V V Smith

Great Ormond Street Hospital for Children NHS Foundation Trust, Londinium, England, United Kingdom

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Publications (70)324.39 Total impact

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    ABSTRACT: Background Insulinoma is a rare cause of hyperinsulinemic hypoglycaemia in children. The clinical features, investigations, management and histology of these rare pancreatic tumours in children have not been described in a large cohort of patients.Methods We conducted a retrospective review of cases diagnosed between 2000 and 2012 presenting to two referral centres in the United Kingdom. Clinical, biochemical, imaging (MRI and 18F-DOPA-PET/CT scanning) and histological data were collected.ResultsNine children (age range 2-14.5yr) were diagnosed during the study period at Great Ormond Street Hospital (n=5) and Royal Manchester Children's Hospital (n=4). The combination of abdominal MRI scan (7/8) and 18F-DOPA-PET/CT scan (2/4) correctly localised the anatomical location in all insulinoma. Prior to surgery diazoxide therapy was used to treat the hypoglycaemia but only 4 patients responded. After surgical resection of the insulinoma, hypoglycaemia resolved in all patients. The anatomical localisation of the insulinoma in each patient was head (n=4), uncinate process (n=4) and tail (n=2, one second lesion) of the pancreas. Histology confirmed the diagnosis of insulinoma with the presence of sheets and trabeculae of epithelioid and spindle cells staining strongly for insulin and proinsulin, but not for glucagon or somatostatin. Two children were positive for MEN1, one of whom had two separate insulinoma lesions within the pancreas.Conclusions We describe a cohort of paediatric insulinoma patients. Although rare, insulinoma should be included in the differential diagnosis for HH, even in very young children. In the absence of a single imaging modality in the preoperative period, localisation of the tumour is achieved by combining imaging techniques, both conventional and functional.
    European Journal of Endocrinology 03/2014; · 3.14 Impact Factor
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    ABSTRACT: Primary gastrointestinal neuropathies are a heterogeneous group of enteric nervous system (ENS) disorders that continue to cause difficulties in diagnosis and histological interpretation. Recently, an international working group published guidelines for histological techniques and reporting, along with a classification of gastrointestinal neuromuscular pathology. The aim of this article was to review and summarize the key issues for pediatric gastroenterologists on the diagnostic workup of congenital ENS disorders. In addition, we provide further commentary on the continuing controversies in the field. Although the diagnostic criteria for Hirschsprung disease are well established, those for other forms of dysganglionosis remain ill-defined. Appropriate tissue sampling, handling, and expert interpretation are crucial to maximize diagnostic accuracy and reduce interobserver variability. The absence of validated age-related normal values for neuronal density, along with the lack of correlation between clinical and histological findings, result in significant diagnostic uncertainties while diagnosing quantitative aberrations such as hypoganglionosis or ultrashort Hirschsprung disease. Intestinal neuronal dysplasia remains a histological description of unclear significance. The evaluation of cellular quantitative or qualitative abnormalities of the ENS for clinical diagnosis remains complex. Such analysis should be carried out in laboratories that have the necessary expertise and access to their own validated reference values.
    Journal of pediatric gastroenterology and nutrition 11/2013; 57(5):677-86. · 2.18 Impact Factor
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    ABSTRACT: OBJECTIVE: Necrotising enterocolitis (NEC) remains one of the primary causes of morbidity and mortality in neonates and alternative strategies are needed. Stem cells have become a therapeutic option for other intestinal diseases, which share some features with NEC. We tested the hypothesis that amniotic fluid stem (AFS) cells exerted a beneficial effect in a neonatal rat model of NEC. DESIGN: Rats intraperitoneally injected with AFS cells and their controls (bone marrow mesenchymal stem cells, myoblast) were analysed for survival, behaviour, bowel imaging (MRI scan), histology, bowel absorption and motility, immunofluorescence for AFS cell detection, degree of gut inflammation (myeloperoxidase and malondialdehyde), and enterocyte apoptosis and proliferation. RESULTS: AFS cells integrated in the bowel wall and improved rat survival and clinical conditions, decreased NEC incidence and macroscopic gut damage, improved intestinal function, decreased bowel inflammation, increased enterocyte proliferation and reduced apoptosis. The beneficial effect was achieved via modulation of stromal cells expressing cyclooxygenase 2 in the lamina propria, as shown by survival studies using selective and non-selective cyclooxygenase 2 inhibitors. Interestingly, AFS cells differentially expressed genes of the Wnt/β-catenin pathway, which regulate intestinal epithelial stem cell function and cell migration and growth factors known to maintain gut epithelial integrity and reduce mucosal injury. CONCLUSIONS: We demonstrated here for the first time that AFS cells injected in an established model of NEC improve survival, clinical status, gut structure and function. Understanding the mechanism of this effect may help us to develop new cellular or pharmacological therapies for infants with NEC.
    Gut 03/2013; · 10.73 Impact Factor
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    ABSTRACT: Background  Severe pediatric slow transit constipation (STC) is commonly due to intrinsic colonic neuromuscular disease. We sought to correlate neuromuscular histological phenotypes in pediatric STC with colonic manometric phenotypes using high-resolution manometry (HRM). We tested the hypothesis that failure of motor quiescence (FQ) between bisacodyl-induced high amplitude propagating sequences (HAPSs) might predict neuromuscular pathology. Methods  Eighteen children (10 males, median age: 7.5 years) with refractory STC underwent stationary colonic HRM before segmental colonic resection. Six age-matched constipated children with normal colonic transit served as controls. Colonic resection specimens underwent histopathological analysis. Conventional manometric parameters and area under the curve (AUC) during a 1-min period following bisacodyl-induced HAPSs [PBAUC(1) ], as measure of FQ, were calculated. Key Results  Numbers of postbisacodyl HAPSs in descending and sigmoid segments were lower in patients than controls (P < 0.01, respectively). Low amplitude propagating sequences (LAPSs) were common prebisacodyl in controls and rare in STC (P < 0.001), whereas postbisacodyl LAPS were more common in STC (P < 0.001). Postbisacodyl, both retrograde propagating contractions and bursts of contractions were present in STC patients only (P < 0.001 and P < 0.01). Postbisacodyl simultaneous pressurization was seen only in STC (P < 0.05 and P < 0.001, in descending and rectosigmoid segments). Histological abnormalities were present in 17/18. Fourteen were neurogenic, one neuro-myogenic, and two myogenic. In segments with HAPS, PBAUC(1) was predictive of colonic neuropathy using a cutoff of 205 mmHg.s(-1) (Sensitivity 100%, specificity 86%, PPV92%, NPV100%). Conclusions & Inferences  PBAUC(1) is increased in multiple colonic segments in neuropathic pediatric STC and constitutes a sensitive and specific biomarker of neuropathy.
    Neurogastroenterology and Motility 10/2012; · 2.94 Impact Factor
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    ABSTRACT: Growth during childhood is a consequence of the equilibrium of energy balance. Obesity results from a shift of the equilibrium towards increased energy intake over expenditure. A clinical description of extreme leanness and failure to thrive secondary to a shift of the equilibrium towards increased energy expenditure over energy intake has not been previously described in the medical literature. We report the case of a female child born premature with a birth weight of 1.1 kg who presented with extreme failure to thrive, persistent hypoglycaemia, paucity of fat in the adipose tissue with increased brown fat and increased resting energy expenditure. Complete cessation of weight and height was noted between 3 months to 3.5 years of age. Hypoglycaemia was secondary to depleted energy stores and increased insulin sensitivity. Increased resting energy expenditure was demonstrated on indirect calorimetric assessment. Biopsy of adipose tissue demonstrated paucity of stored fat with increase in brown fat. No gain in weight and height was demonstrated despite high calorie intake of enteral and parenteral feeds. We describe a unique case of extreme failure to thrive with increased energy expenditure and severe hypoglycaemia. Unravelling the molecular basis of this novel disorder has the potential to provide insights into the prevention of obesity.
    Hormone Research in Paediatrics 04/2012; 77(4):261-8. · 1.55 Impact Factor
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    ABSTRACT: Management of intestinal failure remains a clinical challenge and total parenteral nutrition, intestinal elongation and/or transplantation are partial solutions. In this study, using a detergent-enzymatic treatment (DET), we optimize in rats a new protocol that creates a natural intestinal scaffold, as a base for developing functional intestinal tissue. After 1 cycle of DET, histological examination and SEM and TEM analyses showed removal of cellular elements with preservation of the native architecture and connective tissue components. Maintenance of biomechanical, adhesion and angiogenic properties were also demonstrated strengthen the idea that matrices obtained using DET may represent a valid support for intestinal regeneration.
    Biomaterials 04/2012; 33(12):3401-10. · 7.60 Impact Factor
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    ABSTRACT: Congenital hyperinsulinism (CHI) is a cause of persistent hypoglycemia due to unregulated insulin secretion from pancreatic β-cells. Histologically, there are two major subgroups, focal and diffuse. Focal CHI is typically unresponsive to diazoxide and can be cured with surgical removal of the focal lesion. We report on three patients with focal CHI to illustrate the marked clinical, genetic, radiological, and histological heterogeneity. The first two patients had focal CHI due to a paternal (c.3992-9G→A) ABCC8 mutation. One of these patients was fully responsive to a small dose (5 mg/kg · d) of diazoxide, whereas the other patient was medically unresponsive. In both patients, the focal lesions were accurately localized preoperatively by [(18)F]dihydroxyphenylalanine (DOPA) positron emission tomography (PET) and surgically resected. The third patient had a paternally inherited ABCC8 (A1493T) mutation, and the initial [(18)F]DOPA PET scan indicated extensive uptake of DOPA in the body and tail of the pancreas. However, despite surgical resection of the body and tail, this patient continued to have severe CHI. A subsequent [(18)F]DOPA PET scan now showed markedly increased DOPA uptake in the remaining body and head of the pancreas. This focal lesion occupied virtually the whole of the pancreas. conclusions: These three cases illustrate that focal lesions even with the same genotype (c.3992-9G→A) may have a different clinical presentation and that [(18)F]DOPA PET scans in very large focal lesions may be difficult to interpret.
    The Journal of clinical endocrinology and metabolism 01/2012; 97(1):E94-9. · 6.50 Impact Factor
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    ABSTRACT: Recessive inactivating mutations in the ABCC8 and KCNJ11 genes encoding the adenosine triphosphate-sensitive potassium (K(ATP)) channel subunit sulphonylurea receptor 1 (SUR1) and inwardly rectifying potassium channel subunit (Kir6.2) are the most common cause of hyperinsulinaemic hypoglycaemia (HH). Most of these patients do not respond to treatment with the (K(ATP)) channel agonist diazoxide. Dominant inactivating ABCC8 and KCNJ11 mutations are less frequent, but are usually associated with a milder form of hypoglycaemia that is responsive to diazoxide therapy. We studied five patients from four families with HH who were unresponsive to diazoxide and required a near total pancreatectomy. Mutations in KCNJ11 and ABCC8 were sought by sequencing and dosage analysis. Three novel heterozygous ABCC8 mis-sense mutations (G1485E, D1506E and M1514K) were identified in four probands. All the mutations affect residues located within the Nucleotide Binding Domain 2 of the SUR1 subunit. Testing of family members showed that the mutations had arisen de novo with dominant inheritance in one pedigree. This study extends the clinical phenotype associated with dominant (K(ATP)) channel mutations to include severe congenital HH requiring near total pancreatectomy in addition to a milder form of diazoxide responsive hypoglycaemia. The identification of dominant vs recessive mutations does not predict clinical course but it is important for estimating the risk of HH in future siblings and offspring.
    Clinical Genetics 06/2011; 79(6):582-7. · 4.25 Impact Factor
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    ABSTRACT: 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.
    Neurogastroenterology and Motility 02/2011; 23(2):115-24. · 2.94 Impact Factor
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    ABSTRACT: In congenital hyperinsulinism (CHI) of infancy, the use of preoperative fluorine-18-L-3,4-dihydroxyphenylalanine-positron emission tomography-computed tomography ((18)F-DOPA-PET-CT) scan has recently been reported. The aim of this study was to evaluate the accuracy of this technique in discriminating between diffuse and focal CHI and the anatomical localization of focal lesions. Between 2006 and 2010, (18)F-DOPA-PET scan was performed in 19 children with CHI (median age, 2 months; range, 1-12 months) who were not responding to medical therapy and underwent laparoscopic or open surgery. The findings of (18)F-DOPA-PET scan were correlated with histology. In 5 children, (18)F-DOPA-PET scan showed diffuse pancreatic uptake, confirmed at histology and supporting the genetic suspicion of diffuse disease. In 14 children, (18)F-DOPA-PET scan indicated focal pancreatic uptake, which corresponded to histology. However, in 5 patients (36%), (18)F-DOPA-PET scan was inaccurate in defining the location of the lesion (n = 3), size of the lesion (n = 1), or both location and size (n = 1), leading to an inaccurate pancreatic resection. Fluorine-18-L-3,4-dihydroxyphenylalanine-positron emission tomography-computed tomography scan discriminates between diffuse and focal forms of CHI. In focal forms, (18)F-DOPA-PET scan is useful in 2/3 of patients in defining the site and dimension of the focal lesion. Intraoperative histologic confirmation of complete focal lesion resection is needed.
    Journal of Pediatric Surgery 01/2011; 46(1):204-8. · 1.38 Impact Factor
  • Digestive and Liver Disease - DIG LIVER DIS. 01/2011; 43.
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    ABSTRACT: Background: Loss of function mutations in the genes encoding the pancreatic β-cell ATP-sensitive potassium (KATP) channel are identified in approximately 80% of patients with diazoxide unresponsive hyperinsulinemic hypoglycemia (HH). For a small number of patients HH can occur as part of a multisystem disease such as Beckwith-Wiedemann syndrome (BWS). In approximately 20% of patients, BWS results from chromosome 11 paternal uniparental disomy (UPD), which causes dysregulation of imprinted growth regulation genes at 11p15.5. There is a considerable range in the clinical features and phenotypic severity associated with BWS which is likely to be due to somatic mosaicism. The cause of HH in these patients is not known. Research Design and Methods: We undertook microsatellite analysis of 12 markers spanning chromosome 11p in two patients with severe HH and diffuse disease requiring a pancreatectomy. In both patients mutations in the K(ATP) channel genes had not been identified. Results: We identified segmental paternal UPD in DNA extracted from pancreatic tissue in both patients. UPD was not observed in DNA extracted from the patient's leukocytes or buccal samples. In both cases the UPD encompassed the differentially methylated region at chromosome 11p15.5. Despite this neither patient had any further features of BWS. Conclusion: Paternal UPD of the chromosome 11p15.5 differentially methylated region limited to the pancreatic tissue may represent a novel cause of isolated diazoxide unresponsive HH. Loss of heterozygosity studies should therefore be considered in all patients with severe HH who have undergone pancreatic surgery when K(ATP) channel mutation(s) have not been identified.
    Frontiers in Endocrinology 01/2011; 2:66.
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    ABSTRACT: Congenital hyperinsulinism (CHI) is a cause of persistent hypoglycemia. Histologically, there are two subgroups, diffuse and focal. Focal CHI is a consequence of two independent events, inheritance of a paternal mutation in ABCC8/KCNJ11 and paternal uniparental isodisomy of chromosome 11p15 within the embryonic pancreas, leading to an imbalance in the expression of imprinted genes. The probability of both events occurring within siblings is rare. We describe the first familial form of focal CHI in two siblings. The proband presented with medically unresponsive CHI. He underwent pancreatic venous sampling and Fluorine-18-L-dihydroxyphenylalanine positron emission tomography scan, which localized a 5-mm focal lesion in the isthmus of the pancreas. The sibling presented 8 yr later also with medically unresponsive CHI. An Fluorine-18-L-dihydroxyphenylalanine positron emission-computerised tomography scan showed a 7-mm focal lesion in the posterior section of the head of the pancreas. Both siblings were found to be heterozygous for two paternally inherited ABCC8 mutations, A355T and R1494W. Surgical removal of the focal lesions in both siblings cured the Hyperinsulinaemic hypoglycaemia. This is the first report of focal CHI occurring in siblings. Genetic counseling for families of patients with focal CHI should be recommended, despite the rare risk of recurrence of this disease.
    The Journal of clinical endocrinology and metabolism 10/2010; 96(1):24-8. · 6.50 Impact Factor
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    ABSTRACT: Guidelines on histopathological techniques and reporting for adult and paediatric gastrointestinal neuromuscular pathology have been produced recently by an international working group (IWG). These addressed the important but relatively neglected areas of histopathological practice of the general pathologist, including suction rectal biopsy and full-thickness intestinal tissue. Recommendations were presented for the indications, safe acquisition of tissue, histological techniques, reporting and referral of such histological material. Consensual processes undertaken by the IWG and following established guideline decision group methodologies. This report presents a contemporary and structured classification of gastrointestinal neuromuscular pathology based on defined histopathological criteria derived from the existing guidelines. In recognition of its origins and first presentation in London at the World Congress of Gastroenterology 2009, this has been named 'The London Classification'. The implementation of this classification should allow some diagnostic standardisation, but should necessarily be viewed as a starting point for future modification as new data become available.
    Gut 07/2010; 59(7):882-7. · 10.73 Impact Factor
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    ABSTRACT: To review the gastrointestinal mucosal histological features of biopsies from children with Shwachman-Diamond syndrome (SDS) examined at a single specialist centre. Search of a clinical database was performed to identify SDS cases and their gastrointestinal biopsies were reviewed for morphological parameters such as crypt:villous ratio, crypt hyperplasia and abnormal inflammatory infiltrates. Histological sections were also immunostained with CD4, CD20 and HLA-DR to determine the nature of the inflammatory infiltrate. 15 SDS cases were included, 7 (47%) of which showed morphologically normal duodenal villous architecture, whereas 8 (53%) showed varying degrees of enteropathic histological features ranging from villous blunting to partial villous atrophy and duodenitis. 11/15 (73%) showed some degree of duodenal inflammation, including increased lamina propria density of plasma cells, macrophages and eosinophils. Varying degrees of duodenal inflammatory enteropathic features are present in more than 50% of symptomatic children with SDS. This suggests that, in addition to pure pancreatic exocrine failure, an enteropathic component may contribute to symptoms in some cases, and be potentially responsive to appropriate therapy.
    Journal of clinical pathology 07/2010; 63(7):592-4. · 2.43 Impact Factor
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    ABSTRACT: The rat gavage model is used to explore the pathogenesis and treatment of necrotizing enterocolitis (NEC). Although intestinal histological damage is seen in this model, intestinal perforation is rarely observed. Whether organ failure occurs in this model is largely unknown. We hypothesised that increased intestinal permeability leads to organ failure in experimental NEC. NEC was induced in neonatal rats by gavage feeding of hypertonic formula plus exposure to hypoxia plus oral lipopolysaccharide (4 mg/kg per day daily). Breast-fed rats were used for comparison. At 92 h, lactulose (3 mg) and mannitol (2 mg) were administered orally in 0.1 ml water. Four hours later, rats were killed and blood samples collected. Lactulose and mannitol were measured by gas chromatography-mass spectrometry and lactulose/mannitol ratio calculated as index of intestinal permeability. Plasma cardiac troponin-I was measured by ELISA as a marker of cardiac damage and plasma creatinine measured spectrophotometrically as a marker of renal failure. Experimental NEC induced an increase in intestinal permeability (P = 0.0002). This was associated with cardiac damage (P < 0.0001), and renal failure (P = 0.004). Intestinal permeability is increased in experimental NEC in association with increased cardiac damage. Rat mortality may be due to cardiac failure secondary to an inflammatory response caused by increased intestinal permeability.
    Pediatric Surgery International 10/2009; 26(1):85-9. · 1.22 Impact Factor
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    ABSTRACT: Cystic fibrosis (CF) is a multisystem disorder intrinsically associated with inflammation of mucosal surfaces. Because inflammation can result in enteric neuromuscular dysfunction we hypothesized that terminal ileitis in patients with CF may predispose to distal ileal obstruction syndrome (DIOS). Full-thickness terminal ileal tissues from 6 children with CF and severe DIOS, 6 infants with complicated meconium ileus (MI), and 6 children with non-CF intestinal atresia were studied. Lymphocyte-predominant mucosal and transmural ileal inflammation was present in 6 of 6 patients with DIOS. Lymphocytic ganglionitis was present in 4 of 6 although numbers of myenteric neurons were not decreased (5/5). Myocyte proteins were preserved (6/6). Mild submucosal fibrosis was common in DIOS (5/6) and transformation of submucosal fibroblasts to a myofibroblastic phenotype was noted in 4 of 6. Inflammatory changes were distinct from those described in fibrosing colonopathy. Antroduodenal manometry in an individual who had experienced MI/DIOS was consistent with a neuropathic pseudo-obstructive process. Submucosal or transmural lymphocyte predominant inflammation was also present in 6 of 6 infants with complicated MI, which, when coupled with submucosal myofibroblast proliferation (5/6), appeared highly predictive of CF rather than non-CF atresia. Histological findings at birth were similar, although milder, than those seen in DIOS, suggesting that these changes are a primary abnormality in CF. Submucosal or transmural inflammation of the ileum is common in newborns with CF and MI and older children with DIOS. Severe recurrent DIOS should be investigated with seromuscular and mucosal biopsy of the ileum to seek a transmural ileitis potentially amenable to anti-inflammatory therapies.
    Journal of pediatric gastroenterology and nutrition 08/2009; 49(1):42-51. · 2.18 Impact Factor
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    ABSTRACT: The term gastrointestinal neuromuscular disease describes a clinically heterogeneous group of disorders of children and adults in which symptoms are presumed or proven to arise as a result of neuromuscular, including interstitial cell of Cajal, dysfunction. Such disorders commonly have impaired motor activity, i.e. slowed or obstructed transit with radiological evidence of transient or persistent visceral dilatation. Whilst sensorimotor abnormalities have been demonstrated by a variety of methods in these conditions, standards for histopathological reporting remain relatively neglected. Significant differences in methodologies and expertise continue to confound the reliable delineation of normality and specificity of particular pathological changes for disease. Such issues require urgent clarification to standardize acquisition and handling of tissue specimens, interpretation of findings and make informed decisions on risk-benefit of full-thickness tissue biopsy of bowel or other diagnostic procedures. Such information will also allow increased certainty of diagnosis, facilitating factual discussion between patients and caregivers, as well as giving prognostic and therapeutic information. The following report, produced by an international working group, using established consensus methodology, presents proposed guidelines on histological techniques and reporting for adult and paediatric gastrointestinal neuromuscular pathology. The report addresses the main areas of histopathological practice as confronted by the pathologist, including suction rectal biopsy and full-thickness tissue obtained with diagnostic or therapeutic intent. For each, indications, safe acquisition of tissue, histological techniques, reporting and referral recommendations are presented.
    Acta Neuropathologica 05/2009; 118(2):271-301. · 9.73 Impact Factor
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    ABSTRACT: A neonatal rat model of necrotizing enterocolitis (NEC) is useful to investigate this devastating and obscure disease. The aim of this study was to assess a neonatal rat model of NEC to evaluate whether the histological appearance of the damaged intestine could be predicted by the clinical behaviour of the animals and the macroscopic appearance of the gut. Neonatal rats were delivered at term and assigned either to a control group consisting of breastfeeding and no stress factors, or to a NEC group in which NEC was induced by gavage feeding + hypoxia + oral lipopolysaccharide (4 mg/kg/day once daily for the first 2 days of life). Clinical status was assessed on day 4 using a clinical sickness score (general appearance, response to touch, natural activity, body colour; 0 - 3 for each variable). Neonatal rats were sacrificed at 4 different time points: day 1, day 2, day 3, and day 4. At sacrifice, a macroscopic assessment of the gut was performed using a new scoring system based on: colour (0 - 2), consistency (0 - 2) and degree of dilatation (0 - 2). The resected gut was stained with haematoxylin/eosin, and evaluated microscopically by 2 independent blinded scorers, including a consultant histopathologist. The histology results were used to validate the macroscopic gut assessment. Results were compared by ANOVA and linear regression analysis. Ethics Committee and Home Office approvals were obtained. In the control group NEC was not present either macroscopically or histologically. The clinical sickness score was higher in the NEC group (median = 4.5; range = 2 - 6) compared to controls (median = 0; range = 0 - 1; p < 0.0001). In the NEC group the macroscopic appearance (from day 2) and histological score (from day 1) increased significantly (p < 0.0001) and were strongly correlated (r (2) = 0.74, p < 0.0001). The clinical behaviour and macroscopic appearance of the intestine are valid tools to assess gut damage in our neonatal rat model of NEC. This allows future studies that are not exclusively based on histology.
    European Journal of Pediatric Surgery 11/2008; 18(6):423-6. · 0.84 Impact Factor
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    ABSTRACT: Functional dyspepsia in childhood is commonly triggered by food allergen in sensitised individuals. We investigated the topography of eosinophils and mast cells in gastric antral lamina propria, the interaction of mast cell products with mucosal nerve fibres, and changes in gastric antral muscle slow wave activity in children with atopy and non-atopy-related functional dyspepsia. Open label study of gastric mucosal cow's milk challenge in 10 atopic and 6 nonatopic children (ages 2-12 years) investigated consecutively with gastroscopy for functional dyspepsia. Simultaneous surface electrogastrography and milk challenge were undertaken and laser scanning fluorescence microscopy used to examine the association of mast cell tryptase with mucosal nerves in the gastric mucosa before and after challenge. Eosinophils and mast cells within the lamina propria were increased in number in children with atopic functional dyspepsia and degranulated rapidly after cow's milk challenge in the atopic group. For degranulating eosinophils, median = 13.0% (interquartile range = 3.7-31.0) premilk versus 32.0% (12.0-42.0) after milk biopsies (P < 0.05); for degranulating mast cells, 5.35% (2.7-10.9) premilk biopsies versus 18.75% (12.9-22.1) after milk biopsies (P < 0.05). No such differences were seen in nonatopic patients. Mast cells were closely associated with mucosal nerve fibres and released tryptase, which colocalised with proteinase-activated receptors on mucosal nerve fibres. The gastric antral slow wave became abnormal within 2 minutes of antigen challenge in atopics with an increase in dominant frequency instability coefficient (P < 0.005), decrease in 3 cycles per minute myoelectrical activity (P < 0.01), and increase in bradygastria (P < 0.01). Early-onset neuroimmune interactions induced by cow's milk in the gastric mucosa of atopic children are associated with rapid disturbance of gastric myoelectrical activity and dyspeptic symptoms.
    Journal of pediatric gastroenterology and nutrition 10/2008; 47(4):472-80. · 2.18 Impact Factor

Publication Stats

1k Citations
324.39 Total Impact Points

Institutions

  • 1996–2012
    • Great Ormond Street Hospital for Children NHS Foundation Trust
      • • Department of Endocrinology
      • • Department of Gastroenterology
      • • Department of Histopathology
      Londinium, England, United Kingdom
  • 2009
    • UK Department of Health
      Londinium, England, United Kingdom
  • 2008
    • The University of Sheffield
      Sheffield, England, United Kingdom
  • 1999–2008
    • University College London
      • • Department of Pathology
      • • Institute of Child Health
      London, ENG, United Kingdom
    • Dana-Farber Cancer Institute
      Boston, Massachusetts, United States
  • 2006
    • Universität Mannheim
      Mannheim, Baden-Württemberg, Germany
  • 1997
    • Queen Elizabeth Hospital Birmingham
      Birmingham, England, United Kingdom