1,721,146 research outputs found
Indicatori di dose biologicamente efficace
No full textBiologically effective dose markers –DNA and protein adducts- are classified among the exposure biomarkers, and nowadays they are used to assess the biologically active fraction of xenobiotics, able to interact with cellular macromolecules at the target site.
Actually, macromolecular adducts can be considered not only as exposure indicators, but their biological significance can be extended also to biomarkers of effect and of susceptibility. The achievement of such a goal need research programs aimed both to study molecular mechanisms related to each steps along the continuum of events between exposure and disease, and to establish quantitative relationships between exposure levels and adducts formation, between adducts and early biological effects, effects and cellular structural/functional modifications, till the development and eventually the incidence increment of specific pathologies. Besides, different factors must be considered during data evaluation, such as: the interindividual variability, the background levels of biomarkers in non occupationally exposed population, the lower and lower doses of genotoxic agents involved in occupational exposures, confounding factors such as diet and smoking habits.
Despite the large body of literature documenting DNA and protein adduct molecular dosimetry for many carcinogen exposures, many authors claimed the necessity of systematic interlaboratory comparisons and collaborations by measuring the same biomarkers with different techniques and/or different biomarkers related to the same exposure levels. There is also a general agreement in the need of validated and standardized analytical procedures without neglecting analytical times and costs, so that dosimetric analyses could be economically advantageous and accessible in all cases they prove to be useful in preventing health risks
Dall’igiene e tossicologia industriale all’igiene e tossicologia ambientale: problemi e prospettive
No full textRelation between adherence to dietary patterns and urinary selenium levels in an Italian cohort
No full textAssociation between serum selenium species and 8-oxo-7,8-dihydro-2’deoxyguanosine levels: an Italian cross-sectional study
No full textIntroduction: Selenium (Se) is a metalloid present in trace amounts in the organism, with toxicological and nutritional properties depending on the dose and the species considered. Both organic and inorganic selenium species are involved in oxidoreduction reaction regulation and pathways. 8-oxo-7,8-dihydro-2’deoxyguanosine (8-oxodG) is a derivative of deoxyguanosine, used as biomarker of oxidative stress in urine. In this study, we aimed to assess total serum selenium levels along with its species in a population in Northern Italy and to evaluate the associations between selenium exposure with 8-oxodG levels.
Material and methods: The present study consisted in a cross-sectional survey carried out in blood donors aged 30-60 years enrolled in the Transfusion Medicine Center ‘Casa del Dono’ of the AUSL-IRCCS of Reggio Emilia, Northern Italy, in the period April 2017-April 2019. Of 148 eligible subjects, 137 were eventually enrolled. They were all non-smokers, and not affected by any disease or clinical condition. Each participant gave urinary and blood samples in order to quantify selenium levels in these matrices; urinary samples were used to quantify cotinine and 8-oxodG levels, while speciation analysis was performed in serum samples. We performed spline regression analyses to assess the possible nonlinear associations of the different biomarkers of selenium exposure with 8-oxodG levels using a multivariable model adjusted for potential confounders.
Results: Our population had a mean age of 47.4 years. Mean (standard deviation) level of serum selenium was 117.4±19.1 mcg/L, respectively. Association of serum selenium level with 8-oxodG levels adjusted for urinary creatinine was almost null. For what concerns selenium species, selenoprotein P-bound-Se showed a slightly inverted U-shaped association with 8-oxodG levels with a positive association until 90 mcg/L and negative above that amount. Selenomethionine-bound-Se, glutathione peroxidase-bound-Se, and selenocysteine-bound-Se were positively associate with 8-oxodG, though for the latter two the association was very imprecise. A negative association emerged for thioredoxin reductase-bound-Se. Total inorganic selenium along with the two inorganic species, i.e., selenite and selenate, were negatively and linearly associated with 8-oxodG levels. For Se-bound to human serum albumin-bound-Se the association was almost null.
Conclusion: Our results suggest that even though total selenium exposure seems not associated with 8-oxodG, selected selenium species may largely differ in their association with this oxidative stress biomarker, thus strengthening the importance of selenium speciation analysis for the evaluation of selenium health effects
Use of plant protection products in lombardy, Italy and the health risk for the ingestion of contaminated water
Full text linkPesticides used to protect agricultural crops may contaminate groundwater. This work aimed to identify the pesticides used in Lombardy, Italy, in 2016, their concentration in the ground-water and the risk for health associated with the intake of drinkable water in the adult population. The risk was evaluated for the presence of single and multiple active substances in the groundwater, calculating the hazard quotient (HQ) and the hazard index (HI), respectively. Lombardy utilises an agricultural area of 980,112 h, which is mainly cultivated with cereals (74%). Approximately 2354 pesticides (about 1.3 × 107 kg), containing 410 active substances (about 4.5 × 106 kg) were sold. There were groundwater contamination measurements in 158 monitoring points, which were investigated twice a year for 31 active substances, and a total of 9152 determinations. Only 17 cur-rently used active substance were measured in the groundwater, among which three belonged to the 10 best-sold pesticides. The exceedance of the environmental quality standard was observed for about 1.5% determinations. The intake of contaminated water in the adult population resulted in a HQ typically ranging between 10−3 and 10−4 and a HI of about 10−3. Although the number of pesticides sold in 2016 in Lombardy was big, only a small fraction of active substances was monitored in the groundwater. Considering these monitored substances, the intake of contaminated groundwater in the adult general population posed an irrelevant risk for health
Association between dietary patterns and urinary cadmium levels in an Italian population
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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