Full-thickness Intestinal Biopsies Research Articles

Congenital Myenteric Hypoganglionosis.

Congenital myenteric hypoganglionosis is a rare developmental disorder characterized clinically by severe and persistent neonatal intestinal pseudoobstruction. The diagnosis is established by the prevalence of small myenteric ganglia composed of closely spaced ganglion cells with sparse surrounding neuropil. In practice, the diagnosis entails familiarity with the normal appearance of myenteric ganglia in young infants and the ability to confidently recognize significant deviations in ganglion size and morphology. We review clinical, histologic, and immunohistochemical findings from 12 patients with congenital myenteric hypoganglionosis in comparison with similar data from age-matched controls and clearly delineate the diagnostic features of the condition. Practical guidelines are provided to assist surgical pathologists, who are likely to encounter this condition only infrequently. The diagnosis typically requires full-thickness intestinal biopsy as the abnormality is confined to the myenteric plexus in many patients. Immunohistochemistry for Hu C/D may be used to confirm hypoganglionosis. Reduced staining for calretinin and NeuN implicates a selective deficiency of intrinsic primary afferent neurons in this disease.

S2048 Awareness of Early Diagnosis and Surgical Management of Pediatric Intestinal Pseudo-Obstruction

INTRODUCTION: Gastrointestinal motility is produced by two types of smooths of muscles in the gastrointestinal tract which are circular muscles and longitudinal muscles. These muscles are stimulated by a complex multifaceted connection between intrinsic enteric nervous system and central nervous system. The enteric nervous system is composed of Interstitial cells of Cajal, submucosal plexus, myenteric plexus, migratory motor complex and gut neuromodulators. Gut motility disorders are derived from numerous etiologies that arise from the muscular, nervous, cellular, molecular components. Pediatric intestinal pseudo obstruction is a disorder that needs early diagnosis and prompt treatment to avoid associated life-threatening complications. CASE DESCRIPTION/METHODS: A 27 weeks gestational age baby girl born to a 25 year G1P0 mother with history of abruptio placenta and chorioamnionitis was admitted to the neonatal intensive care unit due to extreme low birth weight and prematurity. Patients developed disseminated Herpes Simplex Virus infection complicated with left grade 2 intraventricular hemorrhage. Afterwards, patient developed persistent total parenteral nutrition dependence, enteral food intolerance, marked intestinal dilation and constipation for 4 months since birth. Rectal biopsies rule out Hirschsprung disease. Multiple abdominal x-rays showed marked diffuse intestinal dilation. Water soluble enema study revealed inflammatory changes suggestive necrotizing enterocolitis. Patient was taken to the operation room since no clinical improvement. Intraoperative findings included viable intestinal tissue without ischemic change and no mechanical obstruction. After negative exploratory laparotomy we decided to perform a rigorous review of literature regarding intestinal dysmotility disorders. DISCUSSION: Our patient was diagnosed with pediatric intestinal pseudo obstruction based in our review of literature which is a intestinal motility disorder. Our plan was to perform multiple full thickness intestinal biopsies to confirmed diagnosis and surgical management with decompressive gastrostomy and ileostomy. Unfortunately, patient developed acute-clinical deterioration due to septic shock, catheter-related bacteremia and multiple organ failure. Functional motility disorders should be included as a differential diagnosis once mechanical obstruction rule out. Our aim is to provide awareness of early identification of PIPO and management since life-threatening complications may develop.

Pathogenesis of chronic constipation in a Polish group of paediatric patients - an attempt to create the optimal histopathological diagnostic protocol.

IntroductionHistopathological diagnosis of chronic constipation in children is difficult and time-consuming because the aetiology of the problem is heterogenous.AimTo create the optimal immunohistochemical (IHC) and histological diagnostic protocol using novel antibodies and assessing precisely their patterns.Material and methodsTwenty-eight paediatric patients were enrolled to the study. The study group consisted of the following: 9 patients with confirmed Hirschsprung’s disease (HD), 11 patients with desmosis of the colon (DC) (3) or with chronic constipation of unknown aetiology (3), and eight children operated on due to other problems. Retrospective analysis of full-thickness material from the large intestine was performed. In each specimen the number of ganglion cells was estimated per square millimetre as well as the number of submucosal and intramuscular ganglion cells per ganglion. The following IHC and histological stains were also performed: calretinin, CD117, picrosirius, and trichrome gomori. Patterns (nuclear vs. cytoplasmic vs. membranous) and intensity (strong vs. faint) of the stainings were analysed.ResultsThere was no statistically significant difference between groups while comparing the intensity and pattern of each staining, except HD (no staining due to lack of ganglion cells), p > 0.001. Calretinin was positive in each patient with ganglion cells; however, it did not unequivocally stain all cells identified in routine haematoxylin and eosin staining.ConclusionsCalretinin is helpful in identifying ganglion cells; however, it cannot replace an experienced paediatric pathologist. In children with chronic constipation it is worth obtaining a full thickness intestinal biopsy in order to perform additional histological and immunohistochemical stains starting with picrosirius red.

Functional neuromuscular impairment in severe intestinal dysmotility.

Chronic intestinal pseudo-obstruction (CIPO) and enteric dysmotility (ED) are severe intestinal motility disorders usually associated with underlying neuromuscular abnormalities. To evaluate the in vitro neuromuscular function of patients with severe intestinal motility disorders. Full-thickness intestinal biopsies (16 jejunum and 3 ileum) obtained from patients with CIPO (n=10) and ED (n=9) were studied using muscle bath and microelectrode techniques. Control samples (n=6 ileum and n=6 jejunum) were used to establish the range of normality. Fourteen parameters were defined to assess muscle contractility and nerve-muscle interaction: five to evaluate smooth muscle and interstitial cells of Cajal (ICC) and nine to evaluate inhibitory neuromuscular transmission. For each sample, a parameter was scored 0 if the value was inside the normal range or a value of 1 if it was outside. Patients' samples (CIPO/ED) had more abnormal parameters than controls (P<0.001 for both jejunum and ileum). Functional abnormalities were found to be heterogeneous. The most prevalent abnormality was a decreased purinergic neuromuscular transmission, which was detected in 43.8% of jejunal samples. Abnormalities of neuromuscular intestinal function are detected in vitro in severe intestinal dysmotility. However, consistent with the heterogeneity of the disease pathophysiology, functional impairment cannot be attributed to a single mechanism. Specifically, defects of purinergic neuromuscular transmission may have an important role in motility disorders of the gastrointestinal tract.

Endoscopic techniques for full thickness intestinal biopsy.

Accurate diagnosis of gastrointestinal neuromuscular diseases requires full thickness biopsy for adequate histologic evaluation of the enteric neuromuscular and ancillary cells. Historically, this has been achieved by surgical approaches. An overview of procedure evolution and current techniques of endoscopic full thickness biopsy (EFTB) for diagnosis of gastrointestinal neuromuscular disorders will be presented. Emergence and advancement of endoscopic full thickness resection techniques has offered a less invasive, nevertheless an effective modality of tissue acquirement. Recently, clip-assisted close-then-cut EFTB has been utilized in clinical practice under research protocol. Early experience has shown that this technique provides an adequate full-thickness specimen including the myenteric plexus and ganglia cells, with acceptable safety profiles. EFTB is a promising means in diagnosing the nature of the disease and guiding therapy. Available animal and human studies have shown the noninferiority of endoscopic methods to surgical ones in term of adequacy of tissue samples, while potentially decreasing the risk and occurrence of complications. Further large prospective studies are needed to assess its efficacy, safety and impacts on patient's outcomes.

Japanese clinical practice guidelines for allied disorders of Hirschsprung's disease, 2017.

Despite the presence of ganglion cells in the rectum, some patients have symptoms similar to those of Hirschsprung's disease. A consensus has yet to be established regarding the terminology for these diseases. We defined this group of diseases as "allied disorders of Hirschsprung's disease" and compiled these guidelines to facilitate accurate clinician diagnosis and provide appropriate treatment strategies for each disease. These guidelines were developed using the methodologies in the Medical Information Network Distribution System (MINDS). Of seven allied disorders, isolated hypoganglionosis; megacystis-microcolon-intestinal hypoperistalsis syndrome; and chronic idiopathic intestinal pseudo-obstruction were selected as targets of clinical questions (CQ). In a comprehensive search of the Japanese- and English-language articles in PubMed and Ichu-Shi Web, 836 pieces of evidence related to the CQ were extracted from 288 articles; these pieces of evidence were summarized in an evidence table. We herein outline the newly established Japanese clinical practice guidelines for allied disorders of Hirschsprung's disease. Given that the target diseases are rare and intractable, most evidence was drawn from case reports and case series. In the CQ, the diagnosis, medication, nutritional support, surgical therapy, and prognosis for each disease are given. We emphasize the importance of full-thickness intestinal biopsy specimens for the histopathological evaluation of enteric ganglia. Considering the practicality of the guidelines, the recommendations for each CQ were created with protracted discussions among specialists. Clinical practice recommendations for allied disorders of Hirschprung's disease are given for each CQ, along with an assessment of the current evidence. We hope that the information will be helpful in daily practice and future studies.

Loss of alpha-smooth muscle actin expression associated with chronic intestinal pseudo-obstruction in a young Miniature Bull Terrier

BackgroundChronic intestinal pseudo-obstruction (CIPO) is a rare clinical syndrome in veterinary medicine characterized by severe intestinal dysmotility without evidence of mechanical occlusion of the intestinal lumen. The exact pathogenesis of CIPO is unknown.Case presentationA 1-year-old male Miniature Bull Terrier dog was presented with a history of chronic weight loss, regurgitation, lethargy, vomiting and diarrhea. The dog was submitted for exploratory laparotomy. A full thickness intestinal biopsy was taken and a CIPO was suspected. The clinical condition deteriorated and the dog was euthanized. At gross examination the small intestine was severely dilated. Histologically severe fibrosis of the submucosa and severe atrophy of the tunica muscularis were present in small intestine and colon. Immunohistochemical examination with a panel of antibodies for gastro-intestinal neuromuscular disease-associated antigens revealed a severely reduced expression of alpha-smooth muscle actin in the tunica muscularis.ConclusionsThis case report describes the gross, histological and immunohistochemical findings of CIPO affecting a 1-year-old Miniature Bull Terrier; on the basis of these findings a myopathic form of CIPO is hypothesized in this case.

Comparison between small bowel manometric patterns and full-thickness biopsy histopathology in severe intestinal dysmotility.

Intestinal manometry is the current standard for direct evaluation of small bowel dysmotility. Patients with abnormal motility can either be diagnosed of pseudo-obstruction when there are radiological findings mimicking mechanical intestinal obstruction or of enteric dysmotility when these findings are absent. The aim of the present study was to prospectively compare small bowel manometric abnormalities with histopathological findings in intestinal full-thickness biopsies in patients with severe dysmotility disorders. We investigated 38 patients with intestinal manometry and a subsequent full-thickness intestinal biopsy. Manometric recordings were read by 4 investigators and a diagnostic consensus was obtained in 35 patients. Histopathological analysis, including specific immunohistochemical techniques of small bowel biopsies was performed and compared to manometric readings. Patients with abnormal intestinal manometry had abnormal histopathological findings in 73% of cases. However, manometric patterns did not match with the specific neuromuscular abnormalities. Among patients with a neuropathic manometry pattern and abnormal histopathology, only 23% had an enteric neuropathy, whereas 62% had neuromuscular inflammation, and 15% an enteric myopathy. On the other hand, patients with a myopathic manometry pattern all had abnormal histopathology, however, none of them with signs of enteric myopathy. Small bowel dysmotility detected by intestinal manometry is often associated with abnormal neuromuscular findings in full-thickness biopsies. However, there is no correlation between the specific manometric patterns and the histopathological findings.

Familiar Occurrence of Desmosis of the Colon – Report of Two Cases and Literature Review

Gastrointestinal motility disorders are relatively common in children and adolescents. The diagnosis is often difficult and time-consuming as the etiology of the problems includes different pathological entities such as enteric neuropathies, myopathies and collagenopathies. Hirschsprung's disease (HD) is one of the most common and best recognized disorders, particularly in infants. Whereas, desmosis of the colon is a rare condition characterized by total or focal lack of connective-tissue net of the circular and longitudinal muscles without any abnormalities within enteric nervous system (ENS). Its diagnosis is based on full-thickness intestinal biopsy or post-operative material followed by histological staining with pricrosirius red. We present two adolescent girls who were familiar related (the same mother, different fathers) and both of them suffered from chronic constipations. HD was excluded in these cases and surgical removal of impaired part of intestines was performed. Material from post-operative specimens proved desmosis of the colon in each patient.

EFFECTS OF CORN OIL ADMINISTERED ORALLY ON CONSPICUITY OF ULTRASONOGRAPHIC SMALL INTESTINAL LESIONS IN DOGS WITH LYMPHANGIECTASIA

Lymphangiectasia is one of the causes of protein-losing enteropathy in dogs and characteristic ultrasonographic small intestinal lesions have been previously described. The purpose of this study was to determine whether corn oil administered orally (COAO) would result in increased conspicuity of these characteristic small intestinal ultrasonographic lesions in dogs with lymphangiectasia. Affected dogs were included if they underwent corn oil administered orally and had a surgical full-thickness intestinal biopsy diagnosis of lymphangiectasia. Control dogs had normal clinical examination and standard laboratory test findings. Ultrasound images of duodenum, jejunum, and ileum were obtained prior to and 30, 60, 90, and 120 min after corn oil administered orally for all dogs. Parameters recorded for each ultrasound study were intestinal wall thickness, mucosal echogenicity, and presence or absence of hyperechoic mucosal striations (HMS) and a parallel hyperechoic mucosal line (PHML). Nine affected and five controls dogs were included in the study. Seven of the nine dogs with lymphangiectasia had hyperechoic mucosal striations prior to corn oil administered orally. Jejunal hyperechoic mucosal striations were significantly associated with lymphangiectasia at multiple time points (P < 0.05) and were best identified in dogs with lymphangiectasia 60 or 90 min after corn oil administered orally. Increased mucosal echogenicity was observed in all dogs at multiple time points after corn oil administered orally. A parallel hyperechoic mucosal line was present in the jejunum in 4/5 healthy and 6/9 dogs with lymphangiectasia at one or more time points after corn oil administered orally. Findings indicated that corn oil administered orally improves conspicuity of characteristic ultrasonographic lesions in dogs with lymphangiectasia, however some of these lesions may also be present in healthy dogs that recently received a fatty meal.

Isolated adult hypoganglionosis presenting as sigmoid volvulus: a case report

IntroductionIsolated hypoganglionosis is a rare cause of intestinal innervation defects. It is characterized by sparse and small myenteric ganglia, absent or low acetylcholinesterase activity in the lamina propria and hypertrophy of the muscularis mucosae, principally in the region of the colon and rectum. It accounts for 5% of all intestinal neuronal malformations. To the best of our knowledge, only 92 cases of isolated hypoganglionosis were reported from 1978 to 2009. Isolated hypoganglionosis usually manifests as enterocolitis or poor bowel function, and is diagnosed in infancy or childhood. We report the first case of isolated hypoganglionosis presenting with sigmoid volvulus in a 34-year-old woman.Case presentationA 34-year-old Asian woman had progressively increasing abdominal pain and had not passed stool or flatus for two days. A physical examination revealed a distended abdomen with sluggish gut sounds. A computerized tomography (CT) scan demonstrated gross dilatation of the sigmoid colon (maximal diameter 14.3 cm) suggestive of sigmoid volvulus. During emergency laparotomy, sigmoidectomy with a side-to-side colorectal anastomosis was performed. Histopathology of the resected specimen showed occasional ganglion cells and hypertrophied nerve bundles in the muscle layers, suggesting hypoganglionosis. Colonoscopy was performed, and multiple full-thickness biopsies were taken that showed hypoganglionosis of the entire large bowel. Our patient underwent total colectomy with an ileorectal anastomosis. Subsequently our patient reported a dramatic improvement in her bowel function.ConclusionsIsolated hypoganglionosis is a rare cause of intestinal dysganglionosis and cannot be differentiated from Hirschsprung's disease based on clinical presentation. This case report describes an atypical presentation of the disease. A definitive diagnosis requires histopathological analysis of full-thickness intestinal biopsies. Treatment should be tailored to the extent of hypoganglionosis.

Mucosal inflammation as a potential etiological factor in irritable bowel syndrome: a systematic review

The causes of irritable bowel syndrome (IBS) remain obscure. Some investigators have proposed chronic low-grade mucosal inflammation as a potential etiological factor. We performed a systematic review to examine this issue in detail. MEDLINE, EMBASE, and EMBASE classic were searched up to December 2010 to identify studies of case-control design applying tests for low-grade inflammation to either full-thickness intestinal or endoscopic mucosal biopsies from patients with IBS. Controls were required to be healthy individuals, or asymptomatic patients undergoing investigation for reasons other than the reporting of upper or lower gastrointestinal symptoms. Individual study results were summarized descriptively. The literature search identified 1388 citations, of which 16 studies were eligible for inclusion. Individual study results were diverse, partly as a consequence of the different surrogate markers for inflammatory mechanisms studied. Mast cells, T lymphocytes, B lymphocytes, and mucosal cytokine production all appeared altered among cases with IBS in individual studies, while no study demonstrated a significant difference in numbers of plasma cells, neutrophils, or eosinophils. Some studies suggested a relationship between mast cell abnormalities and symptom severity and frequency, as well as co-existent fatigue and depression. Studies were limited by the lack of comparability of controls, and the fact that most were conducted in highly selected groups of patients with IBS. Low-grade mucosal inflammation, particularly mast cell activation, may be a contributory factor in the pathogenesis of IBS. Mast cell stabilizers warrant further assessment as a potential therapy in the condition.

Treatment of Feline Gastrointestinal Small-Cell Lymphoma With Chlorambucil and Glucocorticoids

Gastrointestinal (GI) lymphoma is the most frequently diagnosed form of lymphoma in the cat and is categorized into two distinct forms based on the size of neoplastic lymphocytes. Treatments for both large- and small-cell GI lymphoma have been described previously; however, multiple chemotherapy protocols were used, a minimal amount of histopathological characterization was provided, and, in most studies, the majority of diagnoses were obtained via endoscopic pinch biopsies. Twenty-eight cats (24 with full-thickness intestinal biopsies) were diagnosed with small-cell GI lymphoma and treated with a combination of chlorambucil and glucocorticoids. The majority of cases were strongly CD3+, and many displayed epitheliotropism. The overall clinical response rate was 96%, with a median clinical remission duration of 786 days. Follow-up identified seven cats with relapsed disease-all of which were treated with a rescue protocol of cyclophosphamide and glucocorticoids; the response rate was 100%, and four of the 28 cats were diagnosed with a second malignancy.

THE SONOGRAPHIC APPEARANCE OF INTESTINAL MUCOSAL FIBROSIS IN CATS

The medical records of 11 cats with full-thickness intestinal biopsies and histopathologic confirmation of segmental mucosal fibrosis were reviewed. All cats received an abdominal ultrasonographic evaluation. The sonographic feature of a small intestinal mucosal hyperechoic band paralleling the submucosa was present in all cats. Other intestinal sonographic findings included wall thickening, and altered wall layering (increased mucosal echogenicity, thickened submucosa, and/or muscularis layer). None of the cats had complete loss of wall stratification. All cats had clinical signs related to the gastrointestinal (GI) tract at the time of presentation. Three of the 11 cats had palpably thickened small intestinal loops, 3/11 abdominal pain, and 2/11 abdominal fluid. Histopathologically, mucosal fibrosis was associated with inflammatory cell infiltrates in all cats. In those cats with histopathologic evidence of mural fibrosis, all cats had a visible hyperechoic band through several intestinal segments. We speculate that the hyperechoic mucosal band represents the zone of mucosal fibrosis. Independently and prospectively, we reviewed the clinical presentation of 35 cats having this visible hyperechoic mucosal band on ultrasound. Twenty-four of these 35 cats had clinical signs related to the digestive system at the time of record. Our study suggests that the hyperechoic mucosal band represents fibrosis, and in presence of concurrent GI signs, further diagnostic tests may be warranted.

Chronic inflammatory and non-inflammatory diseases of the gastrointestinal tract in cats: Diagnostic advantages of full-thickness intestinal and extraintestinal biopsies

An evaluation of histological findings in full-thickness biopsies from the gastrointestinal tract (GIT) and extraintestinal samples of 43 cats with chronic GIT disease signs was performed. In the majority of cases (46.5%) inflammatory bowel disease, ie, lymphocytic-plasmacytic enteritis/colitis (32.6%), eosinophilic gastroenterocolitis (11.6%) and mixed inflammatory infiltration (2.3%), was diagnosed. Furthermore, in four animals non-inflammatory mucosal band-shaped fibrosis (9.3%), and in 10 cats (23.3%) a diffuse lymphoma, was found. Six cats displayed only a gastritis (7.0%) or lymphangiectasia (7.0%), respectively. In two cats a mast cell tumour (4.7%) was diagnosed. In one cat no histopathological lesions were found. The availability of transmural biopsies from all segments of the intestine and the collection of extraintestinal samples, especially mesenteric lymph nodes, is especially helpful for diagnosing intestinal tumours such as lymphomas and tumours of mast cell origin.

A novel locus for syndromic chronic idiopathic intestinal pseudo-obstruction maps to chromosome 8q23–q24

Chronic idiopathic intestinal pseudo-obstruction (CIIP) is a rare and severe clinical syndrome characterized by symptoms and signs of intestinal occlusion, in the absence of any mechanical obstruction of the gut lumen. In the attempt to identify the genetic basis of CIIP, we analyzed a Turkish pedigree with a high degree of consanguinity in which three siblings presented with a syndromic form of CIIP. All affected family members were characterized by recurrent, self-limiting subocclusive episodes, long-segment Barrett esophagus, and a variety of minor cardiac valve or septal defects. In some patients full-thickness intestinal biopsy samples were obtained and tissues were processed for immunohistochemistry using antibodies to different markers of the intestinal neuromuscular tract. Full-thickness biopsies of the gut wall showed abnormalities of both the neural and muscular components suggesting an underlying intestinal neuro-myopathy. Blood samples were collected for DNA extraction from each available family member and DNAs were genotyped using 382 microsatellites spanning the entire genome with the aim to take advantage of the homozygosity mapping approach. Linkage analysis identified a new syndromic locus on chromosome 8q23-q24 (multipoint LOD score=5.01). Our data strongly support the presence of a new genetic locus associated with CIIP, long-segment Barrett esophagus, and cardiac involvement on chromosome 8.

Pseudo-obstruction intestinale chronique

Chronic intestinal pseudo-obstruction (CIPO) is a disease characterized by episodes resembling mechanical obstruction in the absence of organic, systemic, or metabolic disorders. Pseudo-obstruction is an uncommon condition and can result from primary (40%) or secondary (60%) causes. The most common symptoms are nausea, vomiting, abdominal distension, abdominal pain and constipation or diarrhea. These symptoms are usually present many years before CIPO diagnosis. They can lead to severe electrolyte disorders and malnutrition. Principles for management of patients with CIPO are: to establish a correct clinical diagnosis in excluding mechanical obstruction; to perform a symptomatic and physiologic assessment of the gastrointestinal tract involved; to look for extra-intestinal manifestations, especially for myopathy and neuropathy; to discuss in some cases a surgery for full-thickness intestinal biopsies, and/or a neuromuscular biopsy in case of mitochondrial cytopathy suspicion. The management is primarily focused on symptom control and nutritional support to prevent weight loss and malnutrition. Treatment of CIPO includes prokinetic agents which may help to reduce gastrointestinal symptoms Courses of antibiotics may be needed in patients with symptoms suggestive of bacterial overgrowth. When necessary, enteral nutrition is preferred. In carefully selected patients, feeding jejunostomy with or without decompression gastrostomy may be tried. Long term parenteral nutrition should be reserved for patients who can not tolerate enteral nutrition. Intestinal transplantation can be discussed in selected patients.

Distribution of mRNA coding for 5-hydroxytryptamine receptor subtypes in the intestines of healthy dairy cows and dairy cows with cecal dilatation-dislocation

To investigate the distribution of mRNA coding for 7 subtypes of 5-hydroxytryptamine receptors (5-HTRs) in the intestines of healthy dairy cows and dairy cows with cecal dilatation-dislocation (CDD). Full-thickness intestinal wall biopsy specimens were obtained from the ileum, cecum, proximal loop of the ascending colon, and external loop of the spiral colon (ELSC) of 15 cows with CDD (group 1) and 15 healthy dairy cows allocated to 2 control groups (specimens collected during routine laparotomy [group 2] or after cows were slaughtered [group 3]). Amounts of mRNA coding for 7 subtypes of 5-HTRs (5-HT1A, 5-HT1B, 5-HT1D, 5-HT1F, 5-HT2A, 5-HT2B, and 5-HT4) were measured by quantitative real-time reverse transcriptase-PCR assay. Results were expressed as the percentage of mRNA expression of a housekeeping gene. Expression of mRNA coding for 5-HTR1B, 5-HTR2B, and 5-HTR4 was significantly lower in cows with CDD than in healthy cows. For 5-HTR2B and 5-HTR4, significant differences between cows with CDD and control cows were most pronounced for the ELSC. Expression of mRNA for 5-HTR1D, 5-HTR1F, and 5-HTR2A was extremely low in all groups, and mRNA for 5-HTR1A was not detected. Relative concentrations of mRNA coding for 5-HTR1B, 5-HT2B, and 5-HTR4 were significantly lower in the intestines of cows with CDD than in the intestines of healthy dairy cows, especially for 5-HT2B and 5-HTR4 in the ELSC. This supports the hypothesis that serotonergic mechanisms, primarily in the spiral colon, are implicated in the pathogenesis of CDD.

RE: CHRONIC CONSTIPATION IN CHILDREN: ORGANIC DISORDERS ARE A MAJOR CAUSE

27 April 2005 Dear Editor, In the recent review article: ‘Chronic constipation in children: Organic disorders are a major cause’, the authors suggest that 50% of children with severe constipation have an organic cause, where surgical management has a major role.1 They pose the question: ‘Why are some paediatricians and gastroenterologists sceptical?’. We suggest that there are many good reasons for our scepticism. First, the authors are confused about the term ‘functional’. They use it as a synonym for behavioural/psychological and suggest that any demonstration of a physiological difference from control subjects results in a diagnostic ‘paradigm’ shift to an organic pathology, that ‘completely change(s) the way they are treated’. However, the term ‘functional’ as originally used, implied that ‘morbid manifestations may be independent of anatomic change’.2 The term has now been expanded to encompass a broad range of syndromes that cannot be accounted for by observed abnormalities, but which are frequently associated with physiologic and anatomic (histologic) alterations.3 It is certainly not appropriate to assume that demonstration of slow transit constipation (STC), or of changes in neurotransmitter levels, or of impaired rectal sensation, equates with organic pathology. Second, the scientific evidence that many children with STC have a primary abnormality in intestinal innervation is weak. Yes, one can show differences in levels of an increasing number of neurotransmitters, when one compares children with STC to adults with colon cancer; but is this real or just a problem with selection of controls? Even if it is a real observation, there is almost no evidence suggesting that the abnormalities are causal rather than secondary to the constipation itself, or even its treatment. Third, we disagree with the suggestion that demonstration of any alteration of intestinal neurotransmitter levels automatically means that the condition is permanent, therefore unresponsive to conservative treatment, and therefore requires surgery. Both functional and organic diseases of the intestine are frequently both self-limiting and responsive to non-surgical treatment. This is our experience in almost all children with constipation. Finally, many of the facts and logic presented in the article are either wrong or defy comprehension (or both). In the interests of space we can only point out a few of these. (i) The statement: ‘The colon is the site of water absorption’ shows a gross misunderstanding of basic intestinal physiology. (ii) If STC is a permanent organic condition, then what is the logic of submitting a child to an end-ileostomy with retention of the colon to allow for future reconnection if recovery occurs and (iii) how is one to show recovery of colonic function in a disconnected colon? (iv) We also reject the implication that surgical management has become less invasive. Colectomy for constipation was always a rare operation in children, as opposed to the current situation in the authors' unit where they state that they have more than 50 children with colostomy for management of constipation, many of whom have also been subjected to laparoscopic full-thickness intestinal biopsy at multiple sites. Overall, the level of surgical invasion seems to have dramatically increased, at least in their unit. The editor's decision to present the paper as a review article incorrectly suggests that its content is well accepted. The reality, as the authors correctly identify, is that most paediatricians and gastroenterologists remain unconvinced by their arguments – for many good reasons.

Lymphatics in the Alimentary Tract of Children in Health and Disease: Study on Mucosal Biopsies Using the Monoclonal Antibody D2-40

Primary intestinal lymphangiectasia and intestinal lymphatic hypoplasia are 2 causes of protein-losing enteropathy in children and share many common clinical features. For the diagnosis of lymphatic hypoplasia on endoscopic biopsies of the intestine, i.e., based on a negative finding in a small specimen, a very sensitive and specific method for identifying lymphatics is essential. In the present study, lymphatic vessels were labelled using D2-40 immunostaining in mucosal biopsy specimens of the alimentary tract of children in whom no histologic abnormality was noted and of those who had different relatively common pediatric conditions, including inflammatory and neoplastic diseases. Using this method, lymphatic vessels were well visualized even in young infants and not destroyed by diseases. The presence of the muscularis mucosae in specimens was important for adequate assessment. In the duodenum and esophagus, lymphatics were observed in every single section; in the stomach, ileum, and colon, they were less regular and several sections were sometimes required. The extreme sensitivity of this method for demonstrating lymphatic vessels in the duodenum makes it ideal for the histologic diagnosis of intestinal lymphatic hypoplasia. In 4 patients who were considered to have this diagnosis based on clinical features, full-thickness intestinal biopsies and electron microscopy, D2-40 immunostaining confirmed the absence or marked paucity of lymphatics.