Coccidiosis in swine

It is clear that although the clinical history, pathologic lesions, and endogenous stage life cycle of I. suis are well understood, the epidemiology of this parasite is not understood or is misunderstood. Consequently, treatment of individual piglets and prophylactic use of coccidiostats in sows have not been consistently rewarding. The best control at present is achieved through use of extensive sanitation, particularly steam cleaning. The incidence of clinical coccidiosis in piglets continues to be a major component (approximately 20 per cent) in the differential etiology of scours in baby pigs.     

Isolation of symbiont and associated fungi from ectomycorrhizas of Sitka spruce

Isolation of symbiont and associated fungi from ectomycorrhizas of Sitka spruce from three Irish forest plantations is described. Frequent emergence of dark sterile mycelia and Oidiodendron spp., predominantly O. maius, restricted the recovery of potential symbionts. Inhibition of the former by benomyl resulted in a sixfold increase in basidiomycetes isolated. Pure culture syntheses confirmed the ectomycorrhizal ability of potential symbiont isolates and demonstrated the parasitic nature of dark sterile mycelial types. Antagonism of Mycelium radicis atrovirens, Phytophthora cinnamomi and Heterobasidion annosum by O. maius observed in paired cultures supports the possible involvement of this species in biological control of conifer root pathogens.     

Conjugation of antibiotic resistance in Streptococcus suis.

Forty-eight clinical isolates of Streptococcus suis were examined for antibiotic sensitivity and the presence of plasmid DNA. It was determined that isolates from this study showed a substantial increase in resistance to erythromycin (ery), clindamycin, and tetracycline (tet) compared to a similar study conducted five years earlier. Eleven of the 48 isolates contained plasmid DNA as revealed by DNA isolation and gel electrophoresis. Plasmid DNA from four strains resistant to the above three antibiotics was tested for the ability to transform an antibiotic sensitive recipient. No transformation of antibiotic resistance could be demonstrated. In other experiments, the above four strains, along with four plasmid-negative triply resistant strains were tested for the ability to transfer tet or ery resistance to tet and ery sensitive recipients by conjugation. In each mating, antibiotic resistance was transferred at frequencies averaging 2.4 x 10(-6) recombinants/recipient for ery and 3.4 x 10(-6) recombinants/recipient for tet resistance. DNA from each clinical specimen, as well as the recombinants mentioned above was probed with tn916. Autoradiographs revealed that several clinical isolates and recombinants bound the probe. It is concluded that conjugation of antibiotic resistance in these clinical strains is possibly mediated by a transposon similar to tn916.     

Integrating a bovine rectal palpation simulator into an undergraduate veterinary curriculum

There are problems associated with teaching bovine rectal palpation to undergraduate veterinary students. The students need opportunities to examine enough cows to develop the required skills, but increasing student numbers and limitations on access to cows have made this more and more difficult to achieve. A virtual reality-based teaching tool, the Bovine Rectal Palpation Simulator, has been developed as a supplement to existing training methods. The student palpates computer generated virtual models of the bovine reproductive tract while interacting with a haptic (touch feedback) device. During training sessions, the instructor follows the student's actions inside the virtual cow on the computer screen and gives instruction. A trial integration of the simulator into the fourth-year bovine reproduction course was undertaken at the University of Glasgow Veterinary School during the 2003/2004 academic year. Students were offered two training sessions, and feedback was gathered using questionnaires. In the first session, all students were taught a range of basic skills using a standardized teaching protocol. The second training session was customized to each student's learning needs and included practice in dealing with a range of on-farm scenarios. Student feedback indicated that the training had been useful for learning various aspects of bovine rectal palpation and provided information that helped in the further development of the simulator as a teaching tool.     

Type I immune-mediated polyarthritis in dogs: 39 cases (1997-2002)

OBJECTIVE: To determine clinical signs, laboratory findings, relationship to vaccination, and response to treatment for type I immune-mediated polyarthritis (IMPA) in dogs. DESIGN: Retrospective study. ANIMALS: 39 dogs PROCEDURE: Clinical records and radiographic reports from 3 university referral hospitals were reviewed. Clinical signs, laboratory and investigative findings, relationship to vaccination, and response to treatment were evaluated. RESULTS: Clinical signs and initial laboratory and clinical investigative findings were frequently abnormal but were nonspecific and not associated with likelihood of recovery. Time of vaccination was not associated with onset of disease. Chemotherapeutic immunosuppression resulted in complete cure in 56% of dogs. Continuous medication was required in 18% (7/39) of dogs, relapses were treated successfully in 13% (5/39) of dogs, and 15% (6/39) of dogs died or were euthanatized as a result of disease. CONCLUSIONS AND CLINICAL RELEVANCE: The possible involvement of vaccination in type I IMPA was not made clear from this study because of the small population size. Signalment, clinical signs, and results of diagnostic tests other than multiple synovial fluid analyses were generally nonspecific. Most dogs with type I IMPA responded to initial immunosuppressive treatment, but 31% (12/39) of dogs relapsed, required further treatment, or both.     

Effects of racing and nontraining on plasma thyroid hormone concentrations in sled dogs

OBJECTIVE: To determine the effects of racing and nontraining on plasma thyroxine (T4), free thyroxine (fT4), thyroid-stimulating hormone (TSH), and thyroglobulin autoantibody (TgAA) concentrations in sled dogs and compare results with reference ranges established for dogs of other breeds. DESIGN: Cross-sectional study. ANIMALS: 122 sled dogs. PROCEDURE: Plasma thyroid hormone concentrations were measured before dogs began and after they finished or were removed from the Iditarod Trail Sled Dog Race in Alaska and approximately 3 months after the race. RESULTS: Concentrations of T4 and fT4 before the race were less than the reference range for nonsled dogs in 26% and 18% of sled dogs, respectively. Immediately after racing, 92% of sled dogs had plasma T4 concentrations less than the reference range. Three months after the race, 25% of sled dogs had plasma T4 concentrations less than the reference range. For T4, fT4, TSH, and TgAA, significant differences were not detected in samples collected before the race versus 3 months later. CONCLUSIONS AND CLINICAL RELEVANCE: Plasma T4, fT4, and TSH concentrations decreased in dogs that complete a long distance sled dog race. Many clinically normal sled dogs have plasma T4 and fT4 values that are lower than the reference range for nonsled dogs. We suggest that the reference ranges for sled dogs are 5.3 to 40.3 nmol/L and 3.0 to 24.0 pmol/L for plasmaT4 and fT4 concentrations, respectively, and 8.0 to 370 mU/L for TSH.     

Seemingly anomalous angular distributions in H + D₂ reactive scattering

When a hydrogen (H) atom approaches a deuterium (D(2)) molecule, the minimum-energy path is for the three nuclei to line up. Consequently, nearly collinear collisions cause HD reaction products to be backscattered with low rotational excitation, whereas more glancing collisions yield sideways-scattered HD products with higher rotational excitation. Here we report that measured cross sections for the H + D(2) → HD(v' = 4, j') + D reaction at a collision energy of 1.97 electron volts contradict this behavior. The anomalous angular distributions match closely fully quantum mechanical calculations, and for the most part quasiclassical trajectory calculations. As the energy available in product recoil is reduced, a rotational barrier to reaction cuts off contributions from glancing collisions, causing high-j' HD products to become backward scattered.     

Crystal structure of a lipid G protein-coupled receptor

The lyso-phospholipid sphingosine 1-phosphate modulates lymphocyte trafficking, endothelial development and integrity, heart rate, and vascular tone and maturation by activating G protein-coupled sphingosine 1-phosphate receptors. Here, we present the crystal structure of the sphingosine 1-phosphate receptor 1 fused to T4-lysozyme (S1P(1)-T4L) in complex with an antagonist sphingolipid mimic. Extracellular access to the binding pocket is occluded by the amino terminus and extracellular loops of the receptor. Access is gained by ligands entering laterally between helices I and VII within the transmembrane region of the receptor. This structure, along with mutagenesis, agonist structure-activity relationship data, and modeling, provides a detailed view of the molecular recognition and requirement for hydrophobic volume that activates S1P(1), resulting in the modulation of immune and stromal cell responses.