77 research outputs found
Effectiveness of Highly Active Antiretroviral Therapy among Injection Drug Users with Late-Stage Human Immunodeficiency Virus Infection
Highly active antiretroviral therapy (HAART) has been shown to be effective in different populations, but data
among injection drug users are limited. Human immunodeficiency virus-infected injection drug users recruited into
the Acquired Immunodeficiency Syndrome Link to Intravenous Experiences (ALIVE) Study as early as 1988 were
tested semiannually to identify their first CD4-positive T-lymphocyte cell count below 200/ll; they were followed for
mortality through 2002. Visits were categorized into the pre-HAART (before mid-1996) and the HAART eras and
further categorized by HAART use. Survival analysis with staggered entry was used to evaluate the effect of
HAART on acquired immunodeficiency syndrome-related mortality, adjusting for other medications and demographic,
clinical, and behavioral factors. Among 665 participants, 258 died during 2,402 person-years of follow-up.
Compared with survival in the pre-HAART era, survival in the HAART era was shown by multivariate analysis to be
improved for both those who did and did not receive HAART (relative hazards ~ 0.06 and 0.33, respectively; p <
0.001). Inferences were unchanged after restricting analyses to data starting with 1993 and considerations of leadtime
bias and human immunodeficiency viral load. The annual CD4-positive T-lymphocyte cell decline was less in
untreated HAART-era participants than in pre-HAART-era participants (-10/microliter vs. -37/microliter, respectively), suggesting
that changing indications for treatment may have contributed to improved survival and that analyses restricted
to the HAART era probably underestimate HAART effectiveness.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/40266/2/Vlahov_Effectiveness of Highly Active Antiretroviral Therapy_2005.pd
Defining the genetic susceptibility to cervical neoplasia - a genome-wide association study
Funding: MAB was funded by a National Health and Medical Research Council (Australia) Senior Principal Research Fellowship. Support was also received from the Australian Cancer Research Foundation. JL holds a Tier 1 Canada Research Chair in Human Genome Epidemiology. The Seattle study was supported by the following grants: NIH, National Cancer Institute grants P01CA042792 and R01CA112512. Cervical Health Study (from which the NSW component was obtained) was funded by NHMRC Grant 387701, and CCNSW core grant. The Montreal study was funded by the Canadian Institutes of Health Research (grant MOP-42532) and sample processing was funded by the Reseau FRQS SIDA-MI. The Swedish Research Council, the Swedish Foundation for Strategic Research, the ALF/LUA research grant in Gothenburg and UmeĂ„, the Lundberg Foundation, the Torsten and Ragnar Soderbergâs Foundation, the Novo Nordisk Foundation, and the European Commission grant HEALTH-F2-2008-201865-GEFOS, BBMRI.se, the Swedish Society of Medicine, the KempeFoundation (JCK-1021), the Medical Faculty of UmeĂ„ University, the County Council of Vasterbotten (Spjutspetsanslag VLL:159:33-2007). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptPeer reviewedPublisher PDFPublisher PD
Chronic typhoid infection and the risk of biliary tract cancer and stones in Shanghai, China
Previous studies have shown a positive association between chronic typhoid carriage and biliary cancers. We compared serum Salmonella enterica serovar Typhi antibody titers between biliary tract cancer cases, biliary stone cases without evidence of cancer, and healthy subjects in a large population-based case-control study in Shanghai, China
Recommended from our members
HPV16 Seropositivity and Subsequent HPV16 Infection Risk in a Naturally Infected Population: Comparison of Serological Assays
Background: Several serological assays have been developed to detect antibodies elicited against infections with oncogenic human papillomavirus (HPV) type 16. The association between antibody levels measured by various assays and subsequent HPV infection risk may differ. We compared HPV16-specific antibody levels previously measured by a virus-like particle (VLP)-based direct enzyme-linked immunoassay (ELISA) with levels measured by additional assays and evaluated the protection against HPV16 infection conferred at different levels of the assays. Methodology/Principal Findings Replicate enrollment serum aliquots from 388 unvaccinated women in the control arm of the Costa Rica HPV vaccine trial were measured for HPV16 seropositivity using three serological assays: a VLP-based direct ELISA; a VLP-based competitive Luminex immunoassay (cLIA); and a secreted alkaline phosphatase protein neutralization assay (SEAP-NA). We assessed the association of assay seropositivity and risk of subsequent HPV16 infection over four years of follow-up by calculating sampling-adjusted odds ratios (OR) and HPV16 seropositivity based on standard cutoff from the cLIA was significantly associated with protection from subsequent HPV16 infection (OR = 0.48, CI = 0.27â0.86, compared with seronegatives). Compared with seronegatives, the highest seropositive tertile antibody levels from the direct ELISA (OR = 0.53, CI = 0.28â0.90) as well as the SEAP-NA (OR = 0.20, CI = 0.06, 0.64) were also significantly associated with protection from HPV16 infection. Conclusions/Significance: Enrollment HPV16 seropositivity by any of the three serological assays evaluated was associated with protection from subsequent infection, although cutoffs for immune protection were different. We defined the assays and seropositivity levels after natural infection that better measure and translate to protective immunity
Single Nucleotide Polymorphisms in the PRDX3 and RPS19 and Risk of HPV Persistence and Cervical Precancer/Cancer
Host genetic factors might affect the risk of progression from infection with carcinogenic human papillomavirus (HPV), the etiologic agent for cervical cancer, to persistent HPV infection, and hence to cervical precancer and cancer.We assessed 18,310 tag single nucleotide polymorphisms (SNPs) from 1113 genes in 416 cervical intraepithelial neoplasia 3 (CIN3)/cancer cases, 356 women with persistent carcinogenic HPV infection (median persistence of 25 months) and 425 randomly selected women (non-cases and non-HPV persistent) from the 10,049 women from the Guanacaste, Costa Rica HPV natural history cohort. For gene and SNP associations, we computed age-adjusted odds ratio and p-trend. Three comparisons were made: 1) association with CIN3/cancer (compared CIN3/cancer cases to random controls), 2) association with persistence (compared HPV persistence to random controls), and 3) progression (compared CIN3/cancers with HPV-persistent group). Regions statistically significantly associated with CIN3/cancer included genes for peroxiredoxin 3 PRDX3, and ribosomal protein S19 RPS19. The single most significant SNPs from each gene associated with CIN3/cancer were PRDX3 rs7082598 (P(trend)<0.0001), and RPS19 rs2305809 (P(trend)=0.0007), respectively. Both SNPs were also associated with progression.These data suggest involvement of two genes, RSP19 and PRDX3, or other SNPs in linkage disequilibrium, with cervical cancer risk. Further investigation showed that they may be involved in both the persistence and progression transition stages. Our results require replication but, if true, suggest a role for ribosomal dysfunction, mitochondrial processes, and/or oxidative stress, or other unknown function of these genes in cervical carcinogenesis
Evidence for single-dose protection by the bivalent HPV vaccine-Review of the Costa Rica HPV vaccine trial and future research studies.
The Costa Rica Vaccine Trial (CVT), a phase III randomized clinical trial, provided the initial data that one dose of the HPV vaccine could provide durable protection against HPV infection. Although the study design was to administer all participants three doses of HPV or control vaccine, 20% of women did not receive the three-dose regimens, mostly due to involuntary reasons unrelated to vaccination. In 2011, we reported that a single dose of the bivalent HPV vaccine could be as efficacious as three doses of the vaccine using the endpoint of persistent HPV infection accumulated over the first four years of the trial; findings independently confirmed in the GSK-sponsored PATRICIA trial. Antibody levels after one dose, although lower than levels elicited by three doses, were 9-times higher than levels elicited by natural infection. Importantly, levels remained essentially constant over at least seven years, suggesting that the observed protection provided by a single dose might be durable. Much work has been done to assure these non-randomized findings are valid. Yet, the group of recipients who received one dose of the bivalent HPV vaccine in the CVT and PATRICIA trials was small and not randomly selected nor blinded to the number of doses received. The next phase of research is to conduct a formal randomized, controlled trial to evaluate the protection afforded by a single dose of HPV vaccine. Complementary studies are in progress to bridge our findings to other populations, and to further document the long-term durability of antibody response following a single dose
Methodology for Evaluating a Partially Controlled Longitudinal Treatment Using Principal Stratification, With Application to a Needle Exchange Program
We consider studies for evaluating the short-term effect of a treatment of interest on a time-to-event outcome. The studies we consider are partially controlled in the following sense: (1) Subjectsâ exposure to the treatment of interest can vary over time, but this exposure is not directly controlled by the study; (2) subjectsâ follow-up time is not directly controlled by the study; and (3) the study directly controls another factor that can affect subjectsâ exposure to the treatment of interest as well as subjectsâ follow-up time. When factors (1) and (2) are both present in the study, evaluating the treatment of interest using standard methods, including instrumental variables, does not generally estimate treatment effects. We develop the methodology for estimating the effect of treatment in this setting of partially controlled studies under explicit assumptions using the framework for principal stratiĆœ cation for causal inference. We illustrate our methods by a study to evaluate the efĆœ cacy of the Baltimore Needle Exchange Program to reduce the risk of human immunodeĆœ ciency virus (HIV) transmission, using data on distance of the programâs sites from the subjects
- âŠ