Presence of Ganglia and Telocytes in Proximity to Myocardial Sleeve Tissue in the Porcine Pulmonary Veins Wall

Ganglia and telocytes were identified inside the porcine pulmonary veins wall near myocardial sleeve tissue at the atriopulmonary junction. These structures are reported to play a role in the initiation of pulses from outside the heart, which potentially can cause cardiac conduction disorders such as atrial fibrillation. In‐depth knowledge on the fine structure of the pulmonary vein wall is a pre‐requisite to better understand the underlying pathophysiology of atrial fibrillation and the origin and conduction of ectopic pulses. The importance of pulmonary vein myocardial sleeves as triggering foci for atrial fibrillation has been shown in human patients. In this context, the fine structure of the pulmonary vein wall was investigated qualitatively by light and transmission electron microscopy in the pig, which is a frequently used animal model for development of new treatment strategies. Additionally, intra and extramural ganglia, containing telocytes that create a network near the neurone cell bodies, were identified in pigs. Detailed illustration of the distribution and organization of tissues and cell types, potentially involved in the origin and propagation of ectopic stimuli originating from the pulmonary veins, might lead to a better insight on the actual composition of the tissues affected by ablation as studied in pigs.     

CD117‐ and vimentin‐positive telocytes in the bovine teat sphincter

Mastitis is a common economically relevant problem in dairy farming. As the major entry for pathogens is the papillary duct, one of the first defence mechanisms is the teat sphincter. This sphincter shows a rhythmic contractility of yet unknown origin. Searching for possible modulatory pacemaker cells, teat sphincters of eight cows were stained immunohistochemically with antibodies against CD117 and vimentin and evaluated microscopically for the presence of telocytes. CD117‐ and vimentin‐positive telocytes with telopodes were found in close contact with smooth muscle cells. Our findings present a first evidence of telocytes in the teat of bovines.     

山东潍坊地区PMWS临床病例的病理学研究

本研究对山东省潍坊地区8个猪场的断奶后仔猪多系统衰竭综合征(postweaning multisystemic wasting syndrome,PMWS)疑似病例在进行病原学诊断的基础上,作了系统的病理学研究,旨在为潍坊地区PMWS的诊断提供病理学诊断依据。结果表明潍坊地区PMWS病猪主要组织病理学变化表现为淋巴结和脾脏中缺少淋巴细胞,严重的单核、巨噬细胞和嗜酸性粒细胞浸润。在淋巴组织中出现类上皮样细胞以及合胞体性多核巨细胞形成的肉芽肿,巨噬细胞胞浆内有病毒包涵体。肺有间质性、支气管性肺炎;肝脏出现以肝细胞局灶性坏死、淋巴细胞浸润为特征的病变;肾脏有轻至重度的多灶性间质性肾炎;并表现不同程度的间质性心肌炎和非化脓性脑炎的病变。     

Renal tubular necrosis and interstitial hemorrhage ("turkey-egg kidney") in a circovirus-infected Yorkshire cross pig.

A juvenile Yorkshire cross pig with rapidly progressive acute renal failure was submitted for necropsy. There was marked edema and disseminated petechiation of both kidneys, producing the "turkey-egg" appearance that is characteristic of exotic diseases such as African and classical swine fever. Microscopic findings included renal tubular epithelial necrosis with extensive interstitial edema and hemorrhage; lymphoplasmacytic, eosinophilic, and histiocytic tubulointerstitial nephritis; and numerous botryoid intracytoplasmic inclusions within the renal tubular epithelium and interstitial macrophages. Porcine circovirus 2 (PCV2) was readily identified within these lesions by both PCV2-specific immunohistochemistical staining and electron microscopy. Tests for African and classical swine fever viruses, as well as bacterial cultures, were negative. The striking renal lesions in this pig were attributed to PCV2 infection and are distinct from those that are typical of other PCV2-associated diseases.     

Interstitial lung disease associated with Equine Infectious Anemia Virus infection in horses

EIA (Equine Infectious Anemia) is a blood-borne disease primarily transmitted by haematophagous insects or needle punctures. Other routes of transmission have been poorly explored. We evaluated the potential of EIAV (Equine Infectious Anemia Virus) to induce pulmonary lesions in naturally infected equids. Lungs from 77 EIAV seropositive horses have been collected in Romania and France. Three types of lesions have been scored on paraffin-embedded lungs: lymphocyte infiltration, bronchiolar inflammation, and thickness of the alveolar septa. Expression of the p26 EIAV capsid (CA) protein has been evaluated by immunostaining. Compared to EIAV-negative horses, 52% of the EIAV-positive horses displayed a mild inflammation around the bronchioles, 22% had a moderate inflammation with inflammatory cells inside the wall and epithelial bronchiolar hyperplasia and 6.5% had a moderate to severe inflammation, with destruction of the bronchiolar epithelium and accumulation of smooth muscle cells within the pulmonary parenchyma. Changes in the thickness of the alveolar septa were also present. Expression of EIAV capsid has been evidenced in macrophages, endothelial as well as in alveolar and bronchiolar epithelial cells, as determined by their morphology and localization. To summarize, we found lesions of interstitial lung disease similar to that observed during other lentiviral infections such as FIV in cats, SRLV in sheep and goats or HIV in children. The presence of EIAV capsid in lung epithelial cells suggests that EIAV might be responsible for the broncho-interstitial damages observed.     

Meat Science and Muscle Biology Symposium: stem cell niche and postnatal muscle growth

Stem cell niche plays a critical role in regulating the behavior and function of adult stem cells that underlie tissue growth, maintenance, and regeneration. In the skeletal muscle, stem cells, called satellite cells, contribute to postnatal muscle growth and hypertrophy, and thus, meat production in agricultural animals. Satellite cells are located adjacent to mature muscle fibers underneath a sheath of basal lamina. Microenvironmental signals from extracellular matrix mediated by the basal lamina and from the host myofiber both impinge on satellite cells to regulate their activity. Furthermore, several types of muscle interstitial cells, including intramuscular preadipocytes and connective tissue fibroblasts, have recently been shown to interact with satellite cells and actively regulate the growth and regeneration of postnatal skeletal muscles. From this regard, interstitial adipogenic cells are not only important for marbling and meat quality, but also represent an additional cellular component of the satellite cell niche. At the molecular level, these interstitial cells may interact with satellite cells through cell surface ligands, such as delta-like 1 homolog (Dlk1) protein whose overexpression is thought to be responsible for muscle hypertrophy in callipyge sheep. In fact, extracellular Dlk1 protein has been shown to promote the myogenic differentiation of satellite cells. Understanding the cellular and molecular mechanisms within the stem cell niche that regulate satellite cell differentiation and maintain muscle homeostasis may lead to promising approaches to optimizing muscle growth and composition, thus improving meat production and quality.     

原位杂交技术用于虹彩病毒对美国青蛙侵染的诊断

蛙虹彩病毒（Rana grylio virus,RGV)能引起鱼类、两栖类和爬行类水生动物严重的系统性疾病，RGV是从我国患病蛙中分离到一种虹彩病毒。体外扩增的RGV经人工方法感染幼龄美国青蛙（Rana grylio)，运用原位杂交技术，分别对感染1-3d后的蛙心、肺、肾、肠、脾、肝等6种组织进行RGV分子定位和检测，结果显示，在幼蛙的肺和肠中有较强的阳性信号，在其他组织中也检测到RGV的存在。本试验探讨了RGV感染早期在宿主体内的增殖及在不同组织中的分布状况，建立了一种彩虹病毒的早期诊断方法，并为揭示RGV的致病机制奠定了基础。     

Expression of nitric oxide synthase isoforms in the testes of pigs

This study examined the expression of three isoforms of nitric oxide synthase (NOS) in the testes of pigs. Immunohistochemical studies demonstrated the presence of nNOS, eNOS and iNOS in interstitial cells, primary spermatocytes and spermatids. Positive immunoreactions for eNOS and iNOS were detected in peritubular myoid cells. Some vascular endothelial cells were positive for nNOS and eNOS. The expression of nitrotyrosine was detected in interstitial cells. In addition, the histochemical study revealed that all the interstitial cells were stained positively for NADPH-diaphorase, although some spermatids and vascular endothelial cells displayed moderate enzymatic activity. These findings suggest that three isoforms of NOS are expressed in the testis of pig and that they play important roles in the biology of interstitial cells that produce testosterone, as well as in spermatogenesis in the seminiferous tubules.     

In vitro production of porcine embryos: current status,future perspectives and alternative applications

The pig is considered to be a suitable source of cells and organs for xenotransplants, as well as a transgenic animal to produce specific proteins, given the biological similarities it shares with human beings. However, the in vitro embryo production system in pigs is inefficient compared with those in other mammals, such as cattle or mice. Although numerous modifications have been applied to improve the efficiency of in vitro embryo production systems in pigs, not much progress has been made to overcome the problem of polyspermy, and low developmental ability due to insufficient cytoplasmic abilities of in vitro matured oocytes and improper culture conditions for the in vitro produced embryos. Recent achievements, such as the establishment of chemically defined medium and utilization of ‘zona hardening’ technique, have gained some success. However, further research for the reduction of polyspermy and detrimental effects of the culture systems in pigs is still needed.     

猪生物医学模型研究进展

猪与人不仅在体重、生理特点、器官形成和疾病的发生方面都有高度的相似性,而且二者在基因组序列和染色体结构上有很高的同源性,所以猪已被作为人类研究中最主要的哺乳动物模型.目前,小型猪已被广泛应用于皮肤烧伤、肿瘤、免疫学、心血管病、糖尿病、畸形学和产期生物学、牙科、药理学等多方面的模式研究,以及对黑色素瘤和感染性疾病的基因组学研究中.在控制猪繁殖与呼吸系统综合征发生中的一些可行的基因组学方法,将为人类相似的病毒感染性疾病研究提供重要的参考.     

Multiorgan engraftment of human somatic cells in swine foetuses after intra-blastocyst transplantation

Adult human stem cells, mainly from hematopoietic lineage, have been injected into developing pre-immune animal foetuses, and xenogenic engraftment of liver and other organs has been reported. We isolated a rare cell population from adult human liver, fat and skin. Colonies with few cells became visible as early as 2-3 days, and a fully formed colony took 10-14 days to form. These colonies were named as liver-derived cell lines (LDCs), fat-derived cell lines (FDCs) and skin-derived cell lines (SDCs). All these cells express few pluripotency markers like Klf4, c-myc and Sox2. Pig blastocysts were injected with LDCs, FDCs and SDCs and transferred to recipient pigs. We achieved an overall pregnancy rate of 71.4% at day 35. The foetuses were analysed for human cell chimerism in liver, kidney and heart both by RT-PCR and real-time PCR using primers specific to human and pig mitochondrial DNA. The percentage of foetuses showing chimerism was 17.4% (4/23), 12.5% (2/16) and 11.1% (1/9) for LDCs, FDCs and SDCs, respectively. Of these, 42.9% (three out of seven) showed chimerism in liver and 71.4% (five out of seven) showed kidney chimerism. However, we did not detect any chimerism in the heart. The level of chimerism varied and was in the range of one human cell per one hundred thousand to one million pig cells.     

Processing of ingredients and diets and effects on nutritional value for pigs

A conventional diet based on corn and soybean meal fed to pigs is usually provided in a mash form and in most cases, processing other than grinding and mixing is not used. However, due to the high cost of energy in pig diets,use of high fiber ingredients such as soybean hulls, distillers dried grains with solubles, and wheat middlings has increased. High fiber concentrations in the diet usually results in reduced energy and nutrient digestibility due to the low capacity of pigs to digest fiber, which negatively impacts growth performance and carcass composition of the pigs. Feed processing technologies such as changes in grinding procedures, expansion, extrusion, pelleting, use of enzymes or chemical treatments may, however, be used to solubilize some of the cel ulose and hemicel ulose fractions that form the cel wal of plants in the ingredients, and therefore, increase nutrient availability. This may have a positive effect on energy digestibility, and therefore, also on pig growth performance and carcass composition, but effects of different feed technologies on the nutritional value of feed ingredients and diets fed to pigs are not fully understood. It has however, been demonstrated that reduced particle size of cereal grains usually results in increased digestibility of energy, primarily due to increased digestibility of starch. Extrusion or expansion of ingredients or diets may also increase energy digestibility and it appears that the increase is greater in high fiber diets than in diets with lower concentrations of fiber. Chemical treatments have not consistently improved energy or nutrient digestibility, but a number of different enzymes may be used to increase the digestibility of phosphorus, calcium, or energy. Thus, there are several opportunities for using feed technology to improve the nutritional value of diets fed to pigs.     

Expression of porcine endogenous retroviruses (PERVs) in melanomas of Munich miniature swine (MMS) Troll

Porcine endogenous retroviruses (PERVs) are integrated in the genome of all pig breeds. Since some of them are able to infect human cells, they might represent a risk for xenotransplantation using pig cells or organs. However, the expression and biological role of PERVs in healthy pigs as well as in porcine tumours is largely unknown. Since we and others have recently shown overexpression of a human endogenous retrovirus, HERV-K, in human melanomas, we studied the expression of PERVs in melanomas of selectively bred Munich miniature swine (MMS) Troll. This breeding herd of MMS Troll is characterised by a high prevalence of melanomas, which histologically resemble various types of cutaneous melanomas in humans. Several genetic factors have been defined when studying inheritance of melanomas and melanocytic nevi in MMS Troll. Here we show that the polytropic PERV-A and PERV-B as well as the ecotropic PERV-C are present in the genome of all melanoma bearing MMS Troll investigated. Most interestingly, in the spleen, but not in other organs, recombinant PERV-A/C proviruses were found. PERV expression was found elevated in melanomas when compared to normal skin and viral proteins were expressed in melanomas and pulmonary metastasis-derived melanoma cell cultures. During passaging of these cells in vitro the expression of PERV mRNA and protein increased and virus particles were released as shown by RT activity in the supernatant and by electron microscopy. Genomic RNA of PERV-A, -B and -C were found in pelleted virus particles. Although PERV expression was elevated in melanomas and pulmonary metastasis-derived cell cultures, the function of the virus in tumour development is still unclear.     

Epidemiology of trichinellosis in Mexico, Central and South America

Trichinella species are widely distributed throughout the world and are found in a large number of carnivorous animals, humans and incidental hosts. The data presented in this review show that Trichinella infection has been reported in both humans and animals in Mexico, Argentina and Chile since the end of the 19th century, and more recently in Bolivia. This parasitic infection is still a public health problem in countries such as Argentina and Chile. Although efforts have focused on the control and prevention of trichinellosis in these countries, there were still human cases and outbreaks of trichinellosis reported. Diagnosis of infection in animals such as pigs still includes, in many endemic areas, the use of trichinoscopy. In Argentina, however, artificial digestion has been recently introduced in slaughterhouses to detect Trichinella infection in pigs. In some endemic areas in Mexico, the use of serological assays for human trichinellosis and pig infections have resulted in improved detection. Most of the outbreaks of human trichinellosis in Mexico, Argentina and Chile have occurred as a result of the consumption of undercooked pork or pork products from animals raised under poor hygienic conditions and which are clandestinely slaughtered. In several studies, rats, dogs and cats have been found to be infected with Trichinella and may be considered a risk for transmission of the infection to pigs or other animals intended for human consumption. Another potential source of transmission of Trichinella to humans is horsemeat; however, information related to horse trichinellosis in Latin-American countries is scarce. In most cases the etiological agent of human trichinellosis in Central and South America has been reported to be Trichinella spiralis; however, only in a few cases has the parasite species been properly identified. Based on the reports available, it is clear that there is a need to carry out better controlled epidemiological studies to determine the true prevalence of the infection in this region of the world. Also, more sensitive methods of diagnosis and improvements in conditions for pig production as well as better sanitary inspection systems, are needed for controlling and preventing transmission of trichinellosis in these countries.     

A review of porcine pathophysiology: a different approach to disease

Diseases are often thought to result from a single cause. Although this is sometimes the case, e.g. with a highly virulent infection such as Classical Swine Fever (CSF), more often clinical disease in swine herds results from multiple predisposing factors. This is especially true in modern intensive pig husbandry, in which the role of highly infectious diseases is limited to (nonetheless devastating) outbreaks. More important nowadays are diseases, although associated with an agent, without a clear pathogenesis. The emphasis in disease control thus far has been on treatment, eradication and prevention. This has been achieved by focusing attention on husbandry factors, such as climate, housing, hygiene, management, and nutrition. Although this approach has been successful for a number of diseases, several health problems are persistent. There are strong indications that in the latter, intrinsic animal factors are important. Successful handling of these problems requires knowledge of the (patho)physiology of the pig. In this article, several characteristics of pig physiology associated with the occurrence of disease are described. It appears that the modern (fattening) pig is exceptional among other animal species in that its cardiovascular system is mismatched to its body weight. It is argued that this particular disposition causes relatively minor disturbances to have major consequences in the pig. This concept of pig physiology is central to the understanding of the hitherto poorly understood pathogenesis of several diseases, such as oedema disease.     

Activity of fiber-degrading microorganisms in the pig large intestine

The large intestine is comparable to the rumen fermentation in many aspects; however, it is understood less well. Fiber in the form of cellulose and hemicellulose is one of the major substrates fermented in the large intestine. Various studies suggest that the pig can utilize fiber for growth, and up to 30% of its maintenance energy may be derived from volatile fatty acids produced in the large intestine. The total number of microorganisms in the pig large intestine do not change when a high fiber diet such as 50 or 80% alfalfa meal is fed. However, the fiber-degrading organisms increase and obviously replace others. The increase in fibrolytic bacteria normally coincides with an increase in enzyme activity (cellulase and xylanase), indicating that diet can be used to enhance fibrolytic activity. This is true for growing pigs and adult animals. The cellulolytic organisms in the pig, Bacteroides succinogenes and Ruminococcus flavefaciens, are similar to those in the rumen and are present at comparable numbers. This partly explains why adult pigs can maintain themselves by merely grazing on forage in pastures. Assuming other conditions are met, there is a significant potential for fiber degradation in the pig large intestine. Whether various genotypes such as the genetically selected obese and lean pigs have different abilities to degrade fiber is unknown. More work is required to understand the interaction of the fibrolytic organisms with the other organisms present in the large intestine, similar to that which has been done in the rumen, as well as the microbe-host interaction.     

Induced pluripotent stem cells from pigs and other ungulate species: an alternative to embryonic stem cells?

Robust embryonic stem cell (ESC) lines from livestock species have been difficult to derive and maintain, and unlike mouse ESC, have not contributed to our ability to understand directed differentiation in vitro. Nor have such cells yet provided a simpler means than pronuclear injection to manipulate the genomes of agriculturally important species, such as cattle, sheep and pigs. Induced pluripotent stem cells (iPSC) generated by reprogramming somatic cells, such as fibroblasts, with a set of stemness genes, most usually but not exclusively POU5F1, SOX2, KLF4 and c-MYC, offer an alternative to ESC in these regards, as they exhibit a pluripotent phenotype resembling that of ESC, yet are readily generated in the laboratory. Accordingly, such cells, in association with cloning technologies, may be useful for introducing complex genetic changes into livestock, although this potential has yet to be demonstrated. Porcine iPSC may be especially valuable because the pig is a prime biomedical model for tissue transplantation. In general, iPSC from livestock, like those from humans, are of the epiblast type and depend upon FGF2 and activin/nodal signalling systems to maintain their pluripotency and growth. Recent experiments, in which newly reprogrammed porcine and bovine cells were selected on a LIF-based medium in presence of specific protein kinase inhibitors, have allowed iPSC cells of the na?ve type, resembling the more amenable blastocyst-derived mouse ESC and iPSC to be isolated. However, hurdles still remain if such cells are to achieve their biotechnological promise.     

Infection with Actinobacillus Suis in Pigs

Actinobacillosis in pigs seems to be relatively rare and when it does occur, it usually manifests itself as acute septicaemia during the first weeks of life (Zimmermann 1965). Polyarthritis, pneumonia and heart lesions as well as petechial haemorrhages in skin, viscera and kidneys are also frequently found (MacDonald et al. 1976, Jones & Simmons 1971). Both Actinobacillus suis and Actinobacillus equuli have been isolated from such cases (Pedersen 1977).     

Molecular mechanisms underlying pig oocyte maturation and fertilization

Since the pig is not only an important farm animal, but also a model animal for biomedical applications, the development of reproductive technologies in this species has been very important. In vitro oocyte maturation and fertilization (IVM-IVF) are basic techniques for a number of oocyte- or embryo-related technologies. The practical aspects for pig oocyte IVM-IVF have been reviewed, while the molecular mechanisms underlying oocyte meiotic maturation and fertilization have not been well summarized, although accumulating data have been obtained in recent one decade. This review will focus on what is known about the molecular mechanisms of porcine oocyte maturation and fertilization such as first meiosis resumption, meiotic spindle assembly, second meiosis metaphase (MII) arrest during oocyte maturation, sperm-egg recognition and fusion, sperm acrosome reaction, second meiosis resumption, sperm chromatin decondensation, and pronucleus formation during fertilization, as well as the establishment of polyspermy block.     

猪乳头数性状QTL研究进展

乳头数是种猪繁殖性能选育的重要指标之一。母猪乳头数与其繁殖性能有着较强的相关性,乳头数越多,则窝产仔数越多。因此,在选择种公猪及母猪时要着重考虑乳头数,对乳头数性状施予较高的选择强度,选育出乳头数较多的种猪,以满足高产仔数的需要。论文综述了猪乳头的形成和调控机制,猪乳头数性状QTL定位方法及其研究进展,旨在深入理解猪乳头数性状在猪繁殖性能中的重要作用,为种猪选育提供参考。