Search PubMed⌕ Search

Biomedical subjects

P D Bridge

Publications and source records attributed to P D Bridge.

At least 19 recordsLinked to original sources
PubMed2005

Skin-prick testing as a diagnostic aid for childhood asthma.

Diagnosing asthma is problematic when based solely on reported symptoms. The purpose of this study was to evaluate skin-prick testing as a diagnostic aid for asthma in children. Skin-prick testing (SPT) was undertaken in children aged 2-10 years with either no history of wheeze (n = 149) or recent doctor-observed wheeze which responded to treatment with a bronchodilator, the "gold standard" (n = 164). Children with moderate or severe asthma were excluded. SPT positivity increased sharply at age 5 years in wheezers. Data were therefore divided into two age groups: 2- < 5 years (57 controls, 97 wheezers) and 5-10 years (92 controls, 67 wheezers). The sensitivity, specificity, and likelihood ratios of SPT positivity for wheeze were 32%, 89%, and 2.9, respectively, in the younger children, and 82%, 85%, and 5.5, respectively, in the older children. For a prevalence of 30% for asthma, the positive predictive values of a positive SPT were 55% and 70% for the younger and older age groups, respectively. The test characteristics of SPT for helping diagnose asthma in schoolchildren are good. The prevalence of wheeze in preschool children is high, and so SPT should be helpful even in this group. We suggest that clinicians consider skin-prick testing as a diagnostic aid for asthma.

Age Factors↗
PubMed2005

Following basal stem rot in young oil palm plantings.

The PCR primer GanET has previously been shown to be suitable for the specific amplification of DNA from Ganoderma boninense. A DNA extraction and PCR method has been developed that allows for the amplification of the G. boninense DNA from environmental samples of oil palm tissue. The GanET primer reaction was used in conjunction with a palm-sampling programme to investigate the possible infection of young palms through cut frond base surfaces. Ganoderma DNA was detected in frond base material at a greater frequency than would be expected by comparison with current infection levels. Comparisons are made between the height of the frond base infected, the number of frond bases infected, and subsequent development of basal stem rot. The preliminary results suggest that the development of basal stem rot may be more likely to occur when young lower frond bases are infected.

Age Factors↗
PubMed2005

Ganoderma diseases of perennial crops in India--an overview.

The species of Ganoderma recorded from India as causing diseases of perennial crops are listed, and their host range and taxonomy discussed. Four new hosts of G. lucidum are also reported. A decline in productivity and the death of trees are the main economic impacts due to Ganoderma diseases, and the fungus is identified as a serious pathogen of cash crops, forest plantations and trees in natural forests in the country. Ganoderma diseases have been recorded on 144 hosts in India, the major pathogens being G. lucidum and G. applanatum. G. lucidum has been recorded on 91 hosts, and appears to cause the most widespread diseases. Identification has largely been made from morphological and cultural characters, and the names currently in use should therefore be treated with caution. Cultural methods of disease control are largely inefficient in minimising inoculum pressure and in reducing the disease incidence. Chemical methods in combination with soil amendments form short-term solutions for managing the disease and improving productivity. The immediate priorities for developing an efficient management system for Ganoderma diseases in India are: (1) a thorough understanding of the etiology and epidemiology of the diseases on different hosts, (2) clarifying current ambiguity in species names, (3) assessing the inter-relationships between populations of Ganoderma on different hosts and (4) developing tools for early detection of diseases in important crops.

Ganoderma↗
PubMed2005

Diagnostic accuracy of bronchodilator responsiveness in wheezy children.

BACKGROUND: The aim of this study was to evaluate the diagnostic accuracy of bronchodilator responsiveness for asthma in 5-10 year old children. METHODS: Spirometric measurements were made in 142 children (58 wheezers) before and after 400 mug inhaled salbutamol. RESULTS: On a receiver operating characteristic curve, a 9% increase in predicted forced expiratory volume in 1 second was the cut off point that provided an acceptable balance of sensitivity and specificity for previous wheeze. This figure was 50% (95% CI 38 to 62) sensitive and 86% (95% CI 78 to 92) specific for detecting previous wheeze and multiplied the initial odds in favour of wheeze by a factor of 3.6 (95% CI 2.0 to 6.3). DISCUSSION: With an estimated pretest probability of wheeze of 10% in the community and 50% in a specialist clinic, the positive predictive values are 29% and 78%, respectively, for a 9% change. The value of bronchodilator responsiveness testing depends on the prevalence of wheeze in the population in which it is to be used.

Administration, Inhalation↗
PubMed2005

The secretin G-protein-coupled receptor family: teleost receptors.

Twenty-one members of the secretin family (family 2) of G-protein-coupled receptors (GPCRs) were identified via directed cloning and data-mining of the Fugu Genome Consortium database, representing the most comprehensive description of secretin GPCRs in a teleost fish to date. Duplicated genes were identified for many of the family members, namely the receptors for pituitary adenylate cyclase-activating polypeptide (PACAP)/vasoactive intestinal peptide (VIP), calcitonin, calcitonin gene-related peptide (CGRP), growth hormone releasing hormone (GHRH), glucagon receptor/glucagon-like peptide (GLP) and parathyroid hormone-related peptide (PTHrP)/PTH. Mining of other teleost genomes (zebrafish and Tetraodon) revealed that the duplicated genes identified in the Takifugu genome were also present in these fish. Additional database searching of the Escherichia coli, yeast, Drosophila, Caenorhabditis elegans and Ciona genomes revealed that the family 2 of GPCRs were only present in the multicellular organisms. Orthologues of all the human secretin receptors were identified with the exception of secretin itself. Additional database searches in the Fugu Genome Consortium database also failed to reveal a secretin ligand and so it is hypothesised that both the receptor and the ligand evolved after the divergence of teleost/tetrapod lineages. Phylogenetic analysis at both the protein and the DNA level provided strong support for each of the individual receptor family groupings, but weak support between groups, making evolutionary inferences difficult. A more critical analysis of the PACAP/VIP receptor family confirmed previous hypotheses that the vasoactive intestinal peptide receptor (VPAC(1)R) gene is the ancestral form of the receptor.

Animals↗
PubMed2003

Molecular relatedness within the "Ascochyta pinodes-complex".

The morphological, molecular and pathological characters of 34 isolates identified as Ascochyta pinodes, A. phaseolorum, and Phoma medicaginis var. pinodella were determined. Initial molecular findings, based on PCR fragment size and RFLPs of sections of the mitochondrial genome, the rRNA gene cluster and the beta-tubulin gene complex, were further investigated by sequencing of the total rRNA ITS regions. Isolates were homogenous for all characteristics determined, with the exception of conidial size and septation, and RFLPs of AT rich (presumptive mitochondrial) DNA. The results suggest that the isolates represent host preferential forms of a single taxon, and this finding is discussed in relation to the known teleomorphs and reference material of the species studied.

Ascomycota↗
PubMed2003

Repeatability of airway resistance measurements made using the interrupter technique.

BACKGROUND: To be able to interpret any measurement, its repeatability should be known. This study reports the repeatability of airway resistance measurements using the interrupter technique (Rint) in children with and without respiratory symptoms. METHODS: Children aged 2-10 years who were healthy, had persistent isolated cough, or who had previous wheeze were studied. On the same occasion, three Rint measurements were made 15 minutes apart, before and after placebo and salbutamol given in random order. Results from those given placebo first were analysed for within-occasion repeatability. Between-occasion repeatability measurements were made 2-20 weeks apart (median 3 weeks). RESULTS: For 85 pairs of measurements before and after placebo the limits of agreement were 20% expected resistance and were unaffected by age or health status. The change in resistance following bronchodilator in one of 18 healthy children, 12 of 28 with cough, and 22 of 39 with wheeze exceeded this threshold. For between-occasion measurements the limits of agreement were 32% in 72 healthy subjects, 49% in 57 with cough, and 53% in 95 with previous wheeze. CONCLUSION: The measurement of airways resistance by the interrupter technique is clinically meaningful when change following an intervention such as the administration of bronchodilator is greater than its within-occasion repeatability. Between-occasion repeatability is too poor to judge change confidently.

Airway Resistance↗
PubMed2002

Phenotypic degeneration occurs during sector formation in Metarhizium anisopliae.

AIMS: The formation of sectors was observed during subculturing of an isolate of the entomopathogenic fungus Metarhizium anisopliae, a fungus used for biological control of insect pests. The aim of the investigation was to establish whether sector formation was accompanied by changes in physiological characters. METHODS AND RESULTS: Four degenerative morphological states, with reduced sporulation capacity, were characterized. Subcultures were taken from each sector and four new culture lines established. The new lines were further subcultured every 21 d. A physiological assessment of each line was undertaken after 42 d using TLC of secondary metabolites and fluorogenic enzyme tests. Full sporulation capacity was not regained on subculture, although some cultures recovered partially. Changes in secondary metabolite profiles and the loss in detection of activity of specific enzymes were observed. CONCLUSIONS: Sector formation was frequently accompanied by changes in the ability to produce secondary metabolites and enzymes. SIGNIFICANCE AND IMPACT OF THE STUDY: The results illustrate the importance of maintaining the stability of important cultures during routine subculture. The consequences could have significant implications if degenerate cultures are used as inocula for liquid fermentation cultures or industrial scale production.

Enzymes↗
PubMed2002

Airway resistance measured by the interrupter technique: normative data for 2-10 year olds of three ethnicities.

BACKGROUND AND AIMS: The measurement of airway resistance using the interrupter technique (R(int)) is feasible in preschool children and other subjects unable to undertake spirometry. This makes it potentially useful for the measurement of lung function in these groups. Commercial devices use different algorithms to measure pressure and flow from which R(int) is derived. This study provides normative values for British children using devices from a single manufacturer. METHODS: R(int) was measured in 236 healthy children of three ethnic groups (Afro-Caribbean and black African, Bangladeshi, and white British) aged 2-10 years using Micro Medical devices. Software in the devices calculated R(int) from pressure measured by the two point, back extrapolation method from the pressure transient during valve closure, with flow measured just before valve closure. RESULTS: R(int) is related to both age and height, but when age is allowed for there is not a significant relation with height. Neither gender nor any of the ethnicities studied was significantly related to R(int). DISCUSSION: These measurements in healthy children using this technique may be used as reference data for similar populations.

Aging↗
PubMed2001

Lung function tests for pre-school children.

There are a few devices for measuring lung function in pre-school children. Neither the interrupter technique nor the forced oscillation techniques have been standardised. We highlight some of the issues around the measurement of airway resistance using the interrupter technique and emphasise that, as with other lung function measurements, operators should have a proper understanding of the methods before they can be applied. Both methods for measuring airway resistance have potential for clinical and research application.

Airway Resistance↗
PubMed2001

Bronchodilator responsiveness and atopy in 5-10-yr-old coughers.

Cough-variant asthma is considered by some to be an asthma phenotype. Bronchodilator responsiveness (BDR) is an undisputed feature of asthma. Of school-aged wheezers, 90% are atopic. Are school-aged coughers who demonstrate BDR also atopic? If so, then it would be reasonable to reserve the diagnosis cough-variant asthma for this particular group. Airway resistance was measured by the interrupter technique (Rint) before and after salbutamol in controls (n=73), coughers (n=63) and previous wheezers (n=63) aged 5-10 yrs. Immunoglobulin (Ig)-E was measured in coughers and wheezers. BDR was expressed as the ratio baseline:post-salbutamol Rint. Groups were of similar age (mean 6.7, range 5-9.9 yrs). Geometric mean baseline Rint was similar in controls and coughers (0.66 and 0.68 kPa x L(-1) x s), but the baseline Rint for wheezers (0.73 kPa x L(-1) s) was greater than that for controls (p=0.05) but not significantly different from coughers (p=0.17). Geometric mean BDR in coughers was 1.22, controls 1.13 and wheezers 1.30 (p=0.01 for coughers and controls; p=0.08 for coughers and wheezers; p<0.001 for controls and wheezers). IgE was lower in coughers than wheezers (geometric means 36 and 364 International Units (IU) x L(-1), p<0.001) and was unrelated to BDR in both groups. In summary, atopy, and not bronchodilator responsiveness, distinguishes groups of coughers from groups of wheezers. A diagnosis of cough-variant asthma cannot be reserved for even those school-aged coughers, who demonstrate bronchodilator responsiveness.

Airway Resistance↗
PubMed2001

Airway resistance measured by the interrupter technique: expiration or inspiration, mean or median?

The measurement of airway resistance by the interrupter technique (Rint) needs standardization. Should measurements be made be during the expiratory or inspiratory phase of tidal breathing? In reported studies, the measurement of Rint has been calculated as the median or mean of a small number of values, is there an important difference? Subjects were 2.5-5.0 yrs (median 4.0 yrs) who had previous respiratory symptoms. The Rint in expiration (RintE) and inspiration (RintI) pre and postsalbutamol, the coefficient of variation (CV) of values contributing to measurements, and bronchodilator responsiveness(BDR) in both phases were compared. Measurements using median and mean were compared. RintE was higher than RintI by 4% (p < 0.01). The CV of values making up RintE and RintI, and BDR measured in expiration and inspiration were similar. The median difference between means and medians of values making up measurements was 0.6% (range -6-11%). RintE has been shown to be consistently greater then RintI but the difference in this study is small. It is suggested that one or the other is chosen as the standard. In the present data the mean of a set of values contributing to a measurement was not significantly different from the median. However, the use of the median has been recommended since it is less affected by possible outlying values such as might be included by fully automated equipment.

Airway Resistance↗
PubMed2000

Airway resistance and atopy in preschool children with wheeze and cough.

The extent to which the measurement of airways resistance by the interrupter technique (Rint) distinguishes preschool children with previous wheeze from those with no respiratory symptoms and helps to classify subjects with persistent cough, was investigated. Rint was measured before and after salbutamol treatment in 82 children with recurrent wheeze, 58 with isolated cough and 48 with no symptoms (control subjects). Their mean age (range) was 3.7 yrs (2-<5 yrs). Median baseline Rint was higher (p<0.0001) in wheezers than in either coughers or control subjects (1.16, 0.94 and 0.88 kPa x L(-1) x s(-1) respectively); coughers did not differ significantly from control subjects (p=0.14). The median ratios of baseline to post-salbutamol measurements (bronchodilator response (BDR)) in the groups differed significantly (1.40, 1.27 and 1.07, p< or =0.01 for all), suggesting that coughers occupy an intermediate position. A BDR ratio of >1.22 had a specificity and sensitivity for wheeze of 80% and 76% respectively. Twenty-eight coughers had a BDR ratio >1.22. Wheezers' immunoglobulin E was inversely related to baseline Rint. It is concluded that measurements of airway resistance by the interrupter technique are useful for classifying preschool children with respiratory symptoms and could be used to monitor the effect of interventions. The relation between atopy and airways resistance suggests that they have separate roles in preschool wheezing. Coughers with a high bronchodilator response could represent "cough-variant" asthma in children who have baseline airway resistance by the interrupter technique measurements similar to control subjects. Whether these children develop classical asthma will only be known at follow-up later in childhood.

Airway Resistance↗
PubMed2000

Using evaluation methods to guide the development of a tobacco-use prevention curriculum for youth: a case study.

BACKGROUND: Fundamental to the development of educational programs and curricula is the evaluation of processes and outcomes. Unfortunately, many otherwise well-designed programs do not incorporate stringent evaluation methods and are limited in measuring program development and effectiveness. Using an advertising lesson in a school-based tobacco-use prevention curriculum as a case study, the authors examine the role of evaluation in the development, implementation, and enhancement of the curricular lesson. METHODS: A four-phase formative and summative evaluation design was developed to divide the program-evaluation continuum into a structured process that would aid in the management of the evaluation, as well as assess curricular components. RESULTS AND CONCLUSIONS: Formative and summative evaluation can provide important guidance in the development, implementation, and enhancement of educational curricula. Evaluation strategies identified unexpected barriers and allowed the project team to make necessary "time-relevant" curricular adjustments during each stage of the process.

Adolescent↗
PubMed2000

Terminal-sequence conservation identifies spliceosomal introns in ascomycete 18S RNA genes.

Twenty-four new insertions were obtained from seven different locations in the nuclear 18S rDNA for seven species of the lichen-forming fungal genus PHYSCONIA: They were analyzed allowing for terminal sequence conservation by adopting a flexible approach to exact insertion site position, and they were compared with 12 previously reported small insertion sequences from the 18S ribosomal RNA gene. Such insertions have previously been proposed to be degenerate self-splicing group I introns; however, the methodology used here identified consensus terminal sequences characteristic of spliceosomal introns. This finding is the first suggestion that multiple spliceosomal introns occur in ribosomal genes.

Ascomycota↗