Homozygosity for a dominant negative thyroid hormone receptor gene responsible for generalized resistance to thyroid hormone.

Generalized resistance to thyroid hormones (GRTH) commonly results from mutations in the T3-binding domain of the c-erbA beta thyroid hormone receptor gene. We have reported on a novel deletion mutation in c-erbA beta in a kindred, S, with GRTH. One patient from this kindred was the product of a consanguineous union from two affected members and was homozygous for the beta-receptor defect. This patient at 3.5 weeks of age had unprecedented elevations of TSH, free T4, and free T3 (TSH, 389 mU/L; free T4, 330.8 pmol/L; free T3, 82,719 fmol/L). He displayed a complex mixture of tissue-specific hyperthyroidism and hypothyroidism. He had delayed growth (height age, 1 3/12 yr at chronological age 2 9/12 yr) and skeletal maturation (bone age, 4 months), and developmental delay (developmental age, 8 months), but he was quite tachycardic. The homozygous patient of kindred S is markedly different from a recently reported patient with no c-erbA beta-receptor. This difference indicates that a dominant negative form of c-erbA beta in man can inhibit at least some thyroid hormone action mediated by the c-erbA alpha-receptors.

The Klinefelter syndrome of testicular dysgenesis.

Klinefelter syndrome of testicular dysgenesis is the most common form of male hypogonadism. It may be suspected and identified by specific physical signs in infants, children, and adolescents as well as in adults. This review discusses the genetics, clinical manifestations, complications, and treatment of Klinefelter syndrome and its variants.

Dextrothyroxine in the treatment of generalized thyroid hormone resistance in a boy homozygous for a defect in the T3 receptor.

The dextroisomer of thyroxine (D-T4) has been shown to have suppressive effects on pituitary TSH secretion in euthyroid individuals and patients with mild thyroid hormone resistance. We treated a 3-year-old boy with D-T4 who was homozygous for a T3 receptor defect, resulting in a complex clinical picture of tissue-specific hyperthyroidism and hypothyroidism. There was no evidence of significant alteration in thyroid physiology, including serum concentrations of basal and TRH stimulated TSH or echocardiographic parameters measuring systolic time interval. We conclude that D-T4 at a daily dose of 6 mg (0.65 mg/kg) was ineffective in this boy with homozygous dominant negative thyroid hormone resistance.

Pituitary abscess: an unusual presentation of "aseptic meningitis".

Granulomatous inflammation of the pituitary and pituitary abscesses are rare entities. These conditions are found even more rarely in the pediatric aged population. We report a case of a radiographic and clinical, sterile pituitary abscess with non-caseating granulomatous inflammation in a girl who presented with hypopituitarism, meningeal irritation, and symptoms of pituitary apoplexy.

Growth during and after a trial of growth hormone releasing hormone 1-29 in children with idiopathic short stature or growth hormone neurosecretory dysfunction.

The growth promoting effects of once nightly subcutaneous injections of growth hormone releasing hormone (GHRH) 1-29 (30 microg/kg) for 6 months were studied in 16 slowly growing prepubertal children with idiopathic short stature (ISS; Group 1) and 8 similar children with growth hormone neurosecretory dysfunction (GHND; Group 2). Each child underwent endogenous growth hormone evaluation using both pharmacological and physiological testing; each had stimulated values > 10 microg/l and were subsequently placed into one of two groups based on pooled 12-hour overnight GH of < or > or = 3 microg/l. Each patient was followed every three months for one year. There were no significant differences in the two groups throughout the study with the exception of the endogenous GH levels. Both groups responded to GHRH therapy with similar significant increases in their rates of growth. Although a subset of patients (6 of 21) continued to grow at a rate significantly greater than the pre-therapy rate of growth, overall rates of growth were not significantly different from the pre-therapy growth rates 6 months following the discontinuation of GHRH treatment. We conclude that GHRH 1-29, given in the doses provided, leads to similar changes in growth rates in short, slowly growing children who are GH sufficient and those with GHND. Despite prior reports to the contrary, GHND patients do not experience a sustained increased in growth rate upon discontinuation of GHRH.

Left pleural effusion: masking subphrenic abscess--caused by Salmonella enteritidis serotype Heidelberg.

The authors describe a young girl presenting with fever and respiratory distress and a chest x-ray showing a left lower lobe infiltrate and an effusion. She also had splenomegaly. Salmonella enteritidis serotype Heidelberg was isolated by thoracentesis. Further evaluation disclosed an occult but large left subphrenic abscess, explaining the misleading presentation and radiograph. A review of salmonella infections associated with subphrenic abscess is discussed.

Verapamil-induced "primary" polydipsia.

An 11-month-old male infant with recurrent supraventricular tachycardia (SVT) was treated with oral verapamil. Shortly thereafter he developed marked changes in behavior including lethargy, intensely increased thirst and urination, and irritability when denied fluids. "Primary" polydipsia was diagnosed following an evaluation which showed no evidence of adrenal insufficiency, diabetes insipidus, diabetes mellitus, hypercalcemia, hyperosmolality, or renal disease. The symptoms resolved 1 week after verapamil was discontinued.

Trial of beclomethasone dipropionate by metered-dose inhaler in ventilator-dependent neonates less than 1500 grams.

Beclomethasone dipropionate administered by metered-dose inhaler to ventilated infants with early chronic lung disease was evaluated in a double-blind, placebo-controlled study to determine the feasibility and safety of administration. Patients selected for study were less than 1500 g birthweight, had previous radiographic evidence of respiratory distress syndrome with early changes of bronchopulmonary dysplasia (BPD), were greater than 2 weeks of age, and had failed attempts at extubation. The metered-dose inhaler was connected to the respirator circuit by an in-line spacer device and either saline placebo or beclomethasone was delivered for 7 days or until extubated. Beclomethasone was delivered in a dose calculated to be approximately 1 mg/kg/day in three divided doses. Nineteen infants were enrolled. Nine received placebo and 10 received beclomethasone. No adverse effects on blood pressure, heart rate, respiratory rate, ventilator settings, concentration or duration of oxygen therapy, incidence of retinopathy of prematurity (ROP) or infections, blood glucose, daily weight, or serum cortisol levels before and after adrenal stimulation tests were observed in the beclomethasone group compared with the placebo group. One infant in the placebo and six infants in the steroid group were extubated during the study period (p = 0.03). These data indicate that beclomethasone dipropionate may be administered safely to intubated neonates without adverse effects of hypertension, hyperglycemia, diminished weight gain, or adrenal suppression frequently seen with systemic steroid administration. Beclomethasone may enhance extubation in infants with early BPD, however, further data are required to substantiate this preliminary observation.

Effects of long-term growth hormone releasing hormone 1-29 in significantly short children.

Seven children with significant idiopathic short stature (SISS) whose heights were significantly below the third percentile (SD score for height -2.5 to -3.5) and who had normal levels of growth hormone (GH) were treated with growth hormone releasing hormone (GH-RH) in a dose of 30 micrograms/kg/day. Therapy was discontinued if patients failed to increase their rates of growth by more than 2.0 cm/year over their pre-therapy growth rate. Treatment was discontinued in two of the patients after 12 months but was continued in the other five for 24 months. These data demonstrate that some patients with SISS grow well during the first 2 years of treatment with GH-RH.

Prolactinoma associated with transient growth hormone deficiency but persistent growth retardation.

A 14.8 year old boy was evaluated for galactorrhea of two months duration and growth deceleration for greater than three years. He was 3.7 standard deviations (SD) below the mean for age in height and euthyroid with uncompromised vision, bilateral galactorrhea, and pubertal arrest. MRI demonstrated a 10 x 8 mm left pituitary mass. Bone age was 11.5 years. Serum prolactin (PRL) decreased by more than 85% after 5 weeks of treatment with bromocriptine (Br). After five months, the prolactinoma (PRLoma) measured 5 x 4 mm. Hypothalamic-pituitary function indicated growth hormone (GH) deficiency and hypogonadotropic hypogonadism as assessed by ITT-TRH-GnRH-clonidine. After nine months of Br, despite return of adequate gonadotropin and GH secretion as assessed by repeat ITT-TRH-GnRH-clonidine, pooled 12 hour nocturnal spontaneous GH secretion, and clinical progression of puberty, there was no linear "catch-up growth" (growth rate = 4.4 cm/yr and height 4.2 SD below the mean for age). Growth rate increased following supplemental GH administration without untoward effect. We conclude that there may be discordance/lag between reduction in secretion and size of PRLomas and growth despite resolution of other anterior pituitary dysfunction. Other possibilities are discussed.

Linear growth response to exogenous growth hormone in children with short stature.

Response to growth hormone (GH) therapy was evaluated in 38 short children (28 males and 10 females; less than 1% in height for chronologic age [CA]) who were clinically categorized into three groups based on their endogenous mean 24-hour GH concentration (mean 24-hour GH) and peak GH response to two or more provocative agents (peak GH). All patients were treated with biosynthetic somatropin (human growth hormone) (0.15 to 0.30 mg/kg per week) injected subcutaneously three to seven times per week for a mean duration of 12.5 months. Group 1 consisted of 17 subjects (CA, 12.5 +/- 2.9 years [mean +/- SD]; bone age, 9.4 +/- 2.9 years; height velocity [HV], 3.4 +/- 1.8 cm/y; peak GH, 5.8 +/- 2.6 micrograms/L; mean 24-hour GH, 1.7 +/- 0.6 micrograms/L; and insulinlike growth factor-I, 0.40 +/- 0.24 U/mL. Group 2 consisted of 10 subjects (CA, 11.7 +/- 2.7 years; bone age, 9.2 +/- 3.0 years; HV, 3.4 +/- 1.6 cm/y; peak GH, 16.4 +/- 5.2 micrograms/L; mean 24-hour GH, 1.7 +/- 0.5 micrograms/L; and insulinlike growth factor-I, 0.49 +/- 0.27 U/mL. Group 3 consisted of 11 subjects (CA, 12.7 +/- 2.2 years; bone age, 10.2 +/- 2.4 years; HV, 3.5 +/- 1.5 cm/y; peak GH, 22.5 +/- 8.6 micrograms/L; mean 24-hour GH, 3.8 +/- 1.1 micrograms/L; and insulinlike growth factor-I, 1.07 +/- 0.69 U/mL. Following administration of somatropin, an increase (delta) in HV of 2.0 cm/y or greater occurred in 94% (16/17) of the group I subjects (delta HV of 5.1 +/- 2.6 cm/y), in 90% (9/10) of the group 2 subjects (delta HV of 4.3 +/- 2.2 cm/y), and in 73% (8/11) of group 3 subjects (delta HV of 3.7 +/- 2.3 cm/y). However, regardless of provoked and/or endogenous GH secretory dynamics, 88% of the children whose pretreatment HV was 2.0 cm/y or less, 94% whose pretreatment HV was between 2.0 and 4.0 cm/y, and 79% whose pretreatment HV was greater than 4.0 cm/y increased their HVs to 2.0 cm/y or greater while they were receiving somatropin. Significant negative correlations were observed between delta HV and pretreatment HV (r = -.67), delta HV and GH concentration expressed as a 24-hour area under the curve (r = -.33), and delta HV and peak GH (r = -.34).(ABSTRACT TRUNCATED AT 400 WORDS)

"Low-dose" growth hormone therapy during peritoneal dialysis or following renal transplantation.

The minimal effective dose of growth hormone (GH) to promote growth in children on dialysis or following renal transplantation remains unsettled. In order to study the issue, "low-dose" GH was administered to children with end-stage renal disease (ESRD) receiving chronic automated peritoneal dialysis (APD, n = 6, 4 males, 2 females) or following renal transplantation (T, n = 9, 8 males, 1 female). No APD patient was GH deficient, while 1 T patient (no. 2) had data consistent with GH deficiency, although he was obese (body mass index = 34 kg/m2). The mean dose of GH after 6 and 12 months of treatment was 0.16 +/- 0.02 and 0.22 +/- 0.07 versus 0.16 +/- 0.03 and 0.27 +/- 0.21 mg/kg per week for APD and T patients, respectively. When analyzing all patients, there were no significant differences before or after 6 and 12 months of GH therapy within or between the two groups, in terms of height velocity, bone age, renal function (in the T group) and height Z-scores (Z-Ht). However, the height velocity Z-score (Z-HV) increased significantly at 6 and 12 months compared with baseline in the APD patients only (P < 0.05). When the 2 T patients with the most impaired renal function were excluded from the analysis, Z-HV also increased significantly in the T patients after 12 months of GH (P < 0.02). We conclude that following "low-dose" GH therapy, children with ESRD treated with APD or T have similar increases in HV, allowing maintenance of Z-Ht but not "catch-up" growth.

Neurotransmitter control of growth hormone secretion in children after cranial radiation therapy.

Cranial radiation for childhood cancer can cause growth hormone deficiency (GHD), usually due to hypothalamic rather than pituitary dysfunction. To investigate whether this hypothalamic dysfunction is secondary to altered neurotransmitter input from other brain centers, we used neurotransmitter-excitatory substances to study the GH secretory response in 17 children who had received 12 to 60 Grey (Gy) to the cranium and 40 short children with normal endocrine function. As expected, the irradiated children had decreased mean GH secretion in response to insulin-induced hypoglycemia and arginine infusion, and decreased mean 24 hour GH concentrations, compared to the control group. In contrast, the two groups had similar GH secretory responses to GHRH stimulation and somatostatin suppression. Assessment of neurotransmitter pathways in the irradiated children revealed significantly lower mean peak GH concentrations in response to 5 of the 6 substances tested compared to control children: alpha-adrenergic stimulation (clonidine), beta-adrenergic blockade (propranolol), cholinergic stimulation, dopaminergic stimulation (L-dopa), and GABA-ergic stimulation (valproic acid). Results of serotonergic stimulation (L-tryptophan) were not statistically significant. Eleven patients who had abnormal GH secretion underwent 4 or more tests with neurotransmitter-stimulatory agents; 3 patients had peak GH concentrations of < 2.5 micrograms/l to all tests, whereas 4 patients had a peak GH concentration of > or = 7 micrograms/l to one or more tests but < 5 micrograms/l to one or more other tests. These observations suggest that radiation damage may sometimes spare growth hormone-releasing hormone (GHRH) and somatostatin secretion while affecting neurotransmitter pathways. We postulate that the hierarchy of sensitivity to radiation damage may be hypothalamic and extra-hypothalamic neurotransmitters > hypothalamic GHRH and/or somatostatin secretion > pituitary GH secretion.