Neuroendocrine cells are of the peptide and amine secreting cells and because of endodermal origin, exist in respiratory and gastrointestinal system. The report confirms the presence of a tumor using immunohistochemical methods. A hepatic mass was detected in a 10-year-old male mixed–breed dog which was referred with clinical history of frequent vomiting, anorexia, lethargy and syncope. Biochemical and hematological abnormalities included elevation of ALT and AST levels, leukocytosis and anemia. Radiographically the large hepatic mass and multifocal metastatic nodular areas in the other organs were observed. At necropsy the liver had a multilobulated firm mass involving whole caudate lobe of the liver. On the cut section, the tumor was grey sanguineous with hemorrhagic surface and numerous necrotic foci. Microscopically, there were unencapsulated, highly cellular neoplastic proliferations with few hemorrhagic foci in the liver that had a trabecular pattern to Rosette formation which were separated by a fibrovascularstroma. The neoplastic cells were round to oval, with granular eosinophilic cytoplasm and hyperchromatic nuclei. Metastases were observed in lungs, kidneys, mesenteric lymph nodes and even in the arteries of the tunica albuginae of the testes. Immunohistochemically, neoplastic cells were immunoreactive for NSE and S100 protein. They were negative for CEA, Chromogranine A, CD34, AE1/AE3, CK20 and Hepatic Antigen (HA). Negative CEA, CK20, CD34 and HA disproved the probability for collangiocarcinoma, metastatic carcinoma, hematopoietic and vascular origin and hepatocellular carcinoma of this tumor respectively. Immunohistochemical demonstration of NSE and S100 protein supported the diagnosis of the Carcinoid like. However, negative reaction for Chromogranine A does not disprove neuroendocrine carcinoma diagnosis.

Testin is a protein involved in cell mobility, adhesion and colony formation. In rats, testin presence has been reported in the testes, and its possible role in spermatogenesis has been suggested. Studies in humans also suggest a possible role of testin as a cancer suppressor protein. In the dog, which represents both an important pet species and a good animal model for studying biological and pathological testicular processes, the presence of testin has never been reported.

Enhancer of zeste homologue 2 (EZH2) is the human homologue of Drosophila zeste gene enhancer. The aim of this study was to determine the expression of EZH2 in canine mammary carcinomas (CMCs) and its relationship with clinicopathological features. The expression of EZH2 mRNA and protein in 53 CMC tissue and 8 normal mammary gland tissue samples was measured by quantitative real-time PCR and immunohistochemical staining assay, respectively. The relationship between EZH2 protein expression and clinicopathological features was analysed by χ2 test to further explore the clinical significance of EZH2 in CMCs. Compared with normal mammary gland tissues, EZH2 mRNA expressions were significantly increased in CMC tissues (P < 0.01). Moreover, normal mammary glands did not express the EZH2 protein but carcinomic glands did, and expression increased in CMCs with high histological grades, especially in histological grade II (P < 0.05). However, EZH2 expression was not related to age, tumour size, or metastasis (P > 0.05). The expression of EZH2 in one type of CMC was not significantly different from the expression in any other type (P > 0.05). EZH2 is highly expressed in CMCs, indicating that it can be used as a molecular marker for early diagnosis, prognosis, or therapy of CMCs.

Coinfection of goose parvovirus (GPV) and duck circovirus (DuCV) occurs commonly in field cases of short beak and dwarfism syndrome (SBDS). However, whether there is synergism between the two viruses in replication and pathogenicity remains undetermined. We established a coinfection model of GPV and DuCV in Cherry Valley ducks. Tissue samples were examined histopathologically. The viral loads in tissues were detected by qPCR, and the distribution of the virus in tissues was detected by immunohistochemistry (IHC). Coinfection of GPV and DuCV significantly inhibited growth and development of ducks, and caused atrophy and pallor of the immune organs and necrosis of the liver. GPV and DuCV synergistically amplified pathogenicity in coinfected ducks. In the early stage of infection, viral loads of both pathogens in coinfected ducks were significantly lower than those in monoinfected ducks (P < 0.05). With the development of the infection process, GPV and DuCV loads in coinfected ducks were significantly higher than those in monoinfected ducks (P < 0.05). Extended viral distribution in the liver, kidney, duodenum, spleen, and bursa of Fabricius was consistent with the viral load increases in GPV and DuCV coinfected ducks. These results indicate that GPV and DuCV synergistically potentiate their replication and pathogenicity in coinfected ducks.

This study determined the presence of nitric oxide synthesis isoforms (nNOS, iNOS, and eNOS) in thoracic spinal cord segments and nodose ganglia of rats with gamma-irradiated livers. Male rats (n = 32) were divided into equal groups A, B, C, and D. In group A, the controls, no radiation was applied, while groups B, C, and D received 10 Gy of ionising gamma radiation. The rats of group B were euthanized at the end of the first day (d1), those of group C on the second day (d2), and those of group D on the third day (d3). The liver, spinal cord segments, and nodose ganglion tissues were dissected and fixed, and the liver sections were examined histopathologically. The other tissues were observed through a light microscope. Regeneration occurred at the end of d3 in hepatocytes which were radiation-damaged at the end of d1 and d2. On d1, some nNOS-positive staining was found in the neuronal cells of laminae I–III of the spinal cord and in neurons of the nodose ganglion, and on d3, some staining was observed in lamina X of the spinal cord, while none of note was in the nodose ganglion. Dense iNOS-positive staining was seen on d1 in the ependymal cells of the spinal cord and in the glial cells of the nodose ganglion, and on d3, there was still considerable iNOS staining in both tissues. There was clear eNOS-positive staining in the capillary endothelial cells of the spinal cord and light diffuse cytoplasmic staining in the neurons of the nodose ganglion on d1, and on d3, intense eNOS-positive staining was visible in several endothelial cells of the spinal cord, while light nuclear staining was recognised in the neurons of the nodose ganglion. The nNOS, iNOS, and eNOS isoforms are activated in the spinal cord and nodose ganglion of rats after ionising radiation insult to the liver.

The study of histopathological changes caused by influenza A (H5N8) viral infection in bird species is essential for the understanding of their role in the spread of this highly infectious virus. However, there are few such studies under natural conditions in minor gallinaceous species. This article describes the pathomorphological findings in Colchis pheasants infected naturally with H5N8 during an epizootic outbreak in Bulgaria. Samples of internal organs of 10 carcasses were collected for histopathological and immunohistochemical evaluation, virus isolation and identification, and nucleic acid detection. Consistent macroscopic findings were lesions affecting the intestine, heart, lung, and pancreas. Congestion and mononuclear infiltrate were common findings in the small intestine, as were necrosis and lymphoid clusters in the lamina propria of the caeca. Congestion with small focal necrosis and gliosis with multifocal nonpurulent encephalitis were observed in the brain. Myocardial interstitial oedema and degenerative necrobiotic processes were also detected. Immunohistological analysis confirmed systemic infection and revealed influenza virus nucleoprotein in all analysed organs. Variable necrosis was observed in the brain, liver, trachea, heart, small intestine, and caeca. Viral antigen was commonly found in the brain, heart, lung and trachea. Contact with migrating waterfowls was suspected as a reason for the outbreak.

Glucagon-like peptide-1 (GLP-1) is a polypeptide that is mainly produced by intestinal L cells and is encoded by the proglucagon gene. In this study, GLP-1 localisation was investigated in the ileum of healthy and diabetic mice by immunohistochemistry and proglucagon gene expression was assayed by reverse transcription-polymerase chain reaction. This study included 18 male Balb/c mice that were divided into diabetic, sham, and control groups. Mice in the diabetic group received 100 mg/kg of streptozotocin. Immunohistochemical expression of GLP-1 was determined using the avidin–biotin–peroxidase complex technique, and proglucagon gene expression was determined by RT-PCR. Analysis of GLP-1 immunohistochemical localisation showed that GLP-1-immunopositive cells (L cells) were present between epithelial cells in the intestinal crypts. The intensity and localisation of GLP-1 immunoreactivity were similar among the mice in all the groups. Proglucagon gene expression levels were also statistically similar among the mice in all the groups. No difference was demonstrated among the mice in the diabetic, sham, or control groups with respect to proglucagon gene expression and GLP-1 localisation in the ileum, suggesting that diabetes does not affect proglucagon gene expression in the ileum.

p63 is a homologous molecule of p53 and was recently identified as playing important roles in several key cellular processes, including epithelial development and proliferation. Since then, several studies have demonstrated altered p63 expression in various cancers of epithelial origin. Canine perianal gland tumour is one of the most common skin neoplasms in dogs; however, the molecular characteristics of this tumour remain poorly understood. The objective of the present study was to analyse and compare the expression of p63 in canine perianal gland adenomas and carcinomas.

This study consisted in histopathological and immunohistochemical examinations of the central nervous system of 15 sheep suspected of infection with Coenurus cerebralis. The sheep displayed compulsive circling and were submitted for necropsy in 2012–2016.

Immunohistochemical studies have become an indispensable element of establishing the correct histopathological diagnosis of poorly differentiated lesions, proving particularly suitable, and occasionally indispensable, for diagnosis of poorly differentiated neoplastic tumours. Knowledge of the mechanism of action and normal reaction of individual proteins is required in selection of the antibody pattern for a given tissue and in evaluation of the obtained results. This paper aims to promote the application of immunohistochemical techniques in routine diagnosis, especially in cases of poorly differentiated or undifferentiated tumours.