Relationships between anthropometric adiposity indexes and bone mineral density in a cross-sectional Chinese study

Background ContextPrevious studies have reported conflicting results for the relationships between anthropometric adiposity indexes and bone mineral density, based on dual-energy X-ray absorptiometry (DXA). However, few studies were published based on quantitative computed tomography (QCT), especially for Chinese population.PurposeTo evaluate the associations of spine bone mineral density (BMD) with body mass index (BMI), waist circumstance (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and a body shape index (ABSI) using QCT.Study Design/SettingA Cross-sectional study.Patient SampleAround 3,457 participants in multiple communities across 7 administrative regions of China.Outcome MeasuresSpine BMD was measured using QCT, and the classification of osteoporosis was defined as follows: 1) osteoporosis if BMD <80mg/cm³, 2) osteopenia if BMD 80–119 mg/cm³, and 3) normal bone mass if BMD≥120 mg/cm³.MethodsThis study was conducted using convenient sampling between 2013 and 2017. Multivariable linear regression model and logistic regression models were used for the associations of continuous and categorical BMD, respectively.ResultsAround 3,405 participants were included in the final analyses, including 1,272 males and 2,133 females, with spine BMD of 111.00±35.47 mg/cm³ and 99.38±40.60 mg/cm³, respectively. Spine BMD decreased significantly with the increase of ABSI in females (adjusted β, ?5.74; 95% confidence interval [CI], ?8.50 to ?2.98), and this trend also was kept in females aged at less than 60 years (adjusted β, ?14.54; 95% CI, ?20.40 to ?8.68), and females with age ≥60 years (adjusted β, ?7.59; 95% CI, ?10.91 to ?4.28). However, this inverse association was observed only in males with age ≥ 60 years (adjusted β, ?5.19; 95% CI, ?10.08 to ?0.29). Except ABSI, negative associations of Spine BMD with WC (adjusted β, ?0.46; 95% CI, ?0.77 to ?0.15), WHR (adjusted β, ?6.25; 95% CI, ?10.63 to ?1.86), WHtR (adjusted β, ?6.80; 95% CI, ?11.63 to ?1.97) were shown in females aged at <60 years, and positive association with BMI in males with age ≥60 years (adjusted β, 0.92; 95% CI, 0.29–1.55).ConclusionsABSI had more remarkable association with spine BMD, compared with the other four indexes.     

A capnography and transcutaneous CO2 profile of bariatric patients during early postoperative period after opioid-sparing anesthesia

BackgroundNoninvasive monitoring of partial pressure of carbon dioxide can be accomplished indirectly with capnography (P_ETCO₂) or with transcutaneous carbon dioxide monitoring (P_TCCO₂). The use of capnography has been shown to offer an advantage over pulse oximetry alone in the early detection of adverse respiratory events when supplemental oxygen is administered. Furthermore, capnography allows for the monitoring of various respiratory measures, including end-tidal carbon dioxide, respiratory rate, tidal volume, and changes in breathing patterns. Transcutaneous CO₂ also closely approximates arterial CO₂ values, but is not as easy to monitor for prolonged periods. The purpose of this study was to examine the usefulness of capnography and of transcutaneous carbon dioxide monitoring in patients recovering from obesity surgery at high risk of developing postoperative obstructive sleep apnea.MethodsIn a prospective observational study, 64 bariatric surgery patients at risk of developing obstructive sleep apnea were monitored in the postanesthesia care unit (PACU) with either capnography alone (31 patients) or capnography plus transcutaneous carbon dioxide monitoring (33 additional patients) every 3–5 minutes for the duration of their recovery. Primary endpoints included end-tidal and transcutaneous carbon dioxide, peripheral oxygen saturation, respiratory rate, pain scores, and incidence of adverse respiratory events.ResultsAlthough no adverse pulmonary events were observed, capnography detected several patients who experienced short periods of respiratory apnea while maintaining pulse oximetry readings within normal limits. Transcutaneous values were slow to change and averaged 4.5 ± 5.5 mm Hg (P < .05) higher than corresponding end-tidal measurements.ConclusionsThese results indicate the capabilities of both these noninvasive techniques for postoperative monitoring. Capnography acutely monitors changes in respiration, whereas transcutaneous monitoring more accurately reflects arterial CO₂ levels.     

微型心电监视仪的研制

本文介绍我们近年研制成功的一种全新的微型化的心电监视仪。该仪器集主机，显示器，电极导联于一体，适合医务人员随身携带，用于需要快速、简易、准确地获取人体心电图形与心率数据的场合。     

超抗原SEA抗肿瘤研究进展

超抗原是指一些细菌或病毒编码的蛋白分子，只需极低浓度即可激活大量的淋巴细胞克隆．作为一种强大的T细胞激活剂，超抗原成为肿瘤免疫治疗研究的热点之一．本文对其特性及目前的研究进展作一综述．     

Synthesis of substituted 7,12-dihydropyrido[3,2-b:5,4-b']diindoles: rigid planar benzodiazepine receptor ligands with inverse agonist/antagonist properties

A series of 1-, 2-, 3-, 4-, 5-, 6-, 7-, 10-, and 12-substituted pyridodiindoles were synthesized and screened in vitro against [3H]diazepam for activity at the benzodiazepine receptor (BzR). In vitro, the 2-substituted pyridodiindoles were found to be the most potent (IC50 less than 10 nM) of this new class of BzR ligands. In vivo, 2-methoxypyridodiindole 19a (IC50 = 8 nM) was found to be the most potent partial inverse agonist (proconvulsant) of the series. The parent compound 2 (IC50 = 4 nM) was only slightly less potent. In addition, 2-hydroxypyridodiindole 21a (IC50 = 6 nM) was found to exhibit potent proconvulsant activity when administered as a prodrug derivative, pivaloyl ester 22. 2-Chloropyridodiindole 16a (IC50 = 10 nM) was devoid of preconvulsant activity; however, 16a was found to be the most potent antagonist of the anticonvulsant effects of diazepam in this class of BzR ligands. From the in vivo data available, substitution on ring E of 2 with electron-withdrawing groups results in antagonists at BzR, while replacement of hydrogen at C-2 with electron-releasing groups provides enhanced inverse agonist activity. The pyridodiindoles were used as "templates" for the formulation of a model of the inverse agonist/antagonist active site of the BzR. The proposed model consists of a hydrogen bond acceptor site (A1) and a hydrogen bond donor site (D2) disposed 6.0-8.5 A from each other on the receptor protein. The hydrogen-bonding sites are believed to be located at the base of a narrow cleft. A large lipophilic pocket at the mouth of the narrow cleft serves to direct molecules into the binding site, while the presence of a small lipophilic pocket permits substitution only at position 2 of the pyridodiindole nucleus for maximum binding potency.     

绝经后骨质疏松大鼠模型的综合评价

利用双能X线骨密度仪、扫描电镜和骨生物力学试验综合评价大鼠去卵巢后的骨骼状况。结果显示：①大鼠卵巢切除后,活体、离体腰椎以及股骨（除R3区）、胫骨近端干骺端（R1区）的离体骨密度显著下降（P＜0.01),离体L5和L6的骨丢失率最大,达13%;②骨小梁减少、变细,连接中断,骨小梁表面有吸收陷窝;③腰椎压缩强度和股骨力学性均下降,前者更明显,腰椎最大压缩力下降率达33.32%。提示：①类似于绝经后妇女,6月龄大鼠在卵巢切除4个月后骨量和骨质量均下降,特别在富含松质骨的部位,如腰椎、股骨远端等;②利用绝经后骨质疏松大鼠模型评价骨质疏松新药的有效性,应包括该新药对骨量、骨结构和骨强度的作用。     

老年人低位硬膜外麻醉围术期自主神经功能的变化

目的：应用心率变异性（HRV）分析仪监测评估低位硬膜外麻醉围术期自主神经的改变。方法：选择低位硬膜外麻醉下择期手术患者20例,ASAⅠ-Ⅱ级,按年龄分为老年组和年轻组,每组10例,观察术前1d、麻醉完善后切皮前、切皮后30min、术后2h,1d,3d,7d处时相点的心率（HR）、平均动脉压（MAP）以及HRV分析各成分变化。结果：围术期老年组HRV显示RMSSD（相邻RR间期差值均方根）、总频（TP）、低频（LF）、代频标化（LFnorm)均呈显著性下降,同时伴有心率减慢、平均动脉下降。年轻组TP和LF在麻醉完善后切皮前、术后2h,1d下降显著,于术后3d恢复,而R和MAP在围术期无显著改变。两组两比较,老年组TP和LF在麻醉后各时相占 明显低于年轻组（P＜0．01）。老年组高频（HF）及高频标化（HFnorm)在麻醉给药后切皮瓣均无明显变化,但在术中和术后各时相点的下降,而年轻组仅切皮后30min,出现一过性下降。结论HRV可较好地评估围术期机体自神经变化;术期麻醉和手术创伤均可使机体自主神系统调节受损,尤其老年人受损程度大,恢复慢,恢复慢,术后1周仍不能完全恢复。     

血液分离胶的制备研究

目的 :对血液分离胶的制备进行研究。方法 :用天然橡胶和特效触变剂等原料制备具有触变性的凝胶 ,研究该凝胶分离血清的较优组成。结果 :血液分离胶的较优组成是天然橡胶 12 .8%、特效触变剂 2 8.0 %和溶剂汽油 5 8.2 %。结论 :所制备的血液分离胶具有制备容易、分离效果好和成本较低等优点。     

成都地区汉族人群ACE基因多态性与血清ACE活性的相关性

为调查中国汉族人群血管紧张素转换酶(ACE) 基因多态性分布及与血清ACE(SA CE)活性的相关性.采用比色法和PCR技术,对90例健康汉族人群进行SACE活性和ACE基因插入/缺失(I/D)多态性的检测.结果显示:中国汉族人群ACE基因DD型占18%,DI型占44%,II 型占38%, D和I等位基因频率分别为0.40和0.60.ACE基因多态性与SACE活性密切相关,提示不同种族间ACE基因分布存在着差异,中国汉族人群ACE基因多态性以II型和I等位基因占优势;SACE活性受ACE基因I/D多态性的影响.