肠运动昼夜节律及其外科临床意义

肠运动存在昼夜节律，表现为白天活跃，夜间减弱或消失，这是一种内生性的、由时钟基因控制的生物节律。肠运动节律既可与中央节律保持高度一致，也可独立于中央节律而对外周环境刺激做出反馈。外科手术会破坏肠运动的昼夜节律，而围手术期合理使用褪黑素、五羟色胺（5-HT）受体激动剂和非甾体类解热镇痛药等药物则有助于促进此节律的恢复。外科医生了解肠运动节律的机制，有助于加深术后肠麻痹（POI）的认识，再基于时辰药理学，在合适的时机以适宜的剂量给药，或许能进一步缩短POI时间，促进肠运动功能尽早恢复。     

Effect of chlorhexidine digluconate on antimicrobial activity,cell viability and physicochemical properties of three endodontic sealers

ObjectiveAssess the biological and physicochemical properties of AH Plus, BioRoot RCS and Pulp Canal Sealer (PCS) leachates with and without chlorhexidine (CHX).MethodsThe sealers were studied in no contact and 1-minute contact with CHX. For biological properties (antibacterial activity and cytotoxicity), leachates were formed in saline of freshly mixed, 1-, 7- and 28 days set sealers. The antibacterial properties of sealer leachates were investigated for planktonic and biofilm growth of E. faecalis, S. mutans, S.epidermidis and S.aureus. The 3-(4,5 dimethylthiazolyl-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate murine fibroblast cell viability after exposure to the leachates. The physical properties (water uptake, sorption, solubility, porosity, surface characteristics) of sealers and the pH of the immersion liquid (saline or distilled water) were also assessed over a 28-days period.ResultsCHX improved the antibacterial properties of the sealer leachates and reduced cell viability for all sealer leachates, except for freshly mixed PCS. BioRoot RCS leachates presented the highest antibacterial properties and cell viability with and without CHX contact. PCS was the material most affected by CHX in terms of physical properties, whereas for AH Plus, solubility was increased. CHX did not affect the physical properties of BioRoot RCS, except for solubility that was decreased. CHX contact did not change sealers’ alkalinity in distilled water whereas it increased it for AH Plus and BioRoot RCS in saline.SignificanceCHX improved the antibacterial efficacy of sealer leachates and either compromised or did not affect cell viability. CHX affected to various extent sealers’ physicochemical properties.     

Newly recruited intraepithelial Ly6A+CCR9+CD4+ T cells protect against enteric viral infection

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Assessment of oral ciprofloxacin impaired gut barrier integrity on gut bacteria in mice

Gut bacteria and gut barrier plays important roles in body homeostasis. Ciprofloxacin (CPFX) is widely used to treat bacterial infections. However, whether high dosage of CPFX has side effects on gut barrier integrity is still unclear. Our results indicated that the High CPFX treatment (1 mg/ml) caused weight loss, nervousness, anorexia, and increased apoptosis cells in gut, but less influence was observed in the Low CPFX group (0.2 mg/ml). Meanwhile, the High CPFX treatment impaired tight junction molecules Ocln/ZO-1 level and down-regulated antibacterial genes expression (reg3γ, pla2g2α and defb1). Further, the High CPFX treatment increased pro-inflammatory cytokine IL-1β in intestinal tract, decreased IL-17A of duodenum but increased IL-17A of colon at day 37. In addition, the gut bacterial diversity and richness behaved significantly loss regarding CPFX treatment, especially in the High CPFX group during the experiment. Indole exhibited sharply decline in both Low and High CPFX groups at day 7, and the High CPFX mice needed longer time on restoring indole level. Meanwhile, CPFX treatment strongly decreased the concentrations of butyric acid and valeric acid at day 1. Correlation analysis indicated that the linked patterns between the key bacteria (families Bacteroidales_S247, Ruminococcaceae and Desulfovibrionaceae) and metabolites (indole and butyric acid) were disturbed via the CPFX treatment. In conclusion, the High CPFX treatment impaired the gut barrier with the evidence of reduced expression of tight junction proteins, increased apoptosis cells and inflammatory cells, decreased the bacterial diversity and composition, which suggesting a proper antibiotic-dosage use should be carefully considered in disease treatment.     

Antibiotic resistant bacteria and resistance genes in biofilms in clinical wastewater networks

Increasing isolation rates of resistant bacteria in the last years require identification of potential infection reservoirs in healthcare facilities. Especially the clinical wastewater network represents a potential source of antibiotic resistant bacteria. In this work, the siphons of the sanitary installations from 18 hospital rooms of two German hospitals were examined for antibiotic resistant bacteria and antibiotic residues including siphons of showers and washbasins and toilets in sanitary units of psychosomatic, haemato-oncological, and rehabilitation wards. In addition, in seven rooms of the haemato-oncological ward, the effect of 24 h of stagnation on the antibiotic concentrations and MDR (multi-drug-resistant) bacteria in biofilms was evaluated. Whereas no antibiotic residues were found in the psychosomatic ward, potential selective concentrations of piperacillin, meropenem and ciprofloxacin were detected at a rehabilitation ward and ciprofloxacin and trimethoprim were present at a haemato-oncology ward. Antibiotic resistant bacteria were isolated from the siphons of all wards, however in the psychosomatic ward, only one MDR strain with resistance to piperacillin, third generation cephalosporins and quinolones (3MRGN) was detected. In contrast, the other two wards yielded 11 carbapenemase producing MDR isolates and 15 3MRGN strains. The isolates from the haemato-oncological ward belonged mostly to two specific rare sequence types (ST) (P. aeruginosa ST823 and Enterobacter cloacae complex ST167). In conclusion, clinical wastewater systems represent a reservoir for multi-drug-resistant bacteria. Consequently, preventive and intervention measures should not start at the wastewater treatment in the treatment plant, but already in the immediate surroundings of the patient, in order to minimize the infection potential.     

碘乙酸钠诱导的大鼠膝骨关节炎模型肠道菌群变化及其潜在影响

目的:研究碘乙酸钠诱导的大鼠膝骨关节炎(KOA)模型肠道菌群变化情况,探究肠道菌群与KOA的潜在联系。方法:将SPF级大鼠分为空白对照组和KOA组,通过膝关节局部注射碘乙酸钠制造大鼠KOA模型。通过16SrDNA检测大鼠粪便中的肠道菌群变化情况,蛋白印记法检测结肠组织中NF-κB和TNF-α蛋白表达,RT-qPCR检测结肠组织中Caspase-1和IL-1β基因表达情况,苏木精-伊红染色观察结肠黏膜通透性变化,苏木精-伊红染色观察关节滑膜和软骨组织的病理变化情况。ELISA检测血液上清中LBP,IL-1β,TNF-α及IL-10炎症因子水平。结果:与空白对照组相比,从KOA组中筛选出明显变化的肠道菌群,以Akkermansia和疣微菌门变化最为显著,结肠黏膜通透性增加,结肠组织中NF-κB p65及TNF-α蛋白表达升高,结肠组织中Caspase-1和IL-1β基因表达升高,血液中促炎因子LBP,IL-1β及TNF-α蛋白含量升高,抗炎因子IL-10蛋白含量降低。结论:KOA病理状态下肠道菌群发生变化,结肠炎症反应增强,结肠炎症反应或许在提高全身炎症反应水平、促进与肠道菌群相关的KOA的病理进程中起到重要的桥梁作用。     

中药肠道灌洗联合血液净化治疗急性农药中毒的临床疗效探讨

目的 探讨中药肠道灌洗联合血液净化治疗急性农药中毒的临床疗效。方法 选取2014年4月～2019年10月本院收治的50例急性农药中毒患者为研究对象,并根据不同的治疗方案将患者分为对照组与观察组,各25例,对照组采用常规治疗联合血液净化治疗,而观察组在对照组的基础上采用中药肠道灌洗治疗,比较两组患者的临床疗效及血压、血气指标情况。结果 治疗后,观察组的临床总有效率为96.00%,对照组为76.00%,两组比较,观察组明显高于对照组;同时观察组的收缩压(SBP)、舒张压(DBP)与酸碱度(pH)高于对照组,动脉血氧分压(PaO2)与动脉血二氧化碳分压(PaCO2)低于对照组,组间比较差异有统计学意义(P0.05)。结论 对急性农药中毒患者实施中药肠道灌洗联合血液净化治疗,能有效改善患者的血压、血气指标,具有显著的临床疗效。     

人参、白术有效组分群对慢性萎缩性胃炎大鼠口腔、肠道菌群的影响

目的研究人参、白术有效组分群对慢性萎缩性胃炎大鼠口腔、肠道菌群的影响。方法将大鼠随机分为空白组、模型组、给药(人参白术有效组分群)组,用主动免疫法复制慢性萎缩性胃炎模型。HE染色、扫描电子显微技术观察胃黏膜组织显微及超微结构,高通量测序技术检测肠道及口腔菌群,利用SPSS软件进行相关性分析。结果人参、白术有效组分群能改善慢性萎缩性胃炎大鼠胃组织病理形态(P<0.05);增加大鼠肠道、口腔菌群多样性及丰富度(P<0.05);减少肠道、口腔中致病菌群(普雷沃氏菌科_UCG-003、梭杆菌属)的数目(P<0.05)。其中,大鼠病理学评分与其口腔、肠道菌群的丰度、多样性以及门、属水平上的差异菌具有相关性(P<0.05)。结论人参、白术有效组分群对慢性萎缩性胃炎大鼠有良好的保护作用,缓解胃黏膜萎缩,其作用机制可能与改善肠道和口腔菌群有关。     

中药调节黏膜免疫系统用于防治COVID-19的思路探索

机体免疫功能低下患者,极易出现新型冠状病毒感染,与中医所说正气不足、邪毒侵扰一致。目前集中在抗病毒药物研发是必须的,但对于调节机体免疫系统制剂的研究也较为迫切。黏膜组织是人体免疫系统的一道重要屏障,具有独特功能和结构的独立免疫体系,是机体抵抗感染的第一道防线,与外界抗原(比如食物、共生菌、病毒等)直接接触。其在抵抗病毒、抗感染方面,黏膜免疫(如呼吸道黏膜、肠道黏膜等)起着极其重要的作用,可以消灭外来病原微生物或其他外来抗原,不至于病毒侵入机体组织而对机体造成损伤。中药通过黏膜免疫系统发挥治疗作用的研究报道日益增多,该文拟针对黏膜免疫系统与新型冠状病毒肺炎(COVID-19)的关系以及中药的干预机制展开探讨,以期为COVID-19的防治提供可借鉴的研究方法与治疗思路。