Biomedical subjects

A J Dobson

Publications and source records attributed to A J Dobson.

At least 55 records · Page 3Linked to original sources

PubMed1998

What is a healthy weight for middle aged women?

OBJECTIVE: To explore associations between body mass index (BMI) and selected indicators of health and well-being and to suggest a healthy weight range (based on BMI) for middle aged Australian women. DESIGN: Population based longitudinal study (cross-sectional baseline data). SUBJECTS: 13431 women aged 45-49 y who participated in the baseline survey for the Australian Longitudinal Study on Women's Health. RESULTS: Forty-eight percent of women had a BMI>25 kg/m2. Prevalence of medical problems (for example, hypertension, diabetes), surgical procedures (cholescystectomy, hysterectomy) and symptoms (for example, back pain) increased monotonically with BMI, while indicators of health care use (for example, visits to doctors) showed a 'J' shaped relationship with BMI. Scores for several sub-scales of the MOS short form health survey (SF36) (for example, general health, role limitations due to emotional difficulties, social function, mental health and vitality) were optimal when BMI was around 19-24 kg/m2. After adjustment for area of residence, education, smoking, exercise and menopausal status, low BMI was associated with fewer physical health problems than mid-level or higher BMI, and the nationally recommended BMI range of 20-25 was associated with optimum mental health, lower prevalence of tiredness and lowest use of health services. CONCLUSIONS: Acknowledging the limitations of the cross-sectional nature of these data, the results firmly support the benefits of leanness in terms of reducing the risk of cardiovascular disease, diabetes and gall bladder disease. The findings are moderated, however, by the observation that both low and high BMI are associated with decreased vitality and poorer mental health. The optimal range for BMI appears to be about 19-24 kg/m2. From a public health perspective this study provides strong support for the recommended BMI range of 20-25 as an appropriate target for the promotion of healthy weight in middle aged Australian women.

Australia↗

PubMed1998

Changes in cigarette smoking among adults in 35 populations in the mid-1980s. WHO MONICA Project.

OBJECTIVE: To examine changes in the prevalence of cigarette smoking in 35 study populations of the World Health Organisation's MONICA Project. DESIGN: Data from two independent, community-based surveys conducted, on average, five years apart. SETTING: Geographically defined populations in 21 countries mainly in eastern and western Europe. SUBJECTS: Randomly selected men and women aged 25-64 years. Numbers of participants in each study population ranged from 586 to 2817 in each survey. MAIN OUTCOME MEASURES: Changes in proportions of current smokers, ex-smokers, and never-smokers by age and sex using data collected by standardised methods. RESULTS: Among men, smoking prevalence decreased in most populations, by three to four percentage points over five years. In Beijing, however, it increased in all age groups--overall by 11 percentage points. Among women there were increases in smoking in about half the populations. The increases were mainly in the age group 35-54 years and often in those populations where smoking prevalence among women has been relatively low. CONCLUSIONS: Smoking initiation by middle-aged women in parts of southern and eastern Europe and among men of all ages in Beijing is a matter of concern. The various public health measures that have helped to reduce smoking among men in developed countries should be vigorously extended to these other groups now at growing risk of smoking-related disease.

Adult↗

PubMed1998

Coronary events and exposure to environmental tobacco smoke: a case-control study from Australia and New Zealand.

OBJECTIVES: To estimate the relative risk of coronary heart disease (CHD) associated with exposure to environmental tobacco smoke (ETS). DESIGN: Population-based case-control study. SUBJECTS: Cases were 953 people identified in a population register of coronary events, and controls were 3189 participants in independent community-based risk factor prevalence surveys from the same study populations. SETTING: Newcastle, Australia and Auckland, New Zealand. MAIN OUTCOME MEASURES: Acute myocardial infarction or coronary death. RESULTS: After adjusting for the effects of age, education, history of heart disease, and body mass index, women had a statistically significant increased risk of a coronary event associated with exposure to ETS (relative risk (RR) = 1.99; 95% confidence interval (CI) = 1.40-2.81). There was little statistical evidence of increased risk found in men (RR = 1.02, 95% CI = 0.81-1.28). CONCLUSION: Our study found evidence for the adverse effects of exposure to ETS on risk of coronary heart disease among women, especially at home. For men the issue is unclear according to the data from our study. Additional studies with detailed information on possible confounders and adequate statistical power are needed. Most importantly, they should use methods for measuring exposure to ETS that are sufficiently accurate to permit the investigation of dose-response relationships.

Adult↗

PubMed1998

Women's Health Australia: recruitment for a national longitudinal cohort study.

The Women's Health Australia (WHA) project is a longitudinal study of several cohorts of Australian women, which aims to examine the relationships between biological, psychological, social and lifestyle factors and women's physical health, emotional well-being, and their use of and satisfaction with health care. Using the Medicare database as a sampling frame (with oversampling of women from rural and remote areas), 106,000 women in the three age groups 18-23, 45-50 and 70-75 were sent an invitation to participate and a 24-page self-complete questionnaire. Reminder letters, a nation-wide publicity campaign, information brochures, a freecall number for inquiries, and the option of completing the questionnaire by telephone in English or in the respondent's own language, were used to encourage participation. Statutory regulations precluded telephone follow-up of non-respondents. Response rates were 41% (N = 14,792), 54% (N = 14,200) and 36% (N = 12,614) for the three age groups. Comparison with Australian census data indicated that the samples are reasonably representative of Australian women in these age groups, except for a somewhat higher representation of women who are married or in a defacto relationship, and of women with post-school education. The most common reason for non-participation was lack of interest or time. Personal circumstances, objections to the questionnaire or specific items in it, and concerns about confidentiality were the other main reasons. Recruitment of three representative age-group cohorts of women, and the maintenance of these cohorts over a number of years, will provide a valuable opportunity to examine associations over time between aspects of women's lives and their physical and emotional health and well-being.

Adult↗

PubMed1998

Changes in estimated coronary risk in the 1980s: data from 38 populations in the WHO MONICA Project. World Health Organization. Monitoring trends and determinants in cardiovascular diseases.

The World Health Organization (WHO) MONICA Project is a 10-year study monitoring trends and determinants of cardiovascular disease in geographically defined populations. Data were collected from over 100,000 randomly selected participants in two risk factor surveys conducted approximately 5 years apart in 38 populations using standardized protocols. The net effects of changes in the risk factor levels were estimated using risk scores derived from longitudinal studies in the Nordic countries. The prevalence of cigarette smoking decreased among men in most populations, but the trends for women varied. The prevalence of hypertension declined in two-thirds of the populations. Changes in the prevalence of raised total cholesterol were small but highly correlated between the genders (r = 0.8). The prevalence of obesity increased in three-quarters of the populations for men and in more than half of the populations for women. In almost half of the populations there were statistically significant declines in the estimated coronary risk for both men and women, although for Beijing the risk score increased significantly for both genders. The net effect of the changes in the risk factor levels in the 1980s in most of the study populations of the WHO MONICA Project is that the rates of coronary disease are predicted to decline in the 1990s.

Adult↗

PubMed1997

Estimating correlations from epidemiological data in the presence of measurement error.

Analysis of a major multi-site epidemiologic study of heart disease has required estimation of the pairwise correlation of several measurements across subpopulations. Because the measurements from each subpopulation were subject to sampling variability, the Pearson product moment estimator of these correlations produces biased estimates. This paper proposes a model that takes into account within and between sub-population variation, provides algorithms for obtaining maximum likelihood estimates of these correlations and discusses several approaches for obtaining interval estimates.

Adult↗

PubMed1997

2-Aminonicotinic acid.

2-Aminonicotinic acid, C6H6N2O2, crystallized in the centrosymmetric space group P2(1)/c in the zwitterionic form. Intermolecular N--H...O hydrogen bonds with N...O distances of 2.652 (2) and 2.807 (2) A link molecules into two sets of zigzag chains propagating along the b axis. The two sets of chains are crosslinked by C--H...O interactions. The dihedral angle between the planes of adjacent molecules in a chain is 9.77 (7) degrees. An intramolecular N--H...O hydrogen bond is also present.

Crystallography, X-Ray↗

PubMed1997

Alpha and beta phases of 4-aminoquinoline-2-carboxylic acid monohydrate.

The structures of two phases of the title compound, C10H8N2O2.H2O, are reported. While the organic molecule has very nearly the same molecular geometry in the two phases, the hydrogen-bonding patterns are quite different. In each case, however, a three-dimensional network of hydrogen bonds is formed. In the alpha phase, six N-H ... O hydrogen bonds have donor-acceptor distances ranging from 2.681 (2) to 3.206 (2) A, while three O-H...O hydrogen bonds range from 2.837 (2) to 3.173 (2) A, and in the beta phase, four N-H ... O hydrogen bonds range from 2.668 (2) to 3.038 (2) A, while two O-H...O hydrogen bonds are 2.951 (3) and 2.959 (3) A in length.

Aminoquinolines↗

PubMed1997

How much alcohol and how often? Population based case-control study of alcohol consumption and risk of a major coronary event.

OBJECTIVE: To quantify the effects of quantity and frequency of alcohol consumption on risk of acute myocardial infarction and coronary death. DESIGN: Case-control study. SETTING: Lower Hunter region of New South Wales, Australia, 1983-94. SUBJECTS: Men and women aged 35-69 years. MAIN OUTCOME MEASURE: Acute myocardial infarction or coronary death. RESULTS: Alcohol consumption patterns were compared between 11,511 cases of acute myocardial infarction or coronary death and 6077 controls randomly selected from the same study population. After adjusting for the effects of age, smoking, and medical history, men and women who consumed one or two drinks of alcohol on five or six days a week had a reduction in risk of a major coronary event compared with men and women who were non-drinkers (odds ratios: men 0.31 (95% confidence interval 0.22 to 0.45); women 0.33 (0.18 to 0.59)). A similar reduction in risk was found after excluding non-drinkers who were formerly moderate to heavy drinkers. An acute protective effect of alcohol consumption was also found for regular drinkers who consumed one or two drinks in the 24 hours preceding the onset of symptoms (odds ratios: men 0.74 (0.51 to 1.09); women 0.43 (0.20 to 0.95)). CONCLUSIONS: Frequency and quantity of alcohol consumption are important in assessing the risk of a major coronary event. Risk is lowest among men who report one to four drinks daily on five or six days a week and among women who report one or two drinks daily on five or six days a week.

Adult↗

PubMed1997

Declining rates of coronary heart disease in New Zealand and Australia, 1983-1993.

The authors report the results of 10 years of monitoring of trends in the rates of major nonfatal and fatal coronary events and in case fatality in Auckland, New Zealand, and in Newcastle and Perth, Australia. Continuous surveillance of all suspected myocardial infarctions and coronary deaths in people aged 35-64 years was undertaken in the three centers as part of the World Health Organization's Multinational Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA) Project. For nonfatal definite myocardial infarction, there were statistically significant declines in rates in all centers in both men and women, with estimated average changes between 2.5% and 3.7% per year during the period 1984-1993. Rates of all coronary deaths also declined significantly in all three populations for both men and women. In absolute terms, there was, in general, a greater reduction in prehospital deaths than in deaths after hospitalization. Although 28-day case fatality remains high at between 35% and 50%, in the Australian centers it declined significantly by between 1.0% and 2.9% per year, and in Auckland there was also a small decline. However, since most deaths occur outside the hospital in people without a previous history of coronary heart disease, an increased emphasis on primary prevention is necessary.

Adult↗

PubMed1997

N-acetyl-L-glutamic acid.

In the structure of N-acetyl-L-glutamic acid, C7H11NO5, each molecule is directly hydrogen bonded to four others by a total of six hydrogen bonds. Two carboxylic O atoms and the N atom are donors, while all three acceptors are O atoms. There is also an intramolecular hydrogen bond with the N atom as donor and a carboxylic O atom as acceptor. The carboxyl O and H atoms are ordered. The conformation of the carbon chain with respect to the C3-C4 bond is trans as in L-glutamic acid hydrochloride, rather than gauche as in the beta form of L-glutamic acid.

Glutamates↗

PubMed1997

Smoking and relative body weight: an international perspective from the WHO MONICA Project.

STUDY OBJECTIVE: To investigate the magnitude and consistency of the associations between smoking and body mass index (BMI) in different populations. DESIGN: A cross sectional study. SETTING AND PARTICIPANTS: About 69,000 men and women aged 35-64 years from 42 populations participating in the first WHO MONICA survey in the early and mid 1980s. MAIN RESULTS: Compared to never smokers, regular smokers had significantly (p < 0.05) lower median BMI in 20 (men) and 30 (women) out of 42 populations (range -2.9 to 0.5 kg/m2). There was no population in which smokers had a significantly higher BMI than never smokers. Among men, the association between leanness and smoking was less apparent in populations with relatively low proportions of regular smokers and high proportions of ex-smokers. Ex-smokers had significantly higher BMI than never smokers in 10 of the male populations but in women no consistent pattern was observed. Adjustment for socioeconomic status did not affect these results. CONCLUSIONS: Although in most populations the association between smoking and BMI is similar, the magnitude of this association may be affected by the proportions of smokers and ex-smokers in these populations.

Adult↗

PubMed1997

The impact of diabetes on survival among patients with first myocardial infarction.

OBJECTIVE: The purpose of this paper is to estimate the impact of diabetes on survival among patients with first acute myocardial infarction, using data from the World Health Organization (WHO) Monitoring Trends and Determinants of Cardiovascular Disease (MONICA) Project in Newcastle, New South Wales, Australia. RESEARCH DESIGN AND METHODS: The WHO MONICA Project is a community-based surveillance system that monitors coronary heart disease morbidity and mortality. All patients with suspected coronary events were observed for 28 days after the onset of symptoms. RESULTS: Of 5,322 patients with acute myocardial infarction and no previous history of ischemic heart disease (3,643 men and 1,679 women), 333 men (9%) and 224 women (13%) had a history of diabetes. The age-adjusted 28-day case fatality for women with diabetes (25%) was significantly higher than for women without diabetes (16%); relative risk 1.56 (95% CI: 1.19-2.04). The difference for men was also significant (25% with diabetes and 20% without diabetes); relative risk 1.25 (95% CI: 1.02-1.53). Age-specific case fatality increased significantly with age in both men and women without diabetes, but systematic age effects were not so apparent in patients with diabetes. Case fatality significantly decreased over the study period in patients without diabetes, but not among the diabetic patients. CONCLUSIONS: The increased risk of death in the diabetic patients remained after accounting for their poorer risk factor profiles; even if they reached the hospital alive, diabetic patients were also less likely to survive than nondiabetic patients. The relative impact of diabetes on survival is greater in women than in men.

Adult↗

PubMed1996

4-(2-Naphthyl)butanoic acid.

4-(2-Naphthyl)butanoic acid, C14H14O2, crystallizes in the centrosymmetric space group P2(1)/a. The single type of hydrogen bond forms cyclic dimers about inversion centers. The carboxylic-O atoms are ordered as is the acid-H atom. The structure comprises double layers of aromatic rings in a herringbone array separated by double layers of hydrogen-bonded aliphatic strings, a pattern seen previously in related substances.

Butyrates↗

PubMed1996

gamma-Aminobutyric acid: a novel tetragonal phase.

In the tetragonal phase of gamma-aminobutyric acid, C4H9NO2, the single type of molecule adopts a partially folded zwitterionic form. Whereas in the previously characterized monoclinic phase the partially folded zwitterionic molecules exhibit a gauche conformation with respect to the C2-C3 bond, in this phase the molecules exhibit a trans conformation. The altered pattern of intramolecular N...O distances may be of significance with respect to the neurotransmission behavior of this substance. In addition to three strong hydrogen bonds involving the three H atoms bound to the N atom, as in the monoclinic phase, there is a fourth weaker one which results in a two-center bifurcated bond. There is also evidence suggestive of an intramolecular bridging hydrogen bond involving the N atom, an O atom and a methylene H atom, as previously proposed as a stabilizing factor for the gauche conformation observed in the monoclinic phase.

Crystallography, X-Ray↗

PubMed1996

sym-Hexahydropyrene.

In 1,2,3,6,7,8-hexahydropyrene, C16H16, the unsaturated rings lie essentially in a plane, the r.m.s. deviation of the atoms defining this plane form the best-fit plane being 0.006 (2) A. The saturated rings are substantially non-planar, but the character of the non-planarity of the saturated rings is quite different from that observed in octahydrochrysene. The C-C bond distances in the saturated rings are quite uniform, ranging from 1.505 (2) to 1.520 (2) A. No intermolecular distance is less than the sum of the corresponding van der Waals radii; closest approaches involve both C...H and H...H interactions.

Crystallography, X-Ray↗

PubMed1996

2-Acetylbenzoic acid: phthalide form.

In the structure of the phthalide form of 2-acetylbenzoic acid, C9H8O3, there is a single type of hydrogen bond. Each molecule donates one and accepts one hydrogen bond. The hydrogen-bonded molecules form sets of puckered ribbons running along the c direction which are not crosslinked to each other. The dihedral angle between the planes of adjacent molecules along a hydrogen-bonded ribbon is 77.4(1) degrees.

Benzofurans↗

PubMed1996

2-Hydroxybiphenyl-3-carboxylic acid (3-phenylsalicylic acid).

In the title compound, C13H10O3, there is a single type of intermolecular hydrogen bond. From this is formed a cyclic dimer about a twofold axis. In addition, there is an intramolecular hydrogen bond which is virtually identical to that observed in salicylic acid.

Crystallography, X-Ray↗