Identifying decomposition products in extracts of cellular metabolites

Most methods of analyzing intracellular metabolites require extraction of metabolites from the cells. A concern in these methods is underestimation of metabolite levels due to incomplete extraction. In comparing extraction methods, then, it would seem that the best method for extracting a particular metabolite is the one that gives the largest yield. In extracting Escherichia coli with different methanol:water mixtures, we observed that >or=50% water gave an increased yield of nucleosides and bases compared with 相似文献   

Assessing quality of hybridized RNA in Affymetrix GeneChip experiments using mixed-effects models

The technology for hybridizing archived tissue specimens and the use of laser-capture microdissection for selecting cell populations for RNA extraction have increased over the past few years. Both these methods contribute to RNA degradation. Therefore, quality assessments of RNA hybridized to microarrays are becoming increasingly more important. Existing methods for estimating the quality of RNA hybridized to a GeneChip, from resulting microarray data, suffer from subjectivity and lack of estimates of variability. In this article, a method for assessing RNA quality for a hybridized array which overcomes these drawbacks is proposed. The effectiveness of the proposed method is demonstrated by the application of the method to two microarray data sets for which external verification of RNA quality is known.     

Evaluation of newly developed devices for denture placement and removal in the dependent elderly

doi: 10.1111/j.1741‐2358.2011.00547.x Evaluation of newly developed devices for denture placement and removal in the dependent elderly Objective: The purpose of this study was to subjectively evaluate the utility of newly developed denture placement and removal devices. Objective observations were also made to support the evidence. Materials and method: Twenty‐one subjects were instructed to place and remove their dentures with and without the devices. We evaluated the device based on a questionnaire. Objective observations were based on a 2‐D image analysis. We analysed three factors: the time, the area and the circumference required to insert and remove the dentures. Results: Image analysis showed that the effectiveness and ease with which the subject used the device significantly improved with practice. The questionnaire data showed that a majority of the subjects appreciated the device after the first and second time. While there was no significant decrease in time required to place and remove dentures even with the device, the area and circumference of the movement on 2‐D images were significantly reduced. Conclusion: In this study, the utility of denture placement and removal devices was evaluated both subjectively and objectively. Our data reveal that the device is effective in the elderly. Further minor improvement in the device might be required to increase its effectiveness.     

Searching for a needle in the haystack: comparing six methods to evaluate heteroplasmy in difficult sequence context

Mitochondrial DNA (mtDNA) mutations have been involved in disease, aging and cancer and furthermore exploited for evolutionary and forensic investigation. When investigating mtDNA mutations the peculiar aspects of mitochondrial genetics, such as heteroplasmy and threshold effect, require suitable approaches which must be sensitive enough to detect low-level heteroplasmy and, precise enough to quantify the exact mutational load. In order to establish the optimal approach for the evaluation of heteroplasmy, six methods were experimentally compared for their capacity to reveal and quantify mtDNA variants. Drawbacks and advantages of cloning, Fluorescent PCR (F-PCR), denaturing High Performance Liquid Chromatography (dHPLC), quantitative Real-Time PCR (qRTPCR), High Resolution Melting (HRM) and 454 pyrosequencing were determined. In particular, detection and quantification of a mutation in a difficult sequence context were investigated, through analysis of an insertion in a homopolymeric stretch (m.3571insC).     

Comparative study with two different enrichments in the culture media used in the disinfectant efficacy assay

Recent changes in Brazilian legislation for commercial disinfectants have been published due to the recent epidemic of nosocomial infections caused by rapidly growing mycobacteria (RGM) in many states of Brazil over the last 8 years. One of these documents requires that all the manufacturers provide evidence of efficacy of sterilizing and disinfectant products, used for semi critical medical devices, against the Mycobacterium bovis BCG Moreau and Mycobacterium abscessus subsp. bolletii INCQS 00594 strains by using the Confirmative in vitro Test for Determining Tuberculocidal Activity of Disinfectants recommended by the Association of Official Analytical Chemists. These changes have caused additional costs and increased problems for importation of enrichment products at national laboratories where disinfectant efficacy assay service is performed. Middlebrook ADC Enrichment (ADC) is provided by a unique manufacturer and used in the official protocol. The aim of the present study was to evaluate an alternative in house low-cost enrichment composed of fetal bovine serum and glucose (FBSG) with ADC for performance of disinfectant efficacy assay against mycobacteria. After obtaining the growth curves for M. abscessus ATCC 19977, M. abscessus subsp. bolletii INCQS 00594, Mycobacterium chelonae ATCC 35752, and Mycobacterium fortuitum ATCC 6841 by using ADC enrichment and FBSG in Kirchners and 7H9 culture media. Through statistical analysis via the Kruskal-Wallis test on the evaluation of microorganism growth rate, it was observed that there was no inhibition of RGM growth by any of the enrichments used. These results suggest that low-cost enrichment FBSG may be used as a potential substitute of ADC for composition of media for mycobacterial growth, including in disinfectant tests.     

Human high temperature requirement serine protease A1 (HTRA1) degrades tau protein aggregates

Protective proteases are key elements of protein quality control pathways that are up-regulated, for example, under various protein folding stresses. These proteases are employed to prevent the accumulation and aggregation of misfolded proteins that can impose severe damage to cells. The high temperature requirement A (HtrA) family of serine proteases has evolved to perform important aspects of ATP-independent protein quality control. So far, however, no HtrA protease is known that degrades protein aggregates. We show here that human HTRA1 degrades aggregated and fibrillar tau, a protein that is critically involved in various neurological disorders. Neuronal cells and patient brains accumulate less tau, neurofibrillary tangles, and neuritic plaques, respectively, when HTRA1 is expressed at elevated levels. Furthermore, HTRA1 mRNA and HTRA1 activity are up-regulated in response to elevated tau concentrations. These data suggest that HTRA1 is performing regulated proteolysis during protein quality control, the implications of which are discussed.     

Old World monkeys are more similar to humans than New World monkeys when playing a coordination game

There is much debate about how humans' decision-making compares with that of other primates. One way to explore this is to compare species' performance using identical methodologies in games with strategical interactions. We presented a computerized Assurance Game, which was either functionally simultaneous or sequential, to investigate how humans, rhesus monkeys and capuchin monkeys used information in decision-making. All species coordinated via sequential play on the payoff-dominant Nash equilibrium, indicating that information about the partner's choice improved decisions. Furthermore, some humans and rhesus monkeys found the payoff-dominant Nash equilibrium in the simultaneous game, even when it was the first condition presented. Thus, Old World primates solved the task without any external cues to their partner's choice. Finally, when not explicitly prohibited, humans spontaneously used language to coordinate on the payoff-dominant Nash equilibrium, indicating an alternative mechanism for converting a simultaneous move game into a sequential move game. This phylogenetic distribution implies that no single mechanism drives coordination decisions across the primates, while humans' ability to spontaneously use language to change the structure of the game emphasizes that multiple mechanisms may be used even within the same species. These results provide insight into the evolution of decision-making strategies across the primates.     

Farm animal milk proteomics

Milk is one of the most important nutrients for humans during lifetime. Farm animal milk in all its products like cheese and other fermentation and transformation products is a widespread nutrient for the entire life of humans. Proteins are key molecules of the milk functional component repertoire and their investigation represents a major challenge. Proteins in milk, such as caseins, contribute to the formation of micelles that are different from species to species in dimension and casein-type composition; they are an integral part of the MFGM (Milk Fat Globule Membrane) that has being exhaustively studied in recent years. Milk proteins can act as enzymes or have an antimicrobial activity; they could act as hormones and, last but not least, they have a latent physiological activity encoded in their primary structure that turns active when the protein is cleaved by fermentation or digestion processes. In this review we report the last progress in proteomics, peptidomics and bioinformatics. These new approaches allow us to better characterize the milk proteome of farm animal species, to highlight specific PTMs, the peptidomic profile and even to predict the potential nutraceutical properties of the analyzed proteins.     

Potency testing of veterinary vaccines: The way from in vivo to in vitro

Current quality control of inactivated animal vaccines still focuses on the potency of final products in a batch-wise manner. Animal welfare concerns as well as scientific considerations have led to the ‘3Rs-concept’ that comprises the refinement of animal procedures, the reduction of animal numbers, and the replacement of animal models. Although the 3Rs-concept has been widely accepted as a fundamental principle, the number of approved alternatives for in vivo tests is still limited. To promote further progress, the international scientific workshop ‘Potency Testing of Veterinary Vaccines: The Way from in vivo to in vitro’ was held at the Paul-Ehrlich-Institut in Langen, Germany, on 01-03 December 2010. More than 130 participants from industry, academia and regulatory authorities discussed the current state of the 3Rs-concept, examples of its successful implementation as well as still existing hurdles. Special emphasis was laid on the ‘consistency approach’ that aims to ensure relevant quality attributes of vaccine batches by in vitro analyses during production rather than by in vivo potency tests on the final product. This report provides an overview of the insights gained, including the recommendations produced at the end of the workshop.     

基于全过程医疗质量管理思想的临床数据存储库设计

全过程医疗质量管理是指医院对患者诊疗全流程的每个环节、每个处置都处于受控的状态,把影响医疗质量的问题降到最低,以取得最佳的医疗效果。全过程医疗质量管理除了对终末质量（大约占质控点的20%）进行控制外,重点是对过程中质量（大约占质控点的80%）进行控制,如何把全过程医疗质量管理与IT技术更好的结合起来,利用临床数据存储库（Clinical Data Repository,CDR）的建立来实现对医疗质量的实时管控,已成为当前医院信息化建设工作的主要任务。