19 research outputs found
There\u27s A Girl in the Heart of Maryland (With a Heart that Belongs to Me) / music by Harry Caroll; words by Ballard Mcdonald
Cover: a photo of a girl sitting on the floor near the fireplace and reading a letter; Publisher: Shapiro Bernstein and Co. (New York)https://egrove.olemiss.edu/sharris_c/1062/thumbnail.jp
Anti-dense fine speckled 70 (DFS70) autoantibodies: correlates and increasing prevalence in the United States
ObjectiveRecent studies report high-titer anti-dense fine speckled 70 (DFS70) autoantibodies in persons with inflammatory conditions, but the clinical significance remains unclear. Our goals were to estimate anti-DFS70 autoantibody prevalence, identify correlates, and assess time trends.MethodsSerum antinuclear antibodies (ANA) were measured by indirect immunofluorescence assay on HEp-2 cells in 13,519 participants ≥12 years old from three time periods (1988–1991, 1999–2004, 2011–2012) of the National Health and Nutrition Examination Survey. ANA-positive participants with dense fine speckled staining were evaluated for anti-DFS70 antibodies by enzyme-linked immunosorbent assay. We used logistic models adjusted for survey-design variables to estimate period-specific anti-DFS70 antibody prevalence in the US, and we further adjusted for sex, age, and race/ethnicity to identify correlates and assess time trends.ResultsWomen were more likely than men (odds ratio (OR)=2.97), black persons were less likely than white persons (OR=0.60), and active smokers were less likely than nonsmokers (OR=0.28) to have anti-DFS70 antibodies. The prevalence of anti-DFS70 antibodies increased from 1.6% in 1988-1991 to 2.5% in 1999-2004 to 4.0% in 2011-2012, which corresponds to 3.2 million, 5.8 million, and 10.4 million seropositive individuals, respectively. This increasing time trend in the US population (P<0.0001) was modified in some subgroups and was not explained by concurrent changes in tobacco smoke exposure. Some, but not all, anti-DFS70 antibody correlates and time trends resembled those reported for total ANA.ConclusionMore research is needed to elucidate anti-DFS70 antibody triggers, their pathologic or potentially protective influences on disease, and their possible clinical implications
Effect of double-fibre reinforcement on localized bulging of an inflated cylindrical tube of arbitrary thickness
Is Cortisol Excretion Independent of Menstrual Cycle Day? A Longitudinal Evaluation of First Morning Urinary Specimens
Background
Cortisol is frequently used as a marker of physiologic stress levels. Using cortisol for that purpose, however, requires a thorough understanding of its normal longitudinal variability. The current understanding of longitudinal variability of basal cortisol secretion in women is very limited. It is often assumed, for example, that basal cortisol profiles do not vary across the menstrual cycle. This is a critical assumption: if cortisol were to follow a time dependent pattern during the menstrual cycle, then ignoring this cyclic variation could lead to erroneous imputation of physiologic stress. Yet, the assumption that basal cortisol levels are stable across the menstrual cycle rests on partial and contradictory evidence. Here we conduct a thorough test of that assumption using data collected for up to a year from 25 women living in rural Guatemala.
Methodology
We apply a linear mixed model to describe longitudinal first morning urinary cortisol profiles, accounting for differences in both mean and standard deviation of cortisol among women. To that aim we evaluate the fit of two alternative models. The first model assumes that cortisol does not vary with menstrual cycle day. The second assumes that cortisol mean varies across the menstrual cycle. Menstrual cycles are aligned on ovulation day (day 0). Follicular days are assigned negative numbers and luteal days positive numbers. When we compared Models 1 and 2 restricting our analysis to days between −14 (follicular) and day 14 (luteal) then day of the menstrual cycle did not emerge as a predictor of urinary cortisol levels (p-value >0.05). Yet, when we extended our analyses beyond that central 28-day-period then day of the menstrual cycle become a statistically significant predictor of cortisol levels.
Significance
The observed trend suggests that studies including cycling women should account for day dependent variation in cortisol in cycles with long follicular and luteal phases
Investigating the use of the accelerated hazards model for survival analysis
This project contrasts the Proportional Hazards, Accelerated Failure Time and Accelerated Hazards (AH) models in the analysis of time to event data. The AH model handles data that exhibit crossing of the survival and hazard curves, unlike the other two models considered. The three models are illustrated on five contrasting data sets. A simulation study is conducted to assess the small sample performance of the AH model by quantifying the mean squared error of the predicted survivor curves under scenarios of crossing and non-crossing survivor curves. The results show that the AH model can perform poorly under model misspecification for models with a crossing hazard. Problems with variance estimation of parameters in the AH model are observed for small sample sizes and a bootstrap approach is offered as an alternate method of quantifying precision of estimates
Antinuclear antibodies and mortality in the National Health and Nutrition Examination Survey (1999-2004).
Recent studies suggest antinuclear antibodies (ANA) may be related to mortality risk, but evidence is sparse and inconclusive. Thus, we investigated ANA associations with all-cause and cause-specific mortality in U.S. adults.Our sample included 3357 adults (ages ≥20 years) from the 1999-2004 National Health and Nutrition Examination Survey with ANA measurements (1:80 dilution) and mortality data through 2011 (median follow-up: 9.4 years). We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) via weighted Cox regression to assess ANA associations with mortality from all causes, cardiovascular disease (CVD), and cancer. Models adjusted for age, sex, race/ethnicity, education, and obesity. Analyses examined mortality in the full sample and in subgroups based on self-reported histories of CVD and cancer, both overall and stratified by sex and age at enrollment.Overall, ANA were not strongly associated with death from all causes (HR: 1.13; CI: 0.79, 1.60), from CVD (HR: 1.60; CI: 0.80, 3.20), or from cancer (HR: 1.58; CI: 0.75, 3.33), though all three HR estimates exceeded 1. In the subgroup with a history of cancer, ANA were associated with elevated all-cause mortality in men (HR: 2.28; CI: 1.01, 5.14) and in participants who enrolled at age ≥75 years (HR: 1.99; CI: 1.04, 3.80).These findings suggest that ANA are not strongly associated with mortality in the general population. Longitudinal studies with repeated assessments are needed to understand the temporal relationship between ANA, aging-associated diseases, and mortality
Endotoxin Exposure: Predictors and Prevalence of Associated Asthma Outcomes in the United States
Developmental Effects of the ToxCastâ„¢ Phase I and Phase II Chemicals in Caenorhabditis elegans
Covariate-adjusted associations between baseline ANA status and cause-specific mortality within selected groups.
<p>Covariate-adjusted associations between baseline ANA status and cause-specific mortality within selected groups.</p
Baseline sample characteristics, their age-adjusted associations with ANA prevalence, and their unadjusted associations with all-cause mortality.
<p>Baseline sample characteristics, their age-adjusted associations with ANA prevalence, and their unadjusted associations with all-cause mortality.</p