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Biomedical subjects

E Mozos

Publications and source records attributed to E Mozos.

At least 37 records · Page 2Linked to original sources

Immunohistochemical characterization of canine transmissible venereal tumor.

The collective immunohistochemical expression of human lysozyme, human alpha-1-antitrypsin, human CD3 antigen, calf vimentin, human keratins, human lambda light chains,canine immunoglobulins IgG, IgM, and bovine protein S-100 has been analyzed on formalin-fixed, paraffin-embedded tissue sections of 25 spontaneous canine transmissible venereal tumors (CTVT) from both genital and extragenital locations using the avidin-biotin-peroxidase complex technique. Lysozyme immunoreactivity was detected in 10/25 CTVT, alpha-1-antitrypsin in 14/25 CTVT, and vimentin in 25/25 CTVT. All CTVT cells were negative to keratins 5 + 8 of the Moll catalogue (RCK-102), S-100 protein, lambda light-chain immunoglobulins, IgG, IgM, and CD3 antigen. The intratumoral T-and B-lymphocyte infiltrate was differentiated using CD3 antigen, lambda light-chain immunoglobulins, IgG, and IgM, and this technique could be useful to evaluate the regressive or progressive growth stage of venereal tumors. Our findings support the hypothesis of a histiocytic immunophenotype for CTVT, and these staining techniques could be used in the differential diagnosis with lymphomas.

Animals↗

Leishmania infection of canine skin fibroblasts in vivo.

In this paper we describe two cases of naturally occurring leishmaniasis in dogs in which Leishmania sp. amastigotes are found within the cytoplasm of fibroblasts. The infected cells were identified histologically, immunohistochemically, and ultrastructurally as fibroblasts. This is the first report of leishmaniasis in any species in which amastigotes were identified in vivo within fibroblasts.

Animals↗

Immunohistochemical evaluation of canine primary liver carcinomas: distribution of alpha-fetoprotein, carcinoembryonic antigen, keratins and vimentin.

The immunohistochemical expression of the oncofetal proteins alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA), and the intermediate filament proteins keratin and vimentin was analysed in 18 canine liver carcinomas. All the tumours other than hepatocellular carcinomas, with the exception of one poorly differentiated carcinoma, were AFP negative, and only cholangiocarcinomas and mixed (hepatocellular and cholangiocellular) carcinomas were CEA positive. All the histological types of tumours expressed high and low molecular weight keratins, and keratin and vimentin were both expressed in three tumours (one moderately differentiated hepatocellular carcinoma, one mixed carcinoma and one poorly differentiated carcinoma). The findings demonstrate the use of immunohistochemical staining methods for analysing the expression of some tumour markers in routinely processed tissue samples of canine liver carcinomas, and suggest that some of the tumour markers are correlated with histological types of tumour.

Animals↗

Immunophenotype analysis of dendritic cells and lymphocytes associated with cutaneous malignant melanomas.

The purpose of this study was to investigate the relationship between changes in density and distribution of dendritic cells, both in epidermis and in peritumoral infiltrate, and lymphocyte subset variations in malignant melanomas (MM) of patients belonging to different risk groups. The collective immunoreactive expression of six markers (S100 protein, CD1-a, HLA-DR, CD4, CD8 and CD25) was analyzed in 13 cutaneous malignant melanomas. Changes were observed in density and distribution of Langerhans cells (LC) (S100+, CD1-a+) in the epidermis overlying the tumor, as well as in peritumoral and intratumoral locations, independently of the tumor-invasion level. A decrease was recorded in LC (S100+, CD1-a+) in the epidermis overlying six tumors, whereas most of the MM studied showed an increase of LC (S100+, CD1-a+) in peritumoral infiltrate. The expression of HLA-DR in tumor cells was controversial; it was observed in three moderate-risk MM, but it was negative in high-risk tumors. The percentage of CD4+ cells was in most cases greater than that of CD8+ in the peritumoral infiltrate, irrespective of the degree of histopathological malignancy. The concomitant expression of the lymphocytic activation marker CD25 (receptor for interleukin 2) in lymphocytic infiltrate was variable. Peritumoral infiltrate in three high risk MM contained few CD25+ cells, and a concomitant decrease was recorded in LC. This preliminary report shows that alterations in the density and distribution of LC may be responsible for determining the degree or T lymphocyte activation, and this may be critical for the development of effective tumor-directed immunity. Further studies are required to demonstrate these hypothetical interrelations.

Adult↗

HLA molecule expression in cutaneous squamous cell carcinomas: an immunopathological study and clinical-immunohistopathological correlations.

A correlation between the lack of MHC class I gene expression on murine tumor cells and their ability to grow and metastasize has recently been established. This paper studies HLA-ABC and HLA-DR antigen expression in tumor cells and mononuclear infiltrate of 26 cutaneous squamous cell carcinomas (SCC). Our results showed a heterogeneous expression of HLA class I molecules in these tumors. No significant correlation between the degree of HLA class I molecule expression and anatomical-clinical parameters was found. Class II antigen expression was correlated to the histopathological type and to the degree of cell differentiation. Most mononuclear cells infiltrating the tumor were T-lymphocytes. No correlation with anatomical-clinical parameters was found.

Antigens, CD↗

Epithelioid sarcoma in a dog.

A tumour in an 11-year-old male crossbred Fox Terrier, showing the clinical and pathological features of epithelioid sarcoma in man is reported. Clinical aspects, location, peculiar pattern of spread and evolution, together with histopathological and immunohistological findings of this rare tumour simulating a granuloma are described. Controversial histogenesis is discussed.

Animals↗

Inclusion bodies containing adenovirus-like particles in the intestine of a psittacine bird affected by inclusion body hepatitis.

This paper reports a case of inclusion body hepatitis with intranuclear inclusion bodies in the liver and the intestine of a Yellow-naped Amazon parrot (Amazona ochrocephala). Structurally, basophilic intranuclear inclusion bodies were found in hepatic cells and enterocytes. Ultrastructurally, icosahedral adenovirus-like particles, 60-75 nm in diameter, were found in the same cells.

Adenoviridae Infections↗

Kupffer cells and PIMs in acute experimental African swine fever.

An ultrastructural study of Kupffer cells and pulmonary intravascular macrophages (PIMs) of healthy and African Swine Fever (ASF)-infected pigs was carried out. A vascular perfusion method was performed in order to obtain an optimal intravascular morphology and tissue fixation. The infection developed acute ASF lesions in both organs. Both Kupffer cells and PIMs were studied at different stages of infection. The differences observed in both macrophagic cells from uninfected and infected tissues are shown and discussed.

African Swine Fever↗

Caprine peripheral neuroblastomas: structural and ultrastructural features, intermediate filaments profile and neuro-endocrine characterization.

In this report the morphological and immunohistochemical features with respect to intermediate filament proteins and the neuroendocrine nature of bilateral neuroblastomas possibly originating from the adrenal medulla in a goat kid are presented. Histologically, the tumours were composed of small, round, blue cells organized in highly cellular nests and sheets separated by fibrovascular septa. Isolated cells mimicking the morphological features of neurones were observed in both tumours. Ultrastructurally, dense-core neurosecretory granules, about 100 nm in diameter, and irregularly organized neurotubular networks were seen. The small tumour cells were only labelled by vimentin, while the neurone-like cells were labelled by both neurone-specific enolase and synaptophysin. The lack of staining of the tumour cells by the neurofilament proteins antiserum, which was also observed in a human neuroblastoma (used as positive control) has been previously reported and is probably the result of the tissue processing and/or the poor differentiation stage of the tumours. The vimentin labelling of tumour cells could be explained by the poor differentiation stage of the tumours, since vimentin is the only intermediate filament protein in presumptive neuroblasts, being replaced by neurofilament proteins in later stages of neurogenesis.

Animals↗

HLA expression in basal cell carcinomas.

Decreased expression of MHC class I molecules in tumor cells has been reported to be associated with enhanced malignancy both in human and murine tumors. This paper studies HLA-ABC and HLA-DR expression in 56 basal cell carcinomas. Our results show that these tumors have a heterogeneous expression of MHC class I molecules: 11% exhibit uniform staining of most tumor cells; 25% are only partially positive, and the remaining 64% are MHC class I negative. A positive correlation between the level of HLA-ABC molecule expression and the degree of histological differentiation has been found. The expression pattern of tumor cells with anti-class II monoclonal antibodies shows weak homogeneous staining in 5%, staining in only a few areas of the tumor in 32%, whereas 63% has no significant staining for MHC class II antigens. Most mononuclear cells infiltrating the tumor were T lymphocytes (CD-3 positive). Results also show that 68% of the tumors express class II molecules homogeneously in the infiltrate. The expression of class II antigens in infiltrating lymphocytes correlated with the level of class II expression in the tumor cells probably as a consequence of lymphokine production by activated T cells.

Antigens, Differentiation, T-Lymphocyte↗

Ultrastructural modifications of the cavities formed by folliculo-stellate cells in chicken adenohypophysis under septic shock conditions.

Effects of septic shock by repeated inoculations with Escherichia coli on the ultrastructure of the folliculo-stellate cells and cavities of the adenohypophysis of the chicken were investigated in order to determine the function of these cavities. The principal morphological modifications were dilation of the Golgi apparatus, endoplasmic reticulum and autophagic vacuoles, and necrosis phenomena in the stellate cells. The follicular cavities showed dilation, and there was heterogeneous dense material and granular elements in the follicular lumen. Based on results reported in the literature, the observations reported here are evidence of a "cleaning-role", for the removal of cell debris, when there is endocrine disfunction.

Animals↗

Ovine squamous cell carcinoma: immunocharacterisation of neoplastic cells and peritumoural cellular infiltrate.

An immunohistochemical characterisation of neoplastic cells and peritumoural cellular infiltrate of ovine squamous cell carcinomas (OSCC) in different stages of growth was carried out using a commercially-available panel of seven antibodies, and formalin-fixed and paraffin-embedded tissue samples. Neoplastic cells reacted with the anti-keratin monoclonal antibody RCK-102 and with an anti-keratin polyclonal antibody, whereas they were unreactive with the anti-keratin monoclonal antibody NCL-5D3. The tumour cells were unreactive with the anti-vimentin polyclonal antibody. Increased numbers of CD3+ T-lymphocytes, IgG-containing plasma cells and lysozyme+ macrophages were associated with precancerous lesions (actinic keratosis) and with early OSCC. These results show that early lesions of OSCC induce an in situ cellular and humoral immune response. In advanced OSCC, the number of CD3+ T-lymphocytes and macrophages in the peri- and intratumoural cellular infiltrate remained high, whereas a significant decrease of IgG-containing plasma cells was found compared with early OSCC. This finding suggests an in situ decrease in the humoral immune response in advanced OSCC.

Animals↗

Immunohistochemical characterization of hepatic lesions associated with migrating larvae of Ascaris suum in pigs.

This paper describes the histopathological features and the cellular distribution of T lymphocytes (CD3), B cells (CD79a), immunoglobulin (IgG, IgA, IgM)-bearing plasma cells, macrophages (Mac387 and alpha-1-antitrypsin), MHC class II antigen and S-100 protein in hepatic white spots associated with naturally occurring Ascaris suum parasitism in 35 pigs. Hepatic granulomas were observed in 10 pigs, whereas lymphoid proliferation with a diffuse or lymphonodular pattern was the main histopathological lesion in 14 other pigs, and portal fibrosis in a further 11 animals. In lymphonodular lesions, the distribution of immunoreactive cells with all antibodies tested was closely similar to that found in the cortex of lymph nodes. Thus, lymphoid follicles were composed mainly of CD79a(+)B cells and interfollicular tissue was composed mainly of CD3(+)T lymphocytes. The presence of follicular dendritic and interdigitating cells expressing S-100 protein and MHC class II antigen in lymphonodular lesions suggested that these are highly organized structures developed to enhance antigen presentation to B and T cells, and consequently the local immune response against the parasite. The humoral local response was represented mainly by IgG-secreting plasma cells.

Animals↗

Right-sided heart failure in a dog with primary cardiac rhabdomyosarcoma.

A seven-year-old, female German shepherd mixed-breed dog was presented with weakness, inappetence, and a distended abdomen. Right-sided heart failure with pleural, pericardial, and abdominal effusions; dyspnea; and tachycardia were identified. The radiographic and electrocardiographic examinations did not allow a conclusive diagnosis. Echocardiographic findings included a mass in the wall of both the right atrium and right ventricle, partially occupying the right heart cavities. A diagnosis of cardiac tumor was made, and the owner elected euthanasia. The necropsy confirmed a tumor mass located in the right atrium and right ventricle. A definitive diagnosis of primary cardiac rhabdomyosarcoma was based on histopathological and immunohistochemical analyses.

Animals↗