Tumour-specific microRNA expression pattern in canine intestinal T-cell-lymphomas

Intestinal T-cell lymphomas are common in dogs, but histopathological diagnosis remains challenging because of accompanying enteritis with lymphocyte involvement. Invasively taken full-layer biopsies are still required for reliable differentiation. The detection of specific microRNA expression patterns in canine intestinal T-cell lymphoma could provide new possibilities to differ intestinal lymphoma from benign inflammation and could lead to further understanding of lymphomagenesis. The objective of this study was to characterize microRNA expression in distinct groups of formalin-fixed and paraffin-embedded samples from canine intestinal T-cell lymphomas, lymphoplasmacellular enteritis and healthy intestinal tissue. In a preliminary test with two samples per group, total RNA was extracted (RNEasy FFPE Kit, Qiagen), reverse transcribed (miScript II RT Kit, Qiagen) and pre-amplified (miScript PreAmp PCR Kit, Qiagen). We performed comparative quantitative PCR on microRNA PCR Array plates (Qiagen) with pre-fabricated reactions for 183 different mature canine microRNAs. Subsequently, 12 microRNAs with conspicuous expression changes in the lymphoma group were selected and microRNA expression of all samples (n = 8) per group was analysed with individual microRNA assays (miScript Primer Assays, Qiagen) on the reverse transcribed RNA without pre-amplification. Our results revealed lymphoma-specific expression patterns, with down-regulation of the tumour-suppressing microRNAs miR-194, miR-192, miR-141 and miR-203, and up-regulation of oncogenic microRNAs, including microRNAs from the miR-106a~363 cluster. In addition, we detected only slight expression alterations between healthy intestinal tissue and lymphoplasmacellular enteritis cases. We conclude that microRNA expression patterns can be used to separate T-cell lymphomas from healthy tissue and benign inflammatory disorders.

Morphology of Naturally-Occurring Tuberculosis in Cattle Caused by Mycobacterium caprae

This study describes the pathomorphological alterations of bovine tuberculosis through gross and histopathological examinations, assessment of the distribution of lesions and the demonstration of mycobacteria. Samples from lungs, liver, small intestine, their regional lymph nodes and retropharyngeal lymph nodes were collected from 84 cattle with tuberculosis from the Allgäu, Germany. Organs were evaluated grossly, histopathologically and by transmission electron microscopy. Mycobacteria and mycobacterial antigens were demonstrated using acid-fast staining and immunohistochemistry (IHC). Bacteriological tests revealed Mycobacterium caprae in all animals. Gross alterations were classified into five patterns (I to V) with an additional pattern of acute exudative pulmonary inflammation (pattern VI). Histological lesions were classified into four types (1-4) with additional lesions occurring in lungs only. Acid-fast staining revealed a low number of bacteria in all tissues, while IHC showed comparatively more mycobacterial antigens within the lesions and also at their periphery. The alimentary tract (68%) was the main portal of entry followed by an aerosol infection (19%). It was assumed that the observed lesions reflect a continuous primary period of infection; there were no lesions typical of a secondary (post-primary) period, as reported in man and also described in the older literature on bovine tuberculosis. The broad spectrum of changes described formerly was not observed in the present cases and the route of infection and nature of acid fast staining showed differences when compared with previous studies of naturally-occurring bovine tuberculosis.

Intestinal lesions in dogs with acute hemorrhagic diarrhea syndrome associated with netF-positive Clostridium perfringens type A

Acute hemorrhagic diarrhea syndrome (AHDS), formerly named canine hemorrhagic gastroenteritis, is one of the most common causes of acute hemorrhagic diarrhea in dogs, and is characterized by acute onset of diarrhea, vomiting, and hemoconcentration. To date, histologic examinations have been limited to postmortem specimens of only a few dogs with AHDS. Thus, the aim of our study was to describe in detail the distribution, character, and grade of microscopic lesions, and to investigate the etiology of AHDS. Our study comprised 10 dogs with AHDS and 9 control dogs of various breeds, age, and sex. Endoscopic biopsies of the gastrointestinal tract were taken and examined histologically (H&E, Giemsa), immunohistochemically ( Clostridium spp., parvovirus), and bacteriologically. The main findings were acute necrotizing and neutrophilic enterocolitis (9 of 10) with histologic detection of clostridia-like, gram-positive bacteria on the necrotic mucosal surface (9 of 10). Clostridium perfringens isolated from the duodenum was identified as type A (5 of 5) by multiplex PCR (5 of 5). In addition, each of the 5 genotyped isolates encoded the pore-forming toxin netF. Clostridium spp. (not C. perfringens) were cultured from duodenal biopsies in 2 of 9 control dogs. These findings suggest that the pore-forming netF toxin is responsible for the necrotizing lesions in the intestines of a significant proportion of dogs with AHDS. Given that the stomach was not involved in the process, the term "acute hemorrhagic diarrhea syndrome" seems more appropriate than the frequently used term "hemorrhagic gastroenteritis."

The Munich MIDY Pig Biobank - A unique resource for studying organ crosstalk in diabetes

OBJECTIVE

The prevalence of diabetes mellitus and associated complications is steadily increasing. As a resource for studying systemic consequences of chronic insulin insufficiency and hyperglycemia, we established a comprehensive biobank of long-term diabetic INSC94Y transgenic pigs, a model of mutant INS gene-induced diabetes of youth (MIDY), and of wild-type (WT) littermates.

METHODS

Female MIDY pigs (n = 4) were maintained with suboptimal insulin treatment for 2 years, together with female WT littermates (n = 5). Plasma insulin, C-peptide and glucagon levels were regularly determined using specific immunoassays. In addition, clinical chemical, targeted metabolomics, and lipidomics analyses were performed. At age 2 years, all pigs were euthanized, necropsied, and a broad spectrum of tissues was taken by systematic uniform random sampling procedures. Total beta cell volume was determined by stereological methods. A pilot proteome analysis of pancreas, liver, and kidney cortex was performed by label free proteomics.

RESULTS

MIDY pigs had elevated fasting plasma glucose and fructosamine concentrations, C-peptide levels that decreased with age and were undetectable at 2 years, and an 82% reduced total beta cell volume compared to WT. Plasma glucagon and beta hydroxybutyrate levels of MIDY pigs were chronically elevated, reflecting hallmarks of poorly controlled diabetes in humans. In total, ∼1900 samples of different body fluids (blood, serum, plasma, urine, cerebrospinal fluid, and synovial fluid) as well as ∼17,000 samples from ∼50 different tissues and organs were preserved to facilitate a plethora of morphological and molecular analyses. Principal component analyses of plasma targeted metabolomics and lipidomics data and of proteome profiles from pancreas, liver, and kidney cortex clearly separated MIDY and WT samples.

CONCLUSIONS

The broad spectrum of well-defined biosamples in the Munich MIDY Pig Biobank that will be available to the scientific community provides a unique resource for systematic studies of organ crosstalk in diabetes in a multi-organ, multi-omics dimension.