Edward V. O'Loughlin

Nationwide study of haemolytic uraemic syndrome: clinical, microbiological, and epidemiological features

AIMS To establish the incidence and aetiology of haemolytic uraemic syndrome (HUS) in Australia and compare clinical and microbial characteristics of sporadic and outbreak cases. METHODS National active surveillance through the Australian Paediatric Surveillance Unit with monthly case notification from paediatricians, July 1994 to June 1998. Children under 15 years presenting with microangiopathic haemolytic anaemia, thrombocytopenia, and acute renal impairment were identified. RESULTS Ninety eight cases were identified (incidence 0.64 per 105 children <15 years/annum and 1.35 per 105 children <5 years/annum). Eighty four were associated with diarrhoea (64 sporadic, 20 constituting an outbreak) and 14 were atypical. Shiga toxin producingEscherichia coli (STEC) O111:H− was the most common isolate in sporadic HUS and caused the outbreak. However O111:H− isolates from outbreak and sporadic cases differed in phage type and subtyping by DNA electrophoresis. STEC isolates from sporadic cases included O26:H−, O113:H21, O130:H11, OR:H9, O157:H−, ONT:H7, and ONT:H−. STEC O157:H7 was not isolated from any case. Only O111:H− isolates produced both Shiga toxins 1 and 2 and possessed genes encoding E coli attaching and effacing gene (intimin) and enterohemolysin. Outbreak cases had worse gastrointestinal and renal disease at presentation and more extrarenal complications. CONCLUSIONS Linking national surveillance with a specialised laboratory service allowed estimation of HUS incidence and provided information on its aetiology. In contrast to North America, Japan, and the British Isles, STEC O157:H7 is rare in Australia; however, non-O157:H7 STEC cause severe disease including outbreaks. Disease severity in outbreak cases may relate to yet unidentified virulence factors of the O111:H− strain isolated.

Detection and isolation of Campylobacter species other than C. jejuni from children with Crohn's disease.

ABSTRACT The presence of Campylobacter species other than Campylobacter jejuni and antibodies to Campylobacter concisus in children were investigated. A significantly greater presence of C. concisus and higher levels of antibodies to C. concisus were detected in children with Crohns disease (CD) than in controls. Campylobacter species other than C. jejuni were isolated from intestinal biopsy specimens of children with CD.

Structural and functional adaptation following jejunal resection in rabbits: Effect of epidermal growth factor

BACKGROUND/AIMS Remnant small intestine undergoes adaptation following massive resection. The aim of this study was to examine the effect of epidermal growth factor (EGF) on ileal adaptation following proximal resection. METHODS New Zealand white rabbits, aged 8 weeks, underwent 2/3 proximal resection, and ileal mucosal adaptation was assessed 10 and 21 days postsurgery. In a second series of experiments, animals with resection received oral EGF (40 micrograms.kg-1.day-1) for 5 days, and the effect on adaptation was assessed 10 days postsurgery. RESULTS Transection alone stimulated mucosal hyperplasia, intestinal sucrase specific activity, and glucose transport at 10 days but not at 21 days. Resection resulted in mucosal hyperplasia at both time periods and increased disaccharidase specific activity at 10 days postresection. In contrast, 3 O-methyl-D-glucose transport was significantly decreased compared with both groups at both time periods. EGF treatment in animals with resection did not alter mucosal proliferation but did stimulate maltase specific activity and caused a 3-4-fold increase in glucose transport and phlorizin binding. CONCLUSIONS Following proximal resection, adaptation of intestinal digestive and absorptive function does not parallel mucosal hyperplasia. Administration of EGF to resected animals enhances glucose absorption and may have a therapeutic role in the management of short gut syndrome.

Normal growth in cystic fibrosis associated with a specialised centre

OBJECTIVE To assess the impact of lifetime continuous care within the John Hunter Hospital cystic fibrosis (CF) clinics on growth and lung function. DESIGN A cross sectional survey of variables affecting nutritional status in CF was undertaken for 1993 and 1997. Data were retrieved from medical records and grouped into 5 year age bands. MAIN OUTCOME MEASURES Change in height z-score, weight centile, and forced expiratory volume in one second (FEV1) between patient cohorts receiving specialised care for different lengths of time. RESULTS Improved mean height z-score (−0.880 v −0.047) and weight centile (28.3% v 48.1%) for the 10–15 year age group in 1997, who had received continuous lifetime care within the clinic, compared with the same age group in 1993, for whom continuous medical care started at an older age. There was no corresponding improvement in FEV1, as an indicator of lung function, in this group (81.6% predicted v89.5% predicted). CONCLUSIONS This study suggests that lifetime continuous care within a specialised CF centre is associated with improved growth but not improved lung function.

Modulation of host response to Escherichia coll 0157:H7 infection by anti-CD18 antibody in rabbits

BACKGROUND/AIMS Escherichia coli O157:H7 infection induces diarrhea, severe colitis, and colonic electrolyte transport abnormalities characterized by decreased Na absorption and Cl secretion. The aim of this study was to examine the role of the host inflammatory response in inducing distal colonic transport changes during infection with E. coli O157:H7. METHODS New Zealand white rabbits aged 10 days were infected with E. coli O157:H7 strain EDL933 (plasmid+, verotoxin 1+, verotoxin 2+). Studies were performed daily from day 1 to day 5 postinfection and compared with uninfected controls (10 days old). Distal colonic ion transport was studied in vitro under short-circuited conditions in Ussing chambers, and tissue inflammation was assessed by mucosal myeloperoxidase activities and mucosal neutrophil (polymorphonuclear neutrophil [PMN]) counts. In a second study, PMN infiltration was inhibited by an anti-CD18 (leukocyte adhesion molecule) monoclonal antibody, IB4, and histology and transport were studied on day 5 postinfection. RESULTS Infection with O157:H7 induced diarrhea and inhibition of Na absorption by day 3. CI secretion occurred on day 5, coincident with tissue infiltration with PMN. Pretreatment with IB4 prevented histological damage and tissue infiltration with PMN, and it inhibited the transport abnormalities induced by infection alone. CONCLUSIONS Infection with O157:H7 reduces Na absorption and stimulates Cl secretion in the distal colon. Disruption of the epithelium and changes in colonic electrolyte transport during enterohemorrhagic E. coli are mediated by the host inflammatory response.

The effect of gastrostomy tube feeding on body protein and bone mineralization in children with quadriplegic cerebral palsy

Aim  The aim of this study was to investigate the effect of gastrostomy tube feeding on body protein and bone mineralization in malnourished children with cerebral palsy (CP).

Cyclic AMP-dependent anion secretion in human small and large intestine

Cyclic AMP‐dependent Cl secretion is the major secretion pathway in human intestine. The aim of the present study was to examine mechanisms involved in cAMP‐dependent anion secretion in human small and large intestine. Surgical resection specimens from both jejunum and distal colon were studied under short circuited conditions. Addition of the phosphodiesterase inhibitor IBMX induced an increase in the short‐circuit current (Isc) equivalent to the net increase in Cl secretion. The Isc was inhibited by diphenylamine decarboxylate (DPC; Cl channel blocker), bumetanide (basolateral Na+/K+/2Cl cotransporter), BaCl2 (basolateral K+ channel) and Cl free buffer in both segments and indomethacin (cyclo‐oxygenase inhibitor) in colon alone. Diphenylamine decarboxylate appears to directly inhibit secretion in jejunum, although its inhibitory effect is possibly mediated by inhibition of cyclo‐oxygenase in the colon. A small component of IBMX‐stimulated Isc was inhibited by acetazolamide. Cyclic AMP‐dependent secretion is largely apical Cl secretion, although a small component appears to be HCO3. Secretion is dependent on basolateral K+ channels and Na+/K+/2Cl cotransporters and, in the colon, is inhibited by indomethacin, implying a role for cyclo‐oxygenase metabolites. The chloride channel blocker DPC inhibits secretion in both areas. This class of compounds may have potential for treatment of secretory diarrhoea.

Home-based management of children hospitalized with acute gastroenteritis

Objective: To determine the source of medical advice to parents and treatment administred at home for children admitted to hospital with acute gastroenteritis.

Discrepancies between males and females with cystic fibrosis in dietary intake and pancreatic enzyme use

BACKGROUND Length of survival of females with cystic fibrosis is worse than it is in males. Results of current research have shown an important correlation among dietary intake, nutritional status, lung function, and survival. The purpose of this study was to explore gender differences in dietary intake and pancreatic enzyme replacement therapy in males and females with cystic fibrosis. METHODS The study was a cross-sectional measurement of clinical characteristics, energy, and fat intakes in males and females attending the cystic fibrosis outpatients clinics of the John Hunter Hospital, Newcastle, Australia. Twenty-nine subjects, (17 females and 12 males), completed 4-day weighed food records to measure total energy intake and the contribution of macronutrients and to document use of pancreatic enzyme replacement therapy. Energy intake was assessed as the percentage of the recommended energy intake for age and sex. RESULTS Females with cystic fibrosis had significantly lower energy and fat intakes than males, whereas the females used significantly more pancreatic enzyme replacement therapy. There were no significant differences in clinical characteristics between groups. CONCLUSION The results support the possibility that gender differences in the energy and fat intakes of older patients may contribute to differential median survival time of males and females with cystic fibrosis.

Membranous glomerulonephritis in a patient with Crohn's disease of the small bowel.

A 12-year-old girl presented with concurrent onset of membranous glomerulonephritis and Crohns disease of the small intestine. Subsequent investigations failed to implicate any other systemic disease as a cause of the giomerulonephritis. Membranous giomerulonephritis is an immune complex-mediated glomerulopathy frequently associated with underlying systemic disease: The association of immune complex phenomenon with Crohns disease and the variation of renal abnormalities in parallel with activity of bowel disease in this patient suggest that the glomerulonephritis may be due to the underlying Crohns disease.