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Biomedical subjects

S H Chan

Publications and source records attributed to S H Chan.

At least 307 records · Page 17Linked to original sources
PubMed1982

Loss of concanavalin A induced suppressor T-lymphocyte function in patients with mesangial IgA nephritis.

Using the method of concanavalin A (Con a) inducible suppressor activity the peripheral mononuclear cells (PMC) of 17 patients with Mesangial IgA nephritis, 13 patients with idiopathic mesangial proliferative glomerulonephritis but with no IgA deposits on immunofluorescence (Non-IgA nephritis) and 18 healthy subjects were studied. DNA synthesis was measured by incorporation of 3H Thymidine. The mean suppression index (S.I.) of 0.94 +/- 0.08 (SEM) in the IgA nephritic patients was significantly different from that of the non-IgA nephritic patients (0.67 +/- 0.05) (P less than 0.01) as well as the group of normal healthy controls (0.64 +/- 0.05) (P less than 0.0025). The data show that patients with IgA nephritis have abnormal suppressor cell function and suggest an autoimmune basis in the pathogenesis of IgA nephritis.

Adult↗
PubMed1982

Immunology of kidney transplantation.

Despite the increasing knowledge of antigen recognition, tissue matching, effector mechanisms and immune suppression, rejection of renal transplants remains a major problem. This article reviews some of these problems and discusses HLA matching in cadaveric and live related transplants, pregraft blood transfusion and the immunological evaluation of the potential and transplanted recipient.

Graft Rejection↗
PubMed1982

Effect of immune serum on Brugia malayi microfilaria: ultra structural observations.

The in vitro effect of immune monkey serum on microfilariae of Brugia malayi was investigated using the electron microscope. The sheaths of microfilaria incubated with immune serum were seen to be covered with electron dense precipitates. After 24 hours of incubation, majority of microfilariae incubated with immune serum exhibited degenerative changes. Comparable changes were not seen in microfilariae incubated with normal serum. The significance of these observations are discussed.

Animals↗
PubMed1982

Immunology in Singapore--past and future.

In the past, immunology in Singapore was mainly confined to serology for the diagnosis of certain infectious diseases. Postgraduate education for immunology was not well developed and its undergraduate training was restricted to a few lectures within bacteriology. With the establishment of the W.H.O. IRTC in 1969, training and research in immunology were further developed and a group of scientists and technicians to conduct research work was subsequently built up. This enabled the Centre to provide some immunological services to the Government and University, and soon extended these to our neighbouring countries as well. Further research and the maintenance of international standards are essential for the future development of immunology in Singapore. And this is only possible with the moral and financial support of the Government, University and private granting bodies.

Allergy and Immunology↗
PubMed1981

Morphine suppression of bradycardia induced by electrical stimulation of gigantocellular reticular nucleus in the cat.

In chloralose-urethane-anesthetized cats, intravertebral injection of morphine (1,2 and 4 mg/kg) promoted a drastic suppression of the bradycardia elicited by stimulating the medullary gigantocelular reticular nucleus (GRN). The degree of blockadge of GRN-induced cardioinhibition was directly dependent upon the dose of morphine and inversely related to the reticular stimulus train intensity and pulse frequency. The possibility that the GRM may be a site of action for morphine in its production of hypotension and bradycardia was discussed.

Animals↗
PubMed1981

HLA and systemic lupus erythematosus in Chinese.

Seventy-five unrelated Chinese SLE patients were HLA typed and subdivided into mild and severe disease. The HLA-B13 was associated with mild disease. Fourteen of 30 (46.7%) mild disease patients had B13 compared to 63/330 (19.1%) normal subjects (p less than 0.0005, corrected p less than 0.013, RR = 3.7). The HLA-B17 on the other hand was observed in 29% of 45 severe disease patients compared to 13.9% of 330 normal subjects (p less than 0.01, RR = 2.5). The frequency of HLA-B17 in 11 patients who died was even higher (45.5%).

China↗
PubMed1981

Alpha-fetoprotein on human peripheral blood lymphocytes does not block complement-dependent lymphocytotoxicity.

Using a direct immunofluorescence assay, we showed that alpha-fetoprotein (AFP) both in purified form and in hepatocellular carcinoma (HCC) sera was capable of binding onto 10-20% of T lymphocytes and 5-10% of B lymphocytes in human peripheral blood when these lymphocytes were preincubated in AFP-positive fluids at 4 degrees C in the presence of sodium azide. But when the preincubation temperature was raised to 37 degrees C, most of the membrane-bound AFP was internalized or shed, and, consequently, less than 3% of the cells showed positive membrane fluorescence. In addition, binding of AFP onto lymphocyte surface membrane and the continuous presence of large amounts of AFP in these lymphocyte cultures did not interfere with the action of cytotoxic antibodies directed against HLA determinants on the lymphocyte surface.

Cells, Cultured↗