992 resultados para Persistence change
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Methods. We studied participants with acute and/or early HIV infection and TDR in 2 cohorts (San Francisco, California, and Sao Paulo, Brazil). We followed baseline mutations longitudinally and compared replacement rates between mutation classes with use of a parametric proportional hazards model. Results. Among 75 individuals with 195 TDR mutations, M184V/I became undetectable markedly faster than did nonnucleoside reverse-transcriptase inhibitor (NNRTI) mutations (hazard ratio, 77.5; 95% confidence interval [CI], 14.7-408.2; P < .0001), while protease inhibitor and NNRTI replacement rates were similar. Higher plasma HIV-1 RNA level predicted faster mutation replacement, but this was not statistically significant (hazard ratio, 1.71 log(10) copies/mL; 95% CI, .90-3.25 log(10) copies/mL; P = .11). We found substantial person-to-person variability in mutation replacement rates not accounted for by viral load or mutation class (P < .0001). Conclusions. The rapid replacement of M184V/I mutations is consistent with known fitness costs. The long-term persistence of NNRTI and protease inhibitor mutations suggests a risk for person-to-person propagation. Host and/or viral factors not accounted for by viral load or mutation class are likely influencing mutation replacement and warrant further study.
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Due to high rates of human papillomavirus (HPV) infection, the incidence of intraepithelial neoplasia and anal cancer, most studies concerning HPV in men seropositive for HIV have focused on the anal canal. Few studies have targeted the penile region in HIV-infected men. A total of 72 men seropositive for HIV and 72 men seronegative for HIV were followed-up for 6 months, and their penile exfoliated cells were tested for HPV DNA. There were no significant differences between the HIV-positive and HIV-negative men in persistence (respectively, 69.5% vs. 66.9%), clearance (respectively, 15.3% vs. 23.1%), and those men never infected with HPV during the four follow-up visits (15.2% for HIV-positive vs. 20% for HIV-negative). High-risk HPV types were detected more frequently in penile smears from men infected with HIV, while, in HIV-seronegative men, the low-risk HPV types were more abundant (P=0.001). Multiple infections with both high- and low-risk HPV types were significantly more frequent in HIV-seropositive compared to those who were HIV-seronegative (P=0.0004). The attendance rates at follow-up visits were 86%, 78%, and 58% in months 1, 2, and 6, respectively, for men infected with HIV and 93%, 72%, and 60% for the HIV-negative group. It is concluded that HIV infection can be considered a risk factor for clearance and persistence of HPV. Multiple infections with different types of HPV including high-risk HPVs are frequent in men who are infected with HIV. J. Med. Virol. 83:127-131, 2011. (C) 2010 Wiley-Liss, Inc.
Beyond the 'war for talent' hype: Occupational and organizational change in the business professions
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PURPOSE. To evaluate and compare rates of change in neuro-retinal rim area (RA) and retinal nerve fiber layer thickness (RNFLT) measurements in glaucoma patients, those with suspected glaucoma, and normal subjects observed over time. METHODS. In this observational cohort study, patients recruited from two longitudinal studies (Diagnostic Innovations in Glaucoma Study-DIGS and African Descent and Evaluation Study-ADAGES) were observed with standard achromatic perimetry (SAP), optic disc stereophotographs, confocal scanning laser ophthalmoscopy (HRT-3; Heidelberg Engineering, Heidelberg, Germany), and scanning laser polarimetry (GDx-VCC; Carl Zeiss Meditec, Inc., Dublin, CA). Glaucoma progression was determined by the Guided Progression Analysis software for standard automated perimetry [SAP] and by masked assessment of serial optic disc stereophotographs by expert graders. Random-coefficients models were used to evaluate rates of change in average RNFLT and global RA measurements and their relationship with glaucoma progression. RESULTS. At baseline, 194 (31%) eyes were glaucomatous, 347 (55%) had suspected glaucoma, and 88 (14%) were normal. Forty-six (9%) eyes showed progression by SAP and/or stereophotographs, during an average follow-up of 3.3 (+/-0.7) years. The average rate of decline for RNFLT measurements was significantly higher in the progressing group than in the non-progressing group (-0.65 vs. -0.11 mu m/y, respectively; P < 0.001), whereas RA decline was not significantly different between these groups (-0.0058 vs. -0.0073 mm(2)/y, respectively; P = 0.727). The areas under the receiver operating characteristic (ROC) curves used to discriminate progressing versus nonprogressing eyes were 0.811 and 0.507 for the rates of change in the RNFLT and RA, respectively (P < 0.001). CONCLUSIONS. The ability to discriminate eyes with progressing glaucoma by SAP and/or stereophotographs from stable eyes was significantly greater for RNFLT than for RA measurements. (Invest Ophthalmol Vis Sci. 2010;51:3531-3539) DOI: 10.1167/iovs.09-4350
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Background Suicide is a leading cause of death worldwide, but the precise effect of childhood adversities as risk factors for the onset and persistence of suicidal behaviour (suicide ideation, plans and attempts) are not well understood. Aims To examine the associations between childhood adversities as risk factors for the onset and persistence of suicidal behaviour across 21 countries worldwide. Method Respondents from nationally representative samples (n = 55 299) were interviewed regarding childhood adversities that occurred before the age of 18 years and lifetime suicidal behaviour. Results Childhood adversities were associated with an increased risk of suicide attempt and ideation in both bivariate and multivariate models (odds ratio range 1.2-5.7). The risk increased with the number of adversities experienced, but at a decreasing rate. Sexual and physical abuse were consistently the strongest risk factors for both the onset and persistence of suicidal behaviour, especially during adolescence. Associations remained similar after additional adjustment for respondents` lifetime mental disorder status. Conclusions Childhood adversities (especially intrusive or aggressive adversities) are powerful predictors of the onset and persistence of suicidal behaviours.
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The aim of this study was to determine whether estrogen therapy enhances postexercise muscle sympathetic nerve activity (MSNA) decrease and vasodilation, resulting in a greater postexercise hypotension. Eighteen postmenopausal women received oral estrogen therapy (ET; n = 9, 1 mg/day) or placebo (n = 9) for 6 mo. They then participated in one 45-min exercise session (cycle ergometer at 50% of oxygen uptake peak) and one 45-min control session (seated rest) in random order. Blood pressure (BP, oscillometry), heart rate (HR), MSNA (microneurography), forearm blood flow (FBF, plethysmography), and forearm vascular resistance (FVR) were measured 60 min later. FVR was calculated. Data were analyzed using a two-way ANOVA. Although postexercise physiological responses were unaltered, HR was significantly lower in the ET group than in the placebo group (59 +/- 2 vs. 71 +/- 2 beats/min, P < 0.01). In both groups, exercise produced significant decreases in systolic BP (145 +/- 3 vs. 154 +/- 3 mmHg, P = 0.01), diastolic BP (71 +/- 3 vs. 75 +/- 2 mmHg, P = 0.04), mean BP (89 +/- 2 vs. 93 +/- 2 mmHg, P = 0.02), MSNA (29 +/- 2 vs. 35 +/- 1 bursts/min, P < 0.01), and FVR (33 +/- 4 vs. 55 +/- 10 units, P = 0.01), whereas it increased FBF (2.7 +/- 0.4 vs. 1.6 +/- 0.2 ml (.) min(-1) (.) 100 ml(-1), P = 0.02) and did not change HR (64 +/- 2 vs. 65 +/- 2 beats/min, P = 0.3). Although ET did not change postexercise BP, HR, MSNA, FBF, or FVR responses, it reduced absolute HR values at baseline and after exercise.