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Biomedical subjects

A Bush

Publications and source records attributed to A Bush.

At least 19 recordsLinked to original sources
PubMed2006

Ultrastructure of the reticular basement membrane in asthmatic adults, children and infants.

Reticular basement membrane (RBM) thickening in asthma is considered to be the result of subepithelial fibrosis. Thus, the RBM in asthma should contain an excess of fibrils identified as interstitial collagen and the ratio of fibril to matrix should be increased above normal levels. Electron micrographs of the RBM were compared with those of interstitial collagen deeper in the bronchial wall using endobronchial biopsy specimens from adult asthmatics (aged 18-41 yrs (n = 10)), children with difficult asthma (aged 6-16 yrs (n = 10)), wheezy infants with reversible airflow limitation (aged 0.3-2 yrs (n = 10)) and age-matched nonasthmatic controls: 10 adults, nine children and nine symptomatic infants with normal lung function. Fibrils in the RBM were significantly thinner (median (range) width 39 (30-52) nm versus 59 (48-73) nm), and fewer fibrils were banded than in the interstitial collagen (ratio of banded to non-banded fibrils 0.08 (0-0.17) versus 0.22 (0-1.3)). The ratio of fibrils to matrix in the thickened RBM of asthmatics did not differ from that of their respective controls (1.34 (0.63-2.49) versus 1.18 (0.31-2.6)). The ratio of fibril to matrix in the thickened reticular basement membrane of asthmatics is normal, and, contrary to what is expected in fibrosis, the fibrils do not resemble those of interstitial collagen.

Adolescent↗
PubMed2006

Can HRCT be used as a marker of airway remodelling in children with difficult asthma?

BACKGROUND: Whole airway wall thickening on high resolution computed tomography (HRCT) is reported to parallel thickening of the bronchial epithelial reticular basement membrane (RBM) in adult asthmatics. A similar relationship in children with difficult asthma (DA), in whom RBM thickening is a known feature, may allow the use of HRCT as a non-invasive marker of airway remodelling. We evaluated this relationship in children with DA. METHODS: 27 children (median age 10.5 [range 4.1-16.7] years) with DA, underwent endobronchial biopsy from the right lower lobe and HRCT less than 4 months apart. HRCTs were assessed for bronchial wall thickening (BWT) of the right lower lobe using semi-quantitative and quantitative scoring techniques. The semi-quantitative score (grade 0-4) was an overall assessment of BWT of all clearly identifiable airways in HRCT scans. The quantitative score (BWT %; defined as [airway outer diameter - airway lumen diameter]/airway outer diameter x100) was the average score of all airways visible and calculated using electronic endpoint callipers. RBM thickness in endobronchial biopsies was measured using image analysis. 23/27 subjects performed spirometry and the relationships between RBM thickness and BWT with airflow obstruction evaluated. RESULTS: Median RBM thickness in endobronchial biopsies was 6.7(range 4.6-10.0) microm. Median qualitative score for BWT of the right lower lobe was 1(range 0-1.5) and quantitative score was 54.3 (range 48.2-65.6)%. There was no relationship between RBM thickness and BWT in the right lower lobe using either scoring technique. No relationship was found between FEV1 and BWT or RBM thickness. CONCLUSION: Although a relationship between RBM thickness and BWT on HRCT has been found in adults with asthma, this relationship does not appear to hold true in children with DA.

Adolescent↗
PubMed2006

Safety of endobronchial biopsy in children with cystic fibrosis.

There is little found in the published literature regarding the use of endobronchial biopsy (EBB) in children with cystic fibrosis (CF). One concern over the use of the technique may relate to safety, in particular increased risk of bleeding from a hypertrophied bronchial circulation. The aim of this retrospective study was to compare the safety of EBB in children with CF and those with other conditions, the most frequent of which included primary ciliary dyskinesia and recurrent lower respiratory tract infections. Case notes of all children undergoing EBB in our institution between February 2003 and May 2004 were reviewed. EBB was performed during 45 bronchoscopies in 42 CF patients (19 males, group mean age 7.13 +/- 4.48 years) and in 39 controls (20 males, group mean age 6.59 +/- 4.48 years). There were no significant differences between disease groups in the number, type, or severity of complications occurring during or in the first 12 hr after the procedure. We conclude that EBB performed as part of fibreoptic bronchoscopy (FOB) under general anaesthesia can be performed safely in children with CF, when both bronchoscopist and anaesthetist are suitably experienced. Studies of such samples would allow us to determine the early pathological changes in the CF airway and possibly find new treatments to prevent the progression to bronchiectasis and end stage airway destruction.

Anesthesia, General↗
PubMed2006

Cystic fibrosis presenting with haematological abnormalities.

Although cystic fibrosis (CF) is common, the diagnosis (and subsequent treatment) may be delayed if the presentation is atypical. We present three cases of children with CF who presented with haematological abnormalities. In all cases, they underwent extensive and invasive investigations prior to the diagnosis.

Anemia↗
PubMed2006

Investigation of young children with severe recurrent wheeze: any clinical benefit?

The management of young children with severe recurrent wheeze is difficult because symptoms are often refractory to conventional asthma therapy and other diagnoses must be excluded. The present authors aimed to evaluate the outcome of detailed, invasive investigations in such patients. Children aged between 3 months and 5 yrs with severe recurrent wheezing, who had been referred to a tertiary centre, underwent a protocol of investigations including a chest computed tomography scan, blood tests, nasal ciliary brushings, fibreoptic bronchoscopy, bronchoalveolar lavage (BAL), endobronchial biopsy and passage of an oesophageal pH probe. A total of 47 children (25 males) with a median age of 26 (range 5-58) months underwent investigation. Of these, 39% were atopic, two-thirds had evidence of gastro-oesophageal reflux and 37 out of 47 had an abnormal bronchoscopy. Findings included structural abnormalities (13 out of 37), excessive mucus (20 out of 37) and macroscopic inflammation (10 out of 37). BAL revealed bacterial growth in 12 out of 44 (27%) patients. Good quality endobronchial biopsies were obtained from 36 out of 46 (78%) patients; of these, 44% had tissue eosinophilia and 28% had a thickened reticular basement membrane. Additional investigations (including bronchoscopy) in young children with severe wheeze may help to identify positive diagnoses and provide information to support a clinical diagnosis of asthma. This hypothesis-generating work should form the basis of future interventional studies.

Asthma↗
PubMed2005

A video questionnaire identifies upper airway abnormalities in preschool children with reported wheeze.

BACKGROUND: Accurate characterisation of subjects is essential to interpret data from studies investigating preschool wheezing. AIM: To assess whether a video questionnaire (VQ) identifies upper airway abnormalities in preschool children with reported wheeze. METHODS: Forty three children (median age 17 months, range 3-58) undergoing fibreoptic bronchoscopy for clinical investigation of troublesome noisy breathing at a tertiary centre were studied. Parents were shown a VQ with four clips (wheeze, stridor, and two other upper respiratory noises) and chose the clip(s) resembling their child's main symptom. Doctor observed symptoms, parental reported symptoms, and symptoms identified on VQ were related to bronchoscopy. RESULTS: Thirty subjects had wheeze as the main symptom: 19 had doctor observed wheeze (DOW) and 11 had parental reported wheeze (RW). Parents of two of the subjects with RW identified wheeze alone on VQ and both had normal bronchoscopic findings. Five of the remaining nine subjects with RW had upper airway abnormalities at bronchoscopy. Parents of six subjects with RW identified a noise other than wheeze on VQ; four of these had upper airway abnormalities. Parents of two subjects with RW did not identify a noise on VQ; one had upper airway abnormalities. Of the 19 with DOW, nine parents identified wheeze alone on VQ, and all had a normal upper airway. Parents of nine subjects with DOW identified a noise other than wheeze as an equal or only symptom, (no noise identified in one), and five had upper airway abnormalities. CONCLUSION: A VQ helps to identify upper airway abnormalities in preschool children with a history of wheezing.

Airway Obstruction↗
PubMed2005

Nitric oxide levels and ciliary beat frequency in indigenous New Zealand children.

New Zealand children's morbidity from respiratory disease is high. This study examines whether subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. A prospective study enrolled a group of healthy children who were screened for respiratory disease by questionnaire and lung function. Skin-prick tests were performed to control for atopy. Exhaled and nasal NO was measured online by a single-breath technique using chemiluminescence. Ciliary specimens were obtained by nasal brushings for assessment of structure and function. The ciliary beat frequency (CBF) (median CBF, 12.5 Hz; range, 10.4-16.8 Hz) and NO values (median exhaled NO, 5.6 ppb; range, 2.3-87.7 ppb; median nasal NO, 403 ppb; range, 34-1,120 ppb) for healthy New Zealand European (n=58), Pacific Island (n=61), and Maori (n=16) children were comparable with levels reported internationally. No ethnic differences in NO, atopy, or CBF were demonstrated. Despite an apparently normal ciliary beat, the percentage of ciliary structural defects was 3 times higher than reported controls (9%; range, 3.6-31.3%), with no difference across ethnic groups. In conclusion, it is unlikely that subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. The high percentage of secondary ciliary defects suggests ongoing environmental or infective damage.

Adolescent↗
PubMed2005

Rapidly progressive lung disease in a patient with cystic fibrosis on long-term azithromycin: possible role of mycoplasma infection.

Macrolides is effective therapy in patients with cystic fibrosis (CF). We describe a girl with CF given long-term azithromycin who died of rapidly progressive lung disease. She was found to have rising titers of mycoplasma serology, suggesting a possible causative role of a resistant mycoplasma infection. Mycoplasma infection should be considered in CF patients who are deteriorating, even if they are being treated with macrolides, to which these organisms are usually susceptible.

Adolescent↗
PubMed2005

Respiratory management of the infant with type 1 spinal muscular atrophy.

A recent paper has highlighted the differences in the respiratory management offered to infants with type 1 spinal muscular atrophy (SMA-1). Current views appear polarised between those who would offer nothing, to those who would proceed as far even as tracheostomy and long term invasive ventilation for these infants. Here we offer a personal view, as a possible template for managing a vexed and emotional problem. The complex non-respiratory aspects of the holistic care of these infants will not be discussed.

Humans↗
PubMed2005

How has research in the last five years changed my clinical practice?

UNLABELLED: The first instruction to examination candidates is to read and answer the question actually set. Doing so in this case leads to the following CONCLUSIONS: how research has changed my clinical practice includes the act of doing research, as well as reading about the work of others. Thus, this article refers to my own clinical practice (tertiary referral paediatric respiratory medicine in a setting where we do not service an accident and emergency department), rather than that of others. This means excluding important conditions such as acute croup and uncomplicated community acquired pneumonia. I should write about what has changed my practice, not what other people think I ought to have changed. So this will be a personal view, limited to research published in a peer review format at the time of writing. I shall also assume that change is an ongoing process, so I shall include change in progress, provided it is supported by published literature.

Asthma↗
PubMed2005

Non-CF bronchiectasis: does knowing the aetiology lead to changes in management?

The aim of the current study was to review the aetiology of non-cystic fibrosis (CF) bronchiectasis from two tertiary paediatric respiratory units in order to determine how often making a specific aetiological diagnosis leads to a change in management, and to assess the contribution of computed tomography (CT) in determining the underlying diagnosis. The case records of all patients who were diagnosed as having bronchiectasis by CT, currently being seen at the Royal Brompton Hospital and Great Ormond Street Hospital for Children (London, UK), were reviewed. All patients had undergone extensive investigations, and the underlying aetiology and the area of pulmonary involvement (as seen on CT) were recorded. A total of 136 patients were identified; there were 65 young males and the group median (range) age was 12.1 yrs (3.1-18.1). Immunodeficiency, aspiration and primary ciliary dyskinesia accounted for 67% of the cases. In 77 (56%) children, the identification of a cause led to a specific change in management. There was no association between aetiology and the distribution of CT abnormalities. In conclusion, immunodeficiency and other intrinsic abnormalities account for the majority of cases of non-cystic fibrosis bronchiectasis seen in the current authors' units. Computed tomography scans do not contribute towards identifying the aetiology and, most importantly, a specific aetiological diagnosis frequently leads to a change in management.

Adolescent↗
PubMed2004

Competition between helimagnetism and commensurate quantum spin correlations in LiCu2O2.

Neutron diffraction and bulk measurements are used to determine the nature of the low-temperature ordered state in LiCu2O2, a S=1/2 spin-chain compound with competing interactions. The spin structure is found to be helimagnetic, with a propagation vector (0.5,zeta,0), zeta=0.174. The nearest-neighbor exchange constant and frustration ratio are estimated to be J(1)=5.8 meV and J(2)/J(1)=0.29, respectively. For idealized quantum spin chains, these parameter values would signify a gapped spin-liquid ground state with commensurate spin correlations. The observed temperature dependence of the magnetic propagation vector in LiCu2O2 is attributed to a competition between incommensurate helimagnetism in the classical spin model and commensurability in the quantum case. It is also proposed that long-range ordering in LiCu2O2 is facilitated by intrinsic nonstoichiometry.

Journal Article↗
PubMed2004

Serum vitamin D levels in children with cystic fibrosis.

Osteopenia is increasingly recognized in adults with cystic fibrosis (CF), and is potentially related to vitamin D deficiency in both adulthood and childhood. Vitamin D supplements are recommended and prescribed to all pancreatic-insufficient patients. We aimed to ascertain whether vitamin D deficiency in children with CF was prevalent. 25-hydroxyvitamin D (25-OHD) was measured in 290 children attending a specialist pediatric CF clinic for annual assessment. 25-OHD levels were compared with reference values and to other biochemical markers, lung function, and growth. Levels were also analyzed by pancreatic status and by the presence of CF-related liver disease. Median 25-OHD was 65 (range, 9-190) nmol/l. One percent had levels below 15 nmol/l, and 6% had levels less than 25 nmol/l. Levels were lower in adolescents (P < 0.001) and during the "winter" months (P < 0.001). No relationship was found with pancreatic status or liver disease. In conclusion, the majority of children had normal 25-OHD levels. Interpretation is difficult due to a lack of knowledge of optimal levels of 25-OHD required for healthy bone accretion. Lower levels in adolescents may be a precursor to low levels in adulthood, and did not seem to be simply related to poor compliance with supplementation. This may reflect normal physiology.

Adolescent↗
PubMed2004

Wheeze detection: recordings vs. assessment of physician and parent.

BACKGROUND: Parental and professional agreement as to the presence of wheezing in infants and preschool children has been shown to be poor. Agreement on the absence or presence of physical signs on chest examination in these populations is far from perfect, even among experienced physicians. OBJECTIVES: We sought to compare the assessment of a parent, nurse, and physician with the "gold standard" of acoustic analysis for the presence of wheezing in infants and preschool children attending a hospital clinic. SETTING AND SUBJECTS: Urban district general hospital in North London, England. Wheezy children under 6 years old attending a "walk-in" emergency pediatric ambulatory care unit. RESULTS: Comparisions were completed on 31 children (age range 4-62 months). The severity of wheeze was independently evaluated by a parent, nurse, and experienced pediatrician, and these were compared with breath sounds recorded and analyzed by acoustic techniques for the presence and severity of wheezing. In only 10 of 31 (32%) children did the parent and the physician agree on the wheeze severity score. In 13 infants, the parent scored higher than the doctor and in 8 the parent scored lower. In 16 (52%) of the children, there was complete agreement as to the severity of wheezing by the nurse and the physician. In 24 of the 31 children (77%), the acoustic wheeze score agreed with the physician wheeze score; in 6 children the acoustic score was lower and in 1 it was higher. CONCLUSIONS: The physician was able reliably to judge the severity of wheeze measured objectively, whereas nurses and parents were not. This study has important implications for the interpretation of parental questionnaire studies of asthma prevalence and severity.

Acoustics↗
PubMed2004

Intravenous immunoglobulin for cystic fibrosis lung disease: a case series of 16 children.

BACKGROUND AND OBJECTIVE: Some children with severe cystic fibrosis (CF) lung disease develop chest tightness, recurrent dry cough, and intractable wheeze, often accompanied by deteriorating lung function and failure to expectorate sputum. In an attempt to reduce the use of regular oral corticosteroids, we treated a group of such children with monthly courses of intravenous immunoglobulin (IVIG). METHODS: This is a retrospective case note review of 16 children, aged 3-16 years (median 13.0 years) who received 1-66 (median 7.5) courses of monthly IVIG, at a dose of 1 g/kg on two successive days for the first dose, followed by 1 g/kg monthly as a 12 hour infusion, with corticosteroid and antihistamine cover. RESULTS: FEV1 improved from a median (95% confidence interval (CI)) of 50% (39 to 61%) to 54% (48 to 66%), with a median (95% CI) difference of +7.5% (-1.5 to 14.5%; NS). FVC improved from 65% (60 to 77%) to 83% (70 to 89%), with a difference of +13% (4 to 22%, p = 0.01). The total daily dose/kg body weight of oral prednisolone was reduced from 0.6 (0.3 to 1.0) to 0 (0 to 0.1) mg/kg/day, with a reduction of -0.6 (-1.0 to -0.1, p = 0.006) mg/kg/day. The total daily dose of inhaled corticosteroid (budesonide equivalent) was a median (range) of 2000 microg (800-6000 microg), which was reduced to 1500 microg (0-3200 microg). The median (95% CI) difference was -400 microg (-1600 to 0 microg), p<0.05. IVIG was well tolerated and the regimen acceptable to all but one of the children. The following transient adverse reactions were seen in only one patient each: headache, fever, hypotension, aseptic meningitis, and chest tightness. CONCLUSION: We suggest that an n = 1 trial of IVIG in carefully selected patients with severe obstructive CF lung disease is worth considering, as for some it may lead to significant benefit.

Adolescent↗
PubMed2004

Longitudinal study of grass pollen exposure, symptoms, and exhaled nitric oxide in childhood seasonal allergic asthma.

BACKGROUND: Exhaled nitric oxide (NO) has been proposed as a marker of airway eosinophilic inflammation in asthma. There is currently a paucity of longitudinal data relating it to allergen exposure and asthma symptoms. METHODS: Forty four children (6-16 years) with seasonal allergic asthma were sequentially followed before and during the grass pollen season. Asthma symptoms, lung function, NO levels, and pollen counts were recorded. The relationship between exhaled NO and both the pollen levels and asthma control were assessed longitudinally, comparing a subject's measurements with their previous ones. RESULTS: The median exhaled NO concentration was significantly increased during the pollen season (6.2 v 9.2 parts per billion (ppb), p<0.002; median change 2.9 ppb, 95% confidence interval 1.5 to 5.4). Exhaled NO was best associated with the mean pollen count in the week before measurement. It was also significantly associated with asthma control. CONCLUSIONS: The results suggest that, within a longitudinal model, the exhaled NO concentration is related to preceding allergen exposure and asthma control. It may be clinically more useful to compare exhaled NO values with a subject's previous values than to compare them with a population based normal range.

Adolescent↗