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Biomedical subjects

D R Mishell

Publications and source records attributed to D R Mishell.

At least 253 records · Page 14Linked to original sources
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

Classification of secondary amenorrhea based on distinct hormonal patterns.

Patients with secondary amenorrhea have been classified into 4 clincal groups. In order to further investigate these 4 groups, LH, FSH, and estradiol (E2) were measured at 15 min intervals for 4 h in 21 patients with secondary amenorrhea. Patients within each group had similar hormonal patterns, but there was a distinct variation among the groups. Three patients in group 1 (polycystic ovaries [PCO]) had elevated basal levels of only LH with marked irregular fluctuations. Seven patients in group II (hypothalamic-pituitary dysfunction) had normal basal levels of LH, FSH, and E2. Only LH showed oscillations of varying mahnitude and frequency. Eight patients in group III (hypothalamic-pituitary failure) had low or low-normal levels of LH, FSH, and low E2 with minimal or absent fluctuations. Three patients in group IV (ovarian failure) had high basal levels of FSH and LH and irregular fluctuations. This study confirmed the rationality of separating patients with secondary amenorrhea into 4 different groups. In addition, it was found that in group III patients, the total amount of LH secreted in a 4-hour period of time appears to be insufficient to stimulate E2 production from the ovary even when a single sample was found to be in the normal range.

Adult↗
PubMed1975

Randomized comparative study of the copper T 300, Dalkon shield, and Shell Loop in parous women.

A randomized comparative study of the Copper T 300, the standard Dalkon Shield and the Silicone Shell Loop D was conducted on 776 parous women. Net cumulative first event rates at 1 year and at 18 months, calculated by life-table analysis, were as follows: Copper T 300--pregnancy 1.2/1.9, expulsion 6.4/7.0, removal for pain or bleeding 7.4/10.8; Dalkon Shield--pregnancy 2.7/4.5, expulsion 5.8/5.8, removal for pain or bleeding 7.7/14.7; Shell Loop--pregnancy 3.8/4.9, expulsion 0.5/0.5, removal for pain or bleeding 9.1/13.1. None of the differences in event rates, except the lower expulsion rate of the Shell Loop, were significant. The continuation rates for the three devices at both 12 and 18 months were similar, indicating that there was little difference in their performance. As the results of this study showed a similarity of the incidence of events among very differently disigned IUD's, previously reported differences in performance of these and possibly other types of IUD's may very likely be more related to differences among clinics than to differences among the devices themselves.

Adolescent↗
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↗
PubMed1975

The effect of pH on radioimmunoassay of LH and FSH.

Freezing and thawing of human serum produces alkaline changes in the pH. Weak buffers were of insufficient capacity to compensate for these pH changes. Thus the effect of serum pH on modified solid-phase and double-antibody radioimmunoassay (RIA) of LH and FSH was studied. Pooled postmenopausal serum standardized against the Second International Reference Preparation of Human Menopausal Urinary Gonadotropon was used as a laboratory standard. In the solid phase RIA for LH and FSH, slopes with the greatest maximum binding were obtained at pH 6.4, whereas for the double-antibody method best results were obtained at pH 8.0. Since there is individual variation in the pH of various serum samples, different values will be obtained from samples containing the same amount of hormone. It is sum samples be standardized by the use of buffers with the capacity to keep the pH of the serum constant and that serum standards be dialyzed.

Animals↗