Thyroid Stimulating Hormone and Bone Mineral Density: Evidence From a Two‐Sample Mendelian Randomization Study and a Candidate Gene Association Study

With population aging, prevalence of low bone mineral density (BMD) and associated fracture risk are increased. To determine whether low circulating thyroid stimulating hormone (TSH) levels within the normal range are causally related to BMD, we conducted a two‐sample Mendelian randomization (MR) study. Furthermore, we tested whether common genetic variants in the TSH receptor (TSHR) gene and genetic variants influencing expression of TSHR (expression quantitative trait loci [eQTLs]) are associated with BMD. For both analyses, we used summary‐level data of genomewide association studies (GWASs) investigating BMD of the femoral neck (n = 32,735) and the lumbar spine (n = 28,498) in cohorts of European ancestry from the Genetic Factors of Osteoporosis (GEFOS) Consortium. For the MR study, we selected 20 genetic variants that were previously identified for circulating TSH levels in a GWAS meta‐analysis (n = 26,420). All independent genetic instruments for TSH were combined in analyses for both femoral neck and lumbar spine BMD. In these studies, we found no evidence that a genetically determined 1–standard deviation (SD) decrease in circulating TSH concentration was associated with femoral neck BMD (0.003 SD decrease in BMD per SD decrease of TSH; 95% CI, –0.053 to 0.048; p = 0.92) or lumbar spine BMD (0.010 SD decrease in BMD per SD decrease of TSH; 95% CI, ?0.069 to 0.049; p = 0.73). A total of 706 common genetic variants have been mapped to the TSHR locus and expression loci for TSHR. However, none of these genetic variants were associated with BMD at the femoral neck or lumbar spine. In conclusion, we found no evidence for a causal effect of circulating TSH on BMD, nor did we find any association between genetic variation at the TSHR locus or expression thereof and BMD. © 2018 The Authors. Journal of Bone and Mineral Research Published by WileyPeriodicals, Inc.     

Diminished Bone Strength Is Observed in Adult Women and Men Who Sustained a Mild Trauma Distal Forearm Fracture During Childhood

Children and adolescents who sustain a distal forearm fracture (DFF) owing to mild, but not moderate, trauma have reduced bone strength and cortical thinning at the distal radius and tibia. Whether these skeletal deficits track into adulthood is unknown. Therefore, we studied 75 women and 75 men (age range, 20 to 40 years) with a childhood (age <18 years) DFF and 150 sex‐matched controls with no history of fracture using high‐resolution peripheral quantitative computed tomography (HRpQCT) to examine bone strength (ie, failure load) by micro–finite element (µFE) analysis, as well as cortical and trabecular bone parameters at the distal radius and tibia. Level of trauma (mild versus moderate) was assigned using a validated classification scheme, blind to imaging results. When compared to sex‐matched, nonfracture controls, women and men with a mild trauma childhood DFF (eg, fall from standing height) had significant reductions in failure load (p < 0.05) of the distal radius, whereas women and men with a moderate trauma childhood DFF (eg, fall while riding a bicycle) had values similar to controls. Consistent findings were observed at the distal tibia. Furthermore, women and men with a mild trauma childhood DFF had significant deficits in distal radius cortical area (p < 0.05), and significantly lower dual‐energy X‐ray absorptiometry (DXA)‐derived bone density at the radius, hip, and total body regions compared to controls (all p < 0.05). By contrast, women and men with a moderate trauma childhood DFF had bone density, structure, and strength that did not differ significantly from controls. These findings in young adults are consistent with our observations in children/adolescents with DFF, and they suggest that a mild trauma childhood DFF may presage suboptimal peak bone density, structure, and strength in young adulthood. Children and adolescents who suffer mild trauma DFFs may need to be targeted for lifestyle interventions to help achieve improved skeletal health. © 2014 American Society for Bone and Mineral Research.     

Influence of Aromatase Inhibition on the Bone‐Protective Effects of Testosterone

The influence of the aromatase enzyme in androgen‐induced bone maintenance after skeletal maturity remains somewhat unclear. Our purpose was to determine whether aromatase activity is essential to androgen‐induced bone maintenance. Ten‐month‐old male Fisher 344 rats (n = 73) were randomly assigned to receive Sham surgery, orchiectomy (ORX), ORX + anastrozole (AN; aromatase inhibitor), ORX + testosterone‐enanthate (TE, 7.0 mg/wk), ORX + TE + AN, ORX + trenbolone‐enanthate (TREN; nonaromatizable, nonestrogenic testosterone analogue; 1.0 mg/wk), or ORX + TREN + AN. ORX animals exhibited histomorphometric indices of high‐turnover osteopenia and reduced cancellous bone volume compared with Shams. Both TE and TREN administration suppressed cancellous bone turnover similarly and fully prevented ORX‐induced cancellous bone loss. TE‐ and TREN‐treated animals also exhibited greater femoral neck shear strength than ORX animals. AN co‐administration slightly inhibited the suppression of bone resorption in TE‐treated animals but did not alter TE‐induced suppression of bone formation or the osteogenic effects of this androgen. In TREN‐treated animals, AN co‐administration produced no discernible effects on cancellous bone turnover or bone volume. ORX animals also exhibited reduced levator ani/bulbocavernosus (LABC) muscle mass and elevated visceral adiposity. In contrast, TE and TREN produced potent myotrophic effects in the LABC muscle and maintained fat mass at the level of Shams. AN co‐administration did not alter androgen‐induced effects on muscle or fat. In conclusion, androgens are able to induce direct effects on musculoskeletal and adipose tissue, independent of aromatase activity. © 2014 American Society for Bone and Mineral Research.     

Older men with low serum IGF‐1 have an increased risk of incident fractures: The MrOS Sweden study

Osteoporosis‐related fractures constitute a major health concern not only in women but also in men. Insulin‐like growth factor 1 (IGF‐1) is a key determinant of bone mass, but the association between serum IGF‐1 and incident fractures in men remains unclear. To determine the predictive value of serum IGF‐1 for fracture risk in men, older men (n = 2902, mean age of 75 years) participating in the prospective, population‐based Osteoporotic Fractures in Men (MrOS) Sweden study were followed for a mean of 3.3 years. Serum IGF‐1 was measured at baseline by radioimmunoassay. Fractures occurring after the baseline visit were validated. In age‐adjusted hazards regression analyses, serum IGF‐1 associated inversely with risk of all fractures [hazard ratio (HR) per SD decrease = 1.23, 95% confidence interval (CI) 1.07–1.41], hip fractures (HR per SD decrease = 1.45, 95% CI 1.07–1.97), and clinical vertebral fractures (HR per SD decrease = 1.40, 95% CI 1.10–1‐78). The predictive role of serum IGF‐1 for fracture risk was unaffected by adjustment for height, weight, prevalent fractures, falls, and major prevalent diseases. Further adjustment for bone mineral density (BMD) resulted in an attenuated but still significant association between serum IGF‐1 and fracture risk. Serum IGF‐1 below but not above the median was inversely related to fracture incidence. The population‐attributable risk proportion was 7.5% for all fractures and 22.9% for hip fractures. Taken together, older men with low serum IGF‐1 have an increased fracture risk, especially for the two most important fracture types, hip and vertebral fractures. The association between serum IGF‐1 and fracture risk is partly mediated via BMD. © 2011 American Society for Bone and Mineral Research.     

广东省广藿香土壤生态适宜性评价

[目的]分析广藿香的适宜生长区域,为确定广藿香种植产区以及合理规划生产布局提供科学依据.[方法]通过在作物环境需求数据库--Ecocrop 1 中筛选重点土壤生态环境因子作为评价指标,以地理信息系统空间分析技术为手段,对广藿香的土壤生态适宜性进行分析和评价.[结果]在珠江三角洲以及粤东粤西的沿海区域仍然存在适宜广藿香生...     

“五项选择连续反应时间任务”实验系统的研制

【目的】建立检测实验大鼠持续性主动注意力和冲动行为的实验系统。【方法】利用"五项选择连续反应时间任务"(5-choice serial reaction time task,5-CSRTT)的设计原理建立检测实验大鼠持续性主动注意力和冲动行为的实验系统。【结果】实验系统由实验箱及相应控制部分构成,并由微型电脑软件控制,能实现对大鼠相关行为的自动检测。【结论】所建立的实验系统能较好且真实地自动检测实验大鼠的持续性主动注意力和冲动行为,为注意缺陷多动障碍(ADHD)动物研究的进一步深入提供良好的条件。     

乳癌的外科治疗

目的　探讨乳癌外科治疗的策略。方法　回顾性分析 2 5 8例乳癌的临床资料。结果　 (1)13 6例Ⅰ～Ⅱ期患者行改良根治术 ,总生存率为 10 0 % ,无复发生存率为 92 .6%。 (2 )保留乳房的乳癌手术 2例 ,1例 (5 0 % )术后 5个月局部复发。 (3 )Ⅲ期乳癌行改良根治术 88例 ,行根治术 2 0例 ,两者的无瘤生存率与总生存率差异无显著性。 (4 )Ⅳ期患者有 5例行根治性手术 ,取得了较好的效果。 (5 )采用特制乳腺刀游离皮瓣和电刀切除 ,并合理清扫腋窝 ,手术输血率为 3 .5 %。局部并发症有术后皮下积血 2 .7% ,皮瓣坏死 7.4% ,皮下积液 18.6% ,患侧肢体水肿 4.3 %。结论　改良根治术是治疗Ⅰ～Ⅲ期乳癌的主要术式 ,乳腺刀和电刀的使用 ,可以减少手术输血 ,缩短手术时间 ;合理的腋窝清扫可以减少患侧肢体水肿的发生。