Sugar absorption in healthy preterm and full-term infants.

We have studied carbohydrate absorption in 40 healthy term infants and 10 preterm neonates (31-35 weeks gestation) by respiratory H2, fecal pH, and chromatographic analysis of stools. Sequential studies of H2 excretion (24-h collection) in response to breast feeding were carried out in premature infants during the first 8 weeks of life. Five expired H2 during the first 2 weeks, and two continued to do so in the 3rd to 4th weeks. Breath H2 excretion fell below 10 ppm by 8 weeks and was not related to feeding or sleep. In term neonates, the frequency of incomplete carbohydrate absorption (4-h test) at the end of the first week was 36% for 14 breast-fed, 42% for 12 formula-fed, and 64% for 14 mixed-fed neonates (not significant differences). There were no significant differences between the absorbing and malabsorbing subjects in fecal pH. Chromatographic analysis showed only small quantities of sugars. In summary, incomplete carbohydrate absorption occurred in a high percentage of the newborns studied; the 24-h test evaluated better than the 4-h test; and negative breath H2 excretion indicated development of the capacity of the small intestine to hydrolyze carbohydrates. In the majority of the preterm malabsorbing babies, completely functional lactase occurs within the first month of life. The growth modulators in human milk may increase the rate of maturing of the small intestine.

Lactose absorption and malabsorption in healthy Italian children: do the quantity of malabsorbed sugar and the small bowel transit time play roles in symptom production?

Using breath hydrogen analysis after an oral lactose load (2 g/kg; maximum 50 g), we investigated the prevalence of lactose malabsorption in 61 healthy Italian children aged 6-13 years. We also examined the relationship between symptoms and small bowel transit time and the degree of sugar malabsorption. Three of 61 subjects produced no H2 after both lactose and lactulose load and thus were eliminated at the outset. Lactose malabsorption was defined as excretion of greater than 20 ppm H2. Lactose intolerance was classified as mild (colicky pain, flatulence, abdominal distension, borborygmi) or severe (diarrhea). The frequency of lactose malabsorption in the children aged 6-8 years (group I) was 25%; in the children aged 8-11 years (group II), it was 35%, and in the children aged 11-13 years (group III) 56%. The differences in frequency between the first and the third groups were significant (p = 0.05). Three of 20 (15%) in group I, two of 20 (10%) in group II, and three of 18 (17%) in group III were classified not only as lactose malabsorbing, but also as lactose intolerant, with symptoms during and after the test. We found no difference in the small bowel transit times or in the quantities of malabsorbed lactose in symptomatic and asymptomatic malabsorbing subjects. Other factors that may play a role in symptom production are discussed.

[Giardiasis in children. Ultrastructural study of the parasite]. / Giardiasi in etá pediatrica. Studio ultrastrutturale del parassita.

Giardia lamblia is the first protozoan to be identified and recognized as an important pathogen in human disease. We studied 8 pediatric patients with giardiasis in order to examine the clinical spectrum, the structural changes of the small intestinal mucosa and mainly the protozoan's ultrastructural features. The most common clinical manifestations were diarrhea, abdominal pain, anorexia, vomiting, failure to thrive. Infection was confirmed by excreted cysts in the stools in one patient, by the presence of trophozoites in duodenal aspirate and on jejunal mucosa. Giardiasis was not associated with hypogammaglobulinemia in our patients and no or only slight mucosal abnormalities were present in jejunal biopsies, except one which showed a flat mucosa. Specimens for transmissions and scanning electron microscopy were taken. We could establish the protozoan's features, its normal distribution, its relationship to intestinal mucosa and structural indications of the normal reaction of intestine with the use of ultrastructural techniques. The trophozoites colonized the proximal intestine, adhered to microvilli of columnar cells near the bases of villi, wedged or lodged in mucus. The sticky mucus producing an effective diffusion barrier to nutrients could explain malabsorption phenomena. Numerous intraluminal lymphocytes were seen, suggesting an immune response. These observations indicate that in giardiasis the clinical spectrum and structural changes of the small intestinal mucosa vary widely, suggesting a different reaction of immune system and/or a different degree of infection.

[Validity of the H2 breath test and limits of blood xylose in the evaluation of malabsorption in children]. / Validità del breath H2 test e limiti della xilosemia nella valutazione del malassorbimento in età pediatrica.

Many authors have recently discussed the real value of the xylose test in the evaluation of intestinal malabsorption, especially its correlation with the morphological damage of the duodenal-jejunal mucosa. In our study we have performed in 48 pediatric patients one-hour blood xylose test and breath H2 test, method used for the diagnosis of sugar malabsorption, in order to value small bowel function and to know indirectly small intestinal mucosal structure. We have compared the values of the xylose test with those of the breath H2 test and both with hystological findings. The D-xylose absorption test was performed using the technique described by Roe and Rice. A serum concentration of more than 25 mg/dl was considered normal. For the breath H2 test the technique described by Douwes was used. A hydrogen concentration lower than 20 p.p.m. in expired air was considered normal. All of the patients in whose breath hydrogen was not detected after lactose oral load (2g/Kg body-weight, maximum 50 g), underwent a second test with lactulose (0,8 - 1 g/Kg body-weight), is not absorbed. We performed this test to rule out a false negative result (2% of the normal population). On histologic criteria, the patients were assigned to one of three study groups. Group I: normal duodenal-jejunal mucosal structure (11 patients). Group II: structural abnormalities not diagnostic of celiac diseases (7 patients). Group III: mucosal structural abnormalities typical of celiac disease (30 patients). In the first group the one-hour blood xylose test was normal in 9 patients (81.81%), whilst the breath H2 test was normal in 11 patients (100%).(ABSTRACT TRUNCATED AT 250 WORDS)

[Gastrointestinal fiber endoscopy in children: diagnostic and therapeutic contribution]. / La fibroendoscopia digestiva in età pediatrica: contributo diagnostico e terapeutico.

The diagnostic and therapeutic value of gastrointestinal endoscopy in adults is well established. Our study, performed in pediatric patients confirms its usefulness and emphasises its easy execution and little risk in children. The availability of small caliber fiberendoscopes and the simple medication permit its wide and sure use. The direct visualization of mucosal surface allows to see even small alteration always not found by roentgenological examination and to pick up aimed bioptic specimens. The therapeutic contribution revealed itself affective in our experience, permitting polipectomy and consequently rectal bleeding removal. It was possible at last by this technique to make the follow-up of patients with ulcerative colitis avoiding them repeated irradiations. We can thus conclude that gastrointestinal endoscopy has an important diagnostic and therapeutic value also in pediatric patients for the study of gastrointestinal diseases.

[Intestinal lymphangiectasis: late complication of transportation of the great vessels corrected by the Mustard technic. A clinical case]. / Linfangectasia intestinale: complicanza tardiva di una trasposizione dei grossi vasi arteriosi corretta con tecnica di Mustard. Caso clinico.

The Great Arteries Transposition corrected by Mustard's repair is often complicated with inferior vena cava obstruction with consequent intestinal lymphangiectasia and protein-losing enteropathy. We report a case of a 9 years old boy who underwent Mustard's repair and presented diarrhoea, abdominal pain, hypoproteinemia and ascites. The fecal elimination of 51Cr-labeled albumin was remarkable increased and the intestinal biopsy showed a noteworthy lymphangiectasia due to an hemodynamic overload. Therefore subjects with Great Arteries Transposition corrected by Mustard's repair should be valued in the post-surgical follow-up by 51Cr-labeled albumin fecal elimination and by intestinal biopsy, already sensitive in asymptomatic phase.