Effects of smooth and rough Pasteurella haemolytica lipopolysaccharides on plasma cyclic-nucleotides and free fatty acids in calves

The present study examined the potency of smooth or rough Pasteurella haemolytica lipopolysaccharide infusion (LPS, 24 ng kg-1 min-1 for 500 min) on plasma cyclic-nucleotides and several free fatty acids (FFA) in calves. Both smooth or rough LPS increased plasma cAMP immediately to its maximum at 1 h of infusion, whereas plasma cGMP levels rose slowly and peaked 12 h later. The increases in cAMP levels were more prolonged for smooth LPS than rough LPS. The maximum plasma cAMP rise coincided with increases of several plasma FFA. Rough LPS increased plasma oleic greater than palmitic greater than stearic greater than linoleic acids in the second hour and reached their steady state levels between 2 h of infusion and 5 h post-infusion. Thereafter, oleic acid remained maximally elevated, while stearic acid decreased and other FFA returned to baseline. Smooth LPS had no effects on palmitic and stearic acids, but elevated oleic acid in an essentially similar manner to rough LPS and increased linoleic acid initially at 5 h, followed by decreases throughout post-infusion. These results demonstrate that endotoxemia produces early marked elevations in plasma cAMP, a gradual rise in plasma cGMP and disproportionate increases in several plasma FFA. The data also demonstrate that smooth and rough LPS differ in their abilities to increase plasma cAMP and FFA and these may be attributed to differences in their in vivo mechanisms of action. The study suggests that cAMP and cGMP may mediate actions of endotoxin at the cellular level and that differences exist in release and/or utilization of each FFA at different stages of endotoxemia.     

Effect of cutting and vacuum cleaning on the digestibility of oats by horses

Three mature Quarter Horse geldings were used in 2 Latin square experiments to measure the effect of cutting and vacuum cleaning of oats on digestibility. The horses were fed at the maintenance level of digestible energy (DE) as recommended by the NRC.¹²The data were analyzed by Latin square analysis of variance, and Tukey's t test was used to determine any differences between specific means.No significant differences among treatments were observed during either experiment, indicating that the digestibility of nutrients from oats was not affected by cutting and vacuum cleaning. Differences in the digestibility of the ether extract (EE) fraction between periods of experiment 1 were noted.     

In vitro dose–response of carvacrol, thymol, eugenol and trans-cinnamaldehyde and interaction of combinations for the antimicrobial activity against the pig gut flora

In vitro simulations of the gastric and small intestinal fermentation with varying doses of carvacrol, thymol, eugenol and trans-cinnamaldehyde and binary combinations thereof were carried out to calculate dose–response equations for the antimicrobial effect against the main pig gut flora components. Interaction effects were evaluated following the isobole method. In gastric simulations eugenol and trans-cinnamaldehyde showed clearly less inhibitory activity towards lactobacilli than carvacrol and thymol, which could also be observed in the small intestinal simulations. The minimum concentration for carvacrol, thymol, eugenol and trans-cinnamaldehyde in small intestinal simulations to reduce the number of total anaerobic bacteria compared to control with a probability of 99.7% was 255, 258, 223 and 56 mg/l respectively. This strong activity of trans-cinnamaldehyde was due to its effect against coliform bacteria; a dose of 104 mg/l gave a reduction of 1 log CFU/ml vs. 371, 400 and 565 mg/l for carvacrol, thymol and eugenol respectively. Few combinations demonstrated synergism; most mixtures showed zero interaction or antagonism. Only carvacrol + thymol was slightly synergistic.     

Prepuce and partial penile amputation for treatment of preputial gland neoplasia in two ferrets

Preputial tumours in ferrets are frequently malignant and therefore warrant prompt investigation. As many cases do not respond favourably to surgery, even in combination with radiation therapy, wide surgical resection has been recommended. Such a procedure may necessitate partial or total penile resection but outcomes have thus far not been well described. The current case series describes two ferrets in which surgical resection, including penile amputation, was performed using 10 and 5 mm margins, respectively. In the first case, no recurrence of preputial gland adenocarcinoma was noted for 32 months postsurgery, whereas multiple attempts at surgery and radiation therapy were unsuccessful in the second. These cases suggest that margins of at least 1 cm may help achieve a better outcome. Penile amputation for the treatment of preputial tumours appears to be well tolerated by ferrets, as demonstrated by these cases.     

多重聚合酶链反应筛选方法的研究

本文提出了筛选多重聚合酶链反应的常用方法，根据该法将56个牛微卫星组成的21个多重聚合酶链反应组合，其中14个三微卫星组合，7个二微卫星组合，这些多重聚合酶链反应组合可用于大批量测定微卫星的试验，如基因定位及亲子鉴定等。     

Expression of receptor tyrosine kinases VEGFR-1 (FLT-1), VEGFR-2 (KDR), EGFR-1, PDGFRa and c-Met in canine primary brain tumours

Inhibition of tumour growth and angiogenesis by targeting key growth factor receptors is a promising therapeutic strategy for central nervous system tumours. Characterization of these growth factor receptors in canine primary brain tumours has not been done. Using quantitative real‐time TaqMan polymerase chain reaction (PCR), we evaluated the expression of messenger RNA (mRNA) for five tyrosine kinase growth factor receptors (vascular endothelial growth factor receptor [VEGFR]‐1, VEGFR‐2, endothelial growth factor receptor [EGFR]‐1, platelet‐derived growth factor receptor a [PDGFRa], and c‐Met) relative to normal cerebral cortex in 66 spontaneous canine primary brain tumours. Increased expression of VEGFR‐1 and VEGFR‐2 mRNA was greatest in grade IV astrocytomas (glioblastoma multiforme) and grade III (anaplastic) oligodendrogliomas. EGFR‐1 mRNA expression was more consistently increased than the other receptors in all tumour types, while increased PDGFRa mRNA expression was mostly restricted to oligodendrogliomas. The similarities in increased expression of these tyrosine kinase growth factor receptors in these canine tumours, as compared to data from their human counterparts, suggest that common molecular mechanisms may be present.     

CNS mastitis: nothing to worry about?

In this paper, we analyzed a very large field data set on intramammary infections (IMI) and the associated somatic cell count (SCC) in dairy cows. The objective of the study was to analyze the impact of coagulase-negative staphylococci (CNS) IMI on cow SCC, both mean and variability, and on the potential of these infections to have a major impact on the bulk milk SCC (BMSCC). Data and milk samples for bacterial culture were collected by Quality Milk Production Services (QMPS) between 1992 and March of 2007. The QMPS program services dairy farms in New York State and other states in the Northeastern USA and operates in conjunction with Cornell University. Only records from cows where SCC and milk production data were available, and where only one organism was isolated from bacterial cultures of milk samples (or where culture was negative) were used for this analysis. A total of 352,614 records from 4200 whole herd mastitis screening sampling qualified for this study. Within herds an average of 15% (S.D. 12%) of cows sampled were infected with CNS, ranging between 0 and 100%. Average within herd prevalence of cows with a CNS IMI and an SCC over 200,000 cells/ml was 2% (S.D. 4%) with a minimum of 0% and a maximum of 50%. Results of linear mixed models showed three distinct populations of IMI statuses: negative cultures with the lowest SCC; CNS and Corynebacterium bovis with a moderate increase in SCC, and Streptococcus agalactiae, Streptococcus spp. and Staphylococcus aureus showing an important increase in SCC. Surprisingly, milk production was slightly but significantly higher in CNS infected cows compared to culture-negative cows, whereas it was strongly reduced in cows with a major pathogen IMI. The percentage contribution of CNS infections to the BMSCC was 17.9% in herds with a BMSCC less than 200,000 cells/ml. This value decreased to 11.9 and 7.9% in herds with bulk milk SCC between 200,000 and 400,000 and over 400,000 cells/ml, respectively. We concluded that very few herds with milk quality problems would have an important increase in BMSCC that could be mostly attributed to CNS infections. On the other hand, in herds with low BMSCC, CNS infections may be an important contributor to the total number of somatic cells in the bulk milk.