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Biomedical subjects

S L Yang

Publications and source records attributed to S L Yang.

At least 163 records · Page 9Linked to original sources
PubMed1984

NK cell activity and skin test antigen stimulation of NK like CMC in vitro are decreased to different degrees in pregnancy and sarcoidosis.

Peripheral blood mononuclear cells (PBMNC) isolated from normal subjects, pregnant women and patients with sarcoidosis were assayed for natural killer (NK) cell activity on day 0 and for NK like cell-mediated cytolysis (CMC) after 5 days of exposure, in vitro to Candida antigen, purified protein derivative (PPD), and human leucocyte interferon (IFN). Pregnant women and women with sarcoidosis had significantly decreased levels of NK cell activity compared to normal women. Pregnant women had the lowest mean NK cell activity. Cells from women with sarcoidosis and from pregnant women also had lower levels of killing than those from the normal women after in vitro stimulation of NK like CMC with Candida antigen, PPD and IFN. The lowest stimulations of NK like killing occurred in the cells from women with sarcoidosis. Skin test antigen stimulation of NK like CMC in vitro and the DTH response in vivo were strongly correlated for both Candida antigen and PPD in the sarcoidosis patients. There was no correlation between the level of NK cell activity in the PBMNC of sarcoid patients on day 0 and the amount of NK like CMC that was present in cells from those patients after 5 days of culture with Candida antigen, PPD or IFN. A significant correlation was found, however, between Candida antigen stimulation of NK like CMC and IFN stimulation of NK like CMC in both pregnant and sarcoid groups. Reduced NK cell activity on day 0 in a given patient thus did not necessarily indicate that skin test antigen or IFN stimulation of NK like CMC on day 5 would also be depressed. In addition, NK cell activity was often noted to be normal in patients with depressed in vitro stimulation of NK like CMC.

Adult↗
PubMed1983

T-cell subsets in patients with preeclampsia.

Peripheral blood mononuclear cells from patients with preeclampsia were enumerated by means of monoclonal anti-T-cell antibodies. The percentage of total T cells was significantly decreased in this group of patients, as compared with normal term pregnant women. The low proportion of T cells was due to a proportional reduction in both helper and suppressor T cells; therefore, the ratio of helper to suppressor T cells was not different from that in normal pregnant women. There was no correlation between the degree of reduction in percentage of T cells and severity of the disease. The absolute numbers of T cells were slightly, but not significantly, decreased. Our findings support previous evidence of reduced, not increased, immune reactivity in preeclampsia.

Animals↗
PubMed1983

Long-term use of cyclosporine in liver recipients. Reduction of dosages in the first year to avoid nephrotoxicity.

Cyclosporine is a potent immunosuppressive drug, which has dose-related nephrotoxicity. In renal transplantation, the differentiation between rejection and toxicity is difficult and even with the aid of blood levels of the drug, it may be difficult to establish a chronic maintenance dose. Long-term survivors after liver transplantation can provide modes with which to establish maintenance doses, as these are dictated by nephrotoxicity in these patients. Twenty-nine liver transplant patients who survived one year or more were followed for changes in their cyclosporine doses. Daily oral cyclosporine dose, BUN, serum creatinine and bilirubin were monitored. The reductions in cyclosporine were dictated almost entirely by the findings of nephrotoxicity.

Adolescent↗
PubMed1983

Relationship between the mouse colonizing ability of a human fecal Escherichia coli strain and its ability to bind a specific mouse colonic mucous gel protein.

Escherichia coli F-18, isolated from the feces of a healthy human, is an excellent colonizer of the large intestines of streptomycin-treated CD-1 mice. E. coli F-18 Col-, a poor mouse colonizer relative to F-18, lacks a 3 X 10(7)-dalton plasmid present in E. coli F-18. Both strains are human type A erythrocyte hemagglutination negative, have identical surface hydrophobicities, contain the same number of lipopolysaccharide molecules with the same O-side chain length, and have identical amounts of capsule. Differences between the two strains were observed. The relative amounts of specific outer membrane proteins differed, and E. coli F-18 was less motile than E. coli F-18 Col-. The abilities of the two strains to bind mouse large intestine mucous gel was also examined. Although each strain was able to use mucous gel as the sole source of carbon and nitrogen with equal ability, E. coli F-18 bound between two and three times more mucous gel than did E. coli F-18 Col-. Most of the difference in mucous gel binding ability of the two strains was accounted for by the greater ability of E. coli F-18 lipopolysaccharide to bind a single 26,000-dalton mucous gel protein. E. coli J5-3, a typical K-12 strain that is also a poor colonizer relative to E. coli F-18, was identical to E. coli F-18 Col- with respect to mucous gel binding ability.

Animals↗
PubMed1983

Immunoglobulin concentrations in newborn infants associated with intrauterine growth retardation.

Immunoglobulin G, A, and M (IgG, IgA and IgM) levels were measured in paired maternal and cord serum samples from 18 pregnancies with intrauterine growth retardation (IUGR) and 55 with normal growth (adequate-for-gestational-age pregnancies) delivered vaginally at 36 weeks' gestation or later. Cord blood levels of IgG, IgA, and IgM in IUGR infants were found significantly lower than those in infants with adequate-for-gestational-age growth. Lower Lower levels of cord IgG in IUGR may be due to a defect in the active transport of IgG across the placenta. Lower levels of cord IgM and IgA suggest an impairment of synthesis of immunoglobulins in the IUGR infants. There was no difference in cord immunoglobulin concentrations between infants with intrapartum fetal heart rate (FHR) decelerations and those without FHR decelerations in either the IUGR or the adequate-for-gestational-age group. No difference was observed in maternal immunoglobulin concentrations among the study groups.

Adult↗
PubMed1983

Specific antibodies and immunoglobulins in the oviductal fluid of the rhesus monkey.

Levels of specific antibodies against model antigens, immunoglobulins G and A and also albumin, in oviductal fluid were studied in the rhesus monkey during the periovulatory period. Animals were systemically or intravaginally immunized against T4 coliphages. Attempts to induce ovulation were made with human menopausal gonadotropin (hMG) and human chorionic gonadotropin (hCG) monitored by radioimmunoassay of serum estrogen and progesterone. Collection of tubal fluid over 6 to 13 days was accomplished by surgical cannulation using a refrigerated extracorporeal collection device for each side. The results indicated the following: (1) The levels of specific antibodies against T4 coliphage and immunoglobulins (IgG, IgA) in the oviduct fluid averaged approximately one tenth of the serum values and showed a characteristic decrease and subsequent increase by a factor of 4 to 5 during and following treatment with hMG/hCG. The nadir was observed on the first or second day after hCG injection. (2) This pattern was similar in both ovulatory or nonovulatory cycles; therefore, these changes seem to be associated with the changes in serum estrogen levels. (3) There was a striking difference in serum and tubal fluid antibody levels after systemic versus after vaginal immunization by a factor of 10(3) and 10(4); however, the patterns in tubal fluid under treatment with hMG/hCG were very similar. (4) Specific antibodies in oviductal fluid and serum were mainly of the IgG class. (5) A concomitant change of total protein and albumin in oviduct fluid was also observed. The presence of sperm agglutination antibody in oviductal fluid was demonstrated in two monkeys after systemic immunization with homologous spermatozoa. The sperm antibody titers showed a similar pattern of change after hMG/hCG treatment.

Albumins↗
PubMed1982

Sperm specific antigen(s) in detergent extract of rhesus monkey spermatozoa.

Sperm surface antigens were prepared by detergent extraction (Hyamine-Triton, Rohm and Haas Co., Philadelphia, PA) of spermatozoa from rhesus monkeys. Heterologous antisera against the extracts were produced in female New Zealand White (NZW) rabbits by hyperimmunization. The antiserum was absorbed initially with sperm-free monkey seminal plasma and then with lyophilized tissue homogenates of liver, kidney, spleen, and pancreas from male rhesus monkeys. The unabsorbed antiserum produced at least three precipitin lines against detergent extract in double immunodiffusion tests and possessed sperm immobilization and sperm agglutination antibody activity. The absorbed antiserum showed one precipitin line against the detergent extract and retained sperm agglutination antibody activity only. The sperm agglutination antibody in the absorbed antiserum was completely removed by either epididymal or washed ejaculated rhesus monkey spermatozoa. The same results were obtained with ammonium-sulfate-precipitated immunoglobulin preparations. Immunoelectrophoresis revealed only one precipitation line with the absorbed immunoglobulin preparation. It is concluded that Hyamine-Triton extract of rhesus monkey spermatozoa contains a component which can be characterized as sperm-specific by immunoabsorption techniques and is apparently associated with sperm agglutination but not with immobilization.

Animals↗