Vinca alkaloids are used extensively in the treatment of childhood acute lymphoblastic leukemia (ALL) and despite their usefulness, drug resistance remains a serious clinical problem. Vinca alkaloids bind to the beta-tubulin subunit of the alpha/beta-tubulin heterodimer and inhibit polymerization of microtubules. Recent studies have implicated altered beta-tubulin isotype expression and mutatio...

Vinpocetine, a synthetic derivative of the Vinca minor alkaloid vincamine, is a widely used drug in neurological practice. We tested the hypothesis that vinpocetine binds to peripheral benzodiazepine binding sites (PBBS) and is therefore a potential ligand of PBBS. Positron emission tomography (PET) measurements in two cynomolgous monkeys showed that pretreatment with vinpocetine markedly reduc...

In two hamster cell lines that differed 100-fold in their vinblastine sensitivity, dissolution of the mitotic spindle by vinblastine in living cells correlated with cytotoxicity from vinblastine expressed as suppression of colony formation. The effect on the spindle apparatus occurred in 30 sec or less and thus provides a rapid assay for determining the cytotoxic effects of the Vinca alkaloids,...

Naturally occurring vinca alkaloids, vincristine and vinblastine, at micromolar concentrations enhanced the ornithine decarboxylase activity in a dose-response manner in primary cultures of Ehrlich ascites carcinoma cells. After 8 h of culture in the presence or absence of vinblastine, cycloheximide was added to the medium, a 4.5-fold increase in the half-life of the ornithine decarboxylase act...

Vinflunine is a novel Vinca alkaloid presently in Phase I clinical trials. In preclinical studies, it exhibited superior antitumor activity to that of other Vinca alkaloids, including vinorelbine from which it was synthetically derived. Vinca alkaloids appear to inhibit cell proliferation by affecting the dynamics of spindle microtubules. Here we have analyzed the effects of vinflunine and vino...

Vinflunine is a novel Vinca alkaloid presently in Phase I clinical trials. In preclinical studies, it exhibited superior antitumor activity to that of other Vinca alkaloids, including vinorelbine from which it was synthetically derived. Vinca alkaloids appear to inhibit cell proliferation by affecting the dynamics of spindle microtubules. Here we have analyzed the effects of vinflunine and vino...

background: the seeds of some medicinal plants and their compounds have long been valued for their numerous health benefits. objective:to investigate some physical and chemical properties of salvia spp. methods: some physico-chemical properties in five species of salvia seeds (consisted of s. officinalis l., s. macrosiphon l., s. hypoleuca l., s. sclarea l. and s. nemorosa l.) were measured at ...

Robertson and Seymour proved that every graph with sufficiently large treewidth contains a large grid minor. However, the best known bound on the treewidth that forces an l × l grid minor is exponential in l. It is unknown whether polynomial treewidth suffices. We prove a result in this direction. A grid-like-minor of order l in a graph G is a set of paths in G whose intersection graph is bipar...

Robertson and Seymour proved that every graph with sufficiently large treewidth contains a large grid minor. However, the best known bound on the treewidth that forces an l × l grid minor is exponential in l. It is unknown whether polynomial treewidth suffices. We prove a result in this direction. A grid-like-minor of order l in a graph G is a set of paths in G whose intersection graph is bipar...