Insulin and glucose regulation.

Abnormally high or low blood glucose and insulin concentrations after standardized glucose tolerance tests can reflect disorders such as pituitary dysfunction, polysaccharide storage myopathies, and other clinical disorders. Glucose and insulin responses, however, are modified by the diet to which the animal has adapted, time since it was last fed, and what it was fed. Body fat (obesity), fitness level, physiologic status, and stress also alter glucose and insulin metabolism. Therefore, it is important to consider these factors when evaluating glucose and insulin tests, especially if only one sample it taken. This article describes the factors affecting glucose and insulin metabolism in horses and how they might influence the interpretation of standardized tests of glucose tolerance.     

Hematology and serum biochemistry values of captive Attwater's prairie chickens (Tympanuchus cupido attwateri).

Hematology and serum biochemistry values are reported for 33 Attwater's prairie chickens (Tympanuchus cupido attwateri) that were captive-reared at the San Antonio Zoo as part of a federal reintroduction program in Texas. Hematologic values include packed cell volume, and total and differential white blood cell counts. The biochemical values include concentrations of serum calcium, total protein, albumin, phosphorus, glucose, uric acid, and cholesterol. Mathematic computation of globulin concentration and albumin: globulin ratios were conducted. Also, determination of the serum activities of creatine kinase and aspartate aminotransferase was done.     

Immunocompetence of sheep experimentally infected with bovine leukemia virus

The humoral and cellular immunological reactivity of sheep were studied throughout the first 32 weeks following experimental infection with bovine leukemia virus (BLV). Seroconversion of BLV-inoculated sheep occurred within 4 weeks, but infection was not transmitted to contact control sheep. Despite the persistence of the viral infection, no differences were demonstrated in leukograms, serum IgG concentrations, humoral response to immunization with an irrelevant antigen (rabbit red blood cells), phytomitogen (Concanavalin A and Pokeweek mitogen)-induced lymphocyte blastogenesis, or chemical (1-chloro, 2-4 dinitrobenzene) skin contact hypersensitivity, between BLV-infected and uninfected contact control sheep. These results demonstrate the absence of a nonspecific immunosuppressive effect of BLV and further negate the influence of a generalized immunological deficit on the development of clinical disease in BLV-infected animals.     

Markers, old and new, for examining Phytophthora infestans diversity

Late blight, caused by Phytophthora infestans , is an ongoing threat to potato and tomato crop production worldwide and considerable fundamental and applied research is conducted with the long-term aim of improved disease control. Understanding the mechanisms, processes and rates of P. infestans evolution is an important factor in predicting the effectiveness and durability of new management practices. A range of phenotypic and genotypic tests has been applied to achieve this goal, but each has limitations and new methods are sought. Recent progress in P. infestans genomics is providing the raw data for such methods and new high-throughput codominant biomolecular markers are currently being developed that have tremendous potential in the study of P. infestans population biology, epidemiology, ecology, genetics and evolution. This paper reviews some key applications, recommends some changes in approach and reports on the status and potential of new and existing methods for probing P. infestans genetic diversity.     

MAGNETIC RESONANCE IMAGING FEATURES OF EQUINE NIGROPALLIDAL ENCEPHALOMALACIA

Magnetic resonance imaging (MR) was used to make a diagnosis of equine nigropallidal encephalomalacia in a horse. Equine nigropallidal encephalomalacia is a neurodegenerative disease that has many characteristics with Parkinson-like diseases in humans. Historically, horses were euthanized based on clinical signs and exposure to the toxic weed, yellow star thistle (Centaurea solstitialis). Previously, the disease has only been confirmed on necropsy. MR imaging can provide accurate and sensitive visualization of typical lesions seen in the brain of horses affected with equine nigropallidal encephalomalacia. Lesions were seen on T1-weighted, T2-weighted and proton density images. There was no contrast enhancement following Gd-DTPA administration. Lesions seen on MR were confirmed at necropsy. Using MR to confirm a diagnosis of equine nigropallidal encephalomalacia will prevent unnecessary suffering of horses and expense to owners that would otherwise incur, while further diagnostics are performed.     

Preductal aortic coarctation and patent ductus arteriosus in a Sumatran tiger (Panthera tigris sumatrae) cub.

Preductal aortic coarctation and patent ductus arteriosus are described in a neonatal Sumatran tiger, Panthera tigris sumatrae. Eight days postpartum, the cub appeared weak, and it was separated from the dam for hand rearing. On examination it was dehydrated and hypothermic. Despite treatment, the animal's condition worsened and the cub died 12 days postpartum. Gross postmortem and histologic examinations revealed a preductal aortic coarctation and patent ductus arteriosus with a patent foramen ovale and moderate dilatation of the right ventricle of the heart. Focal pneumonia and mild hepatitis were also present; however, diffuse pulmonary congestion and edema were considered to be the proximate cause of death.