Search PubMed⌕ Search

Biomedical subjects

D Howel

Publications and source records attributed to D Howel.

At least 19 recordsLinked to original sources
PubMed1995

Psychological morbidity and the availability of assisted conception: a group comparison study.

BACKGROUND: Given its limited availability, it is worth while to explore the relationship between the non-availability of assisted conception and psychological morbidity among subfertile women, to see if those denied the procedure experience poorer health. METHODS: A non-randomized group comparison study was carried out in Bradford Health Authority, England. Sixty-six women who had reached the point at which assisted conception was deemed appropriate, but for whom such treatments were not available, were compared with 49 parous women, and 73 newly diagnosed subfertile women. The General Wellbeing Index (GWI) was used to measure their psychological wellbeing. RESULTS: Cases and subfertile controls have similar levels of wellbeing, whereas parous controls have significantly higher average levels than cases. This pattern is seen in the simple unadjusted comparison and also when adjustments are made for the distributions of age, life event score and social class. CONCLUSIONS: Subfertile women experience poorer psychological health than similar parous women. Subfertile women, for whom assisted conception is an appropriate but unavailable treatment option, appear to have similar psychological health to those who are being investigated and treated by other means.

Adaptation, Psychological↗
PubMed1994

Statistical analysis of compositional data in anatomy.

BACKGROUND: Variables which describe the composition, or relative size of components, of an organism need to be analysed in an appropriate manner. METHODS: A few of the appropriate descriptive and inferential techniques have been described and applied to a number of anatomical data sets. RESULTS: When applied to data on the composition of the vastus medialis in adults, a small but significant difference in average muscle fibre type distribution was demonstrated between males and females. There was little evidence for a relationship between fibre type distribution and age over the range considered. CONCLUSIONS: Graphical displays via ternary diagrams are a simple way of illustrating compositional data simultaneously between and within groups. Numerical analysis is likely to involve transformation of original variables before standard univariate or multivariate statistical techniques can be used.

Adult↗
PubMed1993

The health care experience and health behaviour of the Chinese: a survey based in Hull.

Lack of knowledge about the health care experience and health behaviour of an important ethnic minority group prompted a study to inform the provision of health care and promote local action in Hull. Thirty Chinese 'takeaway' shops were randomly selected from the Yellow Pages of the Hull telephone directory, and all Chinese people working in them asked to complete a questionnaire. It contained questions on their knowledge, use and experience of primary health care and health promotion, together with aspects of their health behaviour. The same questionnaire in English was delivered to all workers in 30 fish and chip shops, to provide a White comparison group. Eighty (71 per cent) of the Chinese returned their questionnaire, and 73 (67 per cent) were returned from the chip-shop workers. The results indicate that the Chinese in Hull are not making optimal use of health services; they use some services inappropriately, whereas others, such as preventive health programmes, are under-used. One of the main reasons is identified as the language/communication difficulties faced by many Chinese. Other reasons are also highlighted and their implications discussed. The findings of this survey are in keeping with the mainly unpublished work undertaken elsewhere on this comparatively little researched ethnic minority group.

Adult↗
PubMed1990

Prophylactic intravenous immunoglobulin in pre-term infants: a controlled trial.

Sixty-six pre-term infants of less than 30 weeks gestation consecutively admitted to either of two neonatal intensive care units were randomized to receive routine intensive care only or prophylactic intravenous immunoglobulin, 200 mg/kg body weight at 3-weekly intervals in addition to routine intensive care. Eleven babies, 6 in the control group and 5 in the treatment group, were withdrawn from the trial due to early death from extreme prematurity (7 babies), early return to the referring hospital (3 babies), and elective treatment with intravenous immunoglobulin for severe congenital septicaemia (1 baby). Of the 55 who remained in the trial, significantly fewer babies in the treatment group had infection, 8 compared to 17 (p = 0.01). This difference was not significant when blood-culture-proven septicaemia only was considered, 8 compared to 14 (p = 0.09). Twenty-seven (84%) of 32 blood-culture-positive episodes of infection were caused by coagulase-negative staphylococci. Serum IgG was significantly higher with treatment and achieved levels comparable to those of normal full-term babies at the same post-natal age.

Bacterial Infections↗
PubMed1988

A test to detect clustering applied to muscle fibres.

The random arrangement of a chosen uncommon element type within a mosaic has been assessed by the new statistics, 'Number of Clusters' and 'Mean Cluster Size'. Their distributions were obtained by simulation assuming the mosaic has a hexagonal arrangement. When this assumption was relaxed to allow mosaics nearer to those observed in nature, the results were little changed. This method was then applied to a set of muscle fibre data to test hypotheses about the likely targets in inflammatory muscle disorders.

Computer Simulation↗
PubMed1988

Should maternal alpha-fetoprotein estimation be carried out in centers where ultrasound screening is routine? A sensitivity analysis approach.

We describe a case of small, open spina bifida that was detected on the basis of maternal serum alpha-fetoprotein levels but consistently missed on careful ultrasound examination. This prompted us to reexamine the policy (adopted by an increasing number of departments) of relying exclusively on ultrasound examination for the detection of spinal lesions. In this article we therefore analyze the number of additional cases of spina bifida that could be detected by offering maternal serum alpha-fetoprotein screening in addition to a routine ultrasound examination. Our calculations are made on the basis of published assessments of the performance of these tests and on the assumptions about test independence. We test our conclusions against a wide variety of test performance values in a detailed sensitivity analysis. The final decision to carry out maternal serum alpha-fetoprotein testing is a value judgment, but this decision should be based on realistic numeric estimates of the potential benefits and hazards of this procedure.

Adolescent↗
PubMed1987

Spatial distribution of muscle necrosis in biopsies from patients with inflammatory muscle disorders.

Muscle biopsies from 56 patients with polymyositis (PM), juvenile dermatomyositis (JDM) and adult dermatomyositis (ADM) were investigated using a range of quantitative histological techniques. The objective was to present data on the extent and distribution of muscle fibre degeneration in these patients and to determine whether these data were compatible with postulated mechanisms of fibre injury. Atrophy of one or more of the major fibre types was found in 45/56 biopsies but there was no evidence that particular patterns of type-specific atrophy were characteristic of any individual disease group. However, selective atrophy and/or necrosis of perifascicular fibres was much more common in JDM patients than in ADM or PM groups. In virtually all biopsies where abnormalities of the microvasculature were apparent (7/8 JDM biopsies, 4/13 ADM biopsies and 5/33 PM biopsies) the distribution of acute muscle necrosis was found to be non-random (clustered). However, a substantial proportion of biopsies in the PM group showed clustering of necrotic fibres in the absence of evidence of vascular involvement. This finding suggests that non-random targetting of muscle fibres by effector cells may occur.

Adolescent↗
PubMed1987

A simple test for the random arrangement of muscle fibres.

The random arrangement of a given muscle fibre class has been assessed by estimating 'mean cluster size' in transverse sections of skeletal muscle. The method was found to be useful when the proportion of the fibre class of interest was low. The statistical distribution of this measure was investigated by computer simulation using a hexagonal lattice model of muscle fibre arrangement. An approximate significance test was developed by considering the extreme points of the distribution. Minor changes to the hexagonal lattice model were incorporated to give a more realistic representation of fibre arrangement and these were found to give very similar results to the simpler model.

Computer Simulation↗
PubMed1987

F-response frequency in motor neuron disease and cervical spondylosis.

During a train of 200 stimuli, F-response frequency, frequency of identical responses, and F-response shape were studied in the ulnar nerve of 17 patients with motor neuron disease (MND) and 16 patients with cervical spondylosis (CS). In MND patients, F-response frequency varied between 5% and 96% with a median of 39% which was significantly lower than controls (p less than 0.001), and showed a significant rank correlation with the M-response amplitude (r = 0.62, p less than 0.004). Identical responses occurred more frequently than in controls (median 30.8%, p less than 0.001). F-response frequency was normal in CS patients (median 76.3%, range 35% to 97%), but the frequency of identical responses (median 6.3%) was higher than normal (p less than 0.01). Reduced F-response frequency in MND was thought to reflect loss of lower motor neurons, while the presence of spasticity was probably the major factor underlying the increased frequency of identical responses in both disorders. F-response shape tended to be simpler in MND and rather more complex in CS patients than controls.

Adult↗