143 research outputs found
Regulated mitochondrial DNA replication during oocyte maturation is essential for successful porcine embryonic development.
Cellular ATP is mainly generated through mitochondrial oxidative phosphorylation, which is dependent on mitochondrial DNA (mtDNA). We have previously demonstrated the importance of oocyte mtDNA for porcine and human fertilization. However, the role of nuclear-encoded mitochondrial replication factors during oocyte and embryo development is not yet understood. We have analyzed two key factors, mitochondrial transcription factor A (TFAM) and polymerase gamma (POLG), to determine their role in oocyte and early embryo development. Competent and incompetent oocytes, as determined by brilliant cresyl blue (BCB) dye, were assessed intermittently during the maturation process for TFAM and POLG mRNA using real-time RT-PCR, for TFAM and POLG protein using immunocytochemistry, and for mtDNA copy number using real-time PCR. Analysis was also carried out following treatment of maturing oocytes with the mtDNA replication inhibitor, 2',3'-dideoxycytidine (ddC). Following in vitro fertilization, preimplantation embryos were also analyzed. Despite increased levels of TFAM and POLG mRNA and protein at the four-cell stage, no increase in mtDNA copy number was observed in early preimplantation development. To compensate for this, mtDNA appeared to be replicated during oocyte maturation. However, significant differences in nuclear-encoded regulatory protein expression were observed between BCB(+) and BCB(-) oocytes and between untreated oocytes and those treated with ddC. These changes resulted in delayed mtDNA replication, which correlated to reduced fertilization and embryonic development. We therefore conclude that adherence to the regulation of the timing of mtDNA replication during oocyte maturation is essential for successful embryonic development
Trapped in the prison of the mind: notions of climate-induced (im)mobility decision-making and wellbeing from an urban informal settlement in Bangladesh
The concept of Trapped Populations has until date mainly referred to people ‘trapped’ in environmentally high-risk rural areas due to economic constraints. This article attempts to widen our understanding of the concept by investigating climate-induced socio-psychological immobility and its link to Internally Displaced People’s (IDPs) wellbeing in a slum of Dhaka. People migrated here due to environmental changes back on Bhola Island and named the settlement Bhola Slum after their home. In this way, many found themselves ‘immobile’ after having been mobile—unable to move back home, and unable to move to other parts of Dhaka, Bangladesh, or beyond. The analysis incorporates the emotional and psychosocial aspects of the diverse immobility states. Mind and emotion are vital to better understand people’s (im)mobility decision-making and wellbeing status. The study applies an innovative and interdisciplinary methodological approach combining Q-methodology and discourse analysis (DA). This mixed-method illustrates a replicable approach to capture the complex state of climate-induced (im)mobility and its interlinkages to people’s wellbeing. People reported facing non-economic losses due to the move, such as identity, honour, sense of belonging and mental health. These psychosocial processes helped explain why some people ended up ‘trapped’ or immobile. The psychosocial constraints paralysed them mentally, as well as geographically. More empirical evidence on how climate change influences people’s wellbeing and mental health will be important to provide us with insights in how to best support vulnerable people having faced climatic impacts, and build more sustainable climate policy frameworks
N-Acetylcysteine as modulator of the essential trace elements copper and zinc
N-acetylcysteine (NAC) is a frequently prescribed drug and known for its metal chelating capability. However, to date it is not well characterized whether NAC intake affects the homeostasis of essential trace elements. As a precursor of glutathione (GSH), NAC also has the potential to modulate the cellular redox homeostasis. Thus, we aimed to analyze effects of acute and chronic NAC treatment on the homeostasis of copper (Cu) and zinc (Zn) and on the activity of the redox-sensitive transcription factor Nrf2. Cells were exposed to 1 mM NAC and were co-treated with 50 µM Cu or Zn. We showed that NAC treatment reduced the cellular concentration of Zn and Cu. In addition, NAC inhibited the Zn-induced Nrf2 activation and limited the concomitant upregulation of cellular GSH concentrations. In contrast, mice chronically received NAC via drinking water (1 g NAC/100 mL). Cu and Zn concentrations were decreased in liver and spleen. In the duodenum, NQO1, TXNRD, and SOD activities were upregulated by NAC. All of them can be induced by Nrf2, thus indicating a putative Nrf2 activation. Overall, NAC modulates the homeostasis of Cu and Zn both in vitro and in vivo and accordingly affects the cellular redox balance
Improving the selenium supply of vegans and omnivores with Brazil nut butter compared to a dietary supplement in a randomized controlled trial
Purpose: A vegan diet is associated with health benefits but may also lead to inadequate intake of essential nutrients. Due to the lower selenium content in plant-based compared to animal-based foods, many vegans do not reach the recommended selenium intake in Europe. The only plant-based food with high selenium content is the Brazil nut, even though there is also a high variability. Therefore, we investigated the effectiveness of Brazil nut butter compared to a dietary supplement as selenium source to improve the selenium status of vegans and omnivores. Methods: 44 vegans and 42 omnivores were randomly assigned to one of three intervention groups, either receiving placebo or consuming additional 55 µg of selenium daily as Brazil nut butter or supplement for two weeks. Serum selenium concentrations, glutathione peroxidase 3 (GPX3), and selenoprotein P (SELENOP) were measured at baseline and after intervention. Additionally, dietary selenium intake was estimated using a five-day dietary protocol. Results: The estimated selenium intake was significantly lower in vegans compared to omnivores and correlated with all three selenium biomarkers. Independent of the dietary pattern (vegan or omnivore), Brazil nut butter as well as supplement significantly increased serum selenium and SELENOP concentrations, while there were no changes in the placebo groups. Both interventions were equally effective in increasing selenium levels, but the upregulation of SELENOP was more pronounced in vegans than in omnivores. Conclusion: Brazil nuts are a plant-based source of selenium suitable for vegans and omnivores to improve their selenium status when consumed once in a while. Trial registration number and date of registration Clinical trials registration number: NCT05814874, April 18 2023
Risks to human and animal health related to the presence of deoxynivalenol and its acetylated and modified forms in food and feed
Peer reviewedPublisher PD
Practice priorities for acute care nursing: A Delphi study
Aims and objectives: To describe the risk and frequency of challenges in acute care nursing, and the practice priorities in Australian hospital wards based upon expert consensus. Background: Health care is facing increasing demands that are negatively impacting upon the safety and quality of nursing care. Design: Delphi Method. Method: A three-round electronic Delphi method was used to collect and synthesise expert consensus opinion of 30 participants in Rounds One and Two of the survey, and 12 participants in Round Three. The study was carried out from July to December 2016. This study complied with the STROBE checklist. Results: High patient acuity or complexity, as well as inadequate bed space on wards, are “very high” risks that occur “often” and “very often,” respectively. The pressure to admit patients, delayed medical review and patient boarding are all “high” risks that occur “often.” Though only occurring “sometimes,” inadequate numbers and skill mix of staff, suboptimal communication and early or inappropriate discharge all pose a “very high” risk to patient care. Conclusion: The key practice priorities for nurse managers should include the design, implementation and evaluation of sustainable system-wide frameworks, processes and models of care that address patient boarding, communication and discharge processes, job satisfaction, staffing numbers and expertise. Relevance to clinical practice: This study provides a description of the challenges that face acute care nursing in the provision of safe and high-quality care. © 2020 John Wiley & Sons Lt
Climate change adaptation in conflict-affected countries:A systematic assessment of evidence
People affected by conflict are particularly vulnerable to climate shocks and climate change, yet little is known about climate change adaptation in fragile contexts. While climate events are one of the many contributing drivers of conflict, feedback from conflict increases vulnerability, thereby creating conditions for a vicious cycle of conflict. In this study, we carry out a systematic review of peer-reviewed literature, taking from the Global Adaptation Mapping Initiative (GAMI) dataset to documenting climate change adaptation occurring in 15 conflict-affected countries and compare the findings with records of climate adaptation finance flows and climate-related disasters in each country. Academic literature is sparse for most conflict-affected countries, and available studies tend to have a narrow focus, particularly on agriculture-related adaptation in rural contexts and adaptation by low-income actors. In contrast, multilateral and bilateral funding for climate change adaptation addresses a greater diversity of adaptation needs, including water systems, humanitarian programming, and urban areas. Even among the conflict-affected countries selected, we find disparity, with several countries being the focus of substantial research and funding, and others seeing little to none. Results indicate that people in conflict-affected contexts are adapting to climate change, but there is a pressing need for diverse scholarship across various sectors that documents a broader range of adaptation types and their results
Excessive copper impairs intrahepatocyte trafficking and secretion of selenoprotein P
Abstract 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.Selenium and copper are two essential trace elements whose homeostasis and distribution is regulated by hepatic release of selenoprotein P (SELENOP) and ceruloplasmin, respectively. Here, the authors show that excessive copper results in hepatic SELENOP accumulation in the trans Golgi which might limit the selenium transport to peripheral organs
Risks for human health related to the presence of pyrrolizidine alkaloids in honey, tea, herbal infusions and food supplements
The Panel wishes to acknowledge all European competent institutions, Member State bodies and other organisations that provided data for this scientific output. Adopted: 21 June 2017Peer reviewedPublisher PD
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