We aim to investigate the effect of vasectomy on the histology of the testis as well as to evaluate DNA fragmentation in testicular tissue of male mice. Methods: Bilateral vasectomy was performed on 20 mature male mice; 10 control mice underwent sham-operation. After 6 weeks, the testes were evaluated for histological changes and DNA fragmentation by single cell gel electrophoresis (comet assay). Results: Marked alterations were observed in the testes of vasectomized mice, including degeneration of spermatids, thickened basement membrane, dilatation of the seminiferous tubules, exfoliation of germ cells, reduction in the seminiferous cell population, vacuolated appearance of the epithelium in the tubules and marked interstitial fibrosis. Single cell gel electrophoresis showed a highly significant (P<0.0001) increase in DNA damage among vasectomized mice (46.02%) compared with control group (%27.17) after six weeks of operation. Conclusion: Vasectomy induced deterioration in the seminiferous tubules associated with increased testicular cell’s DNA fragmentation.

To draw inferences about the sensitivity and specificity of the newly developed ELISA test for bovine paratuberculosis (PTB) diagnosis and posterior distribution on the prevalence of PTB in a province of Korea, we applied Bayesian approach with Gibbs sampler to the data extracted from the prevalence study in 1999. The data were from a single test results without a designated gold test. The prevalence estimates for PTB in study population ranged 3.2~5.3% for conservative and 6.7~7.1% for liberal, depending on the priors used. The simulated specificities of the ELISA close to one another, ranging 84.7~90.6%, whereas the sensitivity was somewhat spread out depending largely on the priors with a range of 46.4~88.2%. Our findings indicate that the ELISA method appeared useful as a screening tool at a minimum level in comparison to other diagnostic tests available for this disease in terms of sensitivity. However, this advantage comes at a cost of having low specificity of the test.
Animals ; Bayes Theorem ; Cattle ; Cattle Diseases/*epidemiology ; Enzyme-Linked Immunosorbent Assay/*methods ; Korea/epidemiology ; Paratuberculosis/*epidemiology ; Prevalence