Biomedical subjects

R Taylor

Publications and source records attributed to R Taylor.

At least 91 records · Page 5Linked to original sources

PubMed2001

Variability of erythrocyte and serum lithium levels correlates with therapist treatment adherence efforts and maintenance treatment outcome.

This study investigated the relationship between psychotherapeutic interventions and pharmacologic measures of pharmacotherapy treatment adherence in patients with bipolar I disorder, as well as the relationship between these measures and treatment outcome. Subjects were participating in an ongoing maintenance treatment study. Audiotaped therapy sessions were rated for frequency of psychotherapeutic interventions related to pharmacotherapy treatment adherence. Pharmacologic measures of medication adherence were compared to the tape ratings as well as to treatment outcome. Variability in log erythrocyte (RBC) lithium-a marker of probable nonadherence to the pharmacotherapy regimen-for individual patients correlated significantly with treatment adherence interventions scale ratings. This marker of nonadherence was significantly related to maintenance treatment outcome, as was variability of the serum lithium level/dose (L/D) ratio; however, no relationship was found between treatment adherence interventions scale ratings and outcome.

Adult↗

PubMed2001

Glycerol dehydrogenase. structure, specificity, and mechanism of a family III polyol dehydrogenase.

BACKGROUND: Bacillus stearothermophilus glycerol dehydrogenase (GlyDH) (glycerol:NAD(+) 2-oxidoreductase, EC 1.1.1.6) catalyzes the oxidation of glycerol to dihydroxyacetone (1,3-dihydroxypropanone) with concomitant reduction of NAD(+) to NADH. Analysis of the sequence of this enzyme indicates that it is a member of the so-called iron-containing alcohol dehydrogenase family. Despite this sequence similarity, GlyDH shows a strict dependence on zinc for activity. On the basis of this, we propose to rename this group the family III metal-dependent polyol dehydrogenases. To date, no structural data have been reported for any enzyme in this group. RESULTS: The crystal structure of B. stearothermophilus glycerol dehydrogenase has been determined at 1.7 A resolution to provide structural insights into the mechanistic features of this family. The enzyme has 370 amino acid residues, has a molecular mass of 39.5 kDa, and is a homooctamer in solution. CONCLUSIONS: Analysis of the crystal structures of the free enzyme and of the binary complexes with NAD(+) and glycerol show that the active site of GlyDH lies in the cleft between the enzyme's two domains, with the catalytic zinc ion playing a role in stabilizing an alkoxide intermediate. In addition, the specificity of this enzyme for a range of diols can be understood, as both hydroxyls of the glycerol form ligands to the enzyme-bound Zn(2+) ion at the active site. The structure further reveals a previously unsuspected similarity to dehydroquinate synthase, an enzyme whose more complex chemistry shares a common chemical step with that catalyzed by glycerol dehydrogenase, providing a striking example of divergent evolution. Finally, the structure suggests that the NAD(+) binding domain of GlyDH may be related to that of the classical Rossmann fold by switching the sequence order of the two mononucleotide binding folds that make up this domain.

Amino Acid Sequence↗

PubMed2001

Combined calcaneal and metatarsal osteotomies for the treatment of cavus foot.

Cavovarus foot can be painful and disabling owing to deformity and instability. A method of surgical correction is presented with osteotomies of the forefoot and the hindfoot. The technique avoids arthrodesis while preserving joint motion, lowering the height of the arch, and correcting varus and adductus deformity. Increased ankle stability, elimination of the risk of stress fracture, decreased pain are expected outcomes.

Calcaneus↗

PubMed2001

A paradox: urgent BRCA genetic testing.

Diagnostic or predictive testing for germline mutations in cancer predisposition genes is inherently slow as result of both genetic counselling and mutation analysis. The overall time taken for mutation testing is not generally perceived as harmful to the individual and may be positively beneficial in order to permit full reflection on the implication of the genetic test results. However, we present three cases where we considered urgent genetic testing for the presence of mutations in th BRCA 1 and 2 genes to be necessary as the test result would have altered the subsequent clinical management of these individuals or their families.

Breast Neoplasms↗

PubMed2001

Minimum information about a microarray experiment (MIAME)-toward standards for microarray data.

Microarray analysis has become a widely used tool for the generation of gene expression data on a genomic scale. Although many significant results have been derived from microarray studies, one limitation has been the lack of standards for presenting and exchanging such data. Here we present a proposal, the Minimum Information About a Microarray Experiment (MIAME), that describes the minimum information required to ensure that microarray data can be easily interpreted and that results derived from its analysis can be independently verified. The ultimate goal of this work is to establish a standard for recording and reporting microarray-based gene expression data, which will in turn facilitate the establishment of databases and public repositories and enable the development of data analysis tools. With respect to MIAME, we concentrate on defining the content and structure of the necessary information rather than the technical format for capturing it.

Computational Biology↗

PubMed2001

Probability of axillary node involvement in patients with tubular carcinoma of the breast.

BACKGROUND: The aim of this study was to investigate the frequency of axillary metastasis in women with tubular carcinoma (TC) of the breast. METHODS: Women who underwent axillary dissection for TC in the Western Sydney area (1984--1995) were identified retrospectively through a search of computerized records. A centralized pathology review was performed and tumours were classified as pure tubular (22) or mixed tubular (nine), on the basis of the invasive component containing 90 per cent or more, or 75--90 per cent tubule formation respectively. A Medline search of the literature was undertaken to compile a collective series (20 studies with a total of 680 patients) to address the frequency of nodal involvement in TC. A quantitative meta-analysis was used to combine the results of these studies. RESULTS: The overall frequency of nodal metastasis was five of 31 (16 per cent); one of 22 pure tubular and four of nine mixed tumours (P = 0.019). None of the tumours with a diameter of 10 mm or less (n = 16) had nodal metastasis compared with five of 15 larger tumours (P = 0.018). The meta-analysis of 680 women showed an overall frequency of nodal metastasis in TC of 13.8 (95 per cent confidence interval 9.3-18.3) per cent. The frequency of nodal involvement was 6.6 (1.7--11.4) per cent in pure TC (n = 244) and 25.0 (12.5--37.6) per cent in mixed TC (n = 149). CONCLUSION: A case may be made for observing the clinically negative axilla in women with a small TC (10 mm or less in diameter).

Adenocarcinoma↗

PubMed2001

Tissue insulin sensitivity and body weight in polycystic ovary syndrome.

OBJECTIVE: Polycystic ovarian syndrome (PCOS) and obesity both affect insulin sensitivity. This study was designed to investigate the biochemical indices of PCOS and tissue insulin sensitivity in groups of lean and obese women with clinically equivalent degrees of the syndrome, relative to control subjects. DESIGN: A prospective study of in vivo parameters and in vitro study of adipocytes to assess insulin sensitivity. PATIENTS: Six lean and 14 overweight patients fulfilling formal diagnostic criteria for PCOS were studied. The degree of hirsutism and amenorrhoea was similar in each group. Eight control subjects were also studied. MEASUREMENTS: Endocrine and metabolic parameters were measured in lean and overweight patients with PCOS and control subjects. In vitro studies of adipocyte insulin receptor binding and adipocyte insulin action were performed. RESULTS: The mean plasma LH level was elevated in both groups of PCOS but was significantly higher in the lean group (LH levels were 25.1 +/- 3.1 and 14.5 +/- 1.6 iu/l in lean PCOS and obese PCOS, respectively (P = 0.01)). There was a strong inverse correlation between BMI and LH levels (R = - 0.70, P = 0.001). Fasting insulin levels were elevated in both lean and obese groups (11.5 +/- 2.8 and 26.8 +/- 8.1 mU/l, respectively; P = 0.068). Mean serum testosterone and serum androstenedione levels were also elevated in PCOS compared to control subjects but there was no difference between the two groups of PCOS subjects. Insulin receptor binding in amenorrhoeic subjects with PCOS was low in both lean and obese patients with PCOS but was not significantly different between the two groups (0.79 +/- 0.17% and 0.66 +/- 0.07% per 10 cm2 cell membrane, respectively). Maximally insulin-stimulated rates of 3-O-methylglucose transport were low in both groups compared to previously studied normal subjects (0.96 +/- 0.21 and 0.64 +/- 0.07 pmol per 10 cm2 membrane in lean and obese PCOS subjects, respectively; P = NS). CONCLUSIONS: Lean subjects with a given phenotypic expression of PCOS have an equivalent degree of tissue insulin resistance compared to obese PCOS subjects. This implies that the insulin resistance may be a primary feature of PCOS. If this is so, a similar clinical degree of the syndrome may be brought about by genetically determined insulin resistance in lean subjects or by insulin resistance which is secondary to obesity.

Adipocytes↗

PubMed2001

Development and validation of a questionnaire to evaluate the effectiveness of evidence-based practice teaching.

AIM: The aim of this study was to develop and validate a questionnaire to evaluate the effectiveness of evidence-based practice (EBP) teaching. METHODS: The 152 questionnaires completed by health care professionals with a range of EBP experience were used in this study. Cronbach's alpha for the knowledge and attitude questions indicated a satisfactory level of internal consistency (i.e. >0.60). RESULTS: The discriminative validity was evidenced by a statistically significant difference in the knowledge and attitude scores of 'novices' (i.e. little or no prior EBP education) compared with 'experts' (i.e. health care professionals and academics currently teaching EBP). Moderate to good (> or =0.4) sensitivity index scores were observed for both knowledge and attitude scores as the result of comparing individuals before and after an EBP intervention. CONCLUSIONS: The results of this validation study indicate that the developed questionnaire is a satisfactory tool with which to evaluate the effectiveness of EBP teaching interventions.

Education, Medical↗

PubMed2001

System validation and work practice efficiency gains of a new localization method for stereotactic radiotherapy.

The increased procedural demands of stereotactic localization techniques when compared with conventional treatment practices reduces machine efficiency, an outcome likely to be greatly magnified by the introduction of fractionation to stereotactic techniques. Currently in Australia and New Zealand there are no guidelines for the definition of efficiency. We sought to devise a system to simultaneously validate the accuracy and efficiency of the technique. The frameless relocation methods employed in the Medtronic Sofamor Danek (MSD) stereotactic radiotherapy (SRT) system were studied in the clinical setting. Accuracy has been determined according to the accumulation of errors throughout the planning and treatment process. The clinical demands of the system (staffing and resources) were analysed relative to conventional treatment approaches. Timing studies indicate a mean time of 19.7 min for treatment of a daily SRT fraction (4-5 arcs, single isocentre). Cost and staffing requirements are similar to those for conventional radiotherapy. It is concluded that with the system used, SRT is efficient for routine clinical implementation, with the level of efficiency increasing with increasing patient numbers. It is recommended that a common acceptance standard be developed to allow cross-institutional comparison of the clinical efficiency of new treatment techniques.

Brain Neoplasms↗

PubMed2001

Frequency and predictors of axillary lymph node metastases in invasive breast cancer.

BACKGROUND: The objectives of the present study were to evaluate the incidence and predictors of axillary lymph node metastases (ALNM) in patients with breast cancer, and to identify if axillary surgery could be safely omitted in selected patients. METHODS: Between January 1996 and May 2000, 492 patients underwent 501 axillary lymph node dissections (ALND). The incidence of ALNM was correlated with clinical and pathological characteristics by univariate and multivariate analyses. RESULTS: Axillary lymph node metastases were found in 41% (207/501) of cases. Univariate analysis showed that palpability of primary and axillary lymph node (ALN), pathological tumour size, grade, lymphovascular invasion (LVI) and multifocality or multicentricity were significant predictors of ALNM. By multivariate analysis, palpability of ALN, pathological tumour size, LVI and multifocality or multicentricity remained as independent predictors. Among the 431 cases without palpable ALN, no ALNM were found if the tumour was < or = 5 mm, non-multifocal or multicentric, and without LVI, or the tumour was a tubular or mucinous carcinoma < or = 15 mm (n = 21). The frequency of ALNM in the absence of the other risk factors was 11% (7/64) if the tumour size was > 5-10 mm, and 17% (19/113) if the tumour was > 10-20 mm. However, the incidence of ALNM was 72% for the 32 clinically node-negative cases with multifocal or multicentric tumour > or = 10 mm and LVI. Those patients with palpable ALN (n = 66) had a greater than 50% risk of ALNM. CONCLUSIONS: Routine ALND could be omitted in clinically node-negative patients with either a < or = 5-mm, LVI-negative tumour, or a < or = 15-mm tubular or mucinous carcinoma. Axillary lymph node dissection is still useful for determining pathological nodal status in all other cases, and in most cases with palpable ALN, as a therapeutic manoeuvre.

Adult↗

PubMed2001

Couch or crouch? Examining the prostate: a randomized study comparing the knee-elbow and the left-lateral position.

OBJECTIVE: To compare two methods of examining the prostate, the knee-elbow (KE) and left-lateral (LL) positions, to establish which allows a more complete examination, and to determine if there is any difference in patients' perception of pain or embarrassment for either method. PATIENTS AND METHODS: All men attending two urology clinics who required a prostate examination were eligible for the study. Both the KE and LL methods were used for each participant, by the same clinician. The order in which the examinations were conducted was randomized using the last digit of the patient's hospital number. RESULTS: Five clinicians examined 117 men; three patients refused to participate and the examination data were incomplete for two. Irrespective of the order in which the examinations were conducted (P = 0.6), the KE position permitted a greater proportion of the prostate to be palpated (Wilcoxon signed-ranks test, z = -4.7, P < 0.001) in 35% of patients, but there was no difference in 60%. Most patients found the examinations equally painful and embarrassing. However, for those who expressed a difference, the KE was 1.9 times more comfortable than the LL position and twice as embarrassing. CONCLUSION: The two methods of prostate examination were equal for completeness of examination, pain and embarrassment in most patients. However, the KE offers an alternative to the LL position for those patients in whom the prostate is difficult to palpate or who find the examination painful.

Adult↗

PubMed2001

Total costs and predictors of costs in patients with systemic lupus erythematosus.

OBJECTIVE: To determine the annual direct, indirect and total costs and predictors of costs in patients with systemic lupus erythematosus (SLE). METHODS: One hundred and five patients with SLE completed questionnaires on health-care utilization and employment history. Predictors of costs were determined by multiple regression analyses using direct, indirect and total costs as outcome variables. Demographics, health status, disease activity, end-organ damage, social support and satisfaction with care were used as predictor variables. RESULTS: The mean annual total cost per patient was pounds sterling 7913. Direct costs were a third and indirect costs two-thirds of the total cost. Higher education level, greater disease activity and lower physical functioning were associated with higher direct, indirect and total costs. Higher direct costs were also associated with greater damage and younger age. CONCLUSION: SLE has a considerable impact on the health-care system and society. Improvement in disease activity and physical health and prevention of end-organ damage may reduce costs in SLE.

Adolescent↗

PubMed2001

Exercise training, vascular function, and functional capacity in middle-aged subjects.

PURPOSE: The aim of this study was to investigate the effect of 8 wk of exercise training on functional capacity, muscular strength, body composition, and vascular function in sedentary but healthy subjects by using a randomized, crossover protocol. METHODS: After familiarization sessions, 19 subjects aged 47 +/- 2 yr (mean +/- SE) undertook a randomized, crossover design study of the effect of 8 wk of supervised circuit training consisting of combined aerobic and resistance exercise. Peak oxygen uptake (.VO(2peak)), sum of 7 maximal voluntary contractions and the sum of 8 skinfolds and 5 segment girths were determined at entry, crossover, and 16 wk. Endothelium-dependent and -independent vascular function were determined by forearm strain-gauge plethysmography and intrabrachial infusions of acetylcholine (ACh) and sodium nitroprusside (SNP) in 16 subjects. RESULTS: Training did not alter ACh or SNP responses. .VO(2peak), (28.6 +/- 1.1 to 32.6 +/- 1.3 mL.kg(-1).min(-1), P < 0.001), exercise test duration (17.4 +/- 1.1 to 22.1 +/- 1.2 min, P < 0.001), and muscular strength (465 +/- 27 to 535 +/- 27 kg, P < 0.001) significantly increased after the exercise program, whereas skinfolds decreased (144 +/- 10 vs 134 +/- 9 mm, P < 0.001). CONCLUSION: These results suggest that moderate intensity circuit training designed to minimize the involvement of the arms improves functional capacity, body composition, and strength in healthy, middle-aged subjects without significantly influencing upper limb vascular function. This finding contrasts with previous studies in subjects with type 2 diabetes and heart failure that employed an identical training program.

Anthropometry↗

PubMed2001

Cervical screening: population-based comparisons between self-reported survey and registry-derived Pap test rates.

OBJECTIVE: To compare self-reported cervical screening rates, as recorded in the 1998 NSW Health Survey, with registry-based cervical screening rates for NSW for the same period; and to examine factors associated with over-estimates of cervical screening rates by self-report. METHODS: Self-reported cervical screening data was extracted from the 1998 NSW Health Survey, biennial screening rates estimated and compared with biennial cervical screening rates for 1997-98, as recorded on the NSW Pap Test Register (PTR). Rates and differences were related to socio-demographic characteristics of the 17 Area Health Services of NSW. RESULTS: According to the 1998 NSW Health Survey, 74% of women reported having a Pap test during the previous two years. The equivalent rate recorded on the NSW PTR for 1997-98 was 62% (p<0.0001). Among the 17 Area Health Services of NSW these differences ranged from nine to 19 percentage points. Area-specific differences between self-reported and registry-based screening rates were negatively correlated with the registry-based screening rate. Age-specific differences between self-reported and registry-based screening rates were positively correlated with registry-based screening rates. No SES, regional or migrant population characteristics were predictive of differences between recorded and surveyed screening rates. CONCLUSION: Cervical screening rates in NSW derived from self-reported survey data exceed the rate recorded by the NSW Pap Test Register by 12 percentage points (equivalent to 19% inflation). IMPLICATIONS: The data in this paper can be used indicatively where necessary to adjust for over-reporting in cervical cancer screening surveys.

Adolescent↗

PubMed2001

Passive smoking and lung cancer: a cumulative meta-analysis.

OBJECTIVE: To review the epidemiological evidence for the association between passive smoking and lung cancer. METHOD: Primary studies and meta-analyses examining the relationship between passive smoking and lung cancer were identified through a computerised literature search of Medline and Embase, secondary references, and experts in the field of passive smoking. Primary studies meeting the inclusion criteria were meta-analysed. RESULTS: From 1981 to the end of 1999 there have been 76 primary epidemiological studies of passive smoking and lung cancer, and 20 meta-analyses. There were 43 primary studies that met the inclusion criteria for this meta-analysis; more studies than previous assessments. The pooled relative risk (RR) for never-smoking women exposed to environmental tobacco smoke (ETS) from spouses, compared with unexposed never-smoking women was 1.29 (95% CI 1.17-1.43). Sequential cumulative meta-analysed results for each year from 1981 were calculated: since 1992 the RR has been greater than 1.25. For Western industrialised countries the RR for never-smoking women exposed to ETS compared with unexposed never-smoking women, was 1.21 (95% CI 1.10-1.33). Previously published international spousal meta-analyses have all produced statistically significant RRs greater than 1.17. CONCLUSIONS: The abundance of evidence in this paper, and the consistency of findings across domestic and workplace primary studies, dosimetric extrapolations and meta-analyses, clearly indicates that non-smokers exposed to ETS are at increased risk of lung cancer. IMPLICATIONS: The recommended public health policy is for a total ban on smoking in enclosed public places and work sites.

Developed Countries↗

PubMed2001

Small area population disease burden.

Small area health statistics has assumed increasing importance as the focus of population and public health moves to a more individualised approach of smaller area populations. Small populations and low event occurrence produce difficulties in interpretation and require appropriate statistical methods, including for age adjustment. There are also statistical questions related to multiple comparisons. Privacy and confidentiality issues include the possibility of revealing information on individuals or health care providers by fine cross-tabulations. Interpretation of small area population differences in health status requires consideration of migrant and Indigenous composition, socioeconomic status and rural-urban geography before assessment of the effects of physical environmental exposure and services and interventions. Burden of disease studies produce a single measure for morbidity and mortality--disability adjusted life year (DALY)--which is the sum of the years of life lost (YLL) from premature mortality and the years lived with disability (YLD) for particular diseases (or all conditions). Calculation of YLD requires estimates of disease incidence (and complications) and duration, and weighting by severity. These procedures often mean problematic assumptions, as does future discounting and age weighting of both YLL and YLD. Evaluation of the Victorian small area population disease burden study presents important cross-disciplinary challenges as it relies heavily on synthetic approaches of demography and economics rather than on the empirical methods of epidemiology. Both empirical and synthetic methods are used to compute small area mortality and morbidity, disease burden, and then attribution to risk factors. Readers need to examine the methodology and assumptions carefully before accepting the results.

Actuarial Analysis↗

PubMed2001

Variation in cervical cancer screening by region, socio-economic, migrant and indigenous status in women in New South Wales.

The purpose of this study was to estimate the extent of association of cervical screening in NSW women with socio-economic status (SES), rurality, and proportions of non-English speaking background (NESB) and Indigenous status. Data on women who had at least one Pap test over two years (January 1998-December 1999) were obtained from the NSW Pap test Register. Each local government area (LGA) was allocated to categories of population proportions of NESB and Indigenous status, a rurality classification based on population density and remoteness, and to an SES quintile. The odds ratios (OR) of having a Pap test were estimated and confounding adjusted by multiple logistic regression analysis. Implied Pap test rates in urban NESB and in rural Indigenous women were estimated from the modelled estimates. The adjusted OR for a Pap test in large rural centres (1.14) was significantly higher than those for metropolitan or capital city residents (0.9 and 1.0 respectively). Adjusted OR for a Pap test in other rural centres (0.73) and other remote areas (0.64) were significantly lower than those for metropolitan or capital city residents. In urban populations the lowest OR were in areas with both low SES and high proportion of NESB. The lowest OR for Pap screening in rural populations occurred in the most remote areas with the highest proportion of Indigenous women. For urban NESB women the biennial Pap test rate was estimated as 50%, and for rural Indigenous women 29%, compared with the NSW average of 59%.

Adult↗

PubMed2001

General scales of community reaction to noise (dissatisfaction and perceived affectedness) are more reliable than scales of annoyance.

General measures of reaction to noise, which assess the respondent's perceived affectedness or dissatisfaction, appear to be more valid and internally consistent than more narrow measures, such as specific assessment of noise annoyance. However, the test-retest reliability of general and specific measures has yet to be compared. As a part of the large-scale Sydney Airport Health Study, 97 respondents participated in the same interview twice, several weeks apart. Test-retest reliabilities were found to be significant (p < 0.001) for two general questions and three specific "annoyance" questions. The general measures were significantly more valid for four of the six correlations (with activity disturbance), and more stable than the annoyance scales for five of the six possible test-retest comparisons. Amongst 1,015 respondents at Time 1, the questions regarding general reaction were more internally consistent than the questions regarding annoyance. Taken together, these data indicate that general measures of reaction to noise have superior psychometric properties (validity, internal consistency, and stability) compared with measures of specific reactions such as annoyance.

Adolescent↗