Biomedical subjects

N Owen

Publications and source records attributed to N Owen.

At least 91 records · Page 5Linked to original sources

PubMed1995

Deletions in the survival motor neuron gene on 5q13 in autosomal recessive spinal muscular atrophy.

Autosomal recessive spinal muscular atrophy is a motor neuron disease which affects about 1 in 10,000 births. Recent evidence shows that the candidate region contains multiple copies of genes and pseudogenes and is characterised by genome instability. We have analysed the frequency of deletions in a recently characterised candidate survival motor neuron (SMN) gene. Our data confirm previous analyses and show that this gene is disrupted by deletion in SMA patients. The same deletion frequency is observed in the milder variants of the disease as in patients with the severe form. In addition, we observed one case of a new mutation in a family previously thought not to be segregating for a chromosome 5 linked form of SMA. This assay is a very good diagnostic for SMA although no direct correlation between phenotype and genotype is apparent and carrier status cannot be determined. The implications for the identification of the gene or genes causing the disease are discussed.

Chromosomes, Human, Pair 5↗

PubMed1995

Colorectal cancer and its prevention: prevalence of beliefs, attitudes, intentions and behaviour.

There is so far only limited evidence from randomised controlled trials that screening for colorectal cancer using the faecal occult blood test produces significant mortality reductions in screened groups, but there is considerable activity and interest in the use of such screening in Australia. Beliefs, attitudes, intentions and behaviour in relation to colorectal cancer and screening were examined among participants 40 years and older (n = 1776) who took part in a representative population survey. While there were high levels of awareness of faecal occult blood test screening, most respondents had not had a test, nor did they intend to take a test in the future. Important determinants of participation in screening were a family history of colorectal cancer, a belief that bowel cancer can be cured if detected at an early stage, a perception of personal susceptibility to bowel cancer and an acceptance of the technique. Factors such as these are likely to influence the success of any future screening program in Australia.

Adult↗

PubMed1995

Dietary behaviours of volunteers for a nutrition education program, compared with a population sample.

The dietary behaviours of and recent dietary change by volunteers for a nutrition education program were compared with those of a more population-representative sample. The population sample was randomly selected from the electoral rolls of three Australian cities. Those selected received questionnaires which were to be completed and returned by mail. The sample of volunteers was recruited from the electoral rolls of suburbs of either high or low social status in one of these cities. Volunteers were posted a questionnaire, to be returned in person. A quantified food frequency questionnaire was used to estimate relative intake of 19 nutrients, plus energy intake. Occupation, age, sex, reported recent dietary change and diet-related beliefs were also assessed. The population sample was weighted to the age and occupational distribution of the education program sample. Compared to the 874 respondents in the population sample (70.4 per cent response rate), the 487 volunteers (24.2 per cent response rate) for the nutrition education program had healthier nutrient intakes and reported more dietary behaviour changes. Recruitment in the education program was greater in areas of higher social status (32 per cent) than in areas of lower social status (20 per cent). The potential effect of such a program on the whole population was demonstrated by the proportions that volunteered and the characteristics of these volunteers. The need to provide a range of opportunities for changing dietary behaviour, according to the health-related behaviours and beliefs of target groups and their socio-economic circumstances, was highlighted.

Adolescent↗

PubMed1995

Smoking-related beliefs and behaviour of South Australians with diabetes.

Data cumulated from three representative population surveys (n = 9402) in South Australia were used to determine smoking prevalence of those aged 15 years or over with and without self-reported medically confirmed diabetes. Overall, smoking prevalence in the two groups did not differ. However, among those aged under 40 years with self-reported diabetes, smoking prevalence approached 55 per cent, which was significantly higher than in young respondents without diabetes (32 per cent). Diabetic smokers were no more likely than were nondiabetic smokers to have tried to quit or to be ready to quit; one-quarter of diabetic smokers had no thought of quitting or of modifying their habit. Smokers with diabetes were significantly more likely to be heavy smokers (43.5 per cent) than were nondiabetic smokers (23.4 per cent). Fewer smokers with diabetes tended to believe that smoking causes or aggravates heart disease or circulatory problems than did other smokers, although these differences did not reach statistical significance. Additional effort is required to find methods to assist people with diabetes to refrain from smoking.

Adolescent↗

PubMed1995

An economic evaluation of four work site based cardiovascular risk factor interventions.

We used outcome data from a randomized work site intervention trial to examine the cost-effectiveness of four cardiovascular disease (CVD) risk reduction programs: health risk assessment (HRA), risk factor education (RFE), behavioral counseling (BC), and behavioral counseling plus incentives (BCI). Composite CVD risk scores were derived from measures of serum total cholesterol, blood pressure, number of cigarettes smoked, body mass index, and aerobic capacity. The economic evaluation of the programs focused on the subset of costs most sensitive to the differences between the interventions, and a sensitivity analysis examined some of the relevant cost variations. At the 6-month follow-up (i.e., the "action" or initiation stage of lifestyle change), the RFE, BC, and BCI interventions produced a significant reduction in cardiovascular risk. Incremental analyses demonstrated RFE to be more cost-effective, but not as clinically effective as BC; BC was more cost-effective than RFE when assessment costs were included, and BCI was judged to be the least cost-effective. At the 12-month follow-up (i.e., the "maintenance" stage of lifestyle of change), BC was the only program found to produce a significant reduction in CVD risk. Individualized behavioral counseling was found to be a cost-effective strategy for the initiation and maintenance of CVD risk factor reduction.

Adult↗

PubMed1995

Serial mass-media campaigns to promote physical activity: reinforcing or redundant?

Changes associated with two serial, nationwide, mass-media-based campaigns to promote physical activity conducted by the National Heart Foundation of Australia in 1990 and 1991 were examined. Surveys conducted before and after each campaign found statistically significant differences in message awareness (46% vs 71% in 1990; 63% vs 74% in 1991). In 1990, there were significant increases in walking, particularly among older people, and in intentions to exercise. No such changes were apparent in 1991. In the case of these two campaigns, conducted 1 year apart, the second may have been redundant.

Adolescent↗

PubMed1995

Spirometric standards for healthy adult lifetime nonsmokers in Australia.

The aim of this study was to develop suitable spirometric prediction equations for asymptomatic Caucasian adults in the Australian population. These equations were compared with those of previous studies and constants were presented which, when associated with the prediction equations, permitted the calculation of 5% tolerance intervals for lung function. The 1,302 subjects (aged 18-78 yrs) who underwent pneumotachograph spirometry, using techniques recommended by the American Thoracic Society, were a sample from metropolitan Adelaide, South Australia. The variables recorded were sex, age, height, mass, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow rate (PEFR), forced mid-expiratory flow (FEF25-75%) and FEV1/FVC ratio. Complete data were obtained for 614 females and 621 males, but the sample was reduced to 249 females and 165 males when only lifetime nonsmokers with no adverse bronchial symptoms were selected. Prediction equations of normal lung function were obtained from the reduced sample by multiple regression, with age, height and functions of both age and height as predictors. The derived equations did not differ significantly from the majority of previously reported equations and were generally superior in their ability to predict the lung function of the asymptomatic ex-smokers who were part of the original sample. Analysis of the sensitivity, specificity and predictive power of 5% tolerance limits for the presence of symptoms revealed the important roles of FEV1, FEV1/FVC and FEF25-75% in diagnostic testing. The present prediction equations are recommended for use on the Australian population and on populations with similar Caucasian characteristics.

Adult↗

PubMed1994

The behavioural epidemiology of weight control.

Excess body weight is associated with increased health risk, but there are also risks to health related to weight-control practices. While representative population data are available on the anthropometry of body weight and its sociodemographic correlates in Australia, less is known about the population prevalence and correlates of weight-control behaviours. We examine the prevalence of overweight and obesity, and low body weight, in the Australian population, using data from studies in which height and weight have been objectively measured; we describe the sociodemographic correlates of overweight and obesity; we outline relevant aspects of Australian health-system and private-sector approaches to body weight control; and we describe the findings of Australian studies of weight-control practices and related beliefs and attitudes. These findings relate mainly to women, particularly younger women, and little is known about the weight-control practices of Australian men. We suggest research which may promote a better understanding of weight-control practices in the Australian population.

Adult↗

PubMed1993

Trial of an intervention to reduce chronic benzodiazepine use among residents of aged-care accommodation.

BACKGROUND: Many residents of aged-care accommodation are chronic users of benzodiazepines. This pattern of use contradicts current guidelines and may adversely affect residents. It was hypothesised that a lasting reduction in benzodiazepine use could be achieved through a programme which involved prescribers, residents and caregivers in the change process. AIM: To demonstrate that an intervention which involved education and relaxation training for patients, and education of prescribers and caregivers, could reduce levels of chronic benzodiazepine use among residents of an aged-care facility. METHODS: Two aged-care facilities from metropolitan Adelaide were chosen; one received the intervention, the other was a no-intervention comparison. Pre-test, post-test and follow-up interviews were conducted with 60 residents: 27 from the intervention setting and 33 from the comparison setting. Residents at the intervention setting were provided with relaxation skills training, and their medical practitioners and caregivers were provided with information about alternative strategies for managing sleep disturbance. Outcome measures were: the proportion of residents using benzodiazepines, total medication use, cognitive performance, emotional responsiveness, subjective health and sleep ratings and an index of well-being. RESULTS: The proportion of participants in the intervention condition who used benzodiazepines declined significantly (from 70% to 35%); the reduction was maintained over the subsequent three months. No adverse consequences were associated with cessation of benzodiazepine use; there was improvement in emotional responsiveness among those who ceased benzodiazepine use. This structured intervention strategy is a useful approach for reducing levels of chronic benzodiazepine use among residents of aged-care accommodation.

Affect↗

PubMed1993

Medication use and its correlates among the elderly.

Medication use and its correlates were examined in a randomly selected sample of 178 urban-dwelling elderly people: 89 per cent were currently using medication and 44 per cent were using four or more medications concurrently. Forty percent were using at least one nonprescription medication, usually in combination with prescription medication. The treatment of hypertension was the most commonly given reason for medication use. Respondents demonstrated good knowledge of their medication and how to take it, and good compliance with prescribing instructions. Multiple medication use was associated with advanced age, living in supervised accommodation, and a range of measures indicative of reduced wellbeing. There was no association between cognitive functioning and multiple medication use. These findings suggest that stereotypical images of older people as being poor compliers and having little knowledge about their medication should be treated with caution. However, the extensive use of medication and of multiple medications and concerns about the appropriateness of use of some classes of medication highlight the need for more detailed study of medication use among the elderly.

Aged↗

PubMed1993

Population prevalence and correlates of stages of change in physical activity.

Stages of change for exercise, sociodemographic variables, and beliefs about the health benefits of exercise were obtained for a representative sample of Australian adults (N = 4404). Logistic regression analysis was used to examine the relationship between exercise stage of change and sociodemographic variables and beliefs about the benefits of exercise. Thirteen percent of respondents stated that they did not exercise and did not intend to start; 10% stated that they did not exercise but were thinking of starting; 16% stated that they exercise occasionally and were not thinking of doing more; 23% stated that they exercised occasionally and were thinking of doing more; and 38% stated that they exercised regularly and intended to continue. Intention to do more exercise generally decreased with increasing age, but increased with level of education. An increased frequency of exercise and an intention to do more exercise was associated with the belief that exercise would help to prevent heart disease and with a higher level of education. The results provide a useful profile of the exercise habits (and intention to change those habits) of population subgroups. Public communication campaigns on the benefits of physical activity should focus particularly on those who do not intend to exercise, older adults, and the less well educated.

Adolescent↗

PubMed1993

Work-site cardiovascular risk reduction: a randomized trial of health risk assessment, education, counseling, and incentives.

OBJECTIVES: This study reports an efficacy trial of four work-site health promotion programs. It was predicted that strategies making use of behavioral counseling would produce a greater reduction in cardiovascular disease risk factors than screening and educational strategies. METHODS: Twenty-eight work sites were randomly allocated to a health risk assessment, risk factor education, behavioral counseling, or behavioral counseling plus incentives intervention. Participants were assessed before the intervention and at 3, 6, and 12 months. RESULTS: Compared with the average of the health risk assessment and risk factor education conditions, there were significantly higher validated continuous smoking cessation rates and smaller increases in body mass index and estimated percentage of body fat in the two behavioral counseling conditions. The behavioral counseling condition was associated with a greater reduction in mean blood pressure than was the behavioral counseling plus incentives condition. On average among all groups, there was a short-term increase in aerobic capacity followed by a return to baseline levels. CONCLUSIONS: Work-site interventions that use behavioral approaches can produce lasting changes in some cardiovascular risk factors and, if implemented routinely, can have a significant public health impact.

Adult↗

PubMed1992

Role of Tyr and Trp in membrane responses of Pyrularia thionin determined by optical and NMR spectra following Tyr iodination and Trp modification.

Pyrularia thionin is a strongly basic and bioactive 47 amino acid peptide which contains two Tyr residues at positions 13 and 45 and one Trp at position 8. Limited iodination does not have a significant effect, but prolonged iodination of the peptide leads to progressive inactivation for all known cellular responses (Evans, J. et al. (1989) Proc. natn. Acad. Sci. U.S.A. 86, 5849-5853). 1H NMR spectra of the native Pyrularia thionin show four Tyr bands, two arising from each Tyr residue. One resonance band for the epsilon hydrogens of Tyr 45 disappears early during limited iodination and the band from the delta hydrogens shifts to low field. The two bands corresponding to Tyr 13 remain during limited iodination, but both decrease in intensity during prolonged iodination, with the epsilon hydrogen band decreasing somewhat more. The resonance bands arising from Trp disappear during prolonged iodination. This sequence of reactions is verified by the optical absorbance properties of two small peptide fragments obtained by Staphylococcal V8 protease hydrolysis of thionin which had been iodinated to varying degrees. Limited iodination did not significantly inhibit the thionin's biological activity, yet the fragment from the -COOH terminus showed the conversion of Tyr 45 to diiodoTyr. This treatment did not significantly modify the Tyr 13 or Trp 8 located in the -NH2 terminal fragment. More extensive iodination resulted in a disappearance of Trp 8 absorbance with an accompanying conversion of Tyr 13 to the monoiodo form. Extensive iodination yielded two atoms of iodine in the Tyr 45-containing fragment, and only one atom in the Tyr 13 fragment. The data indicate that Tyr 45 of the native thionin is more readily iodinated, proceeding to the diiodo form without significant loss of activity. Prolonged iodination does not lead to the formation of any diiodoTyr 13, but does lead to modification of Trp 8 and probably formation of monoiodoTyr 13. Modification of Trp 8 with N-bromosuccinimide inhibits the hemolytic activity of the thionin, showing that Trp 8 is necessary for Pyrularia thionin activity. It is most likely Trp 8 modification during prolonged iodination which results in the loss of biological activity.

Antimicrobial Cationic Peptides↗

PubMed1992

Characteristics of heavy smokers.

BACKGROUND: Heavy smokers (those who smoke greater than or equal to 25 or more cigarettes a day) are a subgroup who place themselves and others at risk for harmful health consequences and also are those least likely to achieve cessation. Despite this, heavy smokers are not well described as a segment of the smoking population. METHODS: We used representative population data on 1,048 smokers to examine differences between heavy and lighter smokers (less than or equal to 24 cigarettes per day). RESULTS: Heavy smokers constituted 26.7% of all cigarette smokers. Compared with lighter smokers, heavy smokers were significantly more likely to be male, to be age 30 years or older, to smoke their first cigarette of the day within 30 min of waking, to perceive quitting as very difficult, to have little confidence in their ability to quit, to be less likely to report variation in their rate of smoking between work and leisure days, and to be less likely to be employed. CONCLUSIONS: Public health strategies which may particularly assist heavy smokers include stronger restrictions on smoking in public places, nicotine replacement therapies, and the use of segmentation research to more carefully target campaign messages to influence quit attempts and confidence.

Adult↗

PubMed1992

Associations of social status and health-related beliefs with dietary fat and fiber densities.

BACKGROUND: Lower social status groups have higher mortality rates from some diet-related diseases and higher dietary fat and lower dietary fiber intakes. Such dietary patterns have been found to be related to social status, environmental influences, and health-related beliefs and expectations. METHODS: Associations of social status and diet-related and health-related beliefs and expectations with dietary fat and fiber densities were examined in a population sample of 874 respondents to a postal questionnaire. A food frequency listing of 172 foods was used to assess usual dietary intake. RESULTS: More positive beliefs and expectations were associated with lower dietary fat and higher dietary fiber densities in univariate models; beliefs and expectations differed little between social status groups. In multivariate models, stronger perceptions of external influences on food choices, fewer perceived barriers to eating a healthy diet, and social status were independently associated with low dietary fat density. Diet-related and health-related beliefs and perceptions of external influences on food choices, but not social status, were independently associated with high dietary fiber density. The belief that diet is a major cause of stroke, diabetes, and hypertension was weakly associated with the dietary fiber density of lower social status groups. CONCLUSIONS: Social status and perceptions of external influences on dietary choice, as well as personal beliefs, have independent associations with food intake. Although exclusive targeting of lower social status groups is not indicated, interventions to increase dietary fiber intake should address expectations, attitudes, and beliefs about dietary fiber and health and perceptions of external influences on food choices, especially among lower status groups; interventions to lower dietary fat intake should address a broad range of external and social factors, as well as personal beliefs.

Attitude to Health↗

PubMed1992

Stages of readiness to quit smoking: population prevalence and correlates.

We examined the population prevalence and correlates of stages in smokers' readiness to quit, using data from 1,048 smokers recruited in a self-weighting, multistage, systematic clustered area sample from 0.44% of South Australian dwellings, with an 89% response rate. Smokers in the precontemplation stage comprised 24.1% of the sample, smokers in the contemplation stage comprised 47.2%, and smokers in the preparation stage comprised 28.7%. No sociodemographic variables (i.e., age, sex, marital status, educational level) were found to be significant independent predictors of membership in the different stages. The five significant independent predictors of being in the precontemplation stage (vs. the contemplation stage) were (a) having a higher confidence of quitting, (b) seeing fewer health risks associated with smoking, (c) not having made an attempt to quit, (d) seeing quitting as more difficult, and (e) smoking 25 or more cigarettes a day. The two significant independent predictors of being in the contemplation stage (vs. the preparation stage) were (a) having lower confidence of quitting and (b) not having tried to quit. We discuss implications for the understanding of smoking behavior in populations and also consider how cessation campaigns might address the factors associated with different stages of readiness to quit.

Adaptation, Psychological↗

PubMed1992

The descriptive epidemiology of a sedentary lifestyle in adult Australians.

Regular exercise is important for the maintenance of good health, but many people do very little exercise. There are public health concerns about activating the sedentary and, from an epidemiological measurement perspective, there are advantages in assessing physical inactivity. Using pooled data from 17,053 participants in Australian population surveys, we identified 5078 people (29.7%) who could be classified as sedentary in their recreational exercise habits. Logistic regression analyses found the inactive to be more likely to be older, less well educated, and to have lower incomes. The main reasons given for not exercising were no time (33%), being physically unable (23%), and not wanting to exercise (13%): these were more likely to be reported by those who were older, and who had lower incomes; the only exception was that being 55 years or older was not associated with having less time. Women were more likely to report being physically unable to exercise. Lower income was associated with being physically unable, and with not wanting to exercise. Those with children, while wanting to exercise, were more likely to report having no time. The greatest health benefits will result from the sedentary becoming more active, and inexpensive and convenient activities such as walking need to be emphasized.

Adult↗

PubMed1992

Occupational wood dust exposures, lifestyle variables, and respiratory symptoms.

The quantitative relationship of occupational exposure to airborne wood dust with nasal and pulmonary health problems is not clearly established, particularly for low to moderate exposures in the wooden furniture manufacturing industry. We examined the associations of pulmonary and nasal symptoms, wood dust exposure, and lifestyle variables (cigarette smoking, alcohol use, overweight, physical inactivity, and stress) in a sample of 168 woodworkers. Levels of wood dust exposure were not systematically associated with symptoms. Statistically significant associations were found for cigarette smoking; after controlling for the effects of smoking, heavy drinking was significantly associated with pulmonary symptoms, and perceived stress was associated with both pulmonary and nasal symptoms. These findings suggest that studies of the effects of low-level occupational wood dust exposures should control for the potential effects of lifestyle variables.

Adult↗