Acetylcholine: release from neural tissue and identification by pyrolysis--gas chromatography

Gas chromatographic analysis showed acetylcholine to be the only choline ester released from innervated longitudinal muscle of the guinea pigileum by electrical stimulation. The amount of acetylcholine measured by gas chromatography agreed almost exactly with that measured by bioassay. Denervated longitudinal muscle produced no acetylcholine, and treatment of the muscle with tetrodotoxin markedly reduced acetylcholine output. The method permits the recovery and quantitation of amounts of acetylcholine as low as 5 nanograms in 5 milliliters of tissue perfusates.     

Biosynthesis of a vasotocin-like peptide in cell cultures from pineal glands of human fetuses

Cultured cells from pineal glands of human fetuses release into their media a substance that has antidiuretic and hydroosmotic activities. The ratio of these activities as well as their susceptibility to tryptic digestion, specific oxidative inactivation by tyrosinase, and reductive inactivation by sodium thioglycollate, indicates the presence of a basic peptide, presumably identical with arginine vasotocin. The total amount of this peptide released into the culture media during 38 days of incubation is about ten times greater than the amount contained in nonincubated pineal glands from fetuses of the same age, strongly suggesting that fetal ependymal cells from the pineal gland can synthesize in vitro a peptide similar to arginine vasotocin.     

Opossum fetuses grown in culture

Opossum fetuses explanted at limb bud stages have been successfully grown in culture for periods up to 20 hours. Blood circulation was maintained, and organogenesis continued at about the same rate as in vivo.     

Plantlets from aspen tissue cultures

After 2 weeks in the dark, leafy shoots were initiated on subcultured callus tissue of triploid quaking aspen on Wolter's medium without auxin and with 6-benzylaminopurine at 0.05, 0.10., 0.15, or 0.20 milligram per liter substituted for kinetin. Shoots transferred to Wolter's medium under light (323 milliphots) grew large roots and were isolated as plantlets.     

以鲁西黄牛为受体的高产奶牛胚胎移植研究

以自然发情的鲁西黄牛为受体,移植经性控技术生产的高产奶牛7日龄雌性冷冻胚胎,共移植合格受体牛5 516头,移植后60～80d进行直肠孕检,怀孕2 228头,移植准胎率为40.39％;共繁殖奶牛犊牛1346头,其中母牛1 279头,公牛67头,胚胎性别控制率为95.02％.左侧与右侧卵巢排卵移植准胎率分别为35.14％和43.15％,差异极显著(P＜0.01);春季与秋季的移植准胎率分别为36.93％和43.53％,秋季明显高于春季,差异极显著(P＜0.01);黄牛不同黄体级别A级、B级、C级的准胎率分别为39.16％、41.70％和33.42％,A级与B级移植准胎率差异不显著(P＞0.05),B级与C级移植准胎率差异极显著(P＜0.01);移植单胚与双胚的受体牛准胎率分别为40.73％和38.24％,差异不显著(P＞0.05).     

Transplantation of axolotl heads

Favorable conditions for organ transplantation exist for some populations of European laboratory axolotls, making transplantations of heads possible. Survival of the transplants is prolonged because homograft reactivity of the host animals is absent. Heads transplanted to the backs of other axolotls grow rapidly and show many reactions characteristic of normal axolotl heads. The behavior of the transplants is independent of that of the host animals.     

树木全冠移植

随着城市园林绿化节奏的加快,城市需要更多的绿量来缓解日益严重的环境问题,因而逐步掀起了"大树进城风"等绿化热潮。但"残肢断臂"的大树移植生态效益不高,景观效果差,收效甚微。为弥补其不足,尽快体现绿化效益,达到一定的即时效果,树木全冠移植成为近年来极为推崇的绿化技术。作者通过对树木全冠移植产生的根源及其利弊进行分析,提出了科学合理的树木全冠移植技术,并对其发展方向进行了展望。     

不同移栽方式对秧苗返青分蘖的影响

通过大田对比试验,分析不同移栽方式对秧苗返青分蘖的影响,结果表明,钵育移栽植伤低,返青快,分蘖多,生育进程快,是黑龙江垦区水稻栽培移栽方式的趋势。     

Cyclic adenosine monphosphate, metabolites, and phosphorylase in neural tissue: a comparison a methods of fixation

Fixation of rat brain tissue by freeze-blowing, microwave irradiation, immersion of whole rats in liquid nitrogen, and decapitation into liquid nitrogen indicates that postmortem changes in metabolites and enzyme forms are minimal in freeze-blown brains. Cyclic adenosine monophosphate levels are lowest in microwave-irradiated brains, which has been interpreted by some investigators to indicate rapid fixation and minimal anoxia. However, the changes in phosphocreatine, adenosine triphosphate, lactate, and phosphorylase clearly demonstrate that fixation by freeze-blowing or immersion in liquid nitrogen more closely approximate the state in vivo.     

健康猪扁桃体和流产胎儿分离猪瘟病毒E2基因的序列分析

用RT-PCR技术对来自广西不同地区的120份健康猪扁桃体和84份流产胎儿材料进行猪瘟病毒检测,得到9份阳性病料,选取其中1份健康扁桃体和 5份流产胎儿阳性材料进行猪瘟病毒E2基因克隆测序,应用DNAstar序列分析软件对6个广西毒株与HCLV、Shimen等国内外毒株进行同源性比较.结果显示,广西毒株之间核苷酸和推导的氨基酸同源性分别为93.1%～99.6% 和86.3%～99.2%,6个广西毒株E2基因的所有Cys位点都没有变异,可推测CSFV E2蛋白在抗原结构方面依然保持很高的稳定性;与标准毒株和疫苗毒相比,广西毒株在具有中和特性的B、C区域内721和724氨基酸位点发生了变异;遗传进化树分析表明,猪瘟病毒主要分为两大群和一个另类,广西株皆属于基因群Ⅰ,与我国的主要参考毒株HCLV、Shimen属于同一基因群,说明广西CSFV株与HCLV、Shimen变异不大.