Modeling the Mechanisms by Which Coexisting Biomolecular RNA-Protein Condensates Form.

Liquid-liquid phase separation is an emerging mechanism for intracellular organization. This work presents a mathematical model to examine molecular mechanisms that yield phase-separated droplets composed of different RNA-protein complexes. Using a Cahn-Hilliard diffuse interface model with a Flory-Huggins free energy scheme, we explore how multiple (here two, for simplicity) protein-RNA complexes (species) can establish a heterogeneous droplet field where droplets with single or multiple species phase separate and evolve during coarsening. We show that the complex-complex de-mixing energy tunes whether the complexes co-exist or form distinct droplets, while the transient binding kinetics dictate both the timescale of droplet formation and whether distinct species phase separate into droplets simultaneously or sequentially. For specific energetics and kinetics, a field of droplets driven by the formation of only one protein-RNA complex will emerge. Slowly, the other droplet species will accumulate inside the preformed droplets of the other species, allowing them to occupy the same droplet space. Alternatively, unfavorable species mixing creates a parasitic relationship: the slow-to-form protein-RNA complex will accumulate at the surface of a competing droplet species, siphoning off the free protein as it is released. Once this competing protein-RNA complex has sufficiently accumulated on the droplet surface, it can form a new droplet that is capable of sharing an interface with the first complex droplet but is not capable of mixing. These results give insights into a wide range of phase-separation scenarios and heterogeneous droplets that coexist but do not mix within the nucleus and the cytoplasm of cells.

Nonlinear signatures of entangled polymer solutions in active microbead rheology.

We present experimental data and numerical modeling of a nonlinear phenomenon in active magnetic microbead rheology that appears to be common to entangled polymer solutions (EPS). Dynamic experiments in a modest range of magnetic forces show: 1. a short-lived high viscosity plateau, followed by 2. a bead acceleration phase with a sharp drop in apparent viscosity, and 3. a terminal steady state that we show resides on the shear-thinning slope of the steady-state flow curve from cone and plate data. This latter feature implies a new protocol to access the nonlinear steady-state flow curve for many biological EPS only available in microliter-scale volumes. We solve the moment-closure form of the Rolie-Poly kinetic model for EPS hydrodynamics, together with a decoupling approximation that obviates the need for a full 3D flow solver, and show that the model qualitatively reproduces the dynamic experimental sequence above. In this way, we explain the phenomenon in terms of entangled polymer physics, and show how the nonlinear event (acceleration and termination on the shear-thinning response curve) is tunable by the interplay between molecular-scale mechanisms (relaxation via reptation and chain retraction) and magnetic force controls. The experimental conditions mimic movement of cilia tips, bacteria, and sperm in mucus barriers, implying a physiological relevance of the phenomenon, and compelling further development of the fully coupled, 3D flow-microstructure model to achieve quantitative accuracy.

Congenital adrenal hyperplasia due to point mutations in the type II 3 beta-hydroxysteroid dehydrogenase gene.

Classical 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4-isomerase (3 beta-HSD) deficiency is an autosomal recessive form of congenital adrenal hyperplasia characterized by a severe impairment of steroid biosynthesis in both the adrenals and the gonads. We describe the nucleotide sequence of the two highly homologous genes encoding 3 beta-HSD isoenzymes in three classic 3 beta-HSD deficient patients belonging to two apparently unrelated pedigrees. No mutation was detected in the type I 3 beta-HSD gene, which is mainly expressed in the placenta and peripheral tissues. Both nonsense and frameshift mutations, however, were found in the type II 3 beta-HSD gene, which is the predominant 3 beta-HSD gene expressed in the adrenals and gonads, thus providing the first elucidation of the molecular basis of this disorder.

A minimal physiologically based pharmacokinetic model that predicts anti-PEG IgG-mediated clearance of PEGylated drugs in human and mouse.

Circulating antibodies that specifically bind polyethylene glycol (PEG), a polymer routinely used in protein and nanoparticle therapeutics, have been associated with reduced efficacy and increased adverse reactions to some PEGylated therapeutics. In addition to acute induction of anti-PEG antibodies (APA) by PEGylated drugs, typically low but detectable levels of APA are also found in up to 70% of the general population. Despite the broad implications of APA, the dynamics of APA-mediated clearance of PEGylated drugs, and why many patients continue to respond to PEGylated drugs despite the presence of pre-existing APA, remains not well understood. Here, we developed a minimal physiologically based pharmacokinetic (mPBPK) model that incorporates various properties of APA and PEGylated drugs. Our mPBPK model reproduced clinical PK data of APA-mediated accelerated blood clearance of pegloticase, as well as APA-dependent elimination of PEGyated liposomes in mice. Our model predicts that the prolonged circulation of PEGylated drugs will be compromised only at APA concentrations greater than ~500 ng/mL, providing a quantitative explanation to why the effects of APA on PEGylated treatments appear to be limited in most patients. This mPBPK model is readily adaptable to other PEGylated drugs and particles to predict the precise levels of APA that could render them ineffective, providing a powerful tool to support the development and interpretation of preclinical and clinical studies of various PEGylated therapeutics.

Metabolic clearance rate and blood production rate of testosterone and dihydrotestosterone in normal subjects, during pregnancy, and in hyperthyroidism.

The metabolic clearance rate (MCR) and blood production rate (BP) of testosterone (T) and dihydrotestosterone (DHT), the conversion of plasma testosterone to plasma dihydrotestosterone, and the renal clearance of androstenedione, testosterone, and dihydrotestosterone have been studied in man. In eight normal men, the MCR(T) (516+/-108 [SD] liters/m(2)/day) was significantly greater than the MCR(DHT) (391+/-71 [SD] liters/m(2)/day). In seven females, the MCR(T) (304+/-53 [SD] liters/m(2)/day) was also greater than the MCR(DHT) (209+/-45 [SD] liters/m(2)/day) and both values were less than their respective values in men (P < 0.001). In men the conversion of testosterone into dihydrotestosterone at 2.8+/-0.3% (SD) was greater than that found in females, 1.56+/-0.5% (SD) (P < 0.001). In five pregnant females the MCR(T) (192+/-36 [SD] liters/m(2)/day), the MCR(DHT) (89+/-30 [SD] liters/m(2)/day) and the conversion of testosterone into dihydrotestosterone (0.72+/-0.15%) (SD) were significantly less than the values found in nonpregnant women. In five females with hyperthyroidism, the MCR for testosterone and dihydrotestosterone were similar to those observed in pregnant females, but the conversion of testosterone into dihydrotestosterone (2.78+/-1.7%) (SD) was greater, and similar to that found in men. In men the production of dihydrotestosterone was 0.39+/-0.1 (SD) mg/day, 50% being derived from the transformation of plasma testosterone. In women the production of DHT was 0.05+/-0.028 (SD) mg/day, only 10% coming from testosterone. During pregnancy, the production of testosterone and dihydrotestosterone are similar to that in normal women. In three patients with testicular feminization syndrome (an adult with hyperthyroidism and two children) these two MCRs were greatly reduced compared to the normal females, but the conversion of testosterone into dihydrotestosterone was in the limits of normal male rangeIn the normal subjects the renal clearance of androstenedione was greater than that of testosterone and dihydrotestosterone. Less than 20% of the dihydrotestosterone and less than 10% of the androstenedione in the urine is derived from the plasma dihydrotestosterone and androstenedione.

Hypophyso-gonadal function in humans during the first year of life. 1. Evidence for testicular activity in early infancy.

Total and unbound testosterone and Delta(4)-androstenedione have been determined in 104 cord blood samples. The same sexual steroids and pituitary gonadotropins have been measured in 46 normal male infants aged 27-348 days and 34 normal female infants aged 19-332 days. In cord blood of female neonates mean total and unbound testosterone was 29.6+/-7.5 and 0.89+/-0.4 ng/100 ml, respectively (mean+/-1 SD); Delta(4)-androstenedione was 93+/-38 ng/100 ml. In male neonates mean plasma total and unbound testosterone was 38.9+/-10.8 and 1.12+/-0.4 ng/100 ml; Delta(4)-androstenedione was 85+/-27 ng/100 ml. In female infants testosterone concentrations remained constant during the 1st yr of life with a mean concentration of 7+/-3 ng/100 ml. Mean unbound testosterone and Delta(4)-androstenedione concentrations were 0.05+/-0.03 and 16.7+/-8.3 ng/100 ml, respectively. Mean plasma levels of follicle-stimulating hormone and luteinizing hormone were 8.7+/-3.3 and 12.9+/-7.7 mU/ml. In male infants mean plasma total testosterone concentration increased to 208+/-68 ng/100 ml from birth to 1-3 mo of age, decreasing thereafter to 95+/-53 ng/100 ml at 3-5 mo, 23.2+/-18 ng/100 ml at 5-7 mo, and reached prepubertal levels (6.6+/-4.6 ng/100 ml) at 7-12 mo. Mean unbound testosterone concentration plateaued from birth to 1-3 mo of age (1.3+/-0.2 ng/100 ml) decreasing to prepubertal values very rapidly. Mean Delta(4)-androstenedione concentration, although progressively decreasing during the 1st yr of life to 11.7+/-4.5 ng/100 ml, was higher than in the female at 1-3 mo of life (34+/-11 ng/100 ml). Mean plasma level of follicle-stimulating hormone was 6.7+/-2.9 mU/ml, and that of luteinizing hormone was 19.7+/-13.5 mU/ml, significantly higher than in the female. There was no correlation between gonadotropin and age or testosterone. The present data demonstrate that the testes are active during the first natal period. It is tempting to correlate this phenomenon to a progressive maturation of the hypothalamo-pituitary-gonadal axis. It is possible that the surge in testosterone occurring the first 3 mo could play a role in the future life pattern of the male human being.

Hormonal and cellular regulation of Sertoli cell anti-Müllerian hormone production in the postnatal mouse.

Anti-Müllerian hormone (AMH) is secreted by immature testicular Sertoli cells. Clinical studies have demonstrated a negative correlation between serum AMH and testosterone in puberty but not in the neonatal period. We investigated AMH regulation using mouse models mimicking physiopathological situations observed in humans. In normal mice, intratesticular, not serum, testosterone repressed AMH synthesis, explaining why AMH is downregulated in early puberty when serum testosterone is still low. In neonatal mice, AMH was not inhibited by intratesticular testosterone, due to the lack of expression of the androgen receptor in Sertoli cells. We had shown previously that androgen-insensitive patients exhibit elevated AMH in coincidence with gonadotropin activation. In immature normal and in androgen-insensitive Tfm mice, follicle stimulating hormone (FSH) administration resulted in elevation of AMH levels, indicating that AMH secretion is stimulated by FSH in the absence of the negative effect of androgens. The role of meiosis on AMH expression was investigated in Tfm and in pubertal XXSxrb mice, in which germ cells degenerate before meiosis. We show that meiotic entry acts in synergy with androgens to inhibit AMH. We conclude that AMH represents a useful marker of androgen and FSH action within the testis, as well as of the onset of meiosis.

Rearrangements and point mutations of P450c21 genes are distinguished by five restriction endonuclease haplotypes identified by a new probing strategy in 57 families with congenital adrenal hyperplasia.

Congenital adrenal hyperplasia (CAH) is caused by disorders of the P450c21B gene, which, with the P450c21A pseudogene, lies in the HLA locus on chromosome 6. The near identity of nucleotide sequences and endonuclease cleavage sites in these A and B loci makes genetic analysis of this disease difficult. We used a genomic DNA probe that detects the P450c21 genes (A pseudogene, 3.2 kb; B gene, 3.7 kb in Taq I digests) and the 3' flanking DNA not detected with cDNA probes (A pseudogene, 2.4 kb; B gene, 2.5 kb) to examine Southern blots of genomic DNA from 68 patients and 165 unaffected family members in 57 families with CAH. Of 116 CAH-bearing chromosomes, 114 could be sorted into five easily distinguished haplotypes based on blots of DNA digested with Taq I and Bgl II. Haplotype I (76 of 116, 65.6%) was indistinguishable from normal and therefore bore very small lesions, presumably point mutations. Haplotype II (4 of 116, 3.4%) and haplotype III (8 of 116, 6.9%) had deletions and duplications of the P450c21A pseudogene but had structurally intact P450c21B genes presumably bearing point mutations; point mutation thus was the genetic defect in 88 of 116 chromosomes (75.9%). Haplotypes IV and V lack the 3.7-kb Taq I band normally associated with the P450c21B gene. Haplotype IV (13 of 116, 11.2%) retains all other bands, indicating that the P450c21B gene has undergone a gene conversion event, so that it is now also associated with a 3.2-kb band. Haplotype V (13 of 116, 11.2%) lacks the 2.4-kb Taq I fragment and the 12-kb Bgl II fragments normally associated with the P450c21A pseudogene, as well as lacking the 3.7-kb Taq I fragment, indicating deletion of approximately 30 kb of DNA, resulting in a single hybrid P450c21A/B gene. Most (114 of 116, 98%) CAH alleles thus can easily be classified with this new probing strategy, eliminating many ambiguities resulting from probing with cDNA.

Prenatal treatment of congenital adrenal hyperplasia.

Prenatal diagnosis of congenital adrenal hyperplasia (CAH) is accurate and prenatal therapy is effective in significantly reducing or even eliminating virilization of females affected by CAH, sparing these children the consequences of genital surgery, sex missassignment and gender confusion. However, both the physical and psychological development of these children and the possibility of long-range adverse effects in the mothers need to be evaluated further. Prospective multicentre studies covering several decades are being designed.

[Adrenal hypoplasia congenita: four new cases in children]. / Hypoplasie congénitale des surrénales : à propos de quatre observations.

Adrenal hypoplasia congenita (AHC) is an extremely uncommon disease of early onset. This condition can be lethal in the absence of adapted treatment. Some of these diseases are related to changes in the gene DAX1 that encodes a member of the superfamily of hormone nuclear receptors. It is a transcriptional repressor that is central in the morphogenesis of the adrenals and the gonadic differentiation. Here we report on four cases of X- linked AHC. In the first two familial cases, mutations were identified and mothers were heterozygotes. Abnormally low levels of estriol were evidenced during the pregnancy leading to an early diagnosis and adapted care of the affected male neonates. These children are doing well with a 21-and 20 months follow-up with hormone replacement at the present time. The two last cases corresponded to a contiguous gene syndrome associating AHC to glycerol-kinase deficiency that was revealed respectively at six days and seven years of age by acute adrenal insufficiency.

21-Hydroxylase deficiency: an exemplary model of the contribution of molecular biology in the understanding and management of the disease.

Congenital adrenal hyperplasia (CAH) is a family of autosomal recessive disorders caused by mutations in genes encoding the enzymes involved in one of the various steps of adrenal steroid synthesis. Steroid 21-hydroxylase deficiency (21-OHD) is responsible for over 95% of the 5 forms of CAH, and results due to enzymatic defect owing to mutation in the CYP21 gene. The disease has two major clinical presentations. The "classical" form is severe, and divided into a salt wasting (SW) and simple virilizing (SV) subgroups. In both, affected female fetuses undergo virilization of the external genitalia prenatally and present at birth with sexual ambiguity. In addition, in both sexes infants with SW CAH are at risk of life-threatening adrenal crisis without treatment. This is why it is so important to make a diagnosis and to counsel the families. The diagnosis is easy by measuring the plasma levels of 17-hydroxyprogesterone (17-OHP) in antenatal (amniotic fluid), or perinatal samples (peripheral blood). Confirmation by molecular genetic analysis is advised. The second form of 21-OHD is called "non classical" because the presentation is much less severe and the onset of clinical expression occurs long after birth, often in the peripubertal period, as non-specific symptoms of hyperandrogeny. The unambiguous diagnosis of the latter requires a simple short ACTH test, with the measurement of 17-OHP at 60 min. In both forms, the mutations on the gene CYP21 responsible for the disease are now well known and can be identified by molecular biology techniques. There is a good correlation between phenotypes and genotypes, due to variable amount of the 21-hydroxylase-enzyme activity left (null to 50-60%). SW, SV and NC forms are associated with distinct mutations or combination of mutations. Nowadays, by combining hormonal and molecular tests, it is possible to predict the clinical form of the disease in a given family in the context of a prenatal diagnosis, which can lead to a prenatal treatment. Therefore, 21-OHD genotyping also appears essential for a new approach of genetic counseling, prediction of clinical form after postnatal screening and to define the post-ACTH 17-OHP values indicating the cut-off lines between NC, heterozygote and normal subjects.

Time course of the effect of adrenalectomy on transcortin binding characteristics: appraisal of different methods of calculation.

The time course effect of adrenalectomy on the transcortin-corticosterone association constant (KT), its concentration of binding sites (ST) and the corresponding binding constant (SAKA) of albumin has been investigated by equilibrium dialysis at 37 C on plasma samples collected 0, 3, 6, 12, 24, 48, 96 and 144 h after adrenalectomy in male adult rats. The data have been analyzed by 3 different methods: a graphical Scatchard analysis using bound over unbound versus bound as representation axes and 2 least squares minimization methods in which axes were, respectively, bound over total versus mass of corticosterone added and total versus unbound. Confidence regions can be computed in the last two methods allowing the statistical comparison of the different dialysis experiments. Results obtained by the three methods are quite similar and led to the conclusions that following adrenalectomy KT was constant while ST varied. The observed pattern was a decrease until the first 24 h followed by a rise reaching almost twice the control value at 144 h. It would also appear that SAKA decreases slightly within 24 h following adrenalectomy.

Effects of chronic intermittent immobilization stress on rat testicular androgenic function.

In rats, chronic intermittent immobilization stress induced a drastic fall in the plasma concentration and testicular content of testosterone (T) without detectable changes in plasma LH values. In vitro basal T production by interstitial cell-enriched preparations from stressed rats and the responses to hCG, dibutyryl cAMP, or choleratoxin were suppressed, while cAMP production was not modified. The increase in plasma T concentrations in control animals was identical after the in vivo injection of 5, 10, or 50 IU hCG, while stressed rats failed to respond to 5 IU, but showed a response similar to that of control animals with 10 and 50 IU. These results suggest that chronic intermittent immobilization stress decreases Leydig cell sensitivity to gonadotropins.

Age-related response of plasma testosterone, delta 4-androstenedione, and cortisol to adrenocorticotropin in infants, children, and adults.

The response of plasma testosterone (T), delta 4-androstenedione, and cortisol (F) to the administration of synthetic Zn beta 1-24 ACTH (0.5 mg/m2 im every 12 h for 3 days) was ascertained in 20 infants, 35 prepubertal children, 4 early pubertal boys, and 15 adults. At all ages and in both sexes, a significant rise in delta 4-androstenedione and F was observed (P less than 0.00001), whereas the response of T showed a sex difference: T levels increased in females (P less than 0.001) at all ages in response to ACTH, while they decreased (P less than 0.01) in males at periods of active testicular secretion (early infancy, puberty, and adulthood). In prepubertal boys, in the absence of significant Leydig cell activity, T levels increased after ACTH, as they did in girls. The post-ACTH values of T, expressed as percent-ages of the control levels, were significantly lower (P less than 0.01) in infants (3.17 +/- 16.7%) than in pubertal boys (59.5 +/- 14.6%) or adult men (57.9 +/- 7.7%). F levels were significantly higher after ACTH stimulation at 1-4 months of age (253 +/- 129 micrograms/dl) than at any later age studied (64 +/- 17 micrograms/dl). It would seem, therefore, that the suppressive effect of ACTh on testicular secretion might be glucocorticoid mediated and its magnitude might be related to circulating levels of F.

Pattern of the response of testosterone and its precursors to human chorionic gonadotropin stimulation in relation to age in infants and children.

The pattern of response to 14-day hCG stimulation was studied in 100 apparently normal infants and children and in 2 boys with total adrenal insufficiency. Response was estimated on the levels (nanograms per dl) of testosterone (T), delta4-androstenedione (delta4), and 17-hydroxyprogesterone (17OHP) before and after hCG. Basal levels of T, delta4, and 17OHP increased significantly after 9--10 yr of age and before the onset of puberty. It would thus appear that the changes of adrenarche are also expressed by the secretion of delta4 androgens. After hCG, levels of T (629 +/- 218) did not vary with age in infants or prepubertal children but increased significantly at the onset of puberty (1265 +/- 253). Post-hCG levels of delta4 and 17OHP increased with age, but their increments (respectively, 31.1 +/- 14.6 and 108.6 +/- 42.2) did not vary between 2--12 yr of age. On the other hand, the rise of delta4 after hCG tended to be higher in infancy and early pubescence. These data suggest that 1) testicular unresponsiveness to gonadotropins does not seem to be responsible for the postnatal decline of testicular activity; 2) during the prepubertal period there are no age-related changes in the absolute rises of T, delta4, or 17OHP levels after hCG stimulation; and 3) increasing sensitivity of the testis to gonadotropic stimulation appears to be one of the very first changes occurring at the onset of puberty.

Pattern of plasma dehydroepiandrosterone sulfate levels in humans from birth to adulthood: evidence for testicular production.

Plasma levels of dehydroepiandrosterone sulfate (DHAS) were measured in 513 normal full term newborns, infants, children, adolescents, and adults and the results were expressed in micrograms per dl. In infancy and childhood, DHAS levels were similar in both sexes. In 74 neonates, mixed cord blood mean values /+- SD were 134.6 +/- 64. During the first day of life, plasma DHAS levels were 140 +/- 125 in 33 neonates. During the first month of life, DHAS decreased drastically, then more progressively until the 6th month of life. Between 1-6 months of age, mean levels were 5.9 +/- 4.7 in 40 children. DHAS was very low between 1-6 yr of life (2.3 +/- 1.6) and rose abruptly at the 7th year of life. Thereafter, DHAS continued to increase correlatively with age and pubertal stages in both sexes, a further increase after age 16 or pubertal stage P5 was noted only in male subjects. In adults, DHAS was significantly higher in male (224 +/- 93) than in female (138.3 +/- 51) subjects. DHAS levels were compared to those of dehydroepiandrosterone; at two periods of life, early infancy and adulthood, their patterns differed. After long term hCG stimulation, DHAS increased significantly in 45 normal prepubertal boys and in 2 boys with adrenal insufficiency. These data would suggest a direct testicular production of DHAS.

Unconjugated dehydroepiandrosterone plasma levels in normal subjects from birth to adolescence in human: the use of a sensitive radioimmunoassay.

A specific and sensitive radioimmunoassay for measuring unconjugated plasma dehydroepiandrosterone (DHA) has been developed and the results expressed in ng/100 ml. Mean values +/-1 SD were in mixed cord blood 593.3 +/- 186.5 in 21 females and 712.7 +/- 190.9 in 18 males. During the first day of life the peripheral plasma concentration of DHA was 917.6 +/- 317.8 in 22 female and 922.65 +/- 290 in 17 male neonates. During the first month of age, DHA levels decreased significantly and then more progressively throughout the first year of life. Mean levels observed between the first and 6th month of life were 147.1 +/- 53.6 in 15 girls and 151.6 +/- 62.7 in 28 boys. Between 6 and 12 months of age mean DHA levels were 90.9 +/- 43.3 and 68.14 +/- 30.9 in 11 girls and 24 boys, respectively. In 250 normal children, plasma DHA levels were very low between 1 to 6 years of age, but rising progressively thereafter without any sex difference long before any clinical sign of puberty. A circadian rhythm parallel to that of cortisol was observed as early as 5 years of age. Acute and chronic stimulation of ACTH confirmed the adrenal origin of DHA, while the results of hCG stimulation test and fluoxymesterone suppression test assessed the testicular participation to the DHA production.

Pattern of plasma testosterone and delta4-androstenedione in normal newborns: Evidence for testicular activity at birth.

Plasma testosterone (T) and delta4-androstenedione (delta) levels were measured by a sensitive and specific radioimmunoassay method in 157 blood specimens from normal neonates. In both sexes at birth plasma T and delta were significantly higher in peripheral than in cord blood and drop within the first week of life. In males a secondary increase in both T and delta had occurred by the 2nd week of life while values continue to decrease in females. The present data demonstrate that testicular activity is still present at birth and suggest that the transient fall in T levels likely due to the removal of chorionic gonadotropin (hCG) secretion is responsible for the secondary activation of the hypothalamic pituitary axis by a negative feed-back mechanism.

Familial male pseudohermaphroditism due to 17-20-desmolase deficiency. I. In vivo endocrine studies.

In two siblings with male pseudohermaphroditism (ambiguous external genitalia, XY karyotype) and apparently normal glucocorticoid function, plasma concentrations of 10 progestagens or androgens measured by specific RIAs were found to be abnormal under either basal or dynamic conditions. Basal levels of delta 4-androstenedione, dehydroepiandrosterone, and dehydroepiandrosterone sulfate were subnormal and failed to rise after ACTH stimulation both before and after castration. Meanwhile, levels of pregnenolone, pregnenolone sulfate, 17 alpha-hydroxyprogesterone, and 17 alpha-hydroxypregnenolone were extremely high under basal conditions and rose further after ACTH. All of the progestagens and cortisol were suppressed by dexamethasone. After hCG stimulation, either before treatment or during dexamethasone therapy, the rise in testosterone was less than 100 ng/dl, while the progestagens showed an abnormally high rise. The latter were markedly reduced after castration. These findings are consistent with steroid 17--20-desmolase deficiency in both the testes and adrenal glands. In the third brother, who had only slight abnormalities of his genitalia, a mild form of the same defect was suspected. Low androgens, high 17 alpha-hydroxypregnenolone, and 17 alpha-hydroxyprogesterone levels were found in the amniotic fluid and umbilical cord and peripheral blood at birth. The parents, who were not consanguine, had normal baseline levels of all hormones. The familial occurrence of the disease is suggestive of autosomal recessive inheritance.

Thyroid hormones influences sex steroid binding protein levels in infancy: study in congenital hypothyroidism.

In order to test the hypothesis of a role of thyroid hormones on the circulating levels of sex steroid binding protein (SHBG) in children, SHBG levels were determined in 15 infants with congenital hypothyroidism at diagnosis and during the first 18 months of T4 therapy and in a separate group of 13 children with congenital hypothyroidism (7.1 +/- 0.5 yr, mean +/- SD), treated before 1 month of age, both during adequate L-T4 therapy and 4 weeks after withdrawing therapy. SHBG levels were significantly lower in hypothyroid infants than in controls (48.2 +/- 6.5 vs. 77.8 +/- 7.9 nmol/L; P less than 0.01), and significantly lower in infants with athyreosis compared to those with ectopic or eutopic glands (P less than 0.05). In patients with low values at diagnosis, SHBG increased rapidly and remained normal during LT4 therapy. After 1.5-18 months of treatment, a positive correlation (P less than 0.01) was found between SHBG, FT4, and FT3 levels. In older hypothyroid children, 4 weeks after withdrawal of therapy a significant (P less than 0.05) decrease in SHBG concentrations was observed. Analysis of these results as well as previous reports in adults, indicates that thyroid hormones influence SHBG concentrations in infants and children. This study also indicates that thyroid hormones may play a role in the physiological postnatal increase of SHBG.