Biomedical subjects

C H Lifschitz

Publications and source records attributed to C H Lifschitz.

44 records · Page 3Linked to original sources

PubMed1985

[13C]Acetate oxidation in infants after oral versus rectal administration: a kinetic model.

To study the fate of volatile fatty acids (VFA) in the large bowel, we compared the rate of oxidation of 13C-labeled VFA administered rectally with that of the orally administered substrate. On two different days, 1-[13C]acetate was administered rectally or orally to five infants recovering from diarrhea. Breath samples were collected over 4 h and analyzed for 13C enrichment of breath CO2 by gas isotope ratio mass spectrometry. The percent dose recoveries of 13C in breath were fitted to multicompartmental models using the SAAM-27 program. Following model development procedures, the oral acetate breath test curves could be accounted for only by a compartmental model in which labeled acetate underwent absorption into and mixed with a systemic pool before oxidation took place. The rectal acetate breath test curves could be accounted for by a simpler model in which oxidation occurred directly in the compartment in which the rectal acetate was administered, and required no rate-limiting absorptive process. Our results indicate that the labeled acetate was oxidized more rapidly when the substrate was administered rectally than orally. This observation points to the direct utilization of volatile fatty acids within the colon.

Acetates↗

PubMed1985

Absorption and tolerance of lactose in infants recovering from severe diarrhea.

Nineteen infants were challenged during their convalescence from severe diarrhea with a lactose-containing meal. Twenty-four hour intake, pre- and post-challenge breath H2 levels, clinical responses, and growth were measured at approximately biweekly intervals for 3 months beginning 1 month after hospital discharge. Ten lactose-tolerant infants were assigned randomly to receive one of two formulas similar in composition except for carbohydrates: lactose (Group L) (n = 6) and sucrose (Group S) (n = 4). Infants in Group L had greater intakes and growth rates during the initial 15 days of the study. No difference in weight for age z-scores was detected between groups at the end of the observation period. Infants in Group L had higher baseline and peak breath H2 levels indicating greater colonic carbohydrate fermentation than infants in Group S: however, breath H2 levels were not predictive of tolerance to lactose-containing meals. Carbohydrate absorption by infants in Group S appeared to exceed that of infants in Group L. Thus, colonic fermentation of malabsorbed carbohydrate may have prevented diarrhea and allowed acceptable rates of catch-up growth.

Diarrhea, Infantile↗

PubMed1985

Characterization of HCO3-/CO2 pool sizes and kinetics in infants.

The first bicarbonate pool sizes and kinetic data necessary for the interpretation of substrate oxidation studies have been determined in six fed, nonacidotic infants, ages 2.5 to 5 months. Following an intravenous bolus of NaH13CO3 (50 mumol/kg), breath samples were collected over 240 min for the analysis of breath 13CO2. Each breath 13CO2 disappearance curve was fitted to a multicompartmental bicarbonate model previously derived in adults. The mean sizes of the three bicarbonate pools were: 7.4 +/- 0.8 mmol/kg (central pool), 15.1 +/- 4.8 mmol/kg (rapidly exchanging peripheral pool), and 8.8 +/- 3.5 mmol/kg (slowly exchanging peripheral pool). The mean percentage dose recovery was 57 +/- 10%. The pool sizes suggested that extensive metabolic exchange of carbon between HCO3- and organic metabolites occurred in the infant.

Bicarbonates↗

PubMed1984

Unusual appearance of Crohn's disease.

The association of perianal fistulas and Crohn's disease is well recognized. The appearance of lesions distant from the anal area is, however, uncommon. A young girl appeared with a history of weight loss and extensive mucocutaneous ulcerations. Diarrhea subsequently developed. Colonoscopy revealed friability, edema, and ulcerations. A crypt abscess was found in colonic biopsy specimens. Treatment with prednisolone acetate and sulfasalazine resulted in prompt improvement. A skin biopsy done initially and repeated colon biopsy three months later demonstrated granulomas, consistent with Crohn's disease. The literature regarding skin lesions in association with Crohn's disease is reviewed and the importance of recognizing the cutaneous manifestations of Crohn's disease is emphasized.

Child↗

PubMed1983

Carbohydrate malabsorption in infants with diarrhea studied with the breath hydrogen test.

Fermentation of malabsorbed carbohydrate (CHO) reaching the colon was studied by measuring peak breath hydrogen (H2) production between feedings in 28 H2-producing hospitalized infants with diarrhea. Patients who required fewer than six days of hospitalization had lower breath H2 values when tested soon after admission than those who required longer stays. Patients hospitalized for more than five days had lower H2 amounts at discharge than on admission. Peak breath H2 values decreased when glucose was substituted for glucose polymers in formulas, or when the formula was fed by continuous drip via a nasogastric tube instead of by orally administered bolus. Glucose-positive and acidic stools were encountered occasionally and were associated with decreased H2 levels. The responses of H2 levels, stool pH, and glucose excretion after changes in patient management or intestinal metabolism of CHO reflect alterations in the balance between proximal intestinal absorption and distal colonic fermentation. Malabsorbed CHO that reaches a competent colon is utilized via microbial conversion, as indicated by high H2 levels, in the absence of glucose-positive and acidic stools. The presence of glucose in the feces or acidic stools indicates an inability of the colon to completely metabolize and absorb CHO or its products of fermentation.

Breath Tests↗

PubMed1983

Delayed complete functional lactase sufficiency in breast-fed infants.

Colonic fermentation of unabsorbed lactose was evaluated by measuring breath hydrogen (BH2) after a regular feeding in 17 white, normal, exclusively breast-fed infants 4-5 weeks of age. Interval breath samples were collected with a specially modified face mask and analyzed by gas chromatography for H2 and CO2 concentrations. Five infants (29%) produced 20 ppm or more of H2, four of whom underwent repeated testing. Three infants stopped producing over 20 ppm of H2 as they grew older. On a repeat evaluation, one of these three infants had levels over 20 ppm when other foods were introduced into his diet. The other continued to have elevated BH2 when weaned. Stools of infants with elevated BH2 levels had no detectable glucose, and pH was over 5.5. Weight-for-age of infants with elevated BH2 was at or above the 75th percentile. BH2 levels, normalized for the amount of breast milk ingested, fell significantly with age. These results show that complete small bowel absorption of lactose from breast milk does not occur in all white, normal, term, appropriate-for-gestational-age infants in the first months of life. The absence of glucose in the stool and the normal stool pH suggest that the unabsorbed lactose that produced H2 can be degraded in the colon.

Breast Feeding↗

PubMedDate not supplied

Anaphylactic shock due to cow's milk protein hypersensitivity in a breast-fed infant.

A newborn infant developed anaphylactic shock three times, once after ingesting his mother's milk and once after ingesting a formula containing casein hydrolysate. Symptoms resolved after cow's milk was withdrawn from the mother's diet and lactation was resumed. The case demonstrates that anaphylactic shock may occur in breast-fed infants and emphasizes the need to consider allergic phenomena even in these infants.

Anaphylaxis↗

PubMedDate not supplied

A carbon-13 breath test to characterize glucose absorption and utilization in children.

After the administration of a 5% glucose-water solution that contained tracer amounts of the stable nonradioactive isotope 13C, breath samples were collected from five children with congenital glucose-galactose malabsorption and five with severe small bowel villous atrophy and chronic diarrhea. The 13CO2 breath test curves of the children with the congenital malabsorption and chronic diarrhea were compared with each other and with those from three healthy children and four infants with severe malnutrition but no diarrhea. The breath test curves from the children with glucose-galactose malabsorption and from those with diarrhea were significantly different from those of the other two groups, a finding consistent with impairment of glucose absorption. The [13C]glucose breath test clearly identified the children with severe glucose malabsorption. Further studies are required to determine whether less severe cases of carbohydrate malabsorption also can be identified using the parameters described in our study.

Breath Tests↗