The genetic organization of the capsular polysaccharide biosynthesis region of Actinobacillus pleuropneumoniae serotype 15

Nucleotide sequence determination and analysis of the cps gene involved in the capsular polysaccharide biosynthesis of Actinobacillus pleuropneumoniae serotype 15 revealed the presence of three open reading frames, designated as cps15ABC genes. At the protein level, Cps15A and Cps15B showed considerably high homology to CpsA (67.0 to 68.7%) and CpsB (31.7 to 36.8%), respectively, of A. pleuropneumoniae serotypes 1, 4 and 12, revealing the common genetic organization of the cps among serotypes 1, 4, 12 and 15. However, Cps15C showed no homology to any proteins of A. pleuropneumoniae serotypes, indicating that cps15C may be specific to serotype 15. This study will provide the basic molecular knowledge necessary for the development of diagnostics and a vaccine for A. pleuropneumoniae serotype 15.     

Hyperferritinemia is associated with short survival time in dogs with multicentric lymphoma

In the present study, we examined the relationship between serum ferritin concentration before treatment and survival time in dogs with multicentric lymphoma. Eighteen dogs with multicentric lymphoma were enrolled in the study. When the dogs were classified into high and low ferritin groups on the basis of their serum ferritin concentration (3,000 ng/ml cut-off value), the median survival time of dogs with high concentrations (≥3,000 ng/ml, n=7) was 40 days, whereas it was 360 days among dogs with low concentrations (<3,000 ng/ml, n=11). This difference was statistically significant (P=0.001). This finding suggests that the initial high level of serum ferritin indicates short survival time in dogs with multicentric lymphoma. Large-scale research is necessary to confirm this finding.     

Dark adaptation time in canine electroretinography using a contact lens electrode with a built-in light source

The purpose of this study was to evaluate the dark adaptation time in canine electroretinography (ERG) using a contact lens electrode with a built-in LED. Twelve eyes of six normal laboratory beagle dogs were used and exposed to steady room light at 500 lux for 30 min for light adaption. ERG was recorded at different time points during dark adaptation in sedated and light-adapted beagles. The stimulus intensity was 0.0096 cd/m²/sec. The b-wave amplitude increased significantly until 25 min of dark adaptation, whereas no significant changes in amplitudes were observed after 30 min. Dark adaptation for more than 25 min would be necessary for accurate ERG in canine ERG using a contact lens electrode with a built-in LED.     

Purification and characterization of a nucleoplasmin-like protein from carp (Cyprinus carpio) eggs

ABSTRACT: Nucleoplasmin, first isolated from Xenopus laevis eggs, promotes nucleosome assembly. Hereby, we have purified a nucleoplasmin-like protein from carp ( Cyprinus carpio ) eggs using ion exchange and subsequent gel filtration columns. The protein was recognized by a polyclonal antiserum against Xenopus laevis nucleoplasmin and had an amino acid composition similar to other member of the nucleoplasmin family proteins. Partial amino acid sequences from the cyanogen bromide (CNBr)-cleaved fragments showed high homology with Xenopus nucleoplasmin. The protein was also found to form an oligomeric complex and to be phosphorylated. Moreover, this protein promoted sperm nuclear decondensation as well as that of nucleoplasmin from Xenopus laevis eggs. These results suggest that the fish protein isolated here is a member of nucleoplasmin family.     

新城疫病毒某水禽分离株经鸡体传代后由非致病型转变为速发型的研究

最近，一株无毒力的新城疫病毒（NDV）在鸡体内繁殖时，变成了强毒株，但致今尚未能证实，经鸡体传代的野生水禽新城疫病毒是否也具有变成速发型毒株的能力，为了通过实验证明从水禽中分离的非致病型NDV可以转变为速发型病毒，我们通过在鸡体内传播鹅源性无毒力株，经气囊接种连续传代9次，随后再在鸡脑内传代5次，结果显示，该病毒的毒力变得很强，致死率可达100%，通过致病性试验证实，其具有典型的速发型病毒特征；融合蛋白裂解位点的序列分析表明，原始的分离株含有无毒力型毒株共有的裂解序列；E-R-Q-E-R/L，而通过鸡体反复传代后，该序列变为致癞 性毒株共有的序列：K-R-Q-K-R/F，这些结果表明，野生水禽中自然存在的无毒力毒株，具有无毒力株相应的序列，但当其在鸡群中传播时，则具有变成高致病性病毒的能力，同时研究表明，鸡体提供了该病毒从非致病型向致病型转变的选择机制。     

Annual Changes in Day-length,Temperature, and Circulating Reproductive Hormones in Thoroughbred Stallions and Geldings

Changes in follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, immunoreactive(ir)-inhibin, testosterone, estradiol-17β, and insulin-like growth factor (IGF)-I in Thoroughbred stallions along with changes in prolactin secretion in geldings were studied. The correlations of day-length with changes in the concentrations of these hormones were also studied. Five stallions and thirteen geldings were employed to draw blood samples in monthly basis and radioimmunoassay was performed to measure these hormones. All hormones showed a seasonal pattern, the levels being highest during the breeding season and lowest during the winter months. Most of the hormones were at their highest concentration during the month of April, the mid of spring in northern hemisphere. The concentration of circulating IGF-I also demonstrated seasonality, the peak lying on the month of April. The plasma concentration of prolactin also increased during the breeding season. This phenomenon was similar both in stallions and geldings although geldings had lower concentration than that of stallions. The changes in concentration of prolactin in stallions and geldings correlated more towards the day-length than towards the temperature. These results clearly indicate the seasonality of pituitary and gonadal hormones of Thoroughbred stallions, the activity being highest during the month of April and May of the breeding season.