牦牛脾脏TF理化性质和部分生物学特性的测定

采用冻融—透析法提取了牦牛脾脏转移因子（transfer factor,TF）,并对其澄明度、p H值等理化性质进行了测定和分析,同时对牦牛脾脏TF进行了无菌检验、热原检验、安全性试验、过敏试验、体外抑菌试验等部分生物学特性检测和分析。结果表明,用该方法提纯的牦牛脾脏TF含有DNA、核苷酸等,无菌,无热原,无毒性,无致敏性,无抗原性,符合生物制剂的质量标准。该研究对牦牛脾脏转移因子的开发利用提供了试验依据。     

Localization of linear B-cell epitopes on goose parvovirus structural protein

Goose parvovirus (GPV), a small non-enveloped ssDNA virus, can cause Derzsy's disease, a highly contagious and lethal disease in goslings and muscovy ducklings, leading to a huge economic loss. However, little is known about the localization of B-cell epitopes on GPV structural protein. To address the issue, the structural protein of GPV was dissected into sets of partially overlapping fragments and expressed in Escherichia coli. Then Western blot reactivity of these glutathione S-transferase (GST) fusion short peptides to viral infected sera was surveyed. The results showed linear immunodominant epitopes, which were found in seven fragments covering amino acid residues 35-71, 123-198, 423-444, 474-491, 531-566, 616-669, 678-732. Our findings may provide the basis for the development of immunity-based prophylactic, therapeutic, and diagnostic clinical techniques for Derzsy's disease.     

The occurrence of Codiostomum struthionis in ostriches (Struthio camelus) of different ages and during the dry and rainy seasons at two farms in the State of Rio de Janeiro, Brazil

Ostriches are susceptible to a wide variety of diseases that can affect their commercial breeding. The aim of this study was to identify morphologically Codiostomum struthionis and examine its seasonal occurrence among animals of three age categories in two commercial farms in Areal and Itaboraí, State of Rio de Janeiro, Brazil. Fresh fecal samples were collected monthly, from June 2004 to May 2006. Eggs per gram of feces (EPG) were counted after centrifugal flotation in saturated sugar solutions and infective larvae were evaluated after coproculture. A total of 432 fecal samples were collected from three groups according to ostrich age: up to 90 days, 91-365 days and over 365 days (adults). The dry and rainy seasons were defined according to official meteorological data. Typical eggs of the Strongylida order were identified in 242 samples (235 from adult ostriches). Once obtained, infective larvae were identified as C. struthionis. Adult ostriches exhibited significantly greater numbers of eggs in their feces during the rainy season compared to the dry season (p<0.05). In the Areal farm, significant (p<0.05) values were found when adults ostriches EPG were compared to ostriches up to 90 days and also for ostriches from 91 to 365 days. When comparing adult EPGs between the two commercial breeding farms, Areal exhibited greater EPGs during both the dry (p=0.0215) and rainy (p=0.0011) seasons.     

Development and fast screening of salbutamol residues in swine serum by an enzyme-linked immunosorbent assay in Taiwan

The analysis of salbutamol in swine serum is the more practical basis for large scale surveillance programs in Taiwan. Objectives of the study were to develop a new assay and to compare with a commercially available kit in field test screens. A simple and reliable enzyme-linked immunosorbent assay (ELISA) to monitor the presence of beta-agonist, salbutamol, in 1,358 field samples of swine serum that were collected from local meat markets was described. The method proved to be suitable and sensitive for the detection of beta-agonist residues caused by growth promoting dosage. The limit of detection of the developed ELISA directly performed on diluted serum was 0.25 ng/mL. The application and the results of two ELISA kits (homemade and commercially available) for the screening of salbutamol were presented. For further confirmation, all samples that showed to be ELISA positive for salbutamol residues were analyzed by GC-MS. Adopting 1 ng/mL salbutamol as a cutoff value, the commercial beta-agonist ELISA had a sensitivity of 89.2% and a specificity of 86.7% versus GC-MS at a cutoff of 1 ng/mL. The homemade salbutamol ELISA had a sensitivity of 81.1% and a specificity of 98.6% and gave a low proportion of false-positive rate results. The reliability of the developed kit in terms of the percentage of false-positive rate results is evaluated. In conclusion, a sensitive, specific salbutamol ELISA has been developed that could serve as a rapid screening assay, and the detection of positive samples at the place of sampling can result in more effective control of the illegal use of beta-agonists.     

Using proteomics, immunohistology, and atomic force microscopy to characterize surface damage to lambskins observed after enzymatic dewooling

The effects of conventional lime sulfide depilation and enzymatic depilation on the enamel layer of pickled lamb pelts were examined using atomic force and optical microscopy, immunohistological, and proteomic techniques. Microscopy showed that the surface structure of enzymatically depilated material was visibly less organized than conventionally processed material, implying that the enzymes used for depilation were responsible for this difference. Proteomic analyses identified an absence of collagen VI in the enamel of skins that had been processed with enzymes, in contrast to the skins that had been processed using conventional methods, which was confirmed using immunolocalization studies. It is therefore possible that the destruction of collagen VI during enzymatic depilation may cause the changes to the enamel structure observed during enzyme processing and in turn affect the quality of the finished product.     

Differential production of proinflammatory cytokines: in vitro PRRSV and Mycoplasma hyopneumoniae co-infection model

An in vitro culture system was developed to investigate the induction of proinflammatory cytokines by Mycoplasma hyopneumoniae and porcine reproductive and respiratory syndrome virus (PRRSV). M. hyopneumoniae infected porcine tracheal ring explants were co-cultured with PRRSV infected pulmonary alveolar macrophages (PAMs) for 24h to assess the cytokine production of each pathogen alone and the interaction between the two pathogens in vitro. Semiquantitative RT-PCR was used to measure interleukin (IL) 1alpha, IL1beta, IL6, IL8, IL10, IL12 and tumor necrosis factor (TNF) alpha mRNA in PAMs. Commercial ELISAs were used to measure soluble IL1beta, IL8, IL10 and TNF in the culture supernatant. In the dual infected group, mRNA expression of IL1alpha, IL1beta, IL8 and TNF was increased. Both the M. hyopneumoniae- and PRRSV-infected only groups tended to have increased expression of IL1alpha, IL1beta and IL8 mRNA, although no statistical difference was observed. Increased levels of IL1beta, IL8 and IL10 were present in the supernatant of the dual infected group as measured by ELISA. No increase in soluble TNF was observed in any of the groups. IL8 levels appeared high in all groups independent of infection status. The cause of the elevated IL8 was unknown, however, it may have been a non-specific response by the cells to tissue damage during the harvesting of the tracheal rings. Correlation between mRNA expression and the soluble cytokine levels were similar in the dual infected groups with the exception of IL10 and TNF. Levels of mRNA and soluble protein levels in the single pathogen infected groups were not as consistent. The increased production of proinflammatory cytokines IL1alpha, IL1beta, IL8 and TNF in the group infected with both M. hyopneumoniae and PRRSV suggests that cytokine induced inflammation may play an important role in the severe, chronic pneumonia induced by the concurrent infection of the two pathogens.     

Cattle deaths during sea transport from Australia

OBJECTIVE: To establish the death rate and the causes of death in cattle exported by sea from Australia. PROCEDURE: Cattle deaths on voyages from Australia to all destinations between 1995 and 2000 were analysed retrospectively. On four voyages to the Middle East between December 1998 and April 2001, cattle that died were examined to determine the cause of death. RESULTS: The death rate was 0.24% among 4 million cattle exported, and a greater proportion of deaths occurred on voyages to the Middle East (0.52%, P < 0.05) than to south east Asia (0.13%). The risk of death on voyages to the Middle East was three times greater for cattle exported from southern ports in Australia compared to northern ports. The main causes of death were heat stroke, trauma and respiratory disease. CONCLUSION: Cattle have a low risk of death during sea transport from Australia. The risk of death can be reduced on voyages to the Middle East by preferentially exporting cattle from northern ports, and selecting those with a higher Bos indicus content whenever possible.     

Comparison of colloid,thyroid follicular epithelium,and thyroid hormone concentrations in healthy and severely sick dogs

OBJECTIVES: To compare serum concentrations of total thyroxine (TT4), free thyroxine (fT4), and thyroid-stimulating hormone (TSH), as well as measures of thyroid follicular colloid and epithelium, between groups of healthy dogs and severely sick dogs. DESIGN: Cross-sectional study. ANIMALS: 61 healthy dogs and 66 severely sick dogs. PROCEDURE: Serum samples were obtained before euthanasia, and both thyroid lobes were removed immediately after euthanasia. Morphometric analyses were performed on each lobe, and serum TT4, fT4, and TSH concentrations were measured. RESULTS: In the sick group, serum TT4 and fT4 concentrations were less than reference range values in 39 (59%) and 21 (32%) dogs, respectively; only 5 (8%) dogs had high TSH concentrations. Mean serum TT4 and fT4 concentrations were significantly lower in the sick group, compared with the healthy group. In the healthy group, a significant negative correlation was found between volume percentage of colloid and TT4 or fT4 concentrations, and a significant positive correlation was found between volume percentage of follicular epithelium and TT4 or fT4 concentrations. A significant negative correlation was observed between volume percentages of colloid and follicular epithelium in both groups. CONCLUSIONS AND CLINICAL RELEVANCE: TT4 and fT4 concentrations are frequently less than reference range values in severely sick dogs. Therefore, thyroid status should not be evaluated during severe illness. The absence of any significant differences in mean volume percentages of follicular epithelium between healthy and severely sick dogs suggests that these 2 groups had similar potential for synthesizing and secreting thyroid hormones.