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Biomedical subjects

E Lebenthal

Publications and source records attributed to E Lebenthal.

At least 217 records · Page 12Linked to original sources
PubMed1975

The interrelationship of enterokinase and trypsin activities in intractable diarrhea of infancy, celiac disease, and intravenous alimentation.

Enterokinase initiates digestion of protein by conversion of trypsinogen into trypsin. The interactions between enterokinase and trysin were investigated in 6 patients with intractable diarrhea of infancy and 34 children with celiac disease. The six infants between 2 and 3 months with intractable diarrhea of infancy had reduced mucosal enterokinase activity (9.5 +/- 4.8muM per gram of protein per minute) and reduced intraluminal trypsin activity (2.9 +/- 0.7muM per gram of protein per minute) as compared with healthy controls (109 +/- 34.2muM per gram of protein per minute and 14.3 +/- 5.8muM per gram of protein per minute) respectively. The activities of all enzymes returned toward normal following treatment with intravenous alimentation. The mucosal morphology of all pretreatment biopsies in all cases showed Grade III atrophy which improved. These findings suggest that enterokinase deficiency and reduced intraluminal trypsin activity in intractable diarrhea of infancy may be one of the contributing factors to protein malabsorption and consequent malnutrition. Thirty-four children with celiac disease were between the age of 9 months and 13 years. The 11 newly diagnosed patients with celiac disease demonstrated Grade III to IV atrophy of the mucosa. The 23 patients with treated celiac disease on a gluten-free diet showed a normal to Grade II atrophy. In both treated and untreated celiac disease the enterokinase activities and the intraluminal trypsin activity were within normal limits. The enterokinase activity in celiac disease is near normal in contrast to the marked reduction noted in intractable diarrhea of infancy even though the intestinal mucosa shows marked morphological alteration and the disaccharidase activities are greatly reduced in celiac disease. After a prolonged alimentary fast of up to 26 days on intravenous alimentation, two patients with intractable diarrhea of infancy showed improvement in the activities of enterokinase and trypsin. These findings demonstrate that enterokinase and trypsin activities in the gut were present and improved in the absence of oral feeding.

Adolescent↗
PubMed1972

Effect of carbohydrate and corticosteroids on activity of -glucosidases in intestine of the infant rat.

The activities of intestinal sucrase and isomaltase are not detectable in rats before 15-16 days of age, but administration of corticosteroids precociously induces the activities of these two alpha-glucosidases. 9-day old rats were removed from their mothers, warmed in an incubator, and fed by constant infusion through gastrostomies. The basic diet was a soya preparation to which various sugars were added. When the diet contained 2% sucrose, diarrhea ensued for 48 hr, but subsided when intestinal sucrase and isomaltase appeared precociously. In animals fed sucrose, the activities of sucrase and isomaltase were markedly increased as compared to animals on carbohydrate-free diets (sucrase 2.41+/-0.23 vs. 0.63+/-0.13 U, isomaltase 3.43+/-0.42 vs. 0.78+/-0.18 U). Maltase activity was doubled, while lactase was not altered significantly. The mitotic index of crypt cells, the depth of crypts, and incorporation of thymidine-(3)H into DNA were increased. In adrenalectomized rats, activities of sucrase and isomaltase were not detected nor induced by sucrose. Steroids given to adrenalectomized rats caused appearance of the enzymes; but if cortisone and sucrose were given together, there was synergism evidenced by a marked increase in activities (sucrase 7.2+/-1.1 vs. 0.68+/-0.12 U). In contrast to observations in adult animals, the effect of sucrose on alpha-glucosidases in developing animals demands the participation of the adrenal gland.

Adrenal Glands↗
PubMedDate not supplied

Increased serum antibody levels against cow's milk proteins in children with chronic liver disease.

We measured IgG, IgM and IgA antibodies to cow's milk proteins: alpha-casein, alpha-lactalbumin, bovine serum albumin, beta-lactoglobulin-a and beta-lactoglobulin-b in the sera of 29 pediatric patients with liver disease. IgG antibodies to bovine serum albumin, beta-lactoglobulin-a and beta-lactoglobulin-b and IgA antibodies to alpha-casein were elevated in most of the patients compared to age-matched controls. We postulate that, in patients with liver disease either increased intestinal uptake resulting in increased humoral response, or decreased hepatic clearance of food antigens intensifying a humoral response to these foreign antigens, may occur.

Adolescent↗
PubMedDate not supplied

The effect of dexamethasone and glucagon on the expression of hepatocyte plasma membrane proteins during development.

The regulation of different maturational processes in the liver is believed to be influenced by the hormonal system. The aim of this study was to investigate the effect of two hormones, glucagon and dexamethasone, on levels of plasma membrane proteins in rat liver cells during late fetal and early postnatal stages of development. For this purpose, 18-day-old rat fetuses and 1-day-old newborns were treated with glucagon or dexamethasone and killed at 22 days of gestation and 3, 5 and 7 days of age, respectively. Postnuclei liver membranes were isolated using a sucrose gradient method and assessed for levels of specific membrane proteins. Asialoglycoprotein receptor and 110,000 Mr glycoprotein, denoted GP 110, representing the sinusoidal and bile canalicular domains, respectively, were quantitated using the immunoblot method. Membrane enzymes alkaline phosphatase, leucine aminopeptidase and gamma-glutamyl transferase were evaluated using enzymatic methods. The data showed that glucagon and dexamethasone have a differential effect on membrane constituents according to the stage of development. Glucagon increased the levels of membrane enzymes during the late fetal stage but had no effect on liver membrane proteins in the newborn animal. In contrast, although dexamethasone elevated GP 110 in fetal rat livers, none of the other marker proteins was significantly affected. On the other hand, in newborns dexamethasone reduced the amount of asialoglycoprotein receptor and alkaline phosphatase and leucine aminopeptidase enzyme activities but greatly augmented the level of gamma-glutamyl transferase. Thus, glucagon primarily affects plasma membrane proteins in late gestation while dexamethasone does so during the early postnatal period. The roles that these two hormones may play during ontogeny is discussed with respect to liver development.

5'-Nucleotidase↗
PubMedDate not supplied

Modified food starches in baby foods.

Modified food starches were developed as a stabilizer, providing desirable consistency, texture, and storage ability. They are used primarily in strained and junior foods and, to a minor extent, in infant formulas. However, despite the fact that there is an increasing tendency to introduce solid foods to infants at a very early age, there is few long-term studies to delineate the effect of starch feeding on the growth of young infants. Modified food starches used by the food industry for infants and young children are of concern and there is an urgent need for additional data regarding their bioavailability, effect on nutrient absorption, intestinal changes, and toxic, mutagenic, and carcinogenic effects. Therefore, the inclusion of modified food starches should be used prudently and sparingly.

Animals↗
PubMedDate not supplied

Pancreatic exocrine enzymes during the neonatal period in postmature rats.

Pancreatic content of exocrine enzymes in newborn rat pups shows a sharp decline soon after birth. To investigate if this decline is a preprogrammed and, therefore, inherently controlled phenomenon, or a result of external stimulus, prolonged gestation, or postmaturity (2 extra days in utero) in pregnant dams was induced by daily subcutaneous injection of progesterone from the 20th to 22nd days of gestation. Postmature pups showed the same high levels of lipase, trypsin(ogen), and amylase as control pups at birth. They also exhibited the same decline in these enzymes as control pups by the 2nd day after birth, suggesting that it is a response to external stimulus. Pups prevented from suckling retained the high levels of lipase, amylase, and trypsin(ogen) by the 2nd day. The stimulus, therefore, appeared to be the initiation of suckling. Pups prevented from suckling but given 5% glucose water orally every 4 h starting from birth for 24 h showed a sharp decline in amylase with only slight decreases in lipase and trypsin(ogen) by the 2nd day. The components in the feed, therefore, also seem to be an important determinant for selective enzyme release from the pancreas of the neonates. Electron microscopic studies revealed a sharp decrease in the number of zymogen granules in the continuously-suckled pups as compared to age-matched non-suckled counterparts. The reduction in enzyme content thus is the result of secretion in response to suckling.

Amylases↗
PubMedDate not supplied

Chronic diarrhea: causes, presentation, and management.

Important inroads are being made into understanding the pathophysiology of diarrhea. Clear understanding of key mechanisms should suggest new approaches to combat disease. Exciting developments are occurring in terms of super-ORS solutions, particularly with the promise of short chained glucose polymers and glutamine. Perhaps the most important development is the prospect of a good rotavirus vaccine being available before the end of the decade. Chronic diarrhea seems to be on the increase globally, probably because of the success of ORS. The mechanisms that lead to mucosal injury are elusive, and therapy still largely supportive and empiric. Celiac disease continues to be a puzzle, because of the uncomfortable feeling that a majority of cases may be missed because of atypical presentations. The successful use of long term parenteral nutrition has allowed survival and better characterization of cases that otherwise would have perished as 'lethal protracted diarrhea'. Microvillus inclusion disease may be the commonest congenital secretory diarrhea. The role of the recently reported high prevalence of glucoamlase deficiency may be important. Lastly, attention to micronutrients, particularly low vitamin A and probably zinc may prove to be important in prevention and amelioration of diarrhea and growth failure.

Child↗
PubMedDate not supplied

An optimal rice-based oral rehydration solution: the effect of different concentrations of amylase on production of short chain polymers of glucose.

As part of a plan to develop a rice-based oral rehydration solution containing short polymers of glucose instead of glucose, we determined the concentration of amylase that would yield the largest amount of short chain polymers. Thai rice (25 g) was boiled with 500 ml of distilled water for 30 min. Of 200 ml supernatant rice water obtained, 100 ml were digested with different amounts of amylase after cooling to 50 degrees C for 60 min, boiled for 5 min, and centrifuged (10,000 g, 25 degrees C) for 60 min. The resulting supernatant (80 ml) was freeze-dried; 1.75 g of the powder obtained were dissolved in 3.5 ml of water, passed through a Bio-Gel P2 column to separate short chain polymers (2-9 molecules of glucose) and long chain polymers (> 9 molecules of glucose), which were identified by spectrophotometry (lambda = 190 nm) or by high performance liquid chromatography. Ten mg of amylase (equivalent to 12,000 modified Wohlgemath units) per 100 ml of rice water was optimal for the production of short polymers of glucose from rice.

Amylases↗