scholarly journals Heterogeneity in the penumbra

2011 ◽  
Vol 31 (9) ◽  
pp. 1836-1851 ◽  
Author(s):  
Gregory J del Zoppo ◽  
Frank R Sharp ◽  
Wolf-Dieter Heiss ◽  
Gregory W Albers
Keyword(s):  
Imaging Techniques ◽  
Experimental Studies ◽  
Early Time ◽  
Focal Ischemia ◽  
Vascular Integrity ◽  
Acute Setting ◽  
Molecular Events ◽  
Homogeneous Core ◽  
Penumbral Region ◽  
Definition Of

Original experimental studies in nonhuman primate models of focal ischemia showed flow-related changes in evoked potentials that suggested a circumferential zone of low regional cerebral blood flow with normal K+ homeostasis, around a core of permanent injury in the striatum or the cortex. This became the basis for the definition of the ischemic penumbra. Imaging techniques of the time suggested a homogeneous core of injury, while positing a surrounding ‘penumbral’ region that could be salvaged. However, both molecular studies and observations of vascular integrity indicate a more complex and dynamic situation in the ischemic core that also changes with time. The microvascular, cellular, and molecular events in the acute setting are compatible with heterogeneity of the injury within the injury center, which at early time points can be described as multiple ‘mini-cores' associated with multiple ‘mini-penumbras’. These observations suggest the progression of injury from many small foci to a homogeneous defect over time after the onset of ischemia. Recent observations with updated imaging techniques and data processing support these dynamic changes within the core and the penumbra in humans following focal ischemia.

The methodology of experimental research of the feed components extrusion process in order to improve its energy performance

2020 ◽  
pp. 147-152
Author(s):  
E. M. Ratnikov ◽  
D. O. Milko
Keyword(s):  
Experimental Studies ◽  
Energy Performance ◽  
Extrusion Process ◽  
Mathematical Methods ◽  
Screw Extruder ◽  
Mathematical Planning ◽  
Factors Affecting ◽  
Extrusion Processing ◽  
Definition Of

Annotation Purpose. Development of a program and methods for conducting experimental studies of the extrusion process with the definition of parameters and modes of operation of the extruder to improve its energy performance. Methods. Methods of mathematical statistics, synthesis, analysis, description and modeling were used. Results. The application of mathematical methods, in particular mathematical planning, reduces the number of experiments several times, and allows to evaluate the role of influencing factors, obtain a mathematical model of the process and determine the optimal conditions for its parameters and modes, etc. Conclusions. The methodology for experimental studies of a screw extruder is presented with the necessary equipment and methodology for processing the obtained experimental data. A mathematical method of planning, which reduces the number of experiments several times, allows us to evaluate the role of factors affecting productivity and energy intensity is presented. Keywords: extruder, auger, nutrients, research methodology, extrusion, processing, feed.

scholarly journals AB0677 REVISING THE DEFINITION OF REACTIVE ARTHRITIS AND DIFFERENTIATION FROM UNDIFFERENTIATED SPONDYLOARTHRITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1633.2-1634
Author(s):  
F. Cosan ◽  
O. M. Gedar
Keyword(s):  
Causative Agent ◽  
Reactive Arthritis ◽  
Case Reports ◽  
Experimental Studies ◽  
Classification Criteria ◽  
General Definition ◽  
Parasitic Infections ◽  
Undifferentiated Spondyloarthritis ◽  
Classical Definition ◽  
Definition Of

Background:Reactive arthritis (ReA) is defined by 1999 ACR criteria as arthritis preceding a bacterial genitourinary (GUS) or gastrointestinal (GIS) infection in 3 days-6 weeks and evidence of triggering infection. Recently, ReA is classified as SpA and patients who do not fulfill SpA criteria are classified as undifferentiated spondyloarthritis (USpA) according to ASAS/EULAR SpA classification criteria.Objectives:In several case reports which are associated with other infective agents are reported and the definition is extended for some clinicians so that SpA which is occurred after any infection is called as ReA. On the other hand, some researchers still accept the classical definition of ReA. The problem with the heterogeneity of opinions and unstandardized definition of ReA hinders studies about pathogenesis and standardization of treatments. In this study, we aimed to determine the spectrum of the use of the definition of reactive arthritis in publications in PubMed between 2009-2019.Methods:The ReA keyword is searched in PubMed for the years between 2009-2019. 248 different publications have been identified and included in this research. 89 articles, 47 reviews, 108 case reports, 2 guidelines, and 2 editorials reviewed for the definition of ReA.Results:Only 42.7% (106 patients) of these publications meet the classical definition which suggests ReA after only GIS and GUS infections. In 4 (1.6%) of the publications ReA was defined after GIS, GUS and oropharyngeal infections; in 3 (1,2%) of the publications after any bacterial infection; in 9 (3.6%) of the publications after any infection. In 8 (3.2%) of the publications, ReA and USPA was used correspondingly. In 39 (15,7%) of the publications the term agent related, ReA was used without making a general definition for ReA. 79 publications (31,9%) have not defined ReA.According to causative agent and ReA relationship, in 64 (24,6%) general infective agents, in 75 (30,2%) classical agents, in 22 (8,9%) other bacterial agents, in 23 (9,3%) streptococcus, in 10(4%) intravesical BCG, in 6 (2.4%) HIV, in 6 (2.4%) tuberculosis, in 12 (4,8%) clostrudium difficle, in 2 (0.8%) parasites were reported. In 31 (12,5%) of the publications the causative agent for the ReA was unknown, the diagnosis was made clinically.Conclusion:In this study, it is aimed to draw attention terminology intricacy and the need for the standardization of the definition of ReA and USpA. It is clear that to standardize the definition of Rea and USpA is necessary. Between 2009-2019 there are reported cases diagnosed as ReA associated with bacterial infections (especially with Clostridium difficile, streptococcus and tuberculosis infections), and viral infections (by a majority with HIV), and parasitic infections. It is not clear if we need to define them classically or define them as USPA. Another important consideration is the necessity of extended laboratory investigations to find out the real causative agent even if the patient is clinically diagnosed with ReA. The requirement of the differentiation between ReA and USpA must be revealed for therapeutic researches.References:[1]A proposal for the classification of patients for clinical and experimental studies on reactive arthritis. Pacheco-Tena C, Burgos-Vargas R, Vázquez-Mellado J, Cazarín J, Pérez-Díaz JA. J Rheumatol. 1999 Jun;26(6):1338-46.[2]The Assessment of SpondyloArthritis International Society classification criteria for peripheral spondyloarthritis and for spondyloarthritis in general. Rudwaleit M, van der Heijde D, Landewé R, Akkoc N, Brandt J, Chou CT, Dougados M, Huang F, Gu J, Kirazli Y, et al. Ann Rheum Dis. 2011;70:25–31.Disclosure of Interests:None declared

scholarly journals Cardiotoxic effects and myocardial injury: the search for a more precise definition of drug cardiotoxicity

2021 ◽  
Vol 59 (1) ◽  
pp. 51-57
Author(s):  
Daniela Maria Cardinale ◽  
Martina Zaninotto ◽  
Carlo Maria Cipolla ◽  
Claudio Passino ◽  
Mario Plebani ◽  
...  
Keyword(s):  
Early Detection ◽  
Myocardial Injury ◽  
Randomized Clinical Trials ◽  
Imaging Techniques ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Cardiac Imaging Techniques ◽  
Ventricular Ejection Fraction ◽  
Early Evaluation ◽  
Definition Of

AbstractDrug-induced cardiotoxicity is a major clinical problem; cardiotoxic drugs may induce both cardiac dysfunction and myocardial injury. Several recent studies reported that cardiac troponins measured with high-sensitivity methods (hs-cTn) can enable the early detection of myocardial injury related to chemotherapy or abuse of drugs that are potentially cardiotoxic. Several authors have some concerns about the standard definition of cardiotoxicity, in particular, regarding the early evaluation of chemotherapy cardiotoxicity in cancer patients. Several recent studies using the hs-cTn assay indicate that myocardial injury may precede by some months or years the diagnosis of heart failure (HF) based on the evaluation of left ventricular ejection fraction (LVEF). Accordingly, hs-cTn assay should considered to be a reliable laboratory test for the early detection of asymptomatic or subclinical cardiotoxic damage in patients undergoing cancer chemotherapy. In accordance with the Fourth Universal Definition of Myocardial Infarction and also taking into account the recent experimental and clinical evidences, the definition of drug-cardiotoxicity should be updated considering the early evaluation of myocardial injury by means of hs-cTn assay. It is conceivable that the combined use of hs-cTn assay and cardiac imaging techniques for the evaluation of cardiotoxicity will significantly increase both diagnostic sensitivity and specificity, and also better prevent chemotherapy-related left ventricular (LV) dysfunction and other adverse cardiac events. However, large randomized clinical trials are needed to evaluate the cost/benefit ratio of standardized protocols for the early detection of cardiotoxicity using hs-cTn assay in patients receiving chemotherapy for malignant diseases.

scholarly journals BIMG-04. MAPPING HETEROGENEITY OF HIGH-GRADE GLIOMA METABOLISM USING HIGH RESOLUTION 7T MRSI

2021 ◽  
Vol 3 (Supplement_1) ◽  
pp. i1-i1
Author(s):  
Gilbert Hangel ◽  
Cornelius Cadrien ◽  
Philipp Lazen ◽  
Sukrit Sharma ◽  
Julia Furtner ◽  
...  
Keyword(s):  
High Resolution ◽  
Imaging Techniques ◽  
Basis Set ◽  
Metabolic Imaging ◽  
Tumor Segmentation ◽  
Low Grade ◽  
High Grade ◽  
Isotropic Resolution ◽  
Contrast Enhanced ◽  
Definition Of

Abstract OBJECTIVES Neurosurgical resection in gliomas depends on the precise preoperative definition of the tumor and its margins to realize a safe maximum resection that translates into a better patient outcome. New metabolic imaging techniques could improve this delineation as well as designate targets for biopsies. We validated the performance of our fast high-resolution whole-brain 3D-magnetic resonance spectroscopic imaging (MRSI) method at 7T in high-grade gliomas (HGGs) as first step to this regard. METHODS We measured 23 patients with HGGs at 7T with MRSI covering the whole cerebrum with 3.4mm isotropic resolution in 15 min. Quantification used a basis-set of 17 neurochemical components. They were evaluated for their reliability/quality and compared to neuroradiologically segmented tumor regions-of-interest (necrosis, contrast-enhanced, non-contrast-enhanced+edema, peritumoral) and histopathology (e.g., grade, IDH-status). RESULTS We found 18/23 measurements to be usable and ten neurochemicals quantified with acceptable quality. The most common denominators were increases of glutamine, glycine, and total choline as well as decreases of N-acetyl-aspartate and total creatine over most tumor regions. Other metabolites like taurine and serine showed mixed behavior. We further found that heterogeneity in the metabolic images often continued into the peritumoral region. While 2-hydroxy-glutarate could not be satisfyingly quantified, we found a tendency for a decrease of glutamate in IDH1-mutant HGGs. DISCUSSION Our findings corresponded well to clinical tumor segmentation but were more heterogeneous and often extended into the peritumoral region. Our results corresponded to previous knowledge, but with previously not feasible resolution. Apart from glycine/glutamine and their role in glioma progression, more research on the connection of glutamate and others to specific mutations is necessary. The addition of low-grade gliomas and statistical ROI analysis in a larger cohort will be the next important steps to define the benefits of our 7T MRSI approach for the definition of spatial metabolic tumor profiles.

Intelligent diagnosis and analysis of brain lymphoma based on imaging features

2021 ◽  
pp. 1-11
Author(s):  
Yipu Mao ◽  
Muliang Jiang ◽  
Fanyu Zhao ◽  
Liling Long
Keyword(s):  
Imaging Techniques ◽  
Experimental Studies ◽  
Diagnostic Value ◽  
Imaging Features ◽  
Flow Properties ◽  
Brain Lymphoma ◽  
Diagnosis And Prognosis ◽  
Primary Brain Lymphoma ◽  
Set Up ◽  
Prognosis Evaluation

Currently, DSC has been extensively studied in the diagnosis, differential diagnosis and prognosis evaluation of brain lymphoma, but it has not obtained a uniform standard. By combining DSC imaging features, this study investigated the imaging features and diagnostic value of several types of tumors such as primary brain lymphoma. At the same time, this study obtained data from brain lymphoma patients by data collection and set up different groups to conduct experimental studies to explore the correlation between IVIM-MRI perfusion parameters and DSC perfusion parameters in brain lymphoma. Through experimental research, it can be seen that the combination of two perfusion imaging techniques can more fully reflect the blood flow properties of the lesion, which is beneficial to determine the nature of the lesion.

Defining an Adequate Dose of Acupuncture Using a Neurophysiological Approach – a Narrative Review of the Literature

2008 ◽  
Vol 26 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Adrian White ◽  
Mike Cummings ◽  
Panos Barlas ◽  
Francesco Cardini ◽  
Jacqueline Filshie ◽  
...  
Keyword(s):  
Systematic Reviews ◽  
Acupuncture Treatment ◽  
Experimental Studies ◽  
Basic Research ◽  
Strong Argument ◽  
Treatment Protocols ◽  
Negative Results ◽  
Adequate Dose ◽  
Definition Of ◽  
Patient’S Perception

Many different styles of acupuncture practice exist, and lack of agreement on the optimal acupuncture treatment for any particular condition may mean that some patients do not receive the best treatment. This uncertainty also makes the negative results of sham controlled trials difficult to interpret. Unless we can be sure that both adequate acupuncture and an inactive sham were used in a particular trial, then that trial should not be interpreted as dismissing acupuncture for that condition. Acupuncture practice clearly involves much more than needling procedures, but there is a strong argument for elucidating the role of those needling procedure first. The components of acupuncture needling procedures have been described in the STRICTA document, but it is also clear that the patient's perception of needling is relevant for the outcome of treatment. We therefore recommend the concept of ‘dose’ of acupuncture needling, which should include both the stimulus given to the patient, and certain aspects of the patient's perceptions and response that are known to be linked to the subsequent therapeutic response. We propose the following definition of dose: the physical procedures applied in each session, using one or more needles, taking account of the patient's resulting perception (sensory, affective and cognitive) and other responses (including motor). The dose may be affected by the state of the patient (eg nervous, immune and endocrine systems); different doses may be required for different conditions. The constituents of an adequate dose can be established initially by clinical opinion and subsequently by empirical evidence from experimental studies, which may be either clinical or basic research studies. Systematic reviews which do not consider the adequacy of the acupuncture treatment may have unreliable conclusions. Out of 47 recent systematic reviews, only six have applied some criteria for adequacy. Five used a rating system or conducted a subgroup analysis, and one excluded studies from the analysis altogether if they did not meet criteria for adequacy. Research into what constitutes an adequate dose of acupuncture has long been neglected and is now urgent. Clinical studies that compare the effects of different treatment protocols are probably the most reliable source of evidence, and may also demonstrate a dose-response relationship.

scholarly journals Reasons for discordances between ultrasonography and magnetic resonance imaging in the evaluation of the ankle, hindfoot and heel of the patients with rheumatoid arthritis

2019 ◽  
Vol 21 (4) ◽  
pp. 405 ◽  
Author(s):  
Oana Șerban ◽  
Daniela Fodor ◽  
Iulia Papp ◽  
Mihaela Cosmina Micu ◽  
Dan Gabriel Duma ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Disease Activity ◽  
Activity Index ◽  
Imaging Techniques ◽  
Disease Activity Index ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri ◽  
Definition Of

Aim: To compare the ultrasonography (US) performance with magnetic resonance imaging (MRI) in identifying pathology in ankles, hindfeet and heels of rheumatoid arthritis (RA) patients and to evaluate the reasons for discordances between the two imaging methods.Material and methods: RA patients were enrolled and evaluated using the Clinical Disease Activity Index (CDAI) and the Disease Activity Score 28 with C-reactive Protein (DAS28-CRP). The ankle (tibiotalar joint, tendons), hindfoot (talonavicular, subtalar joints) and heel of the most symptomatic or dominant foot (for the asymptomatic patient)were evaluated by two pairs of examiners using US and contrast-enhanced MRI.Results: Totally, 105 joints, 245 tendons and 35 heels in 35 patients [mean age 59.2±11.25 years old, median disease duration 36 (16.5-114), mean CDAI 19.87±12.7] were evaluated. The interobserver agreements between the two sonographers, and the two radiologists were good and very good (k=0.624-0.940). The overall agreement between US and MRI was very good for subcalcaneal panniculitis (k=0.928, p<0.001), moderate for synovitis (k=0.463, p<0.001) and tenosynovitis (k=0.514, p<0.001), fair for osteophytes (k=0.260, p=0.004), and poor for erosions (k=0.063, p=0.308) and heel’s structures. MRI found more erosions, synovitis, osteophytes,tenosynovitis and retrocalcaneal bursitis, but US found more enthesophytes and plantar fasciitis. Many of the discordancesbetween the two imaging techniques have explanations related to the technique itself or definition of the pathologic findings.Conclusions: US is comparable to MRI for the evaluation of ankle, hindfoot and heel in RA patients and discordances in theinterpretation of the pathological findings/normal structures must be carefully analyzed.

scholarly journals The orchestrated cellular and molecular responses of the kidney to endotoxin define the sepsis timeline

2020 ◽  
Author(s):  
Danielle Janosevic ◽  
Jered Myslinski ◽  
Thomas McCarthy ◽  
Amy Zollman ◽  
Farooq Syed ◽  
...  
Keyword(s):  
Cell Communication ◽  
Tissue Level ◽  
Dynamic State ◽  
Cellular Functions ◽  
Clinical Sepsis ◽  
Human Sepsis ◽  
Molecular Events ◽  
Definition Of ◽  
Injury And Repair ◽  
Recovery Pathways

AbstractClinical sepsis is a highly dynamic state that progresses at variable rates and has life-threatening consequences. Staging patients along the sepsis timeline requires a thorough knowledge of the evolution of cellular and molecular events at the tissue level. Here, we investigated the kidney, an organ central to the pathophysiology of sepsis. Single cell RNA sequencing revealed the involvement of various cell populations in injury and repair to be temporally organized and highly orchestrated. We identified key changes in gene expression that altered cellular functions and can explain features of clinical sepsis. These changes converged towards a remarkable global cell-cell communication failure and organ shutdown at a well-defined point in the sepsis timeline. Importantly, this time point was also a transition towards the emergence of recovery pathways. This rigorous spatial and temporal definition of murine sepsis will uncover precise biomarkers and targets that can help stage and treat human sepsis.

scholarly journals Spatiotemporal Dynamics of Molecular Pathology in Amyotrophic Lateral Sclerosis

2018 ◽  
Author(s):  
Silas Maniatis ◽  
Tarmo Äijö ◽  
Sanja Vickovic ◽  
Catherine Braine ◽  
Kristy Kang ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neuron ◽  
Motor Neurons ◽  
Molecular Mechanisms ◽  
Early Time ◽  
Spatiotemporal Dynamics ◽  
Course Of Disease ◽  
Molecular Events ◽  
Als Patients ◽  
Lateral Sclerosis

AbstractParalysis occurring in amyotrophic lateral sclerosis (ALS) results from denervation of skeletal muscle as a consequence of motor neuron degeneration. Interactions between motor neurons and glia contribute to motor neuron loss, but the spatiotemporal ordering of molecular events that drive these processes in intact spinal tissue remains poorly understood. Here, we use spatial transcriptomics to obtain gene expression measurements of mouse spinal cords over the course of disease, as well as of postmortem tissue from ALS patients, to characterize the underlying molecular mechanisms in ALS. We identify novel pathway dynamics, regional differences between microglia and astrocyte populations at early time-points, and discern perturbations in several transcriptional pathways shared between murine models of ALS and human postmortem spinal cords.One Sentence SummaryAnalysis of the ALS spinal cord using Spatial Transcriptomics reveals spatiotemporal dynamics of disease driven gene regulation.

A KINEMATIC DESCRIPTION OF THE EXPANSION OF THE UNIVERSE

1993 ◽  
Vol 02 (02) ◽  
pp. 197-220 ◽  
Author(s):  
D. SAVICKAS
Keyword(s):  
Early Time ◽  
Static Universe ◽  
Distant Galaxy ◽  
Usual Manner ◽  
Expansion Of The Universe ◽  
Uniform Background ◽  
Radiation Universe ◽  
Standard Solution ◽  
Definition Of ◽  
The Universe

A kinematic expression for the Hubble parameter H is derived which defines it directly in terms of the positions and velocities of all existing mass particles. The derivation is simply based on the concept that the numerical value of H at any instant of time is determined solely by particle positions and velocities that exist at that instant, and it is only indirectly affected by gravity through its actions on particles which change the positions and velocities. This definition of H does not depend on the motion of photons because the motion of a photon in a distant galaxy is determined by H as it moves with a constant velocity in the galaxy’s inertial system at rest in the Hubble drift. The kinematic definition of H is shown to be identical to the conventional expression H=Ṙ/R. Under general conditions it behaves in the usual manner. But in the case when all matter is located in a small volume of space, such as that which could have occurred at the time of origin of the universe, there exists for a brief time a kinematic repulsion which acts in addition to the usual gravitational attraction that is described in the standard solution of relativity. The repulsion could be strong enough to overcome gravitation and cause even a static universe to quickly evolve into an expanding one. In the case of an initially pure and static radiation universe that subsequently expands and creates all matter during the expansion, the kinematically defined H allows matter to be created in clusters at a very early time within a highly uniform background of radiation.

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