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Biomedical subjects

P Nath

Publications and source records attributed to P Nath.

At least 55 records · Page 3Linked to original sources

Ultrastructural changes in parietal cells in iron deficiency anemia.

Eighteen patients with iron deficiency anemia (IDA) and 14 age and sex matched control subjects were studied with regard to ultrastructural changes in parietal cells. The control subjects had normal hemoglobin and serum iron levels and endoscopic examination of the upper gastrointestinal tract. Thirteen cases of iron deficiency anemia had chronic superficial gastritis on light microscopy. Ultrastructural abnormalities in the parietal cells, such as indented or pyknotic nucleus with irregular outline, grossly distorted canalicular system, abnormal large empty spaces in the cytoplasm and paucity of mitochondria, were demonstrated in all IDA patients but not in controls. The presence of superficial gastritis and ultrastructural changes were not related either to hemoglobin or serum iron levels in the IDA group.

Adolescent↗

c-myc mRNA is elevated as differentiating lens cells withdraw from the cell cycle.

Explants of the central region of lens epithelia from early chicken embryos differentiate in vitro to form lens fiber cells when cultured in the presence of chicken vitreous humor. Hybridization of a 32P-labeled v-myc viral oncogene DNA probe to RNA extracted from differentiating explants and immobilized on nitrocellulose filters indicates that levels of 2.5 kb c-myc mRNA are transiently elevated 5-10-fold in the differentiating cells. Increased levels of c-myc mRNA are observed within 30 min of the initiation of differentiation in vitro and persist for 8-9 h. Thymidine labeling of nuclei in differentiating explants indicates that entry of cells into S phase is inhibited during this period, as differentiating cells complete a final round of mitosis and withdraw from the cell cycle. Levels of c-myc mRNA are also elevated in the peripheral region of the lens epithelium, which contains cells undergoing differentiation in vivo, suggesting that the regulation of c-myc mRNA which occurs in vitro may also occur in vivo. c-myc mRNA, c-fos mRNA, and c-src mRNA showed distinct patterns of regulation associated with lens fiber formation in vivo, thus providing evidence that the regulation of c-myc mRNA is specific to this proto-oncogene. The finding that c-myc mRNA undergoes a specific, transient elevation in differentiating lens cells as they withdraw from the cell cycle contrasts with a large body of evidence linking enhanced c-myc expression with increased cell proliferation.

Animals↗

Isolation of an alpha 1 type-IV collagen cDNA clone using a synthetic oligodeoxynucleotide.

We have isolated a cDNA clone (pCIV-1-225) for the alpha 1 subunit of basement membrane (type IV) collagen from a cDNA library made from Engelbreth-Holm-Swarm mouse tumor RNA. The cDNA library was screened with synthetic oligodeoxynucleotides derived from published amino acid (aa) sequences (Schuppan et al., 1982). Nucleotide sequence data established the identity of our cDNA clone to encode an alpha 1 type IV collagen. This clone contains 270 aa of the helical region and has three interruptions in the Gly-X-Y repeat unit.

Amino Acid Sequence↗