核转染对成体骨髓源性干细胞的影响

背景：成体骨髓源性干细胞是实施细胞治疗的重要细胞来源。对成体骨髓源性干细胞的示踪,是研究其移行、分化的规律与机制并进一步阐明再生潜能、疗效的关键。目的：探讨经转染后的成体骨髓呈克隆样干细胞,在细胞表型、增殖能力、心肌分化潜能是否存在的影响。方法：应用核转染技术利用U-23程序将编码maxGFP报告基因的载体对成体骨髓呈克隆样干细胞进行转染,应用MTT法对核转染前后的生长曲线进行测定,使用3μmol/L5-氮胞苷对核转染前后成体骨髓呈克隆样干细胞进行向心肌分化诱导,并利用RT-PCR对向心肌分化的特异性标记物GATA4与MLC-2v的表达进行测定。使用成年SD大鼠心肌梗死左前降支结扎模型,对使用经maxGFP转染的成体骨髓呈克隆样干细胞施心内注射并于注射后的第2天和第7天对经注射心脏行冰冻切片并观察maxGFP在体内的表达情况。结果与结论：经核转染24h后,第47代及第119代成体骨髓呈克隆样干细胞的转染率为49.4%和43.1%,转染后5h,开始出现呈绿色荧光阳性的细胞,经核转染后仍能保持小圆球形、可贴壁、呈克隆样生长。MTT检测结果显示：核转染前后第47代及第119代均具有相似的生长曲线。核转染前第47代及119代细胞平均群体倍增时间分别为8.57,10.28h;核转染后分别为9.42,10.42h,各代前后比较差异无显著性意义（P=0.551,P=0.774）。RT-PCR检测结果显示：核转染前5-氮胞苷处理前后均表达GATA4,处理后MLC-2v条带更强;核转染后5-氮胞苷处理前后均表达GATA4,处理后MLC-2v条带更强,上述2个向心肌分化指标于转染前后变化并不明显。体内实验结果：心内注射经核转染后的成体骨髓呈克隆样干细胞,第2天及第7天可在经注射心肌中发现有少量绿色荧光阳性的细胞。提示,核转染可快速地将外源基因导入细胞,经核转染后的成体骨髓呈克隆样干细胞仍能保持其细胞形态、增殖能力及向心肌分化潜能,然而,经maxGFP基因核转染的成体骨髓呈克隆样干细胞,移植入心肌后只有少数细胞能表达经转染基因。     

Application of biotin-avidin system, determination of circulating immune complexes, and evaluation of antibody response in different hydatidosis patients

The avidin-biotin-peroxidase complex enzyme-linked immunosorbent assay (ABC-ELISA) and standard ELISA were used for the detection of Echinococcus granulosus antibody in sera of 101 patients operated on for hydatid disease, 40 patients with miscellaneous nonhydatid diseases, and 61 normal subjects. Sensitivity and specificity of the two procedures were comparable and the geometric mean antibody titer detected with ABC-ELISA was higher than with standard ELISA. The ABC-ELISA is a sensitive, specific, simple, and convenient method for diagnosing hydatidosis.     

Long-Term Coffee Consumption and Risk of Gastric Cancer: A PRISMA-Compliant Dose–Response Meta-Analysis of Prospective Cohort Studies

Association between coffee consumption and gastric cancer risk remains controversial. Hence, we performed a meta-analysis to investigate and quantify the potential dose–response association between long-term coffee consumption and risk of gastric cancer.Pertinent studies were identified by searching PubMed and Embase from January 1996 through February 10, 2015 and by reviewing the reference lists of retrieved publications. Prospective cohort studies in which authors reported effect sizes and corresponding 95% confidence intervals (CIs) of gastric cancer for 3 or more categories of coffee consumption were eligible. Results from eligible studies were aggregated using a random effect model. All analyses were carried out using the STATA 12.0 software.Nine studies involving 15 independent prospective cohorts were finally included. A total of 2019 incident cases of gastric cancer were ascertained among 1,289,314 participants with mean follow-up periods ranging from 8 to 18 years. No nonlinear relationship of coffee consumption with gastric cancer risk was indentified (P for nonlinearity = 0.53; P for heterogeneity = 0.004). The linear regression model showed that the combined relative risk (RR) of every 3 cups/day increment of total coffee consumption was 1.07 (95% CI = 0.95–1.21). Compared with the lowest category of coffee consumption, the RR of gastric cancer was 1.18 (95% CI = 0.90–1.55) for the highest (median 6.5 cups/day) category, 1.06 (95% CI = 0.85–1.32) for the second highest category (median 3.5 cups/day), and 0.97 (95% CI = 0.79–1.20) for the third highest category (median 1.5 cups/day). Subgroup analysis showed an elevated risk in the US population (RR = 1.36, 95% CI = 1.06–1.75) and no adjustment for smoking (RR = 1.67, 95% CI = 1.08–2.59) for 6.5 cups/day.Current evidence indicated there was no nonlinear association between coffee consumption and gastric cancer risk. However, high coffee consumption (more than 6.5 cups/day) might increase the risk of gastric cancer in the US population. More high quality studies were warranted to further investigate the association.     

Risk Factors for Long-Term Mortality and Progressive Chronic Kidney Disease Associated With Acute Kidney Injury After Cardiac Surgery

The aim of the study was to evaluate risk factors for long-term mortality and progressive chronic kidney disease (CKD) after cardiac surgery in patients with normal preoperative renal function and postoperative acute kidney injury (AKI). From April 2009 to December 2012, we prospectively enrolled 3245 cardiac surgery patients of our hospital. The primary endpoints included survival rates and the secondary endpoint was the incidence of progressive chronic kidney disease (CKD) in a follow-up period of 2 years. Acute kidney injury was staged by KDIGO classification. Progressive CKD was defined as GFR ≤ 30 mL/min/1.73 m² or end-stage renal disease (ESRD) (starting renal replacement therapy or renal transplantation).The AKI incidence was 39.9% (n = 1295). The 1 and 2 year overall survival (OS) rates of AKI patients were significantly lower than that for non-AKI patients (85.9% and 82.3% vs 98.1% and 93.7%, P < 0.001), even after complete recovery of renal function during 2 years after intervention (P < 0.001). The 2-year overall survival (OS) rates of patients with AKI stage 1, 2, and 3 were 89.9%, 78.6%, and 61.4% (P < 0.001), respectively. Multivariate Cox regression analysis of factors for 2-year survival rates revealed that besides age (P < 0.001), chronic cardiac failure (P < 0.001), diabetes (P < 0.001), cardiopulmonary bypass time (P < 0.01), and length of intensive care unit (ICU) stay (P = 0.004), AKI was a significant risk factor for reducing 2-year survival rates even after complete recovery of renal function (P < 0.001). The accumulated progressive CKD prevalence was significantly higher in AKI than in non-AKI patients (6.8% vs 0.2%, P < 0.001) in the 2 years after surgery. Even with complete recovery of renal function at discharge, AKI was still a risk factor for accumulated progressive CKD (RR 1.92, 95% CI 1.37–2.69).The 2-year mortality and progressive CKD incidence even after complete recovery of renal function were significantly increased in cardiac surgery patients with postoperative AKI.     

Up-regulation of CC chemokine ligand 20 and its receptor CCR6 in the lesional skin of early systemic sclerosis

Mononuclear cell (MNC) infiltrate is one of the earliest pathological changes in systemic sclerosis (SSc) skin. However, little is known about the recruitment of these cells into skin lesions. Recently, the role of chemokines has been suggested in the pathogenesis of SSc. Here we studied the expressions and distributions of CC chemokine CCL20 and its receptor CCR6 in early SSc skin lesions and the difference in CCL20 expressions and ability to recruite MNCs of normal dermal fibroblast (NDF) and scleroderma dermal fibroblast (SSDF). We found that the expressions of CCL20 and its receptor CCR6 were obviously up-regulated in SSc in contrast to normal human skin. mRNA levels were significantly expressed in SSc lesional skins vs normal skin tissues. SSDF displayed increased constitutive expressions of CCL20 mRNA and protein. In addition, Th1 cytokines (TNF-α and IL-1β) remarkably increased the expression of CCL20 in both NDF and SSDF in a dose- and time-dependent manner. Supernatants from SSDF showed stronger chemotactic activity to PBMCs than those from NDF. Thus our findings suggest that CCL20 released from cytokine-activated SSDF plays an important role in the induction of SSc by further recruiting more MNCs to the skin.     

Gene therapy of Parkinson's disease using adeno-associated virus (AAV) vectors

Parkinson's disease (PD) is characterized by the progressive loss of the dopaminergic neurons in the substantia nigra and a severe decrease in dopamine in the striatum. A promising approach to the gene therapy of PD is intrastriatal expression of dopamine-synthesizing enzymes [tyrosine hydroxylase (TH) and aromatic L-amino acid decarboxylase (AADC)]. The most appropriate gene-delivery vehicles for neurons are adeno-associated virus (AAV) vectors, which are derived from non-pathogenic virus. Therefore, TH and AADC genes were introduced into the striatum in the lesioned side using separate AAV vectors in parkinsonian rats, and the coexpression of TH and AADC resulted in better behavioral recovery compared with TH alone. Another strategy for gene therapy of PD is the protection of dopaminergic neurons in the substantia nigra using an AAV vector containing a glial cell line-derived neurotrophic factor (GDNF) gene. Combination of dopamine-supplement gene therapy and GDNF gene therapy would be a logical approach to the treatment of PD.