Darko Marinković

The role of hepatic myofibroblasts in liver cirrhosis in fallow deer (Dama dama) naturally infected with giant liver fluke (Fascioloides magna).

BackgroundThis paper describes liver cirrhosis in 35 fallow deer infected with the giant liver fluke, as well as the distribution, origin, and role of myofibroblasts in its development.ResultsIn liver of infected deer, stripes of connective tissue are wound around groups of degenerated and regenerated liver lobuli. In the connective tissue, lymphocytes and macrophages which often contain parasite hematin are also present. The walls of the bile ducts are thickened, the epithelium multiplied with mucous metaplasia, and desquamated cells, parasite eggs and brown pigment are present in their lumen.In the livers with cirrhosis, immunopositivity to α-SMA and desmin was observed in cells in portal and septal spaces, at the edge between fibrotic septa and the surrounding parenchyma and in perisinusoidal spaces. These cells vary in size, they are round, oval, spindle-shaped or irregular in shape, similar to vascular smooth muscle cells. The derangement of epithelial-mesenchymal interactions detected in chronic cholangiopathies is most probably the pro-fibrogenic mechanism in liver cirrhosis of fallow deer (Dama dama) infected with the giant liver fluke (Fascioloides magna).ConclusionMyofibroblasts, especially hepatic stellate cells (HSCs), play an important role in the synthesis of extracellular matrix components in the development of parasitic fibrosis and cirrhosis in the liver of fallow deer.

Cellular basis of chronic obstructive pulmonary disease in horses.

Chronic obstructive pulmonary disease (COPD) is an inflammatory obstructive disease of the airways characterized with hypersensitivity of the airway tissues to various allergens, most commonly the fungi contained in the poor-quality hay and straw bedding-Saccharopolyspora rectivirgula, Aspergillus fumigatus, and Thermoactinomyces vulgaris. It is manifested clinically in middle-aged horses with recurrent episodes of dyspnea, chronic cough, and their reduced athletic and working capacity. Pulmonary emphysema and lack of pulmonary collapse are the most common gross lesion. Pathohistological findings in horses with COPD are chronic bronchitis/bronchiolitis, with characteristic changes in lumen, mucosa, submucosa, and smooth muscle layer and alveolar emphysema, both distensive and destructive form. Increased immunoreactivity in lungs and tracheobronchial lymph nodes is also noted. Most common lesions seen on cytology imprint smears from tracheal bifurcation is thick, viscous, PAS-positive mucus that forms Curschmanns spirals. Dominant cell population consists of desquamated airway epithelial cells, as well as eosinophils, neutrophils, mast cells, erythrocytes, and alveolar macrophages. Primary pulmonary pathogens as well as potential contaminants and secondary infection agents were isolated bacteriologically from lung samples. All of the aforementioned findings correlate pointing to the fact that chronic bronchitis/bronchiolitis represents a basic substrate of COPD, which have combined inflammatory and immunological etiology, and emphysema is secondary to airway obstruction.

An outbreak of fumonisin toxicosis in horses in Serbia

This paper reports on an outbreak of fumonisin toxicosis in a stable with 100 horses. Twenty-one horses were affected and fifteen died within a month. The animals were not febrile and exhibited poor appetite, somnolence, head pressing, blindness, ataxia, lethargy, and seizures, ending with death. The post mortem examination of the head of one 18-month-old colt revealed large, bilateral, slightly asymmetrical large areas of necrosis of the cerebral white matter. The lesions involved the frontal, parietal and occipital lobes only. Histological findings revealed leukomalacia with necrosis, infiltration of macrophages, neutrophils and eosinophils, haemorrhage and oedema of the surrounding grey matter. In response to the pathological findings, which indicated equine leukoencephalomalacia (ELEM), feed samples from the premises were tested for fumonisin B1 and B2 (FB1 and FB2). The milled maize samples contained 6.0 mg/kg FB1 and 2.4 mg/kg FB2, while the maize bran contained 6.05 mg/kg FB1 and 1.68 mg/kg FB2. Th...

Role of hepatic stellate cells (HSCs) in the development of hepatic fibrosis in cats with polycystic kidney disease (PKD).

Hepatic stellate cells (HSCs) play a significant role in hepatic fibrogenesis. In the following study we described the distribution of cells that express alpha-smooth muscle actin (α-SMA) and desmin in the cat liver with various degrees of fibrosis, as well as the significance of hepatic stellate cells and portal myofibroblasts in the genesis of fibrosis in cats with polycistic kidney disease. Liver samples from 15 necropsied Persian cats were examined microscopically, using H&E and Masson-trichrom methods and immunohistology for α-SMA and desmin. Liver fibrosis was confirmed in cats with terminal stage of chronic cholangiohepatitis and it was characterized by connective tissue septa which divide the liver parenchyma into irregular lobuli. Inflammation in the cat liver is connected with the activation of periductal myofibroblasts. The intensity of immunopositivity of perisinusoidal HSCs to α-SMA and desmin varied depending on the degree of fibrosis and was the strongest in livers of cats with cirrhosis.

Retrospective study of canine epithelial and melanocytic tumors

Out of the total number of canine tumors examined at the Department of pathology based on biopsy and section materials over the last five years skin tumors and mammary gland tumors were proved to be the two largest groups diagnosed in 33.4% and 36% of cases, respectively. Cutaneous tumors were diagnosed in 211 cases, i.e., in 123 (58.3%) male dogs and 88 (41.7%) bitches, of different breeds, on average 7 years old. Among the total number of 211 skin tumors, 32 types of cutaneous neoplasms were diagnosed, with epithelial and melanocytic tumors being the most predominant, followed by hematopoietic tumors and mesenchymal tumors of the skin and soft tissues. In our bioptic and section materials, epithelial and melanocytic skin tumors were the most frequent -123 cases (58.75%) with four subgroups within the group tumors with adnexal differentiation - 66 cases (53.23% of all epithelial and melanocytic skin tumors), epidermal tumors - 25 cases (20.16% of all epithelial and melanocytic skin tumors), tumors without squamous or adnexal differentiation -16 cases (12.90% of all epithelial and melanocytic skin tumors) and finally melanocytic tumors -14 cases (11.29% of all epithelial and melanocytic skin tumors). The age of dogs with epithelial and melanocytic cutaneous tumors ranged between 5 months to 15 years. The fact that the number of skin tumors diagnosed in 1999 was doubled in 2002 is of particular importance, which may be, the result of increasingly high interest of clinicians for biopsy-based diagnosis.

MORPHOLOGICAL AND IMMUNOHISTOCHEMICAL EXAMINATION OF TUMOR CELLS IN MAREK'S DISEASE

In this paper are described the macroscopic, microscopic and immunophenotypic characteristics of tumors in Marek’s disease (MD). Liver, kidneys, lungs, heart, proventriclus, ovary and nerves of sciatic plexus collected from 20 chickens aged 8 to 24 weeks were examined. Lymphoproliferative enlargement in various organs of focal and diffuse character was found. The affected organs were enlarged, compact and very brittle, irregular in shape, grayish-red or grayish-white and of fatty consistency. Most often characteristic changes were in the spleen, liver, proventriculus and ovary that usually had a compact or ribbed, fatty cauliflower like formation, different in size. On histological examination proliferation of small and medium size lymphocytes, lymphoblast cells, Marek’s disease cells and activated reticulum cells were found. Tumor proliferates predominantly consisted of lymphoblasts and had all the characteristics of a lymphoma. Immunohistochemical analysis revealed that lymphoma cells in MD are of CD3 + phenotype. In liver proliferates numerous CD79+ cells were found perivasculary, which is an interesting finding demanding further research. .

Cytological And Molecular Identification Of Haemogregarina Stepanowi In Blood Samples Of The European Pond Turtle (Emys Orbicularis) From Quarantine At Belgrade Zoo

Abstract Blood smears stained with Diff Quick are the initial tool for cytological diagnosis of Haemogregarina spp. However, the development of sensitive and specific molecular methods enabled the detection and identification of parasites in the sample and to clarify the evolutionary relationships of adeleorinid parasites within the Apicomplexa. The current study was attempted in order to perform cytological investigation and molecular identification of the hemoparasites in thirty European pond turtles (Emys orbicularis) from the quarantine section at Belgrade Zoo, which have been found in poor health condition with massive skin hemorrhages, based on intraerythrocytic parasitic forms on hematological smears and 18S rDNA sequence, respectively. Different life cycle stages of the Haemogregarina sp. were noticed within the erythrocytes in the peripheral blood. Biochemical analysis indicated lower values of AST and iron in most of the infected turtles while hematological analysis showed a changed hematocrit value, a decrease in the number of red blood cells and low hemoglobin levels. Amplifications of the 18S rDNA sequence of Haemogregarina were detected in 30/30 (100%) turtles with clinical symptoms. The identity of PCR products was confirmed by direct DNA sequencing. Future research concerning H. stepanowi in Serbia should be applied to its definitive host-the leech.

Helicobacter spp. In gastroscopic biopsies in dogs

This paper includes 50 dogs, differing in breed and sex, from 3 months to 12 years of age: 26 samples of endoscopic stomach biopsies were taken from ill animals which displayed chronic vomiting, 12 endoscopic biopsy samples of healthy dogs and 12 stomach samples of autopsied dogs. Helicobacter spp. and Gastrospirillum hominis findings were confirmed in 20 of the 26 ill dogs, 8 of the 12 autopsied animals, and 2 of the 12 healthy animals by histopathology and direct gastric tissue smears. In 26 endoscopic biopsies various clinical and endoscopic findings (7 cases of erosive and 4 of ulcerous gastritis, 12 cases of chronic gastritis and 2 of gastric reflux) were previously determined. Histopathological examination of stomach mucosa of 5 autopsied and Helicobacter positive dogs determined focal lymphocyte infiltrations, mainly located in the subglandular region. Along with such lymphocyte accumulations, in certain cases a diffuse infiltrate consisting of eosinophilic granulocytes and plasma cells was also present. In most biopsied samples, stained with hematoxylin-eosin, histopathological changes were not observed, except in 5 dogs where diffuse lymphocyte infiltration of the mucosa was noted and in two dogs with signs of chronic gastritis, that is hypertrophy and stratification of the mucosa epithelium, and with lymphocyte and plasmocyte infiltration. By modified Giemsa staining of 20 of the endoscopically biopsied animals, spiral microorganisms with varying numbers of spiral curves were observed, which were similar to the necropsy stomach mucosa samples, belong to various types of Helicobacter spp, and some of them morphologically correspond to Gastrospirillum hominis.

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.