腺苷A1受体激动剂对兔血一氧化氮水平及急性心肌梗塞范…

为了解腺苷Ａ１受体激动剂Ｒ－ＰＩＡ对血一氧化氮及急性心肌梗塞的范围的影响,２０只新西兰兔随机分为四组：Ｉ,前降缺血６０ｍｉｎ,再灌注９０ｍｉｎＩＩ缺血前１５ｍｉｎ给予Ｒ－ＰＩＡ,余同Ｉ组,Ⅲ两次缺血１０ｍｉｎ,然后缺血６０ｍｉｎ,再灌注９０ｍｉｎ。     

亲和层析法分离大鼠脂肪细胞膜上腺苷A_1受体

本文采用腺苷亲和层析法从大鼠脂肪细胞膜上分离出了一种亚基分子量为38kD的腺苷结合蛋白质。此蛋白在SDS-聚丙烯酰胺凝胶电泳上显示单一带,糖蛋白染色阳性;能与[8-~3H]腺苷特异结合(Kd=0.269nmol/L,Bmax=6.05pmol/mg.Pr);结合抑制实验表明它与腺苷A_1受体激动剂R-PIA、A_2受体激动剂NECA和腺苷的亲和力大小顺序为:R-PIA>腺苷>NECA。这表明所分离出的38kD蛋白是大鼠脂肪细胞膜上的腺苷A_1受体。     

GLP-1受体激动剂肾功能调节作用的研究进展

GLP-1受体是广泛分布于人体多个组织和器官中的一种G蛋白偶联受体,它参与体内糖代谢的调控,是糖尿病领域的研究热点。GLP-1受体激动剂能够作用于胰岛,调节胰岛素和胰高血糖素的分泌,促进胰岛B细胞增殖并抑制其凋亡;作用于胃肠道,延缓胃排空和抑制糖脂吸收;作用于中枢神经细胞发挥神经保护作用。越来越多的研究发现,GLP-1受体激动剂对肾脏功能具有调节作用。在动物实验中,大鼠给予GLP-1受体激动剂后尿排出量显著增加,尿液中钠离子浓度大幅度升高,此外,钾、碳酸氢等离子的排泄量均有不同程度地增加;同时,肾小球滤过率和肾血流量均明显升高。其作用机制可能涉及两个方面:GLP-1受体激动剂直接作用于肾脏GLP-1受体调节电解质的转运以及作用于肾脏脉管系统影响肾脏血流动力学。本文将对此作用的研究现状做简要综述。     

脑室注射组胺H1受体激动剂对大鼠胃酸分泌的作用机制

本文对中枢注射ＰＥＡ抑制胃酸分泌的作用机制进行分析。雄性Ｗｉｓｔａｒ大鼠,重２００－３００ｇ,用３７（生理盐水通过恒流泵进行连续胃灌流。第三脑室给药,观察其对五促胃液素（１６０μｇ／ｋｇ,ｓ．ｃ．）诱导的胃酸分泌的影响。结果如下：（１）预先注射纳洛酮２．５μｇ可阻断１０μｇＰＥＡ的中枢抑酸效应;（２）双侧膈下迷走神经切除可翻转ＰＥＡ（５－２０μｇ）的抑酸效应,且有量效关系;双侧肾上腺摘除对ＰＥＡ中     

D1及α2受体激动剂对卵母细胞表达的GABAA受体的抑制

目的：研究SKF38393及Clonidine对表达的DRG神经元GABAA受体的调制作用,并与新鲜分离细胞相比较。方法：实施在注射鼠DRG神经元mRNA的卵母细胞上进行,以比电极电压钳技术进行研究。结果：①SKF38393及Clonidine对表达的DRG神经元GABAA受体有明显的抑制作用,其作用呈浓度依赖性。②SKF38393及Clonidine的诱导电流之间有相互抑制作用。③SKF38393及Clonidine对GABAA受体的抑制作用是非竞争性抑制,并且为非电压依赖性。结论：实验结果提示SKF38393及Clonidine可通过胞内转导,由第二信使介导GABAA受体的磷酸化而抑制GABAA诱导电流。     

β3受体激动剂对培养的大鼠心肌细胞搏动频率和细胞内环-磷酸腺苷水平的影响

目的：观察β3受体激动剂(BRL-37344)对培养的大鼠心肌细胞搏动频率和细胞内环-磷酸腺苷(cAMP)水平的影响,以探讨β3受体在心肌细胞中的作用。方法：分离培养乳鼠心肌细胞,随机分为八组：对照组、ISO组、Nadolol ISO组、BRL组、PTX BRL组、L-NAME BRL、Nadolol BRL组和Buprandol BRL组,观察心肌细胞搏动频率,并应用酶联免疫方法测定cAMP含量,逆转录多聚酶链反应(RT-PCR)方法测β3受体mRNA表达。结果：ISO(非选择性β受体激动剂)可显著增加心肌细胞搏动频率和升高cAMP水平,这种作用可被Nadolol(为β1,β2受体抑制剂)阻断。BRL-37344可显著降低心肌细胞搏动频率和cAMP含量,这种作用可被PTX(Gi蛋白抑制剂)和Bupranolol(非选择性β受体阻滞荆)完全阻断,同时可被L-NAME(一氧化氮合酶抑制剂)部分阻断,不受Badolol影响。RT-PCR方法测出心肌细胞中有β3受体mRNA表达。结论：心肌细胞中存在β3受体,它在心肌表现为负性变力作用,β3受体的效应不受β1,β2受体抑制剂影响。心脏β3受体信号途径中可能有Gi蛋白的参与,并且经过一氧化氮合酶途径发挥其作用。     

大鼠侧脑室注射腺苷A1受体反义寡聚脱氧核苷酸抑制脑缺血耐受的诱导

目的:观察侧脑室注射腺苷A1受体(ARA1)反义寡聚脱氧核苷酸(As-ODN)对脑缺血预处理(CIP)脑保护作用的影响,进一步探讨腺苷A1受体在CIP脑保护作用中的作用。方法:将54只凝闭双侧椎动脉的Wistar大鼠分为Sham组、CIP组、损伤性脑缺血组、CIP 损伤性脑缺血组、双蒸水 CIP 损伤性脑缺血组、ARA1As-ODN组、ARA1As-ODN CIP组、和ARA1As-ODN CIP 损伤性脑缺血组。ARA1As-ODN的剂量分为10nmol/5μl和20nmol/5μl,溶于双蒸水中,侧脑室注射。所有动物均在Sham手术后或末次全脑缺血/再灌注后7d断头取脑,硫堇染色观察海马CA1区锥体神经元迟发性死亡(DND)情况。结果:Sham组和CIP组均未见DND。与Sham、CIP组相比,损伤性脑缺血组出现了明显的DND,表现为组织学分级(HG)升高和锥体神经元密度(ND)下降(P<0.05)。CIP可显著抑制损伤性脑缺血引起的DND。与CIP 损伤性缺血组相比,ARA1As-ODN CIP 损伤性脑缺血组出现了显著的DND,表现为HG升高、ND降低(P<0.05),这种变化与ARA1As-ODN的剂量呈明显正相关。结论:腺苷A1受体As-ODN可阻断CIP诱导的脑缺血耐受,进一步证实了腺苷A1受体表达上调参与CIP诱导的脑缺血耐受。     

腺苷A_1R在高压氧致中枢神经系统氧中毒发生中的作用研究

目的:探讨腺苷A1受体(A1R)在高压氧(hyperbaric oxygen,HBO)致中枢神经系统氧中毒(central nervous system oxygen toxicity,CNS-OT)发生中的作用。方法:(1)大鼠侧脑室注射A1R选择性激动剂CCPA后观察氧惊厥潜伏期。采用随机数字法将大鼠分为对照组和5μg、10μg以及20μg CCPA给药组。采用侧脑室注射方法分别给予生理盐水和不同剂量CCPA后,进行0.6MPa HBO暴露,记录大鼠的CNS-OT潜伏期。(2)大鼠侧脑室注射A1R选择性抑制剂DPCPX后观察氧惊厥潜伏期。采用随机数字法将大鼠分为对照组和15μg、30μg以及60μg DPCPX给药组。采用脑室注射方法分别给予DMSO和不同剂量DPCPX后,进行0.6 MPa HBO暴露,记录大鼠的CNS-OT潜伏期。结果:脑室注射5μg CCPA组(32.15分±0.8392分)、10μg CCPA组(60.50分±3.150分)和20μg CCPA组(70.91分±2.975分)惊厥潜伏期显著延长,差异有统计学意义(P0.05)。脑室注射30μg DPCPX组(14.09分±1.363分)和60μg DPCPX组(8.564分±0.645分)惊厥潜伏期显著缩短,差异有统计学意义(P0.05)。结论:中枢局部给予腺苷A1R选择性激动剂CCPA可以有效延长CNS-OT的潜伏期;中枢局部给予腺苷A1R选择性抑制剂DPCPX可以有效缩短CNS-OT的潜伏期。     

LncRNA MNX1-AS1 promotes the progression of cervical cancer through activating MAPK pathway

Long noncoding RNAs (lncRNAs) have been discovered as significant regulators in a wide range of human cancers. Among them, lncRNA MNX1-AS1 has been proved to be an oncogene in ovarian cancer and glioblastoma. However, the regulatory mechanism of MNX1-AS1 in cervical cancer remains to be understood. Therefore, this study planned to explore the role of MNX1-AS1 in cervical cancer. In the beginning, we found that the expression of MNX1-AS1 was obviously upregulated in cervical cancer tissues and cell lines. Kaplan-Meier survival analysis revealed that patients with higher MNX1-AS1 expression level suffered from shorter overall survival time than those with lower MNX1-AS1 level. Moreover, by loss-of-function and gain-of-function assay, the effect of MNX1-AS1 on cell proliferation and apoptosis was examined on cellular level. Results showed that the proliferation of Hela cells was significantly inhibited and apoptosis enhanced by the transfection of shMNX1-AS1, while overexpressing MNX1-AS1 in E6E7 cells presented the contrary results. As for mechanism investigation, it was demonstrated that overexpression of MNX1-AS1 significantly improved the expression of p-ERK1/2 and p-JNK. And the effects of MNX1-AS1 on cell proliferation and apoptosis would be diminished after inactivating the phosphorylation of either ERK or JNK. Taken together, it was identified that MNX1-AS1 promoted proliferation and inhibited apoptosis of cervical cancer cells through MAPK pathway.     

On the Fertilization of Gastrodia elata B1.Orchidaceae

Gastrodia elata B1. is a species of parasitic orchid, its organized structure is much reduced. Although its embryo sac is rather simple (4-celled), the double fertilization proceeds normally. The fusion of sexual nuclei is referred to the premitotic type. The primary endosperm nucleus may divide once or not, and degenerate on the 6th or 7th day after fertilization. The nucleoli of generative and vegetative nuclei in the pollen tube are conspicuous. Generally the sperms form after the contact between the generative cell and vegetative nucleus. The nucleoli of sperms are also clearly distinguished. Daring the fusion of male and female nuclei in fertilization two male nuclei always show the distinct nucleoli.     

抗苏云金杆菌毒素Cry1Ac粉纹夜蛾细胞系的特性研究

为了从离体细胞水平探讨昆虫对苏云金芽孢杆菌杀虫晶体蛋白的部分抗性机制,本文采用活化的Cry1Ac 毒素对粉纹夜蛾BTI-TN-581-4细胞连续筛选86代,获得了高水平抗性细胞,研究了其某些特性。它对Cry1c 产生了低水平的交互抗性,对低渗溶液的耐受性显著增强,双向电泳图谱表明抗性细胞膜蛋白组分发生了明显的变化。膜蛋白组分的变化可能导致了筛选细胞的耐低渗透压和抗Cry1C。     

DNA binding and pairing activity of OsDmc1, a recombinase from rice

A cloned cDNA corresponding to OsDMC1 from rice anther tissue was expressed in Escherichia coli. The OsDmc1 protein was largely present in the inclusion bodies of the cell lysatE., which was solubilized by 8.0 M urea containing buffeR., purified to homogeneity by Ni-CAM agarose column chromatography, followed by renaturation to its native state through stepwise dialysis against reduced concentrations of urea. The purified protein cross-reacted with anti-yeast Dmc1 antibodies. The binding efficiency observed with circular single-stranded DNA (ssDNA) was similar to that with circular double-stranded DNA (dsDNA). The binding to either DNA showed no ATP dependencE., but required 5–10 mM Mg²⁺ in the presence of ATP. Even though the protein binding to dsDNA was as efficient as it was to ssDNA, the former induced no DNA dependent ATPasE., whereas the binding to ssDNA stimulated a significant level of DNA dependent ATPase activity. OsDmc1–ssDNA complex, with its ATPase proficiency, also mediated renaturation of homologous complementary strands as well as assimilation of single strands into homologous supercoiled duplexes leading to D-loop formation. The D-loop formation was lowered by excess of OsDmc1 protein. This D-loop formation activity was promoted by non-hydrolyzable ATP analog, AMP-PNP and was not observed in absence of ATP or presence of ADP/ATP--S. These properties reflected the classical hallmarks of a recombinase and represented the first biochemical characterization of a plant Dmc1 protein.     

小鼠胚泡黏附时子宫内膜nm23-M1/NDPK A的表达

nm23家族除与肿瘤转移抑制有关,它还参与调节正常细胞的发育、增殖、分化及凋亡等过程。运用RT-PCR、Western blot 和免疫组织化学技术,分析小鼠胚泡黏附时子宫内膜着床点和着床旁组织nm23-M1/NDPK A 的表达,以未交配鼠作对照,为进一步阐明胚泡着床的机制提供有意义的实验依据。RT-PCR 结果显示,小鼠胚泡黏附时子宫内膜nm23-M1/NDPK A mRNA 表达明显高于对照组,并且着床点明显高于着床旁,Western blot 和免疫组织化学分析nm23-M1/NDPK A 蛋白表达,也得到一致的结果。提示nm23-M1/NDPK A 参与胚泡着床这一重要生命活动过程。     

1-Kestose consumption during pregnancy and lactation increases the levels of IgA in the milk of lactating mice

To examine the effect of dietary supplementation with 1-kestose on the IgA levels in milk, BALB/c mice were fed diets with or without 5% 1-kestose during pregnancy and lactation. The total and specific IgA levels in the milk were measured at 7 and 14?days after delivery. A two-way ANOVA with repeated measures resulted in a significant effect of 1-kestose-supplementation on total IgA concentrations (p?<?0.05) and the level of anti-Bacteroides IgA (p?<?0.05). A significant positive correlation was found between the mean count of Bacteroides spp. in maternal feces and the total IgA concentration in maternal milk (r?=?0.55, p?<?0.05), suggesting a potential link between the gut and mammary gland immune system. In conclusion, this study demonstrated the effects of dietary prebiotics on milk IgA production.     

转化生长因子-β_1单克隆抗体TB21的生物学特性(英文)

转化生长因子-β_1(TGF-β_1)是转化生长因子家族中的一个重要成员,具有多种生物学功能,特别是调节细胞的生长和分化,参与细胞外基质合成,创伤愈合和胚胎形态发生等生物学过程。近年来,发展了一些抗TGF-β_1多克隆抗体和个别重组人TGF-β_1的单克隆抗体,对研究各种细胞的TGF-β_1的合成,定位和其它生物学效应发挥了作用。本文报道了抗人血小板TGF-β_1单克隆抗体TB 21的制备及其主要生物学特性,尤其是它对TGF-β_1免疫识别的专一性,以及调变对TGF-β_1敏感细胞的生长和增殖抑制的活性。结果表明,TB_(21)单克隆抗体为IgG_1亚型;对TGF-β_1有较高亲和力,亲和常数(Kaff)为1.47×10~8M~(-1);Westernblot 显示TB_(21)抗体能专一地结合25 Kd 成熟型分子和其12.5 Kd 的单体分子,对CCL/64细胞生长抑制和对NRK-49 F 成纤维细胞软琼脂集落形成的鉴定都证明TB21单抗对TGF-β_1的生物学效应有专一性的中和作用,可用于TGF-β_1的有关生物学研究。     

缺氧诱导因子-1结构及功能的研究进展

缺氧诱导因子(hypoxia inducible factor-1,HIF-1)是一种介导机体对缺氧环境产生应答的转录因子。在炎症及实体肿瘤周围的组织大多存在缺氧现象。在缺氧条件下,HIF-1α和HIF-1β两个亚基结合,形成HIF-1并迅速活化,参与机体缺氧环境的适应,并在胚胎发育、多种肿瘤及心肺疾病等发生发展中起到重要作用。因此,更好地认识HIF-1的功能及意义,对进一步地认识与其相关生命过程和疾病本质以及研发新的治疗手段具有重要意义。     

The Compatibility of d-Pinitol and 1d-1-O-Methyl-Muco-Inositol with Malate Dehydrogenase Activity

Pinitol (1d -3-O-methyl-chiro-inositol) and 1d -1-O-methyl-muco-inositol, two cyclitols wide-spread in the plant kingdom, were isolated from plant sources in order to test their compatibility with malate dehydrogenase activity. Both compounds had no inhibitory effect on malate dehydrogenase from Rhizophora mangle in a range of 100 to 1000 mol . m^?3. Their influence on malate dehydrogenase activity from different plant sources (Rh. mangle L., Mesembryanthemum crystallinum L., Cicer arietinum L. and Spinacia oleracea L.) was also small and similar to that observed for a number of well established compatible solutes (e.g. proline, glycine betaine). A possible role of cyclitols as cryoprotectants or radical scavengers is discussed.     

LFA-1/ICAM-1在ConA诱导的小鼠胸腺细胞活化中的作用

用抗LFA-1/ICAM-1粘附分子单克隆抗体和ConA联合刺激小鼠胸腺细胞,初步研究了该膜分子在经TCR/CD3介导的胸腺细胞活化信号传导以及胸腺细胞亚群选择中的作用。在ConA刺激系统中,抗ALFA-1/ICAM-1单抗均能抑制胸腺细胞的增殖应答,且以抗LFA-1单抗的作用更为显著;而在PMA加钙离子载体A23187刺激体系中,抗LFA-1单抗却表现出明显的促活化效应。当加入IL-2 时,抗LFA——1/ICAM-1单抗便不能抑制ConA刺激的胸腺细胞活化。此外,抗体对已活化的胸腺母细胞增殖也无影响。FACS分析的结果还显示,抗LFA-1单抗可明显降低CD4~-CD8~ 胸腺细胞亚群的比例,而抗ICAM-1单抗对此无影响。表明胸腺细胞表面粘附分子LFA-1具有直接参与TCR/CD3途径介导的跨膜信号传导的功能,并对CD4~-CD8~ 胸腺细胞亚群的功能分化与成熟可能起重要作用。