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At least 73 records · Page 4Linked to original sources
PubMed1980

[Selection for affinity to lung tissue in cell populations of experimental neoplasms].

Cell populations of eight experimental tumors (murine and rat rhabdomyosarcomas induced with 20-methylcholantrene, transplantable murine rhabdomyosarcoma A-7, and transplantable rat lymphosarcoma) have been selected for the affinity of their cells to lung tissue. The level of the affinity was measured as the number of lung nodules per 100 000 tumor cells injected intravenously. A 3-4-fold selection appeared to be non-effective, whereas 10-fold or more prolonged selections resulted in a gradual enhancement of the affinity of tumor cells to lung tissue. Thus, the transplantable murine and rat rhabdomyosarcomas were obtained with an increased capacity of their cells of yielding lung nodules. The affinity of rat rhabdomyosarcoma was 200-300 times higher after 40 steps of selection compared to the initial tumor affinity. With the rhabdomyosarcoma of CC57W mice, the affinity increased by 5 times after 20 steps of selection. Using our technique of selection (without an in vitro cultivation), the capacity of cells of persisting in lung tissue and yielding lung nodules looks likely as a quantitative character with a rather low heritability. It has been concluded that in cell populations of tumors examined there are only a few genetic population variations in cell capacity of making non-random metastases.

Animals↗
PubMed1982

Effects of systemic hyperthermia on the growth patterns of experimental neoplasms.

Hyperthermia has been shown to have a detrimental effect on experimental and human neoplasms. A water bath immersion system is described to evaluate the effects of systemic hyperthermia (SH) on the growth patterns of the Morris hepatoma 7777 in male Buffalo rats. SH and anesthesia were observed to have no long-term detrimental effects on weight trends or chow consumption. Inhibition of growth was demonstrated for this experimental tumor model at extreme SH (41.5 degree to 42.0 degree C), and it was statistically different (P less than 0.01) from the patterns of tumor growth observed in controls and tumor-burdened animals treated with moderate SH (39..5 degree to 40.0 degree C). Cessation of extreme SH resulted in acceleration of tumor growth so that no difference in tumor volume or animal survival was identified SH resulted in retardation of tumor growth patterns, but its effects were not sustained once treatments were stopped.

Animals↗
PubMed1986

[Changes in the proteolytic activity and components of the blood kallikrein-kinin system during the growth and metastasis of experimental neoplasms].

Changes in the total blood proteolytic activity, prekallikrein level, serum kallikrein inhibitors and other proteinases were studied during the growth and metastatic spreading of different experimental tumours. It has been established that the dissemination and metastatic spreading of Guérin carcinoma inoculated intratesticularly to rats is accompanied by a decrease in the content of prekallikrein and serum kallikrein inhibitors, which shows the activation of blood kinins. Changes in the total proteolysis and in prekallikrein content in mice with carcinoma 3LL and melanoma B-16 are of two-phase character: at the first stage after tumour inoculation there occurs an increase in the proteolytic activity and in prekallikrein content. At the second stage (14 to 28 days) characterized by the appearance of lung metastases, quite a pronounced and stable inhibition of the total proteolysis and of prekallikrein level was observed together with an increased level of proteinase inhibitors. The data obtained show that disturbances in the reactions of limited proteolysis, in particular shifts of the blood kallikrein-kinin system, play a definite role in the development of the metastatic process.

Animals↗
PubMed1994

[Growth of experimental neoplasms in mice with inhibition of endogenous prostaglandin synthesis].

Prostaglandin inhibitor--indomethacin was found to significantly suppress the growth of 5 epithelial transplantable tumors in mice. Simultaneously, it stimulated the development of leukemias L-1210 and La and intraperitoneal melanoma B-16. It was also shown to stimulate the spontaneous development of leukemia in mice AKR. Its growth-inhibiting effect was in direct correlation with the rate of prostaglandin E2 synthesis in tumor. The data obtained point to a specific metabolism of polyunsaturated fatty acids in experimental tumors of varying histogenesis as well as the importance of prostaglandin E2 level for prognosis of the inhibitive effect of indomethacin.

Animals↗
PubMedDate not supplied

[Bacteriocins as cytotoxic agents in experimental neoplasms: considerations on the role of possible contaminants].

In most recent papers some Authors have demonstrated that several bacteriocins are able to markedly inhibit the division of various neoplastic mammalian cell lines; also in vivo the inhibition of tumor growth or even regression relative to controls are statistically significant. Since such preparations are "crude" and it's possible that contaminating agents may represent a possible source of variability in the results, mostly in vivo; we have examined a preparation of Pyocin employed in this study for the possible endotoxin contamination using the Limulus assay. Such test was positive in triplicate and semiquantitative determination has shown and endotoxin amount of 5 to 10 microgram/ml. This level is, in vitro, not anough to give cytotoxic effect, but in vivo is able to influence experimental results. In addition, since some bacteriocins and enterotoxins are produced under exactly identical conditions, there is this a possibility that the enterotoxin are coproduced in these preparations and are causing some of the cytotoxic effects on experimental tumors. A more complete separation and purification of preparations will be required before definitive comments.

Animals↗
PubMed1978

Glomerulonephritis in malignant extra-renal neoplasms. Experimental study on mice using the method of immunofluorescence.

Histologic and immunofluorescence studies were done in the murine kidneys (strain C3HAvy) suffering a spontaneous cancer of the liver. Proliferative glomerulonephritis has been found in 17 animals and memranproliferative glomerulonephritis with "wire loop" appearance in 6 animals. The glomeruli of all animals presented immune complex deposition in the mesangium and along the glomerular basement membrane. Furthermore, heavy intensity of IgG complex deposition was observed in animals with membranproliferative glomerulonephritis. The latter animals had developed a poorly differentiated liver cancer.

Animals↗
PubMed1991

Comparison of MRI, CT and bone scintigraphy in metastases of experimental neoplasm.

We compared MRI, CT and bone scintigraphy in the examination of experimentally produced metastatic bone tumors. Three Japanese white rabbits with VX-2 bone tumor were used. T1 weighted (T1W) and T2 weighted (T2W) images were obtained in each MRI examination. All the tumors distributed from the bone marrow to the extraosseous region. T2W images were the best to detect the extraosseous tumors. CT was the best to detect the destructions of bone. T1W and T2W images equally detected the invaded bone marrow. Bone scintigraphy detected all the lesions but could not distinguish the lesions of bone marrow, bone and extraosseous regions.

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