PRDX6 contributes to selenocysteine metabolism and ferroptosis resistance.

Selenocysteine (Sec) metabolism is crucial for cellular function and ferroptosis prevention and has traditionally been thought to begin with the uptake of the Sec carrier selenoprotein P (SELENOP). Following uptake, Sec released from SELENOP undergoes metabolisation via selenocysteine lyase (SCLY), producing selenide, a substrate used by selenophosphate synthetase 2 (SEPHS2), which provides the essential selenium donor - selenophosphate - for the biosynthesis of the selenocysteine tRNA. Here, we report the discovery of an alternative pathway mediating Sec metabolisation that is independent of SCLY and mediated by peroxiredoxin 6 (PRDX6). Mechanistically, we demonstrate that PRDX6 can readily react with selenide and interact with SEPHS2, potentially acting as a selenium delivery system. Moreover, we demonstrate the presence and functional significance of this alternative route in cancer cells where we reveal a notable association between elevated expression of PRDX6 with a highly aggressive neuroblastoma subtype. Altogether, our study sheds light on a previously unrecognized aspect of Sec metabolism and its implications in ferroptosis, offering new avenues for therapeutic exploitation.

Acid times in physiology: A systematic review of the effects of ocean acidification on calcifying invertebrates.

The reduction in seawater pH from rising levels of carbon dioxide (CO2) in the oceans has been recognized as an important force shaping the future of marine ecosystems. Therefore, numerous studies have reported the effects of ocean acidification (OA) in different compartments of important animal groups, based on field and/or laboratory observations. Calcifying invertebrates have received considerable attention in recent years. In the present systematic review, we have summarized the physiological responses to OA in coral, echinoderm, mollusk, and crustacean species exposed to predicted ocean acidification conditions in the near future. The Scopus, Web of Science, and PubMed databases were used for the literature search, and 75 articles were obtained based on the inclusion criteria. Six main physiological responses have been reported after exposure to low pH. Growth (21.6%), metabolism (20.8%), and acid-base balance (17.6%) were the most frequent among the phyla, while calcification and growth were the physiological responses most affected by OA (>40%). Studies show that the reduction of pH in the aquatic environment, in general, supports the maintenance of metabolic parameters in invertebrates, with redistribution of energy to biological functions, generating limitations to calcification, which can have severe consequences for the health and survival of these organisms. It should be noted that the OA results are variable, with inter and/or intraspecific differences. In summary, this systematic review offers important scientific evidence for establishing paradigms in the physiology of climate change in addition to gathering valuable information on the subject and future research perspectives.

Cell volume maintenance capacity of the sea anemone Bunodosoma cangicum: the effect of copper.

Cell volume regulation is an essential strategy for the maintenance of life under unfavorable osmotic conditions. Mechanisms aimed at minimizing the physiological challenges caused by environmental changes are crucial in anisosmotic environments. However, aquatic ecosystems experience multiple stressors, including variations in salinity and heavy metal pollution. The accumulation of heavy metals in aquatic ecosystems has a significant effect on the biota, leading to impaired function. The aim of this study was to investigate the capacity of volume regulation in isolated cells of the sea anemone Bunodosoma cangicum exposed to nominal copper (Cu) concentrations of 5 and 50 µg L-1, associated or not with hypoosmotic (15‰) or hyperosmotic (45‰) shock for 15 min. In the absence of the metal, our results showed volume maintenance in all osmotic conditions. Our results showed that cell volume was maintained under all osmotic conditions in the absence of Cu. Similarly, no significant differences were observed in cell volumes under isosmotic and hyperosmotic conditions in the presence of both Cu concentrations. A similar homeostatic response was observed under the hypoosmotic condition with 5 µg L-1 Cu. Our results showed an increase in cell volume with exposure of the cells to the hypoosmotic condition and 50 µg L-1 Cu. The response could be associated with the increased bioavailability of Cu, reduced ability to resist multixenobiotics and their efflux pathways, and the impairment of water efflux in specialized transmembrane proteins. Therefore, B. cangicum pedal disk cells can tolerate osmotic variations in aquatic ecosystems. However, the capacity to regulate cell volume under hypoosmotic conditions can be affected by the presence of a metal contaminant (50 µg L-1 Cu), which could be due to the inhibition of water channels.

Osmoionic homeostasis in bivalve mollusks from different osmotic niches: Physiological patterns and evolutionary perspectives.

Physiological knowledge gained from questions focused on the challenges faced and strategies recruited by organisms in their habitats assumes fundamental importance about understanding the ability to survive when subjected to unfavorable situations. In the aquatic environment, salinity is particularly recognized as one of the main abiotic factors that affects the physiology of organisms. Although the physiological patterns and challenges imposed by each occupied environment are distinct, they tend to converge to osmotic oscillations. From a comparative perspective, we aimed to characterize the osmoregulatory patterns of the bivalve mollusks Corbicula largillierti (purple Asian cockle), Erodona mactroides (lagoon cockle), and Amarilladesma mactroides (white clam) - inhabitants of different osmotic niches - when submitted to hypo- and/or hyperosmotic salinity variations. We determined the hemolymph osmotic and ionic concentrations, tissue hydration, and the intracellular isosmotic regulation (IIR) from the use of osmolytes (organic and inorganic) after exposure to species-specific salinity intervals. Additionally, we incorporated phylogenetic perspectives to infer and even broaden the understanding about the patterns that comprise the osmoionic physiology of Bivalvia representatives. According to the variables analyzed in the hemolymph, the three species presented a pattern of osmoconformation. Furthermore, both ionic regulation and conformation patterns were observed in freshwater, estuarine, and marine species. The patterns verified experimentally show greater use of inorganic osmolytes compared to the participation of organic molecules, which varied according to the osmotic niche occupied in the IIR for the mantle, adductor muscle, and gills. This finding widens the classic vision about the preferential use of certain osmolytes by animals from distinct niches. Our phylogenetic perspective also indicates that environmental salinity drives physiological trait variations, including hemolymph osmolality and the ion composition of the extracellular fluid (sodium, chloride, magnesium, and calcium). We also highlight the important role played by the shared ancestry, which influences the interspecific variability of the hemolymph K+ in selected representatives of Bivalvia.

Determinação do biótipo periodontal através da análise de fotografias intra-orais / Determination of periodontal biotype through analysis of intra-oral photographs

Objetivo: Caracterizar os Biótipos Periodontais (BP) por meio de fotografias, além de verificar a concordância com o método clínico de determinação, bem como com diferentes profissionais em Odontologia. Material e método: A avaliação clínica intra-bucal de 34 pacientes (n=34) e verificação de fotografias padronizadas foram realizadas para caracterização dicotômica do BP em fino e espesso. A avaliação subjetiva, por meio da fotografia, foi comparada ao método clínico da transparência à sondagem. A determinação do BP por meio de fotografias foi realizada através da aplicação de um questionário contendo três categorias (fino, espesso e intermediário), direcionadas a 90 cirurgiões-dentistas divididos igualmente em três grupos: clínicos gerais, periodontistas e protesistas. A concordância em ambas as comparações foi avaliada por meio do Teste Kappa, além dos testes de sensibilidade e especificidade. Resultado: Na comparação entre o método clínico e o fotográfico, não houve concordância (K = 0,264, p = 0,113). Na comparação entre os grupos dos profissionais, foi encontrada uma baixa concordância (kappa = 0,160; p<0,05) entre os periodontistas e protesisas, bem como entre protesistas e clínicos gerais (kappa = 0,110; p = 0,142). Houve maior concordância, ainda que fraca, entre periodontistas e clínicos gerais (kappa = 0,291; p = 0,00). O questionário obteve um valor de sensibilidade e especificidade maior para o diagnóstico do BP espesso. Conclusão: A avaliação clínica do paciente por meio dos parâmetros clínicos ainda é necessária para caracterizar o BP, visto que a determinação usando-se análise visual por meio do fotografia, independentemente da especialidade, não foi efetiva, embora o BP espesso tenha sido o mais facilmente identificado.

Objective: To characterize the Periodontal Biotypes (PB) through photographs and verify the agreement with the clinical method of determination as well as with different Dental professionals. Material and method: Standardized photographs and intraoral clinical evaluation of 34 patients (n = 34) were performed for dichotomous characterization of PB in thin and thick. The subjective assessment, through photography, was compared to clinical method of probing transparency. The PB determination by photographs was performed through the application of a questionnaire containing three categories (thin, thick intermediate) directed to 90 dental professionals. They were equally divided into 3 groups: general practitioners, periodontists and prosthodontists. The concordance in both comparisons was evaluated through the Kappa Test, in addition to the sensitivity and specificity tests. Result: In the comparison between the clinical and the photographic method, there was no agreement (K = 0.264, p = 0.113). However, in the comparison between the groups of professionals, a low agreement (kappa = 0.160; p <0.05) was found between periodontists and prothesis, as well as between prosthesis and general practitioners (kappa = 0.110; p = 0.142). Greater agreement, although weak, between periodontists and general practitioners (kappa = 0.291, p = 0.00). The questionnaire obtained a higher sensitivity and specificity value for the diagnosis of thick PB. Conclusion: The evaluation of patients through clinical parameters is still necessary to characterize PB, since the determination using visual analysis using photography, regardless of specialty, was not effective, although thick PB was the most easily identified.

Relacionamento interpessoal de docentes de enfermagem: conflitos e desafio / Relación interpersonal de docentes de enfermería: los conflictos y los desafíos / Interpersonal relationship of nursing professors: conflicts and challenges

To analyze the interpersonal relations between the professors of the nursing department at a public university in Natal, RN. Method: it is an exploratory, descriptive study with a qualitative approach. Data collection occurred from May to June of 2012 with 17 professors from semi-structured interviews, and the data analyzed through content analysis of Bardin, using the method of thematic analysis. Results: from the speech of the professors, the category of Heterogeneity in interpersonal relationships was structured, divided into subcategories: interpersonal conflicts seen as normal in the workplace, a good relationship in groups/subjects, relationship difficulties in the large faculty group. Conclusion: from this study, it was possible to detect difficulties in the relationship between the professors of the studied reality. The instrument of communication is highlighted as a strategy for improving intergroup relationships...

Analisar o relacionamento interpessoal entre os docentes do departamento de enfermagem em uma universidade pública de Natal-RN.Método: estudo exploratório, descritivo, com abordagem qualitativa. Acoleta de dados ocorreu no período de maio a junho de 2012 com 17 docentes a partir de entrevista semiestruturada, sendo os dados analisados através da Análise de Conteúdo de Bardin, utilizando a modalidade da análise temática. Resultados: a partir das falas dos docentes, foi estruturada a categoria Heterogeneidade nas relações interpessoais,dividida em subcategorias: conflitos interpessoais vistos como normais no ambiente de trabalho, bom relacionamento nos grupos/disciplinas e dificuldades de relacionamento no grande grupo do corpo docente.Conclusão: a partir deste estudo, foi possível detectar as dificuldades existentes no relacionamento entre os docentes da realidade estudada.Aponta-se a ferramenta da comunicação como estratégia para a melhoria das relações intergrupais...

Analizar las relaciones interpersonales entre los profesores del departamento de enfermería de una universidad pública en Natal, RN. Método: estudio exploratorio, descriptivo con un enfoque cualitativo. La recolección de datos tuvo lugar entre mayo y Junio de 2012 con 17 profesores por entrevista semiestructurada, y los datos analizados a través de análisis de contenido de Bardin, utilizando el método de análisis sistemático. Resultados: A partir del discurso de los docentes, fue estructurada la categoría heterogeneidad en las relaciones interpersonales, dividido en subcategorías: conflictos interpersonales se ven como normales en el lugar de trabajo, buenas relaciones en los grupos/disciplinas, dificultades de relación en el gran grupo de profesores. Conclusión: En este estudio, se pudo detectar dificultades en la relación entre los profesores de la realidad estudiada. Se señala la herramienta de la comunicación como una estrategia para mejorar las relaciones intergrupales...

Fatores geradores da Síndrome de Burnout em profissionais da saúde / Factores generadores del Síndrome de Burnout en profesionales de la salud / Generating factors of Burnout Syndrome in health professionals

To identify factors related to the Burnout Syndrome in health professionals. Methods: descriptive study performed by an integrative literature review, with data collection conducted in a virtual library called BIREME. Results: only eight of 410 selected papers met the inclusion criteria. These referred to the Burnout Syndrome in Community Health Workers, in physicians working in Family Health Strategy, mental health professionals, nurses who work in Intensive Care Units, workers of a hospital of medium complexity and in Physical Education teachers. The syndrome above mentioned arises because of a set of factors. Workers who directly deal with people experience it, and it is a result of chronic stress. Conclusion: the improvement of working conditions of professionals helps to provide a more appropriate health care to professionals with signs of the Burnout Syndrome...

Identificar os fatores relacionados à Síndrome de Burnout em profissionais da saúde. Métodos: pesquisa descritiva realizada através de uma revisão integrativa da literatura, com a coleta de dados realizada na biblioteca virtual BIREME. Resultados: dos 410 artigos selecionados, apenas oito satisfaziam os critérios de inclusão. Estes referiam à Síndrome de Burnout em Agentes Comunitários de Saúde, em médicos da Estratégia Saúde da Família, profissionais de saúde mental, enfermeiros da Unidade de Tratamento Intensivo, trabalhadores de um hospital de média complexidade e professores de Educação Física. A síndrome referida aparece como consequência de um conjunto de fatores. Ela é vivenciada por trabalhadores que lidam diretamente com pessoas, sendo resultante do estresse crônico. Conclusão: a melhoria das condições de trabalho dos profissionais contribui para fornecer uma assistência de saúde mais apropriada aos profissionais com sinais da Síndrome de Burnout...

Identificar los factores relacionados al Síndrome de Burnout en profesionales de la salud. Métodos: investigación descriptiva através de una revisión integrativa de la literatura, con la recolección de datos en la Biblioteca virtual BIREME. Resultados: de los 410 artículos seleccionados, ocho satisfacían los criterios de inclusión. Estos se referían al Síndrome de Burnout en Agentes Comunitarios de Salud, en médicos de la Estrategia Salud de la Familia, profesionales de salud mental, enfermeros de la Unidad de Tratamiento Intensivo, trabajadores de un hospital de media complejidad y en profesores de Educación Física. El Síndrome es adquirido por trabajadores que lidian directamente con personas, siendo resultante del estrés crónico. Conclusión: la mejora de las condiciones de trabajo de los profesionales contribuye para proveer una asistencia de salud más apropiada a los profesionales con señales de Síndrome de Burnout...