117 research outputs found
Mortality According to CD4 Count at Start of Combination Antiretroviral Therapy Among HIV-infected Patients Followed for up to 15 Years After Start of Treatment: Collaborative Cohort Study.
BACKGROUND: CD4 count at start of combination antiretroviral therapy (ART) is strongly associated with short-term survival, but its association with longer-term survival is less well characterized.
METHODS: We estimated mortality rates (MRs) by time since start of ART (<0.5, 0.5-0.9, 1-2.9, 3-4.9, 5-9.9, and ≥10 years) among patients from 18 European and North American cohorts who started ART during 1996-2001. Piecewise exponential models stratified by cohort were used to estimate crude and adjusted (for sex, age, transmission risk, period of starting ART [1996-1997, 1998-1999, 2000-2001], and AIDS and human immunodeficiency virus type 1 RNA at baseline) mortality rate ratios (MRRs) by CD4 count at start of ART (0-49, 50-99, 100-199, 200-349, 350-499, ≥500 cells/µL) overall and separately according to time since start of ART.
RESULTS: A total of 6344 of 37 496 patients died during 359 219 years of follow-up. The MR per 1000 person-years was 32.8 (95% confidence interval [CI], 30.2-35.5) during the first 6 months, declining to 16.0 (95% CI, 15.4-16.8) during 5-9.9 years and 14.2 (95% CI, 13.3-15.1) after 10 years' duration of ART. During the first year of ART, there was a strong inverse association of CD4 count at start of ART with mortality. This diminished over the next 4 years. The adjusted MRR per CD4 group was 0.97 (95% CI, .94-1.00; P = .054) and 1.02 (95% CI, .98-1.07; P = .32) among patients followed for 5-9.9 and ≥10 years, respectively.
CONCLUSIONS: After surviving 5 years of ART, the mortality of patients who started ART with low baseline CD4 count converged with mortality of patients with intermediate and high baseline CD4 counts
Analysis of pmpD Expression and PmpD Post-Translational Processing during the Life Cycle of Chlamydia trachomatis Serovars A, D, and L2
BACKGROUND: The polymorphic membrane protein D (PmpD) in Chlamydia is structurally similar to autotransporter proteins described in other bacteria and may be involved in cellular and humoral protective immunity against Chlamydia. The mechanism of PmpD post-translational processing and the role of its protein products in the pathogenesis of chlamydial infection have not been very well elucidated to date. METHODOLOGY/PRINCIPAL FINDINGS: Here we examined the expression and post-translational processing of the protein product of the pmpD gene during the life cycle of C. trachomatis serovars A, D, and L2. Each of these three serovars targets different human organs and tissues and encodes a different pmpD gene nucleotide sequence. Our quantitative real-time reverse transcription polymerase chain reaction results demonstrate that the pmpD gene is up-regulated at 12-24 hours after infection regardless of the Chlamydia serovar. This up-regulation is coincidental with the period of exponential growth and replication of reticulate bodies (RB) of Chlamydia and indicates a probable similarity in function of pmpD in serovars A, D, and L2 of Chlamydia. Using mass spectrometry analysis, we identified the protein products of post-translational processing of PmpD of C. trachomatis serovar L2 and propose a double pathway model for PmpD processing, with one cleavage site between the passenger and autotransporter domains and the other site in the middle of the passenger domain. Notably, when Chlamydia infected culture cells were subjected to low (28 degrees C) temperature, PmpD post-translational processing and secretion was found to be uninhibited in the resulting persistent infection. In addition, confocal microscopy of cells infected with Chlamydia confirms our earlier hypothesis that PmpD is secreted outside Chlamydia and its secretion increases with growth of the chlamydial inclusion. CONCLUSION/SIGNIFICANCE: The results of this current study involving multiple Chlamydia serovars support the general consensus that the pmpD gene is maximally expressed at mid infection and provide new information about PmpD as an autotransporter protein which is post-translationally processed and secreted outside Chlamydia during normal and low temperature induced persistent chlamydial infection
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Predicting breast cancer response to neoadjuvant treatment using multi-feature MRI: results from the I-SPY 2 TRIAL.
Dynamic contrast-enhanced (DCE) MRI provides both morphological and functional information regarding breast tumor response to neoadjuvant chemotherapy (NAC). The purpose of this retrospective study is to test if prediction models combining multiple MRI features outperform models with single features. Four features were quantitatively calculated in each MRI exam: functional tumor volume, longest diameter, sphericity, and contralateral background parenchymal enhancement. Logistic regression analysis was used to study the relationship between MRI variables and pathologic complete response (pCR). Predictive performance was estimated using the area under the receiver operating characteristic curve (AUC). The full cohort was stratified by hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status (positive or negative). A total of 384 patients (median age: 49 y/o) were included. Results showed analysis with combined features achieved higher AUCs than analysis with any feature alone. AUCs estimated for the combined versus highest AUCs among single features were 0.81 (95% confidence interval [CI]: 0.76, 0.86) versus 0.79 (95% CI: 0.73, 0.85) in the full cohort, 0.83 (95% CI: 0.77, 0.92) versus 0.73 (95% CI: 0.61, 0.84) in HR-positive/HER2-negative, 0.88 (95% CI: 0.79, 0.97) versus 0.78 (95% CI: 0.63, 0.89) in HR-positive/HER2-positive, 0.83 (95% CI not available) versus 0.75 (95% CI: 0.46, 0.81) in HR-negative/HER2-positive, and 0.82 (95% CI: 0.74, 0.91) versus 0.75 (95% CI: 0.64, 0.83) in triple negatives. Multi-feature MRI analysis improved pCR prediction over analysis of any individual feature that we examined. Additionally, the improvements in prediction were more notable when analysis was conducted according to cancer subtype
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Genome-wide association study of Tourette Syndrome
Tourette Syndrome (TS) is a developmental disorder that has one of the highest familial recurrence rates among neuropsychiatric diseases with complex inheritance. However, the identification of definitive TS susceptibility genes remains elusive. Here, we report the first genome-wide association study (GWAS) of TS in 1285 cases and 4964 ancestry-matched controls of European ancestry, including two European-derived population isolates, Ashkenazi Jews from North America and Israel, and French Canadians from Quebec, Canada. In a primary meta-analysis of GWAS data from these European ancestry samples, no markers achieved a genome-wide threshold of significance (p<5 × 10−8); the top signal was found in rs7868992 on chromosome 9q32 within COL27A1 (p=1.85 × 10−6). A secondary analysis including an additional 211 cases and 285 controls from two closely-related Latin-American population isolates from the Central Valley of Costa Rica and Antioquia, Colombia also identified rs7868992 as the top signal (p=3.6 × 10−7 for the combined sample of 1496 cases and 5249 controls following imputation with 1000 Genomes data). This study lays the groundwork for the eventual identification of common TS susceptibility variants in larger cohorts and helps to provide a more complete understanding of the full genetic architecture of this disorder
Rare coding variants in PLCG2, ABI3, and TREM2 implicate microglial-mediated innate immunity in Alzheimer's disease
We identified rare coding variants associated with Alzheimer’s disease (AD) in a 3-stage case-control study of 85,133 subjects. In stage 1, 34,174 samples were genotyped using a whole-exome microarray. In stage 2, we tested associated variants (P<1×10-4) in 35,962 independent samples using de novo genotyping and imputed genotypes. In stage 3, an additional 14,997 samples were used to test the most significant stage 2 associations (P<5×10-8) using imputed genotypes. We observed 3 novel genome-wide significant (GWS) AD associated non-synonymous variants; a protective variant in PLCG2 (rs72824905/p.P522R, P=5.38×10-10, OR=0.68, MAFcases=0.0059, MAFcontrols=0.0093), a risk variant in ABI3 (rs616338/p.S209F, P=4.56×10-10, OR=1.43, MAFcases=0.011, MAFcontrols=0.008), and a novel GWS variant in TREM2 (rs143332484/p.R62H, P=1.55×10-14, OR=1.67, MAFcases=0.0143, MAFcontrols=0.0089), a known AD susceptibility gene. These protein-coding changes are in genes highly expressed in microglia and highlight an immune-related protein-protein interaction network enriched for previously identified AD risk genes. These genetic findings provide additional evidence that the microglia-mediated innate immune response contributes directly to AD development
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