Pediatric gastroenterology at the Mount Sinai hospital

The history of pediatric gastroenterology at Mount Sinai begins in 1960. Early publications by Drs. Korelitz and Gribetz on the management of inflammatory bowel disease in children served as the preface to forty years of progress in this important area. The history of pediatric gastroenterology includes important work by many individuals, including Horace Hodes, Lotte Strauss and Frederick Kopel. Early observations on the nature of inflammatory bowel disease (IBD), and its course, preceded work on nutritional therapies for IBD, mechanisms of gene-nutrient interactions, regulation of gene transcription, and molecular processes involved in bile transport in the liver and small intestine. Over the last twenty years, the division has grown in size and reputation. Today there are fourteen full-time faculty - 9 M.D.'s and 5 Ph.D.'s - who work in three funded research laboratories. There are also five advanced practice nurses (including three nurse practitioners), two social workers and two nutritionists, as well as several administrators and assistants. In addition to being recognized as a premier center for the treatment of children with general pediatric gastroenterological problems, especially inflammatory bowel disease, the division is also known as one of the nation's largest pediatric liver and liver transplant centers, and it is rapidly becoming one of the largest pediatric short gut syndrome and small bowel transplant centers.

Living related liver transplantation for acute liver failure in children

The mortality rate among children with acute liver failure (ALF) on the waiting list for liver transplantation is high. We present our experience with living related donor liver transplantation (LRD-LT) in children who required urgent transplantation for ALF. Between December 1995 and July 1997, 6 children underwent LRD-LT for ALF. Cause of liver failure, recipient and donor demographics, clinical and laboratory data, surgical details, complications, and 6-month and 2-year graft and patient survival were recorded. Five boys and 1 girl received left lateral segment grafts from their parents. The mean age was 4 +/- 2.8 years (range, 1 to 9 years). ALF was caused by Wilson's disease in 1 patient and sickle cell intrahepatic cholestasis syndrome in 1 patient; in 4 patients, the cause was unknown. All patients had mental status changes; 2 were on life support. Mean pretransplantation liver function test values were: alanine aminotransferase, 972 +/- 565 U/L (normal, 1 to 53 U/L), total bilirubin, 31.3 +/- 12.4 mg/dL (normal, 0.1 to 1.2 mg/dL), prothrombin time, 34.3 +/- 12.4 seconds (normal, 10.8 to 13.3 seconds), international normalized ratio, 8.46 +/- 5.4 (normal < 2), and fibrinogen, 109 +/- 23.9 mg/dL (normal, 175 to 400 mg/dL). The donors were 5 mothers and 1 father. The mean donor age was 32.5 +/- 7.6 years (range, 19 to 40 years). No donor required blood transfusion, and no donor had any early or late postoperative complications. The donors' mean hospital length of stay was 5 days. In five cases, grafts were blood group-compatible; 1 child received a blood group-incompatible graft. All grafts functioned immediately. No patient had hepatic artery or portal vein thrombosis or biliary complications. The child who received a mismatched graft died of infection of the brain caused by Aspergillus spp at 22 days posttransplantation with a functioning graft. The child with ALF caused by sickle cell intrahepatic cholestasis syndrome developed outflow obstruction 3 months posttransplantation and required retransplantation; he eventually died of vascular complications related to his primary disease. Four children are alive at a mean follow-up of 27 months (range, 14 to 36 months). LRD-LT for children with ALF facilitates timely transplantation without drawing on cadaveric donor resources. The established safety record of LRD-LT made this option appealing to both physicians and parental donors.

Transcriptional repression of the cystic fibrosis transmembrane conductance regulator gene, mediated by CCAAT displacement protein/cut homolog, is associated with histone deacetylation

Human cystic fibrosis transmembrane conductance regulator gene (CFTR) transcription is tightly regulated by nucleotide sequences upstream of the initiator sequences. Our studies of human CFTR transcription focus on identifying transcription factors bound to an inverted CCAAT consensus or "Y-box element." The human homeodomain CCAAT displacement protein/cut homolog (CDP/cut) can bind to the Y-box element through a cut repeat and homeobox. Analysis of stably transfected cell lines with wild-type and mutant human CFTR-directed reporter genes demonstrates that human histone acetyltransferase GCN5 and transcription factor ATF-1 can potentiate CFTR transcription through the Y-box element. We have found 1) that human CDP/cut acts as a repressor of CFTR transcription through the Y-box element by competing for the sites of transactivators hGCN5 and ATF-1; 2) that the ability of CDP/cut to repress activities of hGCN5 and ATF-1 activity is contingent on the amount of CDP/cut expression; 3) that histone acetylation may have a role in the regulation of gene transcription by altering the accessibility of the CFTR Y-box for sequence-specific transcription factors; 4) that trichostatin A, an inhibitor of histone deacetylase activity, activates transcription of CFTR through the Y-box element; 5) that the inhibition of histone deacetylase activity leads to an alteration of local chromatin structure requiring an intact Y-box sequence in CFTR; 6) that immunocomplexes of CDP/cut possess an associated histone deacetylase activity; 7) that the carboxyl region of CDP/cut, responsible for the transcriptional repressor function, interacts with the histone deacetylase, HDAC1. We propose that CFTR transcription may be regulated through interactions with factors directing the modification of chromatin and requires the conservation of the inverted CCAAT (Y-box) element of the CFTR promoter.

Growth failure as the first expression of malnutrition in children with human immunodeficiency virus infection

BACKGROUND

To define the onset, pattern, and earliest manifestations of malnutrition related to HIV infection.

METHODS

A retrospective cross-sectional analysis of changes in weight and growth in a group of 54 children with perinatally acquired HIV infection was conducted. Eight children had asymptomatic HIV infection, 26 had symptomatic infection, and 20 had symptomatic infection and were referred for nutritional support.

RESULTS

We found an early decline in the rate of linear growth with a relative preservation of the weight-for-age. Weight-for-height measurements were preserved until there was advanced HIV-related disease.

CONCLUSIONS

This pattern can result in a false impression of adequate nutrition and emphasizes the importance of longitudinal growth data of the child with HIV infection. Evidence of linear growth failure before clinical wasting is apparent is an absolute indication for aggressive nutritional support.

Recurrence of autoimmune hepatitis in children after liver transplantation

BACKGROUND

Liver transplantation is recognized as the appropriate treatment for end-stage liver disease due to chronic active autoimmune hepatitis. While it was initially thought that the disease did not recur after transplant, it is now generally accepted that adult patients may develop recurrent disease, with studies reporting a recurrence rate of < or = 25%. We have noted a higher incidence of recurrent autoimmune hepatitis in our pediatric patients undergoing liver transplant, with a high incidence of associated morbidity.

METHODS

We reviewed the records of six children followed up for autoimmune hepatitis who underwent orthotopic liver transplant for complications of end-stage liver disease.

RESULTS

Of the six, five developed recurrent autoimmune hepatitis at a mean time of 11.4 months after transplant. The disease was aggressive, leading to cirrhosis and retransplant in three patients, within 1 year of recurrence. A second recurrence of disease occurred in all three retransplanted patients. One patient has received a third liver transplant, one has died, and one patient is asymptomatic on medical therapy. Autoimmune hepatitis recurred in all four patients receiving tacrolimus.

CONCLUSION

We conclude that liver transplant for autoimmune hepatitis is likely to be palliative for most pediatric patients. Potent immunosuppressives such as tacrolimus do not protect against the development of recurrent autoimmune hepatitis.

The role of glutamine, short-chain fatty acids, and nucleotides in intestinal adaptation to gastrointestinal disease

Important first steps have been taken towards establishing how some nutrients interact with genes and affect intestinal adaptation. These mechanisms may be typical of how other nutrients influence cell function and turnover and help to maintain intestinal integrity. The dietary effects of nucleotides on intestinal cell mucosa act at the gene transcription level. The dietary effects of nucleotides on immune suppression also may act through similar mechanisms. The effects of the other trophic agents may interact at this level or at other levels. Scientific interest in how the various tropic factors work to maintain and repair the gastrointestinal tract is manifested by a growing body of research that demonstrates potential mechanisms for nutrient-gene interaction and how much interactions affect intestinal development and turnover. It seems clear that intestinal gene transcription and the activity of transcription factors are at least sometimes directly related to nutrition. The techniques of molecular biology now permit the exploration and explanation of how dietary factors, such as glutamine, SCFAs, and nucleotides, affect normal and pathologic intestinal mucosal development, function, adaptation, and repair.

Transcription of cystic fibrosis transmembrane conductance regulator requires a CCAAT-like element for both basal and cAMP-mediated regulation

The cystic fibrosis transmembrane conductance regulator (CFTR) gene in man is controlled by a tightly regulated and weak promoter. The architecture of the CFTR promoter suggests regulatory characteristics that are consistent with the absence of a TATA-like sequence, including the ability to initiate RNA transcription at numerous positions. Detailed investigation of the most proximal region of the human CFTR gene promoter through deletion and mutational analysis reveals that expression is contingent on the conservation of the inverted CCAAT sequence. Basal expression of CFTR transcription and cAMP-mediated transcriptional regulation require the presence of an imperfect and inverted CCAAT element recognized as 5'-AATTGGAAGCAAAT-3', located between 132 and 119 nucleotides upstream of the translational start site. RNA isolated from a transfected pancreatic cell line carrying integrated wild-type and mutant CFTR-directed transgenes was used to map the 5' termini of the transgenic transcripts. Analysis of the transcript termini by ribonuclease protection analysis reflects the direct association of the conserved inverted CCAAT sequence in promoting transcript initiation. Because of the requirement for the inverted CCAAT sequence for promoting transcription of CFTR, the involvement of CCAAT-binding factors is suspected in the regulation of CFTR gene transcription. To test this, we used electrophoretic mobility shift assays to demonstrate that the majority of the binding to the inverted CCAAT element, between -135 and -116, was easily competed for by binding to cognate nucleotide sequences for CCAAT-enhancer binding protein (C/EBP). An antibody specific for the C/EBP-related protein, C/EBP delta, detected C/EBP delta as part of a nuclear protein complex bound to the inverted CCAAT sequence of the CFTR gene. Also, the detection of specific activating transcription factor/cyclic-AMP response element binding protein antigens by antibody supershift analysis of nuclear complexes suggest that species of this family of transcription factors could be involved in the formation of complexes with C/EBP delta within the CFTR gene inverted CCAAT-like element. These studies raise the possibility of interactions between individual members of the C/EBP and activating transcription factor/cyclic-AMP response element binding protein families potentially contribute to the tight transcriptional control rendered by the CFTR gene promoter.

Gene expression in the intestine: the effect of dietary nucleotides

There is scientific concern regarding the role of dietary nucleotides in the maintenance and repair of the gastrointestinal tract. This concern is based on a growing body of research that demonstrates potential mechanisms for dietary nucleotides to affect intestinal development and turnover. It seems clear that intestinal gene transcription as well as the activity of transcription factors is at least sometimes directly related to nutrition. Implications of this work include the potential role of dietary nucleotides in infant nutrition and in intestinal repair. The techniques of molecular biology will now allow us to explore and explain how dietary factors such as nucleotides affect intestinal mucosal development, function, adaptation, and repair.

Cyclosporine as an alternative to surgery in children with inflammatory bowel disease

Five children with ulcerative colitis for whom surgery was recommended were treated with cyclosporine. The five had received corticosteroids for 1-24 months. The group included two patients with acute-onset ulcerative colitis and three with acute exacerbations of intractable corticosteroid-dependent chronic ulcerative colitis. The average age at initiation of cyclosporine therapy was 13.8 years (range, 11.5-16); all five patients were boys. Cyclosporine was initiated in the hospital by continuous i.v. infusion. Trough levels of 400-600 ng/dl (measured by radioimmunoassay) were achieved, at which point oral cyclosporine was given and oral dosage was adjusted to similar levels. Significant hypertension requiring medical attention was seen in one patient. Of the two recently diagnosed acute cases, one failed to respond and required subtotal colectomy after 2 weeks of treatment, and the other, despite an initial response, had a subtotal colectomy 10 months later. Of the three corticosteroid-dependent children, none was able to be weaned from corticosteroids and all underwent subtotal colectomy. Our experience emphasizes that the appropriate role of cyclosporine as therapy for children with ulcerative colitis is yet to be determined. Cyclosporine was not effective as an alternative to surgery in our patients.

Characterization of DNA-protein interactions within a distal regulatory element upstream of a mammalian housekeeping gene promoter

We have characterized a DNA-protein interaction within a sequence element distal from the site of transcription initiation within the mouse housekeeping gene (HPRT) promoter region. This interaction occurs within a 35-base pair regulatory element which confers cell type-specific gene transcription, designated as the HPRT cis-acting regulatory element (HCRE). Competition analysis by gel mobility shift electrophoresis indicates that this DNA-protein interaction is novel and not related to many transcription factors previously reported. Cell cycle synchronization experiments and gel mobility shift assays have demonstrated that within the HCRE a specific DNA-protein complex responds to G1 activation of the cell cycle. Experiments to purify specific DNA-binding proteins that interact with the HCRE has resulted in the purification of one sequence-specific DNA-binding protein of approximately 66 kDa. To determine the putative DNA-binding sequence, footprinting analysis has mapped the protection from DNase I hydrolysis which confers a core sequence of GTCTGGGT using both affinity purified protein and crude nuclear extract. This DNA motif represents a novel protein-binding sequence. Interestingly, data base searches have identified the same or homologous sequences of this DNA motif in additional genes, potentially related to cellular growth and proliferation. This consensus was most notable within a region 5' upstream of the ornithine decarboxylase gene. The unique cell type-specific regulation of the HPRT gene in the intestinal mucosa is not completely understood at this time but because of the relationship of ornithine decarboxylase expression to cell proliferation and more specifically, to mucosal cell renewal in the intestine, the function of DNA-protein interactions within the consensus sequence may prove analogous. This may account for the cell type-specific and cell-cycle responsive gene regulation previously demonstrated with HPRT. Identification of one sequence-specific DNA-binding protein within the HCRE suggest that this protein contributes to the trans-activation of specific genes during the immediate-early response of the cell cycle.

Helicobacter pylori and gastric lymphonodular hyperplasia in children

The association of gastric lymphonodular hyperplasia and Helicobacter pylori infection has been reported only in children. Lymphonodular hyperplasia of the stomach is a well known radiographic and endoscopic entity. Over the past three decades, it has been associated with many conditions, ranging from a normal variant to a premalignant lesion. We have recently encountered five children with gastric lymphonodular hyperplasia, all of whom had H. pylori infection of the antrum. The literature regarding this association is reviewed, and a possible explanation for this age-dependent expression of H. pylori infection is offered.

Salmonella typhimurium appendicitis

A child with signs and symptoms of acute gastroenteritis developed localization of her pain to the right lower quadrant. A clinical diagnosis of appendicitis was made and an inflamed appendix was found at surgery. The postoperative period was marked by high spiking fevers and profuse nonbloody diarrhea. Cultures of the appendix and the stool revealed Salmonella typhimurium. Nontyphoidal Salmonella organisms are a rare cause of acute suppurative appendicitis. Intraoperative cultures of the appendix and peritoneal fluid as well as postoperative cultures of the diarrheal fluid were crucial in elucidating the cause of this patient's unusual course.

The curious umbilicus: clue to the cause of abdominal pain

Omphalomesenteric duct derivatives cause an assortment of complications, most notably intestinal hemorrhage and obstruction. Intestinal obstruction is the most lethal complication and usually results from a diverticulum with an attachment to the umbilicus. This cause of intestinal obstruction is not generally recognized preoperatively. We report a teenager with episodic abdominal pain, acute small bowel obstruction, and a curious umbilical deformity with an underlying omphalomesenteric duct remnant. We believe that this physical finding suggests the diagnosis in patients with intestinal obstruction who have experienced unexplained episodes of abdominal pain.

Complete spontaneous disruption of the common bile duct: a late complication of necrotizing enterocolitis?

A 20-month-old infant had bile peritonitis from spontaneous complete avulsion of the distal common bile duct. The patient had recovered from extensive neonatal necrotizing enterocolitis that included the duodenum. We believe that this late unusual biliary catastrophe was a consequence of the neonatal necrotizing enterocolitis.

Resting energy expenditure in Gaucher's disease type 1: effect of Gaucher's cell burden on energy requirements

The resting energy expenditure (REE; kcal/d) of 25 patients with Gaucher's disease type 1 was determined by indirect calorimetry. The average observed REE for the group was approximately 44% greater (P less than .01) than that predicted (predicted REE) for these patient's age, sex, height, and weight. The increased caloric requirements of these patients was manifested by a height-for-age less than or equal to the fifth percentile in seven of nine growing children and a muscle mass of less than the fifth percentile in 15 of 19 patients studied. The excess REE (observed REE--predicted REE) for individual Gaucher's disease type 1 patients was directly related to their liver volume as estimated from radionuclide scans and to the mass of the spleen as measured at splenectomy. The relationship between spleen mass and excess REE was demonstrated by an average 22.0% decrease in REE following splenectomy in five patients. Based on these data, the metabolic rate of the splenic tissue removed from the patients was calculated to be 96.8 kcal/d/kg, about twofold to threefold less than that of normal splenic tissue. These findings indicate that the elevated REE observed in these patients resulted from the large mass of Gaucher's cells, which although individually hypometabolic, were cumulatively an excessive metabolic burden. Furthermore, they suggest that indirect calorimetry may be a quantitative tool for measuring disease progression and the effect of therapeutic intervention in Gaucher's disease type 1.

Regulation of types I, III, and IV procollagen mRNA synthesis in glucocorticoid-mediated intestinal development

Administration of dexamethasone (0.8 mg/kg) to 9-day-old rats once daily for 3 consecutive days caused precocious induction of adult specific disaccharidase activity in the small intestine. Maturation-specific disaccharidase activity was accompanied by decreased amounts of types I and III collagen and decreased procollagen type I and III mRNA levels. Conversely, type IV procollagen, fibronectin, and laminin amounts and their respective mRNA levels were increased. In vitro transcription of nuclei isolated from small intestine and colon of suckling rats indicated a decreased rate of synthesis of procollagen types I and III mRNAs and an increased rate of synthesis of procollagen type IV mRNAs and laminin mRNAs after dexamethasone treatment. The data suggest that glucocorticoids mediate a differential regulation of interstitial and basement membrane collagen gene expression in the developing rat intestine.

Esophageal cryptosporidiosis in a child with acquired immune deficiency syndrome

Oral Candida and Candida esophagitis are common findings in patients with the acquired immune deficiency syndrome. The intestinal protozoan, Cryptosporidium, is known to cause gastrointestinal symptoms in these patients. We report a 2-yr-old child with acquired immune deficiency syndrome, who had oral candidiasis, dysphagia, and vomiting. Upper gastrointestinal endoscopy and esophageal biopsy led to a diagnosis of esophageal cryptosporidiosis. We recommend upper gastrointestinal endoscopy as a diagnostic tool in selected patients with acquired immune deficiency syndrome. This is in contradistinction to a previous report that concludes that endoscopy is not necessary in this setting.

Identical twins concordant for Crohn's disease

Identical twin adolescent girls developed Crohn's disease within 15 months of each other. Clinical symptoms, growth retardation, barium studies, disease course, and pathologic findings at the time of resection were remarkably similar. Seventeen pairs of twins concordant for Crohn's disease have now been reported, but only four discordant pairs. Such observations lend support to a considerable genetic influence on the development and course of Crohn's disease.

Fatal massive hepatic necrosis: a probable hypersensitivity reaction to sulfasalazine

Sulfasalazine (salicylazosulfapyridine) is a commonly prescribed oral medication for inflammatory bowel disease. We report a case of a 15-yr-old boy with ulcerative colitis who developed a generalized hypersensitivity reaction with a serum sickness-like syndrome and severe hepatotoxicity while taking sulfasalazine, perphenazine, and amitriptyline. The injury to the liver persisted for 5 months after withdrawal of the drugs, and the patient died of terminal hepatic failure with massive hepatic necrosis. Severe hepatic toxicity to sulfasalazine is uncommon, but it can be fatal.

Failure to thrive associated with chronic ulcer disease in a 9-year-old boy

Chronic peptic ulcer disease is not generally considered to cause failure to thrive. We are reporting a 9-year-old child who suffered from chronic recurrent abdominal pain and failure to thrive. Investigation revealed that the child also had bacterial overgrowth and evidence of malabsorption. These findings were considered to be due to chronic peptic ulcer disease which caused intermittent small bowel obstruction and gastric outlet obstruction. Successful treatment of the ulcer alone resulted in catch-up growth and an end to the chronic recurrent pain. Recurrent abdominal pain when associated with atypical features or failure to thrive should be adequately investigated. Although rare, chronic peptic ulcer disease with its sequelae should be considered in the differential diagnosis of failure to thrive.

Atypical presentation of childhood acquired immune deficiency syndrome mimicking Crohn's disease: nutritional considerations and management

A child with acquired immune deficiency syndrome became severely malnourished presumably as a result of multiple gastrointestinal infections, with numerous organisms including campylobacter, giardia, and cryptosporidium. These opportunistic infections preceded laboratory evidence of immune deficiency. Despite severe diarrhea and marked weight loss, there was no laboratory evidence of significant malabsorption. By using nasogastric feedings, we were successful in promoting a 60% weight gain, and a rise in serum albumin from 1.2 to 4.3 g/dl. While eventual outcome was not altered, this particular patient's clinical course was improved. We suggest that malnutrition should not be accepted as inevitable and that malabsorption should not be assumed in similar acquired immune deficiency syndrome patients. Appropriate studies for malabsorption should be done, and high caloric enteral feedings should be used whenever feasible.

Quantitative blood cultures in the evaluation of septicemia in children with Broviac catheters

We applied quantitative methods of analysis to all blood cultures drawn during the course of treatment in 28 children with Broviac catheters in a central vein. Thirty febrile episodes in 14 of these patients were evaluated. Samples of blood obtained from a peripheral vein and through the central catheter were cultured quantitatively on agar plates and nonquantitatively in standard broth media. Catheters were judged to be a source of septicemia nine times in seven children. In all nine positive catheter samples, the concentration of pathogens was 10 times as great as that observed in the peripheral venous sample. The blood drawn through the Broviac catheter contained greater than or equal to 2000 colony-forming units per milliliter in six cases. Quantitative cultures in two patients with septicemia not attributable to the catheter yielded low colony counts in the catheter sample. Cultures of blood samples drawn through the catheter when a child was well were not helpful in predicting subsequent septicemia. The technique of inoculating blood directly onto agar plates is easily performed and superior to standard broth cultures, because it detected pathogens within 16 hours and identified infections with multiple organisms.

Studies in the use of the intraperitoneal route for parenteral nutrition in the rat

The effects of intraperitoneal administration of normal saline, dextrose, and amino acids were studied in a rat model for intraperitoneal alimentation. No adverse effects from the use of placement of an intraperitoneal catheter were found. Animals who received amino acids demonstrated a specific metabolic advantage over animals who received isocaloric amounts of carbohydrate. They lost less weight and maintained a higher serum albumin. The intraperitoneal route may provide a relatively simple and efficient method of studying parenteral nutrition in laboratory animals. Conceivably, it may also be of value for humans who are on chronic ambulatory peritoneal dialysis, or even as an alternative for central venous alimentation.

De novo purine nucleotide synthesis in the rat small and large intestine: effect of dietary protein and purines

This study assessed the pathway for de novo purine nucleotide synthesis in rat small intestinal and colonic mucosal cells, and determined the effects of dietary purines and protein on de novo purine nucleotide synthetic activity in the small intestine in vitro. Incubation of small intestinal mucosal scrapings with [14C]glycine failed to show an active pathway of de novo synthesis; in contrast, the colon showed incorporation of [14C]glycine into RNA. Rats fed a diet deficient in purines demonstrated increased incorporation of [14C]glycine into RNA-adrenine in small intestinal mucosal cells. Measurement of glutamine-amidophosphoribosyltransferase demonstrated that, regardless of the purine content of the diet, enzyme activity in the small intestine is significantly lower than in the colon or liver. The results indicate that, in the small intestine of the rat, there is an inactive de novo pathway of purine nucleotide biosynthesis that can be stimulated when purines are omitted from the diet.

The role of endoscopy in suspected amebiasis

The diagnosis of amebic colitis can be difficult and confusing. The gross endoscopic appearance as well as the results of endoscopic biopsy can be extremely helpful in differentiating amebiasis from other forms of colitis. Clinical symptoms, laboratory studies, x-ray findings, cultures, and even serological studies may not be sufficient for making an accurate diagnosis. To illustrate the potential difficulties we are reporting three patients in whom the diagnosis of amebiasis was considered but in whom endoscopy was important for arriving at the correct diagnosis.