Effect of Combination Folic Acid, Vitamin B6 , and Vitamin B12 Supplementation on Fracture Risk in Women: A Randomized, Controlled Trial.

Epidemiologic studies have demonstrated an association of elevated plasma homocysteine levels with greater bone resorption and fracture risk. Vitamins B12 , B6 , and folic acid are cofactors in homocysteine metabolism, and supplementation with B vitamins is effective in lowering homocysteine levels in humans. However, randomized trials of supplemental B vitamins for reduction of fracture risk have been limited. Therefore, we performed an ancillary study to the Women's Antioxidant and Folic Acid Cardiovascular Study (WAFACS), a large randomized trial of women with preexisting cardiovascular disease or three or more coronary risk factors, to test whether a daily B vitamin intervention including folic acid (2.5 mg/day), vitamin B6 (50 mg/day), and vitamin B12 (1 mg/day) reduces nonspine fracture risk over 7.3 years of treatment and follow-up. Among 4810 women, we confirmed 349 nonspine fracture cases by centralized review of medical records. In a substudy of 300 women (150 in treatment group and 150 controls) with paired plasma samples at randomization and follow-up (7.3 years later), we measured two bone turnover markers, including C-terminal cross-linking telopeptide of type I collagen (CTX) and intact type I procollagen N-propeptide (P1NP). In Cox proportional hazards models based on intention-to-treat, we found no significant effects of B vitamin supplementation on nonspine fracture risk (relative hazard = 1.08; 95% confidence interval, 0.88 to 1.34). In a nested case-cohort analysis, there were no significant effects of B vitamins on fracture risk among women with elevated plasma homocysteine levels, or low levels of vitamins B12 or B6 , or folate at baseline. Furthermore, treatment with B vitamins had no effect on change in markers of bone turnover. We found no evidence that daily supplementation with B vitamins reduces fracture risk or rates of bone metabolism in middle-aged and older women at high risk of cardiovascular disease. © 2017 American Society for Bone and Mineral Research

Diffuse Ionized Gas in Simulations of Multiphase, Star-Forming Galactic Disks

It has been hypothesized that photons from young, massive star clusters are responsible for maintaining the ionization of diffuse warm ionized gas seen in both the Milky Way and other disk galaxies. For a theoretical investigation of the warm ionized medium (WIM), it is crucial to solve radiation transfer equations where the ISM and clusters are modeled self-consistently. To this end, we employ a Solar neighborhood model of TIGRESS, a magnetohydrodynamic simulation of the multiphase, star-forming ISM, and post-process the simulation with an adaptive ray tracing method to transfer UV radiation from star clusters. We find that the WIM volume filling factor is highly variable, and sensitive to the rate of ionizing photon production and ISM structure. The mean WIM volume filling factor rises to ~0.15 at |z|~1 kpc. Approximately half of ionizing photons are absorbed by gas and half by dust; the cumulative ionizing photon escape fraction is 1.1%. Our time-averaged synthetic H$\alpha$ line profile matches WHAM observations on the redshifted (outflowing) side, but has insufficient intensity on the blueshifted side. Our simulation matches the Dickey-Lockman neutral density profile well, but only a small fraction of snapshots have high-altitude WIM density consistent with Reynolds Layer estimates. We compute a clumping correction factor C = /sqrt~0.2 that is remarkably constant with distance from the midplane and time; this can be used to improve estimates of ionized gas mass and mean electron density from observed H$\alpha$ surface brightness profiles in edge-on galaxies.Comment: Accepted to ApJ; 31 pages, 17 figure

Age-related hyperkyphosis, independent of spinal osteoporosis, is associated with impaired mobility in older community-dwelling women

While many assume hyperkyphosis reflects underlying spinal osteoporosis and vertebral fractures, our results suggest hyperkyphosis is independently associated with decreased mobility. Hyperyphosis is associated with slower Timed Up and Go performance times and may be a useful clinical marker signaling the need for evaluation of vertebral fracture and falling risk. While multiple studies have demonstrated negative effects of hyperkyphosis on physical function, none have disentangled the relationship between hyperkyphosis, impaired function, and underlying spinal osteoporosis. The purpose of this study is to determine whether kyphosis, independent of spinal osteoporosis, is associated with mobility on the Timed Up and Go, and to quantify effects of other factors contributing to impaired mobility. We used data for 3,108 community-dwelling women aged 55-80 years in the Fracture Intervention Trial. All participants had measurements of kyphosis, mobility time on the Timed Up and Go test, height, weight, total hip bone mineral density (BMD), grip strength, and vertebral fractures at baseline visits in 1993. Demographic characteristics included age and smoking status. We calculated mean Timed Up and Go time by quartile of kyphosis. Using multivariate linear regression, we estimated the independent association of kyphosis with mobility time, and quantified effects of other covariates on mobility. Mean mobility time increased from 9.3 s in the lowest to 10.1 s in the highest quartile of kyphosis. In a multivariate-adjusted model, mobility time increased 0.11 s (p = 0.02) for each standard deviation (11.9°) increase in kyphosis. Longer performance times were significantly associated with increasing age, decreasing grip strength, vertebral fractures, body mass index ≥25, and total hip BMD in the osteoporotic range. Kyphosis angle is independently associated with decreased mobility on the Timed Up and Go, which is in turn correlated with increased fall risk. Hyperkyphosis may be a useful clinical marker signaling the need for evaluation of vertebral fracture and falling risk

Energy transport in aluminum targets irradiated by a 263-nm laser

Copyright 1988 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters, 52(10), 786-788, 1988 and may be found at http://dx.doi.org/10.1063/1.9928

Induction of Proinflammatory Cytokines and C-Reactive Protein in Human Macrophage Cell Line U937 Exposed to Air Pollution Particulates

Exposure to particulate matter air pollution causes inflammatory responses and is associated with the progression of atherosclerosis and increased cardiovascular mortality. Macrophages play a key role in atherogenesis by releasing proinflammatory cytokines and forming foam cells in subendothelial lesions. The present study quantified the inflammatory response in a human macrophage cell line (U937) after exposure to an ambient particulate sample from urban dust (UDP) and a diesel exhaust particulate (DEP). The effect of native UDP and DEP was compared with their corresponding organic extracts (OE-UDP/OE-DEP) and stripped particles (sUDP/sDEP) to clarify their respective roles. Exposure to OE-UDP, OE-DEP, UDP, DEP, and 2,3,7,8-tetrachlorodibenzo-p-dioxin led to a greater increase of interleukin (IL)-8, tumor necrosis factor-α, and cyclooxygenase-2 mRNA expression than did the stripped particles, whereas sUDP, sDEP, UDP, and DEP led to a greater production of C-reactive protein and IL-6 mRNA. The particles and the organic extract-induced expression of cyclooxygenase-2 and cytochrome P450 (CYP)1a1 was significantly suppressed by co-treatment with an aryl hydrocarbon receptor (AhR) antagonist, indicating that these effects are mainly mediated by the organic components, which can activate the AhR and CYP1a1. In contrast, the induction of C-reactive protein and IL-6 seems to be a particle-related effect that is AhR independent. The inflammatory response induced by particulate matter was associated with a subsequent increase of cholesterol accumulation, a hallmark of foam cells. Together, these data illustrate the interaction between particulate matter and the inflammatory response as well as the formation of cholesterol-accumulating foam cells, which are early markers of cardiovascular disease

Prospective surveillance of invasive group a streptococcal disease, Fiji, 2005-2007.

We undertook a prospective active surveillance study of invasive group A streptococcal (GAS) disease in Fiji over a 23-month period, 2005-2007. We identified 64 cases of invasive GAS disease, which represents an average annualized all-ages incidence of 9.9 cases/100,000 population per year (95% confidence interval [CI] 7.6-12.6). Rates were highest in those >65 years of age and in those <5 years, particularly in infants, for whom the incidence was 44.9/100,000 (95% CI 18.1-92.5). The case-fatality rate was 32% and was associated with increasing age and underlying coexisting disease, including diabetes and renal disease. Fifty-five of the GAS isolates underwent emm sequence typing; the types were highly diverse, with 38 different emm subtypes and no particular dominant type. Our data support the view that invasive GAS disease is common in developing countries and deserves increased public health attention