Survival after Acute Hemodialysis in Pennsylvania, 2005- 2007: A Retrospective Cohort Study

Abstract Background: Little is known about acute hemodialysis in the US. Here we describe predictors of receipt of acute hemodialysis in one state and estimate the marginal impact of acute hemodialysis on survival after accounting for confounding due to illness severity

Evaluation of polygenic risk scores for breast and ovarian cancer risk prediction in BRCA1 and BRCA2 mutation carriers

Background: Genome-wide association studies (GWAS) have identified 94 common single-nucleotide polymorphisms (SNPs) associated with breast cancer (BC) risk and 18 associated with ovarian cancer (OC) risk. Several of these are also associated with risk of BC or OC for women who carry a pathogenic mutation in the high-risk BC and OC genes BRCA1 or BRCA2. The combined effects of these variants on BC or OC risk for BRCA1 and BRCA2 mutation carriers have not yet been assessed while their clinical management could benefit from improved personalized risk estimates. Methods: We constructed polygenic risk scores (PRS) using BC and OC susceptibility SNPs identified through population-based GWAS: for BC (overall, estrogen receptor [ER]-positive, and ER-negative) and for OC. Using data from 15 252 female BRCA1 and 8211 BRCA2 carriers, the association of each PRS with BC or OC risk was evaluated using a weighted cohort approach, with time to diagnosis as the outcome and estimation of the hazard ratios (HRs) per standard deviation increase in the PRS. Results: The PRS for ER-negative BC displayed the strongest association with BC risk in BRCA1 carriers (HR = 1.27, 95% confidence interval [CI] = 1.23 to 1.31, P = 8.2 x 10(53)). In BRCA2 carriers, the strongest association with BC risk was seen for the overall BC PRS (HR = 1.22, 95% CI = 1.17 to 1.28, P = 7.2 x 10(-20)). The OC PRS was strongly associated with OC risk for both BRCA1 and BRCA2 carriers. These translate to differences in absolute risks (more than 10% in each case) between the top and bottom deciles of the PRS distribution; for example, the OC risk was 6% by age 80 years for BRCA2 carriers at the 10th percentile of the OC PRS compared with 19% risk for those at the 90th percentile of PRS. Conclusions: BC and OC PRS are predictive of cancer risk in BRCA1 and BRCA2 carriers. Incorporation of the PRS into risk prediction models has promise to better inform decisions on cancer risk management

Racial and ethnic differences in contraceptive use among women who desire no future children, 2006–2010 National Survey of Family Growth

ObjectiveTo evaluate racial/ethnic differences in contraceptive use among women who do not desire future pregnancy.Study designWe used the 2006-2010 National Survey of Family Growth to examine the associations between race/ethnicity and 1) use of any contraceptive method at last heterosexual intercourse and 2) effectiveness of contraceptive method used among women who stated that they did not desire any (more) children. We conducted multivariable logistic regression to assess the independent effect of race/ethnicity on these outcomes, adjusting for socio-demographic factors, reproductive characteristics, and indicators of healthcare access and utilization.ResultsThe study sample consisted of 2900 women, aged 15-44 years. The vast majority of women (91.2%) used contraception at last sex, although this varied significantly by race/ethnicity (p<.01). In the fully adjusted model controlling for demographic and reproductive characteristics as well as healthcare access, compared to whites, black women were significantly less likely to use any contraception at last sex (OR: 0.43; 95% CI: 0.27-0.73), while there was no significant difference for Hispanic women (OR: 0.95; 95% CI: 0.52-1.72). Among women who used a method at last sex, the type of contraceptive method varied significantly by race/ethnicity in bivariate analysis (p<.01), although most women (59%) used a highly effective method. In the fully adjusted model, racial/ethnic differences were no longer significant.ConclusionsIn this nationally representative cohort of women who report that they do not desire (more) children, black women were significantly less likely than white women to use any contraception at last intercourse; this difference did not appear to be due to differential access to health care.ImplicationsSignificant racial/ethnic differences exist in contraceptive use among women who have completed childbearing, which do not appear to be explained by differential socioeconomic status, reproductive characteristics or utilization of healthcare. Other factors, including social mobility and locus of reproductive control, that may contribute to these variations should be further explored

The development of youth-onset severe obesity in urban US girls

Objective: To understand the incidence and persistence of severe obesity (≥1.2 × 95th BMI percentile-for-age) in girls across the transition to adolescence, and map developmental trajectories of adolescent severe obesity in a high-risk sample. Methods: We examined ten years of prospectively collected data from a population sample of urban girls (n = 2226; 53% African American, aged 7–10 in 2003–2004). We determined severe obesity prevalence and incidence by age. Logistic regression evaluated for secular trend in the association between age and severe obesity prevalence. Unconditional latent growth curve models (LGCMs) compared BMI development through the adolescence transition between girls with severe obesity versus healthy BMI. Results: Severe obesity prevalence was 8.3% at age 7–10 and 10.1% at age 16–19 (white: 5.9%; African American: 13.2%; p < 0.001). Age-specific prevalence increased more rapidly among the latest-born, versus earliest-born, girls (p = 0.034). Incidence was 1.3% to 2.4% annually. When we compared 12–15 year-old girls with severe obesity versus healthy BMI, average body weight was already distinct 5 years earlier (16.5 kg versus 25.7 kg; p < 0.001) and the BMI difference between groups increased annually. LGCMs between ages 7–10 and 11–14 indicated an increase of 3.32 kg/m2 in the healthy-BMI group and 8.50 kg/m2 in the severe obesity group, a 2.6-fold difference. Conclusions: Youth-onset severe obesity warrants particular concern in urban girls due to high prevalence and an increasing secular prevalence trend. Late childhood and early adolescence may represent a key developmental window for prevention and treatment, but is too late to prevent youth-onset severe obesity entirely

Independent predictors of receipt of acute hemodialysis, Pennsylvania 2005–2007.^a

a<p>Based on the full sample.</p

Unadjusted survival among patients with and without acute hemodialysis, Pennsylvania 2005–2007.

<p>Kaplan-Meier survival curves for patients who did and did not receive acute hemodialysis, with 95% confidence intervals.</p

Sample selection process.

<p>PPD - predicted probability of death in-hospital, calculated from key clinical findings at admission; tx - transplant; CKD - chronic kidney disease; ESRD - end-stage renal disease.</p

Adjusted survival among propensity-score matched patients with and without acute hemodialysis, Pennsylvania 2005–2007.

<p>Cox-adjusted survival curves with covariate adjustment for patients who did and did not receive acute hemodialysis after matching on propensity to receive acute hemodialysis. Variables included in covariate risk adjustment included age; female sex; black race; insurance with Medicare or private insurance vs. no insurance; insurance with Medicaid and/or Medicare vs. no insurance; MediQual predicted probability of death; and the top 25 Clinical Classification Software admission diagnoses for people who received acute hemodialysis, with the exception of hypertension with complications and secondary hypertension (#6) and peripheral and visceral atherosclerosis (#25), which were dropped in the model selection phase.</p

Controlled Synthesis and Single-Particle Imaging of Bright, Sub-10 nm Lanthanide-Doped Upconverting Nanocrystals

Phosphorescent nanocrystals that upconvert near-infrared light to emit at higher energies in the visible have shown promise as photostable, nonblinking, and background-free probes for biological imaging. However, synthetic control over upconverting nanocrystal size has been difficult, particularly for the brightest system, Yb³⁺- and Er³⁺-doped β-phase NaYF₄, for which there have been no reports of methods capable of producing sub-10 nm nanocrystals. Here we describe conditions for the controlled synthesis of protein-sized β-phase NaYF₄: 20% Yb³⁺, 2% Er³⁺ nanocrystals, from 4.5 to 15 nm in diameter. The size of the nanocrystals was modulated by varying the concentration of basic surfactants, Y³⁺:F^– ratio, and reaction temperature, variables that also affected their crystalline phase. Increased reaction times favor formation of the desired β-phase nanocrystals while having only a modest effect on nanocrystal size. Core/shell β-phase NaYF₄: 20% Yb³⁺, 2% Er³⁺/NaYF₄ nanoparticles less than 10 nm in total diameter exhibit higher luminescence quantum yields than comparable >25 nm diameter core nanoparticles. Single-particle imaging of 9 nm core/shell nanoparticles also demonstrates that they exhibit no measurable photobleaching or blinking. These results establish that small lanthanide-doped upconverting nanoparticles can be synthesized without sacrificing brightness or stability, and these sub-10 nm nanoparticles are ideally suited for single-particle imaging