Western blot detection of PrP Sc in archived paraffin-embedded brainstem from scrapie-affected sheep

Scrapie is a naturally occurring fatal neurodegenerative disease of adult sheep and goats, one of a group of mammalian diseases known as transmissible spongiform encephalopathies (TSE) or prion diseases. Immunoassays that identify disease-associated prion protein (PrP Sc) are integral to the diagnosis of scrapie and other prion diseases. Results obtained by either immunohistochemistry (IHC) or Western blot (WB) assay are generally adequate for the definitive diagnosis. Approved or accepted methods for WB diagnosis of TSEs requires the use of fresh or frozen nonfixed tissue samples, whereas formalin-fixed, paraffin-embedded tissue is required for the localization of PrP Sc by IHC. Because disparate processing methods are used for these accepted diagnostic techniques, separate tissue samples are collected from the same animal. Occasions arise in which there is either insufficient quantity of tissue available to complete analysis by both techniques or initial tissue processing is incompatible with one of the assays. Also, results between the assays may differ because of the vagaries of sampling, especially in case material that contains moderate-to-low levels of PrP Sc. The present article describes a method to conduct a WB assay from the same paraffin-embedded brainstem sample used for the IHC diagnosis of experimentally induced sheep scrapie.     

How has the state-of-the-art for quantification of landscape pattern advanced in the twenty-first century?

Landscape Ecology - Landscape ecology was founded on the idea that there is a reciprocal relationship between spatial pattern and ecological processes. I provide a retrospective look at how the...     

Osteoma of the oral and maxillofacial regions in cats: 7 cases (1999-2009)

Objective-To describe clinical features of oral and maxillofacial osteomas in cats. Design-Retrospective case series. Animals-7 cats with oral or maxillofacial osteoma or both. Procedures-Medical records were reviewed for information on signalment, history, clinical signs, physical examination findings, diagnostic imaging findings, results of serum biochemical analyses and histologic testing, surgical procedures performed, and perioperative complications. Outcome was determined on the basis of follow-up telephone interviews of owners. Results-Cats ranged from 1 to 23 years of age. Clinical signs were observed in 5 cats and were attributed to the presence of the mass. Diagnostic imaging (radiography and computed tomography) and histologic examination confirmed the diagnosis of osteoma. Three cats were euthanatized; 1 cat was treated by mandibulectomy, 1 was treated by maxillectomy, and 2 were treated by debulking. At the time of follow-up at least 1 year after surgery, all 4 treated cats were alive, with owners reporting an acceptable quality of life. Conclusions and Clinical Relevance-Osteoma of the oral and maxillofacial regions is an uncommon tumor in cats. Most cats are examined during an advanced stage of the disease, when treatment options may be limited. Although osteoma is a benign tumor, the recommendation is to perform a clinical evaluation, diagnostic imaging, biopsy, and treatment early in the disease process, when less invasive surgical approaches may be feasible.     

Review of African swine fever outbreaks history in South Africa: From 1926 to 2018

The article reviews the outbreaks and distribution of African swine fever (ASF) in South Africa since the first probable outbreak that occurred in the Koedoesrand Ward in 1926. Retrospective data on the ASF outbreaks in South Africa were obtained from the World Organisation for Animal Health (OIE) disease database and the South African veterinary services annual reports in addition to published articles and online sources. South Africa has experienced many outbreaks that can be divided into 2 time periods: the period before the development of the OIE diseases database (1993) and the period after. More than 141 outbreaks of ASF were reported during the first period. Since the development of OIE disease database, 72 outbreaks directly involving 2968 cases, 2187 dead and 2358 killed pigs mainly in smallholder pig farms were reported. The median number of cases for a given ASF outbreak is 17, but in 50% of outbreaks no pigs were killed for prevention. The most important ASF outbreak was reported in April 2014 in the Greater Zeerust district (North West province) involving 326 cases and 1462 killed pigs. However, the outbreak with highest mortality involving 250 pigs was reported in 2016 (Free State province). According to phylogenetic analysis, nine p72 genotypes (I, III, IV, VII, VIII, XIX, XX, XXI and XXII) have been identified in South Africa. Season-wise, more outbreaks were recorded during summer. It was also observed that the OIE disease database could contain errors that would have been introduced through compiled forms at country level. Spatiotemporal studies on ASF outbreaks in South Africa are therefore required in order to assess statistically and quantitatively the clustering of outbreaks over space and time.     

Comparison of radiographic osteoarthritis scores in dogs less than 24 months or greater than 24 months following tibial plateau leveling osteotomy

Radiographic osteoarthritis scores were determined in 60 dogs up to 3 years following tibial plateau leveling osteotomy. Radiographs taken immediately following surgery and at long-term follow-up 1 to 3 years later were evaluated by 2 certified radiologists using a modified 32-point osteoarthritis scale. Changes in osteoarthritis scores were evaluated by paired t-tests and regression analysis. Sub-groups of dogs were formed to evaluate if osteoarthritis scores changed differently for follow-up periods of < 24 months compared with those > 24 months. There was a significant increase in osteoarthritis score from post-operative to follow-up evaluations for all dogs studied. Regression analysis of the relationship of months after surgery to change in osteoarthritis score was not significant. These results indicate that osteoarthritis did progress following tibial plateau leveling osteotomy, but not in a linear fashion over time.     

Susceptibility of Wheat to Tilletia indica During Stages of Spike Development

ABSTRACT Karnal bunt of wheat is caused by the fungus Tilletia indica, which partially converts kernels into sori filled with teliospores. Despite minor overall yield and quality losses, the disease is of considerable international quarantine concern. Plant development stages reported susceptible to infection vary considerably. A study was designed to better define the susceptibility period by inoculating wheat spikes at different growth stages with naturally liberated secondary sporidia under optimal conditions for disease development. Spikes of a resistant and susceptible cultivar were inoculated at eight growth stages from awns emerging to soft dough. Spikes became susceptible only after emerging from the boot and continued to be susceptible up to soft dough stage at which low levels of disease occurred. Disease severity in both cultivars peaked when spikes were inoculated after complete emergence, but before the onset of anthesis. Disease levels tapered off gradually in spikes inoculated after anthesis. The results broaden the known susceptibility period of wheat to T. indica to include stages long after anthesis, and indicate that infection from airborne inoculum is not possible during boot or awns emerging stages, which are commonly referred to as the most susceptible stages.