366 resultados para multivariate electronic spectroscopy
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PURPOSE: O6-methylguanine-methyltransferase (MGMT) promoter methylation has been shown to predict survival of patients with glioblastomas if temozolomide is added to radiotherapy (RT). It is unknown if MGMT promoter methylation is also predictive to outcome to RT followed by adjuvant procarbazine, lomustine, and vincristine (PCV) chemotherapy in patients with anaplastic oligodendroglial tumors (AOT). PATIENTS AND METHODS: In the European Organisation for the Research and Treatment of Cancer study 26951, 368 patients with AOT were randomly assigned to either RT alone or to RT followed by adjuvant PCV. From 165 patients of this study, formalin-fixed, paraffin-embedded tumor tissue was available for MGMT promoter methylation analysis. This was investigated with methylation specific multiplex ligation-dependent probe amplification. RESULTS: In 152 cases, an MGMT result was obtained, in 121 (80%) cases MGMT promoter methylation was observed. Methylation strongly correlated with combined loss of chromosome 1p and 19q loss (P = .00043). In multivariate analysis, MGMT promoter methylation, 1p/19q codeletion, tumor necrosis, and extent of resection were independent prognostic factors. The prognostic significance of MGMT promoter methylation was equally strong in the RT arm and the RT/PCV arm for both progression-free survival and overall survival. In tumors diagnosed at central pathology review as glioblastoma, no prognostic effect of MGMT promoter methylation was observed. CONCLUSION: In this study, on patients with AOT MGMT promoter methylation was of prognostic significance and did not have predictive significance for outcome to adjuvant PCV chemotherapy. The biologic effect of MGMT promoter methylation or pathogenetic features associated with MGMT promoter methylation may be different for AOT compared with glioblastoma.
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BACKGROUND & AIMS: To assess the adherence to the national dietary recommendations and to identify factors contributing to dietary compliance in Switzerland. METHODS: Population-based cross-sectional study in Lausanne, Switzerland (CoLaus study), 2009-2012. Dietary intake was assessed using a validated food frequency questionnaire. Participants were dichotomized according to whether they followed the national recommendations for fruits, vegetables, meat, fish and dairy products. RESULTS: Data from 4371 participants (54% women, mean age ± SD: 57.6 ± 10.5 years) were analyzed. Compliance with the recommendations was low: only 39.4%, 7.1%, 61.3%, 66.4%, and 8.4% complied with the Swiss recommendations for fruit (≥2/day), vegetables (≥3/day), meat (≤5/week), fish (≥1/week) and dairy products (≥3/day), respectively. In multivariate analyses, gender, age, smoking status, Swiss-born status, education, being on a diet and body mass index were associated with dietary compliance, while no difference was found between women before and after menopause. Factors specifically associated with fruits, vegetables, meat, fish or dairy products recommendations were identified. CONCLUSION: The low degree of compliance with dietary recommendations calls for a continued effort to increase the population awareness of the importance of a healthy and balanced diet, especially for vegetables and dairy products. This study identified determinants that should guide this effort.
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BACKGROUND: New HIV infections in men who have sex with men (MSM) have increased in Switzerland since 2000 despite combination antiretroviral therapy (cART). The objectives of this mathematical modelling study were: to describe the dynamics of the HIV epidemic in MSM in Switzerland using national data; to explore the effects of hypothetical prevention scenarios; and to conduct a multivariate sensitivity analysis. METHODOLOGY/PRINCIPAL FINDINGS: The model describes HIV transmission, progression and the effects of cART using differential equations. The model was fitted to Swiss HIV and AIDS surveillance data and twelve unknown parameters were estimated. Predicted numbers of diagnosed HIV infections and AIDS cases fitted the observed data well. By the end of 2010, an estimated 13.5% (95% CI 12.5, 14.6%) of all HIV-infected MSM were undiagnosed and accounted for 81.8% (95% CI 81.1, 82.4%) of new HIV infections. The transmission rate was at its lowest from 1995-1999, with a nadir of 46 incident HIV infections in 1999, but increased from 2000. The estimated number of new infections continued to increase to more than 250 in 2010, although the reproduction number was still below the epidemic threshold. Prevention scenarios included temporary reductions in risk behaviour, annual test and treat, and reduction in risk behaviour to levels observed earlier in the epidemic. These led to predicted reductions in new infections from 2 to 26% by 2020. Parameters related to disease progression and relative infectiousness at different HIV stages had the greatest influence on estimates of the net transmission rate. CONCLUSIONS/SIGNIFICANCE: The model outputs suggest that the increase in HIV transmission amongst MSM in Switzerland is the result of continuing risky sexual behaviour, particularly by those unaware of their infection status. Long term reductions in the incidence of HIV infection in MSM in Switzerland will require increased and sustained uptake of effective interventions.
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The detection of Parkinson's disease (PD) in its preclinical stages prior to outright neurodegeneration is essential to the development of neuroprotective therapies and could reduce the number of misdiagnosed patients. However, early diagnosis is currently hampered by lack of reliable biomarkers. (1) H magnetic resonance spectroscopy (MRS) offers a noninvasive measure of brain metabolite levels that allows the identification of such potential biomarkers. This study aimed at using MRS on an ultrahigh field 14.1 T magnet to explore the striatal metabolic changes occurring in two different rat models of the disease. Rats lesioned by the injection of 6-hydroxydopamine (6-OHDA) in the medial-forebrain bundle were used to model a complete nigrostriatal lesion while a genetic model based on the nigral injection of an adeno-associated viral (AAV) vector coding for the human α-synuclein was used to model a progressive neurodegeneration and dopaminergic neuron dysfunction, thereby replicating conditions closer to early pathological stages of PD. MRS measurements in the striatum of the 6-OHDA rats revealed significant decreases in glutamate and N-acetyl-aspartate levels and a significant increase in GABA level in the ipsilateral hemisphere compared with the contralateral one, while the αSyn overexpressing rats showed a significant increase in the GABA striatal level only. Therefore, we conclude that MRS measurements of striatal GABA levels could allow for the detection of early nigrostriatal defects prior to outright neurodegeneration and, as such, offers great potential as a sensitive biomarker of presymptomatic PD.
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PURPOSE: A number of microarray studies have reported distinct molecular profiles of breast cancers (BC), such as basal-like, ErbB2-like, and two to three luminal-like subtypes. These were associated with different clinical outcomes. However, although the basal and the ErbB2 subtypes are repeatedly recognized, identification of estrogen receptor (ER) -positive subtypes has been inconsistent. Therefore, refinement of their molecular definition is needed. MATERIALS AND METHODS: We have previously reported a gene expression grade index (GGI), which defines histologic grade based on gene expression profiles. Using this algorithm, we assigned ER-positive BC to either high-or low-genomic grade subgroups and compared these with previously reported ER-positive molecular classifications. As further validation, we classified 666 ER-positive samples into subtypes and assessed their clinical outcome. RESULTS: Two ER-positive molecular subgroups (high and low genomic grade) could be defined using the GGI. Despite tracking a single biologic pathway, these were highly comparable to the previously described luminal A and B classification and significantly correlated to the risk groups produced using the 21-gene recurrence score. The two subtypes were associated with statistically distinct clinical outcome in both systemically untreated and tamoxifen-treated populations. CONCLUSION: The use of genomic grade can identify two clinically distinct ER-positive molecular subtypes in a simple and highly reproducible manner across multiple data sets. This study emphasizes the important role of proliferation-related genes in predicting prognosis in ER-positive BC.
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BACKGROUND AND PURPOSE: Electrical bioimpedance spectroscopy (BIS) allows the evaluation of limb extracellular fluid (R0) and total fluid (Rinf). BIS could facilitate post-surgical oedema evaluation after total knee arthroplasty (TKA), as it is easily performed and is non-invasive. However, neither its applicability in this context nor the influence of metallic implants on measurement has been evaluated. The aim of this study was to evaluate the influence of TKA implants on the BIS R0 and Rinf variables used for oedema evaluation. METHOD: This was a prospective non-randomized comparative clinical trial. One oedema-free group of patients with TKA was compared with a group presenting similar characteristics except for the arthroplasty, to assess the influence of the implant on BIS measurement in the absence of oedema. The TKA group included 15 patients who had undergone surgery more than a year previously, and the control group included 19 patients awaiting TKA surgery. Volume and perimeter measurements served as reference criterions. The lower limb percentage differences for BIS, knee perimeter and volume were calculated. The significance of differences between groups was calculated for all measurement methods, using the Mann-Whitney test. The setting was a Department of Orthopedic Surgery and Traumatology in a university hospital. RESULTS: The differences between groups were not significant for R0, Rinf, volume and perimeter. R0 showed the smallest mean difference in limb percentage difference between groups [means (SD): TKA 3.98 (8.09), controls 3.97 (5.16)]. CONCLUSIONS: The lower-leg percentage difference in the TKA group is comparable with that of healthy subjects. R0 can be used for oedema evaluation following TKA surgery, as there was no sign of alteration from the metallic implant. These findings indicate the potential for early oedema evaluation after TKA. More research is warranted to extensively validate the application of BIS for oedema evaluation after TKA. Copyright © 2012 John Wiley & Sons, Ltd.
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Proton T1 relaxation times of metabolites in the human brain have not previously been published at 7 T. In this study, T1 values of CH3 and CH2 group of N-acetylaspartate and total creatine as well as nine other brain metabolites were measured in occipital white matter and gray matter at 7 T using an inversion-recovery technique combined with a newly implemented semi-adiabatic spin-echo full-intensity acquired localized spectroscopy sequence (echo time = 12 ms). The mean T1 values of metabolites in occipital white matter and gray matter ranged from 0.9 to 2.2 s. Among them, the T1 of glutathione, scyllo-inositol, taurine, phosphorylethanolamine, and N-acetylaspartylglutamate were determined for the first time in the human brain. Significant differences in T1 between white matter and gray matter were found for water (-28%), total choline (-14%), N-acetylaspartylglutamate (-29%), N-acetylaspartate (+4%), and glutamate (+8%). An increasing trend in T1 was observed when compared with previously reported values of N-acetylaspartate (CH3 ), total creatine (CH3 ), and total choline at 3 T. However, for N-acetylaspartate (CH3 ), total creatine, and total choline, no substantial differences compared to previously reported values at 9.4 T were discernible. The T1 values reported here will be useful for the quantification of metabolites and signal-to-noise optimization in human brain at 7 T. Magn Reson Med 69:931-936, 2013. © 2012 Wiley Periodicals, Inc.
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BACKGROUND: To determine the outcome of patients with brain metastasis (BM) from lung cancer treated with an external beam radiotherapy boost (RTB) after whole brain radiotherapy (WBRT). METHODS: A total of 53 BM patients with lung cancer were treated sequentially with WBRT and RTB between 1996 and 2008 according to our institutional protocol. Mean age was 58.8 years. The median KPS was 90. Median recursive partitioning analysis (RPA) and graded prognostic assessment (GPA) grouping were 2 and 2.5, respectively. Surgery was performed on 38 (71%) patients. The median number of BM was 1 (range, 1-3). Median WBRT and RTB combined dose was 39 Gy (range, 37.5-54). Median follow-up was 12.0 months. RESULTS: During the period of follow-up, 37 (70%) patients died. The median overall survival (OS) was 14.5 months. Only 13 patients failed in the brain. The majority of patients (n = 29) failed distantly. The 1-year OS, -local control, extracranial failure rates were 61.2%, 75.2% and 60.8%, respectively. On univariate analysis, improved OS was found to be significantly associated with total dose (< or = 39 Gy vs. > 39 Gy; p < 0.01), age < 65 (p < 0.01), absence of extracranial metastasis (p < 0.01), GPA > or = 2.5 (p = 0.01), KPS > or = 90 (p = 0.01), and RPA < 2 (p = 0.04). On multivariate analysis, total dose (p < 0.01) and the absence of extracranial metastasis (p = 0.03) retained statistical significance. CONCLUSIONS: The majority of lung cancer patients treated with WBRT and RTB progressed extracranially. There might be a subgroup of younger patients with good performance status and no extracranial disease who may benefit from dose escalation after WBRT to the metastatic site.
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Lithium is widely used in psychotherapy. The (6)Li isotope has a long intrinsic longitudinal relaxation time T(1) on the order of minutes, making it an ideal candidate for hyperpolarization experiments. In the present study we demonstrated that lithium-6 can be readily hyperpolarized within 30 min, while retaining a long polarization decay time on the order of a minute. We used the intrinsically long relaxation time for the detection of 500 nM contrast agent in vitro. Hyperpolarized lithium-6 was administered to the rat and its signal retained a decay time on the order of 70 sec in vivo. Localization experiments imply that the lithium signal originated from within the brain and that it was detectable up to 5 min after administration. We conclude that the detection of submicromolar contrast agents using hyperpolarized NMR nuclei such as (6)Li may provide a novel avenue for molecular imaging.
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INTRODUCTION: Current literature suggesting a higher bleeding risk during combination therapy compared to oral anticoagulation alone is primarily based on retrospective studies or specific populations. We aimed to prospectively evaluate whether unselected medical patients on oral anticoagulation have an increased risk of bleeding when on concomitant antiplatelet therapy. MATERIAL AND METHODS: We prospectively studied consecutive adult medical patients who were discharged on oral anticoagulants between 01/2008 and 03/2009 from a Swiss university hospital. The primary outcome was the time to a first major bleed on oral anticoagulation within 12months, adjusted for age, international normalized ratio target, number of medications, and history of myocardial infarction and major bleeding. RESULTS: Among the 515 included anticoagulated patients, the incidence rate of a first major bleed was 8.2 per 100 patient-years. Overall, 161 patients (31.3%) were on both anticoagulant and antiplatelet therapy, and these patients had a similar incidence rate of major bleeding compared to patients on oral anticoagulation alone (7.6 vs. 8.4 per 100 patient-years, P=0.81). In a multivariate analysis, the association of concomitant antiplatelet therapy with the risk of major bleeding was not statistically significant (hazard ratio 0.89, 95% confidence interval, 0.37-2.10). CONCLUSIONS: The risk of bleeding in patients receiving oral anticoagulants combined with antiplatelet therapy was similar to patients receiving oral anticoagulants alone, suggesting that the incremental bleeding risk of combination therapy might not be clinically significant.
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BACKGROUND: To determine male outpatient attenders' sexual behaviours, expectations and experience of talking about their sexuality and sexual health needs with a doctor. METHODS: A survey was conducted among all male patients aged 18-70, recruited from the two main medical outpatient clinics in Lausanne, Switzerland, in 2005-2006. The anonymous self-administered questionnaire included questions on sexual behaviour, HIV/STI information needs, expectations and experiences regarding discussion of sexual matters with a doctor. RESULTS: The response rate was 53.0% (N = 1452). The mean age was 37.7 years. Overall, 13.4% of patients were defined as at STI risk--i.e. having not consistently used condoms with casual partners in the last 6 months, or with a paid partner during the last intercourse--regarding their sexual behaviour in the last year. 90.9% would have liked their physician to ask them questions concerning their sexual life; only 61.4% had ever had such a discussion. The multivariate analysis showed that patients at risk tended to have the following characteristics: recruited from the HIV testing clinic, lived alone, declared no religion, had a low level of education, felt uninformed about HIV/AIDS, were younger, had had concurrent sexual partners in the last 12 months. However they were not more likely to have discussed sexual matters with their doctor than patients not at risk. CONCLUSION: Recording the sexual history and advice on the prevention of the risks of STI should become routine practice for primary health care doctors.
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AIM: The specific natural history of superficial soft tissue sarcomas (S-STS) has been rarely considered. We describe the clinical characteristics of a large series of S-STS (N=367) from the French Sarcoma Group (GSF-GETO) database and analyse the prognostic factors affecting outcome. METHODS: We performed univariate and multivariate analyses for overall survival (OS), metastasis-free survival (MFS) and local recurrence-free survival (LRFS). RESULTS: The median age was 59 years. Fifty-eight percent patients were female. Tumour locations were as follows: extremities, 55%; trunk wall, 35.4%; head and neck, 8% and unknown, 1.6%. Median tumour size was 3.0 cm. The most frequent tumour types were unclassified sarcoma (24.3%) and leiomyosarcoma (22.3%). Thirty-three percent of cases were grade 3. Median follow-up was 6.18 years. The 5-year OS, MFS and LRFS rates were 80.9%, 80.7% and 74.7%, respectively. Multivariate analysis retained histological type and wide resection for predicting LRFS and histological type and grade as prognostic factors of MFS. The factors influencing OS were age, histological type, grade and wide resection. STS with early invasion into but not through the underlying fascia had a significantly poorer MFS than with strict S-STS. CONCLUSION: S-STS represent a separate category characterised by a better outcome. Adequate surgery, i.e. wide resection, is essential in the management of S-STS.
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BACKGROUND: Cytomegalovirus (CMV) retinitis is a major cause of visual impairment and blindness among patients with uncontrolled HIV infections. Whereas polymorphisms in interferon-lambda 3 (IFNL3, previously named IL28B) strongly influence the clinical course of hepatitis C, few studies examined the role of such polymorphisms in infections due to viruses other than hepatitis C virus. OBJECTIVES: To analyze the association of newly identified IFNL3/4 variant rs368234815 with susceptibility to CMV-associated retinitis in a cohort of HIV-infected patients. DESIGN AND METHODS: This retrospective longitudinal study included 4884 white patients from the Swiss HIV Cohort Study, among whom 1134 were at risk to develop CMV retinitis (CD4 nadir <100 /μl and positive CMV serology). The association of CMV-associated retinitis with rs368234815 was assessed by cumulative incidence curves and multivariate Cox regression models, using the estimated date of HIV infection as a starting point, with censoring at death and/or lost follow-up. RESULTS: A total of 40 individuals among 1134 patients at risk developed CMV retinitis. The minor allele of rs368234815 was associated with a higher risk of CMV retinitis (log-rank test P = 0.007, recessive mode of inheritance). The association was still significant in a multivariate Cox regression model (hazard ratio 2.31, 95% confidence interval 1.09-4.92, P = 0.03), after adjustment for CD4 nadir and slope, HAART and HIV-risk groups. CONCLUSION: We reported for the first time an association between an IFNL3/4 polymorphism and susceptibility to AIDS-related CMV retinitis. IFNL3/4 may influence immunity against viruses other than HCV.
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CONTEXT: Recent magnetic resonance imaging studies have attempted to relate volumetric brain measurements in early schizophrenia to clinical and functional outcome some years later. These studies have generally been negative, perhaps because gray and white matter volumes inaccurately assess the underlying dysfunction that might be predictive of outcome. OBJECTIVE: To investigate the predictive value of frontal and temporal spectroscopy measures for outcome in patients with first-episode psychoses. DESIGN: Left prefrontal cortex and left mediotemporal lobe voxels were assessed using proton magnetic resonance spectroscopy to provide the ratio of N-acetylaspartate (NAA) and choline-containing compounds to creatine and phosphocreatine (Cr) (NAA/Cr ratio). These data were used to predict outcome at 18 months after admission, as assessed by a systematic medical record audit. SETTING: Early psychosis clinic. PARTICIPANTS: Forty-six patients with first-episode psychosis. MAIN OUTCOME MEASURES: We used regression models that included age at imaging and duration of untreated psychosis to predict outcome scores on the Global Assessment of Functioning Scale, Clinical Global Impression scales, and Social and Occupational Functional Assessment Scale, as well as the number of admissions during the treatment period. We then further considered the contributions of premorbid function and baseline level of negative symptoms. RESULTS: The only spectroscopic predictor of outcome was the NAA/Cr ratio in the prefrontal cortex. Low scores on this variable were related to poorer outcome on all measures. In addition, the frontal NAA/Cr ratio explained 17% to 30% of the variance in outcome. CONCLUSIONS: Prefrontal neuronal dysfunction is an inconsistent feature of early psychosis; rather, it is an early marker of poor prognosis across the first years of illness. The extent to which this can be used to guide treatment and whether it predicts outcome some years after first presentation are questions for further research.
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The treatments for ischemic stroke can only be administered in a narrow time-window. However, the ischemia onset time is unknown in ~30% of stroke patients (wake-up strokes). The objective of this study was to determine whether MR spectra of ischemic brains might allow the precise estimation of cerebral ischemia onset time. We modeled ischemic stroke in male ICR-CD1 mice using a permanent middle cerebral artery filament occlusion model with laser Doppler control of the regional cerebral blood flow. Mice were then subjected to repeated MRS measurements of ipsilateral striatum at 14.1 T. A striking initial increase in γ-aminobutyric acid (GABA) and no increase in glutamine were observed. A steady decline was observed for taurine (Tau), N-acetyl-aspartate (NAA) and similarly for the sum of NAA+Tau+glutamate that mimicked an exponential function. The estimation of the time of onset of permanent ischemia within 6 hours in a blinded experiment with mice showed an accuracy of 33±10 minutes. A plot of GABA, Tau, and neuronal marker concentrations against the ratio of acetate/NAA allowed precise separation of mice whose ischemia onset lay within arbitrarily chosen time-windows. We conclude that (1)H-MRS has the potential to detect the clinically relevant time of onset of ischemic stroke.