Search results for "Cell Division"
showing 10 items of 457 documents
Sustained telomere erosion due to increased stem cell turnover during triple autologous hematopoietic stem cell transplantation.
2007
Telomeres cap chromosomal ends and are shortened throughout a lifetime. Additional telomere erosion has been documented during conventional chemotherapy or hematopoietic stem cell transplantation. Previous studies of stem cell transplantation reported variable amounts of telomere shortening with inconsistent results regarding the persistence of telomere shortening. Here we have prospectively studied telomere length and proliferation kinetics of hematopoietic cells in aggressive non-Hodgkin lymphoma patients who underwent a four-course high-dose chemotherapy protocol combined with triple autologous stem cell transplantation. We observed sustained telomere shortening in hematopoietic cells af…
Blood flow, oxygenation, metabolic and energetic status in different clonal subpopulations of a rat rhabdomyosarcoma.
1998
Differentiation of a tumor plays an important role in terms of biological aggressiveness. The question arises as to whether this is reflected in differences in the metabolic and energetic status of solid tumors. The aim of this study was to analyze the influence of clonal tumor cell differentiation on the microenvironment of rat rhabdomyosarcomas. Two distinct lines of a rhabdomyosarcoma (BA-HAN-1) with different histomorphological properties were used (line F1, co-existence of mononuclear stellate cells and multinuclear myotube-like giant tumor cells; G8, polygonal, mononuclear tumor cells). Solid tumors were grown s.c. on the hind food dorsum of Lewis rats. Tumor oxygenation was measured …
Enzyme histochemical and immunohistochemical characterization of oval and parenchymal cells proliferating in livers of rats fed a choline-deficient/D…
1991
Male outbred Sprague-Dawley rats were fed a choline-deficient diet containing 0.10% DL-ethionine for up to 30 weeks. Liver slices from rats killed 4, 6, 10, 14, 22 and 30 weeks after starting the treatment were histochemically analyzed for the following parameters: basophilia, expression of cytokeratin 19 (which in the liver is bile duct epithelial cell-specific), glycogen content and activities of glycogen synthetase (SYN), glycogen phosphorylase (PHO), glucose-6-phosphatase (G6PASE), glucose-6-phosphate dehydrogenase (G6PDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glycerin-3-phosphate dehydrogenase (G3PDH), 'malic enzyme' (MDH), alkaline phosphatase (ALKPASE) and gamma-glutamyl…
Effects of phenylbutyrate on proliferation and apoptosis in human prostate cancer cells in vitro and in vivo.
1999
Phenylbutyrate (PB) is a potent differentiating agent and currently under investigation for the treatment of prostate cancer (CaP) and other malignancies. We have studied the impact of PB in vitro and in vivo on differentiation, proliferation and apoptosis in the LNCaP and LuCaP 23.1 prostate cancer xenograft models. In vitro we found that i) PB increased PSA secretion/cell, ii) inhibited cell proliferation in a time- and dose-dependent manner resulting in a cell cycle arrest in G1-phase and iii) induced apoptosis at concentrations of 2.5 mM after 3 days of treatment. In PB treated animals tumor growth stabilized or regressed. Combination of castration and PB treatment had a synergistic ant…
Effects of peroxisome proliferator-activated receptor alpha activation on pathways contributing to cholesterol homeostasis in rat hepatocytes
2004
International audience; Peroxisome proliferator-activated receptor alpha (PPARa) activation by fibrates controls expression of several genes involved in hepatic cholesterol metabolism. Other genes could be indirectly controlled in response to changes in cellular cholesterol availability. To further understand how fibrates may affect cholesterol synthesis, we investigated in parallel the changes in the metabolic pathways contributing to cholesterol homeostasis in liver. Ciprofibrate increased HMG-CoA reductase and FPP synthase mRNA levels in rat hepatocytes, together with cholesterogenesis from [14C] acetate and [3H] mevalonate. The up-regulation observed in fenofibrate- and WY-14,643-treate…
Unique pharmacology of KAR-2, a potential anti-cancer agent: absorption modelling and selective mitotic spindle targeting.
2008
Abstract Bis-indols are a large group of the anti-cancer agents, which effectively arrest the uncontrolled division of the cancerous cells. Their use in clinical chemotherapy is still limited because of: (i) the non-specific targeting of the mitotic cells; (ii) low bioavailability of the drugs. KAR-2 has been identified as a tubulin binding agent which displays significantly lower cytotoxicity but favourable anti-cancer potency than its mother molecule, vinblastine. The objective of this paper, on one hand, was to show that the human intestinal epithelial Caco-2 cells, used for pharmacokinetic studies display distinct sensitivity against KAR-2 and vinblastine due to their distinct targeting…
Lack of the Cell-Cycle Inhibitor p27Kip1 Results in Selective Increase of Transit-Amplifying Cells for Adult Neurogenesis
2002
The subventricular zone (SVZ) is the largest germinal layer in the adult mammalian brain and comprises stem cells, transit-amplifying progenitors, and committed neuroblasts. Although the SVZ contains the highest concentration of dividing cells in the adult brain, the intracellular mechanisms controlling their proliferation have not been elucidated. We show here that loss of the cyclin-dependent kinase inhibitor p27Kip1 has very specific effects on a population of CNS progenitors responsible for adult neurogenesis. Using bromodeoxyuridine and [3H]thymidine incorporation to label cells in S phase and cell-specific markers and electron microscopy to identify distinct cell types, we compared th…
Candida arthritis: cellular immune responses of synovial fluid and peripheral blood lymphocytes to Candida albicans.
1991
A case of septic Candida albicans arthritis of the knee in a patient with systemic candidiasis is presented. Systemic and intra-articular cellular immune responses to C albicans and various bacterial antigens were monitored for 15 weeks. It is shown that the candida induced blastogenesis of synovial fluid lymphocytes was much more stimulated than that of peripheral blood lymphocytes, and that the proportion of activated cells expressing HLA class II antigens was markedly increased in the synovial fluid. Strong cellular immune responses to Candida albicans could still be shown many weeks after the synovial fluid aspirates had become sterile. For the first time synovial fluid derived, CD4 pos…
Inhibition of cancer growth by resveratrol is related to its low bioavailability.
2002
The relationship between resveratrol (RES) bioavalability and its effect on tumor growth was investigated. Tissue levels of RES were studied after i.v. and oral administration of trans-resveratrol (t-RES) to rabbits, rats, and mice. Half-life of RES in plasma, after i.v. administration of 20 mg t-RES/kg b.wt., was very short (e.g., 14.4 min in rabbits). The highest concentration of RES in plasma, either after i.v. or oral administration (e.g., 2.6 +/- 1.0 microM in mice 2.5 min after receiving 20 mg t-RES/kg orally), was reached within the first 5 min in all animals studied. Extravascular levels (brain, lung, liver, and kidney) of RES, which paralleled those in plasma, were always1 nmol/g f…
Regulation of glutathione metabolism in Ehrlich ascites tumour cells.
1992
Glutathione metabolism was studied in cancer cells during the growth of an Ehrlich ascites tumour. GSH, but not GSSG, content decreases when cell proliferation and the rate of protein synthesis in the tumour decrease. This change correlates with a decrease in the rate of GSH synthesis and an increase in glutathione peroxidase and glutathione S-transferase activities. Glutathione efflux from tumour cells seems to co-ordinate with the rate of GSH synthesis. Cysteine, and not methionine, promotes GSH synthesis in tumour cells. However, changes in the rate of GSH synthesis are not due to limitations in the supply of blood cysteine or to changes in the intracellular amino acid pool of the cancer…