Experimental ischemia and reperfusion in equine small colon

Sob anestesia geral, com constante controle sobre a pressão arterial e a saturação de oxigênio da hemoglobina arterial, realizou-se celiotomia em 12 eqüinos. No cólon menor exposto foram demarcados três segmentos de 25cm, separados entre si por igual distância. Dois desses segmentos foram submetidos à isquemia arteriovenosa completa por 90 (grupo A) ou 180 minutos (grupo B). O terceiro segmento foi o grupo-controle. Amostras para histopatologia foram colhidas ao final dos períodos de isquemia e após 90 e 180 minutos de reperfusão no grupo A e após 90 minutos de reperfusão no grupo B. No controle, colheram-se amostras no início e final do procedimento. Avaliaram-se as lesões produzidas na mucosa e na submucosa pelos métodos semiquantitativos-escores para desprendimento de epitélio, edema, hemorragia e infiltrado de neutrófilos, e pelos quantitativos-porcentagem de perda de mucosa (PM) e razão cripta:interstício (C:I). As lesões isquêmicas foram mais intensas no grupo B do que no A para PM, C:I, desprendimento de epitélio e edema de mucosa. As amostras obtidas após a reperfusão revelaram que houve agravamento na PM, C:I, desprendimento de epitélio e edema de submucosa em ambos os grupos. Concluiu-se que a reperfusão agravou as lesões isquêmicas no cólon menor e que o modelo proposto é viável para produção dessas lesões.

Light and scanning electron microscopic study of the palatine mucosa of nine-banded armadillo (Dasypus novemcinctus)

The three-dimensional structure of the lamina propria of the hard and soft palatine mucosa of the nine-banded armadillo was observed by scanning electron microscopy. Sodium hydroxide cell maceration method was applied to demonstrate the architecture of the connective tissue papillae. The palatine mucosa of the armadillo had a triangular shape and measured appr. 6.5 cm length. The hard palate showed 9 transverse palatine plicae while the soft palate was smooth. In the 10% NaOH treated specimens, the lamina propria of the hard palatine mucosa showed numerous connective tissue papillae with a general finger-like shape. These structures were composed by a meshwork of collagen fibers arranged in several directions. on the other hand, the connective tissue papillae of the soft palate mucosa were scattered and small. Numerous openings of glandular ducts with circular or elliptical shape were located in the interplicae area and in the soft palate.

Local and remote lesions in horses subjected to small colon distension and decompression

The purpose of this study was to observe and characterize colonic and lung lesions in horses subjected to experimental distension and decompression of the small colon. Sixteen healthy adult horses were divided into 2 groups: 9 horses that were subjected to distension of the small colon by means of a latex balloon surgically implanted in the lumen and inflated to a pressure of 40 mm Hg for 4 h, and 7 horses in which the balloon was implanted but not inflated. Colonic biopsy specimens were collected before balloon implantation, at the end of the period of obstruction, and 1.5 and 12 h after decompression and were examined for hemorrhage, edema, and neutrophil infiltration; myeloperoxidase (MPO) activity and hemoglobin concentration were measured as well. At the end of the experiment, lung samples were also collected and examined for neutrophil accumulation and MPO activity. The mucosa was not affected by luminal distension; lesions were restricted to the seromuscular layer. Neutrophil accumulation and edema were observed in the samples from both groups of horses but were greater in those from the distension group, in which there was also hemorrhage, fibrin deposition, and increased MPO activity in the seromuscular layer. Similarly, there was greater accumulation of neutrophils in the lung samples from the distension group than in those from the sham-operated group, as determined by histologic evaluation and MPO assay. These findings provide new evidence of reperfusion injury and a systemic inflammatory response, followed by remote lesions, in horses with intestinal obstruction.

Microscopic, morphometric and ultrastructural analysis of anastomotic healing in the intestine of normal and diabetic rats

The purpose of this study was to investigate if experimental alloxanic diabetes could cause qualitative changes in intestinal anastomoses of the terminal ileum and distal colon in rats, as compared to controls. 192 male Wistar rats, weighing ± 300g were split into four experimental groups of 48 animals each, after 3 months of follow-up: a control group with ileum anastomoses (G1), a control group with colon anastomoses (G2), a diabetic group with ileum anastomoses (G3) and a diabetic group with colon anastomoses (G4). Animals were evaluated and sacrificed on days 4, 14, 21 and 30 after surgery, and fragments of the small and large intestine where the anastomoses were performed were removed. Samples from 6 animals from each sacrifice moment were submitted to ultrastructural analysis of the collagen fibers using a scanning electron microscope and samples from another 6 animals were submitted to histopathology and optical microscopy studies using picrosirius red-staining. Histopathological analysis of picrosirius red-stained anastomosis slides using an optical microscope at 40x magnification showed that the distribution of collagen fibers was disarranged and also revealed a delay in scar tissue retraction. The morphometric study revealed differences in the collagen filled area for the ileum anastomoses 14 days post surgery whereas, in the case of colon anastomoses, differences were observed at days 4 and 30 post surgery, with higher values in the diabetic animals. Ultrastructure analysis of the ileum and colon anastomoses using a scanning electron microscope revealed fewer wide collagen fibers, the presence of narrower fibers and a disarranged distribution of the collagen fibers. We conclude that diabetes caused qualitative changes in scar tissue as well as in the structural arrangement of collagen fibers, what could explain the reduced wound strength in the anastomosis of diabetic animals. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart.

Avaliação quantitativa de micronúcleos na citologia esfoliativa da mucosa bucal de pacientes dependentes químicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Microbiota fecal, produtos de fermentação, aspectos histológicos da mucosa gastrintestinal e imunidade de cães Beagle de diferentes gurpos etários

Pós-graduação em Medicina Veterinária - FCAV

Colágeno acelular e mucosa oral na substituição parcial da uretra: estudo comparativo em coelhos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Uso do amido resistente na promoção da saúde intestinal de cães idosos: formação de produtos de fermentação e características histológicas da mucosa intestinal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)