胡芦巴生制品降血脂功效研究

目的 对胡芦巴生、制品的降血脂功效进行研究。方法 通过喂养高脂高糖饲料,构建小鼠高血脂模型。将高血脂模型小鼠按TG、TC、体重分为模型组,阳性组,生品组,盐制品组,酒制品组,外加空白组。给予相应药物治疗21天后,对体重、血清中TC、TG、LDL-C、HDL-C、AST、ALT的水平进行测定,取肝脏称重,计算肝指数。结果 与空白组相比：模型组小鼠的体重显著升高（P<0.01）,与模型组相比,胡芦巴生、制品组小鼠的体重显著降低（P<0.05）;模型组小鼠的肝指数显著升高（P<0.01）,与模型组相比,胡芦巴生、制品组小鼠的肝指数显著降低（P<0.05）;模型组小鼠的TG、TC、LDL-C、HDL-C显著升高（P<0.01）,与模型组相比,胡芦巴生、酒制品组小鼠的TG、TC、LDL-C显著降低（P<0.05）,盐制品组TG、TC（P<0.01）、LDL-C（P<0.05）,对TG、TC的调节作用,盐制品组要优于生品组（P<0.05）;模型组小鼠的AST、ALT显著升高（P<0.01）,与模型组相比,胡芦巴生、盐制品组小鼠的AST、ALT显著降低（P<0.05）,酒制品组（P<0.01）。且酒制品组与生品组之间具有显著性差异（P<0.05）。结论 胡芦巴盐制后对高血脂模型中TG和TC的调节作用增强、酒制后对AST和ALT的调节作用增强,说明胡芦巴盐制后降血脂作用增强,酒制后肝保护的作用增强。     

葛根枳椇子栀子提取物对大鼠酒精性脂肪肝的作用研究

目的 探讨葛根枳椇子栀子提取物（PHGE）解酒护肝作用。方法 SPF级Wistar雄性大鼠120只,随机分为对照组、模型组和PHGE低、中、高剂量（0.2、0.5、1.2 g/kg）组,每组24只。除对照组外,其他组别通过喂饲Regular型Lieber-DeCarli酒精液体模型饲料造模,造模过程中,PHGE各组动物ig不同剂量的PHGE。每周测定动物体质量1次,每天测定摄食量1次;给药4周和8周每组分别取半数动物禁食过夜,采血测定血清生化指标;解剖取肝脏称质量并计算脏体系数;取部分肝脏冰冻切片进行油红“O”染色,观察肝脏脂肪肝情况;测定肝脏总脂肪含量,测定肝脏组织超氧化物歧化酶（SOD）、丙二醛（MDA）、总谷胱甘肽（GSH）、乙醇脱氢酶（ADH）和乙醛脱氢酶（ALDH）。结果 4周和8周造模,大鼠体质量均增长减缓（P<0.05、0.01）,第8周PHGE高剂量组动物体质量显著低于模型组（P<0.05）;摄食量未见明显差异。造模4周,模型组血清丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）、总胆固醇（TCHO）、高密度脂蛋白胆固醇（HDL）、低密度脂蛋白胆固醇（LDL）、血糖（GLU）显著高于对照组（P<0.05、0.01）;与模型组比较,PHGE低、中、高剂量组AST、GLU,中、高剂量组ALT、TCHO、HDL,中剂量组LDL均显著下降（P<0.05、0.01）,并呈明显的剂量相关性,造模8周与造模4周结果一致。造模给药8周,模型组GSH显著高于对照组（P<0.01）,PHGE高剂量组GSH显著高于模型组（P<0.01）,高剂量组ADH显著高于模型组（P<0.05）;与对照组比较,造模给药4、8周,模型动物肝脏脂肪量显著升高（P<0.05、0.01）,给药8周,PHGE高剂量组肝脏脂肪量显著低于模型组（P<0.05）。模型组肝脏质量与对照组比较未见显著性差异,而肝脏系数显著增加（P<0.01）,应为动物体质量较小引起,PHGE各剂量组肝脏系数与同期模型组比较未见显著性差异。肝脏脂肪染色后,造模动物主要表现为弥漫性肝细胞内、中央静脉周边肝细胞内红染脂滴,PHGE中、高剂量组评分低于模型组。结论 PHGE发挥明显预防和/或改善酒精性脂肪肝的作用,改善肝功能,降低血糖和胆固醇。     

白头翁汤对链脲佐菌素诱导的糖尿病肝损伤的保护作用研究

目的 观察白头翁汤对链脲佐菌素（STZ）诱导的I型糖尿病小鼠肝损伤的治疗效果。方法 单次ip STZ（180 mg/kg）建立1型糖尿病小鼠模型，对照组给予等量的柠檬酸缓冲液。挑选血糖值≥ 15 mmol/L的小鼠随机分为模型组、二甲双胍组及白头翁汤低、中、高剂量（生药2.5、5.0、10.0 g/kg）组，对照和模型组给予等体积生理盐水，连续ig给药4周。末次给药24 h后，称各组小鼠体质量，测空腹血糖；试剂盒法检测血清中丙氨酸转氨酶（ALT）、天冬氨酸转氨酶（AST）、碱性磷酸酶（ALP）、肿瘤坏死因子-α（TNF-α）、白介素-6（IL-6）水平，检测血清及肝组织中丙二醛（MDA）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）水平，HE染色观察肝组织病理组织学损伤。结果 给药4周后，与模型组比较，白头翁汤中、高剂量组动物体质量显著升高、空腹血糖值显著降低（P<0.05、0.01）；中、高剂量组血清ALT、AST、ALP、TNF-α、IL-6水平显著下降（P<0.05、0.01、0.001）；中、高剂量显著降低血清及肝组织中MDA含量，高剂量显著提升血清及肝组织中SOD活力，中、高剂量显著增加血清GSH-Px水平，高剂量显著增加肝组织GSH-Px水平（P<0.05、0.01）。HE染色显示白头翁汤可以改善肝脏病理组织学损伤。结论 白头翁汤可以有效改善STZ诱导的糖尿病肝损伤，机制与减轻脂质过氧化、增强机体清除自由基能力以及抗炎作用有关。     

樟芝多糖保护小鼠急性肝损伤的机制研究

目的 研究樟芝多糖保护小鼠急性肝损伤的机制。方法 通过D-氨基半乳糖构建急性肝损伤小鼠,C57BL/6小鼠分为对照组、模型组、樟芝多糖高剂量组、樟芝多糖低剂量组,樟芝多糖高、低剂量组每日分别给予50,25 mg·kg^-1的樟芝多糖2次,对照组和模型组给予等体积的生理盐水。给药7 d后紫外比色法测试盒检测大鼠肝组织中谷丙转氨酶（ALT）、谷草转氨酶（AST）水平;TBA法试剂盒检测肝组织中丙二醛（MDA）的水平;ELISA试剂盒检测肝组织中白介素-6（IL-6）的表达;Western-Blot检测肝脏组织中NLRP-3、白介素-1β（IL-1β）、pro-caspase-1和caspase-1的表达;HE染色观察小鼠肝脏病理;RT-qPCR检测肝脏组织中Bcl-2、Bax、caspase-3、caspase-1的mRNA表达。结果 与模型组相比,樟芝多糖可以明显改善急性肝损小鼠的肝脏病理,降低ALT、AST的表达以及MDA和IL-6的表达（P<0.01）,肝脏组织中NLRP-3、IL-1β以及pro-caspase-1和caspase-1的表达相比模型组显著降低（P<0.05）,Bax、caspase-3、caspase-1的mRNA表达相比模型组显著降低（P<0.01）,Bcl-2显著升高（P<0.01）。结论 樟芝多糖对于小鼠急性肝损伤有着很好的保护作用,其作用机制与炎性小体NLRP-3及其相关炎症因子的抑制有关。     

人参皂苷对酒精性肝损伤的保护作用研究

目的 研究人参皂苷提取物(GE)对酒精性肝损伤的保护作用与作用机制.方法 将ICR雄性小鼠分为正常对照组、阳性对照组(联苯双酯)、模型组及人参皂苷提取物高、中、低剂量组,建立慢性酒精性肝损伤模型,用人参皂苷提取物进行干预,ig给药30 d后,称取肝质量,计算肝脏系数,测定小鼠血清丙氨酸氨基转移酶(ALT)和天门冬氨酸氨基转移酶(AST)活力、三酰甘油(TG)、肝脏内丙二醛(MDA)和还原型谷胱甘肽(GSH)的含量,HE染色观察小鼠肝脏病理变化,综合评价人参皂苷提取物对小鼠酒精性肝损伤的保护作用.结果 人参皂苷提取物各剂量组能明显降低酒精性肝损伤小鼠的肝脏系数(P <0.05)、血清TG的含量(P <0.01),可降低其血清中ALT、AST活力(P <0.05或P <0.01),但与正常组ALT、AST活力仍有差异(P <0.05);可在一定程度上降低肝组织中MDA含量(P <0.01),增高肝组织中GSH含量(P <0.01),减少肝组织病理损伤.结论 人参皂苷提取物对酒精性肝损伤有一定保护作用,其机制可能与抑制肝内脂肪堆积,抗氧化作用有关.     

水飞蓟宾对高脂诱导非酒精性脂肪肝大鼠的调脂保肝作用

目的 探讨水飞蓟宾对高脂诱导的非酒精性脂肪肝（NAFL）模型大鼠的调脂保肝作用。方法 采用ig高脂乳剂配合高脂饲料制备大鼠NAFL模型,持续4周,对照组给予生理盐水和普通饲料。模型大鼠随机分为模型组、辛伐他汀（阳性药,1.8 mg/kg）组和水飞蓟宾低、中、高剂量（18.9、37.8、75.6 mg/kg）组,第5周在继续造模的基础上ig给药,每天1次,持续8周。末次给药后,称取肝脏质量并计算肝系数;HE染色观察肝组织病理形态;腹主动脉取血,分离血清,试剂盒法检测三酰甘油（TG）、总胆固醇（TC）、高密度脂蛋白（HDL）、低密度脂蛋白（LDL）、天冬氨酸转氨酶（AST）、丙氨酸转氨酶（ALT）水平。结果 连续治疗8周后,与对照组比较,水飞蓟宾高、中剂量均可明显改善肝组织脂肪变性程度;各剂量组肝系数均显著下降（P<0.05、0.01）;各剂量组均显著降低血清TC、TG、AST、ALT水平（P<0.05、0.01）;高、中剂量组显著降低LDL、升高HDL水平（P<0.01）。结论 水飞蓟宾对NAFL大鼠发挥治疗作用,其作用可能与降脂、保肝有关。     

余甘子鞣质对代谢相关脂肪性肝病小鼠脂质代谢及肠道菌群的调节作用

目的 研究余甘子Phyllanthus emblica L.鞣质对代谢相关脂肪性肝病（MAFLD）小鼠脂质代谢及肠道菌群的调节作用。方法 将C57BL/6小鼠随机分为对照组、模型组和余甘子鞣质低、高剂量（200、400 mg·kg^-1）组及非诺贝特（阳性药,50 mg·kg^-1）组,每组10只。对照组小鼠常规饲料喂养,其余各组小鼠均给予高脂饲料喂养,建立MAFLD小鼠模型;ig给予相应药物干预,对照组及模型组给予同体积生理盐水,每天1次,连续给药8周。处死小鼠,收集血液、肝脏、粪便。计算肝脏系数;HE染色法观察肝组织病理学变化;试剂盒法检测小鼠血清中丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、三酰甘油（TG）、总胆固醇（TC）含量;实时荧光定量PCR （qRT-PCR）及Western blotting法检测肝组织中固醇调节元件结合蛋白（SREBP-1）、脂肪酸合成酶（FASN）、乙酰辅酶A羧化酶（ACC） mRNA和蛋白表达量;PCR扩增法检测实验前后小鼠粪便双歧杆菌、乳酸杆菌的含量变化。结果 与模型组比较,低、高剂量余甘子鞣质干预后小鼠肝脏系数显著降低（P<0.05、0.01）,小鼠肝组织脂肪变程度减轻;小鼠血清中ALT、AST、TG、TC水平均显著降低（P<0.05、0.01）;肝组织中SREBP-1、FASN、ACC mRNA和蛋白水平均显著降低（P<0.05、0.01）;粪便中双歧杆菌、乳酸杆菌的含量显著升高（P<0.01）。结论 余甘子鞣质能够通过SREBP-1/FASN/ACC通路调节脂质代谢、改善肠道菌群平衡,改善MAFLD。     

胡黄连苷Ⅱ对CCl4致大鼠急性肝损伤的保肝利胆作用研究

目的 研究胡黄连苷Ⅱ对四氯化碳（CCl₄）诱导的大鼠急性肝损伤的保肝和利胆作用。方法 保肝作用和利胆作用研究各选取60只健康SD大鼠,均随机分为6组：对照组、模型组、溶剂对照组和胡黄连苷II低、中、高剂量（2.5、5.0、10.0 mg·kg^-1）组,除对照组外,其余5组大鼠分别1次性ip给予CCl₄油溶液（50%橄榄油、2 mL·kg^-1）制备急性肝损伤模型。保肝作用研究：在造模后3、24和48 h ig给药1次,对照组和模型组ig给予等体积生理盐水,溶剂对照组ig给予等体积溶剂,试剂盒法检测血清中丙氨酸氨基转移酶（ALT）、天氨酸氨基转移酶（AST）、碱性磷酸酶（ALP）、总胆红素（TBIL）、总胆汁酸（TBA）、肿瘤坏死因子-α （TNF-α）、白细胞介素-8 （IL-8）及白细胞介素-6 （IL-6）水平和肝组织中丙二醛（MDA）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽S转移酶（GST）、谷胱甘肽（GSH）及谷胱甘肽过氧化物酶（GSH-Px）水平; HE染色观察肝组织病理改变。利胆作用研究：大鼠造模12 h之后进行胆管插管,并通过十二指肠给药,给药前及给药后30、60、90及120 min分别记录胆汁流量。结果 与模型组比较,胡黄连苷II能显著降低血清中肝功能生化指标ALT、AST、ALP、TBA和TBIL水平（P<0.01）;显著降低大鼠肝脏MDA水平,并显著增加肝脏SOD、CAT、GSH、GST及GSH-Px水平（P<0.01）;显著降低血清TNF-α、IL-6及IL-8水平（P<0.01）,且呈剂量相关性。胡黄连苷II各剂量均可不同程度减轻模型大鼠肝脏病变范围与程度。与模型组比较,各给药后时间点胡黄连苷II均可显著增加胆汁流量（P<0.01）,且呈剂量相关性。结论 胡黄连苷II能显著缓解CCl₄诱导的大鼠急性肝损伤并增加胆汁流量。     

原儿茶醛对环磷酰胺诱导急性肾损伤的保护作用及机制研究

目的 研究原儿茶醛对环磷酰胺（CTX）所致急性肾损伤的预防作用及其机制。方法 将 24 只 SPF 级雄性昆明种小鼠随机分为对照组、模型组及原儿茶醛低、高剂量（15、30 mg·kg^-1）组,每组各 6 只。对照组和模型组 ig 给予 0.9% 氯化钠溶液,原儿茶醛低、高剂量组每日 1 次 ig 对应药物。连续给药 14 d,末次给药 1 h 后,除对照组外,其余各组单次 ip 给药CTX （200 mg·kg^-1）。次日,在称体质量麻醉后取血和肾脏,分离血清,检测小鼠血清肌酐 （CRE）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）等生化指标;采用苏木素-伊红（HE）染色观察肾脏病理损伤情况;采用荧光染色检测小鼠肾脏 TUNEL 的表达情况;采用 Western blotting 检测 B 淋巴细胞瘤 2（Bcl-2）和 Bcl-2 相关 X 蛋白（BAX）等凋亡相关蛋白的表达情况。结果 与对照组比较,模型组小鼠的肾脏指数显著降低（P＜0.01）;血清 CRE 水平显著升高（P＜0.001）;血清 SOD、CAT、谷胱甘肽过氧化物酶（GSH-Px）水平显著降低（P＜0.05、0.01、0.001）,丙二醛（MDA）水平显著升高（P＜0.01）;模型组小鼠肾脏细胞排列错乱、可见明显的炎症细胞浸润,伴随肾小管空泡变性和肾小管扩张;模型组小鼠肾脏 TUNEL 阳性表达显著增多（P＜0.001）;且肾脏天冬氨酸特异性半胱氨酸蛋白酶 3（Caspase-3）和 Bcl-2 的表达显著下降（P＜0.01、0.001）,而 cleaved-Caspase3、BAX 蛋白的表达显著上升（P＜0.01、0.001）。与模型组比较,原儿茶醛低、高剂量组小鼠肾脏指数均显著增加（P＜0.05）;原儿茶醛高剂量组小鼠血清中的 CRE 水平明显降低（P＜0.001）;原儿茶醛低、高剂量组小鼠血清中 SOD、CAT、GSH-Px 水平显著上升（P＜0.05、0.01、0.001）,MDA 水平显著下降（P＜0.05）;原儿茶醛低、高剂量组肾脏组织细胞排列比较规整,炎症细胞浸润及肾小管空泡变性和肾小管扩张等病理改变少见;原儿茶醛低、高剂量组肾脏 TUNEL 阳性表达有所下降 （P＜0.01、0.001）,Caspase-3 和 Bcl-2 蛋白表达显著上升 （P＜0.05、0.01、0.001）,cleaved-Caspase-3 和 BAX 蛋白表达显著下降（P＜0.01、0.001）,呈剂量相关性。结论 原儿茶醛可预防 CTX所致急性肾损伤,其机制可能与抗细胞凋亡有关。     

肺热普清散对MHV-A59感染小鼠治疗作用及炎症因子的影响

目的 探讨藏药经典方肺热普清散对小鼠肝炎病毒A59（MHV-A59）感染小鼠模型的影响及其对炎症因子的作用。方法 以雄性昆明种小鼠为实验对象,利用 MHV-A59 滴鼻操作建立小鼠冠状病毒感染模型,设置对照组、模型组、阳性（利巴韦林）组和肺热普清散低、中、高剂量（25、50、100 mg·kg^-1）3组,每天ig给药1次,连续给药10 d,考察记录造模期内小鼠体质量变化,处死后称体质量并计算小鼠肺脏指数和肝脏指数;使用Elisa试剂盒测定小鼠血清中炎症因子白细胞介素-1β（IL-1β）和白细胞介素-18（IL-18）含量;利用实时荧光定量PCR（qRT-PCR）方法检测小鼠肝脏中IL-1β、IL-18 的mRNA表达水平和血清中MHV-A59病毒载量;通过苏木素-伊红（HE）染色,检测肺热普清散对肝脏和肺脏细胞坏死及炎症细胞浸润的影响。结果 与对照组比较,模型组的体质量增长缓慢（P＜0.01）;肺热普清散 3 个剂量组的体质量每日递增,中、高剂量组在第5～8天均与模型组有显著差异（P＜0.01）;各组小鼠肺脏指数组间无显著性差异,肺热普清散中剂量组肝脏指数与模型组有显著性差异（P＜0.05）;模型组病毒感染后血清中炎症因子 IL-1β 和 IL-18 显著性升高（P＜0.001）,与模型组比较,肺热普清散 3个剂量组均可降低血清中 IL-18水平（P＜0.001、0.01）;模型组肝脏组织中 IL-1β和IL-18 的 mRNA 表达水平均显著升高 （P＜0.001）;与模型组比较,肺热普清散高剂量组肝脏中 IL-1β转录水平显著降低（P＜0.01）;与模型组比较,肺热普清散 3组实验动物肝脏组织中 IL-18水平未出现显著性变化;MHV载量测定结果显示,与模型组比较,利巴韦林组和肺热普清散高剂量组血清中MHV载量显著性降低（P＜0.01）;病理切片结果显示,模型组肝脏细胞出现广泛坏死和变性,并出现炎症细胞浸润,气球样变等现象,肺热普清散高剂量和利巴韦林组出现点状病灶、炎症细胞浸润等明显减少现象;模型组肺组织肺泡明显间隔增厚,间质水肿,肺泡被压缩,有炎症细胞浸润,毛细血管扩张充血等现象,而肺热普清散中、高剂量组和阳性组肺组织肺泡间隔较窄,肺泡舒展,局部有炎性浸润和出血,肺泡腔内的分泌物明显减少。结论 肺热普清散对MHV-A59感染小鼠模型具有保护作用,其作用机制与抑制病毒复制和抑制感染后炎症因子有关。     

Synthesis and evaluation of 2,6-piperidinedione derivatives as potentially novel compounds with analgesic and other CNS activities

New 2,6-piperidinediones 2_a–g and 4_a–d were prepared by initial condensation of aromatic aldehydes or cycloalkanones with cyanoacetamide to give α-cyanocinnamides l_a–g or cycloalkylidenes 3_a,b which underwent Michae1 addition with ethyl cyanoacetate or diethylmalonate. Compounds 4_a–d were alkylated by various alkyl halides to produce the N-alkylated 2,6-piperidinedione derivatives 5_a–m. Some new selected compounds 2_a–c,f, 4_a–d & 5_e,h,j were pharmacologically evaluated for potential anticonvulsant, sedative and analgesic activities. These compounds exhibited significant anticonvulsant and analgesic effects after a single I.P. administration 100 mg/kg b.wt. . On the other hand all the investigated compounds induced hypnotic activity and prolonged the phenobarbital sodium- induced sleep as compared with the control group and the most potent compound was found to be 2_f.     

鼻渊净胶囊的HPLC指纹图谱研究

目的 建立鼻渊净胶囊的高效液相色谱(HPLC)指纹图谱.方法 采用Agilent SB-C18(4.6 mm×250 mm,5μm)色谱柱,乙腈-水为流动相、以1.0 ml/min流速行梯度洗脱,检测波长210 nm,柱温30℃,洗脱时间为80 min.采用中药色谱指纹图谱相似度评价系统(2004A版)对检测出色谱进行...     

NEURAMIDE STIMULATES ADRENOCORTICOTROPIN BUT NOT PROLACTIN RELEASE FROM RAT PITUITARY

Neuramide (NMD), a substance found in crude preparations of porcine stomach extract, is a viral inhibitor that also has putative immunostimulatory effects. The effects of NMD on stress-hormone (ACTH and prolactin—PRL) release were assessed inin vivoandin vitrostudies. In the former, blood levels of corticosterone and PRL were measured in NMD-treated male rats.In vitroexperiments were performed to evaluate the effects of NMD and three of its fractions (obtained with high performance liquid chromatography) on ACTH and PRL release from perfused rat pituitary slices. NMD increased plasma corticosterone levelsin vivoand produced dose-dependent increases inin vitropituitary release of ACTH. No effects on PRL secretion were observedin vivoorin vitro. The stimulatory effects on ACTH release were caused by the NMD fraction with a molecular weight of >5000<10000Da.     

EFFECT OF POLICOSANOL SUCCESSIVE DOSE INCREASES ON PLATELET AGGREGATION IN HEALTHY VOLUNTEERS

Policosanol is a cholesterol-lowering drug with hypocholesterolemic effects demonstrated in experimental models, healthy volunteers and type II hypercholesterolemic patients. In addition, antiplatelet effects of policosanol have been shown in experimental models and healthy volunteers. The effect of successively increasing doses of policosanol on platelet aggregation was investigated in a randomized, placebo-controlled, double-blind study conducted in 37 healthy volunteers. The volunteers were on a placebo-baseline period (two tablets per day) for 7 days and thereafter they received randomly, under double-blind conditions, placebo or policosanol (10mgday⁻¹) for 7 days. After this period dosage was doubled to 20mgday⁻¹for the next 7 days and then again doubled to 40mgday⁻¹, while the control group received placebo tablets all the time. Platelet aggregation as well as coagulation time was measured at baseline and after each dosing step. Results showed that antiplatelet effects of policosanol were successfully enhanced throughout the study, thus suggesting a dose-dependent relationship. No significant effect was reached during the first dosing period, but significant reductions of epinephrine and ADP-induced platelet aggregation were observed after the second one. Finally, a significant inhibition of platelet aggregation induced by all the agonists was observed at the last dosing step. Coagulation time remained unchanged during the trial.     

Investigation of the prevalence of tetQ, tetX and tetX1 genes in Bacteroides strains with elevated tigecycline minimum inhibitory concentrations

In this study, the antibiotic susceptibilities to tigecycline and tetracycline of 35 selected Bacteroides fragilis group strains were determined by Etest, and the presence of tetQ, tetX, tetX1 and ermF genes was investigated by polymerase chain reaction (PCR). tetQ was detected in all 12 B. fragilis group isolates (100%) exhibiting elevated tigecycline minimum inhibitory concentrations (MICs) (≥8 μg/mL) as well as the 8 strains (100%) with a tigecycline MIC of 4 μg/mL, whilst tetX and tetX1 were present in 15% and 75% of these strains, respectively. All of these strains were fully resistant to tetracycline (MIC ≥ 16 μg/mL). On the other hand, amongst the group of strains with tigecycline MICs < 4 μg/mL (15 isolates), tetQ, tetX and tetX1 were found less frequently (73.3%, 13.3% and 46.7%, respectively). All but two strains harbouring the tetQ gene in this group were non-susceptible to tetracycline, with a MIC > 4 μg/mL. These data suggest that in most cases tigecycline overcomes the tetracycline resistance mechanisms frequently observed in Bacteroides strains. However, the presence of tetX and tetX1 genes in some of the strains exhibiting elevated MICs for tigecycline draws attention to the possible development and spread of resistance to this antibiotic agent amongst Bacteroides strains. The common occurrence of ermF, tetX, tetX1 and tetQ genes together predicted the presence of the CTnDOT-like Bacteroides conjugative transposon in this collection of Bacteroides strains.     

INDIRECT PARASYMPATHOMIMETIC ACTIVITY OF THE CLASS III ANTIARRHYTHMIC SUBSTANCE / -SOTALOLIN VITRO: REVERSIBLE INHIBITION OF CHOLINESTERASE ISOENZYMES FROM BLOOD AND THE HUMAN CENTRAL NERVOUS SYSTEM

Inhibitory effects of the class III antiarrhythmic compound / -sotalol on acetylcholinesterase (AChE; EC 3.1.1.7) isoenzymes of both erythrocytes and the human caudate nucleus and on serum cholinesterase (ChE; EC 3.1.1.8) were studiedin vitrousing a spectrophotometric kinetic assay with acetylthiocholine (ASCh) as substrate. Sotalol concentrations in the assays varied from 0.32 to 3.2m . All isoenzymes studied were inhibited by / -sotalol in a reversible and concentration-dependent manner. Double reciprocal plots of the reaction velocity against varying ASCh concentrations revealed that / -sotalol reduced substrate affinity (apparent Michaelis constant, KM, increased) of serum ChE, but did not change the enzyme's maximal rate of ASCh hydrolysis (V_max). Thus, / -sotalol inhibition of serum ChE was of the competitive type (rate constant for reversible competitive inhibition: K_i=0.51m ). In contrast, / sotalol reduced the maximal reaction velocity of the AChE isoenzyme from the central nervous system (caudate nucleus), but had no influence on substrate affinity of the enzyme (K_Mwith ASCh unchanged) indicating purely non-competitive inhibition kinetics (rate constant of reversible non-competitive inhibition: K_i′=0.44m ). / -sotalol inhibition of erythrocyte AChE was of mixed competitive/non-competitive type (K_i=0.31m , K_i′=0.49m ). Non-competitive / -sotalol inhibition of caudate nucleus AChE and the non-competitive component of erythrocyte AChE inhibition cannot be overcome by increased concentrations of the cholinergic transmitter acetylcholine (ACh). Peak / -sotalol plasma levels as described in the literature for both humans (15μ ) and experimental animals (dogs: 18μ ; rats: 260μ ) as well as maximal myocardial concentrations of the substance (dogs: 46μ ; rats: 478μ ) are in the range of about 2% to 100% of the sotalol inhibition rate constants determined in the present paper for cholinesterase isoenzymesin vitro. Thus, / -sotalol inhibition of ACh hydrolysisin vivomay contribute to both the well known antiarrhythmic potential and proarrhythmic side effects of the compound.     

AMELIORIATION OF CHEMICALLY-INDUCED HEPATOCYTE INJURY BY CYCLOSPORINE A

Cyclosporine A, beside its current applications, possesses potential hepatoprotective effects. This study was directed to investigate the effect of Cyclosporine A pretreatment on hepatic injury due to carbon tetrachloride (CCl₄) and -galactosamine. Rats were injected by two successive doses of Cyclosporine A (5mgkg⁻¹day⁻¹). Six hours after the second dose, 1mlkg⁻¹of CCl₄was administered i.p. Effects associated with Cyclosporine A pretreatment were examined by using isolated hepatocytes and hepatocytes that were immobilized and continuously perfused. -Galactosamine (5m ) was added directly to the perfusion medium. After isolation, hepatocytes were examined histologically by light and electron microscopy, immobilized and perfused for further metabolic functional activity evaluation. Cyclosporine A pretreatmentin vivoproduced hepatoameliorative effects of various degrees which were statistically significant as manifested by: (1) an increased trypan blue exclusion after CCl₄; (2) an improved ureagenesis after CCl₄; (3) a reduction in the lipid droplets accumulation in the cytoplasm produced by CCl₄administration; (4) well preserved cytoplasmic organelles as mitochondria, endoplasmic reticulum ER, nuclear chromatin structures that were altered by CCl₄; and (5) an increased hepatocytes survival in the agarose gel matrix, reduction of LD leakage and improvement of ureagenesis after -galactosamine addition to the perfusion medium. The beneficial effect of Cyclosporine A pretreatment in modifying hepatotoxicity of chemical insults merits further studies.     

喙果黑面神化学成分研究

目的研究大戟科植物喙果黑面神(Breynia rostrata Merr.)的化学成分。方法利用硅胶、凝胶等色谱技术分离纯化化学成分,根据化合物的理化性质和光谱数据进行结构鉴定。结果从喙果黑面神的正丁醇萃取部分分离得到4个化合物,分别鉴定为6-O-甲基丙酰基-α-D-吡喃葡糖(6-O-methylpropanoyl-α-D-glucopyranose,1);4″-苯酚基-6-O-甲基丙酰基-β-D-吡喃葡糖苷(4″-phenolic-6-O-methylpropanoyl-β-D-glucopyranoside,2);1-O-没食子酰基-β-D-吡喃葡糖苷(1-O-galloyl-β-D-glucopyranoside,3);熊果苷(arbutin,4)。结论化合物1和2为新化合物,3和4均为首次从该种植物分离得到。     

EFFECTS OF 2-GUANIDINE-4-METHYLQUINAZOLINE ON GASTRIC ACID SECRETION IN RATS

In this study 2-guanidine-4-methylquinazoline (2-GMQ) appeared to decrease basal and stimulated gastric acid secretion, while structurally related compounds as dimethyl- biguanide, cyanoguanidine and 2-cyanoamino-4-methylpyrymidine did not. Thus, there is an antisecretory effect when the biguanide group is associated with a lipophilic structure. The antisecretive effects exerted by 2-GMQ are associated with anti H₂-histamine activity.The anti H₂-histamine nature of the effects of 2-GMQ was confirmed by the capacity of this compound of depressing the chronotropic activity of the isolated guinea pig auricle increased by histamine, as well as relaxant activity in rat uterus contracted by histamine, since both preparations are rich in H₂-histamine receptors.     

栝楼不同药用部位质量控制的研究进展

瓜蒌子、瓜蒌皮、瓜蒌、天花粉来源于栝楼的不同药用部位,4味药材均为常用的大宗药材,现行版《中国药典》对其制定的质量标准过于简单,无法科学合理地控制其质量。本文对瓜蒌子、瓜蒌皮、瓜蒌、天花粉安全性和有效组分的研究进行综述,明确了相关研究存在的问题并针对问题提出建议,为科学全面的药材及饮片标准的制定提供参考依据。