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  • Author: Ivana Aleksic x
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Abstract

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial inflammation and destruction of joint cartilage and bone. Different cytokines play important role in the processes that cause articular destruction and extra-articular manifestations in RA. The contribution of cytokines representing the Th1 (INF-γ), Th2 (IL-4) and IL-17A to the pathogenesis of early RA and bone mineral density (BMD) loss in still poorly understood. Serum samples of 38 early RA patients were evaluated for erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), C-reactive protein (CRP), anti-cyclic citrullinated peptide antibodies (anti-CCP) and for the tested cytokines (IL-17A, IL-4 and INF-γ). BMD was evaluated by dualenergyX-ray absorptiometry (DXA). Disease activity score (DAS28) calculation was assessed for all patients. Control serum samples were obtained from 34 healthy volunteers. The levels of tested cytokines were significantly higher (IL-17A, p<0.001; INF-γ, P<0.001; IL-4, P<0.01) in patients with early RA, compared to the healthy controls. In early RA patients, strong correlation of serum IL-17A was found with DAS28, ESR and CRP. Also, a significant negative correlation was found between serum INF-γ levels and the DAS28 score. Significantly positive correlation of BMD values and CRP, DAS28 IL-17A were also demonstrated. DXA analysis revealed that the most common site for osteoporosis was the lumbar spine followed by the femoral neck. BMD values significantly correlated with CRP, DAS28 score and IL-17A serum levels. The mean serum IL-17A levels, in patients with early RA, corresponded with disease activity, severity and BMD loss, indicating the potential usefulness of serum IL-17A in defining the disease activity and bone remodeling.

Abstract

Swine respiratory diseases represent one of the most frequent health issues in pig production worldwide. Despite the great progress that has been made in the field of diagnostics, control and prophylaxis, respiratory diseases still remain the most challenging health problem in modern commercial pig production. The list of infectious agents that cause respiratory diseases in swine is extensive and includes both, bacterial and viral pathogens. In Serbia, more than fifteen years after the introduction of modern vaccines, the list of bacterial pathogens related to swine respiratory infections still include Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae, Haemophilus parasuis and Pasteurella multocida. On the other hand, most commonly involved viral pathogens are Porcine Reproductive and Respiratory Syndrome Virus, Swine influenza virus, Porcine circovirus type 2 and Pseudorabies virus. The morphological features of pneumonia where several agents are involved, depend on the predominant etiological agent. Expanding knowledge of the main pathogens associated with swine respiratory diseases and the effects of their interactions on the disease outcome is important for further investigations of lung diseases and implementation of control strategies in commercial pig populations in Serbia. This review discusses the latest findings on swine respiratory disease and current trends in Serbian pig production.

Abstract

Eight lovebirds of both sexes and different age were admitted showing alterations in behaviour and apathy. During the initial examination delamination of the beak was noted in all birds and discrete areas of alopecia in three of eight birds. Based on clinical experience, molecular diagnostic on PBFD, sequencing of obtained amplicons, and histopathological examination were performed. All birds tested positive on the presence of PBFD virus, despite the fact they did not exhibit expected clinical signs for PBFD. Sequencing results showed 100% match with sequences previously isolated from parrots with PBFD exhibiting classical PBFD manifestation. Histopathological examination showed similar findings as in previously described cases of PBFD in parrots. Other studies on psittacine birds correlate clinical manifestations and nucleotide variations with geographic localization. Our results indicate that the clinical manifestation of the disease is more dependent on bird species than on the genetic variation of the virus or the geographical distribution.

Abstract

Peripheral nerve sheath tumors (PNSTs) comprise a heterogeneous group of neoplasms originating from the elements of the nerve sheath. They are divided into two forms: benign and malignant PNST. Both benign and malignant PNSTs are not very common in domestic animals but they are reported in different animal species. Histologically, PNSTs are composed predominantly of spindle cells arranged in bundles, whorls and sheets, with a different number of pleomorphic cells and mitotic figures.

The aim of this study was a reclassification of 17 dog tumor samples initially diagnosed with peripheral nerve sheath tumors using histopathological analysis. The main criterion for reclassification was immunohistochemical positivity for various antigens.

PNSTs are often histologically very similar to other spindle cell tumors and immunohistochemistry is required for differential diagnosis. PNSTs generally express vimentin, S-100 protein, glial fibrillary acidic protein (GFAP), collagen IV and laminin.

Four tumor samples were positive to muscular marker α-SMA and vimentin and negative for S-100 protein and desmin. The spindle cells whirling around some blood vessels were observed in these tumors so they were reclassified as perivascular wall tumors (PWTs). The other 13 tumors were S-100 protein and vimentin positive and α-SMA and desmin negative, thus classified as PNST.

The use of the immunohistochemical panel is necessary for distinguishing PNSTs from PWTs in routine diagnostics.

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.

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.

Abstract

Canine distemper virus (CDV) is a worldwide distributed RNA virus that can cause severe disease in carnivore and non-carnivore species. Red foxes are highly susceptible and may act as a reservoir of the virus. As in other wild species, distemper in red foxes can manifest as acute, systemic and chronic nervous form. In the present study, we detected antibodies against CDV among red foxes in Western Serbia, and analyzed histopathologically and immunohistochemically for CDV nuclear protein antigen (CDV-NP) brain samples derived from seropositive animals. Seroprevalence of CDV antibodies was 36.8%. Histopathological changes included gliosis, neuronal degeneration, satellitosis, mononuclear inflammation, demyelination and presence of inclusion bodies. Immunostaining showed a diffuse presence of CDV-NP antigen, mainly in the cytoplasm of astrocytes and neurons. Results of this work contribute to the opinion that red foxes act as a potential reservoir of CDV and underline the importance of routine vaccination of dogs that could come in close contact with these animals. Potential active surveillance program would give a better insight in the degree of CDV infection in wildlife.

Abstract

During the epizootic of highly pathogenic avian influenza subtype H5N8 in Serbia in the winter of 2016-2017, the highest percent of mortality due to this infection was recorded in mute swans (Cygnus olor). Besides mute swans, avian influenza virus subtype H5N8 was also diagnosed in a small number of hens in rural households. Pancreatic tissues from avian influenza H5N8 positive mute swans and hens that died during this outbreak were collected to determine the character of morphological lesions and the distribution of the viral antigen in this organ. Macroscopic examination of the pancreas of mute swans revealed hemorrhages as well as necrosis, while there were no macroscopic visible lesions in the pancreas of infected hens. Despite the different macroscopic finding, microscopic examination of the pancreas of both infected bird species revealed lesions in the form of acute pancreatitis and multifocal acinar necrosis. The viral antigen was abundantly expressed in the cytoplasm and nucleus of necrotic cells, as well as in macrophages in both examined bird species. Immunohistochemical expression of the viral antigen in the pancreas was strongly consistent with histological lesions. According to the above described findings, it could be concluded that highly pathogenic avian influenza virus H5N8 has a high affinity to pancreatic tissue in both mute swans and hens and the distribution and the character of the lesions in the pancreas are similar in both bird species.

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.