天然和氧化低密度脂蛋白对人脐静脉内皮细胞VCAM-1表达的影响

目的探讨天然和氧化低密度脂蛋白(n-LDL,ox-LDL)对人脐静脉内皮细胞(HUVEC)VCAM-1表达的影响。方法将n-LDL,ox-LDL作用于培养的HUVEC,用细胞酶联免疫吸附试验(cellELISA)检测VCAM-1蛋白的表达,用原位分子杂交技术检测VCAM-1 mRNA的表达。结果正常培养的HUVEC可表达VCAM-1,n-LDL和ox-LDL均可增强培养的HUVEC表达VCAM-1,尤以ox-LDL作用更明显。结论n-LDL、ox-LDL可能通过促进血管内皮细胞表达VCAM-1而在动脉粥样硬化的早期事件中起作用。     

高脂高糖饮食对自发性高血压大鼠腹主动脉舒张功能及VCAM-1和ICAM-1mRNA表达的影响

目的:探讨高脂高糖饮食对自发性高血压大鼠(spontaneously hypertensive rats,SHR)腹主动脉血管舒张功能及血管间粘附分子-1 (vascular adhesion molecule-1,VCAM-1)和细胞间粘附分子-1(intercellular adhesion molecule-1,ICAM-1)mRNA表达的影响.方法:将24只6周龄雄性SHR大鼠随机分成高脂高糖饲料组(实验组,n=12)和普通饲料组(对照组,n=12).每3周测量其空腹体重,12周后处死大鼠,分别取两组动物的腹主动脉做离体血管环对乙酰胆碱(Acetylcholine,Ach)的舒张功能实验,并提取主动脉总RNA,通过实时定量RT-PCR实验检测其VCAM-1和ICAM-1 mRNA的表达.结果:从第6周开始,实验组SHR的体重较对照组明显增加(P＜0.01).12周时,实验组血管环对Ach的最大舒张率较对照组明显降低(69.20± 5.25 vs.79.10± 3.84,P＜0.01);实验组动脉VCAM-1 mRNA的相对表达量是对照组的1.97倍,差异有统计学意义(197.91±22.16 vs.100.33±11.44,P＜0.01),而两组ICAM-1mRNA表达的比较差异无统计学意义(97.75±8.05 vs.100.25±10.83,P＞0.05).结论:高脂高糖饮食能致SHR腹主动脉血管舒张功能明显降低,可能与其显著增加其主动脉VCAM-1 mRNA的表达有关.     

全反式维甲酸对兔动脉粥样硬化病灶中MCP-1 和TLR-4

目的:观察全反式维甲酸(ATRA)对兔颈动脉粥样硬化性病灶中内膜增生、MCP-1及TLR-4表达的影响,探讨其可能的抗炎机制。方法:新西兰雄性大白兔随机分为9组(n=6):对照组(A、B、C)、治疗组(A、B、C)、假手术组(A、B、C)。除假手术组外,其余两组给予高脂饮食2周后,对照组及治疗组给予颈动脉内膜空气干燥术损伤颈动脉内膜,假手术组分离暴露颈动脉但不损伤内膜,治疗组术前3天给予ATRA灌胃,直至处死。术后分别于7d、14d、28d处死。采取颈动脉标本,对血管粥样硬化病变进行形态学观察及测定,采用免疫组化法检测MCP-1及TLR-4表达水平。结果:从形态学观察及免疫组化检测看,对照组较假手术组内膜明显增生,MCP-1及TLR-4表达增多,治疗组内膜较对照组增生减轻,两种因子表达减少。结论:全反式维甲酸(ATRA)对兔颈动脉粥样硬化性病灶中的抗炎作用可能是通过抑制MCP-1及TLR-4等炎症因子的表达来发挥作用的。     

激活多巴胺Ⅰ类受体对氧化性低密度脂蛋白诱导的人单核细胞THP-1分泌NO/NOS的影响

目的:探讨激活多巴胺Ⅰ类受体(DR1)对氧化型低密度脂蛋白(ox-LDL)诱导的人单核细胞(THP-1)分泌一氧化氮/一氧化氮合酶(NO/NOS)的影响及可能机制。方法:THP-1细胞经佛波酯PMA诱导分化,分为正常对照组(control),氧化型低密度脂蛋白处理组(ox-LDL),DR1激动剂干预组(SKF),DR1阻断剂干预组(SCH),ERK阻断剂干预组(PD98059);应用油红O染色法鉴定泡沫细胞;硝酸还原法检测NO、NOS的变化情况;免疫荧光和Western blot检测各组细胞蛋白表达情况。结果:ox-LDL刺激48 h可形成泡沫细胞;DR1在THP1细胞上表达,oxLDL刺激后,DR1蛋白表达降低(P0.01);激活DR1受体能够明显抑制由ox-LDL引起的NO、i NOS增多(P0.01);在MAPK阻断剂PD98059存在的情况下,SKF的作用部分丧失。结论:激活DR1受体可抑制ox-LDL引起的THP-1细胞NO的大量产生,此过程可能由ERK信号通路所介导。     

扇贝裙边糖氨聚糖对泡沫细胞形成过程中血管内皮生长因子表达的影响

目的:研究扇贝裙边糖氨聚糖时氧化低密度脂蛋白(ox-LDL)诱导的U937细胞泡沫化过程中血管内皮生长因子(VEGF)的影响,探讨其抗动脉粥样硬化作用的机理。方法:采用U937细胞与80mg/L的ox-LDL孵育48h建立U937泡沫细胞模型。将培养的U937细胞随机分为六组,正常对照组、模型组(ox-LDL)、肝素对照组(ox-LDL加100mg/L肝素)和低、中、高浓度的SS-GAG药物组(ox-LDL加200mg/L,400mg/L,800mg/L的SS-GAG)。采用酶联免疫吸附实验(ELISA)检测细胞分泌的VEGF的量,观察不同浓度SS-GAG对U937细胞泡沫化过程中VEGF表达量的影响。结果:培养的U937泡沫细胞中VEGF的表达量明显高于正常U937细胞(P＜0．01),而加入SS-GAG的药物组和肝素对照组则有不同程度降低,以800mg/mL药物组降低最为明显(P＜0．01)。结论:泡沫细胞形成过程中伴有VEGF的高表达,SS-GAG能够抑制其表达从而发挥抗动脉粥样硬化作用。     

BET蛋白通过调控NF-κB通路参与炎症基因转录

目的:探讨特异性抑制溴结构域(bromodomain and extra-terminal,BET)蛋白对血管内皮细胞激活与早期动脉粥样硬化形成的作用及其分子机制。方法:1.原代分离培养脐静脉内皮细胞和小鼠心脏血管内皮细胞后用肿瘤坏死因α(TNFα)刺激模拟炎症过程,以小分子化合物JQ1特异性抑制BET蛋白,分组如下:(1)对照组;(2)TNFα(25 ng/m L)处理组;(3)TNFα+JQ1处理组。采用Realtime-PCR及流式细胞术检测各组细胞炎症因子m RNA及蛋白水平的表达,采用5XκB荧光素酶报告基因检测各组核转录因子kappa B(NF-κB)转录活性。2.LDL受体基因敲除(LDLR-/-)小鼠随机分为2组:JQ1组(n=8,JQ1腹腔注射,50 mg/kg,每天一次)和对照组(n=8,DMSO溶媒组),同时给予高胆固醇饮食8周,采用免疫组化方法检测主动脉弓部血管细胞黏附分子-1(VCAM-1)表达水平。结果:与对照组相比,TNFα组炎症因子m RNA、蛋白表达明显上调(P0.01),使用JQ1干预后,炎症因子E选择素(E-selectin)、P选择素(P-selectin)、VCAM-1及白细胞介素-8(IL-8)m RNA及蛋白表达均明显下调(P0.01)。LDLR-/-小鼠高脂饮食诱导8周后JQ1显著下调了主动脉弓部VCAM-1蛋白表达。5XκB荧光素酶报告基因结果显示,与TNFα(-)相比,TNFα(+)组荧光素酶报告基因活性增强,JQ1可以显著下调报告基因活性(P0.01)。结论:BET蛋白通过调控NF-κB信号通路参与了血管内皮炎症基因转录;抑制BET蛋白下调了NF-κB目的基因表达从而减轻了内皮激活及高脂诱导的早期动脉粥样硬化病理改变。     

葛根素延缓动脉粥样硬化进展的机制研究

目的:明确葛根素(Pur)对小鼠动脉粥样硬化斑块稳定性的治疗作用及其潜在机制。方法:用高脂饮食喂养成年小鼠诱导动脉粥样硬化模型,将小鼠分为Con组,ApoE~(-/-)组,ApoE~(-/-)+Pur组。采用HE染色分别检测各组小鼠中动脉粥样硬化斑块面积,免疫荧光染色检测斑块中MMP2的阳性区域面积。用50μg/mL ox-LDL干预巨噬细胞诱导动脉粥样硬化细胞模型,并用Ad-sh-Sirt3干扰Sirt3表达,将细胞分为Con组、ox-LDL组、ox-LDL+Pur组、ox-LDL+Pur+Ad-sh-Sirt3组。Western-blot检测Sirt3表达含量,TUNEL法检测巨噬细胞凋亡。结果:动物水平,与Con组相比,ApoE~(-/-)组小鼠出现了显著的动脉粥样硬化斑块,ApoE~(-/-)组小鼠MMP2阳性区域面积显著高于Con组(P0.05);Pur处理后,ApoE~(-/-)+Pur组动脉粥样硬化斑块面积明显低于ApoE~(-/-)组(P0.05),MMP2的阳性区域面积显著低于ApoE~(-/-)组(P0.05)。细胞水平,Western结果显示,与对照组相比,ox-LDL组Sirt3表达量显著降低(P0.05),ox-LDL+Pur组Sirt3表达水平显著高于ox-LDL组(P0.05)。相比于Con组,ox-LDL组巨噬细胞凋亡水平显著升高(P0.05);给予Pur处理后,相比于单纯ox-LDL组,ox-LDL+Pur组巨噬细胞的凋亡水平显著降低(P0.05)。Ad-sh-Sirt3处理消除了葛根素对于巨噬细胞凋亡的抑制作用(P0.05)。结论:外源性Pur可能通过激活Sirt3表达,进一步降低巨噬细胞凋亡水平,减少巨噬细胞的浸润,增加动脉粥样硬化斑块稳定性。     

藻蓝蛋白联合全反式维甲酸对HeLa细胞生长抑制作用的研究(英文)

目的:探讨全反式维甲酸和藻蓝蛋白单独及联合用药对HeLa细胞生长的影响,并揭示两者联合用药对细胞周期和细胞凋亡影响的分子机制。方法:MTT法检测全反式维甲酸和藻蓝蛋白单独及联合用药对HeLa细胞生长的影响,原位杂交法检测用药前后细胞内CDK-4基因mRNA的表达情况,免疫组化法检测用药前后bcl-2基因的表达情况,TUNEL法检测用药前后细胞凋亡情况。结果:全反式维甲酸和藻蓝蛋白均具有抑制HeLa细胞生长的作用,当达到相同的抑制率时,联合藻蓝蛋白使用可以显著降低全反式维甲酸的使用剂量从而达到降低毒副作用的目的。两者联合用药可以显著降低CDK-4的表达量从而对HeLa细胞的细胞周期产生影响。两者联合用药可以显著下调bcl-2的表达水平从而引发细胞凋亡。结论:通过联合藻蓝蛋白,可以显著降低全反式维甲酸的使用剂量从而降低毒副作用。全反式维甲酸和藻蓝蛋白联合用药抑制HeLa细胞生长的分子机制可能是通过抑制CDK-4和bcl-2的表达来影响细胞周期并最终导致细胞凋亡。     

熊果酸对ox-LDL诱导的人脐静脉血管内皮细胞NQO1表达的影响(英文)

目的:研究熊果酸对经氧化性低密度脂蛋白(ox-LDL)干预后人脐静脉血管内皮细胞(human umbilical vein endothelial cells,HUVECs)醌还原氧化酶1表达的影响,以进一步探讨熊果酸抗动脉粥样硬化的机制。方法:体外培养人脐静脉内皮细胞,进行分组处理,每组n=5。对照组,不加任何处理;ox-LDL组,加入ox-LDL培养24h,终浓度为20mg/L;ox-LDL+低浓度熊果酸组,先加入ox-LDL(浓度20mg/L)孕育半小时,然后与熊果酸(浓度1.5μmlo/L)共同培养24h;ox-LDL+高浓度熊果酸组,先加入ox-LDL(浓度20mg/L)孕育半小时,然后与熊果酸(浓度4.5μmlo/L)共同培养24h;采用MTT试验测定细胞吸光度值,检测熊果酸对ox-LDL损伤的保护作用,采用RT-PCR法检测NQO1mRNA的表达,采用Western blot法检测NQO1蛋白的表达。结果:熊果酸减弱ox-LDL对HUVECs的损伤作用;ox-LDL组NQO1mRNA的表达量(0.624±0.009)明显高于对照组(0.521±0.007),P0.01。熊果酸呈浓度依赖性的提高NQO1mRNA的表达量(ox-LDL+低浓度熊果酸组vs ox-LDL组:0.722±0.058 vs 0.624±0.009,P0.01;ox-LDL+高浓度熊果酸组vs ox-LDL组:0.826±0.059 vs 0.624±0.009,P0.01)。ox-LDL组NQO1蛋白的表达量(0.624±0.009)明显高于对照组(0.521±0.007),P0.01。熊果酸呈浓度依赖性的提高NQO1蛋白的表达量(ox-LDL+低浓度熊果酸组vs ox-LDL组:0.710±0.058 vs 0.574±0.024,P0.01;ox-LDL+高浓度熊果酸组vs ox-LDL组:0.831±0.034 vs 0.574±0.024,P0.01)。结论:熊果酸可上调ox-LDL诱导的人脐静脉血管内皮细胞NQO1的表达,表明其可能具有抗氧化应激及抗动脉粥样硬化的作用。     

炎症促进大鼠动脉粥样硬化初期内皮功能病变机制研究

目的:观察炎症因素诱导大鼠动脉粥样硬化发病过程中对血管内皮细胞的影响。方法:实验分为单纯高脂对照组和炎症组,分别腹腔注射给予无菌医用液体石蜡和酵母多糖(Zym,20mg/kg,1次/3天)。所有大鼠均喂食含3%胆固醇的高脂饲料,共8周。透射电镜观察主动脉超微结构;应用定量PCR法测定腹主动脉组织中诱导型一氧化氮合酶(iNOS)mRNA、血管细胞粘附分子(VCAM)-1 mRNA、以及基质金属蛋白酶7(MMP7)mRNA的表达。结果:炎症组可见游走于内膜下层的平滑肌细胞和和吞噬脂质颗粒的单核细胞,单纯高脂对照组仅见内皮细胞损伤和退行性变,未见内膜下层形成泡沫细胞,AS样病变较炎症组轻。与对照组相比,炎症组动脉壁iNOS mRNA表达降低,VCAM-1 mRNA及MMP7 mRNA标大量显著升高。结论:炎症刺激能够损伤动脉血管内皮细胞,诱导炎症因子释放增加,促进动脉粥样硬化的发生。     

Land,livestock, and livelihoods: Changing dynamics of gender,caste, and ethnicity in a Nepalese Village

Over the past 10 years, Ghusel VDC, Lalitpur District has moved from primarily subsistence agriculture into the wider cash economy aided by the Small Farmers' Development Program (SFDP), which provides credit to farmers mainly for the purchase of buffalo for milk production, and by the National Dairy Corporation, which supports local dairy cooperatives. Analysis reveals that buffalo-keeping and milk sales are increasing the well-being of many households, while at the same time creating new inequalities in gender roles and responsibilities, greater inequities between Brahmin and Tamang residents in Ghusel, and placing pressures on the ecosystem for increased supplies of fodder and fuelwood. Evidence suggests that there is critical, need for attention to the social, and particularly gender-based, implications of maintaining livestock for milk sales and to the ecological underpinnings of this livelihood system.     

Influence of Fluoride on Rat Kidney Antioxidant System: Effects of Methionine and Vitamin E

The aim of the study has been to determine and compare the influence upon the kidney antioxidative system, exercised by administration of vitamin E, and vitamin E in combination with methionine, under conditions of oxidative stress induced by sodium fluoride. The experiment was carried out on Wistar FL rats (adult males) that, for 35 days, were administered water, NaF, NaF with vitamin E, or vitamin E with methionine (doses: 10 mg NaF/kg of body mass/24 h, 3 mg vitamin E per 10 μl per rat for 24 h, 2 mg methionine per rat for 24 h). The influence of administered sodium fluoride and antioxidants upon the antioxidative system in kidney was examined by analyzing the concentration of malondialdehyde (MDA) and the activity of the most important antioxidative enzymes (SOD, total and both its isoenzymes, GPX, GST, GR, and CAT). The studies carried out confirmed the disadvantageous effect of the administered dose of NaF upon the antixodiative system in rats (increase in the concentration MDA, decrease activity of all antioxidative enzymes). The administration of vitamin E increased the activity of studied enzymes with the exception of glutathione reductase GR; it also reduced the procesess of lipid peroxidation. It has been found that combined doses of vitamin E and methionine were most effective in inhibiting lipid peroxidation processes. The results confirmed the antioxidative properties of methionine.     

Reorientation of Microfibrils and Microtubules at the Outer Epidermal Wall of Maize Coleoptiles During Auxin-Mediated Growth

Auxin-mediated elongation growth of isolated subapical coleoptile segments of maize (Zea mays L.) is controlled by the extensibility of the outer cell wall of the outer epidermis (Kutschera et al., 1987). Here we investigate the hypothesis that auxin controls the extensibility of this wall by changing the orientation of newly deposited microfibrils through a corresponding change in the orientation of cortical microtubules. On the basis of electron micrographs it is shown that cessation of growth after removal of the endogenous source of auxin is correlated with a relative increase of longitudinally orientated microfibrils and microtubules at the inner wall surface. Conversely, reinduction of growth by exogenous auxin is correlated with a relative increase of transversely orientated microfibrils and microtubules at the inner wall surface. These changes can be detected 30–60 min after the removal and addition of auxin, respectively. The functional significance of directional changes of newly desposited wall microfibrils for the control of elongation growth is discussed.     

多马胺能药物对鲇鱼促性腺激素（GtH）分泌活动的影响

以珠江流域鲇鱼（silurus asotus)为实验材料,研究了多巴胺（DA）能药物（DA及其D－2型受体拮抗物 ,DOM）对鲇鱼促性腺激素（GtH)释放的影响,结果表明,在性腺发育的各个时期,单独注射DOM（5ug/g)均不能显著提高鲇鱼血液基础GtH水平,当DOM与LHRH－A联合注射时能显著增强LHRH－A刺激GtH释放的作用;DA只能抑制GnRH诱导的GtH释放,对基础GtH释放无抑制作用,这种生殖内分泌调节方式与鲇形目的革胡子鲇（Clarias gariepinus)和大鳍Hu（Mystus macropterus)相似,而与鲤形目的鲁科（Cyrpindiae)鱼类不同。     

Identification of specific binding sites for leukotriene C4 in human fetal lung

Specific leukotriene C₄ (LTC₄) binding sites were identified in membrane preparations from human fetal lung. Specific binding of [³H]-LTC₄ represented 95 percent of total binding, reached steadystate within 10 minutes and was rapidly reversible upon addition of excess unlabeled LTC₄. Binding assays were performed at 4°C under conditions which prevented metabolism of [³H]-LTC₄ (80 mM serineborate, 10 mM cysteine, 10 mM glycine). Under these conditions, greater than 95 percent of the membrane bound radioactivity, as analyzed by high performance liquid chromatography, co-eluted with the LTC₄ standard. Computer-assisted analyses of saturation binding data showed a single class of binding sites with a dissociation constant (K_d) of 26 + 6 nM and a density (B_max) of 84 ± 18 pmol/mg protein. Pharmacological specificity was demonstrated by competition studies in which specific binding of [³H]-LTC₄ was displaced by LTC₄ and its structural analogs with inhibition constants (K_j) of 10 to 30 nM, whereas LTD₄, diastereoisomers of LTD₁, LTE₄ and the end organ antagonist FPL 55712 were 150 to 700 fold less potent competitors than LTC₄. These results provide evidence for specific, reversible, saturable, high affinity binding sites for [³H]-LTC₄ in human fetal lung membranes.     

Gamma-glutamylcysteine protects ergothioneine-deficient Mycobacterium tuberculosis mutants against oxidative and nitrosative stress

Mycobacterium tuberculosis (M.tb.), the causative agent of tuberculosis (TB), cannot synthesize GSH, but synthesizes two major low molecular weight thiols namely mycothiol (MSH) and ergothioneine (ERG). Gamma-glutamylcysteine (GGC), an intermediate in GSH synthesis, has been implicated in the protection of lactic acid bacteria from oxidative stress in the absence of GSH. In mycobacteria, GGC is an intermediate in ERG biosynthesis, and its formation is catalysed by EgtA (GshA). GGC is subsequently used by EgtB in the formation of hercynine-sulphoxide-GGC. In this study, M.tb. mutants harbouring unmarked, in-frame deletions in each of the fives genes involved in ERG biosynthesis (egtA, egtB, egtC, egtD and egtE) or a marked deletion of the mshA gene (required for MSH biosynthesis) were generated. Liquid chromatography tandem mass spectrometry analyses (LC-MS) revealed that the production of GGC was elevated in the MSH-deficient and the ERG-deficient mutants. The ERG-deficient ΔegtB mutant which accumulated GGC was more resistant to oxidative and nitrosative stress than the ERG-deficient, GGC-deficient ΔegtA mutant. This implicates GGC in the detoxification of reactive oxygen and nitrogen species in M.tb.     

Tuning of electronic properties of one-dimensional cyano-bridged Cu-Ni, Cu-Pd, and Cu-Pt bimetallic assemblies by stereochemistry of ligands

Preparations, XPS and electronic spectroscopy, and magnetism of seven new one-dimensional cyano-bridged coordination polymers, chiral [Cu(RR-chxn)₂][Pd(CN)₄] · 2H₂O (1), [Cu(trans-chxn)₂][M(CN)₄] · 2H₂O (2, 4, and 6 for M = Pd, Ni, and Pt), and [Cu(cis-chxn)₂][M(CN)₄] · 2H₂O (3, 5, and 7 for M = Pd, Ni, and Pt) (RR-chxn = cyclohexane-(1R,2R)-diamine, trans-chxn = racemic trans-cyclohexane-(1,2)-diamine, and cis-chxn = racemic cis-cyclohexane-(1,2)-diamine) have been reported in view of tuning of their electronic properties by stereochemistry of chxn ligands and metal-substitution. Comparison of Cu 2p_1/2 and 2p_3/2 peaks of XPS and broad d-d bands around 18 000 cm⁻¹ of electronic spectra are described systematically for 1-7. Variable-temperature magnetic measurement shows that complexes 1-7 indicate weak antiferromagnetic interactions via cyano-bridges. Because of semi-coordination coupled with pseudo Jahn-Teller elongation and electrostatic interaction for 1, the axial Cu-N coordination bond distances of 2.330(7) and 3.092(8) Å are considerably longer than those of equatorial ones in the range from 2.016(6) to 2.030(6) Å. The former bond distances of 1 are intermediate values among the related Ni (2.324(6) and 3.120(8) Å) and Pt (2.34(1) and 3.09(1) Å) complexes.     

Interactions of an antitumor platinum compound with deoxyribonucleic acid, histones, L-amino acids, poly-L-amino acids, nucleosides and nucleotides

Interaction of cis-dichloro(dipyridine)platinum(II) (cis-PPC) with calf thymus DNA, calf thymus histone, l-amino acids, poly-l-amino acids, nucleosides, and nucleotides has been evaluated by equilibrium dialysis technics. At least a 28 % decrease in the association of cis-PPC with DNA occurs when the platinum compound is pre-incubated with l-amino acids. The greatest decrease in association is seen upon pre-incubation of the platinum compound with the free amino acids. Glut, Asp, Lys, Arg, and CySH, before the addition of a sack containing a solution of DNA. The low level of association between DNA and the amino acids tends to rule out competition between cis-PPC and amino acids for DNA association sites. cis-PPC was repelled from sacks containing positively charged poly-l-Lys, poly-l-Arg, and calf thymus histone; however, in the presence of poly-l-Glut and poly-l-Asp, cis-PPC associated with these negatively charged polymers to a considerable degree. Enhanced chloride dissociation from cis-PPC was observed in the presence of all of the amino acids and the nucleotides GMP, CMP, UMP, and TMP, but not in the presence of AMP or the nucleosides rG and dG. In the presence of calf thymus histone, the association of cis-PPC with calf thymus DNA was reduced by more than 50% at histone/DNA ratios of 0.8–1.0.These data suggest that cis-PPC or cis-Pt(II) may associate with electron-rich areas of not only nucleic acids and proteins but also with body pools of free nucleotides and amino acids. The presence of positively charged histones shielding DNA strands in vivo suggests that the most probable point of platinum-DNA association would be at de-repressed areas of DNA which are undergoing RNA synthesis. The aquated form of the platinum complex may also associate with acidic proteins which appear to be involved in the positive control of RNA synthesis and, as a result, this interaction may be of pharmacological significance.     

八种脑-肠肽侧脑室内注射对大鼠基础胃酸分泌的影响

用乌拉坦麻醉大鼠作急性实验,采用连续灌流胃并收集流出液的方法,观察向侧脑室内注射微量脑-肠肽对大鼠基础胃酸分泌的影响。实验结果如下:(1)雨蛙肽、八肽胆囊收缩素、促甲状腺素释放激素及四肽胃泌素均使总酸排出量增加;(2)生长抑素、胰多肽、P 物质、胰高血糖素则使总酸排出量减少;(3)上述肽类用侧脑室注射的剂量作肌肉注射,除四肽胃泌素也产生明显的刺激胃酸分泌作用外,对胃酸分泌均无明显影响。以上结果提示,脑内的一些肽类可能以神经递质或调制物的方式,参与中枢对胃酸分泌的调节。     

In vitro studies of the rabbit immune system. IV. Differential mitogen responses of isolated T and B cells.

The mitogenic responses of separated rabbit lymphocyte populations functionally analogous to mouse T and B cells have been tested in vitro. Purified T cells were prepared by passage over nylon wool (NW) and purified B cells prepared by treatment with antithymocyte serum and complement (ATS + C). ATS + C kills 70% of peripheral blood lymphocytes (PBL's) and 50% of the spleen cells while passage over NW yields 40% of the applied PBL's and 5–23% of the applied spleen cells. NW-purified T cells from the spleen or PBL's respond fully to concanavalin A (Con A) but have a reduced response to phytohemaglutinin (PHA) and little or no response to goat anti-rabbit immunoglobulin (anti-Ig). PBL's that survive ATS + C (B cells) are stimulated by anti-Ig but not by Con A or PHA. B cells purified from spleen do not respond to Con A or PHA but will respond to anti-Ig under appropriate conditions. A full spleen B-cell response to anti-Ig required removal of Ig produced by the cultures that blocked anti-Ig stimulation. It is concluded that, for rabbit lymphocytes, Con A and PHA are primarily T-cell mitogens and that anti-Ig is primarily a B-cell mitogen. However, the mitogen response of unfractionated PBL or spleen cell populations indicates an overlap in reactivity. This could be due to cells sharing T and B properties, alteration of cell populations by the fractionation procedures used, or recruitment of one population in the presence of a mitogenic response of the other population.