Transfection of chicken embryo fibroblasts with Marek's disease virus DNA

Total DNA from Marek's disease virus (MDV)-infected chicken embryo fibroblasts was transfected into freshly plated secondary chicken embryo fibroblasts using calcium phosphate-mediated transfection. Transfection frequencies were dose-dependent and non-linear. The maximum transfection frequencies of nine MDV DNA preparations using 8-25 micrograms total DNA ranged from 45 to 898 plaques per calcium phosphate/DNA precipitate. Approximately 100-200 plaques per 60-mm tissue-culture dish using 1-5 micrograms total DNA from MDV-infected chicken embryo fibroblasts were typically obtained. Transfection was most efficient when the pH of the HEPES buffer was 7.0, no additional carrier DNA was added to the precipitates, and the cultures were exposed for 3 minutes to 15% buffered glycerol 4 hours after the addition of the calcium phosphate/DNA precipitates.     

Synthesis of Osmotically Active Substances in Winter Wheat Leaves as Related to Drought Resistance of Different Genotypes1)

Water stress increased mono-saccharides and decreased di-saccharides concentration in four field grown genotypes, regardless of their different drought susceptibility. Sandy, a USA genotype known for giving satisfying yields in droughty environments, outstood the other cultivars in terms of betaine and proline concentration in leaf tissues; these aminoacids are therefore considered responsible for the most negative Ψs perceived in this cultivar. PV-curve technique revealed for Tullio, the drought susceptible Italian genotype, an osmotic adjustment of –0.63 MPa, four times greater than in Pandas, though this drought resistant cultivar showed a similar content in osmotically active substances; the authors therefore hypothesize an alternative mechanism in the response to water shortage in Tullio.     

RADIOGRAPHIC CHANGES IN RHESUS MACAQUES AFFECTED BY SCURVY

Spontaneous vitamin C deficiency, or scurvy, was recognized in juvenile rhesus monkeys maintained in a research center as a result of being fed a commercial diet for 2 to 3 months with low levels of vitamin C. Most severely affected animals (13) were radiographed repeatedly up to day 300 following detection of the disease. Early radiographic changes consisted of widened, lucent metaphyses with lateral flaring and radiopaque metaphyseal lines at the junction of the metaphyses and physes. Physeal slippage was noted commonly. Following institution of vitamin C therapy, calcification of subperiosteal hemorrhage occurred in the metaphyseal regions. Metaphyses and physes returned to normal radiographic appearance within 15 to 30 days. Initially, the ubperiosteal hemorrhage progressed and a longer time was required for resolution of the calcified hematomas. The macaques improved clinically and were released from the hospital when fractures were stable at 4–5 weeks after admission. Of the 13 macaques studied, all but one returned as normal members of the colony.     

Assessing repeatability and validity of a visual analogue scale questionnaire for use in assessing pain and lameness in dogs

OBJECTIVE: To develop a visual analogue scale (VAS) questionnaire that is repeatable and valid for use in assessing pain and lameness in dogs. SAMPLE POPULATION: 48 client-owned dogs with mild to moderate lameness. PROCEDURE: The dogs were from 3 studies conducted during a 3-year period. Of the 48 dogs, 19 were used in repeatability assessment, 48 were used in principal component analysis, and 44 were used in model selection procedures and validity testing. A test-retest measure of repeatability was conducted on dogs with a change of < 10% in vertical peak force. A force platform was used as the criterion-referenced standard for detecting lameness. Principal component analysis was used to describe dimensionality of the data. Repeatable questions were used as explanatory variables in multiple regression models to predict force plate measurements. Peak vertical, craniocaudal, and associated impulses were the forces used to quantify lameness. The regression models were used to test the criterion validity of the questionnaire. RESULTS: 19 of 39 questions were found to be repeatable on the basis of a Spearman rank-correlation cut point of > 0.6. Model selection procedures resulted in 3 overlapping subsets of questions that were considered valid representations of the forces measured (vertical peak, vertical impulse, and propulsion peak). Each reduced model fit the data as well as the full model. CONCLUSIONS AND CLINICAL RELEVANCE: The VAS questionnaire was repeatable and valid for use in assessing the degree of mild to moderate lameness in dogs.