Morphogenesis of canary poxvirus and its entrance into inclusion bodies

A virus isolated from a natural outbreak of canarypox was replicated on the chorioallantoic membranes of chicken embryos, and its ultrastructure and development were observed. Electron microscopy of thin sections of pocks produced on the chorioallantoic membranes revealed a variety of developmental forms which appear similar to those demonstrated in studies of vaccinia, ie, viroplasm or viral factories; immature, undifferentiated virions partially enclosed by membranes; completely enclosed nondifferentiated spherical or oval virions; immature virions with discrete nucleoids; and the more compact brick-shaped mature virions. Two types of A-type inclusions were noted: those with virions around the periphery, and those filled with virus particles. The appearance of mature viruses within the inclusion bodies and different stages of viruses outside the inclusion indicate that in a course of development, maturing poxvirus may enter the inclusion bodies as they acquire surface tubules on their envelopes. Mature virions also were seen budding out of the cell membrane, apparently enveloped in a portion of the membrane. Studies showing the entrance of poxvirus into inclusion bodies have not been reported. In this report, electron micrographs are shown of viruses entering inclusion bodies.     

Observations on the New World screwworm fly in Libya and the risk of its entrance into Egypt.

Data on traumatic myiasis caused by Cochliomyia hominivorax in Libya were reported from August 1988 until February 1989. A total of 468 cases of screwworm myiasis were recorded in seven species of livestock and 229 humans, mainly children, were also found to be infested. Cattle and sheep were the most common hosts in livestock. In cattle, the principal infestation site was the umbilicus of neonates; in sheep, it was mainly the fatty tail. Animal myiasis reached its peak in October and November, but disappeared abruptly in winter on the onset of cold weather. Screwworm distribution was confined to the northwest of Libya. The potential dispersion of the fly from this area and the possibility of infestation of other countries, particularly Egypt, are discussed. Food and Agriculture Organization (FAO) efforts to confront the New World screwworm problem in Africa are mentioned.     

亚洲小车蝗飞行能力及其与种群密度的关系

在室内对我国北方草原优势种蝗虫--亚洲小车蝗（Oedaleus asiaticus）成虫连续悬吊飞行测试12 h,分析成虫飞行能力及其与种群密度的关系。结果表明,亚洲小车蝗高密度种群的飞行能力较强,最远的累计飞行距离可达15 km,累计飞行时间超过2 h。不同日龄的成虫飞行能力有显著差异,羽化后4日龄成虫的飞行能力较弱,以13日龄成虫的飞行能力最强,20日龄显示出下降趋势。雌雄个体间飞行能力无显著差异（P>0.05）。低密度种群成虫不具备远距离飞行的能力,各日龄成虫累计飞行距离和飞行时间均极显著短于同日龄的高密度区个体（P<0.01）。     

桑树四倍体的诱导及其应用

采用物理的辐射处理 ,化学的秋水仙碱处理和生物的杂交等技术方法 ,培育出桑四倍体材料 98份。其中用杂种实生幼苗秋水仙碱诱导的四倍体中 ,有些有较高的产叶量 ,可直接应用于生产 ;而大多数人工诱导的桑四倍体 ,则用作培育三倍体的亲本。诱导和利用人工四倍体资源 ,与二倍体桑杂交 ,以及无性固定三倍体或配制三倍体杂优组合 ,仍是桑树多倍体育种的主攻方向。     

温室养蝎新技术及其消除冬眠的效果

蝎 ,俗称蝎子 ,属于节肢动物门 ,蛛形纲 ,蝎目。我国有记载的蝎子有 1 5种 ,其中东亚钳蝎是我国最常见的一种 ,也是我国人工养殖的主要品种 ,它主要分布在华北和东北一带。1　花房型无冬眠养蝎新技术原理常温下 ,蝎子从出生到成年约需 3年 ,时间较长。究其原因 ,主要是蝎子为冷血变温陆栖动物 ,它的体温随环境温度变化而变化。当温度在 0～ 7℃时进入冬眠状态 ,当温度达到2 5～ 39℃时才能正常生长发育和繁殖。根据蝎子的这一生物学特性 ,结合南方 (尤其是广西 )的自然气候特点 ,在气温高的季节采用常温养殖 ,在气温低的季节采用炉火 (用煤 …     

Induction of labor and its synchronization in hogs]

The authors describe the synchronization of farrowing by the induction of parturition with a prostaglandin F2alpha analogue (Cloprostenol). The time sequence of the beginning of parturitions was recorded in 147 sows after administration of 175 microgram Cloprostenol. 93.7% of the parturitions take place between the 14th and 39th hour after administration, the peak time being between the 24th and 27th hour (31.2%). The schedule of the farrowing days is described as a prerequisite for a qualitative change in the organization of work in large pig herds.     

柑橘黄龙病菌在贡柑叶片中的分布分析

本研究从不同黄龙病症、叶片不同部位、不同树势三个方面综合分析贡柑叶片中黄龙病菌（Las）的分布。结果表明：（1）斑驳与均匀黄化是与黄龙病最相关的症状且斑驳黄化贡柑叶片中Las含量最高,缺锌黄化具有黄龙病阳性与阴性两种类型样品,无明显黄化症状但革质化的叶片中也含有Las且含量极高。（2）斑驳与均匀黄化典型黄龙病症的贡柑叶片中,Las的含量从叶尖到叶柄以及从叶片到主叶脉均呈现递增趋势,且主叶脉与叶柄的含量最高。（3）在感染初期顶端抽黄梢而下侧健康的病树中,Las的含量从发病严重的部位到树势强的部位呈现递减趋势。这些研究发现将为黄龙病症的田间诊断以及分子检测的样品采集提供有效线索,对黄龙病的有效防控具有重要意义。     

锅炉的高效操作及维护

饲料成本在畜禽生产的总成本中占有相当大的比例,约在60％～70％。饲料成本中原料是最主要的部分,但加工成本也不容忽视。饲料加工成本很大一部分和制备饲料制粒前调质或蒸汽压片谷物等环节所需的蒸汽有关,这部分成本往往被人所忽视直至导致重大问题。本文旨在综述蒸汽制备的一些基本原理,并提出一些改善锅炉操作效率的原则。     

Role of M cells and macrophages in the entrance of Mycobacterium paratuberculosis into domes of ileal Peyer's patches in calves

Ligated ileal loops of calves were inoculated with live and heat-killed Mycobacterium paratuberculosis and were examined by light and electron microscopy. At 5 hours after inoculation, acid-fast bacilli were in subepithelial macrophages, but not in M cells covering domes. At 20 hours, more than 50 acid-fast bacilli per cross section were in subepithelial macrophages in domes. Both living and heat-killed bacilli passed into domes. Addition of anti-M. paratuberculosis bovine serum to the inoculum enhanced entry of bacteria into domes. By electron microscopy, intact bacilli with electron-transparent zones (peribacillary spaces) were in the supranuclear cytoplasm of M cells at 20 hours. M cells also contained vacuoles, including electron-dense material interpreted as degraded bacilli. Subepithelial and intraepithelial macrophages contained bacilli and degraded bacterial material in phagosomes. These results suggest that calf ileal M cells take up bacilli, and that subepithelial and intraepithelial macrophages secondarily accept bacilli or bacterial debris which are expelled from M cells.     

A novel phenomenon predicting the entry into a state of hibernation in Syrian hamsters (Mesocricetus auratus)

When Syrian hamsters (Mesocricetus auratus) are bred in a cold and short-day environment, most animals go into hibernation after a certain period of time. However, to date it has not been possible to predict which hamster will enter hibernation. In this study, we subcutaneously implanted thermo-loggers in hamsters bred in the cold environment, and recorded the subcutaneous temperature at short intervals until they went into hibernation. A time series analysis of temperature disclosed that a fall of 0.4 to 0.8 degrees C in subcutaneous temperature was seen 5 to 16 days before entering hibernation, and this phenomenon continued for three days or more. No hamster went into the hibernation without displaying this signal. Although the mechanism by which this phenomenon takes place is not clear, it is a sign from the body, which is useful for indicating if a hamster will enter hibernation shortly.     

鸡T淋巴细胞IL－2的体外诱生及活性检测

经Ｌ１６（４５）正交试验选择，并经实验验证，鸡脾脏Ｔ淋巴细胞白细胞介素２（ＩＬ－２）体外诱生和活性检测的最优水平组合及适宜条件为２．５μｇ／ｍＬ伴刀豆蛋白Ａ（ＣｏｎＡ）、ＩＬ－２体外诱生时间２０ｈ、１×１０７／ｍＬ淋巴细胞、１０％小牛血清、靶细胞培养时间４８ｈ、４×１０６／ｍＬ靶细胞、靶细胞接触时间３６ｈ、５ｍｇ／ｍＬＭＴＴ、ＭＴＴ加入时间３ｈ和甲溶解时间２ｈ；胸腺Ｔ淋巴细胞ＩＬ－２体外诱生和活性检测的最优水平组合及适宜条件为５μｇ／ｍＬＣｏｎＡ、ＩＬ－２体外诱生时间４８ｈ，余同脾脏Ｔ淋巴细胞ＩＬ－２体外诱生及活性检测。比较试验表明，ＭＴＴ比色分析法和３Ｈ－胸腺嘧啶核苷（３Ｈ－ＴｄＲ）掺入法有显著的直线回归关系。     

The serological relationship of herpesvirus ovis to other herpesviruses and its possible involvement in the aetiology of jaagsiekte.

Cross-neutralization studies showed that 3 different isolates of herpesvirus ovis from cell cultures derived from the lungs of sheep suffering from jaagsiekte were not only identical but were also related to similar isolate made in Scotland. No relationship, however, could be established between herpesvirus ovis and common bovine or equine herpesviruses. Antibodies to herpesvirus ovis were present in roughly 70% of all animals tested and no evidence was obtained for the involvement of the virus in the aetiology of jaagsiekte. On the other hand, the absence of antibodies in sheep sera from Iceland as well as the other data obtained in this study did not exclude involvement of the virus in jaagsiekte.     

地被植物百里香在干旱区绿化资源利用的评价

通过对百里香的生长特性研究表明:由压条和根状茎形成的具间隔物的游击型克隆生长构型,使百里香能形成天然扩张的特性,冠幅可达150×150cm2/株,盖度可达80%～90%;百里香的萌枝和繁殖枝高度为2～5cm,作为地被植物有免修剪的优势;百里香生长的土壤要求是砂壤土,土壤粒径较大,酸碱度为7.5,对土壤要求较一般的地被植物低,是贫瘠土壤良好的园林绿化植物,群落内株丛的生物多样性低于株丛外,具强的资源竞争力。     

Possible involvement of phosphatidylinositol 3-kinase in the maintenance of metaphase II attest in porcine oocytes matured in vitro

It has been reported that phosphatidylinositol 3-kinase (PI3K)-protein kinase B (PKB) pathway plays a crucial role in the meiotic resumption and progression to the metaphase II (MII) stage of oocytes. However, the role of this pathway in meiotic arrest at the MII stage (cytostatic activity) is not well understood. In this study the effect of a PI3K inhibitor, LY294002, on the MAPK and p34^cdc2 kinase activities of matured porcine oocytes was examined. After maturation culture, both the MAPK and p34^cdc2 kinase activities in the oocytes were gradually decreased in a time-dependent manner. Although 25 µmol/L LY294002 did not affect either the MAPK or p34^cdc2 kinase activities, 50 µmol/L LY294002 suppressed the PKB phosphorylation and slightly decreased MAPK activity, but not the p34^cdc2 kinase activity. Therefore the effect of 10 µmol/L Ca²⁺ ionophore which was reported as inducing a transient decrease of p34^cdc2 kinase but not MAPK activities, was also examined in LY294002-treated oocytes. By additional treatment with LY294002 after Ca²⁺ ionophore, both the MAPK and p34^cdc2 kinase activities were decreased in a time-dependent manner, concomitantly with improvement of pronuclear formation. Therefore, we concluded that PI3K is involved in the maintenance of MAPK activity in matured porcine oocytes.     

家蚕染色体工程及其应用研究——Ⅲ.家蚕雄核发育的诱导

采用适当剂量的丫-射线辐照羽化前2—3日的雌蛹,羽化后与未辐照雄蛾(具有隐性标志基因)进行单杂交或多品种雄蛾混精杂交,产下卵经一定温度热处理,获得并饲养近两万头雄核发育蚕,并将部分雄核发育蚕继代成功。所有雄核发育蚕都为雄性,且只表现父本性状,不表现母本性状。因而推测可能是卵核经Y-射线照射后失活,而进入卵内的精子经一定高温刺激后互相融合发育的结果。调查了经辐射处理后的杂交后代在不同条件热处理以及不同蚕品种在同样条件热处理下的雄核发育情况,证明产下卵须经一定高温处理,两个入卵精子才能融合而发育。     

Effects of serotonin injected into the third ventricle on prolactin and growth hormone secretion in Holstein steers

In order to clarify the role of serotonin (5-HT) in the regulation of pituitary hormones, the effects of 5-HT injected into the third ventricle (3V) on prolactin (PRL) and growth hormone (GH) release were investigated in Holstein steers. A chronic cannula was implanted in 3V by stereotaxic surgery under general anesthesia. After sufficient recovery from surgery, 5-HT (0, 0.1, 1.0, 2.0 mg) was injected into via the cannula and blood samples were collected over 4 h. Plasma PRL and GH concentrations were determined by radioimmunoassay. PRL release was significantly stimulated by the injection of 5-HT. The increase in PRL was observed at 20 min after the injection at three doses and the highest dose (2.0 mg) was the most effective in stimulating PRL release. The injection of 5-HT into 3V, at all doses tested, did not alter GH release significantly. Our results suggest that 5-HT is involved in the regulation of PRL release partly through the hypothalamus in cattle.