Biomedical subjects

S S Yan

Publications and source records attributed to S S Yan.

4 recordsLinked to original sources

PubMed2000

Resistance to multiple fluoroquinolones in a clinical isolate of Streptococcus pyogenes: identification of gyrA and parC and specification of point mutations associated with resistance.

A strain of Streptococcus pyogenes resistant to multiple fluoroquinolones was isolated from the blood of an immunocompromised patient. Resistance to fluoroquinolones in S. pyogenes has not been previously studied. Compared to 10 sensitive strains of S. pyogenes, the fluoroquinolone-resistant clinical isolate of S. pyogenes presented point mutations in gyrA, predicting that serine-81 was changed to phenylalanine and that methionine-99 was changed to leucine, and in parC, predicting that serine-79 was changed to tyrosine. The mechanism of fluoroquinolone resistance in this isolate of S. pyogenes appears to be analogous to previously reported mechanisms for Streptococcus pneumoniae.

Anti-Infective Agents↗

PubMed2000

Performance of three enzyme immunoassays and two direct fluorescence assays for detection of Giardia lamblia in stool specimens preserved in ECOFIX.

ECOFIX is a single-vial stool preservative that is both formalin- and mercury-free. We evaluated the abilities of three commercial Giardia lamblia-specific enzyme immunoassays (EIAs) (ProSpecT Giardia Microplate Assay [Alexon-Trend Inc.], Giardia Test [Techlab], and Premier Giardia lamblia [Meridian Diagnostics, Inc.]) and two commercial direct fluorescent-antibody (FA) assays for G. lamblia (Crypto/Giardia IF Test [Techlab] and Merifluor Cryptosporidium/Giardia [Meridian Diagnostics, Inc.]) to detect G. lamblia in 34 G. lamblia-positive and 44 G. lamblia-negative stool specimens (determined by traditional examination for ova and parasites) preserved in ECOFIX compared to their abilities to detect G. lamblia in the same specimens preserved in formalin as the "gold standard" for each assay. Of the 34 formalin-fixed positive specimens, the number detected by each assay was as follows:, Alexon EIA, 34; Meridian EIA, 27; Techlab EIA, 29; Meridian FA assay, 31; and Techlab FA assay, 28. Both FA tests and the Alexon EIA performed well with ECOFIX, but the other two EIAs detected fewer positive specimens (the difference was statistically significant with the Techlab EIA) when ECOFIX was the preservative. Use of G. lamblia cyst antigen from cultured organisms preserved in formalin and ECOFIX demonstrated that the Alexon EIA could detect smaller amounts of antigen in ECOFIX than the other two EIAs could and suggested that cyst antigen is more stable in formalin. We recommend that laboratories use an FA assay or the Alexon EIA if they plan to use ECOFIX as their stool preservative.

Animals↗

PubMed1989

Meigs' syndrome--a case report.

Bilateral ovarian fibromas combined with as and hydrothorax is a rare disorder. A case of bilateral ovarian fibromas combined with ascites and hyrothorax is presented. The ascites and hydrothorax disappeared spontaneously after removal of the ovarian tumors.

Aged↗

PubMed1983

A modulatory lipoprotein related to cancer cell inhibition.

Three fractions of lipoprotein were isolated from sera and ascites of cancer-bearing mice by polyanion precipitation and density centrifugation. The cancer modulatory activity of isolated lipoproteins was estimated by means of trypan blue exclusion and cell potassium content. The activity of one of the isolated lipoprotein fractions was to kill cancer cells in vitro with little effect on normal bone marrow cells. This lipoprotein migrated as one band on agarose electrophoresis. After incubating cancer cells with the lipoprotein, the membrane fluidity of the cancer cells was markedly changed (p less than 0.01). The mechanism of modulation may be related to interaction of lipoprotein with plasma membrane of cancer cells.

Animals↗