106 resultados para fast preparation


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We present and validate BlastR, a method for efficiently and accurately searching non-coding RNAs. Our approach relies on the comparison of di-nucleotides using BlosumR, a new log-odd substitution matrix. In order to use BlosumR for comparison, we recoded RNA sequences into protein-like sequences. We then showed that BlosumR can be used along with the BlastP algorithm in order to search non-coding RNA sequences. Using Rfam as a gold standard, we benchmarked this approach and show BlastR to be more sensitive than BlastN. We also show that BlastR is both faster and more sensitive than BlastP used with a single nucleotide log-odd substitution matrix. BlastR, when used in combination with WU-BlastP, is about 5% more accurate than WU-BlastN and about 50 times slower. The approach shown here is equally effective when combined with the NCBI-Blast package. The software is an open source freeware available from www.tcoffee.org/blastr.html.

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Astrocytes are the most abundant glial cell type in the brain. Although not apposite for long-range rapid electrical communication, astrocytes share with neurons the capacity of chemical signaling via Ca(2+)-dependent transmitter exocytosis. Despite this recent finding, little is known about the specific properties of regulated secretion and vesicle recycling in astrocytes. Important differences may exist with the neuronal exocytosis, starting from the fact that stimulus-secretion coupling in astrocytes is voltage independent, mediated by G-protein-coupled receptors and the release of Ca(2+) from internal stores. Elucidating the spatiotemporal properties of astrocytic exo-endocytosis is, therefore, of primary importance for understanding the mode of communication of these cells and their role in brain signaling. We here take advantage of fluorescent tools recently developed for studying recycling of glutamatergic vesicles at synapses (Voglmaier et al., 2006; Balaji and Ryan, 2007); we combine epifluorescence and total internal reflection fluorescence imaging to investigate with unprecedented temporal and spatial resolution, the stimulus-secretion coupling underlying exo-endocytosis of glutamatergic synaptic-like microvesicles (SLMVs) in astrocytes. Our main findings indicate that (1) exo-endocytosis in astrocytes proceeds with a time course on the millisecond time scale (tau(exocytosis) = 0.24 +/- 0.017 s; tau(endocytosis) = 0.26 +/- 0.03 s) and (2) exocytosis is controlled by local Ca(2+) microdomains. We identified submicrometer cytosolic compartments delimited by endoplasmic reticulum tubuli reaching beneath the plasma membrane and containing SLMVs at which fast (time-to-peak, approximately 50 ms) Ca(2+) events occurred in precise spatial-temporal correlation with exocytic fusion events. Overall, the above characteristics of transmitter exocytosis from astrocytes support a role of this process in fast synaptic modulation.

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For doping control, analyses of samples are generally achieved in two steps: a rapid screening and, in the case of a positive result, a confirmatory analysis. A two-step methodology based on ultra-high-pressure liquid chromatography coupled to a quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was developed to screen and confirm 103 doping agents from various classes (e.g., beta-blockers, stimulants, diuretics, and narcotics). The screening method was presented in a previous article as part I (i.e., Fast analysis of doping agents in urine by ultra-high-pressure liquid chromatography-quadrupole time-of-flight mass spectrometry. Part I: screening analysis). For the confirmatory method, basic, neutral and acidic compounds were extracted by a dedicated solid-phase extraction (SPE) in a 96-well plate format and detected by MS in the tandem mode to obtain precursor and characteristic product ions. The mass accuracy and the elemental composition of precursor and product ions were used for compound identification. After validation including matrix effect determination, the method was considered reliable to confirm suspect results without ambiguity according to the positivity criteria established by the World Anti-Doping Agency (WADA). Moreover, an isocratic method was developed to separate ephedrine from its isomer pseudoephedrine and cathine from phenylpropanolamine in a single run, what allowed their direct quantification in urine.

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Laser desorption ionisation mass spectrometry (LDI-MS) has demonstrated to be an excellent analytical method for the forensic analysis of inks on a questioned document. The ink can be analysed directly on its substrate (paper) and hence offers a fast method of analysis as sample preparation is kept to a minimum and more importantly, damage to the document is minimised. LDI-MS has also previously been reported to provide a high power of discrimination in the statistical comparison of ink samples and has the potential to be introduced as part of routine ink analysis. This paper looks into the methodology further and evaluates statistically the reproducibility and the influence of paper on black gel pen ink LDI-MS spectra; by comparing spectra of three different black gel pen inks on three different paper substrates. Although generally minimal, the influences of sample homogeneity and paper type were found to be sample dependent. This should be taken into account to avoid the risk of false differentiation of black gel pen ink samples. Other statistical approaches such as principal component analysis (PCA) proved to be a good alternative to correlation coefficients for the comparison of whole mass spectra.

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The aim of this work is to describe the techniques that have been used for preparation and analysis of whole fetal liver extracts destined for in utero transplantation. Nine fetal livers between 12 and 17 weeks of gestation were prepared: cell counts and assessment of the hematopoietic cell viability were performed on cell suspensions. Hepatocytes represented 40 to 80% of the whole cell population. The remaining cells were constituted by hematopoietic cells (mainly erythroblasts), as well as by endothelial cells. The latter expressed CD34 on their surface, interfering with the assessment of CD34+ hematopoietic cells by flow cytometry. Direct visual morphologic control using alkaline phosphatase anti-alkaline phosphatase techniques was needed to differentiate hematopoietic from extra-hematopoietic CD34+ cells. Between 3.0 and 34.6 x 10(6) CD34+ viable hematopoietic cells were collected per fetal liver. Adequate differentiation of these cells into burst-forming units erythroid (BFU-E), colony-forming units granulocyte-macrophage (CFU-GM), and colony-forming units granulocyte erythroid macrophage megakaryocyte (CFU-GEMM) has been shown for each sample in clonogeneic cultures. In conclusion, fetal liver is a potential source of hematopoietic stem cells. Their numeration, based on the presence of CD34, is hampered by the expression of this antigen on other cells contained in the liver cell extract, in particular endothelial cells.

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It is now possible to perform resections of slow-growing tumors in awake patients. Using direct electrical stimulation, real-time functional mapping of the brain can be used to prevent the resection of essential areas near the tumor. Simple clinical observations of patients with a resection of slow-growing tumors have demonstrated substantial recovery within a few days of such 'awake surgery'. The aim of this study was to investigate the kinetics of recovery following the resection of slow-growing tumors invading the left parietal area and to focus mainly on its rapidity. Two patients were assessed by standard line bisection tests and compared with eight healthy individuals. Independently of the pure nature of the symptoms, we report that the patients rapidly and substantially recovered from pronounced right neglect. They were tested 48 hours after the surgery and the recovery was significant for both patients after less than 4 hours. Strikingly, for one patient, recovery was ultra fast and substantial in the first practice session within less than 7 minutes: it occurred without verbal feedback and was substantially retained during the following testing session. Its rapidity suggests a process of unmasking redundant networks. With the slow growth of the lesion, the contralesional hemisphere is probably progressively prepared for rapid unmasking of homologue networks. These results have major clinical implications. For patients with an invading left-side tumor, it is now clear that line bisections are required before, during, and after awake surgery to: plan the surgery, control the quality of the resection, and also optimize the rehabilitation of the patient

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Due to SNR constraints, current "bright-blood" 3D coronary MRA approaches still suffer from limited spatial resolution when compared to conventional x-ray coronary angiography. Recent 2D fast spin-echo black-blood techniques maximize signal for coronary MRA at no loss in image spatial resolution. This suggests that the extension of black-blood coronary MRA with a 3D imaging technique would allow for a further signal increase, which may be traded for an improved spatial resolution. Therefore, a dual-inversion 3D fast spin-echo imaging sequence and real-time navigator technology were combined for high-resolution free-breathing black-blood coronary MRA. In-plane image resolution below 400 microm was obtained. Magn Reson Med 45:206-211, 2001.

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BACKGROUND: Historically, the preoperative and postoperative care of patients with gastrointestinal cancer was provided by surgeons. Contemporary perioperative care is a truly multidisciplinary endeavour with implications for cancer-specific outcomes. METHODS: A literature review was performed querying PubMed and the Cochrane Library for articles published between 1966 to 2012 on specific perioperative interventions with the potential to improve the outcomes of surgical oncology patients. Keywords used were: fast-track, enhanced recovery, accelerated rehabilitation, multimodal and perioperative care. Specific interventions included normothermia, hyperoxygenation, surgical-site infection, skin preparation, transfusion, non-steroidal anti-inflammatory drugs, thromboembolism and antibiotic prophylaxis, laparoscopy, radiotherapy, perioperative steroids and monoclonal antibodies. Included articles had to be randomized controlled trials, prospective or nationwide series, or systematic reviews/meta-analyses, published in English, French or German. RESULTS: Important elements of modern perioperative care that improve recovery of patients and outcomes in surgical oncology include accelerated recovery pathways, thromboembolism and antibiotic prophylaxis, hyperoxygenation, maintenance of normothermia, avoidance of blood transfusion and cautious use of non-steroidal anti-inflammatory drugs, promotion of laparoscopic surgery, chlorhexidine-alcohol skin preparation and multidisciplinary meetings to determine multimodal therapy. CONCLUSION: Multidisciplinary management of perioperative patient care has improved outcomes. Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

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BACKGROUND & AIMS: A fast-track program is a multimodal approach for patients undergoing colonic surgery that combines stringent regimens of perioperative care (fluid restriction, optimized analgesia, forced mobilization, and early oral feeding) to reduce perioperative morbidity, hospital stay, and cost. We investigated the impact of a fast-track protocol on postoperative morbidity in patients after open colonic surgery. METHODS: A randomized trial of patients in 4 teaching hospitals in Switzerland included 156 patients undergoing elective open colonic surgery who were assigned to either a fast-track program or standard care. The primary end point was the 30-day complication rate. Secondary end points were severity of complications, hospital stay, and compliance with the fast-track protocol. RESULTS: The fast-track protocol significantly decreased the number of complications (16 of 76 in the fast-track group vs 37 of 75 in the standard care group; P = .0014), resulting in shorter hospital stays (median, 5 days; range, 2-30 vs 9 days, respectively; range, 6-30; P < .0001). There was a trend toward less severe complications in the fast-track group. A multiple logistic regression analysis revealed fluid administration greater than the restriction limits (odds ratio, 4.198; 95% confidence interval, 1.7-10.366; P = .002) and a nonfunctioning epidural analgesia (odds ratio, 3.365; 95% confidence interval, 1.367-8.283; P = .008) as independent predictors of postoperative complications. CONCLUSIONS: The fast-track program reduces the rate of postoperative complications and length of hospital stay and should be considered as standard care. Fluid restriction and an effective epidural analgesia are the key factors that determine outcome of the fast-track program.

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The prediction of binding modes (BMs) occurring between a small molecule and a target protein of biological interest has become of great importance for drug development. The overwhelming diversity of needs leaves room for docking approaches addressing specific problems. Nowadays, the universe of docking software ranges from fast and user friendly programs to algorithmically flexible and accurate approaches. EADock2 is an example of the latter. Its multiobjective scoring function was designed around the CHARMM22 force field and the FACTS solvation model. However, the major drawback of such a software design lies in its computational cost. EADock dihedral space sampling (DSS) is built on the most efficient features of EADock2, namely its hybrid sampling engine and multiobjective scoring function. Its performance is equivalent to that of EADock2 for drug-like ligands, while the CPU time required has been reduced by several orders of magnitude. This huge improvement was achieved through a combination of several innovative features including an automatic bias of the sampling toward putative binding sites, and a very efficient tree-based DSS algorithm. When the top-scoring prediction is considered, 57% of BMs of a test set of 251 complexes were reproduced within 2 Å RMSD to the crystal structure. Up to 70% were reproduced when considering the five top scoring predictions. The success rate is lower in cross-docking assays but remains comparable with that of the latest version of AutoDock that accounts for the protein flexibility. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011.

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Platelet-rich plasma (PRP) is a volume of plasma fraction of autologous blood having platelet concentrations above baseline whole-blood values due to processing and concentration. PRP is used in various surgical fields to enhance soft-tissue and bone healing by delivering supra-physiological concentrations of autologous platelets at the site of tissue damage. These preparations may provide a good cellular source of various growth factors and cytokines, and modulate tissue response to injury. Common clinically available materials for blood preparations combined with a two-step centrifugation protocol at 280g each, to ensure cellular component integrity, provided platelet preparations which were concentrated 2-3 fold over total blood values. Costs were shown to be lower than those of other methods which require specific equipment and high-cost disposables, while safety and traceability can be increased. PRP can be used for the treatment of wounds of all types including burns and also of split-thickness skin graft donor sites, which are frequently used in burn management. The procedure can be standardized and is easy to adapt in clinical settings with minimal infrastructure, thus enabling large numbers of patients to benefit from a form of cellular therapy.

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A hallmark of schizophrenia pathophysiology is the dysfunction of cortical inhibitory GABA neurons expressing parvalbumin, which are essential for coordinating neuronal synchrony during various sensory and cognitive tasks. The high metabolic requirements of these fast-spiking cells may render them susceptible to redox dysregulation and oxidative stress. Using mice carrying a genetic redox imbalance, we demonstrate that extracellular perineuronal nets, which constitute a specialized polyanionic matrix enwrapping most of these interneurons as they mature, play a critical role in the protection against oxidative stress. These nets limit the effect of genetically impaired antioxidant systems and/or excessive reactive oxygen species produced by severe environmental insults. We observe an inverse relationship between the robustness of the perineuronal nets around parvalbumin cells and the degree of intracellular oxidative stress they display. Enzymatic degradation of the perineuronal nets renders mature parvalbumin cells and fast rhythmic neuronal synchrony more susceptible to oxidative stress. In parallel, parvalbumin cells enwrapped with mature perineuronal nets are better protected than immature parvalbumin cells surrounded by less-condensed perineuronal nets. Although the perineuronal nets act as a protective shield, they are also themselves sensitive to excess oxidative stress. The protection might therefore reflect a balance between the oxidative burden on perineuronal net degradation and the capacity of the system to maintain the nets. Abnormal perineuronal nets, as observed in the postmortem patient brain, may thus underlie the vulnerability and functional impairment of pivotal inhibitory circuits in schizophrenia.