DNA damage in Mytella falcata (Mytiloida, Mytilidae) cells: a new tool for biomonitoring studies in tropical estuarine ecosystems.

Bivalve filter feeders are sessile animals frequently used as sentinels in aquatic environments. For this reason it is important to identify native key species in tropical environments, since the majority of studies were conducted in temperate regions. This study was developed to evaluate if Mytella falcata, a tropical estuarine bivalve, could be used to detect genotoxic damages by means of the comet assay. Individuals of this species were exposed in vivo to methyl methanesulphonate concentrations; a control group, not exposed, was conducted in the same way. Haemolymph and gill cells were submitted to the comet assay, to evaluate the sensitivity of these tissues. DNA damage increase was detected in both tissues, however statistical difference was observed only in haemolymph cells, maybe because of the damages generated during the dissociation process needed in gill cells manipulation. It was concluded that Mytella falcata had the expected response to this direct acting mutagenic substance and that haemolymph cells are better material for genotoxicity studies, because they can be easily obtained

Regulation of CCR4-NOT complex deadenylase activity and cellular responses by MK2-dependent phosphorylation of CNOT2

CCR4-NOT complex-mediated mRNA deadenylation serves critical functions in multiple biological processes, yet how this activity is regulated is not fully understood. Here, we show that osmotic stress induces MAPKAPK-2 (MK2)-mediated phosphorylation of CNOT2. Programmed cell death is greatly enhanced by osmotic stress in CNOT2-depleted cells, indicating that CNOT2 is responsible for stress resistance of cells. Although wild-type (WT) and non-phosphorylatable CNOT2 mutants reverse this sensitivity, a phosphomimetic form of CNOT2, in which serine at the phosphorylation site is replaced with glutamate, does not have this function. We also show that mRNAs have elongated poly(A) tails in CNOT2-depleted cells and that introduction of CNOT2 WT or a non-phosphorylatable mutant, but not phosphomimetic CNOT2, renders their poly(A) tail lengths comparable to those in control HeLa cells. Consistent with this, the CCR4-NOT complex containing phosphomimetic CNOT2 exhibits less deadenylase activity than that containing CNOT2 WT. These data suggest that CCR4-NOT complex deadenylase activity is regulated by post-translational modification, yielding dynamic control of mRNA deadenylation

Study of collaboration methods between nurses and medical social workers during facility transfer of end-of-life cancer patients

Objective: The purpose of this study is to clarify how nurses and medical social workers (hereafter, MSW) collaborate in providing nursing and support to cancer patients who will transition to end-of-life care. Methods: Informants were comprised of 18 nurses and 8 MSW working at a large hospital practicing state-of-the-art cancer treatment. Interviews were conducted by forming focus groups comprised of a mix of nurses and social workers. The focus group interview survey involved the author transcribing audio recordings of these interview sessions, extracting sections relevant to the study purpose, and performing qualitative analysis. Codes relevant to the study purpose were extracted and compiled into cards. These cards were then grouped according to similarity of contents. Sentences expressing the contents of each group were composed, and small tags were appended to meaningful codes. These groups were further grouped together if similar groups were found. Large tags were appended to meaningful codes. Results: Seventeen small tags and six large tags were appended. Based on the remarks of informants in the focus group interview facilitated by the author, storylines were drawn up by arranging the small tags and large tags. The storylines were then compiled into a results diagram. Even if the patient and the family were in agreement as to his care after hospital discharge, the patient himself agreed to the transfer, and good relations had been established between the nurse and patient and the MSW and patient, as collaboration between the nurses and MSW had been insufficient, there were cases in which the hospital transfer did not proceed smoothly. Conclusions: This study reflects how a transfer will not proceed smoothly simply by establishing trusting relations between the patient and nurses, and this study demonstrated that the collaboration between nurses and MSW is indispensable when it concerns transferring the patient to end-of-life care at another facility

Avaliação dos efeitos citotóxicos, genotóxicos e mutagênicos de efluentes de refinaria de petróleo, por meio dos sistemas testes de Allium cepa e Oreochromis niloticus

Atualmente, a degradação dos recursos hídricos é uma das maiores preocupações do homem, uma vez que pode causar danos diretos ou indiretos à biota associada, bem como à saúde e à sobrevivência desses organismos expostos. Um dos fatores que contribui para a alteração da qualidade das águas é a emissão de efluentes, seja ela industrial, doméstica ou de outra origem. Dentre os processos industriais que são considerados preocupantes para o meio ambiente, temos a indústria petrolífera, ligadas ao refino de petróleo. Os efluentes destas indústrias podem causar drásticas alterações nos recursos hídricos, devido à emissão de hidrocarbonetos, podendo comprometer corpos dþágua que são utilizados em abastecimento de muitas cidades. O presente estudo teve como objetivo investigar os possíveis efeitos citotóxico, genotóxico e mutagênico de efluentes de refinaria de petróleo, que são lançados no rio Atibaia, município de Paulínia/SP. Para isso, foram coletadas amostras de água de seis pontos distintos: 1) Montante do Rio Jaguarí (acima da captação da água utilizada pela refinaria); 2) Entrada da lagoa de estabilização da REPLAN; 3) Saída da lagoa de estabilização (água destinada aos despejos no Rio Atibaia); 4) 1Km a montante do ponto 3, no Rio Atibaia; 5) 1 Km a jusante do ponto 3; 6) Após o tratamento físicoquímico e antes do tratamento bacteriológico. Foram empregadas as metodologias de aberrações cromossômicas e de Corantes Vitais em Allium cepa (cebola) e teste de micronúcleo e ensaio de cometa em Oreochromis niloticus (tilápia). A partir dos dados obtidos, pode-se inferir que as águas do ponto 1 apresentaram baixo potencial citotóxico, genotóxico e mutagênico. O ponto 6 apresentou o mais alto índice de citotoxicidade, genotoxicidade e de mutagenicidade...The degradation of the hydric resources is one of the man's main preoccupation, because it can cause direct or indirect damages to health and to the survival of the exposed organisms. One factor that can contribute for the alteration of the water quality is the effluents emissions, such as industrial, domestic or of other origin. These effluents can cause drastic alterations in the hydric resources, due to the emission of hydrocarbons, which can compromise the water that is used in the supplying of many cities. The present work had the objective to investigate the possible citotoxic, genotoxic and mutagenic effects of these petroleum refinery effluents, that are discharged in the Atibaia river, municipality of Paulínia/SP. Water samples were collected in six different sites: 1) Jaguarí river upstream (above the site were the water is collected by the industry); 2) entrance of the stabilization lake of REPLAN; 3) exit of the stabilization lake (water that is destined to be discharged in the Atibaia river); 4) 1 Km upstream of site 3, in the Atibaia river; 5) 1 Km downstream of site 3; 6) after the physic-chemical treatment and before the biological treatment. The methodologies of chromosome aberrations, and vital staining were used in the Allium cepa (onion) and the micronucleus test and comet assay were applied in Oreochromis niloticus (tilápia). From the results observed, we can suggest that the waters of site 1 has low citotoxic, genotoxic and mutagenic potentials. Site 6 had shown the highest citotoxic, genotoxic and mutagenic rates. The waters from sites 2 and 3 presented inferior levels from those observed in the site 6. It has been observed that the effluent that is discharged in the Atibaia river (site 3) had a lower level when compared with sites 4, 5 and 6, wich means that... (Complete abstract, click electronic access below

Avaliação da atividade antimutagênica de alguns produtos naturais de origem animal por meio de ensaios com células HepG2

A exposição do homem às substâncias danosas, sejam estas substâncias de origem natural ou sintética, vem crescendo durante as últimas décadas. Esta exposição é capaz de induzir diversos efeitos deletérios nos organismos expostos, provocando diversas doenças e até mesmo a morte. Da mesma forma que aumenta a quantidade de substâncias promotoras de impactos ambientais, também crescem as pesquisas que buscam por novas substâncias que sejam capazes de proteger os organismos destes efeitos deletérios. Esse trabalho tem como objetivo avaliar a atividade citotóxica, genotóxica e antigenotóxica, mutagênica e antimutagênica de venenos de Hymenoptera (especificamente da abelha Apis mellifera e da vespa Polybia paulista), em diferentes concentrações, utilizando para essa avaliação o sistema teste de HepG2. Foi utilizado o ensaio do MTT para se avaliar a citotoxicidade tanto do veneno de A. mellifera como de P. paulista. As concentrações consideradas não citotóxicas (1, 5 e 10μg/mL de veneno de vespa e 0,1, 0,05 e 0,01 μg/mL do veneno de abelha) foram utilizadas para se avaliar o potencial genotóxico (ensaio do cometa) e mutagênico (teste do micronúcleo). Estas concentrações não citotóxicas mostraram-se genotóxicas e mutagênicas para o sistema teste utilizado. Foram utilizadas outras concentrações, mais baixas que as utilizadas nos testes de genotoxicidade e mutagenicidade (1ng/mL, 100pg/mL e 10pg/mL de veneno de vespa e 10pg/mL, 1pg/mL e 0,1pg/mL para o veneno de abelha), para a realização dos testes de antigenotoxicidade e antimutagenicidade com células HepG2. As concentrações utilizadas nesses ensaios mostraram que ambos os venenos, ao invés de inibirem e/ou diminuirem o efeito genotóxico e mutagênico da substância metilmetano sulfonato, aumentaram ainda mais os danos causados por esta substância...Human exposure to harmful substances, natural or synthetic, is increasing in the last decades. This exposure is able to induce several deleterious effects on the exposed organisms, causing several diseases and even death. As the amount of substances that promote environmental impacts increases, researches seeking for new substances that are able to protect the organisms against these deleterious effects have also increased. This study aimed to evaluate the cytotoxic, genotoxic and antigenotoxic, mutagenic and antimutagenic of Hymenoptera venoms (specifically of the bee Apis mellifera and the wasp Polybia paulista), in different concentrations, using for this evaluation the HepG2 test system. The MTT assay was used to assess the cytotoxicity the venom of A. mellifera and P. paulista. The concentrations considered non cytotoxic (1, 5 and 10μg/mL of the wasp venom and 0.1, 0.05 and 0.01 μg/mL of the bee venom) were used to evaluate the genotoxic (comet assay) and mutagenic potential (micronucleus test). These non cytotoxic concentrations were genotoxic for the test system used. Other concentrations were used, lower than the ones used in the genotoxicity and mutagenicity tests (1ng/mL, 100pg/mL and 10pg/mL of the wasp venom and 10pg/mL, 1pg/mL and 0,1pg/mL for the bee venom), in order to perform the antigenotoxicity and antimutagenicity tests with HepG2 cells. The concentrations used in these assays showed that both venoms, instead of inhibiting and/or decreasing the gentoxic and mutagenic effects of the substance methylmethane sulfonate, increased even more the damages caused by this substance. In order to verify which would be the compound responsible for the effects registered for the venoms, it was also evaluated the effect of phospholipase A2 (PLA2 from A. mellifera)... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Anti-genotoxicity and anti-mutagenicity of Apis mellifera venom

The search for substances able to inhibit and/or diminish the effects of genotoxic and mutagenic substances has been the target of several investigations performed in recent times. Hymenoptera venoms constitute a considerable source of substances with pharmacological potential. The present study aimed to evaluate the cytotoxic, genotoxic and anti-genotoxic, mutagenic and anti-mutagenic potentials of Apis mellifera venom in HepG2 cells. In this evaluation, the MTT test was applied to determine the most appropriate concentrations for the genotoxicity and mutagenicity tests. It was verified that the concentrations of 0.1, 0.05 and 0.01 mu g/mL were not cytotoxic, hence these concentrations were used in the experiments. For the evaluation of the genotoxic and mutagenic potential of the bee venom the comet assay and the micronucleus test were applied, respectively. The concentrations mentioned above presented both genotoxic and mutagenic potential for HepG2 cells and it was necessary to test lower concentrations of the venom (10 pg/mL, 1 pg/mL and 0.1 pg/mL) for the anti-genotoxicity and anti-mutagenicity tests, which were performed subjecting the cells to the action of MMS (methyl methanesulfonate) in order to verify the ability of the venom to inhibit or diminish the action of this compound, which has a recognized action on the genetic material. Pre-, post-treatment and simultaneous treatment with and without incubation with the venom were performed. It was observed that the lowest three concentrations tested did not present any anti-genotoxic and anti-mutagenic activity on the cells. The use of bee venom for pharmacological purposes in treatments such as cancer must be done with extreme caution, since it was observed that even at very low concentrations the venom can induce genotoxicity and mutagenicity in human cells, as was verified for the HepG2 cells. (C) 2014 Published by Elsevier B.V.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES