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.     

Requirement of MyD88 for macrophage-mediated islet xenograft rejection after adoptive transfer

BACKGROUND: Porcine antigen primed and CD4+ T-cell activated macrophages are able to migrate to and destroy porcine xenografts. However, the specific signaling mechanisms involved remain to be identified. METHODS: In this study macrophages which lack the universal toll-like receptor (TLR) adaptor MyD88 were used to investigate the role of TLR in the recognition and activation of macrophages in islet xenograft rejection. Macrophages were isolated from rejecting MyD88(-/-) and wild-type C57BL/6 mice that were recipients of neonatal porcine pancreatic cell cluster (NPCC) xenografts, and were transferred to NPCC recipient NOD-SCID mice. RESULTS: Both wild-type C57BL/6 and MyD88(-/-) mice rejected NPCC xenografts 8 and 10 days, respectively after transplantation, and the grafts were heavily infiltrated with CD4+ T cells and macrophages. However, graft infiltrating macrophages from rejecting MyD88(-/-) recipients demonstrated impaired up-regulation of TLR expression and impaired activation phenotype, when compared to those from rejecting C57BL/6 recipients. Transfer of NOD-SCID recipients with macrophages from rejecting C57BL/6 mice resulted in NPCC xenograft rejection along with massively infiltrated macrophages 8 days after transfer, whereas NPCC xenografts in NOD-SCID mice transferred with macrophages from rejecting MyD88(-/-) mice remained intact until the end of this study, 90 days after transfer, with insulin-positive islets and no infiltration by macrophages. CONCLUSION: This study demonstrates that deletion of MyD88 causes impaired macrophage activation after pig islet xenotransplantation. However, graft survival is not prolonged and xenografts are rejected rapidly by alternate mechanisms.     

供者NK细胞及其嵌合状态在异基因造血干细胞移植中的研究进展

目前,异基因造血干细胞移植(allo-HSCT)已广泛应用于造血系统疾病的治疗,但移植术后也存在一系列并发症。NK细胞的运用为改善allo-HSCT受者预后带来希望,供者来源NK细胞通过其细胞膜上的杀伤细胞免疫球蛋白样受体与其配体错配发挥同种异体反应,该过程具有保留移植物抗白血病和减少移植物抗宿主病双重效应。NK细胞是allo-HSCT后受者体内最早重建的免疫细胞群,因此移植后供、受者NK细胞嵌合状态评估对预测疾病预后及指导干预治疗具有重要意义。基于NK细胞嵌合状态的供者NK细胞输注免疫干预疗法可改善疾病预后,在血液系统疾病治疗中表现出良好的应用前景。本文就近年来供者NK细胞及其嵌合状态在allo-HSCT中的研究进展作一综述。     

The cost-effectiveness of the RSI QuickScan intervention programme for computer workers: Results of an economic evaluation alongside a randomised controlled trial

Background  

The costs of arm, shoulder and neck symptoms are high. In order to decrease these costs employers implement interventions aimed at reducing these symptoms. One frequently used intervention is the RSI QuickScan intervention programme. It establishes a risk profile of the target population and subsequently advises interventions following a decision tree based on that risk profile. The purpose of this study was to perform an economic evaluation, from both the societal and companies' perspective, of the RSI QuickScan intervention programme for computer workers. In this study, effectiveness was defined at three levels: exposure to risk factors, prevalence of arm, shoulder and neck symptoms, and days of sick leave.     

Strontium fructose 1, 6‐diphosphate alleviate cyclophosphamide‐induced oligozoospermia by improving antioxidant and inhibiting testicular apoptosis via FAS/FASL pathway

This study investigated the treatment effects of a new compound, strontium fructose 1, 6‐diphosphate (FDP‐Sr), in cyclophosphamide (CP)‐induced oligozoospermia. FDP‐Sr, with extra high‐energy supply, could reverse male hypogonadism in the testis. Male Wistar rats were randomly divided into three groups: control group (vehicle treated), CP group and CP + FDP‐Sr group. Both CP group and CP + FDP‐Sr groups were orally administered CP (20 mg kg^?1) consecutively for the first 7 days to establish CP‐induced testicular toxic models. Subsequently, CP group was given orally distilled water per day, whereas CP + FDP‐Sr group was received FDP‐Sr (200 mg kg^?1) for 49 days. Compared to the CP group, the FDP‐Sr group showed significantly increased levels of serum testosterone, testis relative weights and epididymal sperm counts in rats. In addition, rats treated by FDP‐Sr showed the recuperative activities of testicular marker enzymes and normalised levels of antioxidants in tissue. Testicular protection of FDP‐Sr was further demonstrated by enhancing expression of P450scc, reducing ability of FAS/FASL and generating cytoprotection in the histopathological study. FDP‐Sr appeared to possess an ability to attenuate CP‐induced reproduction toxicity via the activation of antioxidants and steroidogenesis enzymes, and alleviate oligozoospermia via inhibition of testicular apoptosis by FAS/FASL pathway.     

Comparison between tension band and cerclage with X-Plate and lag screws in treatment of comminuted patellar fractures

BackgroundComminuted patellar fractures are not rare, and the ideal treatment method remains controversial. The present study was conducted to evaluate effects and compare complications of two different methods used to treat comminuted patellar fractures.MethodsFrom March 2010 to August 2016, 102 cases of 34-C2 or 34-C3 comminuted patellar fractures were treated at our hospital, wherein patients received two different treatments: titanium cable tension band with cerclage method (group A) and intrafragmentary screws with X-shaped plating technique (group B). At follow-ups, articular step-off, range of motion (ROM), Lysholm scores, time of union, and complications were recorded and analyzed. Radiographic and clinical data as well as rate of complications were statistically analyzed.ResultsIn total, 87 patients were included in the final analysis (n = 47 in group A and n = 40 in group B). No significant differences were noted in terms of cost of implant, age, gender, rate of 34-C3 fractures, rate of layered inferior pole fractures, postoperative articular step-off and union time. At 2-year follow-up, average Lysholm scores, ROM and rate of complications were (89.0 ± 4.5), (122°±12°) and (27.7%) in group A and (90.2 ± 3.9), (124°±11°) and (17.5%) in group B, respectively, with no significant differences (p > 0.05). The mean time of surgery in group B was shorter than that in group A with significant difference (p < 0.05).ConclusionsTreatment using the intrafragmentary screws and plate method for amenable comminuted patellar fractures achieved similar complication rate and favorable functional outcomes at the 2-year follow-up, which was comparable to the titanium cable tension band with cerclage method. Thus, the intrafragmentary screws and plate method is effective, safe and convenient for 34-C2/C3 comminuted patellar fractures, especially appropriate for patients with layered fragments.     

重视供肝机械灌注研究,推动肝移植高质量发展

随着器官捐献数量不断增加和扩大标准供者(ECD)供肝定义不断拓展,供肝质量必然成为影响肝移植高质量发展的突出问题,也是相关领域的研究重点.最大限度解决器官短缺和推动器官移植高质量发展是我国器官捐献与移植事业发展的方向.近年来,利用机械灌注(MP)对供肝进行灌注、保存、评估及修复,已成为当前国际上提高肝移植质量的研究热点...     

急性脊髓前动脉阻断致颈髓缺血损伤的实验研究

目的观察急性脊髓前动脉阻断后颈髓血流量的变化、组织能量代谢和病理学改变,研究病理机制。方法以家兔为试验模型,阻断C2段脊髓前动脉,在术后6h、24h和72h采用激光多普勒血流测定仪测定颈髓血流灌注量,检测组织能量代谢变化,电镜观察细胞形态学改变。结果术后各时相点血流量下降明显,能量代谢进行性下降,出现急性缺血性改变。结论脊髓前动脉阻断后随着血流量和能量代谢的下降,颈髓组织发生渐进性破坏,但颈髓血供出现部分代偿。     

Frequency of Arteriovenous Shunts in Hepatic Cavernous Hemangiomas in Adults as Seen on Selective Arteriography and Postembolization Radiography

Purpose: To study the frequency and angiographic findings of arteriovenous shunts (AVS) associated with adult cavernous hemangiomas of the liver (CHL) on hepatic artery digital subtraction angiography (DSA) and optimize the imaging technique of DSA to improve its diagnostic efficacy. Methods: We retrospectively analyzed 43 intraarterial DSA procedures performed on 30 adults with CHL. Of the 30 patients 22 were found to have an AVS. Transcatheter arterial embolization with Lipiodol (L-TAE) was performed on 21 of these and radiographs were taken immediately after embolization to observe the distribution of the injected iodized oil. The results were compared with those of the AVS found on DSA images. Results: AVS were identified by DSA in 22 (73.3%) of 30 patients. All AVS were located in the peritumoral liver tissue and had a parallel track appearance, or early filling of small draining veins during the arterial phase of DSA. Radiographs taken immediately after L-TAE in 21 of the 22 cases with AVS showed iodized oil filling a few portal branches or draining veins as a result of incompletely occluded shunts in 11 patients. In 10 patients there was complete occlusion and no filling of any vein, or only the originating end of draining veins filled with iodized oil. No evidence of AVS was found in the other eight patients in this series, and in six of these the DSA was not considered diagnostic. Conclusion: The present study indicates that AVS are frequently seen in adults with CHL. DSA with high-quality images is helpful in identifying small AVS of CHL. The formation of an AVS in CHL may be closely related to the pathological changes in the peritumoral liver tissue.