933 resultados para CRASH ANALYSES


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Phyteuma is a chromosomally and ecologically diverse vascular plant genus and constitutes an excellent system for studying both the role of chromosomal change for species diversification and the evolution of high-mountain biota. This kind of research is, however, hampered by the lack of a sound phylogenetic framework exacerbated by the notoriously low predictive power of traditional taxonomy with respect to phylogenetic relationships in Campanulaceae. Based on a comprehensive taxon sampling and analyses of nuclear and plastid sequence and AFLP fingerprint data, Phyteuma is confirmed as a monophyletic group sister to the monotypic Physoplexis, which is in line with their peculiar flower morphologies. Within Phyteuma two clades, largely corresponding to previously recognized sections, are consistently found. The traditional circumscription of taxonomic series is largely rejected. Whereas distinctness of the currently recognized species is mostly corroborated, some interspecific relationships remain ambiguous due to incongruences between nuclear and plastid data. Major forces for diversification and evolution of Phyteuma are descending dysploidy (i.e., a decrease in chromosome base number) as well as allopatric and ecological differentiation within the Alps, the genus' center of species diversity. (C) 2013 Elsevier Inc. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE To investigate whether it is valid to combine follow-up and change data when conducting meta-analyses of continuous outcomes. STUDY DESIGN AND SETTING Meta-epidemiological study of randomized controlled trials in patients with osteoarthritis of the knee/hip, which assessed patient-reported pain. We calculated standardized mean differences (SMDs) based on follow-up and change data, and pooled within-trial differences in SMDs. We also derived pooled SMDs indicating the largest treatment effect within a trial (optimistic selection of SMDs) and derived pooled SMDs from the estimate indicating the smallest treatment effect within a trial (pessimistic selection of SMDs). RESULTS A total of 21 meta-analyses with 189 trials with 292 randomized comparisons in 41,256 patients were included. On average, SMDs were 0.04 standard deviation units more beneficial when follow-up values were used (difference in SMDs: -0.04; 95% confidence interval: -0.13, 0.06; P=0.44). In 13 meta-analyses (62%), there was a relevant difference in clinical and/or significance level between optimistic and pessimistic pooled SMDs. CONCLUSION On average, there is no relevant difference between follow-up and change data SMDs, and combining these estimates in meta-analysis is generally valid. Decision on which type of data to use when both follow-up and change data are available should be prespecified in the meta-analysis protocol.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Systematic reviews and meta-analyses of randomized trials that include patient-reported outcomes (PROs) often provide crucial information for patients, clinicians and policy-makers facing challenging health care decisions. Based on emerging methods, guidance on improving the interpretability of meta-analysis of patient-reported outcomes, typically continuous in nature, is likely to enhance decision-making. The objective of this paper is to summarize approaches to enhancing the interpretability of pooled estimates of PROs in meta-analyses. When differences in PROs between groups are statistically significant, decision-makers must be able to interpret the magnitude of effect. This is challenging when, as is often the case, clinical trial investigators use different measurement instruments for the same construct within and between individual randomized trials. For such cases, in addition to pooling results as a standardized mean difference, we recommend that systematic review authors use other methods to present results such as relative (relative risk, odds ratio) or absolute (risk difference) dichotomized treatment effects, complimented by presentation in either: natural units (e.g. overall depression reduced by 2.4 points when measured on a 50-point Hamilton Rating Scale for Depression); minimal important difference units (e.g. where 1.0 unit represents the smallest difference in depression that patients, on average, perceive as important the depression score was 0.38 (95%CI 0.30 to 0.47) units less than the control group); or a ratio of means (e.g. where the mean in the treatment group is divided by the mean in the control group, the ratio of means is 1.27, representing a 27%relative reduction in the mean depression score).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Human embryonic kidney cells 293 (HEK293) are widely used as cellular heterologous expression systems to study transfected ion channels. This work characterizes the endogenous expression of TRPM4 channels in HEK293 cells. TRPM4 is an intracellular Ca(2+)-activated non-selective cationic channel expressed in many cell types. Western blot analyses have revealed the endogenous expression of TRPM4. Single channel 22pS conductance with a linear current-voltage relationship was observed using the inside-out patch clamp configuration in the presence of intracellular Ca(2+). The channels were permeable to the monovalent cations Na(+) and K(+), but not to Ca(2+). The open probability was voltage-dependent, being higher at positive potentials. Using the whole-cell patch clamp "ruptured patch" configuration, the amplitude of the intracellular Ca(2+)-activated macroscopic current was dependent on time after patch rupture. Initial transient activation followed by a steady-increase reaching a plateau phase was observed. Biophysical analyses of the macroscopic current showed common properties with those from HEK293 cells stably transfected with human TRPM4b, with the exception of current time course and Ca(2+) sensitivity. The endogenous macroscopic current reached the plateau faster and required 61.9±3.5μM Ca(2+) to be half-maximally activated versus 84.2±1.5μM for the transfected current. The pharmacological properties, however, were similar in both conditions. One hundred μM of flufenamic acid and 9-phenanthrol strongly inhibited the endogenous current. Altogether, the data demonstrate the expression of endogenous TRMP4 channels in HEK293 cells. This observation should be taken into account when using this cell line to study TRPM4 or other types of Ca(2+)-activated channels.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A 318-metre-long sedimentary profile drilled by the International Continental Scientific Drilling Program (ICDP) at Site 5011-1 in Lake El’gygytgyn, Far East Russian Arctic, has been analysed for its sedimentologic response to global climate modes by chronostratigraphic methods. The 12 km wide lake is sited off-centre in an 18 km large crater that was created by the impact of a meteorite 3.58 Ma ago. Since then sediments have been continuously deposited. For establishing their chronology, major reversals of the earth’s magnetic field provided initial tie points for the age model, confirming that the impact occurred in the earliest geomagnetic Gauss chron. Various stratigraphic parameters, reflecting redox conditions at the lake floor and climatic conditions in the catchment were tuned synchronously to Northern Hemisphere insolation variations and the marine oxygen isotope stack, respectively. Thus, a robust age model comprising more than 600 tie points could be defined. It could be shown that deposition of sediments in Lake El’gygytgyn occurred in concert with global climatic cycles. The upper �160m of sediments represent the past 3.3 Ma, equivalent to sedimentation rates of 4 to 5 cm ka−1, whereas the lower 160m represent just the first 0.3 Ma after the impact, equivalent to sedimentation rates in the order of 45 cm ka−1. This study also provides orbitally tuned ages for a total of 8 tephras deposited in Lake El’gygytgyn.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Screening tests for drugs of abuse are regularly used in the clinical routine. These tests identify the targeted substances very differently if tests from different manufacturers are used and sometimes also react positive after the intake of drugs which are not intended to be detected. Therefore, implausible results have to be questioned. A test result can be falsely negative, if a patient has taken a compound which is not detected by the antibody used in the test system. Chromatographic confirmation and screening assays are more laborious to perform and more demanding for the interpretation and are therefore only offered by several specialized clinical laboratories. However, their specificity is excellent and many different compounds can be detected depending on the number of compounds which are part of the mass spectra library used. If the clinical evaluation results in the differential diagnosis of an acute intoxication, screening tests for drugs of abuse can help to identify a single compound or a group of substances. The clinical picture, however, can usually not been explained by a qualitative test result. In addition, there are no published data demonstrating that these tests meaningfully influence triage, treatment, diagnosis or further therapy of a poisoned patient. The quantitative determination of specific compounds in the blood allows for example an appraisal of the prognosis and helps to indicate a specific therapy after intake of acetaminophen or methanol. New designer drugs can not at all be detected by the classic screening tests for drugs of abuse. The have to be identified by chromatographic methods.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Anxiety and depression are the most frequently diagnosed psychological diseases showing a high co-morbidity. They have a severe impact on the lives of the persons concerned. Many meta-analytical studies suggested a positive anxiolytic and depression reducing effect of exercise programs. The aim of the present article is to synthesize metaanalyses on the effects of exercise on anxiety and depression and to describe average effect sizes. For this purpose 37 meta-analyses were included reporting 50 effect sizes for anxiety scores of 42,264 participants and depression scores of 48,207 persons. The average documented anxiolytic effect of exercise in these reviews was small, 0.34. In contrast, the effect of exercise on depression was significantly higher and at a moderate level, 0.56. Data of randomized controlled trials suggest higher sizes for the effect of exercise on anxiety and depression leading to increases up to moderate and large effects, respectively. Additionally, exercise seems to be more beneficial for patients compared to participants within a nonclinical, normal range of psychological disease. Especially for the effect of exercise on anxiety, more high quality meta-analyses of randomized controlled trials are needed. Finally, possible neurobiological explanations are suggested for the positive effect of exercise on psychological disorders like anxiety and depression.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Regulation of colonic epithelial cell proliferation and differentiation remains poorly understood due to the inability to design a model system which recapitulates these processes. Currently, properties of "differentiation" are studied in colon adenocarcinoma cell lines which can be induced to express some, but not all of the phenotypes of normal cells. In this thesis, the DiFi human colon adenocarcinoma cell line is utilized as an in vitro model system in which to study mucin production. In response to treatment with tumor necrosis factor-alpha, DiFi cells acquire some properties of mucin-producing goblet cells including altered morphology, increased reactivity to wheat germ agglutinin, and increased mucin production as determined by RNA expression as well as reactivity with the MUC-1 antibodies, HMFG-1 and SM-3. Thus, TNF-treated DiFi cells represent one of the few in vitro systems in which mucin expression can be induced.^ DiFi cells express an activated pp60$\sp{{\rm c}-src},$ as do most colon adenocarcinomas and derived cell lines, as well as an amplified epidermal growth factor (EGF) receptor. To assess potential changes in these enzymes during induction of differentiation characteristics, potential changes in the levels and activities of these enzymes were examined. For pp60$\sp{{\rm c}-src},$ no changes were observed in protein levels, specific activity of the kinase, cellular localization, or phosphorylation pattern as determined by Staphylococcus aureus V8 protease partial proteolytic mapping after induction of goblet cell-like phenotypic changes. These results suggest that pp60$\sp{{\rm c}-src}$ is regulated differentially in goblet cells than in absorptive cells, as down-modulation of pp60$\sp{{\rm c}-src}$ kinase occurs in the latter. Therefore, effects on pp60$\sp{{\rm c}-src}$ may be critical in colon regulation, and may be important in generating the various colonic epithelial cell types.^ In contrast to pp60$\sp{{\rm c}-src},$ EGF receptor tyrosine kinase activity decreased ($<$5-fold) after TNF treatment and at the time in which morphologic changes were observed. Similar decreases in tyrosine phosphorylation of EGF receptor were observed as assessed by immunoblotting with an anti-phosphotyrosine antibody. In addition, ($\sp{125}$I) -EGF cell surface binding was reduced approximately 3-fold following TNF treatment with a concomitant reduction in receptor affinity ($<$2-fold). These results suggest that modulation of EGF receptor may be important in goblet cell differentiation. In contrast, other published studies have demonstrated that increases in EGF receptor mRNA and in ($\sp{125}$I) -EGF binding accompany differentiation toward the absorptive cell phenotype. Therefore, differential regulation of both EGF receptor and pp60$\sp{{\rm c}-src}$ occur along the goblet cell and absorptive cell differentiation pathways. Thus, my results suggest that TNF-treated DiFi cells represent a unique system in which to study distinct patterns of regulation of pp60$\sp{{\rm c}-src}$ and EGF receptor in colonic cells, and to determine if increased MUC-1 expression is an early event in goblet cell differentiation. ^

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PAX6 is a transcription activator that regulates eye development in animals ranging from Drosophila to human. The C-terminal region of PAX6 is proline/serine/threonine-rich (PST) and functions as a potent transactivation domain when attached to a heterologous DNA-binding domain of the yeast transcription factor, GAL4. The PST region comprises 152 amino acids encoded by four exons. The transactivation function of the PST region has not been defined and characterized in detail by in vitro mutagenesis. I dissected the PST domain in two independent systems, a heterologous system using a GAL4 DNA-binding site and the native system of PAX6. In both systems, the results show consistently that all four constituent exons of the PST domain are responsible for the transactivation function. The four exon fragments act cooperatively to stimulate transcription, although none of them can function individually as an independent transactivation domain. Combinations of two or more exon fragments can reconstitute substantial transactivation activity when fused to the DNA-binding domain of GAL4, but they surprisingly do not produce much activity in the context of native PAX6 even though the mutant PAX6 proteins are stable and their DNA-binding function remains unaffected. I conclude that the PAX6 protein contains an unusually large transactivation domain that is evolutionarily conserved to a high degree, and that its full transactivation activity relies on the cooperative action of the four exon fragments.^ Most PAX6 mutations detected in patients with aniridia result in truncations of the protein. Some of the truncation mutations occur in the PST region of PAX6, resulting in mutant proteins that retain their DNA-binding ability but have no significant transactivation activity. It is not clear whether such mutants are true loss-of-function or dominant-negative mutants. I show that these mutants are dominant-negative if they are coexpressed with wild-type PAX6 in cultured cells and that the dominant-negative effects result from enhanced DNA-binding ability of these mutants due to removal of the PST domain. These mutants are able to repress the wild-type PAX6 activity not only at target genes with paired domain binding sites but also at target genes with homeodomain binding sites.^ Mutations in the human PAX6 gene produce various phenotypes, including aniridia, Peters' anomaly, autosomal dominant keratitis, and familial foveal dysplasia. The various phenotypes may arise from different mutations in the same gene. To test this theory, I performed a functional analysis of two missense mutations in the paired domain: the R26G mutation reported in a case of Peters' anomaly, and the I87R mutation identified in a patient with aniridia. While both the R26 and the I87 positions are conserved in the paired boxes of all known PAX genes, X-ray crystallography has shown that only R26 makes contact with DNA. I found that the R26G mutant failed to bind a subset of paired domain binding sites but, surprisingly, bound other sites and successfully transactivated promoters containing those sites. In contrast, the I87R mutant had lost the ability to bind DNA at all tested sites and failed to transactivate promoters. My data support the haploinsufficiency hypothesis of aniridia, and the hypothesis that R26G is a hypomorphic allele. ^

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Female inmates make up the fastest growing segment in our criminal justice system today. The rapidly increasing trend for female prisoners calls for enhanced efforts to strategically plan the correctional facilities that address the needs of this growing population, and to work with communities to prevent crime in women. The incarcerated women in the U.S. have an estimated 145,000 minor children who are predisposed to unique psychosocial problems as a result of parental incarceration.^ This study examined the patterns of care and outcomes for pregnant inmates and their infants in Texas state prisons between 1994 and 1996. The study population consists of 202 pregnant inmates who delivered in a 2-year period, and a randomly sampled comparison cohort of 804 women from general Texas population, matched on race and educational levels. Both quantitative and qualitative data were used to elucidate the inmates' risk-factor profile, delivery/birth outcomes, and the patterns of care during pregnancy. The continuity-of-care issues for this population were also explored.^ Epidemiologic data were derived from multiple record systems to establish the comparison between two cohorts. A significantly great proportion of the inmates have prior lifestyle risk-factors (smoking, alcohol, and illicit drug abuse), poorer health status, and worse medical history. However, most of these existing risk-factors seem to show little manifestation in their current pregnancy. On the basis of maternal labor/delivery outcome and a number of neonatal indicators, this study found some evidence of a better pregnancy outcome for the inmate cohort when compared to the comparison group. Some possible explanations of this paradox were discussed. Seventeen percent of inmates gave birth to infants with suspected congenital syphilis. The placement patterns for the infants' care immediately after birth were elucidated.^ In addition to the quantitative data, an ethnographic approach was used to collect qualitative data from a subset of the inmate cohort (n = 20) and 12 care providers. The qualitative data were analyzed for their contents and themes, giving rise to a detailed description of the inmates' pregnancy experience. Eleven themes emerged from the study's thematic analysis, which provides the context for interpreting the epidemiologic data.^ Meaningful findings in this study were presented in a three-dimensional matrix to shed light on the apparent relationship between outcome indicators and their potential determinants. The suspected "linkages" between the outcome and their determinants can be used to generate hypotheses for future studies. ^

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study compared four alternative approaches (Taylor, Fieller, percentile bootstrap, and bias-corrected bootstrap methods) to estimating confidence intervals (CIs) around cost-effectiveness (CE) ratio. The study consisted of two components: (1) Monte Carlo simulation was conducted to identify characteristics of hypothetical cost-effectiveness data sets which might lead one CI estimation technique to outperform another. These results were matched to the characteristics of an (2) extant data set derived from the National AIDS Demonstration Research (NADR) project. The methods were used to calculate (CIs) for data set. These results were then compared. The main performance criterion in the simulation study was the percentage of times the estimated (CIs) contained the “true” CE. A secondary criterion was the average width of the confidence intervals. For the bootstrap methods, bias was estimated. ^ Simulation results for Taylor and Fieller methods indicated that the CIs estimated using the Taylor series method contained the true CE more often than did those obtained using the Fieller method, but the opposite was true when the correlation was positive and the CV of effectiveness was high for each value of CV of costs. Similarly, the CIs obtained by applying the Taylor series method to the NADR data set were wider than those obtained using the Fieller method for positive correlation values and for values for which the CV of effectiveness were not equal to 30% for each value of the CV of costs. ^ The general trend for the bootstrap methods was that the percentage of times the true CE ratio was contained in CIs was higher for the percentile method for higher values of the CV of effectiveness, given the correlation between average costs and effects and the CV of effectiveness. The results for the data set indicated that the bias corrected CIs were wider than the percentile method CIs. This result was in accordance with the prediction derived from the simulation experiment. ^ Generally, the bootstrap methods are more favorable for parameter specifications investigated in this study. However, the Taylor method is preferred for low CV of effect, and the percentile method is more favorable for higher CV of effect. ^

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background:Erythropoiesis-stimulating agents (ESAs) reduce the need for red blood cell transfusions; however, they increase the risk of thromboembolic events and mortality. The impact of ESAs on quality of life (QoL) is controversial and led to different recommendations of medical societies and authorities in the USA and Europe. We aimed to critically evaluate and quantify the effects of ESAs on QoL in cancer patients.Methods:We included data from randomised controlled trials (RCTs) on the effects of ESAs on QoL in cancer patients. Randomised controlled trials were identified by searching electronic data bases and other sources up to January 2011. To reduce publication and outcome reporting biases, we included unreported results from clinical study reports. We conducted meta-analyses on fatigue- and anaemia-related symptoms measured with the Functional Assessment of Cancer Therapy-Fatigue (FACT-F) and FACT-Anaemia (FACT-An) subscales (primary outcomes) or other validated instruments.Results:We identified 58 eligible RCTs. Clinical study reports were available for 27% (4 out of 15) of the investigator-initiated trials and 95% (41 out of 43) of the industry-initiated trials. We excluded 21 RTCs as we could not use their QoL data for meta-analyses, either because of incomplete reporting (17 RCTs) or because of premature closure of the trial (4 RCTs). We included 37 RCTs with 10 581 patients; 21 RCTs were placebo controlled. Chemotherapy was given in 27 of the 37 RCTs. The median baseline haemoglobin (Hb) level was 10.1 g dl(-1); in 8 studies ESAs were stopped at Hb levels below 13 g dl(-1) and in 27 above 13 g dl(-1). For FACT-F, the mean difference (MD) was 2.41 (95% confidence interval (95% CI) 1.39-3.43; P<0.0001; 23 studies, n=6108) in all cancer patients and 2.81 (95% CI 1.73-3.90; P<0.0001; 19 RCTs, n=4697) in patients receiving chemotherapy, which was below the threshold (⩾3) for a clinically important difference (CID). Erythropoiesis-stimulating agents had a positive effect on anaemia-related symptoms (MD 4.09; 95% CI 2.37-5.80; P=0.001; 14 studies, n=2765) in all cancer patients and 4.50 (95% CI 2.55-6.45; P<0.0001; 11 RCTs, n=2436) in patients receiving chemotherapy, which was above the threshold (⩾4) for a CID. Of note, this effect persisted when we restricted the analysis to placebo-controlled RCTs in patients receiving chemotherapy. There was some evidence that the MDs for FACT-F were above the threshold for a CID in RCTs including cancer patients receiving chemotherapy with Hb levels below 12 g dl(-1) at baseline and in RCTs stopping ESAs at Hb levels above 13 g dl(-1). However, these findings for FACT-F were not confirmed when we restricted the analysis to placebo-controlled RCTs in patients receiving chemotherapy.Conclusions:In cancer patients, particularly those receiving chemotherapy, we found that ESAs provide a small but clinically important improvement in anaemia-related symptoms (FACT-An). For fatigue-related symptoms (FACT-F), the overall effect did not reach the threshold for a CID.British Journal of Cancer advance online publication, 17 April 2014; doi:10.1038/bjc.2014.171 www.bjcancer.com.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

To provide baseline parasitological data for health surveillance in free-ranging Alpine ibex (Capra ibex ibex), we assessed the endoparasite population and level of parasitism in apparently healthy ibex. Faecal samples from 148 ibex were collected between 2006 and 2008 in two different Swiss ibex colonies. They were analysed by coprology, including combined sedimentation/flotation method, sedimentation method, Baermann funnel technique and Ziehl-Neelsen staining. Gastrointestinal parasites and lungworms were identified in 100% and 81.8% of the examined animals, respectively. Highest prevalences were recorded for gastrointestinal strongylids other than Nematodirus/Marshallagia spp. (100%), Eimeria spp. (100%), Muellerius spp. (79.8%) and Nematodirus/Marshallagia spp. (79.0%). We report for the first time Cryptosporidium sp. in free-ranging Alpine ibex and Cystocaulus spp. in free-ranging ibex from Switzerland. On average, ibex were infected with 3.9 different parasites taxa (range: 1-8). Parasite prevalence and diversity varied significantly between sexes, study sites and seasons. Parasite egg output was low in 95.7% and moderate in 5.3% of the samples. Overall, the results indicate that Alpine ibex are widely infected with endoparasites and suggest that multiple infections are very common in apparently healthy populations. Furthermore, our data underline the potential influence of factors such as sex, study site and season on parasitological findings.