Erythrocyte G protein-coupled receptor signaling in malarial infection

Erythrocytic mechanisms involved in malarial infection are poorly understood. We have found that signaling via the erythrocyte beta2-adrenergic receptor and heterotrimeric guanine nucleotide-binding protein (Galphas) regulated the entry of the human malaria parasite Plasmodium falciparum. Agonists that stimulate cyclic adenosine 3',5'-monophosphate production led to an increase in malarial infection that could be blocked by specific receptor antagonists. Moreover, peptides designed to inhibit Galphas protein function reduced parasitemia in P. falciparum cultures in vitro, and beta-antagonists reduced parasitemia of P. berghei infections in an in vivo mouse model. Thus, signaling via the erythrocyte beta2-adrenergic receptor and Galphas may regulate malarial infection across parasite species.     

白粉病胁迫对甜瓜同工酶谱的影响

[目的]研究甜瓜幼苗叶片中的SOD、POD、CAT同工酶与甜瓜白粉病之间的关系.[方法]以白粉病感病甜瓜品种伽师和白粉病抗病甜瓜品种MR -1为材料,利用PAGE电泳方法分析三种同工酶在接种白粉病前后酶谱的变化.[结果]感病品种伽师和抗病品种MR -1的POD、CAT、SOD受白粉病胁迫后,同工酶谱均有变化,POD酶带在第3d时有新的酶带出现,伽师:P4 (Rf=0.80),MR -1∶P1(Rf=0.68),且感病品种伽师比抗病品种MR-1的POD活性变化更迅速;CAT同工酶无新的酶带出现,但两品种的两条CAT同工酶酶带分别在接种白粉病后3和12d出现两次峰值;SOD同工酶酶活性变化相对较弱,无新的酶带出现,但SOD同工酶酶带S1(Rf=0.50)的活性有变化呈6d增强9d降低的趋势.同时,在接种白粉病后甜瓜白粉病抗病品种MR -1的POD、CAT、SOD酶活性始终比甜瓜白粉病感病品种伽师的酶活性强.[结论]甜瓜幼苗期接种白粉病菌后SOD、CAT、POD的活性变化可以作为衡量甜瓜抗病性的生化指标.     

Malaria parasites adopt host cell superoxide dismutase

Aerobic organisms depend on superoxide dismutase to suppress the formation of dangerous species of activated oxygen. Intraerythrocytic stages of the malaria parasite exist within a highly aerobic environment and cause the generation of increased amounts of activated oxygen. Plasmodium berghei in mice was found to derive a substantial amount of superoxide dismutase activity from the host cell cytoplasm. Plasmodia isolated from mouse red cells contained mouse superoxide dismutase, whereas rat-derived parasites contained the rat enzyme. This is believed to be the first example of the acquisition of a host cell enzyme by an intracellular parasite.     

黄酮类化合物对大强度耐力训练大鼠的影响试验

研究黄酮类化合物对大强度耐力训练大鼠的红细胞抗氧化能力及红细胞膜ATP酶(ATPase)活性的影响。将18只大鼠随机分为安静饲养对照组(静养组)、大强度耐力运动训练组(运动组)和运动训练服药组(运动服药组)。分别进行静养、大强度运动训练和灌服黄酮类化合物,测试大鼠红细胞超丙二醛(MDA)含量、还原型谷胱甘肽含量(GSH)和过氧化氢酶(CAT)活性、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性。试验表明,灌服黄酮类化合物组大鼠力竭运动后MDA的含量极显著低于运动对照组(P0.01),红细胞SOD、GSH-Px、CAT酶活性和GSH含量较显著高于运动对照组(P0.05);红细胞膜ATPase活性较显著高于运动训练对照组(P0.05)。结果显示,黄酮类化合物可以改善长时间大强度耐力运动训练中大鼠红细胞的氧化应激水平,保护膜上ATPase的活性,有利于运动中红细胞结构和功能的完整性,可开发和利用含黄酮类化合物的食物作为耐力运动员的运动补剂。     

4种中药复方对长江鲟幼鱼抗氧化和抗应激指标的影响

【目的】探讨不同中药复方对长江鲟幼鱼抗氧化和抗应激指标的影响,筛选能有效提高长江鲟幼鱼免疫力及抗病力的中药复方,为中药在长江鲟养殖生产中的推广应用提供参考依据。【方法】将17味中药按照中药配伍理论设计4种中药复方,分别是复方I（鱼腥草:金银花:大黄:茯苓:甘草︰黄芪=3:3:1:2:1:2）、复方II（板蓝根:大黄:五加皮:党参=3:3:4:3）、复方III（金银花:杏仁:贯众:大青叶:山豆根:桔梗=3:2:2:2:3:2）、复方IV（黄芪:黄柏:甘草:山楂:五味子:大黄:党参=3:3:1:2:2:2:2）,以不添加中药为对照组,按0.5 g/kg的添加量进行长江鲟幼鱼饲喂试验,并于第7和第14 d采集血样测定各项血清生理指标。【结果】与对照组相比,复方I组和复方II组可不同程度地提高长江鲟血清超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GSH-Px）、过氧化物酶（POD）、碱性磷酸酶（AKP）活性及总抗氧化能力（T-AOC）、热休克蛋白70（HSP70）含量,降低丙二醛（MDA）含量,但仅部分指标差异达显著水平（P<0.05,下同）;复方III组和复方IV组可明显提高长江鲟血清SOD、CAT、GSH-Px、POD、AKP活性及T-AOC,降低MDA和皮质醇（COR）含量,且大部分指标与对照组的差异达显著水平。相关分析结果表明,SOD活性与GSH-Px活性及T-AOC、POD活性与GSH-Px活性呈极显著正相关（P<0.01,下同）,POD活性与SOD活性、CAT活性及T-AOC呈显著正相关,SOD活性与COR含量、T-AOC与COR含量呈极显著负相关,GSH-Px活性与COR含量、T-AOC与MDA含量呈显著负相关。【结论】在基础饲料中添加适宜的中药复方对长江鲟幼鱼抗氧化和抗应激能力有显著促进作用,尤其以复方III（金银花、杏仁、贯众、大青叶、山豆根、桔梗）和复方IV（黄芪、黄柏、甘草、山楂、五味子、大黄、党参）的效果最佳,可有效缓解长江鲟幼鱼机体面临的应激反应,达到保护效果。     

Sporozoite-induced infections of Plasmodium berghei administered by the oral route

Administration of suspensions of Plasmodium berghei sporozoites by the oral route to groups of susceptible animals (A/J mice, young rats, hamsters, and Thamnomys) resulted in high rates of infection (66 to 100 percent).Control animals each given a suspension of 200,000 to 500,000 erythrocytes infected with P. berghei by the same oral route did not develop parasitemia. Direct intubation of sporozoite suspensions into the stomach failed to produce parasitemia. In vitro studies showed that sporozoites kept in medium M 199 acidified to pH 3.6 (the acid environment of the rat stomach) for 5 to 15 mtinutes lost their viability and infectivity. We believe that sporozoites of P. berghei find their way to the bloodstream during their brief sojourn in the esophagus.     

Erratum

In the report "Site-specific nick in the T-DNA border sequence as a result of Agrobacterium vir gene expression" by K. Wang et al. (30 Jan., p. 587), figure 2A on page 588 should have shown a 3.2-kilobase band in lane b that was not visible. Also, 1.9-kilobase bands in lane c and g were not visible. A Print that shows the bands in figure 2, A and B, appears below. In addition, reference 24 should have been to J. L. Slightom, L. Jouanin, F. Leach, R. F. Drong, D. Tepfer, EMBO J. 4, 3069 (1985). [See Table A and B in Source PDF].     

Inhibition of development of exoerythrocytic forms of malaria parasites by gamma-interferon

A specific DNA probe was used to study the effect of recombinant rat, mouse, and human gamma-interferon (gamma-IFN) on the course of sporozoite-induced malaria infections. In mice and rats infected with sporozoites of Plasmodium berghei, mouse and rat gamma-IFN's strongly inhibited the development of the exoerythrocytic forms in the liver liver cells of the hosts, but not the development of the erythrocytic stages. The degree of inhibition of the exoerythrocytic forms was proportional to the dose of gamma-IFN administered, but was independent of the number of sporozoites used for challenge. A 30 percent reduction in the development of exoerythrocytic forms in rat liver was achieved when 150 units (about 15 nanograms of protein) of rat gamma-IFN were injected a few hours before sporozoite challenge; the reduction was 90 percent or more with higher doses of gamma-IFN. The effect was less pronounced if the gamma-IFN was administered 18 hours before or a few hours after challenge. Human gamma-IFN also diminished the parasitemia in chimpanzees infected with sporozoites of the human malaria parasite Plasmodium vivax. The target of gamma-IFN activity may be the infected hepatocytes themselves, as shown by in vitro experiments in which small doses of the human lymphokine inhibited the development of exoerythrocytic forms of Plasmodium berghei in a human hepatoma cell line. These results suggest that immunologically induced interferon may be involved in controlling malaria infection under natural conditions.     

无核雪柑与普通雪柑种胚发育过程蛋白质的差异

采用考马斯亮蓝G 250法测定胚胎蛋白质含量,并用双向电泳技术分析胚胎的特异蛋白质。结果表明:无核雪柑种胚早期的蛋白质含量相对较高,其胚胎不同发育阶段出现了P1~P6 6个特异蛋白质;另外发现了4个特异于普通雪柑胚胎发育的蛋白质P11~P14。认为P11~P14与无核雪柑的无核密切相关,分别是P11(67.0 kD,pI 5.1)、P12(65.5 kD,pI 5.4)、P13(97.0 kD,pI 5.8)及P14(64.3 kD,pI 5.9)。     

不同动物油脂对大鼠血糖血脂及血液相关因子的影响研究

研究羊油、猪油、牛油、马油4种油脂对大鼠血糖、血脂及血液相关因子的影响研究。130只雄性健康SD大鼠随机分为对照组、羊油脂组、猪油脂组、牛油脂组和马油脂组共5组。各油脂组再分为高（2mL／100g体重）、中（1mL／100g体重）、低（0．5mL／100g体重）剂量3个灌胃组,对照组灌胃纯净水（1mL／100g体重）。灌胃56d后,测定各组动物体重、内脏脂肪重量、血糖（GLU）、血脂4项[高密度脂蛋白（HDL-C）、低密度脂蛋白（LDL-C）、胆固醇（TC）、甘油三酯（TG）3的变化以及脂代谢相关血液因子[血浆胰岛素（INS）、瘦素（LEP）、一氧化氮（NO）、超氧化物歧化酶（SOD）和丙二醛（MDA）]的变化。结果表明,与对照相比,4种油脂对大鼠的体重、LEP、NO影响不明显（P〉0．05）;4种动物油脂的高剂量组以及猪油脂和马油脂的中剂量组均能显著增加内脏脂肪的重量（P〈0．05）;羊油脂中剂量组、马油脂高剂量和中剂量组的GLU值均极显著升高（P〈0．01）;羊油脂高剂量组HDL—C水平显著升高（P〈0．05）,猪油脂高剂量组HDL—C水平极显著升高（P〈0．01）;牛油脂高剂量组LDL—C水平显著升高（P〈0．05）;牛油脂和马油脂的各剂量组TC水平均极显著升高（P〈0．01）;仅羊油脂高剂量组TG水平显著升高（P〈0．05）;马油脂的高、中剂量组的血浆INS水平极显著降低（P〈0．01）;羊油脂和猪油脂的各剂量组MDA水平均极显著升高（P〈0．01）;牛油脂和马油脂的各剂量组SOD水平均极显著升高（P〈0．01）;4种油脂对大鼠的体重、血浆LEP、血浆NO没有明显影响;灌服猪油脂对大鼠GLU水平影响不明显;灌服高剂量羊油脂可明显升高大鼠血液HDL-C和TG水平;猪油脂主要表现为升高HDL-C水平;而牛油脂和马油脂各剂量组则可极显著升高血浆总胆固醇。羊油脂和猪油脂均能升高大鼠的MDA水平;牛油脂和马油脂均能升高大鼠的SOD水平,推测牛油脂和马油脂具有抗氧化的作用。     

Corrections and clarifications

Throughout the Research Article "Autoproteolysis in hedgehog protein biogenesis" by John J. Lee et al. (2 Dec., p. 1528) the word "disc" was incorrectly spelled "disk." In figure 4C (p. 1531), lane 9 should have been labeled "flu227," not "flu408."     

Erratum

In the report "Prenatal exposure to carbon monoxide: Learning and memory deficits" by C. F. Mactutus and L. D. Fechter (27 Jan., p. 409), the second sentence of the second full paragraph in column 3 of page 410 should have read, "A 2 by 2 analysis of covariance on the number of avoidance responses with covariates of number of avoidance responses in acquisition and number of adaptation and intertrial responses during reacquisition revealed significant effects of training contingency [F( 1, 57) = 23.8, P < 0.001] and an interaction of CO exposure with training contingency [F(1, 57) = 7.6, P < 0.008].     

实验大鼠、小鼠胚胎的缓慢冷冻和玻璃化冷冻的比较

对3日龄小鼠胚胎和5日龄大鼠胚胎进行了玻璃化低温保存和缓慢冷冻保存的比较研究,从经过超数排卵的小鼠和大鼠中收集到了1897个8－16细胞的胚胎,经筛选后将I级和Ⅱ级胚计1738个（91．62%）分别进行两种低温保存试验,并对其中的881个冷冻胚胎分阶段进行复苏,复苏率分别为65．03％（小鼠69．59％,大鼠60．46％）和68．45％（小鼠72．61％,大鼠64．29％）,两者间无显著性差异（P＞0．05）。在复苏在胚胎中,选择其中的488个胚胎进行移植试验,结果,玻璃化冷冻保存胚胎的移植的受孕率为39．47％（89／222）,缓慢冷冻保存胚胎的移植的受孕率为42．56％（115／266）,两种低温保存方法经方差检验也无显著性差异（P＞0．05）。     

Genomics. Public-private project to deliver mouse genome in 6 months

Research on the mouse genome lurched into the fast lane last week, as private donors joined the U.S. government to step on the gas. A public-private consortium announced on 6 October that it's kicking $58 million into a new fund that will pay to sequence the DNA of the "black six" (C57BL/6J) strain of laboratory mouse. The consortium aims to produce a draft version of the genome by the end of February.     

牛Musclin基因片段克隆与序列分析

[目的]对牛Musclin基因片段进行克隆与序列分析。[方法]通过电子克隆技术克隆牛Musclin基因,并通过软件分析牛Musclin基因与小鼠、大鼠、人、猪和鸡的同源性。[结果]通过电子克隆技术成功克隆了牛Musclin基因;分析结果表明,牛Musclin基因与小鼠、大鼠、人、猪和鸡同源性分别为81．0％、80．8％、90．0％、89．1％和62．4％,预测的氨基酸序列含有“KKKR”结构和与小鼠ANP、BNP、CNP蛋白的同源性区域,并将克隆的牛Musclin基因片段注册GenBank（EF646361）。[结论]该试验为进一步研究Musclin在牛骨骼肌中的生物学功能提供了基础资料。     

虾青素对小鼠肝脏原代细胞氧化应激的影响

【目的】研究虾青素对过氧化氢(H_2O_2)诱导小鼠肝脏原代细胞产生氧化应激的影响。【方法】原位二步灌流法提取ICR小鼠的肝脏原代细胞,用丙二醛(Malondialdehyde,MDA)作为指标、采用H_2O_2处理建立氧化应激模型。采用流式细胞仪测定细胞中活性氧(Reative oxygen species,ROS)含量及凋亡水平变化,生物化学法测定细胞中MDA和谷胱甘肽(Glutathione,GSH)的含量、超氧化物歧化酶(Superoxide dismutase,SOD)和谷胱甘肽过氧化物酶(Glutathione peroxidase,GSH-Px)的活性,用荧光定量PCR检测抗氧化酶SOD、GSH-px mRNA的相对表达量,Western-blot检测细胞核中Nrf2蛋白相对表达量。【结果】使用5μg·mL~(–1)虾青素预保护细胞3 h,10μmol·L–1H_2O_2刺激3 h的情况下氧化应激模型效果最好。虾青素降低了H_2O_2诱导后小鼠肝脏原代细胞的细胞凋亡率以及ROS、MDA和GSH含量,提升了SOD、GSH-px的活性以及SOD、GSH-px的mRNA相对表达量,抑制了Nrf2蛋白的核转移。【结论】虾青素对H_2O_2诱导产生氧化应激的肝脏原代细胞具有保护作用。     

不同笼养条件下蛋鸡健康与福利的比较研究

研究不同笼养条件下蛋鸡的健康和福利状况。选取位于北京地区的3家商品蛋鸡场,场A、B、C,其饲养密度分别为411、420和450 cm2/只。对夏季不同蛋鸡场内环境参数及空气中NH3、CO2和H2S的质量浓度进行测定,记录蛋鸡的产蛋性能和死亡率,分析异常行为的发生频率。结果表明:场C的即时风速、最大风速和平均风速均显著高于场A和B(P<0.05),场C和A的空气温度、风寒温度、应激温度、露点温度均显著低于场B(P<0.05)。NH3和CO2质量浓度各场均有显著差异(P=0.003和P=0.011),其中均以场C最低,分别为1.00和83.73 mg/m3;H2S质量浓度低于测定下限1.00 mg/m3。观察发现,场C鸡群比场A和B鸡群对外界敏感性强。蛋鸡外观评分各场差异不显著,但蛋鸡步态评分及鸡蛋污损评分各场差异显著(P=0.042和P=0.023),其中步态评分场C显著高于场A和B(P<0.05),鸡蛋污损评分场C显著低于场A和B(P<0.05)。各场中蛋鸡异常行为的发生频率无显著差异。场C入舍母鸡产蛋量显著高于场A和B(P<0.05),平均蛋重、料蛋比、平均产蛋率、高峰期产蛋率、腿病发生率、产蛋疲劳症发生率、死亡率各场均无显著差异,但场C蛋鸡生产周期显著短于场A和B(P<0.05)。3家商品蛋鸡场饲养环境、管理措施等综合因素造成的差异远大于单纯饲养密度造成的差异,为了提高现阶段我国笼养蛋鸡的健康和福利状况,应该更加重视蛋鸡整体养殖环境和管理措施的改善。     

萨能奶山羊乳腺组织5-HTR2基因的克隆与序列分析

以容易获取并具代表性的乳腺组织——奶山羊乳腺为载体,进行哺乳动物乳腺组织中5-HTR2基因的克隆,为下一步研究奶牛乳腺组织中5-HTR基因的分布及生物学特性提供理论基础.根据GenBank其他物种5- HT受体- 2(5 - HTR2)基因序列的同源序列,对奶山羊5-HTR2基因设计1对克隆引物,从奶山羊乳腺组织提取总...     

玉米SOD的分离与纯化

探索高速、快速的玉米SOD分离与纯化方法,旨在为玉米SOD的规模化生产提供依据。利用金属螯合亲和层析和DEAE-纤维素离子交换层析相结合的方法分离纯化玉米SOD,得到2种达到电泳纯的SOD组分(A、B),并对它们的基本性质进行了初步分析。SDS-PAGE法测定A、B两组分的亚基分子量分别为20 kD和16.4kD;由电泳后的定位染色情况可知,这2种SOD组分均属于Cu/Zn-SOD;等电聚焦表明,A、B两组分的等电点分别为7.2和6.9。     

Physiological Indices and Selection of Methods on Rapid Identification for Sweet Potato Drought Resistance

The relationships between the changes of relative water content （RWC）, malondialdehyde （MDA） contents, superoxide dismutase （SOD） activity and free proline contents in sweet potato leaves, and drought resistant ability under different concentration of polyethylene glycol （PEG） treatment applied at rhizosphere of sweet potato seedlings were studied. A highly positive correlation between RWC and drought resistance （r =0.783, P〈0.01）, a highly negative correlation between MDA contents and drought resistance （r = -0.848, P〈0.01）, a highly positive correlation between SOD activity and drought resistance （r = 0.777, P〈0.01） was observed. Free proline contents in leaves was not related obviously to the sweet potato drought resistance under 25% PEG treatment. The stronger the drought resistance of variety, the less decrease of RWC and increase of MDA contents, the more increase of SOD activity. By determining these physiological indices in sweet potato leaves under 25% PEG treatment, rapid identification of drought resistant ability of different varieties can be obtained in the lab.