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Cycle Parameters (cycle + parameter)
Selected AbstractsIdentification of a Chr 11 quantitative trait locus that modulates proliferation in the rostral migratory stream of the adult mouse brainEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2010Anna Poon Abstract Neuron production takes place continuously in the rostral migratory stream (RMS) of the adult mammalian brain. The molecular mechanisms that regulate progenitor cell division and differentiation in the RMS remain largely unknown. Here, we surveyed the mouse genome in an unbiased manner to identify candidate gene loci that regulate proliferation in the adult RMS. We quantified neurogenesis in adult C57BL/6J and A/J mice, and 27 recombinant inbred lines derived from those parental strains. We showed that the A/J RMS had greater numbers of bromodeoxyuridine-labeled cells than that of C57BL/6J mice with similar cell cycle parameters, indicating that the differences in the number of bromodeoxyuridine-positive cells reflected the number of proliferating cells between the strains. AXB and BXA recombinant inbred strains demonstrated even greater variation in the numbers of proliferating cells. Genome-wide mapping of this trait revealed that chromosome 11 harbors a significant quantitative trait locus at 116.75 ± 0.75 Mb that affects cell proliferation in the adult RMS. The genomic regions that influence RMS proliferation did not overlap with genomic regions regulating proliferation in the adult subgranular zone of the hippocampal dentate gyrus. On the contrary, a different, suggestive locus that modulates cell proliferation in the subgranular zone was mapped to chromosome 3 at 102 ± 7 Mb. A subset of genes in the chromosome 11 quantitative trait locus region is associated with neurogenesis and cell proliferation. Our findings provide new insights into the genetic control of neural proliferation and an excellent starting point to identify genes critical to this process. [source] Comparison of biomechanical gait parameters of young children with haemophilia and those of age-matched peersHAEMOPHILIA, Issue 2 2009D. STEPHENSEN Summary., Quality of life for children with haemophilia has improved since the introduction of prophylaxis. The frequency of joint haemorrhages has reduced, but the consequences of reduced bleeding on the biomechanical parameters of walking are not well understood. This study explored the differences in sagittal plane biomechanics of walking between a control group (Group 1) of normal age-matched children and children with haemophilia (Group 2) with a target ankle joint. A motion capture system and two force platforms were used to collect sagittal plane kinematic, kinetic and temporal,spatial data during walking of 14 age-matched normal children and 14 children with haemophilia aged 7,13 years. Group differences in maximum and minimum flexion/extension angles and moments of the hip, knee and ankle joints, ground reaction forces and temporal,spatial gait cycle parameters were analysed using one-way anova. Significant changes (P < 0.05) in kinematic and kinetic parameters but not temporal,spatial parameters were found in children with haemophilia; greater flexion angles and external moments of force at the knee, greater ankle plantarflexion external moments and lower hip flexion external moments. These results suggest that early biomechanical changes are present in young haemophilic children with a history of a target ankle joint and imply that lower limb joint function is more impaired than current clinical evaluations indicate. Protocols and quantitative data on the biomechanical gait pattern of children with haemophilia reported in this study provide a baseline to evaluate lower limb joint function and clinical progression. [source] Topoisomerase inhibitor induced dephosphorylation of H1 and H3 histones as a consequence of cell cycle arrestJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2005Nicole Happel Abstract Posttranslational modifications of histones have an integral function in the structural and functional organization of chromatin. Several changes in the modification state of histones could be observed after induction of apoptosis with topoisomerase inhibitors and other inducers. Most of these studies include the analysis of the state of phosphorylation of histones, and the results are to some extent controversial, depending on cell lines and agents used. In the present study we compared the kinetics of the dephosphorylation of H1 and H3 histones with apoptosis markers after treatment of leukemic cell lines with topoisomerase inhibitors. In parallel, we determined cell cycle parameters in detail. Dephosphorylation of both histone classes started within 1 h of induction, and no direct correlation with timing and intensity of the investigated apoptotic features could be observed. In contrast, we show that the effect of topoisomerase inhibitors on the state of H1 and H3 phosphorylation is not directly related to apoptosis, but reflects the changes in the cell cycle distribution of cells treated with these inducers. © 2005 Wiley-Liss, Inc. [source] Multilevel Anthropogenic Cycles of Copper and Zinc: A Comparative Statistical AnalysisJOURNAL OF INDUSTRIAL ECOLOGY, Issue 1-2 2006Barbara Reck Contemporary cycles for copper and zinc are coanalyzed with the tools of exploratory data analysis. One-year analyses (circa 1994) are performed at three discrete spatial levels-country (52 countries that comprise essentially all anthropogenic stocks and flows of the two metals), eight world regions, and the planet as a whole-and are completed both in absolute magnitude and in per capita terms. This work constitutes, to our knowledge, the first multiscale, multilevel analysis of anthropogenic resources throughout their life cycles. The results demonstrate that (1) A high degree of correlation exists between country-level copper and country-level zinc rates of fabrication and manufacturing, entry into use, net addition to in-use stocks, discard, and landfilling; (2) Regional-level rates for copper and zinc cycle parameters show the same correlations as exist at country level; (3) On a per capita basis, countries add to in-use stock almost 50% more copper than zinc; (4) The predominant discard streams for copper and zinc at the global level are different for the two metals, and relative rates of different loss processes differ geographically, so that resource recovery policies must be designed from metalspecific and location-specific perspectives; (5)When absolute magnitudes of life-cycle flows are considered, the standard deviations of the data sets decrease from country level to regional level for both copper and zinc, which is not the case for the per capita data sets, where the statistical properties of the dat sets for both metals approach being independent of spatial level, thus providing a basis for predicting unmeasured per capita metal flow behavior. [source] Proliferative and apoptotic differences between alveolar rhabdomyosarcoma subtypes: A comparative study of tumors containing PAX3-FKHR or PAX7-FKHR gene fusionsPEDIATRIC BLOOD & CANCER, Issue 2 2001Margaret H. Collins MD Abstract Background Most alveolar rhabdomyosarcomas (ARMS) have chromosome translocations and resultant gene fusion products. The more common translocation fuses the PAX3 and FKHR genes; patients who have PAX3-FKHR-positive ARMS have reduced event-free survival compared to patients with ARMS containing the less common translocation that fuses the PAX7 and FKHR genes. Procedure We examined histology, immunohistochemical markers of differentiation, and cell cycle characteristics of a panel of ARMS containing either PAX3-FKHR or PAX7-FKHR transcript to determine if these features differ between the ARMS subsets. Results Cell cycle parameters varied significantly: the number of nuclei that stained with either an immunohistochemical marker of proliferation (MIB1), or a TUNEL-based assay for apoptosis was significantly greater in tumors that expressed PAX3-FKHR compared to tumors that expressed PAX7-FKHR transcript. Conclusions We conclude that compared to PAX7-FKHR-containing tumors, ARMS that contain PAX3-FKHR transcript have (1) increased cell proliferation, consistent with greater loss of cell cycle regulation, and (2) apoptosis that is increased but insufficient to prevent tumor formation. More marked cell cycle dysregulation may contribute to poorer prognosis for patients with ARMS that have PAX3-FKHR fusion. Med Pediatr Oncol 2001;37:83,89. © 2001 Wiley-Liss, Inc. [source] Morphometric changes in a strain of the lineage ,Nevada', belonging to the Brachionus plicatilis (Rotifera) complexAQUACULTURE RESEARCH, Issue 8 2009Venetia Kostopoulou Abstract The rotifer Brachionus plicatilis is an important component of aquaculture as a larval feed. Its taxonomic status has been recently re-defined as a species complex, consisting of at least 14 new species/lineages. This study deals with the lineage Brachionus,Nevada', which has been shown to occur in European hatcheries. A strain of B. ,Nevada' was mass cultured using two commonly applied feeding regimes and analysed in terms of its morphometry. A new formula was proposed for the calculation of volume, which can be used as an index of adequacy of rotifers as feed for fish larvae. The results were related to life cycle parameters. The pre-reproductive and reproductive phases were divided into distinct size groups. Differences were also found between the two diets in morphometry and demography. Rotifers of a larger size (yeast-based diet) showed a lower growth rate and a longer reproductive period, lifespan and mean generation time compared with smaller-sized rotifers (Culture Selco® -based diet). In terms of lorica length, the present study's strain of B. ,Nevada' (238.5 ,m) was intermediate between values reported for Brachionus ibericus (193.5 ,m) and B. plicatilis sensu stricto (299 ,m). [source] | ||||||||||||||||