多年生黑麦草叶片长度数量性状位点(QTLs)研究

选择固定有益等位基因,研究多年生黑麦草叶片长度数量性状位点,结果表明:与叶长最为相关的3个标记所表达的变异占表型总变异的50.9%(r2);在选择中如能将这3个标记最优化地组合在一起,其综合共同作用有望使叶片长度延长和缩短26 mm;鉴于供试材料在最初3个世代的群体选择中所估测到叶片长度的遗传力为0.32,这样在今后的选择工作中,即使只使用现有的两个标记,其效果亦优于传统的表型选择法.     

Aortic to caudal vena cava ratio measurements using abdominal ultrasound are increased in dogs with confirmed systemic hypertension

Chronically sustained systemic hypertension in dogs can damage the kidneys, eye, brain, heart, and vessels. In human medicine, systemic hypertension has been implicated as the most common risk factor for aorta dilation, which can progress to an aneurysm. Abdominal ultrasound has been commonly used to monitor the size of the abdominal aorta in people with systemic hypertension. In this retrospective cross‐sectional abdominal ultrasound study, evaluation of the size of the abdominal aorta relative to the caudal vena cava was performed in 18 control dogs and 128 dogs with confirmed systemic hypertension. Preexisting conditions contributing to systemic hypertension in these dogs were renal disease, hyperadrenocorticism, diabetes mellitus, adrenal tumors, and previous administration of phenylpropanolamine or palladia. The abdominal aorta and caudal vena cava were assessed from longitudinal images cranial to the trifurcation with measurements made from outer border to outer border of the walls, being careful not to compress the caudal vena cava that would alter its size. Our hypothesis was the ratio of the diameter of the abdominal aorta to caudal vena cava would be higher in dogs with systemic hypertension compared to dogs with normal blood pressure. The mean abdominal aorta‐caudal vena cava ratio was 1.028 in control dogs with a normal blood pressure and 1.515 in dogs with systemic hypertension. In dogs with confirmed systemic hypertension, the abdominal aorta was dilated compared to the caudal vena cava in the caudal abdomen. An increase in the abdominal aorta‐caudal vena cava ratio in a dog should raise suspicion for the presence of systemic hypertension and prompt evaluation of blood pressure.     

Cytokine mRNA expression of pulmonary macrophages varies with challenge but not with disease state in horses with heaves or in controls

Heaves in horses is characterized by lower airway neutrophilic inflammation, and reversible airflow obstruction. Pulmonary macrophages contribute to the inflammation observed in a number of human and animal pulmonary diseases, and it has been postulated that they are responsible for the neutrophilic inflammation present in heaves by the release of cytokines and chemokines. To test this hypothesis, the mRNA expression of TNF-α, IL-1β, IL-8, and MIP-2 by macrophages isolated from bronchoalveolar lavage cells was quantified using real-time RT-PCR in horses with heaves (n-6) and controls (n-6). Animals were studied after being pastured for 3 months to induce clinical remission of heaves, and after 24h, and 9 days of a continuous natural antigen challenge consisting of hay feeding and straw bedding. The study was performed during 2 consecutive summers, when 3 horses with heaves and 3 control horses were evaluated. As expected, airway obstruction developed with the challenge only in horses with heaves, while airway neutrophilia was observed in both groups of horses. Stabling resulted in an increased expression of IL-8/?-actin and MIP-2/?-actin after 24h of stabling in both groups of horses. Further analyses revealed that compared to pasture, the expression of these chemokines was significantly increased after 24h of stabling only in Year 1, while the IL-8 expression was significantly decreased at 9 days in Year 2. No significant group, time, or year differences in IL-1β/?-actin and TNF-α/?-actin ratio were observed. The expression of IL-1β was strongly correlated with neutrophil percentages, although at different time points in the two study-years. These results suggest that alveolar macrophages can contribute to the airway inflammation resulting from stabling in horses by the release of IL-8 and MIP-2, but that the release of these chemokines is unlikely to be responsible for the marked airway neutrophilia observed in heaves. The variable expression of IL-8 and MIP-2 by alveolar macrophages between the two-study years are additional novel findings highlighting the complexity of the inflammatory pathways associated with airway inflammation and the importance of evaluating concurrently horses with heaves and controls to ensure identical environmental challenges.     

Animal poisoning in Europe. Part 2: Companion animals

This is the second in a series of three review articles on animal poisoning in Europe and focuses on cases in pet animals and horses in five European countries (Belgium, France, Greece, Italy and Spain) reported over the last decade. In the participating countries, dogs were the most commonly poisoned species, particularly younger animals. The majority of cases in companion animals resulted from exposure to insecticides, although rodenticides (especially anticoagulants and strychnine) posed a significant risk. In all five countries, horses and cats appeared to be more susceptible to plant toxins. Intoxications with herbicides, metals, household products and drugs for veterinary and human use were reported sporadically. The review demonstrates the importance of increased awareness so as to minimise poisoning episodes and emphasises the need to establish a European system for the recording of poisoning data.     

Giant unruptured aneurysm of the left sinus of Valsalva in the left ventricular outflow tract of a young dog

A young adult, 28 kg, intact female Siberian husky-mixed breed dog was presented to the Veterinary Medical Teaching Hospital (VMTH) Emergency Service for evaluation of a dysrhythmia and an abnormal cardiac structure. The dog had been adopted from an animal shelter approximately 3 months before presentation. The dog occasionally showed exercise intolerance, and the owners suspected that she had impaired vision. Initial clinical signs appeared 2 days before presentation during strenuous activity—the dog uncharacteristically stopped and lay down while tachypneic. The dog produced dark liquid feces and was lethargic and anorexic overnight.     

Surgical correction of colonic duplication in a cat

A 2-year-old, castrated male Manx cat was presented for anorexia, obstipation, and straining to defecate. Imaging tests revealed a cystic mass associated with the descending colon. Three surgical explorations over several years were performed before complete resection of the cystic mass was achieved. Histopathology of the mass revealed normal colonic structures consistent with colonic duplication. Complete resection of a noncommunicating duplicate colon may allow successful treatment of this condition and resolution of associated clinical signs.     

Emergence of Salmonella epidemics: the problems related to Salmonella enterica serotype Enteritidis and multiple antibiotic resistance in other major serotypes

Two major changes in the epidemiology of salmonellosis occurred in the second half of the 20th century: the emergence of food-borne human infections caused by S. Enteritidis and by multiple-antibiotic resistant strains of Salmonella. This review updates information on the S. Enteritidis pandemic and focuses on the emergence of Salmonella, carrying the SGI1 antibiotic resistance gene cluster, resistant to extended-spectrum cephalosporins, or resistant to fluoroquinolones. The factors responsible for the emergence of these Salmonella strains could be either of human origin or related to bacterial genome evolution. However, our increasing understanding of the molecular fluidity of the genome shows that any attempt to counteract bacteria results in further bacterial evolution or adaptation of other bacteria to take place in the new free ecological niche. In these conditions, we can ask who is faster: humans who want to eliminate bacterial pathogens or bacteria that continuously evolve to gain new niches.     

Mapping the pork value chain in Vietnam: a systematic review

Tropical Animal Health and Production - In Vietnam, pork is the most commonly consumed type of meat, and the demand is expected to rise even further. Nevertheless, food safety is a major concern,...     

Porcine CD18 mediates Actinobacillus pleuropneumoniae ApxIII species-specific toxicity

Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia, produces Apx toxins that are recognized as major virulence factors. Recently, we showed that ApxIIIA-cytotoxic activity specifically targets Sus scrofa leukocytes. Since both LtxA from Aggregatibacter actinomycetemcomitans (aggressive periodontitis in humans) and LktA from Mannheimia haemolytica (pneumonia in ruminants) share this characteristic, respectively towards human and ruminant leukocytes, and because both use the CD18 subunit to interact with their respective LFA-1, we hypothesized that ApxIIIA was likely to bind porcine CD18 to exercise its deleterious effects on pig leukocytes. A β ₂−integrin-deficient ApxIIIA-resistant human erythroleukemic cell line was transfected either with homologous or heterologous CD11a/CD18 heterodimers using a set of plasmids coding for human (ApxIIIA-resistant), bovine (-resistant) and porcine (-susceptible) CD11a and CD18 subunits. Cell preparations that switched from ApxIIIA-resistance to -susceptibility were then sought to identify the LFA-1 subunit involved. The results showed that the ApxIIIA-resistant recipient cell line was rendered susceptible only if the CD18 partner within the LFA-1 heterodimer was that of the pig. It is concluded that porcine CD18 is necessary to mediate A. pleuropneumoniae ApxIIIA toxin-induced leukolysis.     

Partial sequencing and expression of genes involved in glucose metabolism in adipose tissues and skeletal muscle of healthy cats

Impaired insulin sensitivity is increasingly recognised in cats, but sequences of genes involved in insulin-signalling are largely undetermined in this species. In this study, extended feline mRNA sequences were determined for the adiponectin, glucose transporter-1 (GLUT1), GLUT4, peroxisome proliferative activated receptor-gamma1 (PPARgamma1), PPARgamma2, plasminogen activator inhibitor-1 (PAI-1), monocyte chemoattractant protein-1 (MCP-1) and insulin receptor genes. Conserved dog-specific primers identified from human-dog mRNA alignments were used to amplify feline cDNA in the polymerase chain reaction (PCR). The feline sequences determined by this method were used to design feline-specific primers suitable for real-time PCR for quantification of gene expression in insulin sensitive tissues of healthy cats. Partial sequences of feline mRNAs had 86-95% identity with dog and human genes. Expression of adiponectin, GLUT1, GLUT4, PPARgamma1, PPARgamma2, PAI-1 and insulin receptor mRNA was detected and quantified in subcutaneous and visceral fat and skeletal muscle, whereas MCP-1 mRNA was detected in adipose tissue but not in skeletal muscle. Further characterisation of genes related to glucose metabolism in cats will provide additional insights into insulin-signalling mechanisms in this species.