Search PubMed⌕ Search

Biomedical subjects

D R Mishell

Publications and source records attributed to D R Mishell.

At least 19 recordsLinked to original sources
PubMed1992

A randomized clinical trial of mifepristone (RU486) for induction of delayed menses: efficacy and acceptability.

Mifepristone (RU486) should be useful for inducing menstrual bleeding in women with menses delayed up to 10 days. We evaluated this potential use for "menstrual regulation" in a randomized clinical trial with 16 women, half of whom received a single 600 mg dose and half of whom received a placebo. Four of eight women in each treatment group proved to be pregnant. Seven of eight who received mifepristone were not pregnant at two-week follow-up, in contrast to four of eight who received the placebo (p = 0.15). Mifepristone may hold promise for "menstrual regulation" for women who do not have access to medical confirmation of pregnancy or who choose not to have this determination made.

Abortion, Induced↗
PubMed1992

Rates and outcomes of planned pregnancy after use of Norplant capsules, Norplant II rods, or levonorgestrel-releasing or copper TCu 380Ag intrauterine contraceptive devices.

OBJECTIVES: The objectives were to measure rates of planned pregnancy and factors affecting these rates after use of very-long-acting contraceptive methods (Norplant or Norplant II implants, a levonorgestrel-releasing intrauterine contraceptive device, or the copper T (model TCu 380Ag) intrauterine contraceptive device. STUDY DESIGN: The design was a concurrent, multicenter prospective study of 372 women who stopped contraception for planned pregnancy. Analysis was by life-table, log-rank, and standard chi 2 methods. RESULTS: Pregnancy rates 12 and 24 months after cessation of contraceptive use were 82 and 89 per 100, respectively. Age at removal and family planning intentions at initiation of contraception were both significantly correlated with pregnancy rates (p less than 0.05), but former contraceptive regimen and duration of contraceptive use were not. Pregnancy outcomes did not deviate from normal limits and did not differ by contraceptive formerly used. CONCLUSION: Contraceptive implants releasing 30 micrograms/day of levonorgestrel or intrauterine contraceptive devices releasing 20 micrograms/day of levonorgestrel or having copper surface areas of 380 mm2 are associated with normal fertility after use for women seeking pregnancy at termination. Durations of use do not affect pregnancy rates.

Adult↗
PubMed1992

Oral contraception: past, present, and future perspectives.

Oral contraceptives (OCs) were initially approved for unrestricted use in 1960 in the United States and have been used and studied extensively for 30 years. The initial formulations contained a fixed dose of estrogen and progestogen ingested for 21 days, with a seven-day pill-free interval. Subsequent formulations contained a sequential estrogen dose, a progestogen alone given daily, and variable doses of both progestogen and estrogen. Although the estrogen and progestogen doses employed in currently marketed OCs are markedly lower than those used in the OCs of the 1960s and 1970s, the excellent contraceptive efficacy of these compounds has not been compromised. The estrogen component produces a dose-related increase in serum globulin concentrations, triglycerides, and high-density lipoprotein (HDL) cholesterol, along with a decrease in low-density lipoprotein (LDL) cholesterol, while the progestogen component causes peripheral insulin resistance, a decrease in HDL cholesterol, an increase in LDL cholesterol, and various androgenic effects. The effect of nicotine on thromboxane release acts synergistically with the elevated serum clotting factors to increase the incidence of both arterial and venous thrombotic events, particularly in women smokers over 35 years of age. However, there is no evidence of increased risk of myocardial infarction or stroke in healthy, nonsmoking women of any age who use OCs containing less than 50 micrograms estrogen. Likewise, the lower-dose estrogen/progestogen formulations do not have a clinically significant effect on glucose metabolism and have a neutral effect on lipoprotein metabolism. In addition, the many noncontraceptive health benefits associated with OCs are maintained with the lower-dose formulations. Thus, the low-dose formulations should improve the overall health of healthy, nonsmoking women as well as effectively prevent unwanted pregnancy.

Cardiovascular Diseases↗
PubMed1991

The significance of bleeding patterns in Norplant implant users.

The purpose of this study was to examine the bleeding patterns of 234 Norplant users during 5 years of use and to identify the bleeding patterns of users who conceived. During the first year of use, 26.6% of users had regular bleeding cycles, 66.3% had irregular cycles, and 7.1% were amenorrheic. By the fifth year of use, 62.5% of users had regular cycles, 37.5% had irregular cycles, and none had amenorrhea. Of the ten users who became pregnant, eight had regular menstrual cycles in the 6 months before the diagnosis of pregnancy, one had an irregular pattern, and one did not keep a bleeding record. None had amenorrhea. The 5-years cumulative pregnancy rate for patients with regular cycles was 17.4%; this was significantly higher (P less than .05) than the 5-year cumulative rates of 4.4% in users with irregular cycles and 0% in users with amenorrhea. This study indicates that during the first year of Norplant use, only 26.6% of users have regular cycles, but after the first year, 50-60% of users develop regular cycles. The bleeding patterns of women using Norplant improve after the first year of use, and those with regular cycles are at greatest risk for method failure.

Contraceptive Agents, Female↗
PubMed1991

Oral contraception: past, present, and future perspectives.

Oral contraceptives (OCs) were initially approved for unrestricted use in 1960 in the United States and have been used and studied extensively for 30 years. The initial formulations contained a fixed dose of estrogen and progestogen ingested for 21 days, with a seven-day pill-free interval. Subsequent formulations contained a sequential estrogen dose, a progestogen alone given daily, and variable doses of both progestogen and estrogen. Although the estrogen and progestogen doses employed in currently marketed OCs are markedly lower than those used in the OCs of the 1960s and 1970s, the excellent contraceptive efficacy of these compounds has not been compromised. The estrogen component produces a dose-related increase in serum globulin concentrations, triglycerides, and high-density lipoprotein (HDL) cholesterol, along with a decrease in low-density lipoprotein (LDL) cholesterol, while the progestogen component causes peripheral insulin resistance, a decrease in HDL cholesterol, an increase in LDL cholesterol, and various androgenic effects. The effect of nicotine on thromboxane release acts synergistically with the elevated serum clotting factors to increase the incidence of both arterial and venous thrombotic events, particularly in women smokers over 35 years of age. However, there is no evidence of increased risk of myocardial infarction or stroke in healthy, nonsmoking women of any age who use OCs containing less than 50 micrograms estrogen. Likewise, the lower-dose estrogen/progestogen formulations do not have a clinically significant effect on glucose metabolism and have a neutral effect on lipoprotein metabolism. In addition, the many noncontraceptive health benefits associated with OCs are maintained with the lower-dose formulations. Thus, the low-dose formulations should improve the overall health of healthy, nonsmoking women as well as effectively prevent unwanted pregnancy.

Adult↗
PubMed1991

Characteristics of ovarian follicular development in Norplant users.

Daily transvaginal ultrasound (US) scanning of the ovaries to assess follicular development and daily blood sampling were performed on 19 Norplant (Leiras, Turku, Finland) subdermal contraceptive implant users who had regular menstrual cycles and on 10 normally cycling women. Three groups were identified in the implant users based on US finding. Six (31.6%) of the implant users had US findings that were consistent with a normal ovulatory pattern. However, their mean peak luteinizing hormone levels and peak midluteal phase progesterone (P) levels were significantly lower than control values. Eleven (57.9%) users had persistent follicles, and 2 users (10.5%) had no follicular development. These data suggest that after 2 to 4 years of use, about one third of Norplant users with regular bleeding patterns may ovulate but most have deficient luteal P levels. In this small study, the presence of persistent follicular enlargement in implant users was common.

Contraceptive Agents, Female↗
PubMed1991

Postmenopausal hormone replacement with a combination estrogen-progestin regimen for five days per week.

A group of 15 postmenopausal women who had not recently received estrogen replacement were enrolled in a study during which they received 0.625 mg of conjugated equine estrogen and 2.5 mg of medroxyprogesterone acetate daily from Monday through Friday of each week for six months. No treatment was given on the weekend. Endometrial biopsy specimens at the end of therapy revealed minimal growth of glands and stroma and a low mean mitosis count. Of the 12 women who completed the trial, 5 were completely amenorrheic, and only 4 of the 15 bled beyond the second month of treatment. Of those four, two spotted for only a few days. In the 12 women who completed the trial there was a significant increase in high density lipoprotein cholesterol and a nonsignificant lowering of low density lipoprotein cholesterol. The results of this study indicate that comparative trials between this regimen and one in which the two drugs are given daily for seven days a week are warranted.

Adult↗
PubMed1990

Effect of low-dose oral contraceptives on carbohydrate and lipid metabolism in women with recent gestational diabetes: results of a controlled, randomized, prospective study.

Women with recent gestational diabetes mellitus were randomly assigned to one of two low-dose oral contraceptives to evaluate the effect of low-dose oral contraceptives on carbohydrate and lipid metabolism. A cohort of similar women requesting a non-oral-contraceptive method served as controls. The two oral contraceptives studied were ethinyl estradiol (0.035 mg)-norethindrone (0.40 mg) and ethinyl estradiol (0.030 to 0.040 mg)-levonorgestrel (0.050 to 0.125 mg). A 75 gm, 2-hour oral glucose tolerance test and a fasting lipid profile (total cholesterol, triglyceride, high- and low-density lipoprotein cholesterols) were performed at entry, after 3 months, and after 6 to 13 months of treatment. The prevalence of diabetes at 6 to 13 months (27/156 patients) was not significantly different between groups (non-oral-contraceptive group, 17%; ethinyl estradiol-norethindrone, 15%; ethinyl estradiol-levonorgestrel, 20%). When examined by prior gestational diabetes mellitus class, diabetes mellitus was present in 7% of prior class A1 and 29% of women with prior class A2 disease (p less than 0.001). Mean cholesterol and low-density lipoprotein cholesterol levels were significantly improved in all three groups at 3 months and at 6 to 13 months, whereas triglycerides remained unchanged. There were no differences in cholesterol, low-density lipoprotein cholesterol, or triglycerides levels between the groups. After 6 to 13 months, there was a significant increase in high-density lipoprotein cholesterol in the ethinyl estradiol-norethindrone group compared with the ethinyl estradiol-levonorgestrel and non-oral-contraceptive groups.

Adult↗
PubMed1990

Antiprogestin treatment decreases midluteal luteinizing hormone pulse amplitude and primarily exerts a pituitary inhibition.

Mifepristone (RU 486), a synthetic steroid with antiprogesterone receptor activity, was given with and without naloxone hydrochloride to six women in the midluteal phase to investigate the role of progesterone in the modulation of endogenous opioid activity and the secretion of luteinizing hormone and cortisol. Subjects were evaluated during four sequential monthly admissions during which multiple blood samples were obtained every 15 minutes for 8 hours. Patients were studied during a baseline cycle, after administration of RU 486 alone (100 mg/day), naloxone with RU 486, and naloxone alone. After administration of RU 486 there was a significant decline in total luteinizing hormone secretion (p less than 0.01) and luteinizing hormone pulse amplitude (p less than 0.05), but compared with baseline there was no significant change in luteinizing hormone pulse frequency. After infusion of naloxone there was a significant increase in mean luteinizing hormone values (p less than 0.05) and luteinizing hormone pulse frequency (p less than 0.01) but no change in pulse amplitude. There was no significant difference in mean luteinizing hormone values or luteinizing hormone pulse amplitude and frequency between administration of RU 486 and naloxone plus RU 486. Administration of naloxone alone, RU 486 alone, and RU 486 plus naloxone caused a significant increase in cortisol as compared with baseline cycles (p less than 0.05). These data further support the notion that progesterone is important in the control of luteinizing hormone secretion and suggest that progesterone may primarily influence luteinizing hormone pulse amplitude and pituitary release of luteinizing hormone during the luteal phase.

Adult↗
PubMed1990

Predictors of failed attempted abortion with the antiprogestin mifepristone (RU 486).

The experience of 271 patients who received mifepristone (RU 486) in experimental protocols from July 1984 to January 1989 was analyzed by logistic regression methods. The regimen used was the strongest predictor of failure, followed by Quetelet's index and initial beta-human chorionic gonadotropin level. The relative risk of failure was 2.3 times with 7-day regimens and 6.3 times with the other regimens that obtained with regimens of 600 mg given once or twice. The relative risk of failure increased with increasing Quetelet's index; women in the top quartile were 2.9 times more likely to fail to abort than were women in the bottom quartile. The risk of failure increased with increasing initial beta-human chorionic gonadotropin level; those with an initial level greater than 19,800 mIU/ml were 2.8 times more likely to fail to abort than were women with an initial value less than or equal to 6350 mIU/ml. Body mass appears to influence the likelihood of abortion with mifepristone.

Abortifacient Agents↗
PubMed1990

Leiomyosarcoma in a series of hysterectomies performed for presumed uterine leiomyomas.

The incidence of leiomyosarcoma in uterine leiomyomas is estimated to be between 0.13 to 0.29%. However, the exact incidence of leiomyosarcoma in uteri removed with a preoperative diagnosis of benign uterine leiomyomas has not been previously reported. Between 1983 and 1988, a total of 1432 patients in Women's Hospital, a self-referred indigent population, had a hysterectomy planned because of abnormal uterine bleeding or abdominal pain associated with the presence of uterine leiomyomas, or because of a pelvic mass thought to be uterine leiomyoma of sufficient size or character to warrant surgical exploration. The ages of these women ranged from 36 to 62 years and the presence of leiomyosarcoma in the hysterectomy specimens increased steadily from the fourth to seventh decades of age (0.2%, 0.9%, 1.4%, and 1.7%, respectively). Preoperative histologic examination of the endometrium was performed in eight patients. Three of the eight patients had a preoperative tissue diagnosis of leiomyosarcoma that was clinically confined to the uterus. After the hysterectomy in the 1429 patients with presumed benign disease, histologic diagnosis of leiomyosarcoma was made in seven (0.49%). There was no evidence of malignancy in the endometrial sampling of any of these seven patients and the diagnosis was suspected intraoperatively in only three. Preoperative uterine size ranged from 8 to 20 weeks' gestational size and postoperative uterine weight ranged from 120 to 1100 gm. Seven of the 10 patients had symptoms of abnormal uterine bleeding. Between the ages of 40 and 60 years, 1% (8 of 817) of women with presumed uterine leiomyomas producing symptoms that necessitated hysterectomy in this series had leiomyosarcoma diagnosis postoperatively. Such treatments as gonadotropin-releasing hormone agonists, endometrial ablation, myomectomy by hysteroscopy or laparotomy instead of hysterectomy in such women could delay the diagnosis and definitive treatment of leiomyosarcoma.

Adult↗
PubMed1990

Long-term contraception with the levonorgestrel 20 mcg/day (LNg 20) and the copper T 380Ag intrauterine devices: a five-year randomized study.

An intrauterine device, releasing approximately 20 micrograms/day of levonorgestrel (LNg 20), used by 1124 women, was studied in a randomized trial of five years duration in comparison with the Copper T, model TCu 380Agm in 1121 women. At five years, the gross cumulative pregnancy rate of 1.1 +/- 0.5 per 100 among users of the LNg 20 devices was not significantly different from the rate of 1.4 +/- 0.4 per 100 experienced by users of the Copper T 380Ag. The steroid-releasing IUD had significantly higher termination rates for expulsion and amenorrhea, a significantly lower termination rate for other menstrual problems and pain, and a lower continuation rate. The five-year continuation rate among women using the TCu 380Ag was 40.6 per 100 as compared with that of 33.0 per 100 among women randomized to the LNg 20 device (P less than .001). Terminations attributed to amenorrhea with the LNg device primarily account for differences in continuation. These two intrauterine devices are the most effective long-term, reversible IUDs yet reported in the literature. No other contraceptive methods have exhibited such low long-term pregnancy rates in randomized comparative trials.

Adolescent↗
PubMed1990

The effect of olestra on systemic levels of oral contraceptives.

The effect of olestra, a nonabsorbable, noncaloric fat replacement, on the absorption and efficacy of a highly lipophilic oral contraceptive was investigated in a double-blind, placebo-controlled crossover study with 28 women. Subjects consumed 18 gm/day olestra for 28 days while taking an oral contraceptive containing 300 micrograms of norgestrel and 30 micrograms ethinyl estradiol (Lo/Ovral-28). Blood taken on days 12 to 14 of the treatment cycles was analyzed for ethinyl estradiol and norgestrel. There was no statistically significant difference in time to attain maximum concentration, maximum concentration, or area under the concentration-time curve between the olestra and placebo treatments for either drug component. Measurements of serum progesterone indicated that olestra ingestion did not reduce efficacy as indicated by ovulation. The data show that ingestion of 18 gm/day olestra did not affect the absorption or efficacy of the highly lipophilic oral contraceptive.

Adult↗