296 research outputs found
A Comprehensive Analysis of Fermi Gamma-Ray Burst Data. I. Spectral Components and Their Possible Physical Origins of LAT/GBM GRBs
We present a systematic analysis of the spectral and temporal properties of
17 GRBs co-detected by GBM and LAT on board the Fermi satellite by May 2010. We
performed a time-resolved spectral analysis of all the bursts with the finest
temporal resolution allowed by statistics, in order to avoid temporal smearing
of different spectral components. We found that the time-resolved spectra of 14
out of 17 GRBs are best modeled with the Band function over the entire Fermi
spectral range, which may suggest a common origin for emissions detected by LAT
and GBM. GRB 090902B and GRB 090510 require the superposition between an MeV
component and an extra power law component, with the former having a sharp
cutoff above E_p. For GRB 090902B, this MeV component becomes progressively
narrower as the time bin gets smaller, and can be fit with a Planck function as
the time bin becomes small enough. In general, we speculate that
phenomenologically there may be three elemental spectral components : (I) a
Band-function component (e.g. in GRB 080916C) that extends in a wide energy
range and does not narrow with reducing time bins, which may be of the
non-thermal origin; (II) a quasi-thermal component (e.g. in GRB 090902B) with
the spectra progressively narrowing with reducing time bins; and (III) another
non-thermal power law component extending to high energies. The spectra of
different bursts may be decomposed into one or more of these elemental
components. We compare this sample with the BATSE sample and investigate some
correlations among spectral parameters. We discuss the physical implications of
the data analysis results for GRB prompt emission, including jet compositions
(matter-dominated vs. Poynting-flux-dominated outflow), emission sites
(internal shock, external shock or photosphere), as well as radiation
mechanisms (synchrotron, synchrotron self-Compton, or thermal Compton
upscattering).Comment: 61 pages, 25 figures, 3 tables. 2011 ApJ in pres
Development of an educational intervention for patients with Irritable Bowel Syndrome (IBS) – a pilot study
<p>Abstract</p> <p>Background</p> <p>Many IBS patients experience that they receive limited information and that the health care system does not take their complaints seriously. We aimed to develop a structured patient education, an 'IBS school', and investigate if the efficacy could be evaluated in terms of improved knowledge, symptom severity and health related quality of life (HRQOL).</p> <p>Methods</p> <p>The IBS school consisted of six weekly two hour sessions in a group setting. Five different health care professionals were responsible for one session each. Questionnaires covering patients' experience of the education, perceived knowledge about IBS, gastrointestinal symptoms, and HRQOL, were used for evaluation at baseline and at three, six, and twelve months after education.</p> <p>Results</p> <p>Twelve IBS patients were included. The patients were overall satisfied with the IBS school. In line with this, the gastrointestinal symptoms, HRQOL, and perceived knowledge about IBS improved significantly after the education.</p> <p>Conclusion</p> <p>An IBS school seems to be a proper method to meet the patients' need of information about IBS and also to improve the patients' gastrointestinal symptoms, HRQOL, and knowledge about IBS. Further controlled studies are now needed in larger numbers of patients to confirm these preliminary results in order to implement this intervention in clinical practice.</p
General practitioners apply the usual care for shoulder complaints better than expected – analysis of videotaped consultations
BACKGROUND: The education and activation program (EAP) is a newly developed intervention to prevent the development of chronic shoulder complaints (SCs). Trained general practitioners (GPs) administer the EAP. The EAP addresses inadequate cognitions and maladaptive behavior related to the SCs. The effect of the EAP is evaluated in a randomized clinical trial. The aim of the present study is to use videotaped consultations to study (1) the performance of trained GPs administering the EAP and (2) the presence of key features of the EAP already embedded in usual care (UC). METHODS: Five trained GPs were videotaped while treating a standardized patient with EAP. Additionally, five GPs administering UC were videotaped. Two blinded observers evaluated the videotapes in relation to key features of the EAP which were scored on the EAP checklist. RESULTS: The mean total score on the EAP checklist was 4.7 (SD = 2.9) for the UC group and 7.1 (SD = 2.1) for the EAP group. Neither group reached a score higher than 8, which was considered to reflect an acceptable number of key EAP features. CONCLUSION: Our comparison of the presence of key features of EAP shows that the UC and EAP groups differed less than was expected. GPs in the UC group performed above expectation, with a mean total score of 4.7. Moreover, the low number of key features present in the EAP group may very well have led to a reduced effectiveness of the EAP. The results of this study can be used to optimize the training of GPs using the EAP
Trial design: Computer guided normal-low versus normal-high potassium control in critically ill patients: Rationale of the GRIP-COMPASS study
Background: Potassium depletion is common in hospitalized patients and can cause serious complications such as cardiac arrhythmias. In the intensive care unit (ICU) the majority of patients require potassium suppletion. However, there are no data regarding the optimal control target in critically ill patients. After open-heart surgery, patients have a strongly increased risk of atrial fibrillation or atrial flutter (AFF). In a novel trial design, we examined if in these patients different potassium control-targets within the normal range may have different effects on the incidence of AFF. Methods/Design: The "computer-driven Glucose and potassium Regulation program in Intensive care Patients with COMparison of PotASSium targets within normokalemic range (GRIP-COMPASS) trial" is a single-center prospective trial in which a total of 1200 patients are assigned to either a potassium control-target of 4.0 mmol/L or 4.5 mmol/L in consecutive alternating blocks of 50 patients each. Potassium levels are regulated by the computer-assisted potassium suppletion algorithm called GRIP-II (Glucose and potassium regulation for Intensive care Patients). Primary endpoint is the in-hospital incidence of AFF after cardiac surgery. Secondary endpoints are: in-hospital AFF in medical patients or patients after non-cardiac surgery, actually achieved potassium levels and their variation, electrolyte and glucose levels, potassium and insulin requirements, cumulative fluid balance, (ICU) length of stay, ICU mortality, hospital mortality and 90-day mortality. Discussion: The GRIP-COMPASS trial is the first controlled clinical trial to date that compares potassium targets. Other novel methodological elements of the study are that it is performed in ICU patients where both targets are within the normal range and that a computer-assisted potassium suppletion algorithm is used
Effectiveness of routine third trimester ultrasonography to reduce adverse perinatal outcomes in low risk pregnancy (the IRIS study): nationwide, pragmatic, multicentre, stepped wedge cluster randomised trial
Objectives To investigate the effectiveness of routine ultrasonography in the third trimester in reducing adverse perinatal outcomes in low risk pregnancies compared with usual care and the effect of this policy on maternal outcomes and obstetric interventions.
Design Pragmatic, multicentre, stepped wedge cluster randomised trial.
Setting 60 midwifery practices in the Netherlands.
Participants 13 046 women aged 16 years or older with a low risk singleton pregnancy.
Interventions 60 midwifery practices offered usual care (serial fundal height measurements with clinically indicated ultrasonography). After 3, 7, and 10 months, a third of the practices were randomised to the intervention strategy. As well as receiving usual care, women in the intervention strategy were offered two routine biometry scans at 28-30 and 34-36 weeks’ gestation. The same multidisciplinary protocol for detecting and managing fetal growth restriction was used in both strategies.
Main outcome measures The primary outcome measure was a composite of severe adverse perinatal outcomes: perinatal death, Apgar score <4, impaired consciousness, asphyxia, seizures, assisted ventilation, septicaemia, meningitis, bronchopulmonary dysplasia, intraventricular haemorrhage, periventricular leucomalacia, or necrotising enterocolitis. Secondary outcomes were two composite measures of severe maternal morbidity, and spontaneous labour and birth.
Results Between 1 February 2015 and 29 February 2016, 60 midwifery practices enrolled 13 520 women in mid-pregnancy (mean 22.8 (SD 2.4) weeks’ gestation). 13 046 women (intervention n=7067, usual care n=5979) with data based on the national Dutch perinatal registry or hospital records were included in the analyses. Small for gestational age at birth was significantly more often detected in the intervention group than in the usual care group (179 of 556 (32%) v 78 of 407 (19%), P<0.001). The incidence of severe adverse perinatal outcomes was 1.7% (n=118) for the intervention strategy and 1.8% (n=106) for usual care. After adjustment for confounders, the difference between the groups was not significant (odds ratio 0.88, 95% confidence interval 0.70 to 1.20). The intervention strategy showed a higher incidence of induction of labour (1.16, 1.04 to 1.30) and a lower incidence of augmentation of labour (0.78, 0.71 to 0.85). Maternal outcomes and other obstetric interventions did not differ between the strategies.
Conclusion In low risk pregnancies, routine ultrasonography in the third trimester along with clinically indicated ultrasonography was associated with higher antenatal detection of small for gestational age fetuses but not with a reduced incidence of severe adverse perinatal outcomes compared with usual care alone. The findings do not support routine ultrasonography in the third trimester for low risk pregnancies.
Trial registration Netherlands Trial Register NTR4367
Alteration of Forkhead Box O (Foxo4) Acetylation Mediates Apoptosis of Podocytes in Diabetes Mellitus
The number of kidney podocytes is reduced in diabetic nephropathy. Advanced glycation end products (AGEs) accumulate in patients with diabetes and promote the apoptosis of podocyte by activating the forkhead box O4 (Foxo4) transcription factor to increase the expression of a pro-apoptosis gene, Bcl2l11. Using chromatin immunoprecipitation we demonstrate that AGE-modified bovine serum albumin (AGE-BSA) enhances Foxo4 binding to a forkhead binding element in the promoter of Bcl2lll. AGE-BSA also increases the acetylation of Foxo4. Lysine acetylation of Foxo4 is required for Foxo4 binding and transcription of Bcl2l11 in podocytes treated with AGE-BSA. The expression of a protein deacetylase that targets Foxo4 for deacetylation, sirtuin (Sirt1), is down regulated in cultured podocytes by AGE-BSA treatment and in glomeruli of diabetic patients. SIRT1 over expression in cultured murine podocytes prevents AGE-induced apoptosis. Glomeruli isolated from diabetic db/db mice have increased acetylation of Foxo4, suppressed expression of Sirt1, and increased expression of Bcl2l11 compared to non-diabetic littermates. Together, our data provide evidence that alteration of Foxo4 acetylation and down regulation of Sirt1 expression in diabetes promote podocyte apoptosis. Strategies to preserve Sirt1 expression or reduce Foxo4 acetylation could be used to prevent podocyte loss in diabetes
CRIPTO and its signaling partner GRP78 drive the metastatic phenotype in human osteotropic prostate cancer
CRIPTO (CR-1, TDGF1) is a cell surface/secreted oncoprotein actively involved in development and cancer. Here, we report that high expression of CRIPTO correlates with poor survival in stratified risk groups of prostate cancer (PCa) patients. CRIPTO and its signaling partner glucose-regulated protein 78 (GRP78) are highly expressed in PCa metastases and display higher levels in the metastatic ALDHhigh sub-population of PC-3M-Pro4Luc2 PCa cells compared with non-metastatic ALDHlow. Coculture of the osteotropic PC-3M-Pro4Luc2 PCa cells with differentiated primary human osteoblasts induced CRIPTO and GRP78 expression in cancer cells and increases the size of the ALDHhigh sub-population. Additionally, CRIPTO or GRP78 knockdown decreases proliferation, migration, clonogenicity and the size of the metastasis-initiating ALDHhigh sub-population. CRIPTO knockdown reduces the invasion of PC-3M-Pro4Luc2 cells in zebrafish and inhibits bone metastasis in a preclinical mouse model. These results highlight a functional role for CRIPTO and GRP78 in PCa metastasis and suggest that targeting CRIPTO/GRP78 signaling may have significant therapeutic potential.Oncogene advance online publication, 10 April 2017; doi:10.1038/onc.2017.87
Sex differences in cardiovascular complications and mortality in hospital patients with covid-19: registry based observational study
Objective To assess whether the risk of cardiovascular complications of covid-19 differ between the sexes and to determine whether any sex differences in risk are reduced in individuals with pre-existing cardiovascular disease.
Design Registry based observational study.
Setting 74 hospitals across 13 countries (eight European) participating in CAPACITY-COVID (Cardiac complicAtions in Patients With SARS Corona vIrus 2 regisTrY), from March 2020 to May 2021
Participants All adults (aged ≥18 years), predominantly European, admitted to hospital with highly suspected covid-19 disease or covid-19 disease confirmed by positive laboratory test results (n=11 167 patients).
Main outcome measures Any cardiovascular complication during admission to hospital. Secondary outcomes were in-hospital mortality and individual cardiovascular complications with ≥20 events for each sex. Logistic regression was used to examine sex differences in the risk of cardiovascular outcomes, overall and grouped by pre-existing cardiovascular disease.
Results Of 11 167 adults (median age 68 years, 40% female participants) included, 3423 (36% of whom were female participants) had pre-existing cardiovascular disease. In both sexes, the most common cardiovascular complications were supraventricular tachycardias (4% of female participants, 6% of male participants), pulmonary embolism (3% and 5%), and heart failure (decompensated or de novo) (2% in both sexes). After adjusting for age, ethnic group, pre-existing cardiovascular disease, and risk factors for cardiovascular disease, female individuals were less likely than male individuals to have a cardiovascular complication (odds ratio 0.72, 95% confidence interval 0.64 to 0.80) or die (0.65, 0.59 to 0.72). Differences between the sexes were not modified by pre-existing cardiovascular disease; for the primary outcome, the female-to-male ratio of the odds ratio in those without, compared with those with, pre-existing cardiovascular disease was 0.84 (0.67 to 1.07).
Conclusions In patients admitted to hospital for covid-19, female participants were less likely than male participants to have a cardiovascular complication. The differences between the sexes could not be attributed to the lower prevalence of pre-existing cardiovascular disease in female individuals. The reasons for this advantage in female individuals requires further research
A randomised controlled trial on hypnotherapy for irritable bowel syndrome: design and methodological challenges (the IMAGINE study)
<p>Abstract</p> <p>Background</p> <p>Irritable Bowel Syndrome (IBS) is a common gastro-intestinal disorder in primary and secondary care, characterised by abdominal pain, discomfort, altered bowel habits and/or symptoms of bloating and distension. In general the efficacy of drug therapies is poor. Hypnotherapy as well as Cognitive Behaviour Therapy and short Psychodynamic Therapy appear to be useful options for patients with refractory IBS in secondary care and are cost-effective, but the evidence is still limited. The IMAGINE-study is therefore designed to assess the overall benefit of hypnotherapy in IBS as well as comparing the efficacy of individual versus group hypnotherapy in treating this condition.</p> <p>Methods/Design</p> <p>The design is a randomised placebo-controlled trial. The study group consists of 354 primary care and secondary care patients (aged 18-65) with IBS (Rome-III criteria). Patients will be randomly allocated to either 6 sessions of individual hypnotherapy, 6 sessions of group hypnotherapy or 6 sessions of educational supportive therapy in a group (placebo), with a follow up of 9 months post treatment for all patients. Ten hospitals and four primary care psychological practices in different parts of The Netherlands will collaborate in this study. The primary efficacy parameter is the responder rate for adequate relief of IBS symptoms. Secondary efficacy parameters are changes in the IBS symptom severity, quality of life, cognitions, psychological complaints, self-efficacy as well as direct and indirect costs of the condition. Hypnotherapy is expected to be more effective than the control therapy, and group hypnotherapy is expected not to be inferior to individual hypnotherapy.</p> <p>Discussion</p> <p>If hypnotherapy is effective and if there is no difference in efficacy between individual and group hypnotherapy, this group form of treatment could be offered to more IBS patients, at lower costs.</p> <p>Trial registration number</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN22888906">ISRCTN22888906</a></p
Genetics and not shared environment explains familial resemblance in adult metabolomics data
Metabolites are small molecules involved in cellular metabolism where they act as reaction substrates or products. The term 'metabolomics' refers to the comprehensive study of these molecules. The concentrations of metabolites in biological tissues are under genetic control, but this is limited by environmental factors such as diet. In adult mono- and dizygotic twin pairs, we estimated the contribution of genetic and shared environmental influences on metabolite levels by structural equation modeling and tested whether the familial resemblance for metabolite levels is mainly explained by genetic or by environmental factors that are shared by family members. Metabolites were measured across three platforms: two based on proton nuclear magnetic resonance techniques and one employing mass spectrometry. These three platforms comprised 237 single metabolic traits of several chemical classes. For the three platforms, metabolites were assessed in 1407, 1037 and 1116 twin pairs, respectively. We carried out power calculations to establish what percentage of shared environmental variance could be detected given these sample sizes. Our study did not find evidence for a systematic contribution of shared environment, defined as the influence of growing up together in the same household, on metabolites assessed in adulthood. Significant heritability was observed for nearly all 237 metabolites; significant contribution of the shared environment was limited to 6 metabolites. The top quartile of the heritability distribution was populated by 5 of the 11 investigated chemical classes. In this quartile, metabolites of the class lipoprotein were significantly overrepresented, whereas metabolites of classes glycerophospholipids and glycerolipids were significantly underrepresented.Analytical BioScience
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