Osteoclastogenesis in the nonadherent cell population of human bone marrow is inhibited by rhBMP-2 alone or together with rhVEGF.

During bone development and repair, angiogenesis, osteogenesis, and bone remodeling are closely associated processes that share some common mediators. In the present study nonadherent human bone marrow mononuclear cells under the induction of sRANKL and M-CSF, differentiated into osteoclasts with TRAP-positive staining, VNR expression, and Ca-P resorptive activity. The effects of various combinations of rhBMP-2 (0, 3, 30, and 300 ng/mL) and rhVEGF (0 and 25 ng/mL) on osteoclastogenesis potentials were examined in this experimental system. The percentages of TRAP-positive multiple nucleated cells represent osteoclast differentiation potential, and the percentages of resorptive areas in the Ca-P coated plates resemble osteoclast resorption capability. The presence of rhBMP-2 at 30 and 300 ng/mL showed inhibitory effects on osteoclast differentiation and their resorptive capability in the human osteoclast culture system. rhVEGF (25 ng/mL) enhanced the resorptive function of osteoclast whenever it was used alone or combined with 3 ng/mL rhBMP-2. However, rhVEGF-induced resorptive function was inhibited by 30 ng/mL and 300 ng/mL rhBMP-2 in a dose-dependent manner. Statistical analysis demonstrated that an interactive effect exists between rhBMP-2 and rhVEGF on human osteoclastogenesis. These findings suggested that an interactive regulation may exist between BMPs and VEGF signaling pathways during osteoclastogenesis; exact mechanisms are yet to be elucidated.     

显微外科技术及带蒂包皮岛状皮瓣法在尿道下裂治疗中的应用

目的总结应用显微外科及带蒂包皮皮瓣一期修复尿道下裂的经验,提高手术成功率。方法回顾性分析38例一期尿道下裂修复手术及术后并发症。患儿年龄3～22岁,平均7．5岁。阴茎头冠状沟型12例,阴茎体型19例,阴茎根部型7例,其中6例曾在院外行阴茎下屈矫正术。应用显微外科技术,单纯选择带蒂包皮岛状皮瓣法一期修复尿道下裂32例,联合应用Duplay术式6例。结果随访3个月～2年,35例患儿术后阴茎外观满意,排尿通畅,无明显并发症:术后发生尿瘘2例,再次手术后治愈。1例术后3月出现尿道外口狭窄,经尿道扩张治愈。手术成功率为94．7％。结论应用显微外科及带蒂包皮岛状皮瓣一期修复尿道下裂,成功率高,并发症少,是治疗尿道下裂的良好方法。     

Differentiation plasticity of human fetal articular chondrocytes.

OBJECTIVE: To test chondrogenic differentiation potential, we examined the differentiation plasticity of isolated human fetal articular chondrocytes (HFACs). STUDY AND DESIGN SETTING: Culture-expanded human fetal articular chondrocytes (HFACs) were analyzed for chondrogenic, adipogenic, osteogenic capacity and neural differentiation ability in defined in vitro culture systems. RESULTS: The different assays demonstrated that culture-expanded HFACs have potential to form cartilage in pellet mass culture, to form adipose cells, osteogenic cells, and neural cells in monolayer culture. CONCLUSIONS: These results suggest that within human fetal articular cartilages there are MSC-like cells that exhibit differentiation plasticity that is comparable with that of BM-MSCs and they may be a new kind of seeding cells for head and neck cartilage reconstruction.     

Synergistic induction of the differentiation of WEHI-3B D+ myelomonocytic leukemia cells by retinoic acid and granulocyte colony-stimulating factor.

Retinoic acid (RA) has been shown to be an inducer of the terminal differentiation of several leukemia cell lines in vitro and in clinical trials to produce a high percentage of remissions in patients with acute promyelocytic leukemia. In an effort to increase the therapeutic efficacy of RA, we have measured the capacity of granulocyte colony-stimulating factor (G-CSF) to enhance the differentiation inducing activity of RA in WEHI-3B D+ monomyelocytic leukemia cells. Combinations of G-CSF and RA produced a supra-additive increase in the percentage of WEHI-3B D+ cells reducing nitro blue tetrazolium and expressing Mac-1 (CD11b) antigen on the cell surface, two markers of the mature state. In the presence of 50 ng/ml of G-CSF, which produced only 12% differentiation when used alone, 0.5 microM RA induced the same degree of cellular differentiation as the optimum concentration of RA (i.e. 7 microM) employed alone. The supra-additive differentiation produced by this combination was prevented by the presence of G-CSF monoclonal antibody in the culture medium, resulting in a degree of maturation comparable to that produced by the retinoid alone. When cells were sequentially exposed to G-CSF followed by RA, a much higher level of differentiation was obtained than when the order was reversed, suggesting that WEHI-3B D+ cells were primed to enter a differentiation pathway by G-CSF. The supra-additive terminal differentiation exhibited by the mixture of G-CSF and RA suggests that these agents should be evaluated for the therapeutic efficacy of the combination in patients with acute non-lymphocytic leukemia.     

脐尿管占位性病变的CT诊断及鉴别诊断

目的 探讨CT检查在诊断和鉴别诊断脐尿管占位性病变方面的价值。方法根据临床病理证实的24例脐尿管占位性病变患者的CT影像学特征，分析其大小、部位、形态、性质、Retzius间隙影像学变化及增强后的影像学特征。结果 24例均明确诊断。4例为脐疝，其中3例疝囊内容物为网膜组织，另1例为肠管。20例为脐尿管占位性病变，均位于Retzius间隙内的脐尿管行走区，其中单纯性脐尿管囊肿6例，CT表现为长条椭圆形完整囊状包块，囊壁薄、光滑，囊内容物呈均匀低密度回声，增强后无强化；感染性脐尿管囊肿7例，CT表现为内部回声不均，灶周Retzius间隙内可见絮状或条索状密度增高影，其中4例囊壁明显增厚，3例囊壁不完整，2例呈多房性囊肿；脐尿管憩室伴结石3例，CT表现为中线处膀胱壁内可见高密度结石影；脐尿管肿瘤性病变4例，均于膀胱顶壁区中线处发现不规则软组织肿块影，增强后明显强化。结论 脐尿管占位性病变并不常见，多为感染性囊肿，结合临床术前确诊并不困难。CT是脐尿管占位性病变术前明确诊断和鉴别诊断的重要措施之一。     

一种新的正交参数选优法及其在非线性回归分析中的应用

非线性回归分析是工程中经常采用的一种用来估计数学模型参数的方法，该方法能否顺利运用与参数初始值的选择有极大关系。本研究提出一种新的正交参数选优法——阻尼正交表法，它不仅可以保证非线性回归分析算法的顺利收敛，而且能够显著提高后者的收敛速度，进而极大改善非线性回归分析算法的应用性能。本研究的数值试验及心肌造影超声心动图定量分析应用实例表明，作为对传统正交参数选优法的一种改进，阻尼正交表法在科学与工程计算或信号与信息处理领域有着很好的应用前景。