Gastric emptying of milk feedings in infants and children. Anterior versus conjugate counting

The radionuclide milk scan is a valuable tool for the evaluation of gastroesophageal reflux and gastric emptying in children. There is uncertainty as to whether anterior imaging alone is sufficient for determining gastric emptying in these patients.

METHODS

Twenty-five children underwent Tc-99m sulfur colloid milk scans with images acquired in the anterior and posterior projections. Calculations of the 1 hour and 2 hour percentage of gastric residual activity were performed using the anterior counts alone and the geometric mean of the anterior and posterior counts. The anterior and posterior images were visually assessed for the presence of gastroesophageal reflux.

RESULTS

The means of the absolute differences at 1 and 2 hours for the two methods of gastric residual calculation were 4.1% +/- 2.1% and 3.4% +/- 2.8%, respectively. There was good correlation between the two methods at 1 and 2 hours with r values of 0.991 and 0.997 respectively. Gastroesophageal reflux was more obvious in the anterior images and three small episodes were only seen on the anterior view.

CONCLUSION

Anterior images alone give reliable results for the determination of gastric emptying, and gastroesophageal reflux is more readily visualized anteriorly in the pediatric population.

Lung perfusion patterns after bidirectional cavopulmonary anastomosis (Hemi-Fontan procedure)

Perfusion lung scans were performed immediately prior to Fontan procedure in 45 patients with a functional single ventricle who underwent the hemi-Fontan procedure as an intermediate stage between the initial palliative shunt procedure and the final complete Fontan anastomosis. Symmetric pulmonary blood flow (PBF) distribution was found in 27% of patients, whereas moderately to severely abnormal PBF distribution was found in 35% of patients. The achieved systemic aortic saturation following the hemi-Fontan procedure was not affected by these abnormalities.

Volume-dependent pulmonary aspiration of a swallowed radionuclide bolus

The radionuclide salivagram was introduced as a simple physiologic technique to document the aspiration of saliva in patients with chronic lung disease. We previously reported positive studies to be prevalent in patients with neuromuscular incoordination, as with cerebral palsy, or after surgery involving the upper airway. Many patients referred for a salivagram, however, have an apparent intact swallowing mechanism and are better challenged with a tagged bolus.

Results of dacryoscintigraphy in massage of the congenitally blocked nasolacrimal duct

Between November 1990 and November 1993, 580 children with lacrimal outflow obstruction were examined at the Children's Hospital of Philadelphia. After excluding patients previously treated for nasolacrimal duct obstruction, we obtained a prospectively selected series of 20 children for this study. These patients underwent dacryoscintigraphy before and immediately after lacrimal sac massage to investigate the effect of external compression on fluid movement within the lacrimal outflow system. In 12 patients, tracer did not enter the lacrimal outflow system on the side(s) of obstruction. The absence of radiopharmaceutical correlated with clinical obstruction. In eight patients, tracer was noted to enter the lacrimal sac. After massage of the lacrimal sac, we observed progression of the tracer in five of the eight subjects. In these eight subjects, the pre- and postmassage tear column measurements showed a relative increase of 34.3%. Massage of eight clinically normal ducts showed a relative increase of 2.4% (p = 0.06). We conclude that progression of the tear column after lacrimal massage can be demonstrated on dacryoscintigraphy.

Fetal mouse lung ultrastructural maturation is accelerated by maternal thyrotropin-releasing hormone treatment

Maternal administration of thyrotropin-releasing hormone, alone or in combination with corticosteroid, accelerates functional, morphologic and biochemical fetal lung maturation. However, the dose-response relationship of maternal thyrotropin-releasing hormone treatment and acceleration of fetal lung ultrastructural maturation or disaturated phosphatidylcholine content has not been investigated. We administered (i.p.) saline or thyrotropin-releasing hormone (0.2, 0.4 or 0.6 mg/kg/dose) to the pregnant Balb/c mouse on days 16 and 17 (b.i.d.) and on day 18 of gestation (1 h prior to killing). Morphometric ultrastructural analysis and quantitation of disaturated phosphatidylcholine content was done on the 18-day gestation fetal lung. Maternal thyrotropin-releasing hormone treatment resulted in an increase in the number of lamellar bodies and depletion of glycogen in fetal lung type II cells, and an increase in the lung airspace to parenchymal ratio. In addition, a striking difference in the pattern of lung growth was noted in the thyrotropin-releasing-hormone-treated (0.4 and 0.6 mg/kg/dose) groups. These lungs had larger air spaces, thinner alveolar septae and more air-blood barriers. Maternal thyrotropin-releasing hormone treatment did not influence fetal lung disaturated phosphatidylcholine content. We conclude that in the mouse, maternal thyrotropin-releasing hormone treatment enhances fetal lung structural maturation and propose that thyrotropin-releasing hormone plays a role in mammalian fetal lung growth.

Pediatric gastrointestinal motility studies

Radionuclide studies for evaluating gastrointestinal transit in adults have been adapted for use in infants and children for assessing esophageal transit, gastroesophageal reflux, and gastric emptying. However, the measurement of small- and large-bowel transit times in these patients has been limited.

Langerhans cell histiocytosis: presentation and evolution of radiologic findings with clinical correlation

Radiologic images and medical records of 42 children with Langerhans cell histiocytosis (LCH) (histiocytosis X) were reviewed to evaluate the presentation of the disease and the evolution of the radiologic findings. There were 26 male and 16 female patients aged 3 months to 18 years. Twenty-two patients presented with localized disease; 20 presented with multifocal disease. Four patients developed diabetes insipidus. Two patients had organ dysfunction. The radiologic findings were largely due to destructive bone lesions; 83% of the patients had at least one affected bone. Isolated soft-tissue masses, interstitial lung disease, and central nervous system abnormalities were also seen. Of patients in whom results of appropriate follow-up were available, 91% showed improvement in their lesions, 43% developed new lesions, and 92% had good clinical outcomes. LCH is usually a self-limited disease with a varied clinical and radiologic presentation. The prognosis is generally poor in children with organ dysfunction. In the absence of organ dysfunction, children with either localized or multifocal LCH have an excellent prognosis.

Radionuclide studies of the upper gastrointestinal tract in children with feeding disorders

The case of a female infant with a feeding disorder and with inadequate growth is described. In her workup, there was no evidence of an organic disorder. Barium studies of the upper GI tract showed normal anatomy and function. A radionuclide milk scan was helpful in demonstrating mild reflux and significantly delayed gastric emptying. There was a good response to therapy.

Direct vesicoureteral scintigraphy: quantifying early outcome predictors in children with primary reflux

This study quantifies some of the outcome predictors in a group of children with primary vesicoureteral reflux who were initially managed medically.

METHODS

We studied 133 patients with primary reflux for 7.1 +/- 2.2 yr. Direct vesicoureteral scintigraphy (DVS) was used to prospectively measure the absolute bladder volume at which reflux began and the maximum volume of urine refluxed into the ureters during the filling and voiding phases of their first two DVS studies. Findings were related to outcome as defined by spontaneous resolution or the eventual need for reconstructive surgery.

RESULTS

Medical management eventually failed in 35% of this sample. Patients who did not begin to reflux until their bladders had been filled to more than 60% total bladder capacity had a substantially smaller risk of surgery than those who began to reflux at smaller bladder volumes. Patients who refluxed a volume of urine back into their ureters that was less than about 2% of their total bladder capacity had a substantially smaller risk of surgery than those who refluxed more than 2%. The difference between groups was significant for both DVS variables (p < 0.001).

CONCLUSION

Quantitative DVS contributes to the assessment of prognosis in children with vesicoureteral reflux who are managed medically.

Meckel's diverticulum: possible detection by combining pentagastrin with histamine H2 receptor blocker

A Meckel's scan was performed on a 7-yr-old boy because of rectal bleeding. He was premedicated with pentagastrin (6 micrograms/kg subcutaneously) followed by 259 MBq (7 mCi) [99mTc]pertechnetate intravenously. The study was essentially negative. Because of persistent rectal bleeding and a strong clinical suspicion of a Meckel's, a repeat study was performed 6 wk later. He received pentagastrin as before, but this time was also given a histamine H2 receptor blocker (zantac). A Meckel's diverticulum was clearly evident.

Delayed ultrastructural lung maturation in the fetal and newborn hypothyroid (Hyt/Hyt) mouse

Thyroid hormones influence fetal and neonatal lung growth and maturation. However, the effect of naturally occurring, genetically determined hypo- or hyperthyroidism on fetal or neonatal lung maturation has not been examined. In the hyt/hyt mouse, primary hypothyroidism, which is characterized by a high serum TSH concentration, is transmitted as an autosomal recessive trait. It occurs due to a mutational defect in the beta-subunit of the TSH receptor. We studied the lung ultrastructure of the fetal [18-d-gestation (term = approximately 19.5 d)] and neonatal (< 1-d-old) hyt/hyt mouse. In addition, disaturated phosphatidylcholine and total phospholipid contents of newborn hyt/hyt mouse lungs were determined. Male and female hyt/hyt mice with a high serum TSH concentration were made euthyroid by adding 3,5,3'-triiodothyronine to drinking water and then mated. Balb-c mice served as euthyroid controls. Fetal and neonatal hyt/hyt mice had a higher serum TSH concentration than the Balb-c controls. Fetal hyt/hyt mouse lungs showed a large amount of intracellular glycogen and fewer lamellar bodies in epithelial type II cells compared with Balb-c fetal mouse lungs. The neonatal hyt/hyt mouse also showed signs of lung immaturity such as persistent epithelial cell glycogen, few lamellar bodies, reduced disaturated phosphatidylcholine content, and absent tubular myelin. We conclude that fetal and neonatal lung maturation is delayed in the hyt/hyt mouse with primary hypothyroidism.

Ultrastructure of lung in surfactant protein B deficiency

Congenital alveolar proteinosis (CAP), a cause of respiratory failure in fill-term newborns, often leads to death in infancy despite medical therapy. We recently described an inherited deficiency of surfactant protein B (SP-B) (N. Engl. J. Med. 1993; 328:406-410) in two siblings with CAP. The SP-B deficiency was accompanied by marked abnormalities, both quantitative (increase) and qualitative (distribution), of SP-A and SP-C in the lungs of the affected infants. Ultrastructural studies of the lung of one of these infants and of a third affected sibling born in the index family showed abundant alveolar concentric multilamellated structures and membranous vesicles but no typical tubular myelin. In addition, membranous vesicles from type II cells and immunogold labeled SP-A and SP-C were found between type II cells and their basement membrane despite intact interepithelial cell junctions. These findings suggest an important role for SP-B in the directionality of surfactant secretion and in the formation of tubular myelin.

Molecular and phenotypic variability in the congenital alveolar proteinosis syndrome associated with inherited surfactant protein B deficiency

Congenital alveolar proteinosis (CAP) is an often fatal cause of respiratory failure in term newborn infants, which has been associated with a genetic deficiency of surfactant protein B (SP-B) as a result of a frameshift mutation (121ins2) in a family with three affected siblings. In the index cases the deficiency of SP-B was associated with qualitative and quantitative abnormalities of the surfactant proteins A and C. Immunostaining for lung surfactant proteins and a search for the 121ins2 mutation by restriction enzyme analysis of DNA extracted from paraffin-embedded lung tissue was performed for 7 additional affected infants from 6 families, bringing to 10 the total number of patients with CAP who have been studied. In six infants, the surfactant protein immunostaining pattern was similar to that of the index cases. Of these, three patients were homozygous for the 121ins2 mutation; one was a compound heterozygote with the 121ins2 in one allele and a different mutation in the other; and three patients lacked the mutation in both alleles. One infant had an abundance of SP-B, suggesting phenotypic heterogeneity in CAP. Lung ultrastructural abnormalities, such as a reduced number of lamellar bodies, absent tubular myelin, and basal secretion of surfactant lipids and proteins, suggest a significant derangement of surfactant metabolism. The phenotypic heterogeneity in infants with CAP raises the possibility that variable degrees of SP-B deficiency may be more common than previously suspected.

Nephrotic syndrome as an unusual paraneoplastic syndrome of Hodgkin's disease demonstrated on gallium-67 scan

Nephrotic syndrome, although rare, is recognized as one of the paraneoplastic syndromes. A patient with documented Hodgkin's disease showed increased uptake of Ga-67 in the cortex of both kidneys in addition to multiple sites of lymphomatous involvement. The patient was not receiving chemotherapy or any nephrotoxic drugs, and no other reasons that may account for renal uptake of gallium could be identified. The final clinical diagnosis was nephrotic syndrome as an unusual paraneoplastic syndrome of Hodgkin's disease. Gallium imaging was able to detect multiple sites of lymphoma and the renal uptake due to the associated nephrotic syndrome.

Hyperoxia induces interstitial (type I) and increases type IV collagenase mRNA expression and increases type I and IV collagenolytic activity in newborn rat lung

Oxygen toxicity is attributed to the reaction of oxygen metabolites with cellular components leading to cell destruction. Activation of latent human neutrophil interstitial collagenase by reactive oxygen species has been demonstrated. The potential role of collagenases in hyperoxic lung injury has not been investigated. We studied the effect of hyperoxia on newborn rat lung water content, morphology and ultrastructure, interstitial (type I) and type IV collagenase gene expression and type I and IV collagenolytic activity. We observed that hyperoxia causes pulmonary edema, alters newborn rat lung morphology in a sequential manner and produces ultrastructural alterations, induces type I and increases type IV collagenase mRNA expression, and increases type I and IV collagenolytic activity. A role for type I and IV collagenase in hyperoxic newborn lung injury or in the recovery following the injury is proposed.

Comparison of cardiac function tests after anthracycline therapy in childhood. Implications for screening

BACKGROUND

Numerous methods for evaluating cardiac function after cardiotoxic therapy have been suggested. A practical algorithm for screening a large patient population is needed.

METHODS

Seventy-three patients (median age, 15.3 years [range, 9-29 years) who received anthracyclines (median dose, 300 mg/m2 [range, 50-750 mg/m2) for a childhood malignancy underwent a battery of commonly used tests of cardiac function: (1) echocardiographic shortening fraction (ESF); (2) resting and exercise radionuclide scan (multiple gaited acquisition [MUGA]); (3) electrocardiogram (ECG); (4) 24-hour Holter monitor, and (5) questionnaire concerning exercise tolerance.

RESULTS

Patients with an abnormal resting ejection fraction on MUGA were more likely to have an abnormal ESF (P = 0.023), prolongation of the QTc interval (P = 0.014), and complaints of "difficulty" with exercise (P = 0.04). An abnormal results for a resting study was not predictive of an abnormal MUGA exercise response. There was no association between the presence of significant dysrhythmia on Holter monitor and any resting test. An algorithm was developed using a normal ESF and QTc interval, and a negative history of exercise intolerance to identify patients who need not undergo a MUGA. With the use of such an algorithm, 29 of the 73 patients would not have undergone the MUGA, only 2 of whom had an abnormal resting ejection fraction.

CONCLUSION

Patients at risk for cardiac damage after cancer therapy who have normal ESF and QTc interval results and no history of exercise intolerance are unlikely to have abnormal MUGA results. Significant dysrhythmia may be present in the absence of other abnormalities.

Immunogold localization of SP-A in lungs of infants dying from respiratory distress syndrome

Prematurely born infants can develop the neonatal respiratory distress syndrome (RDS) because of a deficiency of pulmonary surfactant. This lipoprotein complex synthesized by type II pneumocytes has different ultrastructural forms--intra- and extracellular lamellar bodies, which within the alveoli are transformed into tubular myelin, and this in turn gives rise to the surface monolayer, the functionally active form of surfactant. We have previously shown that at autopsy RDS lungs lack tubular myelin and have decreased immunoreactivity for antisera to surfactant protein A (SP-A), an important component of tubular myelin. Therefore, we proposed a role for SP-A in the conversion of lamellar bodies to tubular myelin and in the pathogenesis of RDS. To explore this possibility further, we compared in 14 RDS and 14 control lungs the distribution of SP-A in ultrathin sections, using affinity-purified rabbit anti-human-SP-A IgG and goat anti-rabbit IgG-conjugated with 10 nm colloidal gold particles. In controls, gold label was present in lamellar bodies, endoplasmic reticulum, on the cytoplasmic membrane of type II cells, and on lamellar bodies and tubular myelin either within alveoli or macrophages. In RDS lungs, reduced label was present in the same intracellular compartments and organelles, except in tubular myelin, which is absent. It is postulated that if SP-A is indeed necessary for the conversion of lamellar bodies to tubular myelin, in RDS either there is a deficiency of adequate amounts of functional SP-A or some other important component of surfactant is missing.

Orbital wall infarction in sickle cell disease: MR evaluation

Orbital wall infarction in a patient with sickle cell disease can present with periorbital swelling and subperiosteal collection and thus can mimic infection on CT. However, MR not only provides excellent morphologic information but, by characterizing the nature of the collection as containing blood, and by identifying bone marrow abnormality, can lead to the diagnosis of orbital wall infarction.

Managing apparent ureteropelvic junction obstruction in the newborn

A total of 97 newborns with apparent ureteropelvic junction obstruction was evaluated from mid 1984 to 1989. Evaluation and management are described. Of these patients 39 with an affected kidney showing good initial differential function (greater than 35%) by diethylenetriaminepentaacetic acid scan and 2 showing diminished function (less than 35%) were followed nonoperatively. Six patients (15%) eventually required pyeloplasty for diminishing function (4), urinary tract infections (1) or symptoms of colic (1). The 4 patients with diminishing function improved after pyeloplasty to at least the initial level. A total of 12 patients with good initial function (greater than 35%) of the affected kidney underwent early pyeloplasty (within 6 weeks of diagnosis). They were compared to the similar group of patients managed nonoperatively and followed by sequential renal scans. Eventual changes in percentage differential function in the nonoperative and early surgery groups were +2.8% and +4.1%, respectively. Changes in extraction factor were +0.8% (nonoperative group) and +0.9% (surgery group). No statistically significant difference was found. In the kidney with apparent ureteropelvic junction obstruction and good function, an initial nonoperative approach with sequential renal scan followup and pyeloplasty as needed appears to be reasonable and has resulted in no permanent loss of function.

Mechanism of glycine protection in hypoxic injury: analogies with glycine receptor

Addition of glycine to the recirculating perfusate of isolated perfused rat kidneys protects against hypoxic injury to the medullary thick ascending limb and slows functional deterioration in the course of perfusion. This effect is dependent on dose; the earliest significant protection is seen at 0.25 mM, and the protective effects increase as glycine concentration is increased to 2 mM, the highest level tested. Two specific agonists of the strychnine-insensitive (NMDA) glycine receptor in neural membranes, 1-aminocyclopropane carboxylic acid (ACC) and d-serine, also exerted a cytoprotective effect at a concentration of 2 mM. On the other hand, 1-serine and taurine, ineffective agonists of the NMDA-glycine receptor but effective agonists of the strychnine-sensitive glycine receptor, had no protective effect in this system. Two antagonists to glycine at its binding site on the N-methyl-D-Aspartate (NMDA) receptor, 7-chlorokynurenic acid (2 mM) and indole-2-carboxylic acid (12.5 mM), did not reverse the cytoprotective action of 0.25 mM glycine. The data are consistent with a ligand-acceptor type of interaction to account for cytoprotection. The configuration of the glycine acceptor may resemble, but is not identical with, that of certain glycine receptors in the nervous system.

Skeletal scintigraphy of pseudo-osteomyelitis in Gaucher's disease. Two case reports and a review of the literature

Two patients with known type 1 Gaucher's disease had signs and symptoms of osteomyelitis. Decreased perfusion and impaired uptake were seen on bone scan. Patient 1 had a culture-negative aspirate of the site. Patient 2 had no surgical procedures. Both improved on bed rest and nonsteroidal anti-inflammatory agents. It is difficult to distinguish osteomyelitis clinically from pseudo-osteomyelitis. The authors suggest that photopenia on bone scan performed within 1 to 3 days of presentation is suggestive of pseudo-osteomyelitis in Gaucher's disease.