177 resultados para 164-991A
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Metabolite profiling is critical in many aspects of the life sciences, particularly natural product research. Obtaining precise information on the chemical composition of complex natural extracts (metabolomes) that are primarily obtained from plants or microorganisms is a challenging task that requires sophisticated, advanced analytical methods. In this respect, significant advances in hyphenated chromatographic techniques (LC-MS, GC-MS and LC-NMR in particular), as well as data mining and processing methods, have occurred over the last decade. Together, these tools, in combination with bioassay profiling methods, serve an important role in metabolomics for the purposes of both peak annotation and dereplication in natural product research. In this review, a survey of the techniques that are used for generic and comprehensive profiling of secondary metabolites in natural extracts is provided. The various approaches (chromatographic methods: LC-MS, GC-MS, and LC-NMR and direct spectroscopic methods: NMR and DIMS) are discussed with respect to their resolution and sensitivity for extract profiling. In addition the structural information that can be generated through these techniques or in combination, is compared in relation to the identification of metabolites in complex mixtures. Analytical strategies with applications to natural extracts and novel methods that have strong potential, regardless of how often they are used, are discussed with respect to their potential applications and future trends.
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Aim: Gas6 is known to be elevated in sepsis, correlating with the severity of infection and¦organ failure. We aimed to investigate the performance of Gas6 plasma levels at¦admission to predict the risk of mortality in a cohort of septic patients.¦Methods: We used prospectively collected data and plasma samples from the "Sepsis¦Cohorte Romande". Gas6 level was measured by ELISA at admission and expressed in¦percentage relative to its level in a pool of normal plasma.¦Results: Non-survivors (n=21) presented higher Gas6 levels than survivors (n=73) (median¦258% vs 164%, IQR 194 and 117 respectively) (p=0.0027). Gas6 correlated positively with¦different cytokines and was the best mortality predictor, as shown by the ROC curves area.¦In patients with septic shock (n=66), using 249% as a cut-off value, Gas6 measurement¦had a specificity of 67% and a sensitivity of 81% for predicting mortality. ROC curve area¦was 0.75. Positive and negative predictive values were 57% and 87%, respectively.¦Conclusion: Thus, Gas6 plasma level at admission might be a useful tool to predict¦mortality in patients with septic shock. Although Gas6 hold promise as an early sepsis¦marker, its precise implication in sepsis remains to be elucidated. Our observation should¦be further investigated in larger prospective clinical trials.
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PURPOSE: The Gastro-Intestinal Working Party of the EORTC Radiation Oncology Group (GIWP-ROG) developed guidelines for target volume definition in neoadjuvant radiation of adenocarcinomas of the gastroesophageal junction (GEJ) and the stomach. METHODS AND MATERIALS: Guidelines about the definition of the clinical target volume (CTV) are based on a systematic literature review of the location and frequency of local recurrences and lymph node involvement in adenocarcinomas of the GEJ and the stomach. Therefore, MEDLINE was searched up to August 2008. Guidelines concerning prescription, planning and treatment delivery are based on a consensus between the members of the GIWP-ROG. RESULTS: In order to support a curative resection of GEJ and gastric cancer, an individualized preoperative treatment volume based on tumour location has to include the primary tumour and the draining regional lymph nodes area. Therefore we recommend to use the 2nd English Edition of the Japanese Classification of Gastric Carcinoma of the Japanese Gastric Cancer Association which developed the concept of assigning tumours of the GEJ and the stomach to anatomically defined sub-sites corresponding respectively to a distinct lymphatic spread pattern. CONCLUSION: The GIWP-ROG defined guidelines for preoperative irradiation of adenocarcinomas of the GEJ and the stomach to reduce variability in the framework of future clinical trials.
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Aims: To provide 12-month prevalence and disability burden estimates of a broad range of mental and neurological disorders in the European Union (EU) and to compare these findings to previous estimates. Referring to our previous 2005 review, improved up-to-date data for the enlarged EU on a broader range of disorders than previously covered are needed for basic, clinical and public health research and policy decisions and to inform about the estimated number of persons affected in the EU. Method: Stepwise multi-method approach, consisting of systematic literature reviews, reanalyses of existing data sets, national surveys and expert consultations. Studies and data from all member states of the European Union (EU-27) plus Switzerland, Iceland and Norway were included. Supplementary information about neurological disorders is provided, although methodological constraints prohibited the derivation of overall prevalence estimates for mental and neurological disorders. Disease burden was measured by disability adjusted life years (DALY). Results: Prevalence: It is estimated that each year 38.2% of the EU population suffers from a mental disorder. Adjusted for age and comorbidity, this corresponds to 164.8 million persons affected. Compared to 2005 (27.4%) this higher estimate is entirely due to the inclusion of 14 new disorders also covering childhood/adolescence as well as the elderly. The estimated higher number of persons affected (2011: 165 m vs. 2005: 82 m) is due to coverage of childhood and old age populations, new disorders and of new EU membership states. The most frequent disorders are anxiety disorders (14.0%), insomnia (7.0%), major depression (6.9%), somatoform (6.3%), alcohol and drug dependence (>4%), ADHD (5%) in the young, and dementia (1-30%, depending on age). Except for substance use disorders and mental retardation, there were no substantial cultural or country variations. Although many sources, including national health insurance programs, reveal increases in sick leave, early retirement and treatment rates due to mental disorders, rates in the community have not increased with a few exceptions (i.e. dementia). There were also no consistent indications of improvements with regard to low treatment rates, delayed treatment provision and grossly inadequate treatment. Disability: Disorders of the brain and mental disorders in particular, contribute 26.6% of the total all cause burden, thus a greater proportion as compared to other regions of the world. The rank order of the most disabling diseases differs markedly by gender and age group; overall, the four most disabling single conditions were: depression, dementias, alcohol use disorders and stroke. Conclusion: In every year over a third of the total EU population suffers from mental disorders. The true size of "disorders of the brain" including neurological disorders is even considerably larger. Disorders of the brain are the largest contributor to the all cause morbidity burden as measured by DALY in the EU. No indications for increasing overall rates of mental disorders were found nor of improved care and treatment since 2005; less than one third of all cases receive any treatment, suggesting a considerable level of unmet needs. We conclude that the true size and burden of disorders of the brain in the EU was significantly underestimated in the past.Concerted priority action is needed at all levels, including substantially increased funding for basic, clinical and public health research in order to identify better strategies for improved prevention and treatment for isorders of the brain as the core health challenge of the 21st century. (C) 2011 Published by Elsevier B.V.
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The resting metabolic rate (RMR) and body composition of 130 obese and nonobese prepubertal children, aged 6 to 10 years, were assessed by indirect calorimetry and skin-fold thickness, respectively. The mean (+/- SD) RMR was 4619 +/- 449 kJ.day-1 (164 +/- 31 kJ.kg body weight-1 x day-1) in the 62 boys and 4449 +/- 520 kJ.day-1 (147 +/- 32 kJ.kg body weight-1 x day-1) in the 68 girls. Fat-free mass was the best single predictor of RMR (R2 = 0.64; p < 0.001). Step-down multiple regression analysis, with independent variables such as age, gender, weight, and height, allowed several RMR predictive equations to be developed. An equation for boys is as follows: RMR (kJ.day-1) = 1287 + 28.6 x Weight(kg) + 23.6 x Height(cm) - 69.1 x Age(yr) (R2 = 0.58; p < 0.001). An equation for girls is as follows: RMR (kJ.day-1 = 1552 + 35.8 x Weight (kg) + 15.6 x Height (cm) - 36.3 x Age (yr) (R2 = 0.69; p < 0.001). Comparison between the measured RMR and that predicted by currently used formulas showed that most of these equations tended to overestimate the RMR of both genders, especially in overweight children.
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Experimental allergic encephalomyelitis has been shown to have an immunological basis. In fact, the disease can be induced by T cells specific for myelin basic protein, a molecule found in abundance in the central nervous system. In this article, Ellen Heber-Katz and Hans Acha-Orbea discuss the T-cell receptor (TCR) repertoire of the encephalitogenic T-cell response, and show that a limited V gene pool, in fact a single V beta and two V alpha families, are being used by the PL/J and B10.PL mice and by every rat strain examined, even though the antigenic determinants and the major histocompatibility complex (MHC) molecules are different in all cases. This extraordinary finding suggests that the TCR is involved in encephalitogenicity in a way that not only involves the recognition of antigen in association with MHC, but also as an effector molecule that results in encephalitis. If this is true, it implies that TCRs, in general, play more than one role in mammalian physiology.
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OBJECTIVE: To investigate the merits of vaccination against hepatitis B virus (HBV) in HIV-positive individuals with isolated antibodies to hepatitis B core antigen (anti-HBc). METHODS: HIV-positive patients with isolated anti-HBc and CD4 counts >200 cells/mm(3) received HBV vaccination. An antibody titre to hepatitis B surface antigen (anti-HBs titres) ≥10 IU/L one month post-vaccination was termed an anamnestic response; a titre <10 IU/L was termed a primary response. Patients with primary responses received a 3-dose vaccine course. Anti-HBs titres in all responders were measured 12 and 24 months post-vaccination. RESULTS: 37 patients were studied: 19 (51%) were co-infected with hepatitis C; median CD4 count was 443 cells/mm(3). 8/37 patients (22%) elicited an anamnestic response. 29/37 patients (78%) elicited a primary response. After a 3-dose vaccine course, 15/25 primary responders (60%) achieved anti-HBs titres ≥10 IU/L. HIV acquisition through injecting drug use was the only independent predictor of an anamnestic response (OR 22.9, CI 1.71-306.74, P=0.018). Median anti-HBs titres for anamnestic and primary responders were 51 IU/L (13-127) and 157 IU/L (25-650) respectively. Of all responders, 12/23 (52%) retained anti-HBs titres ≥10 IU/L at 24 months. Anti-HBs duration was not significantly different between anamnestic and primary responders. CONCLUSIONS: 23/37 HIV-positive patients (62%) with isolated anti-HBc achieved anti-HBs titres ≥10 IU/L after 1-3 vaccine doses. However, duration of this immune response was short-lived (
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Oxygen and carbon isotope compositions of well-preserved mammoth teeth from the Middle Wurmian (40-70 ka) peat layer of Niederweningen, the most important mammoth site in Switzerland, were analysed to reconstruct Late Pleistocene palaeoclimatic and palaeoenvironmental conditions. Drinking water (delta(18)O values of approximately -12.3 +/- 0.9 parts per thousand were calculated front oxygen isotope compositions of mammoth tooth enamel apatite using a species-specific calibration for modern elephants. These delta(18)O(H2O) values reflect the mean oxygen isotope composition of the palaeo-precipitation and are similar to those directly measured for fate Pleistocene groundwater from aquifers in northern Switzerland and southern Germany. Using a present-day delta(18)O(H2)o-precipitation-air temperature relation for Switzerland, a mean annual air temperature (MAT) of around 4.3 +/- 2.1 degrees C can be calculated for the Middle Wurmian at this site. This MAT is in good agreement with palaeotemperature estimates on the basis of Middle Wurmian groundwater recharge temperatures and beetle assemblages. Hence, the climatic conditions in this region were around 4 degrees C cooler during the Middle Wurmian interstadial phase, around 45-50ka BP, than they are today. During this period the mammoths from Niederweningen lived in an open tundra-like, C(3) plant-dominated environment as indicated by enamel (delta(13)C values of -11.5 +/- 0.3 parts per thousand and pollen and macroplant fossils found in the embedding peat. The low variability of enamel delta(13)C and delta(18)O values from different mammoth teeth reflects similar environmental conditions and supports a relatively small time frame for the fossil assemblage. (C) 2006 Elsevier Ltd and INQUA. All rights reserved.
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The consequences of variable rates of clonal reproduction on the population genetics of neutral markers are explored in diploid organisms within a subdivided population (island model). We use both analytical and stochastic simulation approaches. High rates of clonal reproduction will positively affect heterozygosity. As a consequence, nearly twice as many alleles per locus can be maintained and population differentiation estimated as F(ST) value is strongly decreased in purely clonal populations as compared to purely sexual ones. With increasing clonal reproduction, effective population size first slowly increases and then points toward extreme values when the reproductive system tends toward strict clonality. This reflects the fact that polymorphism is protected within individuals due to fixed heterozygosity. Contrarily, genotypic diversity smoothly decreases with increasing rates of clonal reproduction. Asexual populations thus maintain higher genetic diversity at each single locus but a lower number of different genotypes. Mixed clonal/sexual reproduction is nearly indistinguishable from strict sexual reproduction as long as the proportion of clonal reproduction is not strongly predominant for all quantities investigated, except for genotypic diversities (both at individual loci and over multiple loci).
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The aim of this study was to evaluate and compare organ doses delivered to patients in wrist and petrous bone examinations using a multislice spiral computed tomography (CT) and a C-arm cone-beam CT equipped with a flat-panel detector (XperCT). For this purpose, doses to the target organ, i.e. wrist or petrous bone, together with those to the most radiosensitive nearby organs, i.e. thyroid and eye lens, were measured and compared. Furthermore, image quality was compared for both imaging systems and different acquisition modes using a Catphan phantom. Results show that both systems guarantee adequate accuracy for diagnostic purposes for wrist and petrous bone examinations. Compared with the CT scanner, the XperCT system slightly reduces the dose to target organs and shortens the overall duration of the wrist examination. In addition, using the XperCT enables a reduction of the dose to the eye lens during head scans (skull base and ear examinations).
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Human cytomegalovirus (CMV) infection may be a serious complication related to immunosuppression after solid organ transplantation. Due to their cytotoxicity, T-cells and natural killer (NK) cells target and clear the virus from CMV-infected cells. Although immunosuppressive drugs suppress T-cell proliferation and activation, they do not affect NK cells that are crucial for controlling the infection. The regulation of NK cells depends on a wide range of activating and inhibitory receptors such as the family of killer-cell immunoglobulin-like receptors (KIRs). Several human genetic studies have demonstrated the association of KIR genes with the clearance of infections. Since the respective activities of the different KIR proteins expressed by NK cells during CMV infection have not been extensively studied, we analyzed the expression of KIRs in a cohort of 22 CMV-IgG(+) renal transplant patients at the time of CMV reactivation, after antiviral therapy and 6 months later. Our data revealed a marked expression of KIR3DL1 during the acute phase of the reactivation. We set up an in vitro model in which NK cells, derived either from healthy donors or from transplanted patients, target allogeneic fibroblasts, CMV-infected or uninfected. Our results demonstrate a significant correlation between the lysis of CMV-infected fibroblasts and the expression of KIR3DL1. Blocking experiments with antibodies to MHC-I, to NKG2D and to NKG2C confirmed the importance of KIR3DL1. Consequently, our results suggest that KIR proteins and especially KIR3DL1 could play an important role during CMV-infection or CMV reactivation in immunosuppressed patients.
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Volcanic flows and tuffs interbedded with ammonite-bearing sediments directly correlatable with the stratotype section of the Bajocian stage have been dated for the first time within the Caucasus area. Three samples, each from a different section, allowed separation of well-preserved brown hornblende; these are considered reliable geochronometers in a region where subsequent volcanic activity occurred. The dated separates are V139: a volcanic layer probably near the base, V142 another layer near the top of the Lower Bajocian substage; V141 a boulder from a latest Bajocian volcanic conglomerate. From bottom to top, apparent ages at 173.5 +/- 2.6, 164.8 +/- 2.5 and 167.1 +/- 1.9 Ma (analytical uncertainty, 95% confidence level) respectively, can be calculated. The consistency of the results is obtained if the dated boulder is interpreted as derived from an underlying layer, The Bajocian-Bathonian boundary is much younger than commonly accepted and younger than 164 Ma.