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Biomedical subjects

D R Brewster

Publications and source records attributed to D R Brewster.

At least 19 recordsLinked to original sources
PubMed2004

Soluble transferrin receptor in Aboriginal children with a high prevalence of iron deficiency and infection.

OBJECTIVES: Aboriginal children in tropical Australia have a high prevalence of both iron deficiency and acute infections, making it difficult to differentiate their relative contributions to anaemia. The aims of this study were to compare soluble transferrin receptor with ferritin in iron deficiency anaemia (IDA), and to examine how best to distinguish the effect of iron deficiency from infection on anaemia. METHODS: We conducted a prospective study of 228 admissions to Royal Darwin Hospital in children from 6 to 60 months of age. Transferrin receptor concentrations were measured by a particle-enhanced immunoturbidimetric assay and ferritin by a microparticle enzyme immunoassay. RESULTS: On multiple regression, the best explanatory variables for haemoglobin differences (r2=33.7%, P<0.001) were mean corpuscular volume (MCV), red cell distribution width (RDW) and C-reactive protein (CRP); whereas transferrin receptor and ferritin were not significant (P>0.4). Using > or =2 abnormal indices (MCV, RDW, blood film)+haemoglobin <110 g/l as the reference standard for IDA, transferrin receptor produced a higher area under the curve on receiver operating characteristic curve analysis than ferritin (0.79 vs. 0.64, P<0.001) or the transferrin receptor-ferritin index (0.77). On logistic regression, the effect of acute infection (CRP) on haemoglobin was significant (P<0.001) at cut-offs of 105 and 110 g/l, but not at 100 g/l when only iron deficiency indicators (MCV, RDW, blood film) were significant. CONCLUSIONS: Transferrin receptor does not significantly improve the diagnosis of anaemia (iron deficiency vs. infection) over full blood count and CRP, but in settings with a high burden of infectious diseases and iron deficiency, it is a more reliable adjunctive measure of iron status than ferritin.

Anemia, Iron-Deficiency↗
PubMed2003

Unique pattern of urinary tract calculi in Australian Aboriginal children.

Young Aboriginal children in remote regions of tropical and desert Australia are at risk of developing urate stones in their upper urinary tract from an early age. These radiolucent calculi were only recognized with the availability of ultrasound diagnosis and are not associated with anatomic anomalies or abnormal uric acid production/metabolism. Although these stones appear to resolve spontaneously after the weaning period, some result in ureteric obstruction and infection which may lead to renal damage. This pattern of urolithiasis differs from the usual global urolithiasis pattern of either endemic bladder stones in young children in developing countries or predominantly calcium-based stones in upper tracts of older children and adults in affluent industrialized countries, where upper tract urate stones account for only a minority of childhood urinary tract stones. Risk factors for urate stones are low urine output and acidic urine. An association between urolithiasis and carbohydrate intolerance leading to chronic acidosis has been suggested for Aboriginal children, but existing limited evidence does not support this as a major aetiological factor. Although further studies on the epidemiology, natural history and management of these urate stones are needed, we believe the focus should be on improving the known social and environmental risk factors of remote Aboriginal children during the weaning period which contribute to the unacceptably high prevalence of failure to thrive, diarrhoeal disease, environmental enteropathy, iron deficiency and urolithiasis.

Australia↗
PubMed2002

Milk formulas in acute gastroenteritis and malnutrition: a randomized trial.

OBJECTIVE: To compare three low-lactose milk formulas differing in osmolality and degree of protein hydrolysis in the treatment of diarrhoea and malnutrition in subjects with high rates of lactose intolerance, osmotic diarrhoea and a tropical/environmental enteropathy. METHODS: A randomized double-blind trial of 180 Aboriginal children under 3 years of age admitted with acute diarrhoea and/or malnutrition was carried out. The intervention milk formulas were: (i) De-Lact, a low-osmolality lactose-free formula; (ii) O-Lac, a lactose-free formula; and (iii) Alfaré, a partially hydrolysed formula. Outcome measures were diarrhoeal severity, weight gain, formula palatability and changes in intestinal permeability (L/R ratios). RESULTS: The duration of diarrhoea in days (mean; 95% confidence interval) was significantly longer on Alfaré (8.5; 7.0-10.0) compared to De-Lact (6.1; 5.0-7.2) and O-Lac (6.9; 5.6-8.1; P = 0.04). There were no differences in mean intake between formulas, but palatability of Alfaré was significantly worse (P < 0.01) than the other formulas. Over the trial 5 days, improvement in L/R ratios was significantly greater (P = 0.05) for De-Lact (18.6; 10.6-26.6) than for Alfaré (8.5; 2.1-14.9). Weight gain was not significantly different between the three formulas, except in a malnourished subgroup who had better weight gain on De-Lact (P = 0.05). CONCLUSIONS: In these Aboriginal children with diarrhoea and growth failure, a low osmolality milk was associated with better outcomes and a partially hydrolysed formula with less improvement in mucosal recovery, suggesting that cow's milk protein intolerance is not contributing to greater diarrhoeal severity or enteropathy in Aboriginal children.

Analysis of Variance↗
PubMed2001

Childhood infections in the tropical north of Australia.

In the tropical north of Australia there are high rates of infections in Aboriginal children living in remote communities. In addition to the burden of respiratory infections, diarrhoeal disease and skin sepsis, there are high rates of acute rheumatic fever, outbreaks of poststreptococcal glomerulonephritis and gonococcal conjunctivitis, endemic trachoma and various intestinal parasites. A number of infections generally restricted to the tropics are also present and can cause disease in both indigenous and non-indigenous children. These include melioidosis, Murray Valley encephalitis and dengue on the east coast. With global warming, these infections may become more common and more widespread within Australia and the potential for establishment of introduced infections such as Japanese encephalitis and malaria may increase.

Adolescent↗
PubMed2000

Dual sugar permeability testing in diarrheal disease.

OBJECTIVE: To assess the validity of the use of a blood specimen for the sugar permeability test because of the high failure rate of 5-hour urine collection in young children with diarrhea. STUDY DESIGN: Simultaneous 5-hour urine collections and timed blood tests were taken after ingestion of an isotonic solution of lactulose (L) and L-rhamnose (R) in 24 children with acute gastroenteritis and 25 children without diarrhea in a control group. Sugars were measured with high performance liquid chromatography, and the percent of recovered sugars was expressed as an L-R ratio. RESULTS: With acute gastroenteritis the geometric mean L-R ratios (95% confidence intervals) were 12.4 (9.3 to 16.3) in urine and 9.4 (6.7 to 13.1) in blood compared with 6.7 (5.0 to 8.8) and 5.9 (4.4 to 7.8), respectively, in the control group. The level of agreement (kappa) among normal, intermediate, and high ratios for blood and urine was 0.71 (0.51 to 0.92). The failure rate of L-R tests was significantly reduced with a blood specimen (urine 37% vs blood 10%; P <.0001). CONCLUSIONS: Intestinal permeability testing on a blood specimen is a valid alternative to urine collection in young children and has a significantly lower test failure rate.

Blood Specimen Collection↗
PubMed2000

Intensive nursing care of kwashiorkor in Malawi.

The case fatality rate for children with kwashiorkor in central hospitals in Malawi was 30.5% (275/901) in 1995. The purpose of this study was to determine whether improved case management with intensive nursing care could lower this case fatality rate. A total of 75 children admitted with kwashiorkor in Blantyre, Malawi, received intensive nursing care. This included nursing in individual clean beds with blankets, a nurse:child ratio of 1:3, supervised feedings every 2 h, a paediatrician with expertise in treating kwashiorkor always available for consultation, laboratory evaluation for systemic infection and empiric use of ceftriaxone. Nineteen of these children died (25%). The causes of death were life threatening electrolyte abnormalities (hypokalaemia, hyponatraemia, hypophosphataemia) in nine cases, overwhelming infection in eight cases and congestive heart failure in two children. Children infected with the human immunodeficiency virus were more likely to die (9/20), as were children with life threatening electrolyte abnormalities (9/15) and children with more severe wasting. When compared with 225 children treated in the same year at the same institution, who were carefully matched for severity of kwashiorkor, intensive nursing did not improve overall survival.

Cause of Death↗
PubMed1999

An iron treatment trial in an aboriginal community: improving non-adherence.

OBJECTIVE: To compare supervised vs unsupervised oral iron treatment in anaemic Aboriginal children living in a remote community with a 40% prevalence of iron deficiency anaemia. METHODOLOGY: A randomised unblinded clinical trial in children < 6 years presenting to a remote Health Centre with anaemia. Oral iron prescribed as a daily unsupervised dose (group A) was compared to twice weekly supervised administration (group B) over 12 weeks. Parenteral iron (group C) was reserved for failure of oral treatment. RESULTS: Only 3 of 25 children in group A responded to treatment compared to 23 of 26 children in group B (odds ratio = 7.7, 95% confidence interval 2.6-25.0). After six weeks of treatment, the mean haemoglobin rise was 0.96 g/L in group A compared to 10.9 g/L in group B and 12.4 g/L in group C. On entry to the study, 29.4% of subjects were underweight, 33.3% stunted and 35.3% microcephalic. The mean catch-up in weight/height on iron treatment over the study was only 0.28 (0.08, 0.48) Z-scores. CONCLUSIONS: Oral iron as directly observed twice weekly treatment is superior to unsupervised therapy. In view of the poor compliance with unsupervised treatment and the high prevalence of iron deficiency anaemia (along with stunting and microcephaly) in Aboriginal children in northern Australia, we propose to undertake in partnership with communities a nutritional intervention program with a high energy weaning food fortified with micronutrients (iron, vitamin A, zinc, folate) as the most effective strategy to address these nutritional problems in the weaning period.

Administration, Oral↗
PubMed1999

Intestinal permeability and diarrhoeal disease in Aboriginal Australians.

BACKGROUND: Northern Territory Aboriginal children hospitalised with acute gastroenteritis have high rates of acidosis, hypokalaemia, and dehydration. AIMS: To determine whether Aboriginal children with and without diarrhoea have greater impairment in intestinal function than non-Aboriginal children, as assessed by increased permeability ratios. METHODS: A descriptive study of 124 children (96 Aboriginal and 28 non-Aboriginal) hospitalised with and without diarrhoea. Intestinal permeability was assessed by the lactulose to rhamnose (L-R) ratio from a five hour urine collection. RESULTS: In Aboriginal children, mean L-R ratios (95% confidence intervals) were 18.3 (17.1 to 19.6) with diarrhoea and 9.0 (7.3 to 11.0) without diarrhoea, and in non-Aboriginal children they were 5.9 (2.8 to 12. 3) and 4.2 (3.3 to 5.2), respectively. In patients with diarrhoea, L-R ratios were significantly raised when accompanied by acidosis (mean, 22.8; 95% CI, 17.0 to 30.5), hypokalaemia (mean, 20.7; 95% CI, 15.4 to 27.9), and >/= 5% dehydration (mean, 24.3; 95% CI, 19.0 to 29.6) compared with none of these complications (mean, 7.0; 95% CI, 3.5 to 13.8). CONCLUSION: The high incidence of acidosis, hypokalaemia, and dehydration in Aboriginal children admitted with diarrhoeal disease is related to underlying small intestinal mucosal damage.

Acidosis↗
PubMed1997

Case management of kwashiorkor: an intervention project at seven nutrition rehabilitation centres in Malawi.

OBJECTIVES: (1) To improve case management of kwashiorkor at seven Nutritional Rehabilitation Centres (NRCs) through 2-4 weekly paediatric supervisory visits. (2) To evaluate the impact of the use of routine tube-feeding and a micronutrient supplement (Nutriset). DESIGN: An intervention project with descriptive clinical data in which Nutriset was introduced halfway through the project, and routine tube-feeding at one NRC was compared to no tube-feeding at a similar one. SETTING: NRCs located at two central hospitals, two district hospitals and three rural clinics in southern Malawi. SUBJECTS: 1625 consecutive kwashiorkor admissions from January-December 1995. RESULTS: The overall case-fatality rate was 24.2% (393/1625), varying by facility level (central 30.5%, district 25.8% and rural 7.5%), reflecting different severity of cases. From ELISA testing and a clinical protocol, we estimate that 21.7% (353/1625) of these kwashiorkor cases were HIV-infected, including 121 breastfed children. Routine tube-feeding was associated with better weight gain (8.24 g/kg/d) than no tube-feeding (4.51 g/kg/d) at central NRCs, but with no reduction in mortality (31.4% vs 30.3%). The introduction of Nutriset was associated with improved weight gain (6.06 vs 4.66 g/kg/d) and a lower mortality (20.8 vs 25.8%), but was confounded by seasonal factors. CONCLUSIONS: From a clinical perspective, HIV infection has transformed kwashiorkor in this part of Africa. Routine tube-feeding was associated with improved body weight gain in the treatment of kwashiorkor. The benefit of paediatric supervision was limited by the infrequency of visits, by constraints of health worker motivation, by a lack of resources and by the severity of disease. Efforts need to focus-not just on case management protocols-but on how to actually improve clinical practice in this setting.

Case Management↗
PubMed1997

Protein metabolism in children with edematous malnutrition and acute lower respiratory infection.

This study tested the hypothesis that wholebody protein kinetics remain low in children with edematous malnutrition and acute infection. Thirteen children with edematous malnutrition and acute infection (subjects) were compared with 14 uninfected children with edematous malnutrition early in recovery (control children). Protein kinetics were determined by using a primed, constant intravenous infusion of [13C]leucine and [15N2]urea in the postabsorptive state. Calculations of rates of whole-body protein synthesis and breakdown were based on the rate of leucine appearance; the rate of leucine oxidation was estimated from the rate of urea appearance. Protein synthesis and breakdown rates were lower in subjects than in control children (97 +/- 30 compared with 153 +/- 67, P < 0.01, and 103 +/- 30 compared with 160 +/- 67 mumol leucine.kg-1.h-1, P < 0.01). No difference was found between the two groups in the rate of urea appearance, but this analysis only had a statistical power of 54%. The absence of the expected increase in the rate of protein turnover during acute infection in edematous malnutrition implies that acute phase proteins are made with a corresponding depletion of muscle, hepatic, and other body proteins such as albumin, and that there may also be a blunting of the acute phase response.

Acute Disease↗
PubMed1997

Whole-body protein kinetics in children with kwashiorkor and infection: a comparison of egg white and milk as dietary sources of protein.

This study tested the hypothesis that during treatment of kwashiorkor (including marasmic kwashiorkor) with infection there is a lower rate of amino acid oxidation when the dietary intake of amino acids resembles the amino acid composition of acute phase proteins (APPs). Twenty-two children in Blantyre, Malawi, with kwashiorkor and acute infection were fed an isoenergetic, isonitrogenous diet with either egg white or milk as a protein source. The whole-body amino acid oxidation rate was measured after 24 h by determining the plasma urea rate of appearance, and whole-body protein breakdown and synthesis rates were determined from the plasma leucine rate of appearance. Plasma concentrations of C-reactive protein, alpha1-antitrypsin, tumor necrosis factor alpha (TNF-alpha), and interleukin 6 (IL-6) were determined on admission and at 24 and 48 h. The 11 children who received milk had a lower rate of amino acid oxidation than the children who received egg white (x +/- SD: 137 +/- 65 compared with 195 +/- 66 micromol urea x kg body wt(-1) x h(-1), P < 0.05). No significant differences were found between the two groups in the rate of whole-body protein breakdown or protein synthesis. The TNF-alpha concentration correlated inversely with whole-body protein breakdown and synthesis rates, and the IL-6 concentration correlated directly with C-reactive protein. We conclude that by making the amino acid composition of the diet resemble that of APPs in the treatment of acute kwashiorkor, the rate of amino acid oxidation can be decreased.

C-Reactive Protein↗
PubMed1997

Potassium supplementation in kwashiorkor.

BACKGROUND: Kwashiorkor is an edimatous form of severe malnutrition and is the predominant form of childhood malnutrition in Malawi. Potassium depletion is common and contributes to the high mortality. The aim of this study was to determine if high potassium supplementation improves the outcome of kwashiorkor treatment. METHODS: We performed a randomised, double-blind, placebo-controlled, clinical trial of high potassium supplementation in 99 children with kwashiorkor. Controls (n = 51) received a standard potassium intake of 4.7 mmol/kg/day. The intervention group (n = 48) received 7.7 mmol/kg/day. All cases (intervention and control groups) were treated in the hospital-based Nutrition Rehabilitation Center and received a standard treatment regime of mild feeds, mineral and vitamin supplements, and antibiotics. RESULTS: There was no significant difference in length of hospitalization, or time for resolution of oedema between groups. The case-fatality rate was reduced by 33% in the high potassium intervention group (13/48) compared to controls (21/51). There was a significant reduction in late deaths (13 in controls vs 3 in intervention group; odds ratio 5.3, 95% confidence interval 1.2-31.0) but no difference in early deaths (0-5 days). The intervention group also had significantly fewer presumed septic episodes (3 vs 18, odds ratio 8.9, confidence interval 2.2-50.9), respiratory symptoms, and new skin ulcerations than controls. CONCLUSIONS: The high potassium supplementation reduced mortality and significant morbidity in kwashiorkor. This may be due to improved myocardial and immune function from earlier repletion of intracellular potassium. We recommend that the standard potassium supplement for the initial phase of treatment of kwashiorkor be increased from 4 to 8 mmol/kg/day.

Administration, Oral↗
PubMed1997

Intestinal permeability in kwashiorkor.

UNLABELLED: Intestinal permeability can be assessed non-invasively using the lactulose-rhamnose (L-R) test, which is a reliable measure of small intestinal integrity. AIMS: To determine risk factors for abnormal intestinal permeability in kwashiorkor, and to measure changes in L-R ratios with inpatient rehabilitation. DESIGN: A case-control study of 149 kwashiorkor cases and 45 hospital controls. The L-R test was adapted to study kwashiorkor in Malawi, with testing at weekly intervals during nutritional rehabilitation. Urine sugars were measured by thin layer chromatography in London. RESULTS: The initial geometric mean L-R ratios (x100) (with 95% confidence interval) in kwashiorkor were 17.3 (15.0 to 19.8) compared with 7.0 (5.6 to 8.7) for controls. Normal ratios are < 5, so the high ratios in controls indicate tropical enteropathy syndrome. Abnormal permeability in kwashiorkor was associated with death, oliguria, sepsis, diarrhoea, wasting and young age. Diarrhoea and death were associated with both decreased L-rhamnose absorption (diminished absorptive surface area) and increased lactulose permeation (impaired barrier function) whereas nutritional wasting affected only L-rhamnose absorption. Despite, clinical recovery, mean L-R ratios improved little on treatment, with mean weekly ratios of 16.3 (14.0 to 19.0), 13.3 (11.1 to 15.9) and 14.4 (11.0 to 18.8). CONCLUSION: Abnormal intestinal permeability in kwashiorkor correlates with disease severity, and improves only slowly with nutritional rehabilitation.

Case-Control Studies↗
PubMed1997

Comparison of milk and maize based diets in kwashiorkor.

UNLABELLED: The dual sugar test of intestinal permeability is a reliable non-invasive way of assessing the response of the small intestinal mucosa to nutritional rehabilitation. AIM: To compare a local mix of maize-soya-egg to the standard milk diet in the treatment of kwashiorkor. DESIGN: The diets were alternated three monthly in the sequence milk-maize-milk. There were a total of 533 kwashiorkor admissions of at least five days during the study who received either milk or maize. Intestinal permeability was assessed at weekly intervals by the lactulose-rhamnose test in 100 kwashiorkor cases, including 55 on milk and 45 on the maize diet. RESULTS: Permeability ratios (95% confidence interval) on the milk diet improved by a mean of 6.4 (1.7 to 11.1) compared with -6.8 (-16.8 to 5.0) in the maize group. The improved permeability on milk occurred despite more diarrhoea, which constituted 34.8% of hospital days (29.8 to 39.8) compared with 24.3% (17.8 to 30.8) in the maize group. Case fatality rates for all 533 kwashiorkor admissions were 13.6% v 20.9%, respectively, giving a relative risk of death in the maize group of 1.54 (1.04 to 2.28). The maize group also had more clinical sepsis (60% v 31%) and less weight gain (2.9 v 4.4 g/kg/day) than the milk group. IMPLICATIONS: Milk is superior to a local maize based diet in the treatment of kwashiorkor in terms of mortality, weight gain, clinical sepsis, and improvement in intestinal permeability.

Animals↗
PubMed1996

Chloramphenicol-resistant bacterial meningitis in Malawi.

Three recent cases of chloramphenicol-resistant pyogenic meningitis are reported from Malawi. The implications of the emergence of antibiotic-resistant strains of Streptococcus pneumoniae and Haemophilus influenzae type b causing childhood meningitis are discussed.

Child↗