[en] The relation between neoplasm growth kinetics and its radiosensitivity is considered. The growth kinetics investigations were carried out for pairs of neoplasms, one of which is relatively radiostable, and the other is radiosensitive. The investigations have shown that in all the compared pairs the neoplasms with a higher radiosensitivity had a greater growth kinetics and more intensive proliferation

No abstract available

[en] At present, scientists are resorting more frequently to nature in order to develop drugs against various illnesses such as cancer. The origin of natural products is diverse and their structure is very complex with the capacity of inhibiting through indirect effect the development of tumors by stimulating the defense mechanisms of the body

[en] Spin-echo nuclear magnetic resonance measurements may be used as a method for studying the influence of pH upon T₂. The transverse relaxation time T₂ was measured on Ehrlich ascites and Ehrlich solid tumors. An increase of T₂ with 184 ms in the case of Ehrlich ascties and 16 ms for Ehrlich solid tumor could be observed when the pH values decrease. The data are in accordance with a model that explains the change of T₂ with the tetanic isometric contraction

[en] A single intraperitoneal injection of hydroxyurea (0.5 mg/g) in mice bearing Ehrlich ascites tumour synchronized the growth of tumour cells. The fraction of cells synthesizing (H³-thymidine pulse label) was reduced to less than 10 per cent 30 to 90 min after hydroxyurea administration and reached maximum up to 90 per cent 6-8 hours later. Radioresistance of cells determined by the rate of tumour growth and the number of cells without chromosome aberrations was higher in the population exposed in the S phase. The endogenous thiol content of cellscorrelates well with their radiosensitivity, depending on the growth phase

[en] Histologic grading has been considered the most important prognostic factor for soft tissue sarcomas. Several grading systems have been proposed based on the assessment of morphologic features in heterogeneous groups of sarcomas. Currently, the French Federation of Cancer Centers (FNCLCC) and the National Cancer Institute (NCI) grading systems are the most commonly used. These systems are based on a few morphologic predictors of biologic behavior, which is justifiable because of the rarity of soft tissue sarcomas. Nonetheless, over- or underestimation of prognosis may occur because of an uneven representation of specific sarcomas with rather distinct biologic behaviors among studies of grading systems. In addition, lack of standardization of morphologic criteria and frequent omission of the influence of clinical factors on the final survival analyses preclude universal acceptance of a particular grading system. New advances in diagnostic imaging, quantitative morphometric technologies, cytogenetics, and molecular genetics, allied with alternative analytic data systems, may provide better validation, reproducibility, and prognostic capabilities for current and future grading systems. This article summarizes and critically analyzes the various important grading systems that have thus far been proposed and suggests alternatives for the elaboration of more reproducible systems with higher predictive capabilities. (orig.)

[en] Ziyuglycoside II is an active compound of Sanguisorba officinalis L. that has anti-inflammation, antioxidation, antibiosis, and homeostasis properties. We report here on the anticancer effect of ziyuglycoside II on human gastric carcinoma BGC-823 cells. We investigated the effects of ziyuglycoside II on cell growth, cell cycle, and cell apoptosis of this cell line. Our results revealed that ziyuglycoside II could inhibit the proliferation of BGC-823 cells by inducing apoptosis but not cell cycle arrest, which was associated with regulation of Bax/Bcl-2 expression, and activation of the caspase-3 pathway. Our study is the first to report the antitumor potential of ziyuglycoside II in BGC-823 gastric cancer cells. Ziyuglycoside II may become a potential therapeutic agent against gastric cancer in the future

[en] Using a polarographic method the kinetics of oxygen consumption by Ehrlich ascites tumour cells has been studied varying times after inoculating. The level of original cell oxygenation was shown to influence the rate of cell respiration and its dependence on pO₂ within the extracellular medium. The analys of the chronoamperograms prompts the conclusion that O₂ permeability of the cytoplasmic membrane increases as the tumour grows and its oxygen deficiency rises. The data obtained, compared to experimental results showing a reduced radiomodifying effect of acute hypoxia on Ehrlich ascites tumour cells with low original oxygenation level, are discussed in terms of the adaptation hypothesis

[en] A study was made of the survival rate of Ehrlich ascites clonogenic cells on the 7th day following inoculation depending on ⁶⁰Co-γ-radiation dose delivered under hypoxic and oxygenating conditions in vitro. In both cases the survival curves had a small shoulder and an exponential part. The oxygen enhancement ratio determined as a ratio of D₀ for hypoxic (6.59 Gy) and oxygenated (2.06 Gy) cells was 3.2

[en] It is known from experimental and theoretical considerations that the shoulder in the usual dose-survival curve for mammalian cells is due to repair of potentially lethal lesions (PLL). As a consequence, reappearance of the shoulder in a split-dose experiment should also be related to repair of PLL. A procedure for calculation of cell survival curves for split-dose irradiation is described which takes into consideration repair of PLL only. Ehrlich ascites tumor cells were used. The reproduction of the shoulder with increasing tie interval between the two dose fractions can be seen to take place with a time constant closely related to that of repair of PLL. Other quantitative parameters such as the dose dependence of this recovery time constant can be predicted quantitatively from the calculation. (author)