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Single Time Point (single + time_point)
Selected AbstractsRapid and easy semi-quantitative evaluation method for diacylglycerol and inositol-1,4,5-trisphosphate generation in orexin receptor signallingACTA PHYSIOLOGICA, Issue 3 2010M. E. Ekholm Abstract Aim:, Fluorescent protein-based indicators have enabled measurement of intracellular signals previously nearly inaccessible for studies. However, indicators showing intracellular translocation upon response suffer from serious limitations, especially the very time-consuming data collection. We therefore set out in this study to evaluate whether fixing and counting cells showing translocation could mend this issue. Methods:, Altogether three different genetically encoded indicators for diacylglycerol and inositol-1,4,5-trisphosphate were transiently expressed in Chinese hamster ovary cells stably expressing human OX1 orexin receptors. Upon stimulation with orexin-A, the cells were fixed with six different protocols. Results:, Different protocols showed clear differences in their ability to preserve the indicator's localization (i.e. translocation after stimulus) and its fluorescence, and the best results for each indicator were obtained with a different protocol. The concentration,response data obtained with cell counting are mostly comparable to the real-time translocation and biochemical data. Conclusion:, The counting method, as used here, works at single time point and looses the single-cell-quantitative aspect. However, it also has some useful properties. First, it easily allows processing of a 100- to 1000-fold higher cell numbers than real-time imaging producing statistically consistent population-quantitative data much faster. Secondly, it does not require expensive real-time imaging equipment. Fluorescence in fixed cells can also be quantitated, though this analysis would be more time-consuming than cell counting. Thirdly, in addition to the quantitative data collection, the method could be applied for identifying responsive cells. This might be very useful in identification of e.g. orexin-responding neurones in a large population of non-responsive cells in primary cultures. [source] Follicle-stimulating hormone and oestradiol levels during perimenopause in a cohort of Japanese womenINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 10 2008M. Yamada Summary Context:, There had been a lack of longitudinal studies regarding follicle-stimulating hormone (FSH) and oestradiol (E2) during perimenopause for non-Caucasian populations. Objective:, To investigate FSH and E2 levels during perimenopause in a Japanese cohort. Design and setting:, The Adult Health Study is a longitudinal population-based study. Perimenopausal women from this study cohort were followed between 1993 and 2003. Participants and main outcome measures:, Non-menopausal women, aged 47,54 years, were measured in terms of FSH and E2 levels every 6 months. For 89 women whose FSH and E2 levels were measured within 3 months from their final menstrual period (FMP), trends of FSH and E2 within 21 months of FMP were investigated at 6-month intervals. Results:, Follicle-stimulating hormone and E2 levels within 3 months from FMP showed wide ranges. Neither FSH nor E2 levels differed by age, weight or duration of amenorrhoea. Although FSH increased and E2 decreased during perimenopause, FSH and E2 levels at a single time point were found to not be a reliable marker of biological menopause, as hormone levels in and between the subjects showed wide variation and any trend in one individual was not necessarily one directional. Conclusions:, Among Japanese women who had natural menopause around the age of 50, hormone levels in and between individuals showed wide variation throughout perimenopause with a converged biochemical menopausal pattern characterised by high FSH and low E2 at about 2 years after FMP. [source] THE STATE OF THE FIELD: Combining contemporary and ancient DNA in population genetic and phylogeographical studiesMOLECULAR ECOLOGY RESOURCES, Issue 5 2010MIGUEL NAVASCUÉS Abstract The analysis of ancient DNA in a population genetic or phylogeographical framework is an emerging field, as traditional analytical tools were largely developed for the purpose of analysing data sampled from a single time point. Markov chain Monte Carlo approaches have been successfully developed for the analysis of heterochronous sequence data from closed panmictic populations. However, attributing genetic differences between temporal samples to mutational events between time points requires the consideration of other factors that may also result in genetic differentiation. Geographical effects are an obvious factor for species exhibiting geographical structuring of genetic variation. The departure from a closed panmictic model require researchers to either exploit software developed for the analysis of isochronous data, take advantage of simulation approaches using algorithms developed for heterochronous data, or explore approximate Bayesian computation. Here, we review statistical approaches employed and available software for the joint analysis of ancient and modern DNA, and where appropriate we suggest how these may be further developed. [source] Impact of acute cellular rejection on coagulation and fibrinolysis biomarkers within the immediate post-operative period in pediatric liver transplantationPEDIATRIC TRANSPLANTATION, Issue 3 2010Jun Mimuro Mimuro J, Mizuta K, Kawano Y, Hishikawa S, Hamano A, Kashiwakura Y, Ishiwata A, Ohmori T, Madoiwa S, Kawarasaki H, Sakata Y. Impact of acute cellular rejection on coagulation and fibrinolysis biomarkers within the immediate post-operative period in pediatric liver transplantation. Pediatr Transplantation 2010:14: 396,376. © 2009 John Wiley & Sons A/S. Abstract:, We studied restoration of the coagulation and fibrinolysis system in pediatric patients following liver transplantation and biomarkers of blood coagulation and fibrinolysis for suspecting the occurrence of acute cellular rejection. Coagulation activity recovered rapidly within two days following transplantation, but it took approximately 21,28 days for full recovery of the coagulation and fibrinolysis factors synthesized in the liver. PAI-1 levels were significantly higher in patients at the time of acute cellular rejection compared with levels after control of AR, and levels on days 14 and 28 in patients without AR. Plasma protein C and plasminogen levels at the time of rejection were significantly lower than those on day 14 in patients without AR. Statistical analysis suggested that an increase in plasma PAI-1 at a single time point in the post-operative period is a reliable marker among the coagulation and fibrinolysis factors for suspecting the occurrence of acute cellular rejection. These data suggested that appropriate anticoagulation may be required for 14 days after liver transplantation in order to avoid vascular complications and measurement of plasma PAI-1 levels may be useful for suspecting the occurrence of acute cellular rejection in pediatric patients following liver transplantation. [source] Genotype and time of day shape the Populus drought responseTHE PLANT JOURNAL, Issue 4 2009Olivia Wilkins Summary As exposure to episodic drought can impinge significantly on forest health and the establishment of productive tree plantations, there is great interest in understanding the mechanisms of drought response in trees. The ecologically dominant and economically important genus Populus, with its sequenced genome, provides an ideal opportunity to examine transcriptome level changes in trees in response to a drought stimulus. The transcriptome level drought response of two commercially important Populus clones (P. deltoides × P. nigra, DN34, and P. nigra × P. maximowiczii, NM6) was characterized over a diurnal period using a 4 × 2 × 2 complete randomized factorial anova experimental design (four time points, two genotypes and two treatment conditions), using Affymetrix Poplar GeneChip microarrays. Notably, the specific genes that exhibited changes in transcript abundance in response to drought differed between the genotypes and/or the time of day that they exhibited their greatest differences. This study emphasizes the fact that it is not possible to draw simple, generalized conclusions about the drought response of the genus Populus on the basis of one species, nor on the basis of results collected at a single time point. The data derived from our studies provide insights into the variety of genetic mechanisms underpinning the Populus drought response, and provide candidates for future experiments aimed at understanding this response across this economically and ecologically important genus. [source] | |||||||||||||