Bone growth patterns in Chinese children and adolescents: a 6-year follow-up study provides evidence for sexual dimorphism and tracking

Summary We prospectively examined bone growth patterns in 894 children aged 6–17 years at the baseline visit, with a 6-year follow-up. Results show bone “tracking” over a six-year interval and sexual dimorphism of bone attained levels and timing of peak bone growth. Our findings underscore childhood and adolescence as critical periods for building bone and developing gender differences. Introduction Bone growth patterns were prospectively examined in 894 Chinese children (496 males), aged 6–17 yrs, from a population-based twin cohort. Whole-body bone area (BA), bone mineral content (BMC), and bone mineral density (BMD) were measured by DEXA at baseline and a 6-yr follow-up. Methods Graphic smoothing plots and generalized estimating equations were used to model bone attained levels, growth, and “tracking”. Results Attained levels of BMC and BA increased curvilinearly with age. Male attained levels were higher than females after age ∼15 yr, but BMD was lower between 13–17 yrs (Tanner stage I to IV). In both genders, peak BMC and BMD growth lagged ∼2 yrs behind peak BA growth, which lagged 2 yrs behind peak height growth. Peak bone growth occurred 1–3 yrs later in males. Over the 6-yr follow-up, all bone measurements “tracked”, but “shifting” across ranks also occurred, and baseline tertile ranking influenced bone growth. Females with early menarche had higher attained levels than females with late menarche at age 12–13 yrs. Conclusion Our findings confirm and expand previous studies on peak bone growth conducted in Caucasian cohorts, particularly sexually dimorphic and maturational effects. The significant “tracking” of bone measurements in this 6-yr follow-up study underscores the importance that osteoporosis prevention should begin in childhood and adolescence. Fengxiu Ouyang and Binyan Wang contributed equally to this article. Source(s) of support: This study is supported in part by grant R01 HD049059, R01 HL0864619 and R01 AR045651 from the National Institute of Health and by the Food Allergy Project.     

Bone Mineral Density Determinations by Dual-Energy x-ray Absorptiometry in the Management of Patients with Marfan Syndrome—Some Factors Which Affect the Measurement

Reduced bone mineral density (BMD) was sporadically reported in patients with Marfan syndrome. This may or may not place the Marfan patient at increased risk for bone fracture. In comparing the BMDs of our patients with those reported in the literature, it seemed that agreement between values, and hence the degree of osteoporosis or osteopenia reported, was dependent on the instrumentation used. The objective of this study was to statistically assess this impression. Bone mineral density measurements from our previously published study of 30 adults with Marfan syndrome performed on a Lunar DPXL machine were compared with studies published between 1993–2000 measured using either Lunar or Hologic bone densitometry instruments. The differences of our measurements compared with those made on other Lunar machines were not statistically significant, but did differ significantly with published results from Hologic machines (P < 0.001). Before progress can be made in the assessment of BMD and fracture risk in Marfan patients and in the evidence-based orthopedic management of these patients, standardization of instrumental bone density determinations will be required along with considerations of height, obesity, age, and sex.     

自制稀土永磁夹板对骨折愈合作用的观察

目的观察稀土永磁夹板对家兔骨折愈合质量及骨形态发生蛋白（BMP-2）、血管内皮细胞生长因子（VEGF）表达情况的影响,从分子生物学水平探讨磁场促进骨折愈合的作用机制。方法健康成年家兔50只,建立双前肢桡骨中段骨折模型。左侧用稀土永磁夹板固定,作为实验侧;右侧用内镶铅片小夹板固定,作为对照侧。分别于术后1、2、3、4、6周摄双前肢X线片后取材,进行HE及BMP-2、VEGF免疫组化染色并在光镜下观察。结果X线片图像定量分析结果比较,实验侧愈合明显快于对照侧。两侧差异有显著性（P〈0.05）。实验侧在1、2、3、4周VEGF的表达均比对照侧强,两侧差异有显著性（P〈0.05）。实验侧在2、3、4周BMP-2的表达均比对照侧强,两侧差异有显著性（P〈0.01）。结论静磁场在骨折愈合过程中可加强BMP-2、VEGF的表达。自制稀土永磁夹板对实验性骨折愈合有明显的促进作用。     

复合干细胞生物陶瓷在裸鼠异位成骨中的评价

目的 研究h-BMP-2基因转染骨髓间充质干细胞(BMSCs)在复合煅烧骨、β-TCP或直接植入裸鼠股部后的成骨能力。方法 通过影像学、组织学和形态计量学等方法,观察未经诱导、OS液诱导和h-BMP-2基因转染BMSCs在复合煅烧骨,或多孔β-TCP后植入裸鼠皮下,或直接制成细胞悬液注入,在4、8、12周诱导成骨和材料降解情况。结果 在裸鼠皮下,单纯生物陶瓷不能诱导成骨,而复合了未诱导、OS液诱导和h-BMP-2基因转染BMSCs的生物陶瓷均能成骨,成骨量为h-BMP-2基因转染组>OS液诱导组>未经诱导组(P<0.05),B-TCP可随骨长入而降解;注入裸鼠肌肉的OS液诱导的和h-BMP-2转染的BMSCs均能诱导成骨,而未经诱导MSCs则不能成骨。结论 复合人BMP基因转染BMSCs的β-TCP是一种理想的骨修复材料。     

BMSCs胶原刮膜对松质骨缺损的修复

目的 研究成骨蛋白-2(hBMP-2)基因转染骨髓间充质千细胞(BMSCs)胶原刮膜对兔股骨髁松质骨缺损的修复能力。方法 应用影像学、组织学、形态计量学和生物力学等方法,观察未经诱导、OS液诱导和hBMP-2基因转染BMSCs胶原刮膜植入兔股骨髁部直径6 mm、深12 mm松质骨缺损后的修复情况。结果 未经处理的兔股骨髁缺损不能自行愈合;细胞刮膜植入对股骨髁松质骨缺损的修复能力,在8和12周时hBMP基因转染BMSCs组>OS液诱导BMSCs组>未诱导BMSCs组(P<0.05),12周时hBMP基因转染BMSCs组的骨缺损区生物力学强度接近正常松质骨。结论 hBMP基因转染BMSCs胶原刮膜是治疗大块松质骨缺损的理想修复材料。     

乳腺癌骨髓微转移的检测及其临床意义

目的　检测乳腺癌骨髓微转移 ,探讨其与乳腺癌临床病理学因素的关系。方法　采用RT -PCR法 (一步法 )检测骨髓中CK19mRNA表达。结果　 10 2例乳腺癌患者骨髓CK19mR NA表达阳性率 5 6.9%。骨髓CK19mRNA表达率随乳腺癌肿块增大而增高 ;随临床分期增加而增高 ;随组织学分级增加而增高。但与腋淋巴结转移与否无关 ,亦与乳腺癌患者年龄、月经状况及病理类型无关。结论　乳腺癌骨髓微转移与某些临床病理学因素有关。癌细胞播散无固定模式 ,早期乳腺癌亦可发生远处转移。骨髓微转移应作为常规检测方法 ,以更早、更准确地预测全身转移情况 ,进行个体化治疗。     

接触镜与泪液形态关系的临床评价

目的 :观察配戴不同种类接触镜后眼表面泪膜的形态、稳定性及泪液量的变化。方法 :对日戴SCL、RGPCL和Ortho KCL的 2 14名近视患者 4 2 8只眼 ,利用表面泪膜观察装置 (DR 1)观察戴镜前后眼表泪液膜和戴镜状态下镜上泪液膜的形态分级 ,同时测定泪膜破裂时间 (BUT)。利用酚红染色棉丝测定SCL戴镜前后的泪液量 ,并用折射仪 (AtagoCL 1)测量SCL含水量的变化。结果 :SCL配戴者随戴镜时间延长 ,BUT明显缩短 (P <0 .0 1) ,RGPCL和Ortho KCL配戴者戴镜 5年以内 ,BUT无明显变化 (P >0 .0 5 )。戴镜后RGPCL ,Ortho KCL和非戴镜正常眼三组间眼表泪膜分级比例差异无显著性 ,SCL组Ⅰ级比例为 6 .5 % ,显著低于其他组(16 .1%～ 2 3.0 % )。镜上泪膜 ,SCL、RGPCL和Ortho KCL三组均以Ⅳ级为主 (分别占 5 4 .4 %、5 3.4 %和 5 1.5 % ) ,SCLⅠ级比例仅 1.9% ,显著低于另二组 (分别占 6 .2 %和 12 .4 % )。SCL配戴者随戴镜时间延长 ,泪液量轻度减少 ,SCL含水量在戴镜 1w后即显著降低。结论 :科学配戴接触镜对泪液膜质量无明显影响 ,但SCL长期使用可能对泪膜有一定干扰作用。     

外固定支架加自体骨髓多能干细胞治疗桡骨远端骨折

[目的]探讨外固定支架结合骨折端局部注射自体骨髓多能干细胞治疗桡骨远端粉碎性骨折的有效性。[方法]应用外固定支架结合骨折端局部注射自体骨髓多能干细胞治疗桡骨远端粉碎性骨折18例。[结果]随访6～15个月(平均8个月),优10例,良6例,可2例,差0例。优良率为88.9%。没有一例出现针道浅表感染等并发症。[结论]外固定支架结合骨折端局部注射自体骨髓多能干细胞是治疗桡骨远端粉碎性骨折的一种方便、有效的方法,不仅骨折愈合效果满意,而且固定确实可靠,并能早期功能调整和训练。     

鼻骨外伤X线摄影技术探讨

本文通过分析鼻骨外伤X线成像特点,重点探讨了常规X线与DR检查在鼻骨外伤中的应用价值,旨在提高对鼻骨骨折诊断的准确率。结果表明DR摄影是鼻骨常规检查的理想手段。     

透明质酸对BMP-2转染的羊BMSCs增殖、分化的影响

目的观察透明质酸（HA）对携带人骨形态发生蛋白-2的腺病毒（Adv-BMP-2）转染的羊骨髓基质干细胞（BMSCs）体外增殖、分化的影响。方法将羊骨髓体外分离、扩增BMSCs,分成5组：转染Adv-BMP-2的BMSCs＋HA组（Ⅰ组）,转染Adv-BMP-2的BMSCs组（2组）,BMSCs＋HA组（3组）,BMSCs组（4组）,转染携带β半乳糖苷酶的腺病毒（Adv-β-gal）的BMSCs组（5组）。采用细胞计数、绘制细胞生长曲线和流式细胞分析观测细胞增殖;采用碱性磷酸酶（ALP）检测以及RT-PCR检测Ⅰ型胶原（Col-Ⅰ）、骨连接素（ON）和骨涎蛋白（BSP）的mRNA表达。结果①细胞增殖：3 d后各组细胞增殖无显著差异,1周后第1组和第3组的细胞增殖明显高于其他组。②ALP活性：3 d后第3组ALP活性明显低于第4、5组,而第1、2组则显著高于第4、5组;7 d后前3组ALP活性较后两组均显著增加,而第1、2组ALP活性增加更为显著。③Col-Ⅰ、ON和BSP的mRNA表达：3 d和7 d后前3组较后两组均有不同程度的增多。结论HA与BMSCs体外复合培养后可促进BMSCs的增殖、增加ALP的活性以及Col-Ⅰ、ON和BSP基因的表达。