169 resultados para Differences-in-Differences method
Resumo:
Recognition by the T-cell receptor (TCR) of immunogenic peptides presented by class I major histocompatibility complexes (MHCs) is the determining event in the specific cellular immune response against virus-infected cells or tumor cells. It is of great interest, therefore, to elucidate the molecular principles upon which the selectivity of a TCR is based. These principles can in turn be used to design therapeutic approaches, such as peptide-based immunotherapies of cancer. In this study, free energy simulation methods are used to analyze the binding free energy difference of a particular TCR (A6) for a wild-type peptide (Tax) and a mutant peptide (Tax P6A), both presented in HLA A2. The computed free energy difference is 2.9 kcal/mol, in good agreement with the experimental value. This makes possible the use of the simulation results for obtaining an understanding of the origin of the free energy difference which was not available from the experimental results. A free energy component analysis makes possible the decomposition of the free energy difference between the binding of the wild-type and mutant peptide into its components. Of particular interest is the fact that better solvation of the mutant peptide when bound to the MHC molecule is an important contribution to the greater affinity of the TCR for the latter. The results make possible identification of the residues of the TCR which are important for the selectivity. This provides an understanding of the molecular principles that govern the recognition. The possibility of using free energy simulations in designing peptide derivatives for cancer immunotherapy is briefly discussed.
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The increase in VLDL TAG concentration after ingestion of a high-fructose diet is more pronounced in men than in pre-menopausal women. We hypothesised that this may be due to a lower fructose-induced stimulation of de novo lipogenesis (DNL) in pre-menopausal women. To evaluate this hypothesis, nine healthy male and nine healthy female subjects were studied after ingestion of oral loads of fructose enriched with 13C6 fructose. Incorporation of 13C into breath CO2, plasma glucose and plasma VLDL palmitate was monitored to evaluate total fructose oxidation, gluconeogenesis and hepatic DNL, respectively. Substrate oxidation was assessed by indirect calorimetry. After 13C fructose ingestion, 44.0 (sd 3.2)% of labelled carbons were recovered in plasma glucose in males v. 41.9 (sd 2.3)% in females (NS), and 42.9 (sd 3.7)% of labelled carbons were recovered in breath CO2 in males v. 43.0 (sd 4.5)% in females (NS), indicating similar gluconeogenesis from fructose and total fructose oxidation in males and females. The area under the curve for 13C VLDL palmitate tracer-to-tracee ratio was four times lower in females (P < 0.05), indicating a lower DNL. Furthermore, lipid oxidation was significantly suppressed in males (by 16.4 (sd 5.2), P < 0.05), but it was not suppressed in females ( -1.3 (sd 4.7)%). These results support the hypothesis that females may be protected against fructose-induced hypertriglyceridaemia because of a lower stimulation of DNL and a lower suppression of lipid oxidation.
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Age trajectories for personality traits are known to be similar across cultures. To address whether stereotypes of age groups reflect these age-related changes in personality, we asked participants in 26 countries (N = 3,323) to rate typical adolescents, adults, and old persons in their own country. Raters across nations tended to share similar beliefs about different age groups; adolescents were seen as impulsive, rebellious, undisciplined, preferring excitement and novelty, whereas old people were consistently considered lower on impulsivity, activity, antagonism, and Openness. These consensual age group stereotypes correlated strongly with published age differences on the five major dimensions of personality and most of 30 specific traits, using as criteria of accuracy both self-reports and observer ratings, different survey methodologies, and data from up to 50 nations. However, personal stereotypes were considerably less accurate, and consensual stereotypes tended to exaggerate differences across age groups.
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Several observations support the hypothesis that differences in synaptic and regional cerebral plasticity between the sexes account for the high ratio of males to females in autism. First, males are more susceptible than females to perturbations in genes involved in synaptic plasticity. Second, sex-related differences in non-autistic brain structure and function are observed in highly variable regions, namely, the heteromodal associative cortices, and overlap with structural particularities and enhanced activity of perceptual associative regions in autistic individuals. Finally, functional cortical reallocations following brain lesions in non-autistic adults (for example, traumatic brain injury, multiple sclerosis) are sex-dependent. Interactions between genetic sex and hormones may therefore result in higher synaptic and consecutively regional plasticity in perceptual brain areas in males than in females. The onset of autism may largely involve mutations altering synaptic plasticity that create a plastic reaction affecting the most variable and sexually dimorphic brain regions. The sex ratio bias in autism may arise because males have a lower threshold than females for the development of this plastic reaction following a genetic or environmental event.
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BACKGROUND: Literature on the disease profile of prisoners that differentiates by age and gender remains sparse. This study aimed to describe the health of correctional inmates in terms of substance abuse problems and mental and somatic health conditions, and compare it by gender and age. METHODS: This study examined cross-sectional data from the Canton of Vaud in Switzerland on the health conditions of detainees who were in prison on January 1, 2011 or entered prison in 2011. Health conditions validated by physician examination were reported using the International Classification of Diseases (ICD) version 10. The analyses were descriptive by groups of prisoners: the entire sample (All), Men, Older adults and Women. RESULTS: A total of 1,664 individuals were included in the analysis. Men comprised 91.5 % of the sample and had a mean age of 33 years. The other 8.5 % were women and had an average age of 39. Older adults (i.e., age 50 and older) represented 7 % of the total sample. Overall, 80 % of inmates were non-Swiss citizens, but the proportion of Swiss prisoners was higher among the older adults (51 %) and women (29 %). Overall, 41 % of inmates self-reported substance abuse problems. Of those, 27 % were being treated by psychiatrists for behavioral disorders related to substance abuse. Chronic infectious diseases were found in 9 % of the prison population. In addition, 27 % of detainees suffered from serious mental health conditions. Gender and age had an influence on the disease profile of this sample: compared to the entire prison population, the older inmates were less likely to misuse illegal drugs and to suffer from communicable infections but exhibited more problems with alcohol and a higher burden of chronic health conditions. Female prisoners were more disposed to mental health problems (including drug abuse) and infectious diseases. In terms of chronic diseases, women suffered from the same conditions as men, but the diseases were more prevalent in women. CONCLUSION: It is important to understand the different disease profiles of prisoners by gender and age, as it helps identify the needs of different groups and tailor age-and gender-specific interventions.
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Bradyrhizobium japonicum is a symbiotic nitrogen-fixing soil bacteria that induce root nodules formation in legume soybean (Glycine max.). Using 13C- and 31P-nuclear magnetic resonance (NMR) spectroscopy, we have analysed the metabolite profiles of cultivated B.japonicum cells and bacteroids isolated from soybean nodules. Our results revealed some quantitative and qualitative differences between the metabolite profiles of bacteroids and their vegetative state. This includes in bacteroids a huge accumulation of soluble carbohydrates such as trehalose, glutamate, myo-inositol and homospermidine as well as Pi, nucleotide pools and intermediates of the primary carbon metabolism. Using this novel approach, these data show that most of the compounds detected in bacteroids reflect the metabolic adaptation of rhizobia to the surrounding microenvironment with its host plant cells.
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BACKGROUND: Recent studies suggest that inequalities in premature mortality have continued to rise over the last decade in most European countries, but not in southern European countries. METHODS: In this study, we assess long-term trends (1971-2011) in absolute and relative educational inequalities in all-cause and cause-specific mortality in the Turin Longitudinal Study (Turin, Italy), a record-linkage study including all individuals resident in Turin in the 1971, 1981, 1991 and 2001 censuses, and aged 30-99 years (more than 2 million people). We examined mortality for all causes, cardiovascular disease (CVD), all cancers and specific cancers (lung, breast), as well as smoking and alcohol-related mortality. RESULTS: Overall mortality substantially decreased in all educational groups over the study period, although cancer rates only slightly declined. Absolute inequalities decreased for both genders (SII=962/694 in men/women in 1972-1976 and SII=531/259 in 2007-2011, p<0.01). Among men, absolute inequalities for CVD and alcohol-related causes declined (p<0.05), while remaining stable for other causes of death. Among women, declines in absolute inequalities were observed for CVD, smoking and alcohol-related causes and lung cancer (p<0.05). Relative inequalities in all-cause mortality remained stable for men and decreased for women (RII=1.92/2.03 in men/women in 1972-1976 and RII=2.15/1.32 in 2007-2011). Among men, relative inequalities increased for smoking-related causes, while among women they decreased for all cancers, CVD, smoking-related causes and lung cancer (p<0.05). CONCLUSIONS: Absolute inequalities in mortality strongly declined over the study period in both genders. Relative educational inequalities in mortality were generally stable among men; while they tended to narrow among women. In general, this study supports the hypothesis that educational inequalities in mortality have decreased in southern European countries.
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OBJECTIVE: We evaluated whether regional differences in physical activity (PA) and sedentary behaviour (SB) existed along language boundaries within Switzerland and whether potential differences would be explained by socio-demographics or environmental characteristics. METHODS: We combined data of 611 children aged 4 to 7 years from four regional studies. PA and SB were assessed by accelerometers. Information about the socio-demographic background was obtained by questionnaires. Objective neighbourhood attributes could be linked to home addresses. Multivariate regression models were used to test associations between PA and SB and socio-demographic characteristics and neighbourhood attributes. RESULTS: Children from the German compared to the French-speaking region were more physically active and less sedentary (by 10-15 %, p < 0.01). Although German-speaking children lived in a more favourable environment and a higher socioeconomic neighbourhood (differences p < 0.001), these characteristics did not explain the differences in PA behaviour between French and German speaking. CONCLUSIONS: Factors related to the language region, which might be culturally rooted were among the strongest correlates of PA and SB among Swiss children, independent of individual, social and environmental factors.
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OBJECTIVES: To analyse the similarities and discrepancies between the official rheumatology specialty training programmes across Europe. METHODS: A steering committee defined the main aspects of training to be assessed. In 2013, the rheumatology official training programmes were reviewed for each of the European League Against Rheumatism (EULAR) countries and two local physicians independently extracted data on the structure of training, included competencies and assessments performed. Analyses were descriptive. RESULTS: 41 of the 45 EULAR countries currently provide specialist training in rheumatology; in the remaining four rheumatologists are trained abroad. 36 (88%) had a single national curriculum, one country had two national curricula and four had only local or university-specific curricula. The mean length of training programmes in rheumatology was 45 (SD 19) months, ranging between 3 and 72 months. General internal medicine training was mandatory in 40 (98%) countries, and was performed prior to and/or during the rheumatology training programme (mean length: 33 (19) months). 33 (80%) countries had a formal final examination. CONCLUSIONS: Most European countries provide training in rheumatology, but the length, structure, contents and assessments of these training programmes are quite heterogeneous. In order to promote excellence in standards of care and to support physicians' mobility, a certain degree of harmonisation should be encouraged.
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BACKGROUND: An important component of the policy to deal with the H1N1 pandemic in 2009 was to develop and implement vaccination. Since pregnant women were found to be at particular risk of severe morbidity and mortality, the World Health Organization and the European Centers for Disease Control advised vaccinating pregnant women, regardless of trimester of pregnancy. This study reports a survey of vaccination policies for pregnant women in European countries. METHODS: Questionnaires were sent to European competent authorities of 27 countries via the European Medicines Agency and to leaders of registries of European Surveillance of Congenital Anomalies in 21 countries. RESULTS: Replies were received for 24 out of 32 European countries of which 20 had an official pandemic vaccination policy. These 20 countries all had a policy targeting pregnant women. For two of the four countries without official pandemic vaccination policies, some vaccination of pregnant women took place. In 12 out of 20 countries the policy was to vaccinate only second and third trimester pregnant women and in 8 out of 20 countries the policy was to vaccinate pregnant women regardless of trimester of pregnancy. Seven different vaccines were used for pregnant women, of which four contained adjuvants. Few countries had mechanisms to monitor the number of vaccinations given specifically to pregnant women over time. Vaccination uptake varied. CONCLUSIONS: Differences in pandemic vaccination policy and practice might relate to variation in perception of vaccine efficacy and safety, operational issues related to vaccine manufacturing and procurement, and vaccination campaign systems. Increased monitoring of pandemic influenza vaccine coverage of pregnant women is recommended to enable evaluation of the vaccine safety in pregnancy and pandemic vaccination campaign effectiveness.
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BACKGROUND: The outcome of cancer patients with acute venous thromboembolism (VTE) may differ according to gender. METHODS: We used the RIETE database to compare the rate of VTE (pulmonary embolism [PE] or deep vein thrombosis [DVT]) recurrences), major bleeding and mortality during the course of anticoagulation, according to gender. RESULTS: As of August 2014, 11,055 patients with active cancer were enrolled in RIETE, of whom 5,104 (46%) were women. During the course of anticoagulation (mean: 142 days), 505 patients developed recurrent VTE, 429 bled and 2730 died. Compared with men, women had a significantly lower rate of fatal bleeding (risk ratio [RR]: 0.69; 95% CI: 0.47-0.99) and death (RR: 0.90; 95% CI: 0.83-0.97), and a non-significantly lower rate of PE recurrences (RR 0.83; 95% CI: 0.65-1.06) and major bleeding (RR: 0.89; 95% CI: 0.74-1.08). CONCLUSIONS: During the course of anticoagulation, cancer women with VTE had a better outcome than men.