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Rous sarcoma virus (RSV) stimulates in quail embryo neuro-retina (NR) cultures the specific activity of glutamic acid decarboxylase (GAD), the enzyme responsible for the synthesis of gamma-aminobutyric acid, a major inhibitory neurotransmitter in NR and in central nervous system. In quail embryo NR
DL-alpha-Hydrazino-delta-aminovaleric acid (DL-HAVA) is a potent and fairly specific inhibitor of ornithine decarboxylase (EC 4.1.1.17). Its effect on polyamine metabolism and cell proliferation was investigated in sarcoma-180, inoculated into the axillary region of mice. In the tumor tissues, the
The increase in S-adenosyl-L-methionine decarboxylase activity in chick embryo fibroblasts after infection with Rous sarcoma virus has been studied. It has been shown that enzyme levels in transformed cells were two or three times higher than those of the non-infected controls. The activity of this
Ornithine decarboxylase (ODC) induction during G1 phase of the cell cycle was compared in Rat-1 fibroblasts and in Rat-1 fibroblasts transformed by the B77 wild-type Rous sarcoma virus (RSV) and by the thermosensitive mutant LA24/RSV. In Rat-1 cells, maximal enzyme activity detectable at mid G1
Tumor cell kinetics were studied in C57 Bl/J mice with a transplantable sarcoma, MCG 101, exposed to hyperbaric oxygen (HBO2), 2.8 atm abs, 2 hours daily for 9 days or until spontaneous death. The isoenzymatic pattern of lactate dehydrogenase (LDH) confirmed that there was a significant shift toward
In vitro exposure of Syrian hamster fetal cells to nickel subsulfide (alpha Ni3S2) yielded positive colony assays for morphological transformation. A dose-response relationship was found between the concentration of alpha Ni3S2 and the incidence of morphological transformation. Exposures of alpha
When monolayer Chinese hamster cells are treated with trypsin for short periods of time, ornithine decarboxylase (ODCase) activity increases two- to fourfold. This increase can be blocked by aprotinin, a protease inhibitor, and is not observed when cultures are dislodged from substrate mechanically
We evaluated the usefulness of L-dopa decarboxylase (DDC) as a tumor marker of neuroendocrine (NE) cell differentiation by measuring its expression in 432 human tumors of diverse types and origins. A subset of these tumors and cell lines derived from them also were studied for expression of two
(2R,5R)-6-Heptyne-2,5-diamine hydrochloride (MDL 72175) is a new, potent, and selective inhibitor of mammalian ornithine decarboxylase. MDL 72175 given p.o. in drinking fluid reduced by 80% the growth of EMT6 sarcoma in mice and of HTC hepatoma in rats. It prolonged the survival of mice bearing
The dose limiting toxicity of difluoromethylornithine (DFMO), when administered by continuous infusion, is thrombocytopenia. DFMO-induced antitumor activity and thrombocytopenia were time- and dose-dependent up to 1700 mg/kg/d when administered continuously for 12 days. Concomitant ornithine
During the fractionation of various enzymes concerned with DNA synthesis from the postmicrosomal supernatant fraction of various tissues, DNA polymerace [EC 2.7.7.7], thymidine kinase [EC 2.7.1.75], dTMP kinase [EC 2.7.4.9], deoxycytidine kinase [EC 2.7.1.74], and deoxycytidine monophosphokinase
A subpopulation of cells was derived from the Hs431 connective tissue sarcoma cell line which possessed high affinity (estimated Kd = 0.38-0.55 nM) binding sites for human recombinant [125I]-IL-1 alpha. Binding at 4 degrees C was slow approaching equilibrium by 4 hrs. Dissociation of [125I]-IL-1