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1.
Acta Neuropathol ; 142(2): 361-374, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34003336

RESUMO

Loss of nuclear SMARCB1 (INI1/hSNF5/BAF47) protein expression due to biallelic mutations of the SMARCB1 tumor suppressor gene is a hallmark of atypical teratoid/rhabdoid tumors (ATRT), but the presence of cytoplasmic SMARCB1 protein in these tumors has not yet been described. In a series of 102 primary ATRT, distinct cytoplasmic SMARCB1 staining on immunohistochemistry was encountered in 19 cases (19%) and was highly over-represented in cases showing pathogenic sequence variants leading to truncation or mutation of the C-terminal part of SMARCB1 (15/19 vs. 4/83; Chi-square: 56.04, p = 1.0E-10) and, related to this, in tumors of the molecular subgroup ATRT-TYR (16/36 vs. 3/66; Chi-square: 24.47, p = 7.6E-7). Previous reports have indicated that while SMARCB1 lacks a bona fide nuclear localization signal, it harbors a masked nuclear export signal (NES) and that truncation of the C-terminal region results in unmasking of this NES leading to cytoplasmic localization. To determine if cytoplasmic localization found in ATRT is due to unmasking of NES, we generated GFP fusions of one of the SMARCB1 truncating mutations (p.Q318X) found in the tumors along with a p.L266A mutation, which was shown to disrupt the interaction of SMARCB1-NES with exportin-1. We found that while the GFP-SMARCB1(Q318X) mutant localized to the cytoplasm, the double mutant GFP-SMARCB1(Q318X;L266A) localized to the nucleus, confirming NES requirement for cytoplasmic localization. Furthermore, cytoplasmic SMARCB1(Q318X) was unable to cause senescence as determined by morphological observations and by senescence-associated ß-galactosidase assay, while nuclear SMARCB1(Q318X;L266A) mutant regained this function. Selinexor, a selective exportin-1 inhibitor, was effective in inhibiting the nuclear export of SMARCB1(Q318X) and caused rapid cell death in rhabdoid tumor cells. In conclusion, inhibition of nuclear export restores nuclear localization and residual tumor suppressor function of truncated SMARCB1. Therapies aimed at preventing nuclear export of mutant SMARCB1 protein may represent a promising targeted therapy in ATRT harboring truncating C-terminal SMARCB1 mutations.


Assuntos
Transporte Ativo do Núcleo Celular/fisiologia , Neoplasia Residual/genética , Tumor Rabdoide/metabolismo , Proteína SMARCB1/metabolismo , Neoplasias do Sistema Nervoso Central/genética , Neoplasias do Sistema Nervoso Central/metabolismo , Pré-Escolar , Feminino , Genes Supressores de Tumor/fisiologia , Humanos , Lactente , Masculino , Mutação/genética , Neoplasia Residual/metabolismo , Neoplasias Neuroepiteliomatosas/genética , Neoplasias Neuroepiteliomatosas/metabolismo , Tumor Rabdoide/genética , Proteína SMARCB1/genética , Teratoma/genética
2.
Nucleic Acids Res ; 41(1): 76-89, 2013 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-23161683

RESUMO

A remarkable number of guanine-rich sequences with potential to adopt non-canonical secondary structures called G-quadruplexes (or G4 DNA) are found within gene promoters. Despite growing interest, regulatory role of quadruplex DNA motifs in intrinsic cellular function remains poorly understood. Herein, we asked whether occurrence of potential G4 (PG4) DNA in promoters is associated with specific function(s) in bacteria. Using a normalized promoter-PG4-content (PG4(P)) index we analysed >60,000 promoters in 19 well-annotated species for (a) function class(es) and (b) gene(s) with enriched PG4(P). Unexpectedly, PG4-associated functional classes were organism specific, suggesting that PG4 motifs may impart specific function to organisms. As a case study, we analysed radioresistance. Interestingly, unsupervised clustering using PG4(P) of 21 genes, crucial for radioresistance, grouped three radioresistant microorganisms including Deinococcus radiodurans. Based on these predictions we tested and found that in presence of nanomolar amounts of the intracellular quadruplex-binding ligand N-methyl mesoporphyrin (NMM), radioresistance of D. radiodurans was attenuated by ~60%. In addition, important components of the RecF recombinational repair pathway recA, recF, recO, recR and recQ genes were found to harbour promoter-PG4 motifs and were also down-regulated in presence of NMM. Together these results provide first evidence that radioresistance may involve G4 DNA-mediated regulation and support the rationale that promoter-PG4s influence selective functions.


Assuntos
Deinococcus/genética , Quadruplex G , Regiões Promotoras Genéticas , Tolerância a Radiação/genética , Metabolismo dos Carboidratos/genética , DNA Bacteriano/química , Deinococcus/efeitos da radiação , Genes Bacterianos , Genoma Bacteriano , Guanina/química , Ligantes , Motivos de Nucleotídeos , Especificidade da Espécie
3.
Indian J Microbiol ; 54(4): 450-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25320445

RESUMO

Superoxide dismutase (SOD), a well known antioxidant enzyme, is known to exert its presence across bacteria to humans. Apart from their well-known antioxidant defense mechanisms, their association with various extremophiles in response to various stress conditions is poorly understood. Here, we have discussed the conservation and the prevalence of SODs among 21 representative extremophiles. A systematic investigation of aligned amino acid sequences of SOD from all the selected extremophiles revealed a consensus motif D-[VLE]-[FW]-E-H-[AS]-Y-[YM]. To computationally predict the correlation of SOD with the various stress conditions encountered by these extremophiles, Exiguobacterium was selected as a model organism which is known to survive under various adverse extremophilic conditions. Interestingly, our phylogenetic study based on SOD homology revealed that Exiguobacterium sibiricum was one of the closest neighbors of Deinococcus radiodurans and Thermus thermophilus. Next, we sought to predict 3-D model structure of SOD for E. sibiricum (PMDB ID: 0078260), which showed >95 % similarity with D. radiodurans R1 SOD. The reliability of the predicted SOD model was checked by using various validation metrics, including Ramachandran plot, Z-score and normalized qualitative model energy analysis score. Further, various physicochemical properties of E. sibiricum SOD were calculated using different prominent resources.

4.
Int Rev Cell Mol Biol ; 385: 1-39, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38663957

RESUMO

Cancer remains the leading cause of global mortality, prompting a paradigm shift in its treatment and outcomes with the advent of targeted therapies. Among the most prevalent mutations in RAS-driven cancers, Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations account for approximately 86% of cases worldwide, particularly in lung, pancreatic, and colon cancers, contributing to poor prognosis and reduced overall survival. Despite numerous efforts to understand the biology of KRAS mutants and their pivotal role in cancer development, the lack of well-defined drug-binding pockets has deemed KRAS an "undruggable" therapeutic target, presenting significant challenges for researchers and clinicians alike. Through significant biochemical and technological advances, the last decade has witnessed promising breakthroughs in targeted therapies for KRAS-mutated lung, colon, and pancreatic cancers, marking a critical turning point in the field. In this chapter, we provide an overview of the characteristics of KRAS mutations across various solid tumors, highlighting ongoing cutting-edge research on the immune microenvironment, the development of KRAS-driven mice models, and the recent progress in the exploration of specific KRAS mutant-targeted therapeutic approaches. By comprehensive understanding of the intricacies of KRAS signaling in solid tumors and the latest therapeutic developments, this chapter will shed light on the potential for novel therapeutic strategies to combat KRAS-driven tumors and improve patient outcomes.


Assuntos
Neoplasias , Proteínas Proto-Oncogênicas p21(ras) , Transdução de Sinais , Humanos , Animais , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/genética , Transdução de Sinais/efeitos dos fármacos , Mutação , Terapia de Alvo Molecular , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Microambiente Tumoral/efeitos dos fármacos
5.
Biology (Basel) ; 13(5)2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38785789

RESUMO

Cancer immune evasion represents a leading hallmark of cancer, posing a significant obstacle to the development of successful anticancer therapies. However, the landscape of cancer treatment has significantly evolved, transitioning into the era of immunotherapy from conventional methods such as surgical resection, radiotherapy, chemotherapy, and targeted drug therapy. Immunotherapy has emerged as a pivotal component in cancer treatment, harnessing the body's immune system to combat cancer and offering improved prognostic outcomes for numerous patients. The remarkable success of immunotherapy has spurred significant efforts to enhance the clinical efficacy of existing agents and strategies. Several immunotherapeutic approaches have received approval for targeted cancer treatments, while others are currently in preclinical and clinical trials. This review explores recent progress in unraveling the mechanisms of cancer immune evasion and evaluates the clinical effectiveness of diverse immunotherapy strategies, including cancer vaccines, adoptive cell therapy, and antibody-based treatments. It encompasses both established treatments and those currently under investigation, providing a comprehensive overview of efforts to combat cancer through immunological approaches. Additionally, the article emphasizes the current developments, limitations, and challenges in cancer immunotherapy. Furthermore, by integrating analyses of cancer immunotherapy resistance mechanisms and exploring combination strategies and personalized approaches, it offers valuable insights crucial for the development of novel anticancer immunotherapeutic strategies.

6.
Int Rev Cell Mol Biol ; 385: 227-261, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38663961

RESUMO

Cervical cancer is the leading cause of cancer-related deaths for women globally. Despite notable advancements in prevention and treatment, the identification of novel therapeutic targets remains crucial for cervical cancer. Toll-like receptors (TLRs) play an essential role in innate immunity as pattern-recognition receptors. There are several types of pathogen-associated molecular patterns (PAMPs), including those present in cervical cancer cells, which have the ability to activate toll-like receptors (TLRs). Recent studies have revealed dysregulated toll-like receptor (TLR) signaling pathways in cervical cancer, leading to the production of inflammatory cytokines and chemokines that can facilitate tumor growth and metastasis. Consequently, TLRs hold significant promise as potential targets for innovative therapeutic agents against cervical cancer. This book chapter explores the role of TLR signaling pathways in cervical cancer, highlighting their potential for targeted therapy while addressing challenges such as tumor heterogeneity and off-target effects. Despite these obstacles, targeting TLR signaling pathways presents a promising approach for the development of novel and effective treatments for cervical cancer.


Assuntos
Transdução de Sinais , Receptores Toll-Like , Neoplasias do Colo do Útero , Humanos , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/tratamento farmacológico , Receptores Toll-Like/metabolismo , Feminino , Animais , Terapia de Alvo Molecular
7.
Vaccines (Basel) ; 12(5)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38793710

RESUMO

Understanding the antibody response to SARS-CoV-2, the virus responsible for COVID-19, is crucial to comprehending disease progression and the significance of vaccine and therapeutic development. The emergence of highly contagious variants poses a significant challenge to humoral immunity, underscoring the necessity of grasping the intricacies of specific antibodies. This review emphasizes the pivotal role of antibodies in shaping immune responses and their implications for diagnosing, preventing, and treating SARS-CoV-2 infection. It delves into the kinetics and characteristics of the antibody response to SARS-CoV-2 and explores current antibody-based diagnostics, discussing their strengths, clinical utility, and limitations. Furthermore, we underscore the therapeutic potential of SARS-CoV-2-specific antibodies, discussing various antibody-based therapies such as monoclonal antibodies, polyclonal antibodies, anti-cytokines, convalescent plasma, and hyperimmunoglobulin-based therapies. Moreover, we offer insights into antibody responses to SARS-CoV-2 vaccines, emphasizing the significance of neutralizing antibodies in order to confer immunity to SARS-CoV-2, along with emerging variants of concern (VOCs) and circulating Omicron subvariants. We also highlight challenges in the field, such as the risks of antibody-dependent enhancement (ADE) for SARS-CoV-2 antibodies, and shed light on the challenges associated with the original antigenic sin (OAS) effect and long COVID. Overall, this review intends to provide valuable insights, which are crucial to advancing sensitive diagnostic tools, identifying efficient antibody-based therapeutics, and developing effective vaccines to combat the evolving threat of SARS-CoV-2 variants on a global scale.

8.
Methods Mol Biol ; 2807: 45-59, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38743220

RESUMO

Latent HIV-1 reservoirs are a major obstacle to the eradication of HIV-1. Several cure strategies have been proposed to eliminate latent reservoirs. One of the key strategies involves the reactivation of latent HIV-1 from cells using latency-reversing agents. However, currently it is unclear whether any of the latency-reversing agents are able to completely reactivate HIV-1 provirus transcription in all latent cells. An understanding of the reactivation of HIV-1 provirus at single-cell single-molecule level is necessary to fully comprehend the reactivation of HIV-1 in the reservoirs. Furthermore, since reactivable viruses in the pool of latent reservoirs are rare, combining single-cell imaging techniques with the ability to visualize a large number of reactivated single cells that express both viral RNA and proteins in a pool of uninfected and non-reactivated cells will provide unprecedented information about cell-to-cell variability in reactivation. Here, we describe the single-cell single-molecule RNA-FISH (smRNA-FISH) method to visualize HIV-1 gag RNA combined with the immunofluorescence (IF) method to detect Gag protein to characterize the reactivated cells. This method allows the visualization of subcellular localization of RNA and proteins before and after reactivation and facilitates absolute quantitation of the number of transcripts per cell using FISH-quant. In addition, we describe a high-speed and high-resolution scanning (HSHRS) fluorescence microscopy imaging method to visualize rare and reactivated cells in a pool of non-reactivated cells with high efficiency.


Assuntos
Imunofluorescência , HIV-1 , Hibridização in Situ Fluorescente , RNA Viral , Imagem Individual de Molécula , Análise de Célula Única , Ativação Viral , Latência Viral , HIV-1/fisiologia , HIV-1/genética , Humanos , Hibridização in Situ Fluorescente/métodos , RNA Viral/genética , Análise de Célula Única/métodos , Imagem Individual de Molécula/métodos , Imunofluorescência/métodos , Infecções por HIV/virologia , Provírus/genética
9.
Viruses ; 16(2)2024 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-38400039

RESUMO

SARS-CoV-2 infection remains a global burden. Despite intensive research, the mechanism and dynamics of early viral replication are not completely understood, such as the kinetics of the formation of genomic RNA (gRNA), sub-genomic RNA (sgRNA), and replication centers/organelles (ROs). We employed single-molecule RNA-fluorescence in situ hybridization (smRNA-FISH) to simultaneously detect viral gRNA and sgRNA and immunofluorescence to detect nsp3 protein, a marker for the formation of RO, and carried out a time-course analysis. We found that single molecules of gRNA are visible within the cytoplasm at 30 min post infection (p.i.). Starting from 2 h p.i., most of the viral RNA existed in clusters/speckles, some of which were surrounded by single molecules of sgRNA. These speckles associated with nsp3 protein starting at 3 h p.i., indicating that these were precursors to ROs. Furthermore, RNA replication was asynchronous, as cells with RNA at all stages of replication were found at any given time point. Our probes detected the SARS-CoV-2 variants of concern, and also suggested that the BA.1 strain exhibited a slower rate of replication kinetics than the WA1 strain. Our results provide insights into the kinetics of SARS-CoV-2 early post-entry events, which will facilitate identification of new therapeutic targets for early-stage replication to combat COVID-19.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , COVID-19/metabolismo , Replicação do RNA , Hibridização in Situ Fluorescente/métodos , Espécies Reativas de Oxigênio/metabolismo , RNA Subgenômico , RNA Guia de Sistemas CRISPR-Cas , Imunofluorescência , Proteínas/metabolismo , RNA Viral/genética , RNA Viral/metabolismo
10.
Res Sq ; 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38699331

RESUMO

HIV-1 eradication strategies require complete reactivation of HIV-1 latent cells by Latency Reversing Agents (LRA). Current methods lack effectiveness due to incomplete proviral reactivation. We employed a single-molecule RNA-FISH (smRNA-FISH) and FISH-Quant analysis and found that proviral reactivation is highly variable from cell-to-cell, stochastic, and occurs in bursts and waves, with different kinetics in response to diverse LRAs. Approximately 1-5% of latent cells exhibited stochastic reactivation without LRAs. Through single-cell RNA-seq analysis, we identified NR4A3 and cMYC as extrinsic factors associated with stochastic HIV-1 reactivation. Concomitant with HIV-1 reactivation cMYC was downregulated and NR4A3 was upregulated in both latent cell lines and primary CD4+ T-cells from aviremic patients. By inhibiting cMYC using SN-38, an active metabolite of irinotecan, we induced NR4A3 and HIV-1 expression. Our results suggest that inherent stochasticity in proviral reactivation contributes to cell-to-cell variability, which could potentially be modulated by drugs targeting cMYC and NR4A3.

11.
Indian J Microbiol ; 53(2): 130-6, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24426098

RESUMO

A gram positive, extreme haloalkaliphilic, radioresistant bacterium was isolated from mangrove region of Kerala (India) which was characterized as Exiguobacterium sp. HKG-126 using morphological, physiological, biochemical and molecular characterization. Present investigation was undertaken to examine Exiguobacterium sp. as a potential source of broad-spectrum antimicrobial activity and enhancement in this activity was observed due to cross-species/cross-genera induction and also in response to high dose of gamma (γ) irradiation. Individual studies on the antimicrobial activity of all the co-cultivated bacterial strains before and after mixed culture fermentation, showed excellent enhancement in antimicrobial activity of Exiguobacterium sp. against a variety of clinical pathogens. To the best of our knowledge, this is the first report showing existence of an extremely high radioresistant strain of (up to 15 kGy) Exiguobacterium sp.

12.
Viruses ; 15(11)2023 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-38005893

RESUMO

G-quadruplexes (G4s) are unique non-canonical four-stranded nucleic acid secondary structures formed by guanine-rich DNA or RNA sequences. Sequences with the potential to form quadruplex motifs (pG4s) are prevalent throughout the genomes of all organisms, spanning from prokaryotes to eukaryotes, and are enriched within regions of biological significance. In the past few years, the identification of pG4s within most of the Baltimore group viruses has attracted increasing attention due to their occurrence in regulatory regions of the genome and the subsequent implications for regulating critical stages of viral life cycles. In this context, the employment of specific G4 ligands has aided in comprehending the intricate G4-mediated regulatory mechanisms in the viral life cycle, showcasing the potential of targeting viral G4s as a novel antiviral strategy. This review offers a thorough update on the literature concerning G4s in viruses, including their identification and functional significance across most of the human-infecting viruses. Furthermore, it delves into potential therapeutic avenues targeting G4s, encompassing various G4-binding ligands, G4-interacting proteins, and oligonucleotide-based strategies. Finally, the article highlights both progress and challenges in the field, providing valuable insights into leveraging this unusual nucleic acid structure for therapeutic purposes.


Assuntos
Quadruplex G , Vírus , Humanos , DNA/química , Sequências Reguladoras de Ácido Nucleico , Genoma Viral , Antivirais/farmacologia , Antivirais/uso terapêutico , Antivirais/química
13.
PLoS One ; 18(3): e0282263, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36989283

RESUMO

COVID-19 caused by the SARS-CoV-2 virus is widespread in all regions, and it disturbs host immune system functioning leading to extreme inflammatory reaction and hyperactivation of the immune response. Kabasura Kudineer (KSK) is preventive medicine against viral infections and a potent immune booster for inflammation-related diseases. We hypothesize that KSK and KSK similar plant compounds, might prevent or control the COVID-19 infection in the human body. 1,207 KSK and KSK similar compounds were listed and screened via the Swiss ADME tool and PAINS Remover; 303 compounds were filtered including active and similar drug compounds. The targets were retrieved from similar drugs of the active compounds of KSK. Finally, 573 genes were listed after several screening steps. Next, network analysis was performed to finalize the potential target gene: construction of protein-protein interaction of 573 genes using STRING, identifying top hub genes in Cytoscape plug-ins (MCODE and cytoHubba). These ten hub genes play a crucial role in the inflammatory response. Target-miRNA interaction was also constructed using the miRNet tool to interpret miRNAs of the target genes and their functions. Functional annotation was done via DAVID to gain a complete insight into the mechanism of the enriched pathways and other diseases related to the given target genes. In Molecular Docking analysis, IL10 attained top rank in Target-miRNA interaction and also the gene formed prominent exchanges with an excellent binding score (> = -8.0) against 19 compounds. Among them, Guggulsterone has an acute affinity score of -8.8 for IL10 and exhibits anti-inflammatory and immunomodulatory properties. Molecular Dynamics simulation study also performed for IL10 and the interacting ligand compounds using GROMACS. Finally, Guggulsterone will be recommended to enhance immunity against several inflammatory diseases, including COVID19.


Assuntos
COVID-19 , MicroRNAs , Humanos , Interleucina-10/genética , SARS-CoV-2/genética , Simulação de Acoplamento Molecular , Farmacologia em Rede , MicroRNAs/genética
14.
bioRxiv ; 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36561180

RESUMO

SARS-CoV-2 infection has caused a major global burden. Despite intensive research, the mechanism and dynamics of early viral replication are not completely understood including the kinetics of formation of plus stranded genomic and subgenomic RNAs (gRNA and sgRNA) starting from the RNA from the first virus that enters the cell. We employed single-molecule RNA-fluorescence in situ hybridization (smRNA-FISH) to simultaneously detect viral gRNA and sgRNA in infected cells and carried out a time course analysis to determine the kinetics of their replication. We visualized the single molecules of gRNA within the cytoplasm of infected cells 30 minutes post-infection and detected the co-expression of gRNA and sgRNA within two hours post-infection. Furthermore, we observed the formation of a replication organelle (RO) from a single RNA, which led to the formation of multiple ROs within the same cells. Single molecule analysis indicated that while gRNA resided in the center of these ROs, the sgRNAs were found to radiate and migrate out of these structures. Our results also indicated that after the initial delay, there was a rapid but asynchronous replication, and the gRNA and sgRNAs dispersed throughout the cell within 4-5 hours post-infection forming multiple ROs that filled the entire cytoplasm. These results provide insight into the kinetics of early post-entry events of SARS-CoV-2 and the formation of RO, which will help to understand the molecular events associated with viral infection and facilitate the identification of new therapeutic targets that can curb the virus at a very early stage of replication to combat COVID-19. Author Summary: SARS-CoV-2 infection continues to be a global burden. Soon after the entry, SARS-CoV-2 replicates by an elaborate process, producing genomic and subgenomic RNAs (gRNA and sgRNAs) within specialized structures called replication organelles (RO). Many questions including the timing of multiplication of gRNA and sgRNA, the generation, subcellular localization, and function of the ROs, and the mechanism of vRNA synthesis within ROs is not completely understood. Here, we have developed probes and methods to simultaneously detect the viral gRNA and a sgRNA at single cell single molecule resolution and have employed a method to scan thousands of cells to visualize the early kinetics of gRNA and sgRNA synthesis soon after the viral entry into the cell. Our results reveal that the replication is asynchronous and ROs are rapidly formed from a single RNA that enters the cell within 2 hours, which multiply to fill the entire cell cytoplasm within ~4 hours after infection. Furthermore, our studies provide a first glimpse of the gRNA and sgRNA synthesis within ROs at single molecule resolution. Our studies may facilitate the development of drugs that inhibit the virus at the earliest possible stages of replication to minimize the pathogenic impact of viral infection.

15.
Biol Trace Elem Res ; 199(6): 2266-2271, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32851540

RESUMO

Lithium is an integral drug used in the management of acute mania, unipolar and bipolar depression, and prophylaxis of bipolar disorders. Thyroid abnormalities have been associated with treatment with lithium. Zinc is an essential trace element that plays a role in several biological activities. Therefore, the present study was aimed at investigating the potential role of zinc in the thyroid gland following lithium administration to explore the role of zinc under such conditions. To achieve this goal, male Wistar rats (150-195 g) were divided into four groups: Group 1 animals were fed standard pellet feed and tap water ad lib; Group 2 rats were fed lithium in the form of lithium carbonate through diet at a concentration of 1.1 g/kg body weight; Group 3 animals received zinc treatment in the form of zinc sulfate (ZnSO4·7H2O) at a dose level of 227 mg/L mixed with drinking water of the animals; and Group 4 animals were given lithium and zinc in a similar manner as was given to the animals belonging to groups 2 and 4 respectively. The role of zinc on thyroid functions in lithium-treated rats was studied after 2, 4, and 8 weeks of different treatments. Zinc has been observed to have the capability to nearly normalize the altered 2-h uptake of 131I, biological and effective half-lives of 131I, and circulating T4 levels that were altered after lithium treatment. The present study concludes that zinc may be an effective agent in normalizing the adverse effects caused by lithium on thyroid functions.


Assuntos
Preparações Farmacêuticas , Zinco , Animais , Suplementos Nutricionais , Lítio/farmacologia , Masculino , Ratos , Ratos Wistar , Glândula Tireoide , Zinco/farmacologia
16.
Nat Commun ; 12(1): 2743, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980829

RESUMO

INI1/SMARCB1 binds to HIV-1 integrase (IN) through its Rpt1 domain and exhibits multifaceted role in HIV-1 replication. Determining the NMR structure of INI1-Rpt1 and modeling its interaction with the IN-C-terminal domain (IN-CTD) reveal that INI1-Rpt1/IN-CTD interface residues overlap with those required for IN/RNA interaction. Mutational analyses validate our model and indicate that the same IN residues are involved in both INI1 and RNA binding. INI1-Rpt1 and TAR RNA compete with each other for IN binding with similar IC50 values. INI1-interaction-defective IN mutant viruses are impaired for incorporation of INI1 into virions and for particle morphogenesis. Computational modeling of IN-CTD/TAR complex indicates that the TAR interface phosphates overlap with negatively charged surface residues of INI1-Rpt1 in three-dimensional space, suggesting that INI1-Rpt1 domain structurally mimics TAR. This possible mimicry between INI1-Rpt1 and TAR explains the mechanism by which INI1/SMARCB1 influences HIV-1 late events and suggests additional strategies to inhibit HIV-1 replication.


Assuntos
Integrase de HIV/metabolismo , HIV-1/fisiologia , RNA Viral/metabolismo , Proteína SMARCB1/metabolismo , Replicação Viral , Genoma Viral , Integrase de HIV/química , Integrase de HIV/genética , Interações Hospedeiro-Patógeno , Humanos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Simulação de Acoplamento Molecular , Ligação Proteica , Domínios Proteicos , RNA Viral/química , Proteína SMARCB1/química , Proteína SMARCB1/genética , Vírion/crescimento & desenvolvimento , Vírion/metabolismo
17.
Dig Endosc ; 22(4): 351-3, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21175496

RESUMO

Splenic rupture is a life-threatening condition characterized by internal hemorrhage, often difficult to diagnose. Colonoscopy is a gold standard routine diagnostic test to investigate patients with gastrointestinal symptoms as well as to those on the screening program for colorectal cancer. Splenic injury is seldomly discussed during consent for colonoscopy, as opposed to colonic perforation, as its prevalence accounts for less than 0.1%. A 66-year-old Caucasian woman with no history of collagen disorder was electively admitted for routine colonoscopy for surveillance of adenoma. She was admitted following the procedure for re-dosing of warfarin, which was stopped prior to the colonoscopy. The patient was found collapsed on the ward the following day with clinical shock and anemia. Computed tomography demonstrated grade 4 splenic rupture. Immediate blood transfusion and splenectomy was required. Splenic rupture following routine colonoscopy is extremely rare. Awareness of it on this occasion saved the patient's life. Despite it being a rare association, the seriousness warrants inclusion in all information leaflets concerning colonoscopy and during its consent.


Assuntos
Dor Abdominal/etiologia , Colonoscopia/efeitos adversos , Ruptura Esplênica/etiologia , Idoso , Anticoagulantes/administração & dosagem , Feminino , Humanos , Ruptura Esplênica/diagnóstico por imagem , Ruptura Esplênica/cirurgia , Tomografia Computadorizada por Raios X , Varfarina/administração & dosagem
18.
J Vasc Surg Venous Lymphat Disord ; 6(4): 546-550, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29680439

RESUMO

OBJECTIVE: The aim of this review was to identify the evidence regarding the optimal duration of compression therapy after endovenous ablation of varicose veins. METHODS: Electronic databases were searched for studies assessing the use of compression after endovenous ablation in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The primary outcomes for this study were pain score and complications. Secondary outcomes were time to full recovery, quality of life score, leg circumference, bruising score, and compliance rates. RESULTS: Following strict inclusion and exclusion criteria, five studies were included in our review, including a total of 734 patients. The short-duration compression therapy ranged from 4 hours to 2 days, whereas the longer duration ranged from 3 to 15 days. A single study showed a better outcome in terms of complications with a short compression therapy. A single study showed a benefit to pain and quality of life with extended compression therapy, whereas the others did not. There was no significant difference in terms of bruising, recovery time, and leg swelling. CONCLUSIONS: Our review showed that there is no evidence for the extended use of compression after endovenous ablation of varicose veins.


Assuntos
Ablação por Cateter , Bandagens Compressivas , Procedimentos Endovasculares , Terapia a Laser , Varizes/cirurgia , Ablação por Cateter/efeitos adversos , Bandagens Compressivas/efeitos adversos , Procedimentos Endovasculares/efeitos adversos , Humanos , Terapia a Laser/efeitos adversos , Qualidade de Vida , Recuperação de Função Fisiológica , Fatores de Tempo , Resultado do Tratamento , Varizes/diagnóstico por imagem , Varizes/fisiopatologia
19.
Mater Sci Eng C Mater Biol Appl ; 80: 659-669, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28866213

RESUMO

This study demonstrates the therapeutic potential of silver nanoparticles (AgNPs), which were biosynthesized using the extracts of Citrus maxima plant. Characterization through UV-Vis spectrophotometry, Dynamic Light Scattering (DLS), Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) confirmed the formation of AgNps in nano-size range. These nanoparticles exhibited enhanced antioxidative activity and showed commendable antimicrobial activity against wide range of microbes including multi-drug resistant bacteria that were later confirmed by TEM. These particles exhibited minimal toxicity when cytotoxicity study was performed on normal human lung fibroblast cell line as well as human red blood cells. It was quite noteworthy that these particles showed remarkable cytotoxicity on human fibrosarcoma and mouse melanoma cell line (B16-F10). Additionally, the apoptotic topographies of B16-F10 cells treated with AgNps were confirmed by using acridine orange and ethidium bromide dual dye staining, caspase-3 assay, DNA fragmentation assay followed by cell cycle analysis using fluorescence-activated cell sorting. Taken together, these results advocate promising potential of the biosynthesized AgNps for their use in therapeutic applications.


Assuntos
Nanopartículas Metálicas , Animais , Anti-Infecciosos , Resistência a Múltiplos Medicamentos , Citometria de Fluxo , Humanos , Camundongos , Prata , Difração de Raios X
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