The action of Pseudomonas aeruginosa biofilms in intrinsic drug resistance

Background There is a growing interest in studying the relationship between intrinsic resistance and biofilms resistance to drugs. However, the relationship still remains unclear in the macroscopic bacterial growth. Our study is to illuminate the change of bacterial drug resistance of gyrA mutant and active efflux pump during the development of Pseudomonas aeruginosa （ P. aeruginosa ） biofilms. Methods The strains of typeⅡ topoisomerase gene mutant （gyrA mutant） and multidrug resistance （MDR） efflux pump were clinical isolates and detected by polymerase chain reaction （PCR）. The process of bacterial biofilms development was observed by scanning electron microscope. Triparental mating experiments were performed to transfer report gene of green fluorescent protein （GFP） into P. aeruginosa biofilms strains and followed by analysis of bacterial survival rate between intrinsic resistance and biofilms resistance. Results The fluorescent strains with pGFPuv could develop mature biofilms on Teflon surface. Before a period of 72 hours, the survival rate of biofilms bacteria and intrinsic resistance strains in ciprofloxacin solution was significantly different （ P 〈 0.05）. The survival number of intrinsic resistance strains （gyrA mutation and active efflux pump） was illustriously higher than biofilm strain in the initial stage of biofilms development. After 72 hours incubation, there was no clearly difference between mutants and biofilms strains in the survival rate （P 〉 0.05）. The carbonyl cyanide m-chlorophenylhydrazone and azithromycin could significantly reduce the drug resistance of biofilm strains and efflux pump strains. Conclusions In the development of P. aeruginosa biofilms, the strains of gyrA mutation and MDR efflux could be conferred with new level of drug resistance. When co-cultured mutated strains with biofilm strains, biofilms may play a major role in bacterial resistance. But after 72 hours incubation （ a mature biofilms had been developed） , there was no clearly difference between the number of mutant strains and biofilm strains.     

流场压力信号变化对内皮细胞形态和黏附功能的影响

人体血循环系统是一个有压的封闭系统,血管流场中,由于血管自然走行或病变导致其几何形状的改变,必然导致局部流场压力发生变化,进而可能引起血管内皮细胞发生一系列生理或病理变化.本研究拟考察流场内培养的内皮细胞(Endothelial cells, ECs)在不同压力信号作用下细胞浆内肌动蛋白纤维F-actin排列、表达强度以及血管内皮细胞黏附分子(Vascular cell adhesion molecule, VCAM)和整合素Integrin αVβ3等细胞黏附分子的表达强度,探讨分析其与流场内压力变化之间的关系.通过设置静态培养、单纯剪切力对照组,应用免疫荧光双重标记、激光共聚焦扫描显微镜和计算机图像分析等技术,观察了在平板流室内于不同压力加载下培养的内皮细胞表面VCAM和Integrin αVβ3 的表达强度及细胞骨架F-actin 的变化.研究结果初步表明,随着压力降值的变化,内皮细胞表面VCAM和Integrin αVβ3以及F-actin的表达强度呈现出明显的规律性改变现象.压力降信号的改变导致了内皮细胞骨架F-actin的变化,同时影响了以VCAM为代表的细胞黏附功能和以Integrin αVβ3为代表的压力信号跨膜传递通路的生理功能.     

两种不同古典针刺手法的实时中枢整合特征研究:一项基于近红外光谱成像技术的随机交叉试验研究方案（英文）

Background:Reinforcing-reducing manipulations are a crucial part of acupuncture therapy.The reinforcing manipulation with heat sensation(RMHS) and the reducing manipulation by inducing cool sensation(RMCS) are two representative methods of reinforcing-reducing manipulations.This trial aims to investigate the characteristic of cerebral responses to these two typical acupuncture manipulations.Methods:A total of 35 healthy participants will be included and receive acupuncture stimulation with RMHS ...     

视黄酸对培养的HepG2细胞分泌载脂蛋白AⅠ、AⅡ、B100、CⅢ及E的影响

OBJECTIVE: This study inquired into the role of retinoic acid in lipoprotein metabolism. METHODS: We observed the effect of retinoic acid on the secretion of apolipoproteins A I, A II, C III, B100 and E by cultured HepG2 cells. The apolipoprotiens contents in culture media were measured by radioimmunodiffusion assay (RID) kits developed by our research laboratory. 20-fold lyophilizely condensed culture media were used for the assays. RESULTS: Retinoic acid increased the secretion of apoA I, B100, C III and A II, and it inhibited the secretion of apoE. The effect of retinoic acid was strengthened in a dose-dependent manner. When the concentration of retinoic acid in cultured media was 2 x 10(-4) mol/l, the secretion of apoA I, A II, B100 and C III increased by 14.3% (P < 0.01), 23.8% (P < 0.05), 16.1% (P < 0.01) and 47.6% (P < 0.01) respectively, and the secretion of apoE decreased by 37.2% (P < 0.01). CONCLUSION: These findings indicate that retinoic acid does not have a general effect on apolipoprotein secretion in HepG2 cells.     

抗MDA5抗体阳性皮肌炎患者预后影响因素研究及生存分析

目的 探究抗黑色素瘤分化相关基因5（MDA5）抗体阳性皮肌炎患者的预后影响因素及生存分析。方法 选取四川大学华西医院2018年1月至2021年9月期间确诊的178名抗MDA5抗体阳皮肌炎患者,收集相关临床资料并进行随访,根据随访期内是否死亡将入选患者分为生存组和死亡组,采用 Cox 回归分析影响患者预后的因素,Kaplan-Meier法比较在快速进展型间质性肺病、吸烟情况、乳酸脱氢酶及白蛋白水平几种因素影响下的生存情况。结果 共纳入抗MDA5抗体阳性皮肌炎患者178例,其中生存组136例,死亡组42例,两组患者平均年龄（49.56±11.63）岁。多因素Cox回归结果显示,吸烟（HR=2.23,95%CI:1.06~4.66,P=0.033）、白蛋白<30g/L（HR=2.47,95%CI:1.15~5.31,P=0.021）、乳酸脱氢酶≥400IU/L（HR=2.70,95%CI:1.26~5.76,P=0.010）、合并快速进展型间质性肺病（HR=20.56,95%CI:2.64~159.97,P=0.004）是影响抗MDA5抗体阳性皮肌炎患者预后的因素。结论 吸烟、低白蛋白血症、高乳酸脱氢酶血症、合并快速进展型间质性肺病都可能是影响抗MDA5抗体阳性皮肌炎患者不良预后的因素,应密切关注患者患病期间各因素的变化情况,积极采取治疗措施,以改善患者预后。     

β-淀粉样蛋白在Alzheimer病中的神经毒性

文综述了β淀粉样蛋白多肽(βamyloid peptide,Aβ)在老年性痴呆症(Alzheimer's disease,AD)中的毒性作用。Aβ是老年斑形成的始动因子,也是老年斑核中的核心成分;Aβ沉积所形成的神经炎性斑,即老年斑是AD脑内特征性病理变化之一;Aβ本身也可形成自由基损伤神经元;Aβ引起的细胞凋亡在AD病神经元丢失中起着重要作用;Aβ可作用于胆碱能神经元末梢,通过抑制胆碱的摄取而减少乙酰胆碱合成,减少海马和皮质脑片释放乙酰胆碱。总之,Aβ是通过多个环节引发神经毒性作用的。     

额下-翼点入路显微切除颅咽管瘤

目的探索额下-翼点入路手术切除颅咽管瘤的适应证、手术方法和并发症的预防。方法对158例颅咽管瘤患者采取经额下-翼点入路切除肿瘤,并分析患者术前症状和体征、影像学检查、手术效果、随访情况。结果158例颅咽管瘤患者经额下-翼点入路切除肿瘤,术中全切138例（87.34%）,围手术期死亡4例（2.53%）。术后尿崩129例（81.64%）,癫痫发作9例（5.69%）。患者术后综合效果良好。平均随访56.3个月,27例患者复发,复发率17.53%。结论经额下-翼点入路能安全切除颅咽管瘤,死亡率、致残率低,术后并发症可预防,手术效果好。     

青石棉污染区恶性肿瘤9年回顾队列研究

为了证实非职业性环境接触青石棉与恶性肿瘤，特别是肺癌和间皮瘤危险的关系，采用回顾性队列调查方法对大姚县青石棉污染区进行９年的死亡率调查。选择同省无石棉污染的禄丰县作为对照。结果表明：恶性肿瘤的死亡率为１８２．６０／１０万，其中肺癌死亡率为５３．２６／１０万，相对危险度高于对照，ＲＲ分别为１．４７，２．１４（Ｐ＜０．０１）；观察组中７例死于间皮瘤。提示：间皮瘤的死亡率在青石棉污染区是很高的，在３０岁以上人中，年死亡率为１７．７５／１０万人年，而对照组中未观察到间皮瘤。     

盲法研究细菌性胶原酶对创伤感染的影响

目的探讨细菌性胶原酶对创口感染情况的影响。方法 2006年11月-2006年12月,对28只新西兰兔分为实验组和对照组,分别予细菌性胶原酶溶液及生理盐水浸润创口并缝合。观察创口感染及局部皮肤的炎性细胞浸润情况。结果实验组与对照组创口感染率差别无统计学意（P〉0.05）,炎性细胞差别无统计学意义（P〉0.05）。结论细菌性胶原酶在创伤修复过程中不能直接降低感染率,对炎性细胞的迁移并无明显的作用。     

妊娠期抑郁138例回顾分析

目的总结妊娠期抑郁的临床表现、治疗和妊娠结局。方法回顾我院2009年1月至2010年12月期间就诊的妊娠抑郁患者138例,分析这些患者的临床表现、治疗效果及妊娠结局。结果①妊娠期抑郁的常见症状是焦虑失眠和消化道症状。②在妊娠抑郁危险因素中,对怀孕存在矛盾心理和婚姻不和睦占有较高的比例。③138例患者中,110例妊娠至足月,25例早产,3例放弃妊娠。结论妊娠期抑郁经过治疗,绝大部分妊娠结局良好。