Evaluation of sperm head dimensions and chromatin integrity of epididymal sperm from domestic cats using the toluidine blue technique.

When using assisted reproductive technologies, there is seldom an evaluation of DNA integrity during sperm analysis, which is an important variable for proper embryo development. The toluidine blue staining technique allows the simultaneous evaluation of sperm chromatin and sperm head dimensions. The objectives of this study were to evaluate the applicability of the toluidine blue staining method for analyzing DNA abnormalities in epididymal sperm (from the caput, corpus, and cauda) of cats and to investigate the correlations among DNA condensation, morphology, and sperm head dimensions. The DNA alteration indexes were obtained using the toluidine blue and acridine orange techniques, and comparisons of these indexes indicated there was a 65.4% (r = 0.654; P < 0.001) correlation. The sperm from the cauda had greater chromatin stability (97.9%) than the sperm from the epididymal head (92.1%; P = 0.0023). There, however, was no difference in chromatin stability between sperm obtained from the corpus and cauda regions, indicating that these sperm were already mature. The sperm head dimension was correlated with chromatin decondensation, and the sperm head size decreased as the sperm were transported through the three epididymal regions (P < 0.0001). In addition, the percentage of sperm that were deficient in chromatin condensation decreased as the sperm were transported through the epididymal caput, corpus and cauda (26.4, 15.7, and 3.4%, respectively; P < 0.0001). Thus, the sperm head size predicts the quality of chromatin condensation in sperm cells.

Influence of apoptosis on liver and spleen resistance in dogs with visceral leishmaniosis.

The aim of this study was to evaluate apoptosis and parasite load in the liver and spleen of dogs with visceral leishmaniosis (VL), using immunohistochemistry. Liver and spleen samples from 71 dogs with VL were used. The parasite load in the spleen and liver showed significant difference between organs in infected group (P=0.0219). The density of the parasite load in the spleen (median=2.4) was higher than liver (median=0.8). Immunodetection of apoptotic cells was predominant in lymphocytes and differ between the infected and control group in spleen (P=0.0307) and liver (P=0.0346). There was a significant correlation between apoptosis and parasite load (P = 0.0084; r=0.3104) only in the spleen of the infected group, where it was observed that, when increasing the number of apoptotic cells increases the parasitic load. It was concluded that the liver and spleen of infected dogs presented greater numbers of cells undergoing apoptosis (lymphocytes) than the control group, thus suggesting that this process may be contributing towards the survival of Leishmania in these organs, because lymphocyte in apoptosis did not have the ability to present and recognize the antigen, allowing the survival of the parasite.

Influence of apoptosis on liver and spleen resistance in dogs with visceral leishmaniosis / Influência da apoptose na resistência hepática e esplênica de cães com leishmaniose visceral

Abstract The aim of this study was to evaluate apoptosis and parasite load in the liver and spleen of dogs with visceral leishmaniosis (VL), using immunohistochemistry. Liver and spleen samples from 71 dogs with VL were used. The parasite load in the spleen and liver showed significant difference between organs in infected group (P=0.0219). The density of the parasite load in the spleen (median=2.4) was higher than liver (median=0.8). Immunodetection of apoptotic cells was predominant in lymphocytes and differ between the infected and control group in spleen (P=0.0307) and liver (P=0.0346). There was a significant correlation between apoptosis and parasite load (P = 0.0084; r=0.3104) only in the spleen of the infected group, where it was observed that, when increasing the number of apoptotic cells increases the parasitic load. It was concluded that the liver and spleen of infected dogs presented greater numbers of cells undergoing apoptosis (lymphocytes) than the control group, thus suggesting that this process may be contributing towards the survival of Leishmania in these organs, because lymphocyte in apoptosis did not have the ability to present and recognize the antigen, allowing the survival of the parasite.

Resumo O objetivo deste estudo foi avaliar a apoptose e a carga parasitária no fígado e baço de cães com leishmaniose visceral (LV), pela técnica de imuno-histoquímica. Foram utilizadas amostras de fígado e baço de 71 cães com LV. A carga parasitária no baço e fígado mostrou diferença significativa entre os órgãos no grupo infectado (P=0,0219). A densidade da carga de parasita no baço (média=2,4) foi maior do que no fígado (média=0,8). A imunodetecção de células em apoptose foi predominante nos linfócitos, com diferenças entre o grupo infectado e controle no baço (P=0,0307) e fígado (P=0,0346). Houve uma correlação positiva fraca entre apoptose e carga parasitária (P=0,0084; r=0,3104) apenas no baço do grupo infectado, onde observou-se que quando aumentava o número de células em apoptose aumentava a carga parasitária. Concluiu-se que o fígado e o baço de cães infectados apresentam um maior número de células que sofrem apoptose (linfócitos) do que o grupo controle, sugerindo que este processo possa contribuir para a sobrevivência de Leishmania nestes órgãos, pois os linfócitos em apoptose não tiveram a capacidade de apresentar e reconhecer o antígeno, permitindo a sobrevivência do parasita.

Influence of apoptosis on liver and spleen resistance in dogs with visceral leishmaniosis / Influência da apoptose na resistência hepática e esplênica de cães com leishmaniose visceral

Abstract The aim of this study was to evaluate apoptosis and parasite load in the liver and spleen of dogs with visceral leishmaniosis (VL), using immunohistochemistry. Liver and spleen samples from 71 dogs with VL were used. The parasite load in the spleen and liver showed significant difference between organs in infected group (P=0.0219). The density of the parasite load in the spleen (median=2.4) was higher than liver (median=0.8). Immunodetection of apoptotic cells was predominant in lymphocytes and differ between the infected and control group in spleen (P=0.0307) and liver (P=0.0346). There was a significant correlation between apoptosis and parasite load (P = 0.0084; r=0.3104) only in the spleen of the infected group, where it was observed that, when increasing the number of apoptotic cells increases the parasitic load. It was concluded that the liver and spleen of infected dogs presented greater numbers of cells undergoing apoptosis (lymphocytes) than the control group, thus suggesting that this process may be contributing towards the survival of Leishmania in these organs, because lymphocyte in apoptosis did not have the ability to present and recognize the antigen, allowing the survival of the parasite.

Resumo O objetivo deste estudo foi avaliar a apoptose e a carga parasitária no fígado e baço de cães com leishmaniose visceral (LV), pela técnica de imuno-histoquímica. Foram utilizadas amostras de fígado e baço de 71 cães com LV. A carga parasitária no baço e fígado mostrou diferença significativa entre os órgãos no grupo infectado (P=0,0219). A densidade da carga de parasita no baço (média=2,4) foi maior do que no fígado (média=0,8). A imunodetecção de células em apoptose foi predominante nos linfócitos, com diferenças entre o grupo infectado e controle no baço (P=0,0307) e fígado (P=0,0346). Houve uma correlação positiva fraca entre apoptose e carga parasitária (P=0,0084; r=0,3104) apenas no baço do grupo infectado, onde observou-se que quando aumentava o número de células em apoptose aumentava a carga parasitária. Concluiu-se que o fígado e o baço de cães infectados apresentam um maior número de células que sofrem apoptose (linfócitos) do que o grupo controle, sugerindo que este processo possa contribuir para a sobrevivência de Leishmania nestes órgãos, pois os linfócitos em apoptose não tiveram a capacidade de apresentar e reconhecer o antígeno, permitindo a sobrevivência do parasita.