Cytochrome P450 3A, NADPH cytochrome P450 reductase and cytochrome b5 in the upper airways in horse

Gene and protein expression as well as catalytic activity of cytochrome P450 (CYP) 3A were studied in the nasal olfactory and respiratory mucosa and the tracheal mucosa of the horse. We also examined the activity of NADPH cytochrome P450 reductase (NADPH P450 reductase), the amount of cytochrome b(5) and the total CYP content in these tissues. Comparative values for the above were obtained using liver as a control. The CYP3A related catalytic activity in the tissues of the upper airways was considerably higher than in the liver. The CYP3A gene and protein expression, on the other hand, was higher in the liver than in the upper airway tissues. Thus, the pattern of CYP3A metabolic activity does not correlate with the CYP3A gene and protein expression. Our results showed that the activity of NADPH P450 reductase and the level of cytochrome b(5) in the relation to the gene and protein expression of CYP3A were higher in the tissues of the upper airways than in the liver. It is concluded that CYP3A related metabolism in horse is not solely dependent on the expression of the enzyme but also on adequate levels of NADPH P450 reductase and cytochrome b(5).     

Evaluation of a new strategy to modulate skeletal development in Thoroughbred performance horses by imposing track-based exercise during growth

REASON FOR PERFORMING STUDY: No data exist on the intensity of exercise required or on possible harmful effects of increasing exercise in foals over the natural level when free at pasture. OBJECTIVES: To investigate whether an increase in workload over free pasture exercise in the period from directly after birth to the start of training is tolerated by Thoroughbred (TB) foals without increasing injury rate or producing other undesired side effects. METHODS: Thirty-three TB foals were allocated to one of 2 exercise groups directly after birth. One group (PASTEX) was raised on pasture and the other (CONDEX) kept under identical circumstances, but was additionally subjected to an exercise protocol of gradually increasing intensity. Foals were monitored periodically and scored for the presence of clinical signs related to the musculoskeletal system (joint effusion, pain at flexion, occurrence of physeal swelling), and radiographs taken at the end of the conditioning phase. Also, behavioural studies were performed to detect any changes in behaviour related to the exercise programme. Cortisol levels were measured in both groups, to assess the level of stress. RESULTS: Workload in the CONDEX group was significantly higher than in the PASTEX group (approximately 30%). Conditioning increased the likelihood for joint effusion in the antebrachiocarpal joint, but reduced tarsocrural effusion and physeal swelling at the lateral distal radius, the third metacarpal bone (medial aspect) and lateral and medial aspects of the third metatarsal bone. CONCLUSIONS: The 30% increase in workload did not affect the animals' welfare, effects of conditioning exercise on clinical musculoskeletal health were few and there were no adverse effects. POTENTIAL RELEVANCE: This study supports the feasibility of imposing early conditioning exercise in horses and is a benchmark for its effects on the development of equine musculoskeletal tissues.     

A multicentric retrospective study of serum/plasma urea and creatinine concentrations in dogs using univariate and multivariate decision rules to evaluate diagnostic efficiency

BACKGROUND: Urea and creatinine are the most frequently used indirect markers in plasma and serum of glomerular filtration rate in dogs. Both have been shown to lack sensitivity but their diagnostic efficiency for the diagnosis of kidney disease has been minimally investigated. OBJECTIVE: The purpose of this retrospective study was to investigate the influence of possible factors of variation on both analytes and to determine whether specific decision rules should be drawn up for subpopulations of dogs. METHODS: The results of urea and creatinine measurements, breed, sex, age, and health status (healthy, renal disease, or nonrenal disease) of 3822 dogs were collected from the archives of 5 veterinary clinics. Data were analyzed with univariate and multivariate decision rules with and without adjustment. RESULTS: There were significant effects and interactions of almost all of the sources of variation. Slight improvements in diagnostic efficiency were obtained by adjusting the decision rules to these sources of variations. Univariate decision rules gave approximately the same diagnostic efficiency for urea and creatinine concentrations, with sensitivity and specificity in the range of 70% and 90%, respectively, using the upper limit of the reference interval as the threshold value. Multivariate decision rules provided only minor improvements in diagnostic efficiency. CONCLUSION: Simultaneous measurement of both urea and creatinine is of limited diagnostic value over the analysis of a single variable. Creatinine is the preferred analyte as it is affected by fewer extrarenal factors of variation.     

Efficacy of dog-appeasing pheromone in reducing stress associated with social isolation in newly adopted puppies

This study was designed to determine the potential value of dog-appeasing pheromone (dap) in reducing stress in puppies newly adopted from a pet shop. The trial was triple-blinded and placebo-controlled. After their arrival at the pet shop, 32 puppies were fitted with a dap collar and 34 were fitted with a control collar, according to a randomisation protocol. Adopting owners were contacted by telephone, three and 15 days after they had adopted a puppy, to obtain information about the puppy's integration into the family, and particularly about any signs of distress shown by the puppy when it was socially isolated. All the isolated puppies from the control group vocalised during the first night. Signs of distress, particularly vocalisation, were significantly lower in the dap group on day 3 and throughout the rest of the study, and vocalisation during the night ceased significantly sooner in this group. These differences were observed in puppies of small, medium and large breeds. The dap collars had no effect on the incidence of house soiling.     

A survey of beef cattle farmers in New Zealand, examining management practices of primiparous breeding heifers

AIM: To obtain an estimate of the incidence of assistance at calving in primiparous (first-calving) beef heifers and the prevalence of breeding heifers at 15 months of age in New Zealand in 2006, and to identify factors contributing to farmers' decisions regarding breeding strategies for heifers, using a survey of beef cattle farmers. METHODS: A questionnaire was sent to farmers listed in a Massey University database and to members of selected breed societies, as well as published in an industry newspaper; 331 valid responses were received. Information was gathered on the age and number of primiparous heifers, number of heifers assisted, and the importance of various reasons for and against breeding heifers at 15 months of age. Respondents were also required to outline the criteria used for selecting bulls to join with heifers, and the strategies used to manage dystocia in primiparous heifers. RESULTS: Sixty-five (95% CI=58-71)% of respondents had only 2-year-old primiparous heifers in 2006, whilst a further 11 (95% CI=8-16)% had both 2- and 3-year-old primiparous heifers. The mean reported incidence of assisted calving was 7.0 (95% CI=6.4-7.5)% for 2-year-old primiparous heifers and 1.7 (95% CI=1.2-2.2)% for 3-year-old primiparous heifers. The reported incidence of assistance at calving within individual herds ranged from 0 to 100% for 2-year-old heifers. Respondents with bull-breeding herds most commonly observed their primiparous 2-year-old heifers twice daily, whilst respondents with commercial herds most commonly observed them once daily during calving. The most important reason for breeding heifers at 15 months of age was increased profit, whereas the most important reason for not breeding them at that age was concern about rebreeding performance of 2-year-old heifers. Estimated breeding value (EBV) for birthweight was the factor considered most frequently when selecting bulls to join with maiden heifers; age of bull and body shape of bull were the next most frequently considered factors. Selection of an appropriate bull was the most common strategy used to manage dystocia in 2-year-old beef heifers. CONCLUSIONS: The majority of respondents calved their heifers at 2 years of age, and increased profit was the primary motivator. Concern about the rebreeding performance of 2-year-old heifers was the most important reason among the remainder of respondents for not breeding heifers at 15 months of age. Dystocia in 2-year-old heifers was not a problem or a minor problem in most herds, but there was much variation amongst herds.     

Canine lymphoproliferative disease characterized by lymphocytosis: immunophenotypic markers of prognosis

BACKGROUND: Canine lymphoproliferative disease often presents with lymphocytosis and is immunophenotypically diverse. HYPOTHESIS: Immunophenotype predicts prognosis in canine lymphoproliferative disorders involving circulating lymphocytosis. ANIMALS: Dogs that had peripheral blood evaluation performed by flow cytometry by the Clinical Immunology Service at Colorado State University between 2003 and 2005. METHODS: Outcome data regarding treatment and survival were sought on patients with lymphocytosis comprising a single lymphocyte subset. Ninety-six patients that met the inclusion criteria had sufficient follow-up information to be included in the study. RESULTS: Four main phenotypic classifications were found: CD8+ T-cell, CD21+ B-cell, CD4-8-5+ (aberrant T-cell phenotype), and CD34+ (undifferentiated progenitor). Expression of CD34 predicted poor outcome with median survival of 16 days (P < .0001) compared with other phenotypes. Within the CD8+ phenotype, dogs presenting with a lymphocytosis >30,000 lymphocytes/muL had significantly shorter median survival (131 days) than those presenting with <30,000 lymphocytes/muL (1098 days, P < .0008). Within the T-cell leukemias, there was no difference in outcome between dogs with CD4-8-5+ leukemia and dogs with the CD8+ T-cell phenotype nor was the loss of expression of the pan-leukocyte marker CD45 associated with decreased survival time. A CD21+ lymphocytosis composed of large cells was associated with shorter survival time (129 days) than those with smaller circulating cells (median survival not reached, P < .01). CONCLUSIONS AND CLINICAL IMPORTANCE: Immunophenotyping provides an objective method for determining prognosis in lymphoproliferative disorders characterized by lymphocytosis.     

3D-X-ray microcomputer tomography and optical coherence tomography as methods for the localization of the blastoderm in the newly laid unincubated chicken egg

The routine culling of the male offspring of hybrid layer type chickens is met with increasing public disapproval for both ethical and legal reasons. Until now practice-oriented methods for reliable sex diagnosis prior to hatch could not be developed. Molecular genetical analysis of blastodermic cells can be used for sex determination in unincubated eggs; however, knowledge of the precise localization of the germinal disc is crucial for the extraction of a carefully directed cell biopsy. In principle, 3D-X-ray micro computed tomography (3D-CT) has been proven a suitable method to localize the germinal disk in the unincubated egg without damaging the egg shell. No negative effects on embryogenesis and hatching rate of irradiated hatching eggs were established. The pictorial representation of the germinal disk using optical coherence tomography (OCT) failed in the unopened egg. The egg shell formed an impenetrable barrier for the currently available measuring method which utilized near infrared (NIR) wavelength regions. After opening the egg shell, the germinal disk could be visualized without any difficulties. In conclusion, technical possibilities for localization of the germinal disk in the unincubated egg already exist, but regarding technical parameters, the procedures have to be adapted to the specific purpose.     

Use of extensible internal device in the femur of young dogs.

An extensible internal device (EID) was developed to preserve growth plate during the treatment of fracture complications or segmental bone loss from tumour resection in children. Since this type of extensible, transphyseal, internal fixation device has only been used in a few paediatric cases; the aim of this study was to evaluate an in vivo canine study, a surgical application of this device, and its interference with longitudinal growth of the non-fractured distal femur. Ten clinically healthy two- to three-month-old poodles weighing 1.5-2.3 kg were used. Following a medial approach to the right distal femur, one extremity of the EID, similar to a T-plate, was fixed in the femoral condyle with two cortical screws placed below the growth plate. The other extremity, consisting of an adaptable brim with two screw holes and a plate guide, was fixed in the third distal of the femoral diaphysis with two cortical screws. The EID was removed 180 days after application. All of the dogs demonstrated full weight-bearing after surgery. The values of thigh and stifle circumferences, and stifle joint motion range did not show any difference between operated and control hindlimbs. The plate slid in the device according to longitudinal bone growth, in all but one dog. In this dog, a 10.5% shortening of the femoral shaft was observed due to a lack of EID sliding. The other dogs had the same longitudinal lengths in both femurs. The EID permits longitudinal bone growth without blocking the distal femur growth plate if appropriately placed.