Temperature effect on muscle growth of the axial musculature of the sea bass (Dicentrarchus labrax L.)

In order to determine the temperature effect on the axial muscle growth of sea bass, a stock of larvae was subjected to the following incubation and cultivation temperatures, respectively: 15 degrees C/ambient, 15/17 degrees C, 17 degrees C/ambient and 17/17 degrees C. In all groups the cross-sectional area of white and red muscles and the number and average area of the white and red muscle fibres were quantified. Results showed that the embryonic period, pre-larval phase and the end of metamorphosis were accelerated at higher temperatures. During the endogenous feeding period, muscle growth took place by fibrillar hypertrophy, and was not influenced by the temperature. Thereafter (external feeding) muscular hyperplasia began, and growth of all the muscular parameters was favoured by the effect of high incubation and cultivation temperatures, with the latter having higher influence. High incubation temperature had an slight effect on muscle growth and body length, which was only observed from 15 days. Metamorphosis finished at 3 +/- 0.4 cm in all the larvae, but this length was earlier reached at higher temperatures. At 120 days, the largest growth was obtained in the larvae maintained at a higher temperature.     

Lateral musculature in the whitemouth croaker (Micropogonias furnieri): its characterization with respect to different gonadal conditions

Histochemical and ultrastructural studies were performed on the lateral musculature from individual female whitemouth croaker, Micropogonias furnieri, at the anterior, medium and posterior regions. Based upon histochemical myosin-ATPase (m-ATPase) determination, diverse types of red, pink and white fibres were discerned. Red muscle had abundant mitochondria and stained intensely for aerobic enzymes, white muscle scarcely stained for the same enzymes and pink muscle responded in an intermediate manner. Both white and pink muscle had few mitochondria. The relative proportion of red muscle increased towards the caudal region; pink muscle diminished towards this region and white muscle modified its proportion only in the anterior region. m-ATPase activity showed differences in relation to the gonadal condition along the body, particularly in the white fibres at the anterior and medium regions.     

Comparison of bacterial cultivation, PCR, in situ hybridization and immunohistochemistry as tools for diagnosis of Haemophilus somnus pneumonia in cattle

The aim of the present study was to compare the potential of bacterial cultivation (BC), PCR, in situ hybridisation (ISH), and immunohistochemistry (IHC) in the diagnosis of Haemophilus somnus, when applied to pneumonic bovine tissue. Lungs from 65 field cases submitted for bacteriological examination were included in the study. The PCR-detection was performed on three different samples: plate-PCR (detection on plate washes after incubation of lung tissue on agar plates); swab-PCR (direct detection on a swab from the cut surface); and, whenever possible, a bronchus-PCR (direct detection on a swab from the main bronchus of the right cranial lung lobe). In order to examine the pathological significance of the findings, a histopathological examination of the cases was performed. H. somnus was detected by one or more techniques in 33 cases in total. By BC the bacterium was isolated from 10 cases, IHC and ISH were positive in 17 and 19 cases, and plate- and swab-PCR were positive in 21 and 29 cases, respectively. The bronchus-PCR was positive in 30 out of 61 cases examined. The PCR-technique was the most sensitive method, and as this technique is fast and relatively inexpensive, it should be considered as a supplementary tool in the diagnosis of H. somnus induced calf pneumonia.     

Cyclical endometrial steroid hormone receptor expression and proliferation intensity in the mare

The aims of this study were to investigate the steroid hormone receptor expression and the proliferation intensity during the equine endometrial cycle by immunohistological methods, established for routine examination of formalin-fixed, paraplast-embedded specimens. Endometrial biopsy specimens were obtained during one cycle from 7 mares. In comparison with the blood steroid hormone levels the quantity and distribution of oestrogen (ER) and progesterone receptors (PR) and the proliferation marker Ki-67 antigen expression were investigated. Rising 17beta-oestradiol concentrations in preoestrus induce a synchronous expression of ER, PR and Ki-67 antigen in stromal cells. In the early dioestrus 17beta-oestradiol levels decrease and progesterone levels reach their maxima. This correlates with an intense proliferation activity and the highest hormone receptor expression in epithelial cells. In accordance to the morphological features of asynchronous glandular differentiation in fibrotic areas (endometrosis) their epithelial hormone receptor expression is out of phase.     

Radiographic and clinical survey of degenerative joint disease in the distal tarsal joints in Icelandic horses

The prevalence of degenerative joint disease (DJD) in the distal tarsal joints and the relation between radiographic and clinical signs compatible with the disease were estimated in a population of Icelandic horses used for riding. The material consisted of 614 horses age 6-12 years (mean age = 7.9 years). Radiographs with 3 projections of each tarsus were made and a clinical examination, including palpation of the medial aspect of the distal tarsus and motion evaluation of the hindlimbs before and after a flexion test of the tarsus, was performed. Radiographic signs of DJD in the distal tarsal joints were found in 30.3% of the horses and the prevalence was strongly correlated with age. Hindlimb lameness before and after flexion test and palpation abnormalities were significantly associated with the radiographic findings. The lameness was usually mild and, in most cases, detectable only after the flexion test. The prevalence of lameness was not significantly correlated with age. Lameness could not be predicted by details of the radiographic findings.     

Induction of early immunopotentiation to Fimbriae of Salmonella Enteritidis (SE) by administering thymulin and zinc to SE-vaccinated chicken breeders: relationship to protection

The purpose of this study is to attempt the induction of early immunopotentiation of antibodies specific to fimbriae of Salmonella enterica serovar Enteritidis (SE), by administering thymulin and zinc to SE-vaccinated chicken breeders, and the improvement of protection against a controlled-live challenge by SE. The first two groups of breeders were administered subcutaneously at 15 and 19 weeks of age a killed SE vaccine. Breeders of the third and fourth groups were left unvaccinated. Breeders of the first group, immunopotentiated by thymulin and zinc, were able to induce the earliest antibodies in their pooled sera at 2 weeks post the first SE-vaccination, specific to fimbriae (approximately 21 KDa) of SE. However, the second group that was only vaccinated with the same SE-vaccine produced specific antibodies to fimbriae at 3 weeks following the second vaccination (22 weeks of age). Breeders of the third group, that were neither SE-vaccinated nor immunopotentiated by thymulin and zinc, but were challenged by live SE at 22 weeks of age, were able to show specific antibodies to fimbriae at 3 weeks post challenge (25 weeks of age). The fourth group that was deprived of SE-vaccination, immunopotentiators, and challenge didn't show any background antibodies specific to SE-fimbriae. The presence of the earliest antibody-immunopotentiation to fimbriae of SE in breeders of the first group, administered thymulin and zinc, was associated with the lowest frequency of SE-infected ceca (10%) among the challenged groups. In addition, breeders of the first group were the only challenged birds resulting in absence of SE infection in their cecal tonsils. The first group-vaccinated, immunopotentiated, and challenged, and the second group-vaccinated and challenged only resulted in breeders with absence of SE infection in their oviducts and spleens. In conclusion, immunopotentiation of chicken breeders by thymulin and zinc induces the earliest specific antibodies to fimbriae of SE associated with the lowest frequency of SE-infected ceca, and absence of SE infection from cecal tonsils, oviducts and spleens.     

Arrhythmogenic right ventricular cardiomyopathy in a dog

An 8-month-old Labrador retriever bitch was evaluated for sudden-onset, progressive abdominal distension. Physical examination revealed an exaggerated inspiratory effort, severe ascites, bilateral jugular vein distension, and hypokinetic femoral arterial pulses. Thoracic auscultation detected tachycardia with muffled heart sounds, without audible cardiac murmurs. Thoracic radiographs identified severe right ventricular enlargement and pleural effusion. The electrocardiogram was consistent with incomplete right bundle branch block or right ventricular enlargement. Echocardiography demonstrated severe right ventricular and atrial dilation, secondary tricuspid regurgitation, and thinning and hypocontractility of the right ventricular myocardium. Left heart chamber sizes were slightly decreased, with normal left ventricular contractility. A diagnosis of arrhythmogenic right ventricular cardiomyopathy was reached, based on the characteristic clinical, electrocardiographic, radiographic and echocardiographic findings, and the exclusion of other causes of isolated right ventricular failure. Treatment effected good control of clinical signs, until acutely decompensated congestive right heart failure led to euthanasia after 4 months. Arrhythmogenic right ventricular cardiomyopathy is a well-described clinical entity in humans, and has previously been documented in 3 male dogs. The condition is characterised by progressive fibro-adipose replacement of right ventricular myocardium, while the left ventricle usually remains unaffected. It should be considered a differential diagnosis in any young dog presented with isolated right heart failure, syncope, or unexplained ventricular tachyarrhythmias. This article reports the 1st case of arrhythmogenic right ventricular cardiomyopathy in a female dog, and highlights its echocardiographic features.     

Bush cover and range condition assessments in relation to landscape and grazing in southern Ethiopia

Progressive growth of bush cover in dry savannahs is responsible for declines in range conditions. In southern Ethiopia, the Booran pastoralists assisted our understanding of spatial patterns of bush cover and range conditions in 54 landscape patch types grouped into six landscape units within an area of 30000 km². The size of landscape patches sampled was 625 m². We assessed the relationships between bush cover, grass cover and bare soil and grazing pressure and soil erosion and changes in range condition. Externally, political conflicts and internally, break down of land use, and official bans on the use of fire promoted bush cover and the decline in range conditions. Bush cover was negatively correlated with grass cover, and positively correlated with bare soil. Grass cover was negatively correlated with bare soil and grazing pressure in most landscape patch types. Grazing pressure was not significantly correlated with bush cover or bare soil, while soil erosion was directly related to bare soil. Soil erosion was absent in 64% of the landscape patch types, and seemingly not a threat to the rangelands. The relationship between bush cover, grass cover, bare soil and soil erosion is complex and related to climate, landscape geology, and patterns of land use. Main threats to range conditions are bush climax, loss of grass cover and unpalatable forbs. Currently, >70% of the landscape patch types are in poor to fair range conditions. Decline in range conditions, unless reversed, will jeopardise the pastoral production system in southern Ethiopia.     

Biological, serological, and molecular variability suggest three distinct polerovirus species infecting beet or rape

Yellowing diseases of sugar beet can be caused by a range of strains classified as Beet mild yellowing virus (BMYV) or Beet western yellows virus (BWYV), both belonging to the genus Polerovirus of the family Luteoviridae. Host range, genomic, and serological studies have shown that isolates of these viruses can be grouped into three distinct species. Within these species, the coat protein amino acid sequences are highly conserved (more than 90% homology), whereas the P0 sequences (open reading frame, ORF 0) are variable (about 30% homology). Based on these results, we propose a new classification of BMYV and BWYV into three distinct species. Two of these species are presented for the first time and are not yet recognized by the International Committee on Taxonomy of Viruses. The first species, BMYV, infects sugar beet and Capsella bursa-pastoris. The second species, Brassica yellowing virus, does not infect beet, but infects a large number of plants belonging to the genus Brassica within the family Brassicaceae. The third species, Beet chlorosis virus, infects beet and Chenopodium capitatum, but not Capsella bursa-pastoris.     

新扬州鸡早期增重的OPAY02-SCAR分子标记研究

OPAY02型2条多态性条带经克隆、测序和引物设计后,转换成SCAR标记,并对86个新扬州鸡随机交配后代基因组DNA进行了PCR扩增.2条带DNA序列与红色原鸡基因组序列比对结果表明,大分子量条带与位于红色原鸡第3号染色体上序列有98%的同源性,共检测到8个SNPS,其中195位的碱基T→G,316位的A→T,538位的G→A,731位的T→A,1 147位的G→A,1 329位的T→C,1 927位的C→T,2 081位的C→T,小分子量条带与红色原鸡没有同源序列,推测新扬州鸡野祖除红色原鸡外,还有其它来源.SCAR标记分析表明,经条件优化随机扩增的OPAY02型标记稳定、可靠,可用于遗传分析.2条带所在座位群体基因型平衡性测验结果表明,所测新扬州鸡群体处于平衡状态,选择可以打破平衡,有利于动物育种.