Search

Simple Summary: Chalkbrood is a mycological brood disease of the Western honey bee (Apis mellifera), caused by the fungus Ascosphaera apis. To date, the course of this disease (pathogenesis) has not been investigated in depth. In this study, the pathogenesis will be described in detail using macroscopy and histology under controlled experimental conditions. For this purpose, Apis mellifera larvae were artificially reared and experimentally infected with Ascosphaera apis spores. The infected larvae were then evaluated macroscopically and histologically, and the findings were compared to non-infected control larvae. Histological signs of infection were observed in 26 out of 64 infected larvae, first on day 3 p.i. Of these 26 larvae, 23 were already dead at the time of collection and showed macroscopic changes. The histological findings indicate a fulminant infection process from the germination of the spores in the intestinal lumen to the death of the larva. This study's results are crucial for an improved understanding of the pathogenesis of chalkbrood disease. Chalkbrood is a mycological brood disease of the Western honey bee (Apis mellifera), caused by the fungus Ascosphaera apis. The aim of this study was the investigation of the pathology of artificially reared Apis mellifera larvae, experimentally infected with A. apis spores (1.0 × 103 spores/larva). Non-infected larvae served as control. Five living larvae and every dead larva were collected daily (day 1–7 p.i.). All larvae were macroscopically measured, photographed, formalin-fixed, and histologically processed (hematoxylin-eosin stain, Grocott silvering). Histological sections were digitized, and the size of the larvae was measured (mouth-after length, area) and statistically analyzed. Twenty-six larvae from the collected larvae (n = 64; 23 dead, 3 alive) showed histological signs of infection from 3 d p.i. onwards. The dead larvae showed macroscopically white/brown deposits, indistinct segmentation, and a lack of body elongation. Infected larvae were significantly smaller than the controls on days 3 p.i. (p < 0.05), 4 p.i. (p < 0.001), and 6 p.i. (p < 0.05). The early time of death, the low number of transitional stages, and the strong penetration of the larval carcass with fungal mycelium indicate a rapid and fulminant infection process, which is probably relevant for spreading the disease within the colony. [ABSTRACT FROM AUTHOR]

Although atrial dilation is a common finding in feline cardiac disease, detailed investigations of atrial pathology are rare in cats. The aim of the study was to investigate the correlation between pathohistological findings, morphometric data and the degree of dilation of the left atrial appendage (LAA) in 53 cats. Based on the LAA volume, the samples were grouped into normal/control (group 0, ≤1 ml [n = 9]), mildly dilated (group 1, >1 to ≤2 ml [n = 16]), moderately dilated (group 2, >2 to ≤3 ml [n = 14]) and markedly dilated (group 3, >3 ml [n = 14]) groups, independent of the underlying disease. Samples from the LAA and the left atrium (LA) were histologically evaluated using haematoxylin and eosin- and Picrosirius red-stained sections, and morphometrically analysed using an image analysis system. The degree of endo-, myo- and epicardial fibrosis was directly correlated with increased LAA dilation. Due to cardiomyocyte hyperplasia and hypertrophy, the mean thickness of the atrial wall was significantly greater in groups 1 and 2 than in group 0. Conversely, group 3 had a lower mean atrial wall thickness than groups 1 and 2, which was attributed to increased transmural fibrosis and cardiomyocyte atrophy. These findings reflect intensive dynamic remodelling processes during LA and LAA dilation, indicating that reversibility appears to be limited in cases of severe left atrial dilation. [ABSTRACT FROM AUTHOR]

Tumors of mesenchymal origin are rarely reported in the pancreas. Therefore, this study characterized 17 feline non-epithelial pancreatic tumors, including clinical data, histopathology, and immunohistochemistry. Seventeen feline pancreatic tissue samples were investigated histopathologically and immunohistochemically. Selected pancreatic and inflammatory serum parameters, e.g., feline pancreatic lipase immunoreactivity (fPLI), 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(60-methylresorufin) ester (DGGR) lipase and serum amyloid A (SAA), were recorded, when available. The neoplasms were characterized as round (n = 13) or spindle (n = 4) cell tumors. Round cell tumors included 12 lymphomas and one mast cell tumor in ectopic splenic tissue within the pancreas. Lymphomas were of T-cell (n = 9) or B-cell (n = 3) origin. These cats showed leukocytosis (3/3) and increased fPLI (5/5), DGGR lipase (3/5) and SAA(4/5) values. Spindle cell tumors included two hemangiosarcomas, one pleomorphic sarcoma and one fibrosarcoma. The cat with pleomorphic sarcoma showed increased SAA value. Overall survival time was two weeks to seven months. These are the first descriptions of a pancreatic pleomorphic sarcoma and a mast cell tumor in accessory spleens within feline pancreas. Although rare, pancreatic tumors should be considered in cats presenting with clinical signs and clinical pathology changes of pancreatitis. Only histopathology can certainly distinguish solitary pancreatitis from a neoplasm with inflammation. [ABSTRACT FROM AUTHOR]

In breast cancer of women, the estrogen receptor–α (ERα) and progesterone receptor (PR) status has prognostic and therapeutic significance. The aim of this study was (1) to characterize by immunohistochemistry the expression of ERα and PR in nonneoplastic and neoplastic mammary gland tissue of pet rabbits and (2) to correlate the ERα/PR status and histological features. All 124 rabbits included in this study had a mammary tumor; in addition, 2 rabbits had lobular hyperplasia and 25 had multiple cysts. Of the 124 neoplasms, 119 (96%) were carcinoma, 2 (2%) were carcinoma in situ, and 3 (2%) were adenoma. ERα or PR or both were detected in 2 of 2 carcinomas in situ, 3 of 3 adenomas, 19 of 25 cysts, and 2 of 2 lesions of lobular hyperplasia. Most carcinomas (75/119, 63%) were negative for both ERα and PR; 22 of 119 carcinomas (18%) were double-immunopositive. The ERα and PR expression was not influenced by histotype or histological tumor grade. In carcinomas, there was a statistically significant correlation between increased mitotic count and reduced expression of ERα and PR, and the mitotic count was higher in double-immunonegative carcinomas (75/119). The findings suggest that in rabbit mammary carcinomas, proliferative activity is mainly influenced by factors other than estrogen and progesterone and provides the basis for future investigations into the prognostic significance of the ERα and PR status of mammary tumors. [ABSTRACT FROM AUTHOR]