Relationship between insulin-like growth factor I, dehydroepiandrosterone sulfate and proresorptive cytokines and bone density in cystic fibrosis

Introduction Patients with cystic fibrosis (CF) are known to be at risk for early osteoporosis, and the mechanisms that mediate bone loss are still being delineated. The aim of the present investigation was to investigate if a correlation exists in these patients between skeletal measurements by dual-energy x-ray absorptiometry (DXA) and two anabolic factors, dehydroepiandrosterone (DHEA) and insulin-like growth factor I (IGF-I), and proresorptive factors such as the cytokines interleukin-1β, tumor necrosis factor α, and interleukin-6. Methods We studied 32 outpatients (18 females; mean age: 26.2 ± 7.9 years) at a tertiary care medical center. The subjects had venous samples obtained, underwent anthropometric and bone mineral density (BMD) measurements, and completed a health survey. Serum IGF-I concentrations were below the age-adjusted mean in 78% of the participants, and DHEA sulfate (DHEAS) concentrations were low in 72%. Serum concentrations of all cytokines were on the low side of normal; nonetheless, there was a modest inverse correlation between IL-1β and BMD at all sites. Results In univariate analyses, IGF-I and DHEAS were significant correlates of BMD or bone mineral content. In final multivariate models controlling for anthropometric and other variables of relevance to bone density, only IGF-I was identified as a significant independent skeletal predictor. While alterations in DHEAS, IGF-I, and specific cytokines may contribute to skeletal deficits in patients with CF, of these factors a low IGF-I concentration appears to be most strongly correlated with BMD. Conclusions These findings may have therapeutic implications for enhancing bone density in these patients.     

老年女性2型糖尿病肾病的骨密度及相关因素分析

2型糖尿病(T2DM)和骨质疏松症的发病率越来越高,它们之间有无关系越来越引起人们的重视,本研究探讨了老年女性2型糖尿病肾病(DN)的骨矿物质密度(BMD)变化与相关因素,报道如下。1对象与方法1.1研究对象按1999年WHO诊断标准确诊为T2DM的≥60岁女性114例,年龄60～75岁,平均(66.3±     

2型糖尿病患者绝经期骨密度与甲状旁腺素、雌激素相关性研究

目的 观察2型糖尿病妇女绝经期骨密度与甲状旁腺素、雌激素相关性研究.方法 测定绝经期2型糖尿病妇女伴骨质疏松（A）组及绝经期2型糖尿病妇女无骨质疏松（B）组的左侧髋部股骨颈、大转子、华氏三角区、及腰椎L2～L4正侧位的骨密度和血清中骨代谢指标,如：骨钙素、碱性磷酸酶、钙、磷、甲状旁腺素、雌二醇、Ⅰ型胶原羧基末端终肽（β-CTx）的浓度,对骨密度与多个变量之间的关系进行相关分析,并对（A）组血清中的甲状旁腺素、雌二醇、骨钙素、β-CTx与不同部位的骨密度之间的关系进行多元逐步回归分析.结果绝经期2型糖尿病妇女（B）组的腰椎、大转子、华氏三角区、股骨颈等骨密度指标明显低于对照组（A）（P＜0.05）;2型糖尿病绝经期妇女血清中雌二醇水平与腰椎L2～L4骨密度呈正相关（P＜0.032）;甲状旁腺素水平与股骨颈骨密度呈负相关（P＜0.034）.结论 绝经期2型糖尿病患者甲状旁腺素和雌激素水平与骨密度密切相关,分别可以用于预测骨质疏松发生的不同部位.     

三维骨建模在全膝关节置换术中韧带平衡的作用

目的探讨以三维骨建模为基础、无需影像的计算机辅助系统在人工全膝关节置换术(totalknee arthroplasty,TKA)中韧带平衡的作用。方法2002年11月～2003年6月,采用后稳定型人工全膝关节,在Ceravision无需影像资料的三维骨建模系统导航监控下,辅助完成TKA21例。男5例,女16例,年龄64～79岁,平均72.4岁。其中2例既往行胫骨近端截骨术,1例行股骨远端截骨术。14例膝内翻,7例膝外翻。术前下肢全长X线正位片测量,内翻13°～外翻13°,平均2.36°;膝关节X线正位片测量,应力下内翻平均8.47°(内翻2°～内翻20°),应力下外翻平均3.63°(内翻7°～外翻12°)。结果术中导航系统测量,额面内翻12°～外翻10°,平均3.33°,与术前比较差异有统计学意义(P<0.05);额面应力下内翻平均6.47°(内翻0°～内翻24°),应力下外翻平均4.32°(内翻8°～外翻15°),与术前比较差异有统计学意义(P<0.05)。术毕导航系统测得膝内外翻平均0.175°(内翻2°～外翻3°),而术后下肢全长X线正位片测量平均0.3°(内翻3.5°～外翻1.5°),二者差异无统计学意义(P>0.05)。术后3个月关节活动度为105～130°,平均115°,膝关节额面松弛度0.2～0.5cm,平均0.27cm。人工膝关节胫、股骨假体取得满意的对位置入和韧带平衡,无关节失稳和髌骨脱位等并发症发生。结论以三维骨建模为基础、无需影像的Ceravision系统,具有三维立体定位、优化截骨,并通过旋转对位和韧带松解获得伸屈膝关节等距间隙与韧带平衡稳定的作用,近期临床疗效满意,可在TKA中常规使用。     

胰淀素及肾上腺髓质素与骨代谢关系的研究进展

胰淀素及肾上腺髓质素属于降钙素/降钙素基因相关肽家族成员,有相似的二级结构,均可促进骨合成代谢。分子生物学研究显示,降钙素受体、降钙素受体样受体及受体活性调节蛋白等相关分子可能是它们的受体,而蛋白激酶A、蛋白激酶C及细胞外信号调节激酶与其胞内信号转导有关。临床研究发现血浆胰淀素水平在骨质疏松患者体内下降。作为新发现的骨代谢调节因子,它们将成为治疗代谢性骨病的一类新型药物。     

后路治疗胸腰椎爆裂骨折

目的：探讨后路环椎管减压，椎弓根钉系统复位固定并植骨治疗胸腰椎爆裂骨折的疗效。方法：1996－2001年，环椎环椎管减压，结合具有钉杆角的椎弓根钉系统复位固定，并横突及小关节突间植骨或椎间植骨治疗128例病人，从伤椎椎体前后缘高度恢复，Cobb角矫正度及神经功能恢复情况评价疗效。结果：128例病人脊髓神经损害无加重，神经功能有不同程度恢复；伤椎高度恢复理想，Cobb角明显减少，植骨融合成功108例（占84．4％），术后部分病例出现伤椎复位度丢失现象。结论：后路环椎管减压内固定治疗胸腰椎骨折效果好，应重视植骨融合以获得良好稳定性。     

Risedronate Reduces the Risk of First Vertebral Fracture in Osteoporotic Women

Risedronate treatment reduces the risk of vertebral fracture in women with existing vertebral fractures, but its efficacy in prevention of the first vertebral fracture in women with osteoporosis but without vertebral fractures has not been determined. We examined the risk of first vertebral fracture in postmenopausal women who were enrolled in four placebo-controlled clinical trials of risedronate and who had low lumbar spine bone mineral density (BMD) (mean T-score =–3.3) and no vertebral fractures at baseline. Subjects received risedronate 5 mg (n= 328) or placebo (n= 312) daily for up to 3 years; all subjects were given calcium (1000 mg daily), as well as vitamin D supplementation (up to 500 IU daily) if baseline serum 25-hydroxyvitamin D levels were low. The incidence of first vertebral fracture was 9.4% in the women treated with placebo and 2.6% in those treated with risedronate 5 mg (risk reduction of 75%, 95% confidence interval 37% to 90%; P= 0.002). The number of patients who would need to be treated to prevent one new vertebral fracture is 15. When subjects were stratified by age, similar significant reductions were observed in patients with a mean age of 64 years (risk reduction of 70%, 95% CI 8% to 90%; P= 0.030) and in those with a mean age of 76 years (risk reduction of 80%, 95% CI 7% to 96%; P= 0.024). Risedronate treatment therefore significantly reduces the risk of first vertebral fracture in postmenopausal women with osteoporosis, with a similar magnitude of effect early and late after the menopause. Received: 12 September 2001 / Accepted: 11 December 2001     

Load-induced proteoglycan orientation in bone tissuein vivo andin vitro

Summary Previous studies of Alcian blue-induced birefringence in adult avian cortical bone showed that a short period of intermittent loading rapidly produces an increased level of orientation of proteoglycans within the bone tissue. In the absence of further loading, this persists for over 24 hours. We have proposed that this phenomenon could provide a means for “capturing” the effects of transient strains, and so provide a persistent, constantly updated strain-related influence on osteocyte populations related to the bones' averaged recent strain history, in effect, a “strain memory” in bone tissue. In our present study, we use the Alcian blue-induced birefringence technique to demonstrate that proteoglycan orientation also occurs after intermittent loading of both cortical and cancellous mammalian bonein vivo andin vitro. We also show that the change in birefringence is proportional to the magnitude of the applied strain, and that the reorientation occurs rapidly, reaching a maximal value after only 50 loading cycles. Examination of electron micrographs of bone tissue after staining with cupromeronic blue allows direct visualization and quantification of the change in proteoglycan orientation produced by loading. This shows that intermittent loading is associated with a realignment of the proteoglycan protein cores, bringing them some 5 degrees closer to the direction of collagen fibrils in the bone matrix.     

胫骨骨条植骨结合多根克氏针内固定治疗股骨颈骨折

从1985年起,应用胫骨骨条植骨结合多根克氏针内固定治疗股骨颈骨折21例,经随访7个月—48个月,优17例、良3例、差1例。通过临床观察,用自体胫骨骨条植骨提供活的骨细胞及诱导成骨,能促进加速骨折愈合。本手术方法简单、安全     

Prevention of Bone Loss by Clodronate in Early Postmenopausal Women with Vertebral Osteopenia: A Dose-Finding Study

This double-masked, placebo-controlled study was undertaken to determine the efficacy and safety of oral clodronate in the prevention of bone loss in early postmenopausal women with vertebral osteopenia. Altogether 610 women with a mean age of 53 years were recruited for the study. They were 1–5 years postmenopausal and their lumbar spine bone mineral density (BMD) was at least 1 standard deviation below the mean of premenopausal women (T-score ≤−1). The subjects were randomized into five study groups to receive either placebo, clodronate 65 mg, 400 mg or 800 mg daily, or intermittent clodronate in 3 month cycles with 400 mg daily for 15 days followed with no treatment for 75 days for 3 years. One hundred and eighty-seven of 509 women who completed the primary study continued in the extension study of 2 years in which previous placebo users were switched to clodronate 800 mg daily, while previous users of 400 mg or 800 mg of clodronate used either placebo or 800 mg of clodronate daily. In the primary study clodronate was administered in the evening, and in the extension 1 h before breakfast on an empty stomach. In the primary study mean changes in lumbar spine BMD were −3.4% in the placebo group and +0.4% in 800 mg clodronate group [difference between groups at 3 years 3.8% (95% CI 2.7% to 4.9%, p<0.0001)], and in the trochanter area BMD −1.1% in the placebo group, and + 0.4% in the 800 mg clodronate group [difference between groups at 3 years 1.5% (95% CI 0.05% to 2.9%)]. During the extension study mean changes in lumbar spine BMD were +1.5% in the clodronate group and −0.2 % in the placebo group [difference between groups 1.7% (CI 0.4% to 3.0%, p = 0.010)] and in trochanter BMD were +2.5% in the clodronate group and no change in the placebo group [difference between groups 2.1% (CI 0.3% to 3.9%, p = 0.007)]. No statistically significant differences between the placebo and 800 mg clodronate groups were found in the femoral neck BMD. In the primary study the urinary excretion of type I collagen aminoterminal telopeptide (NTX) decreased by 44% (p<0.0001 compared with placebo) and that of deoxypyridinoline by 18% (p<0.0001) in the clodronate 800 mg group. In the extension study urinary NTX decreased by 51% (p<0.0001) in those who were switched to 800 mg of clodronate and increased by 67% (p<0.0001) in those who stopped using that dose. There was no difference in the frequency of gastrointestinal complaints between clodronate- and placebo-treated patients in the primary study, but they were more common among women who received clodronate in the extension phase. Clodronate in daily doses of 400–800 mg caused a slight elevation of aminotransferase levels, usually within the reference range. In bone biopsies no defect in mineralization was found. In conclusion, clodronate in a daily dose of 800 mg prevents early postmenopausal bone loss at the sites of the skeleton in which cancellous bone predominates. It effectively reduces bone resorption and bone turnover rate. Antifracture efficacy of clodronate remains to be established by prospective, placebo-controlled trials. Received: 4 March 2002 / Accepted: 9 July 2002