Ivana Vučićević

Association of the severity of lung lesions with carcass and meat quality in slaughter pigs

The aim of this study was to determine the association of lung lesions with carcass and meat quality traits in slaughter pigs and to describe the main morphological features associated with lung lesions. Macroscopic lesions on the lungs were detected in 67.09% of a total of 79 pigs examined. Histopathological examination revealed that acute and chronic interstitial pneumonia represented the commonest changes, detected in 26.67% and 33.33% of the cases, respectively. Bronchopneumonia was found in 33.33% of the cases. By immunohistochemical examination, 26.67% of the lungs showed the presence of severe peribronchiolar and perialveolar infiltration composed predominantly of CD3+ T lymphocytes, which finding may be indicative of viral pneumonia. Regarding the production traits, it was confirmed that pigs with severe lung lesions had the lowest liveweight, hot carcass weight and meatiness, the highest pH value 45 min after slaughtering (pH45) and the highest incidence of dark, firm, dry (DFD) and pale, soft, exudative (PSE) meat. The presence of lung lesions significantly downgraded carcass value and caused a significant deterioration in pork quality.

Mast cell tumor within a lipoma in a white toy poodle

Uprkos cinjenici da su mastocitomi jedna od najcescih neoplazmi kod pasa, postoji samo jedan objavljeni slucaj mastocitoma u lipomu. U ovom slucaju, kod 11-godisnje ženke toj pudle primeceno je prisustvo dobro ogranicene, pokretne, meko-elasticne mase na lateralnoj strani grudnog kosa. Histopatoloski pregled je pokazao dobro ogranicenu masu koja se sastojala od zrelih adipocita između kojih se nalaze skupine celija sa granuliranom citoplazmom. Bojenjem toluidin plavim je dokazano prisustvo metahromatskih granula u citoplazmi mastocita. Histopatoloske i imunohistohemijske karakteristike ukazale su na to da je ispitani mastocitom niskog stepena maligniteta.

Malignant mast cell tumour within a benign lipoma in a toy poodle

Despite the fact that mast cell tumours (MCT) are one of the most common neoplasms in dogs there is only one published case of MCT within a lipoma. In this case, in 11-years old female toy poodle was observed the presence of a well-demarcated, freely movable, softy mass on the chest. Histological examination showed a well-circumscribed mass consisted of mature adipocytes and multiple foci of round cells with granulated cytoplasm between adipocytes. Toluidine blue staining demonstrated metachromatic granules in the cytoplasm of mast cells.

The Role of Myofibroblasts in Granulomatous Lymphadenitis in Pigs Naturally Infected with M. Avium Subsp. Hominissuis

Abstract The most important morphological characteristic of infections caused by M. avium subsp. hominissuis (MAH) is granuloma formation. The growth of mycobacteria is in accordance with anti-bacterial effector mechanisms of the host within granuloma. The most important cytokines for „orchestrating“the host defense are interferon γ (INF-γ), tumor necrosis factor α (TNF-α) and transforming growth factor β1 (TGF-β1). Myofibroblasts that make up a peripheral layer of granuloma largely express receptors for TGF-β1. This cytokine is believed to affect the induction of myofibroblast proliferation. The aim of this paper is to point out the importance of myofibroblasts in the formation and sustainability of granuloma during natural infection of pigs with M. avium subsp. hominissuis. Examinations have been performed on the samples of Lnn. jejunales, Lnn. ileocolici and Lnn. colici of 100 pigs with a positive tuberculin skin test. The molecular method confirmed the presence of a genome M. avium subsp. hominissuis. The microscopic examination of lymph node samples stained by the routine hematoxyilin-eosin (HE) method, showed the presence of granulomatous lymphadenitis. The method of double immunohistochemical staining revealed that myofibroblasts which express TGF-β1 receptor type I (TGF-β1RI) and α smooth muscle actin (α SMA) have an important role in the morphogenesis of granulomatous lymphadenitis in pigs infected with MAH.

Histological and immunohistochemical characteristics of cerebral amyloid angiopathy in elderly dogs

ABSTRACT Background: Cerebral amyloid angiopathy (CAA) is a disorder characterized by amyloid deposition in the wall of cerebral blood vessels. The deposits of amyloid occur frequently in the blood vessels of the frontal, parietal and occipital cortex. Objective: To examine the characteristics of CAA classified according to the Vonsattel scale in elderly dogs histologically and immunohistochemically as well as the semi-quantitative evaluation of the amyloid deposits in the different segments of the brain. Animals and methods: The brains of 36 dogs of different breeds and sexes, which had been routinely necropsied, were used and divided into two groups: dogs from 1 to 5 and 10 to 18 years old. The tissue sections were stained by hematoxylin–eosin, Congo red and immunohistochemically. Results: Amyloid was accumulated in the wall of cerebral blood vessels in 70% of dogs over the age of 10 years predominantly in the frontal cortex. CAA was demonstrated in elderly dogs as follows: in the frontal cortex (n = 19 or 63%), the parietal cortex (n = 12 or 40%), the hippocampus (40%) and the cerebellum (n = 5 or 17%). The deposits of amyloid in the wall of blood vessels detected by Congo red staining were also Aβ1-14 and Aβ1-42 immunohistochemically positive. Most commonly, the amyloid deposits affected a moderate number of blood vessels. The accumulation of amyloid was immunohistochemically revealed in the blood vessel walls as well as in the senile plaques and neurons. Conclusion: The amount of amyloid in the arterial walls increased with age in dogs, whereas the amyloid accumulated in plaques was Congo red negative.

Kit Receptor Expression in Canine Cutaneous Mast Cell Tumors (CMCTs) Without C-Kit Mutation

Abstract Histopathological examination, grading, immunohistochemical staining and molecular genetic examinations are the proposed criteria that should be used for cutaneous mast cell tumors (CMCTs) classification. The presence of aberrant CD117 expression and mutations of the c-kit proto-oncogene could be an indicative parameter for final histological grading. Determination of the connection between the localization of KIT receptor expression and the histological grade of CMCTs without c-kit proto-oncogene mutations was the main goal of this study. The study included twenty four CMCTs and six control skin samples from 30 dogs of different ages, breed and sex. Formalinfixed and paraffin-embedded tissue samples were stained with hematoxylin-eosin and toluidine blue and immunohistochemically tested for CD117 expression. DNA was extracted from the same paraffin blocks and subsequent polymerase chain reaction amplification was performed using PE1 and PE2 primers. Degree of malignancy was determined based on the presence of mitotic figures, multinucleated cells, bizarre nuclei and karyomegaly in 10 high power fields. Based on histological features, fourteen of 24 CMCTs were of a high histological grade, while ten were classified as a lowgrade malignancy. CD117 cytoplasmic expression was observed in nine of fourteen high-grade malignancy CMCTs, which confirms the link between the aberrant CD117 expression and increased cell proliferation.

Gastric Dilatation and Volvulus in Brown Bear (Ursus arctos)

Abstract Gastric dilatation and volvulus is a life-threatening condition characterized by rapid accumulation of food and gases that cause displacement and distension of the stomach. The large and giant, deep-chested breeds of dogs are at higher risk for developing the gastric dilatation and volvulus. Uncommonly, it can also develop in cats, but it is also described in free-range polar bears. A case of gastric dilatation and volvulus in a brown bear (Ursus arctos) is described in this paper. This case was characterized by lack of any previous symptoms, sudden death, as well as macroscopic findings during necropsy - twisted distended stomach, congested displaced spleen and necrotic gastric wall. According to the available data this is the first described case report of the gastric dilatation and volvulus in brown bear (Ursus arctos).

Morphological Features and KIT Receptor Expression in Canine Cutaneous Mast Cell Tumor and Systemic Mastocytosis / Morfološke Karakteristike I Ekspresija KIT Receptora Kod Kutanih Mastocitoma I Sistemske Mastocitoze Pasa

Abstract Mast cell neoplasia in dogs can occur in two different forms: common as cutaneous tumor, or less common as a systemic form of neoplastic mast cell proliferation - systemic mastocytosis. The aim of this study was to compare the histological and cytological features, KIT receptor expression and presence of c-KIT proto-oncogene mutations in neoplastic cells of dogs with canine cutaneous mast cell tumor (CMCT) and systemic mastocytosis. Microscopical examination of the cytological smears obtained from all selected dogs revealed that cellular specimens were constituted mostly of round cells with a central nuclei and fine to coarse purple cytoplasmic granules. Histopathological examination of skin samples of dogs with CMCT and a dog with systemic mastocytosis showed proliferation of the neoplastic mast cells in the superficial and/or deep dermis. Similar findings were observed in tissue samples derived from lymph nodes, spleen, liver, myocardium and kidneys of a dog with systemic mastocytosis. Three dogs with high grade CMCT as well as one dog with systemic mastocytosis showed cytoplasmic CD117 expression, while 3 dogs with low grade CMCT, had membranous expression of CD117. Based on our study, histological features and cytoplasmic CD117 expression in neoplastic cells of dogs with systemic mastocytosis are similar to those in dogs with high grade CMCTs. Nevertheless, mutations of c-KIT proto-oncogene were not found in tumor samples either from dogs with CMCT or dog with systemic mastocytosis. Neoplazme poreklom od mastocita mogu da se jave u dva različita oblika: uobičajeno kao kožni tumori - kutani mastocitomi ili ređe kao sistemska forma neoplastične proliferacije mastocita - sistemska mastocitoza. Svrha ovog istraživanja je da se uporede histološke i citološke karakteristike, ekspresija KIT receptora i prisustvo mutacija c-KIT proto-onkogena u neoplastičnim ćelijama kod pasa sa kutanim mastocitomima i sistemskom mastocitozom. Mikroskopskim pregledom citoloških razmaza svih ispitanih pasa utvrđeno je da se ćelijska populacija sastoji uglavnom od okruglih ćelija koje imaju centralno postavljeno jedro i sitne ljubičaste citoplazmatske granule. Histopatološkim pregledom uzoraka kože pasa sa kutanim mastocitomima i sistemskom mastocitozom zapaženo je umnožavanje mastocita u površinskom i/ili dubokom dermisu. Sličan nalaz uočen je i u isečcima tkiva limfnih čvorova, slezine, jetre, miokarda i bubrega psa sa sistemskom mastocitozom. Kod tri psa sa kutanim mastocitomima visokog stepena maligniteta, kao i kod psa sa sistemskom mastocitozom zapažena je citoplazmatska ekspresija CD117, dok je kod tri psa sa kutanim mastocitomima niskog stepena maligniteta uočena membranska ekspresija CD117. Na osnovu našeg istraživanja, histološke karakteristike i citoplazmatska ekspresija CD117 na neoplastičnim ćelijama su slične kod pasa sa sistemskom mastocitozom i pasa sa kutanim mastocitomima visokog stepena maligniteta. I pored toga, mutacije c-KIT proto-onkogena nisu uočene ni kod pasa sa kutanim mastocitomima, ni kod psa sa sistemskom mastocitozom.