Triggering ovulation with 250 µg or 500 µg of r-hCG in oocyte donors treated with antagonist protocol has no effect on the number of mature oocytes retrieved: a randomized clinical trial.

The aim of this study is to compare two r-hCG doses to trigger ovulation (250 µg vs. 500 µg of r-hCG) in an oocyte donation program. A prospective, randomized study was conducted in 118 oocyte donors. Group DI received 250 µg and Group DII received 500 µg of r-hCG. Both the groups were homogeneous. No significant differences were found in the total dose of gonadotropins, duration of the treatment, total number of oocytes, or Metaphase II (MII)oocytes. The pregnancy rate per embryo transfer in the corresponding recipients was similar for both the groups (58.2% for DII recipients and 56.1% for DI recipients). Mild hyperstimulation was observed in 17 donors in Group DI (29%) and in 23 donors in Group DII (39%). No cases of severe ovarian hyperstimulation syndrome (SOHSS) were observed. In conclusion, a double dose of r-hCG in oocyte donors to trigger ovulation after stimulation with r-FSH and antagonist does not translate into a higher number of MII oocytes retrieved or into higher pregnancy rates among recipients. Our results confirm that the optimal dose to induce the final oocyte maturation with r-hCG is 250 µg, and that a higher dose does not add any benefit.

Ultrasound-assisted solvent extraction of total polycyclic aromatic hydrocarbons from mussels followed by spectrofluorimetric determination.

An ultrasound-assisted solvent extraction procedure has been optimised to speed up total polycyclic aromatic hydrocarbons (T-PAHs) extraction from mussel soft tissue. The T-PAHs releases have been evaluated by spectrofluorimetry (excitation and fluorescence emission wavelengths of 300 and 382nm, respectively, and using chrysene as calibrant). Variables such as sonication time, ultrasound frequency, n-hexane volume, dichloromethane volume, number of repeated extractions with n-hexane and number of repeated extraction with dichloromethane were simultaneously studied by applying a Plackett-Burman design (PBD) approach. Results showed that ultrasound frequency and n-hexane and dichloromethane volumes were statistically significant variables (confidence interval of 95%). These last two variables were finally optimised by using central composite designs (CCD), yielding optimum n-hexane and dichloromethane volumes of 2.5 and 6.5ml, respectively. The lowest T-PAHs releasing at high ultrasound frequency (35kHz) led to choice the lowest ultrasound frequency (17kHz) to perform the extraction. Variables such as sonication time and number of repeated extraction with n-hexane or dichloromethane were statistically non-significant and they were fixed at 10min and the extraction with n-hexane and dichloromethane were performed once. The limit of detection was 0.021mugg(-1) (referred to dried mass), the repeatability of the overall method was 4.7% (n=9) and the analytical recoveries were between 98 and 105%. The proposed method was finally applied to 16 mussel samples (Mytilus galloprovincialis) from Ría de Arousa estuary (Galicia, northwest Spain).