Activation and early parthenogenesis of bovine oocytes treated with ethanol and strontium

Efficient artificial activation is indispensable for the success of cloning programs. Strontium has been shown to effectively activate mouse oocytes for nuclear transfer procedures, however, there is limited information on its use for bovine oocytes. The present study had as objectives: (1) to assess the ability of strontium to induce activation and parthenogenetic development in bovine oocytes of different maturational ages in comparison with ethanol; and (2) to verify whether the combination of both treatments improves activation and parthenogenetic development rates. Bovine oocytes were in vitro matured for 24, 26, 28, and 30 h, and treated with ethanol (E, 7% for 5 min) or strontium chloride (S, 10 mM SrCl2 for 5 h) alone or in combination: ethanol + strontium (ES) and strontium + ethanol (SE). Activated oocytes were cultured in vitro in synthetic oviductal fluid (SOF) medium and assessed for pronuclear formation (15-16 h), cleavage (46-48 h) and development to the blastocyst stage (M). Treatment with ethanol and strontium promoted similar results regarding pronuclear formation (E, 20-66.7%; S, 26.7-53.3%; P > 0.05) and cleavage (E, 12.8-40.6%; S, 16.1-41.9%; P > 0.05), regardless of oocyte age. The actions of both strontium and ethanol were influenced by oocyte age: ethanol induced greater activation rates after 28 and 30 h of maturation (48.4 and 66.7% versus 20.0 and 23.3% for 24 and 26 It, respectively; P < 0.05) and strontium after 30 It (53.3%) was superior to 24 and 26h (26.7% for both). Blastocyst development rates were minimal in all treatments (0.0-6.3%; P > 0.05), however, when the mean (+/-S.D.) cell number in blastocysts at the same maturational period was compared, strontium treatment was superior to ethanol for activation rates (82 +/- 5.7 and 89.5 +/- 7.8 versus 54 and 61, at 28 and 30 h, respectively). Improved results were obtained by combined treatments. The combination of ethanol and strontium resulted in similar pronuclear formation (ES, 36.7-83.9%; SE, 53.1-90.3%) and cleavage rates (ES, 31.3-81.3%; SE, 65.6-80.7%). Regarding embryo development, there was no difference (P > 0.05) between treatments, and blastocysts were only obtained in treatment SE at 24 and 26 h (6.5% for both). It is concluded that, SrCl2 induces activation and parthenogenetic development in bovine oocytes. (C) 2003 Elsevier B.V. All rights reserved.

Avaliação de parentais e híbridos experimentais de melão rendilhado

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

Validade e reprodutibilidade do Wii Balance Board para avaliação do equilíbrio vertical estático: um novo método de avaliação.

The Wii Balance Board (WBB) began to be investigated as a low-cost alternative for assessing static balance in vertical posture. However, studies employed methodological procedures that did not eliminate result variability between the tests and equipment used. Objective: Determine the validity and reproducibility of the WBB as an instrument for assessing static balance in the vertical position, using simultaneous data analysis and superimposed equipment. Methods: This is an accuracy study of 29 healthy young individuals of both sexes aged 18 to 30 years. Subjects were assessed 24h apart (test-retest), using unipodal and bipodal support tests, with eyes closed and open. To that end the WBB was placed on top of a force platform (FP) and data (postural sway) were collected simultaneously on both devices. Validity and reproducibility were analyzed using the interclass correlation coefficient (ICC). Finally, Bland-Altman analysis was applied to assess agreement. Results: The sample was composed of 23 women and 6 men, with mean age of 24.2±6.3 years, 60.7±6.3 kg and 1.64±4.2 m. The validity of the WBB compared to the FP was excellent for all 4 tasks proposed (ICC = 0.93 0.98). The reproducibility analyzed by test-retest was excellent for the bipodal support tasks (ICC = 0.93-0.98) and only moderate for the unipodal support tests (ICC = 0.46 0.70). Graphic analysis exhibited good agreement between the devices, since most of the measures were within the limits of agreement. Conclusion: this study proved the validity and reproducibility of the Wii Balance Board as an instrument for assessing static balance in vertical posture, using simultaneous analysis with superimposed equipment. Thus, the WBB has been increasingly used by physical therapists and other health professionals in their clinical practice, as both a rehabilitation and assessment tool