Direct pathway to the brain

Whole-body autoradiographic stuidies demonstrated that, when isotopically labeled glucose is placed in the ligated oropharynx, there is a rapid movement of the isotope directly to the intracranial cavity. This passage involves nonspecific diflision, bypassing all recognized rouctes to the brain.     

野生动物用狂犬病口服疫苗复合免疫佐剂与诱饵的筛选及其对免疫效果的影响

本研究旨在筛选最佳的复合佐剂和口服疫苗诱饵组方,并将筛选出的复合佐剂口服免疫试验小鼠,检测免疫小鼠血清IgG和肠道IgA抗体效价。采用牛肉粉、鸡肉粉、鱼肉粉、奶粉、血粉为主要原料,以细菌脂多糖、氢氧化锌、枸杞多糖、甘露低聚糖为疫苗免疫佐剂,通过正交试验方法将复合免疫佐剂和口服疫苗诱饵与狂犬病SRV₉病毒混匀后口服免疫试验小鼠,并对免疫动物血清IgG抗体效价进行检测。优化的复合佐剂组方是细菌脂多糖100 μg、氢氧化锌0.8 mg、枸杞多糖50 mg、甘露低聚糖10 mg,免疫小鼠血清IgG抗体含量为3.24 mg/L,肠道IgA抗体含量为1.56 ng/mL;在疫苗诱饵的投喂试验中,狼、狐狸、犬、猫对鱼肉味诱饵的采食率最高,其次是血味和奶味诱饵;诱饵与狂犬病SRV₉病毒混匀后口服免疫小鼠28 d后,血清IgG平均值为1.20 U/L。本试验筛选出口服疫苗复合免疫佐剂,经筛选制备的鱼肉味诱饵具备高采食性,适合野生食肉类动物口服疫苗的制备。可增加狂犬病SRV₉病毒的免疫效应,为进一步研发重组减毒狂犬病口服疫苗提供了必要的技术支撑。     

狂犬病口服疫苗SRV9毒株基因序列的生物信息学分析

为了解狂犬病口服疫苗SRV₉毒株的基因序列与生物学特性的关系,并就其主要抗原位点与国内外现用狂犬病疫苗生产毒株进行比较,明确其作为口服疫苗株的分子基础,本试验通过RT-PCR方法对狂犬病口服疫苗SRV₉毒株的N、P、M、G、L基因分别进行克隆,并分别连接于pMD19-T载体,经酶切、测序鉴定后,用DNAStar软件对全基因序列进行分析,并与11株目前生产用狂犬病疫苗株进行基因序列比对分析和主要抗原位点的比较.狂犬病口服疫苗SRV₉毒株N、P、M、G、L基因序列与其他毒株的序列同源性为81.8%~100.0%,由全基因组进化树可知,SRV₉毒株与所有疫苗株在同一个大的分支内,均属于基因Ⅰ型,其中狂犬病口服疫苗SRV₉毒株与ERA、SAD B19、SAG-2等口服疫苗株的进化距离最近,而与疫苗生产毒株aG、RC-HL 之间的进化距离则较远.狂犬病口服疫苗SRV₉毒株与各疫苗株的糖蛋白不同结构区的氨基酸同源性分析表明,狂犬病口服疫苗SRV₉毒株与SAD B19、SAG-2、ERA口服疫苗株的膜外区、跨膜区和膜内区的同源性最高.狂犬病口服疫苗SRV₉毒株的基因组结构和抗原基因位点特征均与目前生产用口服疫苗株相似,这为今后狂犬病口服疫苗的研制和通过分子生物学技术构建基因重组弱毒疫苗株的研究提供了试验依据.     

Emesis in birds

Comparative studies of emesis in the herring gull, pigeon, chicken, and cowbird were conducted, using orally administered copper sulfate and intravenously administered copper sulfate, hydergine, apomorphine, and lanatoside C. A response to every emetic was elicited from some birds. However, the individual and species differences among the birds were as great as those among mammals. Further, the response of the avian species studied did not indicate that any of them could be used to predict how a specific mammal would react. The differences in response to the emetics by the birds do not offer any simple pattern related to feeding behavior.     

NaCl胁迫对扁桃砧木可溶性蛋白质和脯氨酸含量的影响

利用3种扁桃砧木，进行不同浓度盐胁迫处理。结果表明：石头扁桃叶片可溶性蛋白质含量在NaCl胁迫下5，10，20d后随盐浓度的增大先升高后下降，但盐胁迫20d后比其他处理区下降幅度大。脯氨酸含量各处理区随盐浓度的增大而升高，盐胁迫5d和10d后浓度为350mmol／L时达到最大值，20d后各处理区出现大幅度下降趋势，而且盐浓度为350mmol／L处理区的植株因高盐浓度．处理时间长而死亡。桃扁桃叶片可溶性蛋白质含量在盐处理5d和10d后随盐浓度的增大先升高后下降，在300mmol／L时达到最大值，20d后随盐浓度的增加有明显下降。这说明桃扁桃受到一定的盐胁迫时间后才表现出反应。脯氨酸含量均随盐浓度的增大而迅速升高，在盐胁迫5，10，20d后均在浓度为350mmol／L时达到最大值。毛桃叶片可溶性蛋白质含量在10d和20d后各处理区都出现下降趋势。但20d后各处理区的变化趋势比较平缓，差异变化不太明显。脯氨酸含量均在浓度为350mmol／L时达到最大值，而且每个处理区积累的脯氨酸含量比其它两个砧木的pro含量高。5，10，20d的含量分别比对照提高了18．64倍、9．16倍和18．10倍。这就说明蛋白质达到平衡时．脯氨酸急剧上升。通过本研究初步判断毛桃具有较强的抗盐能力。     

The behaviour of calcium-deficient chickens

Growing broilers were deprived of calcium to ascertain whether they could form a specific hunger for calcium. When their blood‐calcium levels were significantly lower than those of the control birds they were allowed a choice between two mashes, differing only by the absence or presence of a calcium salt. In two experiments the deprived birds discriminated in favour of the calcium rich mash. However the preference broke down when the calcium salt was offered in the form of calcium lactate in the drinking water, for both the deprived and control birds preferred distilled water. Finally deprived birds were tested to find out whether calcium deprivation led to a greater interest in bizarre objects of edible size, for specific hungers may lead to exploratory behaviour from which the animal may learn to correct its deficiency. The calcium deprived birds were found to show more interest in bizarre objects of edible size.     

Effects of excessive dietary zinc or zinc/cadmium and tapeworm infection on the biochemical parameters in rats

The main objective of this study was to determine which biochemical blood parameters can serve as indicators of Zn or Zn/Cd burden and tapeworm infection. This study was performed on 44 Wistar male rats during a 6-week period, when rats were or were not fed a zinc/cadmium rich diet and were or were not infected with tapeworms (Hymenolepis diminuta). Total protein, albumin, urea, glucose, triacylglycerols, non-esterified fatty acids, cholesterol, alkaline phosphatase, aspartate aminotransferase, uric acid, Mg, Ca, P and Zn levels were analysed. Control rats with tapeworm infection had significantly higher (p ≤ 0.05) total protein, urea and phosphorus concentrations than did rats unaffected by any experimental factor. Rats given overdoses of zinc lactate exhibited significantly lower glucose levels than did the other rats, especially those infected with tapeworms. Low glucose level in uninfected rats indicate a Zn overdose; high doses of zinc lactate likely decrease levels of glucose via cortisol, which is released during stress. Rats fed the Zn/Cd hyperaccumulating plant Arabidopsis halleri and infected with tapeworms had significantly higher (p ≤ 0.01) cholesterol and urea levels but lower zinc, triacylglycerol, and alkaline phosphatase levels than did rats fed the same diet but free of tapeworms. The increase of alkaline phosphatase level in uninfected rats may indicate both Zn/Cd burden and rat liver damage. Overall, this study not only supports the theory that H. diminuta can serve as a promising model for helminth therapy of the host mammal but also confirmed that this tapeworm is capable to protect somehow the host organism from the harmful effects of heavy metals.