Effects of fever and hyperthermia on the embryonic development of rabbits.

The effects of viral induced fever and environmental hyperthermia on embryonic development in pregnant rabbits are described. Embryonic development was not disturbed following fever, but there were anomalies in development following hyperthermia. Possible explanations for the different effects of hyperthermia and fever are discussed.     

Prenatal and postnatal development of Sertoli cells in rams

The morphological picture of Sertoli cells was studied in view of development. The testicular tissue of rams was studied from the 80th to the 140th day of intrauterine development and the testes of ram-lambs were studied from the 1st to the 40th day from birth; further, the testes were studied in adult rams. The development and differentiation of Sertoli cell precursors were examined, including their change into differentiated mature Sertoli cells. The electron-microscopic picture of these cells was described with special emphasis on those morphological changes in cells which are closely related with their functional activity during the development of the testes. The findings obtained so far in this field are incomplete and concern mainly laboratory animals and man. The results of the study extend the theoretical knowledge in the fields of histology, embryology, physiology, endocrinology and andrology. At the same time, they may serve as starting material for the study of the control of spermatogenesis under experimental conditions.     

洛阳奶业发展情况调查

为促进洛阳市奶业健康快速发展,对奶业发展情况进行了调查。目前制约奶业发展的瓶颈问题是奶牛单产低、生产技术落后,养殖规模小、管理水平低,产品研发和市场开拓能力不足,品牌影响力有限、经营理念滞后。今后应该转变发展理念,积极整合奶业资源,加强培训提高饲养和管理水平,稳定培育奶源、分化奶农风险以促进奶业健康快速发展。     

喀纳斯景区草原民俗旅游资源评价及开发模式

喀纳斯景区是中国图瓦人唯一的聚居区,其草原民俗旅游资源丰富而且分布合理,但开发的力度不强,不能满足旅游者日益多元化的消费需求。为了合理开发该区草原民俗旅游资源,通过特菲尔法和层次分析法,得到单项旅游资源中图瓦人饮食民俗和节庆民俗开发价值最大,综合评价得到喀纳斯景区3个村落均为二级景区,开发价值禾木村白哈巴河村喀纳斯村。并提出了适合喀纳斯的4种开发模式,即耦合型开发模式、节事庆典型开发模式、专项旅游开发模式和区域中心多元化开发模式。     

基于AHP法的河北省奶业SWOT分析

受到三鹿婴幼儿奶粉事件、国际金融危机和进口奶粉冲击的影响,河北省奶业发展形势严峻。基于AHP法将决策问题定量化,运用SWOT分析方法对河北省奶业发展现状进行研究,以期为河北省制定奶业发展战略提供依据。     

成黑色素细胞生成过程中信号调节的研究进展

动物体内的黑色素细胞合成了黑色素从而决定其肤色和毛色。全身各处的黑色素细胞有2种来源:①由神经管上皮细胞分化而来的视网膜色素上皮细胞;②由神经嵴细胞在胚胎发育早期分化为成黑色素细胞进而发育成熟为黑色素细胞从而行使其功能。通过对小鼠和人类的发育遗传学研究,结果表明神经嵴细胞衍生的黑色素细胞的发育分化是一个非常复杂的过程,受到多重信号因子的调控。其中影响黑色素细胞发育过程的转录因子有SOX10、MITF和PAX3,信号通路有KIT及其配体KITL信号通路、WNT/β-catenin信号通路、EDN3及其受体EDNRB信号通路。MITF被认为是黑色素细胞发育过程中非常关键的调控因子,而3条通路也被认为与神经嵴细胞来源的黑色素细胞的发育有极为密切的关系且能调节MITF功能及其活性。作者总结了这个领域的研究进展并指出早期神经嵴细胞的发育调控可能是乌骨鸡和乌骨绵羊乌质性状形成的根本原因。     

试述草原地区可持续发展的生态承载力评价体系

简要地介绍了承载力及生态承载力的概念及由来,以及利用承载力衡量可持续发展的理论与方法.分别论述了生态承载力的自然植被净第一性生产力估测方法、资源与需求的差量方法、生态承载力综合评价方法及状态空间法的度量方法.依据草原生态系统特性构建了草原区域生态承载力指标体系,探讨了生态承载力在草原区域可持续发展评价中的应用前景.     

Pilot study to assess the effects of early flea exposure on the development of flea hypersensitivity in cats

This pilot study was to determine if early oral flea exposure reduces the incidence of flea allergy dermatitis (FAD) in cats. Eighteen kittens, assigned to three groups, received no flea exposure, oral flea exposure or flea infestation for 12 weeks. Then all the kittens were exposed continually to fleas for 31 weeks. Sensitization was monitored using intradermal testing (IDT), in vitro measurement of anti-flea saliva immunoglobulin E (IgE) and development of FAD. There was no statistically significant difference between groups in IDT reactions, in vitro data or clinical scores. The development of FAD was not associated with the presence of anti-flea saliva IgE. However, the development of a delayed reaction to flea bite was associated with symptoms after flea exposure. Although not statistically significant, the FAD scores in the oral group were lower than in the controls. Further studies are required to determine the role of oral flea exposure in the development of FAD in cats.     

肉鸡胚胎发育过程中肝脏的组织学观察

肝脏是家禽体内最大的消化腺,其发生发育与功能的行使紧密相连。本研究从组织学的角度观察肉鸡肝脏组织在胚胎发育过程中的特点,并比较高、低脂系间肝脏组织在发育过程中的区别。结果发现,肝叶体积随日龄的增长而增加;胚胎发育至12日龄时肝小叶结构基本发育完整;在胚胎发育后期,肝细胞内脂滴明显增加,且肝叶周边的肝细胞较肝叶中心的肝细胞增殖活动旺盛。而在整个胚胎发育过程中,两系间肝细胞内脂滴沉积并没有明显的区别。     

谈化隆县以牧促农发展生态农业

通过分析化隆县的社会、自然概况,认为化隆县宜农宜牧,具有发展生态农业的优越条件,并对发展本区的生态农业提出建议。     

A Quantitative Study of Muscle Development in the Bovine Foetus (Bos indicus)

The investigation was carried out in order to quantify the changes in various cell parameters which take place in the normal prenatal development bovine muscle. Sections of muscles, taken from 36 Zebu foetuses (Bos indicns) of about 75 to 245 days gestation, were examined microscopically. Results are given on the numbers and sizes of myotubes and myofibres seen section at various stages of development. The relative contribution of increases in cell size and cell number to overall muscle size increase are discussed.     

Molecular evolutionary analysis of the duck MYOD gene family and its differential expression pattern in breast muscle development

1. The objective of the research was to investigate the molecular evolutionary relationships between the duck myogenic determination factors (MYOD) gene family members and their roles in muscle development. 2. The four members of the duck MYOD gene family were cloned using RT-PCR, and their relative mRNA expression during duck muscle development was measured using qRT-PCR. 3. The results showed that MyoD and Myf5 clustered together, as did MyoG and MRF4 based on their complete amino acid sequence and the basic helix-loop-helix domain. Results of the evolutionary level analysis were consistent with that of the differential expression patterns during duck breast muscle development. As determined by qRT-PCR, MyoD and Myf5 were highly expressed in 22-day embryos, while MyoG and MRF4 expression was high in 14-day embryos. 4. We conclude that the entire MYOD gene family in the duck originated from a common ancestral gene and evolved after two duplication events. The roles of the MYOD gene family members in duck muscle development are similar to those in mammals.     

Fasciola hepatica: comparative effects of host resistance and parasite intra-specific interactions on size and reproductive histology in flukes from rats infected with isolates differing in triclabendazole sensitivity

The efficacies of putative fasciolicides and vaccines against Fasciola hepatica are frequently monitored in clinical and field trials by determination of fluke egg output in host faeces and by worm counts in the host liver at autopsy. Less often used are parameters based on fluke size and histology, yet these can provide important indications of specific effects on the development of particular germ-line or somatic tissues, especially in relation to the timing and profligacy of egg production. In this study, F. hepatica metacercariae of two distinct isolates, the triclabendazole (TCBZ)-sensitive Cullompton isolate and the TCBZ-resistant Oberon isolate, were administered to rats as single-isolate or mixed-isolate infections. At autopsy 16 weeks later individual adult flukes were counted, measured and the reproductive organs were examined histologically. The degree of development of the testis tubules in each fluke was represented by a numerical score, based on the proportion of the histological section profiles occupied by testis tissue. The level of anti-F. hepatica antibody in the serum of each rat was determined by ELISA. It was found that Cullompton flukes were significantly larger than Oberon flukes, and that significantly more Cullompton metacercariae developed to adults than Oberon metacercariae. The Cullompton flukes showed histological evidence of aspermy and spermatogenic arrest, which was reflected in quantitatively reduced testicular development, as compared with the Oberon isolate. In Cullompton flukes, parthenogenetic egg development is implied. The size of Cullompton and Oberon flukes was significantly related to the number of adult flukes recovered, to the number of metacercariae administered, and to the percentage success of infection. The testis development score in both isolates was significantly related to the number of adult flukes recovered but not to the number of metacercariae administered, or to the percentage success of infection. Fluke size was positively related to testis score for both isolates, and a significant negative relationship was found between percentage success of infection and metacercarial dose. The results are interpreted in terms of differing interactions between various numbers of young flukes and host immunity during invasion of and migration in the hepatic parenchyma, and of fluke intra-specific (possibly pheromonal) stimulatory effects in the final stages of development, within the host bile ducts. No significant relationships were found between host antibody levels and fluke size or testis score. False positive serological reactions were found in some rats that had been infected, but found to harbour no flukes at autopsy. Clearly the act of eliminating the flukes involved generation of an immune response.     

山东省毛皮动物养殖业发展现状与对策

山东省是我国毛皮动物(水貂、狐和貉)养殖第一大省,年出栏率占全国的一半以上,近年来发展迅速,在部分地区已成为当地的农业支柱产业。但是整个山东省毛皮动物养殖业仍然存在产业化程度低、产业链不完善、发展不够规范等问题。文中通过对山东省毛皮动物现状的描述,探讨了山东省毛皮动物养殖业的发展策略,以期对毛皮动物养殖业的健康稳定发展起到借鉴作用。     

Indoor confinement and physical inactivity rather than the proportion of dry food are risk factors in the development of feline type 2 diabetes mellitus

With domestication and urbanisation, cats have transformed from being hunting animals that eat protein-rich prey into more sedentary animals that eat a carbohydrate-rich diet. It was hypothesised that a high intake of dry cat food and a lack of physical activity may play a role in the development of feline type 2 diabetes mellitus. Information on dietary history and physical activity of 96 cats with diabetes mellitus and 192 matched controls was collected retrospectively, using a telephone questionnaire. Conditional logistic regression analysis was used to investigate the association between questionnaire-derived variables and the development of diabetes mellitus. The energy percentage of dry food in the diet was not significantly correlated with the development of diabetes mellitus (P=0.29), whereas both indoor confinement (P=0.002) and low physical activity (P=0.004) were. The results indicated that the proportion of dry food in a cat's diet may not be an independent risk factor for the development of type 2 diabetes mellitus, whereas physical inactivity and indoor confinement are.     

猪骨骼肌发育过程中免疫相关基因的表达分析

为探究猪骨骼肌发育过程中免疫相关基因的表达模式以及相关生物学功能,本研究根据蓝塘猪和长白猪骨骼肌10个发育时期的转录组数据,对各时期免疫相关基因的表达数目和表达量进行分析,鉴定了相邻发育时期之间以及同一时期品种间差异表达的免疫相关基因,并对后者进行功能注释分析。结果表明:在蓝塘猪与长白猪骨骼肌发育过程中存在1 129个表达的免疫相关基因;胚胎期35 d和49 d、胚胎期91 d和生后期2d这2组相邻时期之间的差异表达免疫相关基因数目最多;品种间差异表达免疫相关基因数目则在胚胎期49d以及生后期180d最多,且趋向于在蓝塘猪上调表达,并富集在NIK/NF-κB信号传导、细胞凋亡的负调控等生物学过程中。本研究表明免疫相关基因在猪骨骼肌发育过程中存在表达,长白猪与蓝塘猪骨骼肌生长发育差异可能与NF-κB介导的细胞凋亡有关。     

Bovine stephanofilarial dermatitis in alberta

The nematode, Stephanofilaria stilesi was recovered from two mature beef cattle in Alberta. The appearance of the skin and the histological lesions are described. The life cycle of the parasite and the development of lesions are reviewed.     

胰岛素和白血病抑制因子对猪卵母细胞体外成熟和孤雌激活胚胎的影响

为探讨胰岛素(Insulin)和白血病抑制因子(Leukemia inhibit factor,LIF)对猪卵母细胞体外成熟(IVM)和猪孤雌激活胚胎(PAEs)的影响,在卵母细胞体外成熟或者胚胎培养基中添加Insulin和LIF,研究卵裂率和囊胚率的变化。结果:添加了5μg/mL Insulin后猪卵母细胞体外成熟效果显著提高,但成熟后孤雌激活发育能力与非添加组相近;而胚胎培养基中添加Insulin对孤雌胚的卵裂和囊胚的形成也没有明显促进作用;添加1 000 U/mL的LIF后,卵母细胞核成熟率没有明显提高,反而孤雌激活后囊胚率急剧下降,但对卵裂率以及囊胚总细胞数影响不大;在胚胎培养基中添加LIF后,孤雌胚的卵裂和囊胚形成并没有明显的提高。表明:Insulin对卵母细胞体外成熟有益,但是对孤雌胚胎的最佳处理程序还需要摸索;本文所采用的LIF处理对猪卵体外成熟以及孤雌胚胎体外发育没有帮助,还需要进一步研究其他浓度和处理程序对猪卵母细胞体外成熟和孤雌激活胚胎发育能力的影响。     

内蒙古绒山羊Hox基因家族成员在毛囊中表达的研究

Hox基因作为一类重要的转录因子,在胚胎发育组织分化过程中有重要作用。为了探索Hox基因在绒山羊毛囊发育中的作用机制,本研究采用原位杂交技术,检测Hox基因家族成员Hoxa4、Hoxa5、Hoxa6基因在绒山羊毛囊的表达模式。结果显示,Hoxa4、Hoxa5、Hoxa6基因分别在绒山羊胚胎期和兴盛期毛囊的不同部位表达,说明Hox基因在绒山羊毛囊生长发育过程中扮演着重要的角色。     

Cervical hygroma in the calf as an absolute cause of dystocia. An unusual malformation possibly of hereditary genesis in Braunvieh x Brown-Swiss breeds

Large cervical lymphocytes causing dystocia were observed in two Braunvieh x Brown-Swiss calves. The cysts were located on both sides of the neck and contained aqueous liquid. One of the animals was necropsied. The volumetric capacity of the cysts was 11 and 4 liters respectively. The hygroma are supposed to be the result of an interruption in the development of the lymphatic system resulting in the persistence of embryonic lymph sacs. Hypoplasia of the diaphragm, the pericardium and the mediastinum, and malformations of internal organs and the skeletal system were additional pathological findings. The lymphocysts and the other morphological anomalies, except those which may be explained as a consequence of cyst development are considered to be combined accidentally. Analysis of the pedigrees indicates that the lymphocysts may represent a hereditary malformation.