Biomedical subjects

Christina Lee

Publications and source records attributed to Christina Lee.

26 records · Page 2Linked to original sources

PubMed2004

Country of birth, country of residence, and menopausal transitions and symptoms: British birth cohort and Australian Longitudinal Study on Women's Health.

OBJECTIVE: To explore endocrine-related and general symptoms among three groups of middle-aged women defined by country of birth and country of residence, in the context of debates about biological, cultural and other factors in menopause. METHODS: British-born women participating in a British birth cohort study (n=1,362) and age-matched Australian-born (n=1,724) and British-born (n=233) Australian women selected from the Australian Longitudinal Study on Women's Health (ALSWH) responded to two waves of surveys at ages 48 and 50. RESULTS: Australian-Australian and British-Australian women report reaching menopause later than British-British women, even after accounting for smoking status and parity. Hormone replacement therapy (HRT) use was lower and hysterectomy was more common among both Australian groups, probably reflecting differences in health services between Britain and Australia. The Australian-Australian and British-Australian groups were more likely to report endocrine-related symptoms than the British-British group, even after adjusting for menopausal status. British-British women were more likely to report some general symptoms. CONCLUSIONS: Symptom reporting is high among Australian and British midlife women and varies by country of residence, country of birth and menopausal status. IMPLICATIONS: The data do not support either a simple cultural or a simple biological explanation for differences in menopause experience.

Australia↗

PubMed2004

Optimism, health-related hardiness and well-being among older Australian women.

This article examines whether optimism and health-related hardiness contribute to health and well-being among older women. Positive psychological characteristics, including optimism and health-related hardiness, are correlated with good self-rated health, but these variables are all affected by socioeconomic status, social support, physical illness and access to services. Using data from 9501 Australian women aged 73 to 78, we show that optimism and health-related hardiness explain a significant proportion of variance in all subscales of the SF-36, and in stress, even after these confounders are taken into account. The data, although cross-sectional, suggest that positive personal characteristics may contribute to well-being.

Aged↗

PubMed2004

Measurement of cytokines in autoimmune disease.

Systemic autoimmune diseases are characterized by extensive alterations in immune system function, with cytokines and autoantibodies contributing to impaired immunoregulation and tissue damage. Characterization of the expression and function of cytokines is important for elucidation of pathogenic mechanisms and for identification of therapeutic targets and strategies. We reviewed the utility of assays that reflect individual variability in cytokine gene sequence, expression of messenger ribonucleic acid (mRNA) or protein, as well as measurement of expression of target genes regulated by cytokines. Real-time reverse transcriptase polymerase chain reaction and intracellular staining for cytokine expression are two sensitive and quantitative approaches for analysis of cytokine mRNA and protein, respectively. Detailed methods are provided for these assays.

Autoimmune Diseases↗

PubMed2003

Effects of physical activity on emotional well-being among older Australian women: cross-sectional and longitudinal analyses.

OBJECTIVE: To explore relationships between physical activity and mental health cross-sectionally and longitudinally in a large cohort of older Australian women. METHOD: Women in their 70s participating in the Australian Longitudinal Study on Women's Health responded in 1996 (aged 70-75) and in 1999 (aged 73-78). Cross-sectional data were analyzed for 10,063 women and longitudinal data for 6472. Self-reports were used to categorize women into four categories of physical activity at each time point as well as to define four physical activity transition categories across the 3-year period. Outcome variables for the cross-sectional analyses were the mental health component score (MCS) and mental health subscales of the Medical Outcomes Study Short Form (SF-36). The longitudinal analyses focused on changes in these variables. Confounders included the physical health component scale (PCS) of the SF-36, marital status, body mass index (BMI) and life events. Adjustment for baseline scores was included for the longitudinal analyses. RESULTS: Cross-sectionally, higher levels of physical activity were associated with higher scores on all dependent variables, both with and without adjustment for confounders. Longitudinally, the effects were weaker, but women who had made a transition from some physical activity to none generally showed more negative changes in emotional well-being than those who had always been sedentary, while those who maintained or adopted physical activity had better outcomes. CONCLUSION: Physical activity is associated with emotional well-being among a population cohort of older women both cross-sectionally and longitudinally, supporting the need for the promotion of appropriate physical activity in this age group.

Aged↗

PubMed2003

Localized neurotransmitter release for use in a prototype retinal interface.

PURPOSE: Current neural prostheses use electricity as the mode of stimulation, yet information transfer in neural circuitry is primarily through chemical transmitters. To address this disparity, this study was conducted to devise a prototype interface for a retinal prosthetic based on localized chemical delivery. The goal was to determine whether fluidic delivery through microfabricated apertures could be used to stimulate at single-cell dimensions. METHODS: A drug delivery system was microfabricated based on a 5- or 10- microm aperture in a 500-nm thick silicon nitride membrane to localize and limit transmitter release. The aperture overlies a microfluidic delivery channel in a silicone elastomer. To demonstrate the effectiveness of this transmitter-based prosthesis, rat pheochromocytoma cells (PC12 cell line) were grown on the surface of the device to test the precision of stimulation, using bradykinin as a stimulant and measuring fluorescence from the calcium indicator, fluo-4. RESULTS: The extent of stimulation could be controlled accurately by varying the concentration of stimulant, from a single cell adjacent to the aperture to a broad area of cells. The stimulation radius was as small as 10 microm, corresponding to stimulation volumes as small as 2 pL. The relationship between the extent of stimulation and concentration was linear. CONCLUSIONS: The demonstration of localized chemical stimulation of excitable cells illustrates the potential of this technology for retinal prostheses. Although this is only a proof of concept of neurotransmitter stimulation for a retinal prosthesis, it is a significant first step toward mimicking neurotransmitter release during synaptic transmission.

Aniline Compounds↗

PubMed2002

Psychological stress, coping, and symptoms of disordered eating in a community sample of young Australian women.

OBJECTIVE: To investigate the relationships among stress, coping, and symptoms of disordered eating in a community sample of young Australian women. METHOD: A longitudinal study design was employed. Two mail-out surveys, assessing perceived psychological stress, coping strategies, body weight dissatisfaction, dieting, and disordered eating behaviors, were completed 6 months apart by 415 young women selected from a cohort of the Women's Health Australia Study. RESULTS: Strong cross-sectional relationships among the study variables were found. Results of longitudinal analyses, however, demonstrated only tenuous relationships among stress, coping, and later symptoms of disordered eating. DISCUSSION: These results did not support the hypothesis that stress and coping strategies would predict disordered eating over time. Some evidence was found for a modest reverse relationship between stress and disordered eating. Although contrary to generally accepted theoretical models of disordered eating, these findings are consistent with those of the few previous longitudinal studies reported. Theoretical implications are discussed.

Adaptation, Psychological↗

PubMed2002

Menopausal transitions, symptoms and country of birth: the Australian Longitudinal Study on Women's Health.

OBJECTIVE: To assess differences among the menopausal transitions and symptoms experienced by women participating in the Australian Longitudinal Study on Women's Health, according to their countries of birth. METHODS: Data from 8,466 women aged 45-50 in 1996, who responded to surveys in 1996 and 1998 and had not had a hysterectomy, were analysed. Women were categorised by country of birth and cross-sectionally by menopausal status at Survey 1 and 2, as well as longitudinally by transition through menopause between Surveys 1 and 2. Four endocrine-related and 10 general symptoms were assessed. RESULTS: Women bom in Asia were twice as likely as Australian-bom women to be post-menopausal at Survey 1, twice as likely to become post-menopausal between surveys, less likely to remain peri-menopausal, and less likely to report hot flushes and night sweats. Odds ratios for each symptom at Survey 2 were near unity for all country of birth groups compared with Australian bom women, with or without adjustment for symptoms at Survey 1, menopausal transition category, behaviour, lifestyle and demographics. CONCLUSIONS: Asian-born women entered menopause earlier and passed through it more quickly, but once this was taken into account all women showed the same prevalences of symptoms. There may be differences between ethnic groups that influence the timing of menopause, but the subjective experience appears similar. IMPLICATIONS: The timing of menopause may be affected by biological or dietary differences. Asian-bom women's lower reported prevalence of symptoms may be explained by a more rapid peri-menopausal transition. With increasing numbers of Asian-Australian women reaching menopause, an understanding of country-of-birth differences has implications for public health.

Asia↗

PubMed2002

Number of social roles, health, and well-being in three generations of Australian women.

The relation between multiple social roles and health is a particular issue for women, who continue to take major responsibility for childcare and domestic labor despite increasing levels of involvement in the paid workforce. This article analyzes Survey 1 data from the Australian Longitudinal Survey on Women's Health to explore relations between role occupancy and health, well-being, and health service use in three generations of Australian women. A total of 41,818 women in three age groups (young, 18-23; mid-age, 40-45; older, 70-75) responded to mailed surveys. Young and mid-age women were classified according to their occupancy of five roles--paid worker, partner, mother, student, and family caregiver--whereas older women were classified according to occupancy of partner and caregiver roles only. Common symptoms (headaches, tiredness, back pain, difficulty sleeping), diagnosis of chronic illness, and use of health services were compared across groups characterized by number of roles. Comparisons were also conducted on the physical and mental component scores of the SF-36 and perceived stress, with and without adjustment for confounders. Among young women, the best health was associated with occupancy of one role; among mid-age women, those with three or more roles were in the best health; and for older women, those with one role were in the best health. Young women with none or with four or more roles, and mid-age and older women with none of the defined social roles tended to be in the poorest health. Different patterns of results may be explained by differences in the extent to which women at different life stages feel committed to various social roles, and to the extent to which they are able to draw on social, material, and economic supports.

Adolescent↗