Growth hormone isoforms in a girl with gigantism

Several previous investigations have suggested that there may be different growth hormone isoforms in patients with acromegaly. We used three different site-specific monoclonal antibodies (MAbs) to investigate growth hormone (GH) isoforms in serum from an 8 year-old girl with a GH and prolactin secreting adenoma. The pattern of GH-immunoreactivity was dependent on the circumstances of collection. Serum obtained after oral glucose had very little cross reactivity with MAb 352 although concentrations of up to 15 micrograms/l were found with two other MAbs, 033 and 665. MAb 352 does not recognize the 20,000 dalton isoform of GH (20K) while both MAb 033 and 665 do. The same pattern of GH immunoreactivity (low MAb 352, equal and higher MAb 033 and 665) was seen in other baseline samples. In contrast, samples obtained after TRH/GnRH showed immunoreactivity patterns expected for a mixture of 22,000 dalton isoform of GH (22K) with only a small amount of 20K. GH samples obtained during sleep showed both patterns with episodic peaks with equal immunoreactivity superimposed on the basal pattern (decreased activity with MAb 352). Affinity chromatography of basal samples showed that a portion of the GH immunoreactivity was neither 22K nor 20K, although in stimulated samples, over 70% of GH was 22K or 20K GH. In conclusion, the nature of GH isoforms present in serum varies with GH concentration. These differences may contribute to the known difficulty in correlating disease activity and random GH measurements in patients with GH secreting adenomas.

Evaluation of differential effects of carbohydrate and fat intake on weight gain, serum IGF-1 and erythrocyte Na+K+ATPase activity in suboptimal nutrition in rats

OBJECTIVE

Suboptimal nutrition leads to growth delay, frequently without over clinical or biochemical signs. We hypothesize that changes in serum IFG-1 and erythrocyte sodium-potassium ATPase activity (ENKA) may be indices of suboptimal nutrition.

METHODS

Male Sprague-Dawley rats were pair-fed for 4 weeks with balanced diets of different carbohydrate (CHO) to fat (FAT) ratios (3:1, 2:1, and 1:1) and three levels of energy intake (ad-libitum, 80%, and 60%), corrected for actual body weight). Daily weight gain and weekly tail growth were monitored while ENKA, serum total protein, T3, insulin and IGF-1 were measured after four weeks. Refeeding experiments were also performed with the 3:1 and 1:1 CHO:FAT diets, including 4 weeks of dietary restriction and one week of ad-libitum feeding.

RESULTS

Weight gain, tail growth, and IGF-1 decreased (p < 0.05) in all groups after 1 week of dietary restriction. A decrease in ENKA (p < 0.05) was found in rats that consumed 60% of ad-libitum energy intake only after 4 weeks. At the end of dietary treatment, weight gain was higher (p < 0.05) in rats fed the 3:1 CHO:FAT diet. In contrast, when energy was restricted to 80% or 60% of ad-libitum intake, rats fed the 1:1 CHO:FAT diet gained more weight (p < 0.05) compared to the 3:1 and 2:1 CHO:FAT diets. After 1 week of refeeding body weight, tail growth and ENKA returned to control values while serum IGF-1 levels remained depressed.

CONCLUSIONS

Acute nutritional changes are clearly detected by a reduction of serum IGF-1 while ENKA may be a useful index for assessing chronic suboptimal nutrition.

Carbohydrate absorption from one serving of fruit juice in young children: age and carbohydrate composition effects

OBJECTIVES

To test the hypotheses that: the efficiency of carbohydrate absorption in childhood increases with age, and decreased carbohydrate absorption occurs more frequently with juices containing more fructose than glucose and/or sorbitol than with juices which contain equal amounts of fructose and glucose and are sorbitol-free.

METHODS

One hundred and four healthy children were recruited from the Ambulatory Center at Maimonides Children's Center. They were assigned to one of three age groups: approximately 1, 3 and 5 years of age. Each child received one age-specific dose (by randomization) of one of four juices: a) pear juice which contains fructose in excess to glucose and a large amount of sorbitol; b) apple juice which is similar to pear juice in its fructose to glucose ratio but contains four times less sorbitol than pear juice; c) white grape juice or d) purple grape juice both of which contain equal amounts of fructose and glucose and are sorbitol-free. Breath hydrogen excretion (BH2) was utilized as the index of carbohydrate absorption. It was measured in fasting children and at 30-minute intervals for 3 hours after drinking the single serving of juice. Multiple breath hydrogen related parameters were quantified and results were expressed as: BH2 peak, area under the curve, and degree of carbohydrate malabsorption. After the test, parents completed a questionnaire and recorded signs and symptoms of intestinal malabsorption for 24 hours.

RESULTS

Pear juice related BH2 levels were significantly higher among children 1 and 3 years of age as compared to the levels achieved after the other juices. Apple juice related BH2 levels were significantly higher only among the youngest age group of children. There was no significant difference in carbohydrate absorption among the 5 year old children regardless of the juice consumed. Incomplete carbohydrate absorption (BH2 peak above 20 ppm) occurred more frequently after pear juice consumption (84%) than after apple juice (41%) or grape juice (white 20%, purple 24%) [p < 0.05]. Further outcome measures of BH2 excretion did not elicit differences beyond those detected by the above-mentioned parameters. Parents reported diarrhea in six children after pear juice, two after apple juice and two after purple grape juice and these children had the highest BH2 levels in their respective groups. No other symptoms were reported.

CONCLUSIONS

The data show that the efficiency of carbohydrate absorption of one age-specific serving of juice increases with advancing age of children. Decreased carbohydrate absorption occurs more often after ingestion of juices that contain more sorbitol, a nonabsorbable sugar and higher concentrations of fructose over glucose than after ingestion of juices which lack sorbitol and contain equal amounts of fructose and glucose.

Testing cord blood human chorionic gonadotropin as a surrogate marker for early identification of human immunodeficiency virus-1 infection in children

We measured human chorionic gonadotropin (hCG) in cord sera of 22 infants born to women infected with the human immunodeficiency virus-1 (HIV-1). hCG was also determined in cord sera from 173 infants born at a suburban hospital to HIV-1-seronegative women. The findings indicate that 16 (9%) of 173 HIV-1-seronegative samples had hCG levels greater than 90 IU/L (values were distributed as a Poisson curve). In contrast, 8 (36%) of the 22 infants born to HIV-1-infected women had hCG levels in excess of 90 IU/L, and 7 (88%) of these were shown to be HIV-infected. The remaining 14 infants born to HIV-1-infected women had low hCG levels, and 3 (21%) of the 14 had HIV infection. Mean follow-up time for HIV-uninfected infants was 17.5 months (range 9 months to 3 years). A statistically significant association between maternal-fetal HIV-1 transmission and hCG levels > or = 90 IU/L in cord sera was observed (p = 0.02). The difference between CD4 counts among mothers who transmitted HIV and those who did not was also statistically significant (p = 0.025). On the basis of this study's findings, we propose that cord blood hCG may serve as a surrogate marker for HIV-1 infection. Testing hCG levels in cord sera is an inexpensive and readily available screening test for early identification of infants at increased risk for getting HIV-1 from their mothers.

Carbohydrate absorption from fruit juice in young children

OBJECTIVE

To compare carbohydrate absorption following ingestion of apple juice and white grape juice in 28 healthy children.

DESIGN

Randomized, double-blind crossover study.

SETTING

Outpatient pediatric clinic at Maimonides Medical Center.

PARTICIPANTS

A total of 18 healthy infants (mean age 6.3 months) and 10 toddlers (mean age 18.0 months), representing those ages when juice is first introduced (6 months) and when juice comprises a large portion of the diet (18 months).

METHODS

Breath hydrogen (H2) testing was performed after age-specific servings of white grape juice or apple juice, 4 and 8 ounces respectively, were consumed. These portions provided approximately 1 g of fructose per kg of body weight. Breath H2 responses of > 20 ppm were considered positive, indicating incomplete absorption of fruit juice carbohydrates.

RESULTS

In the combined age groups, carbohydrate malabsorption occurred more frequently after apple juice consumption (54%) than after white grape juice (19%; P < .001). Significant differences in area under the breath H2 curve (AUC) were also found between the two juices in both age groups. Among toddlers, the differences between the mean peak breath H2 responses were significant (48 ppm after apple juice consumption compared with 12 ppm after white grape juice; P < .001). These differences were not significant in the infant group. Significant differences (P < .05) were seen between the two age groups after consumption of apple juice; the toddlers exhibited a greater number of positive breath H2 responses and higher peak responses compared with the infants. Data from the children who drank both juices showed significant differences in peak breath H2 responses after consumption of apple juice compared with white grape juice (P < .005).

CONCLUSIONS

The study demonstrated less carbohydrate malabsorption following ingestion of white grape juice compared with apple juice in healthy 6- and 18-month-old children.

Disturbances in growth hormone secretion and action in adolescents with anorexia nervosa

Women in whom anorexia nervosa develops during adolescence have failure of linear growth associated with low levels of insulin-like growth factor I (IGF-1). To investigate the pathophysiology of growth retardation in adolescents with anorexia nervosa, we measured basal growth hormone (GH), growth hormone-binding protein (GHBP), IGF-1, and insulin-like growth factor binding protein-3 (IGFBP-3) in three groups of patients: (1) 28 recently hospitalized female adolescents with anorexia nervosa, (2) 23 of the same patients after partial weight restoration, and (3) 28 healthy control subjects matched for age, sex, and pubertal stage. Fasting GH levels in group 1 did not differ significantly from those in group 3. In contrast, serum GHBP (p < 0.001), IGF-1 (p < 0.001), and IGFBP-3 (p < 0.01) were significantly lower in group 1 than in group 3. Serum GHBP and IGFBP-3 levels were positively correlated with body mass index. Serum GHBP levels were low in patients in all five pubertal stages and even in those shown to have adequate GH secretion. In group 2 (after refeeding) the serum IGF-1 concentration increased significantly and GHBP and IGFBP-3 returned to normal. We conclude that patients with anorexia nervosa have diminished GH action resulting in decreased secretion of IGF-1. The positive correlation with body mass index and the reversibility with refeeding suggest that these changes are secondary to malnutrition. Altered GH function that occurs during the years of active growth can explain the growth retardation seen in anorexia nervosa.

Thyroid function in children with perinatally acquired antibodies to human immunodeficiency virus

We measured T4, T3, TSH, and TBG in 53 children (both asymptomatic and symptomatic) with human immunodeficiency virus (HIV) antibodies, and 17 controls. Although most had normal T3 and T4 levels, two children with acquired immuno-deficiency syndrome (AIDS), who were very ill when studied, had low T3 values. TBG and TSH levels were higher in children with AIDS than in other HIV-infected children or controls (P < 0.005). Increased TSH levels were found in 5 children with AIDS who were recovering from severe illnesses. TSH levels returned to normal without treatment. In summary: 1) the pattern of thyroid abnormalities in children with AIDS was different from that seen in healthy controls, critically ill children, other HIV-infected children, and HIV-infected adults; 2) if an increased TSH is found, measurement should be repeated before instituting thyroxine therapy; 3) an increased TBG is not seen in HIV-infected children until clinically evident AIDS is present.

Circulating growth hormone isoforms in girls with Turner's syndrome

To evaluate the presence of different GH isoforms in serum of girls with Turner's syndrome, we measured the serum GH content using RIAs with three different site-specific monoclonal antibodies (MAbs). We compared the results to those obtained with authentic GH and GH isoforms. Compared to pituitary GH (mol wt, 22K daltons) as the standard for all three MAbs, serum from girls with Turner's syndrome did not displace tracer [125I]GH equally with all three MAbs. The relative amounts of GH-immunoreactive material found in Turner's syndrome were different from the amounts observed in normal adults and most children with idiopathic short stature. The presence of GH, other than 22K GH, in serum from girls with Turner's syndrome was confirmed by affinity chromatography. The existence of different isoforms of GH, as shown by different cross-reactivity patterns with different MAbs to GH, may explain the conflicting results reported for GH secretion in girls with Turner's syndrome.

L-arginine decreases the infiltration of the kidney by macrophages in obstructive nephropathy and puromycin-induced nephrosis

We examined the effect of 1% L-arginine in the drinking water on the infiltration of the kidney by macrophages in rats with puromycin aminonucleoside-induced nephrosis (PAN) and in rats with bilateral ureteral obstruction (BUO) of 24 hours duration. Rats given L-arginine in the drinking water for three days before BUO or PAN was initiated had a greater glomerular filtration rate after release of BUO or induction of PAN than similar rats not given L-arginine (P < 0.0001). Administration of L-arginine decreased the renal infiltration by macrophages in rats with PAN (P < 0.0001) or BUO (P < 0.0001) compared to rats with PAN or BUO given tap water alone. Chemotaxis studies suggested that macrophages were activated during obstruction as evidenced by the greater random migration of peritoneal macrophages obtained from rats with 24-hour urethral obstruction than from sham-operated rats (SOR; P < 0.0001). In vitro, maximal chemotaxis induced by 7% zymosan-activated serum (ZAS) in peritoneal macrophages from SOR was enhanced by low (10(-6) to 10(-5) M) and decreased by high concentrations (10(-3) to 10(-2) M) of L-arginine in the incubation medium. Migration of macrophages from rats with urethral obstruction was increased by 7% ZAS but the increase diminished with high concentrations of L-arginine (10(-3) to 10(-2) M). Random migration of peritoneal macrophages obtained from rats with urethral obstruction given L-arginine prior to obstruction was significantly lower than that of peritoneal macrophages obtained from similar rats given tap water alone prior to obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Gonadotropin-associated psychosis in perimenstrual behavior disorder

Sexually provocative and violent behavior have been reported as a result of excess androgens. We now report a temporal relationship between increased gonadotropin levels and behavioral changes in two adolescent girls who presented with a history of aggressive and bizarre sexual behavior coincident with the onset of menarche. We evaluated the possibility of a cyclical hormonal cause with daily measurements of gonadotropins, androgens and estradiol levels and correlated the results with periodic reports on the girls' behavior. We concluded that a correlation exists between periods of extremely violent and sexually provocative behavior and peaks of gonadotropin hormone secretion, even though androgen levels were normal. Treatment with medroxyprogesterone acetate (Depo-Provera) in one case and with leuprolide acetate (Lupron-Depot) in the other suppressed gonadotropin levels, and behavior improved markedly. Thus, the behavioral changes (or psychosis) seen in these girls might have been induced by increased levels of gonadotropins.

Correlation between puberty and the development of autoimmunity to spermatozoa in men with cystic fibrosis

OBJECTIVE

To test the hypothesis that puberty is a necessary factor in the pathogenesis of autoimmunity to sperm in men with cystic fibrosis (CF), we studied prepubertal and postpubertal males with CF versus an age-matched group of males with type 1 diabetes as controls.

DESIGN

Sera from CF and diabetic males treated at University Hospital, State University of New York, Stony Brook, were tested by indirect immunobead binding for antisperm antibodies and by radioimmunoassay for testosterone (T), luteinizing hormone, and follicle-stimulating hormone. The finding of autoantibodies to spermatozoa was correlated with chronological age, as well as with clinical and hormonal pubertal status.

RESULTS

Autoimmunity to sperm, as detected by humoral antisperm antibodies, was documented solely in postpubertal males, as judged by hormonal and clinical criteria. Eighty-three percent of sexually mature CF males and 6.3% (1 of 16) diabetic males exhibited autoantibodies to sperm. These antibodies were only detected when serum T levels were > 8.7 nmol/L (250 ng/dL).

CONCLUSIONS

These results suggest that puberty, and presumably, active spermatogenesis is a requirement for the development of autoimmunity to sperm in men with CF.

Sustained improvement in growth velocity and recovery from suboptimal growth hormone (GH) secretion after treatment with human pituitary GH-releasing hormone-(1-44)-NH2

The sustained effect of human pancreatic GH-releasing hormone [hpGHRH-(1-44)-NH2] on growth rate and GH secretory patterns was studied in 14 patients (10 males and 4 females; aged 10-16 yr; all Tanner stage I or II). Nine children had inadequate spontaneous GH secretion (ISGHS), while 5 had classic GH deficiency. Seven of 9 patients with ISGHS and 1 of 5 patients with GH deficiency were given 2 sc injections/day of 5 micrograms/kg GHRH for 2-3 months; the others received 5 pulses of GHRH (5 micrograms/kg BW.pulse) for 6 nights a week for 2-13 months, given every 3 h. Six of the nine ISGHS patients increased their growth velocity in response to GHRH therapy. These same six patients maintained an increased growth velocity for up to 24 months after GHRH was discontinued. The remaining three ISGHS patients did not show a significant growth response to GHRH administration. Neither a temporary nor a sustained growth response was correlated with spontaneous overnight GH secretion in these patients. In contrast, three of five classical GH deficiency patients exhibited increased growth velocity while undergoing GHRH therapy, but growth returned to preintervention rates upon discontinuation of treatment. The other two of the five classic GH deficiency patients failed to demonstrate any growth response to GHRH treatment. The increased growth velocity that was sustained for long intervals even after discontinuation of GHRH in ISGHS patients may indicate restoration of normal regulation of the hypothalamic-pituitary GH secretion axis.

The role of adrenocorticotropin testing in evaluating girls with premature adrenarche and hirsutism/oligomenorrhea

To identify biochemical predictors for future development of hirsutism and/or oligomenorrhea (H/O) in girls with premature adrenarche (PA), we performed dexamethasone-suppressed ACTH stimulation tests in girls with PA (n = 46), young women (n = 44) with H/O, and adult women (n = 31). Cortisol, androstenedione, dehydroepiandrosterone, and 17-hydroxyprogesterone were measured. Seven girls with PA (15%) and seven with H/O (16%) had evidence of nonclassical adrenal steroid biosynthetic defects [nonclassical congenital adrenal hyperplasia (NCAH)]. Twenty-five girls with PA (54%) and 28 girls with H/O (64%) had the moderately elevated 17-hydroxyprogesterone response to ACTH that has been reported in obligate heterozygotes for 21-hydroxylase deficiency. There were no clinical features that distinguished the girls with NCAH from the others. ACTH testing is an important tool in distinguishing those girls with PA and H/O who have NCAH. Although we could find no differences in other adrenal steroid hormones that might predict which of the other girls with PA might late develop H/O, black girls comprised a substantially smaller fraction of the population with H/O than of the population with PA (2% vs. 26%; chi 2 = 8.5; P less than 0.005). This observation suggests that PA, in blacks who do not have NCAH, is more likely to be a benign condition/than in other ethnic groups.

Characterization of digoxin-like materials in human cord serum

Human cord serum contains substantial amounts of materials that cross-react in radioimmunoassays for digoxin. The average content of digoxin-like immunoreactivity in mixed cord serum is 0.3 +/- 0.05 ngE/ml compared to less than 0.05 ngE/ml in serum from normal adults. After solvent extraction, the major digoxin-like materials present in cord serum coelute on Sephadex LH-20 column with the steroid sulfate fraction. The steroid sulfates are digoxin-like materials because they cross-react in the digoxin RIA. If the amount of dehydroepiandrosterone sulfate, 16 alpha-hydroxydehydroepiandrosterone sulfate, and 15 beta-hydroxydehydroepiandrosterone sulfate present in cord serum and the amount of digoxin-like material present in the same serum are considered, then up to 90% of the digoxin-like materials present can be accounted for on the basis of the steroid sulfates present. However, although steroid sulfates contribute to the digoxin immunoreactivity in both serum and breast cyst fluid, digoxin-like materials are present in breast cyst fluid that are not present in cord serum.

Digoxinlike materials in human breast cyst fluids

Digoxinlike materials (DLMs) are compounds found in animals that (1) cross-react with digoxin antibodies in specific radioimmunoassay procedures and (2) bind to Na+, K(+)-ATPase and inhibit its activity. DLMs may play a part in the regulation of electrolyte composition. We have determined DLM concentrations in breast cyst fluids and found that these fluids were a rich source of DLMs. Total DLMs were elevated in fluids with type 1 electrolyte composition (high K+ and low Na+ content) when compared to fluids with type 2 composition (low K+ and high Na+ content). Chromatographic studies showed that the basis for the increase was the presence of an additional DLM in the type 1 cyst fluids rather than an increased concentration of the same DLM present in both types of fluids. We propose that this additional DLM may have a role in the accumulation of K+ ions in type 1 fluids. In addition, 7 of 80 cyst fluid samples subjected to high-performance liquid chromatography had a large UV-absorbing peak at 6.4 minutes. Four of these samples were taken from women who later developed breast cancer; information on the subsequent medical history of the other 3 women was unavailable. We suggest that the presence of this material in cyst fluid may be a marker of risk for development of breast cancer.

Blunted growth hormone responses to clonidine in adolescent girls with early anorexia nervosa. Evidence for an early hypothalamic defect

We studied growth hormone (GH) levels in 14 adolescents with anorexia nervosa (AN), 12-20 years of age. All had amenorrhea and the duration of symptoms ranged from 2-24 months. There was no difference in unstimulated GH between the girls with AN and endocrinologically normal girls. However, the GH response to the alpha-adrenergic agent clonidine was blunted (less than 10 ng/ml) in 11 of 14 girls with AN. Our results of a normal basal GH level and blunted response to stimulation is in contrast to some reports of high basal GH levels and an exaggerated response to pituitary stimulation although it agrees with other studies. Our patient population was younger and at an earlier stage of the disease (12 with symptoms for less than 1 year) than the AN patients previously reported to have elevated GH secretion. In view of studies that report an elevated GH response to growth hormone releasing factor, our results suggest that the AN patient's abnormalities in GH secretion may result from an abnormal hypothalamic response to adrenergic stimuli. This hypothalamic abnormality might also contribute to the growth failure seen in adolescent girls with AN.

Dehydroepiandrosterone sulfate levels are not suppressible by glucocorticoids before adrenarche

We measured dehydroepiandrosterone sulfate (DHEA-S) levels in children before and after high dose prednisone therapy. In older children (postadrenarchal), there was a 70% decrease in DHEA-S levels after 1 week. However, even after a month of therapy, DHEA-S was detectable in serum. In contrast, in younger (preadrenarchal) children, the low initial DHEA-S levels were not decreased by prednisone therapy. These findings suggest that there are two distinct regulatory pathways leading to DHEA-S, one of which is independent of ACTH.

Serum levels of dehydroepiandrosterone sulfate as determined by commercial kits and reagents

We measured serum dehydroepiandrosterone sulfate (DHEA-S) levels by nine different radioimmunoassay (RIA) methods. Although each method was adequate for determining the amount of authentic DHEA-S, there were marked differences observed between the methods when serum samples were tested. Further, the pattern of these differences varied in different clinical situations. We suggest that the differences in the apparent DHEA-S content resulted from the presence of structurally related compounds which differ in their cross-reactivity in the different RIAs. One of these cross-reacting materials may be a functional androgen.

Overnight dexamethasone suppression test: normal responses and the diagnosis of Cushing's syndrome

Serum cortisol levels were measured the morning after the administration of 1 mg of dexamethasone. Only 5 of 190 subjects had serum cortisol levels greater than 2 micrograms/dL. Thus, the normal value after dexamethasone suppression is less than 2 micrograms/dL rather than less than 5 micrograms/dL as has generally been accepted. The distinction is important because some individuals with Cushing's syndrome partially suppress their cortisol levels to less than 5 but more than 2 micrograms/dL during the test procedure. Thus, the use of 5 micrograms/dL as the normal value may lead to an unnecessary delay in diagnosis.

Endogenous digoxin-like material in normotensive and hypertensive strains of rats

We measured the concentration of endogenous digoxin-like materials (EDLM) in the serum of spontaneously hypertensive rats (SHR) and three normotensive rat strains at four stages during growth using a sensitive RIA. In the SHR, there was a significant peak in the EDLM level between 0.057-0.087 ngE/mL at 6 to 8 weeks of age, shortly after the onset of hypertension. The EDLM concentration returned to normal levels by 20 weeks of age. Sprague-Dawley and Wistar-Kyoto rats had EDLM levels below 0.050 ngE/mL at all time points studied. In contrast, Fischer 344 rats displayed persistently elevated serum EDLM concentrations that exceeded 0.124 ngE/mL from 3 to 20 weeks of life. We conclude that (1) there are significant interstrain differences in serum EDLM levels in rats; and (2) the SHR has a unique peak in serum EDLM levels at 6 to 8 weeks of age, indicating a possible role for the substance in the inception of hypertension.

The relationship between biochemical adrenarche and decreasing alpha-2-macroglobulin levels in children

Alpha-2-macroglobulin (alpha 2-MG) is one of the major serum protease inhibitors in adults and appears to be even more important in children. Previous studies have suggested that alpha 2-MG levels are dependent upon age and sex. In order to evaluate the influence of biochemical adrenarche on alpha 2-MG, we compared alpha 2-MG concentrations in normal children and children with premature adrenarche (PA) with levels of dehydroepiandrosterone sulfate (D-S), the marker for biochemical adrenarche. We found that alpha 2-MG was inversely correlated with age and with log10 [D-S] in the normal children. In the children with PA, the alpha 2-MG levels were significantly lower than predicted based on age alone and were similar to the predicted values based on log10 [D-S] levels. We suggest that adrenarche is the process that causes the age-related changes in alpha 2-MG.

Sex hormone-binding globulin and thyroxine-binding globulin levels in premature thelarche

Premature thelarche is defined as the isolated development of breast tissue in girls less than 8 years of age. Although breast development is an estrogen-dependent process, these girls do not have elevated serum estrogen levels, and the hormonal basis for their condition is unclear. We studied the levels of two estrogen-dependent transport proteins, sex hormone-binding globulin (SHBG) and thyroxine-binding globulin (TBG), in order to determine if there was evidence for a more subtle estrogen effect in girls with premature thelarche. SHBG levels in girls with premature thelarche were not significantly different from those of prepubertal girls of the same ages and were significantly lower than those in girls undergoing pubertal development at the appropriate age (P less than 0.05) and in normal women (P less than 0.001). There was no statistically significant difference in TBG levels between the girls with premature thelarche and prepubertal controls. There was also no significant difference in TBG levels between prepubertal girls and girls in early puberty. In contrast, women had TBG levels that were significantly lower than those in all girls studied. We conclude that the estrogen exposure (whether endogenous or exogenous) of girls with premature thelarche is less than that of girls in early true puberty and similar to that of other prepubertal girls. Further, changes in serum TBG are not as sensitive an indicator of estrogen effect as is breast development or changes in SHBG. This study also suggests that large amounts of exogenous estrogens are not an element in the development of premature thelarche.

Dehydroepiandrosterone sulfate (DHEA-S) and DHEA-S-like compounds in fibrocystic disease of the breast

We assayed Type 1 (high K+) and Type 2 (high Na+) human breast cyst fluids for DHEA-S. When an antibody specific for the 3-sulfoconjugate end of DHEA-S was used, Type 1 cyst fluids (n = 18) showed a content of 114 +/- 68 micrograms/mL (mean +/- sigma) and Type 2 cyst fluids (n = 14) of 35 +/- 17 micrograms/mL (P less than 0.01). Using an antibody specific for the D-ring, the results were 151 +/- 91 micrograms/mL and 51 +/- 32 micrograms/mL, respectively (P less than 0.01). The apparent concentrations of DHEA-S were statistically different, even though both assays gave equal results in serum from normal adults. The presence of other compounds in individual cyst fluid samples was examined by extraction and chromatography. DHEA-S immunoreactivity was found in both early and late eluting fractions in Type 1 cyst fluids and in late eluting fractions from Type 2 cyst fluids. Only the late eluting fraction from Type 2 fluids had approximately equal immunoreactivity with both antibodies. In addition to authentic DHEA-S, breast cyst fluids contain other materials that react with DHEA-S antibodies. Radioimmunoassays for DHEA-S in cyst fluid must be specifically validated because of the presence of these compounds.

Steroid metabolic disturbances in Prader-Willi syndrome

We have studied steroid sulfate conjugates in serum samples from 17 children with Prader-Willi syndrome (PWS) by extraction, enzymatic hydrolysis and chromatography of the hydrolysed, free steroids. The chromatograms in patients with PWS can be divided into 2 classes. Ten (4 with the deletion on chromosome 15 and 6 without) of 17 had a normal pattern with dehydroepiandrosterone (DHEA) as the only steroid detected. However, 7 out of 17 (3 with the deletion and 4 without) had a very different pattern. The chromatogram derived from these hydrolysates had 5 major peaks. One of these was DHEA; a second peak was tentatively identified as 16 alpha-hydroxy-DHEA on the basis of column retention time and immunoreactivity. The remaining 3, more polar, compounds have not yet been identified. The presence of unusual steroid sulfoconjugates in serum may correlate with other features of PWS and may be the basis for dividing PWS into two separate disease states: a) PWS-1 associated with DHEA-S as the only sulfo-conjugate and b) PWS-2 associated with unusual sulfo-conjugates. One interesting possibility is that these sulfo-conjugates may have a hormonal function, even though no function has yet been recognized for DHEA-S. Then, PWS may be the common clinical manifestation of a variety of different defects in the sulfo-conjugate metabolic pathway.

Adrenal steroid secretion in girls with pseudoprecocious puberty due to autonomous ovarian cysts

To evaluate the role of adrenal steroids in pseudoprecocious puberty due to large ovarian follicular cysts, we studied the serum 17-hydroxyprogesterone response to a combination of dexamethasone suppression followed by iv ACTH administration in two girls and compared the results to those in girls with premature thelarche, normal prepubertal girls, and a girl with true precocious puberty. Although basal serum 17-hydroxyprogesterone levels were normal in all subjects, there was incomplete suppression of 17-hydroxyprogesterone with dexamethasone in the two girls with pseudoprecocious puberty and large ovarian cysts. The 17-hydroxyprogesterone response to ACTH was much greater in these girls (360 and 540 ng/dl) than in the girls with other types of precocious puberty (mean +/- SD, 71 +/- 15 ng/dl) or in normal prepubertal girls (80 +/- 20 ng/dl). The girls with large ovarian cysts had decreased gonadotropin responses to GnRH, which were reversed subsequent to removal of the cyst. Removal of the ovarian cysts also restored the dexamethasone suppressibility of serum 17-hydroxyprogesterone and abolished the progression of pubertal development. However, 17-hydroxyprogesterone responses to ACTH were still elevated (160 and 350 ng/dl). Preoperatively, both girls had increased levels of dehydroepiandrosterone sulfate, 16-hydroxydehydroepiandrosterone sulfate, and another unidentified steroid sulfate. These steroid sulfates were also found in the cyst fluid from the one patient from whom the fluid was obtained. These results suggest that steroid production by the adrenal gland may stimulate the development of small ovarian cysts (which may be present in normal prepubertal girls) into large ovarian cysts capable of causing gonadotropin-independent precocious puberty.

18q deletion syndrome in a child with steroid-17,20-lyase deficiency

The del (18q) syndrome is characterised by poor growth, variable mental retardation, facial dysmorphism, and abnormalities of the genitalia. In genetic males, genital abnormalities vary from testicular ectopia, and microphallus to severe hypospadias. Genetic females frequently have hypoplasia of the labia minora. We describe a child with del (18q) syndrome and severe ambiguous genitalia. Serum testosterone after 4 doses of hCG (5000 IU/m2/dose) was only 50 ng/dL (expected greater than 300 ng/dL). When testicular tissue was incubated with [1,2-3H]progesterone and 17-hydroxy-[4-14C]progesterone, there was synthesis of 17-hydroxy-[1,2-3H]progesterone but no further metabolism of 17-hydroxyprogesterone to androgens. These data suggested the presence of steroid-17,20-lyase deficiency. In order to determine if steroid-17,20-lyase deficiency was a common feature in del (18q) syndrome we examined 6 other patients (3 girls; 3 boys) with a deletion of the long arm of chromosome 18 distal to band q21. All 6 had dehydroepiandrosterone sulfate (DHEA-S) levels which were lower than those of age-matched controls. Four had delayed puberty. Serum testosterone levels were also low in 2 of the 3 affected boys. These results together with the findings in the index case suggest that a structural or regulatory gene for steroid-17,20-lyase may be located on the long arm of chromosome 18, distal to band q21.

Possible abnormalities of steroid secretion in children with Smith-Lemli-Opitz syndrome and their parents

In early infancy, two unrelated children with Smith-Lemli-Opitz syndrome were found to have elevated levels of androgen sulfates. When the steroid conjugates in the serum of normal infants were hydrolyzed and chromatographed on Sephadex LH-20, 4 androgen containing peaks (I, II, III, IV) were found. In the serum from these two infants with Smith-Lemli-Opitz syndrome, Peaks I and III were increased, but Peaks II and IV were absent. The parents of the two children, and of three additional unrelated children with Smith-Lemli-Opitz syndrome, had exaggerated 17-hydroxyprogesterone responses to an intravenous bolus of ACTH. These findings suggest that a defect in steroid metabolism may be linked to the Smith-Lemli-Opitz syndrome.

Modulation of glucocorticoid secretion by growth hormone

We measured the cortisol and corticosterone responses to insulin-induced hypoglycemia in 13 growth hormone (GH)-deficient children and 30 short children without GH deficiency. Although there was no difference between the two groups in degree of hypoglycemia attained, baseline cortisol, baseline corticosterone, or cortisol 40 min after insulin injection, GH-deficient children had a significantly greater corticosterone response to this stress (3.6 +/- 0.4 versus 1.9 +/- 0.2 micrograms/dl). (All data are presented as mean +/- SEM.) In order to explore the effect of GH on corticosterone secretion, we measured cortisol and corticosterone responses to synthetic (1-24) ACTH before and after 3 days of exogenous GH (0.2 unit/kg/day). In 13 GH-deficient children, GH treatment caused a significant decrease in the corticosterone response to ACTH (2.2 +/- 0.2 micrograms/dl before GH to 1.6 +/- 0.2 micrograms/dl; t = 5.22, p less than 0.001; paired t test) despite the fact that there was no significant change in the cortisol response to ACTH (18 +/- 2 micrograms/dl before and 16 +/- 2 micrograms/dl after). When seven short children who were not GH deficient underwent a similar 3-day course of GH, the decrease in their corticosterone response was much less although still statistically significant (2.0 +/- 0.5 to 1.8 +/- 0.5 micrograms/dl; paired t test, p less than 0.05). Again, the stimulated levels of cortisol were not affected by GH treatment (19 +/- 4 versus 18 +/- 3 micrograms/dl) These results indicate that GH modulates the adrenal response to ACTH by suppressing corticosterone secretion without affecting cortisol secretion. In summary, this study presents two new findings.(ABSTRACT TRUNCATED AT 250 WORDS)

17-Hydroxyprogesterone responses to adrenocorticotropin in children with premature adrenarche

The adrenal secretory response to an iv bolus dose of ACTH was measured in 10 girls (4-8 yr of age), 5 boys (4-9 yr) with premature adrenarche (PA), and 20 normal children. The evening before the ACTH test, each subject took dexamethasone (1 mg at bedtime) to suppress the early morning surge of ACTH. The next morning, 2 serum samples were obtained before the administration of ACTH (Cortrosyn; 0.25 mg), and 2 samples were collected 30 and 45 min after ACTH administration. All samples were assayed for cortisol, dehydroepiandrosterone (DHEA), DHEA sulfate, 17-hydroxyprogesterone (17-OHP), and androstenedione. There was no significant difference in the dexamethasone-suppressed steroid levels between the children with PA and the normal children. After ACTH injection, cortisol, DHEA, 17-OHP, and androstenedione increased significantly. There was no significant change in DHEA sulfate. The mean 17-OHP response to ACTH in girls with PA was significantly higher than that in girls and women whose pubertal development was normal. This response was similar in magnitude to that in a group (n = 5) of obligate heterozygotes for congenital adrenal hyperplasia (CAH). These data suggest that many girls with PA have a mild adrenal steroid secretory defect that resembles the response in adult obligate heterozygotes for CAH due to 21-hydroxylase deficiency. In contrast to the girls, none of the boys with PA had an exaggerated 17-OHP response to ACTH. Thus, these boys had no evidence for an adrenal steroid secretory defect. In summary, although the clinical presentation of boys with PA is similar to that of girls with PA, there is a significant difference in the adrenal steroid secretory response to ACTH. Thus, the biochemical events that cause PA in boys may be different from the corresponding events in girls.

Dehydroepiandrosterone (DHEA) measurements in cord blood

Antibodies to dehydroepiandrosterone (DHEA) can be generated by coupling DHEA to carrier proteins. This report describes the use of antibodies to three different DHEA-protein complexes for the measurement of DHEA in serum and cord plasma. Each of the three antibodies produces an assay with equivalent results in serum from adults and older children. However, with cord plasma samples, two of the antibodies detected much more cross-reacting material than was detected with the third antibody. In order to determine the basis for this discrepancy, a pool of cord plasma was extracted in a manner similar to that used in the assay procedure. The steroids in the extract were separated by chromatography on a Sephadex LH-20 column and individual fractions were assayed for DHEA with each of the antibodies. There were several peaks of cross-reacting material present in cord blood that were not present in comparable amounts in serum from adults. These results indicate that assays for DHEA need to be separately validated with samples from adults and from infants.

Partial deficiency in 17-ketosteroid reductase presenting as gynecomastia

We report a 14 year-old male with severe, long-lasting gynecomastia. Baseline serum androstenedione levels were elevated compared to testosterone levels (330 ng/dl vs 28 ng/dl). In order to evaluate testosterone biosynthesis by this patient in more detail, androstenedione, testosterone, dehydroepiandrosterone (DHEA) and estradiol responses to a single dose of hCG were measured. The responses observed were different from those reported in normal males in two respects: 1) there was no immediate rise in testosterone two to four hours after the injection of hCG, and 2) levels of androstenedione and estradiol at 24, 36 and 48 hours after injection were much higher than expected. We postulate that a partial defect in testicular 17-ketosteroid reductase activity was responsible for the abnormal androstenedione to testosterone ratio in our patient. This, in turn, lead to an increased peripheral synthesis of estrogens and marked gynecomastia.

An improved method for evaluating testosterone biosynthetic defects

A double-label, double-substrate incubation technique has been developed and used to study the conversion of progesterone to testosterone in testes extracts from incompletely virilized males. The procedure involves separation of the microsomes from a testicular homogenate, incubating the microsomes with 1 microM [7-3H] progesterone, 1 microM 17-hydroxy[4-14C]progesterone, and 0.25 mM NADPH in pH 7.4 phosphate buffer at 37 degrees C. Steroid precursors and products are separated by column chromatography on Sephadex LH-20 with a solvent system of isoctane:ethyl acetate:methanol (4:1:1 by volume). These procedures can be completed in 2 days, and thus the method represents an improvement in time, reproducibility, and simplicity when compared to techniques based on thin layer or paper chromatography. The method has been used to distinguish the biochemical abnormality in three cases with XY sex chromatin, posterior labial fusion, clitoromegaly, and hypospadias. The abnormalities identified were: Case 1, no defect in testosterone synthesis (probable androgen insensitivity); Case 2, 17-ketosteroid reductase deficiency; and Case 3, steroid-17, 20-lyase deficiency.

Cytoplasmic malic enzyme and testicular steroidogenesis in mice

The malate shuttle has been hypothesized as a source of the intramitochondrial NADPH required for cholesterol side-chain cleavage. In the present report, the role of the malate shuttle in testicular steroidogenesis was investigated by employing mouse mutants deficient in cytoplasmic malic enzyme, a required component of the shuttle. Androgen-dependent parameters plus testosterone secretion by in vitro perfused testes were similar for the mutants and their normal siblings. The data suggest that an active malate shuttle is not required for cholesterol side-chain cleavage in mouse testes.

Use of a two-site immunoradiometric assay for growth hormone (GH) in identifying children with GH-dependent growth failure

Children with GH-dependent growth failure have normal GH responses to provocative stimuli, but, nonetheless, show increased growth rates when treated with replacement doses of human GH. We studied the GH secreted by 8 such children using a 2-site immunoradiometric assay for GH (IRMA-GH). To be detected in this assay, a GH molecule must be able to react simultaneously with two different monoclonal antibodies, each specific for a different region of the GH molecule. We compared the GH values observed in the IRMA to those obtained using classical RIA for GH (RIA-GH). The IRMA-GH to RIA-GH ratio was not affected by time of sample collection relative to peak GH serum levels in either normal individuals or children with GH-dependent growth failure. The ratios in serum samples from children with GH-dependent growth failure were significantly lower than those observed in normal individuals [0.35 +/- 0.005 vs. 0.48 +/- 0.02 (+/- SE); P less than 0.001]. All of the children with GH-dependent growth failure had IRMA-GH to RIA-GH ratios less than 0.4, while only 7 of 24 normal individuals had ratios this low (P less than 0.005). We suggest that a comparison of IRMA-GH with RIA-GH may supplement other clinical measurements and aid in identifying children with GH-dependent growth failure.

Elevation of postmortem triiodothyronine in sudden infant death syndrome and in infants who died of other causes: a marker of previous health

We measured serum concentrations of thyroxine (T4), triiodothyronine (T3), reverse T3, free T4, thyroid-stimulating hormone, and cortisol in 62 victims of sudden infant death syndrome (SIDS) in 30 infants who died of known causes and in 15 living controls. The mean T3 value was elevated in 69% of those with SIDS. 37% of the others who died, and in no control infants. After excluding those who died of known cause who had abnormal thyroid function (abnormal postmortem concentrations of T4, free T4, or reverse T3), the T3 values were elevated in 63% of those remaining. When the data were analyzed on the basis of case histories and autopsy findings, those infants who were in good health and died suddenly of accidental causes had an elevation in mean T3 similar to that seen in SIDS victims; those who died under conditions known to alter thyroid metabolism did not. The T4, free T4, reverse T3, thyroid-stimulating hormone, and cortisol values were not useful in differentiating those with SIDS from the living controls, or those who were healthy at the time of death. We were unable to find any difference in T3 serum concentrations between the total group who had SIDS and those who had SIDS with minor infections, with petechiae on intrathoracic organs, with premature birth, or those who were resuscitated. Our data point out the importance of using appropriate controls when evaluating SIDS. The normal reverse T3 values in SIDS, as well as confirmation of the normal T4 and free T4 values, constitute evidence against chronic persistent alveolar hypoventilation or prolonged episodes of hypoxia immediately preceding death from SIDS.

A new assay and solubilization procedure for steroid 17,20-lyase from rat testes

We report an assay for testicular 17,20-lyase which depends on the use of [21-14C]progesterone as a substrate. The method is made possible by a simplified procedure for the synthesis of [21-14C]progesterone. A chromatographic separation of the unreacted substrate and the 2-carbon by-product on mini silica gel columns permitted a quantitative assay of the lyase activity. The lyase complex from rat testes has been solubilized by treatment with Triton CF-54 detergent. The solubilized enzyme complex catalyzes the formation of androstenedione (4-androstene-3,17-dione) from progesterone without equilibrium with added 17-hydroxyprogesterone and the solubilized enzyme complex responds to the presence of cytosol activator. Both of these characteristics are similar to the properties of the intact microsomes. Thus, solubilization with this detergent preserves the special properties of the microsome bound enzyme complex.

Autosomal factors with correlated effects on the activities of the glucose 6-phosphate and 6-phosphogluconate dehydrogenases in Drosophila melanogaster

Isogenic lines, in which chromosomes sampled from natural populations of C. melanogaster are substituted into a common genetic background, were used to detect and partially characterize autosomal factors that affect the activities of the two pentose phosphate pathway enzymes, glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD). The chromosome 3 effects on G6PD and 6PGD are clearly correlated; the chromosome 2 effects, which are not so great, also appear to be correlated, but the evidence in this case is not so strong. Examination of activity variation of ten other enzymes revealed that G6PD and 6PGD are not the only pair of enzymes showing a high positive correlation, but it is among the highest in both sets of lines. In addition, there was some evidence that the factor(s) affecting G6PD and 6PGD may also affect two other metabolically related enzymes, transaldolase and phosphoglucose isomerase.--Rocket immunoelectrophoresis was used to estimate specific CRM levels for three of the enzymes studied: G6PD, 6PGD and ME. This experiment shows that a large part of the activity variation is accounted for by variation in CRM level (especially for chromosome 3 lines), but there remains a significant fraction of the genetic component of activity variation that is not explained by CRM level.--These results suggest that the autosomal factors are modifiers involved in regulation of the expression of the X-linked structural genes for G6PD and 6PGD, but a role in determining part of the enzymes' primary structure cannot be excluded with the present evidence.

The activation of microsomal steroid 21-hydroxylase by cytosol from the cortex of bovine adrenals

At low microsome concentrations, the addition of cytosol from bovine adrenal cortex markedly accelerates the rate of hydroxylation of 17-hydroxyprogesterone at C-21. The detection of this effect was made possible by the development of a new, rapid, and sensitive procedure for the measurement of the initial rate kinetics of steroid 21-hydroxylase. This procedure is based on the fact that the reactant, 17-hydroxyprogesterone, possesses solvent partition properties which are different from those of the product, cortexolone. The specificity of the assay was confirmed by the isolation of only one product which was identified as cortexolone by radiochemical techniques. This assay procedure has great sensitivity and makes possible the accurate determination of the Michaelis constant at low enzyme concentrations. The Km for 17-hydroxyprogesterone with saturating amounts of TPNH was found to be 0.3 micronM. At the low microsome concentrations permitted by this assay, the addition of cytosol has a profound effect upon the rate of hydroxylation. The rate is markedly accelerated although the Km for the substrate is not altered. Neither the substrate nor the carbon monoxide-induced difference spectra are changed by the addition of cytosol, suggesting that activation by cytosol dose not affect the catalytic unit of the 21-hydroxylase complex.