Biomedical subjects

P A Baghurst

Publications and source records attributed to P A Baghurst.

At least 37 records · Page 2Linked to original sources

PubMed1993

Antioxidant vitamins and low-density-lipoprotein oxidation.

Low-density-lipoprotein (LDL) oxidation was examined in 22 subjects (10 men, 12 women) after a daily dose of 18 mg beta-carotene, 900 mg vitamin C, and 200 mg alpha-tocopherol for 6 mo. Control subjects (12 men, 11 women) took no vitamin supplements. After 3-mo supplementation plasma concentrations of beta-carotene, alpha-tocopherol, and ascorbic acid increased fivefold (P < 0.001), 55% (P < 0.01), and 27% (P < 0.05), respectively. There was no difference from baseline in rate of oxidation or total amount of conjugated diene produced between subjects taking or not taking vitamins. Malondialdehyde in LDL before and after oxidation was not different between the two groups. Lag time before the onset of oxidation was significantly lengthened after antioxidant supplementation (28% and 35% after 3 and 6 mo, respectively, P < 0.001). There was a significant independent correlation between percent change in lag time and percent change in plasma alpha-tocopherol (r = 0.47, P < 0.01).

Adult↗

PubMed1993

Childhood emotional and behavioural problems: a comparison of children's reports with reports from parents and teachers.

Paediatricians are often asked to assess children with emotional and behavioural problems and are faced with the dilemma that reports about the children's behaviour obtained from the children, and from their parents and teachers, may differ. This study compares the number of childhood emotional and behavioural problems reported by children living in the community, with the number of problems reported by their parents and teachers. When describing both internalizing and externalizing problems, the children consistently reported that they had more problems than were reported by either their parents or teachers. This pattern was particularly evident with reports from older female children who reported many more internalizing problems than were reported by their parents and teachers. Possible reasons for the differences between reports from children and the other informants are discussed.

Adolescent↗

PubMed1993

Emotional and behavioural problems experienced by children living in single-parent families: a pilot study.

This study compared the prevalence of emotional and behavioural problems experienced by 10-11 year old and 14-15 year old children living in single-parent and two-parent families in South Australia. The 10-11 year old male children living in single-parent families were found to have significantly more emotional and behavioural problems than 10-11 year old male children living in two-parent families. In particular, the younger male children living in single-parent families experienced more externalizing behaviour problems than younger male children living in two-parent families. It is suggested that paediatricians and general practitioners need to be aware of children who are at particular risk for developing emotional and behavioural problems, and the approaches which may be employed to provide help.

Adolescent↗

PubMed1993

A prospective study of the psychological adjustment of parents and families of children with cancer.

This study compared the psychological adjustment of parents and families of children with cancer, with the adjustment of parents and families in the community. In the weeks after their children's diagnoses, the mothers of children with cancer reported significantly more anxiety and insomnia, somatic symptoms and social dysfunction than mothers in the community. These problems had declined by the time of a 1 year follow-up assessment. However, at the follow-up assessment the mothers of children with cancer reported significantly more symptoms of depression and somatic symptoms than mothers in the community. A similar pattern of findings was evident among the fathers although the fathers generally reported less distress than was reported by the mothers. The results also suggest that a year after the children's diagnoses, the families in which there was a child with cancer were functioning less effectively than the families in the community.

Adaptation, Psychological↗

PubMed1992

Environmental exposure to lead and children's intelligence at the age of seven years. The Port Pirie Cohort Study.

BACKGROUND: Exposure to lead in early childhood is thought to result in delayed neuropsychological development. As yet there is little longitudinal evidence to establish whether these effects persist into later childhood. METHODS: We measured IQ scores in 494 seven-year-old children from the lead-smelting community of Port Pirie, Australia, in whom developmental deficits associated with elevated blood lead concentrations had already been reported at the ages of two and four years. Exposure to lead was estimated from the lead concentrations in maternal blood samples drawn antenatally and at delivery and from blood samples drawn from the children at birth (umbilical-cord blood), at the ages of 6 and 15 months and 2 years, and annually thereafter. Data relating to known covariates of child development were collected systematically for each child throughout the first seven years of life. RESULTS: We found inverse relations between IQ at the age of seven years and both antenatal and postnatal blood lead concentrations. After adjustment by multiple regression for sex, parents' level of education, maternal age at delivery, parents' smoking status, socioeconomic status, quality of the home environment, maternal IQ, birth weight, birth order, feeding method (breast, bottle, or both), duration of breast-feeding, and whether the child's natural parents were living together, the relation with lead exposure was still evident for postnatal blood samples, particularly within the age range of 15 months to 4 years. For an increase in blood lead concentration from 10 micrograms per deciliter (0.48 mumol per liter) to 30 micrograms per deciliter (1.45 mumol per liter), expressed as the average of the concentrations at 15 months and 2, 3, and 4 years, the estimated reduction in the IQ of the children was in the range of 4.4 points (95 percent confidence interval, 2.2 to 6.6) to 5.3 points (95 percent confidence interval, 2.8 to 7.8). This reduction represents an approximate deficit in IQ of 4 to 5 percent. CONCLUSIONS: Low-level exposure to lead during early childhood is inversely associated with neuropsychological development through the first seven years of life.

Australia↗

PubMed1992

A collaborative case-control study of nutrient intake and pancreatic cancer within the search programme.

Case-control studies of pancreatic cancer were conducted in 5 populations with moderate to high rates and differing dietary practices, using a common protocol and questionnaire. Comprehensive diet histories were completed for a total of 802 cases and 1669 controls identified in Adelaide (Australia), Montreal and Toronto (Canada), Utrecht (The Netherlands) and Opole (Poland). Positive associations were observed with intake of carbohydrates and cholesterol, and inverse associations with dietary fiber and vitamin C. These relationships were generally consistent among the 5 studies, and showed statistically significant and generally monotonic dose-response relationships. The relative risks for highest vs. lowest quintile of intake were estimated for carbohydrates to be 2.57 (95% confidence interval 1.64-4.03), cholesterol 2.68 (1.72-4.17), dietary fiber 0.45 (0.30-0.63), and vitamin C 0.53 (0.38-0.76). The consistency, strength, and specificity of these associations provides evidence for the hypothesis that some or all of these dietary factors may alter the risk of pancreatic cancer.

Adult↗

PubMed1992

Diet, prolactin, and breast cancer.

Relationships between dietary nutrients and plasma prolactin concentration were studied in 249 women with a history of nonskin cancers among first-degree female relatives. For each quintile of nutrient density, the odds ratio (OR), relative to the lowest quintile, of having an elevated (above the median) prolactin concentration was estimated by logistic regression, taking into account parity, menopausal status, and current tobacco-smoking habits. For nutrient densities estimated from 24-h recall data there was a significant positive association between plasma prolactin concentration and increasing saturated fatty acid intake; the OR of elevated prolactin in the top quintile was 3.1 [95% confidence interval (CI) 1.2-8.1] and there was a negative association with vitamin C [OR in the top quintile 0.28, (95% CI 0.10-0.78)]. For usual nutrient densities (estimated by quantitative food frequency questionnaire) there was a statistically significant trend (P = 0.04) toward lower prolactin concentrations with increasing sodium density, and a marginally significant positive trend (P = 0.07) with increasing dietary density of refined sugars.

Adult↗

PubMed1992

A case-control study of smoking and gallbladder disease: importance of examining time relations.

We report a case-control study of gallbladder disease and cigarette smoking. Subjects were 252 incident cases and 233 age-sex-residence-matched community controls. Three quarters of the subjects were women. The age-matched risk of gallbladder disease was increased in current smokers vs never-smokers [odds ratio (OR) = 1.6 and 1.3 in women and men, respectively] and in past smokers (OR = 1.5 for each sex). In light of earlier research, showing that, in women, certain risk factors for gallbladder disease may act maximally soon after first exposure, we examined time relations. In women, multivariable analysis showed that the risk increase was especially high in current-smoking women less than 35 years of age [OR = 3.5, 95% confidence interval (CI) = 1.2-9.8] and in women who had been smoking for 1-8 years (OR = 2.8, 95% CI = 1.1-7.1). These results indicate that, in women, the smoking-related risk of gallbladder disease is greatest soon after first exposure--as has also been reported for oral contraceptive use. The findings highlight the potential for mis-estimating risk in case-control studies when late-occurring cases have a different relation to the exposure factor than do the early-occurring cases within the original, albeit undocumented, exposure cohort.

Adult↗

PubMed1992

Effects of maternal smoking upon neuropsychological development in early childhood: importance of taking account of social and environmental factors.

Data from a prospective study of 548 children followed from birth to 4 years of age were analysed to determine whether maternal smoking during and/or after pregnancy affects children's neuropsychological development. The differences in mean developmental test scores between children whose mothers smoked and those of mothers who did not smoke were slight, with subscale scores only 2.4 to 4.1% lower in children whose mothers smoked. These differences were not statistically significant after adjustment for socio-economic status, quality of home environment and mother's intelligence, suggesting that the social and environmental factors are major confounders of the association of exposure to maternal smoking and neuropsychological development in childhood. In order to gain a better understanding of this area, more precise measures of exposure to environmental tobacco smoke and comprehensive consideration of confounders will be required.

Child, Preschool↗

PubMed1992

Public perceptions of the role of dietary and other environmental factors in cancer causation or prevention.

STUDY OBJECTIVE: The aim was to establish the public's perception of the relative importance of various environmental risk factors for cancer. DESIGN: A postal survey was undertaken using a questionnaire to assess the public's knowledge of cancer morbidity and mortality and the role of lifestyle and genetic risk factors. Sociodemographic data were also collected. SETTING: The survey was completed in the state of South Australia. PARTICIPANTS: A random sample of 1500 names were selected from the electoral rolls of the state. These rolls contain the names of all Australian citizens over the age of 18 years. A response rate of 73% was achieved. MEASUREMENTS AND MAIN RESULTS: The results of the survey showed that the knowledge base of the community was generally high, with few differences across sociodemographic groups. The relative importance of cancer as a contributor to mortality was, however, overestimated and the potential for "cure" underestimated. The role of both diet and cigarette smoking in cancer promotion was widely recognised but there was an overemphasis on the importance of pollution of the food supply compared to imbalance of nutrients. Respondents were more able to assign risk in relation to diet using a food based assessment, compared to a nutrient approach. There was wide acceptability that lifestyle change could have a profound effect on the cancer profile of the community. CONCLUSIONS: With the relatively high degree of awareness and acceptance of lifestyle factors as cancer risk determinants, campaigns which involve skill transfer and removal of barriers to change would appear to be the most relevant approach to improvement in community behaviour.

Adult↗

PubMed1991

A case-control study of diet and cancer of the pancreas.

In a population-based case-control study carried out in Adelaide, South Australia, during the years 1984-1987, the diets of 104 cases of cancer of the pancreas 1 year prior to diagnosis were compared with the diets of 253 community controls. A quantitative food-frequency questionnaire was used to assess usual dietary intakes of 179 food items. Cases were compared with controls in terms of both the amounts of individual food items consumed and the estimated contributions of 48 nutrients to the diet. Food items consumed more by cases than controls included boiled eggs and omelettes as well as a number of items that could be collectively described as sweet and fatty. Food items consumed less by cases than controls included several vegetables and fruits. Conditional logistic regression analysis of nutrient intake adjusted for total energy and for alcohol and tobacco usage yielded an estimate of relative risk of 3.19, with a 95% confidence interval of 1.58-6.47 for the highest quartile of cholesterol intake (relative to the lowest quartile). For the top quartile of refined sugar intake, the estimated relative risk was 2.21 (95% confidence interval 1.07-4.55). Several nutrients derived principally from plant foods were statistically significantly associated with lower risks. Alcohol consumption was significantly lower among cases than controls. Current smokers had a relative risk of 1.76 (95% confidence interval 0.93-3.34) relative to those who had never smoked. There was no association of pancreatic cancer with coffee drinking.

Aged↗

PubMed1991

Fracture rates as a function of forearm mineral density in normal postmenopausal women: retrospective and prospective data.

Fracture histories were obtained from 492 normal postmenopausal women in 1983 and again in 1988, and related to forearm mineral content and density determined in 1983. All peripheral fractures, except those attributable to road traffic accidents, were included. There was only one hip fracture in the series. The total number of postmenopausal fractures was 183 in 149 subjects. In both the retrospective and prospective studies, fracture rates were inversely related to bone status and more significantly to bone density than to bone mass. In the pooled data, the fracture rate was three times as high in women with bone densities more than 4 standard deviations below the young normal mean as in those with bone densities above the mean. On logistic regression, the adjusted relative risk of fracture (odds ratio) in subjects more than 4 standard deviations below the young mean compared with those above the mean was 5.5 (2.7-11.4).

Bone Density↗

PubMed1991

Lead in the placenta, membranes, and umbilical cord in relation to pregnancy outcome in a lead-smelter community.

As part of a cohort study of the effects of chronic exposure to lead on pregnancy outcome and child development, lead concentrations in the umbilical cord and placental tissues (body and membranes) from 9 late fetal deaths, 23 preterm births, and 18 births associated with premature rupture of the amniotic membranes were compared with the lead concentrations in the tissues obtained at 22 normal births. Modest elevations in lead concentration were found in the placental body of late fetal deaths (stillbirths) and preterm births as well as in the cord tissue associated with preterm births and premature rupture of membranes. The geometric mean lead concentration in the membranes from late fetal deaths was 2.73 micrograms/g of dry tissue (95% confidence limits 0.69-10.8), which was 3.5 times higher than the mean found in normal births (0.78 micrograms/g, 95% confidence limits 0.61-1.00). The concentration in the membranes of preterm births was also significantly high, being 1.24 micrograms/G (0.91-1.67). Low correlations of membrane and antenatal blood lead concentrations suggest that other factors in addition to exposure to environmental lead may influence the amount of lead accumulated in the placental membranes.

Chemical Industry↗

PubMed1990

Sociodemographic determinants in Australia of the intake of food and nutrients implicated in cancer aetiology.

In recent years, there has been a growing awareness of the role that diet can play in the promotion, retardation or amelioration of the cancer process. This has led to the development of dietary guidelines for cancer prevention by health authorities in several Western societies. However, there is still limited information about the sociodemographic determinants of intake of foods and nutrients of interest in many of these countries. A study of the dietary intake of a random sample of residents of the State of Victoria in Australia showed that women, those in the older age groups and in the higher occupational ranks, had diets more in line with current recommendations for cancer prevention--the most marked differences being between men and women. However, the sociodemographic differences were relatively small compared with the low rate of overall compliance with the guidelines.

Adolescent↗

PubMed1990

Induction of micronuclei in cultured murine splenocytes exposed to elevated levels of ferrous ions, hydrogen peroxide and ultraviolet irradiation.

The frequency of micronuclei in cultured mouse splenocytes increased positively and in a dose-related manner to exposure to ferrous ions and ultraviolet irradiation, but not to hydrogen peroxide. Combined treatments, especially when ferrous ions were present with hydrogen peroxide or with ultraviolet irradiation, led to a synergistic enhancement in micronucleus frequency. The results indicate that a significant level of chromosome damage is associated with exposure to ultraviolet light and to general cellular pro-oxidative stress, and indicate that under these conditions the micronucleus assay can provide an effective in vitro model for the study of genotoxicity in relation to oxygen-derived free radicals.

Animals↗

PubMed1990

The prevalence of emotional and behaviour disorders and patterns of service utilisation in children and adolescents.

This study compared the prevalence of emotional and behavioural disorders in children attending schools of different socio-economic class. In addition, the study compared the rate of service utilization by children with and without disorders. Using cutoff scores recommended for use with Australian children, the prevalence of disorders in schools of different socio-economic class ranged from 2.3 +/- 2.2 to 13.9 +/- 5.3 per 100 children, with the highest prevalence being found in the lower socio-economic class schools. Although few children with disorders had been seen in a mental health clinic, advice had been sought from other services with regard to 66% of these children. This high rate of service utilization by children with disorders highlights the key role that general practitioners, school guidance officers and hospital services could play in facilitating the early identification and management of children with emotional and behavioural disorders.

Adolescent↗

PubMed1989

Intakes and sources of a range of dietary sugars in various Australian populations.

Data from the Apparent Consumption of Foodstuffs publications of the Australian Bureau of Statistics have, until recently, been the major source of information in Australia about the consumption of refined sugars. This database, which relies on national figures for production, importation, export, storage and stocks, and on population statistics, had indicated that some 14% of the total energy that was available in Australia was derived from refined sugars. Similar figures have been derived for both the United States and United Kingdom by means of this kind of national food-availability database. However, a recent reanalysis of a large-scale dietary survey of individuals in the United States has indicated a much lower level of consumption of refined sugars. In recent years, several large-scale surveys of individuals' consumption patterns in the Australian population have been carried out by the Social Nutrition Program at the CSIRO Division of Human Nutrition. These surveys indicate that the mean level of consumption of refined sugars is not as high as that which previously was estimated from Apparent Consumption data. However, there was a wide range of intakes and a substantial proportion of individuals with intakes that were above recommended levels.

Adult↗

PubMed1989

Early childhood development: a comparative study of beliefs held by adolescents, medical students and mothers.

This study examined beliefs about the normal development of preschool children held by adolescents, medical students and mothers. A consistent pattern was identified, with adolescents estimating that young children can do the least, medical students' estimations lying between those of adolescents and mothers, and mothers estimating that the children can do the most. In addition, medical students were found to change their beliefs during the time that they participated in their paediatric teaching programme. It is suggested that paediatricians and other child health professionals take into account the varying beliefs held by different groups in the community when providing advice or teaching about early child development.

Adolescent↗