Stephen M. Rosenthal

Update of guidelines for the use of growth hormone in children: the Lawson Wilkins pediatric endocrinology society drug and therapeutics committee

The Lawson Wilkins Pediatric Endocrinology Society Drug and Therapeutics Committee guidelines for the use of growth hormone were first published in 1983, near the end of the era of human pituitary-derived growth hormone (GH), and again in 1995, a decade after the introduction of recombinant human (rh)GH. The LawsonWilkins Pediatric Endocrine Society also endorsed an international consensus document led by the Growth Hormone Research Society published in 2000. This report serves to update those guidelines with an emphasis on new recommendations. The recommendations included here are limited primarily to the use of GH in infants, children and adolescents.

Differential Regulation of Insulin-like Growth Factor-I (IGF-I) Receptor Gene Expression by IGF-I and Basic Fibroblastic Growth Factor

Insulin-like growth factor-I receptor (IGF-IR) gene expression is regulated by various stimuli, including hormones, growth factors, and nutritional status. We have investigated the molecular mechanism by which two growth factors, insulin-like growth factor-I (IGF-I) and basic fibroblast growth factor (bFGF) regulate IGF-IR gene expression. bFGF increases the endogenous IGF-IR mRNA levels and IGF-IR promoter activity. This effect is mediated by a region of the IGF-IR promoter located between nucleotides −476 and −188 in the 5′-flanking region. In contrast, IGF-I decreases the IGF-IR mRNA levels. IGF-I down-regulates IGF-IR transcriptional activity as deduced from experiments in which the levels of pre-mRNA and mRNA were measured. IGF-I reduced pre-mRNA and mRNA levels in parallel, while the mRNA stability was found to be unchanged by IGF-I treatment. While these results strongly suggest an effect of IGF-I on IGF-IR transcriptional activity, no specific IGF-I response element was demonstrated in the 5′-untranslated region or 5′-flanking region studied. Thus, bFGF and IGF-I have differential effects on IGF-IR gene transcription, with the IGF-I response region as yet unidentified.

Regulation of insulin-like growth factor (IGF) I receptor expression during muscle cell differentiation. Potential autocrine role of IGF-II.

Muscle is an important target tissue for insulin-like growth factor (IGF) action. The presence of specific, high affinity IGF receptors, as well as the expression of IGF peptides and binding proteins by muscle suggest that a significant component of IGF action in this tissue is mediated through autocrine and/or paracrine mechanisms. To explore autocrine/paracrine action of IGFs in muscle, we studied the regulation of the IGF-I receptor and the expression of IGF peptides during differentiation of the mouse BC3H-1 muscle cell line. Differentiation from myoblasts to myocytes was associated with a 60% decrease in IGF-I receptor sites determined by Scatchard analysis. Analysis of mRNA abundance and protein labeling studies indicated that the decrease in IGF-I receptor sites was associated with similar reductions in IGF-I receptor gene expression and receptor biosynthesis. IGF-II peptide gene expression was detected in myoblasts and increased 15-fold with differentiation; the increase in IGF-II gene expression preceded the decrease in IGF-I receptor gene expression. In contrast, IGF-I peptide gene expression was low in myoblasts and decreased slightly with differentiation. To explore the potential role of endogenous IGF-II in the differentiation-associated decrease in IGF-I receptor expression, we investigated the effects of IGF-II treatment in myoblasts. The addition of IGF-II to undifferentiated myoblasts resulted in downregulation of the IGF-I receptor which was associated with decreased IGF-I receptor biosynthesis and decreased IGF-I receptor mRNA abundance. These studies suggest, therefore, that IGF-I receptor expression during muscle cell differentiation may be regulated, at least in part, through autocrine production of IGF-II.

Anti-thymocyte globulin/G-CSF treatment preserves β cell function in patients with established type 1 diabetes

BACKGROUND Previous efforts to preserve β cell function in individuals with type 1 diabetes (T1D) have focused largely on the use of single immunomodulatory agents administered within 100 days of diagnosis. Based on human and preclinical studies, we hypothesized that a combination of low-dose anti-thymocyte globulin (ATG) and pegylated granulocyte CSF (G-CSF) would preserve β cell function in patients with established T1D (duration of T1D >4 months and <2 years). METHODS A randomized, single-blinded, placebo-controlled trial was performed on 25 subjects: 17 subjects received ATG (2.5 mg/kg intravenously) followed by pegylated G-CSF (6 mg subcutaneously every 2 weeks for 6 doses) and 8 subjects received placebo. The primary outcome was the 1-year change in AUC C-peptide following a 2-hour mixed-meal tolerance test (MMTT). At baseline, the age (mean ± SD) was 24.6 ± 10 years; mean BMI was 25.4 ± 5.2 kg/m²; mean A1c was 6.5% ± 1.1%; insulin use was 0.31 ± 0.22 units/kg/d; and length of diagnosis was 1 ± 0.5 years. RESULTS Combination ATG/G-CSF treatment tended to preserve β cell function in patients with established T1D. The mean difference in MMTT-stimulated AUC C-peptide between treated and placebo subjects was 0.28 nmol/l/min (95% CI 0.001-0.552, P = 0.050). A1c was lower in ATG/G-CSF-treated subjects at the 6-month study visit. ATG/G-CSF therapy was associated with relative preservation of Tregs. CONCLUSIONS Patients with established T1D may benefit from combination immunotherapy approaches to preserve β cell function. Further studies are needed to determine whether such approaches may prevent or delay the onset of the disease. TRIAL REGISTRATION Clinicaltrials.gov NCT01106157. FUNDING The Leona M. and Harry B. Helmsley Charitable Trust and Sanofi.

Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons: An Endocrine Society Clinical Practice Guideline

Objective: To update the “Endocrine Treatment of Transsexual Persons: An Endocrine Society Clinical Practice Guideline,” published by the Endocrine Society in 2009. Participants: The participants include an Endocrine Society‐appointed task force of nine experts, a methodologist, and a medical writer. Evidence: This evidence‐based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The task force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies. Consensus Process: Group meetings, conference calls, and e‐mail communications enabled consensus. Endocrine Society committees, members and cosponsoring organizations reviewed and commented on preliminary drafts of the guidelines. Conclusion: Gender affirmation is multidisciplinary treatment in which endocrinologists play an important role. Gender‐dysphoric/gender‐incongruent persons seek and/or are referred to endocrinologists to develop the physical characteristics of the affirmed gender. They require a safe and effective hormone regimen that will (1) suppress endogenous sex hormone secretion determined by the persons genetic/gonadal sex and (2) maintain sex hormone levels within the normal range for the persons affirmed gender. Hormone treatment is not recommended for prepubertal gender‐dysphoric/gender‐incongruent persons. Those clinicians who recommend gender‐affirming endocrine treatments—appropriately trained diagnosing clinicians (required), a mental health provider for adolescents (required) and mental health professional for adults (recommended)—should be knowledgeable about the diagnostic criteria and criteria for gender‐affirming treatment, have sufficient training and experience in assessing psychopathology, and be willing to participate in the ongoing care throughout the endocrine transition. We recommend treating gender‐dysphoric/gender‐incongruent adolescents who have entered puberty at Tanner Stage G2/B2 by suppression with gonadotropin‐releasing hormone agonists. Clinicians may add gender‐affirming hormones after a multidisciplinary team has confirmed the persistence of gender dysphoria/gender incongruence and sufficient mental capacity to give informed consent to this partially irreversible treatment. Most adolescents have this capacity by age 16 years old. We recognize that there may be compelling reasons to initiate sex hormone treatment prior to age 16 years, although there is minimal published experience treating prior to 13.5 to 14 years of age. For the care of peripubertal youths and older adolescents, we recommend that an expert multidisciplinary team comprised of medical professionals and mental health professionals manage this treatment. The treating physician must confirm the criteria for treatment used by the referring mental health practitioner and collaborate with them in decisions about gender‐affirming surgery in older adolescents. For adult gender‐dysphoric/gender‐incongruent persons, the treating clinicians (collectively) should have expertise in transgender‐specific diagnostic criteria, mental health, primary care, hormone treatment, and surgery, as needed by the patient. We suggest maintaining physiologic levels of gender‐appropriate hormones and monitoring for known risks and complications. When high doses of sex steroids are required to suppress endogenous sex steroids and/or in advanced age, clinicians may consider surgically removing natal gonads along with reducing sex steroid treatment. Clinicians should monitor both transgender males (female to male) and transgender females (male to female) for reproductive organ cancer risk when surgical removal is incomplete. Additionally, clinicians should persistently monitor adverse effects of sex steroids. For gender‐affirming surgeries in adults, the treating physician must collaborate with and confirm the criteria for treatment used by the referring physician. Clinicians should avoid harming individuals (via hormone treatment) who have conditions other than gender dysphoria/gender incongruence and who may not benefit from the physical changes associated with this treatment.

Exogenous growth hormone inhibits growth hormone-releasing factor-induced growth hormone secretion in normal men.

Previous studies from this laboratory and by others in rats, monkeys, and humans support the concept that growth hormone (GH) can regulate its own secretion through an autofeedback mechanism. With the availability of human growth hormone-releasing factor (GRF), the possible existence of such a mechanism was reexplored by examining the effect of exogenous GH on the GH response induced by GRF-44-NH2 in six normal men (mean age, 32.4 yr). In all subjects the plasma GH response evoked by GRF-44-NH2 (1 microgram/kg i.v. bolus) was studied before and after 5 d of placebo (1 ml normal saline i.m. every 12 h), and then before and 12 h after 5 d of biosynthetic methionyl human GH (5 U i.m. every 12 h). The GH response to GRF (maximal increment over time 0 value) was significantly inhibited after GH treatment (0-1.3 vs. 2.3-11.2 ng/ml before treatment, P = 0.05), but was not significantly affected by placebo. This impaired pituitary response to GRF persisted for at least 24 h following exogenous GH treatment in two subjects who underwent further study. Serum somatomedin-C concentrations were significantly increased after 5 d of GH treatment (2.66-5.00 vs. 0.92-1.91 U/ml before treatment, P = less than 0.01). The impaired pituitary response to GRF may be mediated indirectly through somatomedin, somatostatin, by a direct effect of GH on the pituitary somatotropes, or by all of these mechanisms. These data suggest that after GH treatment, the blunted GH response to synthetic GRF is not solely a consequence of the inhibition of hypothalamic GRF secretion.

The gender affirmative model: What we know and what we aim to learn

in which he stated: ‘‘Cur-rently experts can’t tell apart kids who outgrow gender dysphoria (desisters) from those who do not (persisters), and how to treat them is controversial’’ [Drescher, 2013, p. 1]. As members of a four-site child gender clinic group, we concur with Dr. Drescher regarding the controversy, but take issue with his assessment of experts and their inability to differentially assess ‘‘persisters’’ and ‘‘desisters’’ in childhood. We would like to take this opportunity to outline the gender affirmative model from which we practice, dispel myths about this model, and briefly outline the state of knowledge in our field regarding facilitators of healthy psychosocial development in gender-nonconforming children. The major premises informing our modes of prac-tice include: (a) gender variations are not disorders; (b) gender presentations are di-verse and varied across cultures, therefore requiring our cultural sensitivity; (c) to the best of our knowledge at present, gender involves an interweaving of biology, devel-opment and socialization, and culture and context, with all three bearing on any in-dividual’s gender self; (d) gender may be fluid, and is not binary, both at a particular time and if and when it changes within an individual across time; (e) if there is pathol-ogy, it more often stems from cultural reactions (e.g., transphobia, homophobia, sex-ism) rather than from within the child.Our goals within this model are to listen to the child and decipher with the help of parents or caregivers what the child is communicating about both gender identity and gender expressions. We define gender identity as the gender the child articulates

Insulin-like growth factor I (IGF-I) levels in follicular fluid from human preovulatory follicles: correlation with serum IGF-I levels *

Insulin-like growth factor I (IGF-I) levels were measured in both serum and fluid of preovulatory follicles (n = 156) in 43 women undergoing in vitro fertilization (IVF). The mean IGF-I level in follicular fluid (FF) was significantly lower than in serum (0.52 +/- 0.02 IU/L versus 0.66 +/- 0.23 IU/L), and FF levels were significantly correlated with individual serum IGF-I levels as well as with follicular size and FF volume but not with oocyte maturity, granulosa cell appearance, or IVF. This suggests that FF IGF-I levels cannot serve as a clinical indicator for the degree of oocyte/granulosa cell differentiation or a predictor for IVF. Serum IGF-I levels were inversely correlated with the number of human menopausal gonadotropin ampules administered during treatment, suggesting that IGF-I might enhance ovarian gonadotropic stimulation.

Growth Factor-Stimulated Phosphorylation of Akt and p70S6K Is Differentially Inhibited by LY294002 and Wortmannin*

The phosphoinositide 3-kinase (PI3K) inhibitors, LY294002 (LY) and wortmannin (WM), are widely used to examine the role of PI3K in growth factor signaling. These compounds inhibit the kinase action of PI3K, thus preventing the accumulation of PI(3,4,5)P3 and PI(3,4)P2 (PIs) and subsequent phosphorylation and activation of the downstream effectors of PI3K, Akt and p70S6K. The efficacy of these inhibitors has been demonstrated by measuring cellular levels of PIs or the kinase activity of immunoprecipitated PI3K. However, their effects on activation of Akt and p70S6K, more widely used markers of PI3K activation, has not been formally tested. We have examined the effects of LY and WM on phosphorylation of Akt and p70S6K by insulin-like growth factor-I, insulin, and platelet-derived growth factor in skeletal muscle cells. LY is much less effective in blocking the phosphorylation of Akt than p70S6K; at concentrations which completely inhibit phosphorylation of p70S6K, phosphorylation of Akt is only partially in...

Functional Characterization of Vasopressin Type 2 Receptor Substitutions (R137H/C/L) Leading to Nephrogenic Diabetes Insipidus and Nephrogenic Syndrome of Inappropriate Antidiuresis: Implications for Treatments

Substitution of arginine-137 of the vasopressin type 2 receptor (V2R) for histidine (R137H-V2R) leads to nephrogenic diabetes insipidus (NDI), whereas substitution of the same residue to cysteine or leucine (R137C/L-V2R) causes the nephrogenic syndrome of inappropriate antidiuresis (NSIAD). These two diseases have opposite clinical outcomes. Still, the three mutant receptors were shown to share constitutive β-arrestin recruitment and endocytosis, resistance to vasopressin-stimulated cAMP production and mitogen-activated protein kinase activation, and compromised cell surface targeting, raising questions about the contribution of these phenomenons to the diseases and their potential treatments. Blocking endocytosis exacerbated the elevated basal cAMP levels promoted by R137C/L-V2R but not the cAMP production elicited by R137H-V2R, demonstrating that substitution of Arg137 to Cys/Leu, but not His, leads to constitutive V2R-stimulated cAMP accumulation that most likely underlies NSIAD. The constitutively elevated endocytosis of R137C/L-V2R attenuates the signaling and most likely reduces the severity of NSIAD, whereas the elevated endocytosis of R137H-V2R probably contributes to NDI. The constitutive signaling of R137C/L-V2R was not inhibited by treatment with the V2R inverse agonist satavaptan (SR121463). In contrast, owing to its pharmacological chaperone property, SR121463 increased the R137C/L-V2R maturation and cell surface targeting, leading to a further increase in basal cAMP production, thus disqualifying it as a potential treatment for patients with R137C/L-V2R-induced NSIAD. However, vasopressin was found to promote β-arrestin/AP-2-dependent internalization of R137H/C/L-V2R beyond their already elevated endocytosis levels, raising the possibility that vasopressin could have a therapeutic value for patients with R137C/L-V2R-induced NSIAD by reducing steady-state surface receptor levels, thus lowering basal cAMP production.