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Biomedical subjects

J Simons

Publications and source records attributed to J Simons.

At least 55 records · Page 3Linked to original sources
PubMed1997

Prediction of adult stature and noninvasive assessment of biological maturation.

The Tanner-Whitehouse method to predict adult stature uses current stature, current skeletal age (SA), and chronological age (CA), and, if available, change (gain) in stature and SA over the previous year. Since assessment of SA requires invasive techniques, a method is proposed to predict adult stature noninvasively and to use percentage of adult stature as a maturity indicator. Age-specific multiple regression equations were calculated in a sample of 102 Flemish boys 13 through 16 yr who were followed during adolescence and remeasured at 30 yr of age. The proposed procedure, the Beunen-Malina method for prediction of adult stature, includes four somatic dimensions (current stature, sitting height, subscapular skinfold, triceps skinfold) and CA. In this age range multiple correlations (Rs between 0.70 and 0.87) and SEEs (between 3.0 and 4.2 cm) compare favorably with the original Tanner-Whitehouse method. Furthermore, when maturity groups based on percentage of adult stature calculated from the Beunen-Malina predictions are contrasted for somatic dimensions and performance characteristics, differences are similar to those observed when maturity grouping is based on skeletal maturity.

Adolescent↗
PubMed1996

Apparent discontinuation rates in patients prescribed lipid-lowering drugs.

OBJECTIVE: To evaluate apparent discontinuation rates in patients newly prescribed lipid-lowering drugs. DESIGN AND SETTING: A prospective survey of 12 months' dispensing data in 138 community pharmacies across metropolitan Sydney. PATIENTS: 610 adults (49% men) with a mean age of 58 years; 91% of prescriptions were from general practitioners; prescribed drugs were simvastatin (54%), pravastatin (31%) and gemfibrozil (15%). MAIN OUTCOME MEASURE: The number of patients failing to collect prescription refills. RESULTS: 60% of patients (95% confidence interval [CI], 56%-64%) apparently discontinued their medication over 12 months. Half of the apparent discontinuations occurred within three months and a quarter within one month of starting treatment. The predominant reasons for discontinuation were: patient unconvinced about need for treatment (32%), poor efficacy (32%) and adverse events (7%). Only half of those experiencing poor efficacy were switched to another drug. The relative risk (RR) of discontinuation was lower in older patients (age 65+ v. <50 years: RR 0.66; 95% CI 0.47-0.93) and in those using other cardiovascular drugs (RR 0.69; CI 0.56-0.86), but was increased in those showing early evidence of poor compliance (RR 1.77; CI 1.33-2.35). Discontinuation appeared to be unrelated to sex, the source of the prescription (general practitioner or specialist), past use of lipid-lowering drugs or the cost of medication. CONCLUSIONS: High apparent discontinuation rates with lipid-lowering drugs suggest significant wastage of resources in treatments that are initiated but not continued and a lost opportunity for heart disease prevention. Many patients appear to discontinue therapy for illogical reasons and this may be amenable to intervention.

Aged↗
PubMed1996

Development of a high-efficiency method for gene marking of Dunning prostate cancer cell lines with the enzyme beta-galactosidase.

Although the bacterial enzyme beta-galactosidase has been used as a reporter gene in a variety of mammalian systems; the variability and instability of its expression has limited its use. Transfection of Dunning rat prostatic cell lines with beta-galactosidase expression plasmids resulted in 5-10% of cells expressing the enzyme transiently, and < 5% of G418-resistant clones showing any level of expression. To address this problem, we developed a labeling protocol using a replication defective retrovirus containing a beta-galactosidase expression cassette. Between 30-50% of cells transduced expressed high levels of this enzyme. Homogeneous cell populations were isolated by subsequent fluorescence-activated cell sorting, using a fluorescent beta-galactosidase substrate. Using a modification of standard staining procedures, small metastatic foci of cells expressing beta-galactosidase in mouse lung tissue were detected with high sensitivity. This method has several advantages over standard transfection protocols, including the expedient and efficient transfer of the beta-galactosidase gene and the stability of its expression in a variety of Dunning sublines.

Animals↗
PubMed1996

M235-->T polymorphism of the angiotensinogen gene predicts hypertension in the elderly.

OBJECTIVE: To determine whether the M235-->T polymorphism (exon 2) of the angiotensinogen gene is associated with hypertension in elderly patients with isolated systolic hypertension [ISH: systolic blood pressure (SBP) > or = 160 mmHg, diastolic blood pressure (DBP) < 90 mmHg) or systolic-diastolic hypertension (SDH: DBP > or = 90 mmHg, SBP > or = 160 mmHg) compared with normotensive controls (SBP < 160 mmHg, DBP < 90 mmHg). DESIGN: A case-control study in 769 non-institutionalized, elderly (aged > or = 60 years; female:male ratio 0.85) residents of Dubbo, New South Wales. METHODS: Individuals were classified as having ISH (n = 171), having SDH (n = 218) and being normotensive controls (n = 366) with age and sex matching. MM, TT and MT genotypes were determined by a nested polymerase chain reaction strategy using DNA extracted from serum. The prediction of ISH or SDH by genotype or allele was examined in a multiple-logistic regression model that controlled for various confounders. RESULTS: SBP (mean +/- SD, mmHg)/DBP (mean +/- SD, mmHg) was 176 +/- 16/79 +/- 8 in the ISH group, 167 +/- 23/97 +/- 7 in the SDH group and 134 +/- 14/74 +/- 9 in the normotensive control group. The frequencies of M and T alleles in the normal population (0.69 and 0.31, respectively) were altered significantly in the ISH group (0.61 and 0.39, respectively; chi 2 = 6.0, P < 0.02) and the SDH group (0.62 and 0.38, respectively; chi 2 = 6.0, P < 0.02). The presence of the TT genotype predicted both ISH (odds ratio 1.9, 95% confidence interval 1.1-3.3) and SDH (1.7, 1.0-3.0) as did that of the T allele (ISH: 1.3, 1.0-1.7; SDH: 1.3, 1.0-1.7). CONCLUSIONS: The M235-->T polymorphism may be a marker for both forms of hypertension in the elderly. Whether the TT genotype represents a genetic risk factor for the development of hypertension in later life requires confirmation.

Aged↗
PubMed1996

Inheritance of physical fitness in 10-yr-old twins and their parents.

This study focuses on the quantification of genetic and environmental sources of variation in physical fitness components in 105 10-yr-old twin pairs and their parents. Nine motor tests and six skinfold measures were administered. Motor tests can be divided into those that are performance-related: static strength, explosive strength, running speed, speed of limb movement, and balance; and those that are health-related: trunk strength, functional strength, maximum oxygen uptake, and flexibility. The significance and contribution of genetic and environmental factors to variation in physical fitness were tested with model fitting. Performance-related fitness characteristics were moderately to highly heritable. The heritability estimates were slightly higher for health-related fitness characteristics. For most variables a simple model including genetic and specific environmental factors fitted the observed phenotypic variance well. Common environmental factors explained a significant part of the variation in speed components and flexibility. Assortative mating was significant and positive for speed components, balance, trunk strength, and cardiorespiratory fitness, but negative for adiposity. Static strength, explosive strength, functional strength, and cardiorespiratory fitness showed evidence for reduced genetic transmission or dominance. The hypothesis that performance-related fitness characteristics are more determined by genetic factors than health-related fitness was not supported. At this prepubertal age, genetic factors have the predominant effect on fitness.

Adult↗
PubMed1996

Predictors of mortality in the prospective Dubbo study of Australian elderly.

BACKGROUND: A prospective study in non-institutionalised Australian elderly 60 years and over commenced in Dubbo, NSW in 1988. AIM: To examine clinical and socio-demographic predictors of all-causes mortality. METHODS: The data were derived from a community-based sample comprising 1236 men and 1569 women followed for a median period of 62 months. RESULTS: Two hundred and thirty five men (19%) and 184 women (12%) died, 46% of male and 53% of female deaths respectively related to cardiovascular disease. In a proportional hazards model, the significant predictors of mortality were: older age, being married (relative risk [RR] = 0.71 for men, 0.74 for women), current smoking for men (RR = 3.11), taking more than three alcoholic drinks per day for men (RR = 0.37), prior coronary heart disease for men (RR = 1.36), severe hypertension for women (RR = 1.99), use of anti-hypertensive medication for men (RR = 1.74), diabetes for men (RR = 1.62), poor-fair self-rated health for women (RR = 1.74) and physical disability for men (RR = 1.72). Serum cholesterol was associated with mortality in a 'J-shaped' relationship in men and in a reciprocal relationship in women. Blood pressure predicted mortality in an incremental fashion below 75 years, but in older subjects lower pressure was associated with excess mortality. CONCLUSION: Some predictors of mortality in the well elderly have been identified and a more extended period of follow-up will possibly resolve contradictory findings in some areas.

Aged↗
PubMed1996

Diabetes, mortality and coronary heart disease in the prospective Dubbo study of Australian elderly.

BACKGROUND: A prospective study of Australian elderly living in Dubbo has shown that diabetes is a significant predictor of all-causes mortality and coronary heart disease (CHD). AIM: To examine and contrast clinical and socio-demographic predictors of these outcomes in those with and without diabetes. METHODS: The data are derived from a community-based sample of subjects 60 years and older followed over 62 months since 1988. Of 1155 men and 1472 women, 9.2% and 6.9% respectively manifested diabetes at baseline, based on history or fasting hyperglycaemia. RESULTS: In the presence of diabetes, all-causes mortality was increased twofold in both sexes, CHD incidence was increased twofold in men and threefold in women, stroke incidence was increased twofold in women but little changed in men. Proportional hazards models were derived separately for persons with and without diabetes and risk factors differentially predictive in diabetes were sought. Significant predictors of death in diabetes were old age and current smoking. Those factors differentially predictive were 'being married' (Relative Risk [RR] 1.60 with diabetes and 0.69 without diabetes) and higher body mass index (BMI) (RR 1.03 with diabetes and 0.79 without diabetes). Significant predictors of CHD in diabetes were old age, prior CHD, severe hypertension, low HDL cholesterol and self-rated health. Those factors differentially predictive were higher body mass index (RR 1.14 vs 0.83) and physical disability (RR 0.69 vs 1.55). Differential predictions with regard to BMI may relate in part to excess CHD and mortality at low BMI in non-diabetic subjects. CONCLUSION: The vascular disease burden of diabetes in the elderly has been confirmed, especially in women. A number of conventional risk factors are contributing to this burden and may be amenable to treatment.

Aged↗
PubMed1996

Alcohol intake and survival in the elderly: a 77 month follow-up in the Dubbo study.

BACKGROUND: A prospective study in non-institutionalised Australian elderly aged 60 years and over commenced in Dubbo, NSW in 1988. AIM: To examine the relationship between all-causes mortality and alcohol intake. METHODS: The data were derived from a community-based sample comprising 1236 men and 1569 women followed for a median period of 77 months. Regular alcohol intake was reported by 78% of men and 52% of women. Eighty-seven per cent of men and 44% of women primarily drank beer. RESULTS: Death occurred in 305 men and 236 women, 34% and 39% respectively from coronary heart disease (CHD). In a proportional hazards model, the hazard ratio (HR) for all-causes mortality in male drinkers, compared with abstainers, was 0.75 at one-seven drinks/week, 0.76 at eight-14 drinks/week, 0.69 at 15-28 drinks/week and 0.49 at > 28 drinks/week (p < 0.04), an inverse relationship. In female drinkers, HR was 0.78 at one-seven drinks/week, 0.49 at eight-14 drinks/week (p < 0.04) and 0.62 at 15-28 drinks/weeks, potentially a U shaped relationship. The effect on all-causes mortality could not be attributed to a differential effect of beer versus wine/spirit intake. Although the mortality rate was lower in those taking any alcohol compared with abstainers, those taking any alcohol exhibited an increased proportion of deaths due to cancer at the expense of a reduced proportion of CHD and stroke deaths. CONCLUSIONS: Alcohol intake in the Dubbo elderly appears to be independently associated with a significant increase in life expectancy. Mechanisms underlying the effect may emerge at a longer interval of follow-up.

Aged↗
PubMed1996

Patterns and costs of post-acute care: a longitudinal study of people aged 60 and over in Dubbo.

Declining length of stay of older people in hospital has caused concern about shifting of costs from acute to community care services. Because the two types of care are funded through different programs and from different jurisdictions, the coordination of acute and post-acute care has become the major issue. There is, however, little information available on patterns of use and costs of post-acute care either in Australia or elsewhere. In an existing longitudinal community study of older people in Dubbo, New South Wales, data on use of services by people aged 60 years and over for 12 months of hospitalisations was collected by linkage to the records of Home and Community Care providers. Only a quarter of older people received any type of Home and Community Care service in the 12 weeks after discharge and two-thirds of these received only one type of service. While less than 5 per cent received a service from an occupational therapist, physiotherapist or speech therapist, 78 per cent visited a general practitioner after discharge. The average cost of all Home and Community Care services received after hospital discharge was around $12.50 per week per person discharged. The predictors of higher costs of service use were: living alone, and the interactions of high levels of disability with owning a house. Results on service coordination, the identification of post-acute services, cost consequences of program funding, assessment and discharge planning are related to debates emerging from the Commonwealth Heads of Government.

Aftercare↗
PubMed1996

I/D polymorphism of the angiotensin-converting enzyme gene does not predict isolated systolic or systolic-diastolic hypertension in the elderly.

To determine whether insertion/deletion (I/D) polymorphism (intron 16) of the angiotensin converting-enzyme (ACE) gene is associated with isolated systolic hypertension (ISH: systolic blood pressure (BP) > or = 160, diastolic BP < 90 mm Hg) or systolic-diastolic hypertension (S-D hypertension: diastolic BP > or = 90 +/- systolic BP > or = 160 mm Hg) compared with normotensive controls (systolic BP < 160, diastolic BP < 90 mm Hg), we conducted a case-control study of 733 non-institutionalised, elderly (> or = 60 years) residents of Dubbo, NSW. Individuals were classified as: ISH (n = 167), S-D hypertension (n = 207) and normotensive control (n = 359) with age and sex matching. II, DD and ID genotypes were determined by a nested PCR strategy using DNA extracted from serum. The frequencies of D and I alleles in the control population (0.70 and 0.30 respectively) were not significantly different in the ISH group or the S-D hypertension group (chi 2: 1.7, P = 0.42). After adjustment for several potential confounders, neither genotype nor allele predicted ISH (II vs DD: odds ratio (OR): 1.06, 95% confidence interval (CI): 0.55-2.03; I vs D: 1.09, 0.82-1.46) or S-D hypertension (II vs DD: 1.19, 0.67-2.10; I vs D: 1.16, 0.89-1.52) in this elderly cohort. The I/D polymorphism of the ACE gene is not a marker for either form of hypertension in this large elderly sample.

Aged↗
PubMed1995

Withholding consent to lifesaving treatment: three cases.

The refusal of children or their parents to consent to treatment that professionals regard as essential always results in a dilemma. Responding to such refusals demands careful and sensitive clinical and thicolegal intervention and close cooperation among professionals, in particular doctors and social workers. Since the introduction of the Children Act 1989 the number of cases in which children have withheld consent to lifesaving treatment has risen, and it is now increasingly recognised that children have a right to have their views legally represented if a local authority or health authority seeks a court's leave to carry out treatment. Professionals have to consider which legal route, under either the Children Act or the Mental Health Act, is likely to be best for the individual child.

Abdominal Pain↗
PubMed1995

Fatness and physical fitness of girls 7 to 17 years.

A two-fold approach was used to investigate the association between fatness and fitness of girls 7 to 17 years of age: first, age-specific correlations between fatness and measures of health-related and motor fitness, and second, comparisons of fitness levels of girls classified as fat and lean. A representative sample of 6700 between 7 to 17 years was surveyed. Adiposity (fatness) was estimated as the sum of five skinfolds (biceps, triceps, subscapular, suprailiac, medial calf). Physical fitness included health-related items (step test, PWC170, the sit and reach, sit-ups and leg lifts, flexed arm hang) and motor performance items (standing long jump, vertical jump, arm pull strength, flamingo stand, shuttle run, plate tapping). Age-specific partial correlations between fatness and each fitness item, controlling for stature and weight, were calculated. In addition, in each age group the fattest 5% (presumably the obese) and the leanest 5% were compared on each fitness test. After controlling for stature and weight, subcutaneous fatness accounts for variable percentages of the variance in each fitness item. Estimates for health-related fitness items are: cardiorespiratory endurance-step test (3% to 5%) and PWC170 (0% to 16%), flexibility-sit and reach (3% to 8%), functional strength-flexed arm hand (6% to 17%) and abdominal strength-sit-ups/leg lifts (1% to 8%). Corresponding estimates for motor fitness items are more variable: speed of limb movement-plate tapping (0% to 3%), balance-flamingo stand (0% to 5%), speed and agility-shuttle run (2% to 12%), static strength-arm pull (4% to 12%), explosive strength-standing long jump/vertical jump (11% to 18%). At the extremes, the fattest girls have generally poorer levels of health-related and motor fitness.

Adolescent↗
PubMed1995

On the effect of garlic on plasma lipids and lipoproteins in mild hypercholesterolaemia.

The ingestion of garlic has been reported to have many cardiovascular effects, including a reduction in plasma cholesterol concentration and the susceptibility of LDL to oxidation. A double-blind, placebo-controlled, randomised crossover study was conducted in subjects with mild to moderate hypercholesterolaemia who were subject to strict dietary supervision and assessment. After a baseline dietary period of 28 days, subjects took Kwai garlic powder tablets 300 mg three times daily or matching placebo for 12 weeks, followed by 28 days washout, followed by a 12 weeks crossover on the alternative preparation. In the analysis hypercholesterolaemia was defined as those subjects in the range 5.5-8.05 mmol/l. Three subjects were withdrawn, one allocated to garlic and complaining of garlic body odour, one using placebo having intercurrent health problems, and one with a baseline cholesterol below 5.5 mmol/l, yielding analysable results in 28 subjects. Comparing the period on garlic with that on placebo, there were no significant differences in plasma cholesterol, LDL cholesterol, HDL cholesterol, plasma triglycerides, lipoprotein(a) concentrations, or blood pressure. Mean LDL cholesterol concentration was 4.64 +/- 0.52 mmol/l on garlic and 4.60 +/- 0.59 mmol/l on placebo. There was no demonstrable effect of garlic on oxidisability of LDL, on the ratio of plasma lathosterol/cholesterol (a measure of cholesterol synthesis), nor on LDL receptor expression in lymphocytes. This study found no demonstrable effect of garlic ingestion on lipids and lipoproteins.

Administration, Oral↗
PubMed1995

Risk factors for coronary heart disease in the prospective Dubbo Study of Australian elderly.

A new prospective study of non-institutionalised Australian elderly 60 years and over commenced in Dubbo in 1988, comprising 1236 men and 1569 women. This report examines clinical and socio-demographic predictors of coronary heart disease (CHD) over a median 62 months follow-up. CHD incidence rates (ICD-9-CM codes 410-414) were higher in men than women until 79 years, thereafter, the rates for recurrent disease were higher in women. Incidence rates for recurrent disease were three-fold those for initial disease. In Cox proportional hazards analysis, the significant predictors of all CHD were: advancing age, prior CHD (relative risk (RR) = 2.50 and 2.15 in men and women, respectively), use of anti-hypertensive medication (RR = 1.92 and 1.75 in men and women, respectively). diabetes (RR = 1.67 and 1.53 in men and women, respectively), serum cholesterol, low density lipoprotein cholesterol and serum apo B in men (RR = 1.24), serum triglycerides in women (RR = 1.23), high density lipoprotein cholesterol in men (RR = 0.82), lipoprotein (a) in women (RR = 1.99), and poorer self-rating of health (RR =1.48 and 1.93 in men and women, respectively). Serum cholesterol was not predictive of CHD in men beyond 74 years. Isolated systolic hypertension predicted CHD in women (RR = 3.76), but not in men (RR = 1.20). The findings highlight key risk factors for CHD in the elderly.

Aged↗