995 resultados para Multivariate association
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Objective and study design: A case-control study was conducted on 42 Brazilian women presenting with human papilloma virus (HPV) infection and cervical lesion and 87 HPV-negative women to evaluate single nucleotide polymorphisms observed in TNF-alpha, TGF-beta, IL-10, IL-6, and IFN-gamma genes. Results and conclusion: No significant association was observed on the cytokine polymorphisms analyzed in this series. Larger studies using cytokine polymorphisms may be useful for providing further information regarding their influence or not in HPV-related cervical lesions. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
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In this paper, we propose a method based on association rule-mining to enhance the diagnosis of medical images (mammograms). It combines low-level features automatically extracted from images and high-level knowledge from specialists to search for patterns. Our method analyzes medical images and automatically generates suggestions of diagnoses employing mining of association rules. The suggestions of diagnosis are used to accelerate the image analysis performed by specialists as well as to provide them an alternative to work on. The proposed method uses two new algorithms, PreSAGe and HiCARe. The PreSAGe algorithm combines, in a single step, feature selection and discretization, and reduces the mining complexity. Experiments performed on PreSAGe show that this algorithm is highly suitable to perform feature selection and discretization in medical images. HiCARe is a new associative classifier. The HiCARe algorithm has an important property that makes it unique: it assigns multiple keywords per image to suggest a diagnosis with high values of accuracy. Our method was applied to real datasets, and the results show high sensitivity (up to 95%) and accuracy (up to 92%), allowing us to claim that the use of association rules is a powerful means to assist in the diagnosing task.
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Methods: We assessed the outcome of 56 patients with Chagas` cardiomyopathy ([31 men]; mean age of 55 years; mean left ventricular ejection fraction [LVEF] 42%) presenting with either sustained ventricular tachycardia (VT) or nonsustained VT (NSVT), before therapy with implantable cardioverter-defibrillator was available at our center. Results: Over a mean follow-up of 38 +/- 16 months (range, 1-61 months), 16 patients (29%) died, 11 due to sudden cardiac death (SCD), and five from progressive heart failure. Survivors and nonsurvivors had comparable baseline characteristics, except for a lower LVEF (46 +/- 7% vs 31 +/- 9%, P < 0.001) and a higher New York Heart Association class (P = 0.003) in those who died during follow-up. Receiver-operator characteristic curve analysis showed that an LVEF cutoff value of 38% had the best accuracy for predicting all-cause mortality and an LVEF cutoff value of 40% had the best accuracy for prediction of SCD. Using the multivariate Cox regression analysis, LVEF < 40% was the only predictor of all-cause mortality (hazard ratio [HR] 12.22, 95% confidence interval [CI] 3.46-43.17, P = 0.0001) and SCD (HR 6.58, 95% CI 1.74-24.88, P = 0.005). Conclusions: Patients with Chagas` cardiomyopathy presenting with either sustained VT or NSVT run a major risk for mortality when had concomitant severe or even moderate LV systolic dysfunction. (PACE 2011; 54-62).
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OBJECTIVE-This study sought to investigate an association of HbA1c (A1C) with incident heart failure among individuals without diabetes and compare it to fasting glucose. RESEARCH DESIGN AND METHODS-We studied 11,057 participants of the Atherosclerosis Risk in Communities (ARIC) Study without heart failure or diabetes at baseline and estimated hazard ratios of incident heart failure by categories of A1C (<5.0, 5.0-5.4 [reference], 5 5-59, and 6.0-6.4%) and fasting glucose (<90, 90-99 [reference], 100-109, and 110-125 mg/dl) using Cox proportional hazards models. RESULTS-A total of 841 cases of incident heart failure hospitalization or deaths (International Classification of Disease, 9th/10th Revision, 428/150) occurred during a median follow-up of 14.1 years (incidence rate 5.7 per 1,000 person-years). After the adjustment for covariates including fasting glucose, the hazard ratio of incident heart failure was higher in individuals with A1C 6.0-6.4% (1.40 [95% CI, 1 09-1.79]) and 5.5-6.0% (1.16 [0.98-1 37]) as compared with the reference group. Similar results were observed when adjusting for insulin level or limiting to heart failure cases without preceding coronary events or developed diabetes during follow-up. In contrast, elevated fasting glucose was not associated with heart failure after adjustment for covariates and A1C. Similar findings were observed when the top quartile (A1C, 5.7-6.4%, and fasting glucose, 108-125 mg/dl) was compared with the lowest quartile (<5 2% and <95 mg/dl, respectively). CONCLUSIONS-Elevated A1C (>= 5.5-6 0%) was associated with incident heart failure in a middle-aged population without diabetes, suggesting that chronic hyperglycemia prior to the development of diabetes contributes to development of heart failure. Diabetes 59:2020-2026, 2010
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The aim of this study was to describe the status of oxidative stress and antioxidant biomarkers and their association with metabolic and body composition components of HIV-lipodystrophy syndrome. In a cross-sectional study of blood samples from HIV-infected men with lipodystrophy syndrome (HIV+LIPO+ = 10), HIV-infected men without lipodystrophy syndrome (HIV+LIPO- = 22), and healthy subjects (control = 12), the following oxidative stress biomarkers were analyzed: total hydroperoxide, thiobarbituric acid reactive substances (TBARS), and advanced oxidation protein products (AOPP). In addition, antioxidant biomarkers, including total glutathione, uric acid, alpha-tocopherol, and metabolic components were tested. Dual-energy x-ray absorciometry (DXA) was used to measure the fat mass. The duration of HIV infection and the duration and type of highly active antiretroviral therapy were similar between the two HIV-infected groups. Higher levels of total hydroperoxide were observed in the HIV+LIPO+ (50 +/- 33 H(2)O(2)/L) group compared to the HIV+LIPO-(19 +/- 13 H(2)O(2)/L) and control (5 +/- 5 H(2)O(2)/L) groups (p < 0.05). Similarly, higher levels of AOPP were observed in the HIV+LIPO+ (326 +/- 173 mu mol/L) group compared to the HIV+LIPO- (105 +/- 92 mu mol/L) and control groups (80 +/- 20 mu mol/L) (p < 0.05). Total hydroperoxide significantly correlated with insulin serum levels in the HIV+LIPO+ (r = 0.47, p < 0.05) and HIV+LIPO- groups (r = 0.29, p < 0.05), while AOPP significantly correlated with insulin serum levels in the HIV+LIPO+ (r = 0.73, p < 0.05) and HIV+LIPO- (r = 0.54, p < 0.05) groups. Therefore, higher lipid and protein oxidation were found in HIV-infected patients with lipodystrophy syndrome, and both were associated with insulin levels.
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Activation of the immune response in hantavirus cardiopulmonary syndrome (HCPS) leads to a high TNF production, probably contributing to the disease. The polymorphic TNF2 allele (TNF -308G/A) has been associated with increased cytokine production. We investigated the association of the TNF2 allele with the outcome of hantavirus infection in Brazilian patients. A total of 122 hantavirus-exposed individuals (26 presenting HCPS and 96 only hantavirus seroconversion) were studied. The TNF2 allele was more frequently found in HCPS patients than in individuals with positive serology for hantavirus but without a history of HCPS illness, suggesting that the TNF2 allele could represent a risk factor for developing HCPS.
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Objective: To investigate the association of different types of magnetic resonance imaging (MRI)-detected medial meniscal pathology with subregional cartilage loss in the medial tibiofemoral compartment. Methods: A total of 152 women aged >= 40 years, with and without knee osteoarthritis (OA) were included in a longitudinal 24-month observational study. Spoiled gradient recalled acquisitions at steady state (SPGR) and T2-weighted fat-suppressed MRI sequences were acquired. Medial meniscal status of the anterior horn (AH), body, and posterior horn (PH) was graded at baseline: 0 (normal), 1 (intrasubstance meniscal signal changes), 2 (single tears), and 3 (complex tears/maceration). Cartilage segmentation was performed at baseline and 24-month follow-up in various tibiofemoral subregions using computation software. Multiple linear regression models were applied for the analysis with cartilage loss as the outcome. In a first model, the results were adjusted for age and body mass index (BMI). In a second model, the results were adjusted for age, BMI and medial meniscal extrusion. Results: After adjusting for age, BMI, and medial meniscal extrusion, cartilage loss in the total medial tibia (MT) (0.04 mm, P=0.04) and the external medial tibia (eMT) (0.068 mm, P=0.04) increased significantly for compartments with grade 3 lesions. Cartilage loss in the total central medial femoral condyle (cMF) (0.071 mm, P=0.03) also increased significantly for compartments with grade 2 lesions. Cartilage loss at the eMT was significantly related to tears of the PH (0.074 mm; P=0.03). Cartilage loss was not significantly increased for compartments with grade 1 lesions. Conclusion: The protective function of the meniscus appears to be preserved in the presence of intrasubstance meniscal signal changes. Prevalent single tears and meniscal maceration were found to be associated with increased cartilage loss in the same compartment, especially at the PH. (C) 2009 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.
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Epidermal growth factor (EGF) plays an important role in cancer. A functional single nucleotide polymorphism (SNP) in the 5`-untranslated region of the EGF gene (+61 A>G) may influence its expression and contribute to cancer predisposition and aggressiveness. Aiming to investigate the role of EGF +61 A>G in the susceptibility to glioma and its prognosis, we performed a case-control study with 165 patients and 200 healthy controls from Brazil. Comparisons of genotype distributions and allele frequencies did not reveal any significant differences between the groups. The mean overall survival was 9.2 months for A/A, 8.2 months for A/G, and 7.7 months for GIG. When survival curves were plotted we found that the +61G allele is associated with poor overall survival (p=0.023) but not with disease-free survival (p=0.527). Our data suggest that, although there is no association between the EGF +61 A>G genotype and glioma susceptibility, this SNP is associated with shorter overall survival of glioma patients in the Brazilian population. Nevertheless, future studies utilizing a larger series are essential for a definitive conclusion. (Int J Biol Markers 2009; 24: 277-81)
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Background: Recent studies have suggested that impaired nitric oxide (NO) formation in preeclampsia may result from increased concentrations of an endogenous NO synthase inhibitor, the asymmetric dimethylarginine (ADMA). However, no previous study has examined whether a negative association exists between ADMA and nitrite concentrations in preeclampsia. Moreover, no previous study has compared ADMA and nitrite levels in black and white preeclamptic pregnant women. Methods: We measured plasma nitrite concentrations using an ozone-based chemiluminescence assay, and plasma ADMA levels using enzyme immunoassays in 94 pregnant (47 healthy pregnant: 16 blacks and 31 whites; and 47 preeclamptic: 14 blacks and 33 whites). Results: We found higher ADMA (2.199 +/- 0.016 mu mol/l vs. 2.112 +/- 0.012 mu mol/l; P < 0.0001) and lower plasma nitrite levels (102 +/- 7.1 nmol/l vs. 214.8 +/- 26.1 nmol/l; P<0.0001) in preeclamptic compared with healthy pregnant women. Black pregnant had higher ADMA levels than white pregnant women (P<0.05), both in preeclamptic (2.239 +/- 0.020 mu mol/l vs. 2.144 +/- 0.019 mu mol/l) and in healthy pregnant (2.172 +/- 0.025 mu mol/l vs. 2.077 +/- 0.018 mu mol/l). Conversely, we found no significant effects of ethnicity on the plasma nitrite levels, both in healthy pregnant and in preeclamptic women (P>0.05). We found a significant negative correlation (P<0.05) between these markers (r = 0.28; P<0.05). Conclusions: Our findings show higher ADMA and lower nitrite levels in preeclamptic compared with healthy pregnant, and the concentrations of these biomarkers are inversely associated. While ethnicity affected ADMA concentrations, no such effect was found with respect to nitrite levels. These results may have important implications for studies on NO biology and therapeutic approaches of preeclampsia. (C) 2010 Elsevier B.V. All rights reserved.
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SETTING: Five medical schools in three cities in Rio de Janeiro State, Brazil, with different tuberculosis (TB) incidence rates. OBJECTIVE: To evaluate the prevalence of the booster phenomenon and its associated factors in a voting universally BCG-vaccinated TB-exposed population. DESIGN: A two-step tuberculin skin test (TST) was performed among undergraduate medical students. Boosting was defined as an induration >= 10 mm in the second TST (TST2), with an increase of at least 6 mm over the first TST (TST1). The association of boosting with independent variables was evaluated using multivariate analysis. RESULTS: Of the 764 participants (mean age 21.9 +/- 2.7 years), 672 (87.9%) had a BCG scar. The overall booster SUMMARY phenomenon prevalence was 8.4% (95%CI 6.5-10.6). Boosting was associated with TST1 reactions of 1-9 mm (aOR 2.5, 95%CI 1.04-5.9) and with BCG vaccination, mostly after infancy, i.e., after age two years (aOR 9.1, 95%,CI 1.2-70.7). CONCLUSION: The prevalence of the booster phenomenon was high. A two-step TST in young BCG-vaccinated populations, especially in those with TST1 reactions of 1-9 mm, can avoid misdiagnosis as a false conversion and potentially reduce unnecessary treatment for latent TB infection.
Temporomandibular Disorders Are Differentially Associated With Headache Diagnoses A Controlled Study
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Objectives: Temporomandibular disorders (TMDs) are considered to be comorbid with headaches. Earlier population studies have suggested that TMD may also be a risk factor for migraine progression. If that is true, TMD should be associated with specific headache syndromes (eg, migraine and chronic migraine), but not with headaches overall. Accordingly, our aim was to explore the relationship between TMD subtypes and severity with primary headaches in a controlled clinical study. Methods: The sample consisted of 300 individuals. TMDs were assessed using the Research Diagnostic Criteria for TMD, and primary headache was classified according to International Classification for Headache Disorders-2. Univariate and multivariate models assessed headache diagnoses and frequency as a function of the parameters of TMD. Results: Relative to those without TMD, individuals with myofascial TMD were significantly more likely to have chronic daily headaches (CDHs) [ relative risk (RR) = 7.8; 95% confidence interval (CI), 3.1-19.6], migraine (RR = 4.4; 95% CI, 1.7-11.7), and episodic tension-type headache (RR = 4.4; 95% CI, 1.5-12.6). Grade of TMD pain was associated with increased odds of CDH (P < 0.0001), migraine (P < 0.0001), and episodic tension-type headache (P < 0.05). TMD severity was also associated with headache frequency. In multivariate analyses, TMD was associated with migraine and CDH (P = 0.001). Painful TMD (P = 0.0034) and grade of TMD pain (P < 0.001) were associated with headache frequency. Discussion: TMD, TMD subtypes, and TMD severity are independently associated with specific headache syndromes and with headache frequency. This differential association suggests that the presence of central facilitation of nociceptive inputs may be of importance, as positive association was observed only when muscular TMD pain was involved.
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Until recently, neuromyelitis optica (NMO) was considered to be a sub-type of multiple sclerosis (MS), which has a strong predilection for Caucasian populations, whereas NMO is more frequent in non-Caucasian individuals. The objective of this study was to compare the HLA-DRB profile in Brazilian Mulatto patients with NMO spectrum disorders (NMOSDs) with that observed for Mulatto MS patients and healthy Mulatto controls. Twenty seven NMOSD patients (20 women), all seropositive for NMO-IgG, 29 MS patients and 28 Mulatto healthy blood donors were evaluated for HLA-DRB allele groups. HLA-DRB1*03 allele group was overrepresented in NMO patients compared with healthy controls (p = 0.0401; OR = 3.23, 95% CI: 1.07-9.82). In contrast, the HLA-DRB1*15 allele group was overrepresented in Brazilian MS patients (OR = 15.89, 95% CI: 3.51-71.85; p<0.0001). DRB3 was overrepresented in NMO (p = 0.0064), and DRB5 overrepresented in MS patients (p = 0.0001). The low frequency of HLA-DRB1*15 alleles was associated with the presence of long and central cord lesions at magnetic resonance. In addition, DRB1*15 alleles were associated with the fulfillment of the Barkhof criteria. In conclusion, these results indicate that the DRB profile of NMO patients is different from that observed for MS patients, further corroborating the distinction between NMO and MS.
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Association between insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) has been reported. This prompted us to evaluate the power of the insulin sensitivity index (ISI) in association with IGFBP-1 to identify IR early in obese children/adolescents. OGTT was performed in 34 obese/overweight children/adolescents. Glucose, insulin and IGFBP-1 were measured in serum samples and ISI was calculated. Considering the presence of three or more risk factors for IR as a criterion for IR, ISI <4.6 showed 87.5% sensitivity and 94.5% specificity in diagnosing IR. IGFBP-1 was lower in the group with ISI <4.6 (p <0.01). In this group, three patients had higher than expected IGFBP-1, suggesting hepatic IR, while three patients with ISI >4.6 showed very low IGFBP-1 levels. Conclusion: ISI <4.6 is a good indicator of early peripheral IR and, associated with IGFBP-1, can identify increased risk of hepatic IR. Low IGFBP-1 levels among non-IR children may indicate increased portal insulin levels.
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More than 30% of the patients on peritoneal dialysis show chronic systemic inflammatory activity with high levels of C-reactive protein. The purpose of this cross-sectional study was to investigate the influence of the inflammatory state on clinical and nutritional markers in patients on peritoneal dialysis. Twenty-seven patients were included: mean age was 57.6 +/- 19 years, 48% were male, and median time on peritoneal dialysis was 16.0 (8.3; 35.8) months. Clinical, dialytic, laboratory, anthropometric and electric bioimpedance data were collected with the sample stratified for C-reactive protein. In patients, the levels of Interleukin-6 and tumor necrosis factor-a were higher, while adiponectin levels were lower than in healthy individuals (p <= 0.001), indicating the presence of inflammatory activity in the sample. When compared to patients with C-reactive protein < 1 mg/dL, those with = 1mg/dL showed higher body mass index (29.4 +/- 6.1 vs. 24.4 +/- 4.5 kg/m(2); p = 0.009), percent of standard body weight (124.5 +/- 25.4 vs. 106.8 +/- 17.9 %; p = 0.012), and percent of body fat as assessed by both anthropometry (31.3 +/- 9.9 vs. 23.9 +/- 9.1%; p = 0.056) and bioimpedance (38.9 +/- 6.3 vs. 26.2 +/- 12.6 %; p < 0.001). Patients with C-reactive protein = 1mg/dL also exhibited higher levels of ferritin (701 +/- 568 vs. 532 +/- 356 ng/mL; p = 0.054) and lower total lymphocyte count (median 1838 vs. 1638 mm(3); p = 0.001). In conclusion, higher body mass index and body fat markers were associated with C-reactive protein = 1mg/dL, and higher C-reactive protein was associated with immunocompetence impairment evidenced by the lower total lymphocyte count. Our findings confirm the relationship between inflammation, body fat, and immunocompetence, which may be superimposed potentializing the inflammatory status.