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Biomedical subjects

P B Sullivan

Publications and source records attributed to P B Sullivan.

At least 37 records · Page 2Linked to original sources

Nutritional management of acute diarrhea.

Despite recommendations from several bodies such as the World Health Organization and others that feeding should be continued during diarrhea, the practice of withholding food during the early stages of diarrhea is still widespread. This contributes to a deterioration in patients' nutritional state. The principal controversy in the nutritional therapy of acute gastroenteritis centers on the relative risks of cows'-milk feeds. The two things that need to be considered in determining the optimum approach to feeding the child with acute diarrhea are the optimum timing for feeding children in relation to the onset of and recovery from symptoms and, secondly, the effects of specific food ingredients in the diet. Recent studies have demonstrated that the vast majority of young children with acute diarrhea can be successfully managed with continued feeding of undiluted non-human milk. Routine dilution of milk and routine use of lactose-free formula are not necessary, especially when oral rehydration therapy and early feeding (in addition to milk) form the basic approach to the clinical management of diarrhea in children. Confounding factors are the severity of the diarrhea, coexistent malnutrition, and young age (< 1 y); such infants are much more likely to have complications from early feeding with undiluted milk and some would advocate use of specifically designed lactose-free formula in such children. Children who are fed exclusively with human milk and those who receive solid foods with or without human milk may safely continue to receive their usual diets during diarrhea. Those who are fed exclusively with non-human milk--especially when very young and with severe diarrhea or malnutrition--should be closely observed if they continue to consume milk or they should receive a special formulation (e.g., a cereal-milk mixture or fermented milk product). The use of nutrient-dense mixtures of common foods may be advisable to promote compensatory growth in those who lose weight during illness or because of anorexia or malabsorption.

Acute Disease↗

Gastrointestinal problems in the neurologically impaired child.

Damage to the developing central nervous system may result in significant dysfunction in the gastrointestinal tract and is reflected in impairment in oral-motor function, rumination, gastro-oesophageal reflux, with or without aspiration, delayed gastric emptying and constipation. These problems can all potentially contribute to feeding difficulty in disabled children. Early recognition of an infant with neurological impairment that is compromising the normal feeding process is crucial. Detailed assessment of the nature of the feeding difficulties will help to predict the anticipated future nutritional needs and will allow decisions to be made about the appropriateness of input from different professionals (speech therapy, dietitians, gastroenterologists). Only when such information has been carefully assembled will rational and directed medical and surgical therapy be possible. Nutritional rehabilitation of disabled children can be associated with increased mortality and morbidity secondary to gastro-oesophageal reflux, retching, dumping syndrome or aspiration. It may also entail an increased work for care givers and increase costs of care. It is therefore necessary to document the impact of such rehabilitation on growth and quality of life for both patient and care giver.

Cerebral Palsy↗

Helicobacter pylori in an institution for disabled children in Hong Kong.

Anti-Helicobacter pylori antibodies were determined in 157 institutionalised Cantonese children, mean age 9.5 +/- 3.9 (SD) years, with profound neurodevelopmental disabilities. Eighty-seven (55.4%) were H. pylori seropositive compared with four of 50 (8%, P > 0.0002) of an age-matched control group, mean age 7.2 +/- 4.3 (SD) years. Eight of 15 seropositive children with a recent history of upper gastrointestinal bleeding underwent endoscopy and in all cases gastric infection with H.pylori was confirmed. Anthropometric data from institutionalised children revealed marked malnutrition but showed no significant difference between seropositive and seronegative children. Disabled children receiving long-term residential care in Hong Kong are confirmed to be at increased risk of H.pylori infection.

Adolescent↗

Ultrasound assessment of swallowing in malnourished disabled children.

Oral motor dysfunction is common in children with neurological impairment. Nutritional advice depends upon an accurate assessment of feeding potential in these cases. Videofluoroscopic assessment of oral motor function has been the accepted "gold standard" investigation for several years but has significant drawbacks, including the time constraints set by the use of ionizing radiation and the problems posed by the cumbersome equipment needed in mimicking the child's normal feeding situation. Ultrasonography (US) has been suggested as an alternative or additional investigation of oral motor function in children with neurological impairment. We prospectively evaluated a scoring system derived from US assessment of oral motor function in 32 malnourished disabled children with feeding problems by comparing them with a group of matched control children without neurological impairment. US imaging provided useful information with regard to the oral cavity and the soft tissue structures, capturing the salient features of tongue/hyoid/palate activity and bolus transport across the tongue and through the hypopharyngeal area. The mean percentage score obtained by US assessment of oral motor function in children with neurological impairment was 54.3 +/- 23.2 and from children without neurological impairment 91.9 +/- 12.7 (p < 0.0001). Scores for the oral and pharyngeal phases of swallowing were also very significantly lower than that in the control group, both phases being equally impaired in the disabled children. This study has demonstrated that a scoring system based on US assessment of different components of oral motor activity detects statistically significant differences in the feeding capabilities of children with neurological impairment.

Adolescent↗

Recurrent abdominal pain and Helicobacter pylori in a community-based sample of London children.

Helicobacter pylori is accepted as an important factor in the pathogenesis of peptic ulcer disease. Infection is probably most commonly acquired in early life but there is still limited information on the prevalence or symptomatology of H. pylori infection in childhood. The aim of the present study was to establish the prevalence of H. pylori infection in a large sample of urban school children and to determine its relationship, if any, to a history of recurrent abdominal pain. Using a commercial ELISA significant levels of anti-H. pylori IgG antibody were detected in 107/640 (16.7%) of school children (M, 383; F, 257; mean age 9.15 years, range 4-13). No relationship was demonstrated between H. pylori seropositivity and a personal or family history of recurrent abdominal pain or the nature of the pain.

Abdominal Pain↗

Molecular epidemiology of Escherichia coli diarrhea in children in Hong Kong.

This pediatric hospital-based study of 388 diarrhea cases and 306 controls analyzed predominant E. coli colonies from primary culture (253 cases and 177 controls) with eight DNA probes for enteropathogenic, enterotoxigenic, enteroaggregative, and diffusely adherent E. coli. Only enteropathogenic E. coli adherence factor was identified significantly more frequently in cases (10) than in controls (0).

Adolescent↗

Hirschprung's disease.

Current evidence on the pathogenesis of Hirschprung's disease, then, favours the 'abnormal microenvironment' hypothesis wherein the developing and migrating normal neural crest cells confront a segmentally abnormal and hostile microenvironment in the colon. This hypothesis would account both for the congenital absence of ganglion cells in the wall of colon and also for the range of enteric neuronal abnormalities encountered including neuronal dysplasia, hypoganglionosis, and zonal aganglionosis. The abnormal constitution of the mesenchymal and basement membrane extracellular matrix in the affected segment of colon is presumably genetically determined and further understanding of the pathogenesis of this disorder will emerge as molecular geneticists characterise the specific genes and gene products associated with Hirschprung's disease. Advances in this field should permit gene probes to be developed to facilitate prenatal and postnatal diagnosis.

Enteric Nervous System↗

Helicobacter pylori in children.

Helicobacter pylori is the major cause of antral gastritis in children, however, it is not always associated with symptoms. The exception to this occurs in duodenal ulcer disease with which H. pylori is linked in children albeit less strongly than in adults. Duodenal ulcers do not recur in older children following eradication of H. pylori. The importance of asymptomatic carriage of H. pylori in children, particularly in relation to the duration of this infection and the subsequent development of gastric cancer, remain to be established. Helicobacter pylori is associated with both hypochlorhydria and persistent diarrhoea in children in developing countries, but the significance of this association is still unknown. Although there is no consensus on the optimal regimen for treating H. pylori infection in children, dual therapy with amoxycillin and bismuth subcitrate for 2 weeks followed by monotherapy with bismuth subcitrate for a further 6 weeks will eradicate H. pylori infection in the majority of children. Those who relapse may be treated with a repeat course plus metronidazole for 4 weeks. Compliance with such regimens is a problem and shorter treatment courses that are equally effective in children need to be defined. Similarly, studies are required on the influence of the intrafamilial reservoir of H. pylori infection on relapse after treatment and the need for whole family eradication therapy.

Adult↗

Clinical applications of epidermal growth factor.

Epidermal growth factor (EGF) is a molecule with a broad pharmacological activity which has been used clinically, with promising results, to treat patients affected by necrotizing enterocolitis, Zollinger-Ellison syndrome, gastrointestinal ulceration and congenital microvillus atrophy. In theory, EGF may find a clinical application in a variety of other pathologies of both the gastrointestinal tract and other systems. Examples of gastrointestinal diseases that could benefit from treatment with EGF include colitis, gastrointestinal ulcerations of various causes, atrophic conditions, conditions of defective maturation and development and even cancer. However, the clinical use of EGF may be associated with a variety of problems and side-effects; careful selection of patients and evaluation of risk-benefit ratios are required.

Adult↗

Enteropathogenic and enteroadherent-aggregative Escherichia coli in children with persistent diarrhoea and malnutrition.

Our investigation of 61 children with persistent diarrhoea and malnutrition (PDM) aimed to characterize in them the range of enteropathogenic E. coli. Age- and sex-matched control groups consisted of 42 healthy children and 16 children with marasmus but without diarrhoea. E. coli isolates from stool cultures were serotyped, examined for Vero cells cytotoxicity, tested for enterotoxin production (LT, ST, VTI, and VTII). Synthetic oligonucleotide probes were used to test for enteroinvasivity, EPEC adherence factor, and for EAggEC. Classical E. coli serotypes commonly associated with diarrhoea (O18, O26, O119, O126) were isolated from six of 60 (10%) children with PDM. Serotype O126 was isolated from two of 42 (4.8%) healthy children and serotype O119 from one of 16 (6%) marasmic controls. Testing for Vero toxin production was negative in all isolates. Classical ETEC were confirmed in four of 60 (ST 2; LT 2) cases of PDM; no ETEC were recovered from 58 control patients. EAggEC were identified in five children with PDM and in five healthy controls without diarrhoea or malnutrition. This controlled study has shown that, in The Gambia, E. coli carrying known virulence factors are prevalent but, with the exception of enterotoxigenic E. coli, the various forms of pathogenic E. coli do not seem to be important pathogens in children with persistent diarrhoea.

Bacterial Adhesion↗

Impaired IgA response to Giardia heat shock antigen in children with persistent diarrhoea and giardiasis.

The serum antibody response in Gambian children with persistent diarrhoea and giardiasis has been studied. Total serum IgG, IgA, and IgM concentrations were increased in these patients as compared with controls from the same area. Determination of the concentrations of Giardia specific antibodies by enzyme linked immuno adsorbent assay (ELISA), however, revealed that only IgM was raised while those of IgA and IgG were similar to the controls. Analysis of the antigenic determinants of the IgG and IgA responses by immunoblotting showed that patients with chronic infection unlike those who clear the infection have no IgA response to a 57 kDa Giardia heat shock antigen. The association of high concentrations of Giardia specific IgM, low concentrations of Giardia specific IgA and IgG and inability to clear the infection suggests that the switch from an IgM to an IgG or IgA response is inefficient.

Animals↗

Persistent diarrhea and malnutrition--the impact of treatment on small bowel structure and permeability.

Previous studies using dual sugar permeability tests suggested that damage to the small intestinal mucosa plays an important part in the development of persistent diarrhea in The Gambia. The present study has extended these findings by examining the effect of nutritional rehabilitation on intestinal permeability and mucosal morphology. Intestinal permeability, measured by lactulose:mannitol (L:M) absorption, and mucosal structure, measured by a quantitative, computerised morphologic technique, were evaluated in 20 children before and after such treatment. L:M ratios were high on admission, (0.66 +/- 0.36) and, despite some temporary improvement, did not significantly improve (0.49 +/- 0.30) following rehabilitation for one month. The changes in L:M ratio were largely due to an increase in lactulose absorption, showing that the small intestinal mucosa becomes more "leaky" as a result of nutritional rehabilitation. Although no correlation was found between measures of intestinal permeability and mucosal morphology, nutritional restitution was associated with a significant increase in size of the mucosal crypt cell compartment, but not in villous epithelial volumes during the same period. It is necessary to establish, by further prospective studies, the interval required for full restitution of small intestinal structure and function during treatment for persistent diarrhea.

Anti-Bacterial Agents↗

Parasitic infection of the gut and protein-losing enteropathy.

Parasitic infection of the gut is highly prevalent in developing countries and contributes to the severe malnutrition associated with persistent diarrhoea in children. Using random faecal alpha 1-antitrypsin measurements as an index of protein-losing enteropathy, we examined children with and without parasitic infection of the gut. Seventeen percent of children with persistent diarrhoea had evidence of protein-losing enteropathy. This was found to be associated with hypoalbuminaemia in children infected with Strongyloides stercoralis. Only a minority (2 of 17) of children infected with Giardia lamblia had raised faecal alpha 1-antitrypsin excretion and this was not associated with hypoalbuminaemia. This study emphasises the need for rapid diagnosis and treatment of Strongyloides infection in children with persistent diarrhoea and severe nutrition.

Animals↗