Search PubMed⌕ Search

Biomedical subjects

A Bush

Publications and source records attributed to A Bush.

At least 73 records · Page 4Linked to original sources
PubMed2001

Inspiratory flow reserve in boys with Duchenne muscular dystrophy.

Patients with advanced muscular dystrophy frequently develop ventilatory failure. Currently respiratory impairment usually is assessed by measuring vital capacity and the mouth pressure generated during a maximal inspiratory maneuver (PI,max), neither of which directly measures ventilatory capacity. We assessed inspiratory flow reserve in 26 boys [mean (SD) age 12.8 (3.8) years] with Duchenne muscular dystrophy (DMD) without ventilatory failure and in 28 normal boys [mean (SD) age 12.6 (1.9) years] by analyzing the ratio between the largest inspiratory flow during tidal breathing (V'I,max(t)) and during a forced vital capacity maneuver (V'I,max(FVC), (V'I,max(t)/V'I,maxFVC). We have compared this ratio with the forced vital capacity FVC and PI,max measured at functional residual capacity. Mean PI,max was -90(30)cmH2O, average 112% (range 57-179%) of predicted values in control boys and -31(11)cmH2O, average 40% predicted values in DMD boys (control vs DMD, P < 0.001). FVC was reduced in DMD boys [59(20)% predicted values vs 86(10)% predicted values in controls, P < 0.01]. Absolute V'I,max(FVC) was strongly related to FVC in both control and DMD boys; V'I,max(FVC) (expressed as FVC. s(-1)) was not related to PI,max in either group. The mean V'I,max(t)/V'I,max(FVC); ratio was higher in DMD 0.22 (0.08) than in controls 0.12 (0.03) (P < 0.001) indicating a reduction in inspiratory flow reserve in DMD. Inspiratory flow reserve was within the normal range in 8 of 19 DMD patients with PI,max less than 50% of predicted values. We conclude that measurement of inspiratory flow reserve (V'I,max(t)/V'I,maxFVC ratio) provides a simple and direct assessment of dynamic inspiratory muscle function which is not replicated by static measurement of PI,max or vital capacity and might be useful in assessment of respiratory impairment in boys with Duchenne muscular dystrophy. Follow-up studies are required to establish whether measures of inspiratory flow reserve are of clinical value in predicting subsequent ventilatory failure.

Adolescent↗
PubMed2001

Anti-inflammatory effects of macrolides in lung disease.

During the past five decades there has been increasing interest in the potential anti-inflammatory effects of macrolide antibiotics. Low-dose macrolide therapy has dramatically increased survival in patients with diffuse panbronchiolitis, a disease with many similarities to cystic fibrosis (CF). This has led to further investigation into the potential use of macrolides in chronic lung diseases with an inflammatory component. This review summarizes the proposed anti-inflammatory mechanisms for this group of antibiotics, and examines the effect of macrolides on modulation of the inflammatory pathways, neutrophil function, bronchoconstriction, Pseudomonas biofilm, mucus rheology, bacterial adherence, and multidrug-resistant protein. It discusses the current status of clinical studies in children with CF, bronchiectasis, and asthma. While there are much in vitro data for different proposed anti-inflammatory effects, randomized controlled clinical trials in children with CF, bronchiectasis, and asthma are still just beginning. The benefits and potential side effects need to be determined before routine use can be advised.

Anti-Bacterial Agents↗
PubMed2001

Congenital lung disease: a plea for clear thinking and clear nomenclature.

Antenatal ultrasound has allowed the discovery of abnormalities which in the past often escaped detection. It may be unclear what advice to offer. Many large lung malformations seen at the routine 20-weeks gestation scan have largely disappeared at term. There is now even more confusion in terms of how these malformations should be described. The nomenclature of congenital lung disease was never very clear, with terms such as sequestrated segment, cystic adenomatoid malformation, hypoplastic lung, and malinosculation being used to describe often overlapping abnormalities. However, today these terms are used inconsistently in the ante- and postnatal periods. For example, congenital cystic adenomatoid malformation (CCAM) is used prenatally to describe a lesion which may well disappear before birth, but is used postnatally to describe an abnormality which may require lobectomy. CCAM may have a pulmonary arterial supply, or be supplied like a sequestration from the aorta, and histological features of both lesions may coexist. Thus, a complete reappraisal of the nomenclature of congenital lung disease is timely; this review does not discuss treatment options.

Female↗
PubMed2001

Routine ventilation scans in children with cystic fibrosis: diagnostic usefulness and prognostic value.

Krypton ventilation scans (VS) provide an index of peripheral lung function, and may be particularly useful in children unable to perform pulmonary function testing. This communication reports on three linked studies which investigated whether a routine VS in young children with cystic fibrosis (CF) is diagnostically or prognostically useful. Study 1: In a preliminary study in 1991, VS were compared with clinical examination and chest radiography (CXR) in 50 CF children (29 females, 21 males) aged 0.4-5.2 years (median 2.2 years). The chest was divided into six zones, and abnormalities scored from 0 (normal) to 2 (very abnormal). Clinical examination was unhelpful in predicting abnormalities on imaging. In five children (10%) with a normal CXR, VS was abnormal, and in a further eight children (16%), CXR markedly underestimated VS changes. Study 2: In order to determine the long-term prognostic significance of VS abnormalities, we followed up 27 (19 females, 8 males) of the children from study 1, who had had their first VS at presentation at median age 1.6 years (range 0.4-5.2), scoring the same six zones from 0 to 2. Follow-up was for a mean of 11.6 years (range 7.8-14.8). Spirometry at age 7 years showed a mean forced expiratory volume in 1 s (FEV1) of 96% (range 46%-145%) and a mean forced vital capacity (FVC) of 96% (range 46%-145%). A poor VS score at presentation was correlated with percent predicted FEV1 at age 7 (r=0.4, P=0.042, 16% of variance explained). Those with a normal VS at presentation had a mean FEV1 at presentation of 99% (range 80%-129%). Whereas four patients had an abnormal VS, a normal CXR and a low FEV1 at age 7 years, no patient had a normal VS, an abnormal CXR and a low FEV1 at age 7 years. Study 3: Fifty children (29 females, 21 males) aged 0.5-6.0 years (median 3.8) were prospectively studied in 1998, to determine whether the findings in study 1 were stable over time, and to assess whether VS altered clinical management. Symptoms and clinical examination did not predict abnormalities on imaging. Thirty (60%) children had a normal VS while only five (10%) had a normal CXR. There was a significant correlation between the total scores of CXR and VS (P=0.007, 14% of variance explained). Further, VS detected additional abnormalities in seven patients (14%). Sixty-five percent of patients with an abnormal VS had modifications of treatment, including bronchoscopy, compared with 23% of those with a normal VS. We conclude that VS is a simple, safe and non-invasive technique giving additional information to that provided by clinical examination and chest radiography in a number of children with CF and can be used to modify clinical management. VS at presentation gives prognostic information, which may be of use in early intervention studies. Whether using VS to guide treatment improves long-term prognosis requires a larger prospective trial.

Child↗
PubMed2001

Physical activity in first-degree relatives of breast cancer patients.

This study sought to evaluate physical activity in women at moderate risk for breast cancer, the correlates of engaging in regular physical activity, and whether physical activity relates to psychological well-being. The results revealed that 55% of women were regularly active. Logistic regression models indicated that positive affect was associated with increased and negative affect was associated with decreased overall and leisure activity. Older, married, and employed women were more likely to engage in household/occupational activity, whereas women who perceived their risk for breast cancer as high were less likely. More educated women and those with higher perceived risk were more likely to engage in leisure activity, and married women were less likely. These results suggest a need to increase activity levels in women at moderate risk for breast cancer, provide variables upon which interventions can be tailored to promote activity, and point to psychological benefits of activity in this population.

Adolescent↗
PubMed2001

Asthma severity and inflammation markers in children.

UNLABELLED: The relationship of airway inflammation with asthma severity remains unclear. Our aim was to correlate the results of recommended methods of assessment of inflammation with measures of asthma control, in children with a wide range of asthma severity. The study was a cross-sectional investigation of 58 children receiving a wide range of treatment, including 10 treated without regular maintenance therapy and 29 treated with high-dose inhaled corticosteroids (CS). Exhaled nitric oxide (NO), serum eosinophil cationic protein (ECP), and induced sputum (processed for eosinophil count and ECP level) were related to recent symptoms, lung function, and bronchial responsiveness. There was no significant correlation between the results of any METHOD: Neither did any marker of airway inflammation relate to recent symptoms, unlike PC20, which did. There was a significant, inverse correlation between the forced expiratory volume in 1 s (FEV1) and both NO and sputum ECP (r=-0.46, p=<0.001; r=-0.48, p=0.004, respectively). Sputum eosinophils were inversely related to the dose of methacholine that corresponded to a 20% fall in FEV1 (PC20) (r=-0.57, p=0.02). Serum ECP did not relate to any measure of asthma control. There was no association of any recommended inflammation markers with current symptoms and only a weak relationship between them and physiological measures. The place of these markers remains unclear and their use in clinical practice needs further investigation by long-term longitudinal studies.

Adolescent↗
PubMed2001

Genetic contributions to rare childhood lung diseases.

Epidemiological studies have suggested that many rare diseases with respiratory involvement have a genetic component. Molecular advances have increased the understanding of the pathophysiology of these diseases which has led to better diagnostic and prognostic methods. There may be many genes responsible for diseases such as primary ciliary dyskinesia and systemic lupus erythematosus in addition to the effect of modifier genes. The genotype:phenotype correlation in these diseases remains to be elucidated. In some diseases, such as familial dysautonomia and sickle cell, the gene has been identified which allows for accurate pre-natal testing. Further, in diseases where the genetic abnormality is known, such as chronic granulomatous disease, gene therapy remains a realistic prospect and phase I studies are about to commence or currently underway. This article reviews those rare diseases in which there is or is likely to be a significant genetic contribution.

Anemia, Sickle Cell↗
PubMed2001

Guest editorial.

Explore the source record for details and available documents.

Journal Article↗
PubMed2001

Attention-Deficit Hyperactivity Disorder (ADHD) symptoms and smoking patterns among participants in a smoking-cessation program.

Previous research has suggested an increased liability to smoking among individuals with Attention-Deficit Hyperactivity Disorder (ADHD). This link is thought to be attributable, in part, to nicotine's beneficial effects on attention and performance. In the present study, we examined the association of ADHD symptoms of inattention and hyperactivity with smoking behavior in a sample of 226 male and female smokers ages 18 and older who were enrolled in a smoking-cessation program. Prior to treatment, they completed measures of ADHD symptoms and standardized measures of smoking patterns. Hierarchical linear regression models were used to characterize the smoking patterns associated with ADHD inattention and hyperactivity symptoms, controlling for potential confounder variables. Smoking for stimulation purposes and the urge to smoke to minimize withdrawal symptoms were the primary patterns associated with ADHD inattention symptoms, while hyperactivity symptoms were not associated with smoking patterns. Consistent with a self-medication hypothesis, these results suggest that smokers with frequent symptoms of inattention may use nicotine as a stimulant drug to help manage these symptoms. Future studies of the role of inattention symptoms in response to smoking treatment are warranted.

Adolescent↗
PubMed2001

Safety and ethics of bronchoscopy and endobronchial biopsy in difficult asthma.

AIM: To investigate the safety of bronchoscopy and endobronchial biopsy in children with difficult asthma, and discuss the ethical issues associated with the procedure. METHODS: A three year prospective observational study was performed in two tertiary paediatric respiratory centres specialising in the management of children with difficult asthma. A total of 48 children with difficult asthma and 35 non-asthmatic children were studied. RESULTS: Flexible bronchoscopy was performed under general anaesthesia in 38 children with difficult asthma, and rigid bronchoscopy was performed in 10, following a two week course of prednisolone. Endobronchial biopsy was performed in 47 patients. Perioperative complications occurred in one asthmatic undergoing flexible bronchoscopy (desaturation) and in two undergoing rigid bronchoscopy (desaturation in one, and bronchospasm and desaturation in one). There were no cases of significant bleeding or pneumothorax among the asthmatics. Flexible bronchoscopy was performed in 35 non-asthmatic patients with a variety of clinical indications. The total number of perioperative complications was greater in the non-asthmatics undergoing flexible bronchoscopy than in the asthmatics (17 complications in 35 children versus one in 38). Fever requiring hospital admission was documented in two asthmatics following bronchoscopy. Four asthmatics reported an increase in symptoms in the week following bronchoscopy. CONCLUSIONS: Bronchoscopy and endobronchial biopsy under general anaesthesia can be performed safely in children with difficult asthma, when the bronchoscopist and anaesthetist are suitably trained. The procedure is acceptable to the families involved.

Adolescent↗
PubMed2001

Use of cough swabs in a cystic fibrosis clinic.

We audited prospectively 322 cough swabs taken from cystic fibrosis children and compared cough swabs with concomitant sputum samples in 30 expectorating patients. A positive cough swab is a strong predictor of sputum culture. However, a negative cough swab does not rule out infection. Persistent symptoms should be further investigated.

Adolescent↗
PubMed2001

Computerised cognitive assessment of concussed Australian Rules footballers.

BACKGROUND: "Paper and pencil" neuropsychological tests play an important role in the management of sports related concussions. They provide objective information on the athlete's cognitive function and thus facilitate decisions on safe return to sport. It has been proposed that computerised cognitive tests have many advantages over such conventional tests, but their role in this domain is yet to be established. OBJECTIVES: To measure cognitive impairment after concussion in a case series of concussed Australian Rules footballers, using both computerised and paper and pencil neuropsychological tests. To investigate the role of computerised cognitive tests in the assessment and follow up of sports related concussions. METHODS: Baseline measures on the Digit Symbol Substitution Test (DSST), Trail Making Test-Part B (TMT), and a simple reaction time (SRT) test from a computerised cognitive test battery (CogState) were obtained in 240 players. Tests were repeated in players who had sustained a concussive injury. A group of non-injured players were used as matched controls. RESULTS: Six concussions were observed over a period of nine weeks. At the follow up, DSST and TMT scores did not significantly differ from baseline scores in both control and concussed groups. However, analysis of the SRT data showed an increase in response variability and latency after concussion in the injured athletes. This was in contrast with a decrease in response variability and no change in latency on follow up of the control players (p<0.02). CONCLUSION: Increased variability in response time may be an important cognitive deficit after concussion. This has implications for consistency of an athlete's performance after injury, as well as for tests used in clinical assessment and follow up of head injuries.

Adolescent↗
PubMed2001

Predicting hypoxaemia during flights in children with cystic fibrosis.

BACKGROUND: We have previously suggested that it is possible to predict oxygen desaturation during flight in children with cystic fibrosis and chronic lung disease by non-invasive measurement of oxygen saturation following inhalation of 15% oxygen--the pre-flight hypoxic challenge. This study reports on the results of measurements over 5 years. METHODS: The study comprised a pre-flight hypoxic challenge measuring oxygen saturation by finger tip pulse oximetry (SpO(2)) during tidal breathing of 15% oxygen in nitrogen and spirometric testing 1 month before the flight followed by SpO(2) measurements during intercontinental flights to and from holidays abroad with children in wake and sleep states. RESULTS: Pre-flight tests were completed on 87 children with cystic fibrosis. Desaturation of <90% occurred in 10 children at some stage during the flight, three of whom received supplementary oxygen. Using a cut off SpO(2) of 90%, the pre-flight hypoxic challenge correctly predicted desaturation in only two of these children. The sensitivity and specificity of the pre-flight hypoxic challenge were 20% and 99%, respectively, compared with 70% and 96% for spirometric tests (using a cut off for forced expiratory volume in 1 second (FEV(1)) of <50% predicted). Overall, pre-flight spirometric tests were a better predictor of desaturation during flight with the area under the Receiver Operating Characteristic (ROC) curve of 0.89 compared with 0.73 for the hypoxic challenge test. CONCLUSIONS: In this group of subjects pre-flight spirometric testing was a better predictor of desaturation during flight than the pre-flight hypoxic challenge.

Adolescent↗
PubMed2001

Evidence for different subgroups of difficult asthma in children.

BACKGROUND: Children with difficult asthma experience frequent symptoms despite treatment with high dose inhaled steroids. Persistent symptoms may result from persistent airway inflammation which can be monitored by measuring exhaled nitric oxide (NO). This study aimed to assess the role of airway inflammation, using NO as a surrogate, in children with difficult asthma and to investigate the response to oral prednisolone. METHODS: NO was measured in 23 children (mean age 11.7 years) with difficult asthma, before and after 2 weeks of treatment with oral prednisolone. The clinical response was assessed by spirometric tests, peak flow, bronchodilator use, and symptoms. Adherence to treatment was assessed by measuring serum prednisolone and cortisol concentrations. NO was measured in 55 healthy children to establish a normal range. RESULTS: NO concentrations were higher in asthmatic patients than in controls (geometric mean 11.2 v 5.3 ppb, p<0.01). Using grouped data, the concentration of NO fell following prednisolone (11.2 v 7.5 ppb, p<0.01) accompanied by an improvement in morning peak flow (p<0.05). The baseline NO concentration was raised (>12.5 ppb) in nine asthmatic patients and remained high after prednisolone in five. Thirteen had normal levels of NO (<12.5 ppb) before and after prednisolone. Thirteen asthmatic patients remained symptomatic following prednisolone; NO levels were raised on both occasions in five of these and were normal in seven. CONCLUSIONS: As a group, the asthmatic subjects demonstrated evidence of airway inflammation which responded to prednisolone. At least two subgroups of patients were identified: one with persistently raised NO levels despite treatment with oral prednisolone indicating ongoing steroid insensitive inflammation, and another with normal levels of NO. Both subgroups included patients with persistent symptoms, which suggests that different patterns of difficult asthma in children exist.

Adolescent↗
PubMed2001

Persistent spontaneous pneumothorax in an adolescent with Marfan's syndrome and pulmonary bullous dysplasia.

A 16-year-old boy with Marfan's syndrome was admitted with progressive dyspnea due to a large spontaneous pneumothorax. Bullous pulmonary dysplasia was confirmed and pleural tube drainage did not affect the air leak. Complete recovery required surgical resection of the bulla responsible for the ongoing air leak. This case report highlights the issue of management for severe spontaneous pneumothorax in general, showing that the choice of treatment should not depend on the presence of pulmonary bullous dysplasia but on the clinical evaluation of the individual patient.

Adolescent↗