四氯化碳联合二乙基亚硝胺对小鼠肾脏毒性作用的研究

为了研究四氯化碳(carbon tetrachloride,CCl_4)联合二乙基亚硝胺(diethylnitrosamine,DEN)对小鼠肾脏组织的毒性损伤作用,将30只雄性昆明鼠随机分为对照组和实验组,其中实验组小鼠每周2次腹腔注射15%CCl_4花生油溶液,并且自由饮用0.07%DEN溶液;而对照组小鼠注射等量的纯花生油,自由饮用纯净水,观察并记录各组小鼠的饮水、进食情况和体重变化,以及生活状态的改变。在实验过程中,分别于第3、6、8周解剖两组小鼠各4只,取其肾脏组织样本进行病理方面的组织切片观察。体重统计结果显示,与对照组相比,实验组小鼠体重明显下降。同时,实验组小鼠的肾脏系数明显高于对照组,并且具有显著差异(P0.05)。组织切片观察发现,对照组小鼠肾脏组织结构比较清晰,排列较规则,而实验组小鼠肾脏组织呈现出显著的变性和坏死;且随着处理时间的延长,肾脏组织变得散乱无规则,细胞凝集现象越来越明显,肾小管与集合小管管腔变窄,颗粒样变性。上述结果表明CCl_4联合DEN对小鼠肾脏具有损伤效应,处理时间越长,损伤作用越严重。     

粗糙沼虾精巢发育的组织学

利用光镜技术,对粗糙沼虾精巢发育进行了研究,根据精子发生过程中每种生殖细胞所占的比例和发生的次序,并结合精巢的形态特征,把精巢发育过程分为五个时期,即精原细胞期,精母细胞期,精细胞期,成熟精子期及退化期,精原细胞期,精巢小,透明乳白色,生精小管内的生殖细胞以精原细胞为主;精母细胞期;精巢体积增大,半透明乳白色,主要由处于初级精母细胞的次级精母细胞阶段的生殖细胞组成;精细胞期,精巢体积继续增大,颜色加深,生精小管内的生殖细胞以精细胞为主;成熟精子期,精巢体积可达最大,紫红色,生精小管内充满着成熟的精子,退化期;精巢体积减小,半透明乳白色,生精小管内的成熟精子几乎排空。     

乙酰基亚硝基脲(ENU)对C57BL/6J雄鼠睾丸组织的影响

目的 观察乙酰基亚硝基脲(ENU)对雄鼠睾丸及其他组织器官的影响,分析引起小鼠死亡的原因,探索ENU处理雄鼠后的最佳配种时间.方法 将8～10周龄的C57BL/6J雄鼠分为实验组和对照组.实验组腹腔注射ENU 100 mg/kg,每周1次,共3次,对照组以同样方法注射生理盐水.首次注射ENU后的第1周至12周,每周分别取4只实验组小鼠和对照组小鼠剖检及组织病理学观察;取其睾丸附睾称重及精子计数.记录死亡小鼠数量,并对其剖检及组织病理学观察.结果 对死亡小鼠剖检发现胸腔纵隔内有巨大肿块,明显压迫心脏;组织切片观察发现睾丸和肝脏有明显病变.实验组小鼠睾丸从ENU处理的第2周起开始萎缩,第9周开始恢复;精子数量第4周至第9周稀少.结论 ENU为小鼠的一种强诱变剂,纵隔肿瘤是导致雄鼠死亡的主要原因,雄鼠注射ENU后最佳配种时间应在首次注射后的第9周.     

链脲佐菌素糖尿病小鼠睾丸内生精细胞减少与PCNA和Ki67表达降低

目的通过检测增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)及Ki67在正常及糖尿病小鼠睾丸组织中表达的差异,探讨糖尿病对生精细胞增殖的影响。方法 30只正常雄性C57BL/6小鼠,随机分为对照组(10只)和糖尿病组(20只)。采用腹腔注射链脲佐菌素的方法建立糖尿病小鼠模型,对照组注射相同体积的柠檬酸—柠檬酸钠缓冲液。造模成功3周后处死动物,取睾丸组织,常规固定、石蜡包埋、切片HE染色观察睾丸组织的形态学变化;免疫组织化学SP法检测PCNA及Ki67在睾丸组织中的表达;图像分析技术分析组织中PCNA及Ki67免疫组织化学表达水平。结果 HE染色显示,糖尿病小鼠睾丸内处于精子发生前半期的生精小管内生精细胞排列疏松,细胞层数偏少,附睾管内精子密度相对较低;免疫组织化学染色显示,PCNA和Ki67在糖尿病小鼠睾丸生精小管中的表达均明显降低。结论高糖可能通过降低生精细胞的增殖进而影响睾丸精子的发生。     

秦岭北坡中国林蛙精巢显微结构的年周期变化

用光镜观察了秦岭北坡中国林蛙(Ranachensinensis)精巢显微结构的年周期变化,结合精巢系数的变化探讨其生殖规律。结果显示,秦岭北坡中国林蛙的生精周期属于非连续型。精巢系数的变化与精子发生的活动周期相一致。精子发生从每年5月开始,翌年4月结束,历时1年。生精周期可划分为5个时期。Ⅰ期,精原细胞增殖期,5～7月,精巢系数最小,精原细胞进行有丝分裂;Ⅱ期,精母细胞成熟分裂期,8～9月,精巢系数最大,精原细胞、精母细胞和精子细胞在生精小管内共存;Ⅲ期,精子形成期,9～1 0月,精子细胞变态形成精子;Ⅳ期,成熟精子贮存越冬期,1 1月至翌年2月,成熟精子贮存在生精小管中;V期,精子排放期,翌年3～5月,精巢系数显著下降,成熟精子从生精小管脱离,通过输精管道排出体外。     

壬基酚对雄性黑斑蛙生殖毒性的研究

通过研究壬基酚对雄性黑斑蛙(Rana nigromaculata)成体的精子和精巢的影响,探讨壬基酚对黑斑蛙的生殖毒性.用不同剂量的壬基酚对雄性黑斑蛙进行处理,对黑斑蛙的精巢系数、精子数、形态结构、畸形率和精巢显微结构等分别进行研究.结果表明,与对照组相比,随着壬基酚浓度的升高,染毒组黑斑蛙的精巢系数下降,精子数减少,精子畸形率明显增大;畸形精子主要表现为其头部出现肥大、弯曲和圆形等现象;精巢显微结构发生变化,表现为生精小管萎缩,生精细胞层次减少,间质区不明显.说明壬基酚对雄性黑斑蛙生殖系统具有毒性效应.     

镉对小鼠精子和生精细胞超微结构及生精细胞bcl-2、bax基因表达的影响

研究镉暴露对小鼠附睾精子和睾丸生精细胞超微结构的变化以及镉对生精细胞凋亡相关基因bcl-2、bax表达水平的影响。采用24只雄性ICR小鼠随机分为4组,每组6只,分别以0.183、0.915、1.83mg/kg氯化镉腹腔注射,每天1次,连续5次,设阴性对照生理盐水组。于第6天透射电镜观察附睾精子超微结构、睾丸生精细胞核和线粒体超微结构的变化,免疫组化方法检测生精细胞Bcl-2、Bax表达水平。透射电镜观察显示,0.183mg/kg组精子超微结构无显著性变化,0.915mg/kg组精子头部两侧膜与头部胞质间隙轻微扩大,线粒体嵴间腔扩大且轻度空泡化,但与对照组相比无统计学意义(P>0.05)。1.83mg/kg组头部两侧膜与胞质间隙扩大,与对照组相比有显著性差异(P<0.05),尾部线粒体嵴间腔扩大且轻度空泡化,与对照组相比有显著性差异(P<0.05)。3种剂量处理组睾丸生精细胞核超微结构异常发生率显著高于对照组(P<0.05),且随着处理浓度的升高异常发生率升高;1.83mg/kg组线粒体肿胀空泡化发生率显著高于对照组(P<0.05)。3种剂量实验组生精细胞Bcl-2表达水平(吸光度)显著低于对照组(P<0.01),0.915mg/kg组Bax表达水平显著高于对照组和0.183、1.83mg/kg组(P<0.01)。3种剂量实验组Bcl-2/Bax吸光度比值显著低于对照组(P<0.01);0.915mg/kg组Bcl-2/Bax比值显著低于1.83mg/kg组(P<0.01)。上述结果提示:高浓度镉诱导附睾精子超微结构改变,高中低浓度镉致睾丸生精细胞超微结构的改变,生精细胞超微结构发生凋亡现象。镉对Bcl-2、Bax表达水平的改变可能是生精细胞凋亡的分子机制之一。     

多氯联苯对成年公鸡生精功能和睾酮分泌的影响

目的：多氯联苯（PCB）与DDT结构类似,可作为内分泌干扰物（环境激素）使动物和人发生神经,内分泌和生殖功能紊乱,本试验研究PCB对公鸡生殖功能的影响。方法：对照组成年鸡口服花生油,实验组口服PCB（50mg/kg体重）,每周一次,连续六周,最后用多聚甲醛灌流,取出性腺并固定,组织块经石蜡切片和伊红－苏木精染色,并进行图象分析,结果：对照组与实验组分鸡和母鸡在体重,呼吸,心率,体温方面无显差异,红细胞和白细胞数目也无显变化。组织学切片观察发现;实验组公鸡睾丸曲细精管破损,管壁明显变薄,支持细胞数目减少,各级精母细胞及精子数目下降,间质在原有基础上变得散乱。定量结果表明,实验组与对照组公鸡相比,睾丸重量明显降低（P＜0．05）,并且曲细精管管壁厚度显下降（P＜0．01）。睾酮含量结果为,实验组公鸡睾酮水平显下降,与公鸡的结果不同,相同剂量的PCB处理后,母鸡所产蛋除蛋重下降外,其他品质包括蛋形指数,蛋壳强度,蛋白高度,蛋黄颜色和哈夫单位均无显变化,结论：PCB对成年鸡生殖功能的影响存在明显的性别差异,公鸡对PCB有较高的敏感性,可使生精功能损伤,睾酮分泌减少。     

麻黄素对仔鼠睾丸组织结构和Bax、EGF蛋白的影响

为探讨麻黄素对各发育期昆明小鼠(Mus musculus)仔鼠睾丸组织结构及Bax蛋白和表皮生长因子(epidermal growth factor,EGF)阳性表达的影响,选取雄性仔鼠采用递增剂量腹腔连续注射麻黄素,应用生物显微技术观察睾丸组织结构的变化,用免疫组织化学和体视学半定量方法检测Bax和EGF蛋白在睾丸组织中的表达.结果表明,麻黄素组仔鼠各发育阶段生精小管直径及上皮厚度明显小于对照组(P＜0.01或P＜0.05),初级精母细胞直径小于对照组(P＜0.01或P＜0.05),生精小管上皮各级生精细胞的发生较晚,且排列疏松而凌乱,细胞间空隙多,发育成熟期管腔内成熟精子较少;麻黄素组各发育期仔鼠睾丸中Bax和EGF蛋白的阳性表达与对照组相比显著增强(P＜0.01或P＜0.05).上述结果表明,麻黄素影响仔鼠睾丸组织的发育,麻黄素对各发育期仔鼠睾丸组织的损伤可能与Bax和EGF蛋白表达的增强有关.     

小鼠原发性肝癌建模方法的优化

目的建立良好、快捷、稳定的小鼠原发性肝癌模型。方法将128只雄性KM小鼠随机均分为8组:正常组给予自由饮食;二乙基亚硝胺(DEN)水溶液组每天给予含DEN(16.5 mg/kg)的水溶液;高剂量DEN麻油组(7次/周、3次/周、1次/周),经口给予含DEN(16.5 mg/kg)的麻油溶液;而低剂量DEN麻油组、nano-DEN组、纳米载体组则分别每周经口给予含DEN(8.25 mg/kg)的麻油溶液和nano-DEN或同量的纳米载体。20周后,处死小鼠,取肝脏标本,固定后行HE染色。结果 (1)含DEN的各组小鼠均出现不同程度毛色枯燥、无光泽、行动迟缓、体重增长缓慢;(2)20周时,同DEN水溶液组,高剂量DEN麻油组小鼠均出现肿瘤,且其1次/周的小鼠死亡率较低;(3)Nano-DEN组小鼠无死亡,且其肝脏损伤的HE评分较低剂量DEN麻油组严重。结论 DEN溶于麻油的经口给药增加了小鼠服药的顺应性,长期低频率给药能大大降低造模过程中的死亡率。而DEN的纳米微乳制剂,能增强对肝脏的损伤程度。     

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.     

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.     

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.     

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.     

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.     

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.     

邻苯二甲酸二丁酯对翡翠贻贝抗氧化酶及脂质过氧化水平的影响

实验室条件下,研究了不同浓度邻苯二甲酸二丁酯(DBP)长期胁迫(15 d)对翡翠贻贝内脏团和外套膜抗氧化酶(超氧化物歧化酶SOD、过氧化氢酶CAT)及脂质过氧化(LPO)水平(以MDA含量表示)的影响,以及受胁迫翡翠贻贝在清洁海水中恢复阶段上述生化指标的变化特征.结果表明:胁迫阶段,0.5和2.5 mg.L-1DBP下翡翠贻贝内脏团SOD活性表现为先抑制后逐渐恢复,12.5和62.5 mg.L-1下则持续受到显著抑制;不同浓度组CAT活性均明显被抑制.LPO水平明显升高.外套膜中,2.5 mg.L-1下SOD活性受到持续诱导,其他浓度组则先被抑制,后随曝露时间延长逐渐被诱导;各浓度组CAT的变化波动较大,没有明显规律;而LPO水平明显升高.净化恢复阶段,12.5和62.5 mg.L-1DBP胁迫下的内脏团SOD和CAT活性恢复较慢,其LPO水平随时间延长逐渐恢复至对照组水平;外套膜中SOD活性呈持续升高趋势,CAT活性和LPO水平则随时间延长恢复到对照组水平.     

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。     

X-ray induction of dominant lethals in late spermatids and mature spermatozoa of Drosophila melanogaster: the role of oxygenation

The role of oxygenation in determining the sensitivity to the induction of dominant lethals was examined in late spermatids and mature spermatozoa of Drosophila melanogaster. 0–2-h-old or 7-day-old Oregon-K males were irradiated with different X-ray exposures in nitrogen, air or in oxygen and the frequencies of dominant lethals induced in these stages were studied. The results obtained confirm and extend Sobels' earlier observations and the interpretation derived therefrom namely, that under normal conditions in air, mature spermatozoa are characterised by a higher degree of oxygenation than late spermatids and this difference is sufficient to explain the differential response of these stages. Similar Oxygen-Enhancement-Ratios(OERs) (of about 2) were obtained for both the cell stages. The present data also revealed that late spermatids are significantly less sensitive than mature spermatozoa to the X-ray-induction of dominant lethals in a nitrogen atmosphere. A plausible mechanism is suggested to explain this observation.