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排序方式: 共有163条查询结果,搜索用时 46 毫秒
41.
Clarke DH Pérez-Bello D Riverón-Rojas AM Jiménez-Alemán G Acosta MZ Perera RP Carrazana MS Miranda ND Rodríguez-Tanty C Gutiérrez Calzado E 《Preparative biochemistry & biotechnology》2005,35(1):1-15
In the present work, a label immunoquantification procedure was developed in order to determine the number of markers introduced into DNA. A non-enzymatic, in vitro labeling method for introducing the p-bromobenzoyl radical (label), through transamination and acylation reactions of the cytidine nucleotides in calf thymus DNA, was carried out. Three spacer arms with different lengths were used for separating the label from the nucleotide and three labeled DNA were obtained. Anti-p-bromobenzoyl chicken IgY polyclonal antibodies were obtained. The antibodies detected the label, into three-labeled DNA, with different sensitivities, in relation to spacer arm length used. About 3-11 labels per 4 x 10(6) bases into thermally denatured DNA were immunoquantified. 相似文献
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Viana Manrique Suárez David Higginson Clarke Ana María Riverón 《Preparative biochemistry & biotechnology》2013,43(1):40-50
Abstract DNA molecules suitable for amplification by Polymerase Chain Reaction were obtained by immobilizing whole blood or isolated leukocytes and incubating the immobilized cells for one hour with the known non‐enzymatic solution described for preparing intact DNA molecules for PFGE. Cell immobilization was done in agarose gels and punches of 1.2 mm of diameter had the amount of DNA needed for amplifying chromosomal and mitochondrial sequences, many times. The approach was successfully used in preparing DNA molecules from multiple samples in flat‐bottom 96‐well ELISA plates. The procedure is simple and does not demand special conditions for sample transportation or conservation; thus, it should be useful to collect and process samples under field conditions in epidemiological studies. 相似文献
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Knee osteoarthritis (OA) detrimentally impacts the lives of millions of older Americans through pain and decreased functional ability. Unfortunately, the pathomechanics and associated deviations from joint homeostasis that OA patients experience are not well understood. Alterations in mechanical stress in the knee joint may play an essential role in OA; however, existing literature in this area is limited. The purpose of this study was to evaluate the ability of an existing magnetic resonance imaging (MRI)-based modeling method to estimate articular cartilage contact area in vivo. Imaging data of both knees were collected on a single subject with no history of knee pathology at three knee flexion angles. Intra-observer reliability and sensitivity studies were also performed to determine the role of operator-influenced elements of the data processing on the results. The method's articular cartilage contact area estimates were compared with existing contact area estimates in the literature. The method demonstrated an intra-observer reliability of 0.95 when assessed using Pearson's correlation coefficient and was found to be most sensitive to changes in the cartilage tracings on the peripheries of the compartment. The articular cartilage contact area estimates at full extension were similar to those reported in the literature. The relationships between tibiofemoral articular cartilage contact area and knee flexion were also qualitatively and quantitatively similar to those previously reported. The MRI-based knee modeling method was found to have high intra-observer reliability, sensitivity to peripheral articular cartilage tracings, and agreeability with previous investigations when using data from a single healthy adult. Future studies will implement this modeling method to investigate the role that mechanical stress may play in progression of knee OA through estimation of articular cartilage contact area. 相似文献
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Muscle atrophy is one of many factors contributing to post-stroke hemiparetic weakness. Since muscle force is a function of muscle size, the amount of muscle atrophy an individual muscle undergoes has implications for its overall force-generating capability post-stroke. In this study, post-stroke atrophy was determined bilaterally in fifteen leg muscles with volumes quantified using magnetic resonance imaging (MRI). All muscle volumes were adjusted to exclude non-contractile tissue content, and muscle atrophy was quantified by comparing the volumes between paretic and non-paretic sides. Non-contractile tissue or intramuscular fat was calculated by determining the amount of tissue excluded from the muscle volume measurement. With the exception of the gracilis, all individual paretic muscles examined had smaller volumes in the non-paretic side. The average decrease in volume for these paretic muscles was 23%. The gracilis volume, on the other hand, was approximately 11% larger on the paretic side. The amount of non-contractile tissue was higher in all paretic muscles except the gracilis, where no difference was observed between sides. To compensate for paretic plantar flexor weakness, one idea might be that use of the paretic gracilis actually causes the muscle to increase in size and not develop intramuscular fat. By eliminating non-contractile tissue from our volume calculations, we have presented volume data that more appropriately represents force-generating muscle tissue. Non-uniform muscle atrophy was observed across muscles and may provide important clues when assessing the effect of muscle atrophy on post-stroke gait. 相似文献
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JS Osombause SNM Mandiki JA-P Ulyel J-C Micha P Kestemont 《African Journal of Aquatic Science》2019,44(1):61-70
Distichodus antonii is an endemic fish species of the Congo River basin in which the stocks of wild populations are threatened by overfishing pressure. Knowledge of its reproductive biology would be useful in consideration of conservation and management options for the species. Therefore, this study investigated changes in ovarian activity and levels of steroid profiles in wild populations in relation to variation in temperature and rainfall. Adult females (n = 101, body weight of 3 183 ± 14.75 g, SE) were captured monthly over one year (2013–2014). Apart from evaluation of oocyte diameters and gonad developmental stages, gonado-, hepato-, lipososomatic indices (GSI, HSI, LSI) and plasma levels of sex steroids (testosterone-T, estradiol-17β-E2) were determined. The results suggested a synchronous development of oocytes with two annual reproductive seasons over the one-year study. Plasma T and E2 levels peaked during spawning periods likely reflecting active oogenesis. The highest values of morphosomatic indices were observed during the longest rainfall period in September, and were associated with high steroidogenic activity evidenced by increased E2 production. In addition, more vitellogenic oocytes (September and October) were observed during the latter season than during the short rainy season (in May). 相似文献
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Surendra Kumar ?smund Skj?veland Russell JS Orr P?l Enger Torgeir Ruden Bj?rn-Helge Mevik Fabien Burki Andreas Botnen Kamran Shalchian-Tabrizi 《BMC bioinformatics》2009,10(1):357