Compartmental modeling with nitrogen-15 to determine effects of degree of fat saturation on intraruminal N recycling

Two- and three-compartment models were developed to describe N kinetics within the rumen using three Holstein heifers and one nonlactating Holstein cow fitted with ruminal and duodenal cannulas. A 4 x 4 Latin square design included a control diet containing no supplemental fat and diets containing 4.85% of diet dry matter as partially hydrogenated tallow (iodine value = 13), tallow (iodine value = 51), or animal-vegetable fat (iodine value = 110). Effects of fat on intraruminal N recycling and relationships between intraruminal N recycling and ruminal protozoa concentration or the efficiency of microbial protein synthesis were determined. A pulse dose of 15(NH4)2SO4 was introduced into the ruminal NH3 N pool, and samples were taken over time from the ruminal NH3 N and nonammonia N pools. For the three-compartment model, precipitates of nonammonia N after trichloroacetic acid and ethanol extraction were defined as slowly turning over nonammonia N; rapidly turning over nonammonia N was determined by difference. Curves of 15N enrichment were fit to models with two (NH3 N and nonammonia N) or three (NH3 N, rapidly turning over nonammonia N, and slowly turning over nonammonia N) compartments using the software SAAM II. Because the three-compartment model did not remove a small systematic bias or improve the fit of the data, the two-compartment model was used to provide measurements of intraruminal N recycling. Intraruminal NH3 N recycling (45% for control) decreased linearly as fat unsaturation increased (50.2, 43.0, and 41.7% for partially hydrogenated tallow, tallow, and animal-vegetable fat, respectively). Intraruminal nitrogen recycling was not correlated with efficiency of microbial protein synthesis or ruminal protozoa counts.     

Analysis of risk factors for the development of equine protozoal myeloencephalitis in horses

OBJECTIVE: To investigate risk factors for development of equine protozoal myeloencephalitis (EPM) in horses. DESIGN: Case-control study. ANIMALS: 251 horses admitted to The Ohio State University Veterinary Teaching Hospital from 1992 to 1995. PROCEDURE: On the basis of clinical signs of neurologic disease and detection of antibody to Sarcocystis neurona or S neurona DNA in cerebrospinal fluid, a diagnosis of EPM was made for 251 horses. Two contemporaneous series of control horses were selected from horses admitted to the hospital. One control series (n = 225) consisted of horses with diseases of the neurologic system other than EPM (neurologic control horses), and the other consisted of 251 horses admitted for reasons other than nervous system diseases (nonneurologic control horses). Data were obtained from hospital records and telephone conversations. Risk factors associated with disease status were analyzed, using multivariable logistic regression. RESULTS: Horses ranged from 1 day to 30 years old (mean +/- SD, 5.7 +/- 5.2 years). Risk factors associated with an increased risk of developing EPM included age, season of admission, prior diagnosis of EPM on the premises, opossums on premises, health events prior to admission, and racing or showing as a primary use. Factors associated with a reduced risk of developing EPM included protection of feed from wildlife and proximity of a creek or river to the premises where the horse resided. CONCLUSIONS AND CLINICAL RELEVANCE: Development of EPM was associated with a number of management-related factors that can be altered to decrease the risk for the disease.     

Anemia, splenomegaly, and increased osmotic fragility of erythrocytes in Abyssinian and Somali cats

OBJECTIVE: To determine clinical and clinicopathologic features of a chronic intermittent severe hemolytic anemia characterized by erythrocyte osmotic fragility in Abyssinian and Somali cats. DESIGN: Case series. ANIMALS: 13 Abyssinian and 5 Somali cats. PROCEDURES: History, pedigree information, and results of routine laboratory tests, special erythrocyte studies, and histologic evaluation of splenic and hepatic specimens were analyzed. RESULTS: Age at which clinical signs of anemia were first apparent ranged from 6 months to 5 years. Ten cats had splenomegaly. Most often, the PCV was between 15 and 25%, but it was as low as 5% at some times. The anemia was characterized by macrocytosis and mild to moderate reticulocytosis, but no poikilocytosis. Hyperglobulinemia, lymphocytosis, mild hyperbilirubinemia, and high hepatic enzyme activities were common findings. Results of Coombs tests and tests for infectious diseases were negative. The erythrocytic osmotic fragility was high in affected cats (mean osmotic fragility, 0.66 to 0.78%), compared with healthy cats (0.48 to 0.58). No specific membrane protein abnormality, erythrocyte enzyme deficiency, or hemoglobinopathy was identified. Histologic evaluation of splenic and hepatic specimens revealed extramedullary hematopoiesis and hemosiderosis. Four of the 5 Somali cats were closely related. CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of results of pedigree analyses, the apparent breed predilection, and the exclusion of other known causes of anemia in cats, we believe that the hemolytic anemia in these cats was likely a result of a novel hereditary erythrocyte defect. A genetic predisposition to immune-mediated destruction of erythrocytes could not be ruled out.     

Climate Change During the Last Deglaciation in Antarctica

Greenland ice core records provide clear evidence of rapid changes in climate in a variety of climate indicators. In this work, rapid climate change events in the Northern and Southern hemispheres are compared on the basis of an examination of changes in atmospheric circulation developed from two ice cores. High-resolution glaciochemical series, covering the period 10,000 to 16,000 years ago, from a central Greenland ice core and a new site in east Antarctica display similar variability. These findings suggest that rapid climate change events occur more frequently in Antarctica than previously demonstrated.     

INDEPTH Wide-Angle Reflection Observation of P-Wave-to-S-Wave Conversion from Crustal Bright Spots in Tibet

Three-component wide-angle seismic data acquired in southern Tibet during Project INDEPTH show strong P-to-S converted reflections from reflectors that are aligned at a depth of approximately 15 kilometers beneath the northern Yadong-Gulu rift. These converted reflections are locally higher in amplitude than the corresponding P-wave reflections. Modeling of reflection mode conversion as a function of incidence angle indicates that this condition obtains for a reflector that is a solid over fluid interface; it is not typical of a solid-solid interface. The likely candidates for a fluid trapped within the crystalline crust of southern Tibet are granitic magma and water (brine).     

Thyroid gangliosides with high affinity for thyrotropin: potential role in thyroid regulation

Thyroid cell membranes contain a multiplicity of gangliosides, some of which inhibit thyrotropin binding to thyroid membranes. The most potent inhibitor is a ganglioside which is present in only trace amounts and appears to have a novel structure. Thyroid gangliosides may play a role in relaying the hormonal message to the thyroid cell.     

Defect in conversion of procollagen to collagen in a form of Ehlers-Danlos syndrome

Three patients with a form of the Ehlers-Danlos syndrome, a generalized disorder of connective tissue, have detectable amounts of procollagen in extracts of their skin and tendon. The activity of procollagen peptidase, the enzyme that converts procollagen to collagen, is reduced in cultures of fibroblasts. The clinical manifestations of this syndrome may be related to impaired enzymatic conversion of procollagen to collagen. Cultures of skin fibroblasts from these patients have an increased rate of synthesis of collagenous protein (collagen and procollagen), possibly related to the inability of these cells to convert procollagen to collagen.     

Image reconstruction of the interior of bodies that diffuse radiation

A method for reconstructing images from projections is described. The unique aspect of the procedure is that the reconstruction of the internal structure can be carried out for objects that diffuse the incident radiation. The method may be used with photons, phonons, neutrons, and many other kinds of radiation. The procedure has applications to medical imaging, industrial imaging, and geophysical imaging.     

Infections with Anaplasma phagocytophilum in dogs in Germany

The main objectives of this prospective study were to establish prevalence of Anaplasma phagocytophilum infections in dogs from Northeast Germany; and to evaluate the hematological parameters of sero- or real-time PCR-positive clinically healthy dogs. The mean prevalence of A. phagocytophilum seropositivity of 522 dogs (258 suspected to have anaplasmosis, 264 healthy) was 43%. There was no difference between sick (46.9%) and healthy dogs (39.8%) (p = 0.100). The PCR test was positive in 30 dogs (20 sick, 10 healthy); morulae were found in 12 of them. Twenty-six of 30 dogs tested PCR-positive between May and September (p < 0.05). There was no difference with regard to abnormal CBC parameters between seropositive and seronegative clinically healthy dogs. The CBC was within reference range in 10 PCR-positive clinically healthy dogs suggesting a routine examination of blood donors for A. phagocytophilum in endemic areas to minimize the risk of transmission.