The protective effects of triptolide on age-related bone loss in old male rats.

BACKGROUND: Previous studies have showed that triptolide have a critical role in inhibiting osteoclast formation, bone resorption and attenuating regional osteoporosis. However, the protective role of triptolide on age-related bone loss has not been investigated. In the study, we assessed the effect of triptolide supplementation on bone microstructure and bone remolding in old male rat lumbars. METHODS: Fifty-two 22-month-old male Sprague-Dawley rats were randomly assigned to either triptolide treatment group or control group. Triptolide (15 µg/kg/d) or normal saline was administered to the rats of assigned group for 8 weeks. Lumbar bone mineral density (BMD) and bone microstructure were analyzed by micro-CT. Fluorochrome labeling of the bones was performed to measure the mineral apposition rate (MAR) and bone formation rate (BFR). Osteoclast number was also measured by TRAP staining. Plasma level of osteocalcin and tartrate-resistant acid phosphatase 5b (Tracp 5b) was also analyzed. RESULTS: Micro-CT results revealed that triptolide-treated rats had significant higher BMD, bone volume over total volume (BV/TV), trabecular thickness (Tb.Th), bone trabecular number (Tb.N), and lower trabecular separation (Tb.Sp) compared to the control group. Although fluorochrome labeling result showed no significant difference in MAR and BFR between the groups, triptolide decreased osteoclast number in vivo. In addition, a significant higher level of plasma Tracp 5b was observed in the triptolide-treated rats. Furthermore, triptolide also reduced the expression of receptor for activation of NF-κB ligand (RANKL) and increased osteoprotegerin (OPG) expression in the lumbars. CONCLUSION: These results suggested that triptolide had a protective effect on age-related bone loss at least in part by reducing osteoclast number in elder rats. Therefore, triptolide might be a feasible therapeutic approach for senile osteoporosis.

Effect of Bone Cement Volume Fraction on Adjacent Vertebral Fractures After Unilateral Percutaneous Kyphoplasty.

STUDY DESIGN: A retrospective study. SUMMARY OF BACKGROUND DATA: Complications of the bone cement used in vertebroplasty and kyphoplasty procedures have received increasingly more attention, especially for bone cement volume. OBJECTIVE: The aim of the study was to retrospectively assess the relationship between bone cement volume fraction and adjacent vertebral fracture (AVF) after unilateral percutaneous kyphoplasty (PKP). MATERIALS AND METHODS: Between 2006 and 2011, 495 patients with single-level osteoporotic vertebral compression fracture (OVCF) were surgically treated by unilateral PKP and had completed 12-month follow-up in our hospital. According to the new OVCF, they were divided into 3 groups: AVF group, non-AVF group, and normal group (who were not new OVCF). On the basis of the value of the plain radiography, the cement volume fraction for the vertebral body was calculated, and cement leakage, bone mineral density, visual analog scale, and Cobb angle of preoperative and postoperative were analyzed. RESULTS: During the follow-up, 110 (22.2%) patients had new OVCF, and others were normal (n=385). Fifty-two cases were AVF and 58 were non-AVF. The cement volume fraction of AVF group, non-AVF group, and normal group were 32.5%±5.5%, 27.3%±1.8%, and 27.1%±2.6%, respectively. The 95% confidence interval of volume fraction were (31.0, 34.1), (26.8, 27.7), and (26.9, 28.5), respectively. The AVF group showed higher cement volume fraction in 3 groups (P<0.05), and there were no significant difference between non-AVF and normal group (P>0.05). There were 19 (36.5%) patients with cement leakage in AVF group, 12 (20.7%) in non-AVF group, and 68 (17.7%) in normal group. The AVF group showed higher cement leakage (P<0.05). Compared with AVF group and normal group, non-AVF group had lower bone mineral density in preoperation. All groups reported significantly improved visual analog scale scores and Cobb angle on the day of surgery. However, there were no significant difference between the 3 groups. CONCLUSIONS: Unilateral PKP is an effective and safe procedure for patients with OVCF. However, cement volume should be determined in terms of the vertebral body fraction to obtain a favorable outcome. The risk of AVF and cement leakage will increase obviously with the cement volume fraction increased. We recommend that a bone cement volume fraction of about one fourth is suitable for unilateral PKP.

Emergent surgical reduction and fixation for Pipkin type I femoral fractures.

The purpose of this study was to assess the effect of timing of large fragment fixation in patients with Pipkin type-I fractures. Patients with Pipkin type-I fractures from the authors' trauma center were prospectively observed between July 2007 and July 2010. Fragments that constituted more than one-fourth of the femoral head were included. Thirty-six patients were equally randomized to undergo emergent surgical reduction and fixation or secondary operative fixation after emergent closed reduction. No significant differences existed between the 2 groups with regard to the baseline characteristics, operating time, and blood loss (P>.05). However, the emergent surgical reduction and fixation group had a shorter hospital stay (P<.05). The results after more than 2-year follow-up showed that the complication and avascular necrosis rates were higher in the secondary operative fixation after emergent closed reduction group compared with the emergent surgical reduction and fixation group (P<.05). It was difficult to achieve an anatomically reduced femoral head when the fragments constituted more than one-fourth of the femoral head. Patients who underwent secondary operative fixation after emergent closed reduction had a high avascular necrosis rate and a relatively poor outcome. Emergent surgical reduction and fixation should be performed shortly after injury to enhance the treatment outcome.

[Screening and identification of polypeptides specifically binding to human B type natriuretic peptide from 12TM phage display peptide library].

OBJECTIVE: To identify and characterize the polypeptides specifically binding to human B type natriuretic peptide (BNP) screened from 12TM phage display peptide library. METHODS: The BNP-binding peptides were screened from 12TM phage display peptide library and identified by ELISA. RESULTS: After 4 rounds of screening, 10 of the 16 phage clones were identified as the positive clones which could bind to BNP. Five amino acid sequences were obtained in the 10 positive clones. Dose-dependent ELISA results demonstrated that the screened polypeptides could specifically bind to BNP. CONCLUSION: These screened polypeptides can bind specifically to BNP, which provides a basis for further research on expression and purification of anti-BNP polypeptides and the development of the detection kit of BNP.