Oral Vancomycin Prophylaxis as Secondary Prevention Against Clostridioides difficile Infection in the Hematopoietic Stem Cell Transplantation and Hematologic Malignancy Population

Clostridioides difficile infection (CDI) is a common complication in the hematopoietic stem cell transplantation (HSCT) and hematologic malignancy (HM) population. CDI is associated with increased hospital length of stay, health care and societal costs, morbidity, and mortality. Identifying strategies for secondary prevention of CDI is of extreme importance in the HSCT/HM population. In this study, our primary objective was to evaluate the effectiveness and safety of an oral vancomycin prophylaxis (OVP) protocol for secondary prevention of CDI in a retrospective cohort of adult autologous/allogeneic HSCT recipients and patients with HM who did not undergo HSCT with a first CDI episode treated with concomitant broad-spectrum antibiotics (BSA). Patients were diagnosed and treated for CDI as inpatients and/or outpatients and were divided into 2 groups based on a preprotocol versus postprotocol analysis: the OVP group, comprising patients who received planned monotherapy with oral vancomycin 125 mg every 6 hours for 14 days for a first episode of CDI and subsequently received OVP posttreatment and a no OVP (NOVP) group, comprising patients who received planned monotherapy with oral vancomycin 125 mg every 6 hours for 14 days for a first episode of CDI and subsequently did not receive OVP posttreatment. OVP was defined as vancomycin 125 mg every 12 hours for up to 7 days after BSA discontinuation. The primary endpoint was recurrent CDI (rCDI), defined as symptoms of loose stools/diarrhea with high clinical suspicion for CDI prompting empiric therapy within 60 days of completion of treatment/prophylaxis for the first CDI episode. The incidence of vancomycin-resistant enterococcal (VRE) infection and 60-day mortality were also compared between the 2 groups. Multivariate logistic regression was created from associated variables to identify independent associations with rCDI. A total of 50 patients were included, 21 in the OVP group (42%) and 29 in the NOVP group (58%). The mean patient age was 58 years, and the cohort was 60% male and 86% Caucasian. HSCT was performed in 60% of the patients, and 76% of CDI cases were diagnosed during hospitalization. The rate of rCDI was significantly lower in the OVP group compared with the NOVP group (5% [1 of 21] versus 35% [10 of 29]; P= .016), with no subsequent increase in VRE infection rate (14% [3 of 21] versus 10% [3 of 29]; P = .686). By multivariable logistic regression, rCDI was inversely associated with OVP (odds ratio [OR], .14; 95% confidence interval [CI], .007 to .994; P = .049) and directly associated with outpatient CDI diagnosis (OR, 8.72; 95% CI, 1.816 to 49.158; P = .007). No between-group differences were found in 60-day mortality (10% [2 of 21] for OVP versus 7% [2 of 29] for NOVP; P > 0.999). OVP appears to be safe and effective for secondary prevention of CDI in the HSCT/HM population. Prospective trials are needed to validate the effectiveness of OVP in this vulnerable population to prevent rCDI.     

左旋丁苯酞对脑缺血大鼠皮质β-淀粉样肽含量及Tau蛋白磷酸化的影响

目的:观察左旋丁苯酞(L-3-n-Butylphthalide,L-NBP)对脑缺血大鼠皮质β-淀粉样肽(Aβ1-42)水平以及Tau蛋白磷酸化的影响,探讨其可能的机制。方法:大鼠双侧颈总动脉结扎90 d,制备脑低灌注模型。实验分假手术组(Sham)、溶剂对照组(Vehicle)、药物治疗组(L-NBP 30 mg/kg和L-NBP 120 mg/kg组)。L-NBP治疗组连续给药45 d后,用Morris水迷宫检测大鼠的空间学习和记忆的能力后取大鼠脑皮质组织,用ELISA法检测Aβ1-42含量,用Westron blot方法检测Tau蛋白的磷酸化水平。结果:在水迷宫实验中,L-NBP组与溶剂对照组相比,增加了脑缺血大鼠在目标象限活动时间(P<0.05)。L-NBP组比溶剂对照组减少了大鼠皮质Aβ1-42含量(P<0.01),降低脑缺血大鼠皮质Tau蛋白Ser396的磷酸化水平(P<0.01)。结论:左旋丁苯酞可以改善脑缺血大鼠的学习记忆缺陷,减少了皮质Aβ1-42含量,从而降低Tau蛋白的磷酸化水平,并且具有一定的剂量依赖性。     

电针调控新西兰兔骨关节炎性疼痛及对脊髓IL-17、IL-17R表达的影响

目的 研究电针是否通过抑制脊髓内白细胞介素(IL)-17及IL-17R的表达来调控新西兰兔骨关节炎性疼痛.方法 新西兰兔随机分为假手术组、炎症模型组、假手术+IL-17组、炎症+抗IL-17组、炎症+电针组、炎症+假电针组,每组8只,4％木瓜蛋白酶构建兔骨关节炎模型,IL-17及IL-17抗血清采用椎管内注射,电针组选择电针刺激足三里(30 min,2 Hz连续波,1～2 mA),假电针组采用非穴位刺激,测定兔痛阈,采用实时荧光定量PCR(RT-qPCR)检测兔脊髓组织IL-17、IL-17R的mRNA表达,Western bolt检测IL-17、IL-17R蛋白表达.结果 在构建骨关节炎模型后新西兰兔痛阈显著下降(P＜0.05),椎管注射IL-17后可以显著降低假手术新西兰兔痛阈(P＜0.05),而椎管注射IL-17抗血清后可明显增加骨关节炎模型兔痛阈值.选择足三里电针刺激可显著提升兔痛阈(P＜0.05).骨关节炎模型组IL-17、IL-17R的mRNA及蛋白表达显著增加(P＜0.05),而电针刺激后其表达显著下降(P＜0.05).结论 新西兰兔骨关节炎性疼痛发生可能涉及脊髓IL-17异常表达,而电针可能通过抑制脊髓IL-17、IL-17R的表达来调控骨关节炎性疼痛.     

苯并(a)芘对健康人胚肝细胞DNA损伤作用的研究

目的探讨苯并（a）芘[B（a）P]在体外实验条件下致健康人胚肝细胞（L-02细胞）DNA损伤的作用,建立B（a）P致肝细胞DNA损伤的体外实验研究模型.方法对L-02细胞分别用高（50μM）、低（25μM）剂量的B（a）P染毒2 h,然后用单细胞凝胶电泳（SCGE）技术检测细胞DNA的损伤情况,选用Oliver尾矩值作为DNA损伤的分析指标,并依据尾部DNA含量/总DNA含量统计DNA损伤分级.结果在本试验条件下,高低剂量的B（a）P均能引起L-02细胞明显的DNA单链断裂损伤,其Oliver尾矩值与溶剂对照组相比差异有统计学意义（P＜0.01）,并且高、低剂量的B（a）P对L-02细胞的DNA损伤差异也具有统计学意义（P＜0.01）,随着B（a）P剂量升高,引起肝细胞损伤的Oliver尾矩值也增大.实验组的总彗星样细胞数均较对照组高（P＜0.01）,高、低剂量的B（a）P引起的总彗星样细胞数间差异没有显著性.高、低剂量的B（a）P诱导不同损伤级别的细胞数不同（P＜0.01）,B（a）P组与溶剂对照组相比,无损伤及轻度损伤细胞数较少,而中、重度损伤细胞数增多.结论低剂量的B（a）P即可引起L-02细胞DNA的明显损伤.     

左卡尼丁对慢性肺心病的治疗作用

目的:观察左卡尼丁(雷卡)注射液治疗慢性肺心病的疗效。方法:将48例患者随机分为2组,试验组23例采用静脉滴注雷卡配合常规治疗,对照组25例单用常规治疗,观察两组疗效。结果:试验组较对照组临床显效率明显提高(P<0.05)、心肌酶明显降低(P<0.05,P<0.01);两组治疗后缓解率、血氧分压比较,试验组优于对照组。结论:左卡尼丁注射液治疗慢性肺心病可提高疗效。     

稳定性核素测定大鼠小肠蛋白质合成

目的：建立稳定性核素（[L-^15N]亮氨酸）测定大鼠小肠蛋白质合成率的方法。方法：分别测定静脉注射相同剂量[L-^15N]亮氨酸不同时相的大鼠小肠^15N丰度及不同剂量[L-^15N]亮氨酸同一时相的大鼠小肠^15N丰度。结果：大鼠小肠游离氨基酸池中^15N核素丰度在注射后0．5h内呈线性上升并达高峰，维持4h后缓慢下降，小肠蛋白质中的^15N丰度0．5h至12h基本维持不变；随着注射剂量的增加，大鼠小肠蛋白质分数合成率（FSR）亦增加，当[L-^15N]亮氨酸剂量在1．0mmol／kg以上，FSR并不随施加[L15N]亮氨酸剂量的加大而增加。结论：在进行大鼠小肠蛋白质合成率测定时，一次性静脉注射的测量最佳时限为0．5h，剂量为1．0mmol／kg。     

莲房原花青素对乙醇诱导肝细胞凋亡的拮抗机制

目的研究莲房原花青素（LSPC）对乙醇诱导的人胚肝细胞株L－02凋亡的拮抗作用机制。方法观察5、10、25mg／L的LSPC与200mmol／L乙醇共同作用于肝细胞L-0224h后，对细胞生存率、凋亡率的影响，对细胞凋亡通路的相关基因MAPK38、Caspase3、p53以及生长抑制DNA损伤诱导基因（growth arrest and DNA damage-inducible gene，GADD）GADD34、GADD45β、GADD153表达的影响。结果与乙醇组相比，5mg／L和10mg／L LSPC使细胞的生存率由73．14％上升到84．79％和90．52％。通过抑制细胞p53和Caspase3通路，并通过降低DNA损伤而降低GADD34、GADD45β、GADDl53的表达（P〈0．01），从而有效降低细胞的凋亡率。从11．54％分别降至8．21％和9．10％（P〈0．05）；抑制凋亡率的效果以LSPC5mg／L组最佳，10mg／L组效果次之，但高剂量组（25mg／L）对乙醇所致凋亡的拮抗作用不明显，对细胞生存率也无影响。乙醇和LSPC处理均不影响L～02细胞的MAPK38表达。结论适当浓度的莲房原花青素对乙醇诱导的肝细胞L-02的凋亡有拮抗作用。其抑制凋亡的作用主要是通过p53、Caspase3和GADD途径，而与MAPK途径无关。     

寻常性银屑病患者血清可溶性白细胞介素2受体的检测

应用双抗体夹心ＥＬＩＳＡ法测定４２例寻常性银屑病患者血清ｓＩＬ－２Ｒ水平。结果显示银屑病患者的ｓＩＬ－２Ｒ明显高于正常人（Ｐ＜０．０１），且与疾病的活动性和皮损范围无关。该结果提示银屑病患者存在细胞因子的异常。