急性肺损伤大鼠肺组织基质金属蛋白酶2及其抑制因子蛋白和mRNA的表达

目的探讨内毒素致急性肺损伤（ALI）大鼠肺组织核转录因子-κB（NF-κB）、基质金属蛋白酶2（MMP-2）及其抑制因子（TIMP-2）蛋白和mRNA表达的变化。方法 20只雄性Wistar大鼠随机分为2组：对照组、LPS模型组,每组再分为4 h和8 h两个亚组。尾静脉注射脂多糖（LPS）（10 mg/kg）建立大鼠急性肺损伤模型。检测血白细胞计数、支气管肺泡灌洗液（BALF）蛋白含量,采用免疫组化ABC法和实时荧光定量PCR分别测定肺组织NF-κB、MMP-2、TIMP-2蛋白及其mRNA的表达,并观察肺组织病理变化。结果与对照组相比,模型组4 h和8 h时大鼠肺组织中的NF-κB、MMP-2蛋白染色阳性面积率及其mRNA表达均显著增高（P〈0.01）、TIMP-2蛋白染色阳性面积率及其mRNA表达均明显降低（P〈0.05或P〈0.01）。病理学观察显示,模型组大鼠肺组织出现出血及坏死。结论内毒素致急性肺损伤的发病机制可能与NF-κB、MMP-2蛋白及其mRNA表达升高、TIMP-2蛋白及其mRNA表达降低有关。     

L-精氨酸对脂多糖诱导大鼠肺损伤的保护作用及其机制的研究

目的：观察一氧化氮供体L-精氨酸（L-Arg）对脂多糖诱导大鼠肺损伤炎症反应和核因子-κB（NF-κB）信号通路的影响,探讨L-Arg对肺损伤的保护作用及其机制。方法：健康雄性SD大鼠采用舌下静脉注射脂多糖（LPS）复制肺损伤模型,分别于给予LPS3h和6h后给予生理盐水（对照组及LPS组,ip）和L-Arg（500mg/kgip）（L-Arg治疗组）,治疗3h。每组8只动物。免疫组化染色分析肺组织中NF-κB的核移位;逆转录多聚酶链反应（RT-PCR）检测肺组织细胞间粘附分子-1（ICAM-1）基因表达;放射免疫法分别测定肺组织中肿瘤坏死因子α（TNF-α）和白介素6（IL-6）的含量;光镜观察肺组织病理变化。结果：与对照组比较,大鼠肺损伤后NF-κB活化,明显从细胞浆移位于细胞核,表达量也显著增加;ICAM-1基因表达上调;肺组织中TNF-α、IL-6含量明显升高。肺损伤3h用L-Arg治疗3h后,NF-κB从细胞浆向细胞核的移位被明显限制,NF-κB的表达量、肺组织中TNF-α、IL-6含量明显低于相应的LPS组,肺组织病理改变减轻;肺损伤6h用L-Arg治疗3h对LPS引起的以上变化没有明显影响。结论：LPS3h后给予L-Arg可减轻内毒素性肺损伤,抑制核因子的活化,在一定程度上阻断NF-κB相关信号通路的传导,减轻炎症反应是其机制之一。     

急性肺损伤大鼠肺组织TOLL样受体4及CD14mRNA的表达

目的 探讨内毒素致急性肺损伤大鼠肺组织TOLL样受体4及CD14 mRNA表达的变化.方法 24只雄性Wistar大鼠随机分为2组:对照组、LPS模型组,每组再分为4 h和8 h两个亚组.尾静脉注射脂多糖(LPS)(10 mg/kg)建立大鼠急性肺损伤模型.检测大鼠动脉血气、肺体指数,实时荧光定量PCR测定肺组织TOLL样受体4及CD14 mRNA的表达,并观察肺组织病理变化.结果 与对照组相比,模型组4 h和8 h时大鼠肺组织中的TLR4及CD14 mRNA表达均显著增高(P＜0.05或P＜0.01).病理学观察显示,模型组大鼠肺组织出现出血及坏死.结论 内毒素致急性肺损伤的发病机制可能与TLR4及CD14 mRNA的表达升高有关.     

人工合成红景天苷对大鼠急性肺损伤的保护作用

为了研究人工合成红景天苷(salidroside,Sal)对脂多糖(lipopolysaccharide,LPS)诱导大鼠急性肺损伤(acute lung injury,ALI)的保护作用及其机制,将雄性Sprague-Dawley大鼠随机分为生理盐水对照组、3 mg/kg LPS损伤组、不同剂量Sal干预组(5、20和80 mg/kg)以及5 mg/kg地塞米松(dexamethasone,Dex)干预组,气管内滴注LPS建立ALI模型,在LPS造模前0.5 h腹腔给予人工合成Sal或Dex,造模6 h后处死动物。计量肺湿/干重比值(wet/dry weight ratio,W/D),苏木素-伊红染色观测肺组织病理形态学变化和肺损伤评分。用瑞氏染色计数肺泡灌洗液(bronchoalveolar lavage fluid,BALF)离心沉淀的中性粒细胞(polymorphonuclear leukocyte,PMN),用BCA法测定BALF离心上清蛋白含量,并用酶联免疫吸附法测定TNF-α、IL-1β和IL-6的含量。测定肺组织中髓过氧化物酶(myeloperoxidase,MPO)和丙二醛(malondialdehyde,MDA)含量,Western blot检测肺组织中磷酸化NF-κB和总NF-κB蛋白表达水平。结果显示,与LPS组比较,人工合成Sal能减轻肺组织损伤程度,降低肺损伤评分和W/D比值(P0.05),减少BALF中PMN计数、蛋白含量以及炎症因子水平(P0.05),降低肺组织中MPO和MDA含量(P0.05),抑制肺组织中磷酸化NF-κB蛋白的表达(P0.05)。以上结果提示,人工合成Sal对LPS诱导的ALI具有保护作用,其机制与抑制肺组织NF-κB蛋白磷酸化以及减少PMN在肺内聚集有关。     

外源性硫化氢对大鼠内毒素性肺损伤的影响及机制研究

目的：应用H2S供体硫氢化钠（NaHS）,观察外源性H2S对中性粒细胞（PMN）在脂多糖（LPS）刺激大鼠肺内聚集的影响及其机制。方法：采用尾静脉注射致Sprague-Dawley（SD）大鼠内毒素急性肺损伤（ALI）模型,将大鼠随机分为4组（n=8～12）。对照组：由尾静脉注射无菌生理盐水（0.5ml/kg）;LPS组：由尾静脉注射LPS（1mg/kg）;LPS＋NaHS组：注射LPS前10min腹腔注射NaHS（28μmol/kg）;NaHS组：腹腔注射NaHS（28μmol/kg）。6h后光镜下观察各组大鼠肺组织学变化并计数肺泡间隔中PMN数目（number/HP）;脱氧核苷酸末端转移酶介导的原位末端标记技术（TUNEL）测定支气管肺泡灌洗液（BALF）中PMN凋亡百分率及应用Western blot检测肺组织细胞间黏附分子（ICAM）-1和核转录因子（NF）-κB表达的变化。结果：注射LPS后动物肺组织出现出血、水肿及PMN聚集等病理征象。LPS组大鼠肺组织中PMN数目较对照组显著增加,PMN凋亡百分率下降,ICAM-1、NF-κB表达显著增高;应用NaHS后每高倍镜PMN数目显著减少,PMN凋亡百分率明显增高,ICAM-1、NF-κB表达显著降低,肺组织损伤减轻。单独应用NaHS组大鼠上述各项指标与对照组大鼠相比无显著差异。结论：NaHS可减少PMN在肺内聚集,其机制与其抑制NF-κB通路,从而下调ICAM-1表达、促进PMN凋亡有关。     

L-精氨酸对实验性大鼠急性肺损伤的保护作用

目的 探讨一氧化氮(NO)前体物质L-精氨酸(L-Arg)在内毒素(LPS)致大鼠急性肺损伤中的作用.方法 SD大鼠24只随机分为空白对照组、LPS组和L-Arg(500 mg/kg)组.腹腔注射LPS(100 μg/kg)复制急性肺损伤动物模型.在LPS注射2 h后,取大鼠肺称其湿重与干重,计算肺湿干比,测定肺灌洗液蛋白含量和白细胞数量,并进行肺组织病理学检查.结果 与对照组相比,LPS组肺湿干比、肺灌洗液蛋白含量和白细胞计数显著增高(P<0.01,n=8),病理学切片见急性肺损伤性变化;与LPS组相比,L-Arg组肺湿干比、肺灌洗液蛋白含量和白细胞计数显著降低(P<0.01,n=8),肺组织急性损伤显著减轻.结论 L-Arg具有抗LPS致急性肺损伤的作用.     

NDRG2 和ZC3H12D在大鼠急性肺损伤中的表达及其相关性的研究

目的:通过建立LPS诱导的大鼠急性肺损伤模型,观察大鼠肺组织中N-myc下游调节基因2(NDRG2)和具有CCCH锌指结构域的蛋白质12d(ZC3H12D)表达水平的变化来讨论二者相互作用的机制。方法:40只健康成年雄性SD大鼠随机分成对照组、LPS注射60 min、120 min和180 min组,获取各组大鼠肺组织,行湿干重比值(W/D)检测、ELISA检测、病理(HE)检测确定肺损伤模型是否建立成功;免疫组化、RT-PCR和Western-blot对NDRG2和ZC3H12D在m RNA水平和蛋白水平进行检测。结果:各LPS损伤组与对照组相比,W/D比值显著升高,180 min组比值最高,为5.68±0.52(P0.05),血清和肺匀浆中TNFα和IL-1β含量明显增加(P0.05);损伤组肺泡壁增宽,炎细胞浸润明显;肺组织NDRG2和ZC3H12D在m RNA水平和蛋白水平的表达都呈相降低后回升的趋势,180 min组NDRG2和ZC3H12D,蛋白含量分别为对照组的0.37和0.44倍(P0.05)。结论:LPS诱导的大鼠急性肺损伤可同时下调肺组织中NDRG2和ZC3H12D的表达,并且NDRG2和ZC3H12D具有潜在的相关性,提示两者可能存在互相调节的机制,并通过调节NF-κB通路对肺损伤的大鼠起保护作用。     

甘草酸二铵对百草枯中毒致急性肺损伤大鼠TLR-4表达的影响

目的探讨甘草酸二铵(DG)对百草枯(PQ)中毒致急性肺损伤(ALI)大鼠的保护作用及其机制。方法选择健康SD大鼠50只,随机分为百草枯组(PQ组)、甘草酸二铵组(DG组)和正常对照组(NS组),PQ组和DG组予百草枯100mg/kg灌胃1次,DG组于灌胃后立即腹腔注射DG 50mg/kg,每日1次,对照组与PQ组注射等剂量的生理盐水。观察至48h处死大鼠,取肺组织检测肺湿干重比;肺组织HE染色评价肺组织损伤情况;采用RT-PCR法检测肺组织TLR-4mRNA和NF-κB mRNA的表达情况。另选择健康SD大鼠50只,分组及各组处置方法同上,观察其7天内死亡率。结果 PQ组与DG组肺湿干比、肺组织TLR-4mRNA和NF-κB mRNA表达较NS组明显升高(P0.01);DG组各指标明显低于PQ组(P0.01)。HE染色结果,NS组肺部结构正常,PQ组、DG组可见肺组织水肿、出血及炎性细胞浸润等肺损伤表现,DG组病变轻于PQ组。群体死亡率比较,PQ组7天死亡率为90%,DG组为40%,NS组无死亡。结论甘草酸二铵可减轻百草枯中毒致急性肺损伤大鼠肺部炎症,其机制可能与降低TLR-4、NF-κB的表达有关。     

血红素加氧酶-1对急性重症胰腺炎相关肺损伤TLR4/NF-κB通路的影响

目的:探讨血红素加氧酶-1(HO-1)对急性重症胰腺炎相关肺损伤(PALI)Toll样受体-4(TLR4)/核因子-κB(NF-κB)信号传导通路的影响。方法:32只SD大鼠随机分为Sham组、PALI组、HO-1促进剂组、HO-1抑制剂组,每组8只。PALI组经胆胰管注入牛磺胆酸钠制备急性重症胰腺炎(ANP)动物模型。Sham组胆胰管内不注入牛磺胆酸钠,其余操作同PALI组。HO-1促进剂组于造模后30 min经腹腔注射牛血晶素75μg/kg;HO-1抑制剂组于造模后30 min经腹腔注射锌-原卟啉20μmol/kg。PALI组和Sham组均于造模后30 min经腹腔注射等量生理盐水。各组大鼠术后24 h,进行肺损伤学评分,统计肺湿/干重比值。检测大鼠术后24 h血清淀粉酶、TNF-α、IL-6、NGAL水平。检测大鼠术后24 h肺组织中TLR4、NF-κB p65蛋白表达。结果:PALI组肺损伤学评分、肺湿/干重比值、淀粉酶、TNF-α、IL-6、NGAL、TLR4、NF-κB p65明显高于Sham组;HO-1促进剂组肺损伤学评分、肺湿/干重比值、淀粉酶、TNF-α、IL-6、NGAL、TLR4、NF-κB p65明显低于PALI组;HO-1抑制剂组肺损伤学评分、肺湿/干重比值、淀粉酶、TNF-α、IL-6、NGAL、TLR4、NF-κBp65明显高于PALI组;差异均有统计学意义(P<0.05)。结论:HO-1能够通过抑制TLR4/NF-κB信号通路的激活,下调TNF-α、IL-6、NGAL等炎症因子的释放,从而发挥减轻急性重症胰腺炎相关肺损伤的作用。     

丙戊酸钠对LPS诱导的急性呼吸窘迫综合征小鼠的治疗作用

为了探讨丙戊酸钠(valproic acid,VPA)对急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)小鼠治疗作用及分子机制,本研究将30只雌性C57BL/6小鼠分为空白组、LPS组、LPS+VPA组,LPS+VPA组小鼠造模前腹腔预注射VPA,以LPS气管内注射诱导ARDS小鼠模型,6 h后检测各组小鼠肺水肿(湿重/干重),检测各组小鼠血液SOD和MDA水平;通过ELISA检测各组小鼠肺泡灌洗液中TNFα和IL-1β水平,Western blotting检测各组小鼠NF-κB p65和p-H2A.X蛋白表达水平。研究结果表明:与空白组相比,LPS组小鼠肺水肿显著升高,与LPS组比较,LPS+VPA组和阳性组小鼠肺水肿显著降低,差异具有统计学意义(p<0.01)。ELISA结果显示,与空白组比较,LPS组小鼠肺组织TNFα和IL-1β含量显著升高,与LPS组比较,LPS+VPA组小鼠肺组织TNFα和IL-1β含量显著降低,差异具有统计学意义(p<0.01)。与空白组比较,LPS组小鼠血液SOD活性显著降低,MDA含量显著升高,与LPS组比较,LPS+VPA组和阳性组小鼠血液SOD活性显著升高,MDA含量显著降低。Western blotting结果显示,与空白组比较,LPS组小鼠肺NF-κB p65和p-H2A.X蛋白表达显著升高,与LPS组比较,LPS+VPA组和阳性组小鼠肺NF-κB p65和p-H2A.X蛋白表达显著降低,差异具有统计学意义(p<0.01)。本研究初步表明:VPA能够抑制NF-κB通路,抑制小鼠氧化应激和炎症反应,保护ARDS小鼠肺组织。     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.