Congenital pulmonary airway malformation.

BACKGROUND: Congenital cystic adenomatoid malformations (CCAMs) are considered rare developmental anomalies of the lower respiratory tract. These are hamartomatous abnormalities of the lung with adenomatoid proliferation of cysts resembling bronchioles and ususally occur sporadically occur and unilaterally with single lobe involvement. METHOD: A 6-year-old girl was admitted to our center because of prolonged fever and non-productive cough lasting3 months before admission. RESULTS: The only other complaint was night sweating. She did not have dyspnea and did not mention any respiratory symptoms. On examination, coarse crackle and decreased lung sounds in the left side were detected. White blood cell count was 9.100 /µL, hemoglobin was 11.2 g/dL, erythrocyte sedimentation rate was 50 and C-reactive protein was 1+. IgA and IgM for hydatid cyst were tested and both were raised (14 and 1.4, respectively). CONCLUSION: The patient underwent surgery, with the probable diagnosis of hydatid cyst but in operating room diagnosis was changed and it was adenomatoid cystic malformation. In follow-up, she was in good general condition without any post-surgical complaints (Fig. 3, Ref. 11).

Adrenocortical carcinoma presenting with heterosexual pseudoprecocious puberty shortly after birth: case report and review.

Adrenocortical tumour is rare in children. We report on a female infant with adrenocortical carcinoma presenting with pseudoprecocious puberty at the age of two. She had a history of gradually increasing public hair growth after birth. Physical examination showed signs of virilisation such as pubic hair growth and hirsutism with evidence of facial hair growth. On biochemical evaluation, DHEA-S, 17-OH progesterone, and testosterone levels were elevated. An abdominopelvic spiral computed tomography (CT) scan with intravenous contrast identified a well-defined heterogeneously enhanced mass with areas of necrosis in the right adrenal gland and downward displacement of the underlying kidney. There was no evidence of distant metastasis on CT imaging. An exploratory laparotomy was performed in which a large, haemorrhagic and necrotic mass in the right adrenal gland with pressure effect on right liver lobe and signs of thrombosis in the inferior vena cava was detected. Pathologic examination confirmed the adrenocortical carcinoma. She received eight cycles of adjuvant chemotherapy with Carboplatin, Etoposide, and Doxorubicin regimens and underwent follow-up visits thereafter in which no sign of recurrence was observed. In conclusion, adrenocortical carcinomas are rare in children, but they should be considered in any child presenting with signs of pseudoprecocious puberty.

Role of rotaviruses in children with acute diarrhea in Tehran, Iran.

BACKGROUND: Rotavirus illness is associated with significant cause of morbidity and is a common cause of hospitalization worldwide. OBJECTIVE: This study was performed to assess the role of rotaviruses in children presenting with acute diarrhea in two main Children's Medical Centers and one general hospital in Tehran. STUDY DESIGN: Stool specimens from 704 children less than 5 years of age suffering from diarrhea were tested for the presence of rotaviruses by a monoclonal antibody-based enzyme immunoassay. A total of 176 fecal specimens collected from healthy children in similar age group were studied as controls. RESULTS: Rotavirus antigen was detected in 15.3% of patients. Infants between 6 and 12 months of age were most frequently affected. Rotavirus infection was significantly less frequent in breast-fed than among bottle-fed babies. Watery diarrhea was present in 68.5% of children. Detection rate was highest in the spring and lowest in summer. Rotavirus can be regarded as a major etiologic agent of acute diarrhea in infants and children up to 5-years-old in Iran, immunization at birth may protect the children before their first symptomatic infection.

FDG imaging of spinal cord primitive neuroectodermal tumor.

PET with 18F-fluoro-2-deoxy-glucose (FDG) is well established as an effective imaging modality for evaluating suspected brain tumor recurrence. Use of FDG PET imaging for spinal cord neoplasms has not yet been studied, in large part due to limitations of spatial resolution. One report of FDG PET imaging of brain involvement with primitive neuroectodermal tumor (PNET) demonstrated mild hypometabolism relative to cortical gray matter. We demonstrate with FDG PET imaging the appearance of recurrent intramedullary PNET affecting the cervical spinal cord.

The effect of non-insulin-dependent diabetes mellitus and obesity on glucose transport and phosphorylation in skeletal muscle.

Defects of glucose transport and phosphorylation may underlie insulin resistance in obesity and non-insulin-dependent diabetes mellitus (NIDDM). To test this hypothesis, dynamic imaging of 18F-2-deoxy-glucose uptake into midthigh muscle was performed using positron emission tomography during basal and insulin-stimulated conditions (40 mU/m2 per min), in eight lean nondiabetic, eight obese nondiabetic, and eight obese subjects with NIDDM. In additional studies, vastus lateralis muscle was obtained by percutaneous biopsy during basal and insulin-stimulated conditions for assay of hexokinase and citrate synthase, and for immunohistochemical labeling of Glut 4. Quantitative confocal laser scanning microscopy was used to ascertain Glut 4 at the sarcolemma as an index of insulin-regulated translocation. In lean individuals, insulin stimulated a 10-fold increase of 2-deoxy-2[18F]fluoro-D-glucose (FDG) clearance into muscle and significant increases in the rate constants for inward transport and phosphorylation of FDG. In obese individuals, the rate constant for inward transport of glucose was not increased by insulin infusion and did not differ from values in NIDDM. Insulin stimulation of the rate constant for glucose phosphorylation was similar in obese and lean subjects but reduced in NIDDM. Insulin increased by nearly twofold the number and area of sites labeling for Glut 4 at the sarcolemma in lean volunteers, but in obese and NIDDM subjects translocation of Glut 4 was attenuated. Activities of skeletal muscle HK I and II were similar in lean, obese and NIDDM subjects. These in vivo and ex vivo assessments indicate that impaired glucose transport plays a key role in insulin resistance of NIDDM and obesity and that an additional impairment of glucose phosphorylation is evident in the insulin resistance of NIDDM.

Limitations of craniocaudal thallium-201 and technetium-99m-sestamibi mammoscintigraphy.

UNLABELLED: Previous studies with 201Tl and 99mTc-sestamibi (MIBI) have used large field of view (LFOV) cameras not optimized for breast imaging. The purpose of this study was to compare these agents and to determine if a small field of view (SFOV) camera designed to minimize the camera-to-breast distance could improve tumor detection. METHODS: A 28-cm (SFOV) camera was fitted with slant-hole and diverging collimators to perform craniocaudal scintigraphy for direct comparison with mammography. Of the 46 patients studied, 20 had 201Tl imaging alone and 26 had combined 201Tl and MIBI imaging. LFOV (40 cm) breast and axillary images also were obtained. Visual and quantitative analyses of tumor uptake were performed. RESULTS: The SFOV camera with nonparallel collimation showed variable 201Tl and MIBI normal breast activity. This was partly due to significant scatter from cardiac and abdominal activity. Overall, 201Tl had a sensitivity of 53%, which was 67% for tumors > or = 1.5 cm and 20% for tumors < or = 1.5 cm. MIBI sensitivity was 90% (9/10) for lesions > or = 1.5 cm. Specificity was 93% for 201Tl and 83% for MIBI. There was no significant difference in 201Tl (1.76 +/- 0.55) and MIBI (1.82 +/- 0.95) tumor uptake ratios (p = 0.75). CONCLUSION: Technetium-99m-MIBI was more sensitive than 201Tl for imaging lesions > or = 1.5 cm. Craniocaudal positioning minimized the camera-to-breast distance but did not increase 201Tl detection of tumors < 1.5 cm and increased background breast activity due to scatter.

Effects of fat on insulin-stimulated carbohydrate metabolism in normal men.

We have examined the onset and duration of the inhibitory effect of an intravenous infusion of lipid/heparin on total body carbohydrate and fat oxidation (by indirect calorimetry) and on glucose disappearance (with 6,6 D2-glucose and gas chromatography-mass spectrometry) in healthy men during euglycemic hyperinsulinemia. Glycogen synthase activity and concentrations of acetyl-CoA, free CoA-SH, citrate, and glucose-6-phosphate were measured in muscle biopsies obtained before and after insulin/lipid and insulin/saline infusions. Lipid increased insulin-inhibited fat oxidation (+40%) and decreased insulin-stimulated carbohydrate oxidation (-63%) within 1 h. These changes were associated with an increase (+489%) in the muscle acetyl-CoA/free CoA-SH ratio. Glucose disappearance did not decrease until 2-4 h later (-55%). This decrease was associated with a decrease in muscle glycogen synthase fractional velocity (-82%). The muscle content of citrate and glucose-6-phosphate did not change. We concluded that, during hyperinsulinemia, lipid promptly replaced carbohydrate as fuel for oxidation in muscle and hours later inhibited glucose uptake, presumably by interfering with muscle glycogen formation.

Effects of lipid on basal carbohydrate metabolism in normal men.

We investigated the effects of infusion of a 20% triglyceride emulsion plus heparin (LH) on carbohydrate (CHO) metabolism during basal insulin and glucose turnover conditions in normal male subjects. In study 1, LH or saline was infused at 0.5 and 1.5 ml/min for 2 h each. Plasma free fatty acids rose from approximately 0.4 to 0.8 mM with the low rate and to between 1.6 and 2.1 mM with the high rate. Similar increases occurred in plasma concentrations of glycerol, acetoacetate, and beta-hydroxybutyrate. LH infusions resulted in significant increases in C-peptide concentrations but had no effects on any of the other measured parameters of CHO metabolism. In study 2, LH or saline was infused as in study 1, but the compensatory insulin release was prevented by intravenous infusion of somatostatin and replacement of basal insulin and glucagon concentrations. This resulted in significant increases in plasma glucose (from 4.5 +/- 0.2 to 7.1 +/- 0.6 mM, P less than 0.001) and hepatic glucose output (from 9.0 +/- 1.5 to 11.3 +/- 1.4 mumol.kg-1.min-1, P less than 0.05) and a decrease in glucose clearance (from 2.32 +/- 0.13 to 1.44 +/- 0.11 ml.kg-1.min-1, P less than 0.05). We conclude that lipids can have adverse effects on CHO metabolism under basal conditions and that healthy individuals can compensate for these effects with additional secretion of insulin.

A radioimmunoassay for human insulin receptor correlation between insulin binding and receptor mass.

We have developed a radioimmunoassay for human insulin receptor. Serum from a patient with Type B severe insulin resistance was used as anti-insulin receptor antiserum. Pure human placental insulin receptor was used as reference preparation and 125I labeled pure insulin receptor as trace. The radioimmunoassay was sensitive (limit of detection less than 17 fmol), reproducible (inter and intra-assay coefficients of variation 12.5% and 1.6% respectively) and specific (no crossreactivity with pure placental IGF-1 receptor, insulin and glucagon). The anti-insulin receptor antibody was, however, able to differentiate between insulin receptor from human placenta and from rat liver. To determine the number of insulin binding sites per receptor, we measured insulin binding (by insulin binding assay) and insulin receptor mass (by radioimmunoassay) in solubilized aliquots from 5 human placentas. The molar ratio of insulin binding to receptor mass was 0.86 +/- 0.12 when binding was determined with monoiodinated 125I-Tyr A 14-insulin. It was 1.94 +/- 0.27 when randomly iodinated 125I-insulin was used. In conclusion, using a sensitive, reproducible and specific radioimmunoassay, we have measured insulin receptor mass independent of insulin binding. Our data are most compatible with binding of one insulin molecule per human placental insulin receptor.

Role of glucagon in disposal of an amino acid load.

Amino acids stimulate the release of glucagon and insulin. To assess the role of aminogenic hyperglucagonemia, we have studied, in healthy young males, the effects of basal (less than 100 pg/ml) and high (200-400 pg/ml) plasma glucagon concentrations on amino acid metabolism during intravenous infusion (0.5 g.h-1.4 h) of a mixture of 15 amino acids. Basal plasma glucagon concentrations were obtained by infusion of somatostatin (0.5 mg/h) plus glucagon (0.25 ng.kg-1.min-1) and high plasma glucagon concentrations by infusion of somatostatin plus glucagon (3.0 ng.kg-1.min-1) or by infusion of amino acids alone. All studies were performed under conditions of euglycemic (83-91 mg/dl) hyperinsulinemia (50-80 microU/ml). Hyperglucagonemia significantly increased 1) net amino acid transport from the extracellular into the intracellular space (by approximately 4%), 2) net degradation of amino acids entering the intracellular space (by approximately 40%), and 3) conversion of degraded amino acids into glucose from 0-10% (basal glucagon) to 70-100% (high glucagon). Hyperglucagonemia did not affect the amount of amino acids excreted in the urine (approximately 4%). We conclude that glucagon plays an important role in the disposition of amino acids by increasing their inward transport, their degradation, and their conversion into glucose.

Stimulation of luteinizing hormone release by melittin and phospholipase A2 in rat pituitary cells.

Gonadotropin release in rat pituitary monolayer cultures was stimulated by phospholipase A2, as well as by its activator melittin. A dose-dependent stimulation of luteinizing hormone secretion by melittin was observed in a dose range of 10(-8) to 10(-4) M. A higher dose (1 mM) melittin had a sub-optimal effect. The stimulatory action of melittin was calcium-dependent and blocked by phospholipase A2 inhibitors, chloroquine and quinacrine. Similar to melittin, phospholipase A2 enhanced the effect of LH release in a dose range of 0.1-100 units/ml. The effect of this enzyme was also calcium-dependent with optimal calcium concentrations at 1.5 mM, as obtained also for melittin. In superfusion experiments, the stimulatory action of melittin and phospholipase A2 was reproducible in their effects on LH release in gonadotrophs. In addition, melittin (10(-7) M) stimulated LH and 3H-arachidonic acid efflux in superfused pituicytes following prelabelling with radiolabelled arachidonate. These data suggest that phospholipase A2, which releases arachidonic acid from phospholipids, may participate in controlling gonadotropin secretion in gonadotrophs, since arachidonic acid and its metabolites have previously been found to enhance gonadotropin release.