Important Role Research Articles

The Importance of Salicylic Acid, Humic Acid and Fulvic Acid on Crop Production

Abstract: Biostimulants are one of the most important substancesfor improving productivity, growth and yield of plants as well as heavy metal detoxification, and stimulating natural toxins, controlling pests and diseases and boosting both water and nutrient efficiency. Google Scholar, Science Direct, CAB Direct, Springer Link, Scopus, Web of Science, Taylor and Francis, and Wiley Online Library have been checked. The search was done to all manuscript sections according to the terms "Salicylic acid," "Humic acid," "Fulvic acid," "Biostimulants" and "Plant growth promotion." On the basis of the initial check, Titles and Abstracts were screened on the basis of online literature, and then articles were read carefully. Salicylic acid may have important roles in abiotic stresses such as salinity, drought, cold, heavy metal and heat stresses, and it has been considered an important environmentally-sound agent with tremendous economical benefits and rapid responses. The positive effects of the application of salicylic acid have been reported in crops such as ajwain, alfalfa, anthurium, artemisia, artichoke, barley, bean, black mustard, broad bean, chickpea, chicory, canola, coriander, corn, cotton, cucumber, cumin, fennel, fenugreek, goji, longan, milk thistle, millet, onion, pea, pepper, pistachio, radish, rice, rosemary, rye, safflower, saffron, savory, sorghum, soybean, spinach, strawberry, sugar beet, tomato, wheat, etc. Humic acid can improve and stimulate plant growth and yield, suppress diseases and promote more resistance to stresses. Fulvic acid can increase root system and promote seed germination, growth rate and final yield. The present manuscript highlights the most important impacts of salicylic acid, humic acid, and fulvic acid ,emphasizing their roles in modern sustainable crop production.

QSAR Studies on a Series of Pyrazole Azabicyclo [3.2.1] Octane Sulfonamides N-acylethanolamine-hydrolyzing Acid Amidase Inhibitors

Background: Inflammation is a common and intractable disease for humans. Current antiinflammatory drugs have a lot of side effects, which cause irreversible damage to the body. Objective: We predict the activity of the N-acylethanolamine-hydrolyzing acid amidase (NAAA) inhibitor to find more effective compounds. Methods: We established a quantitative structure-activity relationship (QSAR) model by gene expression programming to predict the IC50 values of natural compounds. The NAAA inhibitor, as a cysteine enzyme, plays an important role in the therapy of pain, anti-inflammatory effects and application of other diseases. A total of 36 NAAA inhibitors were optimized by the heuristic method in the CODESSA program to build a linear model. The 27 compounds and 9 compounds were in train and test sets. On this basis, we selected three descriptors and used them to build nonlinear models in gene expression programming. Results: The best model in the gene expression programming method was found, the square of correlation coefficients of R2 and mean square error for the training set were 0.79 and 0.14, testing set was 0.78 and 0.20, respectively. Conclusion: From this method, the activity of molecules could be predicted, and the best method was found. Therefore, this model has a stronger predictive ability to develop NAAA inhibitors.

Temporal associations between trauma-related sleep disturbances and PTSD symptoms: An experience sampling study.

There is robust evidence for the influence of sleep disturbances on the maintenance of PTSD symptoms. However, little is known about day-to-day variation in trauma-related sleep disturbances (namely insomnia symptoms and nightmares) and their associations with PTSD symptoms. Therefore, we explored the dynamic interplay of these symptoms in daily life using an experience sampling method (ESM). For 15 consecutive days, participants with PTSD symptomatology as primary complaint (N = 48) reported momentary levels of insomnia symptoms and nightmares as well as PTSD symptoms via a mobile app. Multilevel model analyses revealed that insomnia and nightmares were significant predictors of PTSD symptomatology on the following day; furthermore, nightmares were predictive of each of the four PTSD symptom clusters, namely reexperiencing, avoidance, cognition and hyperarousal as well as symptoms of dissociation. However, PTSD symptoms did not predict insomnia or nightmares during the following night. Multilevel mediation analyses suggested that nightmares mediate the relationship between insomnia and next-day PTSD symptoms. These findings support accumulating evidence that trauma-related sleep disturbances play an important role in the maintenance of PTSD symptoms, by elevating symptoms daily. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Transformation of A1/A2 Astrocytes Participates in Brain Ischemic Tolerance Induced by Cerebral Ischemic Preconditioning via Inhibiting NDRG2.

Cerebral ischemic preconditioning (CIP) has been shown to improve brain ischemic tolerance against subsequent lethal ischemia. Reactive astrocytes play important roles in cerebral ischemia-reperfusion. Recent studies have shown that reactive astrocytes can be polarized into neurotoxic A1 phenotype (C3d) and neuroprotective A2 phenotype (S100A10). However, their role in CIP remains unclear. Here, we focused on the role of N-myc downstream-regulated gene 2 (NDRG2) in regulating the transformation of A1/A2 astrocytes and promoting to brain ischemic tolerance induced by CIP. A Sprague Dawley rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) was used. Rats were divided into the following six groups: (1) sham group; (2) CIP group: left middle cerebral artery was blocked for 10min; (3) MCAO/R group: left middle cerebral artery was blocked for 90min; (4) CIP + MCAO/R group: CIP was performed 72h before MCAO/R; (5) AAV-NDRG2 + CIP + MCAO/R group: adeno-associated virus (AAV) carrying NDRG2 was administered 14 days before CIP + MCAO/R; (6) AAV-Ctrl + CIP + MCAO/R group: empty control group. The rats were subjected to neurological evaluation 24h after the above treatments, and then were sacrificed for 2, 3, 5-triphenyltetraolium chloride staining, thionin staining, immunofluorescence and western blot analysis. In CIP + MCAO/R group, the neurological deficit scores decreased, infarct volume reduced, and neuronal density increased compared with MCAO/R group. Notably, CIP significantly increased S100A10 expression and the number of S100A10+/GFAP+ cells, and also increased NDRG2 expression. MCAO/R significantly decreased S100A10 expression and the number of S100A10+/GFAP+ cells yet increased C3d expression and the number of C3d+/GFAP+ cells and NDRG2 expression, and these trends were reversed by CIP + MCAO/R. Furthermore, over-expression of NDRG2 before CIP + MCAO/R, the C3d expression and the number of C3d+/GFAP+ cells increased, while S100A10 expression and the number of S100A10+/GFAP+ cells decreased. Meanwhile, over-expression of NDRG2 blocked the CIP-induced brain ischemic tolerance. Taken together, these results suggest that CIP exerts neuroprotective effects against ischemic injury by suppressing A1 astrocyte polarization and promoting A2 astrocyte polarization via inhibiting NDRG2 expression.

How Much Does Land–Atmosphere Coupling Influence Summertime Temperature Variability in the Western United States?

Abstract Interannual fluctuations in average summertime temperatures across the western United States are captured by a leading empirical orthogonal function that explains over 50% of the total observed variance. In this paper, we explain the origins of this pattern of interannual temperature variability by examining soil moisture–temperature coupling that acts across seasons in observations and climate models. We find that a characteristic pattern of coupled temperature–soil moisture climate variability accounts for 34% of the total observed variance in summertime temperature across the region. This pattern is reproduced in state-of-the-art global climate models, where experiments that eliminate soil moisture variability reduce summertime average temperature variance by a factor of 3 on average. We use an idealized model of the coupled atmospheric boundary layer and underlying land surface to demonstrate that feedbacks between soil moisture, boundary layer relative humidity, and precipitation can explain the observed relations between springtime soil moisture and summertime temperature. Our results suggest that antecedent soil moisture conditions and subsequent land–atmosphere interactions play an important role in interannual summertime temperature variability in the western United States; soil moisture variations cause distal temperature anomalies and impart predictability at time scales longer than one season. Our results indicate that 40% of the observed warming trend across the western United States since 1981 has been driven by wintertime precipitation trends in the U.S. southwest. Significance Statement Year-to-year fluctuations in summertime temperatures have a large impact on drought, wildfire, and extreme heat across the Western United States. We find strong evidence that soil moisture deficits in the preceding spring may be the primary driver of higher-than-average summer temperatures in this region. Our results suggest that memory in the water cycle may lead to greater predictability in the climate system from season to season and that trends in southwest precipitation have exerted a considerable influence on observed warming over the past 40 years.

Arnicolide D Inhibits Oxidative Stress-Induced Breast Cancer Cell Growth And Invasion Through Apoptosis, Ferroptosis, And Parthanatos.

Breast cancer is the most common malignant tumor in women, and its pathogenesis is very complicated. More and more studies have found that Traditional Chinese Medicine plays an important role in tumor prevention. To investigate the mechanism of arnicolide D isolated from Centipeda minima in breast cancer. Cell Counting Kit-8 (CCK-8), western blot, RT-qPCR, ELISA, flow cytometry, and Transwell were used to detect the effect of arnicolide D on the biological function of breast cancer cells. Arnicolide D promoted reactive oxygen species (ROS) production and induced a decrease in mitochondrial membrane potential in breast cancer cells, thereby inhibiting cell viability and increasing lactate dehydrogenase (LDH) release. Arnicolide D activated the classical apoptosis pathway to induce cell apoptosis; it significantly promoted PARP-1 expression, enhanced the nuclear translocation of apoptosis-inducing factor (AIF), and reduced the expression of AIF in mitochondria, indicating that it can induce the occurrence of parthanatos in a ROS dependent manner. In addition, arnicolide D down-regulated glutathione peroxidase 4 (GPX4) expression and increased the accumulation of Fe2+ and malondialdehyde (MDA), thereby activating ferroptosis. Apoptosis inhibitor, ferroptosis inhibitor, PARP inhibitor, PARP-1 siRNA, AIF siRNA and GPX4 overexpression vector significantly attenuated the inhibitory effect of arnicolide D on cell viability and reduced LDH release, which indicates that arnicolide D inhibits breast cancer cell growth by inducing apoptosis, parthanatos and ferroptosis. Arnicolide D also reduced breast cancer cell invasion and inhibited the expression of matrix metallopeptidase (MMP)-2 and MMP-9. Arnicolide D can activate a variety of cell death modes by inducing oxidative stress, thereby inhibiting the growth and invasion of breast cancer cells, indicating that arnicolide D has a good anti-tumor effect.

Research Progress on the Effect of Autophagy and Exosomes on Liver Fibrosis.

Chronic liver disease is a known risk factor for the development of liver cancer, and the development of microRNA (miRNA) liver therapies has been hampered by the difficulty of delivering miRNA to damaged tissues. In recent years, numerous studies have shown that hepatic stellate cell (HSC) autophagy and exosomes play an important role in maintaining liver homeostasis and ameliorating liver fibrosis. In addition, the interaction between HSC autophagy and exosomes also affects the progression of liver fibrosis. In this paper, we review the research progress of mesenchymal stem cell-derived exosomes (MSC-EVs) loaded with specific miRNA and autophagy, and their related signaling pathways in liver fibrosis, which will provide a more reliable basis for the use of MSC-EVs for therapeutic delivery of miRNAs targeting the chronic liver disease.

Inelastic Neutron Scattering Studies of Propene and 1-Octene Oligomerisation in H-ZSM-5

Neutron scattering methods such as quasielastic neutron scattering (QENS) and inelastic neutron scattering (INS) have been used to study the reactivity of propene and 1-octene over the acid zeolite catalyst H-ZSM-5. The high activity of the catalyst causes the alkenes to form linear oligomers below room temperature. INS has shown that the reaction proceeds through a hydrogen-bonded intermediate. Studies using propane as an inert analogue for propene have found that the adsorbed C3 molecules spend much of their time undergoing short jumps within the pore channels of the zeolite. Hydrothermal dealumination plays an important role in determining the activity of zeolite catalysts. Dealumination was found to delay the onset of catalytic activity for oligomerisation to higher temperatures and increase the mobility of hydrocarbons within the zeolite, both due to reduced acid-hydrocarbon interactions.

Research on the Relationship between Exosome Production and Atherosclerosis.

Atherosclerosis (AS) is the leading cause of cardiovascular disease, causing a major burden on patients as well as families and society. Exosomes generally refer to various lipid bilayer microvesicles originating from different cells that deliver various bioactive molecules to the recipient cells, exerting biological effects in cellular communication and thereby changing the internal environment of the body. The mechanisms of correlation between exosomes and the disease process of atherosclerosis have been recently clarified. Exosomes are rich in nucleic acid molecules and proteins. For example, the exosome miRNAs reportedly play important roles in the progression of atherosclerotic diseases. In this review, we focus on the composition of exosomes, the mechanism of their biogenesis and release, and the commonly used methods for exosome extraction. By summarizing the latest research progress on exosomes and atherosclerosis, we can explore the advances in the roles of exosomes in atherosclerosis to provide new ideas and targets for atherosclerosis prevention, diagnosis, and treatment.

The Tumor Immune Microenvironment plays a Key Role in Driving the Progression of CholangioCarcinoma.

Cholangiocarcinoma (CCA) is an epithelial cancer distinguished by bile duct cell differentiation and is also a fibroproliferative tumor. It is characterized by a dense mesenchyme and a complex tumor immune microenvironment (TME). The TME comprises both cellular and non-cellular components. The celluar component includes CCA cells, immune cells and mesenchymal cells represented by the cancer-associated fibroblasts (CAFs), while the non-cellular component is represented by mesenchymal elements such as the extracellular matrix (ECM). Recent studies have demonstrated the important role of the TME in the development, progression, and treatment resistance of CCA. These cell-associated prognostic markers as well as intercellular connections, may serve as potential therapeutic targets and could inspire new treatment approaches for CCA in the future. This paper aims to summarize the current understanding of CCA's immune microenvironment, focusing on immune cells, mesenchymal cells, ECM, intercellular interactions, and metabolism within the microenvironment.

Supporting Children with Autism Using Visual Arts

The current study aims to develop a special program for both instructors and educators to train children with autism via art while also promoting their positive behaviors and social requirements. To achieve these goals, an experimental study was carried out at the Centre of Community Services for Autism, drawing on previous research in the field of art therapy. The study concentrated on the usage of images and their visual composition from the linguistic, cognitive, emotional, motor, and social perspectives. The study's findings demonstrated that the image, its simulation, and its practical application all play important roles in promoting specific developmental features of children with autism. Keywords: Visual Arts, Image, Arts Therapy, Children with Autism

Kadına Yönelik Şiddet: Kalıcı ve Yükselen Bir Sorun

Violence against women is a widespread global public health problem. It is also a serious violation of women's human rights. Violence has traumatic effects on the health and well-being of women and the children who witness it. Violence against women is associated with physical, mental, emotional, sexual health, reproductive health problems and death. Violence and gender norms, which are one of the risk factors causing the continuation of violence; also have significant effects on families and societies, and these negative effects cross social and economic boundaries. However, it is also clear that current prevention initiatives and policy responses are insufficient. Mental health professionals have an important role to play in identifying, preventing and responding appropriately to violence against women and may take primary, secondary and tertiary measures to reduce the risk of violence against women. While providing mental health services, İt is very important to be aware of interpersonal violence and to provide gender-sensitive services. When providing these services, the impact of violence against women on mental health and knowledge of potential treatments are considered as a prerequisite. Along with the knowledge about the dynamics of violence, it is considered extremely important to take measures against the risks that weaken women who are disadvantaged due to problems such as gender inequality. For this reason, in this review, the concept of violence against women and the types of violence are explained and in this context, the initiatives that can be made in the field of mental health are included. It is thought that this review will contribute to the awareness of professionals working in the field about the seriousness of the problem and how violence affects women's mental health. It is also hoped that the present study will provide insight into the complex relationship between violence and health outcomes to help improve health policies and prevention responses in the relevant field.

PP1β opposes classic PP1 function, inhibiting spine maturation and promoting LTP.

Protein phosphatase 1 (PP1) regulates synaptic plasticity and has been described as a molecular constraint on learning and memory. There are three neuronal isoforms, PP1α, PP1β, and PP1γ, but little is known about their individual functions. PP1α and PP1γ are assumed to mediate the effects of PP1 on learning and memory based on their enrichment at dendritic spines and their preferential binding to neurabin and spinophilin, major PP1 synaptic scaffolding proteins. However, it was recently discovered that human de novo PP1β mutations cause intellectual disability, suggesting an important but ill-defined role for PP1β. In this study, we investigated the functions of each PP1 isoform in hippocampal synaptic physiology using conditional CA1-specific knockout mice. In stark contrast to classic PP1 function, we found that PP1β promotes synaptic plasticity as well as spatial memory. These changes in synaptic plasticity and memory are accompanied by changes in GluA1 phosphorylation, GluN2A levels, and dendritic spine density and morphology, including silent synapse number. These functions of PP1β reveal a previously unidentified signaling pathway regulating spine maturation and plasticity, broadening our understanding of the complex role of PP1 in synaptic physiology.

Vole genomics links determinate and indeterminate growth of teeth.

Continuously growing teeth are an important innovation in mammalian evolution, yet genetic regulation of continuous growth by stem cells remains incompletely understood. Dental stem cells responsible for tooth crown growth are lost at the onset of tooth root formation. Genetic signaling that initiates this loss is difficult to study with the ever-growing incisor and rooted molars of mice, the most common mammalian dental model species, because signals for root formation overlap with signals that pattern tooth size and shape (i.e., cusp patterns). Different species of voles (Cricetidae, Rodentia, Glires) have evolved rooted and unrooted molars that have similar size and shape, providing alternative models for studying roots. We assembled a de novo genome of Myodes glareolus, a vole with high-crowned, rooted molars, and performed genomic and transcriptomic analyses in a broad phylogenetic context of Glires (rodents and lagomorphs) to assess differential selection and evolution in tooth forming genes. We identified 15 dental genes with changing synteny relationships and six dental genes undergoing positive selection across Glires, two of which were undergoing positive selection in species with unrooted molars, Dspp and Aqp1. Decreased expression of both genes in prairie voles with unrooted molars compared to bank voles supports the presence of positive selection and may underlie differences in root formation. Bulk transcriptomics analyses of embryonic molar development in bank voles also demonstrated conserved patterns of dental gene expression compared to mice, with species-specific variation likely related to developmental timing and morphological differences between mouse and vole molars. Our results support ongoing evolution of dental genes across Glires, revealing the complex evolutionary background of convergent evolution for ever-growing molars.

Single dopaminergic neuron DAN-c1 in Drosophila larval brain mediates aversive olfactory learning through D2-like receptors.

The intricate relationship between the dopaminergic system and olfactory associative learning in Drosophila has been an intense scientific inquiry. Leveraging the formidable genetic tools, we conducted a screening of 57 dopaminergic drivers, leading to the discovery of DAN-c1 driver, uniquely targeting the single dopaminergic neuron (DAN) in each brain hemisphere. While the involvement of excitatory D1-like receptors is well-established, the role of D2-like receptors (D2Rs) remains underexplored. Our investigation reveals the expression of D2Rs in both DANs and the mushroom body (MB) of third instar larval brains. Silencing D2Rs in DAN-c1 via microRNA disrupts aversive learning, further supported by optogenetic activation of DAN-c1 during training, affirming the inhibitory role of D2R autoreceptor. Intriguingly, D2R knockdown in the MB impairs both appetitive and aversive learning. These findings elucidate the distinct contributions of D2Rs in diverse brain structures, providing novel insights into the molecular mechanisms governing associative learning in Drosophila larvae.

Coding attitudes of fourth-grade latinx students during distance learning

ABSTRACT Background and Context Despite the growing initiatives in K-12 computer science (CS), there is a continued disparity in the participation of Latinx and multilingual students, a historically underrepresented group in computing. The inequitable participation may be understood by examining students’ early development of CS attitudes. Objective This study aims to explore shifts and elicitation in coding attitudes of fourth-grade, Latinx students (ages 9-10) who underwent a year-long remote coding curriculum, with consideration of gender and language designation. Method Using a mixed method approach, pre-post survey responses on coding attitudes were analyzed to understand shifts and portrayal of Interest, Confidence, Utility, Social Values, and Perception of Coders, with consideration of gender or designation as an English Language Learner. Findings Gender and language designation did not interact with overall attitude shifts. However, there is a significant difference in Social Values and Confidence over time. Student interviews revealed more nuance in social influences with siblings and cousins as key motivators for extended learning, underlying values of perseverance in confidence, mixed perception of what coders do, and the importance of creativity to develop interest. Implications The key role of social influence in driving higher identity among Latinx students points to the important role of extended family. Moreso, developing students’ confidence in domain-specific tasks should be a focus in curricula in order to have a longer-term impact on motivation. Finally, more research on the role that subjective task values pertaining to cultural values should be explored in early coding motivation in order to broaden participation. Keywords: Coding attitudes, elementary students, remote learning, expectancy-value theory, coding curriculum.

Comprehensive analyses reveal molecular and clinical characteristics of RNA modification writers across 32 cancer types

<p class="MsoNormal" style="text-align: justify;"><span lang="EN-US" style="font-size: 12pt; font-family: Nunito;">Adenosine alterations to RNA, which are largely determined by RNA modification writers (RMWs), are critical for cancer growth and progression. These RMWs can catalyze different types of adenosine modifications, such as N6-methyladenosine (m6A), N1-methyladenosine (m1A), alternative polyadenylation (APA), and adenosine-to-inosine (A-to-I) RNA editing. These modifications have profound effects on gene expression and function, such as immune response, cell development. Despite this, the clinical effects of RMW interactive genes on these cancers remain largely unclear. A comprehensive analysis of the clinical impact of these epigenetic regulators in pan-cancer requires further comprehensive exploration. Here, we systematically profiled the molecular and clinical characteristics of 26 RMWs across 33 cancer types using multi-omics datasets and validated the expression level of some RMWs in various cancer lines. Our findings indicated that a majority of RMWs exhibited high expression in diverse cancer types, and this expression was found to be significantly associated with poor patient outcomes. In the genetic alterations, the amplification and mutation of RMWs were the dominant alteration events. Consequently, the RNA Modification Writer Score (RMW score) was established as a means to assess the risk of RMWs in pan-cancer. We found that 27 of 33 cancers had significantly higher scores compared with normal tissues, and it was significantly correlated with prognosis. We also evaluated their impact on the tumor microenvironment and the response to immunotherapy and targeted therapy. These findings verified the important role of RMWs in different aspects of cancer biology, and provided biomarkers and personalized therapeutic targets for cancer.</span></p>

An Epsilon Class Glutathione S-Transferase Gene Contributes to the Phytochemical Susceptibility of Tribolium castaneum (Coleoptera: Tenebrionidae)

Abstract Evidence is accumulating that insect epsilon class glutathione S-transferases (GSTs) play an important role in the resistance to xenobiotics such as insecticides. A Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) epsilon class GST gene, TcGSTe17, was previously found to be significantly induced following exposure to the plant derivative eucalyptol. However, whether TcGSTe17 is involved in resistance to eucalyptol remains unclear. In this study, TcGSTe17 was cloned from the T. castaneum. Development stage expression profiling revealed that TcGSTe17 was expressed at all development stages of T. castaneum but was highly expressed in late-stage larvae. Subsequent expression profiling of tissues showed that TcGSTe17 was highly expressed in the gut of larvae and the fat body of adults, and also revealed gender-specific expression patterns. In addition, the transcripts of TcGSTe17 were significantly increased following exposure to eucalyptol, and RNAi increased the susceptibility of the beetles to eucalyptol. Collectively, these results suggest that TcGSTe17 contributes to the susceptibility of T. castaneum to eucalyptol. These findings provide new data for the prevention of pest resistance.

Identification of CD44 as a key mediator of cell traction force generation in hyaluronic acid-rich extracellular matrices.

Mechanical properties of the extracellular matrix (ECM) critically regulate a number of important cell functions including growth, differentiation and migration. Type I collagen and glycosaminoglycans (GAGs) are two primary components of ECMs that contribute to mammalian tissue mechanics, with the collagen fiber network sustaining tension, and GAGs withstanding compression. The architecture and stiffness of the collagen network are known to be important for cell-ECM mechanical interactions via integrin cell surface adhesion receptors. In contrast, studies of GAGs in modulating cell-ECM interactions are limited. Here, we present experimental studies on the roles of hyaluronic acid (HA, an unsulfated GAG) in single tumor cell traction force generation using a recently developed 3D cell traction force microscopy method. Our work reveals that CD44, a cell surface adhesion receptor to HA, is engaged in cell traction force generation in conjunction with β1-integrin. We find that HA significantly modifies the architecture and mechanics of the collagen fiber network, decreasing tumor cells' propensity to remodel the collagen network, attenuating traction force generation, transmission distance, and tumor invasion. Our findings point to a novel role for CD44 in traction force generation, which can be a potential therapeutic target for diseases involving HA rich ECMs such as breast cancer and glioblastoma.

Imaging of Cardiac Fibrosis: An Update, From the AJR Special Series on Imaging of Fibrosis.

Myocardial fibrosis (MF) is defined as excessive production and deposition of extra-cellular matrix (ECM) proteins that result in pathologic myocardial remodeling. Three types of MF have been identified: replacement fibrosis from tissue necrosis, reactive fibrosis from myocardial stress, and infiltrative interstitial fibrosis from progressive deposition of nondegradable material such as amyloid. Although echocardiography, nuclear medicine, and CT play important roles in the assessment of MF, MRI is pivotal in the evaluation of MF, with the late gadolinium enhancement (LGE) technique used as a primary end point. The LGE technique focuses on the pattern and distribution of gadolinium accumulation in the myocardium and assists in the diagnosis and establishment of the cause of both ischemic and nonischemic cardiomyopathy. LGE MRI also aids prognostication and risk stratification. In addition, LGE MRI is used to guide the management of patients considered for ablation for arrhythmias. Parametric mapping techniques, including T1 mapping and extracellular volume measurement, allow detection and quantification of diffuse fibrosis, which may not be detected by LGE MRI. These techniques also allow monitoring of disease progression and therapy response. This review provides an update on the imaging of MF, including prognostication and risk stratification tools, electrophysiologic considerations, and disease monitoring.