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Biomedical subjects

P Gillies

Publications and source records attributed to P Gillies.

At least 19 recordsLinked to original sources
PubMed2006

Quantification of MRS data in the frequency domain using a wavelet filter, an approximated Voigt lineshape model and prior knowledge.

Quantification of MRS spectra is a challenging problem when a large baseline is present along with a low signal to noise ratio. This work investigates a robust fitting technique that yields accurate peak areas under these conditions. Using simulated long echo time (1)H MRS spectra with low signal to noise ratio and a large baseline component, both the accuracy and reliability of the fit in the frequency domain were greatly improved by reducing the number of fitted parameters and making full use of all the known information concerning the Voigt lineshape. Using an appropriate first order approximation to a popular approximation of the Voigt lineshape, a significant improvement in the estimate of the area of a known spectral peak was obtained with a corresponding reduction in the residual. Furthermore, this improved parameter choice resulted in a large reduction in the number of iterations of the least-squares fitting routine. On the other hand, making use of the known centre frequency differences of the component resonances gave negligible improvement. A wavelet filter was used to remove the baseline component. In addition to performing a Monte Carlo study, these fitting techniques were also applied to a set of 10 spectra acquired from healthy human volunteers. Again, the same reduced parameter model gave the lowest value for chi(2) in each case.

Computer Simulation↗
PubMed2004

Analysis of p63 and cytokeratin expression in a cultivated limbal autograft used in the treatment of limbal stem cell deficiency.

AIM: To investigate the expression of p63 and cytokeratins throughout the course of producing a cultivated autograft of limbal epithelial cells. METHODS: A 75 year old male with a severe alkali burn to his right eye received two cultivated autografts of limbal epithelial cells on amniotic membrane followed by a corneal allograft. Immunostaining for p63 and cytokeratins was performed during ex vivo expansion with 3T3 fibroblasts, following subcultivation on amniotic membrane, and on the excised corneal button. RESULTS: Cultures grown in the presence of 3T3 fibroblasts or on amniotic membrane displayed positive staining for keratins 14 and 19, and p63, but poor staining for keratin 3 (K3). The excised corneal button possessed a stratified epithelium of K3 positive cells residing on amniotic membrane. CONCLUSIONS: Our results document for the first time the co-expression of cytokeratins 14 and 19 with p63 in a cultivated limbal graft. These data support the conclusion that cultivated grafts of limbal epithelium contain predominantly undifferentiated cells with the potential to regenerate a normal corneal epithelium.

Aged↗
PubMed1998

Smoking and smoking cessation among men whose partners are pregnant: a qualitative study.

Smoking among partners of non-smoking pregnant women has been linked to adverse pregnancy outcome, including low birthweight. Paternal smoking also increases the risk of infant respiratory infections and sudden infant death syndrome, irrespective of maternal smoking status. Furthermore, men's smoking habits are probably one of the strongest influences on the extent to which women are able to quit smoking in pregnancy and maintain cessation post birth. In four focus group discussions, male smokers whose partners were pregnant discussed their beliefs about passive smoking in pregnancy, the barriers they perceived to quitting in pregnancy and their preparedness to support maternal cessation. Men were largely unaware that their own smoking could pose a specific risk to the fetus, but when pregnant women are smokers, men believed their own smoking habits were unimportant. For men, barriers to quitting during their partners' pregnancy were: lack of understanding as to how passive smoking can affect the fetus, including a belief that the fetus is "protected" inside its mother; lack of motivation to quit early in pregnancy due to the baby not being "real"; and concern about stress-induced marital discord associated with cigarette withdrawal. These findings are discussed with regard to messages and strategies which may influence men to quit during their partners' pregnancy.

Female↗
PubMed1996

Is AIDS a disease of poverty?

This paper aims to begin to consider the evidence for AIDS as a disease of poverty. It seeks to describe the important influence of the social and economic context of HIV/AIDS and of those behaviours associated with HIV transmission, and argues for a shift in emphasis in the conceptualization of the 'problem of AIDS'. The relationship between poverty and AIDS is explored, particularly in relation to global economic development, urbanization, homelessness and the disintegration of neighbourhoods, migration and systems of labour and production. Examples of socially-driven community-based responses to the prevention and control of the HIV epidemic in diverse cultures are discussed and the need for new outcome measures for assessing community initiatives is proposed.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Is there life after work? Experiences of HIV and oncology health staff.

A cross-sectional interview survey of 103 HIV/AIDS and 100 oncology staff in nine treatment sites in London aimed to identify ways in which work stress affected domestic and social lives of such staff. In all staff one-third of those without long-term emotional relationships stated they felt their work formed a barrier to their being involved in that way. Most subjects reported spending a considerable amount of time discussing work with partners, and work-related subjects caused conflict for just under half of the total sample. Thirty-nine percent reported their partners complained regularly about their commitment to work, and one-quarter overall reported their relationship had suffered as a result of their work in HIV or oncology. Using tests of association comparing group responses to structured interview and standardized psychometric items, few differences were found overall between staff in HIV/AIDS and staff in oncology. HIV staff were more likely to be motivated to work through peer concern, and friends of HIV staff were more likely to be supportive of their working in such a field. On the other hand, families of oncology staff were more supportive of their work than were families of HIV staff HIV staff were more likely to have had a family member who had suffered from a chronic or life-threatening disease. HIV staff were less likely to avoid discussing their work socially. Suggestions for addressing the potentially corrosive impact of health care in these fields, based on these samples, are made.

Adult↗
PubMed1995

Monitoring plasma levels of fluphenazine during chronic therapy with fluphenazine decanoate.

This study was conducted to examine the interpatient variability in steady-state plasma concentrations of fluphenazine by repeat depot intramuscular administration, and to determine the relationship between these concentrations and clinical state. Steady-state pre-dose concentrations of fluphenazine in plasma were measured using a sensitive and specific gas chromatography/mass spectrometry (GC/MS) assay in 24 patients with schizophrenia who were receiving continuous treatment with depot intramuscular fluphenazine decanoate. Clinical response was measured using the Andreasen Scale for positive and negative symptoms. Steady-state plasma concentrations of fluphenazine ranged from undetectable (< 0.1 ng/ml) to 27.9 ng/ml, with a median of 0.5 ng/ml. No significant associations were found between plasma concentration and dosage, or age and sex of the patient. Steady-state plasma concentrations in patients taking anticholinergic agents were significantly higher than in patients not receiving such drugs (P < 0.05 by Mann-Whitney U-test). Poorer control, expressed as the sum of the negative symptom scores or the sum of the positive and negative symptom scores, was related to higher log transformed plasma concentration of fluphenazine and higher fluphenazine decanoate dosage. The log transformed plasma concentrations of fluphenazine and the fluphenazine decanoate dosages were weakly related. Patients receiving another antipsychotic drug in addition to fluphenazine decanoate tended to have poorer clinical control and higher dosages of fluphenazine decanoate. These results indicate the useful role that plasma level monitoring can fulfil in identifying patients who are therapy-resistant despite high plasma levels.

Adult↗
PubMed1994

Evaluation of the short-term impact of counseling in general practice.

This paper describes the findings of a randomised controlled trial of the short-term impact of counseling in the general practice setting. Compared with patients who received usual advice from their general practitioner for acute problems such as relationship difficulties, anxiety and depression, those who received counseling from qualified counselors working within the primary health care context showed greater improvement in psychological health as measured by the General Health Questionnaire. Significantly fewer of those counselled were prescribed anti-depressant drugs by the general practitioners in the study, or were referred to psychiatrists or clinical psychologists for care. In addition those patients who attended sessions with the practice counselor were more likely to report that they were satisfied with their treatment and more expressed feelings of well-being.

Adult↗
PubMed1994

Sex education in schools: an overview with recommendations.

Recommendations from official sources highlight a number of key principles which are essential for effective sex education within schools. These relate to the planning and teaching of the topic, in-service training of teachers, and the establishment of links between schools and parents. Models of practice in the teaching of sex education vary between schools throughout England; also the wide variations in quality and quantity of provision indicate considerable scope for improvement. Government, despite its key role in shaping provision of sex education in schools, does not appear to be consistently supportive. This paper examines and assesses the impact of a number of key policies, including those related to the 1993 Education Act, which will change the legal framework for the teaching of sex education within schools. It makes a series of practical recommendations for purchasers of health promotion services, with the intention of supporting and furthering the development of sex education in schools.

Adolescent↗
PubMed1994

Smoking prevalence among 15-16-year-olds in Doncaster, England.

An anonymous self-completion questionnaire on smoking was completed by 2065 (60 per cent) 15-16-year-olds attending secondary schools in Doncaster in 1991. Almost one in four girls (23 per cent) and one in six boys (16 per cent) reported they were regular smokers, an overall increase of 8 per cent since a similar survey in 1988. An increase in smoking was recorded in 12 of the 14 schools which took part in both the 1988 and 1991 surveys. Differences in smoking prevalence were recorded between schools. School-based analysis is likely to be important for the development of effective local intervention. Possible reasons for the overall increase in smoking are discussed, and the need for concerted efforts to influence smoking regulation policy decisions is stressed.

Adolescent↗
PubMed1993

Characteristics associated with smoking cessation during pregnancy among working class women.

Although smoking prevalence among pregnant women is highest among those of lower socio-economic status, the factors associated with cessation in this high risk group are poorly documented. This paper reports on data from a survey of working class women in Nottingham and Coventry, who were interviewed 6 months after having delivered a baby. It compares the characteristics of the 32 women who quit smoking during their pregnancy and were still ex-smokers at the 6 month post-natal point, with 472 women who had continued to smoke during their pregnancy or had returned to smoking in the post-partum period. A logistic regression analysis revealed three variables that were independently associated with long term cessation-having previously quit for more than 1 week, having a non-smoking partner, and believing that the children of smokers are more likely to get infections. Among the most disadvantaged, an understanding of how close social ties and economic circumstances influence smoking behaviour is crucial, if we are to develop more effective smoking cessation intervention strategies for working class women.

Adolescent↗
PubMed1993

Evaluation of an AIDS education programme for young adults.

STUDY OBJECTIVES: To evaluate the impact of an AIDS education programme designed for young adults. DESIGN: A randomised trial with a pre-post test design. SETTING: Participants were drawn from six youth training centres in the city of Nottingham, England. STUDY POPULATION: All trainees aged 16-19 years attending the six centres were included in the sample and centres were randomly allocated to experimental (n = 173) and control (n = 164) groups. The response rate to both questionnaires was high (71%). MEASUREMENTS AND MAIN RESULTS: Data on sexual behaviour, knowledge, and attitudes towards HIV/AIDS were obtained by confidential questionnaire. Two thirds of the sample were sexually active. There were no differences between groups at pre-test and no differences by sex. The experimental group had a significantly higher level of knowledge than the control group post-test. Significantly more experimental than control trainees knew post-test that HIV could be transmitted via anal sex and through broken skin. In addition, twice as many experimental (53%) as control trainees (25%; p < 0.001) were aware that a cure for AIDS was unlikely in the near future. There were no observed effects on sexual behaviour, intentions, or attitudes. CONCLUSIONS: The Streetwize UK educational programme had a significant impact on young adults' knowledge of HIV/AIDS transmission and prevention in the short term. If community based AIDS education is to do more than merely inform, however, resources must be made available for peer led interventions and skills training.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Safe working practices and HIV infection: knowledge, attitudes, perception of risk, and policy in hospital.

OBJECTIVES--To assess the knowledge, attitudes, and perceptions of risk of occupational HIV transmission in hospital in relation to existing guidelines. DESIGN--Cross sectional anonymous questionnaire survey of all occupational groups. SETTING--One large inner city teaching hospital. SUBJECTS--All 1530 staff working in the hospital in October 1991 and 22 managers. MAIN MEASURES--Knowledge of safe working practices and hospital guidelines; attitudes towards patients with AIDS; perception of risk of occupational transmission of HIV; availability of guidelines. RESULTS--The response rate in the questionnaire survey was 63% (958/1530). Although staff across all occupational groups knew of the potential risk of infection from needlestick injury (98%, 904/922), significantly more non-clinical staff (ambulance, catering, and domestic staff) than clinical staff (doctors, nurses, and paramedics) thought HIV could be transmitted by giving blood (38%, 153/404 v 12%, 40/346; chi 2 = 66.1 p < 0.001); one in ten clinical staff believed this. Except for midwives, half of staff in most occupational groups and 19% (17/91) of doctors and 22% (28/125) of nurses thought gloves should be worn in all contacts with people with AIDS. Most staff (62%, 593/958), including 38% (36/94) of doctors and 52% (67/128) of nurses thought patients should be routinely tested on admission, 17% of doctors and 19% of nurses thought they should be isolated in hospital. One in three staff perceived themselves at risk of HIV. Midwives, nurses, and theatre technicians were most aware of guidelines for safe working compared with only half of doctors, ambulance, and paramedical staff and no incinerator staff. CONCLUSIONS--Policy guidelines for safe working practices for patients with HIV infection and AIDS need to be disseminated across all occupational groups to reduce negative staff attitudes, improve knowledge of occupational transmission, establish an appropriate perception of risk, and create a supportive and caring hospital environment for people with HIV. IMPLICATIONS--Managers need to disseminate policy guidelines and information to all staff on an ongoing basis.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Noninvasive quantitative evaluation of atherosclerosis using MRI and image analysis.

A new medical image analysis system to quantify atherosclerosis in the lower abdominal aorta using magnetic resonance imaging is described. This medical image analysis and display system permits the quantification of the three-dimensional (3D) properties of the vessel wall and lumen cross-sectional area and volumes. Preliminary results of employing this medical image analysis capability on magnetic resonance images demonstrated a twofold increase in wall volume per unit vessel length, corresponding to intimal thickening, before luminal narrowing was detected. This work demonstrated the feasibility and usefulness of quantitatively evaluating the 3D properties of the vessel lumen and wall by using a combination of magnetic resonance imaging and image analysis. The demonstration that intimal wall thickening is observed in images before observable occlusion of the lumen can be expected to provide an important early indicator of the future development of atherosclerosis. Such capability will permit detailed and quantitative studies to assess the effectiveness of therapies, such as drug, exercise, and dietary regimens.

Aorta↗
PubMed1989

A longitudinal study of the hopes and worries of adolescents.

This paper describes a longitudinal questionnaire study of the future hopes and worries of 547, 11- and 14-year-olds from Nottingham, England. Results from interviews with 152 of the 14-year-olds are also presented. More than half of the teenagers spontaneously expressed hopes for and worries about employment and unemployment. One third of adolescents, and more boys than girls, were concerned about war, including nuclear war. Proportions of pupils worried about unemployment, own mortality, lack of money and AIDS increased significantly with age. Interview and questionnaire findings were in general agreement. However, worries such as exam failure, childbirth and unhappy marriage were more prominent at interview and mentioned significantly more frequently by girls than boys. Worries about employment and nuclear war appear to predominate throughout adolescence, but are not the sole concern of this age group. Consideration should be given to discussing teenage worries in the context of school/family based educational ventures.

Adolescent↗
PubMed1988

Decreased plasma membrane fluidity in the development of atherosclerosis in cholesterol-fed rabbits.

Rabbits were fed a diet supplemented with 3% peanut oil or 3% peanut oil plus 0.5% cholesterol. Aortas from rabbits fed the cholesterol supplemented diet for 2 weeks were free of grossly visible lesions; however, aortas from rabbits fed this diet for 10 weeks exhibited extensive lesion development. Lesions were not observed in aortas of rabbits fed the high-fat supplemented diet. The fluorescence anisotropy of DPH was significantly (P = 0.0001) increased in plasma membranes isolated from aortas of rabbits fed the high-fat plus cholesterol vs. high-fat supplemented diet; the increase in fluorescence anisotropy observed after only 2 weeks on diet (0.201 +/- 0.002 vs. 0.144 +/- 0.002) was similar to that observed after 10 weeks on diet (0.244 +/- 0.002 vs. 0.193 +/- 0.001). The data support the hypothesis that plasma membrane fluidity [is decreased in atherosclerosis and indicate the decrease in membrane fluidity] occurs early in the development of the disease.

5'-Nucleotidase↗
PubMed1987

Effects of hypercholesterolemia on the microsomal membrane fluidity of intimal-medial versus medial layers of swine aorta: implications for the pathogenesis of vasospasm.

The hypothesis was examined that hypercholesterolemia induces a decrease in arterial microsomal membrane fluidity. To investigate this hypothesis, the fluorescence anisotropy (r) of 1,6-diphenylhexa-1,3,5-triene was measured in aortic microsomes isolated from the intimal-medial (IM) and medial (M) layers of swine thoracic aortas. After 10 weeks of feeding a high fat (10% lard) diet, serum cholesterol increased 2.3-fold compared to 3.6-fold in pigs fed a similar diet supplemented with 2% cholesterol. Based upon differences in r, the membrane fluidity of the IM layer was significantly less than the M layers. The membrane fluidity of the IM layer was inversely related to the severity of hypercholesterolemia regardless of dietary treatment. There were no differences in membrane fluidity among the three dissected M layers and the membrane fluidity of these layers was refractory to changes in serum cholesterol. A decrease in the membrane fluidity of the IM layer may contribute to the abnormal regulation of vascular tone which underlies the development of vasospasm in atherosclerotic arteries.

Animals↗