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Biomedical subjects

C H Lifschitz

Publications and source records attributed to C H Lifschitz.

At least 37 records · Page 2Linked to original sources
PubMed1990

High-performance size-exclusion chromatography of porcine colonic mucins. Comparison of Bio-Gel TSK 40XL and Sepharose 4B columns.

A high-performance size-exclusion chromatography (HPSEC) method was developed for the separation of porcine colonic mucins using a Bio-Gel TSK 40XL HPSEC column (300 mm x 75 mm). In addition, porcine gastric and bovine submaxillary mucin preparations were used to describe more fully the separation characteristics of the HPSEC column. For comparison, the same preparations were also separated using a Sepharose 4B column (100 cm x 2.6 cm). The colonic and gastric mucins eluted in the void volume (V0) of both columns. Bovine submaxillary mucin was in the elution volume (Ve) of both columns. Analytical HPSEC of fractions (V0 and Ve) of the various preparations obtained by Sepharose 4B chromatography exhibited retention times identical to those for fractions obtained by HPSEC. After separation by both methods, purified mucins were obtained by CsCl2 density gradient ultracentrifugation; analytical HPSEC profiles, protein contents, and monosaccharide compositions of both gastric and colonic mucins from either column were similar. The HPSEC method, however, is ideally suited to separate microgram to milligram quantities of colonic mucin preparations quickly: 2 to 4 h, compared with 24 to 30 h for the Sepharose 4B method.

Animals↗
PubMed1990

Effect of formula carbohydrate concentration on tolerance and macronutrient absorption in infants with severe, chronic diarrhea.

To determine how the carbohydrate (CHO) content of "semielemental" formulas affects tolerance and macronutrient absorption, we enrolled 12 infants with severe diarrhea in two successive metabolic balance studies. The infants received, in random order, one of two isocaloric formulas that differed mainly in their CHO and fat concentrations. No significant differences were found between the two feeding periods for peak breath hydrogen levels and fecal osmolality. The low-CHO formula was tolerated better than the high-CHO formula, as indicated by a significantly lower stool output (mean +/- SD 387 +/- 230 vs 764 +/- 443 gm, respectively; p less than 0.05), and higher fecal pH (5.9 +/- 0.7 vs 4.9 +/- 0.5; p less than 0.05). Macronutrient absorption was greater during the ingestion of the low-CHO formula, as indicated by a significantly higher coefficient of fat absorption (p less than 0.005) and lower total fecal energy (mean +/- SD for high- vs low-CHO formula, 372 +/- 205 vs 207 +/- 102 kcal; p less than 0.05), which resulted from a lower CHO excretion (p less than 0.05). A correlation coefficient between the energy derived from CHO in feces and the total stool output was significant for both the high-CHO formula (r = 0.83; p less than 0.001) and the low-CHO formula (r = 0.7; p = 0.01). The CHO concentration of the special infant formula that we tested had an overriding effect on stool output and on fat and energy absorption.

Chronic Disease↗
PubMed1990

Nutritional therapy for infants with diarrhea.

The appropriate choice of treatment for infants with diarrhea has long provoked debate. Growth of infants with diarrhea is adversely affected by associated diseases including anorexia, malabsorption, catabolic response to infection, and iatrogenic starvation. To prevent the negative effects of diarrhea on the nutrition of infants, continued feeding during the active and early convalescent phases has been recommended. Although this concept is not new, until recently it has been little used in the treatment of diarrhea. In this article we examine the current knowledge about, and trends in, feeding infants with diarrhea. We will discuss treatments for the well-nourished infant with acute diarrhea, the infant with prolonged diarrhea, and the malnourished infant. Information regarding the use of local staples will also be provided.

Acute Disease↗
PubMed1990

Characterization of carbohydrate fermentation in feces of formula-fed and breast-fed infants.

We wished to characterize the carbohydrate fermentation by intestinal flora in formula-fed infants and in breast-fed infants. We also wished to compare the carbohydrate fermentation process in the two groups to determine whether differences that existed between groups could help explain the observation that breast-fed infants usually have milder forms of acute gastroenteritis. We performed in vitro incubations of fecal samples from nine formula-fed and 14 breast-fed infants and examined the samples for fermentation characteristics, the effect of acid pH on bacterial fermentation, and changes in carbohydrate fermentation in relation to the age of the infant. Fecal samples were incubated, with and without the addition of lactose, at a pH of 6.8 and at a pH of 5.5. Volatile fatty acids and carbohydrates were determined in the incubates. The addition of lactose to the incubate at pH 6.8 resulted in significantly increased volatile fatty acid production and larger amounts of lactose, glucose, and galactose compared with the values observed in 1-h incubates to which no lactose was added. At pH 5.5, volatile fatty acid production was significantly lower in both groups compared with that at pH 6.8, and the accumulation of monosaccharides in the incubate of feces of formula-fed infants increased significantly (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Breast Feeding↗
PubMed1989

Colonic interposition after esophagogastrectomy in a child with Zollinger-Ellison syndrome.

Zollinger-Ellison syndrome is a rare childhood entity that usually presents with peptic ulcer disease and is resistant to medical management. In contrast to the treatment of the disease in adults, total gastrectomy is the procedure of choice for pediatric patients. We report on a child with Zollinger-Ellison syndrome complicated by esophageal stricture in whom we performed a new operative procedure using a colonic interposition. The use of the procedure has obviated the side effects commonly associated with gastrectomy.

Child↗
PubMed1989

Intestinal strictures presenting with gastrointestinal blood loss.

The typical manifestations of intestinal strictures include abdominal distention, bilious vomiting, hematochezia, diarrhea, disaccharide intolerance, and occasional growth failure. However, chronic gastrointestinal (GI) blood loss from ulcers at the site of the stricture has not been noted as a major feature. We report three patients in whom an intestinal stricture presented with minimal evidence of obstruction, but with GI bleeding and anemia. Our experience indicates that intestinal strictures with ulcers must be considered in the differential diagnosis of blood loss, and that surgical intervention may be required if GI blood loss is chronic and laboratory results are negative.

Child↗
PubMed1989

Human milk and the rate of small intestinal mucosal recovery in protracted diarrhea.

STUDY OBJECTIVE: To determine whether human milk accelerates the recovery rate of injured small intestinal mucosa. DESIGN: Randomized, controlled trial. SETTING: County and nonprofit, private urban hospitals. PATIENTS: Moderately to severely malnourished infants less than 6 months of age who required parenteral nutrition for treatment of protracted diarrhea. INTERVENTIONS: Either a human milk preparation (n = 7) or sterile water (n = 9) was administered by continuous nasogastric feeding (14 mL/kg/d) over a 2-week study period while the infants received parenteral nutrition. MEASUREMENTS AND MAIN RESULTS: Small intestine perfusion studies and biopsies were performed at the beginning and end of the study. Age, duration of prior illness, severity of malnutrition, glucose and water absorption, disaccharidase activities, atrophy of villi, and nutritional intake were comparable in both groups of infants. At the end of the 2-week study, improvement toward normal sucrase activity and intraepithelial lymphocytes was found in significantly fewer infants in the milk group than in the water group. No differences were noted in glucose and water absorption or in lactase and maltase activities as a function of the milk versus water treatment. CONCLUSIONS: Human milk did not accelerate functional recovery of the small intestinal mucosa.

Clinical Trials as Topic↗
PubMed1989

Comparison of the D-xylose and polyethylene glycol absorption tests as indicators of mucosal damage in infants with chronic diarrhea.

The determination of serum levels of D-xylose and the urinary excretion of an orally administered mixture of low-molecular-weight polyethylene glycol were compared to assess their sensitivity to predict small-bowel mucosal damage. Eighteen infants with severe diarrhea and villus atrophy were observed. Results of the D-xylose and polyethylene glycol tests were compared with the villus-to-crypt ratios that were determined from biopsy specimens. The D-xylose test predicted accurately 12 (67%) of the 18 small-bowel biopsy results, while the polyethylene glycol test predicted 14 (78%). However, the McNemar test indicated that the two tests did not differ significantly in their ability to predict an abnormal small-bowel biopsy. We conclude that neither the D-xylose nor the polyethylene glycol test is a reliable indicator of small intestinal mucosal damage in infants with chronic diarrhea.

Atrophy↗
PubMed1989

Low-dose methotrexate-induced changes in intestinal permeability determined by polyethylene glycol polymers.

The impact of chemotherapeutic agents on small bowel mucosa has not been investigated adequately in children. To determine the effect of low-dose methotrexate (MTX) on the permeability and mucosal integrity of the small bowel, we administered low molecular weight polyethylene glycol (PEG) to 19 children who were in the maintenance phase of treatment of acute lymphocytic leukemia. PEG was administered before and after the children received their weekly oral or intramuscular doses of MTX. PEG recoveries from a 6-h urine collection were calculated by a mathematical formula to determine the polymer with maximal recovery (PCD0) and the polymer whose recovery was 50% of PCD0 (N1/2). Compared with pre-MTX levels, a significant increase was observed in the polymer with maximal recovery (PCD0) in 15/19 children after MTX administration (p less than 0.015) which indicated increased transmucosal passage of PEG. A decrease in the PEG parameter (N1/2) was observed in 11/38 studies, and may have indicated diminished enterocyte cell mass. These changes indicate that treatment with MTX results in an increase in intestinal permeability by the paracellular pathway, which may affect the absorption of other molecules.

Adolescent↗
PubMed1989

The urinary excretion of polyethylene glycol as a test for mucosal integrity in children with celiac disease: comparison with other noninvasive tests.

We compared the results of various noninvasive tests with small bowel histology in 61 children with celiac disease. The most sensitive predictors of small bowel histology were serum levels of anti-gliadin antibodies (AGAs) (90%) and the urinary excretion of polyethylene glycol (PEG) (69%). The sensitivity for the fecal fat analysis was 61% and for the D-xylose test 34%. The specificity was 96% for both the PEG and the D-xylose tests, 92% for the fecal fat, and 68% for AGAs. The predictive value of the PEG test was significantly better than that of D-xylose (p less than 0.05). The best combination of tests for the prediction of small bowel histology was the PEG test and the measurement of serum levels of AGAs. Agreement in the results of these two tests helps to time appropriately the second and third small bowel biopsies.

Antibodies↗
PubMed1989

Preparation of fecal samples for assay of volatile fatty acids by gas-liquid chromatography and high-performance liquid chromatography.

We describe a procedure for preparing fecal samples for determination of volatile fatty acids (VFAs) by gas-liquid chromatography (GLC) and "high-performance" liquid chromatography (HPLC). The simple, one-step procedure involves only ultrafiltration through a membrane with a molecular-mass cutoff of 3000 Da. As revealed by the GLC chromatograms, ultrafiltration appears to be as effective as steam distillation in sample clean-up. It also enables higher, more reproducible analytical recoveries of long-chain VFAs. The VFA content of the filtrate can also be measured by HPLC. Use of the ion-exclusion mechanism completely resolves isobutyric acid and butyric acid on a cation-exchange column. The mean (+/- SD) percentage distribution values of VFAs (measured by GLC) from five healthy subjects were 56.0 +/- 3.5 (acetic acid), 17.0 +/- 5.3 (propionic acid), 2.9 +/- 1.5 (isobutyric acid), 18.8 +/- 5.8 (butyric acid), 2.3 +/- 1.2 (isovaleric acid), and 2.9 +/- 0.8 (valeric acid).

Acetates↗
PubMed1988

Effects of changes in infusion rate versus glucose concentration on absorption in infant miniature pig small intestine.

The effect of changes in the rate of infusion versus glucose concentration on glucose, water, and sodium absorption was studied in 20 infant miniature pigs using the single-pass small intestinal perfusion technique. During infusions of glucose loads of up to 75.0 mumol/min, glucose absorption increased similarly whether rate of infusion or glucose concentration was increased. Beyond 75.0 mumol/min, glucose absorption was not altered by changes in infusion rate, but was enhanced by increases in glucose concentration (slope of rate vs. concentration, p less than 0.0001). Net water and sodium absorption were similar in the two groups except for a decrease at the highest glucose concentration (rate vs. concentration at 187.5 mumol/min, p less than 0.05). A glucose concentration of 112.5 mM resulted in maximal glucose, water, and sodium absorption.

Animals↗
PubMed1986

Polyethylene glycol polymers of low molecular weight as probes of intestinal permeability. II. Application to infants and children with intestinal disease.

We used a mixture of low molecular weight polymers of polyethylene glycol (PEG) to study intestinal permeability in children with chronic diarrhea. After an oral load, urinary recovery of the longer chain, higher molecular weight polymers was significantly decreased compared with that in healthy adults and infants without disease of the gastrointestinal mucosa. A correlation was observed between clinical severity of disease, histopathologic condition of the small bowel mucosa, and PEG scores. These results indicate that intestinal permeability in children can be studied by noninvasive means and that an assessment of mucosal integrity can be obtained.

Adolescent↗
PubMed1986

Polyethylene glycol polymers of low molecular weight as probes of intestinal permeability. I. Innovations in analysis and quantitation.

The differential passive permeation of polymers of different lengths across the intestinal mucosa has been proposed as a probe to test mucosal integrity under a variety of physiologic and pathologic conditions. Polyethylene glycol (PEG) 400 contains a series of polymers whose pattern of urinary recovery after oral administration has been used to characterize intestinal mucosal function. To extend this method to the low levels of PEG polymers found in the urine of children with diarrhea, we have introduced three methodologic innovations. These alterations involve (1) formulation of a balanced PEG polymer mixture, (2) improved isolation, derivatization, and gas chromatography techniques, and (3) a new quantification of the pattern of PEG urinary recoveries. Urinary recovery of orally administered PEG was assessed in four normal adults, six hospitalized infants without gastrointestinal complains, two infants with prolonged diarrhea and carbohydrate malabsorption, and two children with cystic fibrosis. A parameter characterizing the urinary recovery of PEG, N1/2, which is the theoretical number of subunits in the polymer whose recovery is reduced to 50% of the value of the polymer whose recovery is maximal, gave stable, reproducible, and consistent results in normal adults and infants.

Adult↗
PubMed1985

Effect of a simethicone-containing tablet on colonic gas elimination in breath.

The effect of a tablet containing the antiflatulent, simethicone, on intestinal hydrogen (H2) elimination in breath was studied. In three trials, normal subjects (age 12-52 years) received, on subsequent days, lactulose or lactulose with two tablets of either simethicone or placebo in randomized order. Breath samples were collected over 210 min and analyzed by gas chromatography for H2. The time course of H2 expiration above baseline levels was calculated and compared for the three tests. No significant differences in transit time were found. Cumulative H2 expiration was significantly lower after simethicone compared to placebo. H2 production from stool incubated with simethicone or placebo indicated that the drug had no effect in reducing the fermentative production of H2 in vitro. Interestingly, the vehicle present in the tablets could be fermented by intestinal bacteria. Simethicone reduced the amount of H2 eliminated in breath, but this effect was offset partially by H2 production from the fermentation of unabsorbable substances used in the formulation of the tablets.

Adolescent↗
PubMed1985

Persistence of colitis in Hirschsprung's disease.

Enterocolitis, which is associated frequently with Hirschsprung's disease in the neonatal period, can be prolonged. Recurrence of symptoms has been reported even after surgical correction. We present a neonate with Hirschsprung's disease who developed enterocolitis, and in whom evidence of acute large bowel inflammation persisted until she was 16 months of age.

Colostomy↗