秋季中华蜜蜂（Apis cerana cerana）工蜂有分泌活性的舌腺和无分泌活性的舌腺的超微结构比较

对秋季中华蜜蜂工蜂有分泌活性舌腺（９日龄）和无分泌活性的舌腺（采集蜂）的超微结构进行了观察和比较，发现二者的舌腺细胞的超微结构存在着差异。９日龄工蜂舌腺处在分泌活性状态。细胞核发达，多突起；粗面内质网发达，成平行状排列；胞内管、胞外管中都充满电子致密度均匀的物质，即王浆物质；有大量的分泌块；线粒体内嵴排列紧密，呈板层状。而采集蜂舌腺处在无分泌活性状态。核周边异染色质增多；粗面内质网不太发达，多呈泡状；胞内管中物质为一些不均匀的电子致密度大的粗颗粒物质；胞外管中只有少量水样物质；线粒体内嵴间隙相对变大，多发现内嵴间隙呈管泡状。     

Measurement of the elastic properties of the cancellous bone in the femoral head of the dog

The degenerative wear and pathologic damage of the joints are reasons for total endoprotheses in man as well as in dogs. The main problem is the aseptic loosening of the protheses. By usig the finite-element-method, the total endoprothesis is designed with new features, with the purpose of preventing loosening and being better adapted to load transmission. In order to simulate the femur of the dog for the numerical analysis, a material law is developed. By taking into account the anisotropy and the local density of the cancellous bone in the femoral head, the young's modules are experimentally determined. The measurements are performed by ultrasonic methods on femoral heads of euthanised dogs. The results show planar isotropic cancellous bone.     

Overview of the Immune Dynamics of the Digestive System

The digestive tract of the chicken is a major site of pathogen exposure. Although the bird has a multifaceted set of tools to prevent or resist infection, any activation of the immune system can divert nutrients away from production. Therefore, prevention of pathogenic exposure is preferred. However, it is unlikely that the bird can escape exposure to all pathogens during its life, thus the ability to respond to immunologic challenges is essential. The immune system of birds is similar to that of mammals in terms of structure and function, although some differences do exist, particularly in regulatory aspects. The innate immune system responds nonspecifically to foreign molecules and is essential for the induction of the specific (acquired) immune response. Cells of the innate immune system include macrophages, dendritic cells, heterophils, and natural killer cells. The acquired immune response involves recognition of a specific antigen and response by lymphocytes. Cytotoxic T lymphocytes are especially effective at inducing cells infected with intracellular pathogens to undergo apoptosis. Helper T lymphocytes increase the effectiveness of innate immune cells in combating extracellular pathogens and are also essential for activating B lymphocytes, which produce antibodies specific to the invading pathogen. All aspects of the immune system function together, although one aspect will often dominate, depending on the type and severity of the infection. This paper reviews the basics of avian immune function in general and discusses the immune system in the digestive tract in particular in birds. The consequences of activation of the immune system are presented.Currently, growth-promoting antibiotics are not used in poultry in many countries; the North American industry may be moving in that direction as well, either through legislation or consumer pressure. Several nonantibiotic means of manipulating the immune system to prevent the health- and performance-suppressing effects of immune system activation are presented here.     

Observations on the Ultrastructural Appearance of Endocrine Cells of the Small Intestine of the Calf

The endocrine cells of the small intestine of neonatal calves are described, with the aid of transmission and scanning electron microscopy. It is demonstrated that endocrine cells have long microvilli, and are organized into two populations, similar to those of other species.     

The vascularization of the intervertebral disks of the adult dog

The (mainly lumbar) intervertebral discs of 21 recently euthanatized dogs (aged 3 days to 14 years) were examined grossly, under the dissection microscope and by light microscopy. The findings of the adult animals and the salient differences from the younger ones are reported. A few capillaries were observed in the outer 2-4 layers of the anulus fibrosus; these arose from segmental arteries that lay directly on the intervertebral discs. The principal supply of all intervertebral discs occurs by diffusion emanating from capillary loops. These are visible at 10-30 times enlargement in both unstained and benzidine stained preparations. They pass through the end plate of the vertebral body to where the bone gives way to the softer tissue of the disc. The capillary loops have wider lumina and are more numerous opposite the nucleus pulposus and in the adjacent perinuclear zone than more peripherally where the annular fibers attach to the bone.     

The venous drainage of the cervical vertebrae of the ox (Bos taurus L.).

The venous drainage of the cervical vertebrae of the ox was studied in 16 animals (Friesland, Jersey and Guernsey cross-breeds), ranging from near full-term foetuses to adults. The extra- and intraosseous veins of the cervical vertebrae are described and illustrated. The nutrient vessels are derived from the vertebral, deep cervical, occipital and internal jugular veins. In addition to the dorsal and ventral external venous plexuses, a lateral external venous plexus is described. The intraosseous veins correspond in the main to the arteries. They are described and illustrated with reference to the available literature. In both young and adult animals anastomoses between epi- and metaphysial vessels are reported. The role of the internal ventral vertebral venous system as a collateral pathway is stressed and comments are made on its possible functional role.     

Nutrition of the cat

The requirement of the cat in respect to protein, energy, vitamins and minerals are presented. The special requirements of this carnivore appear to be due to the loss or charge of certain metabolic processes which are normally present in species such as the dog.     

Lameness of the hindlimbs of the cat

About six to seven per cent of cats presented at the clinic show neurological signs. The largest group consists of traumatized cats. A complete neurological examination is essential for localizing the lesion and establishing a prognosis. Differential diagnosis for paraparesis/paraplegia of pelvic limbs in cats are discussed. Cats are demonstrated which had spinal cord trauma, disc protrusion, aortic thromboembolism and lumbosacral stenosis and the importance of the evaluation of x-rays, cerebrospinal fluid examination and myelography is stressed.     

Fine Structure of the Pecten Oculi of the Red-Tailed Hawk (Buteo jamaicensis)

The pecten oculi of the red-tailed hawk (Buteo jamaicensis) has been examined by light and electron microscopy. In this species the pecten is very large and of the pleated type. It consists of 17-18 accordion folds which are joined apically by a heavily pigmented bridge of tissue which holds the pecten in a fan-like shape, widest at its base. It is situated over the optic nerve head and extends into the vitreous. Within each fold are numerous capillaries, larger supply and drainage vessels and melanocytes. The capillaries are specialized and display extensive microfolds on both the luminal and abluminal borders. The endothelial cell bodies are thin with most organelles present in a paranuclear location. The capillaries are surrounded by thick fibrillar basal laminae which are probably structurally important and which often enclose pericytes. The melanocytes which are most plentiful in the bridge region and peripherally in the pecten, form an incomplete sheath around the capillaries and other blood vessels. These melanocytes are also felt to be fulfilling a structural role within the pecten. The morphology of the pecten of the red-tailed hawk is indicative of a heavy involvement in the transport of materials to the avascular avian retina.     

Veld of the karoo areas

The Karoo areas are generally arid to semi‐arid with rainfall varying from less than 100 mm in the west to 400 mm in the east. The topography is mainly flat to undulating and the soils generally shallow and stony. There are 16 veld types present. Typcial Karoo veld is characterised by a dominant sparse to dense short shrubby vegetation (karoo bushes), interspersed to a variable degree, by short grass species and taller shrubs. Succulents are dominant in certain parts. These constituents exhibit different phenological rhythms of which the karoo bushes are largely vernal and autumnal and the grass aestival. Fodder and nutrition supply varies according to season and rainfall. A large numer of insect pests afflict Karoo vegetation. Stock diseases and physiological disturbances caused by certain species, are prevalent. Merino and Dorper sheep are the main defoliating agents of Karoo veld.     

Metabolic basis for some of the nutritional peculiarities of the cat

The nutritional requirements of most mammals exhibit a remarkable degree of similarity, a reflection of common evolutionary origin. However, among mammals two groups, ruminants and carnivores, appear to possess the greatest divergence in dietary requirements. The former group have been extensively studied, their nutritional peculiarities arising from a specialized pregastric digestive system. Carnivores have been largely neglected by nutritionists, and yet offer a most interesting divergence in dietary requirements amongst mammals. It would appear that the specialized diet, i.e. animal tissue, of true carnivores has permitted metabolic adaptation through modification of enzymes and enzyme systems which are expressed as peculiarities in nutritional requirements. The purpose of this paper is to review the metabolic basis for some of the nutritional peculiarities of the domestic cat, a true carnivore which has received the most attention. The following nutrients, or metabolic functions, are discussed: vitamin A, niacin, taurine, arginine, gluconeogenesis, nitrogen conservation and essential fatty acids. The latter two topics are covered by other discussants at this symposium and are only included here for completeness. The reader is requested to consult the relevant papers of Rogers & Morris (1982) and Rivers (1982).     

Diseases of the vitreous in the dog and cat

Diseases of the vitreous body in the dog and cat are reviewed. The anatomy, embryology and methods of examination of the vitreous are described. Congenital and acquired conditions are discussed, in particular relating to opacities within the vitreous, and a brief note on vitreous surgery is included.     

Prospects for the use of embryos in the control of disease and the transport of genotypes

Transfer and low temperature storage of embryos are now proven techniques for a number of mammalian species. These techniques are useful in control of disease and in saving genotypes from infected animals. The place of embryos in the epidemiology of disease depends upon whether the causative organism can gain entry to the oocyte before or at fertilisation and on whether the young embryo can be invaded by organisms in the uterine environment. There is little evidence that important live-stock diseases are transmitted via gametes. The zona pellucida surrounding the embryo is an effective barrier against a number of important disease organisms; in some cases the embryo is susceptible once it has hatched from the zona pellucida. It is important therefore in considering the use of embryos in disease control, to ensure that virus is not attached to the surface of the zona pellucida from where it can infect the recipient and/or the embryo after hatching. Washing procedures have been devised together with the use of enzymes and antisera to remove virus from the surface of embryos. Some viruses enter pores and sperm tracks in the zona and removal of these may present a problem. African swine fever virus has been shown to resist removal by treatment with enzymes. There are no guidelines as to the likely interaction between a certain virus and embryos. Therefore each virus of interest must be tested to determine whether it can be transmitted via washed embryos. Nevertheless there are numerous instances of the use of embryo transfer to eradicate a specific disease or to save valuable genetic material from infected animals without transmitting disease.     

Harnessing the genetic toolbox for the benefit of the racing Thoroughbred

The understanding and application of genetics have grown extremely quickly since it has become possible to sequence the whole genome of an organism. The human genome sequence was completed in 2001 and that of the horse in 2007. The significance of this is that it makes it more feasible to explain how both genetically simple and complex traits are transmitted from one generation to the next and, therefore, to make informed breeding decisions, modify how horses are managed and trained to minimise the risk of disease and injury, and improve methods of prevention, diagnosis and treatment of many conditions. The science of genetics/genomics will continue to grow internationally, limited only by the funds available. The application of the science to man, horses and other species raises very complex moral and commercial issues. Thoroughbred breeders are perceived by some as resistant to change, but their apparent intransigence is often based on a genuine concern for the integrity of the breed. By taking control of the application of the advances in genetics, the Thoroughbred industry potentially has the opportunity to improve both the health and performance of Thoroughbreds. If, however, the science is applied in an uncoordinated manner, driven by commercial interests with no underlying concern for the horses themselves, there is a very real risk that breeders, the Thoroughbred breed and individual horses will all suffer as a consequence.     

Submicroscopic changes in the glandular epithelium of the endometrium in cows during the estrous cycle

During the sexual cycle the structural changes in the cells of the glandular epithelium in the endometrium of a cow are more pronounced than those in the luminal epithelium. Microvilli appear on cell surface during pro-oestrus; in later stages the microvilli disappear and the apical parts penetrate into the lumen. The relative volume of mitochondria increases from pro-oestrus to culminate in oestrus and metoestrus and to drop in dioestrus. The values of the volume and surface area of granular endoplasmic reticulum are also at their highest level in oestrus and metoestrus. The lowest volume and surface area of smooth membranes are recorded in dioestrus, then it markedly increases to culminate in metoestrus. The incidence of lysosomes is variable and their volume culminates in metoestrus. The proliferation of the glandular epithelium has the highest intensity in oestrus and reaches its peak values in metoestrus when the apical parts of cytoplasm contain the largest amounts of smooth-walled vesicles and vacuoles, partly also secretory granules, and when the signs of secretion are observed.     

Fine Structure of the Choriocapillaris, Bruch''s Membrane and Retinal Epithelium of the Cow

The fine structure of the choriocapillaris, Bruch's membrane and retinal epithelium was investigated in both the tapetal and non-tapetal fundus of the bovine eye. In ail locations the retinal epithelium consists of a single layer of cuboidal cells. The epithelial cells are joined laterally by apically located tight junctions and throughout the retina display numerous basal infoldings and fine apical processes which enclose rod outer segments. All retinal epithelial cells are rich in smooth endoplasmic reticulum and mitochondria and contain phagosomes. Although not as abundant, profiles of rough endoplasmic reticulum and polysomes are also noted in all locations. In non-tapetal areas, melano-somes are numerous whereas over the central tapetum fibrosum they are absent. The absence of melanosomes over a functional tapetum is to be expected. While lysosomes are present throughout the epithelial layer, over the tapetal region they appear to be more numerous. The apparent increase in lysosomal numbers in this location may indicate an enhanced shedding of outer segment material over the tapetum. Although some retinal epithelial cells are modified to accomodate a tapetum lucidum their morphology is basically similar throughout the retina and probably indicates that ail regions of the retinal epithelium are capable of the normal functions of this indispensible retinal layer. The choriocapillaris is heavily fenestrated on the border facing the retina and overlying the tapetum also displays fenestrae on its choroidal edge. Bruch's membrane ( complexus basalis ) is pentalaminate throughout the retina and is slightly thicker in the posterior fundus.     

The place of the post-mortem room in the training of the small animal veterinarian

The post-mortem room can be an important focal point in the training of the small animal veterinarian. Repetitive necropsy demonstrations are necessary to provide a firm foundation of gross pathology for the clinician. More importantly, collaborative post-mortem demonstration/discussions involving clinicians, pathologist and laboratory diagnosticians are necessary to develop understanding of clinico-pathological correlation and this has an important function in developing clinical diagnostic skills and confidence.     

A study of the ultrastructure and staining characteristics of the 'dental star' of equine incisors

The objective of this study was to examine the diameter, extent, orientation and contents of dentinal tubules in order to validate the hypothesis of pigment penetration into the dental star of equine incisival occlusal surfaces. The time of appearance and the configuration of the dental star on the incisival occlusal surface are macroscopically visible features that, along with other more reliable parameters, are used for the determination of horses' age. Although dental stars are an integral part of the equine incisor occlusive surface, the exact nature and microstructure of the dental star are poorly documented. Therefore, equine incisor dentine was examined macroscopically and by scanning electron microscopy to elucidate numerical density, diameter and 3-dimensional organisation of the dentinal tubules in the dental star. The dental star is surrounded by primary dentine and consists of a central core of tertiary dentine, an intermediate ring of pale secondary dentine and a peripheral rim of darker, yellowish-brown secondary dentine. The central core of tertiary dentine contains relatively few dentinal tubules (<8000/mm2) that have small diameters (mean +/- s.d. 1.67 +/- 034 microm) and are arranged in an irregular pattern. The surrounding pale ring of secondary dentine comprises manifestly more and wider tubules that lie almost parallel to the occlusal surface. The dark peripheral rim of the dental star contains high numbers of tubules (28,000-58,000/mm2) that have wide luminal diameters (mean +/- s.d. 3.09 +/- 0.31 microm) and open perpendicular to the occlusal surface. In contrast, the primary dentine surrounding the dental star is made up by a lower number of dentinal tubules (<25,000/mm2). The tubules of primary dentine, which are initially mean +/- s.d. 5.15 +/- 0.80 microm wide, are narrowed by circumferential deposits of peritubular dentine and are obliquely exposed at the occlusal surface. From these observations, it was concluded that the regional differences in numerical density, diameter and spatial orientation of the dentinal tubules may influence the penetration of food pigments into the equine occlusal surface and result in the particular staining of the dental star.     

Submicroscopic changes in ciliated cells of the epithelium of the oviduct in cows during the estrus cycle

The submicroscopic changes in the ciliary cells of the ampullar part of oviduct are of qualitative as well as quantitative nature. The mitochondria are mainly located in the supranuclear region. They are small, having densely arranged lamelliform cristae and dense matrix. They have the largest volume in metoestrus and the highest number and the largest surface already during oestrus. The volume and surface of granular endoplasmic reticulum culminates already during pro-oestrus. The reticulum occurs mainly over the nucleus where it produces tubuli densely covered with ribosomes which begin to dilate already during pro-oestrus. The Golgi apparatus and the membranes of smooth reticulum are poorly developed and their quantitative changes during the cycle are not significant. Various forms of lysosomes, whose volume reaches its maximum in dioestrus and during pro-oestrus, constitute a constant component of cytoplasm. Secretory granules occur only rarely in these cells. Kinocilia grow from the basal corpuscles and are more frequent on cells with a light cytoplasm. Higher-density cells have more micro-villi between kinocilia. Deciliation with the disintegration of membrane, filaments and often also the basal corpuscles is observed during metoestrus and at the beginning of dioestrus. Reciliation begins with the formation of basal corpuscles and their replication at the end of dioestrus and in pro-oestrus. The frequency of ciliary regeneration is comparatively small.     

动物源性大肠杆菌耐药性分析

目的:对吉林省长春市伊通地区分离出的113株动物源性大肠杆菌耐药性进行分析,了解猪源和鸡源大肠杆菌耐药程度及其耐药谱。方法:采用K-B纸片扩散法对大肠杆菌耐药性初步定性分析,并从中选出十株耐药谱不同的大肠杆菌测定其抗生素的最小抑菌浓度(MIC)。结果:113株均表现出不同程度的耐药,耐药谱广,且多表现为多重耐药。结论:动物源性大肠杆菌对抗生素的耐药性以多重耐药为主。113株对喹诺酮类、磺胺类、利福平耐药率达到90%以上,其中鸡源、猪源大肠杆菌耐药情况各不相同,二者均对丁胺卡那霉素、先锋必/舒巴坦较敏感,耐药率低于15%,可知丁胺卡那霉素、先锋必/舒巴坦可作为这些地区防治致病性大肠杆菌的首选药物。本实验结果对临床科学合理用药有重要指导意义。