Concentrações plasmáticas de testosterona, triiodotironina (T3) e tiroxina (T4) em bodes submetidos ao estresse calórico

Para verificar o efeito do estresse calórico (EC) nas concentrações plasmáticas de testosterona, triiodotironina (T3) e tiroxina (T4), oito bodes, das raças Saanen (n=4) e Alpina (n=4), foram mantidos em câmara bioclimática, sob condições de termoneutralidade (13,0ºC a 26,7ºC) durante 30 dias e, após um período (60 dias) de descanso, submetidos ao EC (23,7ºC a 34,0ºC) por 30 dias. Para minimizar as variações sazonais nos perfis hormonais devido ao fotoperíodo, durante toda fase experimental, incluindo a de adaptação em condições de termoneutralidade (30 dias), o fotoperíodo foi controlado utilizando-se alternância de dias longos (16h de luz e 8h de escuro) e de dias curtos (8h de luz e 16h de escuro) a cada 30 dias. As amostras de sangue foram coletadas duas vezes por semana durante cinco semanas. No conjunto das raças, o EC não influenciou (P>0,05) as concentrações de testosterona (1,8±0,2 vs 1,3±0,2ng/ml) e nem a de T4 (52,7±2,8 vs 50,0±2,8ng/ml). Houve declínio (P<0,01) das concentrações de T3 nos animais submetidos ao experimento (1,3±0,1 vs 1,0±0,1ng/ml), mas a redução foi observada somente nos bodes Saanen. em ambas as raças, as concentrações de T3 e T4 variaram (P<0,01) conforme o dia da coleta das amostras de sangue. O EC foi suficiente para produzir uma resposta fisiológica com redução das concentrações plasmáticas de T3 em bodes das raças Saanen, mas não da raça Alpina, assim como não foi capaz de alterar os níveis plasmáticos de testosterona e nem de T4.

Lipid peroxidation and generation of hydrogen peroxide in frozen-thawed ram semen supplemented with catalase or Trolox

Semen manipulation and cryopreservation-thaw procedures may accelerate the generation of reactive oxygen species (ROS). Sperm exposure to large amounts of ROS has been shown to cause membrane lipid peroxidation and cellular injury to the sperm. The objective of this study was to overcome the ROS production in frozen-thawed ram semen by the addition of the antioxidants catalase or Trolox to semen following thawing. Frozen-thawed ram semen (100 x 10(6) sperm/straw) was supplemented with PBS (control group), 100 mu g/ml catalase, or 100 mu M Trolox/10(8) sperm (catalase and Trolox being dissolved in PBS) and incubated (37 degrees C) for 5 min. Under the experimental conditions used in this study, the catalase and Trolox antioxidants failed to protect the sperm from the spontaneous production of ROS. However, when lipid peroxidation was induced by iron (FeSO(4)), the addition of Trolox promoted a reduction (P < 0.05) in the formation of TBARS in the semen, compared to the control and catalase semen samples. The generation of TBARS and H(2)O(2) occurred in the extender alone, without the presence of sperm cells. In conclusion, the addition of Trolox to frozen-thawed ram semen could be beneficial as it decreases the production of TBARS when oxidative stress is induced. It is possible that a longer incubation period could lead to different results. The concentration of catalase also needs to be further evaluated. The extender could contribute to the oxidative stress of sperm, as it is a source of ROS during the cryopreservation of semen. (C) 2010 Elsevier B.V. All rights reserved.

Viability of OPS Vitrified Sheep Embryos After Direct Transfer

The aim of this study was to evaluate the viability in the effect of open pulled straw (OPS) vitrification procedure of sheep embryos after direct transference. Embryos were produced in vivo and cryopreserved in slow freezing or OPS vitrification. The survival rates of cryopreserved embryos were compared to non-frozen standard pattern. In a first set of experiments, embryos at morula and blastocyst stages were dived in ethylene glycol (1.5 M) and frozen in an automatic freezer. After being thawed, they were directly or indirectly transferred to ewes recipient. A second group of embryos were drawn into OPS and plunged into liquid nitrogen after being exposed at room temperature for 1 min and 45 s in 10% EG plus 10% dimethyl sulphoxide (DMSO), then again for 30 s in 20% EG + 20% DMSO + 0.5 M sucrose. After being warmed, embryos were also directly transferred using a French mini straw as the catheter for the transplantation process or after in vitro dilution of cryoprotectants (two-step-process). No significant difference was observed among fresh, frozen or vitrified embryos on pregnancy rate (50.0%, 38.6% and 55.8%). However, when we evaluated only the direct transference, the pregnancy rate of OPS vitrified embryos was higher than that of frozen embryos (57.1% vs 34.8%) (p = 0.07). In addition, vitrified morulae had a higher pregnancy rate than the one with frozen embryos (64.0% vs 38.9%) (p = 0.07). Finally, our results indicate that OPS vitrification technique in association with direct transference improves the viability of sheep embryos with potential applications to field conditions.

Motility and viability of ram sperm cryopreserved in a Tris-egg yolk extender supplemented with anti-oxidants

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

Lipid peroxidation and generation of hydrogen peroxide in frozen-thawed ram semen cryopreserved in extenders with antioxidants

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

Peritonite pós-cobertura em cadela Boxer apresentando síndrome de ovário remanescente (SOR)

The ovarian remnant syndrome (ORS) is defined as the persistence of ovarian activity in surgically spayed females, in which part or the entire ovary remains after the surgical procedure. ORS is characterized as a neo-vascular formation that promotes the organ's functions again, and may occur in cats and dogs. This condition causes the return of all undesirable signs of estrus, like male attraction, vaginal secretion (proestral bleeding), anxiety, pseudocyesis, among other symptoms. The recommended treatment is the surgical removal of the remaining ovary tissue. However, this procedure should be performed at the estrogenic stage of the cycle, when the remaining ovary tissue is enlarged due to the presence of follicles, which facilitates its location. Apparently there are no papers on the consequences of an undesirable breeding. Thus, the objective of this article was to report a case of peritonitis in a bitch with ORS after natural breeding, referred to the Hospital Veterinario da Faculdade de Medicina Veterinaria e Zootecnia da UNESP, campus Botucatu, São Paulo, Brazil.

Comparative assessment of the organization of the colors of the Vita Classical color pallet by digital images and visual analysis for dental bleaching

New formularizations, techniques and devices have become the dental whitening most safe and with better results. Although this, the verification of the levels whitening is being continued for visual comparison, that is an empirical, subjective method, subject to errors and dependent of the individual interpretation. Normally the result of the whitening is express for the amplitude of displacement between the initial and the final color, being take like reference the tonalities of a scale of color commanded of darkest for more clearly. Although to be the most used scale, the ordinance of the Vita Classical (R) - Vita, according to recommendations of the manufacturer, reveals inadequate for the evaluation of the whitening. From digital images and of algorithm OER (ordinance of the reference scale), especially developed for the ScanWhite (C), the ordinance of the tonalities of the scale Vita Classical (R) was made. For such, the values of the canals of color R, G, and B of medium part average of the crowns was adopted as reference for evaluation. The images had been taken with the camera Sony Cybershoot DSC F828. The results of the computational ordinance had been compared with the sequence proposal for the manufacturer and with the earned one for the visual evaluation, carried through by 10 volunteers, under standardized conditions of illumination. It statistics analyzes demonstrated significant differences between the ordinances.