MSG-肝再生-大鼠下丘脑神经细胞凋亡及相关基因TGF-β1的表达

目的：探讨MSG－肝再生－大鼠下丘脑神经细胞凋亡的机理。方法：光镜、电镜及原位末端标记技术观察MSG－肝再生－大鼠下丘脑弓状核神经细胞凋亡;免疫组织化学方法观察ARN的TGF－β1的表达。结果：随着ARN神经细胞凋亡指数（AI）增高,其TGF－β1表达亦相应增强。结论：神经元胞浆钙离子过度负荷和TGF－β1蛋白共同参与了MSG－肝再生－大鼠ARN神经细胞凋亡的调控。     

谷氨酸单钠化大鼠弓状核对束旁核痛单位放电的影响

下丘脑弓状核(ARC)是脑内β-内啡肽(β-end)能神经元胞体主要集中的核团(Bloom et al.,1978;Finley et al., 1981)。刺激大鼠ARC能明显抑制丘脑束旁核(PF)痛单位的诱发放电,而且,这种抑制效应可被吗啡受体阻断剂纳洛酮所阻断(陈向阳等,1986)。 新生期大鼠腹腔注射谷氨酸单钠(Monosodium Glutamate,MSG)能选择性地破坏ARC区神经元胞体(Krieger et al.,1979)。本实验在新生期注射MSG的成年大鼠上观察刺激ARC对PF痛单位放电的影响,以进一步探讨ARC在痛觉调制中的作用。     

损毁和刺激下丘脑弓状核区对大鼠脑和脊髓内亮-脑啡肽、多巴胺、去甲肾上腺素含量的影响

本工作分别采用新生期大鼠注射谷氨酸-钠(MSG)损毁弓状核区及电刺激弓状核(ARC)区的方法,观察对脑和脊髓内亮-脑啡肽(LEK)、多巴胺(DA)和去甲肾上腺素(NE)含量的影响。MSG 大鼠脑和脊髓内 LEK、NE 含量较对照组无明显变化,但端脑内 DA 含量显著升高。刺激 ARC 区后脊髓内 NE 含量明显上升。上述结果提示:弓状核区对端脑 DA 能系统可能具有某种紧张性抑制作用,而刺激弓状核产生的镇痛效应可能和下行 NE 能系统有一定关系。     

损毁弓状核区对大鼠脑内β-内啡肽、5-羟色胺、去甲肾上腺素含量及其对针刺镇痛的影响

下丘脑弓状核区是脑内合成β-内啡肽等物质的主要部位,并与脑内中缝背核、蓝斑等结构有密切的交互纤维支配。本实验用新生期大鼠注射谷氨酸—钠(MSG)损毁弓状核区的方法,观察对脑内β-内啡肽、5-羟色胺、去甲肾上腺素含量及针刺镇痛的影响。MSG 处理组大鼠下丘脑弓状核神经元减少72%左右,脑β-内啡肽含量降低67%,针刺镇痛效应明显下降,电针后脑去甲肾上腺素含量明显高于电针对照组;将 MSG 处理大鼠的垂体摘除后,针刺镇痛效应几乎消失,同时电针后脑去甲肾上腺素含量则显著高于单纯 MSG处理组。本文对可能的机理进行了讨论。     

兴奋性氨基酸加强高原低氧大鼠下丘脑前生长抑素原mRNA的表达

目的和方法：应用大鼠高原低氧模型及原位杂交技术和氨基酸测定法,研究下丘脑前生长抑素原（ＰＰＳ）ｍＲＮＡ表达和谷氨酸（Ｇｌｕ）、天门冬氨酸（Ａｓｐ）含量的变化。结果：高原低氧组大鼠下丘脑Ｇｌｕ和Ａｓｐ的含量明显增多,室周核、室旁核、弓状核ＰＰＳ－ｍＲＮＡ阳性神经元数目显著增加;而ＮＭＤＡ受体拮抗抗剂氯铵酮,虽然对Ｇｌｕ和Ａｓｐ含量无明显影响,但可使高原低氧大鼠下丘脑ＰＰＳ－ｍＲＮＡ阳性神经元数目减少     

褪黑素减弱大鼠下丘脑弓状核β-内啡肽免疫反应的强度

为探讨褪黑素（ＭＥＬ）镇痛作用的机制,本文采用免疫组化方法结合计算机图像处理技术,观察了注射ＭＥＬ对大鼠下丘脑弓状核内神经细胞的β－内啡肽免疫反应的影响。实验大鼠分约药组及对照组,分别腹腔注射ＭＥＬ１１０ｍｇ／ｋｇ或配药液,１ｈ后灌注取脑、冰冻切片,进行免疫组化染色,计算机图像处理技术测定染色脑片积分光密度（ＩＯＤ）和平均光密度（ＯＤ）。结果显示,给药组大鼠弓状核内β－内啡肽免疫反应明显减弱,ＩＯ     

四种小哺乳动物四肢长骨重量配置分析

统计分析了甘肃鼢鼠Myospalax cansus、SD大鼠Rattus norvegicus、高原鼠兔Ochotona curzoniae及根田鼠Microtus oeconomu四种小哺乳动物四肢长骨(肱骨、桡尺骨、股骨和胫腓骨)重量分布和相互关联性.结果表明:1)与其他三种动物不同,甘肃鼢鼠前肢长骨重量大于后肢,且桡尺骨重量大于肱骨,体现了地下啮齿类对大量挖掘活动的适应性进化;2)SD大鼠和高原鼠兔虽然隶属不同的科,生活史特征迥异,其四肢长骨重量的分布却具有趋同性;3)四种动物不同骨骼重量之间都呈现出极显著相关性,然而其相关系数大小却表现为甘肃鼢鼠>SD大鼠>根田鼠>高原鼠兔,反映了不同挖掘强度的物种对四肢长骨之间协调性有不同要求;4)在重量百分比相互关系上,近端长骨(肱骨或股骨)和远端长骨(桡尺骨或胫腓骨)之间呈现出负相关关系,而近端或远端长骨之内仅有甘肃鼢鼠的肱骨和股骨呈现出显著正相关关系,显示近端骨骼和远端骨骼分属两类相互竞争的资源投资模块.     

性激素反馈调节下丘脑ARC和AVPV中kisspeptin-GPR54信号通路的核团差异

下丘脑-垂体-性腺（HPG）轴是调控生殖系统的发育和功能的重要内分泌系统。下丘脑中促性腺激素释放激素（GnRH）神经元,能够接收各种神经传导物质和神经调节物质的信号输入,引起HPG轴的级联反应。下丘脑弓状核(ARC）和前腹侧脑室周围核团(AVPV）中的kisspeptin-GPR54信号通路,可以调控GnRH的分泌和释放,影响性腺激素的分泌。近年来研究发现,性激素能够对下丘脑kisspeptin-GPR54信号通路产生反馈调节,且具有核团差异性。本文就性激素在下丘脑ARC和AVPV中对kisspeptin-GPR54信号通路反馈调节的差异性进行了综述,探讨下丘脑中不同核团对性激素刺激作用产生的不同反应。     

电磁脉冲（EMP）辐照对雄性子代大鼠下丘脑GABA_A受体表达的影响

目的：观察电磁脉冲（EMP）辐照亲代大鼠后其雄性子代下丘脑GABAA受体表达的变化。方法：应用免疫组织化学及图像分析观察亲代大鼠接受EMP辐照后其雄性子代下丘脑GABAA受体表达的变化。结果：与对照组相比,100次脉冲组其雄性子代下丘脑室旁核GABAA受体阳性神经元增加,400次脉冲组光密度值显著增强;100次和400次脉冲组弓状核GABAA受体阳性神经元增加,光密度值增强。结论：电磁脉冲可以影响雄性子代下丘脑GABAA受体的表达,这可能与电磁脉冲辐射产生的远期遗传毒性有关。     

下丘脑弓状核PYY对大鼠摄食、胃运动和能量代谢的影响及机制

目的:探究YY肽(PYY)对雄性Wistar大鼠的摄食、胃运动和能量代谢的影响及潜在机制。方法:采用免疫组织化学实验方法观察大鼠下丘脑弓状核(ARC)中Y2受体的表达;通过ARC微量注射PYY,观察其对下丘脑中编码摄食相关代谢激素的m RNA表达以及ARC中PYY反应性神经元的放电频率、食物摄入量及水摄入量、氧气消耗(VO_2)、CO_2产生(VCO_2)及能量代谢的影响。结果:免疫组化结果显示大鼠ARC内存在Y2受体;大鼠ARC注射PYY能够兴奋PYY反应性神经元,上调可卡因-苯丙胺调节转录肽(CART)及促肾上腺皮质释放激素(CRH)等抑食肽m RNA的表达,下调神经肽Y(NPY)及下丘脑泌素(HCRT)等促食肽m RNA的表达;且抑制大鼠食物摄入量,并参与调控大鼠呼吸、能量代谢及胃运动的改变。结论:ARC微量注射PYY可减少食物摄入并调节全身能量平衡,PYY可能是一种新型代谢肽。     

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.     

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.     

Structure and function of S-adenosylhomocysteine hydrolase

In mammals, S-adenosylhomocysteine hydrolase (AdoHcyase) is the only known enzyme to catalyze the breakdown of S-adenosylhomocysteine (AdoHcy) to homocysteine and adenosine. AdoHcy is the product of all adenosylmethionine (AdoMet)-dependent biological transmethylations. These reactions have a wide range of products, and are common in all facets of biometabolism. As a product inhibitor, elevated levels of AdoHcy suppress AdoMet-dependent transmethylations. Thus, AdoHcyase is a regulator of biological transmethylation in general. The three-dimensional structure of AdoHcyase complexed with reduced nicotinamide adenine dinucleotide phosphate (NADH) and the inhibitor (1′R, 2′S, 3′R)-9-(2′,3′-dihyroxycyclopenten-1-yl)adenine (DHCeA) was solved by a combination of the crystallographic direct methods program, SnB, to determine the selenium atom substructure and by treating the multiwavelength anomalous diffraction data as a special case of multiple isomorphous replacement. The enzyme architecture resembles that observed for NAD-dependent dehydrogenases, with the catalytic domain and the cofactor binding domain each containing a modified Rossmann fold. The two domains form a deep active site cleft containing the cofactor and bound inhibitor molecule. A comparison of the inhibitor complex of the human enzyme and the structure of the rat enzyme, solved without inhibitor, suggests that a 17° rigid body movement of the catalytic domain occurs upon inhibitor/substrate binding.     

Chiral Separation of G‐type Chemical Warfare Nerve Agents via Analytical Supercritical Fluid Chromatography

Chemical warfare nerve agents (CWNAs) are extremely toxic organophosphorus compounds that contain a chiral phosphorus center. Undirected synthesis of G‐type CWNAs produces stereoisomers of tabun, sarin, soman, and cyclosarin (GA, GB, GD, and GF, respectively). Analytical‐scale methods were developed using a supercritical fluid chromatography (SFC) system in tandem with a mass spectrometer for the separation, quantitation, and isolation of individual stereoisomers of GA, GB, GD, and GF. Screening various chiral stationary phases (CSPs) for the capacity to provide full baseline separation of the CWNAs revealed that a Regis WhelkO1 (SS) column was capable of separating the enantiomers of GA, GB, and GF, with elution of the P(+) enantiomer preceding elution of the corresponding P(–) enantiomer; two WhelkO1 (SS) columns had to be connected in series to achieve complete baseline resolution. The four diastereomers of GD were also resolved using two tandem WhelkO1 (SS) columns, with complete baseline separation of the two P(+) epimers. A single WhelkO1 (RR) column with inverse stereochemistry resulted in baseline separation of the GD P(–) epimers. The analytical methods described can be scaled to allow isolation of individual stereoisomers to assist in screening and development of countermeasures to organophosphorus nerve agents. Chirality 26:817–824, 2014. © 2014 The Authors. Chirality published by John Wiley Periodicals, Inc.     

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.     

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.     

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.     

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。     

A chromium-tolerant plant growing in Cr-contaminated land

In this paper, a kind of Typhaceae plant species, Typha angustifolia L, with a high tolerance to Cr is described. Experiments were carried out to examine its ability to tolerant Cr and its physiological response. The results showed that there was no difference in growth, plant height, and biomass response to external Cr (VI) between the plants exposed to 100 microM Cr (VI) and control (0 microM), while increasing Cr levels to 200-800 microM induced a significant decrease in plant height and biomass, but no significant injury was detected, even for the plants exposed to 800 microM Cr. Chromium induced significant increases in superoxide dismutase (SOD) and peroxidase (POD) activities. Meanwhile, a significantly positive correlation was found between Cr and Mn or Cu in leaves and roots, respectively. The Cr tolerance of the plant appeared to be associated with the enhancement of SOD and POD activities and the improvement in uptake and translocation of the essential microelements.