Quantitation of cellular components of the enteric nervous system in the normal human gastrointestinal tract--report on behalf of the Gastro 2009 International Working Group

BACKGROUND

Patients with gastrointestinal neuromuscular diseases may undergo operative procedures that yield tissue appropriate to diagnosis of underlying neuromuscular pathology. Critical to accurate diagnosis is the determination of limits of normality based on the study of control human tissues. Although robust diagnostic criteria exist for many qualitative alterations in the neuromuscular apparatus, these do not include quantitative values due to lack of adequate control data.

PURPOSE

The aim of this report was to summarize all relevant available published quantitative data for elements of the human enteric nervous system (neuronal cell bodies, glial cells, and nerve fibers) from the perspective of the practicing pathologist. Forty studies meeting inclusion criteria were systematically reviewed with data tabulated in detail and discussed in the context of methodological variations and limitations. The results reveal a lack of concordance between observations of different investigators resulting in data insufficient to produce robust normal ranges. This diversity highlights the need to standardize the way pathologists collect, process, and quantitate neuronal and glial elements in enteric neuropathologic samples, as suggested by recent international guidelines on gastrointestinal neuromuscular pathology.

LFA-1 and ICAM-1 Molecule Expression in Jejunal Mucosa from Children with Autoimmune Enteropathy

The expression of adhesion molecules by cells of the small intestinal mucosa was compared in gut biopsies from children with autoimmune small intestinal enteropathy and normal controls and related to HLA-DR expression by the same tissue. Jejunal biopsies were stained by IFL with monoclonal antibodies to LFA-1 (TS1/22 and CD11a/25.3.1) and ICAM-1 (RR1/1 and 84H10) molecules. LFA-1 and ICAM-1 positive cells were observed in the lamina propria in all cases and the counts were increased in autoimmune enteropathy compared with controls. In addition, in 4 of 7 cases of autoimmune enteropathy crypt enterocytes were positives for ICAM-1 when stained with RR1/1 and 3 of the 4 were also positive for LFA-1 when stained with both LFA-1 reagents. We speculate on the role of adhesion molecule expression in autoimmune enteropathy.

Systemic vasculitis: a cause of indeterminate intestinal inflammation

OBJECTIVES

Indeterminate intestinal inflammation may result from a variety of inflammatory conditions in addition to ulcerative colitis and Crohn disease. The primary systemic vasculitides may present with intestinal inflammation and an indeterminate colitis. We set out to describe a series of children with primary systemic vasculitis who initially presented with clinical features suggestive of inflammatory bowel disease (IBD) to establish criteria that might help discriminate between IBD and primary systemic vasculitis.

METHODS

Ten children (6 boys, median age at presentation 8.9 years, range 0.9-14.5 years) satisfied inclusion criteria.

RESULTS

All had abdominal pain, weight loss, diarrhea (6 of 10 bloody) and laboratory evidence of a severe acute phase response. Extraintestinal clinical features included vasculitic rash, renal impairment, myalgia, testicular pain and polyarthritis. Endoscopy showed vascular changes or other macroscopic findings suggestive of vasculitis in 5 of 10 patients. Gut histology revealed indeterminate chronic inflammatory mucosal changes and one patient with small artery fibrinoid necrosis in the submucosal vessels. Extraintestinal biopsy was performed in 6 patients and had a higher yield for the demonstration of vasculitis than intestinal biopsy. The results of selective visceral angiography was suggestive of vasculitis in all patients, but was normal in 7 cases of treatment-unresponsive classic IBD. Treatment comprised corticosteroid and azathioprine in all patients. Cyclophosphamide was given to 7 of 10 patients.

CONCLUSIONS

Extraintestinal manifestations and inflammatory responses that may be disproportionate to the degree of intestinal inflammation provide clues to the presence of an underlying primary systemic vasculitis, and these data suggest that selective visceral angiography plays a key role in the diagnosis of vasculitis in this context. It is important to identify and treat any vasculitic component because failure to do so may result in consequential morbidity or mortality.

Consumerism in healthcare can be detrimental to child health: lessons from children with functional abdominal pain

AIMS

To determine prognostic indicators in children with severe functional abdominal pain (FAP) and to test the hypothesis that "healthcare consumerism" in these families might be deleterious to the child.

METHODS

Retrospective analysis of a cohort of 23 children aged <16 years fulfilling the Rome II diagnostic criteria for FAP during the period December 1997 to February 2001. Poor outcome was defined as continued pain and failure to return to normal functioning >12 months after onset.

RESULTS

Poor outcome was associated with refusal to engage with psychological services, involvement of more than three consultants, lodging of a manipulative complaint with hospital management by the child's family, and lack of development of insight into psychosocial influences on symptoms. Three of four adverse prognostic indicators reflected healthcare consumerism by the families.

CONCLUSIONS

Actions of families who lack insight into their child's illness may perpetuate FAP in childhood. A culture of parental consumerism in healthcare, however well intentioned, needs to be accompanied by robust systems to protect the interests of the child.

Hypertrophic eosinophilic gastroenteropathy is associated with reduced enterocyte apoptosis

AIMS

To investigate the cause of grossly elongated villi in four children presenting with obstruction due to a novel form of eosinophilic gastroenteropathy in which there was profound hyperplasia of the intestinal villi with grossly increased villous/crypt ratio and prominent mucosal eosinophilia. Increased eosinophils were also present in the muscularis propria and submucosa. All had intermittent diarrhoea and signs of a protein-losing enteropathy.

METHODS AND RESULTS

The cause of the grossly elongated villi was investigated by studying enterocyte proliferation (Ki67), survival factors (bcl-2) and apoptosis (TUNEL) in these patients (n = 4) and normal (jejunum n = 6, ileum n = 6) and disease (n = 6) controls. The most remarkable finding was that apoptotic enterocytes were undetectable in the elongated villi.

CONCLUSIONS

It seems likely that a defect in the regulation of apoptosis of the epithelium occurs which could explain the remarkable hyperplasia of the villi seen.

The influence of Hox genes and three intercellular signalling pathways on enteric neuromuscular development

Normal intestinal motility requires orderly development of the complex nerve plexuses and smooth muscular layers in the gut wall. Organization of these structures results, in part, from cell autonomous programmes directed by transcription factors, which orchestrate appropriate temporal and spatial expression of specific target genes. Hox proteins appear to function in combination to dictate regional codes that establish major structural landmarks in the gut such as sphincters and muscle layers. These codes are translated in part by intercellular signals, which allow populations of cells in the embryonic gut wall to alter the developmental fate of their neighbours. Some of the best characterized intercellular signalling pathways involved in enteric neurodevelopment are mediated by GDNF/GFRa1/RET, EDN3/ENDRB, and NETRINS/DCC. These signals affect enteric neural precursors as they colonize the gut, and perturbations of these molecules are associated with various types of intestinal neuropathology.

Eosinophilic myenteric ganglionitis is associated with functional intestinal obstruction

The diagnostic features and clinical course of three children (aged 1 month to 15 years) with severe functional intestinal obstruction and inflammation of the colonic lamina propria and myenteric plexus are described. The myenteric inflammatory infiltrate was eosinophil predominant with none of the immunological characteristics of lymphocytic ganglionitis. Neurones in the myenteric ganglia expressed the potent eosinophil chemoattractant interleukin 5. None responded to dietary exclusion but all three responded symptomatically to immunosuppression/anti-inflammatory treatments. Eosinophilic ganglionitis is associated with a pseudo-obstructive syndrome which is amenable to anti-inflammatory treatment.

The histological appearances of Nissen-type fundoplication in the ferret

Nissen fundoplication is of proven effectiveness in the surgical control of gastro-oesophageal reflux. However, our understanding of the effects of fundoplication upon foregut physiology is incomplete and post-operative symptoms are often poorly understood. This experimental study aimed systematically to characterize the tissue response to fundoplication in an animal model, to improve understanding of the effects of anti-reflux surgery upon foregut physiology. Nissen-type fundoplication was performed in the ferret, and the tissue response at 3 months examined histologically. Sham-operated animals that underwent laparotomy but no dissection or wrap, acted as controls. In fundoplicated animals, serosal fibrosis was observed in the gut wall, with patchy replacement of muscle by fibrous tissue. The ventral and dorsal vagal nerve trunks were identified intact within the wrap. In cases where the wrap had spontaneously disrupted, fibrosis was more extensive and there was evidence of nerve damage. This is the first systematic description of the histopathological response to Nissen fundoplication. In the intact wrap, the vagal trunks appear spared, but there is fibrosis in the serosa, extending into the muscularis of the distal oesophagus and region of the cardia. These findings are discussed in relation to the effects of Nissen fundoplication upon gastric physiology and postoperative symptoms.

Faecal elastase 1 concentration is a marker of duodenal enteropathy

BACKGROUND

Measurement of faecal elastase (FE1) is used widely to screen for pancreatic exocrine insufficiency (PI). FE1 does not allow differentiation of primary from secondary PI.

AIMS

To investigate the relation between duodenal morphology and FE1 in children with secondary PI resulting from primary gastrointestinal diseases.

METHODS

A group of 51 children underwent small intestinal biopsy and FE1 measurement. Villus to crypt ratio (VCR) and inflammation within the lamina propria of duodenal mucosal biopsy specimens were scored and compared with FE1 values.

RESULTS

In 51 children from nine diagnostic categories, a highly significant correlation between FE1 and both duodenal morphology and inflammation was found.

CONCLUSION

Small bowel enteropathy is associated with low FE1 concentrations, indicative of secondary exocrine pancreatic insufficiency.

Embryonic gut anomalies in a mouse model of retinoic Acid-induced caudal regression syndrome: delayed gut looping, rudimentary cecum, and anorectal anomalies

Vitamin A and its derivatives such as retinoic acid (RA) are important signaling molecules for morphogenesis of vertebrate embryos. Little is known, however, about morphogenetic factors controlling the development of the gastrointestinal tract and RA is likely to be involved. In the mouse, teratogenic doses of RA cause truncation of the embryonic caudal body axis that parallel the caudal regression syndrome as described in humans. These changes are often associated with anomalies of the lower digestive tract. Overlapping spatiotemporal expression of retinoic acid receptor-beta (RAR beta) and cellular retinol-binding protein I, CRBPI, with Hoxb5 and c-ret in the gut mesoderm imply possible cooperation required for proper neuromuscular development. To determine susceptibility and responsiveness of the developing gut and its neuromusculature to exogenous retinoids we used a mouse model of RA-induced caudal regression syndrome. The results showed that stage-specific RA treatment both in vivo and in vitro affected gut looping/rotation morphogenesis and growth of asymmetrical structures such as the cecum together with delayed differentiation of the gut mesoderm and colonization of the postcecal gut by neural crest-derived enteric neuronal precursors. These observations demonstrate that RA has a direct effect on gut morphogenesis and innervation.

Cloning of HOXD1 from unfertilised human oocytes and expression analyses during murine oogenesis and embryogenesis

We describe the cloning of HOXD1 in human unfertilised oocytes and detailed expression analyses during mouse oogenesis and embryogenesis. The cDNA of 1991bp has an open reading frame of 987bp encoding a protein of 329 amino acids. A comparison of the amino acid sequence with the mouse homologue revealed an overall homology of 85.5% with 99% identity within the homeodomain. Expression was detected in unfertilised human oocytes and 2-, 4-, 8-cell and blastocyst stage embryos. Expression analyses in mature mouse ovaries, early embryos and isolated gut revealed expression in the oocytes of the primary and secondary ovarian follicles, and in embryonal mesodermal derivatives such as dermatomes, urogenital tubercle, tail bud, kidney, ovaries, testes and enteric mesoderm adjacent to the caecum where expression was up-regulated in vitro in response to increasing doses of retinoic acid. Our observations indicate a possible role for HOXD1/Hoxd1 in the ovarian oocytes and the establishment of mesodermal derivatives during embryogenesis.

Retching and vomiting in neurologically impaired children after fundoplication: predictive preoperative factors

BACKGROUND/PURPOSE

In neurologically impaired children, retching and recurrent vomiting are common after Nissen fundoplication. The aim of this study was to identify whether there are preoperative factors that predict their occurrence.

METHODS

Twenty neurologically impaired children (8 boys, 12 girls; age range, 3 months to 8 years) were studied prospectively by taking a detailed history of behaviors and symptoms associated with feeding before and after Nissen fundoplication for gastroesophageal reflux.

RESULTS

Preoperatively, children could be classified into 2 groups. Children in group A had symptoms suggestive of only gastroesophageal reflux (effortless "vomiting" or regurgitation), whereas children in group B exhibited one or more features associated with activation of the emetic reflex (pallor, sweating, retching, forceful vomiting). Postoperatively 0 of 8 in group A retched compared with 8 of 12 in group B (P <.005, Fishers Exact test).

CONCLUSIONS

Children at high risk of retching, and ultimately vomiting, after antireflux surgery may be identified clinically preoperatively. They have symptoms that are specifically caused by activation of the emetic reflex rather than to gastroesophageal reflux. In these cases, antireflux surgery could be considered inappropriate and hence be avoided.

Colitis in chronic granulomatous disease

BACKGROUND

Involvement of the gut in chronic granulomatous disease (CGD) has been previously described and colitis highlighted. However, the nature and histopathology of the colitis are unclear and have been thought to be non-specific or similar to Crohn's disease.

METHODS

Seven patients with CGD, suffering from gastrointestinal symptoms were prospectively studied.

RESULTS

All patients had anaemia; other symptoms were failure to thrive (5/7) and diarrhoea (5/7). Most had microcytic anaemia (5/7), increased platelets (7/7), and increased erythrocyte sedimentation rate (6/6). Endoscopically there was a friable erythematous mucosa in 6/7. The histological features present in all patients consisted of a colitis with paucity of neutrophils, increased numbers of eosinophils, eosinophilic crypt abscesses, pigmented macrophages, and nuclear debris. In some granulomas were present (2/7).

CONCLUSIONS

Colitis is a common cause of gastrointestinal symptoms in CGD and is caused by a non-infective inflammatory process. The histology has specific features, which are distinctive from those seen in Crohn's disease.

A recessive contiguous gene deletion causing infantile hyperinsulinism, enteropathy and deafness identifies the Usher type 1C gene

Usher syndrome type 1 describes the association of profound, congenital sensorineural deafness, vestibular hypofunction and childhood onset retinitis pigmentosa. It is an autosomal recessive condition and is subdivided on the basis of linkage analysis into types 1A through 1E. Usher type 1C maps to the region containing the genes ABCC8 and KCNJ11 (encoding components of ATP-sensitive K + (KATP) channels), which may be mutated in patients with hyperinsulinism. We identified three individuals from two consanguineous families with severe hyperinsulinism, profound congenital sensorineural deafness, enteropathy and renal tubular dysfunction. The molecular basis of the disorder is a homozygous 122-kb deletion of 11p14-15, which includes part of ABCC8 and overlaps with the locus for Usher syndrome type 1C and DFNB18. The centromeric boundary of this deletion includes part of a gene shown to be mutated in families with type 1C Usher syndrome, and is hence assigned the name USH1C. The pattern of expression of the USH1C protein is consistent with the clinical features exhibited by individuals with the contiguous gene deletion and with isolated Usher type 1C.

Nissen-type fundoplication and its effects on the emetic reflex and gastric motility in the ferret

Recurrent vomiting with failure to thrive is a common problem in neurologically impaired children. Many undergo fundoplication to control the underlying gastro-oesophageal reflux. The results of surgery are not always satisfactory and post-operative retching may be a major problem - a symptom indicative of activation of the emetic reflex. An animal model of antireflux surgery has been developed and used to investigate the effects of such surgery upon the emetic reflex and vagal influences on gastric motility. Following surgery, animals responded to a previously subemetic dose of a centrally acting opiate receptor agonist (loperamide), suggesting that fundoplication may sensitize the emetic reflex. A gastric vago-vagal reflex (tonic inhibition of corpus tone) and responses to direct stimulation of vagal motor efferents (both cholinergic and nonadrenergic noncholinergic responses) were not significantly affected by antireflux surgery. Mechanisms by which neural damage may sensitize the emetic reflex are discussed, together with the possible clinical implications for the management of post-operative symptoms in neurologically impaired children.

Coordinated expression of 3' hox genes during murine embryonal gut development: an enteric Hox code

BACKGROUND & AIMS

Hox genes are highly conserved developmental control genes that may be organized and expressed in the form of a code required for correct morphogenesis. Little is known about their control of the embryonal gut. However, Hox paralogues 4 and 5, which are expressed at the sites of origin of vagal neural crest cells and splanchnic mesoderm, are likely to be important. We have studied the expression domains of these genes in the gut both spatially and temporally.

METHODS

CD1 mice embryos of embryonic days E8.5-E17.5 were studied. The spatial and temporal expression patterns of messenger RNA of Hoxa4, b4, c4, d4, a5, c5, and b5 homeoprotein were determined by in situ hybridization and immunohistochemistry in whole embryos, whole gastrointestinal tracts, and vibratome sections.

RESULTS

There were different spatial, temporal, and combinatorial expression patterns in different morphological regions: foregut, prececal gut, cecum, and postcecal gut. Two dynamic gradients, rostral and caudal, were coordinated with nested expression domains along the gut primordium. Region-specific domains were present in the stomach and cecum.

CONCLUSIONS

The expression patterns of genes in paralogous groups 4 and 5 suggest that they are organized to form a specific enteric Hox code required for correct enteric development.

Childhood functional gastrointestinal disorders

This is the first attempt at defining criteria for functional gastrointestinal disorders (FGIDs) in infancy, childhood, and adolescence. The decision-making process was as for adults and consisted of arriving at consensus, based on clinical experience. This paper is intended to be a quick reference. The classification system selected differs from the one used in the adult population in that it is organized according to main complaints instead of being organ-targeted. Because the child is still developing, some disorders such as toddler's diarrhea (or functional diarrhea) are linked to certain physiologic stages; others may result from behavioral responses to sphincter function acquisition such as fecal retention; others will only be recognizable after the child is cognitively mature enough to report the symptoms (e.g., dyspepsia). Infant regurgitation, rumination, and cyclic vomiting constitute the vomiting disorders. Abdominal pain disorders are classified as: functional dyspepsia, irritable bowel syndrome (IBS), functional abdominal pain, abdominal migraine, and aerophagia. Disorders of defecation include: infant dyschezia, functional constipation, functional fecal retention, and functional non-retentive fecal soiling. Some disorders, such as IBS and dyspepsia and functional abdominal pain, are exact replications of the adult criteria because there are enough data to confirm that they represent specific and similar disorders in pediatrics. Other disorders not included in the pediatric classification, such as functional biliary disorders, do occur in children; however, existing data are insufficient to warrant including them at the present time. For these disorders, it is suggested that, for the time being, clinicians refer to the criteria established for the adult population.

Intestinal ganglioneuromatosis and multiple endocrine neoplasia type 2B: implications for treatment

Three infants, who presented with intestinal obstruction due to diffuse transmural intestinal ganglioneuromatosis, are described. Mutation analysis of exon 16 of the RET proto-oncogene revealed germline M918T and thus, a molecular diagnosis of multiple endocrine neoplasia type 2B (MEN 2B). Two infants developed medullary carcinoma of the thyroid. The third had a prophylactic thyroidectomy despite no obvious thyroid masses and normal calcitonin concentrations, but microscopic multifocal medullary carcinoma was found on histological examination. Early recognition of intestinal ganglioneuromatosis with germline RET M918T mutation in pseudo-Hirschsprung's disease is an indication for prophylactic thyroidectomy.

Feeding difficulties and foregut dysmotility in Noonan's syndrome

PURPOSE

Noonan's syndrome is a common dysmorphic syndrome in which failure to thrive and gastrointestinal symptoms are frequent but poorly understood.

DESIGN

Twenty five children with Noonan's syndrome were investigated by contrast radiology, pH monitoring, surface electrogastrography (EGG), and antroduodenal manometry (ADM).

RESULTS

Sixteen had poor feeding and symptoms of gastrointestinal dysfunction. All 16 required tube feeding. Seven of 25 had symptoms of foregut dysmotility and gastro-oesophageal reflux. In the most symptomatic children (four of seven) EGG showed fasting frequency gradient loss along the stomach fundus and pylorus with antral postprandial frequency loss. ADM showed shortened fasting cycle length, with abnormal phase III and shortened postprandial activity containing phasic contractions.

IMPLICATIONS

Gastroduodenal motor activity was reminiscent of 32-35 week preterm patterns. The feeding difficulties appear to resolve as gut motility matures. In Noonan's syndrome, feeding problems appear to be the result of delayed gastrointestinal motor development.

Chronic intestinal pseudo-obstruction: treatment and long term follow up of 44 patients

AIMS

To document the long term course of chronic idiopathic intestinal pseudo-obstruction syndrome (CIIPS) in children with defined enteric neuromuscular disease, and the place and type of surgery used in their management; in addition, to identify prognostic factors.

METHODS

Children with CIIPS were investigated and treated prospectively.

RESULTS

Twenty four children presented congenitally, eight during the 1st year of life, and 10 later. Twenty two had myopathy and 16 neuropathy (11 familial). Malrotation was present in 16 patients, 10 had short small intestine, six had non-hypertrophic pyloric stenosis, and 16 had urinary tract involvement. Thirty two patients needed long term parenteral nutrition (TPN): for less than six months in 19 and for more than six months in 13, 10 of whom are TPN dependent; 14 are now enteral feeding. Prokinetic treatment improved six of 22. Intestinal decompression stomas were used in 36, colostomy relieved symptoms in five of 11, and ileostomy in 16 of 31. A poor outcome (death (14) or TPN dependence (10)) was seen with malrotation (13 of 16), short small bowel (eight of nine), urinary tract involvement (12 of 16), and myopathic histology (15 of 22).

CONCLUSIONS

In CIIPS drugs are not helpful but decompression stomas are. Outcome was poor in 24 of 44 children (15 muscle disorder, 10 nerve disease).

Acquired motility disorders in childhood

Acquired motility disorders in childhood cause a number of gastrointestinal symptoms - principally, recurrent vomiting, abdominal pain and distension, constipation and loose stools. Gastrointestinal motility disorders result from disturbances of the control mechanisms of gut motor activity, which may be produced by organic disease involving enteric nerves and muscle, perturbation of the humoral environment of the nerves and muscle, and altered central nervous system input. In children, both congenital and acquired disease processes may produce these pathogenetic mechanisms, resulting in syndromes that vary in severity from chronic intestinal pseudo-obstruction to the irritable bowel syndrome.

Nitric oxide stimulates cyclic guanosine monophosphate production and electrogenic secretion in Caco-2 colonocytes

Nitric oxide stimulates intestinal ion transport via the activation of enteric nerves, but it is not known whether it regulates intestinal transport function by acting on the epithelium directly. The aim of this study was to determine the influence of nitric oxide on epithelial electrogenic ion secretion, measured as the short-circuit current (Isc), using the human colonic carcinoma cell line Caco-2. The cellular mechanisms were examined by measuring epithelial cGMP production, and nitrite release was monitored as an index of nitric oxide synthesized. The nitric oxide substrate L-arginine methyl ester increased nitrite release, electrogenic secretion and cell cGMP production. Pretreatment with L-NAME (Nomega-nitro-L-arginine methyl ester, 1 mM), but not the D-isomer, significantly reduced the electrogenic secretion and cGMP production evoked by L-arginine methyl ester, implicating nitric oxide synthase involvement. Pretreatment with cystamine, but not Methylene Blue, significantly reduced the maximum Isc and the cGMP release induced by L-arginine methyl ester and the nitric oxide donor sodium nitroprusside, implicating the involvement of particulate guanylate cyclase. In conclusion, nitric oxide stimulates electrogenic ion secretion and cGMP production in intestinal epithelial cells by activating particulate guanylate cyclase. The direct action of nitric oxide on the intestinal epithelium may be important in the regulation of intestinal transport function in health and in inflammatory bowel disease.

Motility disorders in childhood

Motility disorders are very common in childhood, causing a number of gastrointestinal symptoms: recurrent vomiting, abdominal pain and distension, constipation and obstipation, and loose stools. The disorders result from disturbances of gut motor control mechanisms caused by either intrinsic disease of nerve and muscle, central nervous system dysfunction or perturbation of the humoral environment in which they operate. Intrinsic gut motor disease and central nervous system disorder are most usually congenital in origin, and alterations of the humoral environment acquired. Irritable bowel syndrome occurs in children as well as adults and is multifactorial in origin, with an interplay of psychogenic and organic disorders.

Nissen fundoplication may induce gastric myoelectrical disturbance in children

BACKGROUND

Recurrent vomiting with failure to thrive is a common problem in neurologically impaired children. Many undergo fundoplication to control the underlying gastroesophageal reflux, but the results of surgery are not always satisfactory, and postoperative retching may be a major problem. Retching is part of the emetic reflex and is associated with nausea, which is itself associated with disturbed gastric electrical control activity, resulting in a gastric dysrhythmia.

METHODS

By recording gastric electrical control activity before and after Nissen fundoplication using the noninvasive technique of surface electrogastrography, the authors have shown that (1) Neurologically impaired children with gastroesophageal reflux more commonly have a preexisting gastric dysrhythmia (65% neurologically impaired v 20% neurologically normal children with gastroesophageal reflux, P<.05), (2) Children who retch preoperatively are three times more likely to retch postoperatively, and (3) 25% of neurologically impaired children may start to retch postoperatively for the first time.

CONCLUSION

The authors propose that in neurologically impaired children, loss of central inhibitory mechanisms may result in inappropriate activation of the emetic reflex, which may be heightened by antireflux surgery.

Cystic fibrosis: present and future

Cystic fibrosis (CF) is an inherited disorder of epithelial chloride transport affecting primarily pancreas, lungs, gut, liver and exocrine glands. The defect is caused by defects of the cystic fibrosis transmembrane regulation gene on chromosome 7. Genotyping has proved useful in identifying gene carriers, a definitive diagnosis, and in antenetal diagnosis. Genotype/phenotype relationships have shown that the commonest cause of pancreatic insufficiency is the D F508 mutation. Clinical trials are exploring the use of somatic gene therapy but this is not yet a viable treatment option. Liver, lung and intestinal disease result in malnutrition which causes further dysfunction of these organs. Aggressive nutritional and pancreatic enzyme therapy results in improved disease, normal growth and increased survival. However, high-dose enzyme therapy may in some individuals cause a fibrosing colonopathy. For those with end-stage liver and lung disease, transplantation holds out some hope.

Serum immunoglobulin and immunoglobulin G subclasses in children with allergic colitis

Serum immunoglobulin and immunoglobulin G subclasses were measured in thirty children with histologically proven allergic colitis and twenty age matched controls. Serum immunoglobulin A (mean +/- sd) (0.45 +/- 0.25 vs 87 +/- 0.41 Gm/L), IgG2 (29.2 +/- 13.1 vs 49.5 +/- 12.8 mg/dL), and IgG4 (7.58 +/- 3.01 vs 11.2 +/- 2.59 mg/dL) were significantly lower in allergic colitis than in the controls respectively (p < 0.001). There was a significant elevation of serum IgE in those with allergic colitis (p < 0.01). The serum IgG1 and IgG3 levels were not significantly different in allergic colitis and the controls (p > 0.10). Immunoglobulin A, IgG2 and IgG4 subclasses were low in 43.3%, 75.0% and 55.0% of cases of allergic colitis respectively, compared to 5.0% of the controls with low IgG2 and IgG4 (p < 0.005). The IgG1 and IgG3 subclasses were normal and comparable in both groups. Children with food allergic colitis in this study have low levels of IgG A, IgG2 and IgG4 subclasses. IgA, IgG2 and IgG4 subclass deficiency probably have a role to play in the pathogenesis of allergic colitis an mucosal immune defense mechanism.

Gastroesophageal reflux in children and its relationship to erosion of primary and permanent teeth

Gastroesophageal reflux (GOR) is often a self-limiting condition but nevertheless is a common cause of morbidity in childhood. Studies of adult patients with hiatus hernias and GOR have suggested that there is an increased incidence of dental erosion in these individuals. The aim of this study was to investigate the relationship between dental erosion and GOR in children. Fifty-three children aged 2 to 16 yr (mean 4.9 yr) with moderate to severe GOR, defined by pH monitoring, were examined for dental erosion. A questionnaire investigating dietary habits, other relevant medical conditions, and erosion risk factors was also completed. Results showed that the prevalence of dental erosion was low, when compared with the UK National Survey, with only 9 (17%) children showing any signs of erosion, and of these only one had erosion involving dentine. These results suggest that dental erosion may not be as great a problem in children with GOR as it is in adults. It may be that refluxing is limited to the oesophagus, and further work is needed to investigate those children that positively reflux into the mouth.

Rapadilino syndrome--a non-Finnish case

We report on a boy with RAPADILINO syndrome. Including this report seven children with this syndrome have been described. The patient developed a poikilodermatous skin rash, suggesting overlap with the Rothmund-Thompson syndrome.

Vomiting and gastroesophageal motor activity in children with disorders of the central nervous system

BACKGROUND

Vomiting is common in children with disorders of the central nervous system (CNS) and is usually ascribed to gastroesophageal reflux (GER). However, recent acquisitions on the pathophysiology of vomiting suggest that the dysmotility of the foregut may be more widespread.

METHODS

Fifty-five children with CNS disorders, 50 of whom suffered from retching and/or vomiting (18 following fundoplication) were studied. We assessed GER by 24 hour pH monitoring and endoscopy, gastric electrical activity by electrogastrography, and gastric half-emptying time (T1/2) of a milk meal be electrical impedance tomography.

RESULTS

Of the 50 vomiting patients, 29 had GER (reflux index of 5.7%-87.4%; controls: < 5%), and 31 had gastric dysrhythmias (12 tachyarrhythmia at 5.5-11.2 cpm, 4 bradyarrhythmia at 1.7-1.9 cpm, 15 unstable electrical activity; controls; 2.2-4.0 cpm). Sixteen patients had GER and gastric dysrhythmias. Eleven of 18 patients with fundoplication had gastric dysrhythmias. Gastric T1/2 was delayed in 12 of 13 patients with gastric dysrhythmia (6 with GER), versus 2 of 5 with GER alone. No abnormalities were detected in the 5 patients who did not suffer from vomiting.

CONCLUSIONS

Children with CNS disorders who vomit have abnormal gastric motility as often as GER. Following fundoplication, many patients continue to have symptoms possibly related to gastric dysrhythmias, the effects of which may be unmasked by fundoplication. Foregut dysmotility may be related to abnormal modulation of the enteric nervous system by the CNS or to involvement of the enteric nervous system by the same process affecting the brain.

Therapy for persistent hyperinsulinemic hypoglycemia of infancy. Understanding the responsiveness of beta cells to diazoxide and somatostatin

The neonatal disorder persistent hyperinsulinemic hypoglycemia of infancy (PHHI) arises as the result of mutations in the subunits that form the ATP-sensitive potassium (KATP) channel in pancreatic beta cells, leading to insulin hypersecretion. Diazoxide (a specific KATP channel agonist in normal beta cells) and somatostatin (octreotide) are the mainstay of medical treatment for the condition. To investigate the mechanism of action of these agents in PHHI beta cells that lack KATP currents, we applied patch clamp techniques to insulin-secreting cells isolated from seven patients with PHHI. Five patients showed favorable responses to medical therapy, and two were refractory. Our data reveal, in drug-responsive patients, that a novel ion channel is modulated by diazoxide and somatostatin, leading to termination of the spontaneous electrical events that underlie insulin hypersecretion. The drug-resistant patients, both of whom carried a mutation in one of the genes that encode KATP channel subunits, also lacked this novel K+ channel. There were no effects of diazoxide and somatostatin on beta cell function in vitro. These findings elucidate for the first time the mechanisms of action of diazoxide and somatostatin in infants with PHHI in whom KATP channels are absent, and provide a rationale for development of new therapeutic opportunities by K+ channel manipulation in PHHI treatment.

The urological manifestations of hollow visceral myopathy in children

PURPOSE

Hollow visceral myopathy is a rare clinical entity characterized by impaired intestinal function in the absence of mechanical occlusion. It can affect the smooth muscle of the whole or segments of the gastrointestinal tract and occasionally the urinary tract. We examined the urological manifestations of hollow visceral myopathy and management in the pediatric population.

MATERIALS AND METHODS

We reviewed the records of 14 male patients 1 day to 2 years old (mean age 4.6 months) and 10 female patients 1 day to 5 years old (mean age 9.4 months) at presentation to our institution with hollow visceral myopathy. In all patients genitourinary tract ultrasound, voiding cystourethrography and serum creatinine measurement were done at presentation.

RESULTS

All patients had gastrointestinal obstructive symptoms at presentation and 11 (46%) had urological symptoms, including urinary retention in 2, urinary tract infection in 3, and a prenatal diagnosis of megacystis and hydroureteronephrosis in 6. Overall 22 patients (92%) had urological abnormalities, all had poor bladder emptying and recurrent urinary tract infections, and 13 had megacystis associated with bilateral hydroureteronephrosis in 9 and unilateral hydroureteronephrosis in 2. There were 9 deaths from extensive gastrointestinal involvement and sepsis. Of the surviving 15 patients 13 have urological abnormalities, including 8 who perform and tolerate clean intermittent catheterization via the urethra and are well. Of the 4 male infants who did not tolerate clean intermittent catheterization appendicovesicostomy was done in 1, a Casale tube was placed in 1 and vesicostomy was performed in 2. The remaining female patient has day and night wetting.

CONCLUSIONS

Urological abnormalities are common in hollow visceral myopathy and they can contribute to presenting symptoms. Clean intermittent catheterization via the urethra to aid in bladder emptying and decrease the frequency of urinary tract infections is the mainstay of treatment but surgery to construct an alternative catheterizable channel or vesicostomy may be required in intolerant patients.

Tetrahydrobiopterin regulates cyclic GMP-dependent electrogenic Cl- secretion in mouse ileum in vitro

1. Basal electrogenic Cl- secretion, measured as the short-circuit current (Isc), was variable in ileum removed from tetrahydrobiopterin (BH4)-deficient hph-1 mice and wild-type controls in vitro, although values were not significantly different. 2. The basal nitrite release and mucosal cyclic guanosine 3',5'-monophosphate (cyclic GMP) production were similar in control and BH4-deficient ileum. 3. Mucosally added Escherichia coli heat-stable toxin (STa, 55 ng ml-1) increased the nitrite release, cyclic GMP levels and the Isc in control ileum, but its secretory actions were reduced in BH4-deficient ileum. 4. L-Arginine (1 mM) increased the nitrite release, cyclic GMP production and the Isc in control ileum, but the actions were reduced in BH4-deficient ileum. 5. Serosal carbachol (1 mM) stimulated maximum short-circuit currents of similar magnitude in both control and BH4-deficient ileum, whilst nitrite release and cyclic GMP production were minimal. 6. E. coli STa and L-arginine increased electrogenic Cl- secretion across intact mouse ileum in vitro by releasing nitric oxide and elevating mucosal cyclic GMP. The inhibition of these processes in the hph-1 mouse ileum suggests that BH4 may be a target for the modulation of electrogenic transport, and highlight the complexity of the interactions between nitric oxide and cyclic GMP in the gut.

Histological phenotypes of enteric smooth muscle disease causing functional intestinal obstruction in childhood

AIMS

Functional intestinal obstruction or chronic idiopathic intestinal pseudo-obstruction is due to defects either in the enteric innervation or in intestinal smooth muscle. We have studied full-thickness intestinal biopsies from 27 patients with functional intestinal obstruction due to enteric smooth muscle disease by routine histology and electron microscopy together with histochemical and immunohistochemical techniques to detect changes in the intestinal smooth muscle.

METHODS AND RESULTS

Two patients appeared to have an acquired intestinal myopathy as a result of an autoimmune process. In 25 the disorders were congenital, of these seven had segmental abnormalities limited to the rectum and distal colon and 18 had a diffuse disease affecting both the small and large bowel. We identified five apparent histological phenotypes of enteric muscle disease, three of which represent abnormalities in morphogenesis resulting in alterations in intestinal muscle layering and two exemplify intrinsic myocyte defects and/or changes in the extracellular matrix.

CONCLUSIONS

Careful phenotyping of these patients is important in devising optimal treatment and in understanding the underlying defect as well as the possible genetic mechanisms resulting in these abnormalities. Recognition of autoimmune smooth muscle disease is helpful, since making the diagnosis influences the patient's management.

Congenital chloride-losing diarrhoea: absence of the anion-exchange mechanism in the rectum

BACKGROUND

Congenital chloride-losing diarrhoea is characterized by a defect in chloride/bicarbonate exchange, which is normally present in the ileum and colon. Whether the defect is an absence or a reversal of such an exchange is unclear, and we have investigated two young children with the disorder to answer this question.

METHODS

We used a previously described nonequilibrium rectal dialysis method, using different dialysate anion concentrations, to investigate the movement of sodium, potassium, chloride, and bicarbonate in the rectum of the two children.

RESULTS

The results showed that chloride and bicarbonate movements were not linked in any active way, and both ions appeared to move passively in response to the electrochemical gradients generated.

CONCLUSIONS

In the two subjects studied, the defect in the rectum appears to be an absence of the normal anion exchange mechanism present in the bowel, rather than its reversal.

Non infective colitis in infancy: evidence in favour of minor immunodeficiency in its pathogenesis

Forty two infants below the age of two years presenting with chronic non infective diarrhoea and shown to have histologically proven colitis were investigated over a five year period at this hospital. Allergic colitis was the most common cause of colitis accounting for sixty two percent of the cases. Other colitides diagnosed included: non specific colitis, autoimmune enterocolitis and ulcerative colitis accounting for 9.5% each, severe combined immunodeficiency 7.1% and Crohn's disease 2.8%. A positive family history and a personal history of atopy was obtained in 47.6% and 28.6% of the cases. Serum immunoglobulin A, IgG2 and IgG4 were very low in over 50% of the infants with colitis. Sixty six percent of those with severe combined immunodeficiency, autoimmune enterocolitis and ulcerative colitis (n = 11) had low CD3 and CD4 T lymphocytes with an accompanying elevated CD8 in 2/3 of those with severe combined immunodeficiency. T lymphocytes were normal in those with allergic colitis. We conclude that infants with proven non infective colitis show as a group a high prevalence of IgA, IgG2 and IgG4 deficiency. It is likely that this minor deficiency of mucosal associated immunoglobulin production have a role in the pathogenesis of the colitic process.

Acquired intestinal aganglionosis and circulating autoantibodies without neoplasia or other neural involvement

The clinical course, diagnosis, and treatment of 2 patients with acquired intestinal aganglionosis without other neurological involvement or neoplasia are described. They initially presented with constipation and abdominal pain in late childhood. They were found to have enteric ganglionitis with a loss of neurons together with vacuolated nerve cells surrounded by CD3- and CD4-positive T lymphocytes. This process initially affected only the colon but later the entire gastrointestinal tract was involved in 1 patient. Associated with this process there were circulating immunoglobulin G class enteric neuronal antibodies in high titer (1:5000-8000). The staining of central nervous system neuronal nuclei and Western blotting indicated the presence of antineuronal nuclear protein antibodies of the ANNA-1 (anti-Hu) type usually associated with paraneoplastic sensory neuropathy. However, the reaction pattern in enteric neurons was quite different with strong reaction to perikarya and only weak staining of nuclear antigens.

Non-infective colitis in infancy: evidence in favour of minor immunodeficiency in its pathogenesis

Forty two infants below the age of 2 years presenting with chronic non-infective diarrhoea and shown to have histologically proved colitis were investigated over a five year period. Allergic colitis was the most common cause of colitis, accounting for 62% of the cases. Other colitides diagnosed included: non-specific colitis, autoimmune enterocolitis, and ulcerative colitis accounting for 10% each; severe combined immunodeficiency 7%, and Crohn's disease 3%. A positive family history and a personal history of atopy were obtained in 48% and 29% of the cases respectively. Serum immunoglobulin A, IgG2, and IgG4 were very low in over 50% of the entire cohort of infants with colitis; 66% of those with severe combined immunodeficiency, autoimmune enterocolitis, and ulcerative colitis (n = 11) had low CD3 and CD4 T lymphocytes with an accompanying increase in CD8 in two thirds of those with severe combined immunodeficiency. T lymphocytes were normal in those with allergic colitis. Thus infants with proved non-infective colitis as a group show a high prevalence of IgA, IgG2, and IgG4 deficiency. It is likely that this minor deficiency of mucosa associated immunoglobulin production has a role in the pathogenesis of the colitic process.

Counting the cost: hospital versus home central venous catheter survival

We compared catheter survival and sepsis rates in a tertiary paediatric gastroenterology centre with those at home in the same patients. We examined whether there were differences in the safety in the two locations, and estimated the financial and opportunity cost implications of any difference. We used survival analysis to analyse differences. Surgical records were audited to determine venous access workload, and to estimate cost implications. Twenty patients with chronic intestinal failure but stable parenteral nutrition requirements, ranging from 0.04-15.83 years of age were studied. The duration of line survival and sepsis-free intervals and rates of re-operation for venous access were determined to estimate morbidity and costs. The study encompassed 28 patient-years in hospital and 48 patient-years at home. There was a significant reduction in the rate of sepsis at home compared with hospital (Z = 4.30, P < 0.00001), and a similar improvement in line survival (Z = 4.36, P < 0.00001). Line insertions accounted for 21% of minor surgery in our hospital, one third being reinsertions. We conclude that central venous catheter sepsis rates are greatly improved at home. If home results could be achieved in the hospital setting, considerable cost savings would be made.

An evaluation of the role of suction rectal biopsy in the diagnosis of intestinal neuronal dysplasia

BACKGROUND

German pathologists have developed a consensus for histological features of intestinal neuronal dysplasia.

METHODS

A blind reevaluation of ganglionic suction rectal biopsies from infants and children who initially presented with symptoms of intestinal dysmotility was made.

RESULTS

84 of 411 specimens had sufficient depth of submucosa for adequate assessment. Questionnaires or clinical interviews were employed 3-5 years after biopsy in these 84 patients to assess the relationship between histological changes and persistent symptomology. Eighteen children were lost to follow-up, 4 others had Hirschsprung's disease the study biopsy specimen having been taken from the pulled-through bowel after surgical resection of the aganglionic segment. The remaining 62 patients were divided into three groups. There were six patients in group A (both obligatory criteria) and 28 in group B (nonessential, or just one of the obligatory criteria), and 28 in group C (normal appearances). On follow-up, two of the 28 (7%) in group B, and six of the 28 (21%) in group C had persistent dysmotility symptoms.

CONCLUSIONS

Histological criteria of the consensus of German Pathologists for intestinal neuronal dysplasia was unhelpful in predicting the clinical outcome and therefore, should not influence clinical management. As one of the obligatory criteria, hyperplasia of the submucosal plexus was significantly more common in neonates (< 4 weeks), it is concluded that this is an age-related variation.

Neonatal and infantile upper gastrointestinal endoscopy using a new small diameter fibreoptic gastroscope

Using a new prototype (Olympus XPGIF 5.2/ N30) gastroscope, upper gastrointestinal endoscopy was safely performed under sedation on 99 infants (weights 0.9 to 10.1 kg). No complications occurred. Macroscopic and microscopic abnormalities were found in 60%, including abnormal duodenal biopsies in 47% of cases with protracted diarrhoea. Duodenal biopsy material was, however, of suboptimal standard for histologic assessment in 25% of the cases. In 52% of those under 3.5 kg diagnoses were made that would not have otherwise been possible and, in 75% of those in the Intensive Care Unit, abnormalities were found. The use of this new endoscope represents a significant advance in clinical practice.

Loss of functional KATP channels in pancreatic beta-cells causes persistent hyperinsulinemic hypoglycemia of infancy

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) is a disorder of childhood associated with inappropriate hypersecretion of insulin by the pancreas. The pathogenesis of the condition has hitherto remained controversial. We show here that insulin-secreting cells from a homogeneous group of five infants with PHHI lack ATP-sensitive K+ channel (KATP) activity. As a consequence, PHHI beta-cells are spontaneously electrically active with high basal cytosolic Ca2+ concentrations due to Ca2+ influx. Our findings define the pathogenesis of this disease as a novel K+ channel disorder.

Argyrophilia in the developing human myenteric plexus

Silver staining is a useful means of demonstrating enteric neurons, and an absence of argyrophilic neurons has been proposed as a cause of functional intestinal obstruction in infants. No systematic data are available about the origin and development of argyrophilia, or of normal neuronal appearances. Specimens of colon from 48 infants and children (pre-term to 14 years) who had died of nongastrointestinal causes were studied by silver staining. Inter-sample variations in neuronal size, morphology and intensity of staining (strong, faint or absent) were seen: strong argyrophilia (n = 17), age range three days to eight years (median seven months); no argyrophilia (n = 19), pre-term to one year (median eight weeks); weak argyrophilia (n = 12) one day to 14 years (median eight weeks). Neurons in every preterm infant were argyrophobic, and argyrophilic neurons were always found in babies aged over one year. Where argyrophilic neurons were seen, argyrophobes outnumbered them (median ratio of 9:1). This study demonstrated considerable variability in the appearance and argyrophilia of colonic myenteric neurons in the first year of life. The data were consistent with the continuing post-natal development of the enteric nervous system in a manner analogous to the brain, and show the importance of age in the interpretation of silver-stained material from infants with pseudo-obstruction.