Markovian timed Petri nets for performance analysis of semiconductor manufacturing systems

A subclass of generalized stochastic Petri nets (GSPNs) with priorities, called Markovian timed Petri nets, are proposed to model semiconductor manufacturing systems that consider process priorities, routing priorities, resource re-entrance, and nonpreemptive operations. Uniformization technique is used to establish both lower and upper bounds of the performance of interest. These bounds are computable using linear programming. Numerical experiments have been conducted to evaluate the accuracy of the bounds using models adapted from real-world systems. The experiments show that the upper bounds are very close to the simulation results. Thus, performance measures can be accurately estimated using these bounds.

Thyroglossal duct cyst: an infrequently considered diagnosis in pediatric patients with anterior neck masses

OBJECTIVE

To describe a pediatric patient with an anterior neck mass and discuss the evaluation and treatment.

METHODS

We present a case report and a discussion of the differential diagnosis of anterior cervical masses. The workup and therapy for an anterior neck mass, which was a thyroglossal duct cyst, are reviewed.

RESULTS

A thyroglossal duct cyst in pediatric patients is an uncommon finding. For establishing a correct diagnosis, surgical confirmation is necessary. Identification is important because of the high incidence of misdiagnosis, recurrent infections, inadequate treatment, and possible neoplastic change.

CONCLUSION

A thyroglossal duct cyst should be included in the differential diagnosis of an anterior neck mass. Recommended treatment consists of surgical removal of the cyst, the entire thyroglossal duct tract, and the central portion of the hyoid bone.

Co-operative effect of c-Src tyrosine kinase and Stat3 in activation of hepatocyte growth factor expression in mammary carcinoma cells

We have previously shown coexpression of hepatocyte growth factor (HGF) and its receptor Met in the invasive tumor front of human breast carcinomas. We have also demonstrated secretion of HGF, constitutive activation of Met, and increased invasion in a murine breast carcinoma cell line, SP1. These observations suggest the presence of an HGF autocrine loop in some breast carcinoma cells, which confers increased survival, growth, and invasiveness during tumor progression and metastasis. c-Src tyrosine kinase, which is critical in regulating the expression of many genes, is activated in SP1 carcinoma cells, as well as in most human breast cancers. We therefore examined the role of c-Src kinase in HGF expression in breast carcinoma cells. Expression of activated c-Src in SP1 cells increased transcription from the HGF promoter and expression of HGF mRNA and protein, while dominant negative c-Src had the opposite effect. Using deletion analysis, we showed that the region between -254 and -70 base pairs was required for c-Src responsiveness of the HGF promoter. This region contains two putative consensus sequences (at -110 and -149 base pairs) for the Stat3 transcription factor, which bind protein complexes containing Stat3 (but not Stat1, -5A, or -5B). Coexpression of activated c-Src and Stat3 synergistically induced strong HGF promoter activity in SP1 cells, as well as in a nonmalignant epithelial cell line, HC11 (HGF negative). c-Src kinase activity correspondingly increased the tyrosine 705 phosphorylation and DNA binding affinity of Stat3 (but not Stat1, -5A, or -5B). Collectively, our data indicate a cooperative effect of c-Src kinase and Stat3 in the activation of HGF transcription and protein expression in breast carcinoma cells. This process may be important in overriding the strong repression of HGF expression in nonmalignant epithelium, and thereby promote tumorigenesis.

Two regulators of Ste12p inhibit pheromone-responsive transcription by separate mechanisms

The yeast Saccharomyces cerevisiae transcription factor Ste12p is responsible for activating genes in response to MAP kinase cascades controlling mating and filamentous growth. Ste12p is negatively regulated by two inhibitor proteins, Dig1p (also called Rst1p) and Dig2p (also called Rst2p). The expression of a C-terminal Ste12p fragment (residues 216 to 688) [Ste12p(216-688)] from a GAL promoter causes FUS1 induction in a strain expressing wild-type STE12, suggesting that this region can cause the activation of endogenous Ste12p. Residues 262 to 594 are sufficient to cause STE12-dependent FUS1 induction when overexpressed, and this region of Ste12p was found to bind Dig1p but not Dig2p in yeast extracts. In contrast, recombinant glutathione S-transferase-Dig2p binds to the Ste12p DNA-binding domain (DBD). Expression of DIG2, but not DIG1, from a GAL promoter inhibits transcriptional activation by an Ste12p DBD-VP16 fusion. Furthermore, disruption of dig1, but not dig2, causes elevated transcriptional activation by a LexA-Ste12p(216-688) fusion. Ste12p has multiple regions within the C terminus (flanking residue 474) that can promote multimerization in vitro, and we demonstrate that these interactions can contribute to the activation of endogenous Ste12p by overproduced C-terminal fragments. These results demonstrate that Dig1p and Dig2p do not function by redundant mechanisms but rather inhibit pheromone-responsive transcription through interactions with separate regions of Ste12p.

Solitary thyroid nodules in 93 children and adolescents. a 35-years experience

Over a period of 35 years from 1963 to 1998, 93 patients under the age of 18 years, 74 girls and 19 boys, were seen for evaluation of a solitary nodule of the thyroid gland. All patients had preoperative scintiscans of the thyroid gland and had their solitary nodule excised. Seventy-seven of the patients had a cold nodule on scintiscanning. The most common cause of solitary thyroid nodules was follicuar adenoma (68.9%). Fifteen of the 77 cold nodules were malignant (19.9%). The frequency of carcinoma in males was 26.3%, while in females it was 13.5%. Our experience suggests that the incidence of thyroid carcinoma may be decreasing in pediatric patients not exposed to known risk factors. Available diagnostic methods for attempting differentiation of benign from malignant solitary nodules are reviewed and recommendations to the clinical management are presented.

c-Src kinase activity is required for hepatocyte growth factor-induced motility and anchorage-independent growth of mammary carcinoma cells

Overexpression and amplification of hepatocyte growth factor (HGF) receptor (Met) have been detected in many types of human cancers, suggesting a critical role for Met in growth and development of malignant cells. However, the molecular mechanism by which Met contributes to tumorigenesis is not well known. The tyrosine kinase c-Src has been implicated as a modulator of cell proliferation, spreading, and migration; these functions are also regulated by Met. To explore whether c-Src kinase is involved in HGF-induced cell growth, a mouse mammary carcinoma cell line (SP1) that co-expresses HGF and Met and a nonmalignant epithelial cell line (Mv1Lu) that expresses Met but not HGF were used. In this study, we have shown that c-Src kinase activity is constitutively elevated in SP1 cells and is induced in response to HGF in Mv1Lu cells. In addition, c-Src kinase associates with Met following stimulation with HGF. The enhanced activity of c-Src kinase also correlates with its ability to associate with Met. Expression of a dominant negative double mutant of c-Src (SRC-RF), lacking both kinase activity (K295R) and a regulatory tyrosine residue (Y527F), in SP1 cells significantly reduced c-Src kinase activity and strongly blocked HGF-induced motility and colony growth in soft agar. In contrast, expression of the dominant negative c-Src mutant had no effect on HGF-induced cell proliferation on plastic. Taken together, our data strongly suggest that HGF-induced association of c-Src with Met and c-Src activation play a critical role in HGF-induced cell motility and anchorage-independent growth of mammary carcinomas and further support the notion that the presence of paracrine and autocrine HGF loops contributes significantly to the transformed phenotype of carcinoma cells.

Linkage of a commoner form of recessive amyotrophic lateral sclerosis to chromosome 15q15-q22 markers

Autosomal recessive familial amyotrophic lateral sclerosis (RFALS) is a rare form of ALS that usually presents at an early age with slow progression of symptoms. RFALS is clinically and genetically heterogeneous and the locus of RFALS type 3 was mapped to 2q33 (ALS2) in a single family. We now report linkage of a more-common form of RFALS to chromosome 15q15-q22 markers (ALS5) and show further genetic locus heterogeneity in RFALS. ALS5 is the locus for most families with RFALS and appears to be present in both North African and European populations.

Expression of human pro-matrix metalloproteinase 3 that lacks the N-terminal 34 residues in Escherichia coli: autoactivation and interaction with tissue inhibitor of metalloproteinase 1 (TIMP-1)

Human pro-matrix metalloproteinase 3 (proMMP-3) lacking the N-terminal 34 amino acids and the C-terminal hemopexin-like domain was expressed in E. coli and used to investigate the process of proenzyme activation and its interaction with an endogenous inhibitor TIMP-1 during activation. The truncated precursor was purified from the E. coli extract in the presence of 5mM EGTA. The active 23.5 kDa form was generated simply by exposure to Ca2+ and Zn2+ but not either by Ca2+ alone or by Zn2+ alone. The rate of MMP-3(deltaC) formation was concentration dependent, indicating that autoactivation is a bimolecular reaction. The truncated precursor was able to interact with the N-terminal domain of TIMP-1 without losing the 48 residue-long propeptide. However, upon a longer incubation, the propeptide was slowly processed, indicating that the association of the N-terminally truncated proMMP-3 with TIMP-1 is weaker than that of the fully activated MMP-3 and TIMP-1. These results indicate that the expression of MMP activities is regulated by endogenous inhibitor TIMPs during their activation processes which provide an additional control mechanism of extracellular matrix breakdown.

Characterization of the basal and pheromone-stimulated phosphorylation states of Ste12p

The Saccharomyces cerevisiae transcription factor Ste12p is required for basal and activated expression of pheromone-responsive genes, and for invasive growth in haploid cells. In diploid yeast, Ste12p is implicated in pseudohyphal development. The ability of Ste12p to effect these various responses in three different cell types must require stringent regulation of its transcriptional activation function and interaction with additional transcription factors. We have examined the phosphorylation state of Ste12p in untreated and pheromone-treated haploid cells, and found eight constitutively phosphorylated peptides. Phosphorylation at the constitutive sites does not require the protein kinases of the pheromone-response pathway. Treatment of haploid yeast with mating pheromone causes the appearance of novel relatively minor phosphorylations on Ste12p. Brief [35S]methionine labeling reveals novel pheromone-dependent, electrophoretically slower migrating Ste12p species. Similarly, the sole difference we observe in tryptic phosphopeptides generated from Ste12p from pheromone-treated and untreated cells is the transient appearance of two novel minor hydrophobic phosphopeptides. The pheromone-dependent phosphorylation of Ste12p requires an intact pheromone-response pathway and localization of Ste12p to the nucleus, but does not require the Ste12p DNA-binding domain. We conclude from these experiments that the pheromone-response pathway induces the formation of specific hyperphosphorylation on Ste12p, which can only be detected as apparently minor modifications in vivo. We argue that, if Ste12p is regulated by direct pheromone-responsive phosphorylation, then that phosphorylation must be represented by the two novel phosphopeptides. However, we cannot exclude the possibility that pheromone-responsive transcription is controlled by direct phosphorylation of a target other than Ste12p.

Marked neonatal breast hypertrophy in a male with transient hyperprolactinemia

A male neonate with marked breast hypertrophy associated with transient hyperprolactinemia is reported. The breast hypertrophy resolved when the serum prolactin levels decreased to normal. Ultrasonographic finding of the breast hypertrophy are presented. It is not known if the hyperprolactinemia was etiologically related to the breast hypertrophy.

Differential regulation of EGF production, EGF receptor-binding, and cellular growth by sodium-butyrate in hep3b and plc/prf/5 human hepatoma-cells

Hep3B and PLC/PRF/5 human hepatoma cells express epidermal growth factor (ECF) mRNA and secret this polypeptide growth factor into the culture medium. The production of EGF was inhibited by sodium butyrate in a dose-dependent manner. EGF receptor numbers in both cell lines were increased after treatment with butyrate for 2 days, In addition, the binding affinity of EGF to its receptor was decreased in butyrate-treated PLC/PRF/5 cells while it did not change in Hep3B cells. EGF-stimulated cell growth in PLC/PRF/5 cells was attenuated by sodium butyrate whereas no significant inhibition df cell growth of Hep3B cells was found in the same condition. Our results suggest that EGF acts as an autocrine growth stimulator in human hepatoma cells and sodium butyrate can differentially regulate the responses of hepatoma cells to EGF by modulating the differentiation states of these cells.

Pseudohypoparathyroidism type Ia and growth hormone deficiency in two siblings

Pseudohypoparathyroidism type Ia (PHP type Ia) is associated with several endocrinopathies. We describe two siblings with PHP type Ia, hypothyroidism and growth hormone deficiency (GHD). To our knowledge, these patients are the first to have PHP type Ia and GHD. The defect which is most likely responsible for the three endocrinopathies is a deficiency of the stimulatory guanine nucleotide-binding regulatory protein, Gs.

Inactivation of a yeast transactivator by the fused HIV-1 proteinase: a simple assay for inhibitors of the viral enzyme activity

The human immunodeficiency virus type 1 (HIV-1) proteinase (PR) and its flanking sequences have been fused in frame between the DNA-binding domain and the transcription-activation domain of the yeast protein, GAL4. As has been shown before with the 3C proteinase of Coxsackie virus B3 (CVB3) [Das Mahapatra et al., Proc. Natl. Acad. Sci. USA 89 (1992) 4159-4162], the GAL4::PR fusion protein retains its GAL4 function, providing the PR is inactive. When PR is active, its autocatalytic activity in the hybrid protein is shown to inactivate the transactivation function of GAL4. This provides a simple assay to monitor PR activity. A dose-dependent effect of a potent PR-specific inhibitor is demonstrated in this system and illustrates the sensitivity of the assay. The assay is used for high throughput screening to identify novel inhibitors of the viral PR, and provides a method to generate and analyze mutants and revertants of the PR.

Hereditary isolated glucocorticoid deficiency is associated with abnormalities of the adrenocorticotropin receptor gene

Isolated glucocorticoid deficiency (IGD) is an autosomal recessive disorder characterized by progressive primary adrenal insufficiency, without mineralocorticoid deficiency. The cDNA and gene of the human ACTH receptor were recently cloned. The gene encodes a 297-amino acid protein that belongs to the G protein-coupled superfamily of membrane receptors. We hypothesized that the ACTH receptor gene might be defective in IGD. To examine this, we studied its genomic structure by PCR and direct sequencing in a 5-yr-old proband with the disease, his parents, and grandparents. The proband was a compound heterozygote for two different point mutations, one in each allele: (a) a substitution (C-->T), also found in one allele of the mother and maternal grandmother, which introduced a premature stop codon (TGA) at position 201 of the protein; this mutant receptor lacks its entire carboxy-terminal third and, if expressed, should be unable to transduce the signal; and (b) a substitution (C-->G), also found in one of the paternal alleles, which changed neutral serine120 in the apolar third transmembrane domain of the receptor to a positively charged arginine, probably disrupting the ligand-binding site. Standard ovine corticotropin releasing hormone (oCRH) test in the heterozygote parents and maternal grandmother revealed exaggerated and prolonged ACTH responses, suggestive of subclinical resistance to ACTH. We conclude that IGD in this family appears to be due to defects of the ACTH receptor gene. The oCRH test appears to be useful in ascertaining heterozygosity in this syndrome.

Neurosarcoidosis presenting as secondary amenorrhea in a teenager

Sarcoidosis is a systemic inflammatory disease of unknown etiology characterized by non-caseating epithelioid cell granulomata. The lungs and reticulo-endothelial system are typically involved, and virtually any organ system may be affected. Sarcoidosis involving the central nervous system is relatively uncommon, estimated to occur in approximately 5% of patients with sarcoidosis in the United States, while the incidence throughout the world may be as high as 15%. Hypothalamic dysfunction is the most common manifestation of central nervous system parenchymatous disease in neurosarcoidosis. Polyuria and polydipsia are the most frequently occurring symptoms in patients with sarcoidosis who have dysfunction of the pituitary and hypothalamus. We describe a patient with secondary amenorrhea resulting from neurosarcoidosis involving the pituitary and hypothalamus.

Solitary thyroid nodules in 71 children and adolescents

Seventy-one children and adolescents with a solitary nodule of the thyroid gland were seen over a 27-year period and all had their nodules removed surgically. All of the patients had preoperative thyroid scintiscans, 55 of which showed a cold nodule. The most common cause of solitary thyroid nodules was follicular adenoma. Fourteen of the 55 cold nodules were malignant (25.5%) while no malignancies were present in warm or hot nodules. Available diagnostic methods for attempting differentiation of benign from malignant solitary nodules are reviewed and recommendations to their clinical management as derived from our experience are presented.

The primary empty-sella syndrome and diabetes insipidus in a child

The empty-sella syndrome is uncommon in pediatric patients. Hypothalamic-pituitary dysfunction is common in these patients but involvement of the posterior pituitary gland is very rare. We report a seven-year-old girl with empty-sella syndrome who first developed arginine-vasopressin deficient diabetes insipidus and then anterior pituitary gland deficiency. The empty-sella syndrome should be included among the causes of arginine-vasopressin deficient diabetes insipidus in pediatric patients.

Nodular thyroid disease and thyroid carcinoma

The primary challenge in the management of a solitary nodule of the thyroid or a multinodular thyroid gland is to rule out a malignancy.

Sonography in neonatal congenital adrenal hyperplasia

Adrenal gland size was evaluated in six infants with congenital adrenal hyperplasia. All of the infants had a severe deficiency of the 21-hydroxylase enzyme resulting in the salt-losing form of congenital adrenal hyperplasia. The adrenal measurements were compared with those of 40 consecutive age-matched, asymptomatic infants. Mean adrenal length was 14.4 mm and width was 1.9 mm in asymptomatic infants, whereas in infants with congenital adrenal hyperplasia mean adrenal length was 23.7 mm and width was 5.3 mm. Although infants with congenital adrenal hyperplasia may have normal-sized adrenal glands, mean length measurements of 20 mm or greater and mean width measurements of 4 mm or greater suggest the diagnosis.

Pituitary enlargement due to lingual thyroid gland and primary hypothyroidism

Pituitary enlargement can occur as a result of primary hypothyroidism. We present a newborn with pituitary enlargement and congenital hypothyroidism secondary to a lingual thyroid gland. Thyroid hormone therapy caused a regression of pituitary enlargement.

Growth hormone neurosecretory dysfunction. A treatable cause of short stature

Pulsatile growth hormone (GH) secretion was assessed in a subgroup of short children to determine whether they had GH secretory abnormalities, and these results were compared with those of normal and GH-deficient children. This subgroup of children was defined as having GH neurosecretory dysfunction and met the following criteria: height, less than first percentile; growth velocity, 4 cm/yr or less; bone age, two or more years behind chronological age, normal findings from provocative GH tests (peak, greater than or equal to 10 ng/mL), low somatomedin-C level, and abnormal 24-hour GH secretory patterns. When compared with controls, both children with GH neurosecretory dysfunction and GH-deficient patients had a significant decrease in parameters relating to the total GH secretion during the 24-hour period. As with GH-deficient children, the group with GH neurosecretory dysfunction more than doubled their growth velocity after replacement therapy with exogenous human GH during the first year of treatment. As a result of these detailed studies on pulsatile GH secretion, we suggest that there is a spectrum of GH secretory abnormalities from absolute deficiency to an intermittent irregularity in GH secretion.

The effects of sex steroids on ulnar growth during adolescence

To investigate the relative effects of androgens and estrogens on long bone growth, we evaluated the 3-week ulnar growth velocities of 10 boys before and after the iv administration of testosterone (T; 15 mg/day), dihydrotestosterone (DHT; 7 mg/day), and estradiol (E2; 90 micrograms/day) for 4 days. Ulnar growth is a sensitive index of short term growth in children. Mean 3-week ulnar growth velocities increased from 0.49 +/- 0.11 (+/- SEM) to 1.09 +/- 0.14 mm/3 weeks after the T infusion (P less than 0.005), from 0.42 +/- 0.09 to 0.84 +/- 0.13 mm/3 weeks after the DHT infusion (P less than 0.02), and from 0.67 +/- 0.07 to 0.96 +/- 0.26 mm/3 weeks after the E2 infusion (P = NS). The mean T level was 2555 +/- 234 ng/dl during the T infusion. Mean E2 levels were 53 +/- 4 pg/ml during the T infusion and 102 +/- 7 pg/ml during the E2 infusion. Mean DHT levels were 73 +/- 7 ng/dl during the T infusion and 1115 +/- 124 ng/dl during the DHT infusion. Mean somatomedin-C levels increased to a similar degree during all infusions, but were significantly higher only during the E2 infusion (P less than 0.01). We conclude that T and DHT given for 4 days stimulated ulnar growth, while E2 at concentrations greater than those derived from T did not cause a significant increase in ulnar growth. None of the ulnar growth rates after T, DHT, or E2 treatment, however, differed significantly.

L-glutamine D-fructose-6-P aminotransferase regulation by glucose-6-P and UDP-N-acetylglucosamine

L-Glutamine D-Fructose-6-P aminotransferase regulates hexosamine synthesis. An affinity purified human fibroblast aminotransferase and specific radioisotope assays developed by us were used to show an independent inhibition of the aminotransferase by Glucose-6-P. More interestingly, at concentration of UDP-N-Acetylglucosamine and glucose-6-P where either sugar has no independent inhibitory effect, there is an allosteric and significant inhibition of the aminotransferase.

Solitary thyroid nodules in children and adolescents

Thirty-nine children and adolescents with a solitary nodule of the thyroid gland were seen over a 16-yr period and 35 had their nodules removed surgically. All of the patients had preoperative thyroid scintiscans, of which 27 showed a cold nodule. The most common cause of solitary thyroid nodules was follicular adenoma. Five of the 27 cold nodules were malignant (18.5%) while no malignancies were present in the warm or hot nodules. Available diagnostic methods of attempting differentiation of benign from malignant solitary nodules are reviewed and an approach to the clinical management of such nodules as derived from our experience is presented.

Relationships between control and serum lipids in juvenile-onset diabetes

The relationship between control and serum lipids was examined in 147 children with juvenile-onset diabetes (JOD). Control was assessed by fasting blood glucose, 24-h urine glucose, and fast hemoglobin. There was a significant positive correlation (P less than 0.001) between each of the measures of control. Serum cholesterol (P less than 0.001), triglycerides (P less than 0.001), and low-density lipoprotein plus very low-density lipoprotein cholesterol (P less than 0.001) were strongly positively correlated with control for the whole group of patients. High-density lipoprotein was not significantly correlated with control when the data for the whole group were analyzed but was significantly positively correlated with fasting blood glucose when patients were analyzed individually.

Computerized tomography in the evaluation of isosexual precocity

Clinical and laboratory observations were made in three children with isosexual precocity. None of the patients showed abnormalities in neurological or visual-field examinations although one patient had arrested hydrocephalus and a head circumference greater than the 98th percentile for her age and another patient had a history of seizures. Roentgenograms of the skull were normal in all patients. Cranial computerized tomography (CT) identified a lesion in each patient. We believe that craniel CT should be performed in any patient with isosexual precocity in whom a specific cause is not evident or in whom a cerebral cause is suggested even though the patient may be otherwise normal. Cranial CT is a safe, accurate, and noninvasive technique.

The effects of stimulant medication on the growth of hyperkinetic children

This article reviews the literature on possible growth-suppressing effects of stimulant medications in the long-term treatment of children with the hyperkinetic behavior syndrome. The evidence clearly indicates a temporary retardation in the rate of growth in weight and suggests a temporary slowing of growth in stature, but no effect on adult stature or weight. This temporary effect on growth is present during the first few years of treatment and seems related to drug dosage and to the presence or absence of drug holidays. These conclusions related specifically to treatment during the prepubertal period; little is known of the growth-related effects of treatment extending through pubescence.

Hyperreninemia and secondary hyperaldosteronism in pheochromocytomas

Foremost in the differential diagnosis of hypertension is the identification of surgically correctable lesions. Increased plasma renin activity in a hypertensive patient suggests the presence of a renovascular or renal etiology. We have recently seen two adolescent patients whose hyperreninemia was cuased by a pheochromocytoma. Secondary hyperaldosteronism was an associated finding.

Hyperthyroidism in juvenile diabetes mellitus

Three cases of hyperthyroidism occurring in juvenile patients with diabetes mellitus are presented. The presence of hyperthyroidism should be suspected in patients with diabetes mellitus when goiters develop and when there is unexplained weight loss, tachycardia, tremors, unexplained increases in insulin requirement, or instability of the diabetes with a tendency toward development of ketosis and/or ketoacidosis.

Hemodialysis and thyroid functions in children

Evaluation of thyroid functions in 16 children receiving maintenance hemodialysis for a mean duration of 17 months showed that the serum T3, T4 and TSH were below normal concentrations for age. However, the measurements of these variables before and after the dialysis procedure did not show any significant changes. The possibility that the chronic uremia may give rise to abnormal TSH secretion and low T3, T4 concentrations is not tested in this study.

Calcitonin therapy of children with osteogenesis imperfecta

Two children, ages 13 2/12 and 6 6/12 years, with osteogenesis imperfecta were treated with salmon calcitonin. During the course of therapy the older child developed calcitonin dose-related hypomagnesemia on two occasions. The younger child, coincident with otitis media and vomiting, developed hypomagnesemia, hypophosphatemia, hyponatremia, and hypokalemia. Since rib biopsies obtained before and after one year of treatment with salmon calcitonin failed to demonstrate any histologic changes, therapy was discontinued because of the induced metabolic consequences of calcitonin therapy.

Impaired glucose, insulin, and adenosine 3',5'-monophosphate responses to glucagon in growth hormone deficient children

The glucose, insulin, and adenosine 3',5'-monophosphate (cyclic AMP) responses to intravenous glucagon were found to be impaired in growth hormone deficient children. The delta plasma glucose response in 22 normal children was 54.5 mg/dl compared to 38.4 mg/dl in the 11 growth hormone deficient children; t = 2.74, P less than 0.02. For serum insulin, the comparative values were 65.3 muU/ml (n = 20) vs. 29.8 muU/ml (n = 11); t = 3.03, P less than 0.01. For urinary cyclic AMP, the comparative values were 0.46 mumol/m2 (n = 22) vs. 0.18 mumol/m2 (n = 10); t = 2.48, P less than 0.02. Growth hormone therapy resulted in a significant improvement in the glucose, insulin, and cyclic AMP responses to intravenous glucagon in the growth hormone deficient group of children.