Changes in three-dimensional architecture of microfilaments in cultured vascular smooth muscle cells during phenotypic modulation

To investigate changes in the three-dimensional microfilament architecture of vascular smooth muscle cells (SMC) during the process of phenotypic modulation, rabbit aortic SMCs cultured under different conditions and at different time points were either labelled with fluorescein-conjugated probes to cytoskeletal and contractile proteins for observation by confocal laser scanning microscopy, or extracted with Triton X-100 for scanning electron microscopy. Densely seeded SMCs in primary culture, which maintain a contractile phenotype, display prominent linear myofilament bundles (stress fibres) that are present throughout the cytoplasm with alpha-actin filaments predominant in the central part and beta-actin filaments in the periphery of the cell. Intermediate filaments form a meshed network interconnecting the stress fibres and linking directly to the nucleus. Moderately and sparsely seeded SMCs, which modulate toward the synthetic phenotype during the first 5 days of culture, undergo a gradual redistribution of intermediate filaments from the perinuclear region toward the peripheral cytoplasm and a partial disassembly of stress fibres in the central part of the upper cortex of the cytoplasm, with an obvious decrease in alpha-actin and myosin staining. These changes are reversed in moderately seeded SMCs by day 8 of culture when they have reached confluence. The results reveal two changes in microfilament architecture in SMCs as they undergo a change in phenotype: the redistribution of intermediate filaments probably due to an increase in synthetic organelles in the perinuclear area, and the partial disassembly of stress fibres which may reflect a degradation of contractile components.

Renewing Australia's mental health strategy

The Second National Mental Health Plan, endorsed by Commonwealth, State and Territory governments on 30 July 1998, will pursue three key themes: (1) Promoting mental health, plus prevention of and early intervention in mental disorders, with a specific focus on depression; (2) continuing structural reform of mental health services, including better integration with general practice and the private psychiatric sector; and (3) implementing quality and outcome measures in mental health services, including evidence-based practice.

Suicide and recency of health care contacts - A systematic review

Background Many countries have set targets for suicide reduction, and suggested that mental health care providers and general practitioners have a key role to play. Method Asystematic review of the literature. Results Among those in the general population who commit suicide, up to 41% may have contact with psychiatric inpatient care in the year prior to death and up-to 9% may commit suicide within one day of discharge. The corresponding figures are I I and 4% for community-based psychiatric care and 83 and 20% for general practitioners. Conclusions Among those who die by suicide. contact with health services is common before death. This is a necessary but not sufficient condition for clinicians to intervene. More work is needed to determine whether these people show characteristic patterns of care and/or particular risk factors which would enable a targeted approach to be developed to assist clinicians in detecting and managing high-risk patients.

Evidence of multiple transcription initiation and termination sites within the rDNA intergenic spacer and rRNA readthrough transcription in the urochordate Herdmania curvata

Analysis of the structure of the urochordate Herdmania curvata ribosomal DNA intergenic spacer (IGS) and its role in transcription initiation and termination suggests that rRNA gene regulation in this chordate differs from that in vertebrates. A cloned H, curvata IGS is 1881 bp and composed predominantly of two classes of similar repeat sequences that largely alternate in a tandem array. Southern blot hybridization demonstrates that the IGS length variation within an individual and population is largely the result of changes in internal repeat number. Nuclease S1 mapping and primer extension analyses suggest that there are two transcription initiation sites at the 3' end of the most 3' repetitive element; these sites are 6 nucleotides apart. Unlike mouse, Xenopus, and Drosophila, there is no evidence of transcription starting elsewhere in the IGS. Most sequence differences between the promoter repeat and the other internal repeats are in the vicinity of the putative initiation sites. As in Drosophila, nuclease S1 mapping of transcription termination sites suggest that there is not a definitive stop site and a majority of the pre-rRNAs read through a substantial portion of the IGS. Some transcription appears to proceed completely through the promoter repeat into the adjacent rDNA unit. Analysis of oocyte RNA by reverse transcription-polymerase chain reaction (RT-PCR) confirms that readthrough transcription into the adjacent rDNA unit is occurring in some small IGS length variants; there is no evidence of complete readthrough of IGSs larger than 1.0 kb.

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 fur 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.

Rectification of the olfactory cyclic nucleotide-gated channel by intracellular polyamines

Polyamine-induced inward rectification of cyclic nucleotide-gated channels was studied in inside-out patches from rat olfactory neurons. The polyamines, spermine, spermidine and putrescine, induced an 'instantaneous' voltage-dependent inhibition with K-d values at 0 mV of 39, 121 mu M and 2.7 mM, respectively. Hill coefficients for inhibition were significantly < 1, suggesting an allosteric inhibitory mechanism. The Woodhull model for voltage-dependent block predicted that all 3 polyamines bound to a site 1/3 of the electrical distance through the membrane from the internal side. Instantaneous inhibition was relieved at positive potentials, implying significant polyamine permeation. Spermine also induced exponential current relaxations to a 'steady-state' impermeant level. This inhibition was also mediated by a binding site 1/3 of the electrical distance through the pore, but with a K-d of 2.6 mM. Spermine inhibition was explained by postulating two spermine binding sites at a similar depth. Occupation of the first site occurs rapidly and with high affinity, but once a spermine molecule has bound, it inhibits spermine occupation of the second binding site via electrostatic repulsion. This repulsion is overcome at higher membrane potentials, but results in a lower apparent binding affinity for the second spermine molecule. The on-rate constant for the second spermine binding saturated at a low rate (similar to 200 sec(-1) at +120 mV), providing further evidence for an allosteric mechanism. Polyamine-induced inward rectification was significant at physiological concentrations.

Women's health Australia: On the progress of the main cohort studies

More than 41,000 women aged 18-23, 45-50, and 70-75 years in 1996 are participating in the Australian Longitudinal Study on Women's Health (Women's Health Australia). Baseline surveys were conducted for all three cohorts in 1996, and the first follow-up survey of the mid-age group in 1998 has achieved a response rate exceeding 90%. The main findings so far reflect the large differences in the life experiences of the three cohorts. The young women report high levels of stress. The physical and mental health of those with young children is worse than for those without children, but confounding by sociodemographic characteristics may account for the differences. Two thirds of young women in the healthy weight or underweight range would like to weigh less, and early onset of dieting is associated with poorer physical and mental health. Most of the women in the mid-age group have multiple roles-in paid work, home duties, and caring for children and other dependents. The potential of the study to investigate the long-term impact of such busy lives on health outcomes is considerable. At this stage, the main health issues for these women relate to tiredness, weight gain, and menopause. The older cohort presents a picture of positive aging. These women are heavier users of health services than the mid-age and younger women, and they are also more satisfied with these services. Although their physical health is poorer, their mental health is better, and they report less stress than women in the other two cohorts. The follow-up survey of this group, planned for 1999, will focus on the coping strategies used by these women. An overall goal of the project is to understand the interactions among social roles, life events, and women's health in order to provide a basis for improved health policies and services. Analysis of these interactions, which relies on both quantitative and qualitative data, poses many challenges that will be addressed as the longitudinal data become available.

Patterns of alcohol consumption in young Australian women: socio-demographic factors, health-related behaviours and physical health

Objective: To determine which sociodemographic factors. health-related behaviours and physical health conditions are associated with non-drinking, binge drinking and hazardous/harmful drinking in young Australian women. Methods: Cross-sectional data were obtained from the baseline survey of 14,762 young women (aged 18-23 years) enrolled in the Women's Health Australia study in 1996. Associations between a range of drinking patterns and sociodemographic factors, health-related behaviours and health conditions were examined. Results: Half the women were 'low intake' drinkers, a third 'rarely drank' and 9% were non-drinkers; however, 70% reported binge drinking with one-quarter of the binge drinkers doing so at least weekly. Nondrinkers were more likely than drinkers to be married, pregnant, non-smokers, born in non-English speaking countries, to live in the Northern Territory, and to have lower levels of education, employment, and private health insurance. Low intake/binge weekly' drinkers (12%) and 'hazardous/ harmful' drinkers (5%) were more likely than 'low risk' drinkers to be unmarried; to live in shared accommodation, alone or with their parents; to live in rural or remote areas; to have ever had any sexually transmitted infection; to be current smokers or ex-smokers and to have used unhealthy weight-control practices. Conclusions: The results confirm findings from other countries about the importance of social conditions as determinants of alcohol consumption by young women. Implications: Health promotion to reduce young women's alcohol consumption needs to be carefully targeted to take account of their demographies, living environments and beliefs.

Perceived need for mental health care, findings from the Australian National Survey of Mental Health and Well-being

Background. The Australian National Survey of Mental Health and Well-being was designed to detect and describe psychiatric morbidity, associated disability, service use and perceived need for care. The survey employed a single-phase interview methodology, delivering a field questionnaire to a clustered probability sample of 10641 Australians. Perceived need was sampled with an instrument designed for this survey, the Perceived Need for Care Questionnaire (PNCQ). This questionnaire gathers information about five categories of perceived need, assigning each to one of four levels of perceived need. Reliability and validity studies showed satisfactory performance of the instrument. Methods. Perceived need for mental health care in the Australian population has been analysed using PNCQ data, relating this to diagnostic and service utilization data from the above survey. Results. The survey findings indicate that an estimated 13.8 % of the Australian population have perceived need for mental health care. Those who met interview criteria for a psychiatric diagnosis and also expressed perceived need make up 9.9 % of the population. An estimated 11.0% of the population are cases of untreated prevalence, a minority (3.6% of the population) of whom expressed perceived need for mental health care. Among persons using services, those without a psychiatric diagnosis based on interview criteria (4.4% of the population), showed high levels of perceived met need. Conclusions. The overall rate of perceived need found by this methodology lies between those found in the USA and Canada. The findings suggest that service use in the absence of diagnosis elicited by survey questionnaires may often represent successful intervention. In the survey, untreated prevalence was commonly not accompanied by perceived need for mental health care.

Common chromosomal fragile site FRA16D sequence: identification of the FOR gene spanning FRA16D and homozygous deletions and translocation breakpoints in cancer cells

Fluorescence in situ hybridization of a tile path of DNA subclones has previously enabled the cytogenetic definition of the minimal DNA sequence which spans the FRA16D common chromosomal fragile site, located at 16q23.2. Homozygous deletion of the FRA16D locus has been reported in adenocarcinomas of stomach, colon, lung and ovary. We have sequenced the 270 kb containing the FRA16D fragile site and the minimal homozygously deleted region in tumour cells. This sequence enabled localization of some of the tumour cell breakpoints to regions which contain AT-rich secondary structures similar to those associated with the FRA10B and FRA16B rare fragile sites. The FRA16D DNA sequence also led to the identification of an alternatively spliced gene, named FOR (fragile site FRA16D oxidoreductase), exons of which span both the fragile site and the minimal region of homozygous deletion. In addition, the complete DNA sequence of the FRA16D-containing FOR intron reveals no evidence of additional authentic transcripts. Alternatively spliced FOR transcripts (FOR I, FOR II and FOR III) encode proteins which share N-terminal WW domains and differ at their C-terminus, with FOR III having a truncated oxidoreductase domain. FRA16D-associated deletions selectively affect the FOR gene transcripts. Three out of five previously mapped translocation breakpoints in multiple myeloma are also located within the FOR gene. FOR is therefore the principle genetic target for DNA instability at 16q23.2 and perturbation of FOR function is likely to contribute to the biological consequences of DNA instability at FRA16D in cancer cells.