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Biomedical subjects

G Leyendecker

Publications and source records attributed to G Leyendecker.

At least 19 recordsLinked to original sources
PubMed1992

[Ganglioneuroma of the pelvis accompanying pregnancy].

Ganglioneuroma is an uncommon benign tumor of the sympathetic nervous system. In most cases it originates from the thoracic or lumbar portion of the gangliated cord or from the medulla of the suprarenal glands. It is the differentiated form of malignant neuroblastoma. The tumor often manifests itself in young adults by displacement of the surrounding structures. In the case presented the special diagnostic problems of locating the tumor in the pelvis in early pregnancy are discussed.

Adult↗
PubMed1990

Influence of the duration of the oestradiol rise on the success rate in GnRH analogue/HMG-stimulated IVF cycles.

The influence of the duration of the serum oestradiol (E2) rise before human chorionic gonadotrophin (HCG) injection on the outcome of in-vitro fertilization (IVF) cycles was investigated. Two different stimulation protocols were compared. In 218 cycles, the Norfolk protocol for stimulation with human menopausal gonadotrophin (HMG) was used (protocol A). In 235 cycles, pituitary function was suppressed by a single injection of a long-acting GnRH analogue ('Decapeptyl microcapsules') before HMG stimulation was started (protocol B). The overall pregnancy rates were significantly higher with protocol B (22% per puncture, 21% per started cycle) than with protocol A (14% per puncture, 9% per started cycle). For each interval of E2 rise duration (5-11 days), the fertilization rates (per oocyte) and the pregnancy rates (per puncture) were evaluated. There was a clear-cut maximum of the pregnancy rates for 6 and 7 days of E2 rise (21 and 16% respectively) for protocol A. For protocol B, pregnancy rates were generally higher than for protocol A. There was also a maximum of the pregnancy rates for 6 (32%) and 7 (29%) days of E2 rise but this maximum was not as clear-cut as for protocol A. The fertilization rates showed no significant differences for each interval of E2 rise in both groups (between 63 and 89%). Therefore, it is concluded that endometrial maturity, and not the oocyte's ability for fertilization, is the most critical factor for success in IVF cycles.(ABSTRACT TRUNCATED AT 250 WORDS)

Chorionic Gonadotropin↗
PubMed1990

Frozen storage of Ham's F10 medium for human in-vitro fertilization.

A method of frozen storage of Ham's F10 medium was investigated that provides 'ready-to-use' culture medium for human in-vitro fertilization, without the necessity of readjusting and testing the medium after thawing. Ham's F10 medium, without bicarbonate, was adjusted to 245 mOsm/kg and stored in aliquots of 33 ml at -20 degrees C. Aliquots of 1 ml of a 7.5% (w/v) sodium bicarbonate solution were stored separately at the same temperature. The two components were mixed together after thawing. In the first test series, mouse embryos were cultured in media stored frozen for varying intervals between 2 weeks and 6 months and no difference in the rates of blastocyst formation was detected. Frozen-stored Ham's F10 medium was then used for human IVF in 256 cycles performed within a 16-month period in two different IVF centres. The pregnancy rates were evaluated and correlated with the duration of the frozen storage (between 1 week and 3 months) and compared to the outcome of 24 cases in which non-frozen medium was used. There was no significant difference in the pregnancy rates in the different groups (19% with non-frozen medium and between 21 and 33% with frozen-stored medium). Thus it was shown that there is no loss of quality of the frozen-stored media within the tested period of 3 months. The prolonged storage interval offers the possibility of extended quality tests and cross-tests between different IVF laboratories.

Animals↗
PubMed1990

Bone mass reduction after estrogen deprivation by long-acting gonadotropin-releasing hormone agonists and its relation to pretreatment serum concentrations of 1,25-dihydroxyvitamin D3.

Estrogen deficiency results in bone mass reduction of largely varying extent in postmenopausal females, indicating that additional mechanisms influence the response of bone. They are by no ways identified in either the animal experiment or under clinical conditions. In search for factors, conditioning the response of bone to estrogen deficiency, we have conducted a study in females under treatment with the GnRH agonist decapeptyl (D-Trp6-LHRH). This drug blocks ovarian function and was administered for treatment of endometriosis or uterine leiomyoma. We determined spinal (dual photon absorptiometry) and forearm (single photon absorptiometry) bone mineral density before and 3 and 6 months after the onset of therapy and measured biochemical parameters of bone metabolism. Our results showed an increase in bone turnover after initiation of estrogen deficiency, as indicated by the elevation of alkaline phosphatase and osteocalcin. This resulted in a secondary decrease in serum intact PTH and 1,25-dihydroxy-vitamin D3. Furthermore, we found a positive correlation between pretreatment values of serum 1,25-dihydroxyvitamin D3 as well as its decrease and the reduction in bone mass during GnRH agonist treatment. This demonstrates that the patients' metabolic conditions predict their response to estrogen deficiency.

Adult↗
PubMed1989

[Early manifestation of severe gestosis (pre-eclampsia) in fetal triploidy--diagnosis and obstetrical management].

A case is reported of early-onset pre-eclampsia combined with severe malformations including holoprosencephaly and hydrocephaly caused by triploidy. By ultrasonic diagnosis, maternal risks caused by either prolonged pregnancy because of immaturity or inappropriate obstetrical management, i.e. by caesarean section, could be avoided. Ventriculocentesis of the macrocephalic fetus was performed and abortion induced.

Abnormalities, Multiple↗
PubMed1989

Reversible bone loss in women treated with GnRH-agonists for endometriosis and uterine leiomyoma.

Oestrogen deficiency at the menopause is associated with changes in calcium and bone metabolism. Hypo-oestrogenism induced by the use of GnRH-agonists is clinically useful in the treatment of oestrogen-dependent diseases. This study was done to investigate calcium homeostasis and bone metabolism of pre-menopausal women in a GnRH-agonist-induced pseudo-menopause. Eighteen patients with endometriosis or uterine leiomyoma received monthly i.m. injections of 3.2 mg of long-acting D-Trp-6-LHRH over a 6-month period. Plasma oestradiol-17 beta and progesterone levels under treatment were significantly decreased to the levels of the early follicular phase. Plasma total calcium, serum osteocalcin and plasma alkaline phosphatase concentrations increased, while plasma phosphate levels did not change. Levels of 1,25-dihydroxyvitamin D3 decreased significantly, but 25-hydroxyvitamin D3 values remained constant. Trabecular bone mineral density of lumbar spine decreased continuously during the 6-month period. Nine women completed 6-9 months follow-up. In these women bone loss was reversible. Cortical bone measurements at the proximal radius showed no change during oestrogen deficiency. In conclusion, our findings demonstrate that GnRH-agonist-induced bone loss is reversible. Furthermore, they suggest that the state of pseudo-menopause induced by GnRH-agonist may serve as a model for further pathophysiological studies on calcium homeostasis and bone metabolism in the post-menopause.

Adult↗
PubMed1987

Clinical and endocrinological characterization of two subjects with Reifenstein syndrome associated with qualitative abnormalities of the androgen receptor.

The androgen receptor in fibroblasts cultured from a biopsy of scrotal skin from 1 subject with Reifenstein syndrome has been found to be normal in amount and to bind dihydrotestosterone with normal affinity but to be qualitatively abnormal as evident by thermolability and instability upon ultracentrifugation. The family study of this subject and endocrine studies document androgen resistance in the index patient and his affected uncle. These findings provide evidence for X-linkage of this disorder, and suggest that the mutations that give rise to this phenotype are probably allelic to the mutations of the androgen receptor that cause testicular feminization.

Adolescent↗
PubMed1987

Pulsatility of serum LH in pathological conditions.

LH pulsatility changes throughout the normal menstrual cycle. The number of LH pulses increases during the first days after menstruation, remains unchanged thereafter until after ovulation and declines progressively during the luteal phase. LH pulse amplitude is highest during midcycle. In hypothalamic amenorrhea, gonadotropin levels are reduced. This appears to be a consequence of a reduction of hypothalamic Gn-RH secretion which is reflected by a diminished frequency and amplitude of LH pulses during the 24-hour span. Administration of an opiate antagonist, naloxone, increases LH pulse frequency in those patients, and in patients with secondary hypothalamic amenorrhea the daily oral administration of naltrexone, another specific opiate antagonist, induces ovulatory cycles. Patients suffering from hyperandrogenemia may present with eumenorrhea, oligomenorrhea or amenorrhea. There is an increase in mean LH levels and of the LH/FSH ratio with increasing severity of the ovarian disturbance. The increase in mean LH levels is a consequence of an increase in LH pulse amplitude while LH pulse frequency is not changed compared to the early follicular phase of the menstrual cycle.

Amenorrhea↗
PubMed1987

Induction of ovulation by the chronic administration of naltrexone in hypothalamic amenorrhea.

Ovulatory menstrual cycles were induced by the administration of the specific opiate antagonist naltrexone at a dose of 50 mg/day for 28 days in 3 women suffering from secondary hypothalamic amenorrhea. The occurrence of ovulation was based on demonstration of follicular growth and corpus luteum formation by ultrasonography and a LH midcycle surge and rise of progesterone. After discontinuation of treatment, the women became amenorrheic again and serum gonadotropins as well as estradiol declined to the low levels found before naltrexone administration. Naltrexone or other specific opiate antagonists may be useful agents for the induction of ovulation in patients with hypothalamic amenorrhea.

Adult↗
PubMed1985

Induction of puberty in a patient with hypogonadotropic hypogonadism: effect of sequentially applied hCG and pulsatile GnRH administration.

Pulsatile substitution with GnRH appears to be the therapy of choice in patients with Kallmann's syndrome, a well defined type of hypogonadotropic hypogonadism. We tried to simplify the treatment and to limit the subcutaneous GnRH therapy to the period absolutely necessary to induce spermatogenesis. Therefore we applied in sequence first hCG to stimulate testicular growth and second pulsatile GnRH application to induce spermatogenesis. We herein report that with this mode of therapy testicular growth from infantile to adult size and normal spermatogenesis could be achieved. We conclude that pulsatile GnRH application is a new effective therapy of hypogonadotropic hypogonadism which can be simplified considerably by pretreatment with hCG.

Adult↗