Respiratory Cancer and Inhaled Inorganic Arsenic in Copper Smelters Workers: A Linear Relationship with Cumulative Exposure that Increases with Concentration

BACKGROUND: Inhalation of high levels of airborne inorganic arsenic is a recognized cause of respiratory cancer. Although multiple epidemiologic studies have demonstrated this association, there have been few analyses of the mathematical relationship between cumulative arsenic exposure and risk of respiratory cancer, and no assessment as to whether and how arsenic concentration may modify this association. OBJECTIVES: The objective is an evaluation of the shape of the relationship between respiratory cancer mortality and cumulative inhaled arsenic exposure among copper smelter workers, and the modification of that relationship by arsenic concentration. METHODS: We used Poisson regression methods to analyze data from a cohort of arsenic-exposed copper smelter workers under a linear-exponential model for the excess relative risk. RESULTS: Within categories of arsenic concentration, the association between respiratory cancer and cumulative arsenic exposure was consistent with linearity. The slope of the linear relationship with cumulative exposure increased with increasing arsenic concentration category. CONCLUSIONS: Our results suggested a direct concentration effect from inhaled inorganic arsenic, whereby the excess relative risk for a fixed cumulative exposure was greater when delivered at a higher concentration and shorter duration than when delivered at a lower concentration and longer duration. KEY WORDS: arsenic, dose–response relationship, lung neoplasms, occupational diseases. Environ Health Perspect 116:1661–1665 (2008). doi:10.1289/ehp.11515 available vi

Daily to decadal modulation of jet variability

The variance of a jet’s position in latitude is found to be related to its average speed: when a jet becomes stronger its variability in latitude decreases. This relationship is shown to hold for observed midlatitude jets around the world and also across a hierarchy of numerical models. North Atlantic jet variability is shown to be modulated on decadal timescales, with decades of a strong, steady jet being interspersed with decades of a weak, variable jet. These modulations are also related to variations in the basin-wide occurrence of high-impact blocking events. A picture emerges of complex multidecadal jet variability in which recent decades do not appear unusual. We propose an underlying barotropic mechanism to explain this behaviour, related to the change in refractive properties of a jet as it strengthens, and the subsequent effect on the distribution of Rossby wave breaking

Community based intervention to optimize osteoporosis management: randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Osteoporosis-related fractures are a significant public health concern. Interventions that increase detection and treatment of osteoporosis are underutilized. This pragmatic randomised study was done to evaluate the impact of a multifaceted community-based care program aimed at optimizing evidence-based management in patients at risk for osteoporosis and fractures.</p> <p>Methods</p> <p>This was a 12-month randomized trial performed in Ontario, Canada. Eligible patients were community-dwelling, aged ≥55 years, and identified to be at risk for osteoporosis-related fractures. Two hundred and one patients were allocated to the intervention group or to usual care. Components of the intervention were directed towards primary care physicians and patients and included facilitated bone mineral density testing, patient education and patient-specific recommendations for osteoporosis treatment. The primary outcome was the implementation of appropriate osteoporosis management.</p> <p>Results</p> <p>101 patients were allocated to intervention and 100 to control. Mean age of participants was 71.9 ± 7.2 years and 94% were women. Pharmacological treatment (alendronate, risedronate, or raloxifene) for osteoporosis was increased by 29% compared to usual care (56% [29/52] vs. 27% [16/60]; relative risk [RR] 2.09, 95% confidence interval [CI] 1.29 to 3.40). More individuals in the intervention group were taking calcium (54% [54/101] vs. 20% [20/100]; RR 2.67, 95% CI 1.74 to 4.12) and vitamin D (33% [33/101] vs. 20% [20/100]; RR 1.63, 95% CI 1.01 to 2.65).</p> <p>Conclusions</p> <p>A multi-faceted community-based intervention improved management of osteoporosis in high risk patients compared with usual care.</p> <p>Trial Registration</p> <p>This trial has been registered with clinicaltrials.gov (ID: NCT00465387)</p

Leukemogenesis Induced by an Activating β-catenin mutation in Osteoblasts

Cells of the osteoblast lineage affect homing, 1, 2 number of long term repopulating hematopoietic stem cells (HSCs) 3, 4, HSC mobilization and lineage determination and B lymphopoiesis 5-8. More recently osteoblasts were implicated in pre-leukemic conditions in mice 9, 10. Yet, it has not been shown that a single genetic event taking place in osteoblasts can induce leukemogenesis. We show here that in mice, an activating mutation of β-catenin in osteoblasts alters the differentiation potential of myeloid and lymphoid progenitors leading to development of acute myeloid leukemia (AML) with common chromosomal aberrations and cell autonomous progression. Activated β- catenin stimulates expression of the Notch ligand Jagged-1 in osteoblasts. Subsequent activation of Notch signaling in HSC progenitors induces the malignant changes. Demonstrating the pathogenetic role of the Notch pathway, genetic or pharmacological inhibition of Notch signaling ameliorates AML. Nuclear accumulation and increased β-catenin signaling in osteoblasts was also identified in 38% of patients with MDS/AML. These patients showed increased Notch signaling in hematopoietic cells. These findings demonstrate that genetic alterations in osteoblasts can induce AML, identify molecular signals leading to this transformation and suggest a potential novel pharmacotherapeutic approach to AML

γ-Glutamyltransferase, but not markers of hepatic fibrosis, is associated with cardiovascular disease in older people with type 2 diabetes mellitus: the Edinburgh Type 2 Diabetes Study

AIMS/HYPOTHESIS: We examined the association of prevalent and incident cardiovascular disease (CVD) with chronic liver disease in a cohort of community-based people with type 2 diabetes, in order to clarify the relationship between these two important conditions. METHODS: 1,066 participants with type 2 diabetes aged 60–75 years underwent assessment of a range of liver injury markers (non-specific injury, steatosis, steatohepatitis, fibrosis, portal hypertension). Individuals were followed up for incident cardiovascular events. RESULTS: At baseline there were 370/1,033 patients with prevalent CVD, including 317/1,033 with coronary artery disease (CAD). After a mean follow-up of 4.4 years there were 44/663 incident CVD events, including 27/663 CAD events. There were 30/82 CVD-related deaths. Risk of dying from or developing CVD was no higher in participants with steatosis than in those without (HR 0.90; 95% CI 0.40, 2.00; p > 0.05). The only notable relationship was with γ-glutamyltransferase (GGT) (incident CVD: adjusted HR for doubling GGT 1.24 [95% CI 0.97, 1.59] p = 0.086; incident CAD: adjusted HR 1.33 [95% CI 1.00, 1.78] p = 0.053), suggesting that in our study population, chronic liver disease may have little effect on the development of, or mortality from, CVD. CONCLUSIONS/INTERPRETATION: An independent association between GGT and CVD warrants further exploration as a potentially useful addition to current cardiovascular risk prediction models in diabetes. However, overall findings failed to suggest that there is a clinical or pathophysiological association between chronic liver disease and CVD in elderly people with type 2 diabetes. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00125-015-3575-y) contains peer-reviewed but unedited supplementary material, which is available to authorised users