Effects of hypoglycemia on human brain activation measured with fMRI.

Functional magnetic resonance imaging (fMRI) was used to measure the effects of acute hypoglycemia caused by passive sensory stimulation on brain activation. Visual stimulation was used to generate blood-oxygen-level-dependent (BOLD) contrast, which was monitored during hyperinsulinemic hypoglycemic and euglycemic clamp studies. Hypoglycemia (50 +/- 1 mg glucose/dl) decreased the fMRI signal relative to euglycemia in 10 healthy human subjects: the fractional signal change was reduced by 28 +/- 12% (P < .

Newer therapeutic options for children with diabetes mellitus: theoretical and practical considerations.

Recent studies in adult patients with type 1 diabetes mellitus (T1DM) and T2DM have examined the potential utility, benefits, and side effects of agents that augment insulin secretion after oral ingestion of nutrients in comparison with intravenous nutrient delivery, the so-called incretins. Two families of incretin-like substances are now approved for use in adults. Glucagon-like peptide-1 (GLP-1) or agents that bind to its receptor (exenatide, Byetta) or agents that inhibit its destruction [dipeptidyl peptidase-IV (DPP-IV) inhibitors, Vildagliptin] improve insulin secretion, delay gastric emptying, and suppress glucagon secretion while decreasing food intake without increasing hypoglycemia.

Laparoscopic adrenalectomy of an adrenal adenoma with myelolipoma relieves severe hypertension in a 16-year-old patient.

Adrenal adenoma with myelolipoma is extremely rare in pediatrics. Although the tumor is usually asymptomatic, sometimes it may result in serious manifestations. A 16-year-old patient was diagnosed with severe hypertension associated with a right adrenal mass.

An unusual presentation of mastocytosis: unilateral swelling of the vulva.

Mastocytosis is a primary, abnormal accumulation of mast cells associated with a broad range of local and systemic symptoms. We report two female adolescents with episodic, unilateral, swelling of the labia majora that was discovered to be an unusual presentation of mastocytosis. Mastocytosis is frequently misdiagnosed because of its rarity and variable clinical presentation, which often mimics other conditions.

Randomized controlled trial evaluating response to metformin versus standard therapy in the treatment of adolescents with polycystic ovary syndrome.

Objective: We evaluated the hypothesis that metformin would improve signs and symptoms of polycystic ovary syndrome (PCOS) in adolescents as compared to oral contraceptive pills (OCP) and have a favorable effect on obesity.

Study Design: Thirty-five obese, post-menarchal, non-sexually active adolescents aged 12-21 years with PCOS and hyperinsulinism were randomly assigned to receive either OCP or metformin for 6 months.

Results: There was a significant decrease in BMI in the two groups over time, from 40.

Congenital hypothyroidism in association with Caroli's disease and autosomal recessive polycystic kidney disease: patient report.

Autosomal recessive polycystic kidney disease (ARPKD) is an important renal disease of childhood. Congenital hypothyroidism has been associated with glomerulocystic kidney disease, but to date no association has been made with ARPKD. To our knowledge this is the first reported case of congenital hypothyroidism in an infant with ARPKD.

The role of amylin and glucagon in the dampening of glycemic excursions in children with type 1 diabetes.

Postprandial hyperglycemia and preprandial hypoglycemia contribute to poor glycemic control in type 1 diabetes. We hypothesized that postprandial glycemic excursions could be normalized in type 1 diabetes by suppressing glucagon with pramlintide acetate in the immediate postprandial period and supplementing glucagon in the late postprandial period. A total of 11 control subjects were compared with 8 type 1 diabetic subjects on insulin pump therapy, using the usual insulin bolus-to-carbohydrate ratio during a standard liquid meal.

Continuous glucose monitoring in children with type 1 diabetes: before and after insulin pump therapy.

Objective: The aim of continuous subcutaneous insulin infusion (CSII) therapy in patients with type 1 diabetes mellitus (T1DM) is to mimic as closely as possible the normal physiologic pattern seen in individuals without diabetes. This study was undertaken to determine the specific areas of improved glycemic control in subjects after initiation of insulin pump therapy and times where further improvement is needed.

Research Design And Methods: Eight patients with T1DM (age 7.

Cardiac response to progressive cycle exercise in moderately obese adolescent females.

Purpose: To assess cardiac responses to exercise and cardiac functional capacity in moderately obese adolescent females.

Methods: Thirteen healthy females (mean age 13.6 +/- 1.

In situ evidence that peripheral insulin resistance in adolescents with poorly controlled type 1 diabetes is associated with impaired suppression of lipolysis: a microdialysis study.

This study was undertaken to examine whether insulin resistance in adolescents with poorly controlled type 1 diabetes mellitus (T1DM) is associated with the failure of insulin to suppress lipolysis in adipose and muscle tissues. Using microdialysis techniques, extracellular fluid concentrations of glycerol was measured in adipose and muscle tissue 3 h before and 3 h during a 0.8 mU x kg-1 x min-1.

The influence of insulin on circulating ghrelin.

Ghrelin is a novel peptide that acts on the growth hormone (GH) secretagogue receptor in the pituitary and hypothalamus. It may function as a third physiological regulator of GH secretion, along with GH-releasing hormone and somatostatin. In addition to the action of ghrelin on the GH axis, it appears to have a role in the determination of energy homeostasis.

Temporal patterns of circulating leptin levels in lean and obese adolescents: relationships to insulin, growth hormone, and free fatty acids rhythmicity.

Alterations in nutritional status, such as obesity, markedly influence insulin, leptin, GH secretion, and free fatty acid (FFA) levels. We measured every hour for 24 h circulating leptin, insulin, GH, and FFA levels in lean and obese adolescents to determine: 1) the impact of adolescent obesity on the diurnal changes in leptin concentrations; and 2) the temporal relationships between the diurnal patterns of circulating leptin levels and insulin, GH, and FFA levels. During puberty, we found that the 24-h profile of circulating plasma leptin levels follows a bimodal pattern with minimal concentrations occurring early in the afternoon and a nocturnal elevation starting after midnight and culminating early morning.

Oral glucose augments the counterregulatory hormone response during insulin-induced hypoglycemia in humans.

It has been suggested that the counterregulatory hormone (CRH) response to acute hypoglycemia is triggered via glucose sensors situated in either the hypothalamus or the portohepatic area. If the latter were critical during hypoglycemia, one would anticipate that ingestion of glucose, by raising glucose levels in the portal circulation, should attenuate CRH responses previously described in animal studies. To evaluate the effect of raising portal, but not peripheral, glucose levels during insulin-induced hypoglycemia, we performed hypoglycemic clamp studies in five healthy adult males on two occasions.

Augmentation of alimentary insulin secretion despite similar gastric inhibitory peptide (GIP) responses in juvenile obesity.

Insulin secretion rates are greater after oral glucose than after parenteral administration of an equivalent glucose load. This augmented beta-cell secretory response to an oral glucose load results from the release of mainly two gut hormones: gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1, which potentiate glucose-induced insulin secretion. Because of their insulinotropic action, their abnormal secretion may be involved in the pathogenesis of the hyperinsulinemia of childhood obesity.

Familial medullary thyroid carcinoma: presymptomatic diagnosis and management in children.

Two kindreds with familial medullary thyroid carcinoma (MTC) are described in which affected family members had variable clinical and pathologic manifestations. Genetic testing in 2 children from one kindred revealed a mutation in exon 10, codon 618 (TGC to AGC) in the extracellular cysteine-rich region of the RET gene. In this kindred an 11-year-old had microscopic evidence of MTC; however, a 17-year-old had no evidence of pathology on thyroidectomy.

Changes in free insulin-like growth factor-1 and leptin concentrations during acute metabolic decompensation in insulin withdrawn patients with type 1 diabetes.

Unlabelled: To determine the effect of acute insulin withdrawal and its subsequent replacement on components of the insulin-like growth factor (IGF)-1 binding protein system and on circulating leptin levels in patients with type 1 diabetes. Seventeen patients (age 31 yr +/-10) with type 1 diabetes treated with continuous subcutaneous insulin infusion (HbA1c 7.6% +/-1.

The metabolic syndrome and insulin-like growth factor I regulation in adolescent obesity.

Although low GH levels are commonly seen in obese adults and children, the effects of obesity on the insulin-like growth factor (IGF)/IGF-binding protein (IGFBP) system have not been established. As GH and IGF-I normally increase during adolescence, we investigated the effects of obesity on circulating total and free IGF-I levels and IGFBP-1, -2, and -3 in 19 obese adolescents [14 +/- 1 yr old; body mass index (BMI), 34 +/- 3], 20 lean adolescents (14 +/- 1 yr old; BMI, 23 +/- 0.5), and 10 lean adults (22 +/- 0.

Decreased insulin sensitivity and compensatory hyperinsulinemia after hormone treatment in children with short stature.

To assess the effects of GH treatment on carbohydrate and protein metabolism, we studied eight patients with short stature before and after the commencement of GH treatment. The hyperglycemic clamp procedure was employed to produce a hyperglycemic stimulus of 50 mg/dL above fasting levels for 120 min. These patients were then treated with 0.