RESUMO
Selenium homeostasis depends on hepatic biosynthesis of selenoprotein P (SELENOP) and SELENOP-mediated transport from the liver to e.g. the brain. In addition, the liver maintains copper homeostasis. Selenium and copper metabolism are inversely regulated, as increasing copper and decreasing selenium levels are observed in blood during aging and inflammation. Here we show that copper treatment increased intracellular selenium and SELENOP in hepatocytes and decreased extracellular SELENOP levels. Hepatic accumulation of copper is a characteristic of Wilson's disease. Accordingly, SELENOP levels were low in serum of Wilson's disease patients and Wilson's rats. Mechanistically, drugs targeting protein transport in the Golgi complex mimicked some of the effects observed, indicating a disrupting effect of excessive copper on intracellular SELENOP transport resulting in its accumulation in the late Golgi. Our data suggest that hepatic copper levels determine SELENOP release from the liver and may affect selenium transport to peripheral organs such as the brain.
Assuntos
Degeneração Hepatolenticular , Selênio , Animais , Ratos , Selenoproteína P , CobreRESUMO
BACKGROUND: The specific compounds that make ambient fine particulate matter (PM2.5) carcinogen remain poorly identified. Some metals contribute to ambient PM2.5 and possibly to its adverse effects. But the challenge of assessing exposure to airborne metals limits epidemiological studies. OBJECTIVE: To analyze the relationships between several airborne metals and risk of cancer in a large population. METHODS: We estimated the individual exposure to 12 airborne metals of â¼ 12,000 semi-urban and rural participants of the French population-based Gazel cohort using moss biomonitoring data from a 20-year national program. We used principal component analyses (PCA) to derive groups of metals, and focused on six single carcinogenic or toxic metals (arsenic, cadmium, chromium, lead, nickel, and vanadium). We used extended Cox models with attained age as time-scale and time-varying weighted average exposures, adjusted for individual and area-level covariables, to analyze the association between each exposure and all-site combined, bladder, lung, breast, and prostate cancer incidence. RESULTS: We identified 2,401 cases of all-site cancer between 2001 and 2015. Over the follow-up, median exposures varied from 0.22 (interquartile range (IQR): 0.18-0.28) to 8.68 (IQR: 6.62-11.79) µg.g-1 of dried moss for cadmium and lead, respectively. The PCA yielded three groups identified as "anthropogenic", "crustal", and "marine". Models yielded positive associations between most single and groups of metal and all-site cancer, with e.g. hazard ratios of 1.08 (95% CI: 1.03, 1.13) for cadmium or 1.06 (95% CI: 1.02,1.10) for lead, per interquartile range increase. These findings were consistent across supplementary analyses, albeit attenuated when accounting for total PM2.5. Regarding specific site cancers, we estimated positive associations mostly for bladder, and generally with large confidence intervals. CONCLUSION: Most single and groups of airborne metals, except vanadium, were associated with risk of cancer. These findings may help identify sources or components of PM2.5 that may be involved in its carcinogenicity.
Assuntos
Poluentes Atmosféricos , Neoplasias , Masculino , Humanos , Poluentes Atmosféricos/análise , Cádmio/análise , Vanádio , Material Particulado/efeitos adversos , Material Particulado/análise , Neoplasias/induzido quimicamente , Neoplasias/epidemiologia , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análiseRESUMO
OBJECTIVE: Clinicians commonly "drift" away from using proven therapeutic techniques. This study examined the degree to which such drift occurs among cognitive behavioral therapy (CBT) clinicians working with a specific clinical population-adults with eating disorders. METHOD: The study used a correlational design. The participants were 80 qualified clinicians (69 women, 11 men; mean age = 39.2 years, range = 23-62 years) who routinely offered what they described as CBT to adults with eating disorders. Each clinician detailed whether and how often he or she used different cognitive behavioral techniques when delivering CBT to such patients, and each completed the anxiety scale of the Brief Symptom Inventory (Derogatis, 1983). RESULTS: Implementation of specific CBT techniques was far lower than protocols would suggest, particularly for clinicians who were anxious, older, or more experienced in working with the eating disorders (p < .05, in all cases). The use of treatment manuals was associated with greater use of recommended CBT techniques (p < .05, in all cases). Cluster analysis showed that clinicians fell into three types-behavior, motivation, and mindfulness oriented. CONCLUSIONS: These findings need to be extended to other therapies and other disorders, but they indicate the need for stronger training and closer supervision if clinicians are to give patients the best chance of recovery. They demonstrate that clinicians' use of the label CBT is not a reliable indicator of the therapy that is being offered.