Melatonin Lowers Plasma Prolactin Levels in Female Red Deer (Cervus elaphus)

The aim of the study was to determine the effect of exogenous melatonin treatment on circulating prolactin levels in red deer. Melatonin was administered from 12 June 1984 (day 1) to lactating and non-lactating hinds in the feed daily at 1600 h, and to non-lactating hinds by a subcutaneous implant. Average concentrations (ng/ml) of prolactin in plasma taken serially over 15-h periods were significantly higher for untreated hinds than for melatonin-treated animals on day 15 whether lactating (66-133 v. 23-28, P less than 0.05) or non-lactating (28-174 v. 8-13, P less than 0.01), remained higher on day 36 (lactating: 41-152 v. 15-21, P less than 0.05; non-lactating: 21-50 v. 1-7, P less than 0.001) but had decreased to similar levels on day 72 (lactating: 5-24 v. 7-17; non-lactating: 2-9 v. 0-4). The advanced reduction in plasma prolactin for all melatonin-treated hinds was associated with an advanced onset of seasonal breeding activity.     

桑椹果酒酵母筛选及发酵性能

从桑椹成熟果实、桑叶以及桑果园的土壤采样，进行桑椹果酒专用酵母的筛选，得到一株在性能上优于对照菌葡萄酒干酵母的酵母菌Y11。该菌起酵快，从第2天开始糖度大幅度下降，酒精度快速上升，发酵第4天酒精体积分数即可达到10％以上。发酵过程pH值变化趋势比较平缓，发酵结束后高级醇量符合要求。综合发酵性能及感官评定，表明该菌能代替葡萄酒干酵母用于桑椹果酒的生产。     

阿弗菌素产生菌SIPI-AV-99081的选育

阿弗菌素链霉菌SIPI-AV-99081采用UV和NTG进行诱变处理。选育得到一高产菌株和几个典型的突变株。高产菌株AV-h-360的阿弗菌素B1的生产能力较出发菌株提高了3倍，AV-m-486和AV-m-796为阿弗菌素合成阻断突变株，它们都不能产生天然的阿弗菌素。     

Breeding for 50-kHz Positive Affective Vocalization in Rats

Adolescent and adult rats exhibit at least two distinct ultrasonic vocalizations that reflect distinct emotional states. Rats exhibit 22-kHz calls during social defeat, drug withdrawal, as well as in anticipation of aversive events. In contrast, 50-kHz calls are exhibited in high rates during play behavior, mating, as well as in anticipation of rewarding events. The neurochemistry of 22-kHz and 50-kHz calls closely matches that of negative and positive emotional systems in humans, respectively. The aim of this study was to replicate and further evaluate selective breeding for 50-kHz vocalization, in preparation for the analysis of the genetic underpinnings of the 50-kHz ultrasonic vocalization (USV). Isolate housed adolescent rats (23–26 days old) received experimenter administered tactile stimulation (dubbed tickling), which mimicked the rat rough-and-tumble play behavior. This stimulation has previously been shown to elicit high levels of 50-kHz USVs and to be highly rewarding in isolate-housed animals. Each tickling session consisted of 4 cycles of 15 seconds stimulation followed by 15 seconds no stimulation for a total of 2 min, and was repeated once per day across 4 successive days. Rats were then selected for either High or Low levels of sonographically verified 50-kHz USVs in response to the stimulation, and a randomly selected line served as a control (Random group). Animals emitted both 22-kHz and 50-kHz types of calls. After 5 generations, animals in the High Line exhibited significantly more 50-kHz and fewer 22-kHz USVs than animals in the Low Line. Animals selected for low levels of 50-kHz calls showed marginally more 22-kHz USVs then randomly selected animals but did not differ in the rate of 50-kHz calls. These results extend our previous findings that laboratory rats could be bred for differential rates of sonographically verified 50-kHz USVs.     

泡桐刨花用作实验小鼠垫料的研究

泡桐茎高大 ,通气组织蓬松 ,富含纤维。测定 4 8h吸水量 ,每克泡桐刨花吸水 3.31± 0 .2 4g ,椴木刨花吸水 3.4 2± 0 .18g ,两者差异无显著性 (P >0 .0 5)。但高于玉米棒芯吸水量 2 .4 3± 0 .17g(P <0 .0 5)。不同年龄小鼠 (指孕鼠、乳鼠、青年鼠 )对泡桐刨花垫料的适应性均较好 ,生长发育和繁殖良好。以泡桐刨花作垫料 ,饲养的KM小鼠在 6个月和 12个月时 ,活体骨髓多染性红细胞微核率分别为 ( 3.2 6± 0 .37)‰和( 3.60± 0 .4 5)‰ ,均在正常范围之内。表明泡桐刨花垫料没有致畸作用。     

哈巴河铁热克提林牧区蜱类调查研究

作者于1999年5月在新疆哈巴河铁热克提林牧区调查莱姆病时,采用布旗法和宿主检蜱法,对当地莱姆病媒介蜱类作了调查研究,捕获蜱类标本3090只,经整理鉴定,共系8种,其中森林革蜱D.silvarum1543,占捕获总数49.94％,银盾革蜱D.niveus1099只,占35.57％,草原草蜱D.nuttalli383只,占12.49％,边缘革蜱D.marginatus58只,占1.88％,嗜群血蜱H.concin-ma、铃头血蜱H.campanulata、全沟硬蜱I.persulcatus和残缘璃眼蜱Hy.detrtum共7只,占0.22％。当地蜱类在不同生境、不同寄主和不同时间内,其种类组成、活动及数量动态各不相同。     

Rats bred for ethanol sensitivity: Impairment of swimming by ethanol and pentobarbital

Rats selectively bred for disparate degrees of ethanol-induced depression of spontaneous locomotor activity (most affected = MA; least affected = LA) were trained on a swim task. Undrugged rats of the MA line swam significantly faster than rats of the LA line. Ethanol, 0.0–2.25 g/kg i.p., produced dose-dependent increases in swim time in rats of the 13th generation (F13). Averaged over trials, these increases were greater in LA than in MA rats and greater in males than in females, but there was no sex difference in peak impairment. Increases in swim time were uncorrelated with predrug performance. These findings were confirmed in younger F17 rats receiving 1.75 g EtOH/kg i.p. Although the lines differed in ethanol-induced impairment, F17 males of the two lines were not differentially impaired by pentobarbital (12.5–22.5 mg/kg, i.p.). The existence of task-dependent line differences in ethanol sensitivity emphasizes the nonunitary nature of ethanol-induced behavioral depression.     

青霉素高产菌株的推理选育

目的：筛选一株优良的抗生素产生菌。方法：通过人为诱变来动摇产生菌原有的严密控制机制。结果：得到一种抗生素生物合成能力异常的突变株。结论：此方法可过量合成人们所期望的抗生素。     

转基因动物的经济开发前景

本文综述了转基因动物在生物反应器、异种移植、品种改良等诸多具有经济开发前景的方面的应用,并评述了其存在的问题和今后的发展趋势。