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Objective: Adults born either extremely preterm (EP, <28 weeks gestation) or extremely low birthweight (ELBW, <1000 g birthweight) have more obstructive airflow than controls of normal birthweight (>2499 g). We compared self-reported adverse respiratory health outcomes in young adults born EP/ELBW with controls following smoke exposure from the 2019/2020 wildfires in the Australian state of Victoria, and explored if any effects were mediated by airway obstruction, reflected in the forced expiratory volume in 1 second (FEV 1 )., Methods: EP/ELBW participants were derived from all survivors born in the state of Victoria in 1991-92. Contemporaneous controls of normal birthweight (>2499 g) were recruited in the newborn period and matched for sociodemographic variables. Both groups had been assessed at intervals through childhood and into adulthood. Those who participated in the most recent follow-up assessment at 25 years of age, when FEV 1 had been measured, were sent a survey when they were approximately 28 years of age asking about respiratory health related outcomes (respiratory symptoms, health services usage, medication uptake) following wildfire smoke exposure over the southern hemisphere summer of 2019-20., Results: A total of 296 participants (166 EP/ELBW; 130 controls) were sent the survey; 44% of the EP/ELBW group and 47% of the control group responded. Compared with controls, EP/ELBW respondents reported more overall respiratory problems (30%vs 20%) and specific respiratory symptoms (breathlessness, wheezing, cough and chest tightness) following wildfire smoke exposure, as well as higher health services usage (e.g. local health clinic, hospital emergency department) and medication uptake for respiratory-related problems. Higher FEV 1 values were associated with lower odds of most self-reported respiratory symptoms; adjusting for FEV 1 attenuated the differences between EP/ELW and control groups., Conclusion: Survivors born EP/ELBW may be at an increased risk of adverse respiratory health outcomes following wildfire smoke exposure in early adulthood, in part related to worse expiratory airflows., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: Facebook is a popular social media platform used globally to keep connected and informed. The aims of this study were to determine the contribution of Facebook to the participation rate of young adults enrolled in a longitudinal cohort study, and to examine systematic differences in participants recruited through Facebook compared with those recruited through traditional methods., Methods: Potential participants comprised 297 consecutive survivors born extremely preterm (<28 weeks' gestation) or extremely low birth weight (<1000 g birth weight) in 1991-92 in the state of Victoria, Australia, and 260 contemporaneously recruited normal birth weight (>2499 g birth weight) controls who had participated previously in a prospective cohort study. At 25 years of age participants were approached initially via traditional methods (mail, telephone, texts), and subsequently by Facebook for those difficult to contact or locate., Results: Contact was attempted with 523 young adults via traditional methods and 49% (n = 255) agreed to participate. Of the 208 participants unable to be located or contacted via traditional methods, 153 were subsequently located via Facebook. Of these 82% (n = 125) responded promptly within a day of receiving the Facebook invite, and 41% (n = 63) ultimately participated. The participation rate increased from 49% (255 of 523) to 61% (318 of 523) with the addition of Facebook, an absolute increase of 12%. Participants recruited by Facebook were slightly older, had lower rates of school completion and lower cognitive score at 18 years of age compared with those recruited via traditional methods., Conclusions: Using Facebook improved participation of young adults enrolled in this longitudinal preterm follow up study, 25 years after original recruitment., (Copyright © 2020 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.)

Measures of dietary patterns have been increasingly used to capture the complex nature of dietary intake. Few studies have investigated the impact of specific dietary patterns on bone health. Areal bone mineral density (BMD) at the lumbar spine and total hip and total body bone mineral content (BMC) were measured using DXA in Australian women aged 18-65 y (n = 527). Dietary patterns were assessed using a 4-d food diary and factor analysis. Scores were calculated based on the amount of each food consumed in the pattern and the weightings determined by factor analysis. Analysis was conducted using generalized estimating equation methods. Factor analysis revealed 5 dietary patterns. Pattern 1 (high consumption of refined cereals, soft drinks, fried potatoes, sausages and processed meat, vegetable oils, beer, and takeaway foods and low consumption of other vegetables, vegetable dishes, tea, coffee, fruit, wholegrain breads, and breakfast cereals) were significantly inversely associated with total body BMC (g) [β = -15.4 (95% CI -27.4, -3.3), adjusted for age, height, physical activity, smoking, education, energy, and calcium intake]. Pattern 4 (high consumption of legumes, seafood, seeds, nuts, wine, rice and rice dishes, other vegetables, and vegetable dishes and low consumption of bacon and ham) were directly associated with BMD at both sites and total body BMC in adjusted models [BMC (g): β = 15.2 (95% CI 2.84, 27.6), fully adjusted model]. The remaining dietary patterns were not consistently associated with BMD or BMC. This study identified specific dietary patterns associated with BMD and total body BMC among women and provides evidence that will contribute to potential food-based strategies for improving bone health.

Purpose: Validation of dual-energy X-ray absorptiometry (DXA) with the Hologic QDR 4500A (QDR 4500) Fan Beam X-ray densitometer for in vivo assessment of body fat content in mice., Methods: Precision of DXA fat measurement was assessed by repeated in vivo scanning and re-positioning of different sized mice (17.6, 24.6, 34.2 g). DXA fat and total mass measurements were correlated with dissected tissue weights in 240 female adult mice of seven strains (mean weights 21.9-26.8 g). Accuracy of DXA fat tissue measurements was assessed by chemical analysis in a subgroup of 40 female decapitated mice (mean weights 19.6-28.4 g)., Results: Precision of the DXA measurements for fat mass was dependent on body weight (mean coefficient of variation, CV, 34.2 g mouse: 7.53 ± 0.13%; 24.6 g mouse: 32.16 ± 0.17%; 17.6 g mouse: 40.64 ± 0.06%). A moderate to high correlation with the dissected fat tissue weights was found for all seven strains: r = 0.52, p ≤ 0.01 (AJ) to r = 0.83, p ≤ 0.01 (CBA, both mean weight = 22 g). The correlation of DXA measurements with the chemical analysis of the carcass was good to excellent (r = 0.80, p ≤ 0.01)., Conclusion: The results demonstrate that the QDR 4500A DXA can be utilised for in vivo measurements of fat content in mice weighing as little as 20 g, with excellent correlations between tissue dissections and chemical analysis demonstrating high consistency of the measurements. DXA values were consistently slightly lower than those by direct chemical analysis; however, the limits of agreement (mean difference 0.96 g) demonstrated good concordance between the two methods., (© 2007 Asian Oceanian Association for the Study of Obesity . Published by Elsevier Ltd. All rights reserved.)

Background: The long-term effects of pregnancy and lactation on measures of bone mineral in women remain unclear., Objective: We studied whether pregnancy or lactation has deleterious long-term effects on bone mineral in healthy women., Design: We measured bone mineral density (BMD; g/cm(2)) in women aged > or = 18 y. Analyses were performed on 3 data sets: study 1, 83 female twin pairs (21 monozygous and 62 dizygous) aged (x +/- SD) 42.2 +/- 15.5 y who were discordant for ever having been pregnant beyond 20 wk; study 2, 498 twin pairs aged 42.3 +/- 15.0 y; and study 3, 1354 individual twins, their siblings, and family members., Results: In study 1, there were no significant within-pair differences in unadjusted BMD or BMD adjusted for age, height, and fat mass at the lumbar spine or total-hip or in total-body bone mineral content (BMC; kg) (paired t tests). In study 2, there was no significant within-pair difference in measures of bone mineral or body composition related to the within-pair difference in number of pregnancies. In study 3, subjects with 1 or 2 (n = 455) and > or = 3 pregnancies (n = 473) had higher adjusted lumbar spine BMD (2.9% and 3.8%, respectively; P = 0.001) and total-body BMC (2.2% and 3.1%; P < 0.001) than did nulliparous women (n = 426). Parous women who breast-fed had higher adjusted total-body BMC (2.6%; P = 0.005), total-hip BMD (3.2%; P = 0.04), and lower fat mass (10.9%; P = 0.01) than did parous non-breast-feeders., Conclusion: We found no long-term detrimental effect of pregnancy or breast-feeding on bone mineral measures.

Low-intensity (<100 mW/cm(2)) pulsed ultrasound (US) is an established therapy for fracture repair. In both animal and human trials, such US has been shown to facilitate fresh fracture repair and initiate healing in fractures with repair defects. However, the mechanism by which US achieves these outcomes is not clear. One possible mechanism is the direct stimulation of bone formation. To investigate this hypothesis, the current study investigated the mRNA response of isolated bone-forming cells (UMR-106 cells) to a single 20-min dose of low-intensity pulsed US. Using a novel US-cell coupling method, US was found to stimulate expression of the immediate-early response genes c-fos and COX-2 and elevate mRNA levels for the bone matrix proteins ALP and OC. These findings suggest that low-intensity pulsed US has a direct effect on bone formation. This may contribute to the beneficial effect of low-intensity pulsed US on fracture repair.

Objective: To compare changes in total and regional body composition using dual energy X-ray absorptiometry (DEXA) after subjects lost weight through change in diet or exercise., Design: A 12-month, randomized, controlled study of two weight-loss interventions-low-fat diet ad libitum or moderate, unsupervised exercise-in free-living, middle-aged men. Compliance was determined at monthly measurement sessions through food records and activity logs; DEXA scans were performed every 3 months., Subjects/setting: Fifty-eight overweight men (mean body mass index = 29.0 +/- 2.6; mean age = 43.4 +/- 5.7 years) recruited from a national corporation were assigned randomly to diet, exercise, or control groups., Interventions: One group reduced dietary fat to 26.4% of energy intake but kept activity unchanged; another group self-selected aerobic exercise (three sessions per week at 65% to 75% maximum heart rate) but kept diet unchanged. A control group maintained weight., Main Outcome Measures: At 12 months, measurements of weight, total and regional fat mass and lean mass, energy intake, and percentage dietary fat; physical activity indexes., Statistical Analyses: Results were analyzed using paired t tests and analysis of variance., Results: Mean weight loss was 6.4 +/- 3.3 kg in dieters and 2.6 +/- 3.0 kg in exercisers; control subjects maintained weight. DEXA scans revealed that 40% of dieters' weight loss was lean tissue; more than 80% of weight lost by exercisers was fat. Exercisers maintained limb lean tissue and lost fat mass., Conclusions: Greater total weight and lean tissue loss occurred when subjects lost weight through a low-fat diet consumed ad libitum than when subjects participated in unsupervised aerobic exercise. Use of DEXA enabled identification of progressive total and regional changes in fat and lean tissue.

The in vitro effect of 1 alpha,25-dihydroxyvitamin D3 on the function of beta cells of the endocrine pancreas was investigated. Neonatal islets maintained in serum-free medium, or medium supplemented with 0.5% fetal bovine serum achieved a 2.5-fold increase in medium insulin levels in response to 10(8) M 1 alpha,25-dihydroxyvitamin D3 (P less than 0.001). The effect of 1,25-dihydroxyvitamin D3 required at least 96 h treatment to become evident and was similar at medium glucose concentrations of 10 and 20 mM. Cell-associated insulin was increased in 1 alpha,25-dihydroxyvitamin D3-treated cultures maintained in 0.5% serum. These data suggest that 1 alpha,25-dihydroxyvitamin D3 may have a direct effect in the beta cell.

Using a commercial kit method we obtained a vitamin D metabolite level within the normal range in a patient with biopsy-proven osteomalacia. This suggested that the ethanol extraction method employed had not removed serum factors known to falsely elevate the measurement of vitamin D metabolites. We therefore compared the levels measured after ethanol extraction and after purification by chromatography on Sep-pak C18 or Sephadex LH-20. Vitamin D metabolite levels after ethanol extraction of sera correlated with, but were higher than, those after chromatography on Sep-pak C18 cartridges (r = 0.84; 134 +/- 76 vs 76 +/- 46 nmol/l: mean +/- SD; p less than 0.01). Results were similar after chromatography on Sep-pak C18 and Sephadex LH-20 (r = 0.95; 79 +/- 46 vs 68 +/- 41 nmol/l). Sera from 5 patients (4 with osteomalacia, 1 with chronic pancreatitis/malabsorption) had vitamin D metabolite levels in the normal range after ethanol extraction but had low levels after Sep-pak C18 chromatography; four of these sera also had low levels after chromatography on Sephadex LH-20. These findings indicate that chromatography of serum on Sep-pak C18 cartridges corrects falsely elevated vitamin D metabolite levels measured by protein binding assay.

In normal volunteers infusion of parathyroid extract raised plasma 1,25-dihydroxyvitamin D (1,25-[OH]2D) levels by 80% (peak 8--40 h after infusion) without producing any significant change in plasma calcium, phosphate, or magnesium. An oral calcium load suppressed plasma 1,25-(OH)2D to 63% of control values within 48--72 h. These responses will be useful in the diagnosis and management of disturbances of calcium and mineral metabolism in which vitamin D metabolism is abnormal.