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Biomedical subjects

S Hsu

Publications and source records attributed to S Hsu.

135 records · Page 8Linked to original sources

Experimental transmission of Japanese encephalitis virus by Culex tritaeniorhynchus and C. fuscocephalus.

Experimental transmission of Japanese encephalitis virus from swine to baby chicks was accomplished using Culex tritaeniorhynchus and Culex fuscocephalus, two of three mosquito species in Taiwan from which the virus has been recovered in nature. Whereas neither species had become infective by the twelfth day, one of ten C. fuscocephalus and 11 of 51 C. tritaeniorhynchus were infective by the seventeenth day of extrinsic incubation as verified by viraemia in chicks fed upon by potentially infective mosquitoes. The highest transmission rate obtained was 81% for C. tritaeniorhynchus on the twenty-first day of extrinsic incubation.

Animals↗

Studies on the immunochemical composition of human thoracic duct lymph of patients with rheumatoid arthritis and polymyositis.

Analysis of immunoglobulins, autoantibodies and third component of complement was carried out on the thoracic duct lymph of 6 patients with rheumatoid arthritis and 2 patients with polymyositis. It was found that the distribution of these immunoproteins between lymph and serum reflected the distribution of total protein and did not appear to be dependent on molecular size. There was no significant difference in the distribution of the macromolecule IgM as compared to the other immunoglobulins. IgD was an exception with an unanticipated and unexplained lower concentration in lymph and higher serum to lymph ratio when compared to the other immunoglobulins.

Adult↗

Alopecia areata with features of loose anagen hair.

A child with alopecia areata (AA) presented initially with clinical features of loose anagen hair (LAH) and had features consistent with LAH on microscopic hair analysis. However, a scalp biopsy specimen demonstrated peribulbar inflammatory infiltrates characteristic of AA. We suggest that AA may mimic LAH clinically and a scalp biopsy may help in making the correct diagnosis.

Alopecia Areata↗

Viscoelastic studies of extracellular matrix interactions in a model native collagen gel system.

We describe an in vitro test of the hypothesis that viscoelastic properties of the collagen fiber network of skin are influenced by interactions between the macromolecular components in the extracellular matrix. Native type I collagen gels were investigated as a mechanical analog for connective tissue. A series of gels were formed under physiological conditions via fibril precipitation in the presence of selected matrix macromolecules, including dermatan sulfate (DS), hyaluronic acid (HA), dermatan sulfate proteoglycan (DSPG), fibronectin (FN) and elastin. Viscoelastic measurements and transmission electron microscopy were performed to explore the relationship between mechanical strength and fibril morphology. The results demonstrate that associative interactions of DSPG and HA with collagen fibrils, as well as variations in collagen fibril size distribution and the amount of elastin, can modify the viscoelastic behavior of the model collagen gels. Addition of DSPG, DS and HA increases both storage and loss moduli, G' and G"; morphological examination shows adhesive binding of these species to the collagen fibrils. At 37 degrees C, elastin increases G' by forming elastic coacervate particles. FN has no effect on the gel viscoelasticity. The observed effects are discussed in terms of current clinical observations on age-related changes in the mechanical properties of skin.

Animals↗

Chemopreventive effects of green tea polyphenols correlate with reversible induction of p57 expression.

Green tea polyphenols are known to induce apoptosis in certain types of tumor cells. However, the mechanism(s) that enables normal cells to evade the apoptotic effect is still not understood. In this study, Western blot analysis combined with cycloheximide treatment was used to examine the effects of green tea polyphenols on the expression levels of p57, a cyclin-dependent kinase and apoptosis inhibitor, in normal human keratinocytes and in the oral carcinoma cell lines SCC25 and OSC2. The results showed that the most potent green tea polyphenol, (-)-epigallocatechin-3-gallate (EGCG), induced p57 in normal keratinocytes in a dosage- and time-dependent manner, while the levels of p57 protein in oral carcinoma cells were unaltered. The differential response in p57 induction was consistent with the apoptosis status detected by annexin V assay. The data suggest that the chemopreventive effects of green tea polyphenols may involve p57-mediated cell cycle regulation in normal epithelial cells.

Aged↗