Oxidative stress in hoof laminar tissue of horses with lethal gastrointestinal diseases.

Tissue damage caused by oxidative stress is involved in the pathogenesis of several diseases in animals and man, and is believed to play a role in the development of laminitis in horses. The aim of this study was to investigate the oxidative stress associated with laminar lesions in horses with lethal gastrointestinal disorders. Laminar tissue samples of the hoof of 30 horses were used. Tissue samples were divided as follows: six healthy horses (control group-CG), and 24 horses that died after complications of gastrointestinal diseases (group suffering from gastrointestinal disorders-GDG). Superoxide dismutase (SOD2) and nitrotyrosine immunostaining and the severity of laminar lesions were evaluated. Presence of laminar lesions and immunostaining for nitrotyrosine and SOD2 were only evident in horses from the GDG group. Thus, oxidative stress may play a role in the pathogenesis of laminar lesions secondary to gastrointestinal disorders.

Anticoagulants on yield of bone marrow-derived mononuclear cells harvested from dogs / Anticoagulantes no rendimento de células mononucleares da medula óssea de cães

Cell therapy with bone marrow-derived mononuclear cells is an alternative to therapy with mesenchymal stem cell cultures. The aim of the present research was the comparison of the yield of bone marrow-derived mononuclear cells harvested from dogs with two different anticoagulants. Bone marrow was harvested from the iliac crest of five healthy dogs aged between 15 and 30 months, and the effect of two anticoagulant solutions, CPDA-1 (citrate phosphate dextrose adenine-1) and heparin, on the isolation of mononuclear cells was compared. Mononuclear cells were isolated in a density gradient and stained for CD9 and CD44 for characterization by flow cytometry. Means were compared using Student's paired t-test. Samples harvested with CPDA-1 yielded an average of 5.16x106 (±1.76x106) to 20.20x106 (±1.55x106) mononuclear cells/mL, whereas the yield of samples harvested with heparin varied between 4.56x106(±0.69x106) and 24.30x106 (±2.12x106) mononuclear cells mL-1. By flow cytometry, mean percentage of double-stained cells varied from 1.96% (±0.64%) to 5.01% (±0.73%) for CPDA-1 and from 2.23% (±0.70%) to 7.27% (±0.97%) for heparin. No significant statistical differences were observed on yield or CD9 and CD44 expression. Further studies are recommended to assess efficacy of CPDA on mononuclear cell isolation.

A terapia com células mononucleares de medula óssea é uma alternativa ao cultivo de células-tronco mesenquimais. O objetivo deste trabalho foi comparar o rendimento de células mononucleares derivadas da medula óssea de cães, colhidas com dois anticoagulantes diferentes. Foram coletadas medulas ósseas de cinco cães hígidos, com idades variando entre 15 e 30 meses, por punção na crista ilíaca. Foi comparado o efeito da solução anticoagulante no isolamento das células mononucleares, utilizando-se CPDA-1 (citrato, fosfato, dextrose, adenina) ou heparina como soluções anticoagulantes. As células mononucleares foram isoladas em gradiente de densidade e caracterizadas fenotipicamente em citometria de fluxo. Os resultados foram submetidos ao Teste t pareado para comparação de médias. Nas amostras coletadas com CPDA-1, o rendimento médio variou entre 5,16 x 106 (±1,76x106) a 20,20x106 (±1,55x106) células mononucleares mL-1, enquanto que, nas amostras coletadas com heparina, o rendimento variou entre 4,56x106 (±0,69x106) a 24,30x106(±2,12x106) células mononucleares/mL. Na citometria de fluxo, a média de células duplo-marcadas variou de 1,96% (±0,64%) a 5,01% (±0,73%) para CPDA-1 e de 2,23% (±0,70%) a 7,27% (±0,97%) para heparina. Não foram observadas diferenças estatísticas no rendimento ou na expressão de CD9 e CD44. Recomendam-se estudos adicionais para avaliar melhor a eficácia do CPDA no isolamento de células mononucleares.

Systemic leukopenia, evaluation of laminar leukocyte infiltration and laminar lesions in horses with naturally occurring colic syndrome.

The present study was aimed at identifying laminar lesions and leukocyte infiltration in hoof laminar tissue of horses with colic syndrome and its correlation with the total leukocyte count before death. Six healthy horses were used as control group (CG), and eighteen horses with lethal gastrointestinal disease were divided into two groups: leukopenic group (LG) with seven leukopenic horses, and non-leukopenic group (NLG) with 11 horses with total leukocyte count within reference range for the species. Leukocyte infiltration was examined by immunohistochemistry. Laminar lesions were observed in both LG and NLG, with no differences in severity between them. LG showed increase of the leukocyte infiltration in the hoof laminar tissue, when compared to CG and NLG. Horses with severe colic syndrome (LG and NLG) developed intense laminar lesions without clinical signs of laminitis, with increased leukocyte infiltration. However, the LG demonstrated an even higher increase of leukocyte infiltration compared to both CG and NLG.