Showing papers in "Journal of Pediatric Gastroenterology and Nutrition in 1988"

The pancreatic duct cell: proliferative capabilities, specific characteristics, metaplasia, isolation, and culture.

Abstract: The pancreatic duct cell, although a minor cell type of the pancreas, plays an important role in fluid/electrolyte and mucin secretion, and has been implicated in the development of pancreatic cancer, alcoholic pancreatitis, and cystic fibrosis. In the normal pancreas, the duct cell has the same low proliferative rate as acinar and endocrine cells. Under certain pathological circumstances, duct cells, as well as acinar and islet cells, may be stimulated to proliferate more rapidly. Pancreatic duct cells exhibit certain features not shared by acinar and/or endocrine cells, including a variety of antigens, mucins, enzymes, and morphological features. Adult duct cells resemble fetal pancreatic duct-like cells morphologically, but they have differentiated to at least a limited extent from their precursor cell type. Although there is no evidence that duct cells differentiate into acinar cells after pancreatic morphogenesis is complete, some islet cells develop from duct epithelium in the early postnatal period. Some pathological conditions may lead to the postnatal formation of islet cells from duct cells and may cause acinar cells to become duct-like in morphology or to die and be replaced by duct cells. A better understanding of duct cells is now possible because of the development of techniques for their isolation and culture free from other cell types. Several such techniques are reviewed.

Anaphylactic Shock Due to Cow's Milk Protein Hypersensitivity in a Breast-Fed Infant

Abstract: 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 Symptoms resolved after cow's milk was withdrawn from the mother's diet and lactation was resumed.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.

Chronic intestinal pseudo-obstruction syndrome in pediatrics. Results of a national survey by members of the North American Society of Pediatric Gastroenterology and Nutrition.

Abstract: A total of 87 cases of chronic intestinal pseudo-obstruction were identified as fitting the criteria for the syndrome. Five families, three with autosomal dominant inheritance, accounted for 15 cases. The remainder were single cases in families, indicating either autosomal recessive inheritance, spontaneous mutation, or acquired disease. Of the 87 patients, 47 were male; 19 patients were symptomatic at birth and 37 (43%) within the first month of life; 64% were diagnosed by the first year of age and the remainder were diagnosed by 18 years of age. Patients currently range in age from 3 months to 24 years. Abdominal distension in 70, vomiting in 50, and constipation in 50 of the 87 cases were the three commonest presenting symptoms. Diarrhea and failure to thrive were present in 20 cases. Urinary tract infection and failure to void were present in 10 cases. Diagnosis was established by clinical presentation, radiographic studies, and at exploratory laparotomy. Esophageal motility was abnormal in 14 patients. Anal manometric studies were done in 16 and showed normal recto-anal inhibitory reflex in all but one. Only 34 patients had biopsy studies as part of their evaluation and, of these, only 12 were full-thickness. Abnormal plexuses were found in eight and degeneration of smooth muscles in four. There was little or no benefit from the use of any medication to promote motility. One patient with intractable pseudo-obstruction benefited from a subtotal enterectomy. Of those patients not lost to follow-up, 31.4% died; 43% of these deaths occurred within the first 6 months from complications of total parenteral nutrition. One infant had a complete spontaneous remission by 1 year of age, with normalization of radiographic findings; another had partial remission by 6 months of age.

A controlled trial on utility of oral zinc supplementation in acute dehydrating diarrhea in infants.

Abstract: A controlled, randomized trial was conducted in 50 infants with acute dehydrating diarrhea to evaluate the effect of oral zinc supplementation in acute diarrhea. After completion of rehydration, 25 infants in Group A received oral zinc sulfate (20 mg elemental zinc twice daily) and an equal number in Group B were given placebo (glucose). Both groups were comparable with respect to various initial characteristics including nutritional status, diarrheal disease, serum alkaline phosphatase, and serum and rectal mucosal zinc content. During therapy all the assessed parameters of zinc status (serum alkaline phosphatase and serum and rectal zinc) recorded significant elevation and reduction in Groups A and B, respectively. At recovery the zinc status of Group A was significantly better and was nearer that of healthy controls. The diarrheal duration and frequency in the zinc-supplemented group were lower, but the differences were not significant (0.05 less than p less than 0.1). However, when only subjects with relatively severe initial zinc depletion (rectal zinc lower than the 15th percentile of healthy controls; 11 in Group A and 14 in Group B) were considered, the diarrheal duration and frequency were significantly (p less than 0.05 and p less than 0.01, respectively) lower in the zinc-supplemented cases. Weight gain in both groups was similar. It is concluded that oral zinc administration in acute diarrhea can replenish body zinc status and this may shorten the diarrheal duration and frequency in children with relatively severe zinc depletion.

Case control study on nutritional risk factors in celiac disease.

Abstract: This study explored whether risk or protective nutritional factors have a role in childhood celiac disease. The effect of bottle feeding and early introduction of gluten to the diet was evaluated in a case control study. For each case, about 10 controls were recruited: sample size was determined as required for the evaluation of the study hypothesis. Patients were significantly less breast fed than were controls. Bottle-fed children had an earlier introduction of gluten to the diet than did controls, but when early gluten introduction was analyzed across strata of breast-fed or bottle-fed children, no risk was attributed to it. Bottle feeding appeared to be a significant risk factor in children who received gluten early as well as in those who received gluten later. Breast-feeding rates for patients and controls were equal at birth, but lower for patients by the age of 1 month: from then onward, there was a constant difference between patients and controls regarding the percentage still at breast. Interruption of breast feeding was a risk factor in celiac disease, but early gluten introduction did not appear to be a similar risk factor in the present study.

The bowel habit of milk-fed infants.

Abstract: A prospective study of the bowel habits of 240 infants aged 2-20 weeks was performed. Half of the infants were breast fed and half were fed cow's milk formula (CMF). Breast-fed infants had a higher mean frequency of defaecation than did CMF-fed infants at 2, 4 and 8 weeks (p less than 0.02). By 16 weeks the mean frequency of bowel actions per day of infants of both feeding groups was 2. With increasing age, infants produced fewer stools of greater firmness (p less than 0.05) though the breast fed tended to pass larger, softer stools than did the CMF-fed infants until the introduction of weaning foods (p less than 0.05). Stool colour was uniformly yellow in both feeding groups until the introduction of weaning foods, when it changed to brown. Weaning foods were introduced at an earlier age in the CMF-fed infants (p less than 0.05), though by 20 weeks 93% of all infants had received some. These data define the normal range of the bowel habits of milk-fed infants and may reflect differences in gastrointestinal function between those fed on the breast and with CMF.

Development of five metabolic activities associated with the intestinal microflora of healthy infants.

Abstract: Summary:The establishment of a functionally active intestinal flora was followed in 17 healthy Swedish children from birth up to 6 months of age. Utilizing gas chroma-tography, spectrophotometry, and gel electrophoresis, feces were analyzed on certain biochemical markers that reflect the action of t

Eosinophilic gastroenteropathy in childhood.

Abstract: Eosinophilic gastroenteropathy (EG) is an uncommon, idiopathic disease in children that is characterized by eosinophilic inflammation of the intestine. Over a 7-year period 17 infants and children with EG were evaluated; the retrospective review of their clinical data constitutes the basis of this report. A scale developed for grading the degree of mucosal eosinophilia was used in the evaluation of the intestinal histopathology; all patients had eosinophilic infiltration that was far more severe than that seen in other intestinal disorders of childhood. Peripheral eosinophilia was observed in 12 patients. However, two more had evidence of rapid turnover of eosinophils with significantly increased numbers of precursors in bone marrow and intense intestinal infiltration. Serum IgE correlated with the severity of the disease; extreme elevations were associated with chronic severe illness similar to that commonly reported in adults. Evidence of viral infection in two patients and dietary responsiveness in two infants bring to question the specificity of diagnosis on histology alone. Treatment with oral cromolyn sodium and/or prednisone was effective, but some patients have remained dependent upon therapy.

Clinical and laboratory correlates of esophagitis in young children.

Abstract: To develop clinical and laboratory criteria to identify young children with gastroesophageal reflux (GER) who are at particular risk for esophagitis and then to monitor their clinical course we have prospectively studied 40 subjects (ages 2-22 months, mean 8 months) with persistent symptoms of GER with 18 h intraesophageal pH monitoring, endoscopy, and grasp and suction esophageal biopsies. Esophagitis was found in 16 of 20 patients under 7 months, 12 of 14 between 7 and 12 months, and five of six between 12 and 24 months. Esophagitis was equally frequent in those patients with or without poor weight gain, wheezing, or irritability. Only 15% of patients with esophagitis had occult blood in their stool. No parameter of intraesophageal pH monitoring was both sensitive and specific in identifying patients who were ultimately found to have either mild or severe esophagitis. Follow-up data (37 patients) revealed that fundoplication was eventually required in four of eight patients with severe esophagitis, three of 22 with mild esophagitis, and none of seven without esophagitis. Currently used clinical and laboratory assessments of GER have limited value in identifying those children with either normal esophageal mucosa or at risk for varying degrees of esophagitis. Preliminary observations suggest that the presence of severe histologic esophagitis at the time of initial evaluation may have prognostic value in identifying those patients most likely to fail medical therapy and require fundoplication.

Relationship of endomysial antibodies to jejunal mucosal pathology: specificity towards both symptomatic and asymptomatic celiacs.

Abstract: Serum immunoglobulin A class antibodies reactive to the endomysial lining of the smooth muscle bundles of the gastrointestinal tract have recently been reported to be specific and sensitive indicators of celiac disease (CD). A total of 203 subjects were examined for serum endomysial antibodies (EmA) and in 103 small bowel biopsies were obtained. EmA were detected in 43 cases including 26 CD patients evaluated during the gluten challenge phase of diagnosis by European Society for Pediatric Gastroenterology and Nutrition criteria, 11 of 53 symptomatic patients, and 6 asymptomatic family members. All patients with detectable antibody at the time of biopsy exhibited grade III-IV villous atrophy. Disaccharidase activities performed in 19 cases revealed severe deficiencies. EmA were not detected in 160 subjects including 42 infants and children with chronic nonspecific diarrhea. Eighteen of these possessed grade II-III villous atrophy with moderate disaccharidase deficiency and 24 were found to have normal histology and enzymes. The EmA were also not detected in 3 CD patients who were well maintained on a gluten-free diet for greater than 1 year and 25 asymptomatic family members exhibiting normal histology and enzymes. An additional 90 infants and children with other gastrointestinal and liver diseases were also negative for the serum EmA. Fourteen of these patients underwent biopsies and were demonstrated to have normal histology.

Feeding gastrostomy in neurologically impaired children: is an antireflux procedure necessary?

Abstract: Some authors recommend a routine "protective" antireflux procedure (ARP) in neurologically impaired children undergoing feeding gastrostomy (FG). Over 4 years, we performed FG in 107 neurologically impaired children aged 1 month to 16 years. Ninety-eight had preoperative radiological assessment for gastroesophageal reflux (GER), which was documented in 44, of whom 33 had FG plus ARP and 11 had FG alone. Seven of the 11 subsequently developed symptomatic GER and 5 of them had a secondary ARP. Of the 54 children with no demonstrable GER preoperatively, 3 children underwent FG plus ARP. The remaining 51 had FG alone. There was one postoperative death. Of the 50 surviving patients, 22 developed symptomatic GER and 17 of these had a subsequent ARP. Mean follow-up of 20.0 months showed that the risk of developing GER after FG alone was not influenced by age, sex, indication for FG, underlying diagnosis, or method of gastrostomy. There was no significant difference in mortality and early morbidity between patients undergoing FG alone and those having FG with simultaneous or subsequent ARP. Only 44% of our patients in whom GER was not demonstrated initially developed symptomatic GER followed FG alone. This incidence does not justify a routine "protective" ARP.

An electron microscopic investigation of time-related changes in the intestine of neonatal mice infected with murine rotavirus.

Abstract: Seven-day-old mice were infected orally with murine rotavirus (EDIM) and regions of the gut examined at 24 h intervals up to 7 days by electron microscopy. Structural changes were correlated with data on viral antigen production, thymidine kinase activity, and clinical signs of diarrhea. No pathological changes were detected in the colon. Infection and structural damage were confined to the small intestine, with middle regions showing the most pronounced changes. Constriction of villus bases, edema of the lamina propria, and vacuolation of enterocytes occurred at 24 h postinfection (PI), i.e., before evidence of major virus replication. Transient villus atrophy occurred at 48 h PI. Recovery of villus length was evident by 72 h PI accompanied by evidence of marked enterocyte replication at villus bases. Many enterocytes were damaged with little evidence for the presence of virus particles. By 96 h PI, villi had almost recovered from infection although some enterocytes were still damaged; no virus particles were detected in these cells. A second phase of villus damage and edema of the lamina propria occurred at 120 h PI; the pathology resembled that at 24-48 h PI. By 144 to 168 h PI, recovery of the mucosa from infection was virtually complete. We suggest that many of the pathological features following rotavirus infection result from rotavirus-induced ischemia of villi and that diarrhea results from malabsorption of fluid by damaged villi and hypersecretion of ions released from increased numbers of dividing cells at villus-crypt borders.

Nonnutritive sucking in tube-fed preterm infants: effects on gastric motility and gastric contents of somatostatin.

Abstract: The present study investigated the way that sucking of a pacifier influences gastric secretory and motor functions in connection with tube feeding. Experiments were performed on eight preterm infants who were tube fed twice--once with and once without sucking of a pacifier. The time for tube feeding was significantly decreased and gastric retention decreased in five of seven infants when sucking a pacifier. Maternal milk was found to contain gastrin-17, somatostatin-14, and a somatostatin-like peptide larger than somatostatin-28. Somatostatin levels were significantly reduced in connection with non-nutritive sucking. Gastrin levels were increased in six of ten experiments 2 h and/or 3 h after bolus feeding, suggesting that these peptides were not only supplied by the milk, but were also released from the gastric mucosa. The presence of gastrin and somatostatin in gastric aspirates was established by use of chromatographic methods. The results indicate that somatostatin and gastrin are released into the gastric lumen in preterm infants and that sucking of a pacifier, in connection with bolus feeding, stimulates the gastric motor functions and facilitates the digestion process, probably via activation of vagal mechanisms.

Infrared analysis for determining macronutrients in human milk.

Abstract: Infrared (IR) analysis is widely used for routine analysis of cow milk in dairies. The aim of this study was to evaluate the precision and accuracy of an IR analyzer (Milko-scan 104) for measuring protein, fat, carbohydrate, and, indirectly, the energy content of human milk. The results of the IR analysis were compared with those of the following reference methods: protein--Kjeldahl (nitrogen minus nonprotein nitrogen); fat--Roese Gottlieb; carbohydrate--lactose enzymatic assay; energy--bomb calorimetry. The precision (repeatability coefficient of variation) of the IR results was high for all four components: protein 0.4%, fat 1.0%, carbohydrate 0.2%, and energy 0.1%. There was a close linear covariation between IR results and reference results. [Protein content was determined with an error (SD) of 0.01 g/100 ml and fat with an error of 0.03 g/100 ml.] The covariation between IR carbohydrate results and the results of the lactose assay was poor, probably because the oligosaccharides in the milk were included in the results from the IR analysis and not in the results from the lactose assay. IR analysis is a valuable method in research, especially in epidemiological surveys, in which large numbers of samples are analyzed, and for continuous monitoring of the nutritional value of human milk in milk banking programs.

Changes in the fatty acids pattern of red blood cell phospholipids induced by type of milk, dietary nucleotide supplementation, and postnatal age in preterm infants.

Abstract: The fatty acid profile of red blood cell phospholipids and the total phospholipid and cholesterol contents of erythrocyte membrane in preterm infants in the first month of life were studied. Influences of human milk and adapted formula and dietary nucleotides supplementation at a level similar to that found in human milk were evaluated. Nineteen preterm newborn infants with adequate weight for gestational age were fed their own mother's preterm human milk, 18 with a standard milk formula and 18 with the same formula supplemented with nucleotides. Blood samples were obtained at birth from cord blood, and at 30 days of age. At 1 month of life, linoleic acid rose in formula fed infants compared to those fed human milk (p less than 0.05) and relative amounts of 20:3w6, 20:4w6, 22:4w6, 22:5w6, and total polyunsaturates of the w6 series greater than 18 carbon atoms were significantly decreased in standard milk formula fed infants (p less than 0.05-0.01). No significant differences for these fatty acids were found between human milk and nucleotide milk formula infants. Docosahexaenoic acid (22:6w3) decreased from birth to 1 month of age in formula fed infants (p less than 0.01) but not in human milk fed infants. Infants fed nucleotide milk formula showed intermediate values for 20:3w6 and 20:4w6 (p less than 0.1) between infants fed human milk and those fed standard milk formula.(ABSTRACT TRUNCATED AT 250 WORDS)

Intestinal enzyme profiles in normal and rotavirus-infected mice.

Abstract: To investigate further the pathophysiology of rotavirus-induced diarrhea, changes in specific activities of eight relevant intestinal enzymes [alkaline phosphatase, thymidine kinase, lactase, maltase, sucrase, Na+,K+-adenosine triphosphatase (ATPase), adenylate and guanylate cyclases] were measured following infection of suckling mice with murine rotavirus (epizootic diarrhea of infant mouse strain) and compared with age-matched control mice. The concentration of lactose within the lumen of the gastrointestinal tract during infection was also measured. During the course of infection, activities of alkaline phosphatase and lactase decreased, whilst the activity of thymidine kinase increased. Precocious maturation profiles of sucrase and maltase enzymes were observed. No significant changes were detected in the activities of Na+,K+-ATPase or the adenylate and guanylate cyclases. These results are discussed in relation to existing and novel hypotheses on the pathogenesis of rotavirus-induced diarrhea.

Pathophysiology of gastroesophageal reflux and distal esophageal motility in children with gastroesophageal reflux disease.

Abstract: We investigated the mechanisms of gastroesophageal reflux (GER) and esophageal motility during endogenous esophageal acid exposure in 17 patients with reflux disease alone (age range 3-20 months) (group A) and in 10 patients with reflux disease complicated by esophagitis (age range 4-19 months) (group B), by simultaneous recording distal esophageal sphincter relaxation was the predominant mechanism of reflux in both groups of subjects; however, it was more frequent in group B patients (Bpts), whereas reflux episodes due to appropriate sphincter relaxation were detected more frequently in group A patients (Apts). During endogenous acid exposure, primary peristalsis was the most frequent esophageal motor event in all patients; furthermore, its amplitude was significantly higher in Apts as compared with Bpts. Primary peristalsis was more efficacious (rise of intraluminal pH by at least 0.5 unit) in patients with reflux disease alone, whereas nonspecific motor irregularities were more common in children with reflux esophagitis. It is concluded that the major mechanism of GER in patients with reflux esophagitis is an inappropriate sphincter relaxation; reflux due to appropriate sphincter relaxation is associated with less severe reflux disease; and patients with esophagitis exhibit a deranged esophageal motility during spontaneous acid exposure.

Iron status in the first year of life.

Abstract: The iron status of babies of different race born at term to mothers in an inner city area was studied at birth and during the first year of life and related to maternal iron status. Haemoglobin and ferritin were measured in the mother at term (n = 81) and in the baby in cord blood (n = 81), at 6 months (n = 55), and at 1 year (n = 51). No relationship was found between the iron status of mothers and their babies at birth. However, iron stores at birth did affect later iron status, cord ferritin being significantly related to ferritin at 6 months (r = 0.42, p less than 0.01) and 1 year (r = 0.55, p less than 0.01) but not to haemoglobin at these ages. No relationship was found between haemoglobin iron at birth and subsequent iron status. Introduction of full cow's milk before the age of 6 months was associated with iron deficiency at this age and at 1 year. By the age of 1 year, iron deficiency was also associated with feeding greater than 900 ml whole cow's milk a day, inadequate feeding with solids, and higher weight gain. No stool parasites were found at the age of 1 year, and the presence of occult blood in stools did not significantly affect iron status at this age. At 1 year of age, 49% of these infants had low iron stores, including 20% with iron deficiency anaemia. Considerable improvement could result from simple changes in dietary practices.

Characterization of binding of simian rotavirus SA-11 to cultured epithelial cells.

Abstract: Rotavirus causes enteritis in both man and animals. The identity of the rotavirus receptor is not known. The nature of the binding interaction and the relationship between virus binding and internalization have not previously been reported. We studied the binding of [5,6-3H]uridine-labeled rotavirus SA11 to confluent monolayers of MA104 cells. We found approximately 13,000 receptor units per cell. The binding was sodium-dependent, pH-insensitive between 5.5 and 8, independent of added calcium, and dependent on sialic acid residues in the membrane. It could be inhibited by mucin. These features may provide clues to the identity of the receptor. Virus was not internalized to significant extent at 4 degrees C. After warming to 37 degrees C, virus was internalized over about 60 min. All binding sites appeared to be equally internalizable. The techniques developed to distinguish between binding and internalization may help to elucidate the mechanism of internalization.

Effect of feeding volume on early postcibal gastroesophageal reflux in infants

Abstract: Using esophageal pH monitoring, we have investigated the effect of feeding volume on early (1 h) postcibal gastroesophageal reflux (GER) in a population of 50 infants referred for evaluation. Two feedings with the volume of both feedings specified (9 and 18 ml/kg) were given to one group of infants. A second group was given one feeding ad libitum and another specified at 9 ml/kg. Volume of intake was a very significant determinant of both the total duration and the maximum single continuous episode of GER during early postcibal esophageal pH monitoring in both groups by paired analyses. This effect was observed in infants with significant GER (n = 44) and in a subgroup of infants who were normal (n = 6).

Immunohistochemical findings in the intestine of IgA-deficient persons: number of intraepithelial T lymphocytes is increased.

Abstract: Summary:We studied jejunal biopsy specimens of 13 IgA-deficient persons (IgAdp) and 12 controls. Four Ig-Adp had celiac disease, in the others the jejunal mucosa appeared normal. Monoclonal antibodies and the peroxidase technique were used to identify T lymphocytes, T-lymphocyte subsets, HLA-DR anti

Liver transplantation therapy for children: Part 1.

Abstract: Amelioration considerable du taux de survie grâce a la selection minutieuse des malades et des donneurs, a la technique operatoire, au traitement pre- et post-operatoire par l'introduction en particulier de la cyclosporine. Les principales indications sont l'atresie des voies biliaires, certains troubles metaboliques, la cirrhose apres hepatite, l'insuffisance hepatique aigue, les tumeurs malignes du foie, la fibrose hepatique congenitale

Unresponsive enteropathy associated with circulating enterocyte autoantibodies in a boy with common variable hypogammaglobulinemia and type I diabetes.

Abstract: Summary: A 13-year-old boy with common variable hypogammaglobulinemia and type I diabetes developed a severe enteropathy that proved to be unresponsive to any treatment, including total parenteral nutrition. No evidence of known etiologies of malabsorption and/or secretory diarrhea was found in this subject. A high titer of complement-fixing enterocyte autoantibody was persistently found in the patient's serum. These features suggest that the enteropathy of this primarily immunodeficient subject had an autoimmune origin. A cycle of cyclophosphamide failed to show any amelioration of the diarrhea or a significant decrease in the autoantibody titer.

Nutritional requirements in cystic fibrosis: a review.

Abstract: Summary Food intake is often low in cystic fibrosis (CF), although the patient usually needs more than the standard recommended daily allowance (RDA). Clinics giving food supplementation from an early age report improved survival and nutritional status. Nutritional improvement has been facilitated by improved forms of pancreatin. An additional calorie intake in CF is required to compensate for losses due to malabsorption and to allow for catch-up growth when necessary. With advanced pulmonary disease there are additional requirements for infection and increased work of breathing. There is also evidence for an increased basal metabolic activity in CF, perhaps related to the fundamental intracellular biochemical disorder. Together these factors add to a daily need for 120%-150% RDA for optimum growth and homeostasis.

Simultaneous pH recordings from multiple esophageal sites in children with and without distal gastroesophageal reflux.

Abstract: We made continuous, simultaneous recordings of esophageal pH from three sites in the esophageal body, for 18-24 h, in 11 children with normal prolonged distal esophageal pH studies (Group I) and in 14 children with abnormal distal esophageal pH recordings (Group II). A flexible catheter housing four antimony microelectrodes was used, and data were stored in a portable recorder. A computer allowed for evaluation of the percent of time esophageal pH was less than 4.0, number of reflux episodes per hour, acid clearance time, and the duration of longest reflux episode. Recordings made while subjects were upright or recumbent could be distinguished and analyzed separately. In the recumbent position, comparison of pH recordings from distal, middle, and proximal esophageal pH electrodes in Group I showed significant decreases in the percent of time spent with pH less than 4.0, reflux episodes per hour, acid clearance time, and duration of longest reflux episode in the proximal esophageal sites, with a near negligible total acid exposure in the most proximal electrode. In Group II subjects, however, comparison of recumbent recordings from distal, middle, and proximal esophagus indicates that the proximal esophagus is highly exposed to acid reflux and that the decrease in acid exposure from distal to proximal esophagus in reflux patients is not proportionally as great as that of Group I. The data suggest that in the recumbent position, the ability of the subjects with abnormal reflux scores to protect the upper esophagus is less than that of subjects with normal amounts of distal esophageal acid exposure.