19 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
Novel foods in the European Union: Scientific requirements and challenges of the risk assessment process by the European Food Safety Authority
The European Food Safety Authority (EFSA) has been involved in the risk assessment of novel foods since 2003. The implementation of the current novel food regulation in 2018 rendered EFSA the sole entity of the European Union responsible for such safety evaluations. The risk assessment is based on the data submitted by applicants in line with the scientific requirements described in the respective EFSA guidance document. The present work aims to elaborate on the rationale behind the scientific questions raised during the risk assessment of novel foods, with a focus on complex mixtures and whole foods. Novel foods received by EFSA in 2003-2019 were screened and clustered by nature and complexity. The requests for additional or supplementary information raised by EFSA during all risk assessments were analyzed for identifying reoccurring issues. In brief, it is shown that applications concern mainly novel foods derived from plants, microorganisms, fungi, algae, and animals. A plethora of requests relates to the production process, the compositional characterization of the novel food, and the evaluation of the product's toxicological profile. Recurring issues related to specific novel food categories were noted. The heterogeneous nature and the variable complexity of novel foods emphasize the challenge to tailor aspects of the evaluation approach to the characteristics of each individual product. Importantly, the scientific requirements for novel food applications set by EFSA are interrelated, and only a rigorous and cross-cutting approach adopted by the applicants when preparing the respective application dossiers can lead to scientifically sound dossiers. This is the first time that an in-depth analysis of the experience gained by EFSA in the risk assessment of novel foods and of the reasoning behind the most frequent scientific requests by EFSA to applicants is made
Safety of zinc l-carnosine as a Novel food pursuant to Regulation (EU) 2015/2283 and the bioavailability of zinc from this source in the context of Directive 2002/46/EC on food supplements
Requestor: European Commission Question number: EFSA-Q-2020-00263 Correspondence: [email protected] reviewedPublisher PD
Scientific opinion on the evaluation of substances as acceptable previous cargoes for edible fats and oils
The Panel wishes to thank the members of the Working Group on acceptable previous cargoes for edible fats and oils â Previous cargoes 2016: Bettina Grasl-Kraupp, Konrad Grob, AndrĂ© Penninks and Christiane Vleminckx and EFSA staff members: Marco Binaglia and Ruth RoldĂĄn Torres. The Panel acknowledges the European Chemicals Agency that provided data on ammonium sulphate.Peer reviewedPublisher PD
Safety of vitamin D2 mushroom powder as a Novel food pursuant to Regulation (EU) 2015/2283 (NF 2019/1471).
Requestor: European Commission Question number: EFSA-Q-2020-00417 Correspondence: [email protected] reviewedPublisher PD
Risk assessment of glycoalkaloids in feed and food, in particular in potatoes and potato-derived products
Acknowledgements: The Panel wishes to thank the following for the support provided to this scientific output: Kelly Niermans. The Panel wishes to acknowledge all European competent institutions, Member State bodies and other organisations that provided consumption and occurrence data for this scientific output.Peer reviewedPublisher PD
Safety of Vitamin D2 mushroom powder (Agaricus bisporus) as a Novel food pursuant to Regulation (EU) 2015/2283
Acknowledgements: The Panel wishes to thank Petra Gergelova for the support provided to this scientific opinion.Peer reviewedPublisher PD
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
EDUCACIĂN AMBIENTAL Y SOCIEDAD. SABERES LOCALES PARA EL DESARROLLO Y LA SUSTENTABILIDAD
Este texto contribuye al anĂĄlisis cientĂfico de varias ĂĄreas del conocimiento como la filosofĂa social, la patologĂa, la educaciĂłn para el cuidado del medio ambiente y la sustentabilidad que inciden en diversas unidades de aprendizaje de la Licenciatura en EducaciĂłn para la Salud y de la MaestrĂa en SociologĂa de la SaludLas comunidades indĂgenas de la sierra norte de Oaxaca MĂ©xico, habitan un territorio extenso de biodiversidad. Sin que sea una ĂĄrea protegida y sustentable, la propia naturaleza de la regiĂłn ofrece a sus visitantes la riqueza de la vegetaciĂłn caracterizada por sus especies endĂ©micas que componen un paisaje de suma belleza
Scientific and technical assistance to the evaluation of the safety of calcidiol monohydrate as a novel food
Abstract EFSA was asked by the European Commission to provide scientific assistance with respect to the EFSA adopted scientific opinion on âSafety of calcidiol monohydrate produced by chemical synthesis as a novel food pursuant to Regulation (EU) 2015/2283â, including its bioavailability as a metabolite of vitamin D3 when added for nutritional purposes to food supplements. On 5 July 2023, EFSA adopted the âScientific opinion on the tolerable upper intake level for vitamin D, including the derivation of a conversion factor for calcidiol monohydrateâ. This opinion concerns an updated exposure assessment for vitamin D and proposes a conversion factor for calcidiol monohydrate into vitamin D3 of 2.5 for labelling purposes. In addition, in reference to the EFSA opinion on the safety of calcidiol monohydrate, the Commission had received a letter from the pharmaceutical company EirGen Pharma Ltd requesting a revision of this opinion based on new data concerning calcidiol. Based on the information and data considered in this scientific technical report, EFSA concludes that the novel food calcidiol monohydrate proposed for use in food supplements is a bioavailable source of the biologically active metabolite of vitamin D, i.e. 1,25âdihydroxyvitamin D, that a conversion factor of 2.5 reflects the relative bioavailability of calcidiol vs vitamin D3 under the proposed conditions of use and use levels, and that it is safe under the proposed conditions of use and use levels, i.e. up to 10âÎŒg/day for children â„â11âyears old and adults, including pregnant and lactating women, and up to 5âÎŒg/day for children 3â10âyears of age