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Biomedical subjects

K S Narayan

Publications and source records attributed to K S Narayan.

35 records · Page 2Linked to original sources
PubMed1980

Effect of 12-O-tetradecanoylphorbol-13-acetate on the morphology and growth of C3H/10T1/2 mouse embryo cells.

The effects of the tumor-promoting phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) on the morphology and growth properties of C3H/10T1/2 clone 8 cells were examined. The morphology of these cells was changed within 30 min following treatment with 0.1 microgram of TPA per ml; they became smaller and refractile with long beady processes. Such changes were observed in both logarithmic and confluent cultures and lasted about 72 hr. Subsequent treatments were much less effective in inducing these changes. Scanning electron microscopy showed cell retraction and rounding as the most significant immediate effects of TPA treatment; many cells remained partially rounded 48 hr afterwards. Long-term surface modifications ascribable to TPA treatment were not detected. TPA had only minor effects on the growth of cultured C3H/10T1/2 cells in the presence of 10% fetal calf serum. Slight increases in plating efficiencies and saturation densities were generally observed in the presence of TPA but not with the related non-tumor-promoting compound phorbol. The cells grew slowly in 1% fetal calf serum and demonstrated serum batch-dependent alterations in their growth properties when exposed to TPA. Under conditions that produce doubling times of 70 hr or greater, TPA, but not phorbol, reduced the doubling time to about 50 hr. Saturation densities were also increased by TPA in 1% fetal calf serum. The effects of TPA on the growth of an oncogenically transformed variant of C3H/10T1/2 were quite different. While minimal effects of TPA were observed quite different. While minimal effects of TPA were observed when transformed cells were treated in the presence of 10% total calf serum, TPA treatment in 1% fetal calf serum significantly inhibited cell growth.

Animals↗
PubMed1979

Establishment and characterization of a human prostatic carcinoma cell line (PC-3).

The establishment, characterization, and tumorigenicity of a new epithelial cell line (PC-3) from a human prostatic adenocarcinoma metastatic to bone is reported. The cultured cells show anchorage-independent growth in both monolayers and in soft agar suspension and produce subcutaneous tumors in nude mice. Culture of the transplanted tumor yielded a human cell line with characteristics identical to those used initially to produce the tumor. PC-3 has a greatly reduced dependence upon serum for growth when compared to normal prostatic epithelial cells and does not respond to androgens, glucocorticoids, or epidermal or fibroblast gowth factors. Karyotypic analysis by quinacrine banding revealed the cells to be completely aneuploid with a modal chromosome number in the hypotriploid range. At least 10 distinctive marker chromosomes were identified. The overall karyotype as well as the marker chromosomes are distinct from those of the HeLa cell. Electron microscopic studies revealed many features common to neoplastic cells of epithelial origin including numerous microvilli, junctional complexes, abnormal nuclei and nucleoli, abnormal mitochondria, annulate lamellae, and lipoidal bodies. Overall, the functional and morphologic characteristics of PC-3 are those of a poorly-differentiated adenocarcinoma. These cells should be useful in investigating the biochemical changes in advanced prostatic cancer cells and in assessing their response to chemotherapeutic agents.

Adenocarcinoma↗
PubMed1978

Replicative epithelial cell cultures from normal human prostate gland.

Epithelial cell cultures of the normal human prostate gland were established. The subculturing of these cultures was accomplished with a novel nonenzymatic technique. These cultures were defined as normal epithelial cells on the basis of ultrastructure, karyotype, and inability to grow in soft agar.

Cell Adhesion↗
PubMed1976

Detection of oncornavirus-like particles in normal and tumorigenic rat liver cell cultures.

Six epithelial cell cultures established from adult Wistar rat liver were examined by electron microscopy for oncornavirus-like particles. Two heteroploid and tumorigenic cultures demonstrated many cells with virus-like particles of type-A and type-C morphology. The remaining four, composed of diploid nontumorigenic cells, demonstrated similar virus-like particles but in few cells and only after bromodeoxyuridine treatment. The virus-like particles in the tumorigenic cultures were identified as a rat type-C virus by serological assays.

Antigens, Viral↗
PubMed1975

Production of ring-shaped particles by normal and metaplastic tissue. I. Human skin.

Maintenance media incubated with biopsy specimens of human skin tissues contained minute (10-12 nm wide), ring-shaped particles (RSP) similar to those described previously in culture media of mammalian cell lines. In addition to the qualitative demonstration of the particles by electron microscopy, a quantitative method was applied to estimate in media the amount of DNA that could be attributed primarily to RSP content. The amounts of DNA, obtained with 146 test specimens, varied with the pathologic condition of the tissue in the following ascending order: normal skin, verruca vulgaris, seborrheic verruca, actinic keratosis, basal cell carcinoma, and squamous cell carcinoma.

Adult↗