Abundant PrP(CWD) in tonsil from mule deer with preclinical chronic wasting disease.

A monoclonal antibody dot-blot assay was used to evaluate detergent lysates of tonsil tissue from mule deer to detect PrP(CWD), the marker for the cervid transmissible spongiform encephalopathy chronic wasting disease (CWD). Samples of formalin-fixed brain and tonsil tissues from mule deer were examined for PrP(CWD) using immunohistochemistry (IHC) with Mab F99/97.6.1, the gold standard for diagnosis of preclinical CWD. The contralateral tonsil from each of the 143 deer was prepared for confirmatory IHC and as a 10% (wt/vol) detergent lysate without purification or enrichment steps for monoclonal antibody dot-blot assay. PrP(CWD) was detected by dot-blot assay in 49 of 50 samples considered positive by IHC. Forty-eight of the positive samples were evaluated with a quantitative dot-blot assay calibrated with recombinant PrP. Tonsillar PrP(CWD) concentrations ranged from 34 to 1,188 ng per 0.5 mg starting wet weight of tissue. The abundant PrP(CWD) in mule deer tonsil will facilitate development and validation of high-throughput screening tests for CWD in large populations of free-ranging deer.     

Analysis of rice blast resistance gene <Emphasis Type="Italic">Pi</Emphasis>-<Emphasis Type="Italic">z</Emphasis> in rice germplasm using pathogenicity assays and DNA markers

The Pi-z gene in rice confers resistance to a wide range of races of the rice blast fungus, Magnaporthe oryzae. The objective of this study was to characterize Pi-z in 111 rice germplasm accessions using DNA markers and pathogenicity assays. The existence of Pi-z in rice germplasm was detected by using four simple sequence repeat (SSR) markers (RM527, AP4791, AP5659-1, AP5659-5) closely linked to Pi-z, and was verified using pathogenicity assays with an avirulent strain (IE1k) and two virulent races (IB33 and IB49). Among 111 germplasm accessions evaluated, 73 were found to contain the Pi-z gene using both SSR markers and pathogenicity assays. The remaining 38 germplasm accessions were found to be inconsistent in their responses to the blast races IB33, IEIk and IB49 with expected SSR marker alleles, suggesting the presence of unexpected SSR alleles and additional R gene(s). These characterized germplasm can be used for genetic studies and marker-assisted breeding for improving blast resistance in rice.     

A rapid method for early generation selection of dwarf genotypes in wheat

Summary In the early generations of a breeding programme to incorporate the successful Norin 10 semidwarfing genes into adapted tall or standard lines, the bread and durum wheat breeder must be able to recognise and discard those lines that are not homozygous for the dwarfing gene. A method which exploits the gibberellin insensitive reaction of lines carrying the genes combined with a single seed descent technique is described in which most unwanted genotypes may be removed as F2 seedlings.     

Cholecalciferol

The primary source of exposure to cholecalciferol in dogs and cats is ingestion of rodenticide baits with vitamin D₃ as the active ingredient. Other sources of this toxin are human medications and rarely, contaminated pet food. Although the reported lethal dose 50% for cholecalciferol is 88 mg/kg, deaths have been seen with an individual exposure of 2 mcg/kg in dogs. Clinical signs are induced by profound hypercalcemia affecting multiple body systems. Clinical presentations may include anorexia, depression, muscle weakness, vomiting, polyuria, polydipsia, dehydration, abdominal pain, hematemesis, melena, and bradycardia. Tissue mineralization may develop if calcium × phosphorous product is greater than 60. Serum testing for hypercalcemia, hyperphosphatemia, and decreased serum parathyroid hormone are confirmatory. Initial treatment relies upon decontamination with emesis induction followed by administration of pulse-dose activated charcoal designed to interfere with the extensive enterohepatic recirculation of toxin. Medical management is designed to decrease serum calcium levels by use of intravenous fluid diuresis with administration of furosemide and prednisolone. Biphosphate pamidronate is used to inhibit calcium release from the bone. Phosphate binders aid in decreasing phosphate availability to interact with calcium. The prognosis is better if treatment is instituted early before development of hypercalcemia and hyperphosphatemia enables tissue mineralization to progress.     

Evaluation of the association between microalbuminuria and the urine albumin-creatinine ratio and systemic disease in dogs

OBJECTIVE: To evaluate semiquantitative and quantitative assays for microalbuminuria and determination of the urine albumin-creatinine (UAC) ratio in detection of systemic disease in dogs without overt proteinuria. DESIGN: Prospective study. ANIMALS: 408 dogs. PROCEDURES: Urine samples that had been obtained from dogs for which a complete medical record was available and in which results of a dipstick test for urine protein were negative were evaluated. Urine protein-creatinine ratios (cutoff values, 0.5 and 0.1), semiquantitative and quantitative microalbuminuria values (cutoff value, 1 mg/dL), and UAC ratios (cutoff values, 100 and 200 mg/g) were determined. Clinical diagnoses rendered within 3 months of enrollment in the study were recorded. Sensitivity and specificity were determined with disease status serving as the standard. Associations with clinical diagnosis, sex, age, BUN and serum creatinine concentrations, blood pressure, results of bacterial culture of urine, temperature, pyuria, hematuria, and bacteriuria were evaluated by use of logistic regression analysis. RESULTS: 48 dogs were healthy, and 360 had at least 1 disease. Significant associations were detected between age, presence of disease, presence of neoplastic disease, BUN and serum creatinine concentrations, and hematuria and results of 1 or both of the microalbuminuria assays. CONCLUSIONS AND CLINICAL RELEVANCE: Microalbuminuria was associated with underlying disease. The sensitivity and specificity of the semiquantitative microalbuminuria test for detection of systemic disease were superior to those of other tests. Microalbuminuria testing in conjunction with other screening procedures may increase diagnosis of subclinical disease, but a prospective study in which the predictive values of screening tests are evaluated, with and without microalbuminuria determination, is needed.     

Theoretical and Empirical Relationships Between Oat Test Weight and Groat Proportion

Test weight and groat proportion are two very important quality characteristics of oat grain. In this study, we pose the hypothesis that these two characteristics are related through characteristics of grain density. Test weight is defined as the product of kernel density and packing proportion. Groat proportion, in theory, is the ratio of the groat mass to the kernel mass. We present two theoretical constructions expressing test weight in terms of groat proportion, packing proportion and kernel density components. To test these, we have applied measurements of test weight, groat proportion, kernel density components, and packing proportion of 18 oat cultivars grown at six environments. Whereas the groat proportion alone accounted for only 34% of the variation in test weight, our theoretical constructions that included groat proportion could account for ≤82% of variation in test weight. Also, we present previously undescribed variation in oat kernel density components across genotypes and environments. Although the kernel density alone could account for most of the variation in test weight across genotypes, packing proportion appeared to be more important in describing variation in test weight of a genotype across different environments. We observed significant variation in both groat and hull density which, together with groat proportion, described most of the variation in kernel density.