Mouse blastocyst vitrification compared with the conventional slow-freezing method.

To compare mouse blastocyst survival after cryopreservation with vitrification and the slow-freezing method, one-hundred and forty-eight in vitro mouse blastocysts were randomly frozen by the two methods: vitrification and conventional slow-freezing. After being thawed, the blastocysts were assessed for survival and hatching rate. The survival rates of blastocysts cryopreserved by vitrification and slow-freezing were 68.33 and 65.52 per cent (p = 0.89), whereas hatching rates were 51.22 and 44.74 per cent, respectively (p = 0.64). Therefore, vitrification of blastocyst-stage-embryos may be a useful, economic method for freezing the excess blastocysts in some centers where blastocysts are routinely transferred.

Fetal metabolism.

Normal reference ranges for apolipoprotein A-I, apolipoprotein A-II, apolipoprotein B, total triglyceride, total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol + chylomicron, plasma glucose, total protein, albumin and globulin were determined from 25 fetal plasma samples between 21-39 weeks' gestation. Pure fetal blood was obtained by cordocentesis under continuous ultrasound guidance. They were referred to us for advanced maternal age and a previous chromosomal aneuploidy baby. All these biochemical parameters excepts total protein and albumin showed no change with gestational age. These normal values of fetal metabolism will improve our knowledge of physiology and help to determine the specific values of a test in fetal pathology.

Estradiol and follicle-stimulating hormone levels in oophorectomized women using vaginal estrogen.

To assess the changing estradiol (E2) and follicle-stimulating hormone (FSH) level in oophorectomized women using vaginal estrogen. Serum estradiol and FSH were evaluated in 32 oophorectomized women using a daily dose of 2 g base of 1.25 mg vaginal conjugated equine estrogen (CEE) cream. The blood sample for hormone assay was collected 8-10 hours from the time of vaginal application. E2 and FSH levels were measured in the serum sample before and after commencing the study at 4, 8 and 12 weeks using the time-resolved fluoroimmunoassay method. Serum estradiol significantly increased from baseline value at 4, 8 and 12 weeks. (Mean +/- SD of E2 value at 0, 4, 8, 12 weeks: 9.97 +/- 12.13, 249.83 +/- 170.46, 299.38 +/- 190.65, 322.82 +/- 218.31 pmol/L, respectively, P < 0.05) On the other hand, serum FSH significantly decreased from baseline value at 4, 8 and 12 weeks. (Mean +/- SD of FSH value at 0, 4, 8, 12 weeks: 77.64 +/- 27.24, 40.33 +/- 21.64, 38.84 +/- 22.33, 30.90 +/- 24.32 IU/L, respectively, P < 0.05) In conclusion, a daily dose of 2 g vaginal CEE cream raised the serum estradiol level close to the normal level in the follicular phase of the normal menstrual cycle. However, even though FSH significantly decreased it did not reach the premenopausal level.