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Biomedical subjects

A Bush

Publications and source records attributed to A Bush.

At least 181 records · Page 10Linked to original sources
PubMed1996

Severe small airways disease resistant to medical treatment in a child with cystic fibrosis.

At the age of 12, a child with cystic fibrosis developed severe small airways obstruction of unknown aetiology, in the absence of significant bronchiectasis. He remained resistant to medical treatment until, following an exacerbation of allergic bronchopulmonary aspergillosis 18 months later, he responded to high dose oral steroids. He now remains steroid-dependent, and suffering from multiple side-effects. Possible aetiology and further therapeutic strategies are discussed.

Aspergillosis, Allergic Bronchopulmonary↗
PubMed1995

Relation of thickening of colon wall to pancreatic-enzyme treatment in cystic fibrosis.

Fibrotic strictures of the colon in association with colon-wall thickening on abdominal ultrasound have been described in children with cystic fibrosis. We determined the prevalence of colon-wall thickening in 99 children with cystic fibrosis (aged 6 months to 17 years, 45 male) and 38 healthy controls (aged 1 month to 39 years, 21 male). In controls, peristalsis was uniformly rapid and maximum wall thickness of the fully relaxed colon was 0.8 mm (median 0.6 mm). 24% of the patients had a colon-wall thickness of 1.5 mm or more (maximum 3.4 mm); 48% of children on high-strength pancreatin receiving more than 265 units/kg per day of protease had thickening of more than 1.5 mm compared with less than 12% of children on any other dose. Children on high-strength pancreatin were 5.2 (95% CI 1.2-21) times more likely to have colon-wall thickness of 1.5 mm or more than children taking less than 265 units/kg per day of protease in a standard-strength preparation. This risk rose to 10 (2.5-39) times more likely if laxatives were taken with a high-strength preparation. Lipase or amylase intake, age, sex, genotype, and other medical or drug history were not significantly associated with colon-wall thickening. 1 child required a hemicolectomy for bowel obstruction and another developed haemorrhagic colitis. In 17 children, 2 months after stopping high-strength, high protease, preparations and efforts to reduce enzyme intake, colon-wall thickness had regressed from a median 2.0 mm (range 1.0-3.4) to 1.8 mm (0.9-2.7) (p = 0.005). The use of high-strength pancreatin preparations in conjunction with a high protease intake probably causes thickening of the wall of the colon.

Adolescent↗
PubMed1995

Comparison of cardiopulmonary adaptation during exercise in children after the atriopulmonary and total cavopulmonary connection Fontan procedures.

BACKGROUND: There are several potential physiological differences between the atriopulmonary (AP) and the total cavopulmonary connection (TCPC) Fontan circulations. Studies suggest that the TCPC reduces energy loss due to turbulence and may have more dependence on respiratory movement for pulmonary blood flow. We compared cardiopulmonary physiology during rest and exercise in patients who had undergone the AP Fontan procedure with those who had undergone the TCPC Fontan procedure. METHODS AND RESULTS: Forty-three children were studied more than 6 months after undergoing a Fontan procedure (23 AP and 20 TCPC); 106 healthy children were also studied as a control group. Measurements of effective pulmonary blood flow, stroke volume, arteriovenous oxygen difference, minute ventilation, heart rate, and oxygen and carbon dioxide consumption were made with an Innovision quadrupole mass spectrometer. Data from the control group allowed calculation of z scores for the Fontan groups matched for age, sex, pubertal stage, and body surface area. Maximal exercise performance was equal in the two Fontan groups, but it was below normal. However, adaptation to exercise was different in the Fontan groups. After 9 minutes of exercise, pulmonary blood flow rose less in the AP group than in the TCPC group (P < .01), and the stroke volume in the AP group also tended to be lower (P = .057) and their arteriovenous oxygen difference was significantly greater (P < .01). Although minute ventilation per unit of carbon dioxide production was similar in the Fontan groups at this level of exercise, children in the TCPC group breathed faster by approximately 10 breaths per minute (P < .005). CONCLUSIONS: At submaximal exercise, children who had undergone the TCPC Fontan procedure had pulmonary hemodynamics superior to those of children who had undergone the AP procedure, largely because of respiratory adaptation that permitted blood to be "sucked" into the lungs. To achieve the same maximal exercise performance, children who had undergone the AP procedure had a superior metabolic adaptation to exercise stress.

Adaptation, Physiological↗
PubMed1995

Effects of pseudomonas aeruginosa colonization on lung function and anthropometric variables in children with cystic fibrosis.

The aim of this study was to evaluate how lung function and growth changed over time in children with cystic fibrosis (CF) colonized with pseudomonas aeruginosa (Pa) compared with those free of the organism. A total of 192 children attended our cystic fibrosis clinic between 1982 and 1992. Sixty-two of these had three or more annual assessments for lung function, and 117 had three or more annual assessments for height and weight. When lung function was expressed as a standard deviation score (SDS), forced expiratory volume in 1 second (FEV1) and forced expiratory flow at 25% of vital capacity (FEF25) decreased significantly more with respect to height in colonized compared with noncolonized children: FEV1, -0.052 verses -0.015 SDS/cm (P < 0.05); FEF25, -0.060 verses -0.007 SDS/cm (P < 0.05); forced vital capacity (FVC), -0.034 versus -0.012 (NS). In actual values those patients colonized with Pa increased their FEV1 by 16.4 versus 31.6 mL/cm (P < 0.01); FVC by 28.8 versus 41.4 mL/cm, P < 0.01; and FEF25 by -0.001 versus 0.015 L/s/cm, P < 0.01. In terms of height, colonized children grew at 5.63 versus 6.96 cm/yr, P < 0.001, and height SDS decreased in colonized compared with noncolonized children at -0.031 verses 0.08 SDS/yr, P < 0.05. Clinically, most children with CF, with or without Pa, grew within +/- 1 SD of the norm for weight and height. However, in terms of lung function despite optimum pulmonary management colonized children deteriorated significantly faster.

Adolescent↗
PubMed1995

Magnetic resonance scanning in cystic fibrosis: comparison with computed tomography.

Comparison has been made between two different spin-echo sequence MR scans and CT scans of the lungs in 17 patients with cystic fibrosis. Scans were assessed for bronchial dilation, bronchial wall thickening and mucus plugging. The resolution of MR does not, at present, compare with CT. TE7 ms matched with CT for demonstrating the extent of bronchiectasis whereas TE30 ms scans were inferior to CT. Stronger background lung signal and less artefact was seen on TE7 ms scans compared with TE30 ms scans. MR is a developing technology that does not involve ionizing radiation which, with further refinement, may prove to be useful in imaging lung pathology in cystic fibrosis.

Adolescent↗
PubMed1995

Prevention of cross infection during outpatient spirometry.

Lung function apparatus may be a source of cross infection in patients with cystic fibrosis and may be prevented using a 'bag in bottle' system. As this system has never been validated in children the flow volume loops performed using a Vitalograph Compact in the usual way were compared with results obtained blowing into the bag and bottle system, in random order, in 20 children with asthma (age 8-15 years). Three reproducible flow volume loops were recorded for each apparatus. There was no order effect. Mean (SE) results for forced expiratory volume in one second, forced vital capacity (FVC), peak expiratory flow rate, and maximum expiratory flow at between 75% and 25% of FVC showed respectively that the bag in bottle results were significantly greater than those obtained blowing directly into the spirometer by 90 (17) ml, 12.7 (5.1) l/min, 130 (60) ml/min. Although statistically significant, these differences are within the previously described coefficients of variation for children with cystic fibrosis and are of doubtful clinical relevance. It is concluded that the bag in bottle system does not introduce any important systematic error. It potentially offers absolute protection from cross infection.

Adolescent↗
PubMed1995

Colonic stricture in a boy with cystic fibrosis.

Many problems may arise within the gastrointestinal tract of patients with cystic fibrosis. We report a new cause of subacute intestinal obstruction due to a fibrotic stricture of the ascending colon in a child with cystic fibrosis. Treatment was with a right hemicolectomy. There has been no recurrence after nine months follow-up. Recent similar cases suggest that this new pathology is linked to the use of enteric-coated high-strength pancreatin microspheres.

Child, Preschool↗
PubMed1995

Inhaled frusemide and exercise-induced bronchoconstriction in children with asthma.

BACKGROUND: Nebulised frusemide has been shown to be protective against bronchoconstricting stimuli in adult asthmatic subjects and against cold air challenge in children. Animal studies suggest that inhaled frusemide may be more effective in the young. METHODS: A double blind placebo, controlled, crossover study on the effect on exercise of pretreatment with frusemide (20 mg) from a metered dose inhaler via a large volume spacer (Volumatic) was performed in 12 asthmatic children. Exercise testing consisted of eight minutes of running on a treadmill in an environmentally controlled laboratory. RESULTS: Deterioration in lung function was less after frusemide than after the placebo exercise tests. The mean (95% CI) maximum percentage falls in forced expiratory volume in one second (FEV1) were 14.4% (7.7 to 21.0) for placebo and 5.7% (2.3 to 9.0) for frusemide. CONCLUSIONS: Inhaled frusemide via a metered dose inhaler reduces exercise-induced bronchoconstriction in children.

Administration, Inhalation↗
PubMed1995

Recombinant human DNase I in cystic fibrosis patients with severe pulmonary disease: a short-term, double-blind study followed by six months open-label treatment.

Chronic pulmonary infection is the major cause of morbidity and mortality in cystic fibrosis (CF). Recombinant human deoxyribonuclease (rhDNase) in vitro has been shown to dramatically reduce the viscoelasticity of the sputum from CF patients. Phase II and III clinical trials have shown the drug to be safe, and that patients with a forced vital capacity (FVC) of > 40% predicted show an improvement in pulmonary function when receiving rhDNase. The current study evaluates the safety and efficacy of rhDNase in the most severly ill CF patients (FVC < 40% predicted). A double-blind, randomized, placebo-controlled trial in which patients received either 2.5 mg rhDNase twice daily or placebo for a period of 14 days followed by a 6 month open extension period (OEP) is reported. Seventy patients were recruited for the double-blind study, and 64 entered the OEP of whom 38 completed. During the OEP, all patients received 2.5 mg rhDNase twice daily. In both the double-blind period and the OEP the drug appeared to be safe. During the double-blind study, forced expiratory volume in one second (FEV1) and FVC improved in both groups but there was no statistically significant difference between the groups. In the OEP, there was mean improvement in percentage predicted FEV1 and FVC, 9 and 18%, respectively, for all patients participating. In conclusion, DNase is safe when administered in conjunction with a rigorous regimen of chest physiotherapy to severely ill patients (FVC < 40% predicted) with CF. The double-blind, 14 day study showed no significant improvement in pulmonary function but some patients may have improved after longer administration of rhDNase.

Administration, Inhalation↗
PubMed1994

Prediction of hypoxaemia at high altitude in children with cystic fibrosis.

OBJECTIVE: To assess the usefulness of a hypoxic challenge in a laboratory at sea level in predicting acute desaturation at altitude in children with lung disease. DESIGN: Comparison of responses to hypoxic challenge in different settings. SUBJECTS: 22 children (12 boys) aged 11 to 16 years with cystic fibrosis in whom the mean forced expiratory volume in one second was 64% (range 24-100%). SETTING: Lung function laboratory, the Alps, and aboard commercial jet aircraft. MAIN OUTCOME MEASURES: Spirometric lung function at sea level and finger probe oximetry with air and 15% oxygen. Oximetry during high altitude flight and on a mountain at altitude of 1800 m. RESULTS: Significant desaturation (range 0 to 12%) occurred with all hypoxic challenges (P < 0.002). The best predictor of hypoxic response from a single reading was the laboratory test (r2 = 76% for flight and r2 = 47% for mountain altitude), but the mean errors of prediction were not clinically significantly different. In six children who showed the greatest desaturation the laboratory test overestimated desaturation, but other predictors underestimated desaturation in three by up to 5%. CONCLUSIONS: The laboratory hypoxic challenge directly predicted the worst case of desaturation during flight and at equivalent high altitude. Spirometry and baseline oxygen saturations may underestimate individual hypoxic response. The test may have wider applications to other patients with stable chronic lung diseases, particularly in determining who needs supplementary oxygen during air travel and who should be advised against holidays at high altitude.

Acute Disease↗
PubMed1994

A new device for ambulatory cough recording.

Nocturnal cough reporting on diary cards has been shown to be unreliable and inconsistent. Whether subjective reporting of daytime cough is equally unreliable remains unknown. We have, therefore, developed a new and easily portable device (RBC-7) that records electromyographic (EMG) and audio cough signals for at least a 24-hr period, with a capacity of over 48 hr. Additional information is obtained from electrocardiographic (ECG) signals, and from an accelerometer indicating the level of the subject's activity. The RBC-7 can be set up with the aid of a notebook computer at the subjects home, school or workplace. Initial studies utilizing a prototype device were performed to determine the optimal position of the EMG leads and the microphone. The optimal position for the EMG leads was determined as the positive electrode in the sixth intercostal space (ICS) in the midclavicular line on the left, the negative electrode in the same position on the right, and the reference electrode in the midline over the abdomen. This position was shown to give the highest EMG voltages and the greatest difference in voltages between cough and other signals. The optimal microphone position for signal strength and comfort was over the first ICS, either right or left, close to the sternum. Recordings were performed simultaneously in 20 subjects with conventional tape recorders and the multiparametric cough monitoring system (RBC-7). Conventional tape recordings limited the duration of the studies due to the inherent restrictions. No significant difference in the number of single coughs recorded by each system was detected (correlation coefficient = 0.996). The RBC-7 offers a unique opportunity to obtain objective information on cough in ambulatory subjects over at least a 24-hr period, and to relate cough to time, activity and heart rate, while normal activities are pursued.

Adult↗
PubMed1994

Weight/height2.88 as a screening test for obesity or thinness in schoolage children.

We wished to determine a weight for height measure for use as a simple screening test throughout the schoolage years for obesity or thinness similar to the body mass index in adults but not correlated with either height or age. Single measurements of height, weight, pubertal stage and two site skinfold thickness were collected on 979 healthy London schoolchildren (559 male) aged 4.6-18.8 years from 11 schools by one anthropometrist. Weight/height2.88 was uncorrelated with height or age in either sex. The median (95% confidence interval of the median) value for boys (12.74, 12.58-12.90) did not vary within this age group, height or pubertal stage. In girls the median value 12.46 (12.20-12.61) was valid for all girls less than breast stage 4 but rose sharply to 13.64 (13.21-14.06) thereafter. Percentile charts and nomograms are provided. Conclusion Weight/height2.88 may be a simple screening test for obesity or thinness throughout the schooling years and that its independence of age and height greatly simplifies longitudinal assessment.

Adipose Tissue↗