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Biomedical subjects

M Andrada

Publications and source records attributed to M Andrada.

10 recordsLinked to original sources

Serological study of contagious agalactia in herds of goats in the Canary Islands.

An indirect ELISA, using local strains of Mycoplasma agalactiae and Mycoplasma mycoides subspecies mycoides large colony (MmmLC), was applied to evaluate the seroprevalence of M agalactiae and MmmLC in flocks of goats on each of the Canary Islands. In total 3890 samples of serum were collected from 204 flocks. The results indicated that the seroprevalence of both organisms is high on all the islands; average values of 55 per cent and 67 per cent were recorded, respectively, for M agalactiae and MmmLC.

Animals↗

Immunohistochemical labelling of cytokines in lung lesions of pigs naturally infected with Mycoplasma hyopneumoniae.

Mycoplasma hyopneumoniae (Mh) is the primary agent of porcine enzootic pneumonia (PEN), a chronic respiratory disease endemic to pig farms, and characterized histologically by infiltration of mononuclear cells in airways and prominent hyperplasia of the bronchus-associated lymphoid tissue (BALT). To gain further insight into the pathogenesis of PEN, cytokine expression in the lung, with particular attention to the BALT, was examined immunohistochemically in pigs naturally infected with Mh. An increase (P < 0.05) in proinflammatory and immunoregulatory cytokines (especially interleukin [IL]-2, IL-4 and tumour necrosis factor [TNF]-alpha, and to a lesser extent IL-1 [alpha and beta] and IL-6) was detected in the BALT, which showed intense lymphoid hyperplasia. IL-1beta and TNF-alpha were also detected in the bronchoalveolar exudate of infected pigs, and IL-6 and IL-8 were demonstrated in mononuclear cells of the alveolar septa. The results showed that in Mh infection, macrophage and lymphocyte activation results in the expression of a number of cytokines capable of inducing lung lesions and lymphoreticular hyperplasia of the BALT.

Animals↗

Hepatic lesions in cetaceans stranded in the Canary Islands.

This article describes the gross, histopathologic, and ultrastructural findings of the livers of cetaceans stranded on the coast of the Canary Islands between 1992 and 2000. A total of 135 cetaceans were included in the study, among which 25 were common dolphins (Delphinus delphis), 23 Atlantic spotted dolphins (Stenella frontalis), 19 striped dolphins (Stenella coeruleoalba), and 15 other species of dolphins and whales. The most common lesion observed in these animals was a nonspecific chronic reactive hepatitis (47/135), followed by hyaline intracytoplasmic inclusions in hepatocytes (33/135). Parasitic cholangitis was detected in 8/135 animals, whereas hepatic lipidosis was presented in 7/135 animals. The ultrastructure of hyaline hepatocytic cytoplasmic inclusions is described, and possible causes of these inclusions are discussed.

Animal Diseases↗

Type A-like retroviral particles in a metastatic intestinal adenocarcinoma in an emerald tree boa (Corallus caninus).

A metastatic intestinal papillary adenocarcinoma was diagnosed histologically in an emerald tree boa (Corallus caninus). Metastasis was detected in the liver, both kidneys, lung, and coelomic wall. Ultrastructural examination of the metastatic intestinal epithelial cells in the liver revealed the presence of a moderate number of viral particles that most closely resembled type A retroviral particles and were mainly associated with granular endoplasmic reticulum membranes. This case is the first description of type A-like retroviral particles in a neoplasm of a snake. The role of the virions in the etiology of the intestinal adenocarcinoma is uncertain. In addition, this is the first confirmed report of a metastatic intestinal adenocarcinoma in a snake.

Adenocarcinoma↗

A morphologic and immunohistochemical study of the bronchus-associated lymphoid tissue of pigs naturally infected with Mycoplasma hyopneumoniae.

Porcine enzootic pneumonia (PEN), caused by Mycoplasma hyopneumoniae (Mh), has been described in pigs in all geographic areas. The disease is characterized by high morbidity and low mortality rates in intensive swine production systems. A morphologic and immunohistochemical study was done to determine the cellular populations present in lung parenchyma of infected pigs, with special attention to the bronchus-associated lymphoid tissue (BALT). Polyclonal and monoclonal antibodies were used for the detection of antigens of Mh, T lymphocytes (CD3+, CD4+, and CD8+), IgG+ or IgA+ lymphocytes, and cells containing lysozyme, S-100 protein, major histocompatibility complex class II antigen or myeloid-histiocyte antigen. Findings in lung tissues associated with Mh infection were catarrhal bronchointerstitial pneumonia, with infiltration of inflammatory cells in the lamina propria of bronchi and bronchioles and alveolar septa. Hyperplasia of mononuclear cells in the BALT areas was the most significant histologic change. The BALT showed a high morphologic and cellular organization. Macrophages and B lymphocytes were the main cellular components of germinal centers. T lymphocytes were primarily located in perifollicular areas of the BALT, lamina propria and within the airway epithelium, and plasma cells containing IgG or IgA at the periphery of the BALT, in the lamina propria of bronchi and bronchioles, in alveolar septa, and around bronchial submucosal glands. The hyperplastic BALT in PEN cases consisted of macrophages, dendritic cells, T and B lymphocytes, and IgG+ and IgA+ plasma cells. CD4+ cells predominated over CD8+ cells. Local humoral immunity appears to play an important role in the infection.

Animals↗

Neuropathological effects and deaths of cattle and sheep in Argentina from Phalaris angusta.

Neuropathological disorders and mortality occurred in cattle and sheep grazing P angusta. This native plant of South America is frequently found as a good quality component of natural pastures. Cattle and sheep feeding in pastures where P angusta was dominant started dying or showing signs 3 to 5 d after rain-falls started following a period of drought. Some animals died suddenly, while others nervous effects( incoordination, inability to walk normal, recumbency) and death for up to 2 w after the beginning of the signs. Postmortem findings were bilaterally symmetrical, greenish pigmented areas in the grey matter of the brain stem and diencephalon. A greenish tinge was also noted between the cortex and the medulla of the kidneys. Granules of a brown pigment were noted within the cytoplasm of neurons. An alkaloid substance was detected in the plant. Morbidity was 2.3 to 10.5% in herds B and A, and 0 to 3.4% in flocks D and C, respectively. Mortality was 0.8 to 1.0% in herds B and C, and 3.4 to 11.7% in flocks D and C, respectively. P angusta behaves, in terms of toxicity, as other Phalaris spp. Its widespread distribution in areas of extensive grazing poses a threat to cattle and sheep production in Argentina.

Alkaloids↗

Hepatosplenic large cell immunoblastic lymphoma in a bottlenose dolphin (Tursiops truncatus) with high levels of polychlorinated biphenyl congeners.

This report describes a large cell immunoblastic lymphoma in a bottlenose dolphin found stranded alive in Gran Canaria, Spain. Diffuse infiltration of round neoplastic cells was observed in the splenic cords and sinuses and in hepatic sinusoids, resulting in moderate organ enlargement. The tumour cells (immunophenotype IgG+ and CD3-) showed scant, lightly eosinophilic or basophilic cytoplasm, distinct cell boundaries and hyperchromatic nuclei, each with one or more nucleoli. Mitoses were common. On the basis of histopathological, immunohistochemical and ultrastructural features, the tumour was classified as an immunoblastic lymphoma. Eleven polychlorinated biphenyl (PCB) congeners, 23 organochlorine pesticides and 16 polycyclic aromatic hydrocarbons (PAHs) were detected in the blubber and liver. High concentrations of PCBs 153, 180, 138 and 187 found in the liver may have been associated with the hepatosplenic lymphoma.

Adipose Tissue↗

[Pathological findings in pigs affected by the postweaning multisystemic wasting syndrome in Argentina].

Postweaning multisystemic wasting syndrome was first described in Canada in 1991 and at present an increasing number of cases has been diagnosed worldwide. In Argentina the first cases of PMWS were reported recently. Forty eight 5 to 12 week old pigs with signs characteristic of PMWS from 19 farms were studied. Although the real distribution of the virus in our country is not known it was observed an increasing number of farms with PMWS distributed in the major producing provinces. The histopathology was an important tool in diagnosis of suspicious cases of PMWS with the observation of different degrees of lesion. In the studied animals, the secondary infections, either by opportunistic pathogens or secondary bacteria could be important.

Animals↗