间歇低氧对大鼠肝糖原的影响及Tempol的干预作用

目的:探讨OSAS模式慢性间歇低氧对普通大鼠肝组织学、肝糖原含量的影响及抗氧化剂Tempol的干预作用。方法:成年雄性Wistar大鼠80只,分为不同频率(10、20、30、40次/h)间歇低氧组、Tempol干预组、生理盐水干预组、间歇正常氧组、空白对照组。间歇低氧暴露时间为每日9:00~17:00,共42天。暴露结束后,肝组织HE染色观察形态学,PAS染色观察肝细胞内糖原含量情况。结果:间歇低氧各组肝细胞肿胀,胞核染色加深,核膜增厚,随频率增加出现肝血窦增宽,肝细胞局灶性坏死,炎性细胞浸润,但未出现肝细胞脂质含量增多及脂肪变性;间歇低氧各组肝细胞肝糖原含量增加,间歇正常氧组及Tempol干预组无细胞水肿或炎性细胞浸润,肝细胞内肝糖原含量相仿。结论:慢性间歇低氧导致普通饮食大鼠肝组织损伤,肝糖原含量增加,抗氧化剂Tempol的干预可改善慢性间歇低氧所致的肝组织损伤,且早诊断早干预效果较好;抗氧化剂Tempol干预能阻断肝糖原贮备,改善CIH所致的代谢紊乱。     

猫儿山小鲵肝的组织结构

通过常规石蜡切片技术对2例猫儿山小鲵（Hynobius maoershanens）肝进行组织学观察。结果显示,猫儿山小鲵肝分为两叶,右叶稍大于左叶。肝组织结构主要由被膜、中央静脉、门管区和肝细胞组成。门管区的小叶间静脉和小叶间胆管清晰可见,但小叶间动脉不易观察。肝内结缔组织少,肝小叶之间界限不清。肝细胞索围绕中央静脉呈放射状排列,但放射状不明显。肝实质中含有大量清晰可见的棕黑色色素团,可能与此物种对低氧环境的适应有关。     

葛根素对大鼠肝脏缺血再灌注损伤的保护作用

目的:观察葛根素预处理时大鼠肝脏缺血再灌注损伤的保护作用.方法:雄性SD大鼠,建立肝脏缺血再灌注模型(HIR).随机分为假手术组、HIR组和HIR-葛根素预处理组.分析各组动物血清中谷草转氨酶(AST)、谷丙转氨酶(ALT)及乳酸脱氢酶(LDH)含量的变化,观察肝组织病理学的改变.结果:肝脏缺血再灌注损伤后,与假手术组比较,血清中AST、ALT、LDH含量均显著增加,同时肝脏门静脉周围瘀血明显,可见少量散在的肝细胞片状坏死灶,有少量炎性细胞和单核细胞浸润,肝细胞肿胀、脂肪空泡变性、核浓缩;经40mg/kg剂量的葛根素预处理7天后,与模型组相比,血清中AST、ALT、LDH均显著降低,肝脏的瘀血明显较模型组轻,肝小叶结构基本正常,微血管未见明显损伤,窦间隙稍宽,细胞变性坏死不明显,偶见少量肝细胞坏死.结论:葛根素预处理对大鼠缺血再灌注肝脏损伤有一定的保护作用.     

D-gal致大鼠急性肝损伤过程中肝卵圆细胞增殖及迁延

目的用D-gal建立大鼠急性肝损伤模型,观察肝损伤后再生过程中肝卵圆细胞的增殖和迁延。方法建立大鼠急性肝损伤模型,于第1、3、7和14天分别取肝组织,分别行病理、免疫组织化学,观察卵圆细胞的分布迁移情况,并取第7天肝组织进行组织电镜观察汇管区新增生细胞超微结构。结果病理切片显示肝细胞变性坏死程度以第7天和第14天为主,出现新增生的细胞。免疫组化示随时间阳性细胞明显增多,分布于汇管区,并向小叶中心迁移,形成大量的胆小管,并有部分向坏死区迁移。透射电镜有新生内源性细胞,小于成熟的肝细胞,细胞器较少,有细胞紧密连接,以数个细胞排列成小胆管,与免疫组化一致。结论在大鼠急性肝损伤时HOC被活化、增殖,并向肝小叶中心迁移,全程参与了肝再生过程。     

芒果苷对大鼠酒精性肝炎的保护作用研究

研究芒果苷(MFN)对大鼠酒精性肝炎(AH)的保护作用及其作用机制。将实验大鼠随机分为正常组、模型组、水飞蓟宾组(SYN,20 mg/kg)和MFN高、低剂量组(100、50 mg/kg),采用灌胃给予40%酒精(10 m L/kg)建立AH大鼠模型,同时给予药物治疗。4周后,检测血清中ALT、AST、TBIL、DBIL和IBIL的浓度,肝组织中TNF-α和IL-6的水平以及NF-κB mRNA的表达,并观察肝组织HE和油红O染色情况。结果表明,模型组大鼠血清中ALT、AST、TBIL、DBIL和IBIL的浓度明显升高(P0.01),肝组织中TNF-α和IL-6含量以及NF-κB mRNA表达水平亦明显升高(P0.01),同时肝脏出现大量空泡病变、肝细胞肿胀、脂肪变性、炎性细胞浸润等现象。MFN高、低剂量组对上述指标异常均有明显的改善作用(P0.01,P0.05),肝细胞病变程度明显减轻,并且具有剂量依赖性。因此,MFN具有良好的抗AH的作用,其作用机制可能与促进肝细胞修复,调节肝细胞炎症因子TNF-α、IL-6水平和NF-κB的mRNA表达有关。     

黑木耳多糖提取物对肝纤维化大鼠肝功能及MPO,MDA,TGF-β的影响

目的:探究黑木耳多糖提取物对肝纤维化大鼠血清髓过氧化物酶(MPO)、丙二醛(MDA)及转化生长因子β(TGF-β)的影响及肝功能的保护作用。方法:将健康的Wistar大鼠30只随机分为3组:对照组、模型组、黑木耳多糖提取物组,利用胆总管结扎术制备肝纤维化动物模型,术后分别用生理盐水0.1 m L/(kg·d)、黑木耳多糖提取物0.1 mg/(kg·d)灌胃1次/d。21 d后腹主动脉采血,测肝功能指标,取肝组织测MDA、MPO、TGF-β,Masson染色。结果:肝纤维化动物模型成功制备。黑木耳多糖提取物组总胆红素(STB)、谷氨酸转移酶(ALT)、天门冬氨酸转移酶(AST)、MPO、MDA较模型组明显降低,TGF-β含量降低。Masson染色可见:模型组肝小叶结构破坏,较对照组汇管区可见大面积胶原纤维的形成;黑木耳多糖提取物组肝细胞轻度水肿、肝索排列欠整齐,肝汇管区及各部位胶原纤维形成量略少。结论:黑木耳多糖提取物可减轻胆总管结扎大鼠脂质过氧化损伤,MPO含量使TGF-β因子释放减少,从而减少胶原纤维形成,减轻或延缓大鼠肝纤维化。     

网络抗氧化剂对大鼠非酒精性脂肪肝炎模型疗效的动态观察

目的:研究网络抗氧化荆对大鼠非酒精性脂肪肝炎的治疗效果.方法:雄性SD大鼠72只,随机分为正常对照组、模型组、网络抗氧化剂组(n=24).正常对照组喂以普通饲料,网络抗氧化剂组及模型组均予高脂饮食.网络抗氧化剂组高脂饮食同时使用维生素E(100mg/kg)、硫辛酸(40mg/kg)、辅酶Q10(100mg/kg)、维生素C(100mg/kg)、还原性谷热水胱甘肽(100mg/kg)联合灌胃治疗,1次/日.分别在8周、10周、12周通过肝功能、血脂及肝组织病理动态观察病情转归情况,检测MDA、SOD评定网络抗氧化剂在病情转归中起到的抗氧化作用.结果:网络抗氧化剂组体重、肝指数、血清ALT、AST、MDA、TC及肝组织MDA均显著低于模型组;血清、肝组织SOD显著高于模型组;病理学模型组在8-10周出现多处肝细胞内脂滴堆积,出现气球样变,且有少量炎细胞浸润,随着进食高脂饮食时间的延长病变程度逐渐加重,至12周脂肪变及炎症程度均有所加重,出现点灶状坏死、桥接坏死.甚至出现部分肝纤维化.同期网络抗氧化剂肝组织病理显示脂肪变及炎症显著轻于模型组,无明显肝纤维化出现.结论:网络抗氧化剂对NASH有较好的防治效果.     

龙丹生血颗粒对骨髓抑制小鼠血象与巨核细胞影响的研究

目的:用环磷酰胺(CTX)复制小鼠骨髓抑制动物模型,观察龙丹生血颗粒对模型动物血液学检查和骨髓巨核细胞的影响。方法:70只昆明种小鼠标记后,除空白组外,其余动物首次尾静脉注射给予环磷酰胺200 mg/kg,第二天后改用每天腹腔注射30mg/kg,连续6天之后,断尾采血行血液学检查。挑选外周血血小板较正常组减少至30%以上的小鼠,随机分为模型、白介素-11、升血小板胶囊、龙丹生血颗粒大、中、小剂量6组,每组10只。龙丹生血颗粒大、中、小剂量组分别灌胃龙丹生血颗粒浸膏粉混悬液13.75 g生药/kg、6.88 g生药/kg、3.44 g生药/kg;升血小板胶囊组灌胃1.125 g内容物/kg;白介素-11组皮下注射白介素-11250μg/kg;正常组、模型组灌胃饮用水。各组每天给药1次,灌胃容积0.2 mL/10g,连续14天。分别于给药第7天、14天采血行外周血象检查,末次采血后处死动物,取股骨骨髓做骨髓涂片,光镜检查分类计数巨核细胞数量。结果:以给药后与给药前差值统计,龙丹生血颗粒大、中剂量组小鼠外周血PLT(给药14天)、WBC(给药7天)比模型组差值明显增大(P0.01或P0.05);龙丹生血颗粒各剂量组给药7天、14天的RBC、Hgb比模型组同期差值明显增大(P0.01或P0.05);龙丹生血颗粒中剂量组小鼠骨髓巨核细胞总数、颗粒巨核细胞比模型组显著增加(P0.05)。结论:龙丹生血颗粒对环磷酰胺导致小鼠外周血PLT、WBC、RBC、Hgb减少具有治疗作用,但对骨髓巨核细胞的恢复作用有待进一步证实。     

二乙基亚硝胺诱导大鼠肝癌模型的建立及评价

目的:通过间断小剂量二乙基亚硝胺(DEN)腹腔注射的方法,建立大鼠肝癌模型,并进行评价.方法:60只健康雄性SD大鼠随机分为C组(对照组,n=10)和M组(造模组,n=50),其中M组动物给予DEN腹腔注射,按体重20mg/kg给药,每周3次,至12周时停药.C组给予同等剂量和频率的生理盐水腹腔注射.观察两组动物不同时期肝脏大体变化及病理改变.结果:16周时诱癌成功率为76.2%(32/42).病理学结果显示,M组动物肝脏病变过程经历肝细胞损伤坏死期、肝细胞增生硬化期和肝细胞癌变期.结论:通过间断小剂量DEN腹腔注射的方法,成功建立了大鼠肝癌模型,该模型可作为一种理想的研究人类肝癌发生的动物模型.     

阿托伐他汀治疗对肾脏衰老的影响

目的：观察长期应用不同剂量的阿托伐他汀对老年大鼠肾脏的影响。方法：正常20月龄Wistar雌性大鼠分为3组（n=9）：①给予大剂量阿托伐他汀10 mg/（kg.d）灌胃;②给予小剂量阿托伐他汀1 mg/（kg.d）灌胃;③给予等剂量生理盐水灌胃,三组均连续灌胃4个月后处死大鼠,以3月龄大鼠（n=9）为对照。测定肾重指数,血清肌酐及血清脂蛋白,行PAS染色、天狼猩红染色观察肾脏病理,计算肾小球硬化指数。结果：三组老年大鼠的肾脏重量均显著减轻。老年大鼠小剂量阿托伐他汀组显著降低老年大鼠的血清肌酐（P〈0.01）。老年大鼠血脂水平显著高于青年大鼠,大剂量阿托伐他汀组显著降低老年大鼠的总胆固醇（CH）和低密度脂蛋白胆固醇（LDL-C,P均〈0.05）,小剂量阿托伐他汀组显著降低老年大鼠的LDL-C（P〈0.05）。大剂量阿托伐他汀组降低血脂的作用强于小剂量阿托伐他汀组。老年大鼠肾脏病理改变为显著的肾小球局灶节段性硬化,肾小球硬化指数显著增高（P〈0.05）,肾间质内大量炎性细胞浸润,肾内小动脉明显硬化。阿托伐他汀组显著减轻肾小球的局灶节段性硬化的程度,减少肾间质内炎性细胞浸润,显著改善肾内小动脉粥样硬化的病变程度。大剂量阿托伐他汀改善肾组织异常病理表现的作用更为明显。结论：长期应用阿托伐他汀可以显著改善老年大鼠肾脏衰老的异常病理改变,这些作用可能是通过阿托伐他汀的降脂作用、显著减轻肾内小动脉硬化及显著减少肾间质内炎性细胞浸润而综合起效的。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.