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Szawarski Z 《Bioethics》1990,4(2):143-153
The author and his colleagues surveyed pediatricians in Warsaw, Poland, to determine the doctors' attitudes toward treating infants with severe handicaps. They used a questionnaire originally designed by Australian researchers to survey pediatricians and compared their findings with those of the Australian study. Szawarski notes important differences between the approaches of Australian and Polish doctors to the treatment of handicapped newborns. Polish physicians tend to display an unconditional respect for life, a paternalistic attitude toward decision making, and an unwillingness to distinguish between ordinary and extraordinary means of prolonging life. Half the Polish respondents would be willing to preserve the lives of severely handicapped infants at all costs. Szawarski discusses six factors that may help to explain why Polish physicians have a different approach from that of their Western colleagues to the question of selective treatment of handicapped newborns. 相似文献
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Ignacy Z. Siemion Artur Pdyczak Jerzy Trojnar Michakl Zimecki Zbigniew Wieczorek 《Peptides》1992,13(6):1233-1237
In connection with our discovery of a strong immunosuppressive activity of cyclolinopeptide A (CLA), we investigated immunosuppressive properties of antamanide and a number of its analogues, including symmetrical antamanide, and compared them with the activities of cyclosporin A and CLA. The peptides were investigated by using plaque forming cell (PFC), graft-versus-host (GvH), delayed type hypersensitivity (DTH), and autologous rosette formation cell (ARFC) tests. Antamanide and symmetrical antamanide exhibit an immunosuppressive activity lower than CLA. Linear antamanide fragments are also active. At higher concentrations of the latter peptides, toxic effects occur. 相似文献
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Szawarski Z 《BMJ (Clinical research ed.)》1992,304(6820):137-142
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Analysis of a cell cycle model based on unequal division of metabolic constituents to daughter cells during cytokinesis 总被引:3,自引:0,他引:3
Marek Kimmel Zbigniew Darzynkiewicz Ovide Arino Frank Traganos 《Journal of theoretical biology》1984,110(4):637-664
We demonstrate that the unequal division of RNA during cytokinesis explains the dispersion of cell generation times in CHO cell cultures. Experimental cytometric results reported previously serve as a basis for a probabilistic model of cytokinesis. Unequal RNA division to daughter cells, together with two simple laws of RNA production, are used as a source of randomness within the cell cycle. The model reproduces the experimental growth of the CHO cell population, including the observed variability in RNA content. The model has stabilizing properties which explain why a cell population with increased RNA content characteristics, a few cell cycles, to the original pattern. Other cell cycle characteristics, like sister-to-sister and mother-to-daughter generation time correlations implied by the model, are close to their experimental analogs. The conceptual basis of the model is general enough to include unequal division of factors other than RNA (cell mass, cell proteins, etc.) as sources of generation time variability. It seems that the observed dispersion of cell generation times, explained previously in the terms of random transitions in some part of the cell cycle (the Smith & Martin A and B state hypothesis), can be reduced to the single random event of unequal division. This supplies a new convenient tool in the investigation of cell cycle kinetics. 相似文献
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Zbigniew Szot Małgorzata Rochalska Maria Wojewódzka Andrzej Chimiak Witold Przychodzen 《Radiation and environmental biophysics》1986,25(1):31-35
Summary Male mice SAS/4 were injected i.v. with239Pu citr(IV) 0.27 µCikg–1–9.99 kBqkg–1. After 1 h 30 µmol kg–1 of 3,4,3 LICAM(C), N, N, N, N-tetra-(2,3-dihydroxybenzoyl)-spermine or Na3CaDTPA as a reference compound was given intraperitoneally. After 4 days the animals were sacrified and the Pu content in livers, kidneys, femurs and carcasses was determined by the liquid scintillation method. It was found that, as compared with the control, 3,4,3 LICAM(C) removed 83% of the Pu activity deposited in the liver, 71% of that in the femur and 79% of the Pu in the whole body. The Pu content in the kidneys exceeded the control value by about 50%. Na3CaDTPA removed 96, 86, 40 and 72% of plutonium from the liver, kidneys, femurs and carcasses respectively.Tetra-DHB-spermine caused the excretion of 50, 57 and 39% of Pu from liver, bone and whole body respectively. The retention of Pu in the kidneys was increased to 400% of the control value. 相似文献
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Stathmokinetic Analysis of Human Epidermal Cells in vitro 总被引:1,自引:0,他引:1
Proliferation kinetics of cultured human epidermal cells is characterized in quantitative terms. Three distinct subpopulations of keratinocytes, two of which are cycling have been discriminated by two parameter DNA/RNA flow cytometry. Based on mathematical modelling, the cell cycle parameters of the cycling subpopulations have been assessed from stathmokinetic data collected at different time points after initiation of cultures (7–15 days). the first subpopulation is composed of low-RNA cells which resemble basal keratinocytes of epidermis and which show some characteristics of stem cells; these cells have a mean generation time of approximately 100 hr. the second subpopulation consists of high-RNA cells, resembling stratum spinosum cells of epidermis, which have an average generation time of approximately 40 hr. the third subpopulation consists of non-cycling cells with Go/G1 DNA content, with cytochemical features similar to those of cells in granular layer of epidermis. The results based on modelling can reproduce with acceptable accuracy the actual growth curve of the cultured cell population. Analysis of kinetics and differentiation of human keratinocytes is of interest in view of the recent application of cultured epidermal cell sheets for transplantation onto burn wounds. the results of this study also reveal the existence of regulatory mechanisms associated with proliferation and differentiation in the cultured epidermal cell population. 相似文献
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K J Rybicki J C Longhurst M P Kaufman 《Journal of applied physiology (Bethesda, Md. : 1985)》1983,55(2):427-432
Although chemical stimulation of abdominal visceral afferents has been shown to reflexly increase cardiovascular and ventilatory function, the effect of stimulating these afferents on airway smooth muscle is unknown. Therefore, we recorded transverse smooth muscle tension from an innervated segment of trachea in chloralose-anesthetized dogs while we topically applied capsaicin (200 micrograms/ml) and bradykinin (0.01-10 micrograms/ml) to the serosal surfaces of the stomach, small intestine, and gallbladder. Application of these irritant substances to the stomach and small intestine decreased tracheal tension and increased mean arterial pressure. However, application of capsaicin and bradykinin to the gallbladder had only small effects on both of these variables. Cutting the splanchnic nerves abolished or greatly attenuated the decreases in tension and increases in mean arterial pressure, whereas cutting the vagi had no effect on them. We conclude that stimulation of splanchnic afferent endings in the stomach and small intestine reflexly relaxes tracheal smooth muscle in dogs. This effect may be one component of the constellation of autonomic responses reflexly evoked by abdominal visceral pain and inflammation. 相似文献
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