损毁弓状核对大鼠骨微构筑学的影响

目的研究损毁大鼠下丘脑弓状核(ARC)对骨微构筑学的影响。方法新生雌性Sprague-Dawley(SD)大鼠12只,用同窝对照的方法,按体质量从轻到重编号,用抽签法随机分为实验组和对照组,每组6只。实验组大鼠于出生后第1、3、5、7、9天皮下注射10%谷氨酸单钠(MSG)4g/kg B.W,对照组同法注射等体积生理盐水。各组大鼠皆存活至200d,以3%戊巴比妥钠腹腔麻醉,用4%多聚甲醛经左心室行全身灌注,取脑作下丘脑弓状核冠状面切片,HE染色。取各组大鼠左侧胫骨,用2.5%戊二醛固定,然后将胫骨近端作矢状面锯开,用作扫描电镜研究。另取右侧胫骨和第四腰椎,常规脱钙,石蜡包埋,矢状面连续切片,胶原特殊染色,用于显示骨小梁结构。用图象分析仪对弓状核正中隆起切面和骨组织进行照片和计量。结果MSG大鼠弓状核神经细胞数量显著减少,骨的微构筑学出现明显破坏,发生了明显骨质疏松。结论(1)损毁大鼠下丘脑弓状核可导致骨微构筑学明显破坏,出现明显骨质疏松,首次命名为大鼠脑源性骨质疏松。(2)ARC参与骨代谢的调控。     

Trophic action of leptin on hypothalamic neurons that regulate feeding

In adult mammals, the adipocyte-derived hormone leptin acts on the brain to reduce food intake by regulating the activity of neurons in the arcuate nucleus of the hypothalamus (ARH). Here, we report that neural projection pathways from the ARH are permanently disrupted in leptin-deficient (Lepob/Lepob) mice and leptin treatment in adulthood does not reverse these neuroanatomical defects. However, treatment of Lepob/Lepob neonates with exogenous leptin rescues the development of ARH projections, and leptin promotes neurite outgrowth from ARH neurons in vitro. These results suggest that leptin plays a neurotrophic role during the development of the hypothalamus and that this activity is restricted to a neonatal critical period that precedes leptin's acute regulation of food intake in adults.     

苯甲酸雌二醇对L-谷氨酸单钠损毁弓状核雌性大鼠血脂代谢的影响

目的观察苯甲酸雌二醇（EB）对L广谷氨酸单钠（MSG）损毁弓状核雌性大鼠体质量、脂肪湿质量及血脂代谢的影响。方法皮下注射MSG建立新生SD雌性大鼠弓状核损毁模型。造模大鼠于30日龄时分别肌肉注射EB0．24mg／kg（MSG＋EBL组）、0．48mg／kg（MSG＋EBH组）,隔天1次,共30次;停止注射后15d处死大鼠,检测体质量、脂肪湿质量、血脂、血清雌二醇（E2）。结果模型组大鼠体质量、脂肪湿质量／体质量、血清总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL—C）都明显升高（P〈0．05）,而E2、高密度脂蛋白胆固醇（HDL-C）显著降低（P〈0．05）。EB处理后大鼠的体质量、脂肪湿质量／体质量、TC、TG、LDL-C均显著回降（P〈0．05）,而E2、HDL—C显著回升（P〈0．05）;MSG＋EBH组与MSG＋EBI组比较,其各项指标差异均无统计学意义（P〉0．05）。结论EB对弓状核损毁的雌性大鼠血脂代谢紊乱有治疗作用。     

Modulation of brain reward circuitry by leptin

Leptin, a hormone secreted by fat cells, suppresses food intake and promotes weight loss. To assess the action of this hormone on brain reward circuitry, changes in the rewarding effect of lateral hypothalamic stimulation were measured after leptin administration. At five stimulation sites near the fornix, the effectiveness of the rewarding electrical stimulation was enhanced by chronic food restriction and attenuated by intracerebroventricular infusion of leptin. In contrast, the rewarding effect of stimulating neighboring sites was insensitive to chronic food restriction and was enhanced by leptin in three of four cases. These opposing effects of leptin may mirror complementary changes in the rewarding effects of feeding and of competing behaviors.     

玉米秸秆饲料饲喂羊的效果研究

玉米秸秆经过青贮和微贮之后,粗纤维含量分别下降1.88、1.96个百分点,而粗蛋白、无氮浸出物含量都有所提高。在羊饲养试验中,青贮玉米秸秆饲喂的湖羊比微贮玉米秸秆饲喂的湖羊日增重高7.1 g,而杜湖杂交羊则是青贮玉米秸秆组比微贮玉米秸秆组日增重高14.5 g;湖羊与杜湖杂交羊饲喂微贮玉米秸秆组日增重分别为73.6 g、75.8 g。可见玉米秸秆通过青贮和微贮能转化为很好的饲料,而微贮不受时间的限制,且营养与青贮差不多,所以在青贮受限的情况下,可采用微贮的方法制作玉米秸秆饲料。     

胶体金免疫层析法快速诊断犬弓首蛔虫病

[目的]建立了一种能快速诊断犬弓首蛔虫病方法。[方法]以胶体金标SPA和犬弓首蛔虫（Toxocara canis）抗原蛋白制备免疫层析试纸条,并对其灵敏度和特异性进行评价。采用该试纸条和虫检法对200份犬血清样本进行检测,以评价该试纸条对现场材料的检测效果。[结果]组装的犬胶体金免疫层析试纸条的最低检测线为0.20μg/ml,灵敏度很好;与犬的其他寄生虫病的阳性血清进行反应,均成阴性;对200份犬血清样本的阳性检出率为10%,而虫检法的阳性检出率为2%。[结论]胶体金免疫层析法诊断犬弓首蛔虫病具有操作简便、灵敏度高、特异性强的优点,可用于犬弓首蛔虫病的快速检测。     

Energy transduction: inhibition of cockroach feeding by naphthoquinone

1,4-Naphthoquinones inhibit feeding of Periplaneta americana by complexing with sulfhydryl groups of receptor protein in sensory neurons, by oxidizing the sulfhydryl groups, and by being reduced.     

Columnar architecture sculpted by GABA circuits in developing cat visual cortex

The mammalian visual cortex is organized into columns. Here, we examine cortical influences upon developing visual afferents in the cat by altering intrinsic gamma-aminobutyric acid (GABA)-mediated inhibition with benzodiazepines. Local enhancement by agonist (diazepam) infusion did not perturb visual responsiveness, but did widen column spacing. An inverse agonist (DMCM) produced the opposite effect. Thus, intracortical inhibitory circuits shape the geometry of incoming thalamic arbors, suggesting that cortical columnar architecture depends on neuronal activity.     

肉鸡添加益生素对比饲养试验

随机抽取艾维茵鸡苗各500羽,分成试验组和对照组,试验组按每100kg饮水添加益生素300g,饲养条件和管理一致,饲养38d。试验组料肉比为1.88∶1,对照组料肉比为1.96∶1。试验组的纯利润为2416.8元,比对照组多收益274.2元。     

Reversal of experimental parkinsonism by lesions of the subthalamic nucleus

Although it is known that Parkinson's disease results from a loss of dopaminergic neurons in the substantia nigra, the resulting alterations in activity in the basal ganglia responsible for parkinsonian motor deficits are still poorly characterized. Recently, increased activity in the subthalamic nucleus has been implicated in the motor abnormalities. To test this hypothesis, the effects of lesions of the subthalamic nucleus were evaluated in monkeys rendered parkinsonian by treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The lesions reduced all of the major motor disturbances in the contralateral limbs, including akinesia, rigidity, and tremor. This result supports the postulated role of excessive activity in the subthalamic nucleus in Parkinson's disease.     

猪水泡病病毒RT-PCR检测方法的建立

根据基因库中的猪水泡病病毒(SVDV)高度保守的VP1基因的序列,设计了与SVDV互补的2对特异性引物,通过对影响PCR扩增因素的筛选,成功地扩增出251bp和366bp特异性条带,将其克隆入pMD18-T载体中,并进行序列测定,与已发表的SVDV基因比较发现,核苷酸的同源性为100%,证实为SVDV的VP1段基因。通过检测FMDV、VSV、BHK21细胞等,对照的扩增结果均为阴性,验证其特异。对SVDVRNA进行10倍系列稀释后检测,结果SVDVRNA在10-4稀释度时仍能检测到阳性,说明具有较好的敏感性。此项试验能稳定、高效、快速地检测出猪水泡病病毒。     

Effects of absence of saliva on blood feeding by mosquitoes

The salivary glands of Aedes stimulans (Walker) are the source of an antigen which produces typical bite reactions in men and laboratory rabbits. If the main salivary duct is cut, the reaction is not produced when the mosquito bites. Lack of saliva does not affect the intake or movement of blood into the mid-gut, nor does it prevent the development of eggs. The presence of ain a-nesthetic component in saliva is suggested.     

性成熟启动时间不同的母鸡瘦素及其受体mRNA表达的差异

为探讨瘦素（leptin）及其受体在禽类性成熟启动过程中的作用,试验采用120羽60日龄伊莎蛋母鸡,随机均分为2组,分别饲养于光照逐渐延长（以光／暗为8h／16h为起点每周增加0．5h光照,简称长光照组）和恒定的短光照（光／暗为8h／16h,简称短光照组）条件下,记录体重变化与性成熟时间。长光照组和短光照组母鸡分别于136和151日龄时开产。在136日龄时,每组取10只鸡宰杀后取血液、脂肪和下丘脑组织,分别检测血清leptin水平、脂肪leptin mRNA与下丘脑leptin受体mRNA的表达。结果表明：136日龄时,长光照组和短光照组母鸡血清雌二醇（E2）和leptin水平均无显著差异（P〉0．05,n=10）。相对定量RT-PCR结果显示：136日龄时,长光照组母鸡脂肪leptin mRNA表达丰度极显著高于短光照组（P〈0．01,n=10）,但下丘脑leptin受体mRNA的表达水平无显著差异（P〉0．05,n=10）。以上结果提示：15d的性成熟时间差异并不伴随产蛋母鸡血清leptin及下丘脑leptin受体mRNA表达水平的显著变化,而脂肪leptin mRNA表达水平与血清leptin蛋白水平的不一致性则提示循环leptin的其他组织来源。     

采用真空泵法快速获取猪卵母细胞

试验比较了真空泵法与传统的手动抽吸法对猪卵母细胞成熟效果的影响,结果表明,真空泵法在平均使用时间、卵母细胞的收集效率及A、B级卵母细胞所占的比例方面均优于手动抽吸法,在卵母细胞的成熟率方面稍低于手动抽吸法。表明真空泵法是一种有效的猪卵母细胞采集方法。     

宿根福禄考组织培养快速繁殖技术

以宿根福禄考茎尖和茎节作外植体进行离体快速繁殖,结果显示：无菌芽诱导的适宜培养基为MS＋1．0mg．L^-1BA＋3％糖＋6．5g·L^-1琼脂粉,茎节在该培养基上无菌芽的诱导率为87．9％;丛芽增殖适宜培养基为MS＋0．5mg．L^-1BA＋3％糖＋6．5g·L^-1琼脂粉,增殖率为6．8;生根的适宜培养基为1／2MS＋0．3mg·L^-1IBA＋0．3mg·L^-1NAA＋2％糖＋6．5g·L^-1琼脂粉,试管苗能在该培养基上分化出良好的根系,生根率达91．7％。     

药用植物头花蓼的组织培养快速繁殖

以头花蓼带节茎段为外植体进行组培快速繁殖试验,结果表明:在MS培养基上腋芽的诱导率最高,迭93.3%;添加6-BA 4.0mg/L对芽的增殖生长效果较好,增殖倍数为4.2;在1/2 MS NAA 0.2 mg/L培养基上生根效果最好,迭100%;组培苗移栽至蛭石:腐殖土(1:1)的基质中成活率最高,迭93.3%,且生长旺盛.