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Biomedical subjects

P Picha

Publications and source records attributed to P Picha.

4 recordsLinked to original sources
PubMed1989

[Cellular thermosensitivity].

(1) modes of expression of thermosensitivity and theoretical interpretation of thermal dose, (2) differential thermosensitivities between strains of cells and the possible correlation to heat shock proteins and their syntheses, (3) cell phase responses to hyperthermia, (4) low hyperthermia and the induction of thermotolerance, (5) comparative thermosensitivities at the temperatures between below and above 42.5 degrees C -43 degrees C, (6) Arrhenius plot and mean cellular lethal heating periods, (7) step-up heating and the thermotolerance induction, (8) step-down heating and the thermoenhancement, (9) fractionated high hyperthermia and the thermotolerance induction and (10) modification of thermosensitivity by chemical substance including anticancer drugs; are compactly reviewed mainly on cell level.

Cell Cycle↗
PubMedDate not supplied

Constituents of Paramichelia baillonii: a new antitumor germacranolide alkaloid.

Paramichelia baillonii has been used by the natives of Northern Thailand for medicinal purposes. Four components have been isolated from the bark of this plant and their structures determined by spectroscopic means. Three of the components had been reported previously: the germacranolide epoxides (--)-dihydroparthenolide [1] and (--)-parthenolide [2] and the oxoaporphinoid alkaloid liriodenine [4]. The fourth component is an unusual new germacranolide alkaloid which has been named (--)-bisparthenolidine [3] because it was presumably formed in the plant from ammonia and two molecules of parthenolide. Parthenolide was reported previously to possess anti-tumor activity, and in the present study we report on the significant activity of the new alkaloid 3 in the KB cell culture assay.

Alkaloids↗
PubMedDate not supplied

Effects of cis-diamminedichloroplatinum (CDDP) and cis-diammine (1,1-cyclobutanedicarboxylate) platinum (CBDCA) on thermotolerance development and thermosensitivity of the thermotolerant cells.

The interactive effects of combined treatment with heat and CDDP (0.5 micrograms/ml) or CBDCA (10 micrograms/ml) were examined on the surviving fractions of V-79 cells. Both CDDP and CBDCA treatment induced a slight enhancement in thermosensitivity of thermotolerant cells. The development of thermotolerance during step-up heating was partially inhibited by simultaneous treatment with CDDP or CBDCA throughout the heating process. Simultaneous heat treatment at 42 degrees C with either drug showed marked interactive effect and inhibited the thermotolerance developed during 42 degrees C heating.

Animals↗