BACKGROUND Different abnormalities of T cell effector function distinguish Crohn's disease (CD) from ulcerative colitis (UC). Because cell cycling determines effector function, pathogenic events in CD and UC may depend on cell cycle changes unique to each condition. METHODS Cell cycle kinetics, cycle regulatory molecule expression, apoptosis, caspase and telomerase activity, and cellular expa...

Fifteen years ago, it was proposed that the cell cycle in fission yeast can be driven by quantitative changes in the activity of a single protein kinase complex comprising a cyclin - namely cyclin B - and cyclin dependent kinase 1 (Cdk1). When its activity is low, Cdk1 triggers the onset of S phase; when its activity level exceeds a specific threshold, it promotes entry into mitosis. This model...

introduction : arsenic trioxide (as2o3) causes antitumor effects by various mechanisms, including degradation of pml-rara in the acute promyelocytic cells, growth inhibition and induction of apoptosis. however, the precise mechanisms of these processes remain incompletely understood. the purpose of this study was to evaluate the effects of arsenic trioxide on cell growth, cell cycle regulation ...

Mole-rats are strictly subterranean and hardly, if ever, come into contact with external light. As a result, their classical visual system is severely regressed and the circadian system proportionally expanded. The family Bathyergidae presents a unique opportunity to study the circadian system in the absence of the classical visual system in a range of species. Daily patterns of activity were s...

The non-pregnant uterus shows wave-like activity throughout the menstrual cycle. This uterine activity was first detected using intra-uterine pressure recordings. The use of ultrasound has made it possible to study the movements of the uterus in a non-invasive manner. Throughout the menstrual cycle, several wavelike activity patterns have been described; these patterns change throughout the men...

Relations between physical activity and prospectively collected menstrual cycle characteristics were examined in two large cohorts. One cohort consisted of women employed in the semiconductor industry in 1989 who participated in a prospective study of reproductive outcomes (n = 367). The other consisted of women living in Tecumseh, Michigan, who completed both the 1992-1993 and 1993-1994 examin...

we give a new recursive method to compute the number of cliques and cycles of a graph. this method is related, respectively to the number of disjoint cliques in the complement graph and to the sum of permanent function over all principal minors of the adjacency matrix of the graph. in particular, let $g$ be a graph and let $overline {g}$ be its complement, then given the chromatic polynomial of...

we present a matching and lp based heuristic algorithm that decides graph non-hamiltonicity. each of the n! hamilton cycles in a complete directed graph on n + 1 vertices corresponds with each of the n! n-permutation matrices p, such that pu,i = 1 if and only if the ith arc in a cycle enters vertex u, starting and ending at vertex n + 1. a graph instance (g) is initially coded as exclusion set ...