2,206 research outputs found

    A study protocol for the evaluation of occupational mutagenic/carcinogenic risks in subjects exposed to antineoplastic drugs: a multicentric project

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    <p>Abstract</p> <p>Background</p> <p>Some industrial hygiene studies have assessed occupational exposure to antineoplastic drugs; other epidemiological investigations have detected various toxicological effects in exposure groups labeled with the job title. In no research has the same population been studied both environmentally and epidemiologically. The protocol of the epidemiological study presented here uses an integrated environmental and biological monitoring approach. The aim is to assess in hospital nurses preparing and/or administering therapy to cancer patients the current level of occupational exposure to antineoplastic drugs, DNA and chromosome damage as cancer predictive effects, and the association between the two.</p> <p>Methods/Design</p> <p>About 80 healthy non-smoking female nurses, who job it is to prepare or handle antineoplastic drugs, and a reference group of about 80 healthy non-smoking female nurses not occupationally exposed to chemicals will be examined simultaneously in a cross-sectional study. All the workers will be recruited from five hospitals in northern and central Italy after their informed consent has been obtained.</p> <p>Evaluation of surface contamination and dermal exposure to antineoplastic drugs will be assessed by determining cyclophosphamide on selected surfaces (wipes) and on the exposed nurses' clothes (pads). The concentration of unmetabolized cyclophosphamide as a biomarker of internal dose will be measured in end-shift urine samples from exposed nurses.</p> <p>Biomarkers of effect and susceptibility will be assessed in exposed and unexposed nurses: urinary concentration of 8-hydroxy-2-deoxyguanosine; DNA damage detected using the single-cell microgel electrophoresis (comet) assay in peripheral white blood cells; micronuclei and chromosome aberrations in peripheral blood lymphocytes. Genetic polymorphisms for enzymes involved in metabolic detoxification (i.e. glutathione <it>S</it>-transferases) will also be analysed.</p> <p>Using standardized questionnaires, occupational exposure will be determined in exposed nurses only, whereas potential confounders (medicine consumption, lifestyle habits, diet and other non-occupational exposures) will be assessed in both groups of hospital workers.</p> <p>Statistical analysis will be performed to ascertain the association between occupational exposure to antineoplastic drugs and biomarkers of DNA and chromosome damage, after taking into account the effects of individual genetic susceptibility, and the presence of confounding exposures.</p> <p>Discussion</p> <p>The findings of the study will be useful in updating prevention procedures for handling antineoplastic drugs.</p

    Causes and consequences of female centrality in cetacean societies

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    Cetaceans are fully aquatic predatory mammals that have successfully colonized virtually all marine habitats. Their adaptation to these habitats, so radically different from those of their terrestrial ancestors, can give us comparative insights into the evolution of female roles and kinship in mammalian societies. We provide a review of the diversity of such roles across the Cetacea, which are unified by some key and apparently invariable life-history features. Mothers are uniparous, while paternal care is completely absent as far as we currently know. Maternal input is extensive, lasting months to many years. Hence, female reproductive rates are low, every cetacean calf is a significant investment, and offspring care is central to female fitness. Here strategies diverge, especially between toothed and baleen whales, in terms of mother–calf association and related social structures, which range from ephemeral grouping patterns to stable, multi-level, societies in which social groups are strongly organized around female kinship. Some species exhibit social and/or spatial philopatry in both sexes, a rare phenomenon in vertebrates. Communal care can be vital, especially among deep-diving species, and can be supported by female kinship. Female-based sociality, in its diverse forms, is therefore a prevailing feature of cetacean societies. Beyond the key role in offspring survival, it provides the substrate for significant vertical and horizontal cultural transmission, as well as the only definitive non-human examples of menopause. This article is part of the theme issue ‘The evolution of female-biased kinship in humans and other mammals’.PostprintPeer reviewe

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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