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Biomedical subjects

S Heyman

Publications and source records attributed to S Heyman.

At least 37 records · Page 2Linked to original sources
PubMed1994

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.

Female↗
PubMed1994

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.

Adolescent↗
PubMed1994

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.

Animals↗
PubMed1994

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.

Autopsy↗
PubMed1994

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.

Animals↗
PubMed1994

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

UNLABELLED: 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.

Child↗
PubMed1994

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.

Child↗
PubMed1993

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.

Adolescent↗
PubMed1993

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.

Extracellular Space↗
PubMed1992

Effects of hypnosis on plasma proenkephalin peptide F and perceptual and cardiovascular responses during submaximal exercise.

Little information is available concerning the influence of subconscious mechanisms on neuroendocrine function, more specifically, proenkephalin peptide F release. Ten men [5 middle distance runners (21.6 (SD 0.54 years) and 5 untrained men (24.0 (SD 4.3 years)] consented to be volunteers in this investigation. Submaximal exercise intensities of 25% and 50% of peak oxygen consumption (VO2) (8 min stages) were used for both the control and hypnosis treatments. A traditional hypnotic induction was used, with the suggestion of two higher intensities of exercise stress (50% and 75% peak VO2) previously experienced in familiarization and testing by each subject. Each minute oxygen consumption was measured using open circuit spirometry, heart rate via an ECG, and ratings of perceived exertion (RPE) using the Borg scale. Plasma peptide F immunoreactivity (ir) [preproenkephalin-(107-140)] in blood sampled from an indwelling cannula was measured by radioimmunoassay at 7-8 min of each stage of the exercise test. Expected significant increases were observed for all cardiorespiratory and perceptual variables over the increasing exercise intensities and there were no significant differences between trained and untrained groups for peptide F if response patterns. Hypnosis did not significantly affect peptide F ir concentrations (P > 0.05) and did not significantly alter exercise heart rate, RPE or minute ventilation (P > 0.05). However, hypnosis did significantly increase oxygen consumption during exercise (P = 0.0095) but not of the magnitude needed for the metabolic demands of the higher exercise intensities. Thus, traditional hypnosis was unable to make functionally significant changes in the cardiorespiratory variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

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.

Follow-Up Studies↗
PubMed1992

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.

Animals↗
PubMed1992

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.

Bone and Bones↗
PubMed1992

Potential deleterious effect of furosemide in radiocontrast nephropathy.

The purpose of the study was to determine the efficacy of furosemide in addition to intravenous fluids in the prevention of radiocontrast nephropathy. 18 patients, referred to a radiocontrast study, considered at risk because of preexisting renal insufficiency, were enrolled in a prospective, randomized, controlled trial, performed at the secondary care center of a 1,100-bed private university hospital. In addition to fluids, the treatment group received furosemide (mean dose 110 mg) intravenously 30 min prior to the injection of contrast material. The control group received fluids (mean 3 liters). Radiological studies were mostly angiographies performed with both ionic and non-ionic contrast material, at an average dose of 245 ml. Renal function significantly deteriorated in the group pretreated with furosemide (p < 0.005 by ANOVA), with a rise in serum creatinine from 145 +/- 13 to 182 +/- 16 mumol/l at 24 h, while no change occurred in the control group (from 141 +/- 6 to 142 +/- 7 mumol/l). Renal failure was associated with weight loss in the furosemide-treated group. Furosemide may be deleterious in the prevention of radiocontrast nephropathy.

Acute Kidney Injury↗
PubMed1991

Multiple foci of increased accumulation of Ga-67 citrate in a horseshoe kidney. Differentiation of infection from nephroblastomatosis.

In the proper clinical setting, Ga-67 citrate appears to be a highly valuable radionuclide which may be used to differentiate an infectious process in the kidney from nephroblastomatosis. The authors present the case of a 7-year-old boy with multiple well-circumscribed foci of intense Ga-67 citrate accumulation in a horseshoe kidney. After a 2-week course of antibiotic therapy, the kidney showed significant improvement.

Bacterial Infections↗