scholarly journals Mechanisms of Drug Resistance in the Pathogenesis of Epilepsy: Role of Neuroinflammation. A Literature Review

2021 ◽  
Vol 11 (5) ◽  
pp. 663
Author(s):  
Elena D. Bazhanova ◽  
Alexander A. Kozlov ◽  
Anastasia V. Litovchenko
Keyword(s):  
Drug Resistance ◽  
Premature Death ◽  
Resistance Mechanisms ◽  
Biomedical Literature ◽  
Drug Resistant ◽  
Psychological Consequences ◽  
Text Documents ◽  
Neural Connections ◽  
Inflammatory Processes ◽  
Drug Resistant Epilepsy

Epilepsy is a chronic neurological disorder characterized by recurring spontaneous seizures. Drug resistance appears in 30% of patients and it can lead to premature death, brain damage or a reduced quality of life. The purpose of the study was to analyze the drug resistance mechanisms, especially neuroinflammation, in the epileptogenesis. The information bases of biomedical literature Scopus, PubMed, Google Scholar and SciVerse were used. To obtain full-text documents, electronic resources of PubMed Central and Research Gate were used. The article examines the recent research of the mechanisms of drug resistance in epilepsy and discusses the hypotheses of drug resistance development (genetic, epigenetic, target hypothesis, etc.). Drug-resistant epilepsy is associated with neuroinflammatory, autoimmune and neurodegenerative processes. Neuroinflammation causes immune, pathophysiological, biochemical and psychological consequences. Focal or systemic unregulated inflammatory processes lead to the formation of aberrant neural connections and hyperexcitable neural networks. Inflammatory mediators affect the endothelium of cerebral vessels, destroy contacts between endothelial cells and induce abnormal angiogenesis (the formation of “leaky” vessels), thereby affecting the blood–brain barrier permeability. Thus, the analysis of pro-inflammatory and other components of epileptogenesis can contribute to the further development of the therapeutic treatment of drug-resistant epilepsy.

scholarly journals The ILAE definition of drug resistant epilepsy and its clinical applicability compared with “older” established definitions

2015 ◽  
Vol 23 (1) ◽  
pp. 39-44
Author(s):  
Alexandra Rohracher ◽  
Judith Dobesberger ◽  
Claudia A. Granbichler ◽  
Julia Höfler ◽  
Giorgi Kuchukhidze ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Epilepsy Surgery ◽  
Treatment Process ◽  
Drug Resistant ◽  
Course Of Disease ◽  
Clinical Applicability ◽  
Specialized Center ◽  
Drug Resistant Epilepsy ◽  
Definition Of ◽  
Mean Time

SUMMARY Background. Early identification of potential epilepsy surgery candidates is essential to the treatment process. Aim. To evaluate the clinical applicability of the ILAE definition of drug resistant epilepsy and its potential in identifying surgical candidates earlier compared to three established “older” definitions of drug resistant epilepsy. Material and Methods. Retrospective analysis of 174 patients who underwent epilepsy surgery between 1998 and 2009. Clinical factors and course of disease were extracted from patients' charts. Drug resistant epilepsy was classified according to four definitions and the time until fulfillment of criteria compared. Results. Mean time to fulfillment of criteria of drug resistant epilepsy ranged from 11.8 (standard deviation (SD) 9.8) to 15.6 years (SD 11.3). Time to drug resistance was significantly longer applying the only definition, requiring failure of three antiepileptic drugs (AEDs) (Canada definition), whereas time to fulfillment of all other definitions did not differ. Fifty percent of all patients experienced a seizure free period of ≥1 year prior to being classified as drug resistant, 13% entered another 1-year remission after fulfilling any criteria for drug resistance. Conclusion. We conclude that the ILAE definition identifies drug resistant epilepsy, with similar latency like two of three formerly used definitions. It is an easy applicable tool to minimize the delay of referral to a specialized center. Intermittent remissions delay assessment of drug resistance for all definitions and 13% of patients enter a remission despite established drug resistance.

scholarly journals Drug Resistant Epilepsy Among Patients Attended The Neurosciences Hospital

2019 ◽  
Vol 13 (1) ◽  
pp. 108-115
Author(s):  
Nael Husain Zaer
Keyword(s):  
Drug Resistance ◽  
Medical History ◽  
Refractory Epilepsy ◽  
Seizure Freedom ◽  
Drug Resistant ◽  
Past Medical History ◽  
Number Of Patients ◽  
Drug Resistant Epilepsy ◽  
Patients With Epilepsy

Background: Drug resistant epilepsy is defined as failure of adequate trials of two tolerated, appropriately chosen and used antiepileptic drug schedules to achieve sustained seizure freedom. Up to 30% of patients referred to clinics with a diagnosis of pharmaco-resistant epilepsy may have been misdiagnosed, and many can be helped by optimizing their treatment.Pseudoresistance, in which seizures persist because the underlying disorder has not been adequately or appropriately treated, must be ruled out or corrected before drug treatment can be considered to have failed. Objectives: The objectives of this study were to determine the causes of drug failure in patients with epilepsy and to differentiate between drug resistant epilepsy and pseudoresistant epilepsy. Type of the study: This is a retrospective study. Method: It is conducted in Baghdad governorate at the epilepsy clinic in the neurosciences hospital during the period from the 1st of February through July 2013. Two hundred patients with refractory epilepsy were involved. These patients attended the epilepsy clinic during 2011 and 2012. The data was collected from the files of the patients including age, gender, weight, history of presenting illness, type of seizure, drugs used, duration of disease, EEG and imaging findings, compliance and follow up. Results: Drug resistance epilepsy constituted a prevalence of 24% (128) as the total number of patients with epilepsy attending the hospital during the same period was 527.The mean age of patients with refractory epilepsy was 25 years. Male were 56.5% (113/200) and urban residents were 70.5% (141/200). The study revealed that 64% (128/200) of refractory epilepsy was attributed to drug resistance; while the remaining proportion was pseudoresistance 36% (72/200). The main cause of pseudoresistance was poor compliance 36.1% (26/72).The most common type of seizure in the sampled patients was generalized tonic clonic seizures in 51.5% (103/200).Compliance was found to be statistically associated with abnormal EEG finding, past medical history (hypertension, cardiac diseases, encephalitis, diabetes mellitus and any significant history) and quality of follow up. The follow-up was found to be statistically associated with the family history, past medical history( encephalitis and hypertension) and compliance of patient. Conclusion:A considerable number of patientsdiagnosed as cases of drug resistant epilepsy had another explanation causing drug failure.The study recommends the application of consensus definition for drug resistant epilepsy and periodic evaluation of patients with drug resistant epilepsy to exclude pseudoresistance.

scholarly journals Continuing Burden of Refractory Epilepsy

2020 ◽  
pp. 106002802094805
Author(s):  
Marnie T. Janson ◽  
Jacquelyn L. Bainbridge
Keyword(s):  
Refractory Epilepsy ◽  
Neurological Diseases ◽  
Intractable Epilepsy ◽  
Premature Death ◽  
Additional Benefit ◽  
Drug Resistant ◽  
Psychological Consequences ◽  
Epilepsy Treatment ◽  
Patients With Epilepsy

Epilepsy is one of the most common neurological diseases, and uncontrolled seizures remain a significant problem for one-third of patients with epilepsy on drug therapy. Ongoing seizures affect the morbidity and mortality of patients with epilepsy. Premature death is up to 3 times higher in those with epilepsy than in the general population. Quality of life is affected by refractory epilepsy with physical, social, and psychological consequences. Patients may be stigmatized by society, institutions, and their own shame surrounding seizures. Questions remain on how to treat refractory epilepsy, also called drug-resistant, pharmacoresistant, or intractable epilepsy. Cenobamate, a novel antiseizure medication, may provide additional benefit for refractory epilepsy treatment.

scholarly journals Evolution of Fluconazole-ResistantCandida albicansStrains by Drug-Induced Mating Competence and Parasexual Recombination

mBio ◽  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Christina Popp ◽  
Bernardo Ramírez-Zavala ◽  
Sonja Schwanfelder ◽  
Ines Krüger ◽  
Joachim Morschhäuser
Keyword(s):  
Drug Resistance ◽  
Mating Type ◽  
Acquired Resistance ◽  
Resistance Mechanisms ◽  
Drug Resistant ◽  
Resistance Mutations ◽  
Type Locus ◽  
Content Type ◽  
Mating Type Locus ◽  
Resistant Progeny

ABSTRACTThe clonal population structure ofCandida albicanssuggests that (para)sexual recombination does not play an important role in the lifestyle of this opportunistic fungal pathogen, an assumption that is strengthened by the fact that mostC. albicansstrains are heterozygous at the mating type locus (MTL) and therefore mating-incompetent. On the other hand, mating might occur within clonal populations and allow the combination of advantageous traits that were acquired by individual cells to adapt to adverse conditions. We have investigated if parasexual recombination may be involved in the evolution of highly drug-resistant strains exhibiting multiple resistance mechanisms against fluconazole, an antifungal drug that is commonly used to treat infections byC. albicans. Growth of strains that were heterozygous forMTLand different fluconazole resistance mutations in the presence of the drug resulted in the emergence of derivatives that had become homozygous for the mutated allele and the mating type locus and exhibited increased drug resistance. WhenMTLa/aandMTLα/α cells of these strains were mixed in all possible combinations, we could isolate mating products containing the genetic material from both parents. The initial mating products did not exhibit higher drug resistance than their parental strains, but further propagation under selective pressure resulted in the loss of the wild-type alleles and increased fluconazole resistance. Therefore, fluconazole treatment not only selects for resistance mutations but also promotes genomic alterations that confer mating competence, which allows cells in an originally clonal population to exchange individually acquired resistance mechanisms and generate highly drug-resistant progeny.IMPORTANCESexual reproduction is an important mechanism in the evolution of species, since it allows the combination of advantageous traits of individual members in a population. The pathogenic yeastCandida albicansis a diploid organism that normally propagates in a clonal fashion, because heterozygosity at the mating type locus (MTL) inhibits mating between cells. Here we show thatC. albicanscells that have acquired drug resistance mutations during treatment with the commonly used antifungal agent fluconazole rapidly develop further increased resistance by genome rearrangements that result in simultaneous loss of heterozygosity for the mutated allele and the mating type locus. This enables the drug-resistant cells of a population to switch to the mating-competent opaque morphology and mate with each other to combine different individually acquired resistance mechanisms. The tetraploid mating products reassort their merged genomes and, under selective pressure by the drug, generate highly resistant progeny that have retained the advantageous mutated alleles. Parasexual propagation, promoted by stress-induced genome rearrangements that result in the acquisition of mating competence in cells with adaptive mutations, may therefore be an important mechanism in the evolution ofC. albicanspopulations.

scholarly journals Exploring Phytochemicals for Combating Antibiotic Resistance in Microbial Pathogens

2021 ◽  
Vol 12 ◽  
Author(s):  
Tushar Khare ◽  
Uttpal Anand ◽  
Abhijit Dey ◽  
Yehuda G. Assaraf ◽  
Zhe-Sheng Chen ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Antibiotic Resistance ◽  
Current Knowledge ◽  
Plant Secondary Metabolites ◽  
Agricultural Practices ◽  
Resistance Mechanisms ◽  
New Drugs ◽  
Microbial Pathogens ◽  
Drug Resistant ◽  
Microbial Drug Resistance

Antibiotic resistance or microbial drug resistance is emerging as a serious threat to human healthcare globally, and the multidrug-resistant (MDR) strains are imposing major hurdles to the progression of drug discovery programs. Newer antibiotic-resistance mechanisms in microbes contribute to the inefficacy of the existing drugs along with the prolonged illness and escalating expenditures. The injudicious usage of the conventional and commonly available antibiotics in human health, hygiene, veterinary and agricultural practices is proving to be a major driver for evolution, persistence and spread of antibiotic-resistance at a frightening rate. The drying pipeline of new and potent antibiotics is adding to the severity. Therefore, novel and effective new drugs and innovative therapies to treat MDR infections are urgently needed. Apart from the different natural and synthetic drugs being tested, plant secondary metabolites or phytochemicals are proving efficient in combating the drug-resistant strains. Various phytochemicals from classes including alkaloids, phenols, coumarins, terpenes have been successfully demonstrated their inhibitory potential against the drug-resistant pathogens. Several phytochemicals have proved effective against the molecular determinants responsible for attaining the drug resistance in pathogens like membrane proteins, biofilms, efflux pumps and bacterial cell communications. However, translational success rate needs to be improved, but the trends are encouraging. This review highlights current knowledge and developments associated challenges and future prospects for the successful application of phytochemicals in combating antibiotic resistance and the resistant microbial pathogens.

scholarly journals Analysis and Construction of a Molecular Diagnosis Model of Drug-Resistant Epilepsy Based on Bioinformatics

2021 ◽  
Vol 8 ◽  
Author(s):  
Tenghui Han ◽  
Zhenyu Wu ◽  
Jun Zhu ◽  
Yao Kou ◽  
Jipeng Li ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Network Analysis ◽  
Protein Interaction ◽  
Resistance Genes ◽  
Recursive Feature Elimination ◽  
Support Vector ◽  
Drug Resistant ◽  
Svm Model ◽  
Drug Resistant Epilepsy ◽  
Patients With Epilepsy

Background: Epilepsy is a complex chronic disease of the nervous system which influences the health of approximately 70 million patients worldwide. In the past few decades, despite the development of novel antiepileptic drugs, around one-third of patients with epilepsy have developed drug-resistant epilepsy. We performed a bioinformatic analysis to explore the underlying diagnostic markers and mechanisms of drug-resistant epilepsy.Methods: Weighted correlation network analysis (WGCNA) was applied to genes in epilepsy samples downloaded from the Gene Expression Omnibus database to determine key modules. The least absolute shrinkage and selection operator (LASSO) regression and support vector machine-recursive feature elimination (SVM-RFE) algorithms were used to screen the genes resistant to carbamazepine, phenytoin, and valproate, and sensitivity of the three-class classification SVM model was verified through the receiver operator characteristic (ROC) curve. A protein–protein interaction (PPI) network was utilized to analyze the protein interaction relationship. Finally, ingenuity pathway analysis (IPA) was adopted to conduct disease and function pathway and network analysis.Results: Through WGCNA, 72 genes stood out from the key modules related to drug resistance and were identified as candidate resistance genes. Intersection analysis of the results of the LASSO and SVM-RFE algorithms selected 11, 4, and 5 drug-resistant genes for carbamazepine, phenytoin, and valproate, respectively. Subsequent union analysis obtained 17 hub resistance genes to construct a three-class classification SVM model. ROC showed that the model could accurately predict patient resistance. Expression of 17 hub resistance genes in healthy subjects and patients was significantly different. The PPI showed that there are six resistance genes (CD247, CTSW, IL2RB, MATK, NKG7, and PRF1) that may play a central role in the resistance of epilepsy patients. Finally, IPA revealed that resistance genes (PRKCH and S1PR5) were involved in “CREB signaling in Neurons.”Conclusion: We obtained a three-class SVM model that can accurately predict the drug resistance of patients with epilepsy, which provides a new theoretical basis for research and treatment in the field of drug-resistant epilepsy. Moreover, resistance genes PRKCH and S1PR5 may cooperate with other resistance genes to exhibit resistance effects by regulation of the cAMP-response element-binding protein (CREB) signaling pathway.

scholarly journals Genome-wide chemical mutagenesis screens allow unbiased saturation of the cancer genome and identification of drug resistance mutations

2016 ◽  
Author(s):  
Jonathan S. Brammeld ◽  
Mia Petljak ◽  
Inigo Martincorena ◽  
Steven P. Williams ◽  
Luz Garcia Alonso ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Point Mutations ◽  
Gene Mutations ◽  
Resistance Mechanisms ◽  
Chemical Mutagenesis ◽  
Specific Gene ◽  
Drug Resistant ◽  
Resistance Mutations ◽  
Drug Resistance Mutations ◽  
Genome Wide

AbstractDrug resistance is an almost inevitable consequence of cancer therapy and ultimately proves fatal for the majority of patients. In many cases this is the consequence of specific gene mutations that have the potential to be targeted to re-sensitize the tumor. The ability to uniformly saturate the genome with point mutations without chromosome or nucleotide sequence context bias would open the door to identify all putative drug resistance mutations in cancer models. Here we describe such a method for elucidating drug resistance mechanisms using genome-wide chemical mutagenesis allied to next-generation sequencing. We show that chemically mutagenizing the genome of cancer cells dramatically increases the number of drug-resistant clones and allows the detection of both known and novel drug resistance mutations. We have developed an efficient computational process that allows for the rapid identification of involved pathways and druggable targets. Such a priori knowledge would greatly empower serial monitoring strategies for drug resistance in the clinic as well as the development of trials for drug resistant patients.

scholarly journals DRUG-RESISTANT EPILEPSY IN CASE OF CRANIOCEREBRAL DISPROPORTION. A PILOT STUDY

2021 ◽  
Vol 83 (3) ◽  
pp. 19-23
Author(s):  
Oleg Biketov
Keyword(s):  
Drug Resistance ◽  
Drug Therapy ◽  
Pilot Study ◽  
Antiepileptic Drugs ◽  
Pathological Process ◽  
Research Trends ◽  
Drug Resistant ◽  
The Past ◽  
Craniocerebral Disproportion ◽  
Drug Resistant Epilepsy

The problem of ineff ective drug therapy of epilepsy continues to be relevant during many decades and determines many key research trends in clinical and fundamental epileptology. Despite the emergence of a large number of various antiepileptic drugs the eff ectiveness of drug therapy for epilepsy has remained almost unchanged over the past decades. In this article drug-resistance in epilepsy is considered as a consequence of a concomitant pathological process in the form of craniocerebral disproportion.

scholarly journals The Genomic Stability at the Coding Regions of the Multidrug Transporter Gene ABCB1: Insights into the Development of Alternative Drug Resistance Mechanisms in Human Leukemia Cells

2019 ◽  
Author(s):  
Kevin G. Chen ◽  
George E. Duran ◽  
Mark J. Mogul ◽  
Yan C. Wang ◽  
Kevin L. Ross ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Resistance Mechanisms ◽  
Leukemia Cells ◽  
Multidrug Transporter ◽  
Drug Resistant ◽  
Transporter Gene ◽  
Cellular Models ◽  
Coding Regions ◽  
Alternative Drug ◽  
Selection Of

ABSTRACTDespite considerable efforts in reversing clinical multidrug resistance (MDR), targeting the predominant multidrug transporter ABCB1/P-glycoprotein (P-gp) based on small molecule inhibitors has been hindered. This may be due to the emergence of alternative drug resistance mechanisms. However, the non-specific P-gp inhibitor cyclosporine (CsA) showed significant clinical benefits in patients with acute myeloid leukemia (AML), which likely represents the only proof-of-principle clinical trial using several generations of MDR inhibitors. Nevertheless, the mechanisms that underlie this successful MDR modulation by CsA are not elucidated because of the absence of CsA-relevant cellular models. In this study, we report the development of two erythroleukemia variants, RVC and RDC, which were derived by step-wise co-selection of K562/R7 drug-resistant leukemia cells with the etoposide-CsA and doxorubicin-CsA drug combinations, respectively. Interestingly, both RVC and RDC, which retained P-gp expression, showed altered MDR phenotypes that were resistant to cyclosporine modulation. The ABCB1 coding regions were genetically stable even under long-term stringent drug selection. Genomically, ABCB1 is likely the most stable ABC transporter gene when comparing with several ABC superfamily members (such as ABCA1, ABCC1, CFTR, and ABCG2). Our findings suggested that non-P-gp mechanisms were likely responsible for the resistance to CsA modulation in both RVC and RDC cells. Moreover, we found that CsA played a role in undermining the selection of highly drug-resistant cells via induction of low level and unstable drug resistance, thus shedding some light on the benefits of CsA in treating certain types of AML patients.

scholarly journals Pathogenesis of drug resistant epilepsy

2019 ◽  
Vol 11 (1) ◽  
pp. 79-87
Author(s):  
S. M. Malyshev ◽  
T. M. Alekseeva ◽  
W. A. Khachatryan ◽  
M. M. Galagudza
Keyword(s):  
Drug Resistance ◽  
Antiepileptic Drugs ◽  
Mechanisms Of Action ◽  
Drug Resistant ◽  
Line Treatment ◽  
First Line ◽  
Receptor Proteins ◽  
Per Se ◽  
Drug Resistant Epilepsy ◽  
First Line Treatment

Pharmacotherapy is the first-line treatment modality for epilepsy. However, in 20-40% of patients, epilepsy is resistant to pharmacotherapy. These numbers have not changed for decades despite the development and use of antiepileptic drugs with novel mechanisms of action. Drug-resistant epilepsy is now considered a separate pathophysiologic and clinical entity. The existing hypotheses on its pathogenesis could be divided in two groups. Firstly, drug-resistance might be caused by an abnormal pharmacokinetics or pharmacodynamics of antiepileptic drugs as a result of congenital or acquired dysfunction of the transporter or receptor proteins. Secondly, it might be a consequence of inherent features of epilepsy per se, such as the so-called “intrinsic severity” or some disorder of the connectome. Taking into account the complexity of this phenomenon, the issue of drug resistance continues to remain in the focus of the current research efforts.

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