Time and dose dependency of bone-sarcomas in patients injected with radium-224

The time course and dose dependency of the incidence of bone-sarcomas among 900 German patients treated with high doses of radium-224 is analysed in terms of a proportional hazards model with a log-normal dependency of time to tumor and a linear-quadratic dose relation. The deduced dose dependency agrees well with a previous analysis in terms of a non-parametric proportional hazards model, and confirms the temporal distribution which has been used in the Radioepidemiological Tables of NIH. However, the linear-quadratic dose-response model gives a risk estimate for low doses which is somewhat less than half that obtained under the assumption of linearity. Dedicated to Prof. W. Jacobi on the occasion of his 60th birthday Work performed under Euratom contracts BI6-D-083-D, BI6-F-111-D, U.S. Department of Energy contract DE-AC 02-76 EV-00119, the U.S. National Cancer Institut

The reverse protraction factor in the induction of bone sarcomas in radium-224 patients

More than 50 bone sarcomas have occurred among a collective of about 800 patients who had been injected in Germany after World War II with large activities of radium-224 for the intended treatment of bone tuberculosis and ankylosing spondylitis.^In an earlier analysis it was concluded that, at equal mean absorbed doses in the skeleton, patients with longer exposure time had a higher incidence of bone sarcomas.^The previous analysis was based on approximations; in particular, it did not account for the varying times at risk of the individual patients.^In view of the implications of a reverse protraction factor for basic considerations in radiation protection, the need was therefore felt to reevaluate the data from the continued follow-up by more rigorous statistical methods.^A first step of the analysis demonstrates the existence of the reverse dose-rate effect in terms of a suitably constructed rank-order test.^In a second step of the analysis it is concluded that the data are consistent with a linear no-threshold dose dependence under the condition of constant exposure time, while there is a steeper than linear dependence on dose when the exposure times increase proportionally to dose.^A maximum likelihood fit of the data is then performed in terms of a proportional hazards model that includes the individual parameters, dose, treatment duration, and age at treatment.^The fit indicates proportionality of the tumor rates to mean skeletal dose with an added factor (1 + 0.18.tau), where tau is the treatment time in months.^This indicates that a protraction of the injections over 15 months instead of 5 months doubles the risk of bone sarcoma

Enlightening Leadership: A Phenomenology

The mechanistic, seventeenth century paradigm that has informed the leadership of our organizations has evolved into the quantum realm. This scientific renaissance is revealing a depth of knowledge that is stirring a new found interest in wisdom traditions as the truths of modern science appear to mirror knowledge found in ancient philosophic and meditative practices. Such Eastern spiritual practices have entered into the American mainstream and are becoming validated from a scientific perspective. Continuing research on meditation has revealed its effectiveness in producing many of the characteristics deemed essential in the field of transformational leadership. Congruently meditation centers are proliferating, many offering courses specifically designed for those in leadership positions. While awareness practices are continually being researched, practiced, and identified as obligatory in the field of transformational leadership, there is little research to date that explores the relationship, impact, and experience of meditation and leadership. This phenomenological study explores the leadership experience of individuals that practice Vipassana meditation. Seven purposefully selected organizational leaders, all of whom have completed at least one, ten day meditation seminar, participated in extensive, semi-structured, telephone interviews. The development of intimate familiarity with the rich data elicited from the interview protocol produced meaning units. These common experiential themes in the leadership of meditators were analyzed and synthesized to reveal the basic, essential essence. Building upon the knowledge gathered through the data analysis and synthesis, this study establishes findings that contribute to the field of leadership

Income Payment Structure and its Influence on Food Security and Fruit Consumption

Background: Despite the growing evidence of the positive effects of fruit consumption on health, many individuals do not consume the recommended dietary guideline amounts. It has been suggested that socioeconomic status and income have an influence on food choices and consumption. The aim of this study is not only to examine whether payment structure has an association with food choices but also to assess fruit consumption independent of vegetables in the US. Methods: The 2011 Behavioral Risk Factor Surveillance System was utilized and the study design led to a sample size that was n= 19,122 respondents. Variables that were selected for associations with sufficient fruit consumption included demographic data, employment status, payment structure, education, and home ownership status. A p-value of \u3c0.05 and 95% confidence intervals were used to determine statistical significance of the analyses performed. Results: Factors that were associated with greater odds of sufficient fruit consumption included being African-American, education- all levels of high school graduate and higher, all income categories above $15,000 annually, those employed, and those who rent a home (p-value\u3c0.01). Multivariate logistic regression analysis indicated that respondents\u27 education defined as having college education was associated with increased odds of sufficient fruit consumption (OR = 7.09: CI =1.86-27.09] (p-value\u3c0.01). Conclusions: Assessing fruit consumption alone did not provide greater insight on sufficiency with the exception of race\u27s (specifically African American) influence. Payment structure was found not associated with increased fruit consumption. Promotion of education on the relevance of fruit consumption to overall health is critical and necessary in the United States

Bone sarcoma cumulative tumor rates in patients injected with 224Ra

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An epidemiological assessment of lens opacifications that impaired vision in patients injected with radium-224

The incidence of lens opacifications that impaired vision (cataract) was analyzed among 831 patients who were injected with known dosages of 224Ra in Germany shortly after World War II. The dependence of the incidence on dosage, i.e., injected activity per unit body weight, and on time after treatment was determined. The observations are equally consistent with proportionality of the incidence of cataract to the square of dosage or with a linear dependence beyond a threshold of 0.5 MBq/kg. The possibility of a linear dependence without threshold was strongly rejected (P less than 0.001). The analysis of temporal dependences yielded a component that was correlated with the injected amount of 224Ra and a component that was uncorrelated. The former was inferred by a maximum likelihood analysis to increase approximately as the square of the time after treatment. The component unrelated to the treatment was found to increase steeply with age and to become dominant within the collective of patients between age 50 and 60. The relative magnitudes of the two components were such that a fraction of 55 to 60% of the total of 58 cataracts had to be ascribed to the dose-related incidence. Impaired vision due to cataract was diagnosed before age 54 in 25 cases. In terms of injected activity per unit body weight no dependence of the sensitivity on age was found; specifically there was no indication of a faster occurrence of the treatment-related cataracts in patients treated at older ages