骨关节炎中影响软骨细胞凋亡的因素

目的:近年来国外对骨关节炎的发生及发展机制有许多研究成果,骨关节炎中软骨细胞凋亡影响因素的研究颇具新意。资料来源:应用计算机检索Medline1985-01/2004-12与骨关节炎中软骨细胞凋亡相关的文献,检索词“osteoarthritis,chondrocyte,apoptosis”并限定文献语种为English。资料选择:对资料的摘要进行阅读初审,选取包括试验组和对照组的文献,开始查找全文。纳入标准:①随机对照试验。②试验包括对照组。排除标准:①没有设立对照组的文献。②综述类文献、Meta分析、重复研究。资料提炼:共收集到111篇关于骨关节炎中软骨细胞凋亡影响因素的试验,纳入符合标准的文献35篇。排除的文献为综述类文献28篇和重复研究48篇。35篇文献多为软骨细胞体外培养有关的试验,分别对各种凋亡影响因素进行评价。资料综合:在骨关节炎患者和老年人的软骨中,由于细胞外基质成分降解或通过高级糖基化、酪氨酸亚硝基化等修饰作用破坏了正常的细胞外基质从而使软骨细胞发生炎症反应并促进其死亡。各种机械性刺激是软骨细胞功能的重要调节因素,施加机械压力的加速率也决定软骨损伤和软骨细胞死亡的类型与程度。经某些细胞因子作用的正常软骨和分离培养的软骨细胞产生高水平的NO,而NO产物又能诱导软骨细胞死亡。肿瘤坏死因子受体超家族成员与相应的死亡配体结合能激活凋亡信号通路,当存在其他前凋亡因子或缺乏某些促存活因子时肿瘤坏死因子α能诱导软骨细胞凋亡。正是由于能量代谢受损使软骨细胞对其他的致死因子变得更加敏感。在发育和骨关节疾病相关过程中,软骨细胞的死亡虽然有p53的参与,但其精确的机制有待阐明,同时没有足够的直接证据表明c-myc能够影响软骨细胞的存活或死亡。结论:骨关节炎中影响软骨细胞凋亡的因素很多,机制复杂,许多因素导致软骨细胞凋亡的通路有待进一步阐明。     

导致高水平氨基糖苷类抗生素耐药的新型16S rRNA甲基化酶研究进展

氨基糖苷类抗生素通过与细菌30S核糖体的16S rRNA亚单位结合，导致读码错误，干扰蛋白合成从而阻止细菌生长。氨基糖苷类抗生素作为一类高效、广谱的抗生素，因其具有浓度依赖性的快速杀菌、可与细胞壁活性抗菌药物产生协同作用的特点，一直是临床上治疗革兰阴性菌所致严重感染的重要药物。但是随着该类药物在临床上的广泛应用，     

The mechanisms and evidence of efficacy of electrical stimulation for healing of pressure ulcer: A systematic review

The objective of this article is to provide a systematic review of the efficacy of electrical stimulation in healing pressure ulcer and to review its mechanism of action. The Cochrane Library, PubMed, CINAHL, Medline, EMBASE, and NHS EED were searched for relevant interventional studies including randomized controlled trials (RCTs) and observational studies. A best‐evidence synthesis was performed to summarize the results of the included studies. A total of seven RCTs and two observational studies met the inclusion criteria. Moderate level of evidence of efficacy with low risk of bias was shown in all seven RCTs. Although some studies have used continuous direct current, most other investigators opted to use high‐voltage pulsed current to minimize the risk of skin burn and to achieve greater current penetration. Overall, the incidence of adverse effects was very low. Two studies that assessed the economic impacts of electrical stimulation revealed substantial health care cost savings. The mechanisms through which electrical stimulation exerts a positive effect on pressure ulcer healing are reasonably well established. Clinical trials have revealed a moderate level of evidence to support its use as an ancillary treatment modality for healing pressure ulcer. Recommendations regarding the optimal electrical stimulation parameters and dosage of use are provided. Further studies to investigate potential barriers that may impede widespread use in different clinical settings are needed.     

Risk Factors Associated With Sphincter-Preserving Resection in Patients With Low Rectal Cancer

Abdominoperineal resection (APR) and sphincter-preserving resection (SPR) are the two primary surgical options for rectal cancer. Retrospectively we collected rectal cancer patients for SPR and APR observation between 2005 and 2007. The patient-related, tumor-related, and surgery-related variables of the SPR and APR groups were analyzed by using logistic regression techniques. The mean distance from the anal verge (DAV) of cancer is significantly higher in SPR than that in APR (P < 0.001). In cancers with DAV <40 mm (SPR, 40 versus APR, 110), multivariate analysis shows that surgeon procedure volume (odds ratio [OR] = 0.244; 95% confidence interval [CI]: 0.077–0.772; P = 0.016) and neoadjuvant radiotherapy (OR = 0.031; 95% CI: 0.002–0.396; P = 0.008) are factors influencing SPR. In cancers with DAV ranging from 40 mm to 59 mm (SPR 190 versus APR 50), analysis shows that patient age (OR = 2.139; 95% CI: 1.124–4.069; P = 0.021), diabetes (OR = 2.657; 95% CI: 0.872–8.095; P = 0.086), and colorectal surgeon (OR = 0.122, 95% CI: 0.020–0.758; P = 0.024), are influencing factors for SPR. The local recurrence and disease-free survival reveal no significant difference. A significant difference exists in DAV, surgeon specialization, procedure volume, age, diabetes, and neoadjuvant radiotherapy between SPR and APR.Key words: Abdominoperineal resection, Sphincter-preserving resection, Anterior resection, Rectal cancer, TreatmentAbdominoperineal resection (APR) with permanent colostomy and sphincter-preserving resection (SPR) of the rectum are the two primary surgical options for the curative treatment of rectal cancer. With the introduction of the concept of total mesorectal excision (TME), combined with the significant effects of adjuvant radiochemotherapy and surgical staplers, SPR indication has been significantly expanded compared with APR in low or ultra-lower rectal cancer.For patients with rectal cancer, sphincter preservation (SP) is often as important as curing cancer. Surgeons need to determine whether a patient with lower rectal cancer is suitable for SP. However, a standard method of determining patient suitability is unavailable because this judgment depends on the different individual experiences of surgeons.In addition to the distance of the tumor from the anal verge (DAV), other important factors such as the patient''s individual condition, oncologic consideration, technical feasibility, and the surgeon''s personal experience, are reported as risk factors that may influence the SP rate.^1–3 This study aims to determine the significance of these factors on achieving SPR in a single large-volume institution.     

The p.R229Q variant of the NPHS2 (podocin) gene in focal segmental glomerulosclerosis and steroid-resistant nephrotic syndrome: a meta-analysis

While many previous studies have reported an association between the p.R229Q variant of the NPHS2 gene and focal segmental glomerulosclerosis (FSGS) or steroid-resistant nephrotic syndrome (SRNS), a conclusive relationship has not been defined. In this study, we performed a meta-analysis of the published data to investigate the impact of the p.R229Q polymorphism on FSGS and SRNS patients. Despite significant heterogeneity within some of the comparisons, the results revealed significantly higher risks of SRNS in individuals homozygous for the variant allele (OR 7.411, 95 % confidence interval 1.876–29.436, p = 0.004) compared to homozygous non-variant individuals. However, the carrier rate of the p.R229Q variant was not significantly different between SRNS patients and steroid-sensitive nephrotic syndrome patients. No statistically significant differences in the p.R229Q carrier rate were observed between FSGS patients and controls or FSGS patients and patients with different pathology classifications. No notable differences in the p.R229Q carrier rate were found between patients and controls in any group with early-onset disease (onset age < 18). In conclusion, our meta-analysis suggests that for adult-onset disease (onset age > 18), the homozygous variant could be a potential predictor of hereditary nephrotic syndrome and that the p.R229Q allele cannot currently be considered a risk factor for predicting FSGS.