Biomedical subjects

Y M Sin

Publications and source records attributed to Y M Sin.

49 records · Page 3Linked to original sources

PubMed1984

Studies on the clearance of calcium pyrophosphate crystals from facsimile synovium.

Calcium pyrophosphate dihydrate crystals have been injected into the air pouch model of facsimile synovium. At various time intervals after crystal injection both infiltrating exudate cells and lining tissue were examined for the presence of crystalline material. The results show that the crystals are initially engulfed by mononuclear cells and to a lesser extent by polymorphonuclear cells in the exudate. Later, crystals became embedded in the lining tissue either within mononuclear cells or as crystal masses confined within granulomas. These studies suggest that the mesenchymal cells ( facsimile synovium) lining rat air pouches can clear calcium pyrophosphate dihydrate crystals from the air pouch cavity. It is therefore inferred that crystals found in the lining of human joint synovium may be incorporated therein by a similar mechanism.

Air↗

PubMed1984

Effect of a lymphocyte-derived pro-inflammatory factor on carrageenan pleurisy in the rat.

An intravenous injection of a lymphocyte pro-inflammatory factor (LpIF), obtained from rat spleen, restored diminished fluid and cellular responses in carrageenan pleurisy in leucopenic animals. A similar filtrate of bone marrow cells had no restorative properties. Previous results from elsewhere indicated a single pro-inflammatory activity on the fluid component of inflammation. We propose that LpIF has a more significant effect by influencing both components of inflammation and suggest that the discrepancy may be due to the different models used.

Animals↗

PubMed1984

Immune inflammation in newly developing facsimile synovia.

The injection of air into the subcutaneous tissue of the back in rodents has previously been shown to induce a lining which closely resembles synovial lining tissue. Air pouches of different ages represent the developmental stages of such tissue. We have found that pouches of 1 day in age induced in animals previously sensitised with bovine serum albumin (BSA) respond with low numbers of infiltrating leucocytes and a small fluid exudate volume 4 h after challenge into the pouch with BSA. In contrast, 3- and 6-day-old pouch tissue when challenged with antigen responds with a greater influx of leucocytes and a larger fluid exudate. These findings suggest that the constituent make-up of the air pouch-lining tissue is important for the full expression of the inflammatory response.

Animals↗

PubMed1984

The effects of levan on the acute inflammatory response.

The fructose polymer levan has been shown to affect the accumulation of leucocytes in inflammatory lesions. The present study has investigated the effect of levan on experimental pleurisy induced by carrageenan and calcium pyrophosphate dihydrate (CPPD) crystals. Total pleural polymorphonuclear leucocyte counts and exudate volumes were significantly reduced by levan treatment. We were, however, unable to detect any effect on mononuclear cell numbers. Furthermore, levan treatment significantly reduced peripheral leucocyte numbers. The counter-irritant activity of levan was compared with that of a known counter-irritant, dextran. The ability of levan to reduce pleural polymorph numbers and exudate volume could not be accounted for totally by counter-irritation. Studies using an in-vitro leucocyte adhesion assay system indicate that levan affects leucocyte adhesion to vascular endothelium.

Animals↗

PubMed1983

Increased inflammatory reactivity in newly formed lining tissue.

The air pouch has been shown to provide a convenient model for studying the behaviour of synovial lining tissue. Air pouches of different ages were used to study the reactivity of newly developing lining tissue towards irritants known to cause inflammation. Pouches of 1 day in age were relatively inert in their reactivity as judged by the number of cells and volume of the exudate accumulating in the pouch. In contrast, 3-day-old pouches responded to a much greater extent, and 6-day-old pouches were highly responsive with a further increase in cell numbers and fluid volume. The different responses of 1-, 3- and 6-day-old pouches could be explained by (a) developing vascularity of the pouch, (b) formation of an organised lining of phagocytic cells, or (c) an increasingly organised mechanical barrier that retains the irritant and products of the inflammatory response. These studies of air pouch lining development permit a dissection of those components necessary for inflammatory reactivity of a lining tissue and may help explain the sensitivity of synovium to chronic inflammation.

Air↗

PubMed1983