of aqueous solutions of heavy metal salts. The dark banded regions of the collagen fibrils are seen to be in near-perfect register throughout the diameter of each fibril and, in many cases, to be continuous across the intervening ground substance. Clusters of uranyl ions form well-defined chains extending across the interfibrillar space between neighbouring fibrils, a distance of several hundred nanometres. It is suggested that the high degree of organization characteristic of collagen fibrils in tissue may perhaps be a property not only of the protein but also of the ground substance in which it is embedded, the fibres merely rendering visible a lattice pattern of their surroundings to which they have conformed.

Animals↗
PubMed1980

Improvement of gliding function of flexor tendons by topically applied enriched collagen solution.

The long flexor tendons of the second, third and fourth toes of 94 chickens were cut and sutured. After operation the birds were divided into three groups. To reduce peritendinous adhesions, an aqueous solution of beta-aminopropionitrile (BAPN) was added to a solution of enriched native collagen (ECS) and applied to the cut tendons of one group; untreated controls and controls treated with collagen solution alone comprised the other groups. Chickens from each group were killed one, two, three, four and five weeks after operation. The results were evaluated both biomechanically and biochemically. It was found that the collagen solution alone had the same effect as the treatment with BAPN. It is suggested that the exogenous collagen present at the site of injury binds the collagenase inhibitor released by tendon cells, thus providing enough active collagenase to control the formation of fibrous adhesions. The inefficiency of BAPN in these experiments might have been due to either inadequate dosage or wrong timing, or both.

Aminopropionitrile↗
PubMed1977

Increased collagen metabolism in granulomata induced in rats deficient in endogenous prostaglandin precursors.

Collagen metabolism was measured (in terms of various hydroxyproline (HP), DNA and protein ratios) in granulomata obtained after s.c. implantation of carrageenan-impregnated and untreated polyether sponges into normal and essential fatty acid deficient (EFAD) rats for 8 and 15 days. Collagen synthesis (HP/protein) in day 8 and 15 untreated granulomata was the same for both normal and EFAD rats, though collagen breakdown (total HP) appeared to be greater in EFAD granulomata on day 15. With carrageenan-impregnated sponges, collagen synthesis in EFAD granulomata was much greater than in normal granulomata on both day 8 and day 15. Ratios of protein and/or HP to DNA (probably indicative of cellular infiltration) were increased in EFAD rats with both sponge types, though this increase was less pronounced with carrageenan-impregnated sponges. It is suggested that endogenous prostaglandin (PG) production (marledly reduced during EFA deficiency) may exert a negative feedback effect on collagen metabolism during proliferative inflammation.

Animals↗
PubMed1976

Lysyl oxidase: a pituitary hormone-dependent enzyme.

Aldehyde-deficient non-crosslinked collagen obtained from lathyritic rats and collagen from penicillamine-treated rats, which is not deficient in aldehydes but the crosslinking of which is also inhibited, were implanted into the peritoneal cavity of hypophysectomized rats using the diffusion chamber technique. The enzyme lysyl oxidase which catalyses the aldehyde formation in certain lysyl residues of collagen and elastin was extracted from the skin of hypophysectomized rats. The activity of the enzyme was determined following its incubation with an L-[4,5-3H] lysine-labeled elastin substrate prepared from aortas of 17-day-old chick embryos. The result showed that the aldehyde deficient collagen did not crosslink while in the hypophysectomized animal indicating the lack of active lysyl oxidase in the rats. The enzyme activity in the skin of hypophysectomized animals was markedly reduced as compared with the controls indicating directly the dependance of lysyl oxidase activity on pituitary gland hormones.

Amino Acid Oxidoreductases↗