茶多酚对大鼠慢性缺氧损伤保护的实验研究

大鼠在高原环境模拟舱内间断缺氧及注射CoCl2溶液以建立红细胞增多症模型,实验分4组：平原组、慢性缺氧组、高剂量TP＋慢性缺氧组、低剂量TP＋慢性缺氧组,研究茶多酚对慢性缺氧诱导的大鼠红细胞增多症及心肌缺氧损伤的影响．结果显示,茶多酚能够显著抑制缺氧大鼠的红细胞数、血红蛋白和红细胞压积的增加,降低骨髓增生程度,减小缺氧大鼠心室重量指数,增加缺氧大鼠Hermannnwillson指数,同时经茶多酚处萼的缺氧大鼠心肌损伤程度较单纯缺氧组轻．提示,茶多酚对大鼠红细胞增多症有一定的预防作用,同时茶多酚还能减轻慢性缺氧对大鼠的心肌损伤程度．     

慢性常压缺氧和缺氧伴CO_2潴留大鼠红细胞变形能力与能量代谢的研究

本工作研究了慢性常压缺氧和缺氧伴ＣＯ＿２潴留肺动脉高压大鼠红细胞变形能力和红细胞内ＡＴＰ含量的变化。结果表明,慢性常压缺氧和缺氧伴ＣＯ＿２潴留大鼠不同切应力下的红细胞变形指数和红细胞内ＡＴＰ含量均明显低于其对照组,且该两组红细胞内ＡＴＰ含量与不同切应力下的红细胞变形指数呈显著正相关。提示慢性缺氧和伴ＣＯ＿２潴留大鼠红细胞内ＡＴＰ含量降低可能是导致红细胞变形能力降低的诸因素之一,后者又可导致和加重肺动脉高压的形成。     

慢性缺氧对两种不同敏感性大鼠肺动脉压和右心功能的影响

将国外引进繁殖的“缺氧敏感大鼠”(Hilltop SD)和国内常用的实验大鼠(Wistar)同时放在模拟5000米高度的低压舱内进行慢性缺氧,(分平原对照和缺氧4、10、20、30、40天六组),发现HT大鼠的肺动脉压升高程度明显大于W大鼠。在缺氧20天以内,随着肺动脉压的升高,两种大鼠右室心肌收缩性能指标[ dp/dt_(max),( dp/dt_(max)(/RVSP)和舒张性能指标[-dp/dt_(max),(-dp/dt_(max)/RVSP]相应增加。但HT大鼠的心脏代偿功能比W大鼠好。缺氧30天以后,上述心肌性能指标均有下降趋势。关于HT大鼠与W大鼠对缺氧敏感性的差异原因尚待进一步研究。     

缺氧诱导因子1α、诱导型一氧化氮合酶在缺氧性肺动脉高压大鼠肺动脉的表达

目的　观察缺氧诱导因子 1α (HIF 1α)与诱导型一氧化氮合酶 (iNOS)基因在缺氧性肺动脉高压大鼠肺动脉的表达情况。方法常压间断缺氧法复制缺氧性肺动脉高压大鼠模型 ;右心导管测定平均肺动脉压 (mPAP) ;H·E染色观察肺血管重塑情况 ;原位杂交和免疫组织化学方法分别检测HIF 1α和iNOSmRNA及蛋白质。结果　缺氧 7天后大鼠mPAP升高 ,出现缺氧性肺血管重塑 (HPSR) ,缺氧 14天后出现右心室肥大。对照组大鼠肺动脉壁iNOS、iNOSmRNA、HIF 1αmRNA弱阳性 ,HIF 1α蛋白质在肺动脉内膜和中膜分别呈阴性和弱阳性 ;肺动脉壁iNOS蛋白质和mRNA表达水平于缺氧 3天增高 ,缺氧 7天上升达高峰 ,以后维持于高峰水平 ;HIF 1αmRNA表达水平于缺氧 14天以后显著升高 ;全部缺氧大鼠肺动脉内膜HIF 1α蛋白质强阳性 ,肺动脉中膜HIF 1α蛋白质表达水平于缺氧 3天上升达高峰 ,缺氧 14天以后逐渐向基线回降。缺氧条件下iNOS蛋白质水平与mPAP (r =0 74 ,P <0 0 1)和HPSR (r =0 78,P <0 0 1)呈正相关 ,与HIF 1α蛋白质水平呈负相关 (r =- 0 5 2 ,P <0 0 1)。结论　HIF 1α和iNOS均参与缺氧性肺动脉高压的发病 ,HIF 1α对iNOS可能具有转录激活作用 ,iNOS对HIF 1α的表达可能具有抑制作用     

钙通道阻断剂异搏定对缺氧性肺动脉高压形成的影响

为考察Ca~( )在缺氧性肺动脉高压形成中的作用,我们观察了钙通道阻断剂异搏定对慢性连续性缺氧大鼠肺动脉压及左右心功能的影响。将动物置于模拟海拔5000m高原的低压舱内,腹腔注射异搏定,剂量为4mg/kg BW,每日两次。实验结果表明:异搏定可以减弱缺氧15天所引起的肺动脉压升高和右心功能加强的程度,对颈动脉压及左心功能无明显影响,提示Ca~( )的跨膜内流是构成缺氧性肺动脉高压形成的重要基础之一。我们还比较了异搏定对缺氧持续时间不同(15天、10天、5天)的大鼠肺循环的影响,并讨论了异搏定发生作用的机制。     

大鼠睡眠呼吸暂停综合征动物模型的建立

目的建立大鼠睡眠呼吸暂停综合征(SAS)动物模型。方法选取Wistar雄性青年大鼠与老年大鼠各30只。各组分为常氧对照组及间歇性缺氧组,每组6只。实验中抽取气体用于气体成分分析,测氧仪监测吸入气氧浓度,在缺氧终点测定右室肥厚指数、右室压力以了解缺氧对右心的影响;取肺、肾组织石腊包埋,病理切片,光镜观察。结果①随缺氧时间延长,出现右室肥大、肺动脉高压。②肺组织学观察:肺血管壁增厚、肺泡间隔增宽;肾小管上皮水肿变性。结论通过模拟间歇性缺氧机制成功建立大鼠睡眠呼吸暂停综合征动物模型。     

慢性常压缺氧和缺氧伴CO2潴留大鼠红细胞变形能力与能…

本工作研究了慢性常压缺氧和缺氧件ＣＯ２潴留肺动脉高压大鼠红细胞变形能力和红细胞内ＡＴＰ含量的变化。结果表明，慢性常压缺氧和缺氧伴ＣＯ２潴留大鼠不同切应力下的红细胞变形指数和红细胞内ＡＴＰ含量均明显低于其对照组，且该两组红细胞内ＡＴＰ含量与不同切应力下的红细胞变形指数呈显著正相关。提示慢性缺氧和伴ＣＯ２潴留大鼠红细胞内ＡＴＰ含量降低可能是导致红细胞变形能力降低的诸因素之一，后者又可导致和加重肺动脉高     

慢性缺氧对大鼠肺组织中G_(α0)的分布及基因表达的影响

为研究Ｇ蛋白变化与慢性缺氧性肺动脉高压发生的关系,本文应用核酸分子杂交方法及免疫组织化学法,测定了慢性缺氧性肺动脉高压大鼠肺组织Ｇ蛋白（Ｇα０）ｍＲＮＡ水平及其在肺组织中的分布。结果发现：Ｇα０分布于肺动脉壁肌层的神经纤维中,慢性缺氧可使Ｇα０阳性神经纤维数目明显增多,而且肺组织中Ｇα０ｍＲＮＡ水平为对照组的１．６８倍。结果提示：慢性缺氧性肺动脉高压发病过程可能有通过Ｇα０起作用的神经机制参与     

内源性CO在缺氧性肺动脉高压大鼠肺血管重构中的作用

目的和方法 :应用逆转录聚合酶链式反应 (RT PCR)、双波长分光光度法、右心导管及维多利亚蓝染色方法 ,动态观察慢性缺氧不同时间点大鼠肺组织中诱导型血红素氧合酶 (HO 1)基因表达、内源性CO生成、肺动脉压力及构型的变化 ,探讨内源性CO在大鼠缺氧性肺动脉高压肺血管重构中的作用。结果 :①正常大鼠肺组织可表达少量HO 1mRNA ,缺氧 5、10、15d大鼠肺组织HO 1mRNA含量分别增加 2 .3、3.6、4 .0倍 (P <0 .0 1) ,动脉血中COHb分别较正常大鼠增加 1.9、2 .6和 2 .9倍 (P <0 .0 1或P <0 .0 5 ) ,同时RVSP升高。光镜下可见IAPA血管壁增厚 ,管腔变窄。②Hemin可使缺氧大鼠肺组织HO 1mRNA和动脉血中COHb保持在高水平 (分别高达正常对照组的 5 .2和 3.7倍 ,P <0 .0 1或P <0 .0 5 ) ,能部分地抑制缺氧时大鼠RVSP的升高 ,减轻IAPA的病理改变。结论 :在慢性缺氧性肺动脉高压大鼠肺组织中HO 1基因的表达增加 ,内源性CO生成增多。Hemin促进HO 1基因表达和内源性CO生成 ,可抑制肺动脉压升高 ,阻抑肺血管重构 ,对缺氧性肺动脉高压的形成有一定的防治作用     

慢性缺氧的猪肺动脉内皮细胞在急性缺氧时PDGF-B链mRNA的表达

采用原位杂交技术结合图象分析检测常氧(PO2±21.3kPa)及慢性缺氧(P025.3±0.7kPa)培养的猪肺动脉内皮细胞PDGF-BmRNA的表达及其对急性缺氧刺激的反应.结果常氧及慢性缺氧培养的肺动脉内皮细胞(PAEC)在急性缺氧后PDGF-BmRNA表达均增加(P＜0.05),以第4、6代慢性缺氧组升高的幅度更大.结果表明慢性缺氧可增强PAEC在急性缺氧时PDGF-BmRNA的表达,可能促进肺血管改建和肺动脉高压的发展.     

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.