补肾活血法调控大鼠骨髓间充质干细胞增殖活性的实验研究

目的:探讨补肾活血汤及其拆方含药血清调控大鼠骨髓间充质干细胞(BMSCs)增殖活性的作用。方法:体外骨髓贴壁法分离培养大鼠BMSCs,取第3代细胞,免疫荧光法鉴定细胞表面抗原,成骨及成脂诱导证实其多向分化潜能;实验分为补肾活血汤全方组、补肾组、活血组及空白对照组,运用补肾活血汤及其拆方含药血清干预第3代BMSCs 48h,并用四甲基偶氮唑盐比色法(MTT)观察细胞增殖活性,流式细胞仪检测细胞周期。结果:MTT结果显示:体积分数5%及10%补肾活血汤全方含药血清均有促进大鼠BMSCs增殖的作用;流式细胞仪检测细胞周期显示:运用补肾活血汤含药血清干预后,处于增值分裂期(S+G2+M期)的BMSCs百分率增多,与其他3组比较差异有统计学意义(P<0.05)。结论:补肾活血汤全方含药血清有促进大鼠骨髓间充质干细胞增殖的作用。     

髋臼骨折术后残留移位与髋关节功能的相关性分析

目的通过术后CT评价髋臼骨折复位质量,探讨累及负重区和非负重区的残留移位(台阶移位和间隙移位)与术后髋关节功能的相关性。方法回顾分析2004年6月-2009年6月48例髋臼骨折患者术后CT检查和临床随访结果。患者均行切开复位内固定。术后均获随访,随访时间24～72个月,平均36个月;骨折均愈合。根据关节面残留移位是否累及负重顶,将患者分为负重区组(30例)和非负重区组(18例)。髋关节功能按Merled’Aubigné-Postel标准评定;术后关节面复位质量采用CT评价,于CT片上测量残留移位的两个指标(台阶移位和间隙移位)最大值。所得数据均采用Spearman秩相关检验分析。结果负重区组残留移位值与髋关节功能成强负相关性(rs=—0.722,P=0.001);非负重区组残留移位值与髋关节功能无相关性(rs=0.481,P=0.059)。临床随访结果与相关性分析一致。负重区组台阶移位值与髋关节功能成极强负相关(rs=—0.825,P=0.002),而间隙移位值与髋关节功能无相关性(rs=0.577,P=0.134)。结论髋臼骨折患者术后髋关节功能不仅与关节面残留移位大小相关,还与残留移位部位相关。与非负重区相比,累及负重区的残留移位是影响术后髋关节功能的关键因素;在负重区台阶移位值越大,髋关节功能越差。     

Radiographic and clinical results of posterior dynamic stabilization for the treatment of multisegment degenerative disc disease with a minimum follow-up of 3 years

Background  

This study aims to compare radiographic and clinical outcomes of Dynesys and posterior lumbar interbody fusion (PLIF) for the treatment of multisegment disease.     

Survival outcomes for men with mediastinal germ-cell tumors: The University of Texas M. D. Anderson Cancer Center experience

ObjectivePrimary mediastinal germ-cell tumors are rare, and the effect of newer drugs and treatment strategies in this disease on overall survival is not known. We retrospectively assessed treatment outcomes at a single institution.Materials and methodsWe identified men seen at our institution from 1998 through 2005 for mediastinal germ-cell tumors. Medical records were reviewed for patient characteristics, histology, tumor markers, treatment, and survival outcome.ResultsThirty-four patients met study criteria, of whom 27 had nonseminomatous germ-cell tumor (NSGCT) and 7 had pure seminoma. Eleven patients (41%) with NSGCT were alive at last contact with a median overall survival time of 33.5 months. Among 13 patients with NSGCT referred to us at initial diagnosis, 7 (54%) were alive and recurrence-free at a median follow-up of 56.5 months. Progression-free survival was associated with absence of risk factors (any histology other than endodermal sinus tumor, β-hCG > 1000 mIU/mL, or disease outside the mediastinum). For the patients whose disease progressed (n = 5) or who had been referred to us for salvage treatment (n = 14), the 3-year overall survival from the date of first progression was 23%. Conversely, patients with seminoma did uniformly well with platinum-based chemotherapy; most did not undergo radiation or surgery.ConclusionChemotherapy given to maximum effect followed by surgical consolidation resulted in long-term progression-free survival for 54% of patients with mediastinal NSGCT. The number of risk factors present at diagnosis may be associated with survival outcome and should be studied in a larger test group.     

Recurrent seminomas: Clinical features and biologic implications

ObjectivesCertain patients with seminoma and clinically atypical phenotypes—visceral metastases, elevated levels of β human chorionic gonadotropin (βHCG), and/or recurrent disease—have a poor prognosis. The primary goal of this pilot study was to characterize the clinical characteristics and treatment profile of these rare patients. We also wished to test whether these tumors expressed any specific biomarkers that might distinguish them as a unique subtype of seminoma.Materials and methodsWe retrospectively identified 25 patients with a history of seminoma plus visceral metastases, βHCG levels >200 mU/ml, and/or recurrent disease. We reviewed these patients' histories for treatment efficacy and clinical outcome. Tissue samples were available from 6 of those patients, and we studied them for expression of the markers OCT 3/4, PLAP, CD30, TRA-1-60, c-kit, and gp200. We compared our results with the expression of those markers in tissue samples from mixed seminoma/embryonal carcinomas and classic seminomas.ResultsOur analysis suggested that certain chemotherapeutic regimens (such as ifosfamide, paclitaxel, and cisplatin) are efficacious for the treatment of patients with these atypical seminomas. Further, specimens from the atypical seminomas generally had staining profiles that resembled those of classic seminomas and the seminoma components in mixed germ-cell tumors, but the profiles differed from those of the embryonal carcinoma components in the same mixed germ-cell tumors.ConclusionsAlthough these atypical seminomas tend to be resistant to chemotherapy, they may still respond to certain chemotherapeutic regimens. Our pilot immunohistochemical study also suggested that the unique phenotypes associated with these atypical seminomas do not result from any relationship with embryonal carcinomas. More study is needed to confirm these initial findings.     

Prevalence of zoonotic bacteria in wild and farmed aquatic species and seafood: a scoping study, systematic review, and meta-analysis of published research

Increased reliance on seafood has brought to light concerns regarding food safety, but the information to inform risk assessment or surveillance needs is lacking. A scoping study (ScS) was conducted to characterize published research investigating selected zoonotic bacteria and public health topics in various wild and farmed aquatic species and seafood. This was followed by a systematic review (SR) on selected bacteria (Aeromonas spp., generic Escherichia coli, Salmonella spp., and Vibrio spp.) and aquatic species (clams, mussels, oysters, salmon, and shrimp [including prawn]); a meta-analysis (MA) was conducted only at the retail level due to considerable variability among various pathogen/seafood combinations. The ScS revealed the most frequently investigated themes were farm-level prevalence and intervention research for Vibrio spp. and Aeromonas spp. Antimicrobial use (AMU) and the association between AMU and antimicrobial resistance were rarely investigated. The SR indicated a consistent lack of reporting regarding study methodology and results, precluding the use of many studies in and full benefits of MA. MA of Aeromonas, E. coli, and Salmonella prevalence in retail salmon resulted in pooled estimates of 13% (6-27%), 2% (0.1-11%), and 1% (0-5%), respectively. When MA of pathogen/seafood combination resulted in statistically significant heterogeneity (p<0.1), median/range were reported at the region level. The results from our ScS, SR, and MA could be used for better design of future bacteriological surveys of seafood and as inputs for risk assessments or surveillance initiatives in this field.     

Addressing the identification problem in age-period-cohort analysis: a tutorial on the use of partial least squares and principal components analysis

In the analysis of trends in health outcomes, an ongoing issue is how to separate and estimate the effects of age, period, and cohort. As these 3 variables are perfectly collinear by definition, regression coefficients in a general linear model are not unique. In this tutorial, we review why identification is a problem, and how this problem may be tackled using partial least squares and principal components regression analyses. Both methods produce regression coefficients that fulfill the same collinearity constraint as the variables age, period, and cohort. We show that, because the constraint imposed by partial least squares and principal components regression is inherent in the mathematical relation among the 3 variables, this leads to more interpretable results. We use one dataset from a Taiwanese health-screening program to illustrate how to use partial least squares regression to analyze the trends in body heights with 3 continuous variables for age, period, and cohort. We then use another dataset of hepatocellular carcinoma mortality rates for Taiwanese men to illustrate how to use partial least squares regression to analyze tables with aggregated data. We use the second dataset to show the relation between the intrinsic estimator, a recently proposed method for the age-period-cohort analysis, and partial least squares regression. We also show that the inclusion of all indicator variables provides a more consistent approach. R code for our analyses is provided in the eAppendix.