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L Roblero

Publications and source records attributed to L Roblero.

17 recordsLinked to original sources
PubMed1992

Pregnancy rate in an oocyte donation program.

Oocyte donation programs offer an alternative treatment for infertile women with ovarian failure or abnormal ovarian function. Seventeen cycles of in vitro fertilization and embryo transfer with donated oocytes were performed in 13 women, with a mean age of 34.8 years. The hormonal replacement therapy consisted of a fixed dose of oral estradiol valerate, 6 mg daily, and intramuscular progesterone in oil, 100 mg daily. Estrogen and progesterone were continued for 10 more weeks after embryo transfer if pregnancy was established. After 13 embryo transfers, 8 pregnancies were obtained, for a pregnancy rate per transfer of 61.5%. Today seven pregnancies are progressing normally, including one set of twins. This results suggest that an oocyte donation program using a fixed and simple hormonal replacement therapy is an adequate treatment for these infertile couples.

Adult↗
PubMed1988

High potassium concentration improves the rate of acrosome reaction in human spermatozoa.

Progressively motile spermatozoa recovered by swim-up method from semen of two fertile men were incubated for 24 hours in culture media containing either 4.7, 15, or 25 mM of potassium (K). Aliquots of each culture condition were obtained at 0, 1, 5, 10, and 24 hours of incubation for the assessment of progressive motility, percentage of dead spermatozoa, and percentage of acrosome reaction (AR), as measured by triple-stain technique. A total of ten experiments including each K concentration were analyzed. The results of this study showed no effect of K concentration on the percentage of progressively motile spermatozoa, irrespective of the time of incubation. The percentage of live spermatozoa was significantly greater in culture medium containing 25 mM K (P less than 0.05). There was a greater percentage of reacted spermatozoa with 25 mM K, as compared with 4.7 and 15 mM (P less than 0.05). Furthermore, the time taken to achieve 20% of AR was 2 hours at 25 mM K compared with 10.9 hours at 4.7 mM K.

Acrosome↗
PubMed1983

Effect of exogenous sex steroids upon the number of germ cells and the growth of foetal ovaries grafted under the kidney capsule of adult ovariectomized hamsters.

The effect of estradiol E, progesterone P and testosterone propionate T upon growth and germ cell population of foetal ovaries transplanted under the kidney capsule of adult ovariectomized hamsters was examined. Foetal ovaries were obtained 15 days postcoitum and the host received daily subcutaneous injections of E (1 micrograms/day), P (5 mg/day), T (500 micrograms/day) or E + P in 0.1 ml oil for 25 days beginning 5 days before grafting. One day after the last injection, the size of the ovary, the germ cell population and plasma steroid levels were assessed. The results of hormone assays indicate that daily steroid administration was able to maintain continuously elevated plasma levels of the corresponding hormone. Interconversions or steroid secretion by the graft, if any, were not reflected in the peripheral circulation. The growth of the graft was stimulated by T and inhibited by P, in comparison with E and oil-treated controls. All germ cells were at the stage of primary oocyte forming part of a primordial or growing follicle. Their absolute number was significantly increased by T and E and significantly decreased by P and E + P. The number of oocytes per mm3 of ovary was increased 80%, 48% and 40% with E, T and E + P, respectively. It is concluded that, in the hamster, exogenous sex steroids given to the host can exert specific effects upon the growth and oocyte population of a grafted foetal ovary. Whether or not the action of steroids upon the graft is a direct one and whether they influenced oogonial mitosis, the evolution of the meiotic prophase or atresia of primary oocytes remains to be determined.

Animals↗
PubMed1981

Embryo development under the effects of a new placental protein (UTPH) and its antiserum.

The effect of a human placental hormone (UTPH) and UTPH-antiserum upon development of preimplantation mouse embryos was studied in vitro. UTPH at a concentration of 90 micrograms/ml had a tendency to increase the mean number of blastomeres pre embryo, and increased significantly (P less than 0.01) upon the cleavage rate. These data suggest an influence of the UT UTPH upon the early development of the embryo in mammals.

Animals↗
PubMed1979

A method for the in vivo experimental study of meiotic prophase in the golden hamster (Mesocricetus auratus).

Gonads of 15 day-old hamster fetuses were grafted under the kidney capsule of adult ovariectomized females. In 81.8% of the grafts, the germ cells developed and completed meiotic prophase; they reached the diplotene stage and gave rise to primordial follicles. These grafts could survive well in the host for at least 20 days. Meiotic prophase was not initiated within 24 h of grafting in contrast to the in vivo condition where it is observed 24 h after birth. In grafted ovaries, 69% of the germ cells were at the leptotene stage on day 3. By day 5, most of them were either at the zygotene (15%) or pachytene stages (60%). Oocytes at the diplotene stage were found from day 5 onwards and on day 7, 30% of the germ cells had already reached this stage. The highest numbers of atretic germ cells could be found on days 1, 9 and 10 post graft. It is noteworthy that the number of germinal cells remaining in the ovary 10 and 20 days after grafting were 11.4% and 12.9% of the total number of germinal cells present in normal animals of the same ages post-partum. This point is discussed in detail.

Animals↗