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Biomedical subjects

S H Murch

Publications and source records attributed to S H Murch.

At least 37 records · Page 2Linked to original sources

Topical tacrolimus may be effective in the treatment of oral and perineal Crohn's disease.

BACKGROUND: Crohn's disease of the mouth or perineum is more common in young people, and notably resistant to treatment. However, there is increasing evidence that topical therapy with tacrolimus (FK506) may be effective in skin diseases resistant to cyclosporin because of its high uptake in inflamed skin and subsequent reduction in keratinocyte chemokine production. PATIENTS AND METHODS: Tacrolimus ointment was made up inhouse from the intravenous or oral formulation and suspended in appropriate vehicles for perioral or perianal administration at an initial concentration of 0.5 mg/g. This was administered open label to eight children (aged 5-18 years) with treatment resistant oral (three patients) and/or ulcerating perineal (six patients) Crohn's disease. RESULTS: Marked improvement was seen in 7/8 patients within six weeks and healing within 1-6 months. One child with gross perineal and colonic disease showed little response. Two of the responders showed rebound worsening when tacrolimus was stopped or the dosage reduced rapidly, and one of these eventually required proctectomy. Slower weaning of drug concentration has been successful in 6/8 patients, with four receiving intermittent treatment and two on regular reduced dosage (0.1-0.3 mg/g) with follow up times of six months to 3.5 years. Serum concentrations of tacrolimus were undetectable in all patients. CONCLUSIONS: Topical tacrolimus at low concentrations (0.5 mg/g) shows promise in the management of childhood perineal and oral Crohn's disease, with no evidence of significant systemic absorption. However, rapid weaning or abrupt cessation of therapy may cause rebound worsening of disease. Further controlled studies are required to assess the efficacy and safety of this treatment.

Administration, Topical↗

The effect of early inhaled budesonide on pulmonary inflammation in infants with respiratory distress syndrome.

UNLABELLED: The aim of this pilot study was to determine the effect of early inhaled budesonide on clinical and inflammatory parameters in preterm infants ventilated for respiratory distress syndrome. CONCLUSION: Neither the inflammatory process associated with respiratory distress syndrome nor the progression to bronchopulmonary dysplasia appeared to be altered by treatment with inhaled budesonide.

Bronchodilator Agents↗

Low-dose intravenous azathioprine may be effective in the management of acute fulminant colitis complicating inflammatory bowel disease.

BACKGROUND: The management of acute fulminant colitis unresponsive to intravenous steroids is usually surgical. However, recent evidence suggests that intravenous administration of azathioprine at very high doses may allow more rapid onset of clinical efficacy, although its use has not previously been reported in the emergency situation. AIM: To report the successful use of intravenous azathioprine in the management of acute fulminant colitis complicating both Crohn's disease and ulcerative colitis. METHOD: We initially used intravenous azathioprine because of the refusal of the family of the first patient to accept surgery following failure of conventional medical management. Importantly the azathioprine was successful at the low dose of 3 mg/kg.day, equivalent to standard oral doses. Two subsequent patients demonstrated a similar resolution. All were weaned successfully to oral azathioprine and have remained in long-term endoscopic and histological remission. CONCLUSION: These preliminary data suggest that low-dose intravenous azathioprine may be helpful adjunct therapy in selected cases of severe fulminant colitis. However, the need for close monitoring and daily surgical assessment remains paramount, and a formal trial of low-dose intravenous azathioprine is required before it may be more widely recommended.

Acute Disease↗

Autoimmune enteropathy with distinct mucosal features in T-cell activation deficiency: the contribution of T cells to the mucosal lesion.

BACKGROUND: Autoimmune enteropathy is normally characterised by crypt hyperplastic villous atrophy with enterocyte autoantibodies, activation of mucosal lymphocytes and increased epithelial HLA-DR. This case involved a severely affected Portuguese infant who was found to have lymphocyte activation deficiency and demonstrated correspondingly distinct mucosal features. METHODS: A female infant of nonconsanguineous parents was treated for vomiting and diarrhoea, first with milk exclusion and then with parenteral nutrition. Lymphocyte subsets and immunoglobulin concentrations were normal, but in vitro testing showed no activation in response to phytohaemagglutinin, Candida, or purified protein derivative, although the response to interleukin (IL)-2 was intact. Interleukin-2 deficiency was excluded. Analysis of jejunal biopsy specimens revealed only mild villous blunting with absent goblet cells, normal epithelial proliferation, and no crypt hyperplasia. The dense infiltrate of CD8+ and CD4+ T lymphocytes showed normal CD2 and CD3 expression but no activation or proliferation markers. HLA-DR was not increased on epithelium or lymphocytes. Thus, in addition to in vitro evidence for lymphocyte activation deficiency, the mucosal specimens showed no evidence of in situ T-cell activation. RESULTS: After development of overwhelming septicaemia, the patient died at 18 months, just before a planned bone marrow transplant. CONCLUSIONS: These findings confirm significant heterogeneity within autoimmune enteropathy. Formal immune function testing should be performed in all affected infants to identify T-cell activation deficiencies. The distinct mucosal findings suggest that activated T cells usually induce the crypt hyperplastic villous atrophy characteristic of classic autoimmune enteropathy.

Autoimmune Diseases↗

Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children.

BACKGROUND: We investigated a consecutive series of children with chronic enterocolitis and regressive developmental disorder. METHODS: 12 children (mean age 6 years [range 3-10], 11 boys) were referred to a paediatric gastroenterology unit with a history of normal development followed by loss of acquired skills, including language, together with diarrhoea and abdominal pain. Children underwent gastroenterological, neurological, and developmental assessment and review of developmental records. Ileocolonoscopy and biopsy sampling, magnetic-resonance imaging (MRI), electroencephalography (EEG), and lumbar puncture were done under sedation. Barium follow-through radiography was done where possible. Biochemical, haematological, and immunological profiles were examined. FINDINGS: Onset of behavioural symptoms was associated, by the parents, with measles, mumps, and rubella vaccination in eight of the 12 children, with measles infection in one child, and otitis media in another. All 12 children had intestinal abnormalities, ranging from lymphoid nodular hyperplasia to aphthoid ulceration. Histology showed patchy chronic inflammation in the colon in 11 children and reactive ileal lymphoid hyperplasia in seven, but no granulomas. Behavioural disorders included autism (nine), disintegrative psychosis (one), and possible postviral or vaccinal encephalitis (two). There were no focal neurological abnormalities and MRI and EEG tests were normal. Abnormal laboratory results were significantly raised urinary methylmalonic acid compared with age-matched controls (p=0.003), low haemoglobin in four children, and a low serum IgA in four children. INTERPRETATION: We identified associated gastrointestinal disease and developmental regression in a group of previously normal children, which was generally associated in time with possible environmental triggers.

Child↗

Local and systemic effects of macrophage cytokines in intestinal inflammation.

The activation of macrophages and newly recruited monocytes appears to be common to both Crohn's disease and ulcerative colitis, despite different inductive stimuli. Similar activation occurs acutely during the course of invasive intestinal infections such as shigellosis, but is then usually downregulated. The macrophage cytokines tumor necrosis factor-alpha and interleukin-1 (IL-1) are centrally involved in the local inflammatory response, and blockade of either cytokine greatly attenuates the inflammatory lesion. Induction of focal vascular thrombosis and matrix degradation are thought to be an important component of this focal damage. Both cytokines and IL-6 are now recognized to contribute to the systemic effects of intestinal disease, including growth suppression, anorexia, and chronic anemia. Disturbance of sleep patterns, mood, and affect may also occur, and recent evidence points towards bidirectional interplay between macrophage cytokines and central nervous system function.

Colitis, Ulcerative↗

Nutrition in inflammatory bowel disease.

Nutrition is clearly disturbed by active intestinal inflammation. Appetite is reduced, yet energy substrates are diverted into the inflammatory process, and thus weight loss is characteristic. The nutritional disturbance represents part of a profound defect of somatic function. Linear growth and pubertal development in children are notably retarded, body composition is altered, and there may be significant psychosocial disturbance. Macrophage products such as tumour necrosis factor-alpha and interleukins-1 and 6 may be the central molecules that link the inflammatory process to this derangement of homeostasis. Intriguingly, there is also increasing evidence that an aggressive nutritional programme may in itself be sufficient to reduce the mucosal inflammatory response. Recent evidence suggests that enteral nutrition alone may reduce many pro-inflammatory cytokines to normal and allow mucosal healing. In addition, specific nutritional components, such as n-3 polyunsaturated fatty acids, may have an anti-inflammatory effect as they may alter the pattern of leukotrienes generated during the immune response. The recent discovery of the specific molecular mediators of appetite and body composition, such as leptin and myostatin, may allow increased therapeutic specificity and further improvement in the nutritional treatment of the inflammatory bowel diseases.

Body Composition↗

The molecular basis of intractable diarrhoea of infancy.

The intractable diarrhoeas of infancy present very major problems of clinical management. However, the conceptual importance of these conditions lies in the information that they may provide about normal small-intestinal function in humans: among such infants will be found the human equivalents of the 'knock-out' mice, in which targeted gene disruption allows sometimes unexpected insight into the regulation of intestinal function. The challenge posed by the intractable diarrhoeal syndromes, of working backwards from an apparently common phenotype to probably multiple genotypes, is, however, immense. Very few of these conditions have been described at the genetic level, although the molecular basis of pathogenesis has been better explored in recent years. The two major groups of intractable diarrhoea are due to (1) primary epithelial abnormalities (which usually present within the first few days of life) and (2) immunologically mediated (which generally present after the first few weeks). The high prevalence of autoimmune enteropathy among infantile autoimmune disease, in contrast to adult autoimmunity, is intriguing and may reflect constitutive abnormality of extrathymic lymphocyte maturation. The use of potent immunosuppressive drugs and increasing expertise with parenteral nutrition are improving the outlook of these previously fatal conditions. Viewed globally, however, the pressing problem is to treat effectively the millions of infants who die from severe persistent diarrhoea and wasting, which would certainly not be considered intractable in wealthy countries.

Animals↗

Time for TNF?

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Adolescent↗

Congenital enterocyte heparan sulphate deficiency with massive albumin loss, secretory diarrhoea, and malnutrition.

BACKGROUND: The molecular basis of protein-losing enteropathy is unknown. However it has been shown that sulphated glycosaminoglycans may be important in regulating vascular and renal albumin loss. METHODS: We describe three baby boys who presented within the first weeks of life with massive enteric protein loss, secretory diarrhoea, and intolerance of enteral feeds. All required total parenteral nutrition and repeated albumin infusions. No cause could be found in any case despite extensive investigations, including small intestinal biopsy sampling, which were repeatedly normal. FINDINGS: By specific histochemistry, we detected gross abnormality in the distribution of small intestinal glycosaminoglycans in all three infants, with complete absence of enterocyte heparan sulphate. The distribution of vascular and lamina propria glycosaminoglycans was, however, normal. INTERPRETATION: The presentation of these infants suggests that enterocyte heparan sulphate is important in normal small intestinal function.

Albumins↗

Proteolytic degradation of intestinal mucosal extracellular matrix after lamina propria T cell activation.

BACKGROUND: Proteoglycans, consisting of glycosaminoglycan (GAG) side chains covalently linked to a protein core, are a major component of the extracellular matrix of the intestinal lamina propria. AIMS: This study investigated the effects of lamina propria T cell activation on the proteoglycan component of the matrix. METHODS: The high degree of sulphation of GAGs means that they are polyanionic and thus can be visualised in tissue sections by means of colloidal-gold labelled cationic probes. RESULTS: In human fetal small intestine there is a dense meshwork of anionic residues in the lamina propria and basement membrane. When explants of human fetal small intestine are cultured ex vivo, and resident lamina propria T cells are activated with pokeweed mitogen, mucosal destruction occurs within three days. This is associated with the rapid loss of anionic sites from the lamina propria. Dermatan sulphate proteoglycan is lost from the tissue and is present at increased concentrations in the organ culture supernatants, indicating that T cell activation has led to solubilisation of lamina propria proteoglycans. Tissue destruction and loss of anionic residues are inhibited in a dose dependent fashion by dexamethasone, and by the protease inhibitor, alpha 2 macroglobulin. CONCLUSIONS: Proteolytic degradation of the lamina propria may therefore be a mechanism by which T cell hypersensitivity injures the intestinal mucosa.

Culture Techniques↗

Mucosal tumor necrosis factor-alpha production and extensive disruption of sulfated glycosaminoglycans begin within hours of birth in neonatal respiratory distress syndrome.

Many of the clinicopathologic features of neonatal respiratory distress syndrome (RDS) may be related to the inflammatory response mounted by the affected infant, although little is known about the interstitial component of this response. We have thus studied the local inflammatory response in this condition by immunohistochemical analysis of whole lung lobes, obtained at postmortem from 40 infants who died from acute RDS in the first week of life. All had demonstrated classical clinical history and histologic features. An archival subgroup from the early 1970s had never received ventilatory support. Immunohistochemical analysis demonstrated rapid temporal increase from birth in the mucosal density of CD68+ macrophages, MAC-387+ monocytes/macrophages, polymorphonuclear neutrophils, and tumor necrosis factor-alpha-immunoreactive cells, maximal in those dying at or after 72 h. Using a cationic probe specific for sulfated glycosaminoglycans (GAGs), the inflammatory infiltration was seen to be associated with striking loss of endothelial, basement membrane, and interstitial GAGs, which was almost complete by 48-72 h. GAG degradation products were found within hyaline membranes in all infants dying after 48 h. This study confirms that neonatal RDS is characterized by intense interstitial inflammation, significantly underestimated on routine staining. This begins within hours of birth and is maximal by 72 h of age. Breakdown of sulfated GAGs within the extracellular matrix follows the same time course and may explain much of the physiologic derangement characteristic of this condition.

Age of Onset↗

Early production of macrophage inflammatory protein-1 alpha occurs in respiratory distress syndrome and is associated with poor outcome.

Although progression to pulmonary fibrosis in preterm infants with respiratory distress syndrome (RDS) is related to the inflammatory response, the nature of this response remains controversial. We have therefore performed sequential bronchoalveolar lavages in 30 infants with RDS (13 of whom developed bronchopulmonary dysplasia) and 7 ventilated control infants, characterizing the cells obtained by immunohistochemical analysis of lineage-specific markers and assaying macrophage-associated chemokines and cytokines in supernatant fluid. At all ages from birth, lavage supernatants demonstrated highly significant increase over controls of the beta-chemokine macrophage inflammatory protein (MIP)-1 alpha, although not of regulated upon activation, normal T cell expressed and secreted (RANTES), of the cytokines tumor necrosis factor (TNF)-alpha and IL-1 beta, and of elastase/alpha-1 antitrypsin. Significantly higher concentrations of MIP-1 alpha in particular were associated with the later development of fibrosis. Increased numbers of macrophages expressing the activation marker RM/3-1 were found at all ages in bronchopulmonary dysplasic infants, whereas neutrophil numbers were increased from d 3. Dexamethasone administered to 10 infants induced rapid decrease in inflammatory cell numbers and concentrations of MIP-1 alpha, tumor necrosis factor-alpha, IL-1 beta, and elastase/alpha-1 antitrypsin. The inflammatory response in neonatal RDS begins within the first day of life. Long-term outcome is associated with the magnitude of this early response, in particular production of MIP-1 alpha. The early introduction of specific therapy is thus likely to be beneficial.

Biomarkers↗