色氨酸对肠屏障免疫的调控作用研究进展

肠道是机体重要的代谢场所,也是动物体内最大的免疫器官.肠道屏障维持着肠道内环境的稳定,是动物肠道健康的保障.色氨酸在机体中通过3条途径被代谢,产生的犬尿氨酸、犬尿酸、5-羟色胺、吲哚等代谢产物可通过芳香烃受体途径、旁分泌等途径调控肠道屏障免疫功能的稳定,促进机体肠道健康.本文综述了色氨酸对动物肠屏障免疫的调控作用及其机...     

Mycoplasma host specificity: fact or fiction?

Bacteria of the genus Mycoplasma are the smallest organisms known to be capable of self-replication. They only occur in association with animal host cells on which they are dependant for many pre-formed nutrients since they lack many of the metabolic pathways associated with energy production and the synthesis of cell components found in other species of bacteria. It is generally thought that most species of Mycoplasma are very host specific but there are many reports of mycoplasmas in hosts that are not perceived as their normal habitat. Sometimes these "crossings" may have a pathological impact particularly where there may be predisposing conditions such as immunodeficiency. These are often reported in humans but may also occur in animals whose immune or physiological status is not known. This review brings together some of these reported incidents and speculates on their potential impact for laboratory diagnosis.     

Diagnosis of heartwater in the live animal: experiences with goats in Guadeloupe

A presumptive diagnosis of heartwater in the living animal can be based on clinical and epidemiologic observations. In Guadeloupe, heartwater can be confused with haemonchosis in goats or cerebral babesiosis in cattle. Confirmation of the clinical diagnosis by brain biopsy is useful in experimental infections but is hardly applicable in the field. Positive results were obtained from 92% of animals 16 to 18 days after experimental infection. In febrile animals the best results were obtained between the 3rd and 6th days of the thermal response. Diagnosis can also be supported by serological tests. These are useful for monitoring experimental infections and for checking recovered animals in the field. Nineteen goats out of 27 were negative on Day 1 of the febrile reaction but positive a week later. The remaining 8 goats were positive on Day 1 and had greatly increased antibody titres a week later. Confirmation of a diagnosis can also be achieved by subinoculating into susceptible animals either blood or suspensions of ticks collected from suspect animals and then homogenized. Ticks that have engorged on a suspect animal can be allowed to moult and then fed on a susceptible animal to test their infectivity. These methods are time consuming but useful for heartwater surveys.     

The "Friedrich-Loeffler-Institut": past, present and future of research in infectious diseases of animals

The Friedrich-Loeffler-Institut, founded in 1910 by Friedrich Loeffler, the discoverer of the first animal virus, foot-and-mouth disease virus, is the oldest virological research facility in the world. Beyond viruses, its area of competence has significantly expanded since its foundation and now also covers bacterial, parasitic and prion diseases of livestock, poultry and aquatic animals. Presently located at four sites within Germany (Insel Riems, Jena,Tübingen,Wusterhausen) the tasks of the institute as delineated in the Animal Disease Act encompass research on infectious animal diseases including zoonoses, import/export examinations, epidemiological studies in case of outbreaks of notifiable animal diseases, acting as reference laboratory for notifiable animal diseases and nationwide quality management of diagnosis of notifiable animal diseases. It is obliged to publish and maintain up-to-date diagnostic regimes for notifiable animal diseases, and it publishes a yearly report on animal health in Germany. With the increasing importance of infectious diseases of animals, in particular those potentially harmful to man (zoonoses), the Friedrich-Loeffler-Institut will be moving into new facilities including laboratories and animal facilities up to the highest biosafety level at its main site Insel Riems on the occasion of its 100th anniversary.     

Diagnosis of hereditary diseases with molecular biology methods

The identification of phenotypically normal carriers of genetic defects is crucial for eliminating recessive defect genes from farm animal populations. Recombinant DNA techniques allow us to identify defect genes on the DNA-basis regardless of the animals age and time of gene expression. Genetic defects also are important as model systems to investigate the regulation of metabolic pathways and the mechanisms of embryonic development.     

Livestock manure as a vector for infectious agents

The causative agents of nearly all bacterial and viral infectious diseases are either directly excreted by the infected animals or they reach the floor via other ways and thus end-up also in the fecal and urinary excretions of the animals. Occasionally pathogens also can be found in slurries of clinically unsuspected livestock for a short period of time while they pass through the gut of individual animals without colonization or invasion of the tissues (e.g. salmonellas). Consequently the manures are a potential for spreading infectious diseases. But their real significance as a vector for infectious agents is to a large extent still unsolved, because in the literature only very few and sometimes doubtful cases are described. During storage of manures the numbers of pathogens are reduced. This effect can be intensified by prolongation of the storage time. To assess the real epidemiological significance of the animal manures as vectors for infectious diseases further research work is urgently needed. After disinfection of animal manures in accordance with the regulations during eradication of notifiable diseases no cases of spread of disease became known in the Federal Republic of Germany. The problems of agricultural utilization of manures in water protection areas are discussed from a microbiological point of view.     

色氨酸的生理功能及其在畜禽饲粮中的应用

色氨酸作为一种功能性必需氨基酸,可提高动物生长性能、调节采食与泌乳、增强机体抗氧化和免疫功能等。色氨酸作为饲料添加剂应用于低蛋白质饲粮中,在保证动物正常生产性能情况下,可减少蛋白质饲喂量,缓解蛋白质饲料原料紧缺问题,减轻养殖废弃物对环境造成的污染。本文从色氨酸在畜禽体内的代谢途径及其对畜禽的生理功能等方面进行综述,为色氨酸在畜牧生产中的科学合理应用提供参考。     

转基因动物在动物营养研究中的应用

本文综述了转基因动物在动物营养中的应用。包括两个主要部分，一是用转基因动物做模型，研究外源基因对动物生长和代谢的调控作用，说明外源基因对动物生长速度、饲料利用率及其胴体的组成均有影响。与此同时，还可以导入新的代谢体系中的主要基因，使动物本身获得对某些必需物质的合成能力，从而达到提高生产性能的目的。另一部分是日粮的营养成分对动物某些基因表达的调控作用，从基因表达水平说明营养成分对动物某些物质的合成、代谢的调控作用。这两个方面都为在分子水平上研究动物营养学提供了有效的手段和方法。     

褪黑素的生物合成及对繁殖性能的影响

褪黑素是一种广泛存在于动物体内的激素,不仅能够调节动物昼夜节律,还能够从多方面影响动物的繁殖性能,对于季节性繁殖动物,褪黑素根据日照时长的变化表现出抑制或促进繁殖性能的作用。对于幼年动物,褪黑素表现出抑制发情的作用,体成熟后则表现促进发情的作用。褪黑素主要通过下丘脑-垂体-性腺轴调控动物繁殖活动,除此之外,褪黑素还能够直接作用于生殖系统甚至早期胚胎,通过提高组织及细胞抗炎及抗氧化功能来改善动物繁殖性能。目前,褪黑素能够用于治疗精神疾病及炎症、促进畜禽繁殖和调节昼夜节律,是相关研究领域的热门话题。本文详细描述了褪黑素的生物合成以及分泌调控,并结合褪黑素的生理功能,阐述了对动物繁殖性能以及辅助生殖的影响。     

Prevalence study of the lungworm Aelurostrongylus abstrusus in stray cats of Portugal

In this study we have investigated the prevalence of aelurostrongylosis, one of the most common feline pulmonary parasitic diseases, in cats from the north-west region of Portugal. For this purpose, 97 faecal samples were collected from cats at risk of being infected by Aelurostrongylus abstrusus in an animal shelter and in a municipal facility. Using the Baermann-Wetzel coprological technique, faecal shedding of first stage larvae (L1) was detected in 17.4% of the cats. Based on this result, it can be concluded that this lungworm infection seems to be common among feral cats in the north-west region of Portugal, in spite of the fact that clinical aelurostrongylosis is not frequently diagnosed by feline practitioners in the area. This parasitic disease should be included in the differential diagnosis of cats presenting with coughing or dyspnoea, and it also should be extended to asymptomatic animals with pulmonary nodules detected by image diagnosis.     

Immunomodulators for prevention and treatment of infectious diseases in food-producing animals.

The goal of immunomodulation in food-producing animals is to regulate immunity for the benefit of the animal and production efficiency. Immunomodulators are substances that exert this control and include cytokines, pharmaceuticals, microbial products, nutraceuticals, and traditional medicinal plants. Although treatment and prevention of infectious diseases are the most common reasons to use immunomodulators, other conditions, such as amelioration of stress-induced immunosuppression, maturation of the neonate's developing immune response, and strategies to reduce the metabolic cost of eliciting an immune response also are well suited for immunomodulation. Continued discovery of new immune regulators and increased understanding of immunity in food-producing animals will ensure new opportunities for the use of immunomodulators in food-producing animals.     

Amphibian skin diseases.

Skin diseases in amphibian species seem to carry an additional degree of seriousness compared with those of other vertebrates. Because of the skin's importance in respiration and ion transport, breaching of the integument of these animals can result in fatal septicemias or metabolic disturbances. The timely diagnosis and treatment of these skin lesions is important. A review of the diseases affecting amphibian skin is provided. This article also describes the clinical signs, appropriate diagnostic steps, and treatment and control of amphibian skin diseases.     

Plant contents of magnesium, calcium and potassium in relation to ruminant nutrition

Grass tetany and wheat pasture poisoning are metabolic diseases of mature, lactating beef cattle. In some other countries, similar problems occur with dairy cattle. In grass tetany, the animals generally are grazing cool-season forages in which Mg concentration or bioavailability of plant Mg is low. Levels of Mg in the blood serum also generally are low. Grass tetany can occur in beef cattle fed hay made from grass, small grains or alfalfa Medicago sativa L.). In wheat pasture poisoning where animals are grazing small grains forages, blood levels of Ca often are low, and blood Mg also may be low. Both grass tetany and wheat pasture poisoning occur when plants are growing rapidly in the spring, at the time of heavy lactation demand by ruminants for Mg and Ca. When the temperature increases and plants start to grow rapidly in the spring, concentrations of K, N, organic acids, and the ratio of K/(Ca + Mg) all increase, and the percent dry matter decreases. Much research remains to be done to understand all the soil, plant, and animal aspects of grass tetany and wheat pasture poisoning.     

Melioidosis in animals: a review on epizootiology, diagnosis and clinical presentation

Melioidosis, an infectious disease caused by Burkholderia pseudomallei is an emerging disease with high impact on animals and man. In different animal species, the clinical course varies and delayed diagnosis poses risks for the dissemination of the agent in non-endemic areas. Not only migration and transport of animals around the world but also tourism increases the risk that melioidosis can leave its endemic boundaries and establish itself elsewhere. Detection of the agent is a major challenge, as the agent has to be handled in laboratories of biosafety level 3 and test kits are not yet commercially available. Veterinarians and doctors should be aware of melioidosis not only as an agent of public interest but also in terms of a bioterrorist attack. The aim of this review is to describe the agent, its aetiology, the manifestation in a variety of animal species as well as to describe diagnostic procedures, typing techniques and countermeasures.     

The veterinary relevance of farm animal ethology

The world expects veterinary knowledge to encompass all aspects of the lives of animals. These include their management and welfare, not just their diseases. Modern research into behaviour is relevant to practical veterinary work, such as animal handling and disease diagnosis, and also to general management and welfare. Hence, all veterinary courses should include instruction in behaviour and those involved in veterinary work should be aware of new developments in the subject.     

叶绿醇对脂肪细胞分化及糖脂代谢的调节作用

叶绿醇(phytol)是植物叶绿素分子上一个支链。动物摄入的叶绿醇在体内可以代谢产生植烷酸和降植烷酸。叶绿醇及其代谢产物不仅是机体氧化代谢的重要能量来源,而且在糖脂代谢、脂肪细胞分化聚酯调控方面具有特殊的生物学功能,近年研究指出该过程与过氧化物酶体增殖激活物受体(PPAR)和视黄醇受体(RXR)的激活密切相关。因此,本文就叶绿醇在体内的基本代谢过程,叶绿醇及其代谢产物调控糖脂代谢的功能及其信号通路的最新研究进展进行简要综述,为深入研究叶绿醇的分子营养学机制提供参考。     

病毒性动物疫病诊断技术研究进展

动物疫病的大暴发不仅严重影响畜牧业的生产与发展，造成巨大经济损失，而且会严重危害人类健康。病毒性疫病的增加使得动物疫病更加复杂，流行趋势更加严峻。灵敏、特异、快速地诊断动物疫病是实施疫病防控措施的关键环节。基于PCR技术及等温扩增技术的分子生物学诊断解决了传统病原学诊断费时费力、免疫血清学存在的窗口期等问题并摆脱了对高精度温控设备的依赖，成为目前常用的病原体筛查方法。但大多数检测方法一次只能检测到一个或几个病原体，且复杂的试验流程及对设施的高要求降低了立即干预突发疫情的能力，同时无法满足某些检测分析需求。近年来，学科间相互渗透融合的高通量诊断技术发展迅速，具有同时监测、检测和表征成百上千个靶点的能力，能满足在多种环境下的病原体快速检测的需求，是生命科学发展过程中一种重要的生物学检测手段。笔者从病原学、免疫血清学、分子生物学及高通量诊断等方面对主要的病毒性动物疫病检测技术进行了综述，展望未来动物疫病诊断检测技术的发展，以期为动物疫病快速诊断提供更多的方案思路，提升动物疫病的防控能力。     

Clinical approach to prostatic diseases in the dog

In small animal practice, prostatic diseases are increasingly encountered. All dogs may experience prostatic disease, but particular care should be addressed to breeding dogs, in which prostatic affection may lead to decrease in semen quality and fertility. The most common prostatic disease is the benign prostatic hyperplasia (BPH) followed by prostatitis, prostatic neoplasia and prostate squamous metaplasia. These diseases do not have pathognomonic symptoms, therefore, making a correct diagnosis may not be easy. An accurate clinical examination and a correct diagnostic protocol are essential in order to begin the most appropriate treatment, and also to do a good prophylaxis where it is possible. BPH therapy is usually recommended when mild‐severe signs are present or if symptoms disturb the patient. New therapeutic approaches, both medical and surgical, allow to maintain fertility in most animals with prostatic disorders. Prostate cancer is relatively infrequent. Elective therapy is the surgical one, but it is considered palliative and can result in important post‐operative complications. The aim of this paper is to lay down the most appropriate diagnostic process describing the aetiologies of prostatic disease, their symptoms, the right investigative tools and therapy.     

Travel medicine of parasitic diseases in the dog

Companion animals are increasingly brought along by their owners to foreign countries. Thus, small animal travel medicine is becoming more important. The field includes both prophylaxis and metaphylaxis against various infectious diseases, as well as their diagnosis and treatment. Dogs returning from Southern Europe, but also from more tropical regions, may be infected with exotic pathogens. In addition, imported pedigree or working dogs, and especially stray dogs imported through welfare organisations, are at high risk.The present overview summarises the clinical and practical aspects of exotic parasitic diseases that may affect such dogs, and the risk of such diseases becoming autochthonously transmitted in Switzerland. Furthermore, the zoonotic potential of these infections will be considered.