Radionuclide biological half-life values for terrestrial and aquatic wildlife

The equilibrium concentration ratio is typically the parameter used to estimate organism activity concentrations within wildlife dose assessment tools. Whilst this is assumed to be fit for purpose, there are scenarios such as accidental or irregular, fluctuating, releases from licensed facilities when this might not be the case. In such circumstances, the concentration ratio approach may under- or over-estimate radiation exposure depending upon the time since the release. To carrying out assessments for such releases, a dynamic approach is needed. The simplest and most practical option is representing the uptake and turnover processes by first-order kinetics, for which organism- and element-specific biological half-life data are required. In this paper we describe the development of a freely available international database of radionuclide biological half-life values. The database includes 1907 entries for terrestrial, freshwater, riparian and marine organisms. Biological half-life values are reported for 52 elements across a range of wildlife groups (marine = 9, freshwater = 10, terrestrial = 7 and riparian = 3 groups). Potential applications and limitations of the database are discussed.

Suicide by gases in England and Wales 2001-2011: evidence of the emergence of new methods of suicide

BACKGROUND

Increases in suicide deaths by gassing, particularly carbon monoxide poisoning from burning barbecue charcoal, have occurred in many parts of East Asia and resulted in rises in overall suicide rates in some countries. Recent trends in gas poisoning suicides outside Asia have received little attention.

METHODS

We analysed suicides by gassing in England and Wales (2001-2011) using national suicide mortality data enhanced by free text searching of information sent by coroners to the Office for National Statistics (ONS). We conducted specific searches for suicides involving barbecue charcoal gas, helium, and hydrogen sulphide. We analysed coroners' records of eight people who used helium as a method of suicide, identified from systematic searches of the records of four coroners.

RESULTS

Gassing accounted for 5.2% of suicide deaths in England and Wales during 2001-2011. The number of gas suicides declined from 368 in 2001 to 174 by 2011 (a 53% reduction). The fall was due to a decline in deaths involving car exhaust and other sources of carbon monoxide. There was a rapid rise in deaths due to helium inhalation over the period, from five deaths in the two year period 2001-2002 to 89 in 2010-2011 (a 17-fold increase). There were small rises in deaths involving hydrogen sulphide (0 cases in 2001-2002 versus 14 cases in 2010-2011) and barbecue charcoal gas (1 case in 2001-2002 versus 11 cases in 2010-2011). Compared to individuals using other methods, those suicides adopting new types of gas for suicide were generally younger and from more affluent socioeconomic groups. The corones' records of four of the eight individuals dying by helium inhalation whose records were reviewed showed evidence of Internet involvement in their choice of method.

LIMITATIONS

We were not able to identify the source of carbon monoxide (car exhaust or barbecue charcoal) for over 50% of cases.

CONCLUSION

Increases in helium inhalation as a method of suicide have partially offset recent decreases in suicide by the use of car exhaust. Public health measures are urgently needed to prevent a potential epidemic rise in the use of helium similar to the recent rises in charcoal burning suicides in East Asia.

Transfer parameters for ICRP reference animals and plants collected from a forest ecosystem

The International Commission on Radiological Protection (ICRP) have suggested the identification of a series of terrestrial, marine and freshwater sites from which samples of each Reference animal and plant (RAP) could be systematically collected and analysed. We describe the first such study in which six of the eight terrestrial RAPs, and associated soil samples, were collected from a site located in a managed coniferous forestry plantation in north-west England. Adult life stages of species representing six of the terrestrial RAPs (Wild grass, Pine tree, Deer, Rat, Earthworm and Bee) were sampled and analysed to determine concentrations of 60 elements and gamma-emitting radionuclides. The resultant data have been used to derive concentration ratios (CR(wo-soil)) relating element/radionuclide concentrations in the RAPs to those in soil. This paper presents the first-reported transfer parameters for a number of the RAP-element combinations. Where possible, the derived CR(wo-soil) values are compared with the ICRPs-recommended values and any appreciable differences discussed.

Abstract P2-01-06: How much agreement can we expect on BI-RADS mammographic findings? Observer agreement among 10 expert mammographers

Purpose: To determine the agreement between expert readers on mammographic findings and calcification patterns.

Materials and Methods: Ten academic radiologists from 5 centers reviewed 250 de-identified mammographic cases without prior exams which were previously assessed as BI-RADS 4 or 5 with subsequent pathologic diagnosis by percutaneous or surgical biopsy. For benign cases diagnosed by percutaneous biopsy, 1 year of benign or negative imaging follow-up was required. Using standardized forms, each radiologist assessed the presence of any suspicious mammographic findings (microcalcifications, asymmetry (1-vew), focal asymmetry (2-view), architectural distortion), and the morphology (none, round/punctate, amorphous, coarse heterogeneous, fine pleomorphic, fine linear branching) and distribution (none, diffuse, regional, grouped, linear, segmental) of any identified microcalcifications. Agreement between radiologists for presence/absence of findings, morphology, and distribution of calcifications was determined by calculating the Kappa (k) coefficient with 95% confidence interval (95% CI). The kappa coefficient proposed strength of agreement is ≤0 = poor, .01-.20 = slight, .21-.40 = fair, .41-.60 = moderate, .61-.80 = substantial, and .81-1 = almost perfect, as established by Landis and Koch.1

Results: Of the 250 lesions, 156 (62%) were benign and 94 (38%) malignant. Agreement among the 10 expert readers was strongest for recognizing the presence/absence of calcifications (k = 0.82, 95% CI: 0.80-84), “almost perfect”). There was substantial agreement among the readers for the identification of a mass (k = 0.67, 95% CI: 0.66-69), whereas agreement was fair for the presence of a focal (2-view) asymmetry (k = 0.21, 95% CI: 0.1900.23) or architectural distortion (k = 0.28, 95%CI: 0.26-0.30). Agreement for asymmetries (1-view) was slight (k = 0.09, 95%CI: 0.08-0.11). Among the 6 categories of microcalcification distribution and morphology, reader agreement was moderate (distribution k = 0.60, 95%CI:0.59-0.61; morphology k = 0.51, 95%CI: 0.50-0.52).

Conclusion: When asked to characterize suspicious mammographic findings, this sampling of 10 expert academic breast imagers across 5 centers revealed varying strength of agreement for different findings, ranging from slight to almost perfect. Strongest agreement (“almost perfect”) was found for identifying the presence or absence of microcalcifications, although agreement drops to moderate when readers are asked to specify microcalcification morphology and distribution.

1 Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics.1977;33:159-174.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-01-06.

Exploring methods to prioritise concentration ratios when estimating weighted absorbed dose rates to terrestrial Reference Animals and Plants

The ICRP and IAEA have recently reported Concentration Ratio values (CRwo-media--equilibrium radionuclide activity concentration in whole organism divided by that in media) for Reference Animals and Plants (RAPs) and a wide range of organism groups, respectively, based on a common online database. Given the large number of data gaps in both publications, there is a need to develop methods for identifying the relative importance of improving currently available CR(wo-media) values. A simple, transparent approach involving the derivation and comparison of predicted internal and external weighted absorbed dose rates for radionuclides considered by ICRP (2009) for terrestrial RAPs is presented. Using the approach of applying a reference value of CR(wo-soil) = 1 or using the maximum reported values where CR(wo-soil) >1, we provisionally identify terrestrial radionuclide RAP combinations which could be considered low priority, notably: Ca, Cr and Ni consistently; Mn for all RAPs except Deer and Pine Tree; and Tc for all RAPs but Wild Grass. Equally, we can systematically identify high priority elements and radioisotopes, which largely, but not exclusively, consist of alpha-emitters (especially isotopes of Ra and Th, but also consistently Am, Cf, Cm, Np, Pa, Po, Pu, U). The analysis highlights the importance of the radiation weighting factor default assumption of 10 for alpha-emitters in the ERICA Tool when comparing the magnitude of the internal dose and trying to identify high priority RAP-isotope combinations. If the unweighted Dose Conversion Coefficient (DCC) values are considered, those for alpha-emitters are often one order of magnitude higher than those due to some beta-gamma emitters for terrestrial RAPs, whereas with the radiation weighting factor applied they are two orders of magnitude higher.

Time trends in coroners' use of different verdicts for possible suicides and their impact on officially reported incidence of suicide in England: 1990-2005

BACKGROUND

Official suicide statistics for England are based on deaths given suicide verdicts and most cases given an open verdict following a coroner's inquest. Previous research indicates that some deaths given accidental verdicts are considered to be suicides by clinicians. Changes in coroners' use of different verdicts may bias suicide trend estimates. We investigated whether suicide trends may be over- or underestimated when they are based on deaths given suicide and open verdicts. Method Possible suicides assessed by 12 English coroners in 1990/91, 1998 and 2005 and assigned open, accident/misadventure or narrative verdicts were rated by three experienced suicide researchers according to the likelihood that they were suicides. Details of all suicide verdicts given by these coroners were also recorded.

RESULTS

In 1990/91, 72.0% of researcher-defined suicides received a suicide verdict from the coroner, this decreased to 65.4% in 2005 (p trend < 0.01); equivalent figures for combined suicide and open verdicts were 95.4% (1990/91) and 86.7% (2005). Researcher-defined suicides with a verdict of accident/misadventure doubled over that period, from 4.6% to 9.1% (p < 0.01). Narrative verdict cases rose from zero in 1990/91 to 25 in 2005 (4.2% of researcher-defined suicides that year). In 1998 and 2005, 50.0% of the medicine poisoning deaths given accidental/misadventure verdicts were rated as suicide by the researchers.

CONCLUSIONS

Between 1990/91 and 2005, the proportion of researcher-defined suicides given a suicide verdict by coroners decreased, largely due to an increased use of accident/misadventure verdicts, particularly for deaths involving poisoning. Consideration should be given to the inclusion of 'accidental' deaths by poisoning with medicines in the statistics available for monitoring suicides rates.

The IAEA handbook on radionuclide transfer to wildlife

An IAEA handbook presenting transfer parameter values for wildlife has recently been produced. Concentration ratios (CRwo-media) between the whole organism (fresh weight) and either soil (dry weight) or water were collated for a range of wildlife groups (classified taxonomically and by feeding strategy) in terrestrial, freshwater, marine and brackish generic ecosystems. The data have been compiled in an on line database, which will continue to be updated in the future providing the basis for subsequent revision of the Wildlife TRS values. An overview of the compilation and analysis, and discussion of the extent and limitations of the data is presented. Example comparisons of the CRwo-media values are given for polonium across all wildlife groups and ecosystems and for molluscs for all radionuclides. The CRwo-media values have also been compared with those currently used in the ERICA Tool which represented the most complete published database for wildlife transfer values prior to this work. The use of CRwo-media values is a pragmatic approach to predicting radionuclide activity concentrations in wildlife and is similar to that used for screening assessments for the human food chain. The CRwo-media values are most suitable for a screening application where there are several conservative assumptions built into the models which will, to varying extents, compensate for the variable data quality and quantity, and associated uncertainty.

Abstract P4-01-13: Practice patterns of MRI utilization for breast cancer treatment within the University of California system as part of the Athena initiative

Background: The appropriate utilization of Breast MRI in breast cancer care remains controversial. As part of a quality improvement initiative for breast cancer screening and treatment, we sent out a survey to physicians who treat breast cancer patients. All respondents are participants in the ATHENA initiative, a program which unites physicians, researchers, and patients at the five University of California medical centers.

Objective: To use the ATHENA infrastructure to perform a qualitative analysis of variations in breast cancer care.

Methods: Surveys were sent to 50 physicians in the ATHENA network whose practices are focused on breast cancer. Respondents were presented with clinical scenarios, and asked whether they would recommend MRI always/usually or sometimes/never. Differences were compared by Chi square.

Results: 39 physicians completed the survey (78% response rate). Of these physicians 29% were surgeons, 26% radiation oncologists and 45% medical oncologists. Athena physicians were more likely to order MRI for high risk screening of mutation carriers than not (85% yes vs. 15% no, p &lt; 0.003) but not based on breast density alone or previous history of breast cancer. They were also more likely to order it for monitoring neo-adjuvant chemotherapy (70% yes vs. 30% no, p &lt; 0.03). Although the majority answered that they would order a Breast MRI for new breast cancer the difference between responses was not significantly different (56% yes vs. 44%, p = 0.07).

Conclusion: Athena physicians follow established published guidelines which demonstrate a benefit for Breast MRI screening for BRCA mutation carriers but not based on density or previous history of breast cancer. The Athena network allows a forum for new practice guidelines to be implemented as data becomes available to improve patient outcomes and utilize the best evidence for patient care, where both the patterns of MRI use as well as the outcomes of practice patterns will be evaluated prospectively.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P4-01-13.

Observations of Fukushima fallout in Great Britain

Following the Fukushima accident in March 2011, grass samples were collected from 42 sites around Great Britain during April 2011. Iodine-131 was measurable in grass samples across the country with activity concentrations ranging from 10 to 55 Bq kg(-1) dry matter. Concentrations were similar to those reported in other European countries. Rainwater and some foodstuffs were also analysed from a limited number of sites. Of these, (131)I was only detectable in sheep's milk (c. 2 Bq kg(-1)). Caesium-134, which can be attributed to releases from the Fukushima reactors, was detectable in six of the grass samples (4-8 Bq kg(-1) dry matter); (137)Cs was detected in a larger number of grass samples although previous release sources (atmospheric weapons test and the 1986 Chernobyl and 1957 Windscale accidents) are likely to have contributed to this.

Epidemiology of smear-negative pulmonary tuberculosis in the United States, 1993-2008

BACKGROUND

Smear-negative tuberculosis (TB) is difficult to diagnose and has been associated with poor treatment outcomes and excessive mortality, particularly in high human immunodeficiency virus (HIV) prevalent settings. However, few studies have used mycobacterial culture to rigorously confirm all smear-negative TB cases in a population-based cohort.

DESIGN

We included all culture-confirmed, pulmonary TB cases reported to the US National TB Surveillance System from 1993 to 2008. We analyzed smear-negative TB risk factors and survival, as compared to smear-positive TB. We calculated prevalence ratios (PRs) and adjusted for confounders (aPR).

RESULTS

From 1993 to 2008, 159,121 cases of culture-confirmed pulmonary TB were reported in the United States, of which 58,786 (37%) were sputum smear-negative. Smear-negative TB cases were more likely to be foreign-born (aPR 1.10, 95%CI 1.08-1.12), incarcerated (aPR 1.52, 95%CI 1.48-1.56) or HIV-infected (aPR 1.27, 95%CI 1.24-1.30). Hispanics and non-Hispanic Blacks were less likely to have smear-negative TB (respectively aPR 0.87, 95%CI 0.85-0.89 and aPR 0.90, 95%CI 0.89-0.92). Smear-negative TB cases had lower mortality (aRR 0.78, 95%CI 0.74-0.81), independent of HIV status.

CONCLUSION

Smear-negative TB represents a large proportion of TB cases in the United States, and occurs more often among persons in groups more likely to undergo TB screening. The lower mortality may indicate earlier TB detection, and underscores the need for continued vigilance in screening of high-risk persons.

Cyclic nucleotide phosphodiesterase assay technology

Because of their critical role in modulating cellular cyclic nucleotide levels, phosphodiesterases (PDEs) are involved in many disease-related signaling pathways. The PDE family is large and diverse, with members having different tissue distribution, sub-cellular localizations, and substrate specificities. Because of these characteristics, the PDEs represent a broad group of potential drug targets. Described in the present unit are the assay development and validation procedures needed to establish a high-throughput screening system for these important enzymes. The assays provide a structured approach for determining the kinetic parameters of related enzyme families to facilitate the characterization of PDE inhibitors.

Experts and performance in histopathology--a study in breast pathology

This study was undertaken to determine if it was possible to identify expertise within Histopathologists (trainees, district general pathologists and pathologists with a special interest in breast disease) using an objective measure of performance. The method of assessment of performance is based on the CWS (Cochran-Weiss-Shanteau) ratio formed by the individual's ability to discriminate between a spectrum of disease categories and their level of inconsistency when assessed at intervals. The slides circulated represented the spectrum of breast disease seen in routine practice. The results demonstrated the average CWS ratio to be lowest in trainees and highest in pathologists with a special interest in breast pathology although there was no statistical difference in the CWS scores obtained between the district general pathologists and pathologists with a special interest. Differences in inconsistency rather than discriminatory ability mainly accounted for the difference in the CWS ratio observed between the groups studied. The study shows that the CWS ratio is potentially a very useful tool in the assessment of pathologists with regard to assessing their progress through training.

Takotsubo cardiomyopathy during emergence from general anaesthesia

Takotsubo cardiomyopathy, or stress-induced cardiomyopathy, is a clinical syndrome mimicking acute myocardial infarction. We report a case of a 55-year-old man who developed Takotsubo cardiomyopathy during emergence from general anaesthesia for an elective procedure to remove a spinal cord stimulator The perioperative state is known to induce stress, but there are few cases describing the onset of Takotsubo syndrome during this period. The case presented demonstrates that Takotsubo cardiomyopathy may occur on emergence from anaesthesia and that the pattern of left ventricular dysfunction produced may not be typical.

Factors associated with positive tuberculin skin test results among HIV-infected persons in Orel Oblast, Russia

BACKGROUND

The treatment of persons living with human immunodeficiency virus/acquired immune-deficiency syndrome (PLWHAs) for latent tuberculosis infection (LTBI) reduces tuberculosis (TB) morbidity. Despite a high TB burden and an expanding human immunodeficiency virus epidemic, Russia had limited data on the utility of the tuberculin skin test (TST) for LTBI diagnosis in PLWHAs.

OBJECTIVE

To determine the prevalence and predictors of positive TSTs in PLWHAs in Orel Oblast.

METHODS

A total of 150 consenting PLWHAs being followed up at the AIDS Center were administered a TST and a questionnaire for risk factors for LTBI. A positive TST result was defined as >or=5 mm induration.

RESULTS

Of the 150 subjects, 67% were male and 74% were aged <30 years. Of the PLWHAs tested, 26% had a positive TST result, while among PLWHAs with CD4(+) >500 cells/ml, 36% were TST-positive. TST positivity varied inversely with CD4(+) cell count. Among PLWHAs with a history of injection drug use, the primary risk factor for HIV, 29 (31.9%) were positive.

CONCLUSIONS

A high proportion of tested PLWHAs had a positive TST and could benefit from preventive therapy (PT) to reduce the risk of TB. A TB control programme in Russia should therefore include TST screening among PLWHAs and PT, besides active TB case finding and treatment.