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Biomedical subjects

R Craven

Publications and source records attributed to R Craven.

At least 19 recordsLinked to original sources
PubMed2006

Multiple sites of impingement of a tracheal tube as it is advanced over a fibreoptic bronchoscope or tracheal tube introducer in anaesthetized, paralysed patients.

Impingement of the tracheal tube on upper airway structures occurs commonly during advancement over a fibreoptic bronchoscope or introducer. In this descriptive study a fibrescope was used to assess the site and mechanism of tracheal tube impingement during advancement over a variety of fibreoptic bronchoscopes and introducers during orotracheal intubation in anaesthetized adults. The effect of the 90 degree counterclockwise rotation manoeuvre in overcoming impingement was also assessed. We recorded impingement at the right arytenoid, left arytenoid, epiglottis, interarytenoid tissue and the left pyriform fossa. Our study found a wider range of sites at which impingement may occur than in previous studies. We also found that when 90 degree counterclockwise rotation of the tip of the tracheal tube was achieved, the impingement was reliably overcome.

Adolescent↗
PubMed2003

A postmortem study of the mediodorsal nucleus of the thalamus in schizophrenia.

Four studies have reported that the mediodorsal nucleus of the thalamus (MD) is smaller and contains fewer neurons in schizophrenia. The MD is a key node in a circuit proposed to be dysfunctional in the disorder. However, one study did not find a MD volume loss in schizophrenia, and all the studies to date are relatively small. Given the importance of establishing unequivocally the presence of MD pathology, we have carried out a study of the volume and number of neurons in the left and right MD in 21 patients with schizophrenia and 27 healthy comparison subjects. We also measured the size of MD neurons, and estimated total thalamic volume. We found no difference in the volume of the MD, the number of MD neurons, or the size of MD neurons in either hemisphere in schizophrenia. Neither was total thalamic volume altered. There are no obvious methodological or clinical factors to explain our failure to replicate the finding of MD involvement in schizophrenia. Hence our negative observations, in the largest sample yet investigated, cast doubt on the robustness and/or the generalisability of MD neuropathology in schizophrenia.

Adult↗
PubMed2002

Placebo-controlled trial of transdermal estrogen therapy alone in postmenopausal women: effects on arterial compliance and endothelial function.

BACKGROUND: The cardiovascular effects of hormone replacement therapy (HRT) are controversial. Improvement in vascular function, potentially mediated, at least in part, via improvements in lipid profiles, is a proposed mechanism of estrogen action; however, there are few controlled human trials. We have studied the effects of HRT, independent of changes in lipid profile, with transdermal estrogen therapy, focusing on blood pressure, lipid profiles and vascular function, encompassing both biomechanical arterial properties (systemic arterial compliance and pulse wave velocity) and endothelial function (flow-mediated vasodilatation). METHODS: In this 2-year, double-blind, placebo-controlled, cross-over study, 34 healthy postmenopausal women were randomized to transdermal estrogen alone (Menorest, 50 micrograms) or placebo. After withdrawals, 25 women completed measurements at baseline, 6 weeks, 6 months and 12 months during both treatment phases. RESULTS: Transdermal estrogen did not improve blood pressure, lipid profiles or arterial function, compared with placebo. CONCLUSION: From this randomized, controlled trial, it appears that transdermal estrogen alone, in healthy postmenopausal women, does not improve lipid profiles or a spectrum of indices of arterial function, compared with placebo. These results would suggest that there might not be a beneficial effect of transdermal HRT on the vasculature in postmenopausal women.

Administration, Cutaneous↗
PubMed2001

Tailored treatments.

Explore the source record for details and available documents.

Black or African American↗
PubMed2001

Proper processing of avian sarcoma/leukosis virus capsid proteins is required for infectivity.

The formation of the mature carboxyl terminus of CA in avian sarcoma/leukemia virus is the result of a sequence of cleavage events at three PR sites that lie between CA and NC in the Gag polyprotein. The initial cleavage forms the amino terminus of the NC protein and releases an immature CA, named CA1, with a spacer peptide at its carboxyl terminus. Cleavage of either 9 or 12 amino acids from the carboxyl terminus creates two mature CA species, named CA2 and CA3, that can be detected in avian sarcoma/leukemia virus (R. B. Pepinsky, I. A. Papayannopoulos, E. P. Chow, N. K. Krishna, R. C. Craven, and V. M. Vogt, J. Virol. 69:6430-6438, 1995). To study the importance of each of the three CA proteins, we introduced amino acid substitutions into each CA cleavage junction and studied their effects on CA processing as well as virus assembly and infectivity. Preventing cleavage at any of the three sites produced noninfectious virus. In contrast, a mutant in which cleavage at site 1 was enhanced so that particles contained CA2 and CA3 but little detectable CA1 was infectious. These results support the idea that infectivity of the virus is closely linked to proper processing of the carboxyl terminus to form two mature CA proteins.

Amino Acid Sequence↗
PubMed2001

An investigation of parents' attitudes to dental health and school dental screening.

OBJECTIVE: The aim of this study was to investigate factors that influence parental responses to school dental screening and dental care for their children. The expectations were that this study would aid reforms to the dental screening service. RESEARCH DESIGN: The study utilised qualitative research methodology involving a series of discussion groups. PARTICIPANTS: Groups were conducted amongst parents who resided in a deprived area of Manchester and whose children had recently undergone school dental screening. RESULTS: During analysis two distinct groups of parents emerged. The first group were regular asymptomatic attenders, however attitudes towards school dental screening and their subsequent behaviour differed within the group. The second group were irregular symptomatic attenders, there were also differences of opinion and behaviour towards school dental screening in this group. For each group there were distinct factors that formed the parent's response to school dental screening and attitudes to their child's dental attendance. CONCLUSIONS: The majority of parents supported school dental screening and some relied solely on screening as the source of dental care for their children. There was a degree of confusion as to who provided the service and some criticism of the communication about screening. This could result in conflict with GDPs and undermining of faith in the profession. Some parents considered dental health to be the responsibility of the child and the profession once children had reached the age of seven or so.

Attitude to Health↗
PubMed2000

An evaluation of a training programme in primary care research for general dental practitioners.

AIMS: To determine whether general dental practitioners would find seminars on research methods in primary care research of interest and whether they would be stimulated to plan their own research. METHOD: Questionnaire with both open and closed questions distributed to participants at the end of the seminars. 10 seminars in locations throughout the north west of England were planned. RESULTS: 98 dentists attended the seminars of whom 81 returned questionnaires, giving a response rate of 82.6%. More than 60% found the seminars and the specially developed teaching manual very useful. However there was somewhat less enthusiasm for undertaking research projects. CONCLUSIONS: The findings suggest that some GDPs are interested in primary care research but are not keen to initiate or plan research themselves.

Dental Research↗
PubMed1999

An investigation into the use of a dental hygienist in school screening.

OBJECTIVE: A pilot study to measure the validity of using a hygienist to carry out school screening. DESIGN: Following a standard training programme a dental hygienist (DH), recruited from general practice, a newly appointed dental officer (DO) and an epidemiologist (SDO), who acted as the standard, all screened the same group of school children on two occasions. SETTING: An inner city school with known high levels of disease. PARTICIPANTS: Ninety-eight 7- and 8-year-old children attending school. MAIN OUTCOME MEASURES: For each clinician the levels of referral, the reasons for referral and the repeatability were measured. RESULTS: The hygienist referred 26 children (27%) for further examination while the DO and the SDO both referred 61 (62%). The DO achieved the required standards of sensitivity and specificity when results were compared with the SDO but the hygienist did not. Intra-examiner reliability in all three clinicians was good. CONCLUSIONS: The standard training programme used to prepare dental officers to carry out school screening to an agreed standard was insufficient for this hygienist's needs.

Chi-Square Distribution↗
PubMed1998

Structure, stability, and development of young children's self-concepts: a multicohort-multioccasion study.

A new, individual administration procedure for assessing multiple dimensions of self-concept for young children 5-8 years of age (Marsh, Craven, & Debus) was the basis of this study. We expanded this application in a multicohort-multioccasion (MCMO) study that provides simultaneous multicohort comparisons (cross-sectional comparisons of different age cohorts) and longitudinal comparisons of the same children on multiple occasions. There was reasonable support for predictions that reliability, stability, factor structure, and the distinctiveness of the SDQ factors would improve with age (a between-group age cohort comparison) and from 1 year to the next (a longitudinal comparison), and that small gender differences were reasonably stable over age. Consistent with the proposal that children's self-perceptions become more realistic with age, Time 1 (T1) teacher ratings were more highly correlated with student self-ratings at T2 than T1 and contributed to the prediction of T2 self-concept beyond effects mediated by T1 self-concepts. The results support and expand the surprisingly good support for the multidimensionality of self-concept responses for very young children using this procedure.

Age Factors↗
PubMed1997

Effects of oestrogen and progesterone on age-related changes in arteries of postmenopausal women.

1. Hormone replacement therapy (HRT) with oestrogen or oestrogen plus progestin may have different effects on arterial structure and function. To examine this question, carotid artery intima-medial thickness (IMT) and indices of systemic and carotid arterial compliance were measured in groups of older men, postmenopausal women not on HRT (non-HRT) and those women on long-term HRT with oestrogen alone (HRT-E) or oestrogen plus progestin (HRT-EP). 2. Sixty men, 90 postmenopausal women taking HRT and 91 not taking HRT participated in the study. The groups were similar for age, body mass index, numbers of smokers, physical activity, alcohol intake and blood pressure. 3. Plasma total cholesterol was reduced and high-density lipoprotein-cholesterol was increased in the HRT group compared with the non-HRT group; low-density lipoprotein-cholesterol, triglyceride and lipoprotein (a) values were similar in these two groups. Results for HRT-E and HRT-EP subgroups were similar. 4. Carotid IMT was significantly reduced in the HRT group compared with men and non-HRT groups. Results for HRT-E and HRT-EP subgroups were similar. 5. Mean systemic arterial compliance (SAC) was significantly greater in men than in women and was related to age; SAC was higher in both HRT-E and HRT-EP groups compared with the non-HRT group. Indices of carotid stiffness were similar in men and in non-HRT groups. The HRT-EP group showed increased carotid stiffness compared with the HRT-E group. 6. There is an apparent protective effect of long-term oestrogen therapy on carotid IMT and age-related changes in arterial stiffness. Progestin does not alter the IMT effects but may adversely influence arterial stiffness.

Aged↗
PubMed1997

A comparison of the subjective oral health status of older adults from deprived and affluent communities.

A comparative study of the subjective oral health status of 60-65-year-old residents was undertaken in two Liverpool electoral wards, Vauxhall, the most deprived, and Woolton, the most affluent in the city. The measuring instrument used was the Subjective Oral Health Status Indicators (SOHSI) questionnaire devised by Locker. The questionnaire was administered by post to random samples of 250 residents from each ward. The main aim of the study was to compare the reported impact of oral conditions on the lives of individuals living in deprived and affluent communities. Responses of 59.6% for the deprived ward and 77.7% for the affluent ward were achieved. The literature suggested that significant differences could be expected between the wards in the reporting of subjective impact. However, significantly greater impact for only one functional sub-scale and one psycho-social sub-scale was reported by residents from the deprived ward. Further analysis of the relationship between impact and socio-demographic variables revealed a strong association between self-reported general health status and the subjective oral health indicators. Finally, a stepwise regression analysis found that pain and chewing problems were the only significant predictors of psycho-social impact. This finding confirms that the individual's socio-economic circumstances are of secondary importance to pain and functional problems in determining the psycho-social effects of oral conditions, as predicted by the conceptual model on which the measuring instrument is based.

Aged↗
PubMed1997

An evaluation of a measure of subjective oral health status in the UK.

OBJECTIVE: To evaluate the performance in the United Kingdom of an instrument to measure the subjective impact of oral conditions; that is, the functional restrictions and symptoms, as well as the disability and disadvantage experienced as a result of oral problems. BASIC RESEARCH DESIGN: The instrument tested was the Subjective Oral Health Status Indicators (SOHSI) that consists of a battery of eight subjective indicators and which has been developed and tested in Canada. A questionnaire containing these indicators was administered by post to two random samples of two hundred and fifty residents aged 60-65 years, one from an affluent and one from a deprived electoral ward in Liverpool. MAIN OUTCOME MEASURES: Reliability was assessed as test-retest, and internal consistency using Cronbach's alpha. Construct and concurrent validity were assessed by determining the association between the subjective indicators and dentate status, reported satisfaction and overall subjective assessment of oral health. The constituent concepts of the theoretical model on which the instrument is based were tested by correlating the subjective indicators and the self-reported number of teeth. CONCLUSIONS: The instrument was found to be reliable both in terms of test-retest reliability and internal consistency. It also demonstrated satisfactory construct and concurrent validity. Correlations between self-reported number of teeth and the subjective indicators confirm the strength of the theoretical model on which the instrument was based and provide further evidence of the content validity of this composite measure.

Aged↗