Incidence in atrial fibrillation in Denmark in relation to country of origin: a nationwide register-based study

Background

Immigrants' healthcare needs can be a considerable challenge, as their risk profile can differ from the native population, and they may experience barriers to accessing health services in recipient countries. Immigration is projected to increase further due to conflicts and climate changes, and awareness on immigrants' health status is therefore warranted. Atrial fibrillation (AF) is the most common sustained arrhythmia with an estimated prevalence of approximately 2%. However, there is a paucity of data on AF epidemiology among immigrants.

Purpose

The aim of this study is to examine incidence of AF hospital diagnoses according to country of origin and to study if there is a difference in risk between immigrants and Danish born individuals.

Methods

The study period included 1st of January 1998 to 31st of December 2017 and the population consisted of all Danish citizens aged 45 or older. We included individuals as they turned 45 during the study period. Individuals who had been diagnosed with AF were excluded. Data was obtained from the Danish National Patient Registry and the Civil Registration System. Country of origin was based on the ten most represented counties in the population. Immigrants were defined as people born outside Denmark with none of the parents being both Danish citizens and born in Denmark. AF was defined as a hospital diagnosis according to international Classification of Diseases (ICD) version 8 and 10. Poisson regression were used to compute relative risk (RR) and associated 95% confidence intervals (CI). RRs were adjusted for sex, age, socioeconomic status, visits to general practitioner and comorbidity.

Results

The study population consist of 3,596,234 Danish-Born and 215,401 immigrants. A total of 334,636 had an incident AF diagnosis during the study period. Compared to Danish-born individuals, migrants from the Nordic countries had a higher adjusted RR of being diagnosed with AF: Norway 1.21 [95% CI: 1.05; 1.40], Sweden 1.16 [95% CI: 0.99; 1.35] and Germany 1.17 [95% CI: 1.06; 1.28]. In contrast, lower adjusted RRs were observed for individuals from Poland (0.82 [95% CI: 0.67; 1.01]), UK (0.89 [95% CI: 0.73; 1.08]), and the US (0.95 [95% CI: 0.72; 1.25]), respectively, and in particular for individuals from the non-Western countries: Turkey (0.49 [95% CI: 0.40; 0.59], Iran (0.48 [95% CI: 0.36; 0.65]), Iraq (0.32 [95% CI: 0.22; 0.45] and Bosnia-Herzegovina (0.63 [95% CI: 0.49; 0.79]).

Conclusion

Substantial variation in the incidence rate of incident AF hospital diagnoses according to country of origin. Further studies are warranted in order to clarify to what extent these differences reflets true differences in AF incidence or ethnic inequalities in the detection of AF in the health care system.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Karen Elise Jensen Foundation

Fundamental ICRP recommendations at the start of the 21st century: Status of the revision of ICRP Publication 60

The basic recommendations of the International Commission on Radiological Protection, ICRP, are either re-stated or revised at intervals of about 15 years, most recently in ICRP Publication 60, adopted in 1990. ICRP plans to issue its next recommendations around 2005. Through extensive consultation, the active participation of the radiological protection community was recruited already at the conceptual stage. Based on the vast input received, ICRP is currently preparing draft recommendations. These are likely to emphasise egalitarian values more than utilitarian ones, to be holistic rather than anthropocentric, and to be formatted as a relatively concise set of actual recommendations underpinned by separate publications with more detail. The draft will again be circulated world-wide and comments will be discussed in 2004 with a view to approval of the recommendations in 2005 and publication in 2005 or 2006. Thus, integration into legislation would be possible sometime between 2006 and 2010, say.

Patients Requiring Conversion to General Anesthesia during Endovascular Therapy Have Worse Outcomes: A Post Hoc Analysis of Data from the SAGA Collaboration

BACKGROUND AND PURPOSE

Endovascular therapy for acute ischemic stroke is often performed with the patient under conscious sedation. Emergent conversion from conscious sedation to general anesthesia is sometimes necessary. The aim of this study was to assess the functional outcome in converted patients compared with patients who remained in conscious sedation and to identify predictors associated with the risk of conversion.

MATERIALS AND METHODS

Data from 368 patients, included in 3 trials randomizing between conscious sedation and general anesthesia before endovascular therapy (SIESTA, ANSTROKE, and GOLIATH) constituted the study cohort. Twenty-one (11%) of 185 patients randomized to conscious sedation were emergently converted to general anesthesia.

RESULTS

Absence of hyperlipidemia seemed to be the strongest predictor of conversion to general anesthesia, albeit a weak predictor (area under curve = 0.62). Sex, hypertension, diabetes, smoking status, atrial fibrillation, blood pressure, size of the infarct, and level and side of the occlusion were not significantly associated with conversion to general anesthesia. Neither age (mean age, 71.3   ± 13.8 years for conscious sedation versus 71.6  ± 12.3 years for converters, P = .58) nor severity of stroke (mean NIHSS score, 17 ± 4 versus 18 ± 4, respectively, P = .27) were significantly different between converters and those who tolerated conscious sedation. The converters had significantly worse outcome with a common odds ratio of 2.67 (P = .015) for a shift toward a higher mRS score compared with the patients remaining in the conscious sedation group.

CONCLUSIONS

Patients undergoing conversion had significantly worse outcome compared with patients remaining in conscious sedation. No factor was identified that predicted conversion from conscious sedation to general anesthesia.

COORDINATION OF MANAGEMENT OF THE ACUTE RADIATION SYNDROME

The acute radiation syndrome (ARS) constitutes the most challenging, immediate medical consequence of exposure to high doses of ionizing radiation in an emergency situation. This report highlights some of the currently available medical guidelines and recommendations on the clinical management of ARS, comments recent trends regarding the approval of targeted pharmaceuticals for ARS, and suggests further initiatives for international collaboration aiming at continuously updating the medical knowledge base of this syndrome.

Gradient-based optimization with B-splines on sparse grids for solving forward-dynamics simulations of three-dimensional, continuum-mechanical musculoskeletal system models

Investigating the interplay between muscular activity and motion is the basis to improve our understanding of healthy or diseased musculoskeletal systems. To be able to analyze the musculoskeletal systems, computational models are used. Albeit some severe modeling assumptions, almost all existing musculoskeletal system simulations appeal to multibody simulation frameworks. Although continuum-mechanical musculoskeletal system models can compensate for some of these limitations, they are essentially not considered because of their computational complexity and cost. The proposed framework is the first activation-driven musculoskeletal system model, in which the exerted skeletal muscle forces are computed using 3-dimensional, continuum-mechanical skeletal muscle models and in which muscle activations are determined based on a constraint optimization problem. Numerical feasibility is achieved by computing sparse grid surrogates with hierarchical B-splines, and adaptive sparse grid refinement further reduces the computational effort. The choice of B-splines allows the use of all existing gradient-based optimization techniques without further numerical approximation. This paper demonstrates that the resulting surrogates have low relative errors (less than 0.76%) and can be used within forward simulations that are subject to constraint optimization. To demonstrate this, we set up several different test scenarios in which an upper limb model consisting of the elbow joint, the biceps and triceps brachii, and an external load is subjected to different optimization criteria. Even though this novel method has only been demonstrated for a 2-muscle system, it can easily be extended to musculoskeletal systems with 3 or more muscles.

Early detection and treatment of mental illness in the workplace – an intervention study

Introduction

Conditions of depression and anxiety among employees’ leads to increased absenteeism and decreased social and professional function.

Objectives

To test a collaborative model for contributing to mental health at work at the lowest interference and highest possible availability among Danish workers.

Aims

To investigate the effect of early detection and treatment in order to interrupt and improve conditions of clinical and sub-clinical levels of mental illness.

Methods

Self-reporting questionnaires were used for identification of clinical and sub-clinical cases of mental illness and for follow-up. Four questionnaires were distributed to all employees in six medium-large companies in Denmark (n = 1292) during a period of 16 months. Employees meeting the screening criteria were assessed diagnostically. Outpatient psychiatric treatment was offered to employees diagnosed with mental illness and preventive CBT-session to those assessed with sub-clinical conditions. Follow-up questionnaires were filled out after 6 and 12 months. Data were analysed using repeated measure mixed effects linear regression.

Results

Of the 587 (55%) employees that returned the questionnaires, 58 were referred to either outpatient psychiatric treatment (n = 38) or preventive treatment (n = 20). Levels of psychopathology decreased significantly in both treated groups. Comparing with the pre-treatment period, a significant positive difference in change in psychopathology was detected for employees in psychiatric treatment. Measured up to healthy controls, the self-perceived level of stress also decreased significantly among employees in psychiatric treatment.

Conclusions

An integrated collaborative model for early detection and treatment was beneficial in order to interrupt and improve the course of mental health problems among Danish employees.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Extended point defects in crystalline materials: Ge and Si

B diffusion measurements are used to probe the basic nature of self-interstitial point defects in Ge. We find two distinct self-interstitial forms--a simple one with low entropy and a complex one with entropy ∼30  k at the migration saddle point. The latter dominates diffusion at high temperature. We propose that its structure is similar to that of an amorphous pocket--we name it a morph. Computational modeling suggests that morphs exist in both self-interstitial and vacancylike forms, and are crucial for diffusion and defect dynamics in Ge, Si, and probably many other crystalline solids.

Scope of radiological protection control measures

In this report, the Commission recommends approaches to national authorities for their definition of the scope of radiological protection control measures through regulations, by using its principles of justification and optimisation. The report provides advice for deciding the radiation exposure situations that should be covered by the relevant regulations because their regulatory control can be justified, and, conversely, those that may be considered for exclusion from the regulations because their regulatory control is deemed to be unamenable and unjustified. It also provides advice on the situations resulting from regulated circumstances but which may be considered by regulators for exemption from complying with specific requirements because the application of these requirements is unwarranted and exemption is the optimum option. Thus, the report describes exclusion criteria for defining the scope of radiological protection regulations, exemption criteria for planned exposure situations, and the application of these concepts in emergency exposure situations and in existing exposure situations. The report also addresses specific exposure situations such as exposure to low-energy or low-intensity adventitious radiation, cosmic radiation, naturally occurring radioactive materials, radon, commodities, and low-level radioactive waste. The quantitative criteria in the report are intended only as generic suggestions to regulators for defining the regulatory scope, in the understanding that the definitive boundaries for establishing the situations that can be or need to be regulated will depend on national approaches.

Managing patient dose in multi-detector computed tomography(MDCT). ICRP Publication 102

Computed tomography (CT) technology has changed considerably in recent years with the introduction of increasing numbers of multiple detector arrays. There are several parameters specific to multi-detector computed tomography (MDCT) scanners that increase or decrease patient dose systematically compared to older single detector computed tomography (SDCT) scanners. This document briefly reviews the MDCT technology, radiation dose in MDCT, including differences from SDCT and factors that affect dose, radiation risks, and the responsibilities for patient dose management. The document recommends that users need to understand the relationship between patient dose and image quality and be aware that image quality in CT is often higher than that necessary for diagnostic confidence. Automatic exposure control (AEC) does not totally free the operator from selection of scan parameters, and awareness of individual systems is important. Scanning protocols cannot simply be transferred between scanners from different manufacturers and should be determined for each MDCT. If the image quality is appropriately specified by the user, and suited to the clinical task, there will be a reduction in patient dose for most patients. Understanding of some parameters is not intuitive and the selection of image quality parameter values in AEC systems is not straightforward. Examples of some clinical situation shave been included to demonstrate dose management, e.g. CT examinations of the chest, the heart for coronary calcium quantification and non-invasive coronary angiography, colonography, the urinary tract, children, pregnant patients, trauma cases, and CT guided interventions. CT is increasingly being used to replace conventional x-ray studies and it is important that patient dose is given careful consideration, particularly with repeated or multiple examinations.

Prevention of high-dose-rate brachytherapy accidents. ICRP Publication 97

High-dose-rate brachytherapy is a rapidly growing technique (HDR) that has been replacing low-dose-rate (LDR) procedures over the last few years in both industrialised and developing countries. It is estimated that about 500,000 procedures (administration of treatment) are performed by HDR units annually. LDR equipment has been discontinued by many manufacturers over the last few years, leaving HDR brachytherapy as the major alternative. HDR brachytherapy techniques deliver a very high dose, of the order of 1.6-5.0 Gy/min, so mistakes can lead to under- or overdosage with the potential for clinical adverse effects. More than 500 HDR accidents (including one death) have been reported along the entire chain of procedures from source packing to delivery of dose. Human error has been the prime cause of radiation events. In the present report, the International Commission on Radiological Protection concludes that many accidents could have been prevented if staff had had functional monitoring equipment and paid attention to the results. Since iridium has relatively short half-life, the HDR sources need to be replaced approximately every 4 months. Over 10,000 HDR sources are transported annually, with the resultant potential for accidents; therefore, appropriate procedures and regulations must be observed. A number of specific recommendations on procedures and equipment are given in this report. The need for an emergency plan and for practising emergency procedures is stressed. The possibility of loss or theft of sources must be kept in mind. A collaborating team of specifically trained personnel following quality assurance (QA) procedures is necessary to prevent accidents. Maintenance is indispensable component of QA; external audits of procedures re-enforce good and safe practice, and identify potential causes of accidents. QA should include peer review of cases. Accidents and incidents should be reported and the lessons learned should be shared with other users to prevent similar mistakes.

Protecting people against radiation exposure in the event of a radiological attack. A report of The International Commission on Radiological Protection

This report responds to a widely perceived need for professional advice on radiological protection measures to be undertaken in the event of a radiological attack. The report, which is mainly concerned with possible attacks involving 'radioactive dispersion devices', re-affirms the applicability of existing ICRP recommendations to such situations, should they ever occur. Many aspects of the emergency scenarios expected to arise in the event of a radiological attack may be similar to those that experience has shown can arise from radiological accidents, but there may also be important differences. For instance, a radiological attack would probably be targeted at a public area, possibly in an urban environment, where the presence of radiation is not anticipated and the dispersion conditions commonly assumed for a nuclear or radiological emergency, such as at a nuclear installation, may not be applicable. First responders to a radiological attack and other rescuers need to be adequately trained and to have the proper equipment for identifying radiation and radioactive contamination, and specialists in radiological protection must be available to provide advice. It may be prudent to assume that radiological, chemical, and/or biological agents are involved in an attack until it is proven otherwise. This calls for an 'all-hazard' approach to the response. In the aftermath of an attack, the main aim of radiological protection must be to prevent the occurrence of acute health effects attributable to radiation exposure (termed 'deterministic' effects) and to restrict the likelihood of late health effects (termed 'stochastic' effects) such as cancers and some hereditable diseases. A supplementary aim is to minimise environmental contamination from radioactive residues and the subsequent general disruption of daily life. The report notes that action taken to avert exposures is a much more effective protective measure than protective measure the provision of medical treatment after exposure has occurred. Responders involved in recovery, remediation and eventual restoration should be subject to the usual international standards for occupational radiological protection, which are based on ICRP recommendations, including the relevant requirements for occupational dose limitation established in such standards. These restrictions may be relaxed for informed volunteers undertaking urgent rescue operations, and they are not applicable for voluntary life-saving actions. However, specific protection measures are recommended for female workers who may be pregnant or nursing an infant. The immediate countermeasures to protect the public in the rescue phase are primarily caring for people with traumatic injuries and controlling access. Subsequent actions include respiratory protection, personal decontamination, sheltering, iodine prophylaxis (if radio-iodines are involved), and temporary evacuation. In the recovery phase, the relocation and resettlement of people may be needed in extreme cases. This phase may require remedial action, including cleanup, management of the resulting radioactive waste, management of any human remains containing significant amounts of radioactive substances, and dealing with remaining radioactive residues. The guidance given in relation to public protection is based solely on radiological protection considerations and should be seen as a decision-aiding tool to prepare for the aftermath of a radiological attack. It is expected to serve as input to a final decision-making process that may include other societal concerns, consideration of lessons learned in the past (especially these involving the public perception of the risks posed by radioactive contamination) and the participation of interested parties. A radiological attack could also be the cause of radioactive contamination of water, food, and other widely consumed commodities. This possible outcome is considered unlikely to lead to significant internal contamination of a large number of people owing to the large amounts of radioactive material that would be required to cause high levels of contamination of water, food, and other commodities. Nonetheless, the report recommends radiological criteria for restricting the use of commodities under such circumstances. The report concludes by re-iterating that the response to radiological attacks should be planned beforehand following the customary processes for optimisation of radiological protection recommended by ICRP, and that optimised measures should be prepared in advance. Such plans should result in a systematic approach that can be modified if necessary to take into account the prevailing conditions and to invoke actions as warranted by the circumstances. Many potential scenarios clearly cannot induce immediate severe radiation injuries. Therefore, in order to prevent over-reaction, response measures prepared in advance should reflect the real expected gravity of the various possible scenarios.

Annals of the ICRP. A report of: doses to infants from ingestion of radionuclides in mothers' milk

In the present report, ICRP provides information on radiation doses to the infant due to intakes of radionuclides in maternal milk. As in Publication 88 (ICRP, 2001) on doses to the embryo and fetus following intakes of radionuclides by the mother, intakes by female members of the public and female workers are addressed. Acute and chronic intakes are considered at various times before and during pregnancy as well as during the period of breastfeeding. Dose coefficients per unit intake by the mother (Sv/Bq) are given for the selected radionuclides of the same 31 elements for which age-specific biokinetic models were given in Publications 56, 67, 69, and 71 (ICRP, 1989, 1993, 1995a,b). For these elements, doses were calculated for the most radiologically significant natural or artificial radionuclides that might be released into the environment due to various human activities. Dose coefficients are also given in this report for radionuclides of an additional four elements: sodium, magnesium,phosphorus, and potassium. Relevant human and animal data on elemental and radionuclide transfer to milk are reviewed. The biokinetic models for adults given in earlier ICRP publications are adapted to include transfer to milk. Model predictions of fractional transfer of ingested or inhaled activity to milk are discussed in the report, and the corresponding dose coefficients for the infant are compared with dose coefficients for in utero exposure, as given in Publication 88 (ICRP, 2001). Illustrative information is also given on doses to the female breast from radionuclides in breastmilk, and external doses received by the child from radionuclides retained in the tissues of the mother. For the additional elements considered in this report, but not in Publication 88 (ICRP,2001), information is also given on doses to the embryo and fetus following maternal intakes of radioisotopes during or before pregnancy. A CD-ROM is to be issued giving data that will supplement the information given in this report. In addition to the dose coefficients given here, committed equivalent doses to the various organs and tissues of the offspring will be given. Dose coefficients will also be given for inhalation of a range of aerosol sizes for the selected radionuclides of the elements covered by this report.

A framework for assessing the impact of ionising radiation on non-human species. ICRP Publication 91

In its 1990 Recommendations, the ICRP indicated that it believed that the standards of environmental control needed to protect man to the degree currently thought desirable would ensure that other species are not put at risk. The ICRP considers that its system of radiological protection has provided a fairly good indirect protection of the human habitat. However, no internationally agreed criteria or policies explicitly address protection of the environment from ionising radiation, and it is difficult to determine or demonstrate whether or not the environment is adequately protected from potential impacts of radiation under different circumstances. The present report suggests a framework, based on scientific and ethical-philosophical principles, by which a policy for the protection of non-human species could be achieved. The primary purpose of developing such a framework is to fill a conceptual gap in radiological protection; it does not reflect any particular concern over environmental radiation hazards. The proposed framework is designed to harmonise with the ICRP's approach to the protection of human beings, but does not intend to set regulatory standards. Instead, the proposed framework is intended to be a practical tool to provide high-level advice and guidance for regulators and operators. An agreed set of quantities and units, a set of reference dose models, reference dose-per-unit-intake (or unit exposure), and reference fauna and flora are required to serve as a basis for the more fundamental understanding and interpretation of the relationships between exposure and dose and between dose and certain categories of effect, for a few, clearly defined types of animals and plants. As a first step, a small set of reference fauna and flora with supporting databases will be developed by the ICRP. Others can then develop more area- and situation-specific approaches to assess and manage risks to non-human species.

Guide for the practical application of the ICRP Human Respiratory Tract Model. A report of ICRP supporting guidance 3: approved by ICRP committee 2 in October 2000

The ICRP Publication 66 Human Respiratory Tract Model for Radiological Protection (HRTM) has been applied to calculate dose coefficients (doses per unit intake) and bioassay functions in ICRP Publications 68, 71, 72 and 78. For these purposes, ICRP assigned numerical values to a range of model parameters, such as the size of the inhaled particles and the breathing rate of the subjects. These are known as 'default' or 'reference' values, and were chosen to be typical, representative values. In any particular situation the actual values of many parameters can be considerably different from the reference values. Usually, doses from intakes of radionuclides are low compared with the relevant limit or constraint, and the resulting difference is unimportant. There are, however, circumstances where more reliable assessments of intake and dose are desirable. This Guidance Document therefore gives advice on applying specific information within the framework of the HRTM for assessing occupational and environmental exposures and for interpreting bioassay data. Chapters on each aspect of the model (morphometry, physiology, deposition, clearance, gases and vapours, dosimetry) provide: A summary of how the HRTM treats that topic;Information on the reference values of relevant parameters;Guidance on choosing between default values;Information on how doses and bioassay quantities (lung retention, urine, and faecal excretion) vary with the values of selected parameters, giving guidance on the importance of obtaining specific information;Simple examples of the use of specific information relating to the topic.Annexes give additional information for those directly involved in applying the HRTM to specific situations, including guidance on obtaining parameter values. A brief overview is given of the deposition, characterisation, and sampling of aerosols, with references to further information, as there are relevant text books already available. Issues specific to radioactive aerosols, such as low particle number concentrations for high specific activity materials are, however, addressed. Guidance on obtaining information about absorption of inhaled radionuclides into blood is given in greater detail, because this is a topic on which ICRP has traditionally given guidance, and because a compilation of such information is not readily available elsewhere. Several detailed examples are also provided. One involves assessment of an individual's intake and committed dose from comprehensive bioassay monitoring data. The others deal with the derivation of HRTM absorption parameter values from experimental data, and their application, with additional information on e.g. size distribution, to calculate dose coefficients and interpret bioassay data.

Basic anatomical and physiological data for use in radiological protection: reference values. A report of age- and gender-related differences in the anatomical and physiological characteristics of reference individuals. ICRP Publication 89

This report presents detailed information on age- and gender-related differences in the anatomical and physiological characteristics of reference individuals. These reference values provide needed input to prospective dosimetry calculations for radiation protection purposes for both workers and members of the general public. The purpose of this report is to consolidate and unify in one publication, important new information on reference anatomical and physiological values that has become available since Publication 23 was published by the ICRP in 1975. There are two aspects of this work. The first is to revise and extend the information in Publication 23 as appropriate. The second is to provide additional information on individual variation among grossly normal individuals resulting from differences in age, gender, race, or other factors. This publication collects, unifies, and expands the updated ICRP reference values for the purpose of providing a comprehensive and consistent set of age- and gender-specific reference values for anatomical and physiological features of the human body pertinent to radiation dosimetry. The reference values given in this report are based on: (a) anatomical and physiological information not published before by the ICRP; (b) recent ICRP publications containing reference value information; and (c) information in Publication 23 that is still considered valid and appropriate for radiation protection purposes. Moving from the past emphasis on 'Reference Man', the new report presents a series of reference values for both male and female subjects of six different ages: newborn, 1 year, 5 years, 10 years, 15 years, and adult. In selecting reference values, the Commission has used data on Western Europeans and North Americans because these populations have been well studied with respect to antomy, body composition, and physiology. When appropriate, comparisons are made between the chosen reference values and data from several Asian populations. The first section of the report provides summary tables of all the anatomical and physiological parameters given as reference values in this publication. These results give a comprehensive view of reference values for an individual as influenced by age and gender. The second section describes characteristics of dosimetric importance for the embryo and fetus. Information is provided on the development of the total body and the timing of appearance and development of the various organ systems. Reference values are provided on the mass of the total body and selected organs and tissues, as well as a number of physiological parameters. The third section deals with reference values of important anatomical and physiological characteristics of reference individuals from birth to adulthood. This section begins with details on the growth and composition of the total body in males and females. It then describes and quantifies anatomical and physiological characteristics of various organ systems and changes in these characteristics during growth, maturity, and pregnancy. Reference values are specified for characteristics of dosimetric importance. The final section gives a brief summary of the elemental composition of individuals. Focusing on the elements of dosimetric importance, information is presented on the body content of 13 elements: calcium, carbon, chloride, hydrogen, iodine, iron, magnesium, nitrogen, oxygen, potassium, sodium, sulphur, and phosphorus.

Avoidance of radiation injuries from medical interventional procedures

Interventional radiology (fluoroscopically-guided) techniques are being used by an increasing number of clinicians not adequately trained in radiation safety or radiobiology. Many of these interventionists are not aware of the potential for injury from these procedures or the simple methods for decreasing their incidence. Many patients are not being counselled on the radiation risks, nor followed up when radiation doses from difficult procedures may lead to injury. Some patients are suffering radiation-induced skin injuries and younger patients may face an increased risk of future cancer. Interventionists are having their practice limited or suffering injury, and are exposing their staff to high doses. In some interventional procedures, skin doses to patients approach those experienced in some cancer radiotherapy fractions. Radiation-induced skin injuries are occurring in patients due to the use of inappropriate equipment and, more often, poor operational technique. Injuries to physicians and staff performing interventional procedures have also been observed. Acute radiation doses (to patients) may cause erythema at 2 Gy, cataract at 2 Gy, permanent epilation at 7 Gy, and delayed skin necrosis at 12 Gy. Protracted (occupational) exposures to the eye may cause cataract at 4 Gy if the dose is received in less than 3 months, at 5.5 Gy if received over a period exceeding 3 months. Practical actions to control dose to the patient and to the staff are listed. The absorbed dose to the patient in the area of skin that receives the maximum dose is of priority concern. Each local clinical protocol should include, for each type of interventional procedure, a statement on the cumulative skin doses and skin sites associated with the various parts of the procedure. Interventionists should be trained to use information on skin dose and on practical techniques to control dose. Maximum cumulative absorbed doses that appear to approach or exceed 1 Gy (for procedures that may be repeated) or 3 Gy (for any procedure) should be recorded in the patient record, and there should be a patient follow-up procedure for such cases. Patients should be counselled if there is a significant risk of radiation-induced injury, and the patient's personal physician should be informed of the possibility of radiation effects. Training in radiological protection for patients and staff should be an integral part of the education for those using interventional techniques. All interventionists should audit and review the outcomes of their procedures for radiation injury. Risks and benefits, including radiation risks, should be taken into account when new interventional techniques are introduced.A concluding list of recommendations is given. Annexes list procedures, patient and staff doses, a sample local clinical protocol, dose quantities used, and a procurement checklist.

Self-treatment of female external genital warts with 0.5% podophyllotoxin cream (Condyline) vs weekly applications of 20% podophyllin solution

Sixty women with genital warts were randomly allocated to treatment with either weekly application of 20% podophyllin solution or self-treatment with 0.5% podophyllotoxin cream twice daily for three days in weekly intervals. After a maximum of 4 treatment cycles a final assessment was carried out after 3 months. Primary clearance after termination of treatment was 82% for podophyllotoxin and 59% for podophyllin solution. After excluding relapses at the 3-month follow-up, final clearance for podophyllotoxin (71%) was significantly better (P < 0.05) than that for podophyllin solution (48%). The total frequency of warts eradicated was 94% with podophyllotoxin and 74% with podophyllin solution (P < 0.001). Local adverse effects were generally mild or moderate. Podophyllotoxin cream provides a mode of easy application for women with external genital warts and had in this study a significantly better effect than podophyllin solution.

Truth or consequence--Bo Lindell's contribution to radiation protection

Bo Lindell, former chairman and emeritus member of ICRP, former chairman of UNSCEAR, former Director General and emeritus worker of the Swedish RAdiation Protection Institute, is a phenomenon. His profound influence on radiation protection, and indeed on environmental protection and risk research in general, includes a profuse flow of scientific publications on all aspects of protection of man against harmful effects of radiation. In this context, perhaps his most important efforts hitherto are those relating to nuclear power. The concept of dose commitment, invented by Bo Lindell, is used worldwide to regulate emissions of radioactive substances, taking into account not only the often trivial dose to immediate bystanders, but the global effect over long time-frames. In the long run, his continuing personal influence on radiation protection as a branch of science and a kind of role model for other types of environmental protection may attain an even greater importance.

Positive cervical smear with subsequent normal colposcopy and histology--frequency of CIN in a long-term follow-up

From a total of 1466 new cases of cervical smears suggesting cervical intraepithelial neoplasia (CIN) II or worse, all examined with colposcopy and biopsies, 328 cases (22.4%) were initially examined with vaginal and cervical colposcopy, directed biopsies of portio, and endocervical curettage (ECC) with normal results. Patients were followed-up with regular colposcopy and cervical smear for an average of 10.6 years (2-19 years). In 72 cases (22%) a CIN occurred, in general more than 1 year (mean 2.96 years) after entering the study. Possible explanations are discussed and careful monitoring of this group of patients is recommended.

Risk comparisons between limit values for ionizing radiation, PAH, and benzene in Sweden

The background of regulatory limit values for carcinogenic agents in Sweden is discussed and exemplified with the ambient and occupational air pollutants benzene and PAH (especially benzo[a]pyrene, BaP), ionizing radiation, and radon. The estimated cancer risks at different limit values are compared, as is the estimated number of cancer cases annually due to existing pollutant levels. Although the individual lifetime cancer risks are much higher at the occupational limit values for benzene and BaP than what is recommended for the general public, the estimated number of cancer cases annually is lower at existing pollutant levels. The individual cancer risk at the occupational dose limit for ionizing radiation is comparable to the occupational cancer risk with BaP, but higher than the one for benzene. At the dose limit for the general public, the radiation risk would be higher than what is recommended for individual air pollutants. However, doses from man-made radiation are usually much lower than the dose limit due to optimization. Thus, the estimated number of cancer cases annually due to radiation is low and comparable to the estimated number due to the chemical air pollutants discussed. In contrast, the lung cancer risk with radon in dwellings both at limit values and existing levels is high and comparable to occupational limits for the chemical carcinogens and for radiation. The estimated number of cancer cases annually at existing radon concentrations (1100 cases) is much higher than for the other discussed pollutants (0.03-7 cases each) and also higher than the estimated number of lung cancer cases due to total air pollution (approximately 100 cases).

Ectopic eruption of maxillary first permanent molars and association with other tooth and developmental disturbances

The associations between tooth and eruption disturbances in four groups of children selected primarily with only one diagnosed eruption or developmental disturbance in each group was analysed. Ninety-two children were primarily diagnosed with ectopic eruption of maxillary first permanent molars, 93 children with infra-occlusion and ankylosis of primary molars, 91 children with ectopic eruption of maxillary canines, and 97 children with aplasia of premolars. Of the children studied 69-79 per cent had only a single one of the four disturbances studied. In 18-28 per cent there was one additional disturbance and in 2-3 per cent two additional disturbances. From chi square contingency tests, it was found that infra-occlusion of primary molars and aplasia of premolars exhibited a higher prevalence in both directions compared to the expected population prevalence. Ectopic eruption of maxillary canines showed a significantly higher prevalence than expected in all the other three groups. Our interpretation is that these results support the hypothesis of a common, presumably hereditary, aetiology. Thus, the four conditions studied would be different manifestations of one syndrome, each manifestation having an incomplete penetrance. With closer follow-up of the maxillary canines during the eruption period in children with some of the other three disturbances, prophylactic, or early interceptive measures may be taken and complicated orthodontic treatment be reduced or avoided.

[Prevention of venous thromboses and cutaneous necroses using physical methods and pressure therapy in the surgery of chronic venous insufficiency of the lower limbs]

The surgical treatment of chronic venous insufficiency in the lower limbs, whether it is a case of so-called 'essential' varices or of post-phlebitic disorders, presents a certain number of risks of venous thrombosis and especially of cutaneous necrosis or of cicatricial detachment in operations of the Lindon or Felder type. Given a less significant set-back, it has been suggested that restorative surgery of the deep venous network, valve repair or insertion of a valvulated section, should be used in the treatment of post-phlebitic illness. Promising results have been obtained through specific kinesitherapy, involving a Leduc type manual lymph drainage together with pressotherapy, in the preparation of patients and in post-operative follow-up care.