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Biomedical subjects

D L Loriaux

Publications and source records attributed to D L Loriaux.

At least 37 records · Page 2Linked to original sources

Characterization of the normal progesterone and placental protein 14 responses to human chorionic gonadotropin stimulation in the luteal phase.

OBJECTIVE: To examine whether midluteal phase administration of the luteotrophic hormone hCG can result in higher and more stable serum levels than random sampling of P and placental protein 14 (PP14). DESIGN: Prospective controlled clinical study. SETTING: Normal human volunteers in an academic research environment. PARTICIPANTS: Twenty-six fertile, regularly cycling women. INTERVENTIONS: Blood samples were drawn at 0, 3, 6, 9, 12, 18, and 24 hours and then daily for the next 6 days, after a single IM injection of 5,000 IU hCG or saline given on day 5, 7, or 9 after the LH surge, as detected by rapid plasma assays. MAIN OUTCOME MEASURES: Serum P and PP14 measurements. RESULTS: Peak P and PP14 concentrations occurred at 6 hours and 5 days, respectively, after hCG stimulation on luteal phase day 9. Progesterone but not PP14 levels were significantly higher and less variable after hCG than after saline administration on this day. Progesterone responses exceeded 11.0 ng/mL (35.0 nmol/L) in all women, suggesting that this represents the cutoff limit for normal luteal function. Because PP14 responses were highly variable and inconsistent, it was not possible to determine a threshold for normal endometrial function. CONCLUSIONS: Midluteal phase administration of hCG in normal women induces consistent serum P levels > 11.0 ng/mL (35.0 nmol/L) but highly variable PP14 responses.

Adult↗

Comparative analysis of progesterone and placental protein 14 measurements in the evaluation of luteal function.

OBJECTIVE: Our purpose was to investigate the diagnostic accuracy of single or summed measurements of progesterone and placental protein 14, a progestin-dependent endometrial glycoprotein, in the evaluation of luteal function. STUDY DESIGN: Forty-five healthy women had daily blood measurements of luteinizing hormone, progesterone, and placental protein 14 during one menstrual cycle. RESULTS: Thirty-nine women had normal and six had deficient luteal function on the basis of serial progesterone determinations. Luteal insufficiency was not accurately diagnosed by single progesterone or placental protein 14 values or by integrated placental protein 14 measurements. In contrast, the condition was correctly identified in all but one cycle when the sum of progesterone on days 4 and 7 was < 49 nmol/L (15.4 ng/ml). A poor correlation was found between peak or integrated measurements of progesterone and placental protein 14. CONCLUSION: Measurement of serum progesterone, but not placental protein 14, on 2 days of the midluteal phase provides a convenient and reliable test of luteal function.

Adult↗

Contraceptive choices for women with endocrine complications.

Previous confusion regarding the interference by oral contraceptives in measurements of endocrine function have been largely eliminated by the advent of improved, more sensitive assays. There are few if any contraindications to oral contraceptive use in patients with thyroid disease. Patients with prolactinoma can be treated with bromocriptine to restore fertility and prevent mineral loss. However, as a less expensive alternative, oral contraceptives can be prescribed to correct mineral loss, because there is no convincing evidence of an adverse effect on prolactinomas by the steroidal content of the pill. Oral contraceptives comprise a near ideal treatment modality for women with polycystic ovary disease because, among other effects, oral contraceptives reduce synthesis of androgen by inhibiting pituitary gonadotropin secretion.

Contraception↗

The relation between clinical manifestations of polycystic ovary syndrome and beta-cell function.

OBJECTIVE: Hyperandrogenism in patients with polycystic ovary syndrome has been shown to correlate with hyperinsulinaemia of insulin resistance. We have investigated if basal levels of insulin and the response to the intravenous administration of glucagon can reveal insulin resistance in patients with polycystic ovary syndrome. PATIENTS: Nine obese (BMI > 25 kg/m2) and nine non-obese (BMI 19-25 kg/m2) women with PCOS, chosen from a population of 91 women attending the infertility clinic, and 19 normally cycling women (seven obese, 12 non-obese) were studied. Oligo or amenorrhoea, hirsutism, and 12 or more follicles in a given ovary were selection criteria. MEASUREMENTS: Glucagon, 1 mg, was given intravenously to 18 of the 91 women and to the control subjects. Blood was taken at -5, 0, 5, 10 and 15 minutes for measurements of integrated areas under the response curve for insulin, C-peptide and glucose, respectively. Basal blood samples were drawn for fasting insulin, C-peptide, glucose, testosterone, sex hormone-binding globulin (SHBG), free fatty acids and IGF-I measurements. The free androgen index was calculated according to the formula FAI = testosterone x 100/SHBG. RESULTS: There were no significant differences in maximal increment and area under the response curve for glucose, C-peptide and insulin. FAI was significantly higher in all patients with features of polycystic ovary syndrome. However, fasting insulin levels were significantly higher only in obese patients when compared with obese control subjects and lean patients. CONCLUSIONS: The administration of 1 mg glucagon i.v. did not distinguish patients with polycystic ovary syndrome from control subjects. The mild insulin resistance of polycystic ovary syndrome is related only to obesity and is therefore unlikely to play an important role in the hyperandrogenism associated with the syndrome.

Adult↗

A simplified morning ovine corticotropin-releasing hormone stimulation test for the differential diagnosis of adrenocorticotropin-dependent Cushing's syndrome.

The objective of this study was to develop criteria for the interpretation of a morning ovine CRH stimulation test for the differential diagnosis of ACTH-dependent Cushing's syndrome. Its design was retrospective review, and its setting was the in-patient unit of a tertiary care center. One hundred and eighteen patients with proven Cushing's disease or ectopic ACTH secretion were studied. The percent change in plasma ACTH and cortisol levels after CRH administration (1 microgram/kg BW) was calculated for each patient using 3 combinations of pre-CRH values (-15, -10, -5, and -1 min) and 6 combinations of post-CRH values (15, 30, 45, and 60 min). The diagnostic performance of these 36 sets of response measures was compared. The mean ACTH concentrations 15 and 30 min after CRH increased by at least 35% above the mean basal value at -5 and -1 min in 93 of 100 patients with Cushing's disease, but in none of the 16 patients with ectopic ACTH secretion. This measure gave the best sensitivity (93%) and specificity (100%). The best cortisol criterion was a mean increase at 30 and 45 min of 20% or more above mean basal values at -5 and -1 min, which gave a sensitivity of 91% and a specificity of 88%. We developed a simplified diagnostic test with 100% specificity using ACTH measurements 5 and 1 min before and 15 and 30 min after CRH administration. Although all patients with ectopic ACTH secretion had less than a 35% increase in ACTH, the probability of Cushing's disease was high at all levels of response, indicating that other tests should be performed to confirm the diagnosis.

ACTH Syndrome, Ectopic↗

Midluteal phase endometrial biopsy does not accurately predict luteal function.

OBJECTIVE: To investigate whether a midluteal phase endometrial biopsy accurately predicts luteal function. DESIGN: One nonpregnant menstrual cycle was evaluated in a prospective fashion. SETTING: Outpatient Clinic of the Clinical Center of the National Institutes of Health. PARTICIPANTS: Fifty healthy, normally cycling women. INTERVENTIONS: Serum progesterone (P) was measured daily throughout the luteal phase. An endometrial biopsy was performed 7 to 9 days after the luteinizing hormone (LH) surge, as detected by rapid plasma assays, and dated histologically according to Noyes' criteria. MAIN OUTCOME MEASURE: To correlate endometrial maturation with luteal P secretion. RESULTS: Mean integrated P measurements were reduced only when the lag between histologic and chronological dating was > or = 3 days or > or = 4 days, depending on whether chronological dates were assigned prospectively from the LH surge or retrospectively from the onset of next menses, respectively. However, these lags did not consistently predict deficient luteal function because subnormal integrated P secretion was seen in only 14% of women with these delays in endometrial maturation. CONCLUSIONS: Midluteal phase endometrial biopsy provides a crude test of luteal function that does not precisely distinguish luteal insufficiency.

Adult↗

Serum levels of placental protein 14 do not accurately reflect histologic maturation of the endometrium.

OBJECTIVE: To determine whether serum levels of placental protein 14, a major product of the progesterone-induced secretory endometrium, accurately reflect histologic maturation of the endometrium. METHODS: Daily serum levels of placental protein 14 were compared in 50 normally cycling women with normal or delayed endometrial maturation, as assessed by histologic dating of an endometrial biopsy in the midluteal phase of the same cycle. Ten of these subjects had placental protein 14 measurements but no biopsy in an additional cycle to examine the potential effects of the biopsy on secretion of this protein. RESULTS: Serum placental protein 14 concentrations started to increase 8 days after the LH surge and peaked at similar levels on the first day of the next menses in biopsy and non-biopsy cycles. The biopsy cycles had a shorter luteal phase but a slightly faster increase in placental protein 14 concentrations. Both the integrated secretion of this protein and single measurements on the day of the biopsy or at the onset of the next menses overlapped substantially in women with different degrees of endometrial development, even when differentiation of the endometrium was severely delayed. CONCLUSION: Serum measurements of placental protein 14 do not accurately predict, and thus should not replace, histologic evaluation of the endometrium at nidation.

Abortion, Habitual↗

Endocrinology.

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Endocrinology↗

Urine free cortisol in the high-dose dexamethasone suppression test for the differential diagnosis of the Cushing syndrome.

OBJECTIVE: To develop criteria for interpreting the high-dose dexamethasone suppression test using urine free cortisol as an end point for the differential diagnosis of the Cushing syndrome. DESIGN: Retrospective review. SETTING: Inpatient research ward. PATIENTS: Patients (118) with surgically confirmed causes of the Cushing syndrome: 94 with pituitary disease, 14 with primary adrenal disease, and 10 with ectopic adrenocorticotropic hormone (ACTH) secretion. MAIN OUTCOME MEASURES: The sensitivity, specificity, and diagnostic accuracy were determined for the high-dose dexamethasone suppression test using urine free cortisol and using 17-hydroxysteroid excretion. For each analysis, patients with pituitary disease were considered to be "diseased" and patients with nonpituitary disease were considered to be "non-diseased". The level of suppression that gave 100% specificity was determined for each steroid. RESULTS: The accuracy of urine free cortisol when used as an end point in the high-dose dexamethasone suppression test was equivalent to that of 17-hydroxysteroid excretion. At all levels of sensitivity and specificity, however, the degree of suppression of urine free cortisol used for the diagnosis of pituitary disease was greater than that of 17-hydroxysteroid excretion. The likelihood ratios for pituitary disease based on urine free cortisol suppression of greater than 50%, of greater than 80%, and of greater than 90% were 4.2, 10.1, and "infinite," respectively. Suppression of urine free cortisol greater than 90% or suppression of 17-hydroxysteroid excretion greater than 64% was associated with 100% specificity. When these criteria were combined, the percentage of correct predictions (102 of 118 [86%; 95% CI, 78% to 92%]) was higher than that obtained using either steroid alone (89 of 118 [75%; CI, 65% to 83%]) (P = 0.009) and higher than that obtained using the traditional criterion of 50% suppression for 17-hydroxysteroid excretion (95 of 118 [80%; CI, 71% to 87%]) (P = 0.016). CONCLUSIONS: In the high-dose dexamethasone suppression test, the degree of suppression of urine free cortisol used for the diagnosis of pituitary disease is greater than that traditionally used for 17-hydroxysteroid excretion. The diagnostic performance of the test is improved by measuring both urine free cortisol and 17-hydroxysteroid excretion and by requiring greater suppression of both steroids.

17-Hydroxycorticosteroids↗

Delayed endometrial maturation induced by daily administration of the antiprogestin RU 486: a potential new contraceptive strategy.

OBJECTIVE: Our objective was to determine if a progesterone antagonist might interdict the development of a secretory endometrium. STUDY DESIGN: Eleven normally cycling women not at risk for pregnancy received RU 486 (1 mg/day orally) or placebo throughout one menstrual cycle in a randomized, double-blind, crossover fashion. Estradiol, progesterone, and placental protein 14 were measured every 3 days; luteinizing hormone was measured until the midcycle surge was detected. An endometrial biopsy was performed on luteal phase day 7 to 9 and interpreted with Noyes' criteria. Differences between treatment groups were analyzed by the Student t test. RESULTS: RU 486 delayed ovulation, retarded endometrial maturation, and reduced peak levels of placental protein 14 without affecting gonadal steroid production. The abnormalities in endometrial morphology and function are similar to those seen in infertile women with luteal phase defects. CONCLUSION: We hypothesize that this regimen of antiprogestin administration may prevent implantation and offer a novel strategy for fertility control.

Adult↗

The effect of pubertal delay on adult height in men with isolated hypogonadotropic hypogonadism.

To determine whether delay of puberty alters adult height, we retrospectively evaluated the adult height of 41 patients who met rigorous criteria for the diagnosis of isolated hypogonadotropic hypogonadism. The adult height of these patients was compared with the mean height of normal American men at age 18 in the 1979 National Center for Health Statistics survey and with the mean adult height of 50 male normal volunteers who had been studied on the same wards as the patients with hypogonadotropic hypogonadism. The mean adult height of the men with isolated hypogonadotropic hypogonadism was 179.7 cm, which exceeded the height of the 50 control subjects and the normal American men (both 176.8 cm) by 2.9 cm (P less than 0.05 and P less than 0.006, respectively). The mean age at treatment to induce puberty was 20.0 yr, which corresponded to a mean delay in the onset of puberty of more than 8 yr relative to normal males. The final height of the men with hypogonadotropic hypogonadism correlated significantly with the duration of pubertal delay (r = 0.32, P = 0.04). Most of the enhanced mean adult height of the patients with isolated hypogonadotropic hypogonadism was attributable to those patients in whom treatment to induce puberty had been delayed to age 18 or greater. The mean adult height of these patients was 182.4 cm, or 5.6 cm greater than the mean height of the 50 controls or of normal American men (P less than 0.001). The mean adult height of patients whose treatment began between 10 and 17 yr of age was 175.0 cm, which did not differ significantly from that of normal men. We conclude that prolonged delay of puberty (6 or more yr) in men with isolated hypogonadotropic hypogonadism is associated with a modest increase (approximately 5 cm) of adult height.

Adolescent↗

Evidence for a critical role of progesterone in the regulation of the midcycle gonadotropin surge and ovulation.

Serum concentrations of progesterone begin to rise just before the midcycle gonadotropin surge that leads to ovulation. To examine the role of progesterone in the regulation of these events, we evaluated the effects of a low dose (1 mg/day, orally) of the antiprogesterone RU 486 on the timing of the gonadotropin surge and ovulation in normally cycling women. The drug or a placebo was given for 5 or 15 days, starting when the dominant follicle reached 14-16 mm. RU 486 consistently delayed the timing of the midcycle gonadotropin surge and the subsequent collapse of the dominant follicle, despite rising estradiol concentrations and normal follicular development. Unexpectedly, RU 486 also delayed the emergence of the periovulatory progesterone rise. The addition of progesterone (5-10 mg/day, im, for 2 days) to a 5-day course of RU 486 after the emergence of a mature follicle readily induced LH and FSH surges and completely reversed the effects of RU 486 at midcycle. Our results suggest that RU 486 delays the midcycle gonadotropin surge and ovulation by suppressing or antagonizing an ovarian progestational signal. Progesterone may, thus, represent the ultimate ovarian signal to the estrogen-primed hypothalamic-pituitary unit to trigger the gonadotropin surge that leads to ovulation.

Adult↗

Petrosal sinus sampling with and without corticotropin-releasing hormone for the differential diagnosis of Cushing's syndrome.

BACKGROUND: Measurement of adrenocorticotropin levels in plasma from the inferior petrosal sinuses of patients with Cushing's syndrome can distinguish adrenocorticotropin-secreting pituitary tumors (Cushing's disease) from other causes of the syndrome, principally ectopic adrenocorticotropin secretion from an occult tumor. However, it is unknown whether such measurement consistently identifies patients with Cushing's disease and whether testing with corticotropin-releasing hormone (CRH) enhances the value of the procedure. METHODS: We prospectively studied 281 patients with Cushing's syndrome to evaluate the diagnostic efficacy of the procedure. Bilateral sampling was successfully accomplished in 278 patients, with no major morbidity; 262 of these patients underwent sampling before and after administration of ovine CRH. The adrenocorticotropin levels in the samples were used to calculate the ratio of the concentration in plasma from the inferior petrosal sinuses to the concentration in peripheral-blood plasma (the IPS:P ratio). RESULTS: The diagnosis of 246 patients was confirmed surgically as Cushing's disease in 215, as ectopic adrenocorticotropin syndrome in 20, and as primary adrenal disease in 11. An IPS:P ratio greater than or equal to 2.0 in basal samples identified 205 of the 215 patients with Cushing's disease (sensitivity, 95 percent), with no false positive results (specificity, 100 percent). A peak IPS:P ratio greater than or equal to 3.0 after CRH administration identified all 203 of the patients with Cushing's disease who received CRH (sensitivity, 100 percent), with no false positive results (specificity, 100 percent). The sensitivity was much lower when the adrenocorticotropin concentrations in the samples from one sinus were considered alone. In patients with Cushing's disease a difference of greater than or equal to 1.4-fold between the concentrations in the two sinuses (the adrenocorticotropin gradient) predicted the location of the microadenoma in 68 percent of 104 patients during basal sampling and in 71 percent of 105 patients after CRH administration. CONCLUSIONS: Simultaneous bilateral sampling of plasma from the inferior petrosal sinuses, with the adjunctive use of CRH, distinguishes patients with Cushing's disease from those with ectopic adrenocorticotropin secretion with high diagnostic accuracy.

ACTH Syndrome, Ectopic↗

A novel testis-stimulating factor in familial male precocious puberty.

BACKGROUND: Familial male precocious puberty is a gonadotropin-independent form of precocious puberty that occurs only in males. The cause of the disorder is unknown. To examine the hypothesis that the plasma of boys with familial male precocious puberty contains a novel stimulator of testicular testosterone production, we developed a bioassay using adult male cynomolgus monkeys. METHODS: We collected plasma from 12 boys with familial male precocious puberty, 7 normal prepubertal boys of similar ages and with similar plasma gonadotropin levels, and 1 boy with hypogonadotropic hypogonadism and infused it into the testicular artery of adult male cynomolgus monkeys that had been pretreated with gonadotropin-releasing-hormone antagonist to inhibit the endogenous secretion of gonadotropins. Testicular venous effluent was collected at 15-minute intervals for 3 or 5 hours for the measurement of testosterone. RESULTS: The mean (+/- SE) peak testosterone response, as compared with base line, was significantly greater in the monkeys infused with plasma from the 12 boys with familial male precocious puberty than in the monkeys infused with plasma from the 7 normal prepubertal boys and the boy with hypogonadotropic hypogonadism (385 +/- 51 vs. 184 +/- 25 percent, P less than 0.005) in the three-hour studies. Plasma from 92 percent of the boys with familial male precocious puberty and 12.5 percent of the normal prepubertal boys stimulated a response greater than 195 percent of base-line values. In the animals studied for five hours after receiving a second dose of antagonist, the mean peak testosterone response, as compared with base line, was significantly greater in the monkeys infused with plasma from three boys with familial male precocious puberty than in the monkeys infused with plasma from three normal prepubertal boys (363 +/- 81 vs. 115 +/- 6 percent, P less than 0.01). The mean area under the testosterone-response curve was significantly larger in the monkeys infused with plasma from the boys with familial male precocious puberty in the five-hour studies (154 +/- 34 vs. -58 +/- 10 percent, P less than 0.005), but not in the three-hour studies. CONCLUSIONS: These findings support the presence of a circulating testis-stimulating factor in the plasma of boys with familial male precocious puberty. The production of such a factor would explain the biologic nature of the disorder.

Animals↗

Daily administration of the progesterone antagonist RU 486 prevents implantation in the cycling guinea pig.

Since progesterone is required to prepare the endometrium for implantation of an embryo, a progesterone antagonist may inhibit nidation and thus prevent pregnancy. We addressed this possibility in the guinea pig, the small laboratory animal whose reproductive physiology most resembles that of women. Daily administration of the antiprogestin RU 486 (0, 1, 2, or 3 mg/kg, subcutaneously) for 9 days after mating inhibited implantation in a dose-dependent fashion. When this compound was given daily throughout the estrous cycle, cyclic vaginal changes, ovulation, and mating were suppressed in up to 17%, 28%, and 55% of animals, respectively. Two of seven mated female animals receiving RU 486, 1 mg/kg/day, had implantation sites. Nidation was completely blocked at higher doses. Thus daily antiprogestin administration prevented pregnancy in sexually active, normally cycling guinea pigs. A similar strategy using a daily antinidatory dose of an antiprogestin may offer a novel approach to human fertility control.

Animals↗

Daily cortisol production rate in man determined by stable isotope dilution/mass spectrometry.

Growth retardation as well as the development of Cushingoid features in adrenally insufficient patients treated with the currently accepted replacement dose of cortisol (33-41 mumol/day.m2; 12-15 mg/m2.day) prompted us to reevaluate the cortisol production rate (FPR) in normal subjects and patients with Cushing's syndrome, using a recently developed thermospray liquid chromatography-mass spectrometry method. The stable isotope [9,12,12-2H3]cortisol was infused continuously for 31 h at about 5% of the anticipated FPR. Blood samples were obtained at 20-min intervals for 24 h, spun, and pooled in 4-h groups. Tracer dilution in plasma was determined by liquid chromatography/mass spectrometry. The method was validated with controlled infusions in 6 patients with adrenal insufficiency. Results from 12 normal volunteers revealed a FPR of 27.3 +/- 7.5 mumol/day (9.9 +/- 2.7 mg/day) or 15.7 mumol/day.m2; 5.7 mg/m2. day). A previously unreported circadian variation in FPR was observed. Patients with Cushing's syndrome demonstrated unequivocal elevation of FPR and cortisol concentration correlated during each sample period in normal volunteers, indicating that cortisol secretion, rather than metabolism, is mainly responsible for changes in plasma cortisol. Our data suggest that the FPR in normal subjects may be lower than previously believed.

Chromatography, Liquid↗

Mitotane enhances cytotoxicity of chemotherapy in cell lines expressing a multidrug resistance gene (mdr-1/P-glycoprotein) which is also expressed by adrenocortical carcinomas.

P-Glycoprotein (Pgp), product of the mdr-1 gene, is a 130- to 180-kDa plasma membrane phosphoglycoprotein which mediates multidrug resistance in cell culture by increasing efflux of the natural product chemotherapeutic agents. High levels of expression of mdr-1/Pgp are found in both the normal adrenal and adrenocortical cancers. By RNA in situ hybridization the expression in adrenocortical cancer is shown to be widely distributed. The present study demonstrates that decreased drug accumulation mediated by mdr-1/Pgp can be overcome by clinically achievable concentrations of mitotane (o,p'-DDD). The increase in drug accumulation with the addition of mitotane is due at least in part to a decrease in drug efflux and results in an increase in cytotoxicity when agents of the natural product class are used. This effect is observed in cells with a broad range of mdr-1/Pgp expression, including levels comparable to those found in most adrenocortical cancers. Similar increases in drug accumulation can be demonstrated in an unselected adrenocortical cancer cell line that expresses mdr-1/Pgp. The finding that multidrug resistance mediated by mdr-1/Pgp can be reversed by mitotane provides a rational basis for exploring the use of mitotane in combination with natural product chemotherapeutic agents in adrenocortical cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗