944 resultados para study time
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Because we live in an extremely complex social environment, people require the ability to memorize hundreds or thousands of social stimuli. The aim of this study was to investigate the effect of multiple repetitions on the processing of names and faces varying in terms of pre-experimental familiarity. We measured both behavioral and electrophysiological responses to self-, famous and unknown names and faces in three phases of the experiment (in every phase, each type of stimuli was repeated a pre-determined number of times). We found that the negative brain potential in posterior scalp sites observed approximately 170 ms after the stimulus onset (N170) was insensitive to pre-experimental familiarity but showed slight enhancement with each repetition. The negative wave in the inferior-temporal regions observed at approximately 250 ms (N250) was affected by both pre-experimental (famous>unknown) and intra-experimental familiarity (the more repetitions, the larger N250). In addition, N170 and N250 for names were larger in the left inferior-temporal region, whereas right-hemispheric or bilateral patterns of activity for faces were observed. The subsequent presentations of famous and unknown names and faces were also associated with higher amplitudes of the positive waveform in the central-parietal sites analyzed in the 320-900 ms time-window (P300). In contrast, P300 remained unchanged after the subsequent presentations of self-name and self-face. Moreover, the P300 for unknown faces grew more quickly than for unknown names. The latter suggests that the process of learning faces is more effective than learning names, possibly because faces carry more semantic information.
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Objectives: Trabecular Bone Score (TBS, Med-Imaps, France) is an index of bone microarchitecture calculated from antero-posterior spine DXA scan and reported to be associated with fracture in prior case-control studies and in a large prospective study with the Prodigy DXA device. Our aim was to assess the ability of TBS to predict incident fracture and improve the classification of fracture prospectively in the OFELY study.Materials/Methods: TBS was assessed in 564 postmenopausal women (66±8 years old) from the OFELY cohort, who had a spine DXA scan (QDR 4500A, Hologic, USA) between year 2000 and 2001. During a mean follow up of 7.8±1.3 years, 94 women sustained a fragility fracture.Results: At the time of baseline DXA scan, women with incident fracture were significantly older (70±9 vs. 65± 8 years), had a lower spine BMD (T-score: −1.9±1.2 vs. −1.3±1.3, p<0.001) and spine TBS (−3.1%, p<0.001) than women without incident fracture. After adjustment for age, BMI and the presence of prevalent fracture, the magnitude of fracture prediction was similar for spine BMD (OR=1.42 [1.11;1.82] per SD decrease [95% CI]) and TBS (OR=1.34 [1.04;1.74]) but the combination of TBS and spine BMD did not improve fracture prediction. Spine BMD and TBS were both correlated with age (respectively r=−0.17 and −0.49, p<0.001) and correlated together with 39% of TBS explained by spine BMD (r=0.63, p<0.001). When using the WHO classification, 38% of the fractures occurred in osteoporotic (fracture rate=29%), 47% in osteopenic (fracture rate=16%) and 15% in women with T-score >−1 (fracture rate=9%). By classifying our population in tertiles of TBS, we found that 47% of the fractures occurred in the lowest tertile of TBS (fracture rate=23%) and 39% of the fracture that occurred in osteopenic women were in the lowest tertile of TBS.Conclusions: Spine BMD and TBS predicted fractures equally well. The addition of TBS to spine BMD added only limited information on fracture risk prediction in our cohort when considering the all range of BMD. Nevertheless combining the osteopenic T-score and the lowest TBS helped defining a subset of osteopenic women at higher risk of fracture.Disclosure of Interest: None declared.
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BACKGROUND: In Western countries, leptospirosis is uncommon and mainly occurs in farmers and individuals indulging in water-related activities. In tropical countries, leptospirosis can be up to 1000 times more frequent and risk factors for this often severe disease may differ. METHODS: We conducted a one-year population-based matched case-control study to investigate the frequency and associated factors of leptospirosis in the entire population of Seychelles. RESULTS: A total of 75 patients had definite acute leptospirosis based on microagglutination test (MAT) and polymerase chain reaction (PCR) assay (incidence: 101 per 100,000 per year; 95% confidence interval [CI]: 79-126). Among the controls, MAT was positive in 37% (past infection) and PCR assay in 9% (subclinical infection) of men aged 25-64 with manual occupation. Comparing cases and controls with negative MAT and PCR, leptospirosis was associated positively with walking barefoot around the home, washing in streams, gardening, activities in forests, alcohol consumption, rainfall, wet soil around the home, refuse around the home, rats visible around the home during day time, cats in the home, skin wounds and inversely with indoor occupation. The considered factors accounted for as much as 57% of the variance in predicting the disease. CONCLUSION: These data indicate a high incidence of leptospirosis in Seychelles. This suggests that leptospires are likely to be ubiquitous and that effective leptospirosis control in tropical countries needs a multifactorial approach including major behaviour change by large segments of the general public.
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The measurement of BMD by dual-energy X-ray absorptiometry (DXA) is the "gold standard" for diagnosing osteoporosis but does not directly reflect deterioration in bone microarchitecture. The trabecular bone score (TBS), a novel gray-level texture measurement that can be extracted from DXA images, correlates with 3D parameters of bone microarchitecture. Our aim was to evaluate the ability of lumbar spine TBS to predict future clinical osteoporotic fractures. A total of 29,407 women 50 years of age or older at the time of baseline hip and spine DXA were identified from a database containing all clinical results for the Province of Manitoba, Canada. Health service records were assessed for the incidence of nontraumatic osteoporotic fracture codes subsequent to BMD testing (mean follow-up 4.7 years). Lumbar spine TBS was derived for each spine DXA examination blinded to clinical parameters and outcomes. Osteoporotic fractures were identified in 1668 (5.7%) women, including 439 (1.5%) spine and 293 (1.0%) hip fractures. Significantly lower spine TBS and BMD were identified in women with major osteoporotic, spine, and hip fractures (all p < 0.0001). Spine TBS and BMD predicted fractures equally well, and the combination was superior to either measurement alone (p < 0.001). Spine TBS predicts osteoporotic fractures and provides information that is independent of spine and hip BMD. Combining the TBS trabecular texture index with BMD incrementally improves fracture prediction in postmenopausal women. © 2011 American Society for Bone and Mineral Research.
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AIM: To study the prevalence of psychoactive substance use disorder (PSUD) among suicidal adolescents, psychoactive substance intoxication at the moment of the attempt, and the association between PSUD at baseline and either occurrence of suicide or repetition of suicide attempt(s). METHODS: 186 adolescents aged 16 to 21 y hospitalized for suicide attempt or overwhelming suicidal ideation were included (T0); 148 of them were traced again for evaluations after 6 mo (T1) and/or 18 mo (T2). DSM-IV diagnoses were assessed each time using the Mini International Neuropsychiatric Interview. RESULTS: At T0, 39.2% of the subjects were found to have a PSUD. Among them, a significantly higher proportion was intoxicated at the time of the attempt than those without PSUD (44.3% vs 25.4%). Among the 148 adolescents who could be traced at either T1 or T2, two died from suicide and 30 repeated suicide attempts once or more times. A marginally significant association was found between death by suicide/repetition of suicide attempt and alcohol abuse/dependence at baseline (OR=3.3, 95% CI 0.7-15.0; OR=2.6, 95% CI 0.7-9.3). More than one suicide attempt before admission to hospital at T0 (OR=3.2, 95% CI 1.1-10.0) and age over 19 y at T0 (OR=3.2, 95% CI 1.1-9.2) were independently associated with the likelihood of death by suicide or repetition of suicide attempt. CONCLUSION: Among adolescents hospitalized for suicide attempt or overwhelming suicidal ideation, the risk of death or repetition of attempt is high and is associated with previous suicide attempts--especially among older adolescents--and also marginally associated with PSUD; these adolescents should be carefully evaluated for such risks and followed up once discharged from the hospital.
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PURPOSE: Health benefits of sport and exercise are well documented in children, adolescents and adults, but little is known about emerging adulthood-a period of life characterized by significant demographic and developmental changes. The present study aimed to assess the health impact of changes in sport and exercise levels during that specific period of life. METHODS: The analysis used baseline and 15-month follow-up data (N = 4,846) from the cohort study on substance use risk factors. Associations between baseline exercise levels or changes in exercise levels and health indicators (i.e., health-related quality of life, depression, body mass index, alcohol dependence, nicotine dependence and cannabis use disorder) were measured using chi-squared tests and ANOVA. Direction of effects was tested using cross-lagged analysis. RESULTS: At baseline, all health indicator scores were observed to be better for regular exercisers than for other exercise levels. At follow-up, participants who had maintained regular exercise over time had better scores than those who had remained irregular exercisers or had discontinued, but their scores for health-related quality of life and depression were close to those of participants who had adopted regular exercise after the baseline questionnaire. Cross-lagged analysis indicated that regular exercise at baseline was a significant predictor of health-related quality of life and substance use dependence at follow-up, but was itself predicted only by health-related quality of life. CONCLUSIONS: From a health promotion perspective, this study emphasizes how important it is for emerging adult men to maintain, or adopt, regular sport and exercise.
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BACKGROUND: Classically, clinical trials are based on the placebo-control design. Our aim was to analyze the placebo effect in Huntington's disease. METHODS: Placebo data were obtained from an international, longitudinal, placebo-controlled trial for Huntington's disease (European Huntington's Disease Initiative Study Group). One-hundred and eighty patients were evaluated using the Unified Huntington Disease Rating Scale over 36 months. A placebo effect was defined as an improvement of at least 50% over baseline scores in the Unified Huntington Disease Rating Scale, and clinically relevant when at least 10% of the population met it. RESULTS: Only behavior showed a significant placebo effect, and the proportion of the patients with placebo effect ranged from 16% (first visit) to 41% (last visit). Nondepressed patients with better functional status were most likely to be placebo-responders over time. CONCLUSIONS: In Huntington's disease, behavior seems to be more vulnerable to placebo than overall motor function, cognition, and function
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BACKGROUND: In order to facilitate and improve the use of antiretroviral therapy (ART), international recommendations are released and updated regularly. We aimed to study if adherence to the recommendations is associated with better treatment outcomes in the Swiss HIV Cohort Study (SHCS). METHODS: Initial ART regimens prescribed to participants between 1998 and 2007 were classified according to IAS-USA recommendations. Baseline characteristics of patients who received regimens in violation with these recommendations (violation ART) were compared to other patients. Multivariable logistic and linear regression analyses were performed to identify associations between violation ART and (i) virological suppression and (ii) CD4 cell count increase, after one year. RESULTS: Between 1998 and 2007, 4189 SHCS participants started 241 different ART regimens. A violation ART was started in 5% of patients. Female patients (adjusted odds ratio aOR 1.83, 95%CI 1.28-2.62), those with a high education level (aOR 1.49, 95%CI 1.07-2.06) or a high CD4 count (aOR 1.53, 95%CI 1.02-2.30) were more likely to receive violation ART. The proportion of patients with an undetectable viral load (<400 copies/mL) after one year was significantly lower with violation ART than with recommended regimens (aOR 0.54, 95% CI 0.37-0.80) whereas CD4 count increase after one year of treatment was similar in both groups. CONCLUSIONS: Although more than 240 different initial regimens were prescribed, violations of the IAS-USA recommendations were uncommon. Patients receiving these regimens were less likely to have an undetectable viral load after one year, which strengthens the validity of these recommendations.
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OBJECTIVE: To investigate the evolution of delirium of nursing home (NH) residents and their possible predictors. DESIGN: Post-hoc analysis of a prospective cohort assessment. SETTING: Ninety NHs in Switzerland. PARTICIPANTS: Included 14,771 NH residents. MEASUREMENTS: The Resident Assessment Instrument Minimum Data Set and the Nursing Home Confusion Assessment Method were used to determine follow-up of subsyndromal or full delirium in NH residents using discrete Markov chain modeling to describe long-term trajectories and multiple logistic regression analyses to determine predictors of the trajectories. RESULTS: We identified four major types of delirium time courses in NH. Increasing severity of cognitive impairment and of depressive symptoms at the initial assessment predicted the different delirium time courses. CONCLUSION: More pronounced cognitive impairment and depressive symptoms at the initial assessment are associated with different subsequent evolutions of delirium. The presence and evolution of delirium in the first year after NH admission predicted the subsequent course of delirium until death.
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Background: The posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) and the combined Pons-midbrain score quantify the extent of early ischemic changes in the posterior circulation. We compared the prognostic accuracy of both scores if applied to CT angiography (CTA) source images (CTA-SI) of patients in the Basilar Artery International Cooperation Study (BASICS).Methods: BASICS was a prospective, observational, multi-centre, registry of consecutive patients who presented with acute symptomatic basilar artery occlusion (BAO). Functional outcome was assessed at 1 month. We applied pc-ASPECTS and the combined Pons-midbrain score to CTA-SI by 3-reader-consensus. Readers were blinded to clinical data. We performed multivariable logistic regression analysis, adjusting for thrombolysis, baseline NIHSS score and age, and used the output to derive ROC curves to compare the ability of both scores to discriminate patients with favourable (modified Rankin Scale [mRS] scores 0-3) from patients with unfavourable (mRS scores 4-6) functional outcome.Results: We reviewed CTAs of 158 patients (64% men, mean age 65 _ 15 years, median NIHSS score 25 [0-38], median GCS score 7 [3-15], median onset-to-CTA time 234 minutes [11-7380]). At 1 month, 40 (25%) patients had a favourable outcome, 49 (31%) had an unfavourable outcome (mRS score 4-5) and 69 (44%) were deceased. Both techniques of assessing CTA-SI hypoattenuation in the posterior circulation showed equally good discriminative value in predicting final outcome (C-statistics; area under ROC curve 0.74 versus 0.75, respectively; p_0.37). Pc-ASPECTS dichotomized at _6 versus _6 was an independent predictor of favourable functional outcome (RR _ 2.2; CI95 1.1-4.7; p _ 0.034).Conclusion: Compared to the combined Pons-midbrain score, the pc-ASPECTS score has similar prognostic accuracy to identify patients with a favourable functional outcome in BASICS. Dichotomized pc-ASPECTS (_6 versus _6) is an independent predictor of favourable functional outcome in this population. Author Disclosures: V. Puetz: None. A. Khomenko: None. M.D. Hill: None. I. Dzialowski: None. P. Michel: None. C. Weimar: None. C.A.C. Wijman: None. H. Mattle: None. K. Muir: None. T. Pfefferkorn: None. D. Tanne: None. S. Engelter: None. K. Szabo: None. A. Algra: None. A.M. Demchuk: None. W.J. Schonewille: None.
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BACKGROUND: A growing number of case reports have described tenofovir (TDF)-related proximal renal tubulopathy and impaired calculated glomerular filtration rates (cGFR). We assessed TDF-associated changes in cGFR in a large observational HIV cohort. METHODS: We compared treatment-naive patients or patients with treatment interruptions > or = 12 months starting either a TDF-based combination antiretroviral therapy (cART) (n = 363) or a TDF-sparing regime (n = 715). The predefined primary endpoint was the time to a 10 ml/min reduction in cGFR, based on the Cockcroft-Gault equation, confirmed by a follow-up measurement at least 1 month later. In sensitivity analyses, secondary endpoints including calculations based on the modified diet in renal disease (MDRD) formula were considered. Endpoints were modelled using pre-specified covariates in a multiple Cox proportional hazards model. RESULTS: Two-year event-free probabilities were 0.65 (95% confidence interval [CI] 0.58-0.72) and 0.80 (95% CI 0.76-0.83) for patients starting TDF-containing or TDF-sparing cART, respectively. In the multiple Cox model, diabetes mellitus (hazard ratio [HR] = 2.34 [95% CI 1.24-4.42]), higher baseline cGFR (HR = 1.03 [95% CI 1.02-1.04] by 10 ml/min), TDF use (HR = 1.84 [95% CI 1.35-2.51]) and boosted protease inhibitor use (HR = 1.71 [95% CI 1.30-2.24]) significantly increased the risk for reaching the primary endpoint. Sensitivity analyses showed high consistency. CONCLUSION: There is consistent evidence for a significant reduction in cGFR associated with TDF use in HIV-infected patients. Our findings call for a strict monitoring of renal function in long-term TDF users with tests that distinguish between glomerular dysfunction and proximal renal tubulopathy, a known adverse effect of TDF.
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OBJECTIVE: To identify predictors of nonresponse to a self-report study of patients with orthopedic trauma hospitalized for vocational rehabilitation between November 15, 2003, and December 31, 2005. The role of biopsychosocial complexity, assessed using the INTERMED, was of particular interest. DESIGN: Cohort study. Questionnaires with quality of life, sociodemographic, and job-related questions were given to patients at hospitalization and 1 year after discharge. Sociodemographic data, biopsychosocial complexity, and presence of comorbidity were available at hospitalization (baseline) for all eligible patients. Logistic regression models were used to test a number of baseline variables as potential predictors of nonresponse to the questionnaires at each of the 2 time points. SETTING: Rehabilitation clinic. PARTICIPANTS: Patients (N=990) hospitalized for vocational rehabilitation over a period of 2 years. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Nonresponse to the questionnaires was the binary dependent variable. RESULTS: Patients with high biopsychosocial complexity, foreign native language, or low educational level were less likely to respond at both time points. Younger patients were less likely to respond at 1 year. Those living in a stable partnership were less likely than singles to respond at hospitalization. Sex, psychiatric, and somatic comorbidity and alcoholism were never associated with nonresponse. CONCLUSIONS: We stress the importance of assessing biopsychosocial complexity to predict nonresponse. Furthermore, the factors we found to be predictive of nonresponse are also known to influence treatment outcome and vocational rehabilitation. Therefore, it is important to increase the response rate of the groups of concern in order to reduce selection bias in epidemiologic investigations.
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OBJECTIVE: To assess whether breath acetone concentration can be used to monitor the effects of a prolonged physical activity on whole body lipolysis and hepatic ketogenesis in field conditions. METHODS: Twenty-three non-diabetic, 11 type 1 diabetic, and 17 type 2 diabetic subjects provided breath and blood samples for this study. Samples were collected during the International Four Days Marches, in the Netherlands. For each participant, breath acetone concentration was measured using proton transfer reaction ion trap mass spectrometry, before and after a 30-50 km walk on four consecutive days. Blood non-esterified free fatty acid (NEFA), beta-hydroxybutyrate (BOHB), and glucose concentrations were measured after walking. RESULTS: Breath acetone concentration was significantly higher after than before walking, and was positively correlated with blood NEFA and BOHB concentrations. The effect of walking on breath acetone concentration was repeatedly observed on all four consecutive days. Breath acetone concentrations were higher in type 1 diabetic subjects and lower in type 2 diabetic subjects than in control subjects. CONCLUSIONS: Breath acetone can be used to monitor hepatic ketogenesis during walking under field conditions. It may, therefore, provide real-time information on fat burning, which may be of use for monitoring the lifestyle interventions.
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Background and Aims: Two distinct e ndoscopic phenotypes of E osinophilic Esophagitis (EoE) h ave been identified: t he inflammatory (IP) a nd the stenosing (SP) p henotype. I t is not known whether these EoE-associated phenotypes are reflective of different phases during disease course. We aimed to assess the phenotype a t initial EoE p resentation and d iagnosis and to evaluate if SP increases over time. Methods: R etrospective a nalysis of t he Swiss EoE Database (SEED) extended b y a review of p atients charts, endoscopy and pathology records. Results: F orty-four E oE p atients were a nalyzed (33 males, mean age at index visit 41 ± 14 years, all Caucasians). Median follow-up t ime was 3.1 years (IQR 1-4, r ange 1 -18 years). Median diagnostic delay w as 5 y ears (IQR 2-16, range 0-34 years). A t first diagnosis, 3 2% ( 14/44) o f EoE patients h ad already presented w ith a stenosis. T he mean d iameter o f the stenoses w as 1 0 ± 2 mm, and the mean length was 2 .8 ± 2 .9 cm. Peak e osinophil count d id n ot c hange over t ime (48 ± 39 eos/HPF at index visit vs. 59 ± 41 eos/HPF at end of follow-up, n=44). The risk of the presence of a stenosis at index visit was 0% f or a d isease duration of 0 -4 y ears, 37% f or a d isease duration between 5-10 years and 67% f or a d isease duration >10 years (p = 0.0035, trend test). Conclusions: T he frequency of e sophageal stenoses i s proportional to the disease duration, whereas the inflammatory activity does n ot s ignificantly c hange over t ime. O ur f indings underscore the necessity to reduce diagnostic delay in EoE and to control the underlying inflammatory processes to prevent esophageal remodeling.
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Estimating the time since the last discharge of firearms and/or spent cartridges may be a useful piece of information in forensic firearm-related cases. The current approach consists of studying the diffusion of selected volatile organic compounds (such as naphthalene) released during the shooting using solid phase micro-extraction (SPME). However, this technique works poorly on handgun car-tridges because the extracted quantities quickly fall below the limit of detection. In order to find more effective solutions and further investigate the aging of organic gunshot residue after the discharge of handgun cartridges, an extensive study was carried out in this work using a novel approach based on high capacity headspace sorptive extraction (HSSE). By adopting this technique, for the first time 51 gunshot residue (GSR) volatile organic compounds could be simultaneously detected from fired handgun cartridge cases. Application to aged specimens showed that many of those compounds presented significant and complementary aging profiles. Compound-to-compound ratios were also tested and proved to be beneficial both in reducing the variability of the aging curves and in enlarging the time window useful in a forensic casework perspective. The obtained results were thus particularly promising for the development of a new complete forensic dating methodology.