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Biomedical subjects

J P Buts

Publications and source records attributed to J P Buts.

At least 37 records · Page 2Linked to original sources
PubMed1995

Orthotopic liver transplantation for Crigler-Najjar type I disease in six children.

Hyperbilirubinemia in Crigler-Najjar disease type I (CN) can be partially controlled by daily phototherapy, but these children remain at permanent risk of developing brain damage due to kernicterus. Because liver transplantation is the only available curative treatment for liver-based inborn errors of metabolism, orthotopic liver transplantation (OLT) was performed in six patients with CN. Mean age at surgery was 52.5 months (range 27 to 100). Despite a mean daily phototherapy of 12.4 +/- 0.8 hr, mean bilirubin of the 6 patients was 388 microM/L (range 175 to 703) before OLT; one of them was also being treated with tin-protoporphyrin. All 6 had elevated AST/ALT, ranging from 1.4 to 6 times upper normal values. Complications occurred in three patients after OLT, including miliary tuberculosis in one, graft rejection and retransplantation in one, and hepatic artery thrombosis in one. All patients survive with normal serum bilirubin level (follow up 6 to 116 months). Four have normal enzymes on post-OLT follow-up (30 to 95 months), follow a normal education program, and have a normal social life. One recently transplanted patient has progressively normalizing liver function tests 6 months after OLT. One patient transplanted at 8 y.o. (now 116 months post-OLT) has moderate neurological delay due to pretransplant kernicterus, and posttransplant chronic persistent hepatitis. Our series shows that OLT cures hyperbilirubinemia in CN patients, with an excellent survival prospect. The procedure should be decided upon before neurological sequelae occur, since these persist after transplantation.

Adolescent↗
PubMed1995

Polyamine profiles in human milk, infant artificial formulas, and semi-elemental diets.

Using a sensitive high-performance liquid chromatography method, we quantified the concentration of polyamines (putrescine, spermidine, and spermine) in human milk as well as in a representative group of commonly used artificial infant formulas. Variations in polyamine levels were also analyzed in human milk during the immediate postnatal period. During the first week postpartum, putrescine levels in human milk remained very low and varied little, while spermidine and spermine concentrations rose markedly during the first 3 days, reaching plateau levels that were 12 and eight times higher, respectively, than the values measured on day 0. The mean total polyamine concentration was 557 +/- 18 nmol/dl with the following profile: spermine, 313 +/- 16; spermidine, 220 +/- 20; and putrescine, 24 +/- 3.5. In artificial powdered formulas, the polyamine concentration was approximately 10 times lower than in human milk, with no difference in putrescine and spermine contents between first-age and second-age formulas. By contrast, semi-elemental diets prepared by hydrolytic procedures using crude extracts of pancreatic enzymes were shown to be major sources of polyamines with a profile similar to that of human milk. Compared with first-age formulas, mean concentrations in spermine and spermidine were 39 and six times higher, respectively, in these semi-elemental diets, whereas putrescine levels remained almost equivalent in all types of milk tested. These data indicate that human milk and some semi-elemental diets provide substantial amounts of spermine and spermidine to neonates and infants that could potentially modulate intestinal maturation.

Chromatography, High Pressure Liquid↗
PubMed1995

Role of hepatitis C virus in chronic liver disease occurring after orthotopic liver transplantation.

Paediatric orthotopic liver transplant recipients may develop chronic hepatitis after surgery. To investigate the role of hepatitis C virus in this pathology a cohort of 249 paediatric orthotopic liver transplant recipients was studied. Sixteen children (6.4%) were found to have chronic hepatitis C virus hepatitis after orthotopic liver transplantation. All but one of them had serum transaminase values which were persistently raised two to eight times the upper limit of normal. Thirteen were positive for both serology and serum hepatitis C virus RNA. Serum hepatitis C virus RNA detection occurred five to 33 months before hepatitis C virus antibodies. Liver tissue hepatitis C virus RNA and hepatitis C virus core antigen were detected in five. In one patient, tissue hepatitis C virus core antigen was detected when other tests for hepatitis C were negative. Two patients had positive human cytomegalovirus serum antibodies and RNA before transplantation. Although serum hepatitis C virus RNA was not detected after transplantation, serum enzyme immunosorbent assay and tissue core antigen were still detectable in both patients. In another child, serum hepatitis C virus RNA was positive and hepatitis C virus core antigen was found on a liver biopsy specimen but antihepatitis C virus antibodies were negative as well as liver hepatitis C virus RNA. No patient developed severe liver disease or cirrhosis during a follow up of up to 72 months. It is concluded that hepatitis C virus is a significant cause of morbidity after paediatric orthotopic liver transplantation. Diagnosis cannot rely on serological testing only. The patients remained stable on follow up, but longer prospective histological studies remain necessary to establish prognosis.

Antigens, Viral↗
PubMed1994

Percutaneous transjugular intrahepatic stent shunt for treatment of intractable varicose bleeding in paediatric patients.

UNLABELLED: Two 10-year and 11-year-old children with oesophageal and gastric varicose haemorrhage unresponsive to medical treatment and repeated endoscopic sclerotherapy underwent percutaneous transjugular intrahepatic portosystemic shunting (TIPSS). A newly developed introducing system was used. The procedure was performed to avoid the increased risk of emergency liver transplantation in children with hepatic failure. Immediately after the procedure bleeding stopped and the patient's condition improved. Ascites disappeared and liver function improved. The stent shunt was shown to be patent by angiography and Doppler ultrasound for a follow up period of more than 1 year. CONCLUSION: TIPSS may be of benefit in children with severe portal hypertension. It allows control of intractable bleeding, and stabilizes the patients preparing them for subsequent elective orthotopic liver transplantation.

Child↗
PubMed1994

Response of rat immature enterocytes to insulin: regulation by receptor binding and endoluminal polyamine uptake.

BACKGROUND/AIMS: The mechanism(s) by which insulin stimulates enzyme expression in rat immature enterocytes are unknown. The purpose of this study was to investigate these mechanism(s). METHODS: The effects of insulin or an antireceptor monoclonal antibody (RPN 538) were assessed on microvillous enzyme activities and the endoluminal uptake of [14C]spermine. Changes in de novo synthesis of polyamines were measured by mucosal ornithine decarboxylase activity. RESULTS: In sucklings (day 14), administration of insulin failed to induce intestinal ornithine decarboxylase activity, whereas in older rats (day 18 and 20), ornithine decarboxylase was enhanced by 2-2.5-fold. Immature enterocytes from sucklings, pretreated with alpha-difluoromethylornithine, remained sensitive to insulin and expressed enzyme activities at levels equal to controls. In response to insulin, the uptake of [14C]spermine and the mucosal concentrations of spermine and spermidine were increased by 30%, 13%, and 39%, respectively. Administration of RPN 538 had no effect on [14C]-spermine uptake, but it prevented the effects of endogenous insulin on enzyme expression. CONCLUSIONS: The enzymatic response of immature enterocytes to insulin is mediated by binding of the hormone to its receptor and is transduced into the cell without de novo synthesis of polyamines. The regulation by insulin of the endoluminal uptake of spermine could be critical for intestinal maturation.

Adrenalectomy↗
PubMed1994

Saccharomyces boulardii enhances rat intestinal enzyme expression by endoluminal release of polyamines.

Saccharomyces boulardii is a yeast widely used in humans for the prevention and treatment of infectious enteritis and Clostridium difficile-associated enterocolopathies. After oral administration to human volunteers or growing rats, S. boulardii enhances markedly the expression of intestinal enzymes as well as the production of the polymeric immunoglobulin receptor by mechanisms that remain unknown. We have analyzed the role of the yeast polyamines as potential mediators in the intestinal trophic response. In weanling rats (d 20 to d 30), a daily dose of 100 mg of lyophilized S. boulardii produced significant (p < 0.025) increases in sucrase (157%) and maltase (47%) activities. This dose corresponded to a total oral load of 678 nmol of polyamines per day (spermidine; 376 +/- 32, spermine: 293 +/- 26, putrescine: 9.5 +/- 1.4 nmol/100 mg). Spermine, given orally to growing rats at doses nearly equivalent (500 nmol) to the load of polyamines provided by the yeast (678 nmol), reproduced similar enzymatic changes, including a 2.5-fold induction of sucrase, and enhanced maltase activity (+24%). Spermidine and spermine concentrations measured in the jejunal mucosa of treated rats were increased over matched controls by 21.4% (p < 0.005) and 21.9%, respectively (p < 0.002). After being centrifuged and filtered to discard residual yeast cells, 2-mL samples of jejunal and ileal fluid collected from S. boulardii-treated rats by intestinal flushing contained higher levels of spermidine (48 and 60%) and spermine (150 and 316%) than did control rats. Our data indicate that lyophilized S. boulardii exerts trophic effects on the small intestine that are likely mediated by the endoluminal release of spermine and spermidine.

Animals↗
PubMed1993

Maturation of villus and crypt cell functions in rat small intestine. Role of dietary polyamines.

To evaluate the role of dietary polyamines in maturation of the rat small intestine, spermine was given orally twice daily to suckling pups from day 10 to day 14 postpartum at different doses: 0, 0.2, 0.5, 1, 2.5, and 5 mumol/dose. Compared to saline treated controls, spermine (5 mumol) produced significant increases in mucosal mass parameters (+12 to +57%, P < 0.05), induced prematurely an adult pattern of microvillous enzymes, and enhanced, respectively, by 19- and 3.5-fold (P < 0.01 vs controls) the concentration of the secretory component of p-immunoglobulins in villous and crypt cells. The response of microvillous enzymes (lactase, sucrase, maltase, and aminopeptidase) to spermine was dose-dependent and -specific since oral administration of arginine (5 mumol) or ornithine (5 mumol) was without effect. Intestinal changes were found to be significant (P < 0.05) for doses of spermine exceeding 1 mumol/day, which is in the range of the amount of polyamines provided by solid pellets at weaning (0.4 mumol/g). However, intestinal changes were undetectable at the physiological amounts of polyamines consumed by pups from rat milk during the suckling period (less than 0.3 mumol/day). Consistent with a direct effect of spermine on the intestinal cell, the cytosolic activity of ornithine decarboxylase was depressed by 27-fold (P < 0.005 vs controls) in the jejunum, while inhibition of ornithine decarboxylase by alpha-difluoromethylornithine did markedly decrease but did not suppress the cell response to spermine. Alternately, plasma corticosteronemia, which was virtually absent by day 14 in controls, ranged between 1.4 and 4.6 micrograms/dl in 60% (N = 9) of the spermine-treated rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Saccharomyces boulardii for Clostridium difficile-associated enteropathies in infants.

Based on experimental evidence in animals showing that the oral administration of Saccharomyces boulardii is effective in reducing morbidity and mortality due to Clostridium difficile-induced pseudomembranous colitis, we conducted an open trial to examine the effects of the living yeast, given as primary therapy, in a selected group of infants and children with persistent intestinal symptoms related to toxinogenic C. difficile overgrowth. Over a period of 10 consecutive months, we studied 19 eligible patients (median age 8 months) who presented with enteral symptoms lasting for > 15 days and who had solely C. difficile in stools with positive cytotoxin B assay. Serotyping of the strains and determination in vitro of production of toxins A and B were performed subsequently. The patients presented with persistent or protracted diarrhea, malabsorption, and failure to grow (n = 8), or with repeated attacks of colics, emesis, and hypermeteorism without diarrhea (n = 4), or with both entities (n = 7). Patients with chronic protracted diarrhea (n = 3) had depressed jejunal disaccharidase activities and ultrastructural changes of enterocytes, including sparce and shortened microvilli. None had evidence of colitis. All the strains of C. difficile tested (n = 17) belonged to pathogenic serotypes (A1, A8, C, F, G, H, and K) and produced in vitro high levels of toxins A (n = 16) and B (n = 17). S. boulardii was given orally in a lyophilized form over 15 days (250 mg two to four times per day according to age).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1993

[Clinical evaluation of the tolerance for a soy-based special milk formula in children with cow's milk protein intolerance/allergy (CMPI/CMPA)].

A study aiming to assess the clinical tolerance of a special follow-up soybean milk formula (Neo-Soyal 2) in children with cow's milk protein intolerance or allergy (CMPI/CMPA) has been conducted in 17 infants and children (9 girls and 8 boys) aged from 6 months to 3 years. All the patients had a past history suggestive of CMPI/CMPA and were fed a restricted hypoallergenic diet with a semi-elemental formula based on protein hydrolysates. At the time of initiation of the study, all the patients were asymptomatic with normal growth while on a semi-elemental diet. The formula with protein hydrolysates was substituted by the test milk (Neo-Soyal 2) and blood samples were taken before and after 2 months. The clinical tolerance to the follow-up soybean formula was considered excellent in 16 children who remained asymptomatic with normal growth velocity. Only one patient developed a severe diarrhoea within 72 hours after introduction of the soybean formula which was stopped. However, after one month he was able to tolerate a certain amount of the soybean milk (240 ml) without symptoms. For all the patients studied, there was no change in the nutritional parameters measured in the blood before and after 2 months of the trial. Likewise, the plasma amino acid levels determined in 2 patients remained unchanged before and after the experimental period. These data indicate that the soybean milk formula used here (Neo-Soyal 2) can be safely given as a substitute of semi-elemental diets during the follow-up of children with CMPI/CMPA after the age of 6 months.

Child Nutritional Physiological Phenomena↗
PubMed1993

Continuous increase of alcohol dehydrogenase activity along the liver plate in normal and cirrhotic human livers.

To determine the zonal distribution of alcohol dehydrogenase in normal and cirrhotic human livers, we measured activities of this enzyme by quantitative cytochemical analysis along the liver cell plate in liver specimens from 10 normal organ donors and from 7 children with extrahepatic biliary atresia cirrhosis. In normal human liver samples, a continuous increase in alcohol dehydrogenase activity was observed along the sinusoid from the periportal to the perivenular hepatocytes (mean extinction units from 16.2 +/- 10.0 to 58.0 +/- 14.8). A similar observation was made in cirrhotic nodules, with activity increasing continuously from nodule periphery to center (7.6 +/- 4.1 to 44.9 +/- 13.3). This study demonstrates a heterogeneous pattern of alcohol dehydrogenase distribution along the sinusoid in normal human liver specimens. In addition, demonstration of this heterogeneity in human cirrhosis suggests that the cirrhotic liver is able to maintain a parenchymal functional organization, with persistence of metabolic zonation.

Adolescent↗
PubMed1992

Liver metabolic zonation in rat biliary cirrhosis: distribution is reverse of that in toxic cirrhosis.

Liver cell functional heterogeneity has been shown to persist in toxic CCl4 cirrhosis in growing rats, but the zonation observed in cirrhotic nodules may be different in other types of cirrhosis. To investigate this possibility, we looked at the zonal activities of two microsomal enzymes, glucose-6-phosphatase and NADPH dehydrogenase, in cirrhotic nodules from growing rats with chronic cholestasis. Zonal activities were measured by quantitative cytochemistry and microdensitometry. Liver cell heterogeneity was demonstrated, and we confirmed that the metabolic zonation is the mirror image of that observed in toxic cirrhosis, with periportal activity at the nodule periphery and perivenular activity at the nodule centers. Glucose-6-phosphatase activity was 2.06 times higher at the peripheries of the nodules than at the centers, whereas NADPH dehydrogenase activity at the nodule periphery was 72% of the nodule center activity. We conclude that a liver cell functional heterogeneity persists in biliary rat cirrhosis, with zonation the reverse of that previously found in toxic CCl4 cirrhosis.

Animals↗
PubMed1992

Upper gastro-intestinal tract bleeding in cirrhotic children candidates for liver transplantation.

Signs of portal hypertension, history of upper gastro-intestinal tract bleeding episodes and outcome of the latter were recorded in 76 cirrhotic children evaluated for liver transplantation. Fifty-three (70%) had varices and 22 (29%) had experienced upper gastro-intestinal tract bleeding. Of these 22, 19 bled from varices and 3 from ulcers. Non bleeding ulcers were also found in five patients bleeding from varices. Iterative sclerotherapy controlled acute variceal bleeding in all but one patient in whom emergency transplantation was performed. Six of the eight patients with ulcers were successfully treated by the H2 histamine receptor antagonist ranitidine. We conclude that iterative sclerotherapy is efficient to control acute variceal bleeding and prevents recurrent bleeding in children with end-stage liver diseases awaiting liver replacement. Bleeding asymptomatic ulcers are frequent and respond to H2 histamine receptor antagonists.

Acute Disease↗
PubMed1992

Ontogeny of the receptor for polymeric immunoglobulins in rat hepatocytes.

Based on in vitro experiments measuring daily secretion rates in the culture media of rat hepatocytes and in vivo experiments using pulse labeling of intracellular precursors, the present study examines the ontogenic expression of the polymeric immunoglobulin receptor and secretory component by hepatocytes during growth. Our data indicate that hepatocytes from infant and suckling rats (day 5, 15) cultured in serum-free and hormone-free conditions only secreted trace amounts of secretory component. Beginning on day 20, basal secretion rate showed a marked upsurge with a 10-fold increase by day 35. The addition of dexamethasone (10(-7) mol/L) to the culture media enhanced by 2.5-fold the basal secretion of secretory component by hepatocytes from 20-, 25-, and 35-day-old rats, while addition of insulin to the media had no effect. The response to dexamethasone was dose-dependent (10(-5), 10(-6), 10(-7) mol/L) and specific. In vivo pulse labeling of receptor precursors in hepatocytes from 40-day-old rats allowed the identification of three intracellular forms: a 105-kilodalton peptide and a 116-120-kilodalton mature doublet. In 13-day-old rats, three immature precursors were detected: a 105-kilodalton peptide and a high molecular weight doublet of 185-190 kilodaltons. Sucklings (13 days) treated with corticosterone showed a pattern of precursors similar to controls. These findings support the following conclusions: (a) hepatocytes from infant and suckling rats synthesize and process immature receptor precursors whose expression is unaffected by corticosterone treatment, and (b) active secretion of secretory component is initiated at weaning independently from humoral and hormonal factors while the magnitude of its production by the liver is under the control of glucocorticoids.

Aging↗
PubMed1992

Prenatal exposure to ethanol in rats: effects on postnatal maturation of the small intestine and liver.

To examine the effects of prenatal exposure to ethanol on postnatal development of small intestinal and liver functions, female rats were accustomed to increasing amounts of ethanol (10 to 25%, vol/vol) in tap water for 1 mo. During pregnancy, ethanol-fed dams had higher daily caloric intake and similar weight gain compared with controls. In ethanol offspring, neonatal mortality was 28.9% compared to 0% in controls. Although ethanol had been withdrawn at birth, pups issued from ethanol-treated mothers showed at 5 and 10 d postpartum decreased values of body weight, jejunal and ileal weights, and intestinal DNA concentration per unit of length, as well as lower specific and total activities in lactase and maltase, compared with controls. DNA synthesis rates, measured by the incorporation of [3H]thymidine into mucosal DNA, were also significantly (-20 to -34%, p < 0.01) depressed in the jejunum and ileum of ethanol pups at 5 and 10 d of age. All these parameters returned to control levels by d 15 postpartum. Electron microscopy of jejunal mucosal samples at 5, 10, and 15 d of age revealed that ethanol pups differed from controls by a fetal-like immature aspect of the enterocytes, which persisted up to d 15. The ontogenic upsurge in sucrase and the decline in lactase occurred at weaning with the same chronology in both groups, but the level reached by sucrase activity was about 50% lower in alcohol offspring than in controls. Except for moderate steatosis, the ultrastructure of hepatocytes was unaltered in sucklings.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗