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Biomedical subjects

B Barlogie

Publications and source records attributed to B Barlogie.

At least 289 records · Page 16Linked to original sources
PubMed1979

Possible mechanisms of action of lithium on augmentation of in vitro spontaneous myeloid colony formation.

To understand the possible mechanisms of lithium carbonate-induced neutrophilia, the in vitro effect on human myeloid progenitor cells was examined. A significant increase in spontaneous colony formation (15 of 24 experiments) was observed with the addition of lithium. Increased colony formation seldom occurred when human placental conditioned media as a source of colony-stimulating activity (CSA) was simultaneously added to the cultures. Further data suggest that lithium requires an adherent marrow cell population for this action and that increases in CSA-containing cultures may be due to suboptimal CSA concentrations. Lithium was shown to release CSA from marrow cells and adherent cell population prepared from human bone marrow. Lithium possibly increases spontaneous human myeloid colony development indirectly through CSA release by adherent cells.

Bone Marrow↗
PubMed1979

Effects of cis-dichlorodiammineplatinum(II) on human colon carcinoma cells in vitro.

The lethal effects of cis-dichlorodiammineplatinum(II) were investigated on an established human colon carcinoma cell line. cis-Dichlorodiammineplatinum(II) was one of the most efficient antineoplastic agents tested thus far on this human colon carcinoma cell line. Survival of exponentially growing cells exposed to increasing concentrations of the drug (both in medium or in Hanks' balanced salt solution) was of the threshold exponential type (Dq = 1.2 microgram/ml, 1 hr; Do = 3.5 microgram/ml, 1 hr). Stationary-phase cells were extremely sensitive to the drug, and the survival curve demonstrated a simple exponential pattern (Do = 3.9 microgram/ml, 1 hr). Long-term exposure to low concentrations of cis-dichlorodiammineplatinum induced a high degree of killing, with only 0.5% of the cells surviving after incubation for 24 hr with 2 microgram/ml. Cells were unable to recover from potentially lethal or sublethal damages induced by the drug.

Adenocarcinoma↗
PubMed1979

Response of exponentially growing, stationary-phase, and synchronized cultured human colon carcinoma cells to treatment with nitrosourea derivatives.

The lethal effects of two nitrosourea derivatives, 1,3-bis(2-chloroethyl)-1-nitrosourea and 4-[3-(2-chloroethyl)-3-nitrosoureido]-cis-cyclohexanecarboxylic acid, on a continuous line of human colon carcinoma cells (LoVo cells) were investigated. The survival response of exponentially growing and stationary-phase LoVo cells to both drugs were of the threshold exponential type. Survival was identical whether drugs were dissolved in medium or in Hanks' balanced salt solution. In contrast to previous results obtained for human lymphoma cells, 1,3-bis(2-chloroethyl)-1-nitrosourea exerted a progressively greater killing effect on LoVo cells as the incubation time was prolonged, while 4-[3-(2-chloroethyl)-3-nitrosoureido]-cis-cyclohexane-carboxylic acid, under similar circumstances presented decreased lethality in comparison to both 1,3-bis(2-chloroethyl)-1-nitrosourea and the effect previously observed for the lymphoma cells. Although no recovery from potentially lethal damage was noted for both exponentially growing and stationary-phase cells treated with each agent, in split-dose experiments, LoVo cells were able to recover from sublethal damage. No significant cell cycle stage dependent differences in killing ability were observed for the two agents.

Carmustine↗
PubMed1979

In vitro cytokinetic response of human colon cancer cells to cis-dichlorodiammineplatinum(II).

The cytokinetic response of a human colon carcinoma cell line to cis-dichlorodiammineplatinum(II) was investigated using flow cytometry of DNA content, autoradiography after pulse and continuous tritiated thymidine exposure, and mitotic accumulation after continuous Colcemid treatment. With increasing concentration and exposure time, cis-dichlorodiammineplatinum(II) delayed and then blocked cycle traverse in S and G2 phases. After prolonged treatment with high concentrations of cis-dichlorodiammineplatinum(II), an additional block in G1 or at the G1-S boundary was established. Irreversibility of cell cycle distribution changes after prolonged observation periods suggests cell death in G2, S, and G1 compartments.

Cell Cycle↗
PubMed1978

Kinetic response to cultured human lymphoid cells to rubidazone.

Analysis of rubidazone, the benzoylhydrazone derivative of daunorubicin, for its effects on cell cycle progression of a human lymphoid cell line showed a kinetic response pattern similar to that of adriamycin. Thus rubidazone induced a G2-block, the magnitude and duration of which were dependent on concentration and incubation time. However, in contrast to adriamycin, a marked phase-dependent sensitivity for the induction of G2-accumulation was observed; cells treated in early and mid-S-phase were most sensitive. This age-dependent kinetic response may account for the smaller G2-accumulation in asynchronous cultures and the closer correlation of the magnitude of this kinetic effect with concentration and duration of rubidazone treatment. Prolonged exposure to high concentrations of rubidazone also delayed the traverse through G1 and/or the G1-S transition, whereas the S-phase transit was not impaired. Interference with cell cycle progression through G1 into S-phase caused a stepwise accumulation of cells in G2-phase.

Cell Cycle↗
PubMed1978

Analysis of the growth kinetics of a human lymphoma cell line.

The growth kinetics of an established human lymphoma cell line were analyzed by a variety of techniques utilizing various cell inocula (5 X 10(4)--5 X 10(5) cells) dispensed into 60 mm diameter dishes. Techniques included pulse-labeled mitosis (PLM), continuous labeling with 3H-TdR, time-lapse photography (TLP), cell counts by electronic particle counter, and DNA histography obtained by pulse cytophotometry (PCP). There were no significant differences among values determined for any kinetic parameters as a function of cell concentration. The average doubling time of exponentially growing cells, regardless of cell inoculum, was 44.1 hr. The generation time determined by PLM was 31.1 hr with a SD of 4.7 hrs. Transit times for each stage were: TG1 = 10.6 hr, TS = 9.9 hr, TG2 = 9.9 hr, and TM = 0.7 hr. Repeated experiments using continuous labeling with 3H-TdR demonstrated a TG2 of 6.3 hr. The longer value determined by PLM is possibly due to the technical manipulations of this procedure which may delay pulse-labeled cells from resuming cell cycle transit. Hence, values for cell cycle stages were recalculated to give TG1 = 14.1 hr, TS = 9.9 hr, TG2 = 6.3 hr, and TM = 0.7 hr. These results were used to compute the size of each cell cycle stage compartment pool and corresponded very closely to values defined directly by PCP. TLP analysis considered only cells that produced colonies of at least thirty-two cells. Generation times ranged from 8 to 89 hr and showed a positive skewness. The average value measured for 330 divisions was 34.5 hr with a SD of 13.2 hr. Thus, the variance predicted by curve fitting of the PLM data did not correlate with that defined by time-lapse photography nor did it encompass the range in generation times observed directly by TLP. There was a positive correlation between sister-sister cell generation times (+0.66) but no relation was noted for mother-daughter values.

Cell Count↗
PubMed1978

Lethal and cytokinetic effects of anguidine on a human colon cancer cell line.

Anguidine is a fungal metabolite with antitumor activity in a murine colon cancer model. Because of disappointing results in clinical trials, we analyzed the lethal and cytokinetic effects of anguidine on cultured human colon cancer cells. The studies revealed a moderate reduction in survival only after prolonged drug exposure. Continuous incubation with anguidine for longer than 48 hr produced a moderate increase in the percentage of S-phase cells and a slight decrease in the proportion of cells in G1/0, by pulse cytophotometry. An immediate reduction in the cumulative labeling index for cells continuously exposed to tritiated thymidine and anguidine and a rapid decrease in the cumulative mitotic index for cells continuously exposed to Colcemid and anguidine indicated a block at the G1 into S and G2 into mitosis transitions. Tumoricidal activity of anguidine in a cultured human colon cancer line is poor and requires prolonged exposure. The kinetic data reflect an almost frozen state of the cell cycle.

Adenocarcinoma↗
PubMed1977

The early detection of remission in acute myelogenous leukaemia by in vitro cultures.

Twenty-eight cases of acute myeloid leukaemia without normal myeloid colony growth in vitro were serially cultured by an in vitro agar culture method during remission induction therapy. Colony formation frequently returned before morphological evidence of remission. Without early return of colony formation drug induced aplasia was prolonged and fatal. Analysis of the pattern of return of in vitro colony forming cells may be of value in designing the chemotherapy schedule.

Bone Marrow Cells↗
PubMed1977

Measurement of mammalian sperm deoxyribonucleic acid by flow cytometry. Problems and approaches.

Measurement of mammalian sperm deoxyribonucleic acid content is of importance in several areas of biomedical research. When measured in flow systems with orthogonal axes of illumination, flow and detection, an unexpected, distorted distribution consisting of a narrow peak with a lateral extension to the right is observed. Several lines of evidence lead to the conclusion that this effect is an optical-geometric artifact attributable to the flat shape and high index of refraction of mammalian sperm heads. This artifact disappears when an epiillumination flow system is used in which the optic axes for illumination and detection and the flow axis are all coincident. Other approaches also eliminate the artifact. The resulting coefficients of variation observed after acriflavine-Feulgen staining are 4-5%, short of the goal of 1.5% required to distinguish between human sperm bearing X and Y chromosomes and to develop a mutagen test system using mice.

Acriflavine↗