Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2015
BACKGROUND
Unintended pregnancy is common and disproportionately occurs among low-income and African-American (AA) women. Male partners may influence women's risk of unintended pregnancy through reproductive coercion, although studies have not assessed whether racial differences in reproductive coercion impact AA women's disparate risk for unintended pregnancy. We sought to describe women's experiences with pregnancy-promoting behaviors by male partners and explore differences in such experiences by race.
METHODS
Semistructured interviews were conducted with low-income, AA and White women aged 18 to 45 years recruited from reproductive health clinics in Western Pennsylvania to explore contextual factors that shape women's contraceptive behaviors. Narratives were analyzed using content analysis and the constant comparison method.
FINDINGS
Among the 66 participants (36 AA and 30 White), 25 (38%) described experiences with male partner reproductive coercion. Narratives provided accounts of contraceptive sabotage, verbal pressure to promote pregnancy and specific pregnancy outcomes, and potential motives behind these behaviors. AA women in the sample reported experiences of reproductive coercion more often than White women (53% and 20%, respectively). AA women were also more likely than White women to attribute a current or prior pregnancy to reproductive coercion. AA women identified relationship transiency and impending incarceration as potential motivations for men to secure a connection with a female partner via pregnancy.
CONCLUSIONS
Our findings suggest that reproductive coercion may be a factor contributing to disparities in unintended pregnancy. More research, including population-level studies, is needed to determine the impact of reproductive coercion on unintended pregnancy and to understand the social and structural factors associated with pregnancy-promoting behaviors.
View on PubMed2015
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2015
B cells activated by nucleic acid-sensing TLR7 and TLR9 proliferate and secrete immune globulins. Memory B cells are presumably more responsive due to higher TLR expression levels, but selectivity and differential outcomes remain largely unknown. In this study, peripheral blood human B cells were stimulated by TLR7 or TLR9 ligands, with or without IFN-α, and compared with activators CD40L plus IL-21, to identify differentially responsive cell populations, defined phenotypically and by BCR characteristics. Whereas all activators induced differentiation and Ab secretion, TLR stimulation expanded IgM(+) memory and plasma cell lineage committed populations, and favored secretion of IgM, unlike CD40L/IL-21, which drove IgM and IgG more evenly. Patterns of proliferation similarly differed, with CD40L/IL-21 inducing proliferation of most memory and naive B cells, in contrast with TLRs that induced robust proliferation in a subset of these cells. On deep sequencing of the IgH locus, TLR-responsive B cells shared patterns of IgHV and IgHJ usage, clustering apart from CD40L/IL-21 and control conditions. TLR activators, but not CD40L/IL-21, similarly promoted increased sharing of CDR3 sequences. TLR-responsive B cells were characterized by more somatic hypermutation, shorter CDR3 segments, and less negative charges. TLR activation also induced long positively charged CDR3 segments, suggestive of autoreactive Abs. Testing this, we found culture supernatants from TLR-stimulated B cells to bind HEp-2 cells, whereas those from CD40L/IL-21-stimulated cells did not. Human B cells possess selective sensitivity to TLR stimulation, with distinctive phenotypic and genetic signatures.
View on PubMed2015
2015
OBJECTIVE
We aimed to ascertain risk factors for acute mountain sickness (AMS) in miners exposed to chronic intermittent high altitude conditions.
METHODS
All new hires (2009-2012) for mine employment (4000 m above sea level) were followed up for 12 months after first ascent. Demographics, physiologic data, and cigarette smoking were assessed at preemployment screening. Mine site clinic care for AMS defined incident events. Cox regression analysis estimated risk of AMS associated with smoking and selected covariates.
RESULTS
There were 46 AMS cases among 569 individuals during the first 12 months of employment. Adjusted for age, sex, and altitude of permanent residence, cigarettes smoked per day before hiring were prospectively associated with AMS (hazard ratio [HR], 1.9; 95% CI, 1.1 to 3.2 per 10 cigarettes smoked). This risk was higher in the subset of workers with less demanding physical work (n=336; HR, 3.3; 95% CI, 1.7 to 6.3), whereas among those with more physically demanding jobs (n=233), smoking was not associated with increased risk (HR, 0.6; 95% CI, 0.1 to 2.3).
CONCLUSIONS
In workers newly hired to work at high altitude, smoking increases the likelihood of AMS, but this effect appears to be operative only among those with less physically demanding work duties.
View on PubMed2015
We evaluated whether a 76-locus polygenic risk score (PRS) and Breast Imaging Reporting and Data System (BI-RADS) breast density were independent risk factors within three studies (1643 case patients, 2397 control patients) using logistic regression models. We incorporated the PRS odds ratio (OR) into the Breast Cancer Surveillance Consortium (BCSC) risk-prediction model while accounting for its attributable risk and compared five-year absolute risk predictions between models using area under the curve (AUC) statistics. All statistical tests were two-sided. BI-RADS density and PRS were independent risk factors across all three studies (P interaction = .23). Relative to those with scattered fibroglandular densities and average PRS (2(nd) quartile), women with extreme density and highest quartile PRS had 2.7-fold (95% confidence interval [CI] = 1.74 to 4.12) increased risk, while those with low density and PRS had reduced risk (OR = 0.30, 95% CI = 0.18 to 0.51). PRS added independent information (P < .001) to the BCSC model and improved discriminatory accuracy from AUC = 0.66 to AUC = 0.69. Although the BCSC-PRS model was well calibrated in case-control data, independent cohort data are needed to test calibration in the general population.
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