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Biomedical subjects

N Wilson

Publications and source records attributed to N Wilson.

At least 109 records · Page 6Linked to original sources
PubMed1996

Chromosome 22q11 microdeletions in tetralogy of Fallot.

Chromosome 22q11 fluorescence in situ hybridisation (FISH) studies were performed on 33 consecutive individuals attending a paediatric cardiology clinic with tetralogy of Fallot. Seven children had 22q11 microdeletions but only four had other clinical features associated with the newly recognised chromosome 22 deletion syndrome (CATCH 22). Chromosome 22q11 FISH studies should therefore be performed on all patients with tetralogy of Fallot.

Child↗
PubMed1996

Role of ECMO in neonatal myocardial infarction.

A neonate with myocardial infarction who failed to respond to conventional treatment was supported by extracorporeal membrane oxygenation (ECMO). Severe mitral valve regurgitation necessitated mitral valve replacement while receiving ECMO following which the infant was successfully weaned. ECMO should be considered for potentially treatable causes of catastrophic heart failure.

Extracorporeal Membrane Oxygenation↗
PubMed1996

Total UK multi-centre experience with a novel arterial occlusion device (Duct Occlud pfm).

OBJECTIVE: To report the total UK multicentre experience of a novel arterial occlusion device (Duct Occlud pfm). DESIGN: Descriptive study of selected non-randomised paediatric patients with a variety of aortopulmonary connections. SETTING: Five UK tertiary referral centres for congenital heart disease. PATIENTS AND METHODS: Between March 1994 and February 1995, 57 children aged 2 weeks to 14 years (median 50 months) underwent attempted closure of their aortopulmonary connection. Fifty one had persistent arterial ducts and 9 of them had had a Rashkind umbrella device implanted. Five patients had superfluous modified Blalock-Taussig shunts (mBTS). In one there was also a native major aortopulmonary collateral artery (MAPCA). Another patient had a native major aortopulmonary connection (APC). Transcatheter occlusion was attempted in all cases through a 4 F delivery catheter. RESULTS: Devices were successfully deployed in 49/57 (86%) patients. Seven of 51 cases with persistent arterial ducts were judged too large for the device and a Rashkind umbrella was used. 40 (91%) of the 44 in whom the detachable coil device was used had complete occlusion at 24 hours on colour flow Doppler echocardiography. Devices were successfully deployed in all 6 remaining patients (4 mBTS, 1 mBTS + MAPCA, and 1 APC). Embolisation of a device occurred on 4 occasions. Two devices were not retrieved but caused no apparent clinical problems. CONCLUSION: This novel detachable coil type occlusion system compares favourably with other methods of transcatheter occlusion of native, residual, or surgically created aortopulmonary shunts. The delivery system allows its use in small children.

Adolescent↗
PubMed1996

Overall symptom measurement: which approach?

The syndrome of preschool wheeze includes a wide range of symptomology, measurement of which necessitates assessment of severity as well as prevalence. Most wheezing in this age group is episodic and associated with viral infections, and it is often difficult to distinguish wheeze from other lower respiratory symptoms. An overall measure of symptom severity should include the frequency, duration and magnitude both of episodes and interval symptoms. However, little attention has been paid to either the distinction of acute virus-related episodes from day-to-day symptoms, or their quantification. The type of medication used is sometimes considered as a measure of symptom severity. Since there is no consensus about either the criteria for the use of anti-inflammatory agents or their modulating effect, this practice is unreliable. Without an agreed method to define symptom severity, it is difficult to assess the validity of either population questionnaires or symptom diaries for use in clinical trials. Validation using objective measures is urgently required.

Asthma↗
PubMed1996

Standardization of pyridinium crosslinks, pyridinoline and deoxypyridinoline, for use as biochemical markers of collagen degradation.

The collagen crosslinks, pyridinoline and deoxypyridinoline, have been developed as urinary markers of bone resorption but, despite wide clinical application of the technique, comparatively little attention has been paid to the standardization of these compounds. In this study, pyridinoline and deoxypyridinoline have been purified from bone and converted completely to monochloride trihydrochloride salts. In addition to mass spectrometry and NMR spectroscopy, the purity of the isolated materials was assessed by microelemental analysis including the chloride counterions. These purified compounds were used to establish individual molar absorptivity values as primary standardization criteria for the two crosslinks. For pyridinoline in 0.1 mol/L HCl, epsilon at 295 nm was 5490 L mol(-1) cm(-1); in 50 mmol/L sodium phosphate, pH 7.5, epsilon at 325 nm was 5785. The corresponding values for deoxypyridinoline at acid and neutral pH were 5160 and 5290 L mol(-1) cm(-1). The availability of standardization criteria for the crosslinks will allow more meaningful comparisons of clinical data between different laboratories.

Amino Acids↗
PubMed1995

Meningococcal disease epidemiology and control in New Zealand.

Epidemiology, surveillance and research New Zealand has a high quality surveillance system for meningococcal disease that successfully integrates notification and laboratory data. Since 1991, New Zealand has had elevated incidence rates of meningococcal disease rising to 6.2 per 100,000 population in 1994. This represents a rate that is four times that recorded in 1989/90. Serogroup B infection predominates and international experience suggests that these elevated rates may continue for 5 to 15 years. Rates of meningococcal disease in Maori and Pacific Islands populations were three times higher than in Europeans at 10.0 and 12.3 per 100,000 respectively in 1994. The rates were particularly high for infants with the rate in Maori infants under 1 year reaching 120 per 100,000. The case fatality rate at 5.3% for 1994 would appear to be relatively low by international standards. Case control studies could be used to investigate potentially modifiable primary risk factors for disease. Intensive case review studies to investigate the role of such factors as preadmission antibiotics in reducing severe outcomes may be of benefit. The Ministry of Health or research funding organisations should consider the potential value of such studies in more detail.

Adolescent↗
PubMed1995

Delivery of hepatitis B immunisations in a selection of computerised general practices.

AIM: To assess the value of computerised general practices in providing information concerning the delivery of hepatitis B immunisation. METHODS: Hepatitis B immunisation data from August 1990 to June 1991 were collected from 27 general practices participating in a sentinel network. RESULTS: The study identified significant limitations in the use of data from computerised general practices for estimating hepatitis B immunisation coverage. While an accurate coverage figure could not be estimated, the results did suggest that hepatitis B coverage for three doses was at least 59.5% and that its use was very similar to the triple vaccine and measles/MMR for the third dose. Hepatitis B immunisation delivery outside the desirable time periods was common at 44%, suggesting a fairly disrupted immunisation schedule for many children. CONCLUSIONS: The relatively infrequent delivery of hepatitis B vaccine at the same time as other vaccinations may reflect provider concern about administering multiple injections at the same visit. Further improvement in the collection of data by computerised practices is necessary before the full value of this data source can be realised. Improvements in reminder/recall systems would improve the efficiency with which hepatitis B immunisation is delivered.

Child, Preschool↗
PubMed1995

Hearing impairment in older adults: new concepts.

OBJECTIVE: To review present information about the epidemiology, etiologies, pathogenesis, evaluation, and quality of life aspects of hearing loss and to present an approach to rehabilitation for hearing loss in older adults. DESIGN: A survey of recent findings on the problem of hearing loss in older adults, efficacy of intervention with amplification, and new developments in intervention strategies. CONCLUSIONS: The complex nature of hearing problems in older adults involves changes in the auditory periphery as well as in the central mechanisms for processing sound input. These changes affect the social and emotional impact of the hearing disorder. The importance of understanding the many implications of hearing loss on quality of life is emphasized. Both older adults and immediate family members need information and advice about the consequences of age-related hearing loss. The physician has a key role in helping them to overcome negative attitudes toward a hearing handicap. For most older persons, hearing aids alleviate many of the handicaps of hearing impairment. For some older persons who do not benefit adequately from conventional hearing aids, assistive listening devices may be helpful. Many old persons and their relatives are reluctant to confront the reality of hearing handicap and try to hide the fact that they need sound amplification. One important future direction is to foster acceptance of hearing loss and to support the more open use of amplification systems.

Aged↗
PubMed1995

Effect of continuous treatment with topical corticosteroid on episodic viral wheeze in preschool children.

Acute episodic wheeze related to viral infections is a common and distressing condition and treatment remains unsatisfactory. Although some benefit from the continuous use of inhaled steroids has been demonstrated in young wheezy children, their effect primarily on acute episodes has not been considered. In this study the effect of budesonide (400 micrograms/day) was assessed in a four month double blind parallel trial, in 41 children (0.7-6.0 years) with predominantly episodic viral wheeze. Analysis of the last three months showed no difference between budesonide or placebo in mean daily total symptom score (median values 0.6 and 0.63), episode number (mean values 2.6 and 2.4), or score/episode (mean value 30 and 31). Four months of treatment with inhaled budesonide had no effect on acute episodes of wheeze in this group of children.

Acute Disease↗
PubMed1995

Reducing donor exposure in preterm infants requiring multiple blood transfusions.

Preterm infants frequently require multiple blood transfusions. Traditionally, 'fresh' (less than seven days old) blood has been used but this often results in transfusions from multiple donors. To reduce donor exposure the policy for top-up transfusions was changed. A unit of blood under five days old with additional satellite packs was ordered for each infant and used up to its expiry date, allowing up to eight transfusions from a single donation to be given. The mean (SD) number of transfusions per infant in 43 infants transfused according to previous policy and in 29 transfused according to the new policy was similar at 5.6 (4.0) and 5.3 (3.1), respectively. However, donor exposure fell following the change in policy from 4.9 (3.5) to only 2.0 (0.9). Only one infant was exposed to more than three donors compared with 24 infants in the control group. Plasma potassium concentrations were not significantly different following transfusion of blood stored for up to 33 days. This simple change in policy has reduced donor exposure in infants requiring multiple top-up transfusions.

Blood Donors↗
PubMed1995

Closure of Blalock-Taussig shunts using a new detachable coil device.

Two children underwent interventional closure of a modified Blalock-Taussig shunt using a new detachable coil system (Duct-Occlud). This procedure has advantages over currently available materials to occlude these and other communications between the systemic and pulmonary circulations.

Arteriovenous Shunt, Surgical↗
PubMed1994

Comparison of interferon-gamma and interleukin-4 production by peripheral blood mononuclear cells and isolated T cells after activation with polyclonal T cell activators.

Controversial data have been reported regarding the ability of peripheral blood T cells to secrete interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) from atopic patients as compared to nonatopic healthy controls. In most of these studies, T cells in peripheral blood mononuclear cell preparations (PBMC) were stimulated with polyclonal T cell activators. Some of these activators are able to activate cells other than T cells in the PBMC preparations which may influence the lymphokine levels in supernatants of PBMC. To evaluate this, we compared the IFN-gamma and IL-4 levels in PBMC and isolated T cell preparations after activation with phytohemagglutinin (PHA), Concanavalin A (ConA), anti-CD3 plus phorbol myristate acetate (PMA), or ionomycin plus PMA. The IFN-gamma and IL-4 levels in the supernatants were calculated based on the percent T cells in the preparations. Whereas all activators induced significant IFN-gamma secretion, only ionomycin plus PMA stimulation induced large IL-4 secretion. In virtually all cases, the IFN-gamma levels calculated on a per T cell basis differed for PBMC versus isolated T cells. Whereas in some donors the IFN-gamma levels were higher in PBMC preparations than in T cells, in others it was the opposite. Similarly, in about one half of both normal and atopic donors tested, the IL-4 levels of activated PBMC were 2- to 7-fold lower than levels in isolated T cells. The data suggest that non-T cells have a significant effect on the IFN-gamma and IL-4 levels in supernatants of polyclonally activated PBMC.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1994

Transesophageal echocardiography in children with cardiac assist.

Transesophageal echocardiography (TEE) is an easy, relatively non-invasive method for evaluation of cardiac function and abnormalities during cardiac assist. We used 19 TEE in 9 children (age: 10 days-4 years, weight: 2.7-12 kg) with mechanically assisted circulation for postcardiotomy cardiogenic shock. TEE provided valuable information: (1) dislocation of the cannula causing hemodynamic instability could be easily diagnosed and corrected; (2) Doppler evaluation of valvular function revealed severe malfunction in two patients; (3) intracardiac thrombus could be clearly detected in two children with seriously impaired hemodynamics. These findings were followed by therapeutic interventions; (4) left-ventricular function before attempted weaning from cardiac assist was moderately reduced or normal in the survivors, but poor in the nonsurvivors. We conclude that TEE is a valuable contribution to improved patient management during cardiac assist.

Child, Preschool↗
PubMed1994

The Audiant Bone Conductor: update of patient results in North America.

The Xomed Audiant Bone Conductor is an implantable hearing device for conductive hearing impairments not adequately relieved by surgical methods or hearing aid amplification. It has now been used long enough for analysis of its present position in our management armamentarium. Data obtained from respondents from the United States and Canada are presented and indicate that this device, properly prescribed and used, almost eliminates the conductive elements of the hearing impairment. During the early years of its use, the device was frequently implanted in patients outside the manufacturer's guidelines for use. Some of the reasons for this discrepancy, as well as evidence that this misapplication is lessening, are presented. When proper guidelines were used, however, the results presented here indicate that socially adequate hearing can be restored to patients with conductive loss by the Audiant. Complications have been few and appear to be diminishing. The results indicate that this device has, in its present state of development, a narrow and restrictive application, but a well-defined and efficient role to play in the management of conductive hearing impairment.

Adolescent↗
PubMed1993

Ultrasound detection of fetal structural abnormalities in Auckland 1988-9.

AIMS: To conduct an audit of ultrasound screening for fetal abnormalities in central Auckland 1988-89. METHOD: All babies born at National Women's Hospital in the time period were examined and fetal abnormalities coded on to a computer database. All terminations of pregnancy for fetal abnormality in the area were similarly audited. RESULTS: There were 12,909 births. 218 babies had a congenital abnormality of whom 88% were scanned antenatally. 48% of abnormalities were detected (27% before 24 weeks). In fetuses that were scanned the detection rate was 52% (44% before 24 weeks). The range of detection of specific abnormalities included neural tube defects 95% and congenital heart defects 16%. CONCLUSIONS: 1. Major abnormalities of the central nervous system, renal tract and abdominal wall have a high detection rate. 2. Cardiovascular, facial and gastrointestinal abnormalities are either not detectable or difficult to detect. 3. Detection rates could be improved by routine scanning, better ultrasound equipment and training, and by the introduction of maternal biochemical screening tests. 4. The detection rate is similar to other overseas surveys.

Abortion, Therapeutic↗
PubMed1993

Obesity and body fat distribution in New Zealanders: a pattern of coronary heart disease risk.

AIMS: To describe the prevalence of obesity and the body fat distribution of New Zealanders. To discuss this in the context of the coronary heart disease risk. METHODS: Body weight and height, body mass index (BMI), waist:hip ratio (WHR) and six skinfold measurements were determined for 3204 randomly selected New Zealanders who responded to an invitation to a health check (response rate 56%). RESULTS: In the study sample BMI generally increased with age. Fifty five percent of men and 38 per cent of women aged 18-64 had a BMI exceeding 25, and of these 13 per cent and 10 per cent were obese (BMI > 30). WHR was greater in men than in women of all ages, and a third of the men and a quarter of the women had values exceeding 0.9 and 0.8 respectively. Central skinfold measurements (subscapular, suprailiac and abdominal) were lowest in young men, but rose markedly with age and were similar to women above age 35. Limb skinfolds were lower in men. CONCLUSIONS: This survey indicates that a large percentage of New Zealanders are overweight or obese and their excess body fat tends to be centrally distributed, especially in men. Obesity is thus a significant health problem in New Zealand.

Adipose Tissue↗