ABSTRACT. Recycling of bile acids through the enterohepatic cycle is very efficacious. Bile acids contribute to bile formation and, by forming micelles, participate in lipid solubilization and absorption. The small fraction which escapes in the feces, is synthesized daily by the liver to compensate for losses. In CF, bile acid malabsorption has been documented; these large losses are accompanied by an interruption in the enterohepatic circulation with concomitant reduction in bile acid pool and disturbances in biliary composition. The various intraluminal factors implicated in bile acid malabsorption include: unhydrolysed triglycerides and phospholipids, precipitation of bile acids in acidic duodenal content, adsorption to residues and modification of colonic microflora. A defect in bile acid ileal uptake has also been advocated. These disturbances in bile acid metabolism associated with CF might lead to aggravation of diarrhea and steatorrhea, cholelithiasis and perhaps liver disease.

Twenty-five pediatric orthotopic liver transplantations (OLTs) performed in 22 patients at Sainte-Justine Hospital were reviewed for infections complications. One patient died within 12 hours posttransplantation and is excluded. The patients had an average age of 6.1 years (range, 1.25 to 19 years) and an average weight of 20.4 kg (range, 11 to 55 kg). Two patients (9%) were cytomegalovirus (CMV) seropositive and 9 of 19 patients (48%) were Epstein-Barr virus (EBV) seropositive preoperatively. Five of the donors (20%) were CMV seropositive. The most common indications for OLT were biliary atresia (8) and tyrosinemia (7). There were 4 deaths, for an overall mortality rate of 19%. In 3 patients, deaths were related to infection (CMV hepatitis and duodenitis with aortoduodenal fistula, adult respiratory distress syndrome [ARDS] with Streptococcus viridans pneumonia, Escherichia coli cholangitis with progressive hepatic failure). Fifteen patients (72%) had 41 major infections, most of them bacterial, during the first month posttransplantation. These include pneumonia (25%), line sepsis (17%), cholangitis (14%), and tracheitis (14%). There was only one major viral infection, a CMV hepatitis that occurred in the first month posttransplantation. Three patients had fungal infections (8%) associated with hepatic artery thrombosis and recurrent cholangitis. All three patients required retransplantation. There was only one protozoal infection (Pneumocystis carinii pneumonia) causing life-threatening respiratory failure, from which patient recovered without sequelae. Infection still remains a serious complication of OLT. Bacterial infection is common and is usually associated with technical complications. The low rate of CMV infection is related to low incidence of CMV in the donor pool and the minimal use of strong immunosuppressants.

Hereditary tyrosinemia results from an inborn error in the final step of tyrosine metabolism. The disease is known to cause acute and chronic liver failure, renal Fanconi's syndrome, and hepatocellular carcinoma. Neurologic manifestations have been reported but not emphasized as a common problem. In this paper, we describe neurologic crises that occurred among children identified as having tyrosinemia on neonatal screening since 1970. Of the 48 children with tyrosinemia, 20 (42 percent) had neurologic crises that began at a mean age of one year and led to 104 hospital admissions. These abrupt episodes of peripheral neuropathy were characterized by severe pain with extensor hypertonia (in 75 percent), vomiting or paralytic ileus (69 percent), muscle weakness (29 percent), and self-mutilation (8 percent). Eight children required mechanical ventilation because of paralysis, and 14 of the 20 children have died. Between crises, most survivors regained normal function. We found no reliable biochemical marker for the crises (those we evaluated included blood levels of tyrosine, succinylacetone, and hepatic aminotransferases). Urinary excretion of delta-aminolevulinic acid, a neurotoxic intermediate of porphyrin biosynthesis, was elevated during crises but also during the asymptomatic periods. Electrophysiologic studies in seven patients and neuromuscular biopsies in three patients showed axonal degeneration and secondary demyelination. We conclude that episodes of acute, severe peripheral neuropathy are common in hereditary tyrosinemia and resemble the crises of the neuropathic porphyrias.

Although dehydrated obstructing mucus is thought to account for the obstructive pathology involving the lungs, the pancreas, the reproductive system, and the intestinal tract, its relationship with CF-associated liver disease remains largely hypothetical and little is known about possible risk factors. Complete clinical and autopsy records were available in 38 of 73 deaths occurring over a 10-year period. The liver was normal in only five cases, and they were all infants. Steatosis was the only lesion present in 9, hypoxic liver disease was documented in 8, and biliary cirrhosis in 16 (focal in 10 and multilobular in 6). There was no relationship between the presence of cirrhosis, gallbladder abnormalities, age at death, and clinical status recorded during the year precoding their demise. Mucus plugs characterized by amorphous eosinophilic material within proliferated bile ductules were present in 75% of children with focal or multilobular biliary cirrhosis as opposed to 14% in those without (p = 0.015). A history of meconium ileus or its equivalent was recorded more frequently (p = 0.038) in those with cirrhosis. Finally, biliary cirrhosis was invariably present when there was a history of meconium ileus or its equivalent and when mucus plugs were noted. These findings suggest that patients with intestinal obstruction are at greater risk for the development of cirrhosis and that strategies should be developed to increase the detergent capacity of bile and its flow in order to decrease the viscosity of mucus in the biliary tree.

The introduction of cyclosporine A in 1980 greatly improved the survival of children with end-stage liver disease undergoing orthotopic liver transplantation. The average 1-year survival rate following hepatic transplantation increased from 30% in 1963 to 70% in 1980. This report summarizes the initial experience of two pediatric hospitals in Montreal--Hôpital Ste-Justine and Montreal Children's Hospital. Since December 1985, 13 orthotopic liver transplantations have been performed in 11 patients: six females and five males. The median age was 18 months (range, 13 months to 17 years) and the median weight was 10 kg (range, 8.5 to 38 kg). The indications for transplantation were biliary atresia (5 patients), tyrosinemia (2 patients), biliary hypoplasia (1 patient), Amerindian cirrhosis (1 patient), Crigler-Najjar syndrome, type I (1 patient), and fulminant non-A, non-B hepatitis with grade IV encephalopathy (1 patient). Immunosuppression was ensured by cyclosporine A, azathioprine, and steroids. The function of 11 grafts was immediate following revascularization of the grafts. One graft had delayed function due to preservation injury, and one had primary nonfunction. Surgical complications included bile peritonitis (1), ruptured aneurysm of an aortic conduit (1), and thrombosis of the hepatic artery necessitating retransplantation (2). Three of our patients died, one from postoperative cerebral edema, one of primary nonfunction of the graft, and one of ruptured aneurysm of an aortic conduit. Our overall survival rate was 72% with a follow-up of 3 to 32 months. Pediatric liver transplantation can now provide successful treatment and cure of liver diseases considered, until recently, dismal and hopeless.

Although dehydrated obstructing mucus is thought to account for the obstructive pathology involving the lungs, the pancreas, the reproductive system, and the intestinal tract, its relationship with CF-associated liver disease remains largely hypothetical and little is known about possible risk factors. Complete clinical and autopsy records were available in 38 of 73 deaths occurring over a 10-year period. The liver was normal in only five cases, and they were all infants. Steatosis was the only lesion present in 9, hypoxic liver disease was documented in 8, and biliary cirrhosis in 16 (focal in 10 and multilobular in 6). There was no relationship between the presence of cirrhosis, gallbladder abnormalities, age at death, and clinical status recorded during the year precoding their demise. Mucus plugs characterized by amorphous eosinophilic material within proliferated bile ductules were present in 75% of children with focal or multilobular biliary cirrhosis as opposed to 14% in those without (p = 0.015). A history of meconium ileus or its equivalent was recorded more frequently (p = 0.038) in those with cirrhosis. Finally, biliary cirrhosis was invariably present when there was a history of meconium ileus or its equivalent and when mucus plugs were noted. These findings suggest that patients with intestinal obstruction are at greater risk for the development of cirrhosis and that strategies should be developed to increase the detergent capacity of bile and its flow in order to decrease the viscosity of mucus in the biliary tree.

Eight infants presented with a malabsorption syndrome, normal fasting triglycerides, hypocholesterolemia (64.3 ± 10.0 mg/dl), and deficiency of vitamins A and E. Plasma low-density lipoprotein, apolipoprotein B, and apolipoprotein A-I were decreased. After a fatty meal, plasma triglycerides did not increase and chylomicrons could not be identified. Lipoprotein composition was characterized by normal apoproteins, high phospholipids, and low cholesterol. Increased triglycerides were present in low-density lipoproteins. Immunoperoxidase localization of apolipoprotein B on fasting biopsy specimens showed increased staining of the lipid-laden intestinal epithelial cells compared to normals. On electron microscopy after a fat load, the enterocytes contained large numbers of fat particles vesiculating the endoplasmic reticulum. These particles, morphologically similar to chylomicrons, were also present as aggregates of well-individualized lipid droplets within dilated vesicles in the Golgi zone, but were not seen in the intercellular spaces and lacteals. This recessively transmitted condition differs from abetalipoproteinemia and from the homozygous form of hypobetalipoproteinemia and may be caused by a defect in the final assembly of chylomicrons or in the mechanism of their exocytosis.

The effect of sulfation of common bile acids on the formation of bile was investigated in male rats by infusing them with the sulfate esters of cholic, chenodeoxycholic, deoxycholic, lithocholic or dehydrocholic acid in four step-wise, increasing doses. Each dose was infused for 30 min and bile collected every 10 min. Control studies were performed by using either albumin solution (the bile acid carrier) or corresponding nonsulfated bile acids at concentrations similar to those of the sulfated products. The secretion of sulfated bile acids was slower and less than that of nonsulfated bile acids, demonstrating transport maximum kinetics rather than the secretory rate maximum characteristic of nonsulfated bile acids. Sulfation significantly increased bile salt-independent bile flow and the choleretic potency of the bile acids tested. With the exception of deoxycholic acid, which had a slight stimulatory effect, bile acid sulfation generally prevented a rise in bile acid-dependent phospholipid and cholesterol secretion. In fact, it reduced biliary phospholipid and cholesterol secretion associated with the secretion of endogenous bile acids. These data are in agreement with the physicochemical properties of sulfated bile acids. They indicate that sulfation prevents the cholestatic action of nonsulfated bile acids, perhaps by increasing bile flow via a high choleretic potential and/or by stimulating bile acid-independent bile flow. The effect of sulfated bile acids on the secretion of biliary phospholipids may protect the canalicular membrane from the detergent properties of bile acids and may thus block the cholestasis which results from high, nonsulfated bile acid concentrations.

Purkinje cells were identified in monolayer cultures obtained from trypsin-dissociated cerebella of embryonic and early postnatal mice by the Purkinje cell-specific monoclonal antibodies PC1, PC2, PC3 and UCHT1. These cells also expressed the neuronal marker L1 antigen but not the glial markers, glial fibrillary acidic protein or 04 antigen. They also expressed tetanus toxin receptors, PC4, M1 and Thy-1 antigens. Survival of Purkinje cells was best: (a) when cerebella were taken from mice not older than one day of age: (b) when cells were seeded at higher plating densities; and (c) cultured in chemically defined medium which facilitates the survival of neurons. No Purkinje cells could be detected in cultures from mice older than 6 days. PC1 antigen expression developed in vitro on the same time scale as in vivo, i.e. it was first detectable at the equivalent of postnatal days 3-4. At this stage cell bodies had a size of 13-14 micron in diameter and few processes. Dendrite-like arborizations, with more than one primary dendrite, extension of usually only one thin and long (0.5-1.6 mm) axon-like process and collaterals directed preferentially towards other Purkinje cells, developed with time in culture until the final form was reached by the equivalent of approximately day 16. Cell body size was 18-19 micron in diameter at this stage. Cell shapes were reminiscent of those described in certain cerebellar mouse mutants and in experimentally produced agranular cerebella. Many ultrastructural features of these cells correlated with those described for the in vivo counterpart. However, there was a lack of spiny branchlets and abnormally long persisting somatic spines. Synaptic contacts of the 'en passant' type could be seen at the Purkinje cell soma. Gray type I synapses were seen on Purkinje cell dendrites and spines.

Five monoclonal antibodies reacting with intracellular constituents of Purkinje cells were investigated by means of indirect immunofluorescence on fresh-frozen sections of the cerebellum and retina from developing and adult normal and mutant mice. Antibodies PC1, PC2 and PC3, which recognize Purkinje cells, but no other cerebellar neuron type, label these cells from day 4 onward. PC4 antigen is expressed in addition to Purkinje cells also in granule cells and neurons of deep cerebellar nuclei and appears in Purkinje cells at day 4. M1 antigen (Lagenaur et al. 1980) is first detectable in Purkinje cell bodies by day 5; it is also detectable in deep cerebellar neurons. In the adult retina, only PC4 antigen is detectably expressed and is localized in the inner segments of photoreceptor cells.

Experimental work has shown that less polar bile acids, although better absorbed passively, have a reduced affinity for the ileal transport system and are more extensively adsorbed to residues and microbes. This study examines the fecal excretion of bile acids and the % adsorbed in relationship with the qualitative pattern in 2 categories of patients with an intact ileum. The contaminated small bowel syndrome was diagnosed in 4 cases of chronic idiopathic intestinal pseudoobstruction with fat (19.3 ± 6.8g/24h) and bile acid (693 85mg/m2/24h) malabsorption. Primary bile acids were essentially absent. The sum of deoxycholic, lithocholic, 3-ketocholanoic and 3-betacholanoic acid accounted for 80.3±6.2% of the total. Only a small % (16.7±5.4) of bile acids could be recovered in the aqueous phase. A marked reduction (P < .001) of the anaerobic flora in a fresh stool obtained from 6 CF children on triple I.V. therapy was associated with a reduction in the concentration of secondary forms (P<.005) and with a 5-fold increase (10.2 vs 52.7) in the % of bile acids in the aqueous phase when compared to 7 studied off antibiotics. In 4 CF patients studied both on oral cloxacillin and during I.V. therapy, there was no change in steatorrhea (15.9±5.7 vs 18.8±7.8g/24h) but a large decrease in bile acid loss (751±182 vs 366±93). This study suggests that the extent of microbial transformations of bile acids in the GI tract plays a role on their absorption.

In this prospective study, 18 consecutive children suspected of cow's milk protein intolerance (C.M.P.I.) on clinical grounds were investigated before and after challenge with cow's milk. One-hour blood-xylose, serum-IgE, eosinophil count, serum-complement (C3) and a jejunal biopsy specimen for histology and disaccharidase activity were obtained from all patients before challenge. Serum-complement was measured again 24 h after the beginning of the challenge and the first three tests were repeated on the fifth day. A second jejunal biopsy was obtained in 9 of the first 10 children. 15 of the 18 children were considered to have C.M.P.I. The one-hour blood-xylose test emerged as a simple and valuable test in the diagnosis of C.M.P.I. A significant drop (51--81%) in the one-hour blood-xylose level was observed in all 15 patients. In all patients but one it dropped below 25 mg/dl. Mean value (+/- S.D.) for the group was 47.5 +/- 11.1 mg/dl before and 17.2 +/- 4.2 mg/dl after cow's milk ingestion.

A retrospective analysis of oral D-xylose tolerance tests in 435 pediatric patients was performed. A significant difference was found between 126 normal subjects and 47 untreated children with celiac disease one hour after load. The one-hour value was found to be more reliable than was fecal fat analysis in screening children for celiac disease. Sex, age, weight, and body surface did not influence the results of the one-hour value in the control subjects. Forty-eight children with cystic fibrosis had one-hour xylose levels within the normal range, but the means at 90, 120, and 180 minutes after load exceeded significantly (P less than 0.01) those of the controls. In a nonceliac group of 63 children with abnormally low xylose levels, almost all were found to have clinical conditions compatible with upper small bowel mucosal impairment. This study shows that a single estimation of xylose in blood one hour after load is a reliable index of small bowel mucosal function. It is a good screening test for celiac disease and small bowel disorders producing malabsorption in children.

The 72 hour fecal output of chymotrypsin expressed in milligrams per kilogram of body weight was measured in 156 children. Values in 35 control subjects and in 56 children with various intestinal and hepatobiliary diseases did not overlap with those of 53 children with cystic fibrosis or with three children who had chronic pancreatic disease with steatorrhea. However, in one child with chronic relapsing pancreatitis and in seven with cystic fibrosis who had a normal fat excretion, enzyme activity was normal. The only value within the range associated with pancreatic insufficiency was seen in a case of intestinal scleroderma. Duodenal enzyme concentration in 35 children correlated well with fecal measurements in primary pancreatic disease with a significant degree of achylia. The 72 hour fecal output of chymotrypsin expressed in milligrams per kilogram of body weight was measured in 156 children. Values in 35 control subjects and in 56 children with various intestinal and hepatobiliary diseases did not overlap with those of 53 children with cystic fibrosis or with three children who had chronic pancreatic disease with steatorrhea. However, in one child with chronic relapsing pancreatitis and in seven with cystic fibrosis who had a normal fat excretion, enzyme activity was normal. The only value within the range associated with pancreatic insufficiency was seen in a case of intestinal scleroderma. Duodenal enzyme concentration in 35 children correlated well with fecal measurements in primary pancreatic disease with a significant degree of achylia.

To test for extrahepatic biliary obstruction in infants and children with persistent cholestatic liver disease, serum samples from 50 patients were examined for the presence of an abnormal low-density lipoprotein (LP-X). LP-X was identified by immunoelectrophoresis in sera from 16 infants aged 2 to 6 months and from 8 infants and children (including follow-up on 1 patient) aged 7 to 46 months with extrahepatic biliary obstruction without hepatic decompensation. However, LP-X was not found in sera from 9 patients (including follow-up on 4 patients) aged 7 to 40 months with extrahepatic biliary obstruction and hepatic decompensation. LP-X was absent in 20 of 22 infants aged 1 to 6 months with neonatal hepatitis, but was detected in the remaining 2 infants with marked intrahepatic cholestasis. These findings suggest that the LP-X test is a sensitive means for detecting the presence of severe cholestatic liver disease in infants. Results of a modified 131 I-Rose Bengal excretion test performed in 11 infants with severe cholestasis with orally administered cholestyramine, 4 Gm. per day, showed that infants with extrahepatic cholestasis excreted 7.8 per cent ± 0.6 (M ± S.E.) and those with intrahepatic cholestasis 26.2 ± 2.9 (M ± S.E.) of the administered radioactive label. The combination of LP-X and modified 131 I-Rose Bengal excretion tests represents, thus, a new diagnostic tool for identification and differentiation of extrahepatic and intrahepatic cholestasis in infants.