Molybdate:sulfate ratio affects redox metabolism and viability of the dinoflagellate Lingulodinium polyedrum.

Molybdenum is a transition metal used primarily (90% or more) as an additive to steel and corrosion-resistant alloys in metallurgical industries and its release into the environment is a growing problem. As a catalytic center of some redox enzymes, molybdenum is an essential element for inorganic nitrogen assimilation/fixation, phytohormone synthesis, and free radical metabolism in photosynthesizing species. In oceanic and estuarine waters, microalgae absorb molybdenum as the water-soluble molybdate anion (MoO4(2-)), although MoO4(2-) uptake is thought to compete with uptake of the much more abundant sulfate anion (SO4(2-), approximately 25 mM in seawater). Thus, those aspects of microalgal biology impacted by molybdenum would be better explained by considering both MoO4(2-) and SO4(2-) concentrations in the aquatic milieu. This work examines toxicological, physiological and redox imbalances in the dinoflagellate Lingulodinium polyedrum that have been induced by changes in the molybdate:sulfate ratios. We prepared cultures of Lingulodinium polyedrum grown in artificial seawater containing eight different MoO4(2-) concentrations (from 0 to 200 µM) and three different SO4(2-) concentrations (3.5 mM, 9.6 mM and 25 mM). We measured sulfur content in cells, the activities of the three major antioxidant enzymes (superoxide dismutase, catalase, and ascorbate peroxidase), indexes of oxidative modifications in proteins (carbonyl content) and lipids (thiobarbituric acid-reactive substances, TBARS), the activities of the molybdenum-dependent enzymes xanthine oxidase and nitrate reductase, expression of key protein components of dinoflagellate photosynthesis (peridinin-chlorophyll a protein and ribulose-1,5-biphosphate carboxylase/oxidase) and growth curves. We find evidence for Mo toxicity at relatively high [MoO4(2-)]:[SO4(2-)] ratios. We also find evidence for extensive redox adaptations at Mo levels well below lethal levels.

Comparison of the skin sensitizing potential of unsaturated compounds as assessed by the murine local lymph node assay (LLNA) and the guinea pig maximization test (GPMT).

The skin sensitization potential of eight unsaturated and one saturated lipid (bio)chemicals was tested in both the LLNA and the GPMT to address the hypothesis that chemicals with unsaturated carbon-carbon double bonds may result in a higher number of unspecific (false positive) results in the LLNA compared to the GPMT. Seven substances (oleic acid, linoleic acid, linolenic acid, undecylenic acid, maleic acid, squalene and octinol) gave clear positive results in the LLNA (stimulation index (SI)> or = 3) and thus would require labelling as skin sensitizer. Fumaric acid and succinic acid gave clearly negative results. In the GPMT, besides some sporadic skin reactions, reproducible skin reactions indicating an allergic response were found in a few animals for four test substances. Based on the GPMT results, only undecylenic acid would have to be classified and labelled as a skin sensitizer according to the European Dangerous Substance Directive (67/548/EEC) (results for linoleic acid were inconclusive), while the other seven test substances would not require labelling. Possible mechanisms for unspecific skin cell stimulation and lymph node responses are discussed. In conclusion, the suitability of the LLNA for unsaturated compounds bearing structural similarity to the tested substances should be carefully considered and the GPMT should remain available as an accepted test method for skin sensitization hazard identification.

The purpose of the general practice consultation from the patient's perspective--theoretical aspects.

BACKGROUND: Medical practice and research are paying increasing attention to what patients want, as reflected by the growth of routine surveys of patients' satisfaction and more formal studies of patients' views of medical care. However, the field lacks conceptual clarity. OBJECTIVES: The aim of this study was to propose a theoretical clarification of the concept of the patients' purpose of a consultation by presenting a patient-centred definition, applicable for clinical work and research in general practice. METHODS: An extensive literature review was conducted to explore presumptions and definitions reported by previous studies. Most authors failed to define or distinguish the concept under investigation. We took these shortcomings as our starting point, added some significant dimensions drawn from a few selected authors who had discussed relevant perspectives in their work and arrived at a proposed working definition of the 'purpose' concept. RESULTS: The proposed definition allows for multiple purposes for the consultation. We incorporate what the patient hopes to gain from the consultation, as opposed to their 'expectations of the most likely outcome'. Our working definition aims to identify patients' a priori wishes and hopes for a specific process and outcome, while acknowledging that these may not be voiced and may be modified by the patient during the consultation. General characteristics of the doctor, such as being considerate or professionally skillful, are not included.

Gendered health resources and coping--a study from general practice.

AIM: The aim of this study was to explore gender and coping in primary health care patients, by comparing self-assessed health resources in men and women. METHODS: Female and male patients' self-assessed health resources were identified by mean of key questions, developed separately for men and women. Patients' answers were audiotaped and analyzed qualitatively. An explorative gender comparative analysis was done. The setting comprised two women GPs and their consultations. The subjects were 37 consecutive female patients and 39 consecutive male patients aged 19-85 years. RESULTS: The analysis indicated notable differences in spite of apparent similarities in self-assessed personal health resources in men and women. In men, personal strength was part of a proud identity, while women reported that they were able to manage because they just had to. Work was often mentioned as a health resource, but while men emphasized their well-being at work and a capacity to relax at home, women handled stressful tensions by diving into household activities. While men spoke of gaining health from being with others, women talked about social relations as contexts for gaining as well as giving health. CONCLUSION: None of the phenomena described by the respondents can be reasonably categorized as respectively problem-focused, emotion-focused or avoidance coping strategies. Asking people about their own ideas regarding health resources may provide more complex understandings of coping and gender. In a clinical setting skilful listening can prevent gender essentialism, where all men are regarded as different from all women.

Men's self-assessed personal health resources: approaching patients' strong points in general practice.

OBJECTIVE: To explore resource-oriented, gender-sensitive approaches in general practice by identifying what men perceive to be their personal health resources. METHODS: A key question was developed to invite men to tell their GPs about personal health resources during ordinary visits. The answers of 39 consecutive male patients (aged 19-84 years) visiting two female GPs were audio taped and analysed, qualitatively inspired by Giorgi's phenomenological approach, supported by theories on salutogenesis, patient-centredness and gender perspectives. The main outcome measures were personal qualities and strategies considered by men to be their health resources. RESULTS: Men considered that the following were personal health resources: optimism, good self-esteem, job satisfaction, ability to cope with stress at work, leisure activities and relaxation with friends producing energy, and fitness and lifestyle activities. CONCLUSION: A key question can give a doctor access to men's thoughts about their strong points. Self-assessed personal health resources can be identified and mobilized by the GP and support a salutogenic approach, which contrasts with the tendency of contemporary medical practice to focus on risk. Asking people about their own ideas may reveal that coping patterns are more complex than reflected in prevailing research.

From risk factors to health resources in medical practice.

The healing and preventive powers of people's health resources and self-assessed knowledge have so far been grossly underestimated in medicine. In this article, we call attention to ethical and epistemological dilemmas related to knowledge, values, communication, and autonomy embedded in the prevailing risk-oriented epidemiology, and suggest a patient-centred salutogenetic approach to promote a better balance between resources and risks in medicine. Identification and intervention upon risk factors can provide hypotheses about origins of disease and predict and sometimes prevent disease at a group level. However, there are several pitfalls related to this perspective concerning causal factors, group level based possibilities, adequate end points for intervention, informed consent, and medicalization, especially in the individualized context of the clinical encounter. By introducing a salutogenic perspective, we urge to shift the attention toward resources, agency and strength, which may counteract risk of disease and empower the patient. Talk can mediate oppression as well as empowerment. A communicative key question approach, and self-assessed health resources identified through this strategy, are briefly presented as examples of empowerment through dialogue.

[Individual registration of children in the national health service. New possibilities for epidemiological research in primary health care]. / Eget sygesikringsbevis til børn. Nye muligheder for epidemiologisk forskning i den primaere sundhedssektor.

Since January 1st 1996 all Danish citizens, children included, have been recorded individually in The National Health Service Register (SSR). Services rendered to children are no longer registered with an adult person. This article describes the implementation of this new arrangement. The part of health services to children recorded under an adult personal identification number is getting asymptotically closer to a minimum of about four percent, which is determined by the average time of naming of children. After the introduction of individual registration of children the SSR has improved considerably as a basis for epidemiological studies in Danish primary care.

Encouraging the strengths of women patients. A case study from general practice on empowering dialogues.

This case study illustrates how the use of empowering dialogues in general practice can contribute to alternative images of women, by identifying and emphasizing their strong points. It is a single case study, sampled theoretically from a series of 37 consultations during which key questions about self-assessed health resources were put to women patients. Two women GPs and their consultations were studied. An 18-min dialogue between a 52-year-old woman GP and a 69-year-old woman patient with asthma and back pain was audiotaped and transcribed according to Nessa's principles, supported by pragmatic linguistic theory. The woman's answers changed the doctor's perception of the patient, from that of a passive and resigned sufferer, to that of a strong woman who was active in spite of her pain. Acknowledging this, alternative paths of management could be chosen. In conclusion, disempowering medicalization of women patients can be opposed by resource oriented dialogues in clinical work. However, to change cultural images requires more than individual action.

Talking with women about personal health resources in general practice. Key questions about salutogenesis.

We want to share experiences from an approach for clinical communication and research, intended to identify and mobilize personal health resources in female patients, and promote strategies for resource oriented talk in general practice. We used an action research design with qualitative evaluation to summarize the process where we developed a key question about self-assessed health resources in women, based on The Health Resource/Risk Balance Model, including salutogenesis, patient-centredness and gender perspectives. From consultations with 49 female patients in our own practices, we have drawn a narrative description of the development process, a summary of issues that facilitated resource talk, and our final version of the key question. We suggest that resource talk is based on 1) an explicit shift of language from disease to health, but nevertheless recognizing the fact that illness occurs, 2) options for answers given by the female patient and not by the doctor, 3) signification of the woman's assessment of her own situation (in contrast to the doctor's assessment), and 4) taking for granted that women's personal health resources exist as numerous strategies which are utilized, and may be identified. We have learnt that communicative action can provide tools for shifting the attention of doctor and patients from risks and diseases to resources and strengths. This is an example of one way to change your practice through systematic reflection in dialogue with a colleague.

[Self-rated health as a predictor of ischemic heart disease development]. / Selvvurderet helbred som praediktor for udvikling af iskaemisk hjertesygdom.

The study objective was to analyse the association between self-rated health and the incidence of fatal and non-fatal coronary heart disease in a Danish cohort followed up over 16 years. The study included 1052 men and women born in 1936. During the 16 years' follow-up 50 cases of coronary heart disease were registered either with the Danish register of deaths or the register of hospital admissions. Univariate analysis showed the following relative risks of coronary heart disease in the four self-rated health groups: "extremely good": 1.0, "good": 4.0, "poor": 5.8, "miserable": 12.1 (p = 0.02). After control for the conventional coronary risk factors and a substantial number of other potential confounders the relative risks were: 1.0, 4.2, 6.5, and 18.6 (p = 0.02) respectively. Self-rated health was an independent predictor of coronary heart disease in this recent cohort. If confirmed, the association between self-rated health and coronary heart disease may lead to new insights into psychosocial processes leading to this disease.

[From risk factors to health resources. From theory to medical practice]. / Fra risikojakt til ressursmobilisering. Fra teori til allmenpraksis.

In this article, we emphasize some of the problems related to the choice of risk factor identification and intervention as the dominant medical strategy for diagnosis, treatment and prevention of disease. Knowledge about risk factors can provide hypotheses about origins of disease and predict disease at a group level. However, there are several pitfalls related to this perspective concerning causal factors, end points, informed consent, group level based possibilities and medicalization. A salutogenic perspective shifts the attention toward resources which might counteract risk of disease. Increased attention to people's personal health resources--assessed by the doctor as well as by the person herself--can contribute to a better balance in medical theory and practice by stimulating the strength of people rather than looking only for weaknesses.

Social and biological predictors of early menopause: a model for premature aging.

OBJECTIVES: To investigate possible social, lifestyle-related and biological predictors of early menopause in middle-aged women, followed prospectively for 11 years. DESIGN: A prospective, population-based, cohort follow-up, observational study. SETTING: Glostrup Hospital, Copenhagen, Denmark. SUBJECTS: A total of 493 female subjects, all aged 40 years at baseline, and divided into three groups according to self-reported menopausal age (40-45, 46-51, 51+ years), after 12 months of amenorrhoea. Women having had medical or surgical interventions to influence menopausal state were excluded. MAIN OUTCOME MEASURES: Body mass index, glucose, insulin, lipids, creatinine, uric acid, thyroid-stimulating hormone (TSH), lung function tests (forced VC, FEV1, peak flow), blood pressure; a self-administered questionnaire with questions on psychosocial variables, lifestyle, and self-rated health. RESULTS: An early menopausal age correlated in an univariate way with impaired lung function, increased smoking habits and low social class (in childhood or present), as well as with a feeling of tiredness, all measured at the baseline investigation. On the contrary, a later menopausal age correlated with higher serum insulin and uric acid levels. In multiple regression analysis, with menopausal age as the dependent variable, it was found that smoking habits (number of years smoking) was inversely (P < 0.001), and insulin as well as uric acid were positively (P < 0.05) correlated with menopausal age. CONCLUSIONS: Females who smoke run an increased risk of early menopause, whereas relative hyperinsulinaemia is independently associated with later menopause. At the age of 40 years, high insulin levels in females might be just a marker for normal female sex hormone physiology, not for insulin resistance, as seen in postmenopausal female subjects. Early menopause might be useful as a potential model of premature ageing.

The Danish National Health Service Register. A tool for primary health care research.

The purpose of the article is to describe the Danish National Health Service Register and its value in primary health care research, using mainly general practice as an example. The Danish National Health Service Register is a data system available for counties and municipalities to manage the National Health Insurance covering primary health care providers. The counties use the register for administrative purposes, especially for the settling of accounts with providers. The register contains data on all citizens, providers, and health care services reimbursed by the health authorities, but holds no data regarding health status. The accuracy and degree of completeness of persons and variables in the National Health Service Register rests on the fact that most primary health care services in Denmark are reimbursed and, therefore, included in the data base. This tie to the economy of both health care authorities and providers is supposed to confer the final register with a high degree of completeness. It is a clear advantage that almost all citizens in Denmark are assigned to only one general practice, and that the attitude towards research is positive among Danish patients and doctors. The register has so far only been used occasionally for research purposes. To take advantage of the register for research purposes within clinical and health services research, however, one must possess not only a detailed knowledge of the Danish society, including the structure of the Danish health care system, but also an intimate acquaintance with rather complex agreement system and the actual interpretation of this.

Women's self-assessed personal health resources.

OBJECTIVE: To contribute to the development of a resource-oriented medical language by identifying self-assessed personal health resources in women. DESIGN: Key questions were developed to invite the patient to tell the general practitioner about such resources. Patients' answers were audiotaped and analysed qualitatively according to Giorgi's phenomenological approach. The theoretical frame of reference included salutogenesis, patient-centredness, and gender perspectives. SETTING: Two female general practitioners and their consultations. SUBJECTS: 37 consecutive female patients aged 24-85 years. MAIN OUTCOME MEASURES: Common aspects of personal qualities and strategies considered by women as their health resources. RESULTS: The material unveiled health resources related to 1) internal strength mobilized by external strain, 2) interactive networks within and outside the family, 3) lifestyle practices, 4) physical and social activity, 5) acceptance and facilitation of the natural course of Disease, and 6) constitution. CONCLUSION: Female patients have explicit and intelligible ideas about their self-assessed personal health resources, which can be identified and mobilized by the general practitioner and form part of potentially empowering strategies in medical practice.

Self rated health as a predictor of coronary heart disease in Copenhagen, Denmark.

STUDY OBJECTIVE: To analyse the association between self rated health and the incidence of fatal and non-fatal coronary heart disease (CHD) in a Danish cohort followed up over 16 years. DESIGN: This was a prospective epidemiological follow up study. SETTING: A cohort from the County of Copenhagen, Denmark. PARTICIPANTS: The study included 1052 men and women born in 1936. During the 16 years' follow up 50 cases of CHD were registered in either the Danish register of deaths or the register of hospital admissions. MAIN RESULTS: Univariate analysis showed the following relative risks of CHD in the four self rated health groups: 'extremely good': 1.0, 'good': 4.0, 'poor': 5.8, 'miserable': 12.1 (p = 0.02). After control for the conventional CHD risk factors and a substantial number of other potential confounders the relative risks were: 1.0, 4.2, 6.5, and 18.6 (p = 0.02) respectively. CONCLUSIONS: Self rated health was an independent predictor of CHD in the present cohort. If confirmed, the association between self rated health and CHD may lead to new insight into psychosocial processes leading to this disease.

The effect of light on the biosynthesis of beta-carotene and superoxide dismutase activity in the photosynthetic alga Gonyaulax polyedra.

Daily oscillations of both beta-carotene and superoxide dismutase (SOD) activity are related to the intracellular control of reactive oxygen species (ROS). It is well established that ROS are present in all aerobic cells. We studied the marine dinoflagellate Gonyaulax polyedra which has been extensively used as a model to understand the biological clock at the molecular level. beta-Carotene, besides suppressing singlet molecular oxygen (1O2), may act as a photoreceptor pigment in many photosynthetic cells. The levels of beta-carotene during the day phase were shown to be twice as high as during the night phase. The dose-response curve for light-induced carotenoid synthesis was linear for up to 45 min of light exposure, after which night phase cells contained the same levels of beta-carotene as day phase cells. Cells exposed to light pulses at different times during the dark period displayed the highest beta-carotene induction in the middle of the night. SOD activity of cell-free extracts of G. polyedra was three to four times higher during the day. This rhythm continued in cells kept in constant light, indicating that the regulation can be attributed to the cellular circadian clock. No-denaturing polyacrylamide gels revealed the presence of several SOD isoenzymes in G. polyedra, including CuZnSOD and MnSOD. Furthermore, G. polyedra SOD cross-reacts with a polyclonal antibody raised against SOD. In addition to being gene regulated by ROS concentration, G. polyedra SOD expression seems also to be under the control of the biological clock.

The effect of light on the biosynthesis of beta-carotene and superoxide dismutase activity in the photosynthetic alga Gonyaulax polyedra

Daily oscillations of both beta-carotene and superoxide dismutase (SOD) activity are related to the intracellular control of reactive oxygen species (ROS). It is well established that ROS are present in all aerobic cells. We studied the marine dinoflagellate Gonyaulax polyedra which has been extensively used as a model to understand the biological clock at the molecular level. beta-Carotene, besides suppressing singlet molecular oxygen (1O2), may act as a photoreceptor pigment in many photosynthetic cells. The levels of beta-carotene during the day phase were shown to be twice as high as during the night phase. The dose-response curve for light-induced carotenoid synthesis was linear for up to 45 min of light exposure, after which night phase cells contained the same levels of beta-carotene as day phase cells. Cells exposed to light pulses at different times during the dark period displayed the highest beta-carotene induction in the middle of the night. SOD activity of cell-free extracts of G. polyedra was three to four times higher during the day. This rhythm continued in cells kept in constant light, indicating that the regulation can be attributed to the cellular circadian clock. Non-denaturing polyacrylamide gels revealed the presence of several SOD isoenzymes in G. polyedra, including CuZnSOD and MnSOD. Furthermore, G. polyedra SOD cross-reacts with a polyclonal antibody raised against SOD. In addition to being gene regulated by ROS concentration, G. polyedra SOD expression seems also to be under the control of the biological clock.

Shifting attention from objective risk factors to patients' self-assessed health resources: a clinical model for general practice.

The study was designed to present and apply theoretical and empirical knowledge for the construction of a clinical model intended to shift the attention of the general practitioner from objective risk factors to self-assessed health resources in male and female patients. Review, discussion and analysis of selected theoretical models about personal health resources involving assessing existing theories according to their emphasis concerning self-assessed vs. doctor-assessed health resources, specific health resources vs. life and coping in general, abstract vs. clinically applicable theory, gender perspective explicitly included or not. Relevant theoretical models on health and coping (salutogenesis, coping and social support, control/demand, locus of control, health belief model, quality of life), and the perspective of the underprivileged Other (critical theory, feminist standpoint theory, the patient-centred clinical method) were presented and assessed. Components from Antonovsky's salutogenetic perspective and McWhinney's patient-centred clinical method, supported by gender perspectives, were integrated to a clinical model which is presented. General practitioners are recommended to shift their attention from objective risk factors to self-assessed health resources by means of the clinical model. The relevance and feasibility of the model should be explored in empirical research.