Keeping the ICRP recommendations fit for purpose.

The International Commission on Radiological Protection (ICRP) has embarked on a review and revision of the system of Radiological Protection that will update the 2007 general recommendations in ICRPPublication 103. This is the beginning of a process that will take several years, involving open and transparent engagement with organisations and individuals around the world. While the system is robust and has performed well, it must adapt to address changes in science and society to remain fit for purpose. The aim of this paper is to encourage discussions on which areas of the system might gain the greatest benefit from review, and to initiate collaborative efforts. Increased clarity and consistency are high priorities. The better the system is understood, the more effectively it can be applied, resulting in improved protection and increased harmonisation. Many areas are identified for potential review including: classification of effects, with particular focus on tissue reactions; reformulation of detriment, potentially including non-cancer diseases; re-evaluation of the relationship between detriment and effective dose, and the possibility of defining detriments for males and females of different ages; individual variation in the response to radiation exposure; heritable effects; and effects and risks in non-human biota and ecosystems. Some of the basic concepts are also being considered, including the framework for bringing together protection of people and the environment, incremental improvements to the fundamental principles of justification and optimisation, a broader approach to protection of individuals, and clarification of the exposure situations introduced in 2007. In addition, ICRP is considering identifying where explicit incorporation of the ethical basis of the system would be beneficial, how to better reflect the importance of communications and stakeholder involvement, and further advice on education and training. ICRP invites responses on these and other areas relating to the review of the System of Radiological Protection.

Endovascular aneurysm repair (EVAR) follow-up imaging: the assessment and treatment of common postoperative complications.

Endovascular abdominal aortic aneurysm repair (EVAR) is a well-established procedure, which has long-term mortality rates similar to that of open repair. It has the additional benefit of being less invasive, making it the favoured method of treating abdominal aortic aneurysms in elderly and high-risk patients with multiple co-morbidities. The main disadvantage of EVAR is the higher rate of re-intervention, due to device-related complications, including endoleaks, limb occlusion, stent migration, kinking, and infection. As a result lifelong surveillance is required. In order to avoid missing these complications, intricate knowledge of stent graft design, good-quality diagnostic ultrasound skills, multiplanar reformatting of CT images, and reproducible investigations are important. Most of these complications can be treated via an endovascular approach using cuff extensions, uncovered stents, coils, and liquid embolic agents. Open surgery is reserved for complex complications, where an endovascular approach is not feasible.

Standards for clinical trials for treating TB.

BACKGROUND: The value, speed of completion and robustness of the evidence generated by TB treatment trials could be improved by implementing standards for best practice.METHODS: A global panel of experts participated in a Delphi process, using a 7-point Likert scale to score and revise draft standards until consensus was reached.RESULTS: Eleven standards were defined: Standard 1, high quality data on TB regimens are essential to inform clinical and programmatic management; Standard 2, the research questions addressed by TB trials should be relevant to affected communities, who should be included in all trial stages; Standard 3, trials should make every effort to be as inclusive as possible; Standard 4, the most efficient trial designs should be considered to improve the evidence base as quickly and cost effectively as possible, without compromising quality; Standard 5, trial governance should be in line with accepted good clinical practice; Standard 6, trials should investigate and report strategies that promote optimal engagement in care; Standard 7, where possible, TB trials should include pharmacokinetic and pharmacodynamic components; Standard 8, outcomes should include frequency of disease recurrence and post-treatment sequelae; Standard 9, TB trials should aim to harmonise key outcomes and data structures across studies; Standard 10, TB trials should include biobanking; Standard 11, treatment trials should invest in capacity strengthening of local trial and TB programme staff.CONCLUSION: These standards should improve the efficiency and effectiveness of evidence generation, as well as the translation of research into policy and practice.

Cuban healthcare providers in Venezuela: a case study.

Approximately 31,000 Cuban healthcare providers reside in Venezuela as part of an initiative to increase Venezuelans' access to health care. The concept began in 1999 as part of the new constitution, and has grown steadily to include 6000 clinics, health promotion and prevention programmes, an integrated healthcare system, and a vision to train and deploy community public health physicians selected from and trained within the neighbourhood. In the case study described herein, physician-patient consultations increased from 3.5 million to 17 million, and the numbers of primary care physicians, nurses and dentists increased dramatically. Furthermore, in Caracas, there has been a 30% reduction in the use of emergency rooms at public hospitals. Estimates are provided for preventive services and potential lives saved. As health care is a politically-laden issue in many countries, all approaches to reducing healthcare disparities are worth analysing for their potential contributions to population health improvement.

The identification of sulfide oxidation as a potential metabolism driving primary production on late Noachian Mars.

The transition of the martian climate from the wet Noachian era to the dry Hesperian (4.1-3.0 Gya) likely resulted in saline surface waters that were rich in sulfur species. Terrestrial analogue environments that possess a similar chemistry to these proposed waters can be used to develop an understanding of the diversity of microorganisms that could have persisted on Mars under such conditions. Here, we report on the chemistry and microbial community of the highly reducing sediment of Colour Peak springs, a sulfidic and saline spring system located within the Canadian High Arctic. DNA and cDNA 16S rRNA gene profiling demonstrated that the microbial community was dominated by sulfur oxidising bacteria, suggesting that primary production in the sediment was driven by chemolithoautotrophic sulfur oxidation. It is possible that the sulfur oxidising bacteria also supported the persistence of the additional taxa. Gibbs energy values calculated for the brines, based on the chemistry of Gale crater, suggested that the oxidation of reduced sulfur species was an energetically viable metabolism for life on early Mars.

An emergency EVAR service reduces mortality in ruptured abdominal aortic aneurysms.

OBJECTIVES: The aim of this study was to compare all in-hospital mortality for ruptured abdominal aortic aneurysms (rAAAs) before and after the establishment of an emergency EVAR (eEVAR) service. DESIGN AND METHODS: An eEVAR service was established in January 2006, since when all patients presenting with rAAAs have been considered for endovascular repair. Data for all rAAAs presenting between January 2006 and December 2007 was prospectively collected (Group 1). This patient group was compared to those presenting with rAAA between January 2003 and December 2005 when eEVAR was not offered at our institution (Group 2). These records had also been collected prospectively and submitted to the National Vascular Database (NVD). RESULTS: A total of 50 rAAAs (17 eEVAR, 29 open repairs, 4 palliated) presented after the introduction of eEVAR (Group 1) and 71 in the historical Group 2 of which 54 underwent open repair and 17 were palliated. The total in-hospital mortality was significantly lower in Group 1 20% (eEVAR (n=1), 6%: Open (n=5), 17%: palliated (n=4), 100%) when compared to Group 2 54% (Open (n=21), 39%: palliated (n=17), 100%) (p=0.000001). Furthermore similar significant differences were seen in 30-day operative mortalities between the two groups 13% in Group 1 versus 39% in Group 2 (p=0.0003). In addition the proportion of patients who were palliated has significantly decreased (8% Group 1 versus 24% Group 2, p=0.01). CONCLUSIONS: The establishment of an eEVAR service has significantly reduced in-hospital mortality for patients presenting with ruptured abdominal aortic aneurysms.

Radiation exposure during endovascular aneurysm repair.

BACKGROUND: Endovascular stent-grafting is an established option for the repair of abdominal aortic aneurysm (AAA) that can involve prolonged manipulation under radiological control. The aim was to determine the average radiation exposure sustained during endovascular aneurysm repair (EVAR) and the first year of postoperative surveillance. METHODS: Prospective radiation dose data were recorded and used to calculate dose area product (DAP) values for 96 patients undergoing EVAR. The DAP data were then used to determine the entrance skin dose (ESD), an indicator of potential skin damage, and the effective dose, an indicator of long-term cancer risk, for each patient. RESULTS: The median ESD during EVAR was 0.85 (interquartile range 0.51-3.74) Gy. The threshold for possible radiation-induced skin damage of 2 Gy was exceeded in 29 per cent of procedures. The effective dose of radiation in the first year following EVAR was 79 mSv. CONCLUSION: Radiation doses administered during EVAR were higher than previously thought, with a potential risk of radiation-induced skin damage and later malignancy.

Internal iliac artery branch graft for common iliac artery aneurysm following previous open abdominal aortic aneurysm repair.

To demonstrate the use of a commercially available branch stent graft system, designed to preserve the internal iliac artery (IIA) in common iliac artery (CIA) aneurysms (CIAA) in two patients, who had undergone previous abdominal aortic aneurysm (AAA) surgery.

Imaging appearances and endovascular management of uncommon pseudoaneurysms.

Pseudoaneurysms are uncommon and their aetiology is varied. They occur in numerous anatomical locations and present with a multitude of clinical presentations sometimes life-threatening. This review describes the causes, sites, and presentations of uncommon pseudoaneurysms, as well as illustrating their diagnostic appearances and endovascular management.

The International Atomic Energy Agency action plan on radiation protection of patients and staff in interventional procedures: Achieving change in practice.

INTRODUCTION: The International Atomic Energy Agency (IAEA) organized the 3rd international conference on radiation protection (RP) of patients in December 2017. This paper presents the conclusions on the interventional procedures (IP) session. MATERIAL AND METHODS: The IAEA conference was conducted as a series of plenary sessions followed by various thematic sessions. "Radiation protection of patients and staff in interventional procedures" session keynote speakers presented information on: 1) Risk management of skin injuries, 2) Occupational radiation risks and 3) RP for paediatric patients. Then, a summary of the session-related papers was presented by a rapporteur, followed by an open question-and-answer discussion. RESULTS: Sixty-seven percent (67%) of papers came from Europe. Forty-four percent (44%) were patient studies, 44% were occupational and 12% were combined studies. Occupational studies were mostly on eye lens dosimetry. The rest were on scattered radiation measurements and dose tracking. The majority of patient studies related to patient exposure with only one study on paediatric patients. Automatic patient dose reporting is considered as a first step for dose optimization. Despite efforts, paediatric IP radiation dose data are still scarce. The keynote speakers outlined recent achievements but also challenges in the field. Forecasting technology, task-specific targeted education from educators familiar with the clinical situation, more accurate estimation of lens doses and improved identification of high-risk professional groups are some of the areas they focused on. CONCLUSIONS: Manufacturers play an important role in making patients safer. Low dose technologies are still expensive and manufacturers should make these affordable in less resourced countries. Automatic patient dose reporting and real-time skin dose map are important for dose optimization. Clinical audit and better QA processes together with more studies on the impact of lens opacities in clinical practice and on paediatric patients are needed.

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.

Nailfold capillary morphology in exfoliation syndrome.

PurposeThe purpose of the study was to investigate nailfold microvascular morphology in exfoliation syndrome with or without glaucoma (XFS/XFG) compared with primary open-angle glaucoma (POAG) and control subjects using nailfold capillary videomicroscopy.Patients and methodsWe used a JH-1004 capillaroscope to perform nailfold capillary videomicroscopy on the fourth and fifth digit of the non-dominant hand. We enrolled 56 XFS/XFG patients, 87 POAG patients, and 75 control subjects. Masked observers graded the videos for hemorrhages, avascular zones ≥200 microns (µm), and degree of microvascular tortuosity on a four-point subjective scale. Multivariable odds ratios, 95% confidence intervals and P-for trends for assessing the relation between morphological changes and POAG or XFS/XFG were obtained from logistic regression analyses. We also assessed this relation with XFS/XFG compared with POAG in multivariable models.ResultsAfter adjusting for multiple covariates, nailfold hemorrhages, avascular zones ≥200 µm, and higher degree of vascular tortuosity were more common in XFS/XFG vs controls (P-for trend ≤0.0001) and in POAG vs controls (P-for trend ≤0.01). For each 100 capillaries, the number of hemorrhages was similar (P-for trend=0.91) between XFS/XFG and POAG patients; however, there were more avascular zones per 100 capillaries with borderline significance (P-for trend=0.04) in the XFS/XFG group. XFS/XFG patients had more tortuosity than POAG patients; specifically, having a tortuosity score ≥1.5 was associated with a 4.4-fold increased odds of XFS/XFG (95% confidence interval: 1.5-13.3) relative to a tortuosity score <1.0 (P-for trend=0.005).ConclusionA high degree of nailfold capillary tortuosity is a distinct non-ocular feature associated with XFS/XFG compared with either POAG or controls.

The future of ICRP: towards a centenary and beyond.

The International Commission on Radiological Protection (ICRP) has been in existence for 87 y, since its establishment in 1928. It remains a leading authority in radiological protection, and its role is to provide recommendations and guidance on all aspects of protection against ionising radiation. The published recommendations of ICRP form the basis of radiation safety standards worldwide. Modernisation of the organisation in recent years has led to new initiatives and changes. These have included writing a strategic plan and code of ethics for the first time. Elections for committee membership have been through open nominations, a process which will shortly be repeated for the membership in the next term, commencing on 1 July 2017. Biennial symposia started in 2011, and the success of the first two symposia has secured this venture as a regular part of the ICRP calendar. ICRP has also revised its method of working with other organisations by establishing 'special liaison organisation' status. This has improved collaboration with the ever-expanding number of organisations working in radiological protection, with whom it is important that ICRP has essential links. ICRP is also looking to review its legal basis and governing documents in the future, in order to ensure that best practices are being followed as ICRP evolves. In addition, the strategic plan will be reviewed and updated regularly. Other ways of working with organisations will be considered to further strengthen engagement with the wider radiological protection community. ICRP aims to make its publications available at low or no cost, and to produce both a plain language overview of the system of radiological protection and a summary of the recommendations. These activities will require additional financial resources, and ICRP has embarked on a fundraising campaign to support such efforts. ICRP can be proud of its history of maintaining its independence and preserving the wide respect earned over many years. Despite long traditions, ICRP has evolved and will continue to do so to perform as a more modern organisation as it heads towards a centenary and beyond.

The stabilizing influence of divalent ions and Na+ on the di-decameric structure of Yoldia limatula hemocyanin.

The stabilizing influence of Ca2+, Mg2+, Ba2+ and Na+ on the di-decameric structure of the hemocyanin of the bivalve, Yoldia limatula has been investigated by light-scattering molecular weight measurements and by analytical ultracentrifugation. The molecular weight (Mw) data, examined as a function of decreasing divalent ion and sodium ion concentrations at pH 8.0 and at a constant hemocyanin concentration of 0.10 g.l-1, show biphasic transition profiles, with a sharp initial decline in Mw as the concentration of the stabilizing cations is reduced. The analysis of the molecular weight data is best described in terms of the four-species, di-decamer-decamer-dimer-monomer scheme of association-dissociation equilibria. About 25 to 35 bound divalent ions and about 10 bound Na+ ions per half-molecule or decamer are required in order to account for the initial step of the observed transitions. The subsequent transitions representing the decamer to dimer and the dimer to monomer steps of the reaction account for the additional binding of three to four and two to four cations per dimer and per monomer, respectively. The relatively large number of divalent ions per decamer suggests strong ionic stabilization of the decamer to decamer contacts within the parent di-decameric assembly of Yoldia hemocyanin. This is consistent with earlier observations showing relatively few hydrophobic groups at the decamer to decamer contact areas.

ICRP: past, present, and future.

The International Commission on Radiological Protection (ICRP) is a premier international organisation for the protection of workers, patients, and the public against ionising radiation. It was established in 1928 to advance, for the public benefit, the science of radiological protection, with its work in the early years focusing mainly on occupational exposure in medicine. The name 'International Commission on Radiological Protection' was adopted in 1950 to reflect the wider and more diverse areas of work that were being undertaken. ICRP has published 13 sets of general recommendations and these form the basis of radiation safety standards worldwide. ICRP consists of the Main Commission and five standing committees. There are 84 official members of the Main Commission and Committees 1-5, but more than 200 members who work with ICRP through its task groups. ICRP has developed a strategic plan for 2011-2017 and has made progress with some of its initiatives. These include establishing close liaison with other radiological protection organisations, responding to the needs and concerns of the radiological protection community, and identifying areas of work that require scrutiny of science and practice to produce relevant recommendations. This strategy means that ICRP will continue to be a leader in radiological protection for many years to come.

Indirect measurement of infarct size. Correlative variability of enzyme, radionuclear angiographic, and body-surface-map variables in 34 patients during the acute phase of first myocardial infarction.

To gain a correlative perspective of indirect indications of the size of a myocardial infarct, we measured several body-surface electrocardiographic variables and several enzyme and radionuclear angiographic indicators of an infarct's size in 34 patients during the acute phase of first infarction. We found that bivariate correlations ranged widely, from an r value of 0.05 to an r value of 0.92, but were significantly (p less than 0.001) higher when variables from the same technique were correlated (mean r, 0.60 +/- 0.27), as opposed to correlations of variables from different techniques (mean r, 0.27 +/- 0.18). Trivariate comparisons among techniques produced significantly (p less than 0.001) higher r values, but the highest, an r value of 0.76 (total wall motion abnormality score; peak lactic dehydrogenase level; ST-segment integral maximum), indicated that even in this best case, only about 60 percent of the variation of one variable was dependent on or due to the two other variables. These data demonstrate that multiple indirect quantitative indicators of myocardial injury can vary widely in their correlations within the same population of infarcts, and much remains unknown in their relationships during the acute phase. Caution should be exercised, therefore, in their clinical application to predict an infarct's size in individual patients with acute myocardial infarction.

The clotting issue: etiologic factors in thromboembolism. II. Clinical considerations.

RATIONALE AND OBJECTIVES: The authors analyze the origins of the "clotting issue," the controversy that began in the 1980s when contrast media, once perceived as good flushing agents for catheters because of their assumed anticoagulant properties, came under attack for allegedly causing thromboembolism. Laboratory studies as well as a number of clinical reports seemed to substantiate this charge. Nonionic agents in particular were accused by some clinicians of being more likely to cause clots to form in syringes contaminated with blood than were ionic agents. The authors wanted to determine whether some lapse in operator technique rather than a fault in the contrast agent might be to blame. The theory that the syringe and catheter materials, and not the contrast agent itself, could be the source of thromboembolic problems in angiography also is examined. METHODS: The authors reviewed studies and reports on both sides of the issue and conducted laboratory and clinical studies of their own. For the syringe materials analysis, they used a fibrinopeptide A (FpA) enzyme-linked immunosorbent assay (ELISA) test to monitor levels as a marker of activation of coagulation. They tested catheter materials using the same technique. RESULTS: Clots were found only in nonionic agents, but under nonclinically relevant circumstances. If the anticoagulant effect of the nonionic contrast agent was maximized by mixing rather than layering blood and agent, clots did not form. In their materials analysis, the authors demonstrated that glass syringes are thrombogenic, causing vigorous contact activation, and that plastic is less so. Polyurethane catheters are more thrombogenic, polyethylene less so. One survey conducted in the 1970s on the clinical incidence of thromboembolism in coronary angiography suggested that the single most important factor in the etiology is poor angiographic technique. The authors' studies supported their thesis. CONCLUSIONS: In terms of the findings from laboratory studies, misinterpretation of data by nonclinicians is one problem. No evidence suggests that nonionic contrast agents are in any way prothrombotic or thrombogenic. On the contrary, in line with their greater inertness, nonionic agents have weaker effects. Ionic contrast media may cause more endothelial injury and associated localized platelet deposition than nonionic contrast media, and more anticoagulant contrast agents are more toxic. If anticoagulation is required, therefore, it should be achieved by such procedures as carefully controlled systemic heparinization rather than by resorting to more toxic materials. The activation of coagulation is caused by endothelial injury and by prolonged contact between blood and foreign surfaces such as syringes or catheters, but is inhibited by the contrast agent. Because a thrombus may form inside the catheter, whatever contrast agent is used, flushing is important. The authors agree with the findings of one study that the incidence of thromboembolism in coronary angiography, and probably in other catheter procedures, is markedly operator dependent. The materials of the syringes and catheters used, as well as the state of the patient's intrinsic clotting, are more important factors than the contrast agent. The authors conclude that materials other than the contrast agents are the cause of thromboembolic problems; and that, being anticoagulant, contrast agents are entirely helpful, if variably so, in angiographic procedures.

Ultrasound enhanced detection of individual meningococcal serogroups by latex immunoassay.

AIMS: To examine A, C, Y, and W135 Neisseria meningitidis serogroup characterisation by ultrasonic standing wave enhanced latex agglutination tests (USELATs) of clinical samples. In addition, to determine USELAT enhancement of detection sensitivity for the individual antigens compared with conventional card latex agglutination tests (LATs). METHODS: Wellcogen (Abbott Murex), Slidex meningite kit 5 (bioMerieux), and Pastorex (Sanofi) kits and beads coated in house with antibodies to Y and to W135 alone were tested. Positive control antigens consisted of A and C polysaccharide preparations and the Pastorex Y/W135 kit sample. The limiting concentrations of antigen detection were determined by USELAT and by LAT. Thirty five clinical samples (plasma), previously characterised by the polymerase chain reaction (PCR) and culture, were tested by USELAT and, when sample volume allowed, by LAT. RESULTS: USELAT enhancement of control antigen detection ranged from 16 to 128 fold for the different latex systems. Enhancements for the different control antigens were comparable between kits. USELAT tests of clinical (A/C/Y/W135) samples (n = 15) with the Wellcogen (A/C/Y/W135) and Slidex meningite (A/C/Y/W135) kits showed comparable specificities. A set (n = 22) of Y and W135 samples gave 18, 19, and 17 positive results for Wellcogen (A/C/Y/W135), Pastorex (A/C/Y/W135), and in house beads (Y/W135), respectively. Positive USELAT PCR and culture results were concordant. A typical sensitivity for the commercial kits was 80% (Wellcogen). CONCLUSIONS: USELAT identified serogroups for 80% of samples, whereas LATs identified only 40%. The USELAT detection of the A, C, Y, and W135 antigen serogroups showed comparable enhancement for the kits tested. The commercial availability of latex beads coated with antibody to the Y and W135 serogroups would expedite their identification.

Assessment of the value of the immediate postoperative chest radiograph after cardiac operation.

The value of the immediate postoperative chest radiograph upon a patient's return to the intensive care unit after a cardiac surgical procedure is uncertain. This study represents a prospective analysis of the immediate postoperative radiograph in 100 consecutive adult patients undergoing cardiac operations. In 11 patients it was found that the routine postoperative radiograph was of value when it was necessary either to clarify or confirm clinical findings or to check the position of an intraaortic balloon catheter. For those chest radiographs that were deemed unnecessary, only one of 89 were found to be of clinical value. Furthermore, in those situations in which an emergency radiograph was obtained, the routine radiograph was not found to be contributory to patient management. We conclude that the policy of obtaining routine, immediate postoperative chest radiographs in the absence of a specific clinical indication provides virtually no additional clinical yield. Residents should therefore request radiographs only to check the position of an intraaortic balloon catheter, and to clarify or confirm a clinical diagnosis.