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Biomedical subjects

R S Chang

Publications and source records attributed to R S Chang.

178 records · Page 10Linked to original sources
PubMed1970

Propagation in human cells of a filterable agent from the ST feline sarcoma.

Nineteen lines of human fibroblasts were inoculated with a filtrate prepared from the ST feline sarcoma. Seven lines showed morphological alteration and released focus-forming activity for feline cells, 2 lines showed morphological alteration but did not release focus-forming activity, and 11 lines showed no morphological alteration and released no focus-forming agent. Morphologically altered cells appeared enlarged, hyper-refractile, and intensely stained by hematoxylin. They neither assumed a crisscross pattern nor piled up to form a visible focus. Time-lapse cinegraph showed that the morphologically altered cells did not divide and were motile. The fluid from two human fibroblast cultures, inoculated 4 and 14 weeks previously with the ST sarcoma filtrate, induced fibrosarcoma in newborn kittens.

Animals↗
PubMed1966

On the nature of the "lipovirus".

Experiments designed to elucidate the nature of the "lipovirus" are described. The development of characteristic nuclear lesions in human cells in vitro depended on the presence of an ameboid cell in the inoculum. The spatial separation of the ameboid cells from the human cells by a membrane filter 150 micro in thickness was sufficient to prevent the development of nuclear lesions. Nuclear lesions appeared to be the primary change of the affected human cells. This development of nuclear lesions was partially suppressed by FUDR and the suppression was reversed by thymidine. Time-lapse microcinematography showed that a 30 min intermittent contact between an ameboid cell and a human cell resulted in the retraction of both progenies of the human cell after a lapse of about 36 hr. Other human cells not in contact with the ameboid cell remained polygonal and continued to divide. Radioautography of the ameboid cell revealed the presence in the cytoplasm of thymidine-containing DNAse-sensitive materials. The development of antigens related to the ameboid cell within the cytoplasm of the human cell is described in the accompanying report (4).

Hepatitis Viruses↗
PubMedDate not supplied

Isolation, purification, and partial characterization of prunellin, an anti-HIV component from aqueous extracts of Prunella vulgaris.

Prunellin, an anti-HIV active compound, was isolated from aqueous extracts of the Chinese medicinal herb, Prunella vulgaris, and purified to chromatographic homogeneity. Infrared and NMR spectroscopy identified prunellin as a polysaccharide. Elemental analyses, precipitation with calcium(II), barium(II), or 9-aminoacridine suggest a sulfated polysaccharide. Paper chromatography of the exhaustively hydrolyzed material indicates the presence of glucose, galactose, xylose, gluconic acid, galactonic acid and galactosamine as the constituent monosaccharides. The molecular size of prunellin, as determined by gel permeation chromatography and the Squire method on Sephadex G-75, is about 10 kDa.

Antiviral Agents↗