The objective of this study was to investigate the effect of follicle stimulating hormone (FSH) priming on the in-vitro maturation (IVM) of human oocytes from healthy ovaries using a chemically defined culture system. Seventeen patients donating oocytes for research received a truncated course of 600 IU FSH over 5 days and a further control group of nine patients received no FSH treatment. Mid-follicular phase cumulus-enclosed oocytes (n = 160) were aspirated from follicles < or =4 mm diameter under transvaginal ultrasound guidance and were cultured for 48 h in microdrops of medium containing 10 mIU/ml FSH and 100 mIU/ ml human chorionic gonadotrophin (HCG). The results demonstrated that human oocytes will efficiently undergo IVM under serum-free conditions. After mild FSH stimulation, a greater number of cumulus-enclosed oocytes was collected, and following culture, a lower rate of degeneration was observed. Significantly more oocytes completed nuclear maturation to metaphase II following FSH stimulation (71.1 versus 43.5%). In conclusion, a truncated course of FSH stimulation in vivo improved the oocyte maturation rate in vitro, giving a mean of 4.8+/-0.7 metaphase II oocytes per patient compared with only 2.1+/-0.7 from control patients, thus yielding more mature oocytes for future IVF treatment.

One hundred and twenty lambs were used to study the effects of breed (Merino or Dorset Horn x (Border Leicester x Merino)), sex (entire or castrate male) and liveweight (birth to 50 kg) on carcass conformation and composition. Merinos were lighter at birth and grew more slowly than crossbreds in both the pre- and post-weaning phases (P < 0.01). Rams grew significantly faster than wethers only after weaning (P < 0.01). Merinos exceeded crossbreds in height at withers and chest depth (P < 0.01), but the reverse was true for width at 'hooks' (P < 0.01) and length of pelvis (P < 0.05). Sex differences were confined to chest girth, which was greatest in wethers (P < 0.01). Eye muscle width and area were greater in crossbreds than Merinos (P < 0.01). Growth coefficients for bone and muscle calculated on the basis of both half-carcass weight and half-carcass muscle-plus-bone weight were comparable with reports in the literature. For fat, however, the coefficients were considerably higher than has been reported previously (1.938-2.010 and 2.364-2.563 for the half-carcass and the muscle-plus-bone bases respectively). When their values were averaged over the range of slaughter weights studied, crossbreds yielded more bone (P < 0.05), muscle and fat (P < 0.01) than Merinos. Rams yielded more bone (P < 0.05) and less fat (P < 0.01) than wethers. Variation in yields of muscle and fat were due largely to differences in tissue deposition in animals slaughtered at 40 and 50 kg liveweight. Partial correlation analysis indicated that changes in carcass composition were largely accounted for by differences in liveweight.

all IVF centres in Germany. This should allow the register to become a reliable instrument for measurement of quality control in this very sensitive field of medicine, which is observed intensely by the social and political public. This may allow the establishment of a German quality standard, taking into account the special conditions of the German embryo protection law. 11.15-11.30 0-020. Initiation of human primordial follicle growth in vitro in ultrathin slices of ovarian cortex

The development of a procedure to culture wool follicles from Merino sheep in serum-free conditions has enabled us to investigate the actions of epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) on follicle function, including fibre growth. Follicles grown in the absence of growth factors maintained their anagen morphology for 6 days as determined by light microscopy. During this time they incorporated [3H]thymidine into the DNA of the bulb matrix and outer root sheath (ORS) cells and produced fibre keratins as detected by immunohistochemistry. In the presence of EGF and TGF alpha, fibre production ceased after 4 days, as it does following the administration of EGF in vivo. Cessation of fibre growth was not accompanied by regression of the follicle bulb which occurs in vivo. Follicle length growth did not differ significantly from controls and cells in the bulb continued to proliferate. Usually, the structure of the dermal papillae resembled that in control follicles, which was also in marked contrast to changes reported in vivo. In EGF- and TGF alpha-treated follicles, [3H]thymidine continued to be incorporated into DNA of the ORS and bulb after fibre growth ceased. Although wool keratin synthesis ceased, cytokeratins of the epidermis and ORS continued to be produced in the bulb as detected by immunochemistry. These bulb cells were also positive for the periodic acid-Schiff (PAS) reaction indicating the presence of glycogen, a normal component of ORS cells. The observations that cell proliferation continued in the bulb, that glycogen was present and that soft keratins were expressed in these cells suggest that the bulb cell population was induced to differentiate into an ORS phenotype by EGF and TGF alpha.

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