950 resultados para Increasing hazard ratio
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OBJECTIVE. The purpose of the study was to investigate patient characteristics associated with image quality and their impact on the diagnostic accuracy of MDCT for the detection of coronary artery stenosis. MATERIALS AND METHODS. Two hundred ninety-one patients with a coronary artery calcification (CAC) score of <= 600 Agatston units (214 men and 77 women; mean age, 59.3 +/- 10.0 years [SD]) were analyzed. An overall image quality score was derived using an ordinal scale. The accuracy of quantitative MDCT to detect significant (>= 50%) stenoses was assessed using quantitative coronary angiography (QCA) per patient and per vessel using a modified 19-segment model. The effect of CAC, obesity, heart rate, and heart rate variability on image quality and accuracy were evaluated by multiple logistic regression. Image quality and accuracy were further analyzed in subgroups of significant predictor variables. Diagnostic analysis was determined for image quality strata using receiver operating characteristic (ROC) curves. RESULTS. Increasing body mass index (BMI) (odds ratio [OR] = 0.89, p < 0.001), increasing heart rate (OR = 0.90, p < 0.001), and the presence of breathing artifact (OR = 4.97, p = 0.001) were associated with poorer image quality whereas sex, CAC score, and heart rate variability were not. Compared with examinations of white patients, studies of black patients had significantly poorer image quality (OR = 0.58, p = 0.04). At a vessel level, CAC score (10 Agatston units) (OR = 1.03, p = 0.012) and patient age (OR = 1.02, p = 0.04) were significantly associated with the diagnostic accuracy of quantitative MDCT compared with QCA. A trend was observed in differences in the areas under the ROC curves across image quality strata at the vessel level (p = 0.08). CONCLUSION. Image quality is significantly associated with patient ethnicity, BMI, mean scan heart rate, and the presence of breathing artifact but not with CAC score at a patient level. At a vessel level, CAC score and age were associated with reduced diagnostic accuracy.
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Objectives This prospective study evaluated the association of obesity and hypertension with left atrial (LA) volume over 10 years. Background Although left atrial enlargement (LAE) is an independent risk factor for atrial fibrillation, stroke, and death, little information is available about determinants of LA size in the general population. Methods Participants (1,212 men and women, age 25 to 74 years) originated from a sex-and age-stratified random sample of German residents of the Augsburg area (MONICA S3). Left atrial volume was determined by standardized echocardiography at baseline and again after 10 years. Left atrial volume was indexed to body height (iLA). Left atrial enlargement was defined as iLA >= 35.7 and >= 33.7 ml/m in men and women, respectively. Results At baseline, the prevalence of LAE was 9.8%. Both obesity and hypertension were independent predictors of LAE, obesity (odds ratio [OR]: 2.4; p < 0.001) being numerically stronger than hypertension (OR: 2.2; p < 0.001). Adjusted mean values for iLA were significantly lower in normal-weight hypertensive patients (25.4 ml/m) than in obese normotensive individuals (27.3 ml/m; p = 0.016). The highest iLA was found in the obese hypertensive subgroup (30.0 ml/m; p < 0.001 vs. all other groups). This group also presented with the highest increase in iLA (+6.0 ml/m) and the highest incidence (31.6%) of LAE upon follow-up. Conclusions In the general population, obesity appears to be the most important risk factor for LAE. Given the increasing prevalence of obesity, early interventions, especially in young obese individuals, are essential to prevent premature onset of cardiac remodeling at the atrial level. (J Am Coll Cardiol 2009; 54: 1982-9) (C) 2009 by the American College of Cardiology Foundation
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PURPOSE. To assess whether baseline Glaucoma Probability Score (GPS; HRT-3; Heidelberg Engineering, Dossenheim, Germany) results are predictive of progression in patients with suspected glaucoma. The GPS is a new feature of the confocal scanning laser ophthalmoscope that generates an operator-independent, three-dimensional model of the optic nerve head and gives a score for the probability that this model is consistent with glaucomatous damage. METHODS. The study included 223 patients with suspected glaucoma during an average follow-up of 63.3 months. Included subjects had a suspect optic disc appearance and/or elevated intraocular pressure, but normal visual fields. Conversion was defined as development of either repeatable abnormal visual fields or glaucomatous deterioration in the appearance of the optic disc during the study period. The association between baseline GPS and conversion was investigated by Cox regression models. RESULTS. Fifty-four (24.2%) eyes converted. In multivariate models, both higher values of GPS global and subjective stereophotograph assessment ( larger cup-disc ratio and glaucomatous grading) were predictive of conversion: adjusted hazard ratios (95% CI): 1.31 (1.15 - 1.50) per 0.1 higher global GPS, 1.34 (1.12 - 1.62) per 0.1 higher CDR, and 2.34 (1.22 - 4.47) for abnormal grading, respectively. No significant differences ( P > 0.05 for all comparisons) were found between the c-index values ( equivalent to area under ROC curve) for the multivariate models (0.732, 0.705, and 0.699, respectively). CONCLUSIONS. GPS values were predictive of conversion in our population of patients with suspected glaucoma. Further, they performed as well as subjective assessment of the optic disc. These results suggest that GPS could potentially replace stereophotograph as a tool for estimating the likelihood of conversion to glaucoma.
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OBJECTIVE-Uncoupling protein 2 (UCP2) is a physiological downregulator of reactive oxygen species generation and plays an antiatherogenic role in the vascular wall. A common variant in the UCP2 promoter (-866G>A) modulates mRNA expression, with increased expression associated with the A allele. We investigated association of this variant with coronary artery disease (CAD) in two cohorts of type 2 diabetic subjects. RESEARCH DESIGN AND METHODS-We studied 3,122 subjects from the 6-year prospective Non-Insulin-Dependent Diabetes, Hypertension, Microalbuminuria, Cardiovascular Events, and Ramipril (DIABHYCAR) Study (14.9% of CAD incidence at follow-up). An independent, hospital-based cohort of 335 men, 52% of whom had CAD, was also studied. RESULTS-We observed an inverse association of the A allele with incident cases of CAD in a dominant model (hazard risk 0.88 [95% CI 0.80-0.96]; P = 0.006). Similar results were observed for baseline cases of CAD. Stratification by sex confirmed an allelic association with CAD in men, whereas no association was observed in women. All CAD phenotypes considered-myocardial infarction, angina pectoris, coronary artery bypass graft (CABG), and sudden death-contributed significantly to the association. Results were replicated in a cross-sectional study of an independent cohort (odds ratio 0.47 [95% CI 0.25-0.89]; P = 0.02 for a recessive model). CONCLUSIONS-The A allele of the -866G>A variant of UCP2 was associated with reduced risk of CAD in men with type 2 diabetes in a 6-year prospective study. Decreased risk of myocardial infarction, angina pectoris, CABG, and sudden death contributed individually and significantly to the reduction of CAD risk. This association was independent of other common CAD risk factors.
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In order to qualify and quantify nerve fiber lesion following an acute crush injury, a morphologic and morphometric study was carried out in 25 Wistar rats divided into live groups of five animals each according to the crushing load applied, i.e., 500,1000, 5000, 10 000, and 15 000 g. The injury was produced under general anesthesia on a 5 mm-long intermediate segment of the right sciatic nerve for 10 min using a dead-weight machine. The animals were killed with an excessive dose of anesthetics 72 h later and submitted to perfusion with a fixing solution through the abdominal aorta immediately after death. Both the right and left sciatic nerves were removed and prepared for histologic and morphometric examinations: 5 mu m-thick sections stained with 1% Toluidine blue were examined under a light microscope equipped with a video camera linked to a computer loaded with a graphic program (KS 400). The morphometric studies included measuring total number of fibers, fiber density, fiber diameter, myelin fiber area, axon diameter, axon area and G ratio. The results showed that damage to the nerve fibers began to appear as early as with the 500g load and was similar in all groups despite the load applied, increasing with the 10000 and 15000g loads, although the external supporting tissues and small diameter fibers were preserved. The predominant type of lesion produced was axonotmesis. (c) 2008 Elsevier B.V. All rights reserved.
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In adolescent idiopathic scoliosis (AIS) there has been a shift towards increasing the number of implants and pedicle screws, which has not been proven to improve cosmetic correction. To evaluate if increasing cost of instrumentation correlates with cosmetic correction using clinical photographs. 58 Lenke 1A and B cases from a multicenter AIS database with at least 3 months follow-up of clinical photographs were used for analysis. Cosmetic parameters on PA and forward bending photographs included angular measurements of trunk shift, shoulder balance, rib hump, and ratio measurements of waist line asymmetry. Pre-op and follow-up X-rays were measured for coronal and sagittal deformity parameters. Cost density was calculated by dividing the total cost of instrumentation by the number of vertebrae being fused. Linear regression and spearman`s correlation were used to correlate cost density to X-ray and photo outcomes. Three independent observers verified radiographic and cosmetic parameters for inter/interobserver variability analysis. Average pre-op Cobb angle and instrumented correction were 54A degrees (SD 12.5) and 59% (SD 25) respectively. The average number of vertebrae fused was 10 (SD 1.9). The total cost of spinal instrumentation ranged from $6,769 to $21,274 (Mean $12,662, SD $3,858). There was a weak positive and statistically significant correlation between Cobb angle correction and cost density (r = 0.33, p = 0.01), and no correlation between Cobb angle correction of the uninstrumented lumbar spine and cost density (r = 0.15, p = 0.26). There was no significant correlation between all sagittal X-ray measurements or any of the photo parameters and cost density. There was good to excellent inter/intraobserver variability of all photographic parameters based on the intraclass correlation coefficient (ICC 0.74-0.98). Our method used to measure cosmesis had good to excellent inter/intraobserver variability, and may be an effective tool to objectively assess cosmesis from photographs. Since increasing cost density only improves mildly the Cobb angle correction of the main thoracic curve and not the correction of the uninstrumented spine or any of the cosmetic parameters, one should consider the cost of increasing implant density in Lenke 1A and B curves. In the area of rationalization of health care expenses, this study demonstrates that increasing the number of implants does not improve any relevant cosmetic or radiographic outcomes.
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Imbalance and weakness of the serratus anterior and upper trapezius force couple have been described in patients with shoulder dysfunction. There is interest in identifying exercises that selectively activate these muscles and including it in rehabilitation protocols. This study aims to verify the UT/SA electromyographic (EMG) amplitude ratio, performed in different upper limb exercises and on two bases of support. Twelve healthy men were tested (average age = 22.8 +/- 3.1 years), and surface EMG was recorded from the upper trapezius and serratus anterior using single differential surface electrodes. Volunteers performed isometric contractions over a stable base of support and on a Swiss ball during the wall push-up (WP), bench press (BP), and push-up (PU) exercises. All SEMG data are reported as a percentage of root mean square or integral of linear envelope from the maximal value obtained in one of three maximal voluntary contractions for each muscle studied. A linear mixed-effect model was performed to compare UT/SA ratio values. The WP, BP, and PU exercises showed UT/SA ratio mean +/- SD values of 0.69 +/- 0.72, 0.14 +/- 0.12, and 0.39 +/- 0.37 for stable surfaces, respectively, whereas for unstable surfaces, the values were 0.73 +/- 0.67, 0.43 +/- 0.39, and 0.32 +/- 0.30. The results demonstrate that UT/SA ratio was influenced by the exercises and by the upper limb base of support. The practical application is to show that BP on a stable surface is the exercise preferred over WP and PU on either surfaces for serratus anterior muscle training in patients with imbalance between the UT/SA force couple or serratus anterior weakness.
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Le taux de triacylglycerol (TAG) qui s`accumule dans le tissu adipeux depend de 2 mecanismes opposes : la lipogenese et la lipolyse. Nous avons montre anterieurement que le poids des lipides du tissu adipeux de l`epididyme (EPI) de meme que leur taux augmentent chez les rats en croissance soumis a une diete hypoproteique hyperglucidique (HPHG) pendant 15 jours. La presente etude a eu pour but d`examiner les voies impliquees dans la lipogenese et la lipolyse qui regulent l`accumulation des lipides dans le tissu. On a evalue in vivo la synthese de novo des acides gras, qui s`est revelee similaire chez les rats soumis a la diete HPHG ou a une diete temoin; toutefois, chez les rats soumis a la diete HPHG, une diminution de l`activite de la lipoproteine lipase dans le tissus adipeux de l`EPI a ete observee, ce qui laisse croire a une diminution de la capture des acides gras des lipoproteines circulantes. La diete HPHG n`a eu aucun effet sur la synthese du glycerol-3-phosphate (G3P) par la glycolyse ou la glyceroneogenese. L`activite de la glycerokinase, c.-a-d. la phosphorylation du glycerol issu de l`hydrolyse du TAG endogene pour former le GP3, n`a pas ete modifiee non plus par la diete HPHG. A l`oppose, les adipocytes des rats HPHG stimules par la norepinephrine ont eu une plus faible reponse lipolytique, meme si le taux lipolytique basal des adipocytes a ete similaire chez les 2 groupes. Ainsi, les resultats donnent a penser que la diminution de l`activite lipolytique stimulee par la norepinephrine joue un role essentiel dans l`augmentation du TAG observee dans le tissu adipeux de l`EPI des animaux HPHG, probablement en perturbant le processus d`activation de la lipolyse.
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Adding a long-acting beta(2)-agonist to inhaled corticosteroids (ICS) for asthma treatment is better than increasing ICS dose in improving clinical status, although there is no consensus about the impact of this regimen on inflammation. In this double-blind, randomized, parallel group study, asthmatics with moderate to severe disease used budesonide (400 mcg/day) for 5 weeks (run-in period); then they were randomized to use budesonide (800 mcg/day - BUD group) or budesonide plus formoterol (400 mcg and 24 mcg/day, respectively - FORMO group) for 9 weeks (treatment period). Home PEF measurements, symptom daily reporting, spirometry, sputum induction (for differential cell counts and sputum cell cultures), and hypertonic saline bronchial challenge test were performed before and after treatments. TNF-alpha, IL-4 and eotaxin-2 levels in the sputum and cell culture supernatants were determined. Morning and night PEF values increased in the FORMO group during the treatment period (p < 0.01), from 435 +/- 162 to 489 +/- 169 and 428 +/- 160 to 496 +/- 173 L/min, respectively. The rate of exacerbations in the FORMO group was lower than in the BUD group (p < 0.05). Neutrophil counts in sputum increased in both groups (p < 0.05) and leukocyte viability after 48 h-culture increased in the FORMO group (p < 0.05). No other parameter changed significantly in either group. This study showed that adding formoterol to budesonide improved home PEF and provided protection from exacerbations, although increase of leukocyte viability in cell culture may be a matter of concern and needs further investigation. (C) 2008 Elsevier Ltd. All rights reserved.
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Sepsis results from an overwhelming response to infection and is a major contributor to death in intensive care units worldwide. In recent years, we and others have shown that neutrophil functionality is impaired in sepsis. This correlates with sepsis severity and contributes to aggravation of sepsis by precluding bacterial clearance. Nitric oxide (NO) is a major contributor to the impairment of neutrophil function in sepsis. However, attempts to inhibit NO synthesis in sepsis resulted in increased death despite restoring neutrophil migration. This could be in part attributed to a reduction of the NO-dependent microbicidal activity of neutrophils. In sepsis, the beneficial effects resulting from the inhibition of soluble guanylyl cyclase (sGC), a downstream target of NO, have long been appreciated but poorly understood. However, the effects of sGC inhibition on neutrophil function in sepsis have never been addressed. In the present study, we show that TLR activation in human neutrophils leads to decreased chemotaxis, which correlated with chemotactic receptor internalization and increased G protein-coupled receptor kinase 2 expression, in a process involving the NO-sGC-protein kinase G axis. We also demonstrate that inhibition of sGC activity increased survival in a murine model of sepsis, which was paralleled by restored neutrophil migratory function and increased bacterial clearance. Finally, the beneficial effect of sGC inhibition could also be demonstrated in mice treated after the onset of sepsis. Our results suggest that the beneficial effects of sGC inhibition in sepsis could be at least in part attributed to a recovery of neutrophil functionality.
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Adrenalectomy-induced hypophagia is associated with increased satiety-related responses, which involve neuronal activation of the nucleus of the solitary tract (NTS). Besides its effects on the pituitary-adrenal axis, corticotrophin-releasing factor (CRF) has been shown to play an important role in feeding behaviour, as it possesses anorexigenic effects. We evaluated feeding-induced CRF mRNA expression in the paraventricular nucleus (PVN) and the effects of pretreatment with CRF(2) receptor antagonist (Antisauvagine-30, AS30) on food intake and activation of NTS neurons in response to feeding in adrenalectomised (ADX) rats. Compared to the sham group, ADX increased CRF mRNA levels in the PVN of fasted animals, which was further augmented by refeeding. AS30 treatment did not affect food intake in the sham and ADX + corticosterone (B) groups; however, it reversed hypophagia in the ADX group. In vehicle-pretreated animals, refeeding increased the number of Fos and Fos/TH-immunoreactive neurons in the NTS in the sham, ADX and ADX + B groups, with the highest number of neurons in the ADX animals. Similarly to its effect on food intake, pretreatment with AS30 in the ADX group also reversed the increased activation of NTS neurons induced by refeeding while having no effect in the sham and ADX + B animals. The present results show that adrenalectomy induces an increase in CRF mRNA expression in the PVN potentiated by feeding and that CRF(2) receptor antagonist abolishes the anorexigenic effect and the increased activation of NTS induced by feeding in the ADX animals. These data indicate that increased activity of PVN CRF neurons modulates brainstem satiety-related responses, contributing to hypophagia after adrenalectomy. (C) 2010 Elsevier Inc. All rights reserved.
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MRI is an important tool for investigating breast cancer. Although recognized as the method of choice for screening highrisk patients, and for other indications the role of MRI for lesion characterization remains controversial. Recently some authors have advocated the use of morphologic and postcontrast features for this purpose. Quantitative breast MRI techniques have not been applied extensively in breast diseases. Magnetization transfer (MT) is a quantitative MR technique commonly used to investigate neurological diseases. In breast diseases the use of MT has been limited to improving visualization of areas of enhancement in postcontrast images. The purpose of this study was to evaluate the feasibility and utility of MT in discriminating benign from malignant breast lesions. Fifty-two lesions, Bl-RADS 4 and 5, from 49 patients, were prospectively evaluated using the MT ratio (MTR). Patients were divided into two groups: benign and malignant lesions. The MTR of fat, pectoralis major muscle, fibroglandular tissue, and breast lesions were calculated. A statistically significant difference was found between MTR from benign and malignant lesions (P < 0.001). Preliminary results suggest that MT can be used to evaluate breast lesions. Further studies are necessary to better define the utility and applicability of this technique.
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Historically, the cure rate model has been used for modeling time-to-event data within which a significant proportion of patients are assumed to be cured of illnesses, including breast cancer, non-Hodgkin lymphoma, leukemia, prostate cancer, melanoma, and head and neck cancer. Perhaps the most popular type of cure rate model is the mixture model introduced by Berkson and Gage [1]. In this model, it is assumed that a certain proportion of the patients are cured, in the sense that they do not present the event of interest during a long period of time and can found to be immune to the cause of failure under study. In this paper, we propose a general hazard model which accommodates comprehensive families of cure rate models as particular cases, including the model proposed by Berkson and Gage. The maximum-likelihood-estimation procedure is discussed. A simulation study analyzes the coverage probabilities of the asymptotic confidence intervals for the parameters. A real data set on children exposed to HIV by vertical transmission illustrates the methodology.
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Background: Women are especially vulnerable to HIV infection because of biological, social, cultural, and economic factors. In Brazil, AIDS was initially seen predominantly in homosexual men, but the epidemic gradually reached a gender balance as increasing numbers of women became infected with HIV. Objective: The aim of the present study was to identify the clinical and epidemiologic characteristics of hospitalized patients with HIV/AIDS of both sexes and compare the differences between them. Methods: This epidemiologic cross-sectional study evaluated gender differences in demographic, social, clinical, and epidemiologic characteristics of patients diagnosed with HIV/AIDS who were admitted for any reason to the Public Hospital of the Medical School of the Federal University of Triangulo Mineiro, Uberaba, Minas Gerais State, Brazil. Results: A total of 363 patients were included in the analysis, with a male/female ratio of 1.1:1.0. Forty-one percent of women were pregnant. Mean age at hospitalization and duration of hospitalization were significantly greater among men (P < 0.05). Men and nonpregnant women were admitted because of infection significantly more often than were pregnant women (P < 0.05). Significantly more single men who reported homosexual, bisexual, or heterosexual behavior associated with drug use were admitted compared with women (P < 0.05). Women admitted for treatment were significantly more likely than men to be employed (P < 0.05). Adherence to antiretroviral treatment and T CD4+ lymphocyte count indicated important differences between the sexes, with better parameters observed among nonpregnant and pregnant women compared with men. Conclusions: In the present study, women with HIV/AIDS who were admitted to the hospital for any reason were in better clinical condition compared with men. This observation may be partially explained by the proportion of pregnant women in the study population. These findings suggest that future studies should examine pregnant women with HIV/AIDS as a separate population group to avoid bias in analysis. (Gend Med. 2010;7:28-38) (C) 2010 Excerpta Medica Inc.