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Biomedical subjects

M I Cedars

Publications and source records attributed to M I Cedars.

29 records · Page 2Linked to original sources
PubMed1992

Pituitary function before, during, and after chronic gonadotropin-releasing hormone agonist therapy.

OBJECTIVE: To examine possible adverse effects on pituitary function of long-term administration of gonadotropin-releasing hormone agonist (GnRH-a). DESIGN: Prospective analysis of blood sampling before, during, and after GnRH-a therapy. SETTING: Tertiary institutional outpatient care. PATIENTS: Twelve normally ovulatory women with a diagnosis of endometriosis. INTERVENTIONS: Six-month suppression with GnRH-a. MAIN OUTCOME MEASURES: Serum levels of follicle-stimulating hormone, luteinizing hormone, free thyroxin index, cortisol (F), growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone (TSH). RESULTS: Basal and stimulated values of gonadotropins, PRL, F, TSH, and GH were normal and unchanged by 6 months of GnRH-a after resumption of menses. CONCLUSIONS: Utilizing dynamic pituitary function tests, we were unable to demonstrate an adverse effect of long-term GnRH-a therapy on pituitary function.

Adult↗
PubMed1992

Hypergonadotropic forms of amenorrhea in young women.

Hypergonadotropic forms of amenorrhea in young women are many and varied, and the disorder is not nearly as uncommon as previously believed. It is likely that all physicians seeing women with amenorrhea will encounter this disorder. Careful evaluation is warranted to eliminate any associated autoimmune disorders. Because of the high likelihood of osteopenia in affected individuals, estrogen replacement therapy is warranted. Although pregnancy is possible in women with secondary hypergonadotropic amenorrhea, remarkably it most commonly occurs in women utilizing exogenous estrogen. Women desirous of achieving a pregnancy are best served by assisted reproductive technology utilizing donor oocytes. Success rates in such patients have been quite high. Thus, physicians today can counsel affected women that pregnancy is indeed possible, even in women with so-called "premature ovarian failure."

Adult↗
PubMed1992

Long-term transdermal estradiol therapy: effects on endometrial histology and bleeding patterns.

Sixty postmenopausal women were enrolled in a 2-year randomized unmasked trial to determine the long-term safety of estradiol (E2) administration by a transdermal therapeutic system. Group I subjects received 0.1 mg of transdermal E2 for 24.5 days of each 28-day cycle for 96 weeks. Group II subjects received the same dosage of transdermal E2 plus 10 mg of medroxyprogesterone acetate, given orally from days 13-25 of each cycle. Vaginal bleeding patterns and endometrial histology were characterized. The subjects recorded bleeding patterns daily. Endometrial biopsies were performed during scheduled follow-up visits at 48 and 96 weeks or as needed to evaluate abnormal bleeding. Data were analyzed by intention to treat. Ten and four subjects dropped out of the study from groups I and II, respectively. A total of 575 and 627 treatment cycles were observed in the same respective groups. Vaginal bleeding was observed in 980 cycles: 381 of 575 cycles in group I (66.3%) and 599 of 627 cycles in group II (95.5%). Bleeding onset, duration, and quantity were similar for both groups. The incidence of hyperplasia was 42 and 4% for groups I and II, respectively, over the 96-week study period. All cases of hyperplasia in group I were treated with sequential medroxyprogesterone acetate for 12 weeks, followed by rebiopsy. In ten of 11 cases, the progestin therapy converted the hyperplasia to a normal endometrium. In one case, the endometrium became hyperplastic again at 96 weeks, but reverted to normal with 12 weeks of medroxyprogesterone acetate.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗
PubMed1990

Leuprolide acetate lowers circulating bioactive luteinizing hormone and testosterone concentrations during ovarian stimulation for oocyte retrieval.

Levels of immunoreactive luteinizing hormone (LH), bioactive LH, and testosterone (T) were determined in 52 women receiving human menopausal gonadotropins (hMG). In 26 women receiving leuprolide acetate (LA) preceding hMG, there was a significant suppression of immunoreactive LH and bioactive LH. The characteristic increase in serum levels of bioactive LH and T were absent. Follicular fluid estradiol and T concentrations, and serum progesterone were not different. The lower circulating levels of T may reflect reduced LH-stimulated androgen accumulation in smaller nonaspirated follicles and may account for the enhanced follicle recruitment observed during LA. The lack of premature luteinization despite marked rises of bioactive LH in the absence of LA is consistent with normal events during the menstrual cycle and was due to the early termination of hMG stimulation.

Chorionic Gonadotropin↗
PubMed1990

Treatment of endometriosis with a long-acting gonadotropin-releasing hormone agonist plus medroxyprogesterone acetate.

Highly potent agonists of gonadotropin-releasing hormone (GnRH) have been shown to reduce pelvic pain due to endometriosis and the size and number of implants seen at laparoscopy. The accompanying symptoms and problems associated with the hypoestrogenism induced by the agonist have reduced its acceptability and raised questions about its safety. In an attempt to optimize this form of therapy, we treated eight women with endometriosis with daily subcutaneous injections of a potent agonist of GnRH plus a daily oral dose of 20-30 mg of medroxyprogesterone acetate for 24 weeks. Ovarian estrogen secretion was reduced to levels seen in castrated women throughout the course of treatment. Markers of hypoestrogenism, such as hot flashes and loss of calcium from bone, were diminished with this regimen compared with previous findings with GnRH agonist alone. Blinded evaluation of laparoscopic photographs failed to reveal improvement or suppression of active endometriosis. The results of this pilot study indicate that the addition of medroxyprogesterone acetate decreases the hypoestrogenic effects of GnRH agonist alone but fails to affect pain or endometriotic implants.

Adult↗
PubMed1989

The effect of gonadotropin suppression on the induction of ovulation in premature ovarian failure patients.

Ovulation induction in patients with hypergonadotropic premature ovarian failure is rarely successful. The authors have attempted to reproduce the results of recent case reports that suggest that ovulation and pregnancy can be successfully achieved when estrogen therapy precedes or coincides with ovarian stimulation with human menopausal gonadotropins (hMG). Fourteen patients with idiopathic premature ovarian failure underwent gonadotropin suppression and attempted ovulation induction with at least one of three regimens, which were as follows: 1) Group A: estrogen-induced suppression followed by hMG stimulation (n = 4). 2) Group B: estrogen-induced suppression followed by hMG stimulation with concomitant estrogen therapy (n = 10). 3) Group C: gonadotropin-releasing hormone agonist-induced gonadotropin suppression followed by concomitant hMG stimulation (n = 6). Despite complete gonadotropin suppression and high-dose hMG therapy in all three groups, ovulation occurred in only a single patient in group C. Pregnancy did not ensue. These data fail to corroborate previous case reports.

Adult↗
PubMed1987

Evolution of a highly successful in vitro fertilization-embryo transfer program.

During the first 2 1/2 years of operation of the University of California at Los Angeles in vitro fertilization-embryo transfer program, 47 clinical pregnancies were achieved in 154 laparoscopies for oocyte aspiration (31%). Two of these pregnancies were achieved through transfer of cryopreserved embryos when ongoing pregnancy did not result from embryo transfer in the stimulated cycle. An increase in clinical implantation was noted with a reduction of transfer volume and proportion of air, with 34% of laparoscopies being followed by clinical pregnancy over the last 18 months. No difference in the rate of clinical pregnancy was noted relative to uterine depth or position. The high rate of multiple implantation (47%) suggested a high level of embryo quality. The success rate was attributed to a strong ovarian, human menopausal gonadotropin stimulation, accurate timing of human chorionic gonadotropin, a high oocyte retrieval rate, meticulous laboratory technique, atraumatic, high-fundal transfer of embryos, and initiation of embryo cryopreservation.

Embryo Transfer↗
PubMed1987

Suppression of the ovary using a gonadotropin releasing-hormone agonist prior to stimulation for oocyte retrieval.

Five women with prior suboptimal ovarian stimulation for in vitro fertilization and embryo transfer (IVF-ET) were pretreated with a long-acting gonadotropin-releasing hormone (GnRH) agonist beginning in the midluteal phase of the preceding menstrual cycle. The four women with normal luteal function had castrate estrogen levels following regression of the corpus luteum, whereas one woman with an abnormal luteal phase and perimenopausal levels of gonadotropins had an agonistic response. In the three women with adequate stimulation, 20 oocytes were obtained and one women became pregnant. Initiation of GnRH agonist therapy during the luteal phase of a normal menstrual cycle may be an efficient way of obtaining ovarian suppression without an agonistic response.

Embryo Transfer↗
PubMed1987

Factors influencing maintenance of sperm motility during in vitro processing.

Addition of serum to culture medium during washing of sperm was shown to significantly improve sperm motility upon subsequent 24-hour incubation, distinct from the beneficial effects of adding serum after washing. Commercial sources of human and bovine albumen tested did not preserve motility as well as serum, but addition to serum showed that the lesser effect was probably due to toxic contaminants. One of the most commonly available disposable plastic syringes was found to be markedly toxic to sperm. The materials found to have sperm toxicity also manifested toxicity to mouse embryos. These findings show that a similar degree of caution is advisable in testing of materials contacting sperm in vitro to that which has become standard practice for culture of human embryos.

Blood↗
PubMed1987

Nonoral routes of estrogen administration.

Thus, the effects that a specific estrogen has on the liver is the summation of several mechanisms, including the first pass mechanism and the enhanced delivery of circulating estrogens to this organ. For example, the major estrogen in conjugated estrogen is estrone sulfate. Based on the present data, very little circulating estrone sulfate is available to the brain or uterus (Fig. 25). Since most of the hypothalamus is behind the blood-brain barrier, it is unlikely estrone sulfate exerts a direct action on gonadotropin-releasing hormone (GnRH) neurons to reduce its secretion and, subsequently, gonadotropin levels. Estrone sulfate also does not interact with the estrogen receptor. It is possible the small amount of estrone sulfate that crosses the blood-brain barrier is converted to unconjugated estrogens locally and these could have function. More likely, the major mechanism by which estrone sulfate suppresses GnRH release is through conversion to unconjugated estrogens, principally estrone, in the liver. The large extraction of estrone sulfate by the liver allows accessibility of the hepatocyte for this conversion. Based on this concept, conjugated estrogen must enter the liver to be converted to its active forms. The route of administration then should have little impact on changing the relative potency of this preparation on hepatic and nonhepatic markers of estrogen action. For ethinyl estradiol, the preparation is orally active because it is rapidly and almost completely absorbed from the stomach and undergoes limited hepatic metabolism before entry into the general circulation (Fig. 26). This limited hepatic metabolism reduces the impact of the first pass mechanism on ethinyl estradiol. Thus, the enhanced hepatic action of ethinyl estradiol is principally related to the greater entry of this estrogen into the liver than other organs (Fig. 27). Consequently, the route of administration should have little impact on the exaggerated hepatic actions of this estrogen. Orally administered estradiol undergoes substantial hepatic metabolism to less active forms, principally estrogen conjugates. The amount of estradiol leaving the liver following oral administration is substantially less than that which enters it through the portal vein. The systemic administration of estradiol avoids this initial hepatic metabolism. Furthermore, only 25 per cent of nonorally administered estrogen will go to the liver at each pass, and nonhepatic tissues would be exposed to a greater extent than after oral administration. Thus, peripheral administration of estradiol reduces the exaggerated hepatic responses in comparison to nonhepatic actions.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Cutaneous↗