Building block aspect ratio controls assembly, architecture, and mechanics of synthetic and natural protein networks

Fibrous networks constructed from high aspect ratio protein building blocks are ubiquitous in nature. Despite this ubiquity, the functional advantage of such building blocks over globular proteins is not understood. To answer this question, we engineered hydrogel network building blocks with varying numbers of protein L domains to control the aspect ratio. The mechanical and structural properties of photochemically crosslinked protein L networks were then characterised using shear rheology and small angle neutron scattering. We show that aspect ratio is a crucial property that defines network architecture and mechanics, by shifting the formation from translationally diffusion dominated to rotationally diffusion dominated. Additionally, we demonstrate that a similar transition is observed in the model living system: fibrin blood clot networks. The functional advantages of this transition are increased mechanical strength and the rapid assembly of homogenous networks above a critical protein concentration, crucial for in vivo biological processes such as blood clotting. In addition, manipulating aspect ratio also provides a parameter in the design of future bio-mimetic and bio-inspired materials.

Intermediate Structural Hierarchy in Biological Networks Modulates the Fractal Dimension and Force Distribution of Percolating Clusters

Globular protein hydrogels are an emerging class of materials with the potential for rational design, and a generalized understanding of how their network properties emerge from the structure and dynamics of the building block is a key challenge. Here we computationally investigate the effect of intermediate (polymeric) nanoscale structure on the formation of protein hydrogels. We show that changes in both the cross-link topology and flexibility of the polymeric building block lead to changes in the force transmission around the system and provide insight into the dynamic network formation processes. The preassembled intermediate structure provides a novel structural coordinate for the hierarchical modulation of macroscopic network properties, as well as furthering our understanding of the general dynamics of network formation.

Control of Nanoscale In Situ Protein Unfolding Defines Network Architecture and Mechanics of Protein Hydrogels

Hierarchical assemblies of proteins exhibit a wide-range of material properties that are exploited both in nature and by artificially by humankind. However, little is understood about the importance of protein unfolding on the network assembly, severely limiting opportunities to utilize this nanoscale transition in the development of biomimetic and bioinspired materials. Here we control the force lability of a single protein building block, bovine serum albumin (BSA), and demonstrate that protein unfolding plays a critical role in defining the architecture and mechanics of a photochemically cross-linked native protein network. The internal nanoscale structure of BSA contains "molecular reinforcement" in the form of 17 covalent disulphide "nanostaples", preventing force-induced unfolding. Upon addition of reducing agents, these nanostaples are broken rendering the protein force labile. Employing a combination of circular dichroism (CD) spectroscopy, small-angle scattering (SAS), rheology, and modeling, we show that stapled protein forms reasonably homogeneous networks of cross-linked fractal-like clusters connected by an intercluster region of folded protein. Conversely, in situ protein unfolding results in more heterogeneous networks of denser fractal-like clusters connected by an intercluster region populated by unfolded protein. In addition, gelation-induced protein unfolding and cross-linking in the intercluster region changes the hydrogel mechanics, as measured by a 3-fold enhancement of the storage modulus, an increase in both the loss ratio and energy dissipation, and markedly different relaxation behavior. By controlling the protein's ability to unfold through nanoscale (un)stapling, we demonstrate the importance of in situ unfolding in defining both network architecture and mechanics, providing insight into fundamental hierarchical mechanics and a route to tune biomaterials for future applications.

Continuum mechanical parameterisation of cytoplasmic dynein from atomistic simulation

Cytoplasmic dynein is responsible for intra-cellular transport in eukaryotic cells. Using Fluctuating Finite Element Analysis (FFEA), a novel algorithm that represents proteins as continuum viscoelastic solids subject to thermal noise, we are building computational tools to study the mechanics of these molecular machines. Here we present a methodology for obtaining the material parameters required to represent the flexibility of cytoplasmic dynein within FFEA from atomistic molecular dynamics (MD) simulations, and show that this continuum representation is sufficient to capture the principal dynamic properties of the motor.

Nano-encapsulated Escherichia coli Divisome Anchor ZipA, and in Complex with FtsZ

The E. coli membrane protein ZipA, binds to the tubulin homologue FtsZ, in the early stage of cell division. We isolated ZipA in a Styrene Maleic Acid lipid particle (SMALP) preserving its position and integrity with native E. coli membrane lipids. Direct binding of ZipA to FtsZ is demonstrated, including FtsZ fibre bundles decorated with ZipA. Using Cryo-Electron Microscopy, small-angle X-ray and neutron scattering, we determine the encapsulated-ZipA structure in isolation, and in complex with FtsZ to a resolution of 1.6 nm. Three regions can be identified from the structure which correspond to, SMALP encapsulated membrane and ZipA transmembrane helix, a separate short compact tether, and ZipA globular head which binds FtsZ. The complex extends 12 nm from the membrane in a compact structure, supported by mesoscale modelling techniques, measuring the movement and stiffness of the regions within ZipA provides molecular scale analysis and visualisation of the early divisome.

The hierarchical emergence of worm-like chain behaviour from globular domain polymer chains

Biological organisms make use of hierarchically organised structures to modulate mechanical behaviour across multiple lengthscales, allowing microscopic objects to generate macroscopic effects. Within these structural hierarchies, the resultant physical behaviour of the entire system is determined not only by the intrinsic mechanical properties of constituent subunits, but also by their organisation in three-dimensional space. When these subunits are polyproteins, colloidal chains or other globular domain polymers, the Kratky-Porod model is often assumed for the individual subunits. Hence, it is implicitly asserted that the polymeric object has an intrinsic parameter, the persistence length, that defines its flexibility. However, the persistence lengths extracted from experiment vary, and are often relatively small. Through a series of simulations on polymer chains formed of globular subunits, we show that the persistence length itself is a hierarchical structural property, related not only to the intrinsic mechanical properties of the underlying monomeric subunits, but emerging due to the organisation of inhomogenous geometry along the polymer contour.

Fluctuating Finite Element Analysis (FFEA): A continuum mechanics software tool for mesoscale simulation of biomolecules

Fluctuating Finite Element Analysis (FFEA) is a software package designed to perform continuum mechanics simulations of proteins and other globular macromolecules. It combines conventional finite element methods with stochastic thermal noise, and is appropriate for simulations of large proteins and protein complexes at the mesoscale (length-scales in the range of 5 nm to 1 μm), where there is currently a paucity of modelling tools. It requires 3D volumetric information as input, which can be low resolution structural information such as cryo-electron tomography (cryo-ET) maps or much higher resolution atomistic co-ordinates from which volumetric information can be extracted. In this article we introduce our open source software package for performing FFEA simulations which we have released under a GPLv3 license. The software package includes a C ++ implementation of FFEA, together with tools to assist the user to set up the system from Electron Microscopy Data Bank (EMDB) or Protein Data Bank (PDB) data files. We also provide a PyMOL plugin to perform basic visualisation and additional Python tools for the analysis of FFEA simulation trajectories. This manuscript provides a basic background to the FFEA method, describing the implementation of the core mechanical model and how intermolecular interactions and the solvent environment are included within this framework. We provide prospective FFEA users with a practical overview of how to set up an FFEA simulation with reference to our publicly available online tutorials and manuals that accompany this first release of the package.

Socioeconomic differences in the consumption of vegetables, fruit and fruit juices. The influence of psychosocial factors

BACKGROUND

The aim was to investigate whether social network and social support factors can explain socioeconomic differences in the risk of consuming low amounts of vegetables, fruit and fruit juices.

METHODS

The Malmö Diet and Cancer Study was a prospective cohort study. The present cross-sectional study examined data from a subpopulation of 11,837 individuals that completed baseline examinations in 1992-1994. Dietary habits were assessed using a modified diet history method, and socioeconomic and social network factors were measured with a structured questionnaire. Low consumption was defined as the lowest consumption quartile for vegetables and fruit, while fruit juice consumption was dichotomized to separate users from non-users.

RESULTS

Socioeconomic differences were most pronounced regarding the consumption of vegetables and fruit juices. For both sexes, unskilled manual workers had a twice as high risk of low vegetable and fruit juice consumption as higher non-manual employees. No socioeconomic differences in fruit consumption were observed for men, and only moderate differences for women with a higher consumption in higher socioeconomic groups. When the psychosocial variables were introduced in the multivariate model, social participation moderately reduced the socioeconomic differences in vegetable consumption, and the female socioeconomic differences in fruit consumption, but had no effect on the socioeconomic differences in fruit juice consumption. The other psychosocial variables had no effect on the socioeconomic differences.

CONCLUSION

Considerable socioeconomic differences in vegetable, fruit and fruit juice consumption were observed. Social participation seemed to be a strong determinant for these food choices. However, this effect was largely independent of the socioeconomic differences.

Socioeconomic differences in leisure-time physical activity: the role of social participation and social capital in shaping health related behaviour

Several studies have shown socioeconomic differences in leisure-time physical activity. One explanation may be socioeconomic differences in relevant psychosocial conditions. The Malmö Diet and Cancer Study is a prospective cohort study including inhabitants in Malmö, Sweden. The baseline questionnaire used in this cross-sectional study was completed by the 11,837 participants born 1926-1945 in 1992-1994. Leisure-time physical activity was measured by an item presenting a variety of activities. These activities were aggregated into a summary measure of leisure-time physical activity that takes both the intensity and duration of each specific activity into consideration. The effects of the psychosocial variables on the socioeconomic differences in leisure-time physical activity were calculated in a multivariate logistic regression analysis. The quartile with the lowest degree of leisure-time physical activity was not evenly distributed between the socioeconomic groups. Socioeconomic differences were seen as odds ratios 1.5 for skilled and 1.5 for unskilled male manual workers, compared to the high level non-manual employees. An OR 1.6 was observed for female unskilled manual workers. Self-employed men and female pensioners also had a significantly increased risk of low leisure-time physical activity. Adjustment for age, country of origin and previous/current diseases had no effect on these SES differences. Finally, adjusting for social participation almost completely erased the SES differences. Among the psychosocial variables, social participation was the strongest predictor of low physical activity, and a strong predictor for socioeconomic differences in low leisure-time physical activity. Social participation measures the individual's social activities in, for example political parties and organisations. It therefore seems possible that some of the socioeconomic differences in leisure-time physical activity are due to differing social capital between socioeconomic groups.

Mortality in elderly men with low psychosocial coping resources using anxiolytic-hypnotic drugs

OBJECTIVE

Insufficient coping with stress may lead to increased susceptibility for disease and death. Use of anxiolytic-hypnotic drugs has been suggested as a coping strategy, and some opinions have proposed their use as preventive medication. The aim of this study was to estimate if use of anxiolytic-hypnotic drugs counters the increased mortality observed in individuals lacking other coping strategies such as emotional support and social participation.

METHODS

A population based cohort study with 10-year (1982/83-1993) survival analysis was performed in 491 men born in 1914, living in the Swedish city of Malmö.

RESULTS

Compared with men with a high level of psychosocial coping resources who did not use anxiolytic-hypnotic drugs, men with a low level of psychosocial coping resources had a higher risk of death irrespective whether they used anxiolytic-hypnotic drugs, RR = 1.7 (95% CI 1.1-2.6) or not RR = 1.8 (95%: 1.3-2.5).

CONCLUSION

Anxiolytic-hypnotic drugs do not seem to counter increased mortality in elderly men with low psychosocial coping resources.

Self-administered questionnaire compared with a personal diary for assessment of current use of hormone therapy: an analysis of 16,060 women

A personal diary may be more appropriate than a questionnaire for assessing self-reported current use of hormone therapy (estrogens, progestagens, or their combination); however, use of a questionnaire is more feasible and less expensive. The authors compared both methods for 16,060 Swedish women aged 45-73 years from the Malmo Diet and Cancer Study (baseline, 1991-1996). In a reliability analysis, the authors investigated the agreement (kappa value) between the questionnaire and the diary regarding current hormone therapy use (yes vs. no), studying the ability to replicate results whether or not they were correct. They also explored associations between discrepancy and individual characteristics. A validity analysis was conducted to determine whether use of the questionnaire achieved an outcome without systematic error (i.e., high specificity and sensitivity); the personal diary was considered the "gold standard." Agreement between both methods was high: 95.5% (kappa = 0.840). The sensitivity was 84.9% and the specificity 97.7%. Higher body mass index and being a widow were associated with agreement, whereas age (50-59 years), use of anxiolytics/hypnotics or opiates, high alcohol consumption, past smoking, and higher educational level were associated with discrepancy. Compared with a personal diary, a simple self-administered questionnaire is a valid method for assessing current use of hormone therapy.

Socioeconomic differences in smoking cessation: the role of social participation

OBJECTIVES

The aim of this study was to investigate whether psychosocial resources explain socioeconomic differences in smoking cessation and its maintenance.

METHODS

A subpopulation of 11,837 individuals from the Malmö Diet and Cancer Study interviewed in 1992-94, age range 45-64 years, was investigated in this cross-sectional study. A multivariate logistic regression model was used to assess relative risks of having stopped smoking, adjusting for age, country of origin, previous/current diseases, and marital status.

RESULTS

An odds ratio of 1.9 (1.4-2.5; 95% CI) for men and 2.0 (1.4-2.7; 95% CI) for women of having stopped smoking was found for higher non-manual employees when compared with unskilled manual workers. A decrease in these odds ratios was found when social participation was introduced into the model. The other three social network and social support variables were non-significant.

CONCLUSION

High social participation is a predictor of maintenance of smoking cessation. It seems possible to interpret parts of the socioeconomic differences in smoking cessation and its maintenance as a consequence of differing social network resources and social capital between socioeconomic groups.

Increased perinatal mortality among sub-Saharan immigrants in a city-population in Sweden

BACKGROUND

The aim of the study was to investigate whether the maternal country of origin affected the risk for perinatal mortality and to determine its relationship to risk factors.

METHODS

A study of 15,639 deliveries in Malmö, Sweden. Data regarding demographic factors, life-style and perinatal risk factors, together with data pertaining to outcome was obtained from the Malmö database and the Swedish Medical Birth Register.

RESULTS

Perinatal mortality was increased among infants to women of Foreign origin as compared to those delivered by women of Swedish origin (OR 1.5, CI 1.0-2.2). Even after adjustments for maternal background and risk factors (diabetes, anemia, pre-eclampsia, placental abruption and small-for-gestational age), the increased risk of perinatal mortality among women of Foreign origin remained statistically significant. Women from sub-Saharan Africa, comprising 7.3% of all immigrants, differed from all other subgroups of women of foreign origin by having a higher risk of adverse outcome (small-for-gestational age OR 1.9, CI 1.0-3.6, neonatal distress OR 2.7, CI 5.1-4.8 and perinatal mortality OR 4.3, CI 2.1-8.6).

CONCLUSIONS

Women of foreign origin, especially from sub-Saharan Africa, have a higher risk of perinatal mortality than native Swedish women. The differences in mortality could not be explained by risk factors. The results suggest that women and newborns from sub-Saharan Africa should be given more intense surveillance on all levels of perinatal care in order to reduce perinatal mortality.

Socioeconomic differences in fat intake in a middle-aged population: report from the Malmö Diet and Cancer Study

BACKGROUND

The objective was to investigate whether socioeconomic differences in fat intake may explain socioeconomic differences in cardiovascular diseases.

METHODS

The Malmö Diet and Cancer Study is a prospective cohort study. The baseline examinations used in the present cross-sectional study were undertaken in 1992-1994. Dietary habits were assessed using a modified diet history method consisting of a 7-day menu book and a 168-item questionnaire. A subpopulation of 11 837 individuals born 1926-1945 was investigated. This study examined high fat intake, defined as >35.9% among men and >34.8% among women (25% quartile limit) of the proportion of the non-alcohol energy intake contributed by fat. The subfractions saturated, mono-unsaturated and poly-unsaturated fatty acids and the P:S ratio (polyunsaturated/saturated fatty acids) were analysed in the same way. The uppermost quartile (75%) of total and subgroup fat intake was also studied. Socioeconomic differences before and after adjustment for low energy reporting (LER), defined as energy intake below 1.2 x Basal Metabolic Rate, were examined.

RESULTS

No socioeconomic differences in fat intake were seen between the SES groups, except for self-employed men, and male and female pensioners. Approximately 20% in most SES groups were LER. The LER and body mass index were strongly related. The SES pattern of fat intake remained unchanged after adjustment for age, country of origin and LER in a logistic regression model. The results for the subfractions of fat and the P:S ratio did not principally differ from the total fat results.

CONCLUSIONS

This study provides no evidence that fat intake contributes to the inverse socioeconomic differences in cardiovascular diseases.

Association of a lack of psychosocial resources and the risk of giving birth to small for gestational age infants: a stress hypothesis

OBJECTIVE

To test the stress hypothesis that women who give birth to small for gestational age infants lack important psychosocial coping resources, such as a sufficient social network, social support and control in daily life.

DESIGN

A prospective cohort study of nulliparous pregnant women.

SETTING

Antenatal care units in the city of Malmö, Sweden.

POPULATION

All women (n = 994) during a one year period (1991-1992) were invited, and 872 (87 x 7%) participated. This study was restricted to pregnancies resulting in singleton live birth (n = 826); 6 x 7% of infants were classified as small for their gestational age.

METHODS

Self-administered questionnaires were given to all women at the time of their first antenatal visit.

MAIN OUTCOME MEASURES

The classification of small for gestational age was based on a gender-specific intrauterine growth reference curve. Newborn babies were classified as being small for gestational age if their birthweight was > 2 SD below the mean weight for gestational age.

RESULTS

Lack of psychosocial resources, such as social stability, social participation, emotional and instrumental support, all increased the likelihood of delivering an infant that was small for gestational age. The odds ratios when controlled for demographic background factors, lifestyle factors and anthropomorphic measures were: OR 1 x 7 (95% CI 0 x 9-3 x 3) for women with poor social stability; OR 2 x 2 (95% CI 1 x 1-4 x 4) for women with poor social participation; OR 2 x 6 (95% CI 1 x 2-5 x 7) for women with poor instrumental support; and OR 1 x 5 (95% CI 0 x 8-2 x 8) for women with poor emotional support. Simultaneous exposure to a poor total network index, as well as a poor total support index showed a significantly increased odds ratio for having a small for gestational age baby: OR 3 x 3 (95% CI 1 x 6-6 x 7) and OR 2 x 7 (95% CI 1 x 3-5 x 6), respectively. A synergy index of 9 x 0 and 6 x 8 supported the assumption of an interaction between immigrant status and poor total network or poor total support, in a synergistic direction.

CONCLUSIONS

The findings support the stress-hypothesis that a lack of psychosocial resources might increase the risk of giving birth to a baby that is small for gestational age.

To prevent alcohol problems in Europe by community actions--various national and regional contexts

The European transformation during the 1990s, concerning political, economic, social and cultural changes, has made alcohol policy in many countries very fragile and uncertain because of new social and economic conditions and decreasing power of national governments. On this background, regions, municipalities, nongovernmental organizations and the civic society are to play a more prominent role in the European alcohol policy arena. In December 1997 the first European research and evaluation symposium on community action alcohol programs was held in Malmö, Sweden. The themes were: Research-based evaluation of community action programs; The interaction between local, national, and European prevention strategies; Local programs in schools, workplaces, health sectors, primary health care, and other community contexts; The role of citizens' movements, consumer organizations, women's groups, and other voluntary organizations; Local political action. This paper is the first attempt to summarize the similarities and differences in the programs presented at the symposium.

Time trends in alcohol habits. Results from the Kirseberg project in Malmö, Sweden

This paper reports on a pilot demonstration to implement an alcohol consumption reduction project in the community of Kirseberg, located in the city of Malmö, Sweden. The objective is to present data on time trends in alcohol use habits and alcohol-use-related problems in the Kirseberg population and to discuss potential effects of the alcohol prevention activities. It was possible to implement an alcohol consumption prevention community program successfully. The analysis of time trends in alcohol use habits and alcohol-use-related problems was, however, mainly inconclusive, but indicated a decrease in alcohol consumption and alcohol-use-related problems among young and middle-aged men.

Does passive smoking in early pregnancy increase the risk of small-for-gestational-age infants?

OBJECTIVES

This study tested the hypothesis that women who deliver small-for-gestational-age infants are more often exposed to passive smoking at home or at work.

METHODS

Among a 1-year cohort of nulliparous women in the city of Malmö, Sweden 872 (87.7%) women completed a questionnaire during their first prenatal visit. The study was carried out among women whose pregnancies resulted in a singleton live birth (n = 826), 6.7% of infants were classified as small for their gestational age.

RESULTS

Passive smoking in early pregnancy was shown to double a woman's risk of delivering a small-for-gestational-age infant, independent of potential confounding factors such as age, height, weight, nationality, educational level, and the mother's own active smoking (odds ratio [OR] = 2.7). A stratified analysis indicated interactional effects of maternal smoking and passive smoking on relative small-for-gestational-age risk.

CONCLUSIONS

Based on an attributable risk estimate, a considerable reduction in the incidence of small-for-gestational-age births could be reached if pregnant women were not exposed to passive smoking.

Intra-urban variation of antibiotic utilization in children: influence of socio-economic factors

OBJECTIVE

The aim of this study was to investigate the intra-urban variation of antibiotic utilization in children in Malmö and to evaluate the influence of socio-economic factors on this variation.

METHODS

In an ecological analysis, the variations in antibiotic utilization in children, expressed as defined daily dose (DDD) or as the number of prescriptions per 1000 inhabitants per day, were compared with variations in socio-economic and demographic factors in the 17 administrative districts of the Swedish city of Malmö (235000 inhabitants).

RESULTS

There were large between-area differences in antibiotic utilization, especially in children aged 0-6 years. Socio-economic factors reflecting a privileged situation correlated positively with antibiotic utilization. Thus, in districts with a high median family income and a high employment rate, the utilization of antibiotics was higher than in other districts. Conversely, in districts with a high proportion of blue-collar workers, people with foreign backgrounds and recipients of social benefit, antibiotic utilization was comparatively low. In contrast, the utilization of penicillin V relative to other antibiotics showed an opposite pattern, including positive correlations with the proportion of social benefit, immigrants and blue-collar workers and a negative correlation with employment rate. Conversely, the utilization of macrolides in relation to other antibiotics in children aged 0-6 years was highest in districts inhabited by those who were socio-economically privileged.

INTERPRETATION

The findings suggest that utilization of antibiotics in children may vary considerably within a city, that it may increase with the degree of parental affluence, and that such affluence may reduce the utilization of penicillin V relative to other antibiotics.

Socioeconomic factors, morbidity and drug utilization—an ecological study

The aim of the present study was to elucidate the relations between demographic and socioeconomic factors, morbidity and the utilization of major drug groups in an urban Swedish population. The study was performed as an ecological analysis during November 1991 in the 17 different districts of Malmö, the third largest Swedish city (235,000 inhabitants). The material comprised 86,228 ACT-coded drug items which corresponded to 76% of all prescriptions dispensed during the study month. Of these, 43,032, dispensed to patients aged 15-64 years, were analysed in the present work. Age standardized drug utilization was expressed as the number of dispensed Defined Daily Doses per 1000 inhabitants per day. Morbidity was measured in terms of reimbursed days on sick leave. The sociodemographic parameters used were socioeconomic status (SES), employment rate, median income per family, households on social allowance, and ethnicity. For four of the five major pharmacological groups (ATC-groups A, C, J, N and R, i.e. alimentation, circulation, infectious diseases, nervous system and respiration), most pronouncedly group N and least so group R, utilization correlated positively with not only the extent of morbidity but also with an unfavourable socioeconomic situation, high proportion of immigrants, and households on social allowance or with low income and/or with a low employment rate. The utilization of antibiotics (group J), however, instead correlated negatively with these parameters. For all five drug groups, these trends were similar among men and women, albeit with varying strength. In conclusion, socioeconomic factors may have a profound influence on the utilization of several major drug groups. At least in the case of antibiotics, the consequence of this influence is irrational drug use.

The effects of cold storage and endotoxin challenge on osteoblast viability and interleukin-6 production

Autogenous hip marrow is an excellent source of pluripotential cells for regenerative procedures. However, before this treatment modality can be employed a method to attenuate osteoclast activity must be developed. The shock of cold storage (4 degrees C) is thought to abate osteoclast activity through the downregulation of osteolytic cytokines produced by osteoblasts. The objective of this study was to evaluate the effects of cold storage (4 degrees C) and endotoxin challenge on bone cell culture viability and interleukin-6 (IL-6) production. These cells (osteoblasts) were primarily harvested from murine calvaria utilizing sequential digestions, separated by density gradient and combined. Twelve-well cell culture plates were inoculated with 2 x 10(4) cells/ml and placed in cold storage for 1-14 d. After cold storage the cultures were then incubated at 37 degrees C for 1-20 d. A set of replicate plates was also challenged with 10 ng/ml endotoxin upon incubation at 37 degrees C for 4 consecutive days. Cells were evaluated daily for alkaline phosphatase activity. Cell culture supernatants were also collected daily and batch assayed for IL-6 production. Cell cultures did not survive more than 48 h of cold storage. There was a decrease in IL-6 secretion in all refrigerated cultures and a significant decrease in those cells refrigerated for 48 h versus control cultures (p < 0.05). Replicate cultures treated with endotoxin secreted significantly increased amounts of IL-6 in both the control cultures and the cultures exposed to 24 h of cold storage versus non-endotoxin-treated control cultures (p < 0.05). These observations suggest that after 48 h of cold storage autogenous marrow may be safe to use because of the dramatic decrease in IL-6 production by osteoblasts.

Equity is out of fashion? An essay on autonomy and health policy in the individualized society

It is widely recognized that there is a discrepancy between principle and practice with respect to the health equity aim of public policy. This discrepancy is analyzed from two theoretical perspectives: the individualization of society and the fact that individual beliefs and values are connected to one's position in the social structure. These mechanisms influence both the choice of health policy measures and the normative judgements of preventive efforts, both of which tend to be consonant with the views of dominant social groups. In particular, we focus on the treatment of the ethical principle of autonomy and how this is reflected in health policy aimed at influencing health-related behaviour. We examine the current trend towards targeting health information campaigns on certain socio-economic groups and argue that it entails an ethical dilemma. The dominant discourse of the welfare state is contemplated as a means to understand why there tend to be a lack of emphasis on measures that are targeted at socio-economic inequalities. It is argued that there is no substantive basis in the individualized society for perceiving health equity as an independent moral principle and that the driving force behind the professed health equity goal may be in essence utilitarian.

Reliability and validity assessments of measures of social networks, social support and control--results from the Malmö Shoulder and Neck Study

The reliability and validity of methods to assess social networks, social support and control were investigated in a population of 12,009 females and males born between 1926 and 1945 (the "Malmö Shoulder and Neck Study"). This study demonstrated an overall reliability with kappa coefficients between 0.70 and 0.47, but the reliability was more varying among females and lower in the youngest age group. The analysis of the construct validity indicated that the different indices measure different aspects of the psychosocial environment, but both theoretical and methodological problems were identified, when the validity of multidimensional concepts are to be determined. The validity of such indices can best be judged by combining quantitative and qualitative methods. Potential validity problems must be kept in mind when these indices are used in epidemiological research. The results from the reliability analysis call for repeated assessments and the sample size must be adjusted vis-a-vis the reliability.

Psychosocial resources and persistent alcohol consumption in early pregnancy--a population study of women in their first pregnancy in Sweden

The aim of the study was to test the impact of psychosocial resources on pregnant women, regarding continued alcohol consumption. The study is based on a one-year cohort of nulliparas followed during pregnancy. From a total of 994 invited women 872 (87.7%) agreed to participate in the study. All women who reported any alcohol consumption within the twelve months prior to the administration of the questionnaire were included in this study population (n = 692, 79.4%). 32.8% of the alcohol consumers continued to drink during pregnancy even though the alcohol intake was moderate. In spite of the official Swedish alcohol recommendation for total abstinence during pregnancy, more socially active, and more highly educated women continued drinking alcohol, with wine being the beverage of choice, maybe more as social behavior rather than to cope with stress caused by insufficient psychosocial resources. Younger women or those with fewer years of education tended to stop drinking to a higher degree, but those who continued to drink tended to drink beer or to binge.

Estrogenic hormones and dental implant therapy: the effects of estrogen and progesterone levels on osseointegration of dental implants

Successful rehabilitation of female service members suffering traumatic injuries to the maxillofacial region is both a physiological and a psychological issue. A clinical evaluation to determine if an association exists between sex hormone levels and dental implant success was undertaken. Endosseous dental implants were placed in three patient groups: (1) male controls, (2) females with high estrogen, and (3) females with low estrogen. Female groupings were based on ovulation cycles. Serum estrogen (ng/dl), serum progesterone [ng/dl], and serum interleukin-6 (pg/ml) were determined at time of implant placement. Pre- and postsurgical photographs and vinyl-polysiloxane impressions were taken to evaluate crestal alveolar bone loss. Upon data analysis, the authors concluded that the balance of alveolar osseous wound healing was not influenced by temporal fluctuations in the ovulatory cycle.

An economic and sociological interpretation of social differences in health-related behaviour: an encounter as a guide to social epidemiology

We argue that the group-centred analyses of social epidemiology should follow from theoretical considerations that take the situation of the individual as their natural starting point. In a tentative dialogue between economics and sociology, we develop a framework for the analysis of health-related behaviour. Such behaviour is modelled as a process of decision-making at the individual level. Within economics, we draw specifically on the demand-for-health literature and the new institutional economics. Within sociology, Bourdieu's habitus theory is presented in combination with a macro-structural approach where the focus is on the process of individualization. The relationship between these different approaches to health-related behaviour and their implications is discussed. We find that the encounter between different sciences provides valuable insights for future work in the socio-epidemiological tradition.

Usage and Users of Natural Remedies in a Middle-Aged Population: Demographic and Psychosocial Characteristics. Results from the Malmö Diet and Cancer Study

BACKGROUND

In Sweden, large amounts of money are spent annually on natural remedies (NRs), in spite of the fact that most products in this category lack scientific documentation of their efficacy and side-effects. The usage and users of natural remedies are not well defined. This paper describes NR use and NR users in a city in southern Sweden, and tests the hypothesis that the use of natural remedies is a strategy for coping with psychosocial stressors.

METHODS

The study cohort consisted of 6545 men and women, aged 45-65 years, who during 1991 and 1992 participated in the Malmö Diet and Cancer Study, a large-scale prospective cohort study. Data on consumption of natural remedies were recorded during seven consecutive days, as part of a dietary assessment. Each participant also completed a questionnaire, covering education, work history, alcohol and smoking habits, perceived health, and psychosocial factors such as social network, social support, job strain and global control. Body composition was also measured.

RESULTS

The prevalence of NR consumption was 26% among women and 17% among men. NR use was most common during winter and spring. The most popular products were ginseng, garlic, and various herb and plant extracts. Important determinants of NR usage were higher education, Swedish origin, and lifestyle factors like low body weight fat percentage and high alcohol consumption among women. Other determinants were higher age and non-smoking among men. None of the psychosocial factors appeared to influence the prevalence of NR consumption.

CONCLUSIONS

The prevalence of NR consumption is influenced by sex, demographic factors, season of the year, and lifestyle. Use of NRs does not appear to be a common strategy for coping with psychosocial stress.

Dental considerations for a Glanzmann's thrombasthenia patient: case report

Glanzmann's thrombasthenia is a qualitative platelet disorder characterized by a deficiency in the platelet membrane glycoproteins (GP) IIb-IIIa. It belongs to a group of hereditary platelet disorders typified by normal platelet numbers and a prolonged bleeding time. The bleeding seen in Glanzmann's thrombasthenia usually includes bruising, epistaxis, gingival hemorrhage, and menorrhagia. Spontaneous, unprovoked bleeding is unusual. The severity of bleeding is unpredictable in thrombasthenia and does not correlate with the severity of the platelet GP IIb-IIIa abnormality. The present case report describes the dental treatment of a patient with Glanzmann's thrombasthenia. A 39-year-old female with a history of Glanzmann's thrombasthenia presented for periodontal therapy for spontaneous gingival hemorrhage. The patient had been sporadically seen in the past and had a record of only returning for appointments on an "emergency" basis. The periodontal findings revealed a diagnosis of moderate to advanced adult periodontitis in all quadrants. After all dental options had been discussed, the treatment of choice was determined to be extraction of the remaining dentition and fabrication of immediate dentures. The patient received a loading dose of 5 grams of aminocaproic acid (EACA) intravenously 3 hours prior to the surgery. At the beginning of the extractions 1 gram of EACA per hour continuous infusion and a 6 pack of platelets was administered. The patient tolerated the extractions well. All sites healed normally. The patient has had no difficulty in adjusting to the dentures. The case report discusses a possible treatment option in a noncompliant patient having Glanzmann's thrombasthenia and briefly discusses other hereditary bleeding disorders with similar presentations.

Importance of participation rate in sampling of data in population based studies, with special reference to bone mass in Sweden

OBJECTIVE

To study the effects of participation rate in sampling on "normative" bone mass data.

DESIGN

This was a comparison between two randomly selected samples from the same population. The participation rates in the two samples were 61.9% and 83.6%. Measurements were made of bone mass at different skeletal sites and of muscle strength, as well as an assessment of physical activity.

SETTING

Malmö, Sweden.

SUBJECTS

There were 230 subjects (117 men, 113 women), aged 21 to 42 years.

RESULTS

Many subjects participated in both studies (163). Those who took part only in the study with the higher participation rate (67) almost invariably had higher values for bone mass density at the sites measured (up to 7.6% for men) than participants in the study with the lower participation rate. No differences in muscle strength were recorded.

CONCLUSION

A high degree of compliance is important to achieve a reliable result in determining normal values in population based studies.

Psychosocial resources and persistent smoking in early pregnancy--a population study of women in their first pregnancy in Sweden

STUDY OBJECTIVE

To test the stress hypothesis by characterising women during their first pregnancy who continue to smoke in early pregnancy in comparison with women who quit smoking, with special reference to psychosocial factors like social network, social support, demands, and control in work and daily life.

DESIGN

The study is based on a cohort of primigravidas followed during pregnancy. Data were collected by self administered questionnaires during the pregnant womens' first antenatal visit at about 12 weeks.

SETTING

The study was performed in the antenatal clinics in the city of Malmö, Sweden.

PARTICIPANTS

The participants were all primigravidas living in the city of Malmö, Sweden, over a one year period, 1991-92. A total of 872 (87.7%) of the 994 invited women agreed to participate. The population of this study on smoking includes all primigravidas who at the time of conception were smoking (n = 404, 46.3%).

MAIN RESULTS

At the first antenatal visit (63.6% (n = 257) of the prepregnancy smokers were still smoking (a total smoking prevalence of 29.5%). The pregnant smokers were on average younger and had a lower educational level. The highest relative risk (RR) of continued smoking was found among unmarried women RR 2.7 (95% confidence interval) (1.5, 4.8), women having unplanned pregnancies RR 2.2 (1.2, 4.0) and those with a low social participation RR 1.6 (1.0, 2.7), low instrumental support RR 2.6 (1.2, 6.0), low support from the child's father RR 2.1 (1.0, 4.2) and those exposed to job strain RR = 2.3 (1.1, 4.8). The associations were independent of potential confounders such as age, educational level, nationality, cohabiting status, passive smoking, and previous years of smoking.

CONCLUSIONS

This study supports the stress hypothesis. Smoking can be one way women handle stress when demands become too great. In order to reduce smoking among pregnant women, maternity centre resources need to be focused more on women with low psychosocial resources who are at highest risk for continued smoking. It is also important to involve actively the woman's partner or other important people in the woman's social network.

Alcohol consumption modifies the total lung capacity in smokers

Smoking-related airflow obstruction can develop with or without emphysema. Moderate alcohol consumption has been suggested to diminish the risk of centrilobular emphysema caused by smoking. Our aim was to study the influence of total energy and nutrient (protein, fat, carbohydrate and alcohol) intake on smoking-related emphysema. Lung function and nutrient intake including alcohol consumption were recorded at age of 68 years in 478 men as part of the population study 'Men Born in 1914' in Malmö, Sweden. In nonsmokers (n = 88) and ex-smokers (n = 223), there were no significant relationships between energy and nutrient intake and lung function. In smokers (n = 167), men in the highest and lowest quintile of total lung capacity (TLC) differed in alcohol intake (p = 0.004) but not in intake of total energy or other nutrients. In smokers with a forced expiratory volume in 1 s/vital capacity ratio of below 70% (n = 81), alcohol intake was positively correlated with TLC (r = 0.31; p = 0.006) after adjustment for smoking and body mass index. We conclude that in men with smoking-related airway obstruction, emphysema defined as large TLC was associated with high alcohol consumption but not with the intake of total energy or other nutrients.

Increased risk of ischaemic heart disease mortality in elderly men using anxiolytics-hypnotics and analgesics. Results of the 10-year follow-up of the prospective population study "Men born in 1914", Malmo, Sweden

OBJECTIVES

An increased risk of all-cause and cardiovascular mortality in users of anxiolytic-hypnotic drugs (AHD) has been reported, and use of analgesics may be an additional factor. Therefore, we examined the association of AHD and analgesic use, alone and in combination, with all-cause and ischaemic heart disease (IHD) mortality.

METHODS

Multivariate 10-year survival analysis in a population based cohort of 500 men born in 1914. Relative risks (RR) were adjusted by relevant confounders (blood pressure, serum cholesterol, diabetes mellitus, smoking habit, high alcohol consumption, history of previous IHD, cancer, and other diseases).

RESULTS

The RR of both all-cause and IHD mortality were significantly increased among those using both AHD and analgesics compared to those who took neither of these drugs: RR = 1.8 for all-cause mortality, and RR = 2.7 for IHD mortality.

CONCLUSION

Although the number of cases was small, warranting interpretative caution, the current study suggests that the combined use of AHD (mainly benzodiazepines) and analgesics seems to be associated with an increase in all-cause and IHD mortality in elderly men.

The effects of intracanal medicaments, fillers, and sealers on the attachment of human gingival fibroblasts to an exposed dentin surface free of a smear layer

To date there has been very little research into the possible effects of endodontic therapy on regeneration of the lost periodontal attachment. The objective of this study was to examine the effects of endodontic medicaments on fibroblast attachment to dentin surfaces free of a smear layer. Pulp chambers of extracted third molars were filled with one of the following medicaments: gutta-percha with Roth's zinc oxide and eugenol-based sealer, warm gutta-percha with sealer, warm gutta-percha without sealer, calcium hydroxide, formocresol, cotton pellet, or left empty. A predetermined dentin surface area was then inoculated with human gingival fibroblasts at a concentration of 2 x 10(4) cells per ml. The cells were allowed to adhere to the dentin surface for either 4 or 24 hours, then cell attachment was quantified using a methyl-tetrazolium assay. The data were analyzed using a Kruskal-Wallis one-way analysis of variance and Dunn's multiple comparison test. It was determined that fibroblast attachment was significantly reduced when exposed to formocresol or warm gutta-percha without sealer at both the 4 and 24 hour interval (P < or = 0.05). This suggests that the use of formocresol or warm gutta-percha without sealer in a root canal may impede periodontal wound healing and regeneration.

Social network, social support and the prevalence of neck and low back pain after retirement. A population study of men born in 1914 in Malmö, Sweden

In this study we investigated the importance of social network and social support systems outside the workplace and workload and psychological job strain in former work for the prevalence of daily neck and low back pain. The study population (n = 621) comprised a random half of all male residents in Malmö, Sweden, born in 1914, of whom 500 (80.5%) participated. Two of the social network and social support indices (social anchorage and availability of material and informational support) were independent of life-style factors (leisure time physical activity, smoking and alcohol consumption) related to daily neck and back pain after retirement (OR = 2.0, 95% CI 1.2-3.4 and OR = 1.7, 95% CI 1.0-2.7, respectively), while the psycho-social and physical factors in former work were not. As no conclusion about the direction of the association can be drawn, prospective studies are needed to further explore these findings.

HIV infection: social network, social support, and CD4 lymphocyte values in infected homosexual men in Malmö, Sweden

STUDY OBJECTIVE

The aim was to determine if there is an association between social network and social support and the CD4 cell count in HIV infected homosexual men.

DESIGN

The study was cross sectional. A structured questionnaire assessing psychosocial factors such as social network and social support was administered at interview. Information on CD4 cell counts and HIV symptoms were obtained from participants' medical records.

SETTING

The study population consisted of all HIV seropositive homosexual and bisexual men who had not been diagnosed as having AIDS seen at the Department of Infectious Diseases, the only hospital clinic in the city of Malmö (230,000 inhabitants), Sweden that provides care for HIV infected patients.

PARTICIPANTS

Altogether 47 (68%) of 69 men in the population agreed to be interviewed.

MAIN RESULTS

A low CD4 cell count was found more frequently in men with low social participation scores (OR 3.3; 95% CI 1.0, 11), in those with a low adequacy of social participation (OR 3.8; 95% CI 1.1, 13), and in men with low material support scores (OR 3.9; 95% CI 1.1, 13). After adjustment for age and time of awareness of the HIV infection, the two former associations remained statistically significant.

CONCLUSIONS

These results, if reproduced in a longitudinal study, might suggest that psychosocial factors can affect an individual's immune system.

Alcohol habits among teenagers in Sweden: factors of importance

This study of 689 secondary school students (13-16 years of age) in Sweden investigates the association between alcohol habits, the availability of alcohol and age, gender, socioeconomic status, ethnic origin and family structure. Data were obtained by anonymous questionnaires in 1991. The availability of alcohol increased from the seventh grade to the ninth as did the proportion of alcohol consumers and students with regular alcohol consumption. Boys in the seventh and eighth grades showed somewhat more advanced alcohol habits than girls, but in the ninth grade the opposite was seen. Students with more advanced alcohol habits and a higher availability of alcohol more often belonged to a lower socioeconomic strata and they lived more often with a single parent. Students of foreign background drank alcohol (especially wine) more regularly. An association was also found between the parents' liberal attitude toward offering alcohol at home and frequent intoxication and the students' experience of illicitly produced liquor, especially among the youngest students. In spite of the Swedish alcohol policy the availability of alcohol is rather high among young people. Special attention in alcohol preventive work should be paid to girls, young people living with one parent, young people in lower socioeconomic groups and young people of foreign origin.

How much can data on days with heavy drinking decrease the underestimation of true alcohol consumption?

An adjusted quantity-frequency method, with questions on occasions with heavy drinking, was used to estimate the consumption of alcohol during the last 30 days. The purpose was to analyze if it was possible to decrease the underestimation of true alcohol consumption. The questionnaire was mailed to a randomized sample of 1,500 individuals, 20-75 years of age, living in the city of Malmö, Sweden; 930 persons (64.3%) participated. Data on alcohol consumption were validated by comparison to sales of alcohol for the city of Malmö. The estimated per capita consumption of alcohol in the population was equivalent to 77.0% of the registered sale of alcohol in Malmö. By adding days with heavy drinking, the estimated weekly per capita consumption of alcohol among the alcohol consumers increased from 74.5 grams to 77.1 grams (+3.5%; p < .001). Of the alcohol consumers, 15.1% increased their reported consumption. In order to decrease even more the underestimation of the true alcohol consumption, we suggest the use of questions about any alcohol consumption that deviates from the typical consumption of each individual.

Social network, social support and dental status in elderly Swedish men

The objective of this study was to investigate whether there were associations between different aspects of social network and social support and dental status. The study sample (n = 621) comprised a random half of all male residents in Malmö, Sweden, born in 1914. Five hundred (80.5%) participated. Eight conceptually different aspects of social networks and social support were measured, and all men were clinically examined regarding number of teeth, prevalence of removable dentures, fixed bridges and anterior open tooth spaces. We found that some aspects of dental status were associated with social class, while others were associated with different aspects of social network and social support. Prevalence of complete dentures and fixed bridges was strongly associated with social class, a low number of functioning teeth was associated with both low social class belonging and an insufficient social network and social support, while anterior open tooth spaces were associated mostly with an insufficient social network and social support. This study shows that there are significant associations between some aspects of dental status and the social network and social support of the individual, while other aspects of dental status are associated with social class, which from a psychosocial perspective contribute to a deeper understanding of the backgrounds of dental status.

Social network, social support and heavy drinking in elderly men--a population study of men born in 1914, Malmö, Sweden

We analysed whether there were associations among different aspects of social network and social support, on one hand, and heavy drinking and alcohol problems on the other. The study sample (n = 621) comprised a random half of all male residents born in 1914 in Malmö, Sweden. Five hundred (80.5%) participated. Heavy drinking was defined as an alcohol consumption above 250 g alcohol per week and alcohol problems were assessed by a modified Michigan Alcoholism Screening test. Eight conceptually differential aspects of social networks and social support were measured. Four of five social network indices (social anchorage, social participation, contact frequency, spousal support) were associated with heavy drinking (OR 1.9-2.5) and two social network indices (social anchorage, spousal support) were associated with alcohol problems (OR 2.1-2.3). The results in this study are independent of social class, but based on a cross-sectional study, so we do not know if heavy drinking has caused social isolation or the contrary. If these results can be verified in a prospective study, a strengthening of the social network of the individual could perhaps lead to more moderate alcohol habits and better health, a finding of potential importance in the field of health promotion.

Serum concentrations of total sialic acid and sialoglycoproteins in relation to coronary heart disease risk markers

This study investigated the relationship between serum sialic acid concentration and cardiovascular mortality. Correlations were determined between lifestyle-related coronary heart disease risk markers (cigarette consumption, alcohol consumption, and leisure time physical activity), biological risk markers (apolipoprotein A1, apolipoprotein B, lipoprotein(a), and diastolic blood pressure) on the one hand and the concentration of sialic acid as well as sialic acid-rich acute phase proteins (orosomucoid, haptoglobin, and alpha 1-antitrypsin) on the other. A total of 145 men aged 21-46 years and with a C-reactive protein concentration below 5 mg/l were included. Total sialic acid concentration correlated significantly with apolipoprotein B (r = 0.48), number of cigarettes smoked daily (r = 0.32), and leisure time physical activity (r = -0.23) after adjustment for age and other cardiovascular risk markers. No significant partial correlations were found between serum total sialic acid concentration on the one hand and alcohol consumption, apolipoprotein A1, lipoprotein(a), and diastolic blood pressure on the other. Of the sialic acid-rich glycoproteins, orosomucoid correlated with apolipoprotein B (r = 0.38), haptoglobin with cigarette consumption (r = 0.35) and leisure time physical activity (r = -0.26) and alpha 1-antitrypsin with cigarette consumption (r = 0.18), leisure time physical activity (r = 0.17), alcohol consumption (r = -0.18), and apolipoprotein B (r = 0.21) after adjustment for age and other cardiovascular risk markers.

The epidemiology of sick leave in an urban population in Malmö, Sweden

The epidemiology of sick leave was studied in the city of Malmö, Sweden, (230,000 inhabitants). Every current and completed sick-leave episode during the year of 1985 was collected for 124,411 persons aged 16 to 65, who were registered with the National Health insurance scheme in 1985. Absence rate, absence incidence, absence prevalence and absence duration were analyzed in relation to age, sex, marital status, nationality, income and place of residence. Absence rate (mean value) in the total population was 25.5 days with a median of three days. The absence rate increased by age. High absence rates were seen for females, single people and some immigrant groups. This was even true for residential areas characterized by a higher proportion of single-person households and households on social welfare, of unemployed and people with a low income and a foreign background. The absence rate gives limited information as to the epidemiology of sick leave. Through adding absence incidence, absence prevalence and absence duration it was possible to get a more comprehensive picture of the phenomenon. Sex-differences in absence rate for instance were mainly explained by differences in absence incidence and prevalence, while differences in absence rate regarding nationality were explained by differences in absence duration. This is an important step towards a better understanding of the factors behind sick leave.

Job strain and mortality in elderly men: social network, support, and influence as buffers

The aim was to investigate whether job strain affects mortality in a representative population of elderly men, and whether social network and social support outside the workplace can buffer the negative health effects of job strain. A higher relative mortality risk (RR) was found among men exposed to job strain (RR = 1.7). The combination of exposure to job strain and seven different measures of weak social network and social support was associated with a further increased RR ranging from 2.1 to 4.6.

Influence of social support on cardiac event rate in men with ischaemic type ST segment depression during ambulatory 24-h long-term ECG recording. The prospective population study 'Men born in 1914', Malmö, Sweden

Three-hundred and ninety-four 68-year-old men, representing 60.3% of a cohort of men born in 1914, were examined with ambulatory ECG during 24 h in 1982-83. Ninety-eight (24.8%) men had one or more episodes of ischaemic type ST segment depression (greater than or equal to 0.10 mV), 79 of whom had no history of previous ischaemic heart disease (IHD). During 63 months follow-up, 17 of the 98 suffered a cardiac event, i.e. fatal or non-fatal myocardial infarction (MI) or death due to chronic IHD. The objective of this study was to assess the influence of psychosocial factors, such as social network and social support, on cardiac event rate in men with ischaemic ST segment depression. A higher risk was found among men with little material and informational support (i.e. access to practical services and material resources and access to guidance, advice and information (crude relative risk 4.8; 95% CI; 1.6-14.8) and men with low availability of emotional support (i.e. opportunity for care, encouragement of personal value and feelings of confidence and trust) (crude relative risk 4.3; 95% CI: 1.4-13.3). This association was independent of history of IHD and other known risk factors for myocardial infarction (MI).

Social network and social support predict improvement of physical working capacity in rehabilitation of patients with first myocardial infarction

A cohort of 50 patients under 70 years of age who had suffered their first myocardial infarction (MI) entered an exercise-based rehabilitation programme. An extensive personal interview concerning psychosocial factors, including social network and social support, as well as an assessment of an array of clinical and laboratory variables was made before the patients were discharged from the hospital. A follow-up 6 months later of the 40 patients that completed the programme showed that material social support and social anchorage at baseline predicted improvement in physical working capacity, independently from age, gender and important clinical variables. The authors conclude that psychosocial factors could be predictors of equal importance as many of the standard risk factors and clinical assessments in the rehabilitation of a majority of post-MI patients. It is suggested that training programmes should provide opportunities for involvement of the patients' social network, in order to benefit from optimal social support during the rehabilitation process.

Risk factors for carotid artery stenosis: an epidemiological study of men aged 69 years

Four hundred and seventy-eight men born in 1914 and residing in the city of Malmö, Sweden, underwent ultrasonic Doppler examination of the carotid arteries in 1982/83. The known risk factors for vascular disease--blood pressure, lipids, glucose, hematocrit, alcohol consumption and Body Mass Index were also measured. A moderate stenosis (diameter reduction 30-59%) of the internal carotid artery was found in 95 men (20%); 15 men (3%) had a greater than or equal to 60% stenosis of the internal carotid artery, while 7 (1.5%) had complete unilateral occlusion. Smoking was found to be significantly related to severe carotid artery disease. There was also a significant correlation between maximum flow velocity in the internal carotid artery and triglycerides. Those quitting smoking before the age of 50 had the same incidence of internal carotid artery disease as non-smokers, while those quitting later in life had a slightly higher incidence than life-long smokers.

Social network, social support and acute chest complaints among young and middle-aged patients in an emergency department--a case-control study

The risk of developing non-specific chest complaints was higher among young and middle-aged persons with a weak social network and low social support, when comparing cases with controls at a hospital emergency department (ED). The study was comprised of 62 cases; two different control groups were recruited from other patients at the medical ED (n = 67) and from patients at the surgical ED with urolithiasis or cholecystitis (n = 31). Relative risks for non-specific chest complaints were 2.3-3.4 for patients with a low score on two of the social network factors (an overall index and social anchorage) and two social support factors (emotional esteem support and support by a confidant). These results could be used for developing guidelines for a more adequate clinical management of these patients, as well as for the prevention of stress-related conditions in general. An analysis was made of the conceptual validity of the instrument used for assessing social network and social support. It was concluded that structural elements, such as social network factors, represented a more valid measurement that was less affected by subjectivity. Future research is of importance for finding overbridging concepts, rather than to further continue the dissection of presently used indices into even more 'specific' variables.

Social support and quitting smoking for good. Is there an association? Results from the population study, "Men born in 1914," Malmö, Sweden

The objective in this study was to analyse whether there is independent association between social network, social support, social influence and quitting smoking for good. The study sample (n = 621) comprised a random half of all male Malmö residents born in 1914, of which 500 (80.5%) participated. A new instrument based on a model with carefully defined and well differentiated concepts was used to measure different aspects of social network, social support and social influence. In logistic regression analysis, emotional support (an important aspect of social support) had an association to quitting smoking for good (odds ratio 3.1, 95% confidence interval 1.9-5.4), when adjustments were made for social class, marital status (spousal support), alcohol consumption, physical activity, smoking of spouse and different medical conditions. Emotional support reflects the individuals' opportunity for care, encouragement of personal value and feelings of confidence and trust. This may contribute to a deeper understanding of mechanisms behind smoking cessation and could be of importance in the field of health promotion, but also for improvement of the long-term results of smoking cessation programs and in our clinical work with patients who smoke.