The effect of exploratory laparotomy on the serum and peritoneal haptoglobin concentrations of the pony.

Serum haptoglobin concentration was used as an indicator of the acute phase response in ponies undergoing exploratory laparotomy. Preoperative, 1 h intraoperative, 3 h, 6 h, 12 h and 24 h postoperative blood samples and 48 h postoperative peritoneal fluid samples were obtained for haptoglobin analysis. A spectrophotometric assay based on cyanmethemoglobin binding capacity (CyanBC) was used to determine haptoglobin concentrations. The preoperative reference range for serum haptoglobin concentrations in these ponies was 25-60 mg CyanBC/dL. Intraoperative and 3 h postoperative blood samples had decreased haptoglobin concentrations when compared to preoperative values. Serum haptoglobin concentrations began to rise by the 6 h postoperative sample and were generally elevated above preoperative values by the 24 h postoperative sample. Two of the ten ponies had mild signs of postoperative colic which were associated with twofold elevations in serum haptoglobin concentrations and fivefold elevations in peritoneal fluid haptoglobin concentrations.     

Feline leukemia virus detection by immunohistochemistry and polymerase chain reaction in formalin-fixed, paraffin-embedded tumor tissue from cats with lymphosarcoma.

The prevalence of feline leukemia virus (FeLV) antigen and DNA was assessed in formalin-fixed, paraffin-embedded tumor tissues from 70 cats with lymphosarcoma (LSA). Tissue sections were tested for FeLV gp70 antigen using avidinbiotin complex (ABC) immunohistochemistry (IHC); DNA was extracted and purified from the same tissue blocks for polymerase chain reaction (PCR) amplification of a 166 base pair region of the FeLV long terminal repeat (LTR). Results were related to antemortem FeLV enzyme-linked immunosorbent assay (ELISA) for serum p27 antigen, anatomic site of LSA, and patient age. Viral DNA was detected by PCR in 80% of cases and viral antigen by IHC in 57% of cases. Seventeen cases were PCR-positive and IHC-negative; one case was PCR-negative and IHC-positive. Clinical records included FeLV ELISA results for 30 of 70 cats. All 19 ELISA-positive cats were positive by PCR and IHC; of the 11 ELISA-negative cats that were negative by IHC, seven were positive by PCR. When evaluated according to anatomic site, FeLV DNA and antigen were detected less frequently in intestinal LSAs than in multicentric and mediastinal tumors. Lymphosarcoma tissues from cats < 7 yr were several fold more likely to be positive for FeLV antigen by IHC than were tumors from cats > or = 7 yr. However, there was no significant difference in PCR detection of FeLV provirus between LSAs from cats < 7 yr and those > or = 7 yr.(ABSTRACT TRUNCATED AT 250 WORDS)     

饲粮不同蛋白质、能量水平对大白鼠生长发育及体成分的影响

本试验所用动物为53—57日龄雄性大白鼠(sprague——Dawley品系),初始体重为121.73±3.95g,试验期为大白鼠生长发育旺期的21天。试验拟研究不同粗蛋白水平(10％、15％、20％、25％和30％)及两个能量水平(消化能:3.6和3.9kcal/g)的饲粮对大白鼠生长发育及各种体成分的影响。结果表明,当饲粮蛋白质供应充分时,大白鼠生长随饲粮能量浓度的提高而改善;而当饲粮蛋白质供应感觉不足时,提高能量浓度对生长无益。机体各项成分指杯中,以蛋白质、脂肪、水分沉积受饲粮蛋白质,能量浓度影响显著;而蛋白质、脂肪沉积在很大程度上受饲粮能朊比的影响,饲粮中添加脂肪可使大白鼠机体肥胖。     

Quantitation of adenine nucleotides in equine colonic mucosal tissue using high performance liquid chromatography.

The objectives were to use high performance liquid chromatography (HPLC) to validate an established method for adenine nucleotide separation in equine colonic mucosal tissue, to determine the inherent variability in the tissue and extraction method, and to determine the stability of ATP, ADP, and AMP in the tissue with time. Equine colonic mucosal tissue obtained from a single horse was immediately submersed in liquid nitrogen, and stored at -70 degrees C. Samples were lyophilized, extracted, and separated by HPLC. The limit of quantitation was 0.05 microg/mL. The coefficient of variation for the instrument was less than 10% for all nucleotides measured. When the tissue was not homogenized prior to sampling, there were significant differences in adenine nucleotide content between samples. However, when the tissue was homogenized prior to analysis, these differences were no longer significant. There was no significant decrease in ATP, ADP, or AMP content over a 54-day analysis period.     

Transmission of porcine reproductive and respiratory syndrome virus from persistently infected sows to contact controls.

The objective of this study was to determine if porcine reproductive and respiratory syndrome virus (PRRSV) could persist in non-pregnant sows and if persistently infected sows could transmit virus to naive contact controls. Twelve PRRSV-naive, non-pregnant sows (index sows) were infected with a field isolate of PRRSV and housed in individual isolation rooms for 42 to 56 days postinfection. Following this period, 1 naive contact sow was placed in each room divided by a gate allowing nose-to-nose contact with a single index sow. Index sows were not viremic at the time of contact sow entry. Virus nucleic acid was detected by polymerase chain reaction, and infectious virus was detected by virus isolation in sera from 3 of the 12 contact sows at 49, 56, and 86 days postinfection. All 3 infected contacts developed PRRSV antibodies. Virus nucleic acid was detected in tissues of all of the 12 index sows at 72 or 86 days postinfection. Nucleic acid sequencing indicated that representative samples from index and infected contacts were homologous (> 99%) to the PRRSV used to infect index sows at the onset of the study. This study demonstrates that PRRSV can persist in sows and that persistently infected sows can transmit virus to naive contact animals.     

家禽核酸疫苗的研究进展

核酸疫苗是当今疫苗研究的最前沿领域，本文就核酸疫苗在家禽传染病中的应用做一综述。     

新颖三相异步电动机错相和缺相保护电路

从理论上分析了错相及缺相判别原理，提出了新颖保护电路，其线路简单、实用。     

双黄杀毒退烧颗粒对畜禽免疫功能的影响

研究了纯中药复方抗病毒制剂--双黄杀毒退烧颗粒对成年兔、鸡的体液免疫及细胞免疫功能的影响.HI抗体检测、MTT实验、E-玫瑰花环形成试验和酯酶染色试验的结果表明,双黄杀毒退烧颗粒能显著增强家兔的体液免疫作用,明显提高家兔和鸡的细胞免疫功能,对家兔的免疫增强作用优于鸡.