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1.
Background
The Circle of Willis (CoW) is the most important collateral pathway of the cerebral artery. The present study aims to investigate the collateral capacity of CoW with anatomical variation when unilateral internalcarotid artery (ICA) is occluded.Methods
Basing on MRI data, we have reconstructed eight 3D models with variations in the posterior circulation of the CoW and set four different degrees of stenosis in the right ICA, namely 24%, 43%, 64% and 79%, respectively. Finally, a total of 40 models are performed with computational fluid dynamics simulations. All of the simulations share the same boundary condition with static pressure and the volume flow rate (VFR) are obtained to evaluate their collateral capacity.Results
As for the middle cerebral artery (MCA) and the anterior cerebral artery (ACA), the transitional-type model possesses the best collateral capacity. But for the posterior cerebral artery (PCA), unilateral stenosis of ICA has the weakest influence on the unilateral posterior communicating artery (PCoA) absent model. We also find that the full fetal-type posterior circle of Willis is an utmost dangerous variation which must be paid more attention.Conclusion
The results demonstrate that different models have different collateral capacities in coping stenosis of unilateral ICA and these differences can be reflected by different outlets. The study could be used as a reference for neurosurgeon in choosing the best treatment strategy.2.
Background
This paper presents quantitative analysis of blood flow shear stress by measuring the carotid arterial wall shear stress (WSS) and the intima-media thickness (IMT) of experimental rabbits fed with high-fat feedstuff on a weekly basis in order to cause atherosclerosis.Methods
This study is based on establishing an atherosclerosis model of high-fat rabbits, and measuring the rabbits’ common carotid arterial WSS of the experimental group and control group on a weekly basis. Detailed analysis was performed by using WSS quantification.Results
We have demonstrated small significant difference of rabbit carotid artery WSS between the experimental group and the control group (P<0.01) from the 1st week onwards, while the IMT of experimental group had larger differences from 5th week compared with the control group (P<0.05). Next, we have shown that with increasing blood lipids, the rabbit carotid artery shear stress decreases and the rabbit carotid artery IMT goes up. The decrease of shear stress appears before the start of IMT growth. Furthermore, our receiver operator characteristic (ROC) curve analysis showed that when the mean value of shear stress is 1.198 dyne/cm2, the rabbit common carotid atherosclerosis fatty streaks sensitivity is 89.8%, and the specificity is 81.3%. The area under the ROC curve is 0.9283.Conclusions
All these data goes to show that WSS decreasing to 1.198 dyne/cm2 can be used as an indicator that rabbit common carotid artery comes into the period of fibrous plaques. In conclusion, our study is able to find and confirm that the decrease of the arterial WSS can predict the occurrence of atherosclerosis earlier, and offer help for positive clinical intervention.3.
Background
The Circle of Willis (CoW) is an important collateral pathway of the cerebral blood flow. An experimental study of the cerebral blood flow (CBF) distribution in different anatomical variations may help to a better understanding of the collateral mechanism of the CoW.Methods
An in-vitro test rig was developed to simulate the physiological cerebral blood flow in the CoW. Ten anatomical variations were considered in this study, include a set of different degrees of stenosis in L-ICA and L-ICA occlusion coexist with common anatomical variations. Volume flow rates of efferent arteries and pressure signals at the end of communicating arteries of each case were recorded. Physiological pressure waveforms were applied as inlet boundary condition.Results
In the development of L-ICA stenosis, the total CBF decreases with the increase of stenosis degree. The blood supply of ipsilateral middle cerebral artery (MCA) was affected most by the stenosis of L-ICA. Anterior communicating artery (ACoA) and ipsilateral posterior communicating artery (PCoA) function as important collateral pathways of cerebral collateral circulation when unilateral stenosis occurred. The blood supply of anterior cerebral circulation was compensated by the posterior cerebral circulation through ipsilateral PCoA when L-ICA stenosis degree is greater than 40% and the affected side was compensated immediately by the unaffected side through ACoA. Blood flow of the anterior circulation and the total CBF reached the minimum among all cases studied when L-ICA occlusion coexist with the absence of PCoA.Conclusion
The results demonstrated the flow distribution patterns of the CoW under anatomical variations and clarified the collateral mechanism of the CoW. The flow ACoA is the most sensitive indexes to the morphology change of ipsilateral ICA. The relative independence of the circulation in anterior and posterior sections of the CoW is not broken and the function of ipsilateral PCoA is not activated until a severe stenosis of unilateral ICA occurs. PCoA is the most important collateral pathway of the collateral circulation and the missing of PCoA has the highest risk of stroke when the ipsilateral ICA has severe stenosis. These findings may provide the basis for future therapeutic and diagnosis applications.4.
Lia Bally Cédric Bovet Christos T. Nakas Thomas Zueger Jean-Christophe Prost Jean-Marc Nuoffer Alexander B. Leichtle Georg Martin Fiedler Christoph Stettler 《Metabolomics : Official journal of the Metabolomic Society》2017,13(7):78
Introduction
Exercise-associated metabolism in type 1 diabetes (T1D) remains under-studied due to the complex interplay between exogenous insulin, counter-regulatory hormones and insulin-sensitivity.Objective
To identify the metabolic differences induced by two exercise modalities in T1D using ultra high-performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC–HRMS) based metabolomics.Methods
Twelve T1D adults performed intermittent high-intensity (IHE) and continuous-moderate-intensity (CONT) exercise. Serum samples were analysed by UHPLC–HRMS.Results
Metabolic profiling of IHE and CONT highlighted exercise-induced changes in purine and acylcarnitine metabolism.Conclusion
IHE may increase beta-oxidation through higher ATP-turnover. UHPLC–HRMS based metabolomics as a data-driven approach without an a priori hypothesis may help uncover distinctive metabolic effects during exercise in T1D.Clinical trial registration number is www.clinicaltrials.gov: NCT02068638.5.
Wen Zeng Xiaorong Wen Li Gong Jiayu Sun Jing Yang Jichun Liao Can Qian Wei Chen Bin Song Fabao Gao 《Biomedical engineering online》2015,14(Z1):S13
Background
Atherosclerosis is one of the main risk factors cause acute cerebral-cardio vascular diseases. It's of great significance to establish an atherosclerosis animal model that can mimic the characteristics and nature course of human patients. Therefore, a rhesus monkey model was induced by high-fat diet to monitor their lipid profile and intima-media thickness (IMT) of artery walls and study atherosclerosis progression.Methods
Fifty male rhesus monkeys were enrolled in this study. All of these monkeys were aged 7 to 14 years with BMI >30 kg/m2. They were fed with high-fat diet containing 10% of fat for the first 48 weeks. Use ultrasound to measure the IMT at bilateral common carotid arteries and their bifurcations and aorta (AO) of the monkeys, and screen out the individuals with thickened IMT for the next phase. In the next 48 weeks, some of these monkeys (n = 4) were fed with standard diet containing 3% fat. Meanwhile the other monkeys (n = 5) were fed with high-fat diet for another 48 weeks. Their serum lipid level was monitored and arterial IMT was also determined periodically.Results
Serum lipid level of all 50 monkeys elevated after fed with high-fat diet for the first 48 weeks. IMT thickening at right common carotid bifurcation and aorta (AO) was thickened in 9 monkeys. Furthermore, 4 of these 9 monkeys were fed with standard diet and other 5 monkeys were fed with high-fat diet in the following 48 weeks. The serum lipid level of the 4 monkeys recovered and their IMT at RBIF and AO did not progress. However, the lipid level of other 5 monkeys remained high, and their IMT thickening of AO progressed, and plaques and calcification focuses were found at the anterior wall of aorta near the bifurcation of common iliac artery.Conclusions
After high-fat diet induction for 96 weeks, serum lipid levels of rhesus monkeys elevated significantly, which subsequently caused IMT thickening and plaques formation. When IMT thickening occurred, further vascular injury may be prevented by reducing diet fat content. Our study indicates that vascular injury of high-fat diet induced rhesus monkey is similar to that of human in position and progression.6.
Hyun Ju Yoon Kye Hun Kim Hyukjin Park Jae Yeong Cho Young Joon Hong Hyung Wook Park Ju Han Kim Youngkeun Ahn Myung Ho Jeong Jeong Gwan Cho Jong Chun Park 《Cardiovascular ultrasound》2017,15(1):19
Background
To investigate the impacts of carotid plaque and intima-media thickness (IMT) on future vascular events (VEs) in the patients with acute ischemic stroke.Methods
A total of 479 consecutive Korean patients with acute ischemic stroke were divided into 2 groups according to development of VEs; VE group (65.4 ± 10.9 years) vs no VE group (62.8 ± 13.2 years). VEs were defined as the development of recurrent stroke, coronary events, peripheral arterial disease, and death. Clinical, laboratory, and imaging findings were compared between the groups.Results
During 105.5 ± 29.0 months of follow up, VEs were developed in 142 patients (29.6%). In univariate analysis, VEs were significantly associated with age, gender, diabetes, renal function, lipid levels, left ventricular function, carotid plaque or IMT. In multivariate analysis, the presence of carotid plaque, diabetes, renal function and male gender were independent predictors of future VEs in the patients with ischemic stroke, but carotid IMT was not a predictor of future VEs. Event free survival was significantly lower in patients with carotid plaque than without carotid plaque on Kaplan-Meier analysis (log rank p < 0.001).Conclusion
The present study demonstrated that diabetes, impaired renal function, male gender, and the presence of carotid plaque rather than IMT were independent predictors of future VEs in Korean patients with acute ischemic stroke. Active medical management and careful monitoring for the development of recurrent VEs are strongly recommended in patients with acute ischemic stroke and carotid plaque.7.
N. Cesbron A.-L. Royer Y. Guitton A. Sydor B. Le Bizec G. Dervilly-Pinel 《Metabolomics : Official journal of the Metabolomic Society》2017,13(8):99
Introduction
Collecting feces is easy. It offers direct outcome to endogenous and microbial metabolites.Objectives
In a context of lack of consensus about fecal sample preparation, especially in animal species, we developed a robust protocol allowing untargeted LC-HRMS fingerprinting.Methods
The conditions of extraction (quantity, preparation, solvents, dilutions) were investigated in bovine feces.Results
A rapid and simple protocol involving feces extraction with methanol (1/3, M/V) followed by centrifugation and a step filtration (10 kDa) was developed.Conclusion
The workflow generated repeatable and informative fingerprints for robust metabolome characterization.8.
Rachel A. Spicer Christoph Steinbeck 《Metabolomics : Official journal of the Metabolomic Society》2018,14(1):16
Introduction
Data sharing is being increasingly required by journals and has been heralded as a solution to the ‘replication crisis’.Objectives
(i) Review data sharing policies of journals publishing the most metabolomics papers associated with open data and (ii) compare these journals’ policies to those that publish the most metabolomics papers.Methods
A PubMed search was used to identify metabolomics papers. Metabolomics data repositories were manually searched for linked publications.Results
Journals that support data sharing are not necessarily those with the most papers associated to open metabolomics data.Conclusion
Further efforts are required to improve data sharing in metabolomics.9.
Joaquín Moreno Alejandro Terrones Ana Juan María Ángeles Alonso 《Plant and Soil》2018,430(1-2):185-204
Aims
Establishing a vegetation-soil model in Mediterranean saltmarshes based on the relationships between the plant communities and the abiotic factors, considering temporary variation.Methods
Relationships between perennial plant species abundances and plant communities were analysed by DCAs. A CCA was performed to study the relationships between floristic composition and edaphic variables. Sixteen soil variables and Pearson correlations between them were considered. Marginal and conditional effects were supported by mixed ANOVA. Statistical analyses were performed to check temporary variation.Results
DCAs results showed eight vegetation types. CCA showed E.C. as the main gradient, with the succulent halophyte communities growing in high E.C. soils. SAR and percentage of sand were considered as secondary gradients. Finally, the highest values of the edaphic variables were observed, in general, during the cold period.Conclusions
The main gradient of salinity, together with sodicity and texture gradients, would markedly influence the plant distribution in Mediterranean saltmarshes. Two principal plant zones were observed: succulent zone vs. non-succulent zone, with a specific edaphic distribution for each plant community and for the proposed Limonium morphotypes treatment. A plant-soil model based on these three gradients is here proposed. Our results would complement the previous knowledge about plant-soil relationships in Mediterranean saltmarshes.10.
Guillaume Foldes-Busque Stéphanie Hamel Geneviève Belleville Richard Fleet Julien Poitras Jean-Marc Chauny Alain Vadeboncoeur Kim L. Lavoie André Marchand 《BioPsychoSocial medicine》2016,10(1):30
Background
Panic disorder (PD) is highly prevalent in patients with non-cardiac chest pain (NCCP). This study aims to explore the role of psychological factors (PD intensity, anxiety sensitivity, heart-related fear, attention and avoidance) common to NCCP and PD in predicting chest pain levels in patients with both conditions.Methods
This association was investigated in emergency department patients with NCCP and PD receiving either evidence-based treatment of PD or treatment as usual. Patients were assessed at baseline and 14 weeks later for post-treatment.Results
Only heart-focused fear and attention for cardiac sensations independently explained a significant portion of the variance in baseline pain (n?=?66). At 3 months follow-up (n?=?53), changes in heart-related fear was the only factor independently associated with changes in chest pain intensity. Even in patients with PD, fear specific to cardiac sensations seems to play a central role in determining NCCP intensity.Conclusion
These results suggest that the efficacy of intervention for patients with PD and comorbid NCCP could be improved by targeting heart-related fear and attention.Trial registration
NCT0073634611.
Andreas Mueller Gian Candrian Juri D Kropotov Valery A Ponomarev Gian-Marco Baschera 《Nonlinear biomedical physics》2010,4(Z1):S1
Background
In the context of sensory and cognitive-processing deficits in ADHD patients, there is considerable evidence of altered event related potentials (ERP). Most of the studies, however, were done on ADHD children. Using the independent component analysis (ICA) method, ERPs can be decomposed into functionally different components. Using the classification method of support vector machine, this study investigated whether features of independent ERP components can be used for discrimination of ADHD adults from healthy subjects.Methods
Two groups of age- and sex-matched adults (74 ADHD, 74 controls) performed a visual two stimulus GO/NOGO task. ERP responses were decomposed into independent components by means of ICA. A feature selection algorithm defined a set of independent component features which was entered into a support vector machine.Results
The feature set consisted of five latency measures in specific time windows, which were collected from four different independent components. The independent components involved were a novelty component, a sensory related and two executive function related components. Using a 10-fold cross-validation approach, classification accuracy was 92%.Conclusions
This study was a first attempt to classify ADHD adults by means of support vector machine which indicates that classification by means of non-linear methods is feasible in the context of clinical groups. Further, independent ERP components have been shown to provide features that can be used for characterizing clinical populations.12.
Nadine Strehmel David Strunk Veronika Strehmel 《Metabolomics : Official journal of the Metabolomic Society》2017,13(11):135
Introduction
Aqueous–methanol mixtures have successfully been applied to extract a broad range of metabolites from plant tissue. However, a certain amount of material remains insoluble.Objectives
To enlarge the metabolic compendium, two ionic liquids were selected to extract the methanol insoluble part of trunk from Betula pendula.Methods
The extracted compounds were analyzed by LC/MS and GC/MS.Results
The results show that 1-butyl-3-methylimidazolium acetate (IL-Ac) predominantly resulted in fatty acids, whereas 1-ethyl-3-methylimidazolium tosylate (IL-Tos) mostly yielded phenolic structures. Interestingly, bark yielded more ionic liquid soluble metabolites compared to interior wood.Conclusion
From this one can conclude that the application of ionic liquids may expand the metabolic snapshot.13.
Background
Adenomyosis is a benign disease with elevated CA125 level.Case presentation
We report 3 cases with adenomyosis who developed ischemic stroke during menstruation. The levels of CA125, CA19–9, and D-dimer were elevated, which dropped markedly after the menstrual phase. The development of nonbacterial thrombotic endocarditis (NBTE) and stenosis of the cerebral arteries associated with hypercoagulable state and the hyperviscosity nature of the mucinous protein may be the underlying mechanisms.Conclusion
Our report suggests that adenomyosis might be a risk factor for ischemic stroke in middle-aged patients.14.
Introduction
Untargeted metabolomics is a powerful tool for biological discoveries. To analyze the complex raw data, significant advances in computational approaches have been made, yet it is not clear how exhaustive and reliable the data analysis results are.Objectives
Assessment of the quality of raw data processing in untargeted metabolomics.Methods
Five published untargeted metabolomics studies, were reanalyzed.Results
Omissions of at least 50 relevant compounds from the original results as well as examples of representative mistakes were reported for each study.Conclusion
Incomplete raw data processing shows unexplored potential of current and legacy data.15.
Background
In recent years the visualization of biomagnetic measurement data by so-called pseudo current density maps or Hosaka-Cohen (HC) transformations became popular.Methods
The physical basis of these intuitive maps is clarified by means of analytically solvable problems.Results
Examples in magnetocardiography, magnetoencephalography and magnetoneurography demonstrate the usefulness of this method.Conclusion
Hardware realizations of the HC-transformation and some similar transformations are discussed which could advantageously support cross-platform comparability of biomagnetic measurements.16.
Prudence Wing Hang Cheung Vivian Tam Victor Yu Leong Leung Dino Samartzis Kenneth Man-Chee Cheung Keith Dip-Kei Luk Jason Pui Yin Cheung 《Scoliosis》2016,11(1):26
Background
Ligamentum flavum (LF) hypertrophy is a common cause of lumbar spinal stenosis and is thought to be degeneration-driven. Developmental spinal stenosis (DSS) is characterized by pre-existing narrowed spinal canals and is likely a developmental problem that occurs in childhood. In these cases, the LF may demonstrate different characteristics as compared to degeneration-driven stenosis. Thus, this study aimed to investigate the relationship between histological changes of LF and canal size.Methods
Patients who had surgical decompression for lumbar spinal stenosis were prospectively recruited and divided into three groups (critical DSS, relative DSS and non-DSS) based on previously defined anteroposterior bony spinal canal diameter measurements on MRI. The degree of disc degeneration and LF thickness were also measured from L1 to S1. Surgical LF specimens were retrieved for histological assessment of fibrotic grade and area of fibrosis.Results
A total of 19 females and 15 males (110 LF specimens) with an overall mean age of 65.9 years (SD?±?9.8 years) were recruited. DSS was found to have a significant negative correlation (p?<?0.001) with LF thickness, its fibrotic grade and area of fibrosis (%). Non-DSS exhibited a significant positive relationship with the degree of LF fibrosis. Disc degeneration and LF thickness had no correlation with LF histology.Conclusions
Our study is the first to definitively note that degeneration is the cause of LF fibrosis in non-DSS patients; however, in contrast, an inverse relationship exists between canal size and LF fibrosis in DSS patients, suggesting a different pathomechanism. Hence, despite a similar degree of LF thickness, DSS patients have LF with less fibrosis compared with non-DSS patients. Further investigation of the cause of LF changes in DSS is necessary to understand this relationship.17.
Ferran Casbas Pinto Srinivarao Ravipati David A. Barrett T. Charles Hodgman 《Metabolomics : Official journal of the Metabolomic Society》2017,13(7):81
Introduction
It is difficult to elucidate the metabolic and regulatory factors causing lipidome perturbations.Objectives
This work simplifies this process.Methods
A method has been developed to query an online holistic lipid metabolic network (of 7923 metabolites) to extract the pathways that connect the input list of lipids.Results
The output enables pathway visualisation and the querying of other databases to identify potential regulators. When used to a study a plasma lipidome dataset of polycystic ovary syndrome, 14 enzymes were identified, of which 3 are linked to ELAVL1—an mRNA stabiliser.Conclusion
This method provides a simplified approach to identifying potential regulators causing lipid-profile perturbations.18.
Sonia Liggi Christine Hinz Zoe Hall Maria Laura Santoru Simone Poddighe John Fjeldsted Luigi Atzori Julian L. Griffin 《Metabolomics : Official journal of the Metabolomic Society》2018,14(4):52
Introduction
Data processing is one of the biggest problems in metabolomics, given the high number of samples analyzed and the need of multiple software packages for each step of the processing workflow.Objectives
Merge in the same platform the steps required for metabolomics data processing.Methods
KniMet is a workflow for the processing of mass spectrometry-metabolomics data based on the KNIME Analytics platform.Results
The approach includes key steps to follow in metabolomics data processing: feature filtering, missing value imputation, normalization, batch correction and annotation.Conclusion
KniMet provides the user with a local, modular and customizable workflow for the processing of both GC–MS and LC–MS open profiling data.19.
Laura M. Losappio Corrado Mirone Michel Chevallard Laura Farioli Fabrizio De Luca Elide A. Pastorello 《Clinical and molecular allergy : CMA》2018,16(1):17
Background
Severe aortic valve stenosis is one of the most common cause of mortality in adult patients affected with metabolic syndrome, a condition associated with an active inflammatory process involving also mast cells and their mediators, in particular tryptase. The aim of this study was to characterize the possible long-term prognostic role of tryptase in severe aortic valve stenosis.Case presentation
The baseline serum tryptase was measured in 5 consecutive patients admitted to our Hospital to undergo aortic valve replacement for severe acquired stenosis. Within 2 years after, the patients were evaluated for the occurrence of major cardiovascular events (MACE). The tryptase measurements were higher in patients experiencing MACE (10.9, 11.7 and 9.32 ng/ml) than in non-MACE ones (5.69 and 5.58 ng/ml).Conclusions
In patients affected with severe aortic stenosis, baseline serum tryptase may predict occurence of MACE. Further studies are needed to demonstrate the long-term prognostic role of this biomarker.20.
Jamie V. de Seymour Stephanie Tu Xiaoling He Hua Zhang Ting-Li Han Philip N. Baker Karolina Sulek 《Metabolomics : Official journal of the Metabolomic Society》2018,14(6):79