Implications of co-twin dependence for twins' social interactions, mental health and alcohol use : A follow-up study of Finnish twins from adolescence to early adulthood

Objective: The aim of the present study was to examine co-twin dependence and its impact on twins' social contacts, leisure-time activities and psycho-emotional well-being. The role of co-twin dependence was also examined as a moderator of genetic and environmental influences on alcohol use in adolescence and in early adulthood. Methods: The present report is based on the Finnish Twin Cohort Study (FinnTwin16), a population-based study of five consecutive birth cohorts of Finnish twins born in the years 1975-1979. Baseline assessments were collected through mailed questionnaires, within two months of the twins' sixteenth birthday yielding replies from 5563 twin individuals. All respondent twins were sent follow-up questionnaires at ages of 17, 18½, and in early adulthood, when twins were 22-27 years old. Measures: The questionnaires included a survey of health habits and attitudes, a symptom checklist and questions about twins' relationships with parents, peers and co-twin. Measures used were twins' self-reports of their own dependence and their co-twin's dependence at age 16, reports of twins' leisure-time activities and social contacts, alcohol use, psychological distress and somatic symptoms both in adolescence and in early adulthood. Results: In the present study 25.6% of twins reported dependence on their co-twin. There were gender and zygosity differences in dependence, females and MZ twins were more likely to report dependence than males and DZ twins. Co-twin dependence can be viewed on one hand as an individual characteristic, but on the other hand as a pattern of dyadic interaction that is mutually regulated and reciprocal. Most of the twins (80.7%) were either concordantly co-twin dependent or concordantly co-twin independent. The associations of co-twin dependence with twins' social interactions and psycho-emotional characteristics were relatively consistent both in adolescence and in early adulthood. Dependence was related to higher contact frequency and a higher proportion of shared leisure-time activities between twin siblings at the baseline and the follow-up. Additionally co-twin dependence was associated with elevated levels of psycho-emotional distress and somatic complaints, especially in adolescence. In the framework of gene-environment interaction, these results suggest that the genetic contribution to individual differences in drinking patterns is dependent on the nature of the pair-wise relationship of twin siblings. Conclusions: The results of this study indicate that co-twin dependence is a genuine feature of the co-twin relationship and shows the importance of studying the impact of various features of co-twin relationships on individual twins' social and psycho-emotional life and well-being. Our study also offers evidence that differences in inter-personal relationships contribute to the effects of genetic propensities.

Statistical analysis of the associations of hereditary factors with the risk of Type 1 diabetes and Diabetic Nephropathy based on the familial data collected through ascertaiment from population-based registers

In genetic epidemiology, population-based disease registries are commonly used to collect genotype or other risk factor information concerning affected subjects and their relatives. This work presents two new approaches for the statistical inference of ascertained data: a conditional and full likelihood approaches for the disease with variable age at onset phenotype using familial data obtained from population-based registry of incident cases. The aim is to obtain statistically reliable estimates of the general population parameters. The statistical analysis of familial data with variable age at onset becomes more complicated when some of the study subjects are non-susceptible, that is to say these subjects never get the disease. A statistical model for a variable age at onset with long-term survivors is proposed for studies of familial aggregation, using latent variable approach, as well as for prospective studies of genetic association studies with candidate genes. In addition, we explore the possibility of a genetic explanation of the observed increase in the incidence of Type 1 diabetes (T1D) in Finland in recent decades and the hypothesis of non-Mendelian transmission of T1D associated genes. Both classical and Bayesian statistical inference were used in the modelling and estimation. Despite the fact that this work contains five studies with different statistical models, they all concern data obtained from nationwide registries of T1D and genetics of T1D. In the analyses of T1D data, non-Mendelian transmission of T1D susceptibility alleles was not observed. In addition, non-Mendelian transmission of T1D susceptibility genes did not make a plausible explanation for the increase in T1D incidence in Finland. Instead, the Human Leucocyte Antigen associations with T1D were confirmed in the population-based analysis, which combines T1D registry information, reference sample of healthy subjects and birth cohort information of the Finnish population. Finally, a substantial familial variation in the susceptibility of T1D nephropathy was observed. The presented studies show the benefits of sophisticated statistical modelling to explore risk factors for complex diseases.

The social patterning of health, smoking and drinking in Estonia, Latvia, Lithuania and Finland in 1994-2004

The Baltic countries share public health problems typical of most Eastern European transition economies: morbidity and mortality from non-communicable diseases is higher than in Western European countries. This situation has many similarities compared to a neighbouring country, Finland during the late 1960s. There are reasons to expect that health disadvantage may be increasing among the less advantaged population groups in the Baltic countries. The evidence on social differences in health in the Baltic countries is, however, scattered to studies using different methodologies making comparisons difficult. This study aims to bridge the evidence gap by providing comparable standardized cross-sectional and time trend analyses to the social patterning of variation in health and two key health behaviours i.e. smoking and drinking in Estonia, Latvia, Lithuania and Finland in 1994-2004 representing Eastern European transition countries and a stable Western European country. The data consisted of similar cross-sectional postal surveys conducted in 1994, 1996, 1998, 2000, 2002 and 2004 on adult populations (aged 20 64 years) in Estonia (n=9049), Latvia (n=7685), Lithuania (n=11634) and Finland (n=18821) in connection with the Finbalt Health Monitor project. The main statistical method was logistic regression analysis. Perceived health was found to be worse among both men and women in the Baltic countries than in Finland. Poor health was associated with older age and lower education in all countries studied. Urbanization and marital status were not consistently related to health. The existing educational inequalities in health remained generally stable over time from 1994 to 2004. In the Baltic countries, however, improvement in perceived health was mainly found among the better educated men and women. Daily smoking was associated with young age, lower education and psychological distress in all countries. Among women smoking was also associated with urbanisation in all countries except Estonia. Among Lithuanian women, the educational gradient in smoking was weakest, and the overall prevalence of smoking increased over time. Drinking was generally associated with young age among men and women, and with education among women. Better educated women were more often frequent drinkers and less educated binge drinkers. The exception was that in Latvian men and women both frequent drinking and binge drinking were associated with low education. In conclusion, the Baltic countries are likely to resemble Western European countries rather than other transition societies. While health inequalities did not markedly change, substantial inequalities do remain, and there were indications of favourable developments mainly among the better educated. Pressures towards increasing health inequalities may therefore be visible in the future, which would be in accordance with the results on smoking and drinking in this study.

The Europeanisation of occupational health services: A study of the impact of EU policies

This study concerns Framework Directive 89/391/EEC on health and safety at work, which encouraged improvements in occupational health services (OHS) for workers in EU member states. Framework Directive 89/391/EEC originally aimed at bringing the same level of occupational health and safety to employees in both the public and private sectors in EU member states. However, the implementation of the framework directive and OHS varies widely among EU member states. Occupational health services have generally been considered an important work-related welfare benefit in EU member states. The purpose of this study was to analyse OHS within the EU context and then analyse the impact of EU policies on OHS implementation as part of the welfare state benefit. The focus is on social, health, and industrial policies within welfare state regimes as well as EU policy-making processes affecting these policies in EU member states. The research tasks were divided into four groups related to the policy, functions, targets,and actors of OHS. The questions related to policy tried to discover the role of OHS in other policies, such as health, social, and labour market policies within the EU. The questions about functions sought to describe the changes, as well as the path dependence, of OHS in EU member states after the framework directive. The questions about targets were based on the general aims of WHO and the ILO in relation to equity, solidarity, universality, and access to OHS. The questions on actors were designed to understand the variety of stakeholders interested in OHS. The actors were supranational (EU, ILO, and WHO), national (ministries, institutes, and professional organisations), and social partners (trade unions and employers organisations). The study data were collected by interviewing 92 people in 15 EU member states, including representatives of ministries, institutions, research,trade unions, employers organisations, and occupational health organisations. Other documents were collected from the Internet,databases, libraries, and conference materials for a systematic review of the policies, strategies, organisation, financing, and monitoring of OHS in EU member states. Different analytical methods were used in the data analysis. The main findings of the study can be summarised as follows. First, occupational health services is a context-dependent phenomenon, which therefore varies according to the development of the welfare state in general, and depends on each country s culture, history, economy, and politics. The views of different stakeholders in EU member states concerning the impact and possibilities of OHS to improve health vary from evidence-based opinions to the sporadic impact of OHS on occupational health. OHS as a concept is vaguely defined by the EU, whereas the ILO defines OHS content. The tasks of OHS began as preventive and protective services for workers. However, they have moved towards multidisciplinary and organisational development as well as the workplace health promotion sphere.Since 1989 OHS has developed differently in different EU member states depending on the starting position of those states, but planning and implementation are crucial phases in the process toward better OHS coverage, equity, and access. Nevertheless, the data used for the planning and legitimisation of OHS activities are mainly based on occupational health data rather than on OHS data. This makes decisions on political or policy grounds inaccurate. OHS is still an evolving concept and benefit for workers, but the Europeanisation of OHS reflects contextual changes, such as the impact of the internal market, competition, and commercialisation on OHS. Stronger cooperation and integration with health, social, and employment services would be an asset for workers, because of new epidemics, an epidemiological shift towards new risks, an ageing labour market, and changes in the labour market. Different methods and approaches are needed in order to study the results of integrated services. In the future, more detailed information will be needed about the actual impact of EU policies on OHS and decision-making processes in order to get OHS into different policies in the EU and its member states. Further results and effects of OHS processes on occupational health need to be analysed more carefully. The adoption of a variety of research strategies and a multidisciplinary approach to understand the influence of different policies on OHS in the EU and its member states would highlight the options and opportunities to improve workers occupational health. Key subject headings: Occupational health services, EU policy, policymaking,framework directive 89/391/EEC

The Functions and Regulation of Ornithine Decarboxylase

Ornithine decarboxylase (ODC) regulates the synthesis of polyamines which are involved in many cellular functions e.g. proliferation and differentiation. Due to its critical role, ODC is a tightly regulated enzyme by antizymes and antizyme inhibitors. If the regulation fails, the activity of ODC increases and may lead to malignant transformation of a cell. Increased ODC activity is found in many common cancers, including colon, prostate, and breast cancer. In a transformed cell, dynamics of the actin cytoskeleton is disturbed. A small G-protein, RhoA regulates organization of the cytoskeleton, and its overactivity increases malignant potential of the cell. The present results indicate that covalent attachment of polyamines by transglutaminase is a physiological means of regulating the activity of RhoA. The translocation of RhoA to the plasma membrane, where it exerts its activity is dependent on the presence of catalytically active ODC. As the overactivity of ODC and RhoA are implicated in cell transformation, the results provide a mechanistic explanation of the interrelationship between the polyamine metabolism and the reorganization of the actin cytoskeleton occurring in cancer cells. ODC and polyamines have also an important role in the function of central nervous system. They participate in the regulation of brain morphogenesis in embryos. In adult nervous tissue, polyamines regulate K+ and glutamate channels. K+ inward rectifying channels control membrane potentials and NMDA-type glutamate receptors (NMDAR) regulate synaptic plasticity. High ODC activity and polyamine levels are considered important in the development of ischemic brain damage and they are implicated in the pathogenesis of Alzheimer s disease (AD). A homolog of ODC was cloned from a human brain cDNA library, and several alternatively spliced variants were detected in human brain and testis. The novel protein was nevertheless devoid of ODC catalytic activity. It was subsequently found to be a novel inductor of ODC activity and polyamine synthesis, called antizyme inhibitor 2 (AZIN2). The accumulation of AZIN2 in vesicle-like formations along the axons and beneath the plasma membrane of neurons as well as in steroid hormone producing Leydig cells and luteal cells of the gonads implies that AZIN2 plays a role in secretion and vesicle trafficking. An accumulation of AZIN2 was detected also in specimens of AD brains. This increased expression of AZIN2 was specific for AD and was not found in brains with other neurodegenerative diseases including CADASIL or dementia with Lewy bodies.