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Biomedical subjects

A Kipar

Publications and source records attributed to A Kipar.

32 records · Page 2Linked to original sources
PubMed2001

Bilateral focal cerebral angiomatosis associated with nervous signs in a cat.

A case of cerebral angiomatosis in a cat was associated with neurologic signs characterized by clusters of severe generalized seizures. Bilaterally in the gray matter, most prominent in the cingulate gyrus, there was focal accumulation of garlandlike arrangements of blood vessels. Vessels exhibited activated, hypertrophic endothelial cells and thickening and progressive dystrophic mineralization of the basement membrane, with complete luminal obstruction of some affected vessels. Thickening of the basement membrane was due to accumulation of endothelium-derived proteins such as laminin and von Willebrand factor. Furthermore, moderate diffuse astrogliosis was observed. Findings indicate an idiopathic angiomatosis, with clinical signs possibly due to ischemia resulting from narrowing or complete obliteration of vessel lumina. Changes represent a unique endothelial cell-derived lesion within the brain not previously described in humans or domestic animals.

Angiomatosis↗
PubMed2001

Comparative examination of cats with feline leukemia virus-associated enteritis and other relevant forms of feline enteritis.

Cats with feline leukemia virus (FeLV)-associated enteritis (FAE), enteritis of other known viral etiology (parvovirus [PV], enteric coronavirus [CoV]), and enteritis of unknown etiology with histologic features similar to those of FAE and PV enteritis (EUE) and FeLV-negative and FeLV-positive cats without enterocyte alterations were examined. Amount and types of infiltrating leukocytes in the jejunum and activity and cellular constituents of mesenteric lymph nodes, spleen, and bone marrow were determined. PV and CoV infections were confirmed by immunohistologic demonstration of PV and CoV antigen, ultrastructural demonstration of viral particles in the intestinal content, and in situ hybridization for PV genome. FeLV infection was detected by immunohistology for gp70, p27, and p15E. Latent FeLV infection was excluded by polymerase chain reaction methods for exogenous FeLV DNA. Enterocyte lesions involved the crypts in cats with PV enteritis, FAE, and EUE and the villous tips in cats with CoV enteritis. Inflammatory infiltration was generally dominated by mononuclear cells and was moderate in the unaltered intestine and in cats with PV enteritis and marked in cats with FAE, CoV enteritis, and EUE. In cats with EUE, myeloid/histiocyte antigen-positive macrophages were relatively numerous, suggesting recruitment of peripheral blood monocytes. Lymphoid tissues were depleted in cats with PV enteritis and with EUE but were normal or hyperplastic in cats with FAE. Bone marrow activity was decreased in cats with PV enteritis; in cats with FAE or EUE and in FeLV-positive cats without enterocyte alterations, activity was slightly increased. In cats with FAE and PV enteritis, a T-cell-dominated response prevailed. EUE showed some parallels to human inflammatory bowel disease, indicating a potential harmful effect of infiltrating macrophages on the intestinal epithelium.

Animals↗
PubMed2000

Expression of viral proteins in feline leukemia virus-associated enteritis.

Fourteen cases of feline leukemia virus (FeLV)-associated enteritis were immunohistologically examined for the expression of FeLV proteins gp70, p27, and p15E in the jejunum, mesenteric lymph nodes, spleen, and bone marrow. Results were compared with those of FeLV-infected cats without intestinal alterations. Other viral infections and specific bacterial, fungal, and parasitic infections were excluded by standard microbiologic methods, histopathology, immunohistology, and in situ hybridization. In FeLV-associated enteritis, FeLV gp70 and p15E were strongly expressed in intestinal crypt epithelial cells. In contrast, FeLV-positive cats without intestinal alterations showed only faint staining for gp70 and p15E and comparatively strong p27 expression in these cells. Findings suggest a direct relation between FeLV infection and alterations in intestinal crypt epithelial cells that may be attributed to the envelope proteins gp70 and p15E and/or their precursor protein. Distinct similarities to the intestinal changes in the experimentally induced FeLV-feline AIDS syndrome are obvious, suggesting that naturally occurring feline AIDS variants may be responsible for FeLV-associated enteritis.

Animals↗
PubMed1999

Feline infectious peritonitis presenting as a tumour in the abdominal cavity.

This paper describes six cases of feline infectious peritonitis (FIP) in which an abdominal tumour had been suspected clinically. Pathological changes were mainly restricted to the massive enlargement of a mesenteric lymph node due to necrogranulomatous lymphadenitis. FIP was diagnosed on the basis of the immunohistological demonstration of coronavirus antigen in intact macrophages within the necrogranulomatous lesions. In the affected lymph node lymphoid tissue was either almost completely effaced or restricted to follicles composed mainly of variable numbers of blasts. From one to many plasma cells positive for coronavirus-specific antibodies were present in the marginal sinuses or capsules. In addition, necrogranulomas were present in the gut-associated lymphoid tissue of the caecum of one cat, and adjacent to the affected lymph node of another.

Abdominal Neoplasms↗
PubMed1998

Cellular composition, coronavirus antigen expression and production of specific antibodies in lesions in feline infectious peritonitis.

Twenty-three cats with spontaneous feline infectious peritonitis (FIP) were examined by light microscopy including immunohistology and histochemistry in order to determine the cellular composition and the expression of viral antigen in lesions in FIP. Furthermore, the presence of plasma-cells producing coronavirus-specific antibodies was evaluated in situ. Macrophages and neutrophils were demonstrated by an antibody against calprotectin (leukocyte protein L1, myeloid/histiocyte antigen), neutrophils were recognized due to their chloroacetate esterase activity, and B- and T-lymphocytes were identified by antibodies against the CD3 antigen and the CD45R antigen, respectively. Expression of viral antigen was immunohistologically demonstrated by a monoclonal antibody (mAb) against coronavirus while coronavirus-specific antibodies in situ were identified by the application of feline coronavirus prior to the coronavirus antibody. Lesions were classified as diffuse alterations at serosal surfaces, granulomas with areas of necrosis, granulomas without extended necrosis, focal and perivascular lymphoplasmocytic infiltrates, and granulomatous-necrotizing vasculitis. Diffuse alterations on serosal surfaces were represented either by activated mesothelial cells with single coronavirus antigen-bearing macrophages or by layers of precipitated exudate containing single to numerous granulomas with areas of necrosis. In liver and spleen, the exudate was often underlaid by a small band of subcapsular B-cells with an occasional plasma-cell producing coronavirus-specific antibodies. In other locations, a variably broad band of B-cells and plasma-cells, often infiltrating between underlying muscle fibers, separated the exudate from the unaltered tissue. Some of these plasma-cells were positive for coronavirus-specific antibodies. In granulomas with areas of necrosis, the central necrosis was surrounded by macrophages usually expressing considerable amounts of viral antigen. Few B-cells and plasma-cells were found in the periphery. In granulomas without extended necrosis, the number of macrophages were lower. Only few macrophages expressing low amounts of viral antigen were present. B-cells and plasma-cells formed a broad rim. Few plasma-cells stained positive for coronavirus-specific antibodies. In both types of granulomas, few neutrophils were found between macrophages. Few T-cells were seen scattered throughout the lesions. Focal and perivascular lymphoplasmocytic infiltrates were mainlyseen in omentum and leptomeninx. B-cells were the predominant cells; some plasma-cells were positive for coronavirus-specific antibodies. Viral antigen was not readily detected in these alterations. Granulomatous-necrotizing vasculitis was occasionally found in kidneys and leptomeninx. It was dominated by macrophages which often stained strongly positive for coronavirus antigen. Different types of alteration were often seen in the same animal and even the same tissue. There was no obvious correlation between the cat's age, gross pathological changes, and the histological types of alteration. Single plasma-cells positive for coronavirus-specific antibodies were found around blood vessels distant from inflammatory alterations, within the lung parenchyma, as infiltrating cells in the mucosa of the small intestine, and in spleen and mesenteric lymph node. Results show that alterations in FIP are heterogeneous concerning cellular composition and expression of viral antigen. The dominance of B-cells in part of the lesions together with the presence of plasma-cells positive for coronavirus-specific antibodies indicate that these cells may play a role in the maintenance of inflammatory processes in FIP.

Animals↗
PubMed1998

Expression of major histocompatibility complex class II antigen in neoplastic cells of canine cutaneous histiocytoma.

Forty five cases of canine cutaneous histiocytoma (CCH) were examined by immunohistology for expression and distribution of major histocompatibility complex (MHC) class II antigen in neoplastic cells. In addition, expression of lysozyme and calprotectin (leucocyte protein L1) in neoplastic cells was investigated. Furthermore, B and T lymphocytes were demonstrated by antibodies against the CD3 antigen, IgG, and IgM. Neoplastic cells showed two staining patterns for MHC class II antigen: focal juxtanuclear cytoplasmic staining and/or rim-like staining along the cell periphery. In 24 cases, a predominant or exclusive focal juxtanuclear cytoplasmic MHC class II antigen reaction in neoplastic cells, and the presence of few diffusely distributed infiltrating CD3 antigen-positive T lymphocytes were observed. Tumors with numerous neoplastic cells exhibiting staining for MHC class II antigen along the cell periphery (n = 21) showed increased inflammatory alterations, represented by disseminated and nodular infiltrations of mainly CD3 antigen-positive T cells. B cells, plasma cells, exudate macrophages, and neutrophils were rarely seen disseminated between neoplastic cells whereas their number increased within focal inflammatory infiltrates. The focal cytoplasmic reaction for MHC class II antigen in neoplastic cells might represent newly synthesized MHC class II molecules stored in vesicles, whereas staining of the cell periphery might occur due to accumulation of MHC class II molecules along the plasma membrane. The increasing expression of MHC class II molecules on the cell surface might be the decisive factor for onset and progression of tumor regression. However, the exact mechanism of priming and activation of T cells by neoplastic cells and the nature of the presented antigen are not yet known.

Animals↗
PubMed1998

Fatal enteritis associated with coronavirus infection in cats.

This report describes five cases of naturally occurring feline coronavirus enteritis. The affected animals, aged 2 months to 7 years, had a clinical history of intestinal symptoms, including diarrhoea or vomiting, or both. They exhibited variable histological changes in the epithelium of the small intestine, ranging from degeneration of single cells and detachment of groups of cells from the villous tips to regenerative processes of the crypt epithelia. Post-mortem diagnosis was based on the immunohistochemical demonstration of coronavirus antigen within intestinal epithelial cells and on the electron microscopical demonstration of coronavirus particles in the faeces. In addition, one animal was immunohistochemically positive for antigens of feline leukaemia virus (FeLV) and exhibited intestinal changes consistent with FeLV-associated enteritis. Two cats were tested serologically for feline immunodeficiency antibodies, with negative results. The findings indicate that natural coronavirus infection is a potential cause of severe enteritis in juvenile and adult cats.

Animals↗
PubMed1998

Immunohistochemical characterization of inflammatory cells in brains of dogs with granulomatous meningoencephalitis.

The inflammatory cells of eleven dogs with canine granulomatous meningoencephalitis were characterized immunohistochemically. Macrophages were identified by antibodies directed against lysozyme and the DH82 antigen (expressed by cells of a malignant histiocytosis). T cells were demonstrated by CD3, CD43, and CD45R antigen, and B cells by immunoglobulin G and immunoglobulin M expression. Furthermore, staining for the major histocompatibility complex (MHC) class II antigen was evaluated. Diseased animals ranged from 1 to 9 years of age. Small and medium-sized breeds were affected predominantly. Lesions were widespread and localized mainly in the brain stem, less frequently in the cerebrum or cerebellum. Alterations were represented by perivascular cuffs, parenchymal granulomas, and leptomeningeal infiltrates. Lymphocytes and macrophages comprised the dominant cell populations; their percentage varied substantially between different animals and between sections from the same individual. Immunohistochemically, the bulk of lymphocytes were CD3 antigen-positive T cells, while only a few cells were CD43 and CD45R antigen-positive or were classified as B cells. The majority of macrophages expressed both lysozyme and DH82 antigen; however, some were positive for only one antigen. MHC class II antigen-expression, observed only within and in close proximity to the lesions, was found on all inflammatory cells, pericytes/endothelial cells, and microglia. Results were negative for canine distemper virus antigen and nucleoprotein mRNA, rabies virus antigen, fungi, bacteria, and protozoal agents. This immunomorphologic study reveals that inflammatory lesions in canine granulomatous meningoencephalitis consist of a heterogeneous population of MHC class II antigen-positive macrophages and predominantly CD3 antigen-positive lymphocytes. The data suggest a T cell-mediated delayed-type hypersensitivity of an organ-specific autoimmune disease as a possible pathogenic mechanism for this unique canine brain lesion.

Animals↗
PubMed1995

Round cell sarcomas of possible myelomonocytic origin localized at the lip of aged dogs.

Four round cell tumors, situated at the lip of dogs older than 4 years of age, which could not be further classified, were examined light and electron microscopically, immunocytochemically and in part functionally and cytochemically. Immunocytochemically they were positive for vimentin, but negative for cytokeratin, desmin, neurofilament, synaptophysin, S-100 protein, neuron specific enolase, lysozyme, IgG and a pan-T-cell marker. Cell lines were established from two malignant neoplasms. In vitro, neoplastic cells had morphological, functional and cytochemical properties of myelomonocytic cells. A tumor cell-specific polyclonal rabbit antiserum reacted immunocytochemically positive with primary and recurrent tumors and metastases of the original and the three other round cell tumors. Immunoblotting demonstrated a main band with approximately 65-75 kDa. All four tumors were present in aged dogs and metastasized. They most likely represent a distinct group of malignant tumors among the canine round cell tumors.

Aging↗
PubMed1995

[Two mesenchymal tumor cell lines for the determination of natural killer (NK) cell activity in the peripheral blood of dogs].

The two mesenchymal cell lines K1 and K6 were established from round cell tumours located at the lips of two dogs. Both cell lines were characterized as being of myelomonocytic origin by morphological, cytochemical, immunocytochemical and functional criteria. In the 51chromium release assay (effector/target cell ratio 100/1) the K6-cell line revealed a mean cytotoxic sensitivity of 53.6% and thus showed a susceptibility similar to that of the epithelial CTAC line (57.8%). The K1-cell line exhibited less cytotoxic activity (41%) when incubated for 14 h, but showed results comparable to the K6-cell line, when the incubation time was reduced to 8 h.

Animals↗
PubMedDate not supplied

A comparison of lymphatic tissues from cats with spontaneous feline infectious peritonitis (FIP), cats with FIP virus infection but no FIP, and cats with no infection.

Lymphatic tissues (spleen, mesenteric lymph nodes, thymus) from 24 cats with spontaneous feline infectious peritonitis (FIP) were examined by light microscopy and immunohistochemistry for cellularity, cellular composition, and degree of cellular turnover. Additionally, the formation of granulomatous lesions in lymphatic tissues in cats with FIP was examined. For comparison, tissues from 14 specific pathogen-free (SPF) cats and seven cats infected with FIP virus (FIPV; as the result of long-term exposure) but free from FIP were examined. In cats with FIP, the precardial mediastinum (including site of the thymus) and mesenteric lymph node parenchyma were often affected by granulomatous-necrotizing processes. In general, lymphoid tissues showed T- and B-cell depletion, often including massive to complete thymic involution or atrophy. In some cases, the number of apoptotic lymphocytes was increased in lymphoid follicles as well as in T-cell zones. The number of macrophages was increased in the splenic red pulp. In contrast, the FIPV-exposed cats without FIP generally showed a distinct lymphoid hyperplasia. The findings indicated that the major difference in lymphatic tissues between FIPV-infected cats with FIP and those without FIP was the development of lymphocyte depletion in the first group and lymphocyte proliferation in the second.

Animals↗