Efficacy and Safety of Liposomal Clarithromycin and Its Effect on Pseudomonas aeruginosa Virulence Factors

We investigated the efficacy and safety of liposomal clarithromycin formulations with different surface charges against clinical isolates of Pseudomonas aeruginosa from the lungs of cystic fibrosis (CF) patients. The liposomal clarithromycin formulations were prepared by the dehydration-rehydration method, and their sizes were measured using the dynamic-light-scattering technique. Encapsulation efficiency was determined by microbiological assay, and the stabilities of the formulations in biological fluid were evaluated for a period of 48 h. The MICs and minimum bactericidal concentrations (MBCs) of free and liposomal formulations were determined with P. aeruginosa strains isolated from CF patients. Liposomal clarithromycin activity against biofilm-forming P. aeruginosa was compared to that of free antibiotic using the Calgary Biofilm Device (CBD). The effects of subinhibitory concentrations of free and liposomal clarithromycin on bacterial virulence factors and motility on agar were investigated on clinical isolates of P. aeruginosa. The cytotoxicities of the liposome preparations and free drug were evaluated on a pulmonary epithelial cell line (A549). The average diameter of the formulations was >222 nm, with encapsulation efficiencies ranging from 5.7% to 30.4%. The liposomes retained more than 70% of their drug content during the 48-h time period. The highly resistant strains of P. aeruginosa became susceptible to liposome-encapsulated clarithromycin (MIC, 256 mg/liter versus 8 mg/liter; P < 0.001). Liposomal clarithromycin reduced the bacterial growth within the biofilm by 3 to 4 log units (P < 0.001), significantly attenuated virulence factor production, and reduced bacterial twitching, swarming, and swimming motilities. The clarithromycin-entrapped liposomes were less cytotoxic than the free drug (P < 0.001). These data indicate that our novel formulations could be a useful strategy to enhance the efficacy of clarithromycin against resistant P. aeruginosa strains that commonly affect individuals with cystic fibrosis.     

P53、nm23基因变化与胃癌转移及预后的研究

目的:探讨P53、nm23基因在人胃癌组织中的表达及其与淋巴转移和预后的关系。材料和方法:胃癌切除术的手术标本(共93例)。采用免疫组织化学法。结果:P53阳性率为49.4％(46/93),nm23为56％(52/93)。P53阳性表达与胃癌患者的年龄、性别、肿瘤组织学分型、浸润深度、淋巴结转移之间无显著性差异,但与胃癌患者预后有统计学意义。nm23低表达与淋巴结转移及预后有显著的相关性。93例胃癌组织中的淋巴结转移者63例,其中nm23表达阳性28例(44％),无转移者30例,其中nm23阳性表达24例(80％),二组之间有非常显著的差异(P<0.01)。nm23表达阳性组1,3,5年生存率分别为80％、65％和24％,而表达阴性者1,3,5年生存率为68％、41％和21％。二组间生存分布差异有显著性(P<0.05)。结论:胃癌nm23低表达有发生淋巴结转移倾向,P53高表达和nm23低表达患者预后差。P53、nm23基因变化对胃癌淋巴结转移和预后起重要作用。     

腹直肌外侧入路与髂腹股沟入路切开复位内固定治疗幼儿Torode-Zieg Ⅳ型骨盆骨折的疗效比较

目的:比较腹直肌外侧入路与髂腹股沟入路切开复位内固定治疗幼儿Torode-Zieg Ⅳ型骨盆骨折的临床疗效。方法:采用回顾性队列研究分析2012年6月至2019年6月右江民族医学院附属医院和南方医科大学第三附属医院收治的12例幼儿Torode-Zieg Ⅳ型骨盆骨折患者临床资料,其中男6例,女6例;年龄13~36个月［...     

Receptor activator of NF-κB ligand-dependent expression of caveolin-1 in osteoclast precursors, and high dependency of osteoclastogenesis on exogenous lipoprotein

Although extensive studies have done much to clarify the molecular mechanisms of osteoclastogenesis during the last ten years, there may still be unknown molecules associated with osteoclast differentiation. Thus, we used fluorescent differential display to screen for genes whose expression is induced by receptor activator of NF-κB ligand (RANKL), a crucial molecule for osteoclast formation. We identified caveolin-1 (Cav-1) as a RANKL-induced gene. Cav-1 is a major structural protein of caveolae and lipid rafts, cholesterol-enriched microdomains in the plasma membrane (PM). The RANKL-induced Cav-1 was immediately conveyed to lipid rafts. Conversely, expression of flotillin-1 (Flot-1), another scaffolding protein of lipid rafts, was reduced during osteoclastogenesis, indicating conversion of Flot-1-predominant rafts into Cav-1-enriched rafts. However, in vitro osteoclastogenesis of precursor cells from Cav-1-null mice was comparable to that of wild-type mice, while Cav-2 expression in the knockout osteoclasts was maintained. Conversely, Cav-2 gene silencing in Cav-1-null osteoclast precursors using siRNA for Cav-2 increased osteoclast formation, suggesting that the Cav-1/Cav-2 complex may act as a negative regulator for osteoclastogenesis. On the other hand, destruction of lipid rafts by removal of cholesterol from the PM by methyl-ß-cyclodextrin (MCD) treatment caused disordered signal transductions for osteoclastogenesis, such as hyperactivation of Erk1/2 and insensitivity of Akt to RANKL stimulus. The abnormal signaling was reproduced by deleting exogenous lipoproteins from the culture medium, which also resulted in reduced osteoclast formation. In addition, the deletion caused delayed expression of nuclear factor of activated T cells c1 (NFATc1), and depressed its activation in the cytosol and inhibited its translocation into nuclei. Simultaneously, the deletion reduced the level of FcRγ, a trigger protein for initiating the calcium signaling needed to activate NFATc1, and decreased Cav-1 in lipid rafts. These findings indicate that the molecular mechanisms of osteoclastogenesis are highly dependent on extracellular lipoprotein and the integrity of lipid rafts, and suggest possible involvement of cholesterol.     

护理风险层级安全干预机制的建立与实施

目的建立护理风险层级安全干预机制并评价应用效果。方法以心内科为试点,建立护理部主任、护理部质控人员(三级),片区总护士长(二级),科室护士长和安全员(一级)组成的护理风险层级安全管理网络,实行由一级到三级逐级报告制度。结果实施护理风险层级安全干预前发生护理差错、纠纷19例,实施后发生护理差错、纠纷4例。实施前后护理差错、纠纷发生率比较,差异有统计学意义(P<0.01)。结论护理风险层级安全干预机制的建立,充分发挥了各部门的职能作用,提高了护理人员对风险的识别与应对能力,降低和避免了护理风险,确保了护理安全。     

CD146在聚乙二醇诱导的小鼠脉络膜新生血管模型中的表达及意义

目的：探讨在聚乙二醇（polyethylene glycol,PEG）诱导的小鼠脉络膜新生血管（choroidal neovascularization,CNV）模型中CD146的表达及意义。方法：将60只8周龄雄性C57BL/6J小鼠采用随机数字表法,将小鼠随机分为第5、10和15天组,每组各20只。设定每组小鼠左眼为正常对照眼,右眼为实验眼,采用在视网膜下注射PEG诱导形成脉络膜新生血管模型。造模后摘取各组小鼠眼球,制作视网膜组织切片及HE染色,鉴定CNV模型。通过比较各组视网膜HE染色切片外核层（outer nuclear layer,ONL）厚度,观察PEG的视网膜毒性作用。采用实时荧光定量PCR法检测小鼠神经视网膜和RPE/脉络膜复合体中CD146、血管内皮生长因子（vascular endothelial growth factor,VEGF）、血管内皮生长因子受体2（vascular endothelial growth factor receptor 2,VEGFR2）的mRNA水平变化。免疫组化染色法检测小鼠眼内CD146、VEGF和VEGFR2的表达。结果：HE染色和ONL层厚度比较均证实,视网膜下注射PEG造模成功且模型可靠,视网膜下注射后第5和10天均有CNV形成。实验组小鼠神经视网膜和脉络膜中CD146、VEGF、VEGFR2的mRNA表达水平与对照组相比明显升高,差异有统计学意义（F=30.412,P=0.000;F=84.974,P=0.000;F=117.423,P=0.000;F=918.786,P=0.000;F=319.110,P=0.000;F=113.896,P=0.000）。Person相关性分析提示在视网膜下注射PEG后,小鼠RPE/脉络膜复合体中CD146与VEGF和VEGFR2的表达量呈正相关（r=0.940,P=0.000;r=0.940,P=0.000;r=0.769,P=0.045;r=0.910,P=0.003;r=0.910,P=0.003;r=0.777,P=0.042）。免疫组化染色的结果显示,在造模第10天后,造模组与正常对照组相比较CD146、VEGFR2在神经节细胞层、内核层、外从状层、外核层的阳性表达均有不同程度增强（P=0.000,P=0.000,P=0.000）。结论：CD146伴随着CNV的形成表达上调,且与VEGF的表达量和VEGFR2的表达量呈正相关性,由此推断CD146可能在CNV形成的病理过程中起到至关重要的作用。     

冠心病病人骨髓间充质干细胞的生物学特征评价

目的　确立胸骨骨髓间充质干细胞分离和培养的方法 ,评价其生物学特征。方法　骨髓取自行冠状动脉旁路移植术的冠心病病人胸骨切口 ,用Percoll液分离骨髓MSCs,体外培养扩增 ,观察细胞生长特性 ,流式细胞仪检测骨髓MSCs表型特征、细胞周期。结果　贴壁的骨髓MSCs多数呈梭形。骨髓MSCs能连续传 15代以上 ,但是第 5代以后或老年病人的细胞增殖速度减慢。骨髓MSCs的表型特征为CD2 9、CD4 4阳性 ,CD34、CD4 5阴性。多数骨髓MSCs在细胞周期的G0 /G1期。结论　冠心病病人手术时从胸骨切口取骨髓并分离培养骨髓MSCs的方法可行 ,骨髓MSCs具有较好的增殖更新潜能 ,是细胞心肌成形术中理想的细胞来源。     

Validity and reliability of Chinese version of the new diabetic foot ulcer assessment scale

A specific assessment tool is urgently needed to guide effective wound care for diabetic foot ulcers. However, the tool has not been available in Chinese. We aimed to culturally translate and verify the validity and reliability of the new Diabetic Foot Ulcer Assessment Scale (DFUAS). The original scale was translated into Chinese according to the Brislin guidelines. Patients satisfying the inclusion and exclusion criteria were recruited. Each of the included foot ulcers was evaluated independently by two wound care specialists using the new DFUAS and by the third wound care specialists at the same time using the Bates-Jensen Wound Assessment Tool according to per guidelines. 210 diabetic foot ulcers were included for data analysis. The S-CVI of the Chinese version of the DFUAS was 0.96, and the I-CVIs ranged from 0.89 to 0.98. The total Cronbach's Alpha of the scale was 0.709, and the corrected item-total correlation of the items ranged from 0.4 to 0.872. The DFUAS had high inter-observer reliability of 0.997, and there were weak, moderate, and strong correlations between each pair of the items. The Bland–Altman plots showed a good agreement between the scale and the Bates-Jensen Wound Assessment Tool. We concluded that the Chinese version of the DFUAS showed good validity and reliability and is a reliable instrument for the assessment of diabetic foot ulcers.