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Biomedical subjects

P F Brenner

Publications and source records attributed to P F Brenner.

54 records · Page 3Linked to original sources
PubMed1977

The effect of contraceptive steroids on hypothalamic-pituitary function.

A study was performed to obtain additional information about the effects of oral contraceptives on pituitary function. A sequential pituitary stimulation test (SST) was used to study normal control women who then received either a combination pill with 50 mug of ethinyl estradiol or an injectable or oral progestin for three weeks, after which the test was repeated. The same test was also performed on five long-term oral contraceptive users. The SST consists of measurement of growth hormone (GH), thyroid-stimulating hormone (TSH), prolactin (PRL), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) at frequent intervals after stimulation by hypoglycemia, thyrotropin-releasing hormone, and gonadotropin-releasing hormone. GH and TSH release following stimulation were unaffected by the use of contraceptive steroids, while PRL release was increased by both the combination pill and the progestin alone. LH and FSH release was decreased in the three short-term and most of the long-term users of the combination pills but was not decreased in two of the long-term users as well as in those receiving the progestin alone. These results indicate that the combination oral contraceptives have a direct effect upon the pituitary gland, causing an increase in prolactin release and a decrease in gonadotropin release. This effect varies among individuals receiving the same formulation and may be related to the development of syndrome of postpill amenorrhea-galactorrhea.

Contraceptives, Oral↗
PubMed1977

Termination of early gestation with a vaginal polysiloxane device impregnated with (15S)-15 methyl prostaglandin F2alpha methylester.

An investigation of the abortifacient activity of (15S)-15 methyl prostaglandin F2alpha methyl ester released from a vaginal polysiloxane device was performed in eleven pregnant women of 49 days gestation or less. Bleeding and contractions were induced in all women, but only seven aborted their pregnancies. Five subjects received a vaginal device impregnated with 3 mg of drug and two aborted fetal tissue. Six women were given a vaginal device containing 5 mg of drug and five aborted fetal tissue. Ten of the patients had significant side effects, nausea, emesis, diarrhea and chills. Six women expelled the device prior to the termination of therapy. This prostaglandin analogue, when administered from a vaginal polysiloxane device in early gestation was an effective abortifacient but was accompanied by systemic side effects and a high incidence of expulsion of the device prior to its scheduled removal.

Abortion, Induced↗
PubMed1977

Ectopic pregnancy following tubal sterilization surgery.

In a consecutive study of 100 women with the surgical diagnosis of ectopic pregnancy confirmed by histologic examination, 7 women were found to have had prior tubal sterilization surgery. In 3 of these cases the sterilization procedure was bilateral tubal fulguration. The diagnosis of ectopic pregnancy must be given careful consideration if patients conceive after a tubal sterilization procedure of any type.

Adult↗
PubMed1976

Studies on the pattern of circulating steroids in the normal menstrual cycle. I. Simultaneous assays of progesterone, pregnenolone, dehydroepiandrosterone, testosterone, dihydrotestosterone, androstenedione, oestradiol and oestrone.

In an attempt to analyze the multiple changes and interactions in circulating steroid levels in the peri-ovulatory and peri-menstrual periods, the plasma levels of immunoreactive luteinizing hormone (LH), progesterone and unconjugated pregnenolone, dehydroepiandrosterone, testosterone, oestradiol and oestrone were assayed daily during a complete cycle in 17 normally menstruating women. In 14 of the 17 subjects studied androstenedione and unconjugated dihydrotestosterone were also estimated. The day of the LH-peak and the first day of menstruation, respectively, were used to synchronize the peri-ovulatory and peri-menstrual plasma levels of the various steroids. With the exception of dehydroepiandrosterone and dihydrotestosterone, the plasma levels of all steroids exhibited significant, but different changes during the cycle. Testosterone levels showed a slight but significant increase around the LH-peak, whereas the levels of pregnenolone and androstenedione were higher in the post-ovulatory than in the pre-ovulation periods. The levels of oestradiol and oestrone, as well as the ratios of oestradiol to oestrone gradually increased from the low values observed in the early proliferative phase to pre-ovulatory peak values. The relationship between peaks of oestradiol and oestrone and that of LH exhibited great individual variation. The same was true for the individual oestradiol to oestrone ratios. The combination of several steroidal signals did not improve the predictive value of the analyses. However, an increase of individual progesterone values by at least 0.35 ng/ml from the day preceding the LH-peak to the day of the LH-peak was observed in 13 of the 17 subjects. It is suggested that for the early detection of the LH surge and prediction of the subsequent ovulation daily assays of plasma progesterone are of more value than the assay of the other steroids investigated.

Adult↗
PubMed1975

Clinical study of a progesterone-releasing intrauterine contraceptive device.

A double-blind clinical study was performed to determine whether the release of progesterone from an intrauterine contraceptive device (IUD) had any effect on IUD event rates. A total of 101 women received intrauterine contraceptive devices containing progesterone, resulting in the accumulation of 877 women-months experience; 100 women received IUD's without steroid, resulting in the accumulation of 780 women-months. The only significant difference was a higher incidence of pregnancy in those patients using devices which did not contain progesterone.

Adult↗
PubMed1975

Radioimmunoassay of serum medroxyprogesterone acetate (Provera) in women following oral and intravaginal administration.

A radioimmunoassay (RIA) method for measuring medroxyprogesterone acetate (MPA, Provera) in serum has been developed utilizing benzene:iso-octane extraction, 3H-MPA to assess procedural losses, goat anti-MPA-3-(0-carboxymethyl) oxime-bovine serum albumin serum and dextran-coated charcoal separation. Control serum blanks were undetectable, 200 pg/ml of MPA was measurable with a high reliability, and intra- and interassay coefficients of variation were 6 and 13 percent, respectively. MPA added to control serum was quantitatively recovered. Serum MPA levels measured in 2 women after ingestion of 10 mg MPA rose to 3.4 to 4.4 ng/ml within 1 to 4 hours after oral intake and fell rapidly thereafter to 0.3 to 0.6 ng/ml within 24 hours. Insertion of Silastic intra-vaginal rings (IVRs), containing 100 or 200 mg of MPA, into 4 women for periods of 3 weeks resulted in a rapid rise of serum MPA after insertion, rather stable MPA levels of 0.9 to 1.6 ng/ml while the IVRs were in place, and a rapid decline of serum MPA following IVR removal. Serum estradiol-17beta and progesterone concentrations, measured about 3 times a week in these patients, indicated that ovulation was consistently inhibited. The serum MPA levels observed in this study were approximately 5 times lower than those reported by other investigators using a double-antibody RIA of MPA in unextracted serum.

Administration, Oral↗
PubMed1975

Indices of gonadal function in the human male. I. Plasma levels of unconjugated steroids and gonadotrophins under normal and pathological conditions.

A radioimmunoassay technique for the simultaneous measurement of eight unconjugated steroids (progesterone, pregnenolone, dehydroepiandrosterone, androstenedione, testosterone, dihydrotestosterone, oestrone and oestradiol) in the peripheral plasma of human males is described. Determinations of these steroids and of immunoreactive FSH and LH were carried out on the plasma of twenty-one normal individuals and the levels were compared to those of eleven and ten males exhibiting oligospermia and azoospermia, respectively. Mean values and tolerance limits for each hormone, based on a lognormal distribution of individual values, are presented for all groups. Oligospermia was associated with a significant reduction in plasma dihydrotestosterone and testosterone levels. Azoospermic subjects also exhibited decreased dihydrotestosterone levels but a normal range of testosterone concentrations. Mean peripheral plasma levels of FSH were significantly elevated in both pathological groups and this was paralleled in the azoospermic men by increased concentrations of plasma LH.

Adult↗
PubMed1975

Progesterone and estradiol patterns in women using an intrauterine contraceptive device.

Levels of progesterone, estradiol, LH, and FSH were measured in daily serum samples obtained from 4 subjects during a control cycle and during the first and fourth menstrual cycles after insertion of an intrauterine device (IUD). In addition, progesterone and estradiol were measured in serum samples obtained from 6 women 3, 4, or 5 months after IUD insertion, and from 6 women more than 1 year after IUD insertion. These measurements were compared to the data obtained from study of a large group of normal cycles. The results indicated that the IUD does not influence follicular maturation, time of ovulation, or corpus luteum function. The IUD did exert a local effect on the endometrium, causing the onset of menses to take place when steroid levels were higher than in control cycles.

Adult↗