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Biomedical subjects

J A Wilson

Publications and source records attributed to J A Wilson.

At least 37 records · Page 2Linked to original sources
PubMed2004

Weight prediction from linear measures of growing Thoroughbreds.

REASON FOR PERFORMING STUDY: Monitoring weight of foals is a useful management practice to aid in maximising athletic potential while minimising risks associated with deviations from normal growth. OBJECTIVE: To develop predictive equations for weight, based on linear measurements of growing Thoroughbreds (TBs). METHODS: Morphometric equations predicting weight from measurements of the trunk and legs were developed from data of 153 foals. The accuracy, precision and bias of the best fitting equation were compared to published equations using a naive data set of 22 foals. RESULTS: Accuracy and precision were maximised with a broken line relating calculated volumes (V(t + l)) to measured weights. Use of the broken line is a 2 step process. V(t + l) is calculated from linear measures (m) of girth (G), carpus circumference (C), and length of body (B) and left forelimb (F). V(t + I) = ([G2 x B] + 4[C2 x F]) 4pi. If V(t + l) < 0.27 m3, weight is estimated: Weight (kg) = V(t + l) x 1093. If V(t + l) > or = 0.27 m3: Weight (kg) = V(t + l) x 984 + 24. The broken line was more accurate and precise than 3 published equations predicting the weight of young TBs. CONCLUSIONS: Estimation of weight using morphometric equations requires attention to temporal changes in body shape and density; hence, a broken line is needed. Including calculated leg volume in the broken line model is another contributing factor to improvement in predictive capability. POTENTIAL RELEVANCE: The broken line maximises its value to equine professionals through its accuracy, precision and convenience.

Animal Nutritional Physiological Phenomena↗
PubMed2003

The reliability of three perceptual evaluation scales for dysphonia.

Perceptual rating scales are widely used in voice quality assessment, yet apart from the GRBAS scale, their reliability has been poorly demonstrated. There are no studies that have compared the optimal reliability of experienced judges using different auditory rating scales in a controlled experimental environment. This study aimed to assess the reliability of three common scales (The Buffalo Voice Profile, The Vocal Profile Analysis Scheme (VPA) and GRBAS. Sixty-five varyingly dysphonic and five normal voices were recorded onto CD in random order. Thirty voices were recorded twice. Seven experienced and trained speech and language therapists rated all voices on the three scales. Only the overall grade was found to be reliable for the Buffalo Voice Profile. The reliability of the VPA scheme was found to be poor to moderate. The VPA may have a use as a multi-dimensional and in-depth evaluation of voice types, but its greater scope is at the expense of reliability. The GRBAS was reliable across all parameters except Strain. Our detailed reliability analysis comparing performance of three commonly used rating scales provides further evidence to support the GRBAS as a simple reliable measure for clinical use.

Adolescent↗
PubMed2003

Vibrating membrane filtration for recovery and concentration of insect killing nematodes.

New experimental data are reported that demonstrate the use of a novel vibrating membrane filter (VMF) for the combined recovery and concentration of two species of nematodes, S. feltiae and P. hermaphrodita, from mature liquid fermentation cultures. The disk membrane module had a working surface area of 0.2 m(2) and was operated at a constant flow rate of 0.2 m(3) h(-1). The recovery of the viable nematodes from the spent media and nonviable nematodes was assisted by an independently imposed oscillatory motion of the disk assembly, which produced an intense shear field at the membrane surface with calculated mean values on the order of 10(4) s(-1). Adult (nonviable) nematodes in the fermentation culture were preferentially dissolved in a detergent (sodium dodecylsulfate) and successfully separated from the juveniles using the VMF equipment. Permeate fluxes on the order of 15 to 30 L/m(2/)h were achieved for an operating transmembrane pressure of 800 mbar. Industrial-scale liquid fermentation for the manufacture of nematodes as biopesticides produces the viable nematode life stages in low-concentration suspension containing large quantities of spent media and other waste material. The VMF equipment provided a flexible operation for separation, cleaning, and concentration of viable nematodes from the fermentation broths.

Animals↗
PubMed2003

Management and outcome of bloodstream infections due to Candida species in England and Wales.

This two-year prospective hospital population-based study of candidaemia is the first to be conducted in the UK. It was carried out on behalf on the British Society for Medical Mycology (BSMM) as part of the European Confederation of Medical Mycology (ECMM) epidemiological survey of candidaemia. Six hospitals in England and Wales acted as sentinel hospitals. Main outcome measures were hospital population-based incidence and 30-day mortality. There were 18.7 episodes of candidaemia per 100,000 finished consultant episodes or 3.0/100,000 bed days and 45.4% cases occurred in intensive care unit (ICU) patients. Candida albicans was isolated in 64.7% of confirmed cases. The majority of isolates were sensitive to standard antifungal agents, including fluconazole. The overall 30-day mortality was 26.4% and removal of the central venous catheter was associated with a significant reduction in mortality. In conclusion, the incidence of candidaemia in England and Wales is similar to that of the USA, the majority of isolates remain sensitive to commonly used antifungal agents and mortality associated with this infection appears to be falling.

Adolescent↗
PubMed2003

Improving the analysis of small precipitates in HSLA steels using a plasma cleaner and ELNES.

The change from producing high strength low alloy (HSLA) steel sheet by conventional thick slab casting to producing it by direct charged thin slab casting causes a major change in the evolution of the precipitation. A key area of interest is the composition of the sub-10nm precipitates used to produce dispersion hardening. Carbon extraction replicas are frequently used to study precipitates in steels and other metals. When used with annular dark field imaging, this technique gives high contrast images of the precipitates while the thin carbon film adds little background or additional characteristic signals to either electron energy loss spectra or energy dispersive X-ray spectra. The method has the additional major advantage of removing the ferromagnetic matrix when studying HSLA steels. However, when the precipitates contain carbon, the C K-edge is dominated by the contribution from the amorphous carbon film. A plasma cleaner can be used to thin this carbon film to approximately 0.5 nm or less and then the contribution from the carbon in the precipitate can be separated from that in the carbon film using the electron energy loss near edge structure. A similar approach can be taken to separate the oxygen content of the precipitate from that of oxides formed from low-level impurities in the amorphous carbon during the plasma thinning process. In most cases, the precipitate studied here contained little or no oxygen even for the smallest sizes examined (approximately 4 nm). The precipitates contain mainly nitrogen with little carbon. For some compositions, the precipitates are clearly sub-stoichiometric.

Algorithms↗
PubMed2003

Sorption of Cu and Zn by bone charcoal.

Bone charcoal is being developed as a treatment for decontaminating polluted water. In particular, its potential to adsorb metal species from contaminated water supplies is being examined. In this study, bone charcoal was used in batch and column experiments designed to investigate the sorption of two cationic metals Cu and Zn. The data from batch experiments fitted the Langmuir isotherm and so theoretical maximum binding capacities could be obtained. These values were compared with experimental values derived from the column experiments. The mechanisms involved in the immobilisation were also investigated.

Adsorption↗
PubMed2003

A comparison of physician and patient perception of the problems of habitual snoring.

Assumptions are often made by doctors about the nature of the impact of uncomplicated snoring. The aim of this study was to provide a comprehensive view of the problems experienced by snoring patients, and to compare these with the perceptions of otolaryngologists. Part 1: 121 snorers and 419 otolaryngologists completed open-ended problems lists; Part 2: 56 snorers and 63 matched controls completed a mood questionnaire and the Golombok Rust Inventory of Marital State (GRIMS.) There was a clear agreement between snorers and otolaryngologists that sleep-related difficulties comprise the most frequent category of problems that may result from snoring. Snorers report a significantly greater number of physical problems and significantly fewer relationship problems than perceived by otolaryngologists. GRIMS scores were similar in patients and controls. Snorers, however, were significantly more depressed. Doctors appear to address snoring from the twin perspectives of damaged relationships and possible sleep apnoea. Their patients are more concerned about disturbing the sleep of others, and are subject to low mood. The snorers' 25 different responses are now being used as the basis for a Snoring Symptom Index.

Attitude↗
PubMed2003

The dysphonic voice heard by me, you and it: differential associations with personality and psychological distress.

Voice production is subject to and indicative of psychological status. The precise relationships of voice disorders and psychological variables remain unclear. We compared the correlations of self-reported and more objective measures of voice quality in dysphonic patients with personality, coping, affect and somatization. Two hundred and four subjects participating in a randomized, controlled trial of speech therapy underwent self-report, observer rating and computer acoustic analysis of voice quality. These three indices of voice quality were compared with regard to their correlations with individual differences in neuroticism, alexithymia, negative emotion coping, anxiety, depression, neurotic symptoms, medically unexplained symptoms and quality of life. Significant correlations were observed between self-reported voice problems and all of the personality/coping and clinical psychological distress measures. People who reported more voice problems had: higher neuroticism and alexithymia; a tendency to use emotion-oriented coping; more psychological distress; poorer quality of life; and more past medically unexplained symptoms. Expert voice rating correlated weakly with neurotic disturbance, quality of life and previous medically unexplained symptoms. Objective voice assessment (amplitude perturbation) showed no significant associations with any psychological measure. The strongest associations of psychological variables and voice measures are with self-report measures. This suggests that it is in part the patients' perception of their own voice quality which accounts for the association of voice production and psychological factors in subjects presenting to voice clinics.

Adolescent↗
PubMed2003

Subclinical aspirin sensitivity in subjects with nasal polyposis.

It is unclear whether subclinical airway responses to aspirin occur in subjects with nasal polyps and/or asthma without overt sensitivity. Sixty-three subjects without known aspirin sensitivity (13 controls, 17 nasal polyps alone, 15 nasal polyps and asthma and 18 asthma alone) inhaled increasing concentrations of nebulized lysine aspirin. Forced expiratory volume in 1 s (FEV1), symptoms and other potential markers of an airway response were measured. Four subjects (one polyps alone, one asthma alone, two with both) had a positive response to lysine aspirin predefined as symptoms plus a >10% fall in FEV1 from baseline. However, there was no evidence of a general subclinical response in any of the subject groups: mean (95% CI) change in FEV1; control 0.07 (-0.02,0.16) L, nasal polyps alone -0.05 (-0.16,0.05) L, nasal polyps with asthma -0.03 (-0.10,0.04) L, asthma alone -0.03 (-0.09,0.03) L. We concluded that in the absence of a suggestive clinical history, only a small proportion of patients with nasal polyposis are likely to be sensitive to aspirin. There is no evidence of general subclinical sensitivity to aspirin in subjects with nasal polyps and no relevant history.

Adult↗
PubMed2002

A fast beam switch for controlling the intensity in electron energy loss spectrometry.

The fast deflection system described in this paper is suitable for controlling the intensity reaching the detector of a magnetic sector electron spectrometer mounted below an analytical transmission electron microscope. Amongst other things, this allows the low loss region of the spectrum to be recorded with the same electron probe conditions used to record core losses, something that is essential for high spatial resolution studies. The plate assembly restricts the width of the electron distribution reaching the viewing screen to a strip approximately 17 mm wide in the direction approximately normal to the dispersion direction of the spectrometer. The resulting deflection has no detectable effect on the FWHM of the zero-loss peak for exposure times as short as 1 micros. At incident energies up to 300 keV, positioning the deflection plates in the 35 mm camera port above the viewing chamber allows voltages of < +/- 3 kV to deflect the electrons out of the spectrometer and beyond the edge of the annular detector. When the deflection is switched on, the electrons are deflected out of the spectrometer in << 40 ns and when the deflection is switched off, the electrons return to within 10 microm of the undeflected position within 100 ns. Thus, even at an exposure time of 30 micros, the smallest time likely to be used in practice with a GATAN 666 spectrometer, < 1% of the signal in the spectrum is from electrons whose scattering conditions differ from those in the undeflected position. The performance of the deflection system is such that it will also be suitable for use with the new and much faster GATAN ENFINA spectrometer system. At incident energies up to 200 keV and possibly up to 300 keV, deflection voltages of +/- 3 kV are sufficient to deflect the electrons off a 1 k x 1 k charge coupled device (CCD) camera placed below the photographic camera. Thus the deflection system can be used as a very fast, non-mechanical shutter for such a CCD camera.

Journal Article↗
PubMed2002

Is electronystagmography of diagnostic value in the elderly?

We aimed to determine the diagnostic value of electronystagmography (ENG) in a community-based sample of dizzy subjects over 65 years old. A total of 96 asymptomatic controls and 149 dizzy subjects underwent ENG. Clinical diagnoses were made on standardized criteria. ENG results were classed as normal or abnormal, according to reference ranges derived from the controls. Rates of ENG abnormality in different diagnostic categories, sensitivities, specificities and predictive values were calculated. Central vascular disease was common (105 out of 149 subjects); peripheral vestibular disease was not (14). Spontaneous nystagmus had a positive predictive value of 95% for central vascular disease, but was only 18%-sensitive, and was usually detectable clinically. ENG had no other significant diagnostic value. ENG failed to discriminate dizzy subjects from controls and failed to differentiate various dizziness syndromes. ENG was of no practical value in this community-derived sample of dizzy elderly subjects.

Age Factors↗
PubMed2002

The quality of life impact of dysphonia.

Dysphonia can affect social life and employment, but formal studies of its general health impact are lacking. The aims of this study were (i) to compare self-rated general health status as measured by the SF-36 in a large cohort of dysphonic patients with those from normative groups; and (ii) to examine the differential impact of dysphonia on the various health status domains. The 163 dysphonic voice clinic attendees (38 men, 125 women) were drawn from recruits to a prospective trial of speech therapy efficacy. The Short-Form 36 (SF-36) scores were compared with published data on 744 age-matched healthy controls. Patients with dysphonia had significantly poorer self-reported health than the controls on all eight SF-36 subscales (limitation of physical activity P < 0.05; other seven, all P < 0.001, Student's t-test). We thus conclude that dysphonia in patients without obvious laryngeal disease has an adverse impact on all health status subscales as measured by the SF-36. The study provides further evidence for the inclusion quality of life measures in otolaryngology baseline and outcome assessments.

Adolescent↗
PubMed2002

Environmental risk factors and gender in nasal polyposis.

The aetiology of nasal polyps remains obscure. Although clinically associated with asthma, notably in women, there is a marked male preponderance of polyposis. This study aimed to explore environmental pollutant triggers and gender differences in risk factors for nasal polyps. In total, 900 patients having surgery for polyposis and 120 new patients with nasal polyps completed a questionnaire with regard to occupational dust and chemical exposure. The male to female ratio was 2:1, and 52% were smokers, although only 37% of women smoked compared with 66% of men. Exposure to occupational dusts and chemicals was noted in 45% (retrospective) and 53% (prospective) of respondents. Women were 1.6 times more likely to be asthmatic and 2.7 times more likely to have allergic rhinitis than men. Men were 2.25 times more likely to be smokers and 2.48 times more likely to have been exposed to chemicals and dusts than women (all statistically significant differences). No significant gender associations were found for hayfever, eczema, aspirin intolerance, alcohol intake or hobby dust exposure.

Air Pollutants↗
PubMed2002

A user evaluation of the Nosocomial Infection National Surveillance System: surgical site infection module.

The Nosocomial Infection National Surveillance Scheme (NINSS) enables hospitals in England to undertake surveillance of healthcare associated infection, compare their results with national aggregated data, and use the information to improve patient care. A surgical site infection (SSI) module was introduced in 1997, and participation has increased steadily since its inception. This survey was undertaken to assess the views of users on the current service, and how the module should be developed to best meet their needs and resources. Survey forms were sent to infection control teams (ICTs) at the 113 hospitals that had participated at any time during the first three years of the programme. The response rate was 90% (102). The views of users were generally very positive and indicated considerable support for the approach to this type of surveillance. The ability to compare hospital infection rates with national data, the availability of standardized surveillance methods, and centralized data analysis and report production were key reasons for participation for over 80% of users. Most did not wish to see any major changes made to the protocol, although more than a third of users suggested additional data items. Overall, users were satisfied with both the content and timescale for receipt of feedback reports, and 77% disseminated them to at least three groups of clinicians and managers. The majority of ICTs (89%) gave the results directly to the surgeons. For some users (29%) it was too early to assess the value of the surveillance. Of the remainder, although results provided evidence of good performance for some, 46% identified high rates of SSI in one or more groups of surgical patients. In about two-thirds of these hospitals, a review or change in clinical practice was initiated as a result. Three main areas for development were identified: an extended range of surgical procedures, post-discharge surveillance and improved local data collection and analysis systems. Users said they would also like training in handling and interpreting surveillance data. These needs should be addressed in order to ensure the continuing success of national surveillance.

Cross Infection↗
PubMed2002

Mixed nasal mucus as a model for sinus mucin gene expression studies.

OBJECTIVE/HYPOTHESIS: It is necessary to obtain sinus mucus from the paranasal sinus cavities to study mucin gene expression occurring in the sinuses during chronic sinusitis. This requires an invasive procedure to access the sinus cavity. There are embryological as well as histological similarities between nasal and sinus epithelia; therefore, we postulated that the mucin expression in the secreted nasal and sinus mucins might be similar. Nasal mucus, which can be obtained easily, could then replace sinus mucus in these studies. STUDY DESIGN: Sinus and nasal mucus from six patients with chronic sinusitis were analyzed in this study. METHODS: High-molecular-weight glycoproteins (mucins) were isolated and purified by sequential density gradient centrifugation in caesium chloride (CsCl). Enzyme-linked immunosorbent assay was performed to identify the antigenic identity of these mucins. RESULTS: The MUC2, MUC5AC, and MUC5B mucin genes were all expressed in the nasal and sinus mucus secretions. Antigenic studies showed an inverse relationship between MUC2 and MUC5AC expression in nasal and sinus mucus secretions. The MUC5B gene was the major mucin gene expressed in sinus mucus but not in nasal mucus. Expression of MUC2 was significantly higher in sinus mucus. Expression of MUC5AC was different between nasal and sinus mucus. CONCLUSIONS: Individual mucin expression in sinus and nasal mucus was markedly different. From this preliminary study, we conclude that nasal mucus is not a suitable substitute for sinus mucus in sinus mucin gene studies and that different pathological processes are taking place in nasal and sinus tissue in chronic sinusitis.

Chronic Disease↗
PubMed2001

Scaleable downstream recovery of nematodes used as biopesticides.

This study assesses the suitability of sieving as a scaleable technique for the separation of adult nematodes from infective juveniles, the latter is an effective bioinsecticide whereas the former is waste material resulting from the fermentation process. Batch and semibatch experiments using conventional flow-assisted wet sieving and a novel cross-flow sieving technique were used to study the separation of juveniles from adult nematodes. The experiments were carried out using small-scale devices and the data were analyzed in terms of the screen effectiveness factor. The results were used to identify the sieve size and operating conditions for optimum juvenile recovery. It was found that, for a given species of nematode, optimum recovery was achieved when sieving was carried out in the cross-flow mode, the maximum recovery being a function of the size of the screen. Industrial-scale self-cleaning equipment capable of large-scale continuous screening was used to confirm the capacity of the small-scale operation for scale-up. Experimental results with this unit showed that in continuous operation sieving time is an additional parameter that influences separation performance.

Animals↗