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Biomedical subjects

J Wray

Publications and source records attributed to J Wray.

At least 37 records · Page 2Linked to original sources
PubMed1998

How does the intervention of cardiac surgery affect the self-perception of children with congenital heart disease?

BACKGROUND: There is little published information about the self-perceptions of children with chronic physical diseases and the ways in which self-perceptions might change as a result of treatment. An innovative measure of self-perception is described, suitable for use by children of widely varying ages as well as by parents. METHODS: The instrument used assessed eight constructs contributing to self-perception, and also measured differences between perceptions of actual and ideal self. Children (n = 31; age 5-15 years) with congenital heart disease (CHD) were assessed prior to surgery and 1 year post-operatively. Comparisons were made with children before and 1 year after bone marrow transplantation (BMT), and with healthy children. RESULTS: There were no differences between the groups in ideal self-perceptions, but the CHD children rated themselves as weaker, more frightened and more ill than the healthy group. Given the differences in symptomatology and illness experience of children with cyanotic and acyanotic lesions, surprisingly few differences emerged in the self-perceptions of these two groups, although differences were found among younger and older children assessed separately. Significant improvements were found in self-perceptions of the CHD and BMT groups following treatment, and at follow-up, no significant differences remained between the CHD and healthy groups. In the latter, self-perception was largely unchanged between the two assessments. CONCLUSIONS: Assessment of self-perception should be an integral part of the assessment of health outcomes in childhood illness. The study demonstrated the significant improvement in self-perception following surgery for CHD. The results also support the validity, reliability and sensitivity to change of the assessment measure.

Adolescent↗
PubMed1994

Cognitive function and behavioural status in paediatric heart and heart-lung transplant recipients: the Harefield experience.

OBJECTIVE: To assess the psychological impact of cardiac and cardiopulmonary transplantation on children. DESIGN: Retrospective cross sectional study. SETTING: One British centre performing paediatric heart and heart-lung transplant operations, four cardiac units in London, three London schools, two London health centres, and the dental department of a London children's hospital. SUBJECTS: 65 children who had been given heart or heart-lung transplants and two reference groups of 52 children who had had other types of cardiac surgery and 45 healthy children. MAIN OUTCOME MEASURES: Development, cognition, and behaviour at home and at school as assessed by measures with proved validity and reliability. RESULTS: Developmental and cognitive measures indicated that children given transplants had significantly lower scores on several parameters, particularly in terms of development in children under 4 1/2 years of age. Performance on all tests, however, was within the normal range. There were no significant differences in behavioural ratings between the transplant and reference groups, though problem behaviour at home was more prevalent in the transplant group. CONCLUSIONS: Though cognitive development may be within the normal range, there are adverse psychological effects associated with cardiac and cardiopulmonary transplantation. These data indicate the need for a controlled prospective study in which children and their families are seen before and at regular intervals after transplantation. Interventions should be developed that are tailored to the particular needs of this very specialised group of paediatric patients and their families.

Achievement↗
PubMed1993

The effect of lattice spacing change on cross-bridge kinetics in rabbit psoas fibers.

The effect of compression on the elementary steps of the cross-bridge cycle was investigated with the sinusoidal analysis technique and ATP hydrolysis rate measurement. The lattice spacing of rabbit psoas muscle fibers was osmotically compressed with a macromolecule, dextran T-500 (0-16%). The effects of MgATP, MgADP, Pi on exponential processes (B), (C), (D), and isometric tension were studied at different dextran concentrations. The experiments were performed at the saturating Ca concentration (pCa 4.5-4.8), 200 mM ionic strength, pH 7.0, and 20 degrees C. Our results show that the fiber width decreased linearly with an increase in the dextran concentration, and the width measurement was perfectly correlated with the lattice spacing measurement using equatorial x-ray diffraction studies. We find that the nucleotide binding steps, the ATP-isomerization step, and the cross-bridge detachment step were minimally affected by the compression. Our results indicate that the rate constant of the reverse power stroke step (k-4) decreases with mild compression (0-6.3% dextran), presumably because of the stabilization of the attached cross-bridges in the AM*DP state. We also found that the rate constant of the power stroke step (k4) decreases with higher compression (> 6.3% dextran), presumably because of increased difficulty in performing the power stroke reaction. Our results further show that the association constant (K5) of phosphate to cross-bridges is not changed with compression. The ATP hydrolysis rate declined almost linearly with an increase in the dextran concentration. This observation indicates that the rate limiting step is also affected by the lattice spacing change so that the associated rate constant (k6) becomes progressively less with compression.

Adenosine Diphosphate↗
PubMed1992

Effect of 2,3-butanedione monoxime on myosin and myofibrillar ATPases. An example of an uncompetitive inhibitor.

2,3-Butanedione monoxime (BDM) reversibly inhibits force production in muscle. At least part of its action appears to be directly on the contractile apparatus. To understand better its mechanism of action, we studied the effect of BDM on the steps of myosin subfragment 1 Mg(2+)-ATPase in 0.1 M potassium acetate, pH 7.4. Because of the rapidity of certain processes, we experimented at 4 degrees C and our main technique was the rapid flow quench method. By varying the experimental conditions (relative concentrations of reagents, time scale, quenching agent), it was possible to study selectively the different steps of the S1 Mg(2+)-ATPase: [formula: see text] At saturation (20 mM), BDM had two major effects on the ATPase. First, it increased the equilibrium constant of the cleavage step (K3) from 2 to > 10. Second, it slowed the kinetics of the release of Pi by an order of magnitude (k4; from 0.054 to 0.004 s-1). By contrast, the kinetics of the binding of ATP (k) and the release of ADP (k6) were little affected by BDM. Thus, the oxime appears to interact specifically with M**.ADP.Pi, and it is a rare example of an uncompetitive inhibitor. Its effect is to reduce the steady-state concentration of the "strong" actin binding state M*.ADP and to increase that of the "weak" binding state, M**.ADP.Pi. The effect of BDM on the initial ATPase of Ca2+ activated myofibrils was very similar to that on S1 ATPase. Thus, with myofibrils too BDM seems to exert its main effect subsequent to the initial binding and cleavage steps.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1992

High protein mobility in skinned rabbit muscle fibres observed by 1H NMR spectroscopy.

1H NMR spectra of skinned rabbit muscle fibers show a group of relatively sharp resonance lines which presumably originate from highly mobile protein domains. Comparison with the spectrum of myosin subfragment 1 suggests that these signals may come at least partly from mobile regions of the myosin head. NMR could possibly be used to characterize the movements of crossbridges in force generation.

Animals↗
PubMed1992

Cognitive and behavioural status of paediatric patients 1 year after cardiac or cardiopulmonary transplantation.

Cardiac and cardiopulmonary transplantation are being increasingly used as methods of treatment for children with end-stage heart or lung disease, but little is documented about their psychological adjustment to such procedures. In all, 45 children who had undergone heart or heart-lung transplantation were studied 1 year after operation and compared with 39 children who had undergone bone marrow transplantation, 49 children who had undergone conventional cardiac surgery and 46 normal healthy children. None of the 3 treatment groups differed significantly with respect to developmental, cognitive or behavioural measures, but there were significant differences between the transplant and normal groups in the areas of developmental and cognitive functioning. The initial diagnosis of the transplant patients was found to be an important factor in the postoperative psychological functioning.

Adolescent↗
PubMed1992

Effect of cardiac or heart-lung transplantation on the quality of life of the paediatric patient.

Despite the increase in the use of heart and heart-lung transplantation as methods of treatment for children with end stage heart or lung disease, there is little documented research about the psychological implications of such procedures or about the effects of transplantation on quality of life. Twenty-eight children were studied before and 3 months after heart or heart-lung transplantation and compared with 28 normal children. Developmental and cognitive function were within the normal range, although performance was at a significantly lower level on a number of parameters compared with the normal group. There were no significant changes in any of the developmental or cognitive parameters after transplantation. Pre-operatively the prevalence of problem behaviour at home was significantly higher in the transplant group compared with the normal group, but there was a significant reduction in the prevalence of problem behaviour following transplantation. Early postoperative findings indicate an improvement in quality of life after heart or heart-lung transplantation but longer term follow-up is now necessary.

Adolescent↗
PubMed1990

Children in an urban township in Zambia. A prospective study of children during their first year of life.

In a prospective study of 257 children in Lusaka during their first year of life the infant mortality rate was 118 per thousand live births. Deaths were due to prematurity and respiratory problems during the first few months of life, and diarrhoea, measles, and malnutrition during the later months. The low birth weight rate was 11 per cent. Growth was good during the first 6 months, but thereafter there was faltering in weight gain and gain in length faltered after 8 months. By age year 1 only 12 per cent attained the average weight-for-age and 8 per cent the average height-for-age. Breast feeding decreased in frequency very gradually over the first year with 66 per cent of children still being breast-fed more than six times a day at a year. Meals were usually given only three times a day and consisted mainly of maize porridge with vegetables, beans, or meat when it could be afforded. Over 70 per cent of children were fully immunized. Milestones were generally achieved at expected ages or even earlier. Where they were delayed most of the children affected died within a couple of months. Recommendations are made on the surveillance of infants in urban areas and the provision of a precooked fortified appropriate weaning food obtained at Health Centres.

Birth Weight↗
PubMed1989

Mothers in an urban township in Zambia.

Two hundred and forty-nine mothers living in an urban township were followed at their home from delivery for 1 year. Sixty-four families were lost to follow up due to moving house. The neonatal mortality was 50.6 per thousand and the infant mortality 118 per thousand live births. Child loss increased after parity 8 of the mother. The mean (SD) weight of mothers was 56.8 kg (8.8), the mean height 157.8 cm (6.1) and the mean ponderal index 22.53 (3.51). The mid-arm circumference was 26.1 cm (2.8). Body size varied considerably with around 10 per cent of mothers being undernourished and 10 per cent obese. Weight and mid-arm circumference generally decreased after 6 months post-partum. Breast feeding became less frequent after 8 months and by a year four babies had stopped receiving any breast milk. Average birth intervals were around 30 months, but thirty-seven mothers (20 per cent of multiparous mothers) had intervals of less than two years often following the loss of a previous child. Women generally received less education than their husbands with 35 (17 per cent) having had no education and only 23 (11 per cent) with some secondary education. Thirty-five mothers (18 per cent) had no men living at home with them although some fathers provided support. By one year fifteen fathers had abandoned the mother. Incomes of most families were insufficient and half the mothers worked, usually by selling food at the market or outside their homes.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Intervals↗
PubMed1985

Neurofibromatosis and fragile-X syndrome in the same patient.

We report on an 11 1/2-year-old boy with neurofibromatosis and the fragile-X syndrome. Clinical manifestation of neurofibromatosis include multiple cafe-au-lait spots, axillary freckles, congenital glaucoma, relative macrocephaly, radiologic findings of overtubulation of the long bones, and precocious puberty. The fragile-X syndrome manifests itself as mental retardation with behavior problems, macro-orchidism, and specific cytogenetic findings. The boy has normal serum hormone levels, but a greatly elevated FSH on a first morning void, which contains the nocturnally secreted gonadotropins. This seems to be the first reported occurrence of the fragile-X syndrome with another inherited disease.

Child, Preschool↗