室内条件下以枣树为寄主的苹褐带卷蛾的生长发育、繁殖及对产卵基质的选择性

【目的】苹褐带卷蛾Adoxophyes orana在陕北红枣种植区对枣树Ziziphus jujube的危害有逐年加重的趋势。本研究旨在明确以枣树为寄主的苹褐带卷蛾发育历期、繁殖能力及雌虫对产卵基质的选择性,为准确预测、高效治理该虫提供理论依据。【方法】在室温25±1℃、相对湿度70%±5%、光周期15L∶9D的条件下,以枣树叶片为食料,观察苹褐带卷蛾实验种群的生长发育及繁殖能力;通过测定补充不同营养物质后雌蛾的单雌产卵量,评价外源营养对苹褐带卷蛾繁殖力的影响;通过观察苹褐带卷蛾雌蛾在硫酸纸、滤纸、白纸、PE保鲜膜及装订胶片5种基质上的总落卵量,确定其对无机产卵基质的选择性。【结果】苹褐带卷蛾卵、幼虫、蛹和成虫的平均发育历期分别为7.38±1.22, 16.59±2.16, 7.01±0.79和16.65±5.15 d,平均世代历期为33.87±3.64 d。苹褐带卷蛾在枣树上的内禀增长率(rm)、周限增长率(λ)和种群加倍时间(Dt)分别为0.15 d^-1,1.16 d^-1和4.67 d,平均产卵量达339.52±129.93粒/雌。雌虫可多次产卵,表现出明显的昼夜节律(多在0:00-8:00时段内);平均产卵次数6.26±2.09次,雌虫羽化后第3-5天达到产卵盛期。雌蛾在PE保鲜膜上的总落卵量显著大于在其他产卵基质上的总落卵量。补给不同浓度白糖水的雌蛾,其产卵量与补给纯净水的雌蛾的产卵量差异不显著。【结论】苹褐带卷蛾能够以枣树叶片为食物完成发育并繁殖可育后代,PE保鲜膜是其雌蛾适宜的无机产卵基质。     

椰子木蛾的产卵节律及其对寄主植物的产卵选择性

【背景】椰子木蛾是近年来新入侵我国棕榈科植物的害虫,研究其产卵习性可为监测和防治该虫提供参考。【方法】在室内条件下,观察、记录了椰子木蛾雌成虫的产卵节律及其对不同寄主植物的产卵选择性。【结果】椰子木蛾最高日产卵量可达34.4粒·头-1,且主要集中在羽化后4 d内产卵,占总产卵量的54.1%;产卵活动主要发生在夜间23:00到次日8:00;在椰子、蒲葵、大王棕、槟榔和散尾葵等寄主植物上的产卵量无显著差异,为89.3~147.7粒·头-1,但产卵位置存在差别。【结论与意义】椰子木蛾雌成虫具有较强的繁殖能力和产卵节律性,且在不同寄主植物上的产卵量一致。     

微红梢斑螟生殖系统及卵巢发育特征研究

【目的】研究了微红梢斑螟Dioryctria rubella Hampson的生殖系统及不同发育阶段卵巢的形态结构,揭示交配过程中雌、雄外生殖器的匹配机制,为该虫生殖生物学及性信息素的研究提供依据。【方法】通过解剖及扫描电镜观察,描述内、外生殖器以及雌蛾卵巢发育特征。【结果】与其他斑螟亚科种类生殖系统比较,微红梢斑螟生殖系统主要具有以下形态特点:(1)微红梢斑螟雌蛾的交配囊片特别发达,导精管从交配囊体的侧腹面发出,导精管内无导精管球;(2)雌蛾腺体环状,位于第8~9腹节节间膜处,雄蛾具有发达的味刷构造,由6对重叠的鳞片刷组成;(3)雌蛾交配囊管表面的棘刺与雄蛾内阳茎外表面的阳茎针在分布位置和方向互补,具有高度匹配的关系。微红梢斑螟雌蛾卵巢发育进度可分为5级,2日龄后雌蛾卵巢饱满,发育良好;4日龄后卵巢衰退。【结论】(1)雄蛾发达的味刷及外生殖器的高度匹配关系提示其复杂的求偶行为和交配模式,加之成虫期较短,可能成虫为单次交配。(2)雌虫羽化后卵巢基本成熟,补充营养似乎并非卵巢发育的必要条件。     

性比对草地螟生殖潜力和寿命的影响

【目的】探明性比对草地螟Loxostege sticticalis L.种群繁殖的影响,为预测预报提供科学指导。【方法】室内条件(温度(22±1℃,相对湿度70%±5%,光周期16L︰8D)下,研究了草地螟成虫雌雄比例(♀︰♂=1︰3,1︰2,1︰1,2︰1,3︰1)对主要繁殖参数和寿命的影响。【结果】草地螟成虫的产卵前期随着雌蛾比例的增大而延长;性比为1︰1时雌蛾的产卵同步性最高;雌蛾的交配次数、产卵量以及最终孵出的后代幼虫量在不同性比组之间差异变化不大,而雄蛾的交配次数、对后代的贡献量却随着雌蛾比例的加大而显著增加,而当雌雄比为3︰1时,雌雄蛾的寿命均显著下降;在雌雄比为3︰1的条件下,雄蛾的交配次数以及对后代的贡献量均为雌蛾的2倍左右。【结论】性比对草地螟雌蛾生殖影响较小,而对雄蛾生殖的影响较大。在雌成虫比例较低(性比为1︰3)的情况下,雄成虫的交配和生殖能力不能得到充分发挥,进而造成种群生殖资源的浪费。根据雌雄成虫交配潜力及对后代贡献量的比较分析,可以推测性比为2︰1至1︰1时,有利于草地螟大发生种群的形成。     

草地贪夜蛾对水稻和玉米的取食和产卵选择性与适合度

【目的】明确草地贪夜蛾Spodoptera frugiperda对寄主植物水稻和玉米的取食和产卵选择性与适合度,进而分析草地贪夜蛾对水稻的为害风险。【方法】采用自由选择法,测定草地贪夜蛾对水稻和玉米的取食、产卵选择性。调查取食水稻和玉米苗的草地贪夜蛾的生长发育、存活率、繁殖力的差异,用种群增长趋势指数(I)评价水稻对草地贪夜蛾的适合度。【结果】草地贪夜蛾对水稻和玉米的取食和产卵选择性存在显著差异。接虫后2-48 h,幼虫对玉米的取食选择率随时间延长而逐渐增加,而幼虫对水稻的取食选择率随时间延长而逐渐降低;接虫后48 h,2龄幼虫和4龄幼虫对玉米的取食选择率分别为93.06%和59.72%,分别是对水稻的取食选择率的66.95倍和21.48倍。自由产卵6 d,在玉米上的产卵量是在水稻上的8.64倍。与取食玉米苗的相比,取食水稻苗的草地贪夜蛾幼虫发育历期延长,卵孵化率、幼虫存活率、化蛹率和成虫羽化率均显著降低,雌性比率下降,雌成虫寿命显著缩短,单雌产卵量显著减少。取食玉米苗的草地贪夜蛾的种群增长趋势指数(I)为165.93,其在水稻上的相对适合度为0.21。【结论】相较于水稻,草地贪夜蛾在玉米上表现出更高的适合度,其偏好在玉米上取食和产卵。水稻不是目前侵入我国的草地贪夜蛾的嗜食寄主,但其可以通过取食水稻幼苗正常生长发育并完成生活史,在其种群密度较大、嗜食寄主植物缺乏时存在转移为害水稻的潜在风险。     

广聚萤叶甲成虫产卵行为及其产卵部位的选择性

【目的】明确广聚萤叶甲成虫产卵行为及其产卵部位的选择性。【方法】在室内条件下,对广聚萤叶甲成虫交配及产卵的系列行为、产卵场所选择、不同部位豚草植株叶片叶绿素b的含量进行了观察和测定:(1)将1对成虫放到养虫笼内的一株豚草上,观察交配时间,记录产卵数量、前后2粒卵之间的产卵时间间隔;(2)在均匀分为5部分(0～10、11～20、21～30、31～40和41～50 cm)的豚草植株上,随机放置10对成虫,观察雌虫对于产卵场所的选择。(3)将上述5个部位的豚草叶片通过丙酮匀浆法处理,用紫外分光光度计测定其在645和663 nm的吸光值,计算叶绿素b含量。【结果】广聚萤叶甲成虫完成一次成功交配平均需96.09 min。雌虫一般需45 min的时间来寻找其适应的产卵场所,在产卵过程中,成虫习惯将卵产于叶片背面,雌虫喜欢用口器来清理刚产下的卵粒。在一株50 cm高的豚草植株上,雌虫喜欢将卵产在植株中部21～30 cm和中上部31～40cm的叶片上(从下往上划分)。卵块数量和豚草不同部位叶片叶绿素b含量呈显著的正相关性。【结论】广聚萤叶甲成虫喜欢产卵在叶绿素b含量较高的叶片背面,可能以视觉识别叶片颜色来选择和定位产卵场所。     

亚洲玉米螟雌蛾产卵偏好寄主植物的筛选及对葎草挥发性化学成分的电生理反应

【目的】鉴定亚洲玉米螟Ostrinia furnacalis雌蛾在寻找产卵寄主时起重要作用的植物挥发性化学物质,以探索亚洲玉米螟和寄主之间的化学通讯机制。【方法】首先利用田间产卵和风洞行为试验,从酸模叶蓼Polygonum lapathifolium、苘麻Abutilon theophrasti、葎草Humulus scandens、玉米Zea mays和稗草Echinochloa crusgalli 5种寄主植物中筛选出亚洲玉米螟雌蛾的产卵偏好寄主;并结合顶空吸附采样法,收集该寄主植物挥发性化学物质;再应用全二维气相色谱与飞行时间质谱联用系统(GC×GC-TOFMS)鉴定植物挥发性物质的化学成分及含量;最后利用气相色谱-触角电位联用仪(GC-EAD)测定亚洲玉米螟雌蛾对提取物中化学成分的触角电位反应。【结果】田间产卵试验结果表明,亚洲玉米螟雌蛾在不同寄主植物上的落卵量依次为玉米酸模叶蓼葎草稗草苘麻。风洞行为试验结果表明,亚洲玉米螟雌蛾对葎草的产卵趋性显著高于其他寄主植物。GC×GCTOFMS结果表明,葎草的植物挥发性化学物质主要成分有45种,其中,萜烯类相对含量高达86.29%,醛类、酮类和酯类相对含量合计仅占15.83%。GC-EAD结果显示,芳樟醇、α-葎草烯、桧烯、月桂烯、2-正戊基呋喃、壬醛、α-法呢烯、反式-罗勒烯和苯甲醛等9种挥发性物质能引起亚洲玉米螟雌蛾明显的电生理反应。【结论】亚洲玉米螟雌蛾对不同产卵寄主的选择具有显著差异性,寄主植物的理化因素是造成选择差异性的主要因素,葎草的植物挥发性化学物质对亚洲玉米螟有较强的吸引作用;芳樟醇、α-葎草烯、桧烯、月桂烯、2-正戊基呋喃、壬醛、α-法呢烯、反式-罗勒烯和苯甲醛9种挥发性化学物质对亚洲玉米螟产卵寄主的选择有重要作用。     

补充营养及产卵底物颜色对粘虫生殖的影响

【目的】进一步探明补充营养和产卵底物颜色对粘虫Mythimna separata(Walker)的影响,为粘虫的室内饲养条件提供参考。【方法】选取5%蜂蜜水、10%蜂蜜水、10%葡萄糖溶液、0.2 mol·L~(-1)麦芽糖溶液、5%葡萄糖+5%蜂蜜混合液、5%果糖+5%蜂蜜混合液、5%葡萄糖+5%果糖混合液、糖醋酒液(3白糖:1白醋:4白酒:2水)8种补充营养,红、黄、绿、蓝、紫、白6种颜色塑料包扎绳作为产卵底物,研究粘虫蛾取食不同补充营养产卵前期、产卵期、寿命及在不同产卵底物上的产卵量。【结果】取食5%葡萄糖+5%果糖混合液和0.2 mol·L~(-1)麦芽糖溶液的雌蛾单雌产卵量最多,取食糖醋酒液的雌蛾单雌产卵量最少,极显著低于前者,取食其余5种补充营养的雌蛾单雌产卵量无显著差异;成虫对蓝色底物的选择性最大,除5%蜂蜜水和10%葡萄糖溶液处理外,其余处理蓝色包扎绳上的平均产卵量显著比其他5种颜色包扎绳上的高,对红、白2种颜色底物的选择性最小,对黄、绿、紫3种颜色底物的选择性介于上述两者之间。【结论】在粘虫室内饲养中,选用5%葡萄糖+5%果糖混合液和0.2 mol·L~(-1)麦芽糖溶液作为补充营养及蓝色物质作为产卵底物,更有利于粘虫的繁殖和种群增长。     

虫害诱导抗性水稻挥发物增强邻近感性水稻品种对褐飞虱的直接和间接抗性

【目的】褐飞虱Nilaparvata lugens是为害水稻的重要害虫。本研究旨在明确褐飞虱为害诱导的抗性水稻品种(IR64, ASD7和IR56)挥发物对感性品种TN1抗虫性的影响,为褐飞虱的绿色生态防控提供理论和技术指导。【方法】以水稻-褐飞虱-稻虱缨小蜂Anagrus nilaparvatae为研究对象,利用未被为害和经褐飞虱雌成虫为害(褐飞虱为害诱导)的水稻(IR64, ASD7, IR56和TN1)挥发物处理TN1植株,测定TN1植株上褐飞虱单雌产卵量和单雌蜜露分泌量、若虫存活率和卵孵化率;分别利用H型嗅觉仪和Y型嗅觉仪测定褐飞虱雌成虫和稻虱缨小蜂对上述不同处理TN1植株的选择性。【结果】褐飞虱为害诱导的抗性水稻挥发物处理TN1植株后均可降低褐飞虱单雌产卵量,而未被为害的抗性水稻挥发物处理后不影响褐飞虱单雌产卵量。健康TN1植株经褐飞虱为害诱导的IR64挥发物处理后可降低单雌蜜露分泌量,但对卵孵化率和若虫存活率无影响;同时还降低对褐飞虱的引诱作用,而增强对稻虱缨小蜂的引诱作用。且健康TN1植株经褐飞虱为害IR64和TN1诱导的挥发物处理后,其挥发物组分中仅2-庚酮的相对含量发...     

广聚萤叶甲成虫交配时长对产卵量与孵化率的影响

【目的】明确不同交配时长对广聚萤叶甲雌虫产卵量和卵的孵化率的影响。【方法】在室内条件下,对不同交配时长下广聚萤叶甲的雌虫产卵量和卵的孵化率进行观察:(1)选取羽化第3d的广聚萤叶甲雌雄虫随机配对,观察24 h,记录交配情况和时长;(2)在交配开始1、5、15、30、60 min时,强行分开雌雄成虫,然后将不同交配时长的雌虫进行单独饲养,以正常交配一次的雌虫作为对照,每个处理选取23组;(3)将15～30 cm健壮豚草小苗插入注满水的塑料小瓶内,将配对的一组雌雄成虫和豚草小苗放入养虫盒中饲养,每天更换带卵的小苗并记录叶片上的产卵量;(4)将上述带卵的小苗至于适宜条件下培养,记录5～7 d内卵块孵化的情况。【结果】广聚萤叶甲正常交配一次的对照组的产卵水平显著高于各处理组,单雌产卵为889粒,交配时间15 min以下各组雌虫的产卵量明显低于交配30 min以上的各组雌虫。同时交配时长5 min以下雌虫产的卵基本不能孵化,而交配时间达到30 min以上的各组卵块的孵化率明显提高。【结论】雄虫转移雌虫受精所需精子量需要耗费的时间为30 min左右,且雄虫有延长交配时间的趋性。该结果为研究广聚萤叶甲的生态特性以及优化种群繁殖提供科学依据。     

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.     

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.     

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.     

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.     

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.     

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.