A survey of the introduction of modern mathematics into the New England public high school curriculum

Thesis (Ed.M.)--Boston Universit

Guanine nucleotides are potent secretagogues in permeabilized parathyroid cells

AbstractWe studied the effects of GTP and its' analogues on PTH release in permeabilized parathyroid cells to assess their role in mediating the unusual inverse relationship between Ca2+ and PTH release in intact parathyroid cells. Both 10-5 M GppNHp and GTPγS, nonhydrolysable analogues of GTP, produce up to an 8-fold enhancement of PTH release, which is dose-dependent. This effect is specific for GTP analogues as we could not mimic it with other nucleotides. 10−3 M GDPβS, a nonhydrolysable GDP analogue, completely abolishes GppNHp-stimulated hormone release, providing further support for mediation of this effect by a guanine-nucleotide regulatory protein. In GppNHp-stimulated cells, PTH release is maximal at free [Ca2+] less than 200 nM and progressively decreases as the free [Ca2+] increases from 300 nM to 100 μM. These results suggest the presence of a guanine-nucleotide binding protein in the parathyroid cell that may play an important role in the regulation of PTH secretion by Ca2+ and perhaps other secretagogues

Effect of Vitamin D on serum markers of bone turnover in SLE in a randomised controlled trial

© 2019 Author(s). Objective Bone health in SLE is adversely affected by vitamin D deficiency, inflammatory cytokines and glucocorticoid use. We hypothesised that vitamin D supplementation would increase markers of bone formation and decrease markers of bone resorption in SLE subjects. Methods We studied 43 vitamin D-deficient SLE subjects who participated in a 12-week randomised controlled trial of 2000-4000 IU/day vitamin D supplementation versus placebo. Subjects had inactive SLE (SLE Disease Activity Index ≤4) and were taking D, N-terminal propeptide of type 1 collagen (P1NP) and C-telopeptide (CTX). We tested the effect of vitamin D versus placebo on change (δ) in P1NP and δCTX in an intention-to-treat analysis. Secondary analyses evaluated whether vitamin D affected bone turnover among subjects achieving vitamin D repletion (≥30 ng/mL) or currently taking glucocorticoids. Results 28 subjects were randomised to vitamin D and 15 to placebo. Mean age was 39 years and 40% were using glucocorticoids at enrolment. Repletion was achieved by 46% in the vitamin D group versus none in the placebo group. Changes in bone turnover markers were not significantly different in the vitamin D group versus placebo group (median δP1NP -0.2 vitamin D group vs -1.1 placebo group (p=0.83); median δCTX +3.5 vitamin D group vs -37.0 placebo group (p=0.50)). The effect of vitamin D did not differ based on achieving vitamin D repletion or baseline glucocorticoid use. Conclusion Vitamin D supplementation did not affect the 12-week change in bone turnover markers among SLE subjects in this trial

Effect of Dietary Composition of Weight Loss Diets on High Sensitivity C-Reactive Protein: The Randomized POUNDS LOST Trial

Overweight and obesity are associated with increased high sensitivity C-reactive protein (hsCRP) levels. The purpose of this study was to determine if weight loss diets differing in fat, protein, or carbohydrate composition differentially reduce hsCRP. POUNDS (Preventing Overweight Using Novel Dietary Strategies) LOST was a two-year trial of overweight and obese adults randomly allocated to one of four weight loss diets with targeted percentages of energy derived from fat, protein, and carbohydrates (20,15,65%;20,25,55%;40,15,45%;40,25,35%, respectively). hsCRP was measured at baseline, 6, and 24 months among 710 participants, and adiposity as measured by dual X-ray absorptiometry (N=340) or abdominal computed tomography (N=126) was correlated with hsCRP change. At 6 months, hsCRP was reduced in all trial participants by −24.7% (IQR +7%,−50%), weight by −6.7% (IQR −3%,−11%), and waist circumference by −6.0% (IQR −3%,−10%) (all P<.002), with no significant differences according to dietary composition. The percent change in hsCRP at 6 and 24 months correlated modestly with change in weight, waist circumference, fasting insulin, fasting glucose, HOMA, and most lipid levels. Reductions in hsCRP persisted despite an approximate 50% regain of weight by 24 months. The percent change in hsCRP at 24 months significantly correlated with changes in total body fat (r=0.42), total abdominal adiposity (r=0.52), subcutaneous abdominal adiposity (r=0.52), visceral adiposity (r=0.47), and hepatic tissue density (r=−0.34) (all P<0.0006). In conclusion, weight loss decreased hsCRP by similar magnitude, irrespective of dietary composition. Clinicians concerned about inflammation and cardiovascular risk should recommend weight loss diets most likely to succeed for their patients

Prevention of Fractures in Older People with Calcium and Vitamin D

The greatest cause of fracture in older people is osteoporosis which contributes to increased morbidity and mortality in older people. A number of meta-analyses have been performed assessing the effectiveness of calcium supplementation alone, vitamin D supplementation alone and the combined therapy on bone loss and fracture reduction in older people. The results of these meta-analyses indicate that vitamin D supplementation alone is unlikely to reduce fracture risk, calcium supplementation alone has a modest effect in reducing total fracture risk, but compliance with calcium supplements is poor in the long term. The combination of calcium supplementation with vitamin D supplementation, particularly in those at risk of marginal and low vitamin D status reduces total fractures, including hip fractures. Therefore older people would be recommended to consume adequate dietary calcium (>1100 mg/day) together with maintaining adequate vitamin D status (>60 nmol/L 25(OH)D) to reduce risk of fracture. It is a challenge to consume sufficient dietary calcium from dietary sources, but the increasing range of calcium fortified foods could assist in increasing the dietary calcium intake of older people. In addition to the usual dairy based food sources, vitamin D supplements are likely to be required for older people with reduced mobility and access to sunlight

Menopausal hormone therapy reduces the risk of fracture regardless of falls risk or baseline FRAX probability — Results from the Women’s Health Initiative hormone therapy trials

Summary In a combined analysis of 25,389 postmenopausal women aged 50–79 years, enrolled in the two Women’s Health Initiative hormone therapy trials, menopausal hormone therapy vs. placebo reduced the risk of fracture regardless of baseline FRAX fracture probability and falls history. Introduction The aim of this study was to determine if the anti-fracture efficacy of menopausal hormone therapy (MHT) differed by baseline falls history or fracture risk probability as estimated by FRAX, in a combined analysis of the two Women’s Health Initiative (WHI) hormone therapy trials. Methods A total of 25,389 postmenopausal women aged 50–79 years were randomized to receive MHT (n = 12,739) or matching placebo (n = 12,650). At baseline, questionnaires were used to collect information on falls history, within the last 12 months, and clinical risk factors. FRAX 10-year probability of major osteoporotic fracture (MOF) was calculated without BMD. Incident clinical fractures were verified using medical records. An extension of Poisson regression was used to investigate the relationship between treatment and fractures in (1) the whole cohort; (2) those with prior falls; and (3) those without prior falls. The effect of baseline FRAX probability on efficacy was investigated in the whole cohort. Results Over 4.3 ± 2.1 years (mean ± SD), MHT (vs. placebo) significantly reduced the risk of any clinical fracture (hazard ratio [HR] 0.72 [95% CI, 0.65–0.78]), MOF (HR 0.60 [95% CI, 0.53–0.69]), and hip fracture (0.66 [95% CI, 0.45–0.96]). Treatment was effective in reducing the risk of any clinical fracture, MOF, and hip fracture in women regardless of baseline FRAX MOF probability, with no evidence of an interaction between MHT and FRAX (p > 0.30). Similarly, there was no interaction (p > 0.30) between MHT and prior falls. Conclusion In the combined WHI trials, compared to placebo, MHT reduces fracture risk regardless of FRAX probability and falls history in postmenopausal women

Vitamin D and Musculoskeletal Status in Nova Scotian Women Who Wear Concealing Clothing

Bone and muscle weakness due to vitamin D deficiency is common among Muslim women who reside in sunny, equatorial countries. The purpose of this study was to determine if living in a northern maritime location additionally disadvantages women who wear concealing clothes. A cross-sectional matched pair design was used to compare women who habitually wore concealing clothing with women who dressed according to western norms. Each premenopausal hijab-wearing woman (n = 11) was matched by age, height, weight and skin tone with a western-dressed woman. Subjects were tested by hand grip dynamometry to assess muscular strength and by quantitative ultrasound at the calcaneus to assess bone status. Nutritional intake was obtained by 24 h recall. Serum 25-hydroxyvitamin D (s-25(OH)D) status was determined in seven matched pairs. The hijab group had lower s-25(OH)D than women who wore western clothes (40 ± 28 vs. 81 ± 32 nmol/L, p= 0.01). Grip strength in the right hand was lower in the hijab-wearing women (p = 0.05) but this appeared to be due to less participation in intense exercise. Bone status did not differ between groups (p= 0.9). Dietary intake of vitamin D was lower in the hijab-wearers (316 ± 353 vs. 601 ± 341 IU/day, p= 0.001). This pilot study suggests that women living in a northern maritime location appear to be at risk for vitamin D insufficiency and therefore should consider taking vitamin D supplements

Association of Physical Activity and Fracture Risk Among Postmenopausal Women

Importance: Physical activity is inversely associated with hip fracture risk in older women. However, the association of physical activity with fracture at other sites and the role of sedentary behavior remain unclear. Objective: To assess the associations of physical activity and sedentary behavior with fracture incidence among postmenopausal women. Design, Setting, and Participants: The Women\u27s Health Initiative prospective cohort study enrolled 77206 postmenopausal women aged 50 to 79 years between October 1993 and December 1998 at 40 US clinical centers. Participants were observed for outcomes through September 2015, with data analysis conducted from June 2017 to August 2019. Exposures: Self-reported physical activity and sedentary time. Main Outcomes and Measures: Hazard ratios (HRs) and 95% CIs for total and site-specific fracture incidence. Results: During a mean (SD) follow-up period of 14.0 (5.2) years among 77206 women (mean [SD] age, 63.4 [7.3] years; 66072 [85.6%] white), 25516 (33.1%) reported a first incident fracture. Total physical activity was inversely associated with the multivariable-adjusted risk of hip fracture ( \u3e 17.7 metabolic equivalent [MET] h/wk vs none: HR, 0.82; 95% CI, 0.72-0.95; P for trend \u3c .001). Inverse associations with hip fracture were also observed for walking ( \u3e 7.5 MET h/wk vs none: HR, 0.88; 95% CI, 0.78-0.98; P for trend = .01), mild activity (HR, 0.82; 95% CI, 0.73-0.93; P for trend = .003), moderate to vigorous activity (HR, 0.88; 95% CI, 0.81-0.96; P for trend = .002), and yard work (HR, 0.90; 95% CI, 0.82-0.99; P for trend = .04). Total activity was positively associated with knee fracture ( \u3e 17.7 MET h/wk vs none: HR, 1.26; 95% CI, 1.05-1.50; P for trend = .08). Mild activity was associated with lower risks of clinical vertebral fracture (HR, 0.87; 95% CI, 0.78-0.96; P for trend = .006) and total fractures (HR, 0.91; 95% CI, 0.87-0.94; P for trend \u3c .001). Moderate to vigorous activity was positively associated with wrist or forearm fracture (HR, 1.09; 95% CI, 1.03-1.15; P for trend = .004). After controlling for covariates and total physical activity, sedentary time was positively associated with total fracture risk ( \u3e 9.5 h/d vs \u3c 6.5 h/d: HR, 1.04; 95% CI, 1.01-1.07; P for trend = .01). When analyzed jointly, higher total activity mitigated some of the total fracture risk associated with sedentary behavior. Analysis of time-varying exposures resulted in somewhat stronger associations for total physical activity, whereas those for sedentary time were materially unchanged. Conclusions and Relevance: In older ambulatory women, higher total physical activity was associated with lower total and hip fracture risk but higher knee fracture risk. Mild activity and walking were associated with lower hip fracture risk, a finding with important public health implications because these activities are common in older adults. The positive association between sedentary time and total fracture risk requires further investigation