It is generally accepted that animal heartbeat and lifespan are often inversely correlated, however, the relationship between productivity and longevity has not yet been described for trees growing under industrial and pre-industrial climates. Using 1768 annually resolved and absolutely dated ring width measurement series from living and dead conifers that grew in undisturbed, high-elevation sites in the Spanish Pyrenees and the Russian Altai over the past 2000 years, we test the hypothesis of grow fast—die young. We find maximum tree ages are significantly correlated with slow juvenile growth rates. We conclude, the interdependence between higher stem productivity, faster tree turnover, and shorter carbon residence time, reduces the capacity of forest ecosystems to store carbon under a climate warming-induced stimulation of tree growth at policy-relevant timescales. 2. Here the authors analyse ring width measurements from 1768 conifers from the Spanish and Russian mountains and demonstrate that longevity requires slow growth rates at least in mountainous regions.Fertilization under greenhouse warming conditions is expected to accelerate tree growth and potentially increase the biological storage of CO Our lack of understanding has an important bearing on the current debate about carbon sequestration2, carbon residence time3, and climate change mitigation7. This knowledge gap is disconcerting as faster tree growth under future climate change is expected to lead to higher forest carbon stocks, thereby contributing to the mitigation of the anthropogenic greenhouse effect via the biological uptake of carbon dioxide (CO2). The assumption that a climate warming-induced increase of tree growth translates into large-scale carbon sequestration is a paradigm that has far-reaching political, ecological and economic consequences9. The concept of negative emission, vis-a-vis secondary forests, has generated much governmental and institutional action10; the Bonn Challenge being one example11, already causing a multitude of societal and environmental implications12.Despite a wide range of recent advancements in tree-ring research13. Accelerated growth rates of juvenile trees in dense forest stands permit individual trees to escape from becoming victims of competitive exclusion, which potentially turns into increased longevity, both within monocultures and mixed populations15. In more open forests, such as those of the upper alpine and northern boreal treeline ecotones, a distinction between interspecific and intraspecific effects on tree longevity is needed. Though it is generally accepted that fast growing, pioneer tree species exhibit overall lower wood density and a shorter life expectancy16, which jointly translates into a limited capacity for carbon sequestration, it is still unknown if later successional species growing under cold and temperate climates could live longer if they grew slower during their late adolescence and early adult life. Since this seems to be the case for many humid tropical taxa18, tree mortality rates are often positively correlated with forest net primary productivity18, whereas our understanding of size-specific tree mortality patterns is challenged by a lack of suitable data19.The putative tradeoff between the rate of tree growth and achieved tree lifespan is complicated by complex interactions between the composition and density of forest stands and the possibility that trees can switch their growth strategy once they reach a certain size20, whereas slower growing individuals get older and taller23. This observation resembles the rate of life concept in animal sciences24, in which high metabolic rates are negatively correlated with longevity. Such a diversity of life histories affects the architecture, age structure, and biomass turnover rates of forest communities25, and thus, to a large degree, the terrestrial carbon stock9. On a global scale, the short but fast life of trees is associated with reduced carbon reservoirs (short carbon residence time)20. For example, the highly productive southern and western Amazonian forests store less carbon26 than their less productive eastern counterparts27, and the same discrepancy is found between temperate and boreal forests28. In tropical Borneo, faster growing forests are found to contain less aboveground carbon density compared to slower growing sites simply due to differences in carbon residence time29. Although old trees reveal substantial annual biomass increments30, relatively little is known about the intraspecific tradeoffs between post-juvenile growth rates, plant height and stem diameter, as well as the lifespan of trees31. Are old, high-carbon-stock trees intrinsically slow growers23? Though, it has been argued that the tallest trees are also among the oldest32, it is not known whether this relates to lower growth rates earlier in life. If the size and/or age distribution of forest stands, together with the occurrence of disturbance events33, determines the extent of forest carbon stock, then the rate of forest carbon turnover (carbon residence time) is of paramount significance for estimating the long-term net CO2 capture from the Earth’s atmosphere35.Trees that grow fast beyond their juvenile seedling-sapling stage, commonly exhibit an accelerated life cycle2 concentrations on tree growth can be examined experimentally under controlled conditions36, their influence on the lifespan of trees cannot. This is where dendroecology can provide unique insights into extra-tropical, inter-annual tree growth variability at centennial to millennial time-scales38. However, dendrochronological candidate collections must fulfill numerous criteria that are commonly not addressed in traditional dendroclimatological/ecological tree-ring studies40. To begin with, a large sample size of several hundreds to thousands of recent (living) and relict (dead) tree stems cross-sections, ideally consisting largely of disc samples that include the innermost ring, or core samples with reliable pith-offset estimates, are needed in order to provide sufficient statistical confidence for precise age and growth rate determinations. In addition, the species- and site-specific inventories of annual tree-ring width measurements, preferably from stem discs, rather than increment cores, must be characterized by a homogeneous distribution of the constituent series’ start and end dates over past centuries to represent pre-industrial climate conditions. The samples also need to contain a wide range of individual tree ages and growth levels. Moreover, the appropriate datasets should represent trees that grow in open environments, where year-to-year and longer-term ring width variations are largely constrained by growing-season temperatures, rather than between-tree competition. Finally, the collection sites should be free of silvicultural treatments, and minimally affected by natural disturbances33, such as cyclic insect defoliations and/or stochastic forest fires.While the influence of climate change, nutrient availability and rising COThis study provides a conceptual framework to examine the growth-lifespan tradeoff in two conifer species and uses tree-ring width measurements from living and relict tree stem cross-sections to address the question: To what extent does the growth rate and lifespan of trees, within given species population, co-vary?To meet the aforementioned criteria, and provide a dendroecological perspective on the relationship between plant lifespan and radial stem growth, we use annually resolved and absolutely dated tree-ring information from 1768 conifers that lived during the past two millennia in the Spanish Pyrenees and the Russian Altai. Due to the sites’ remote locations, we assume there are no direct anthropogenic disturbances affecting tree growth rates (as opposed to possible indirect affects vis-à-vis climate change). We consider the following three categorical hypotheses  in the Spanish Pyrenees42, and 660 comparable samples (147 living and 513 relict tree stems) of Siberian larch (Larix sibirica Ledeb.) from the Russian Altai43 .Based on the evidence of 749 living and 1019 relict tree-ring measurement series, representing species-specific conifer ring widths over the past 1000 and 2000 years at undisturbed high-elevation sites in the Spanish Pyrenees and Russian Altai, this study suggests that accelerated tree growth  is unlikely to translate into enhanced carbon sequestration, thereby mitigating the global greenhouse effect. The data illustrate that increased biomass productivity leads to reduced tree longevity  and gymnosperms (Sequoia sempervirens (D.Don) Endl.; coastal redwood), are believed to relate to apical turgor maintenance45 irrespective of whether trees possess vessels or just tracheid cells, and explains why such giants are confined to humid areas46.By accepting H3 and rejecting H1 and H2  must be rejected.Although site-specific and species-specific, our results warn against scaling from growth rates to carbon stocking without accounting for tree lifespan and stand turnover (shifts in demography)Pinus uncinata Ramond ex DC.) trees were collected at two upper treeline sites in the most northern part of the Aigüestortes i Estany de Sant Maurici National Park in the central Spanish Pyrenees42. This region is characterized by undisturbed, open ecotone habitats between around 2300 and 2600 m asl.During several field campaigns since 2004, disc and core samples from 1108 living and dead Mountain pine (Larix sibirica Ledeb.) trees were collected at five upper treeline sites across the Russian Altai-Sayan Mountains43. This region also is characterized by undisturbed, open forests around 2000–2400 m asl. High-elevation tree growth in both regions is predominantly controlled by summer temperature conditions. Individual trees at all sites can reach ages of up to 1000 years. The abundance of dead wood in the Altai and Pyrenees is indicative of remote locations with little to no modification by humans, or disturbance due to grazing by wild or domestic animals.Over the past decade, stem discs and a few increment cores from 660 living and dead Siberian larch (All disc and core samples were air-dried and polished with sand paper of progressively finer grain size down to 800 grit. Tree-ring width (TRW) was measured at a resolution of 0.001 mm using LINTAB measuring systems, and cross-dated via TSAP-win and PAST4 software. All dating was verified with COFECHA (Version 6.02 P). The germination year (birth) of each tree was defined by the calendar date of its pith. In those cases where samples had no pith, pith-offset estimates were calculated, by fitting a geometric pith locator to the innermost rings and converting this distance into the number of missing rings. The dated TRW measurements were transformed into basal area increments (BAI) to account for the geometric constraints of adding incremental growth to an ever-increasing surface area.Linear functions fitted to the log-transformed data of the first 25, 50, or 75 years of juvenile tree growth in all 1108 and 660 individual series of TRW and BAI from the Pyrenees and Altai, and plotted against total tree age, describe the overall tradeoff between the productivity (growth) and longevity (lifespan) of trees. Mean TRW and BAI of the juvenile tree growth of all samples ≤ 200 and ≥ 400 years further emphasize the tendency of younger trees to grow faster and older trees to grow slower. Finally, we performed the same analysis on the 506 and 513 relict (602 and 147 living) trees from the Pyrenees and Altai to test for the temporal stability in our results.Supplementary InformationSource Data


Then, to infer substructures within complexes, we apply a graph clustering method ) and a gene ontology (GO) semantic similarity based functional clustering on partially- and fully-connected networks, respectively. Computational results show that the proposed framework achieves fairly good performance of cross validation and independent test in terms of detecting direct contacts between subunits. Functional analyses further demonstrate the rationality of partitioning the subunits into substructures via the MMC algorithm and functional clustering.Understanding the physical arrangement of subunits within protein complexes potentially provides valuable clues about how the subunits work together and how the complexes function. The majority of recent research focuses on identifying protein complexes as a whole and seldom studies the inner structures within complexes. In this study, we propose a computational framework to predict direct contacts and substructures within protein complexes. In this framework, we first train a supervised learning model of l Saccharomyces cerevisiae. CORUM [Homo sapiens. Reactome [Homo sapiens. Interested readers can refer to References [Protein complexes have their individual gene products spatiotemporally arranged in place to form the structures required for specific biological activities . Systemae. CORUM  is a pube. CORUM  providesReactome ,7 providferences ,9 for coTo our knowledge, there are only several studies that investigate the inner structure of complexes. For instance, Gavin et al.  propose To gain knowledge about inner substructures of protein complexes, we systematically designed a two-step computational model. The first step was to predict the physical interactions between subunits within complexes, and the second step was to partition the subunit interaction networks into sub-complexes via graph clustering. In the first step, we needed to cautiously restrict the physical interactions within complexes  rather than between genome-scale individual proteins . Both methods ,12 prediThe second step was to infer sub-complexes from the predicted networks of physical subunit interactions within complexes. Drew et al.  calculatIn this study, we propose a computational framework that combined supervised learning and graph clustering to predict physical subunit interactions and infer substructures within human protein complexes. The direct and indirect interactions of training data were restricted within complexes. A graph clustering method, named maximum modularity clustering (MMC) , was useWe first show the flowchart of the proposed framework for easy grasp of the workflow. As illustrated in In the second phase, we conducted clustering on the predicted subunit interaction networks to identify sub-complexes. For partially-connected networks, we used topological clustering via maximum modularity clustering (MMC) ; and forTo learn the patterns of direct and indirect subunit interaction, we restricted the construction of training data within complexes. We first obtained physical protein–protein interactions from HPRD , BioGridWe further mapped the 57,920 physical PPIs to the co-complexed protein pairs from CORUM  and HPRDIn the proposed framework, the negative class refers to indirect subunit interactions within complexes. Besides the 163 indirect interactions from Reactome , we needions see .Two negative independent test sets containing 3326 and 2349 co-complexed indirect interactions were similarly sampled from CORUM , respectGene ontology (GO) has been reported to be the most discriminative feature to depict protein pairs and predict PPIs . Unfortui in the training set U, we obtained the homolog set of GO terms denoted as G is defined as follows.For each protein The feature vectors for target instance and homolog instance for protein pair g of feature vector for the target instance and homolog instance, respectively. The GO terms GO term g, the value of component g in both feature vector is set to 2; if neither protein possesses the GO term g, the value is set to 0; otherwise the value is set to 1. This simple method of feature representation intuitively represents the distribution of GO terms among two proteins without considering the hierarchical and semantic relationship between GO terms. As compared with the method that incorporates the ancestor GO terms in GO directed acyclic graph (DAG) [For a GO term ph (DAG) , this siph (DAG) . Due to 2-regularized logistic regression method [x and labels y that consist of a set of instance-label pairs 2-regularized logistic regression calculates the optimum weight vector Computational complexity and noise tolerance were two major concerns for us to choose the base classifier. Since a regularization technique can counteract the noise from homolog knowledge transfer and logistic regression performs well in fast training of large-scale data, we selected the well-established ln method  that is n method  as the cIn the test or prediction phase, the decision function As illustrated in V and a function f assigns an edge weight to each vertex pair. The degree of vertex v is defined as V into non-empty subsets Assuming that a graph edge set . The modv from its cluster The modularity increase caused by the refining operator that moves a vertex The coarsening and refining operator iterate greedily until no modularity increase , the semantic similarity between GO term GO semantic similarities could be aggregated to define gene similarity via the methods of maximum, average and best-match average . In this2-regularized logistic regression model is evaluated under three experimental settings, namely combined-instance, homolog-instance and target-instance. The combined-instance setting uses both target instances and homolog instances to evaluate the model; the homolog-instance setting uses homolog instances alone to evaluate whether the model is robust against GO unavailability; and the target-instance setting uses target instances to estimate the baseline performance. We adopted five performance metrics, i.e., receiver operating characteristic (ROC) and area under the curve (AUC) (ROC-AUC), precision (PR), specificity (SE), Matthews correlation coefficient (MCC) and F1 score. Among these metrics, PR, SE and MCC were derived from a confusion matrix M, where its element M via Formula (14). The we calculated the class-specific metrics PRl, SEl and MCCl via Formula (15). The overall MCC is calculated via Formula (16).L denotes the number of labels. For binary classification, L is equal to two. The AUC score was calculated on the basis of the decision values calculated via Formula (5). The F1 score is defined as follows:The lP matchec the actual set of sub-complexes C.To measure the performance of graph clustering, we used a Jaccard index to estimate how well the predicted set of sub-complexes P matches C if Given a threshold As mentioned in the subsection “Negative training and independent test data”, the negative data were sampled from two sources: (1) the co-complexed protein pairs that no path existed between them in human physical PPI networks (No-path); and (2) the co-complexed protein pairs connected via paths whose path lengths all were no less than two (No-less-than-two). The sampling ratio As illustrated in The performance measured via precision, sensitivity and MCC on the positive and negative class is provided in N subunits, there are potentially maximum N × (N − 1)/2 physical interactions or edges, i.e., a complete graph. For a complex that is predicted to possess M physical subunit interactions, we define the connection degree as We used the trained model to further predict the physical subunit interactions within complexes from CORUM . After rFor the complexes whose subunits are predicted to be partially connected, we used the maximum modularity clustering method (MMC)  to identWe further conducted functional GO enrichment analyses of the four sub-complexes within the CEN complex. Top five GO terms were provided for each sub-complex. As illustrated in As illustrated in Further GO enrichment analyses of the sub-complexes within ALL-1 supercomplex are illustrated in To our knowledge, there are only two studies on inferring direct contacts and substructures within complexes ,12. BothThe two methods ,12 do noThe two related studies ,12 dividNevertheless, we still compared the maximum modularity clustering method (MMC)  used by om CORUM  and HPRDver, MCL  at most ver, MCL  and HPRDIf the Jaccard index threshold C method  excelledC method  and was 2-regularized logistic regression model. The computational results of cross validation and independent test show that the proposed framework outperformed the related methods in terms of predicting direct subunit contacts within complexes.A fine-grained resolution of direct subunit contacts and inner substructures within complexes is significant to understanding how complexes work. To the best of our knowledge, there are very few computational studies on predicting substructures within complexes to date. The two related studies ,12 use tTopological clustering of directly-contacted subunits requires sophisticated graph clustering techniques to infer the hierarchical and overlap substructures within complexes. In this study, we employed the maximum modularity clustering method (MMC) to infer sub-complexes from the predicted networks of physical subunit interaction. For the fully-connected complexes, we used GO semantic similarity based functional clustering to infer the inner substructures. As compared to the related studies, this proposed framework demonstrated two major advantages. First, the sampling of direct and indirect subunit interactions was restricted within complexes, so that the trained model was more biologically interpretable. Second, we used MMC method and functional clustering method to infer the hierarchical and overlap substructures within partially-connected and fully-connected complexes, respectively. The predicted direct contacts and substructures within complexes potentially provide valuable clues for future biomedical research.


CT). We subsequently describe and test the accuracy of a novel noninvasive FFRCT-derived percutaneous coronary intervention (PCI) planning tool (FFRCT-P) in predicting the true significance of individual stenoses.Fractional flow reserve (FFR) is commonly used to assess the functional significance of coronary artery disease but is theoretically limited in evaluating individual stenoses in serially diseased vessels. We sought to characterize the accuracy of assessing individual stenoses in serial disease using invasive FFR pullback and the noninvasive equivalent, fractional flow reserve by computed tomography (FFRCT-derived post hoc for each vessel and stenosis (FFRCT). Before PCI, the invasive hyperemic pressure-wire pullback was performed to derive the apparent FFR contribution of each stenosis (FFRpullback). The true FFR attributable to individual lesions (FFRtrue) was then measured following PCI of one of the lesions. The predictive accuracy of FFRpullback, FFRCT, and the novel technique (FFRCT-P) was then assessed against FFRtrue. From the 24 patients undergoing the protocol, 19 vessels had post hoc FFRCT and FFRCT-P calculation. When assessing the distal effect of all lesions, FFRCT correlated moderately well with invasive FFR . For lesion-specific assessment, there was significant underestimation of FFRtrue using FFRpullback  and conventional trans-lesional FFRCT . Using FFRCT-P, stenosis underestimation was significantly reduced to a 7% error .Patients with angiographic serial coronary artery disease scheduled for PCI were enrolled and underwent prospective coronary CT angiography with conventional FFRCT significantly underestimate true stenosis contribution in serial coronary artery disease. A novel noninvasive FFRCT-based PCI planner tool more accurately predicts the true FFR contribution of each stenosis in serial coronary artery disease.FFR pullback and conventional FFR CT) growing in popularity.Fractional flow reserve (FFR) is commonly used to assess the functional significance of coronary artery disease with noninvasive estimation using FFR by computed tomography .This study describes a novel noninvasive FFRCT more accurately predicts the true FFR contribution of each stenosis in serial coronary artery disease, compared with conventional FFR pullback and FFRCT outputs.We show that FFRThe findings of this study would support further large-scale studies examining the validity and applicability of this novel noninvasive percutaneous coronary intervention planning tool.2 Owing to a relatively low positive predictive value and inability to determine functional significance,2 CTA has generally been used in patients at a low to intermediate risk with a view to ruling out significant CAD.3 When coronary atheroma is detected, there is growing evidence that the benefit of revascularization is only derived from targeting myocardial ischemia.4 Ischemia-guided revascularization has evolved to identifying vessels with functionally significant disease at the time of angiography using indices such as fractional flow reserve (FFR).7 In recent years it has become possible to estimate FFR from standard coronary CTA data sets with FFR by computed tomography (FFRCT). Based on computational fluid dynamics (CFD), FFRCT has been shown to increase the positive predictive value of coronary CTA and provide clinicians with a noninvasive test to assess coronary anatomy and physiology.10Coronary computed tomographic angiography (CTA) is now established as a noninvasive test for the detection of significant coronary artery disease (CAD).CT have largely been in vessels with single epicardial stenoses.11 In reality, CAD is often diffuse in nature with serial stenoses across the length of a vessel. Assessment of the contribution of each stenosis is challenging because physiological interplay affects the FFR attributable to each stenosis.13 Coronary CTA enables detailed visualization of lesion geometry and a potential to evaluate the true pressure drop across a stenosis by modeling the hemodynamic interplay between serial stenoses.13 FFRCT, therefore, offers the potential to predict the functional significance of individual stenoses within a serially/diffusely diseased vessel, and therefore, to predict the residual functional disease burden following PCI.The studies validating both invasive FFR and FFRCT-derived PCI planning tool (FFRCT-P), which models physiological interplay between stenoses. This tool is based on a reduced order model informed by 3-dimensional simulations of blood flow to estimate post-PCI pressure loss. In this study we aimed to: (1) characterize the accuracy of estimating individual stenosis significance in serially diseased vessels using invasive FFR pullback and conventional FFRCT outputs  and (2) validate the novel noninvasive FFRCT-P in a clinical cohort of patients with serial disease, with the aim of comparing the accuracy to estimations made from conventional FFR pullback and FFRCT.In this study, we describe a novel noninvasive FFRThe data that support the findings of this study are available from the corresponding author on reasonable request.All patients recruited to the study gave informed consent. Patients had presented with symptoms of stable angina and had ≥2 stenoses on an invasive coronary angiogram . Patients were only eligible if the segments of disease were separated by a normal segment of at least 10 mm, if it were felt feasible to treat each lesion independently by PCI. Exclusion criteria were age <18 years, pregnancy, estimated golmerular filtration rate <30, previous coronary artery bypass grafting, and contraindications to FFR assessment or CTA. Cardiac catheterization was performed within 4 weeks of the prior CTA scan. The study protocol was approved by the United Kingdom Health Research Authority and local research ethics committee (15/LO/2011).All patients underwent coronary CT angiography using a 2×192-slice dual source CT scanner , Germany. Eight hundred microgram of sublingual glyceryl trinitrate was administered to all patients along with intravenous metoprolol to achieve a heart rate of <65 bpm in sinus rhythm and <100 bpm in atrial fibrillation. A total of 85 mL intravenous contrast  was injected at 5.5 mL/s) by a power injector into the antecubital vein. Descending aorta contrast triggered, prospective ECG gated scanning with adaptive padding was then performed in a single breath-hold technique after a 10 to 12-second delay. The scanning parameters included a heart rate dependent pitch of 0.2 to 0.45 and a gantry rotation time of 250 ms. The tube voltage was selected semi-automatically, and automated exposure control was used for the tube current. Image slices were reconstructed using a medium sharp kernel (Bv40), using model-based iterative reconstruction strength level 3 .CT analysis was performed by HeartFlow, who were blinded to the invasive angiographic and physiological data. FFRCT data were derived post hoc from the CTA data set using methodology that has been previously described.14 In summary, FFRCT technology involves extraction of a patient-specific geometric model of the coronary arteries from CTA data. Subsequently, this is combined with population-derived physiological models and CFD techniques to solve the governing equations of blood flow velocity and pressure under simulated hyperemic conditions.14 FFRCT physiological models are based on 3 core scientific principles: an allometric scaling law relating coronary flow to myocardial mass and vessel lumen volume, the principle of flow regulation of vessel size, and an assumption of the predictable reduction of microvascular resistance with maximal hyperemia.15FFRCT v2.7 was used. This software runs on the Amazon Web Services cloud and combines deep-learning artificial intelligence methods16 to create physiological models that incorporate vessel lumen volume and myocardial mass data.15 Normal HeartFlow FFRCT outputs involve a color-coded chart of continuous FFRCT values computed along each vessel. The apparent change in these discrete values across each stenosis within the serially diseased vessel was used to define the attributable FFRCT for each stenosis within the serially diseased vessel, using conventional FFRCT methods without the planning tool.In this study, HeartFlow FFRCT for different planning configurations of PCI, an accelerated method for updating FFRCT was used (based on a reduced order model derived from CFD simulations). Without compromising on the accuracy of FFRCT, this approach is able to update FFRCT solutions in real-time in response to changes in lumen geometry. We ensured accuracy was not compromised by comparing the performance of FFRCT-P against full conventional FFRCT 3D simulations performed on the same models (N=80) and observed that the accuracy was statistically equivalent to that of FFRCT . Initially, idealized vessel lumen radii are calculated by first evaluating percent diameter stenosis and subsequently calculating the radius at which there would be no lumen narrowing . Following this, a patient-specific idealized model is constructed using the idealized lumen radii. Finally, a CFD-derived reduced order model is used to calculate the updated FFRCT values.To enable the fast recalculation of FFRR=Rin+RslQ, where Rin and Rsl are the intercept and slope of the resistance-flow relationship, Q is the flowrate and  R= ΔPQis the resistance posed by the epicardial vessel to blood flow. Since these quantities also depend on the epicardial geometry, 2 different flowrates are used to calculate Rin and Rsl. In each of the original and idealized geometries, 2 different boundary conditions, the first being hyperemia as described in the previous section and the second being a 40% lower resistance, are applied. If the flowrates achieved are Q and Q*, and the corresponding resistances calculated from CFD simulations are R and R* then:This method involves CFD-derived reduced order model based on a flow-dependent resistance model for the epicardial arteries, Q*−Q, is too low, then the intercept and slope are replaced with a 1D CFD model parameterized by lumen area (A), viscosity (μ), density (ρ), asIf the flow difference achieved, CT. For the purposes of this study, FFRCT-P of each stenosis was derived following the retrospective application of these calculations to CTA images, blinded to invasive FFR values but with knowledge of stent size and position. Figure CT planner tool in action.These resistances are applied on the updated lumen geometry , to solve for flow rates, pressures, and FFRAngiography was performed via the right radial artery using 6Fr catheters. Before catheterization, all patients received 300 mg of aspirin, 600 mg clopidogrel, and benzodiazepine sedation before local anesthetic was administered. Following arterial puncture, patients received 500 to 1000 μg isosorbide dinitrate into the radial artery before cardiac catheters were advanced and a further intracoronary bolus before the acquisition of standard diagnostic images.−1 min−1 via an antecubital vein. FFR was defined as the lowest Pd/Pa ratio averaged over 5 cardiac cycles following the onset of adenosine.17 Following documentation of FFR, the pressure-wire was pulled back to the guide catheter during continuous adenosine infusion at a constant speed (roughly 1 mm/s). This was done through the whole of the vessel, regardless of what the operator felt was a significant stenosis.Before insertion, the pressure-wire was zeroed outside of the body, against a fluid-filled guiding catheter pressure-transducer positioned at the level of the right atrium. After insertion, the pressure sensor was normalized to aortic pressure at the coronary ostium, with the guide disengaged where necessary. The pressure wire tip was delivered to the distal part of the serially-diseased vessel, beyond the distal stenosis (far enough to minimize the effect of post-stenotic turbulent flow), with wire position documented fluoroscopically. An IV adenosine infusion was administered at a dose 140 µg kgpullback. PCI was then performed, with the choice of stenosis treated at the discretion of the operator using their conventional practice. Following re-calibration, pressure-wire pullback was then repeated (ensuring the stented segment no longer poses any pressure gradient). The subsequent true change in hyperemic pressure gradient across the remaining stenosis in isolation was noted with the stenosis-attributable FFR termed FFRtrue . The difference between FFRtrue and FFRpullback was indicative of the degree of stenosis underestimation in serial CAD. The relationship between the extent of stenosis underestimation and total vessel FFR (the cumulative FFR in the vessel before PCI when both stenoses were present) was also assessed for each invasive and noninvasive index.The apparent change in hyperemic pressure gradient across each stenosis following pressure-wire pullback within the serially diseased vessel was noted with the attributable FFR termed FFRt tests. A 2-tailed test of significance was performed for all analyses with P<0.05 being considered statistically significant. Correlations were assessed using Pearson correlation coefficients (R). Bland-Altman analysis was used to compare the differences between estimated and true value across the range of measurements.SPSS Version 23  and Prism Graphpad 5.0  were used for all analyses. Normality was assessed using a visual assessment of histograms and Q-Q plots. Continuous data are expressed as mean±SD and compared using paired CT or the novel FFRCT-P) and dividing this by the true FFR gradient across the stenosis in question.In addition, methods were compared in estimating the true post-PCI change in FFR across a stenosis. This was done by calculating the mean relative error . This mean error is essentially calculated by evaluating the absolute difference between the true FFR gradient and the predicted FFR gradient  were excluded as satisfactory catheter laboratory data could not be obtained . Of the remaining 24 vessels, 19 (79%) had satisfactory computation of FFRCT of these vessels was 0.68±0.18. The Invasive total vessel FFR showed reasonable agreement with total vessel FFRCT, in line with previous studies9 (Pearsons R=0.71). Scatterplot and a Bland-Altman plot comparing invasive total vessel FFR with total vessel FFRCT are shown in Figure Patients included, in the final analysis, had a median age of 64.7 years . The Table summarizes the patient demographics and details of the serially diseased vessels. FFR of these vessels was 0.67±0.16. Total vessel FFRpullback and FFRtrue of 0.06±0.05 (P<0.001). This corresponded to a mean relative error of 42%. For conventional FFRCT outputs along the course of vessels, similar significant underestimation of stenosis contribution occurred, with a mean difference between FFRCT and FFRtrue of 0.05±0.06 (P<0.001), giving a mean relative error of 37%.With FFR pullback, significant underestimation of stenosis contribution occurred, regardless of whether the proximal or distal lesion was considered, with a mean difference between FFRCT PCI planning tool, we were able to estimate the FFR in the vessel FFRCT-P following PCI of one of the 2 serial stenoses  applying a novel interactive PCI planning tool (FFRCT-P), results in a significant improvement in the accuracy of predicting the residual true FFR contribution of stenoses following treatment of accompanying serial stenoses. To our knowledge, this is the first description and validation of this novel noninvasive method to predict the hemodynamic outcome of a PCI procedure.In this study, we have shown that (1) using an unadjusted trans-lesional gradient from conventional FFR19 There are, however, several well-established limitations of physiological assessment of serial CAD. A simple explanation for this is that a stenosis provides resistance to blood flow, manifesting as a post-stenotic drop in pressure that is magnified in hyperemic conditions to give the true FFR when present in isolation. When another stenosis or diffusely-diseased segment, maximal hyperemia  is not possible because of the additional resistance to flow, with the situation further complicated by flow turbulence when stenoses are particularly severe, close together and nonconcentric.20 The techniques previously described to overcome these limitations have been complex; requiring measurement of coronary wedge pressure12 or the presence of a disease-free daughter branch when serial disease involves the left main coronary artery.21 Although it has been suggested that resting indices  might result in smaller absolute errors than FFR in this setting,22 this is likely to be a reflection of the different operating range of resting indices, which are also prone to significant error.Serial and diffuse CAD is common, particularly within aging and diabetic populations, with estimates of 25% to 40% prevalence in all patients presenting for angiography.CT outputs are presented as color-coded maps of coronary arteries showing how FFRCT values change down the vessel. These color-coded gradients of FFRCT are designed to mirror the changes in measured FFR one would expect with a hyperemic pressure-wire pullback within the catheter laboratory. In keeping with this, our results show that unadjusted trans-lesional gradients from these conventional FFRCT outputs show a similarly significant degree of stenosis underestimation in serially diseased vessels, as is the case with invasive FFR pullback. Given that the physiological interplay largely depends on lesion geometry, which in turn can be well characterized by CTA techniques, a FFRCT-based technique would be expected to have greater potential at predicting the true physiological contribution of an individual stenosis, with the added appeal of being a noninvasive technique. Based on this, the FFRCT-P has been developed to allow real-time recalculation of residual FFR after simulating PCI, with the operator able to choose simulated stent position and length.At present, conventional FFRCT method (FFRCT-P), the variance of the error because of serial disease is still appreciable (SD ± 0.05), particularly when the cumulative burden of disease in the vessel is high . These findings are consistent with previous meta-analyses of FFRCT diagnostic performance that have shown reduced accuracy with more severe stenoses.23 This may be as a result of limited CT visualization of stenosis geometry when stenoses are severe but also variability in microvascular function which is difficult to predict from a noninvasive functional-anatomic test. In addition, the geometry of the untreated lesion can change post-PCI because of a higher operating pressure and can lead to unaccounted changes in FFRCT.21 There are several additional issues when using FFRCT in planning intervention that may limit the utility of such a noninvasive tool: Firstly, there is a need to have an appropriate CT scan within a few weeks of the planned PCI. Secondly, not all prospectively acquired CT scans are of adequate quality for FFRCT computation. Within our study, around 20% of cases could not have post hoc FFRCT computation because of issues such as phase misalignment. This was a rate similar to the NXT trial where 13% of CT scans were unsuitable for analysis owing to inadequate image quality issues such as phase misalignment, stent-related artifacts, and blooming.9Despite the large and significant reduction in mean error using the novel FFRCT-P still represents a significant improvement to current methods of physiologically assessing serial CAD. Furthermore, it has the potential to complement contemporary methods of planning PCI, particularly in patients with serial/diffuse CAD, without requiring the invasive positioning of a coronary guidewire. Further multi-center data will be needed to evaluate this tool and its impact of clinical decision-making.Despite these factors, in patients that are able to have an adequate quality prospective CT coronary angiogram before planned PCI, FFRThe study is limited by its relatively small sample size and, therefore, the results are primarily hypothesis generating and merit further examination in a larger population derived from a multicenter setting.CT has not been validated for patients with previous coronary artery bypass, previous stenting within the same vessel, or significantly abnormal left ventricular function, and therefore, by extension we excluded these patients, and we cannot extrapolate the results from the FFRCT PCI planning tool to those patient groups.In addition, FFRCT provides a comparable estimation of FFR values obtained from routine invasive pressure-wire pullback along a vessel and is prone to a similar degree of physiological underestimation in serial CAD. In this study, we provide validation for a novel noninvasive FFRCT-P and show it to significantly reduce the error of contemporary methods in estimating true stenosis contribution within serially diseased vessels following PCI of an accompanying stenosis.FFRCT patient-specific idealized lumen radii models. We acknowledge the ongoing support of the British Heart Foundation in supporting cardiovascular research in our institution and the United Kingdom as a whole.David Lesage (employee at HeartFlow Inc) helped generate the FFRB. Modi is funded by a British Heart Foundation Clinical Research Training Fellowship (FS/15/78/31678) and D. Perera is supported by the United Kingdom National Institutes for Health Research via the Biomedical Research Centre award to King’s College London.Heart Flow Inc have borne the costs of post-processing CTA data. S. Sankaran, H.J. Kim, C. Rogers, and C.A. Taylor are Heart Flow Inc employees.


Epigenetic information is characterized by its stable transmission during mitotic cell divisions and plasticity during development and differentiation. This duality is in contrast to genetic information, which is stable and identical in all cells in an organism with exception of immunoglobulin gene rearrangements in lymphocytes and somatic mutations in cancer cells. Allele-specific analysis of gene expression and epigenetic modifications provides a unique approach to studying epigenetic regulation in normal and cancer cells. Extension of Knudson's two-hits theory to include epigenetic alteration as a means to inactivate tumor suppressor genes provides better understanding of how genetic mutations and epigenetic alterations jointly contribute to cancer development. High-throughput technology has greatly accelerated cancer discovery. Large initiatives such as TCGA have shown that epigenetic components are frequent targets of mutations in cancer and these discoveries provide new insights into understanding cancer etiology and generate new opportunities for cancer therapeutics. Drosophila  enzymes can catalyze demethylation of 5-methycytosine through sequential conversion of 5-methycytosine to 5-hydroxymethyl cytosine, to 5-formylcytosine, then to 5-carboxylcytosine, which can be converted to unmodified cytosine by terminal deoxynucleotidyl transferase (TDT)  , 24.Histone modifications are far more complicated than DNA methylation. But the general strategy is similar. There exist a pair of enzyme systems, histone post-translational modification “writers” and “erasers.” For examples, histone acetyltransferase (HAT) serves as a writer whereas histone deacetylase (HDAC) serves as an eraser. Likewise, there are histone lysine methyltransferase (KMT) and histone lysine demethylase (KDM) to serve as writer and eraser, respectively. There are also protein arginine methyltransferases (PRMT), which act on arginine. Their opposing enzymes are peptidyl arginine deiminase (PADI). Each family also contains a large number of enzymes that can recognize specific substrate sequences. There is a third class of proteins called “readers” that can specifically bind to these post-translational modifications. For examples, bromodomain binds to acetylated lysine residue and chromodomain recognizes lysine methylation. Interestingly, histone acetyltransferase often contains bromodomain in addition to its activity to add acetylation to lysine. The multi-function structure of HAT enables it to catalyze acetylation in a processive manner to spread this post-translation mark (PTM) to the nearby nucleosome. This provides a potential mechanism for maintaining the PTM through mitotic division. Unlike DNA methylation, which produces semi-methylated DNA after DNA replication, the nucleosomes are randomly distributed into each of the two daughter cells after cell division. Half of the nucleosomes are derived from the parental cell and half are from newly deposited nucleosomes, which don't have PTMs. The ability of HAT to bind acetylated lysine and then catalyze addition of acetyl group to the nearby nucleosome allows the maintaining of this PTM through mitotic cell division.The hallmark of epigenetics is the transmission of epigenetic marks through mitotic cell divisions. The duration of maintaining an epigenetic state varies. In the case of X chromosome inactivation and genomic imprinting, the active or inactive chromatin states are maintained throughout the lifetime. However, in most of cellular response to physiologic needs, the new epigenetic state is established and reversed back to normal state and the duration varies depending on particular physiology. DNA methylation mark is more stable while histone post-translational marks and other chromatin remodeling complexes display wide range of response time, serving different physiologic purposes.X chromosome inactivation and genomic imprinting are characterized by the mono-allelic gene expression and epigenetic modifications. Mono-allelic gene expression also occurs in a number of other biological systems. In B lymphocytes, once an immunoglobulin gene rearrangement takes place on one chromosome, the rearrangement of the same gene from the other chromosome would be prevented. This phenomenum is termed as allelic exclusion, which ensures that an individual lymphocyte expresses a unique amino acid sequence of an immunoglobulin protein . SimilarIn addition, quantitative differences in the degree of gene expression between two alleles, marked with SNPs, are a widespread phenomenon, hereinafter referred to as allele-specific expression (ASE). We initially studied allele-specific gene expression using the Affymetrix SNP arrays and found extensive allelic variation in expression in the human genome . ASE difIt is well-established that cancer is caused by mutations that are acquired either from parents through germline inheritance or generated in somatic cells. Inactivating tumor suppressor genes and activating oncogenes both contribute to cancer development. In the case of inactivation of tumor suppressor genes, both alleles have to be inactivated in the cancer cell. This is best illustrated by Knudson's two-hits theory . The twoEpigenetic alteration through germline inheritance can occur in familial cancer syndrome. Lynch syndrome is caused by mutations in the genes involved in DNA mismatch repair. Germline mutations in MLH1 and MSH2 causes the majority of Lynch syndrome. However, in several Lynch syndrome families, no mutations in mismatch repairs genes were found despite extensive effort of searching for causative mutations. Instead, heritable DNA methylation in the promoter regions of MLH1 or MSH2 was identified that silenced gene expression. Chan et al. analyzed a three-generation family using allele-specific methylation (ASM) and reported that methylation of MSH2 gene in the germ line cells correlated with the loss of the MSH2 protein in the colorectal adenocarcinomas . BesidesBeckwith–Wiedemann syndrome (BWS), is another familial syndrome, which increases risk of developing multiple pediatric cancers. It has served as a model system for studying genomic imprinting and how abnormal genomic imprinting causes cancer. Multiple genetic and epigenetic mechanisms were identified that cause BWS, including mutation in CDKN1C , loss ofTwo papers brought about wide appreciation of quantitative difference in gene expression between two alleles of APC in familial adenomatous polyposis (FAP) , 45. YanAn interesting question is whether DNA methylation causes inactive chromatin state or vice versa. An elegant study from Vogelstein's lab provided an important insight into answering this question . They geThe high-throughput analysis of gene mutations in human cancer was made possible after the human genome sequencing was completed in 2003. Some of the earliest studies that leveraged human genome sequence data to systematically identify mutated genes in human cancer were reported by the researchers from Johns Hopkins and Sanger Institute. These included the large scale analysis of coding sequences of human transcriptome in breast and colorectal cancer from Johns Hopkins in 2006 and 2007 , 48 and A very interesting study came from the comprehensive analysis of mutation in glioblastoma multiforme (GBM) by the Hopkins team in 2008, which led to the discovery of a recurrent mutation R132H in isocitrate dehydrogenase 1 (IDH1) and the mutation was shown to be associated with better survival . The R13In 2010, TCGA team found that a subset of GBM has high CpG island methylation, which was termed as a glioma CpG island methylator phenotype (G-CIMP) . G-CIMP One of the emerging concepts from the high-throughput mutational analysis of human cancer genomes was the finding that chromatin components are the frequent targets of mutations in human cancer –57. SomeDNA methyltransferase inhibitors, 5-azacytidine (Vidaza) and 5-aza-2′-deoxycytidine (decitabine), are FDA approved drugs for myelodysplastic syndrome (MDS) and AML patients. Treatment with 5-azacitidine and decitabine increased overall survival in MDS patients than conventional care in phase III clinical trials , 66. TheVorinostat (SAHA), belinostat (PXD101), and romidepsin are FDA approved histone deacetylase (HDAC) inhibitors for cutaneous T cell lymphoma (CTCL) patients . The resN-methyltransferase (DOT1L), which is involved in leukemogenesis in mixed lineage leukemia (MLL)  ; developia (MLL) .A major concern in cancer therapy, either chemotherapy or targeted therapy, is the development of resistance to cancer drugs. Many mechanisms contribute to drug resistance, including drug efflux and mutations in the targeted genes or related pathways. However, recent studies suggested that epigenetic alterations could provide another mechanism to acquire drug resistance, especially for slowly acquired resistance . The druIn conclusion, the studies of epigenetics and allele-specific gene expression and application of high-throughput technology provide powerful approaches to enhancing our understanding of cancer etiology and progression and also provide new opportunity for cancer therapeutics. There are some limitations when we try to understand cancer through the lens of epigenetic inheritance, allele-specific gene expression, and high-throughput technology. Germline epimutations are very rare events and some of which may be caused by yet unknown genetic variants. Although allele-specific gene expression can provide a unique perspective on the role of genetic variants on gene expression regulation, we are often more interested in the combined gene expression contributed from both alleles and how the gene expression is associated with other biological phenomena. High-throughput technology is powerful for the discovery phase of the research. However, new findings should be rigorously validated by additional experiments.The author confirms being the sole contributor of this work and has approved it for publication.The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer JZ declared a shared affiliation, though no other collaboration, with the author to the handling editor.


The optimal duration of oral anticoagulant therapy for patients with venous thromboembolism (VTE) remains highly uncertain in clinical practice. It is essential to accurately assess the effect of anticoagulant therapy in reducing recurrent VTE against the risk of inducing major bleeding.Randomized controlled trials were identified by searching PubMed, Web of Science, Embase, and the Cochrane library, reporting rates of recurrent VTE and major bleeding in patients taking Vitamin K Antagonists (VKA) with VTE and comparing different durations.Eleven RCTs with 3109 participants utilizing varied durations were included in the meta-analysis. Longer VKA therapy was associated with significantly lower rates of VTE recurrence compared with shorter duration of VKA therapy , with significant difference noted in major bleeding risk . During anticoagulation duration, patients treated by 6-month VKA had higher risk of major bleeding compared with 3-month VKA regimen .Regimen longer than 6 months did not show statistical elevation of major bleeding risk. VKA treatment strongly reduces the risk of recurrent VTE during anticoagulation therapy. The absolute risk of recurrent VTE declines over time while the risk for major bleeding after 6 months’ treatment did not demonstrate a continuous significant increase with extended duration of VKA therapy. Venous thromboembolism (VTE) is a common disorder, which encompasses deep vein thrombosis (DVT) and pulmonary embolism (PE). VTE is regarded as the third major cause of cardiovascular disease after myocardial infarction and stroke . VTE freBleeding is the most important complication associated with patients receiving oral anticoagulants. Previous studies demonstrate that the overall incidence of bleeding events in patients treated with long-term anticoagulation is 2 to 3% per year . The durThe Tenth edition of the American College of Chest Physicians Guidelines updated its recommendation that patients with either a first or a second VTE should receive extended treatment if their bleeding risk is low or moderate . The safFor patients with a first unprovoked VTE, the optimal duration of anticoagulation is a crucial clinical dilemma that has yet to be fully resolved. The decision to stop anticoagulant therapy after the initial 3–6 months or to continue anticoagulation therapy indefinitely, is primarily governed by the long-term risk of recurrence after treatment is discontinued. In this manuscript we performed this network meta-analysis of randomized controlled trials (RCTs) enrolling patients with deep vein thrombosis (DVT) or pulmonary embolism (PE) to compare the relationship of bleeding and the duration of VKA therapy.Eligible studies included in this meta-analysis were randomized clinical trials comparing different durations of anticoagulation in patients with venous thromboembolism. We systematically searched PUBMED , Web of Science, Embase, and Cochrane Library of clinical trials database  to identify randomized clinical trials (RCTs) without restrictions on the publication year, or type of publication [Two investigators  completed the systematic search and reviewed relevant articles according to the following criteria: 1) RCTs involving consecutive patients with venous thromboembolism of more than 50 participants who were assigned to receive VKAs; 2) the diagnose of venous thromboembolism was confirmed by either positive Doppler ultrasonography, radioisotope, venography, angiographic, or other objective tests; 3) studies comparing different durations of anticoagulant therapy in each article sorted by four categories: 3 months, 6 months, 12 months and longer than 24 months; 4) and studies reporting the clinical incidence of recurrent VTE events and major bleeding episodes. Observational studies, trials of shorter than 3 months or less than 50 participants, trials of non-VKA agents, studies in special population , and studies with no available thromboembolic events or major bleeding data were excluded.The primary efficacy clinical outcome of interest was incidence of recurrent VTE and the primary adverse event clinical outcome measure was major bleeding episodes. Recurrent VTE was diagnosed if the symptoms were confirmed by ultrasonography, ventilation-perfusion lung scanning, spiral computerized tomographic angiography, pulmonary angiography, or autopsy.We define major bleeding as clinically overt bleeding associated with 1 or more of the requirements as follows: bleeding occurred in a critical organ ; required transfusion of 2 or more units of whole blood or packed cells; fetal bleeding; and any reasons leading to interruption of anticoagulation treatment.The definitions of clinical outcomes in each original article were integrated and compiled. Analyses were done in the intention-to-treat population. Secondary endpoints included recurrent VTE and major bleeding episodes which occurred during the period of anticoagulation and from discontinuation of VKA therapy to the end of follow-up.Data for eligible study were extracted by two investigators  independently including study design, patient characteristics, outcomes and other relevant information. All extracted data were reviewed by the same two reviewers and discrepancies were resolved through consensus discussion. The risk of bias of each trial were assessed by two review authors according to the Cochrane Risk of Bias assessment tool which comprise the following domains: random sequence generation; allocation concealment; blinding of participants and personnel; blinding of outcome assessment; incomplete outcome data; selective reporting and other bias, and were checked by other two reviewers (Dr Jue Li and Dr. Dachun Xu). Each domain was given a score of “high,” “low,” or “unclear” .netmeta (R package (version)). The odds ratios (ORs) were reported the dichotomous outcomes (recurrent VTE and major bleeding episodes). The pooled estimates were calculated with either fixed effect (Mantel-Haenszel) or random effect (DerSimonian and Laird) models when direct meta-analysis was performed.We performed this meta-analysis using both a traditional frequentist approach and a frequentist network meta-analysis method. Our first analysis was based on the comparison between groups of therapies stratified as “longer duration” versus “shorter duration” of anticoagulation using Stata 14.0 . For indirect treatment estimates, frequentist network meta-analysis was then conducted to synthesize both direct and indirect evidence to provide the most comprehensive results by means of R software by use of 2 statistic across studies, with values higher than 50% representing significant heterogeneity, 25–50% indicating moderate heterogeneity, lower than 25% denoting mild heterogeneity [In the light of different length of follow-up of each trial, the event rates were arithmetically generated as estimates per patient-years of follow-up. For subgroup analyses, we categorized recurrent and major bleeding events both in the period of taking VKA and from discontinuation to the end of follow-up. Heterogeneity was assessed using Iogeneity . StudiesP value less than 0.05 for Egger’s test suggesting publication bias or small study effect. Additionally, we conducted a sensitivity analysis to evaluate the strength of our findings based on removing particular trials.Ranking probabilities for efficacy and safety on different durations were presented using rankograms as their surface under the cumulative ranking (SUCRA) curves to obtain the treatment hierarchy . Small sOverall, a total of 11 RCTs comprising a total of 3109 patients with VTE who met the inclusion criteria in the meta-analysis  and no heterogeneity was apparent for major bleeding risk (I2 = 0).All the included trials reported data on recurrent VTE and major bleeding episodes. Figure best 94.2%, SUCRA 0.979). Nevertheless, a 3-month duration was ranked as the safest regimen relating to major bleeding, followed by 12-month, 6-month and 24-month therapy   in the network meta-analysis. No funnel plot asymmetry was noticeable by visual inspection and the Egger test suggesting no excessive effect exerted by small studies on the overall results  when compared with 3-month regimen, while there were no significant differences for major bleeding risk among four durations (Table 2 = 77.0%) was evident across trials, thus a random effect model was applied. Frequentist network meta-analysis revealed that there were no statistically differences among four VKA regimens, whereas 6-month therapy showed an increased risk of major bleeding  when compared with 3-month . Further, there were no inconsistencies between direct and indirect comparisons.With regard to the period of after discontinuation of VKA, efficacy and safety outcomes were reported in 7 studies and 6 studies separately  of VKA therapy is safe and associated with significant reduction in overall recurrent rate of VTE compared to short term therapy (3 months or 6 months), however, the risk of major bleeding is similar in all groups compared with each other during entire follow-up period. Second, the benefit of anticoagulation for prevention of recurrent VTE was lost after anticoagulation was discontinued and the risk of major bleeding is transiently increased at 6 months with the incidence of major bleeding decreased during the remainder of the time period of prolonged anticoagulation therapy. This meta-analysis emphasizes the need for close monitoring of the increased bleeding risk of VKA during the initial 6-month therapy duration.Establishing the optimum duration of anticoagulation therapy of VTE is crucial for balancing the risks of recurrent VTE and bleeding complications. Consistently with previous studies evaluating extended duration of anticoagulation for prevention of recurrent VTE after a first episode of treatment, longer durations of VKA anticoagulation have reduced rates of VTE recurrence by about 70–90%, but this benefit is partially offset by a higher annual risk of major bleeding –21. VKAsBased on these considerations, Current guidelines from the American College of Chest Physicians advocates at least 3 months anticoagulation therapy to prevent early recurrence , 23. In However, duration of anticoagulation for unprovoked VTE remains unclear, considering extended treatment for all patients with unprovoked VTE will inevitably expose a substantial proportion of patients to an increasing risk of major bleeding. As about 50% of patients with unprovoked venous thromboembolism (VTE) will develop new episodes after discontinuing therapy, this meta-analysis suggests that indefinite treatment be considered in patients with low or moderate bleeding risk.In light of the millions of patients treated with VKAs, a true increase in mortality associated with extended VKAs use in the management of VTE could have profound public health consequences. Conversely, widespread fear over the risks of continued VKA use could results in inappropriate discontinuation, leading to an increased risk of ischemic events. Therefore, it was imperative to examine the impact of extended treatment with VKA on mortality among VTE, to help frame trial-specific results against of the larger body of prior literature evaluating VKA duration.The efficacy of VKA is confirmed while the major bleeding risk is the fundamental consideration for most physicians in clinical practice. To be highlighted, the side effect of taking VKA mainly occurs during the early period of medication. However, bleeding risk did not constantly increase with prolongation of VKA treatment. Our meta-analysis found that the risk of major bleeding of VKA anticoagulation treatment reached its maximum at 6 months and then decreased. The possible reasons are as follows; 1) patients’ medication compliance may have changed, with laxity in the avoidance vegetables rich in Vitamin K and frequency of obtaining an INR, and 2) patients at highest risk for VKA related bleeding may have declared themselves with a major bleeding event in the first 6 months of therapy while longer duration therapy patients are at lower risk for VKA related bleeding.In recent years the use of direct oral anticoagulants (DOAC) is increasing in preference to prescribing VKAs for the treatment of VTE. However, VKA is cheap, effective and is available to regular monitoring and widely used in general hospitalized patients, and will remain the principal anticoagulation therapy of choice for a long time in low and middle-income countries especially for patients with liver or renal dysfunction. Additionally, it is not obvious to be aware of medication noncompliance without monitoring of DOACs. Accordingly, we perform this systematic review and meta-analysis to provide the latest and reliable evidence of randomized controlled trials, focusing on the risk of major bleeding on longer duration of VKA treatment in patients with VTE. We retrieved data both from active treatment phase and follow-up period after therapy discontinuation. This review will help clinical professionals better determine the choice of VKA treatment duration.Our study synthesized and analyzed the existing body of evidence to identify the optimum duration that minimizes the aggregate of harm that occurs from recurrent VTE and major bleeding. By highlighting methodological issues and summarizing the results of different research studies, our study offered useful insights regarding the impact of extended anticoagulation on clinical outcomes. The risk of recurrent VTE was greatly reduced if anticoagulation was continued. If anticoagulation was discontinued in the long-term group, the risk of recurrence during the period of the study with additional follow-up was still diminished.The present meta-analysis demonstrates that the trade-off between VTE recurrence and bleeding events with longer VKA is a matter of concern and should be carefully evaluated when the decision to continue VKA after a recommended period is considered. In current clinical practice guidelines, 3–6 months anticoagulation duration is recommended. However, according to this meta-analysis, once the 6-month major bleeding peak has passed longer anticoagulant therapy should be considered to reduce the risk of VTE recurrence. The optimal duration may vary in terms of diverse risk profiles of patients. For this respect, the decision for applying VKA should balance benefit and risk of the individual risk assessment.There are some limitations in our study. A major limitation in the present study is the lack of patient-level data, resulting in difficulty to provide the time-to-event analyses. Second, heterogeneity of major bleeding and unprovoked VTE definitions are variable across RCTs. This is a potential limitation that can cause challenges to be encountered in this review. We were unable to stratify the included patients into subgroups according to different etiology . In addition, other potential safety endpoints such as fatal bleeding episodes were not assessed in our review since related data cannot be extracted individually.Third, the studies included in the meta-analysis enrolled heterogeneous populations, had differing study protocols and endpoint definitions, and compared different durations of VKA. In addition, as with any meta-analysis, our study is limited by the limitations of the included studies. The included population was not generalizable to those patients in other types of study. More studies are required to derive the optional oral VKA medication duration.In conclusion, the present meta-analysis indicates that longer duration VKA therapy was associated with significantly lower VTE recurrent rates compared with shorter duration. Although 6-month VKA treatment has the highest risk of major bleeding, if no bleeding occurs during the 6-month treatment course, the treatment duration should be extended to 24 months. An individual strategy taking into account risk of VTE recurrence, bleeding risk, therapeutic options, and patient preferences including financial considerations should be fully explored.Additional file 1: Table S1. Characteristics of Included randomized controlled trials. Note: Abbreviations: pts., patients; RCT, randomized controlled trial; DB, double blind; OL, open-label; DVT, deep vein thrombosis; P-DVT, proximal deep vein thrombosis; PE, pulmonary embolism; VTE, venous thromboembolism; C-DVT, calf deep vein thrombosis; TRF, temporary risk factors; PRF, permanent risk factors; VTE, venous thromboembolism; INR, international normalized ratio, mo, month.Additional file 2: Table S2. Subgroup network-meta analysis estimates of during (A) /after (B) treatment duration for VTE patients.Additional file 3: Figure S1. PRISMA flow diagram of study identification for network meta-analysis. Note: PRISMA = Preferred Reporting Items for Systematic reviews and Meta-analysis; RCT = randomized controlled trials; DVT: deep thrombosis; PE: pulmonary embolism.Additional file 4: Figure S2. Network of included studies with direct comparisons for VTE recurrence and major bleeding outcomes. Note: The graph represents the head-to-head Vitamin K Anticoagulants duration comparisons by connecting nodes and lines. Thickness of lines show the proportion of the number of studies comparing the two duration. Size of nodes are related to number of trials. Studies and patients are indicated by numbers above and below each line respectively.Additional file 5: Figure S3. Rankings of available anticoagulation durations for treatment of VTE.Additional file 6: Figure S4. Funnel plot of studies included in the meta-analysis for the risk of recurrent VTE and major bleeding.Additional file 7: Figure S5A-B. Estimates of VTE recurrence and major bleeding risk between longer and shorter duration of anticoagulation in the subgroups. Note: A: During the anticoagulation B: From discontinuation to the end of follow-up.


Coronary vasospasm after coronary artery bypass grafting (CABG) is a rare but potentially lethal complication. It is often refractory to several vasodilators. We report a case of refractory coronary vasospasm relieved by fasudil injection.A 74-year-old woman who had three instances of in-stent stenosis at the left anterior descending artery (LAD) was referred for CABG treatment. Preoperative coronary angiography showed 90% in-stent stenosis of the proximal LAD and 75% stenosis of the diagonal branch. We performed a left internal thoracic artery (LITA)-LAD bypass and a right internal thoracic artery (RITA) diagonal branch bypass. After anastomosis, transit time flow measurement revealed poor blood flow of LITA-LAD bypass even after re-anastomosis. We performed coronary angiography and detected a vasospasm in the native coronary arteries, which was not relieved using conventional vasodilators  However, we were able to relieve the coronary vasospasm by administering fasudil (a Rho kinase inhibitor) injection without causing systemic hypotension.Fasudil may be an important vasodilator, especially in cases of coronary vasospasm after CABG. Coronary vasospasm is a rare but serious complication of coronary artery bypass grafting (CABG). Coronary vasospasm is generally treated using calcium channel blockers, such as isosorbide dinitrate and nicorandil, but is often refractory to these vasodilators. We report a case of refractory coronary vasospasm that was relieved using selective injections of fasudil.A 74-year-old woman was referred for CABG treatment. She had a history of diabetes mellitus and dyslipidemia and previously underwent percutaneous stenting of the mid right coronary artery and the proximal left anterior descending artery (LAD). Preoperative coronary angiography revealed 90% in-stent stenosis of the proximal LAD and 75% stenosis of the diagonal branch Fig. . In addiAt first, we performed RITA diagonal bypass. Subsequently, we performed anastomosis of LITA-LAD bypass. After CABG, the patient had stable circulation  without changes in ST segment as monitored by electrocardiogram. When we examined blood flow of the RITA diagonal bypass, transit time flow measurement revealed reasonable blood flow . On the other hand, the LITA graft showed comparatively poorer blood flow  than the RITA graft. Flow competition between the RITA and LITA was unlikely to occur considering the location of the stenotic lesion. In addition, taking into the consideration the perfused region of the LAD and the severe stenosis in the stent, the graft blood flow was too low and technical anastomotic stenosis was suspected. We re-anastomosed the LITA-LAD bypass. However, even after re-anastomosis of LITA-LAD bypass, transit time flow measurement revealed worsening of graft flow compared to before . We immediately closed the wound and moved the patient to a hybrid operating room to examine the causes of this progressively low graft flow.We performed coronary angiography and detected vasospasms in the native coronary arteries Fig.  without On postoperative day 1, coronary angiography revealed a patent bypass graft and sufficient coronary runoff Fig. . ElectroCoronary vasospasm is a well-known complication of CABG, with an incidence of approximately 0.8–1.3% . Our patIt is recommended that a bypassed ITA graft should be 20 mL/min or more. In our case, LITA-LAD bypass initially showed a blood flow of 15 mL/min. That is a marginal level for predicting ITA graft failure using transit time flow measurement . AdditioCalcium sensitivity relates to the onset of coronary vasospasm. In this context, Rho kinase plays an important role, which has been determined in animal studies . In the Recent reports have indicated that fasudil has therapeutic effects in cases of coronary vasospasm  and incr


Streptomyces phages WheeHeim and Forthebois are two novel members of the Tectiviridae family. These phages were isolated on cultures of the plant pathogen Streptomyces scabiei, known for its worldwide economic impact on potato crops. Transmission electron microscopy showed viral particles with double-layered icosahedral capsids, and frequent instances of protruding nanotubes harboring a collar-like structure. Mass-spectrometry confirmed the presence of lipids in the virion, and serial purification of colonies from turbid plaques and immunity testing revealed that both phages are temperate. Streptomycesphages WheeHeim and Forthebois have linear dsDNA chromosomes  with the characteristic two-segment architecture of the Tectiviridae. Both genomes encode homologs of the canonical tectiviral proteins , as well as PRD1-type virion-associated transglycosylase and membrane DNA delivery proteins. Comparative genomics and phylogenetic analyses firmly establish that these two phages, together with Rhodococcusphage Toil, form a new genus within the Tectiviridae, which we have tentatively named Deltatectivirus. The identification of a cohesive clade of Actinobacteria-infecting tectiviruses with conserved genome structure but with scant sequence similarity to members of other tectiviral genera confirms that the Tectiviridae are an ancient lineage infecting a broad range of bacterial hosts. Tectiviridae are a family of tail-less double-stranded DNA (dsDNA) phages characterized by an internal protein-rich lipid membrane enclosed within a non-enveloped icosahedral proteinaceous capsid . Th. ThStrepve hosts ,70,71. Frus PRD1 . Overalliviruses .Streptomyces phages WheeHeim and Forthebois presented turbid plaques, which can be indicative of lysogeny. Most tectiviruses infecting Gram-positive hosts have been shown to be temperate [S. scabiei cells isolated from apparent colonies within turbid plaques were able to induce plaque formation on a S. scabiei RL-34 lawn, indicating that they are releasing phage , but noxclusion b. Bacillromoters ,74, but erations ,76. In bTectiviridae phages have established the family-wide conservation of three major proteins: a double jelly-roll major capsid protein (DJR MCP), a FtsK-HerA superfamily DNA packaging ATPase and a protein-primed family B DNA polymerase [Streptomyces phages WheeHeim and Forthebois to previously described Tectiviridae phages we first analyzed best-reciprocal BLAST hits with Rhodococcus phage Toil, the only phage for which a BLASTP against the NCBI NR database would return significant results. This analysis revealed significant similarity between six genes across these three phages (Streptomyces phages WheeHeim and Forthebois), the entry lysozyme (Toil_gp23) and a hypothetical protein (Toil_gp11). To detect more distant homologs, we conducted HMM-based searches against these three phages and representative phages from previously described tectiviral genera . These searches confirmed that the three core Tectiviridae proteins  are conserved in these three phages and in all previously described Tectiviridae genera. They also identified ample conservation of a virion-associated transglycosylase (SEA_WHEEHEIM_26) known to be involved in PRD1 phage infection [Streptomyces phages WheeHeim and Forthebois of a homolog of the M23 family metallopeptidase associated with the group of rolling circularly-replicating ssDNA viruses represented by Flavobacterium phage FLiP [Genomic analyses of previously reported lymerase ,8,15. The phages . These infection , and theTectiviridae genomes, we assessed the apparent similarity in genome organization between Rhodococcus phage Toil and Streptomyces phages WheeHeim and Forthebois in the broader context of Tectiviridae genome architecture. The genome maps displayed in Rhodococcus and Streptomyces phages. All genomes contain a first genomic segment that appears to have switched orientation in multiple instances, with the family B DNA polymerase as its only identifiable conserved element. The second segment, consistently oriented in the forward strand, encompasses the signature double jelly-roll major capsid protein and the DNA packaging ATPase, as well as phage membrane DNA delivery proteins and a lytic transglycosylase. The plot also illustrates the lack of substantial sequence conservation between members the three different genera of the family Tectiviridae. In contrast, and as observed for different tectiviral genera [Rhodococcus phage Toil and Streptomyces phages WheeHeim and Forthebois display a high degree of sequence similarity  indicates that they constitute separate species according to the species demarcation criteria of the International Committee on Taxonomy of Viruses (ICTV) [Having established distant orthology with proteins in other l genera ,15, Rhodmilarity . The Aves (ICTV) ,79.Rhodococcus phage Toil and Streptomyces phages WheeHeim and Forthebois define a novel genus in the family Tectiviridae, we performed Bayesian phylogenetic inference with the aligned sequences of the three conserved Tectiviridae proteins , as well as bootstrapped minimal evolution phylogenetic inference with intergenomic protein sequence distances inferred from pair-wise genome-wide tBLASTX. The independently inferred phylogenies (Rhodococcus phage Toil and Streptomyces phages WheeHeim and Forthebois in a cohesive cluster similarly distant from the previously reported genera within the family Tectiviridae as these are from each other, strongly supporting their classification as a new genus within the Tectiviridae. Following the established convention for the family, we have tentatively named this novel genus Deltatectivirus. The inferred phylogenies also conclusively cluster the Alphatectivirus and Gammatectivirus genera together, suggesting that these two groups arose from a common ancestor. The phylogenies indicate that the common ancestor of extant Tectiviridae species emerged at least one billion years ago, prior to the split between Gram-positive and Gram-negative bacteria [To more rigorously ascertain whether logenies  consistebacteria ,81. The Streptomyces scabiei. Based on both morphological and genomic characteristics, we have established that Streptomyces phages WheeHeim and Forthebois should belong to the Tectiviridae family, wherein they could conform a distinct genus, tentatively named Deltatectivirus, that would include also the recently reported Rhodococcus phage Toil. Like other Gram-positive infecting tectiviruses, these phages display a lysogenic cycle, but the mechanism by which they mediate transition to the lytic cycle remains to be elucidated. This work also identifies for the first time the presence of a collar-like structure in the protruding nanotubes of tectiviruses, and provides strong support to the notion that the Tectiviridae define a family of bacteriophages with cohesive genome structure that originated well before the split of their Gram-positive and Gram-negative hosts.This work describes the morphological and genomic characterization of two novel phages infecting


Distal fusiform aneurysms of the superior cerebellar artery (SCA) are rare and present several challenges to clinicians, especially when ruptured. While several treatment options are available, including surgical clipping and endovascular coiling, numerous challenges still remain due to the presence of vital neighboring neurovascular structures. In addition, the complications that arise due to the compromise of brainstem perforators make these aneurysms difficult to treat.This case report demonstrates the successful treatment of a ruptured fusiform aneurysm of the SCA with a flow-diverting device. We also conducted a literature review of the use of flow-diverting devices for treating such aneurysms.When choosing a treatment modality for a ruptured aneurysm, clinicians must consider both the patient-specific variables as well as aneurysm morphology. Treatment options including microsurgical clipping, endovascular coiling, and flow diversion carry risks. Therefore, the clinician must decide which option best fits each situation.  Superior cerebellar artery (SCA) aneurysms are rare, with a reported incidence of 0.2%  and fusiHistory & examinationA 31-year-old African-American female with no significant medical history presented with a sudden onset of severe headaches that were highly suggestive of subarachnoid hemorrhage (SAH). The patient was initially evaluated in the emergency department where a neurological examination revealed no deficits.Pathological findingsA computed tomography (CT) scan revealed a SAH filling the pre-pontine, crural, ambient, and quadrigeminal cisterns more prominently on the left side of the brain, with mild hydrocephalus Figure . A CT-anThe patient was admitted to the neurosurgical intensive care unit (ICU) and treatment was initiated with regular neurological examinations and daily transcranial-doppler (TCD) studies. The patient remained intact, with TCD values showing only moderate vasospasm. The patient did not require any treatment for the mild radiographic hydrocephalus. On Day 14, the patient underwent a repeat DSA which showed a persistent vasospasm in the distal basilar and bilateral posterior cerebral arteries. Three-dimensional (3-D) reformatting also demonstrated a dissecting fusiform SCA aneurysm in the lateral ponto-mesencephalic segment Figure . Due to Endovascular interventionOn Day 21, the patient underwent a successful placement of a low-profile visualized intraluminal support (LVIS Jr.) device  covering the fusiform aneurysm, which measured 3-mm wide and 18-mm in length. After premedication with aspirin and clopidogrel, a 7-Fr sheath was inserted into the common femoral artery and a 6-Fr guide catheter was inserted into the left vertebral artery. The left SCA was catheterized using the microcatheter and microguidewire. The LVIS Jr. device was then deployed successfully along the fusiform segment of the SCA without evidence of contrast extravasation. The treatment goal was to preserve the intraluminal flow with flow diversion from the aneurysm for reduction and eventual obliteration.Postoperative courseAt the three-month follow-up, the patient had no complaint and was neurologically intact on examination. A CTA performed at that time showed the SCA patency proximal and distal to the stent without evidence of persistent dilatation or an aneurysm Figure . A formaSeveral cases have been published regarding the management of ruptured fusiform SCA aneurysms with endovascular treatments prevailing over surgical options. Open surgical options include trapping with or without bypass, clipping of the aneurysmal body, and wrapping . EndovasThe SCA contains four segments: the anterior ponto-mesencephalic, the lateral ponto-mesencephalic, the cerebello-mesencephalic, and the cerebellar cortical segment. The lateral ponto-mesencephalic segment contains perforators to the inferior colliculus and brainstem tegmentum ranging from none to as many as 10 Figure  5]. The. The5]. In 2011, Nelson published the largest study on FDDs used for intracranial aneurysms in the pipeline embolization device for the intracranial treatment of aneurysms (PITA) . FDDs weThe ruptured SCA aneurysm in our patient presented several challenges to treatment. Our patient was right-handed with a body mass index of 52.27. Therefore, a craniotomy via a sub-temporal approach would pose several risks including damage to brainstem perforators and a retraction injury to the dominant temporal lobe during exposure. Additionally, the fusiform morphology would not allow for a simple clipping but rather, a clip reconstruction. An endovascular approach also presented challenges. Coil occlusion would be difficult due to the fusiform morphology. And perforators supplying the midbrain would be at risk if the vessel occluded during coiling. Stenting through the parent vessel would preserve distal vessel patency but (in a ruptured aneurysm) would also require the administration of dual anti-platelet medications which could result in a devastating hemorrhage if the aneurysm re-ruptured. We felt that if an occlusion of the parent vessel occurred distal to the perforators, then a stroke could be clinically silent due to collateral supply from the AICA and PICA. Thus, the decision was made to delay treatment until angiographic evidence of the vasospasm was resolved and then to pursue treatment with a newly designed FDD – the LVIS Jr.Wang et al. highlighted the flow-diverting properties of the LVIS Jr stent and compared them with those of the pipeline embolization device (PED) and the enterprise stent . Wang coA literature review using PubMed and Google Scholar yielded one reported case of an SCA aneurysm treated with an FDD. Briganti described a ruptured proximal SCA aneurysm treated with a PED  which waWhen choosing a treatment modality for a ruptured aneurysm, clinicians must consider both patient-specific factors as well as aneurysm morphology challenges. All treatment options including microsurgical clipping, endovascular coiling, and flow diversion carry risks. Therefore, the clinician must decide which option best fits each situation.