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Biomedical subjects

E Lebenthal

Publications and source records attributed to E Lebenthal.

At least 199 records · Page 11Linked to original sources
PubMed1978

Disaccharidase activities in small intestinal mucosa in patients with cystic fibrosis.

The disaccharidase activities in small intestinal biopsies were related to the morphology of the mucosa and the ages of 63 patients with cystic fibrosis and 177 healthy control subjects of Caucasian origin. In patients with CF and in the healthy control subjects under 5 years of age with normal intestinal mucosa, no low lactase activity was found. In those patients with CF who were over 5 years of age, one group had high and one group had low lactase activity, as occurs in healthy Caucasian control subjects of the same age. This finding supports the view that in patients with CF, lactase deficiency is not related to the disease entity. In patients with or without CF who had the same degree of mucosal atrophy, the decrease of disaccharidase activities followed the same pattern, indicating that enzyme activities are affected to the same extent by the damage of the mucosa. In patients with CF with pancreatic insufficiency, the disaccharidase activities were significantly (P less than 0.001) higher when compared to those in control subjects of the same age and ethnic group, although the increase was not uniform in all patients with cystic fibrosis.

Atrophy↗
PubMed1977

Subcellular localization of enterokinase (enteropeptidase EC 3.4.21.9) in rat small intestine.

The subcellular localization of enterokinase is controversial. In this study, enterokinase was extracted from a soluble fraction and a brush border fraction of rat small intestine by differential centrifugation. The soluble fraction contained 41% of the initial enterokinase activity while the brush border fraction contained only 4.6% of the initial activity. In contrast, alkaline phosphatase monitored as a brush border marker, yielded 26.3% in the brush border fraction and only 6% in the soluble fraction. Further separation of the soluble fraction on a Sepharose 4B column revealed three peaks of enterokinase activity. One small peak (3%) of a bound enzyme (Mr, 2 - 10(6)) and two larger peaks of free enzyme (Mr, 3 - 10(5) and 9 -10). In contrast, alkaline phosphatase major fraction was in a high molecular weight peak of bound enzyme. When the brush border fraction was chromatographed only a single peak of bound enterokinase and alkaline phosphatase were found. In the lower part of the small intestine, no brush border-bound enterokinase was found, while the peak of alkaline phosphatase was the same as in the upper intestine. These data suggest that enterokinase activity in the rat intestine is mainly in a free form localized in the mucin and soluble fraction and to a negligible extent in the brush border.

Alkaline Phosphatase↗
PubMed1977

Disaccharidase and lysosomal enzyme activities in amniotic fluid, intestinal mucosa and meconium. Correlation between morphology and disaccharidase activities in human fetal small intestine.

Brush border membrane bound disaccharidases (sucrase and maltase) and lysosomal enzyme (alpha-glucosidase, beta-D-fucosidase and N-acetyl-beta-glucosaminidase) activities awere studied in amniotic fluid (AF). The above enzymes except N-acetyl-beta-glucosaminidase showed a decrease in activity with gestational age beginning at about the 19th week. The activities of sucrase and maltase correlate with the morphological maturation of fetal intestinal mucosa. The distribution of disaccharidases and lysosomal alpha-glucosidase in AF and intestinal mucosa showed different patterns suggesting that these enzymes originate in diverse fetal tissues.

Acetylglucosaminidase↗
PubMed1977

Induction of fetal rat enterokinase (enteropeptidase EC. 3.4.21.9) in utero by hydrocortisone and actinomycin D.

Enterokinase activity is first detected in the small intestine of the rat at the 20th day of gestation, whereas sucrase activity first appears in the 14th day of postnatal life. Intraperitoneal injection of hydrocortisone to pregnant rats before the normal appearance of enterokinase in fetuses causes the premature appearance of enterokinase (58 +/- 8 units), but not of sucrase activity. The addition of actinomycin D in the pregnant rat results in supermaximal stimulation of enterokinase activity (229 +/- 25 units). Sucrase activity is stimulated by hydrocortisone when given in the first 3 days of life (118 +/- 0.04 units). The maximal induction occurs 2 days before the normal appearance of the enzyme in untreated animals (7.3 +/- 12 units). The addition of actinomycin D diminished the effect of hydrocortisone on sucrase activity in the neonatal rat (1.4 +/- 2 units versus 1.8 +/- 0.4 units in 3-day-old rats). Thus, enterokinase and sucrase of the small intestine of the fetal and infant rat respond differently to combined hydrocortisone and actinomycin D. The response to hydrocortisone is age dependent and the maximal induction occurs before the time of the natural appearance of the enzymes. No effect is elicited after the normal appearance of enterokinase or sucrase. Glucocoticoids stimulate an early appearance of small intestinal enzymes only before the expected time of the natural development burst of activity. In both, sucrase and enterokinase, glucocorticoids have no effect after the enzymes are fully developed. New enzymes develop in clusters during the late fetal, neonatal, and late sucking periods. The effect of glucocorticoids on the "maturation" of the small intestine is limited to the induction of one phase only; i.e., only before the late fetal period is the precocious appearance of enterokinase possible. The induction of enterokinase activity can serve as an indicator for the early phase of maturation. Whereas the induction of sucrase activity can serve as a marker for late phase of maturation of the small intestine in the rat. The superinduction of enterokinase, but not of sucrase activity, by the addition of actinomycin D to glucocorticoids might be related to the different stability of the mRNA's of these enzymes.

Age Factors↗
PubMed1977

Developmental pattern of small intestinal enterokinase and disaccharidase activities in the human fetus.

The concomitant appearance of enterokinase (EK) and trypsin activities in the human intestinal mucosa is indicative of the importance of EK as an activator of trypsinogen and therefore as the key enzyme in protein digestion. Enterokinase can be detected in fetal mucosa from the 26th week of gestation on, paralleling appearance of tryptic activity in meconium. The developmental pattern of EK activity increases with age. Between 26 to 30 weeks of gestation, the EK activity is only 6% and full term babies (40 weeks) 20% of that found in older children. In contrast, lactase studies during development show a lactase activity of only 30% in human fetuses between 26 to 34 weeks of gestation as compared to full term babies. During the same gestational period, sucrase and maltase activities reach 70% of the full term. In addition, the distributional pattern of EK differs from the disaccharidases, showing the highest activity in duodenum and the lowest in ileum, whereas disaccharidases are highest in jejunum with lower activity in duodenum and ileum. Differences in topographical distribution and time of appearance of EK and disaccharidases may be attributed to differences in orgin as well as subcellular localization of these enzymes. It is conceivable that the premature infant, between 26 to 30 weeks of gestation, is better equipped to deal with hydrolysis of alpha-glucosides than of lactose.

Disaccharidases↗
PubMed1976

Enterokinase and trypsin activities in pancreatic insufficiency and diseases of the small intestine.

The interrelationship of enterokinase and trypsin activities were investigated in 133 infants and children with a variety of gastrointestinal and pancreatic disorders. Fourteen patients with diarrhea and grade II mucosal injury revealed a significant (P less than 0.01) reduction of enterokinase, trypsin, and disaccharidase activites as compared to 59 children with normal mucosa. Nine patients with cystic fibrosis and pancreatic insufficiency had normal mucosal enterokinase activity and elevated intraluminal enterokinase activity with very low or no trypsin activity. Patients with hypoproteinemia and gastrointestinal protein loss, associated with intestinal lymphangiectasia (4 patients) and intestinal lymphoid nodular hyperplasia (3 patients), had normal or insignificant decrease of enterokinase and trypsin activities. In patients with steatorrhea, a normal sweat test, normal intestinal mucosa, and absent trypsin activity, two entities were defined. One group (3 patients) was diagnosed as Schwachman-Diamond syndrome with pancreatic insufficiency and normal mucosal and intraluminal enterokinase activity. The second group (2 patients) with absent mucosal and intraluminal enterokinase activity and normal lipase and amylase activities was diagnosed as congenital enterokinase deficiency.

Child↗
PubMed1975

Correlation of lactase activity, lactose tolerance and milk consumption in different age groups.

Small intestinal lactase activity in the health adult is either the same as in early infancy or may drop to very low levels. The behavior of the enzymatic state varies with the ethnic group studied. In those adults with low lactase activity little information is availalbe as to the age at which the lactase decreases. We attempted to determine a) the frequency of low intestinal lactase activity and b) the age at which the change occurs. For this purpose we reviewed in a large number of intestinal biopsies both histologically as well as for disaccharidase activities. The biopsies were obtained from a heterogeneous group of Caucasians, including patients, their siblings and parents. The patients were those with failure to thrive in whom no organic cause could be elicited, and those with the irritable colon syndrome. Patients ranged in age from 6 weeks to 50 years and out of a total of 1, 077 jejunal biopsies, 172 morphologically normal biopsies were selected. The milk drinking habits of 118 subjects and their families were elicited and 31 oral lactose tolerance tests performed. The mucosal lactase activity and sucrase-to-lactase ratio in those 172 individuals were plotted against age. In the first 3 years the mean lactase activity was 32.1 plus or minus 10.1 mumoles/g protein per min and the sucrase-to-lactase ratio was 1.7 plus or minus 0.5 with no change from year to year. However, after age 5 two separate groups emerge. A small group (24.6% of the population) with low lactase activity, and a second group possessing the same mean value for lactase activity as noted in the first 3 years. The low lactase activity group included children and adults with clinical lactose intolerance. These individuals consumed relatively small amounts of milk and when 12 of them were tested with an oral lactose tolerance test the result was a "flat" curve with a maximum rise in blood glucose of 9 plus or minus 3.2 mg/100 ml. The second group consumed more milk averaging 1 quart/day with no discomfort and when 19 were tested with oral lactose tolerance tests the values were normal. This study indicates that low lactase activity in the Caucasian population may make its appearance at the age of 5 years.

Adolescent↗
PubMed1975

Recurrent acute pancreatitis in patients with cystic fibrosis with normal pancreatic enzymes.

Ten adolescent and young adults with cystic fibrosis (CF) have had well-documented recurrent attacks of acute pancreatitis. The diagnosis of CF in each patient was delayed because they did not have pancreatic insufficiency. The diagnosis of CF was documented by the typical pulmonary involvement and elevated sweat sodium and chloride levels in all cases and a positive family history in six of the ten patients. Two patients were diagnosed as having acute pancreatitis before the diagnosis of CF was made, thus indicating that acute pancreatitis may be the presenting complaint in the young adult with CF. The diagnosis of acute pancreatitis was based on the presence of severe abdominal pain, usually with vomiting, tenderness in the mid-epigastrium, elevated serum and urinary amylase and serum lipase. Attacks were precipitated by fatty meals, alcohol ingestion; postcholecystectomy and tetracycline administration. In some patients no precipitating event could be elicited. Intravenous secretin-pancreozymin stimulation tests revealed a diminished bicarbonate secretion with little effect on the secretion of the zymogen enzymes. A mild attack of pancreatitis occurred after secretin-pancreozymin stimulation. The endocrine pancreatic function tested in four patients was normal as revealed by the glucose tolerance tests and determinations of serum insulin, growth hormone and free fatty acid. Transduodenal pancreatograms were performed in three patients; one showed a normal pancreatic duct, one showed duct obstruction and in the third patient a beady type of narrowing was found. The selenomethionine Se 75 uptake of the pancreas was noted only in the head of the pancreas. This suggests that loss of function occurs initially to a greater extent in the tail and body of the pancreas. Three patients died and showed characteristic lesions of CF.

Acute Disease↗
PubMed1975

Intestinal lymphagiectasia: a reappraisal.

Intestinal lymphangiectasia (IL) may vary widely in its manifestations and severity. Fifteen children seen between 1960 and 1974 with histologically proven IL are analyzed by clinical, laboratory, radiologic, and histologic criteria. Remissions occurred in most patients and none died. Exacerbations occurred in five children. Diarrhea was present in 14 patients and in 13 appeared before the age of 3 years. Vomiting occurred in nine patients and growth retardation in seven. Four children had associated peripheral lymphedema and two of these had a family history of lymphedema, both had affected fathers and one had affected siblings and paternal cousins. Seven had hypoproteinemic edema, and of these, four suffered from hypocalcemic seizures. Chylous effusions were present in five. Hypoproteinemia was present in 12 although five had no hypoalbuminemic edema. Six had lymphopenia which was related to the severity of the disease and was the last abnormality to disappear after clinical remission. Lymphopenia may first appear years after the protein loss begins. Upper gastrointestinal tract series were performed in 13 children and had diagnostic supportive value in seven. Six children had two or more small-intestinal biopsies done. They all showed great variation from one examination to the other, ranging from a normal appearance to severe changes. Lymphatic block may occur at different sites-in the lamina propria only, generalized (lamina propria, submucosa, serosa, and mesentery), or conversely in the mesentery alone with minimal changes in the lamina propria. In three patients intravenous hyperalimentation was necessary. Specific treatment with a high-protein, low-fat diet with added medium-chain triglyceride (MCT) is valuable. Surgical resection was of benefit in one patient, and anastomosis of mesenteric to para-aortic lymph nodes in another.

Adolescent↗