Biomedical subjects

I Vlemmas

Publications and source records attributed to I Vlemmas.

23 records · Page 2Linked to original sources

PubMedDate not supplied

Histopathological and immunohistochemical features of natural goat scrapie.

Histopathological and immunohistochemical examinations were performed on the brain and spinal cord of 37 goats from two Greek herds in which scrapie had been reported. Of the 37 animals, 18 were from a herd consisting only of goats and 19 were from a herd of goats mixed with sheep. The goats studied were grouped on the basis of the presence or absence of clinical signs. Distinctive lesions and PrP(sc) (PrP, prion protein) deposition were found in the central nervous system (CNS) of eight clinically affected animals and six symptomless animals. The lesion profile and PrP(sc) distribution varied both between and within groups, variation being particularly pronounced in the symptomless goats. The results concerning the latter group suggested a poor correlation between the intensity of lesions, the amount of PrP(sc) in the CNS, and the manifestation of clinical signs. Immunohistochemical examination revealed 10 different PrP(sc) types, four of which are reported for the first time in goats. All scrapie-affected animals carried the VV(21)II(142)HH(143)RR(154) genotype, with the exception of two goats that carried the HR(143) dimorphism and had detectable PrP(sc) deposits. The results suggest that the histopathological and immunohistochemical profile of the natural disease in goats is influenced by the PrP genotype and age of the animals but may not be directly associated with the presence or otherwise of clinical signs.

Age Factors↗

PubMedDate not supplied

Pathogenesis of encephalomyocarditis virus (EMCV) infection in piglets during the viraemia phase: a histopathological, immunohistochemical and virological study.

Six piglets aged 20 days were inoculated oranasally with 5 ml of a suspension (10(6) TCID(50)/ml) of a Greek myocardial strain of encephalomyocarditis virus (EMCV). The animals either died (n=2) or were killed for examination on days 1,2 or 3 post-inoculation (pi). EMCV was isolated from virtually all organs examined (heart, tonsils, palatine glands, pancreas, spleen, small intestine and mesenteric lymph nodes). Histopathologically, interstitial myocarditis, necrosis of cardiac muscle cells and Purkinje fibres, and necrotizing tonsillitis were detected in all inoculated piglets. Focal interstitial pancreatitis, necrosis of pancreatic acinar cells and Langerhans islet cells, and necrosis of germinal centre lymphocytes of the lymph nodes and Peyer's patches were detected in two piglets that died or were killed on day 3 pi. Immunohistochemically, viral antigen was detected in epithelial cells of all organs examined, including the tonsils, palatine glands, pancreatic interlobular ducts and small intestine. This suggests that EMCV is epitheliotropic, in addition to its known myocardial tropism. The frequent presence of intracytoplasmic EMCV in macrophages of the tonsils and spleen supports the hypothesis that macrophages play a role in viral replication and dissemination in the body.

Animals↗

PubMedDate not supplied

Obstructive, granulomatous tracheitis caused by Onchocerca sp. in a dog.

A 3-year-old spayed female dog was admitted with a history of episodes of dyspnoea and coughing. Severe tracheal stenosis was found on radiography. The dog died during an episode of refractory dyspnoea. Necropsy revealed an obstruction of the thoracic part of the trachea because of a chronic granulomatous inflammation protruding into the tracheal lumen. Histological examination revealed nematodes, which were identified as Onchocerca sp. according to their morphological characteristics. In contrast to the common ocular manifestation in dogs, obstructive tracheitis caused by Onchocerca infection has not been reported before.

Animals↗

PubMedDate not supplied

Effect of the compound L-mimosine in an in vivo model of chronic granuloma formation induced by potassium permanganate (KMNO4).

The plant amino acid L-mimosine has recently been suggested to inhibit cells at a regulatory step in late G1 phase before establishment of active DNA replication forks. In addition, L-mimosine is an extremely effective inhibitor of DNA replication in chromosomes of mammalian nuclei. In this work, the effect of L-mimosine on chronic inflammation induced by dorsal injections of 0.2 ml of a 1:40 saturated crystal solution of potassium permanganate in mice, was studied. Seven days afterwards, all mice developed a subcutaneous granulomatous tissue indicative of chronic inflammatory response at the site of infection. The intraperitoneal administration of L-mimosine (200 microg/dose) to the potassium permanganate treated mice for 5 consecutive days (the first at the same time of inoculation of the KMnO4), produced a significant decrease in size and weight of the granuloma when compared to mice not treated with L-mimosine (controls). In addition, in all mice treated with L-mimosine, there was a strong inhibition of tumor necrosis factor alpha that was revealed in the serum (P<0.05) and in the minced granulomas. Interleukin-6 was not detected in the serum of treated and untreated mice. These findings show for the first time, that L-mimosine may have an anti-inflammatory effect on chronic inflammation and an inhibitory effect on tumor necrosis factor alpha and interleukin-6 generation in supernatant fluids of minced granulomas.

Animals↗

PubMedDate not supplied

Chlamydia-induced bilateral ectropion of the inferior eyelids in pigeons.

In this study we described four cases of bilateral ectropion in pigeons that were investigated in Greece. Anemia, leukocytosis, and increased levels of enzymes lactate dehydrogenase, aspartate aminotransferase, creatine phosphokinase, and total serum proteins were found. Chlamydial elementary bodies were observed by modified Ziehl-Neelsen stain in direct smears of conjunctiva, liver, and spleen as well as in yolk sac samples after egg inoculation with eyelid material. Histologically, significant hyperplasia of the conjunctival epithelium was observed. Using immunohistochemical methods, chlamydial antigen was revealed in eyelid, liver, and spleen paraffin sections. This study suggests that Chlamydia spp. was the causative agent that induced ectropion.

Animals↗