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Biomedical subjects

C Wilkinson

Publications and source records attributed to C Wilkinson.

At least 91 records · Page 5Linked to original sources
PubMed1996

A neutron image plate quasi-Laue diffractometer for protein crystallography.

An instrument which is based on image plate technology has been constructed to perform cold neutron Laue crystallography on protein structures. The crystal is mounted at the center of a cylindrical detector which is 400mm long and has a circumference of 1000mm, with gadolinium oxide-containing image plates mounted on its exterior surface. Laue images registered on the plate are read out by rotating the drum and translating a laser read head parallel to the cylinder axis, giving a pixel size of 200 microm x 200 microm and a total read time of 5 minutes. Preliminary results indicate that it should be possible to obtain a complete data set from a protein crystal to atomic resolution in about two weeks.

Animals↗
PubMed1996

Bone density change and biochemical indices of skeletal turnover.

Although biochemical markers of skeletal turnover cannot replace bone density scanning for the diagnosis of osteoporosis, it is thought that they may help add to prediction of fracture risk and help determine adequacy of osteoporosis therapy. Nevertheless, whether biochemical markers in the serum or urine can predict individual rates of bone loss in the spine or hip region is unknown. We studied a heterogeneous group of women (n = 81) who were premenopausal, untreated postmenopausal, and estrogen-treated postmenopausal with baseline determination of body mass index (BMI), calcium intake, biochemical measurements, and serial bone densitometry over 3 years. Serum assays included bone Gla protein (BGP), total and bone-specific alkaline phosphatase (AP, BSAP), carboxyterminal propeptide of type I procollagen (PICP), carboxyterminal telopeptide of type I collagen (ICTP) and tartrate-resistant acid phosphatase (TRAP). Urine assays included hydroxyproline (OHP), calcium, total pyridinoline, and total deoxypyridinoline. Individual biochemical markers and calcium intake were modestly correlated with bone density changes but were inconsistent regarding the spine versus the hip. All of the formation variables were significantly correlated to spine density change (r = -0.24 to -0.49) whereas the only resorption variable that correlated was urine OHp/Cr (r = -0.31). The only formation variable that correlated with hip density change was serum PICP whereas all of the resorption variables except serum TRAP were correlated (r = -0.23 to -0.35). "High turnover" individuals were defined at those with levels of biochemical variables at least 1 SD above the mean young normal for each variable. Higher bone loss rates were seen in this group for several of the turnover markers compared with bone loss rates in all other individuals. However, the sensitivity of this "high turnover" status for identifying high bone losers did not exceed 60% for any of the variables. In untreated postmenopausal women, a model using urine OHp, serum ICTP, serum BSAP, and calcium intake was able to predict 42% of the variance of change in BMD of the lumbar spine. A model using BMI, serum ICTP, and serum BGP could predict 32% of the variance of change in BMD of the femoral neck. No combination of markers could predict variance in bone density change at either site in estrogenized women (premenopausal and estrogen-treated postmenopausal). We conclude that measuring individual serum and urine markers of bone turnover cannot accurately predict bone loss rates in the spine and hip; however, combinations of demographic and biochemical variables could predict some of the variance in untreated postmenopausal women. Biochemical markers cannot replace serial bone densitometry for accurate determination of change in bone mass at the most clinically relevant sites.

Adult↗
PubMed1995

Activation of macrophage-like cells by multiple grooved substrata. Topographical control of cell behaviour.

We studied the influence of substrata topography on the behaviour of murine P388D1 macrophage cell line. Cells were plated on plain fused silica substrata or substrata with microfabricated grooves of varying depth and width. Cell spread area, elongation, orientation and F-actin content were measured on plain substratum and 6 sets of gratings. The speed and persistence of cell movement were also studied. We found that patterned substrata substantially activated cell spreading and elongation and significantly increased the persistence and speed of cell movement, shallow grooves being more effective than deep ones. The contact of cells with micropatterned substrata significantly increased the F-actin content in cells. The sensitivity of LPS (lipopolisaccharide) stimulated and unstimulated macrophages to topographical cues was also compared.

Actins↗
PubMed1995

The impact of a brief motivational intervention with opiate users attending a methadone programme.

During the 1980s Motivational Interviewing emerged as one of the memes of the addictions field. This occurred despite the lack of scientific evidence supporting its utility. In this paper findings of a controlled trial of a brief motivational intervention with illicit drug users (n = 122) attending a methadone clinic are reported. Clients who met the study's inclusion criteria were randomly allocated to either a motivational (experimental, n = 57) or educational (control, n = 65) procedure. Over the 6-month follow-up period the motivational subjects demonstrated a greater, immediate, commitment to abstention, reported more positive expected outcomes for abstention, reported fewer opiate-related problems, were initially more contemplative of change, complied with the methadone programme longer and relapsed less quickly than the control group. There was, however, no difference in terms of the severity of reported opiate dependence and the control group fared better on reported self-efficacy. It was concluded that motivational interventions of the type investigated are useful adjuncts to methadone programmes.

Adolescent↗
PubMed1994

Image plate detectors for macromolecular neutron diffractometry.

Neutron diffraction studies of macromolecules require large position sensitive detectors. It is proposed that such a device can be based on image plate technology, which relies on re-usable photostimuable phosphors, combined with a neutron to gamma-ray converter. Design parameters such as the best wavelength for the neutron radiation and the optimum sample to detector distance are discussed, and a design for a cylindrical detector is outlined. Presently a prototype of such a detector is being built, and the very first test-recording of an X-ray diffraction pattern from a protein crystal is presented.

Journal Article↗
PubMed1994

Is the potential of teenage consultations being missed?: a study of consultation times in primary care.

There is a paucity of knowledge regarding teenage health even though it features as one of the priority areas in the government's health plans. There have been few reports of adolescent contacts with primary care teams, although there are impressions of a suboptimal service. As a prelude to understanding more about communication between general practitioners and teenage patients, this study aimed to look at the time spent on teenage consultations, which can be used as one method of describing the quality of care provided to teenage patients. Nine-hundred consultations involving six doctors in one surgery were timed over a 3 month period by one observer using a validated method. One-hundred and nineteen consultations with patients aged 11-19 were compared with the 781 consultations for other age groups and showed a statistically significant mean shortfall of nearly 2 minutes (23%). This trend was confirmed for all six doctors, despite a broad range of average consulting times. The study also demonstrated some other characteristics of teenage consultations. Several implications of these results are discussed as well as possible reasons for these findings. The study emphasizes the need for further research in this area.

Adolescent↗
PubMed1994

Mesalamine capsules enhance the quality of life for patients with ulcerative colitis.

Patients with ulcerative colitis tend to be young, potentially at peak lifetime productivity levels, and the disease can be devastating in its effects on the quality of life in these individuals. No treatment for ulcerative colitis can be comprehensively evaluated without careful attention to its impact on such psychosocial issues. The quality of life was evaluated in 374 ulcerative colitis patients using mesalamine capsules at 1 g, 2 g, and 4 g daily versus placebo in an 8-week, randomized, dose-response, placebo-controlled, double-blind, multicentre trial. Function-related quality of life parameters were assessed in this study, including five pertinent clinical symptoms and seven general life capabilities. These parameters have been previously shown to be valid, reliable, and responsive to the disease activity of ulcerative colitis. All of the parameters were recorded using a 10-cm visual analogue scale, except trips to the toilet which were recorded in patients' diaries. The mean change was calculated from baseline and endpoint data. Mesalamine at 2 g and 4 g daily was significantly superior to placebo in improving each of the 12 quality of life parameters (P < 0.05). These results indicate that controlled-release mesalamine significantly enhances the quality of life for patients with either left-sided ulcerative colitis or pancolitis.

Administration, Oral↗
PubMed1993

Using the child behaviour checklist in ordinary primary schools.

The study considers the application of the Child Behaviour Checklist (Achenbach & Edelbrock, 1986) to the identification of children with emotional and behavioural difficulties in ordinary primary schools. Teachers provided checklist data on a sample of 320 boys and 118 girls previously referred to the schools psychological services and a further 183 boys and 39 girls who had not been referred. There was a high level of agreement between referred and non-referred student status and subsequent classification using the CBCL criteria for psychiatric disturbance. An analysis of variance was carried out to determine how far teacher expectations may contribute to CBCL scores. The results indicated that teacher differences within schools are more important than the differences which exist between teachers working in different schools. The results support the validity of the CBCL. The future application of the CBCL in ordinary schools is discussed.

Aggression↗
PubMed1992

Planning palliative care services.

An audit was conducted to assess the use of, and satisfaction with, local services for the care of the dying, which have developed over the past seven years in South Glamorgan. These services include hospice inpatient, outpatient and day care facilities, home care specialist nursing, volunteer services and domiciliary medical consultations. All general practitioners in the district were surveyed about the services by postal questionnaire; respondents represented most of the practices in the district. The results show a variable level of uptake of services for those well established (excluding paediatric oncology), including a high level of satisfaction with the available services. The results identify a lack of provision for patients dying from a non-malignant disease.

Attitude of Health Personnel↗