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Biomedical subjects

L Carrasco

Publications and source records attributed to L Carrasco.

302 records · Page 17Linked to original sources
PubMedDate not supplied

Ultrastructural changes related to the lymph node haemorrhages in acute African swine fever.

In order to determine the pathogenic mechanisms involved in lymph node haemorrhages in acute African swine fever (ASF), eight pigs were inoculated with ASF virus, strain Malawi'83. Lymph node haemorrhages were observed from three days post infection (dpi) onwards, coinciding with ASF virus replication in monocytes and macrophages adjacent to stimulated endothelial cells, phagocytic stimulation of capillary and small-vessel endothelial cells, increase in the number of fenestrations of endothelial cells, and endothelial cell loss, as well as clusters of blood cells and necrotic material beneath the endothelium. Vascular lumina were blocked by platelet plugs and fibrin microthrombi. These phenomena became more marked as the disease progressed. At five dpi, virus replication was also found in circulating neutrophils. At seven dpi, lesions were more intense and were accompanied by virus replication in sinus and capillary endothelial cells, and in other cell populations including pericytes, fibroblasts, smooth muscle fibres and reticular cells. The results obtained in this study suggest that lymph node haemorrhages are related to endothelial stimulation and the onset of disseminated intravascular coagulation. Virus replication in vessel wall cells occurs only in the final stages of the disease and plays a secondary role.

African Swine Fever↗
PubMedDate not supplied

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↗
PubMedDate not supplied

African swine fever: Expression of interleukin-1 alpha and tumour necrosis factor-alpha by pulmonary intravascular macrophages.

To determine, in the acute form of African swine fever (ASF), the relationship between the appearance of pulmonary oedema and viral replication and expression of cytokines by pulmonary intravascular macrophages (PIMs), 14 pigs were inoculated intramuscularly with ASF virus (strain España'70) and killed in pairs on days 1-7 post-inoculation. Samples of lung were examined immunohistochemically and ultrastructurally. The immunohistochemical study was carried out with antibodies against interleukin-1 alpha (IL-1alpha), tumour necrosis factor-alpha (TNF-alpha), viral antigen of ASF (Vp73) and a myeloid marker (SWC3). Viral replication was observed mainly in PIMs, which at the same time showed intense activation, accompanied by the expression of IL-1alpha and TNF-alpha. The occurrence of interstitial oedema, neutrophil sequestration and fibrin microthrombi in septal capillaries coincided with high degrees of cytokine expression by infected PIMs. Alveolar macrophages did not show a significant change in cytokine expression as a result of ASF infection, and viral replication was detected in only a low percentage of these cells.

Acute Disease↗
PubMedDate not supplied

Chronic bronchopulmonary aspergillosis in a horse with Cushing's syndrome.

An atypical case of chronic equine bronchopulmonary aspergillosis with an unusual hyphal morphology was diagnosed in a horse with Cushing's syndrome. Because of the hyphal localization in chronic ectatic bronchi and bronchioles, and juxtabronchiolar processes, the observed type of aspergillosis is similar to 'saprophytic bronchopulmonary aspergillosis' or 'semi-invasive pulmonary aspergillosis' in humans. The aetiological diagnosis of aspergillosis was accomplished by the application of a panel of monospecific polyclonal and monoclonal antibodies in immunohistochemical techniques.

Animals↗
PubMedDate not supplied

Systemic candidosis and concomitant aspergillosis and zygomycosis in two Amazon parakeets (Amazona aestiva).

Systemic candidosis and concomitant aspergillosis and zygomycosis were diagnosed immunohistochemically in two Amazon parakeets (Amazona aestiva). In the bird with systemic candidosis, subacute necrotic lesions were present in the lung and the gastrointestinal tract, whereas chronic giant cell-containing granulomas were located in the liver, heart, spleen and on the serosal lining of the small intestine. Although the lesions in the liver, heart and spleen most likely developed as a result of haematogenous spread, the granulomas on the serosal surface may have developed after a local transmural intestinal invasion. In the second bird, aspergillosis and zygomycosis were restricted to the lung, whereas some zygomycetes were found in the air sacs as well as in the heart and kidneys. In all organs the zygomycotic lesions were dominated by thrombosing vasculitis, supporting haematogenous dissemination.

Animals↗
PubMedDate not supplied

Hemorrhagic enteritis by adenovirus-like particles in turkeys: a possible pathogenic mechanism.

This paper describes an outbreak of hemorrhagic enteritis due to adenovirus in turkeys in Spain. Diagnosis of the disease was confirmed by histopathological examination and the observation of adenovirus in spleen mononuclear cells and intestinal infiltrate. Evidence was also found of intravascular coagulation, which may give rise to the bleeding considered characteristic of this disease.

Adenoviridae Infections↗
PubMedDate not supplied

Application of enzyme-immunohistochemistry for the diagnosis of aspergillosis, candidiasis, and zygomycosis in three lovebirds.

Aspergillosis, candidiasis, and zygomycosis were diagnosed in tissues from three lovebirds (Agapornis roseicollis) using indirect enzyme-immunohistochemical techniques. In these techniques, the first antibody was raised against fungal antigen. A second antibody, which was raised in another animal species, was added to link the first antibody to enzyme-immunocomplexes. The reactivity of specific monoclonal and polyclonal antibodies was visualized by immunoreactivity of alkaline phosphatase anti-alkaline phosphatase and peroxidase anti-peroxidase immunocomplexes. All three birds examined had dermal candidiasis. In addition, one of the birds was diagnosed with concomitant acute ocular aspergillosis, and another bird was diagnosed with chronic zygomycotic myocarditis.

Animals↗