Treatment with a luteinizing hormone-releasing hormone agonist in adolescents with short stature.

BACKGROUND: Treatment with a luteinizing hormone-releasing hormone (LHRH) agonist increases adult height in children with LHRH-dependent precocious puberty and is prescribed by some practitioners to augment height in short adolescents. We performed a randomized clinical trial to determine whether treatment with an LHRH agonist increases adult height in short adolescents with normally timed puberty. METHODS: Fifty short adolescents (18 boys and 32 girls) with low predicted adult height (mean [+/-SD], 3.3+/-1.2 SD below the population mean) received either placebo (24 subjects) or an LHRH agonist (26 subjects). The mean (+/-SD) duration of treatment was 3.5+/-0.9 years in the LHRH-agonist group and 2.1+/-1.2 years in the placebo group (P<0.001). Adult height was measured when bone age exceeded 16 years in girls and 17 years in boys and when the rate of growth was less than 1.5 cm per year. RESULTS: Forty-seven adolescents (94 percent) were followed until they attained adult height. At the time adult height was achieved, the subjects who had been treated with an LHRH agonist were older than those who had received placebo (20.5+/-2.1 years vs. 18.0+/-2.5 years, P=0.01) and were taller (standard-deviation score, -2.2+/-1.1 vs. -3.0+/-1.2; P=0.01). Analysis of covariance showed that LHRH-agonist treatment resulted in an increase of 0.6 (95 percent confidence interval, 0.2 to 0.9) in the standard-deviation score for height, or an increase of 4.2 cm (95 percent confidence interval, 1.7 to 6.7), over the initially predicted adult height (P=0.01). Treatment with an LHRH agonist resulted in significantly greater adult height than did placebo in boys and girls, in adolescents with idiopathic short stature, and in those who had a growth-limiting syndrome. The principal adverse event in the LHRH-agonist group was decreased accretion of bone mineral density (mean lumbar vertebral bone mineral density at the time adult height was achieved, 1.6+/-1.2 SD below the population mean, vs. 0.3+/-1.2 SD below the population mean in the placebo group; P<0.001). CONCLUSIONS: Treatment with an LHRH agonist for 3.5 years increases adult height by 0.6 SD in adolescents with very short stature but substantially decreases bone mineral density. Such treatment cannot be routinely recommended to augment height in adolescents with normally timed puberty.

GNAS mutation detection is related to disease severity in girls with McCune-Albright syndrome and precocious puberty.

BACKGROUND: McCune-Albright syndrome (MAS) is characterized by a triad of gonadotropin-independent precocious puberty, café au lait skin pigmentation and fibrous dysplasia of bone. MAS is due to activating mutations of GNAS, the gene encoding Gsalpha. Interest exists in the use of GNAS mutation analysis to make a definitive diagnosis when the phenotype is not diagnostic, i.e. in partial forms of MAS. The utility of using peripheral blood for mutation analysis in this setting has not been thoroughly evaluated. OBJECTIVE: We performed a systematic analysis of genomic DNA for the detection of GNAS activating mutations in girls with MAS who presented with precocious puberty to evaluate whether identification of an activating mutation in peripheral blood is related to the presence of other features of MAS. STUDY DESIGN: Genomic DNA was isolated from blood from 13 girls with gonadotropin-independent precocious puberty. A polymerase chain reaction (PCR)-based technique was performed for GNAS mutation identification. RESULTS: GNAS activating mutations were identified in 4 patients, all of whom had classic MAS based on clinical evidence. CONCLUSIONS: Detection of activating mutations in leukocyte genomic DNA extracted from peripheral blood samples from girls with gonadotropin-independent precocious puberty was associated with the presence of other phenotypic manifestations of MAS. Until improvements in the diagnostic utility of GNAS activating mutation analysis from leukocyte genomic DNA occur, such testing in patients with atypical forms of MAS should continue to be reserved for research settings.

Mechanisms regulating the constitutive activation of the extracellular signal-regulated kinase (ERK) signaling pathway in ovarian cancer and the effect of ribonucleic acid interference for ERK1/2 on cancer cell proliferation.

The ERK1/2 MAPK pathway is a critical signaling system that mediates ligand-stimulated signals for the induction of cell proliferation, differentiation, and cell survival. Studies have shown that this pathway is constitutively active in several human malignancies and may be involved in the pathogenesis of these tumors. In the present study we examined the ERK1/2 pathway in cell lines derived from epithelial and granulosa cell tumors, two distinct forms of ovarian cancer. We show that ERK1 and ERK2 are constitutively active and that this activation results from both MAPK kinase-dependent and independent mechanisms and is correlated with elevated BRAF expression. MAPK phosphatase 1 (MKP-1) expression, which is involved in ERK1/2 deactivation, is down-regulated in the cancer cells, thus further contributing to ERK hyperactivity in these cells. Treatment of these cancer cell lines with the proteasome inhibitor ZLLF-CHO increased MKP-1 but not MKP-2 expression and decreased ERK1/2 phosphorylation. More importantly, silencing of ERK1/2 protein expression using RNA interference led to the complete suppression of tumor cell proliferation. These results provide evidence that the ERK pathway plays a major role in ovarian cancer pathogenesis and that down-regulation of this master signaling pathway is highly effective for the inhibition of ovarian tumor growth.

Premature thelarche and granulosa cell tumors: a search for FSH receptor and G5alpha activating mutations.

Activating mutations of the Gsalpha gene are responsible for McCune-Albright syndrome and have also been identified in sporadic tumors of the pituitary and thyroid. When associated with malignancy, activating Gsalpha mutations are known as gsp-oncogenes. We hypothesized that similar activating mutations might also account for some cases of premature thelarche and/ or granulosa cell tumors. Polymerase chain reaction and DNA sequencing was used to screen for activating mutations of Gsalpha genes in children with premature thelarche and in pathologic specimens from juvenile and adult granulosa cell tumors. Because these disorders involve over-activity of the FSH-signaling pathway, we also screened for activating mutations of the FSH receptor. No mutations were detected in either the Gsalpha or the FSHR fragment studied. Previously reported polymorphisms (Ser680Asn and Ala307Thr) of the FSHR were detected in 25/27 tumor samples and 9/9 premature thelarche samples. We conclude that activating mutations in previously identified mutation 'hot-spots' in the Gsalpha and FSH receptor genes are probably not a major cause of premature thelarche or granulosa cell tumors. In contrast, polymorphisms of the FSH receptor are common.

Bicalutamide and third-generation aromatase inhibitors in testotoxicosis.

Testotoxicosis, a form of gonadotropin-independent precocious puberty, results from an activating mutation of the luteinizing hormone receptor expressed in testicular Leydig cells. Affected males experience early testosterone secretion, virilization, advancing bone age, and resultant short stature. Recently, the use of combination therapy with a potent antiandrogen agent (bicalutamide) and a third-generation aromatase inhibitor (anastrozole or letrozole) was reported to yield encouraging short-term results. We present here the results of longer-term treatment (4.5 and 5 years) with this combination therapy in 2 boys who demonstrated that it is well tolerated, slows bone-age advancement in the face of continued linear growth, and prevents progression of virilization.

Environmental factors and puberty timing: expert panel research needs.

Serono Symposia International convened an expert panel to review the impact of environmental influences on the regulation of pubertal onset and progression while identifying critical data gaps and future research priorities. An expert panel reviewed the literature on endocrine-disrupting chemicals, body size, and puberty. The panel concluded that available experimental animal and human data support a possible role of endocrine-disrupting chemicals and body size in relation to alterations in pubertal onset and progression in boys and girls. Critical data gaps prioritized for future research initiatives include (1) etiologic research that focus on environmentally relevant levels of endocrine-disrupting chemicals and body size in relation to normal puberty as well as its variants, (2) exposure assessment of relevant endocrine-disrupting chemicals during critical windows of human development, and (3) basic research to identify the primary signal(s) for the onset of gonadotropin-releasing hormone-dependent/central puberty and gonadotropin-releasing hormone-independent/peripheral puberty. Prospective studies of couples who are planning pregnancies or pregnant women are needed to capture the continuum of exposures at critical windows while assessing a spectrum of pubertal markers as outcomes. Coupled with comparative species studies, such research may provide insight regarding the causal ordering of events that underlie pubertal onset and progression and their role in the pathway of adult-onset disease.

The effect of growth hormone supplementation on late nutritional independence in pediatric patients with short bowel syndrome.

PURPOSE: The use of growth hormone (GH) supplementation for intestinal adaptation among adult patients with short bowel syndrome (SBS) has provided mixed results. This report examines the effect of GH supplementation on SBS in pediatric patients. METHODS: Two girls with SBS from neonatal gastrointestinal catastrophes received exogenous GH at 0.3 mg/kg per week subcutaneously and concurrent glutamine supplementation, beginning at 6 and 6(1/2) years of age. Changes in growth (height and weight) and changes in enteral and parenteral energy requirements were evaluated. RESULTS: Treatment duration was 8 and 2.5 years, respectively. Patient weights increased from the 5th to the 41st percentile and from the 17th to the 23rd percentile, respectively. Height increased from the 1st to the 57th percentile in the former patient and increased from less than the 1st to the 17th percentile in the latter. Both patients are independent of parenteral nutrition and take enteral nutrition alone. Tolerance for enteral diets was significantly improved in each girl, with only 2 stools per day maintained in one patient. CONCLUSIONS: The data show that late exogenous treatment with GH and glutamine supplementation improved growth parameters in pediatric patients with SBS. Growth hormone and glutamine supplementation may be beneficial in promoting late intestinal adaptation in pediatric patients with SBS. These data also suggest that these adjuncts may be useful in the early phases of intestinal adaptation.

Definitive diagnosis in children with congenital hypothyroidism.

OBJECTIVES: To investigate the definitive diagnosis and underlying causes of congenital hypothyroidism (CH) in eligible children through the use of a standardized protocol. STUDY DESIGN: Children > or =3 years of age with CH without an identified permanent cause underwent a diagnostic algorithm. Eligible subjects had an anatomically normal thyroid or had not undergone imaging studies. After thyroxine was discontinued for 4 weeks, thyroid function tests and a thyroid ultrasound were obtained. An abnormal ultrasound was followed by a (99m)Tc thyroid scan. A perchlorate washout test was performed in subjects with a normal ultrasound but abnormal thyroid function tests. Children with normal results were followed for 1 year. RESULTS: Of 33 children, 17 were boys. Nine (27%) had an absent or ectopic thyroid, 12 (36%) had dyshormonogenesis, and 12 (36%) had transient CH. Average thyroxine dose before medication discontinuation was 2.9 +/- 0.83 microg/kg in permanent cases versus 2.0 +/- 0.53 microg/kg in transient (P <.002). No complications from discontinuation of thyroxine occurred. CONCLUSIONS: A significant percentage of children with CH have a transient requirement for thyroid hormone. A standardized protocol with thyroid ultrasonography is a safe and sensitive approach to a trial off of thyroxine in select patients.

Low hemoglobin levels in children with in idiopathic growth hormone deficiency.

Multiple lines of evidence have implicated the growth hormone (GH) axis in the regulation of erythropoiesis. To test the hypothesis that GH deficiency is associated with hematologic abnormalities, we analyzed pretreatment hemoglobin levels in 100 children with GH deficiency. Hemoglobin levels were decreased in children with GH deficiency compared with age-corrected norms.

Time course to hypothyroidism after fixed-dose radioablation therapy of Graves' disease in children.

OBJECTIVE: To characterize the development of hypothyroidism in pediatric patients who receive a fixed dose of radioactive iodine (RAI). STUDY DESIGN: Medical records of children treated with fixed-dose RAI for Graves'disease between 1993 and 2001 were reviewed. Multiple variables including sex, age, thyroid hormone levels, thyroid-stimulating immunoglobulin titer, antithyroid medication use, and 24-hour radioiodine uptake were investigated as possible predictive factors for the development of hypothyroidism after treatment. All patients received RAI at a dose of between 13.8 and 15.6 mCi (average, 14.7 mCi; SD, 0.5). RESULTS: Permanent hypothyroidism developed in all 40 patients, although a second dose of RAI was required in one case. The average time to hypothyroidism was 77 days (SD, 32), with a range of 28 to 194 days; 75% of the patients were diagnosed with hypothyroidism between 40 and 90 days. RAI treatment was ineffective in an additional patient, who required subtotal thyroidectomy. CONCLUSIONS: We conclude that a fixed dose of RAI is effective therapy in nearly all pediatric patients with Graves'disease. Factors predicting the time course to hypothyroidism were not identified.

Severe short stature and endogenous growth hormone resistance in twin brothers without growth hormone gene mutations.

Growth failure in children with high growth hormone (GH) levels, low insulin-like growth factor 1 (IGF-1) levels, and accelerated linear growth in response to exogenous GH is presumed to result from biologically inactive GH. A molecular diagnosis has only been made in two such patients. We analyzed the presentations and the GH-1 genes of twin Egyptian brothers with this phenotype. At 8 yr of age, the boys' heights were -4 SD. Their IGF-1 levels were 64 and 60 ng/mL, baseline GH levels were 2.1 and 11.7 mU/L, and growth hormone binding protein levels were normal. Twin B attained a peak GH level of 30.6 mU/L after L-dopa stimulation (Twin A was not tested). After 1 yr of exogenous GH, their growth velocities were >11 cm/year (>97%). Analysis of their GH-1 exons and introns revealed no mutations, but five polymorphisms were identified that have not been previously reported. The GH-1 DNA sequence was transfected into human cells and the resulting GH-1 transcripts were analyzed. Wildtype GH-1 mRNAs were observed, demonstrating that the polymorphisms do not affect transcript processing. Therefore, although no evidence of GH-1 gene mutations or abnormal GH-1 mRNA processing was found, the subjects' excellent response to exogenous GH supports a trial of GH in children with severe short stature, low IGF-1 levels and normal GH responses to stimulation testing.

Tamoxifen treatment for precocious puberty in McCune-Albright syndrome: a multicenter trial.

OBJECTIVE: We undertook a 1-year multicenter trial of tamoxifen treatment for precocious puberty in girls with McCune-Albright syndrome (MAS). STUDY DESIGN: Girls < or =10 years with classic or atypical MAS were recruited. Pretreatment history was collected for 6 months. Patients received 20 mg tamoxifen daily. Diaries were used to record bleeding. Evaluations included physical examination, bone age, pelvic ultrasound, hormone levels, and safety assessments. RESULTS: A total of 28 girls (2.9-10.9 years of age) were enrolled from 20 centers, of whom 25 completed 12 months of tamoxifen treatment. Compared with before the study, vaginal bleeding episodes decreased (3.42+/-3.36/year vs 1.17+/-1.41/year), growth velocity slowed (SDS 1.22+/-2.65 vs -0.59+/-3.06, P=.005), and rate of bone maturation decreased (1.21+/-0.78 vs 0.72+/-0.36, P=.02). Ovarian volumes were enlarged and asymmetric throughout the study, and uterine volumes were increased. No adverse events occurred. CONCLUSIONS: Tamoxifen treatment of precocious puberty in MAS results in a reduction of vaginal bleeding and significant improvements in growth velocity and rate of skeletal maturation.

Determination of trace isoflavone phytoestrogens in biological materials by capillary electrochromatography.

Capillary electrochromatography using a specialty monolithic matrix was utilized in developing a rapid and highly efficient separation of isoflavones in biological materials. Without a preconcentration technique, it is relatively easy to reach ppm-ppb concentrations of these compounds in soy-based foods and verify them structurally using a photodiode array detector. With on-column preconcentration, we were able to measure low-ppb levels in human serum. Using blood samples from human volunteers, whose diet was supplemented by a soy-based product, the method has been validated for high-throughput screening of isoflavones in clinical studies.