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Biomedical subjects

E Lebenthal

Publications and source records attributed to E Lebenthal.

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

Localization of the neuronal class III beta-tubulin isotype in foci of early neuritogenesis supports divergent neuroblastic differentiation potential in Wilms' tumors.

Wilms' tumors are embryonic neoplasms that have been proposed to originate from the metanephric blastema and are capable of divergent epithelial and mesenchymal differentiation. Neuroepithelial differentiation in these tumors remains controversial. The aim of this study was to examine the phenotypic profile of certain neuronal and glial antigenic determinants in a series of 21 Wilms' tumors. Immunohistochemical studies were performed by using monoclonal antibodies against the neuronal class III beta-tubulin isotype (beta III), the phosphorylated and phosphorylation-independent epitopes of neurofilament protein, and synaptophysin; antisera to gamma-enolase (neuron-specific enolase) glial fibrillary acidic protein, and S100 protein were also used. Foci of neoplastic cells with neurite-like processes that exhibited intense beta III staining were demonstrated in blastemalike areas of three of 21 tumors. In one case, Homer Wright rosettes (stained for beta III) were identified. Areas of abortive neuritic development were also labeled with antibodies to gamma-enolase. No reactivity was obtained in these foci for phosphorylated and phosphorylation-independent epitopes of neurofilament protein, synaptophysin, glial fibrillary acidic protein, and S100 protein. The remainder of the tumors (18 of 21) were negative with the panel of neural markers. Our results indicate that divergent neuroblastic differentiation, evidenced as early neoplastic neuritogenesis, may be present in the blastematous component of Wilms' tumor subsets.

Antibodies, Monoclonal↗
PubMed1994

Maturational response of colonic and renal Na+,K(+)-ATPase activity to K+ load and betamethasone in preterm rats.

Preterm human infants demonstrate high fecal K+/Na+ ratio that is inversely related to maturation. Renal and colonic basolateral membrane-located Na+,K(+)-adenosine triphosphatase (Na+,K(+)-ATPase) governs K+ excretion and is enhanced by both steroid administration and K+ loading. However, the response of premature kidney or colon to these stimuli is not well studied. We measured basal as well as stimulated levels of renal and colonic Na+,K(+)-ATPase activity in response to betamethasone and K+ load given separately and betamethasone given after K+ load in premature, mature, and 4-day-old Sprague-Dawley rats. Although preterm rats showed a higher basal level in the kidneys (p < 0.004), an increase in enzyme activity in response to the stimuli was achieved only in the colon (p < 0.001 for betamethasone, p < 0.0001 for K+ load, and p < 0.0007 for the combination). At term and at 4 days of postnatal age, however, the kidneys showed much higher levels than the colon in response to stimuli (p < 0.0001 for all) except for betamethasone at term. The response of colonic tissue of preterm and term rats to betamethasone given 4 days after a K+ load was less marked than response to betamethasone or K+ load given separately (p < 0.001). The stimulated levels achieved in the preterm colon were higher than the basal preterm renal values (p < 0.001). The tissue K+ content increased in response to K+ load in only the preterm colon (p < 0.05). We have demonstrated a tissue specificity in the development of Na+,K(+)-ATPase activity in K+ excretory organs of rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1993

Absorption of glucose polymers from rice in oral rehydration solutions by rat small intestine.

BACKGROUND: This study aims to determine the effect of replacing glucose in oral rehydration solution (ORS) with starch hydrolysates from rice on absorption in the small intestine and levels of glucose in portal venous blood and on disaccharidase levels and morphometric measurements in intestines of rats. METHODS: ORS containing standard composition of salts and 2% glucose (WHO ORS) or 2%, 5%, or 10% starch hydrolysates were infused into duodena of 60 Sprague-Dawley rats (250-350 g). Portal venous blood glucose levels were determined at 0, 30, 60, 90, and 120 minutes. RESULTS: Significantly larger areas under the curve of glucose absorption (AUCs) were produced by ORS containing 10% unfractionated starch hydrolysates (123.2 +/- 3.8), 2%, 5%, and 10% starch hydrolysates with long-chain ( > 9 molecules) glucose polymers (109.5 +/- 10.6, 109.3 +/- 7.4, and 115.3 +/- 7.1, respectively), and 5% and 10% starch hydrolysates with short-chain (2-9 molecules) glucose polymers (124.4 +/- 6.1 and 128.1 +/- 6.8). ORS with 2% and 5% unfractionated starch hydrolysates and 2% short-chain glucose polymers produced AUCs comparable with those of WHO ORS (96.48 +/- 5.7). Disaccharidase levels and morphometric measurements were not significantly different. CONCLUSIONS: Starch hydrolysates from rice containing glucose polymers can be used in ORS in higher concentrations than glucose to provide higher caloric density without increased osmolality.

Animals↗
PubMed1993

Perinatal food restriction in rats reduces the content but not concentration of liver extracellular matrix proteins.

Fibrosis of the liver has been reported to be associated with malnutrition, based on qualitative histological and histochemical approaches. The aim of this study was to quantitatively examine the effect of perinatal food-restriction on the expression of extracellular matrix components of the liver, using rats fed 50% of ad libitum intake, determined by the food consumption of the control group on the previous day. Levels of extracellular matrix proteins were measured by dot blot analysis using monospecific antibodies against collagen types I, III and IV, laminin and fibronectin. The body weights of 4, 8 and 13-wk-old malnourished groups were 25, 35 and 48% of the control group body weights, respectively, and the liver weights were 22, 32 and 60% of the controls. The total contents of the extracellular matrix components were significantly reduced to 30, 34 and 58% of the controls, but when expressed per tissue or per milligram protein there were no significant differences. Indirect immunofluorescence revealed no major changes in extracellular matrix localization. The major histological change in the food-restricted rats was fatty infiltration. Our observations suggest that the effect of perinatal food restriction is mainly liver steatosis, and that the liver of food-restricted animals during the perinatal period has the capacity to preserve its main extracellular matrix components.

Animals↗
PubMed1993

The pre- and postnatal development of Na+/K(+)-ATPase in gastrointestinal organs of the rat: effect of betamethasone treatment.

Developmental changes in Na+/K(+)-ATPase enzyme activity have been documented postnatally in a number of organs, but little is known about prenatal levels or the factors affecting them. This study determined the normal developmental patterns of Na+/K(+)-ATPase activity in the pancreas, liver, small intestine, kidneys, and colon of pre- and postnatal rats. In addition the effect of betamethasone administration on enzyme activity was determined both antenatally and postnatally. The individual organs showed a variable pattern of maturational change in enzyme activity. In the pancreas, changes in Na+/K(+)-ATPase activity appeared to reflect the changing ratio of ductular to acinar cells. The pattern of enzyme activity in the small intestine was similar to that of the kidney and was inversely related to that of the colon. Enzyme induction by administration of betamethasone was also variable and bore no relationship to the DNA/protein ratio. In the preterm rat, betamethasone increased the Na+/K(+)-ATPase activity only in the colon. Use of steroids to increase enzyme activity in the colon at an early stage of development may have therapeutic implications for treating abnormalities of potassium and sodium homeostasis in the preterm infant.

Animals↗
PubMed1992

Chylous ascites: total parenteral nutrition as primary therapeutic modality.

A female infant with Down syndrome and congenital chylous ascites presented at birth with respiratory distress secondary to marked abdominal distension. Total parenteral nutrition (TPN) and paracentesis were the primary therapeutic modality. On hyperalimentation, however, ascites initially recurred, requiring additional paracenteses to improve respiratory distress. The chylous ascites, lymphopenia and hypoalbuminemia were relieved after 10 weeks of TPN administration. We recommend a long-term course (10 weeks) of TPN before an exploratory laparatomy and possible surgical intervention are considered.

Chylous Ascites↗
PubMed1992

Transport of glucose polymer-derived glucose by rabbit jejunum.

Mechanisms for the assimilation of glucose polymers have been inferred from perfusion studies. To further define these mechanisms, the results of measurements of unidirectional glucose fluxes across short-circuited rabbit jejunal segments in vitro are reported. Glucose polymer-stimulated short-circuit current was similar to that of glucose [19 +/- 6.0 microA/cm2 (n = 7) and 26 +/- 5.7 microA/cm2 (n = 13), respectively] and was inhibited by both acarbose and phlorizin. Acarbose, an alpha-glucosidase inhibitor with no effects of glucose transport, was used to uncouple digestion from absorption. Mucosal-to-serosal flux of glucose polymer-derived glucose was lower than that of an equal weight/volume of glucose [124 +/- 62 nmol.h-1.cm-2 (n = 4) vs. 452 +/- 121 nmol.h-1.cm-2 (n = 6); P less than 0.05] and was inhibited by both phlorizin and acarbose. No glucose polymers were detected in the serosal bath solutions by thin-layer chromatography. It is concluded that glucose polymer-derived glucose is transported by a phlorizin-inhibitable process at a rate slower than that of free glucose, a finding that suggests that hydrolysis limits glucose polymer assimilation.

Analysis of Variance↗
PubMed1991

Essential role for polyamine biosynthesis in thyroxine stimulated pancreatic development in neonatal rats.

Administration of thyroxine to rat pups leads to precocious development of the pancreas. The role of ornithine decarboxylase (ODC) and polyamines in thyroxine-induced pancreatic maturation was examined. Rat pups (aged 5 days) were given daily subcutaneous injection of thyroxine (0.1 micrograms/g body wt.) until the day before death. Serial ODC activities were measured in pancreatic homogenates after 1, 2, 3, 4, 5, 6, 7 and 10 days of thyroxine treatment. There was a biphasic induction of ODC activities by thyroxine: an early peak appeared on day 2 of treatment followed by a decrease on day 4; a second peak was evident on day 5 and then a decrease to control values by day 7. Significant increases in tissue concentrations of putrescine and spermidine were observed concomitant with two peaks of ODC activity. Pancreatic amylase concentration, DNA and protein also showed a significant increase after thyroxine treatment. Difluoromethyl ornithine (DFMO), a specific ODC inhibitor, given orally (8% in drinking water) to nursing dams at postnatal day 5 for 5 days caused an 83% inhibition of pancreatic ODC activity in thyroxine-treated pups when compared to thyroxine-treated pups not exposed to DFMO. Concomitantly, the thyroxine-induced increases in pancreatic weight, protein and amylase activity were suppressed. Our results suggest that increases in ODC activities and polyamine levels are critical intermediary steps in the precocious induction of pancreatic development by thyroxine.

Amylases↗
PubMed1991

Gallstones in children. Characterization by age, etiology, and outcome.

Fifty children and adolescents were found to have gallstones at Children's Hospital of Buffalo (NY) during a period of 10 years. The mean (+/- SD) age was 12.2 +/- 6.2 years, with 21 boys and 29 girls. The majority of patients could be categorized into four groups: hemolytic disease (18 patients), parenteral nutrition (eight patients), adolescent pregnancy (seven patients), and idiopathic (10 patients), while seven patients had a variety of other etiologies. Right upper quadrant pain was the most common symptom (32 patients), followed by jaundice (15 patients), vomiting (13 patients), and nonspecific abdominal complaints (13 patients). Ten patients presented with jaundice and underlying hemolytic disease; seven patients were asymptomatic. Clinical presentation was found to vary with age and factors associated with the development of gallstones. Ultrasonography was the mode of diagnosis in 48 patients. Cholecystectomy was performed in 36 patients. In contrast to gallstones in adults, after exclusion of the patients with adolescent pregnancy, there was no female predominance. Pancreatitis was the most common complication, occurring in 8% of the patients; cholecystitis and cholangitis were absent.

Adolescent↗
PubMed1991

Levels of Cu-Zn and Mn superoxide dismutases in rat liver during development.

Superoxide dismutase is the main scavenger of superoxide radicals in the mammalian body. The liver has high levels of two types of superoxide dismutase enzymes, cytosolic Cu-Zn and mitochondrial Mn enzymes. The aim of the present study was to investigate the content of two distinct superoxide dismutases in liver during the perinatal transition from a hypoxic to a hyperoxic environment. Both isozymes were purified to homogeneity and used as immunogens in rabbits. Antisera raised were found to recognize only polypeptides of molecular weight 16,900 or 23,400, which correspond to Cu-Zn and Mn superoxide dismutases, respectively. It was found that the level of Cu-Zn superoxide dismutase enzymatic activity and protein as assessed by immunoquantitation increased 10-fold during the postnatal period, reaching adult levels by 3 weeks. In contrast, the amount of Mn superoxide dismutase content increased only twofold to adult levels during the first week of life. Neither of the superoxide dismutases showed an alteration in specific activity or apparent molecular weight in rat livers during ontogeny. These results show that the levels of two intracellular superoxide dismutases are differentially elevated during the perinatal period. It is suggested that each dismutase plays a different physiological role for superoxide scavenging in liver as a function of the hypoxic/hyperoxic environment at birth.

Animals↗
PubMed1991

Short-chain glucose polymer and anthracene-9-carboxylic acid inhibit water and electrolyte secretion induced by dibutyryl cyclic AMP in the small intestine.

Glucose-stimulated sodium absorption is the rationale for treatment with glucose-based oral rehydration solution in diarrhea. Concurrent treatment with pharmacological inhibitors, which specifically block chloride secretion, may be a useful adjunct to oral fluid therapy. To examine this hypothesis, the authors determined the intestinal water and ion transport rates in rat small intestine during the secretory phase induced by perfusion with N6-2'-0-dibutyryl adenosine 3',5'-cyclic monophosphate (dbcAMP), 1.0 mmol/L. A marker (polyethylene glycol 4000) dilution technique was used to evaluate the antisecretory effects of a defined short-chain glucose polymer, D-glucose, and a chloride channel blocker, anthracene-9-carboxylic acid (A-9-C). The results showed that dbcAMP induced small intestinal water and chloride ion secretion rapidly and reliably. The 2.5% concentration of rice short glucose polymer (G2, 22.7%; G3, 28.2%; G4, 14.0%; G5, 16.6%; G6, 11.6%; G7-9, 6.9%) is a better carbohydrate than the 2.5% concentration of D-glucose in reversing secretion of water, chloride, and sodium ions induced by dbcAMP. The combination of A-9-C and the glucose polymer can reverse dbcAMP-induced intestinal secretion and produces significantly (P less than 0.05) better antisecretory effect on water, sodium, and chloride ions than D-glucose with A-9-C.

Animals↗
PubMed1991

Glucose polymers as an alternative to glucose in oral rehydration solutions.

Several issues involving glucose-based oral rehydration therapy may limit its acceptability and sustained use. Our studies suggest that defined short-chain glucose polymers (2 to 9 glucose units) are hydrolyzed and absorbed faster than isocaloric solutions of D-glucose in the small intestine of the rat. Glucose polymers, primarily from rice-based solutions, have been shown to be as effective as glucose-based solutions. They offer additional advantages in reducing the amount and duration of diarrhea with lesser volumes of solution, thereby reducing the costs of treatment. Rice-based solutions provide high caloric density and increase the absorption of sodium without an osmotic overload. The result is increased net absorption of glucose, sodium, and water. Glucose polymers from rice or other starches in oral rehydration solutions may be effective, inexpensive, easily used, and safe treatments for acute diarrhea.

Animals↗
PubMed1991

A new direct pancreatic function test in pediatrics.

Traditional methods for collecting duodenal fluid are time consuming and technically difficult. A simple endoscopic method is proposed in this report as a means of collecting duodenal fluid to perform exocrine pancreatic function tests. Thirty-five patients between 24 and 36 months of age were studied for pancreatic exocrine function. Twenty-seven presented with chronic diarrhea and 8 with failure to thrive. In 20 patients (group 1), duodenal fluid was collected by means of a double-lumen tube and sequential administration of pancreozymin (PZN) and secretin (SEC). The rest (group 2) had duodenal aspiration from the level of the papilla of Vater through a fiberoptic endoscope following administration of SEC only. The procedure took approximately 3 h in group 1 and 45 min in group 2. Secretin administration produced comparable levels of enzymes in both groups. Pancreozymin produced the highest enzyme levels, but this was only significantly higher than SEC-induced levels in the case of lipase. Endoscopic collection of duodenal fluid following SEC administration is a safe, quick, and reliable method of collecting pancreatic secretion.

Child, Preschool↗