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Biomedical subjects

P Martel

Publications and source records attributed to P Martel.

4 recordsLinked to original sources
PubMed1992

Transforming growth factor beta 1 (TGF-beta 1) inhibits growth of a human ovarian carcinoma cell line (OVCCR1) and is expressed in human ovarian tumors.

The effects of EGF and TGF-beta 1 on the proliferation of 2 ovarian carcinoma cell lines (IGROV1 and OVCCR1) were evaluated. The cell lines were adapted to grow in a restricted serum (0.5%) medium. EGF was required for proliferation of both ovarian cell lines. Low doses of TGF-beta 1 inhibited clonogenic capacity and attenuated the EGF-mediated stimulation of DNA synthesis in OVCCR1 cells. TGF-beta 1 inhibited OVCCR1 cell proliferation by blocking the cell cycle at the G1/S transition. TGF-beta 1 did not affect either clonal or monolayer growth of IGROV1 cells. Both cell lines express type-I and type-III TGF-beta receptors, suggesting that the unresponsiveness of IGROV1 cells to TGF-beta 1 occurs at a post-receptor level. TGF-beta 1 mRNA was detected in OVCCR1 cells and in 8 out of 11 of the ovarian tumor specimens examined.

Cell Division↗
PubMed1979

Base crystallization and base stacking in water.

2H2O solutions of 6-methylpurine and N6,N9-dimethyladenine have been examined by neutron diffraction. Comparison of the scattering from various molar solutions of 6-methylpurine with the scattering from its crystalline precipitates indicated base stacking in solution with a separation of approximately 0.34 nm. In particular at 1.75 M the effective stacking number in 6-methylpurine, as seen by neutron diffraction, was found to be approximately nine. Attempts to observe similar scattering from N6, N9-dimethyladenine were hampered because solutions with a molarity greater than or approximately 0.02 tended to form filamentary crystallites as a function of time. An analysis of the autocatalytic reaction involved in the formation of these dendrites is given. The rate constant is found to be 2.12 +/- 0.05 M-1 h-1. By comparing the diffraction from wet and dry crystallites it is concluded that hydrophilic interactions mediate the aggregation of both bases in water.

Crystallization↗
PubMed1977

Projections from the inferior olive to the cerebellar nuclei in the cat demonstrated by retrograde transport of horseradish peroxidase.

The method of intracerebral injections of horseradish peroxidase has been applied to demonstrate a projection from the inferior olivary nucleus to the intracerebellar nuclei in the cat. Cells labeled by the transported enzyme can be observed in different regions of the olive according to the localization of the injection. The caudal half of the medial and dorsal accessory subdivisions, the dorsal cap and nucleus beta project to the fastigial nucleus. In the rostral half of the olive, the accessory subdivisions of that nucleus and the dorsomedial cell column send fibers to the interposed nuclei while the principal olive and the ventrolateral outgrowth are connected with the dentate nucleus. It is likely that these fibers are collaterals of the climbing fibers.

Animals↗