Chiral inversion of R(-) fenoprofen and ketoprofen enantiomers in cats

The chiral inversion process is a characteristic metabolic pathway for different aryl-2-propionic acids or profens. Important variations have been observed between these individual compounds as well as between animal species. In this study, R(-) fenoprofen [R(-)FPF] and R(-) ketoprofen [R(-) KTF] were used to investigate their comparative stereoconversion in cats. After intravenous (i.v.) administration of R(-) FPF, the percentage of chiral inversion was 93.20+/-13.70%. A highly significant correlation (r: 0.978) was observed between the clearance of R(-) FPF and the chiral inversion process. After i.v. administration of R(-) KTF, the percentage of inversion was only 36.73+/-2.8%. No correlation between the clearance of R(-) KTF and this process was observed. R(-) FPF was metabolized by the pathways of thioesterification - chiral inversion processes. For R(-) KTF, the competitive metabolic pathways, glucuronidation and hydroxylation may be involved. However, these metabolic steps are saturable or less functional in cats. Moreover, the thioesterification of R(-) KTF in in vitro studies has been shown to be important in carnivores. The lack of correlation between clearance and chiral inversion process of R(-) KTF may be finally explained by deviation of thioesterification to other metabolic pathways of lipids and/or aminoacid conjugation, particulary glicine derivatives.     

Persistent activity of doramectin and ivermectin in the prevention of cutaneous myiasis in cattle experimentally infested with Cochliomyia hominivorax

A study was conducted to evaluate the activity of a single administration of doramectin or ivermectin against severe, induced infestations of Cochliomyia hominivorax. Twenty-four Holstein bull calves were allocated to four groups of six animals each and treated either with saline, doramectin 1%, or either one of two formulations of ivermectin 1% at a dose rate of 200 microg/kg. On Day 12 after treatment, each calf was anesthetized and two wounds were created on the left side of the shoulder and rump of each calf and 2 h later, each wound was implanted with 100 newly hatched larvae of C. hominivorax. On Day 15 after treatment, the procedure was repeated on the right side of each calf. Wounds were examined daily for 5 days and evidence of live larvae was recorded. Doramectin provided reduction in myiasis of 90.9 and 83.3% at 12 and 15 days after treatment, respectively, compared to the saline control treatment (P < 0.0001). In contrast, there were no significant differences in the number of calves with myiasis between those treated with either of the ivermectin formulations and the saline control.     

Pathogenicity of Rhodococcus equi expressing a virulence-associated 20 kDa protein (VapB) in foals

Rhodococcus equi strains of intermediate virulence (IMV) for mice possess a 20kDa protein designated Virulence Associated Protein B (VapB) and a virulence plasmid of 79-100kb, and can be recovered from the submaxillary lymph nodes of pigs. The pathogenicity of such R. equi strains for foals is unknown. In this study, two foals, 42 and 43 days of age, were infected intratracheally with 10(6) and 10(9) cells of R. equi IMV strain A5, respectively. The foal infected with 10(9) cells of strain A5 became clinically ill, with the onset of illness (pyrexia and depression) occurring 21 days after inoculation. R. equi was isolated from the feces and tracheal washings of the foal from 14 to 28 days after inoculation. The foal infected with 10(6) cells of A5 showed no clinical signs, and no R. equi was isolated from any of the samples of feces or tracheal washings during the 28 days of observation. Two foals of 45 and 50 days of age were infected with 10(5) or 10(6) of virulent R. equi ATCC 33701 having 15-17kDa surface proteins designated VapA. Both exhibited severe clinical signs (pyrexia, depression and anorexia) at 12 and 13 days after inoculation. Histopathological examination revealed that strain A5 caused focal granulomatous pneumonia in the foals. R. equi IMV strain A5 was isolated from lung lesions of both foals and from the contents of the intestinal tracts of the foal infected with 10(9) bacteria. These results suggest that IMV R. equi having VapB is less virulent than virulent R. equi having VapA in foals. This finding supports our previous results on the pathogenicities of R. equi strains having these virulence-associated antigens assessed by mouse pathogenicity tests.     

Antibody response to toxic shock syndrome toxin-1 of Staphylococcus aureus in dairy cows

Antibody response to toxic shock syndrome toxin-1 (TSST-1) of Staphylococcus aureus in dairy cows was examined by enzyme linked immunosorbent assay (ELISA). Serum antibody to TSST-1 was not detected in 39 (76.5%) of 51 calves, which were 1-6 months of age. In contrast, TSST-1 antibody was demonstrated in 1728 (72.6%) of 2380 lactating cows housed on 36 dairy farms. The ELISA values of antibody ranged from 0.2 to 3.0 OD and presented a distribution with the peak at 1.6 OD. The mean ELISA value differed between farms, and it increased slightly along with parturient history. Somatic cell counts of milk from 174 lactating cows was compared with TSST-1 antibody and tst1,000,000 cells per ml. The mean ELISA values in milk were lower than those of sera, but they rose as somatic cells increased. The tst gene of S. aureus detected in 76.0-86.2% of the milk samples containing somatic cells > 500,000 cells per ml, a level which indicates mastitis. The data suggests that many lactating cows may be infected by TSST-1- producing S. aureus.     

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.     

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.     

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.     

限制肯尼亚小农户养殖场利用家禽粪便作为奶牛蛋白质补充料的因素

在肯尼亚的小农户养殖场，到了干旱季节，利用率低品质差的饲料（农作物残留物）限制了反刍动物的生产性能。本研究在Nakuru、Koibatek和Trans Nzoia3个地区的小农户养殖场进行。实验从2003年开始，持续2年时间，在此之前进行了为期6周的饲料调查。饲料调查的目的是找出饲料缺乏的小农户养殖场可利用的饲料资源，并且列出提高产奶性能的限制因素。实验还收集了有关农场的其他数据，包括牲畜总量（反刍动物和家禽）和每个农场的种群结构等数据。本文将讨论范围限定在试验获得的定量和定性信息，重点集中在家禽粪便及垫料，并与先前的研究进行比较。在饲料普查过程中，收集农场使用饲料的样本，测定干物质，并且在肯尼亚国家畜牧研究中心（纳瓦沙，肯尼亚）进行概略养分分析。     

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.