NRF2 mediated oxidative stress response activity during early in vitro bovine embryo development

Overcoming oxidative stress is one of the various embryo challenges to survive under suboptimal conditions during in vitro production of bovine embryos. Thus, the present study aimed to examine the ability of preimplantation bovine embryos to activate nuclear factor erythroid-derived 2-like 2 (NFE2L2 or NRF2)-mediated oxidative stress response and trigger their survival under oxidative stress conditions. An in vitro model was used to culture embryos under low (5%) oxygen tension as in bovine oviduct or high oxygen tension (20%), which is widely used in vitro culture of embryos. Early stage embryos including 2-, 4-, 8-, 16-cell and blastocyst stage embryos were generated under low (5%) or high (20%) oxygen level culture conditions. NRF2, NRF2 cytoplasmic inhibitor (KEAP1) and selected NRF2 target antioxidant genes expression were measured in each stage using quantitative real time PCR (qPCR). Reactive oxygen species (ROS) were evaluated in the blastocysts using green fluorescent probe. Our results revealed that the ROS level was high under 20 % compared to 5 % oxygen level in blastocysts. The transcription level of NRF2 and its downstream antioxidant genes was dramatically increased in 8-, 16-cell and blastocyst stage embryos under high compared to low oxygen level, while NRF2 inhibitor showed opposite expression pattern. In order to know whether NRF2 activity is associated with the embryo developmental competence, consequently NRF2 activity was compared in developmentally competent versus incompetent embryos. For this, the mRNA and protein expressions of NRF2 and the transcription level of its downstream antioxidant genes were compared in early (competent) vs. late (incompetent) cleaving 2-cell and blastocyst stage embryos. In the early developing blastocysts accompanied by low ROS level, NRF2 and its antioxidant target genes expression were increased. Likewise, protein expression pattern was observed in similar manner with more active nuclear NRF2. In conclusion, this study demonstrated that under oxidative stress conditions, pre-implantation bovine embryos are able to activate the NRF2-mediated oxidative stress response pathway, which is found to be correlated with their survival under in vitro condition.NRF2 vermittelte oxidative Stressreaktion während der frühen bovinen in vitro Embryoentwicklung Für bovine Embryonen ist das Überwinden von oxidativem Stress eine wichtige Herausforderung um in suboptimalen in vitro Entwicklungsbedingungen überleben zu können. Das Ziel dieser Studie war es, die Reaktionsfähigkeit und Überlebensfähigkeit von pre-implantierten bovinen Embryonen auf den durch den nuclear factor erythroidderived 2-like 2 (NFE2L2 oder NRF2)-vermittelten oxidativen Stress zu untersuchen. Für diese Studie wurde ein in vitro Kulturmodell mit unterschiedlicher Sauerstoffkonzentration (5%, 20%) etabliert. Dabei ähnelte die niedrige Sauerstofftension (5%) der im bovinen Eileiter und die höhere (20%) der die normalerweise zur in vitro Kultur von Embryonen benutzt wird. Frühe embryonal Stadien, 2-, 4-, 8-, 16-Zell- und Blastozystenstadien wurden unter geringen (5%) oder hohen (20%) Sauerstoffkonzentrationen kultiviert. Anschließend wurden die Genexpressionen von NRF2, NRF2 cytoplasmic inhibitor (KEAP1) und ausgewählten NRF2 Antioxidans-Zielgenen in den verschieden Stadien mittels quantitative real time PCR (qPCR) analysiert. Reactive oxygen species (ROS) wurden in Blastozyten mittels green fluorescent probe untersucht. Das Ergebnis zeigte, dass der ROS Spiegel in Blastozysten bei einer Sauerstofftension von 20% höher war im Vergleich zu der 5% Gruppe. Die Expression von NRF2 und seinen nachgeschalteten Antioxidans-Genen war unter einem hohen Sauerstoffspiegel im Vergleich zu einem niedrigeren in 8-, 16- Zell- und Blastozytenstadien dramatisch erhöht. Demgegenüber zeigte NRF2 Inhibition ein gegenteiliges Expressionsmuster. Um festzustellen, ob die NRF2 Aktivität mit der Embryoentwicklungsfähigkeit zusammen hängt, wurde die NRF2 Aktivität im Vergleich von entwicklungsfähigen zu nicht entwicklungsfähigen Embryonen untersucht. Dafür wurden die NRF2 mRNA- und Proteinexpressionen und die der Antioxidans-Gene im Vergleich von früh (kompetent) zu spät (inkompetent) entwickelten 2-Zell- und Blastozytenstadien analysiert. Die Genexpression von NRF2 und deren Antioxidans-Zielgenen war in früh entwickelten Blastozyten bei einem geringen ROS Spiegel erhöht. Ein ähnliches Bild zeigte sich für die Proteinexpression mit einem größeren aktiven Anteil an nuklearem NRF2. Schlussendlich zeigte diese Studie, dass unter oxidativen Stress pre-implantiere bovine Embryonen in der Lage sind den NRF2-vermittelten oxidativen Stressreaktionssignalweg zu aktivieren. Dieser steht in Korrelation zu der Überlebensfähigkeit unter in vitro Bedingungen

Strategic aspects of tourism development in UAE

The strategic aspects of the tourism development in the UAE have been discussed on variable forums and in different documents of the native government and refer to infrastructural, marketing, financial and organizational issues. The idea has been to raise the attractiveness and values of the domestic tourist industry. The aim of the paper is to present and analyze strategic aspects related to the competitiveness of the UAE as a tourist destination from a business point of view. The method of comparative analysis is used. The resources and the infrastructure of the destination, as well as the supporting services forming the business environment, have a significant impact on the competitiveness of UAE tourism development. The strategic path of tourism in the country is related to the coordination of all management levels – micro, mezzo and macro

Diagnostic accuracy of cone-beam computed tomography using different voxel sizes versus digital intraoral radiography in detection of vertical root fractures of teeth with metallic post

Background: Conventional radiographs are not an efficient diagnostic method to detect vertical root fracture (VRF). Cone-beam computed tomography (CBCT) overcomes the limitations of conventional radiography in the detection of VRF. In CBCT, metallic structures can cause artifacts in the images. Aim: This study aimed to determine the diagnostic accuracy of CBCT using different voxels in the detection of VRFs of teeth with metallic posts compared to digital intraoral radiography. Materials and Methods: A total of 120 single-rooted extracted human teeth were obtained and endodontically treated, then placed in an acrylic block and metallic posts were inserted. After post insertion, the teeth roots were divided into two groups one with induced VRFs and the other having intact roots with the posts inserted. Then, each tooth was coded and imaged 3 times using CBCT and digital periapical radiography (DPR). Results: DPR showed statistically significantly lower diagnostic accuracy than CBCT, and changing the voxel did not improve the diagnostic accuracy. Conclusion: In case of suspicious VRFs, CBCT is recommended to detect the presence of fractures. Clinical Significance: Since most teeth suspected to have VRFs are endodontically treated and have a metallic post in the root canal, fracture detection may pose a challenge CBCT resolves this issue

Bridging vs Non-Bridging with Warfarin Peri-Procedural Management: Cost and Cost-Effectiveness Analyses

The warfarin peri-procedural management in Qatar is predominantly based on bridging (63%), compared to non-bridging. This study sought to perform a first-time cost analysis of current warfarin peri-procedural management practices, including a cost-effectiveness analysis (CEA) of predominant bridging vs predominant non-bridging practices. From the hospital perspective, a one-year decision-analytic model followed the cost and success consequences of the peri-procedural warfarin in a hypothetical cohort of 10,000 atrial fibrillation patients. Success was defined as survival with no adverse events. Outcome measures were the cost and success consequences of the 63% bridging (vs not-bridging) practice in the study setting, ie, Hamad Medical Corporation, Qatar, and the incremental cost-effectiveness ratio (ICER, cost/success) of the warfarin therapy when predominantly bridging based vs when predominantly non-bridging based. The model was based on Monte Carlo simulation, and sensitivity analyses were performed to confirm the robustness of the study conclusions. As per 63% bridging practices, the mean overall cost of peri-procedural warfarin management per patient was USD 3,260 (QAR 11,900), associated with an overall success rate of 0.752. Based on the CEA, predominant bridging was dominant (lower cost, higher effect) over the predominant non-bridging practice in 62.2% of simulated cases, with a cost-saving of up to USD 2,001 (QAR 7,303) at an average of USD 272 (QAR 993) and was cost-effective in 36.9% of cases. Being between cost-saving and cost-effective, compared to predominant non-bridging practices, the predominant use of bridging with warfarin seems to be a favorable strategy in atrial fibrillation patients