36 research outputs found

    The cardioprotective effects of caffeic acid phenethyl ester (CAPE) on myocardial ischemia/reperfusion (I/R) injury

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    Oxidative stress plays a major role in causing reperfusion injury following prolonged ischemia. CAPE has been shown to have antioxidant, anti-inflammatory, and cardioprotective effects following regional myocardial ischemia/reperfusion injury. The effects and mechanisms of CAPE in global myocardial I/R injury are still unclear. In this study, CAPE was tested in isolated perfused rat hearts following global I (30 min)/R (60 min). We recorded left ventricular developed pressure (LVDP), left ventricular end systolic pressure (LVESP), the peak of the first derivative of left ventricular pressure (dP/dtmax), and infarct size. We found that untreated I/R hearts (n=11) recovered LVDP to 45 ± 8% (p\u3c0.05), LVESP to 106 ± 7% (p\u3c0.05), and dP/dtmax to 33 ± 5% (p\u3c0.05) of baseline values, respectively, at the end of 60 minutes reperfusion. By contrast, CAPE (40 mM, n=6) given at reperfusion for 5 minutes significantly restored LVDP to 75 ± 15%, LVESP to 133 ± 13%, and dP/dtmax to 54 ± 12% of baseline values, respectively (all p\u3c0.05). Moreover, CAPE also significantly reduced infarct size to 19 ± 2% (n=6) compared t

    The Effectiveness of Coenzyme Q1 and Q10 in Mitigating Myocardial Reperfusion/Ischemia (MI/R) Injury

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    Mitochondria may be a principle source of oxidative stress causing MI/R injury. Coenzyme Q10 (CoQ10) is essential for electron transport in normal mitochondria, has antioxidant properties but its bioavailability is likely reduced due to oxidative stress during MI/R. Coenzyme Q1 (CoQ1) is a derivative of CoQ10, but is a more potent antioxidant than CoQ10 due to a shorter isoprene chain. We hypothesize that CoQ1 will exhibit better cardioprotective effects during MI/R. CoQ1 (MW=250 g/mol; 20 μM, n=5) and CoQ10 (MW=863 g/mol; 20 μM, n=5) were given at reperfusion in isolated rat hearts subjected to I (30 min)/R (45 min). We found that MI/R hearts (n=7) and MI/R+DMSO hearts (n=4) (0.2% DMSO was used to solubilize CoQ1 and CoQ10) exhibited significantly compromised cardiac contractile/diastolic pressures and coronary flow during reperfusion compared to those of sham hearts (n=5). By contrast, the final left ventricular developed pressure was significantly improved by CoQ1 treatment (56.0±5.3 mmHg), but not CoQ10 treatment (38.4±8.6 mmHg), when compared to that in MI/R hearts (33.6±6.2 mmHg) and MI/R+DMSO hearts (36.4±9.7 mmHg) (p\u3c0.05). Similarly, the final peak of the firstderivative of left ventricular pressure was significantly higher in CoQ1 treatment (1294.2±104.6mmHg/s), but not CoQ10 treatment (770.6±120.1 mmHg/s), when compared to that in MI/R hearts (700.6±134.7 mmHg/s) and MI/R+DMSO hearts (and 741.5±168.6 mmHg/s) (p\u3c0.05). CoQ1 and CoQ10 treated hearts showed no improvement on diastolic pressure and coronary flow compared to the controls. Moreover, infarct size was reduced by CoQ1 treatment (25±3%) and CoQ10 treatment (29±4%) compared to that in untreated MI/R (44±6%) and MI/R+DMSO (35±3%). In summary, our preliminary results indicate that CoQ1 was more effective than CoQ10 in restoring post-reperfused cardiac contractile function, but not infarct size during MI/R

    Application of Unmanned Aerial Vehicles in Emergency Medical Situations

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    Introduction One of the significant impacts on patient outcome in emergency medical situations is the response time taken for trained personnel and equipment arrival on scene. The National EMS Information System states the average response time to reach adult patients in the United States is 9.4 minutes (1). We are exploring the whether the application of Unmanned Aerial Vehicle (UAV) technology in emergency situations would shorten response time and subsequently could improve patients’ outcome In this reported on first phase (Phase 1) of an envisioned multi-stage project, we tested the ability of a UAV to properly, efficiently transport a a portable ECG device to a mock emergency site and successfully take an ECG reading when used by an untrained personnel on hand. MethodsOur UAV was a DJI Phantom 2 Vision model, a quadcopter equipped with a 14 Megapixel camera and HD video recording capabilities. The onboard camera allows for real time transmission of patient status and appearance, while the quadcopter model allows for maximum weight to lift ratio. In order to record a portable ECG, we equipped an iPhone 5 with an AliveCor Kardia mobile ECG monitor. We included an easy to use protocol for the AliveCor so that a layperson would be able to operate the machine. DataThe total flight time for 100 yards across an open field was two and a half minutes , or approximately 2 feet/second. This data shows a chi-squared distribution of 5.065, with a p-value of .01 (df=1, p\u3c.05). DiscussionDue to the statistically significant p-value, Phase 1 data demonstrates that our UAV was capable of traversing an appropriate distance in an amount of time that drastically improves upon the emergency response call time taken by traditional methods. In addition to our flight data, we were also able to properly operate the ECG and apply it to a mock patient in under 90 seconds, showing that our protocol, with instructions for usage, was clear and precise. Conclusion: This study is considered Phase 1 of a multi-stage investigation. Moving forward, we hope to improve the efficacy of our UAV, while expanding its the technological and medical capabilities, allowing it to not only carry ECG but also possibly AEDs and pharmaceuticals. Ultimately, We hope to apply such technology to emergencies in both rural and urban environments, as well as adapt it for use within the military

    Estimating the infection and case fatality ratio for coronavirus disease (COVID-19) using age-adjusted data from the outbreak on the Diamond Princess cruise ship, February 2020.

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    Adjusting for delay from confirmation to death, we estimated case and infection fatality ratios (CFR, IFR) for coronavirus disease (COVID-19) on the Diamond Princess ship as 2.6% (95% confidence interval (CI): 0.89-6.7) and 1.3% (95% CI: 0.38-3.6), respectively. Comparing deaths on board with expected deaths based on naive CFR estimates from China, we estimated CFR and IFR in China to be 1.2% (95% CI: 0.3-2.7) and 0.6% (95% CI: 0.2-1.3), respectively

    Unexposed populations and potential COVID-19 hospitalisations and deaths in European countries as per data up to 21 November 2021.

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    We estimate the potential remaining COVID-19 hospitalisation and death burdens in 19 European countries by estimating the proportion of each country's population that has acquired immunity to severe disease through infection or vaccination. Our results suggest many European countries could still face high burdens of hospitalisations and deaths, particularly those with lower vaccination coverage, less historical transmission and/or older populations. Continued non-pharmaceutical interventions and efforts to achieve high vaccination coverage are required in these countries to limit severe COVID-19 outcomes

    Response strategies for COVID-19 epidemics in African settings: a mathematical modelling study.

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    BACKGROUND: The health impact of COVID-19 may differ in African settings as compared to countries in Europe or China due to demographic, epidemiological, environmental and socio-economic factors. We evaluated strategies to reduce SARS-CoV-2 burden in African countries, so as to support decisions that balance minimising mortality, protecting health services and safeguarding livelihoods. METHODS: We used a Susceptible-Exposed-Infectious-Recovered mathematical model, stratified by age, to predict the evolution of COVID-19 epidemics in three countries representing a range of age distributions in Africa (from oldest to youngest average age: Mauritius, Nigeria and Niger), under various effectiveness assumptions for combinations of different non-pharmaceutical interventions: self-isolation of symptomatic people, physical distancing and 'shielding' (physical isolation) of the high-risk population. We adapted model parameters to better represent uncertainty about what might be expected in African populations, in particular by shifting the distribution of severity risk towards younger ages and increasing the case-fatality ratio. We also present sensitivity analyses for key model parameters subject to uncertainty. RESULTS: We predicted median symptomatic attack rates over the first 12 months of 23% (Niger) to 42% (Mauritius), peaking at 2-4 months, if epidemics were unmitigated. Self-isolation while symptomatic had a maximum impact of about 30% on reducing severe cases, while the impact of physical distancing varied widely depending on percent contact reduction and R0. The effect of shielding high-risk people, e.g. by rehousing them in physical isolation, was sensitive mainly to residual contact with low-risk people, and to a lesser extent to contact among shielded individuals. Mitigation strategies incorporating self-isolation of symptomatic individuals, moderate physical distancing and high uptake of shielding reduced predicted peak bed demand and mortality by around 50%. Lockdowns delayed epidemics by about 3 months. Estimates were sensitive to differences in age-specific social mixing patterns, as published in the literature, and assumptions on transmissibility, infectiousness of asymptomatic cases and risk of severe disease or death by age. CONCLUSIONS: In African settings, as elsewhere, current evidence suggests large COVID-19 epidemics are expected. However, African countries have fewer means to suppress transmission and manage cases. We found that self-isolation of symptomatic persons and general physical distancing are unlikely to avert very large epidemics, unless distancing takes the form of stringent lockdown measures. However, both interventions help to mitigate the epidemic. Shielding of high-risk individuals can reduce health service demand and, even more markedly, mortality if it features high uptake and low contact of shielded and unshielded people, with no increase in contact among shielded people. Strategies combining self-isolation, moderate physical distancing and shielding could achieve substantial reductions in mortality in African countries. Temporary lockdowns, where socioeconomically acceptable, can help gain crucial time for planning and expanding health service capacity

    Reconstructing the early global dynamics of under-ascertained COVID-19 cases and infections

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    AbstractBackgroundAsymptomatic or subclinical SARS-CoV-2 infections are often unreported, which means that confirmed case counts may not accurately reflect underlying epidemic dynamics. Understanding the level of ascertainment (the ratio of confirmed symptomatic cases to the true number of symptomatic individuals) and undetected epidemic progression is crucial to informing COVID-19 response planning, including the introduction and relaxation of control measures. Estimating case ascertainment over time allows for accurate estimates of specific outcomes such as seroprevalence, which is essential for planning control measures.MethodsUsing reported data on COVID-19 cases and fatalities globally, we estimated the proportion of symptomatic cases (i.e. any person with any of fever &gt;= 37.5°C, cough, shortness of breath, sudden onset of anosmia, ageusia or dysgeusia illness) that were reported in 210 countries and territories, given those countries had experienced more than ten deaths. We used published estimates of the baseline case fatality ratio (CFR), which was adjusted for delays and under-ascertainment, then calculated the ratio of this baseline CFR to an estimated local delay-adjusted CFR to estimate the level of under-ascertainment in a particular location. We then fit a Bayesian Gaussian process model to estimate the temporal pattern of under-ascertainment.ResultsBased on reported cases and deaths, we estimated that, during March 2020, the median percentage of symptomatic cases detected across the 84 countries which experienced more than ten deaths ranged from 2.4% (Bangladesh) to 100% (Chile). Across the ten countries with the highest number of total confirmed cases as of 6th July 2020, we estimated that the peak number of symptomatic cases ranged from 1.4 times (Chile) to 18 times (France) larger than reported. Comparing our model with national and regional seroprevalence data where available, we find that our estimates are consistent with observed values. Finally, we estimated seroprevalence for each country. As of the 7th June, our seroprevalence estimates range from 0% (many countries) to 13% (95% CrI: 5.6% – 24%) (Belgium).ConclusionsWe found substantial under-ascertainment of symptomatic cases, particularly at the peak of the first wave of the SARS-CoV-2 pandemic, in many countries. Reported case counts will therefore likely underestimate the rate of outbreak growth initially and underestimate the decline in the later stages of an epidemic. Although there was considerable under-reporting in many locations, our estimates were consistent with emerging serological data, suggesting that the proportion of each country’s population infected with SARS-CoV-2 worldwide is generally low.FundingWellcome Trust, Bill &amp; Melinda Gates Foundation, DFID, NIHR, GCRF, ARC.</jats:sec

    The genomes of two key bumblebee species with primitive eusocial organization

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    Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

    Inferring the number of COVID-19 cases from recently reported deaths.

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    We estimate the number of COVID-19 cases from newly reported deaths in a population without previous reports. Our results suggest that by the time a single death occurs, hundreds to thousands of cases are likely to be present in that population. This suggests containment via contact tracing will be challenging at this point, and other response strategies should be considered. Our approach is implemented in a publicly available, user-friendly, online tool

    Daily magnesium fluxes regulate cellular timekeeping and energy balance

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    Circadian clocks are fundamental to the biology of most eukaryotes, coordinating behaviour and physiology to resonate with the environmental cycle of day and night through complex networks of clock-controlled genes1, 2, 3. A fundamental knowledge gap exists, however, between circadian gene expression cycles and the biochemical mechanisms that ultimately facilitate circadian regulation of cell biology4, 5. Here we report circadian rhythms in the intracellular concentration of magnesium ions, [Mg2+]i, which act as a cell-autonomous timekeeping component to determine key clock properties both in a human cell line and in a unicellular alga that diverged from each other more than 1 billion years ago6. Given the essential role of Mg2+ as a cofactor for ATP, a functional consequence of [Mg2+]i oscillations is dynamic regulation of cellular energy expenditure over the daily cycle. Mechanistically, we find that these rhythms provide bilateral feedback linking rhythmic metabolism to clock-controlled gene expression. The global regulation of nucleotide triphosphate turnover by intracellular Mg2+ availability has potential to impact upon many of the cell’s more than 600 MgATP-dependent enzymes7 and every cellular system where MgNTP hydrolysis becomes rate limiting. Indeed, we find that circadian control of translation by mTOR8 is regulated through [Mg2+]i oscillations. It will now be important to identify which additional biological processes are subject to this form of regulation in tissues of multicellular organisms such as plants and humans, in the context of health and disease
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