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1.
Traffic ; 23(12): 587-599, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36353954

RESUMO

Chromosomal region maintenance 1 (CRM1 also known as Xpo1 and exportin-1) is the receptor for the nuclear export controlling the intracellular localization and function of many cellular and viral proteins that play a crucial role in viral infections and cancer. The inhibition of CRM1 has emerged as a promising therapeutic approach to interfere with the lifecycle of many viruses, for the treatment of cancer, and to overcome therapy resistance. Recently, selinexor has been approved as the first CRM1 inhibitor for the treatment of multiple myeloma, providing proof of concept for this therapeutic option with a new mode of action. However, selinexor is associated with dose-limiting toxicity and hence, the discovery of alternative small molecule leads that could be developed as less toxic anticancer and antiviral therapeutics will have a significant impact in the clinic. Here, we report a CRM1 inhibitor discovery platform. The development of this platform includes reporter cell lines that monitor CRM1 activity by using red fluorescent protein or green fluorescent protein-labeled HIV-1 Rev protein with a strong heterologous nuclear export signal. Simultaneously, the intracellular localization of other proteins, to be interrogated for their capacity to undergo CRM1-mediated export, can be followed by co-culturing stable cell lines expressing fluorescent fusion proteins. We used this platform to interrogate the mode of nuclear export of several proteins, including PDK1, p110α, STAT5A, FOXO1, 3, 4 and TRIB2, and to screen a compound collection. We show that while p110α partially relies on CRM1-dependent nuclear export, TRIB2 is exported from the nucleus in a CRM1-independent manner. Compound screening revealed the striking activity of an organoselenium compound on the CRM1 nuclear export receptor.


Assuntos
HIV-1 , Transporte Ativo do Núcleo Celular , HIV-1/metabolismo , Carioferinas/metabolismo , Triazóis/metabolismo , Hidrazinas/farmacologia , Hidrazinas/metabolismo , Núcleo Celular/metabolismo
2.
Microb Ecol ; 87(1): 88, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38943017

RESUMO

Plastic pollution poses a worldwide environmental challenge, affecting wildlife and human health. Assessing the biodegradation capabilities of natural microbiomes in environments contaminated with microplastics is crucial for mitigating the effects of plastic pollution. In this work, we evaluated the potential of landfill leachate (LL) and estuarine sediments (ES) to biodegrade polyethylene (PE), polyethylene terephthalate (PET), and polycaprolactone (PCL), under aerobic, anaerobic, thermophilic, and mesophilic conditions. PCL underwent extensive aerobic biodegradation with LL (99 ± 7%) and ES (78 ± 3%) within 50-60 days. Under anaerobic conditions, LL degraded 87 ± 19% of PCL in 60 days, whereas ES showed minimal biodegradation (3 ± 0.3%). PE and PET showed no notable degradation. Metataxonomics results (16S rRNA sequencing) revealed the presence of highly abundant thermophilic microorganisms assigned to Coprothermobacter sp. (6.8% and 28% relative abundance in anaerobic and aerobic incubations, respectively). Coprothermobacter spp. contain genes encoding two enzymes, an esterase and a thermostable monoacylglycerol lipase, that can potentially catalyze PCL hydrolysis. These results suggest that Coprothermobacter sp. may be pivotal in landfill leachate microbiomes for thermophilic PCL biodegradation across varying conditions. The anaerobic microbial community was dominated by hydrogenotrophic methanogens assigned to Methanothermobacter sp. (21%), pointing at possible syntrophic interactions with Coprothermobacter sp. (a H2-producer) during PCL biodegradation. In the aerobic experiments, fungi dominated the eukaryotic microbial community (e.g., Exophiala (41%), Penicillium (17%), and Mucor (18%)), suggesting that aerobic PCL biodegradation by LL involves collaboration between fungi and bacteria. Our findings bring insights on the microbial communities and microbial interactions mediating plastic biodegradation, offering valuable perspectives for plastic pollution mitigation.


Assuntos
Bactérias , Biodegradação Ambiental , Microbiota , Microplásticos , Instalações de Eliminação de Resíduos , Microplásticos/metabolismo , Bactérias/classificação , Bactérias/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Poluentes Químicos da Água/metabolismo , Poliésteres/metabolismo , Sedimentos Geológicos/microbiologia , RNA Ribossômico 16S/genética , Estuários , Polietileno/metabolismo , Polietilenotereftalatos/metabolismo
3.
Sensors (Basel) ; 23(18)2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37765895

RESUMO

This paper discusses the use of networks of Inertial Measurement Units (IMUs) for the reconstruction of trajectories from sensor data. Logistics is a natural application domain to verify the quality of the handling of goods. This is a mass application and the economics of logistics impose that the IMUs to be used must be low-cost and use basic computational devices. The approach in this paper converts a strategy from the literature, used in the multi-target following problem, to reach a consensus in a network of IMUs. This paper presents results on how to achieve the consensus in trajectory reconstruction, along with covariance intersection data fusion of the information obtained by all the nodes in the network.

4.
Mult Scler ; 26(13): 1658-1669, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-31610739

RESUMO

OBJECTIVE: To explore the long-term outcomes of patients with clinically isolated syndromes from the Barcelona cohort. METHODS: We selected patients with a follow-up longer than 10 years to (1) estimate the risks of multiple sclerosis (MS) and disability accumulation according to the baseline number of T2 lesions and to compare treated versus untreated patients and early versus delayed treatment, and (2) to study baseline features of patients with aggressive MS (Expanded Disability Status Scale (EDSS) ⩾6.0 at 10 years). RESULTS: In all, 401 patients were included (mean follow-up of 14.4 (standard deviation of 2.9) years). A higher number of T2 lesions was associated with an earlier MS diagnosis and an earlier risk of irreversible disability. Early treatment was associated with a decreased risk of EDSS of 3.0: adjusted hazard ratio = 0.4, 95% confidence interval = (0.2, 0.7). Patients with aggressive MS differed in their baseline brain magnetic resonance images: The median (interquartile range) number of T2 lesions and contrast-enhancing lesions (CEL) was 71 (28-95) versus 7 (1-19) and 3 (1-24) versus 0 (0-1), respectively. The cut-offs that better classified patients with aggressive MS were 20 for T2 lesions and 2 for CEL. CONCLUSION: Although MS natural history is changing, a high lesion load at onset is helpful to identify patients at risk of presenting an aggressive MS.


Assuntos
Doenças Desmielinizantes , Esclerose Múltipla , Encéfalo , Estudos de Coortes , Avaliação da Deficiência , Progressão da Doença , Humanos , Imageamento por Ressonância Magnética , Esclerose Múltipla/diagnóstico , Esclerose Múltipla/epidemiologia
5.
J Theor Biol ; 484: 110030, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31568789

RESUMO

We introduce an agent-based model describing a susceptible-infectious-susceptible (SIS) system of humans and mosquitoes to predict malaria epidemiological scenarios in realistic biological conditions. Emphasis is given to the transition from endemic behavior to eradication of malaria transmission induced by combined drug therapies acting on both the gametocytemia reduction and on the selective mosquito mortality during parasite development in the mosquito. Our mathematical framework enables to uncover the critical values of the parameters characterizing the effect of each drug therapy. Moreover, our results provide quantitative evidence of what was up to now only partially assumed with empirical support: interventions combining gametocytemia reduction through the use of gametocidal drugs, with the selective action of ivermectin during parasite development in the mosquito, may actively promote disease eradication in the long run. In the agent model, the main properties of human-mosquito interactions are implemented as parameters and the model is validated by comparing simulations with real data of malaria incidence collected in the endemic malaria region of Chimoio in Mozambique. Finally, we discuss our findings in light of current drug administration strategies for malaria prevention, which may interfere with human-to-mosquito transmission process.


Assuntos
Antimaláricos , Quimioterapia Combinada , Malária , Modelos Teóricos , Animais , Antimaláricos/administração & dosagem , Culicidae/parasitologia , Erradicação de Doenças , Doenças Endêmicas/prevenção & controle , Interações Hospedeiro-Parasita , Humanos , Malária/tratamento farmacológico , Malária/epidemiologia , Malária/prevenção & controle
6.
Adv Exp Med Biol ; 1170: 103-125, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32067206

RESUMO

Social robotics is currently challenging researchers to look at virtually every topic with relevance for human societies. The multidisciplinary nature of this new area is emerging at a fast pace and, at the same time, multiple challenges are also emerging.This chapter addresses the development of a social robot, including baseline work developed during the European FP7 Project Monarch on a social robot for edutainment activities for inpatient children in the Pediatrics ward of an oncological hospital, and the work developed in the post-project period. The long period (Monarch started in early 2013) allowed a diversity of experiments that resulted in valuable lessons and in the blossoming of new ideas and challenges.The overview of the Monarch project is the leitmotiv for a critical view of social robotics and the identification of key challenges, on the light of current technologies and social trends and expectations.


Assuntos
Oncologia/instrumentação , Oncologia/métodos , Pediatria/instrumentação , Pediatria/métodos , Robótica/instrumentação , Comportamento Social , Criança , Europa (Continente) , Humanos
7.
J Neurovirol ; 23(5): 786-788, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28831691

RESUMO

Parvovirus B19 (PB19) is a common, widespread, small, single-stranded DNA virus which has been linked with a broad spectrum of clinical illnesses, including a variety of neurological complications such as encephalitis, meningitis, myelitis, stroke, cerebellar ataxia, and neuropathy. The authors describe a case of PB19 infection associated with hemolytic anemia and cranial polyneuropathy involving the second and third cranial nerves in a 23-year-old immunocompetent woman. The diagnosis of acute PB19 infection was established with detection of positive DNA and anti-PB19 IgM antibodies in blood samples. Antiganglioside antibody studies were performed and serum anti-GD1b IgG was strongly positive. Further investigation was normal or negative, excluding other infectious or autoimmune disorders. The patient was initially treated with a 5-day course of intravenous immunoglobulin (IGIV). Because of incomplete neurological recovery, methylprednisolone was also administered 7 days after IGIV therapy initiation. Complete resolution of clinical symptoms was observed 3 months after disease onset at follow-up visit, despite the persistence of PB19 DNA and anti-PB19 IgM antibodies in serum 5 months after the initial presentation. Our report provides evidence that PB19 could affect both the central and peripheral nervous system, possibly by triggering an autoimmune mechanism that leads to autoantibody production.


Assuntos
Anemia Hemolítica/virologia , Eritema Infeccioso/complicações , Doenças do Nervo Oculomotor/virologia , Doenças do Nervo Óptico/virologia , Autoanticorpos/imunologia , Autoantígenos/imunologia , Eritema Infeccioso/imunologia , Feminino , Gangliosídeos/imunologia , Humanos , Polineuropatias/virologia , Adulto Jovem
8.
Intensive Care Med ; 50(4): 493-501, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38526578

RESUMO

An implantable left ventricular assist device (LVAD) is indicated as a bridge to transplantation or recovery in the United Kingdom (UK). The mechanism of action of the LVAD results in a unique state of haemodynamic stability with diminished arterial pulsatility. The clinical assessment of an LVAD recipient can be challenging because non-invasive blood pressure, pulse and oxygen saturation measurements may be hard to obtain. As a result of this unusual situation and complex interplay between the device and the native circulation, resuscitation of LVAD recipients requires bespoke guidelines. Through collaboration with key UK stakeholders, we assessed the current evidence base and developed guidelines for the recognition of clinical deterioration, inadequate circulation and time-critical interventions. Such guidelines, intended for use in transplant centres, are designed to be deployed by those providing immediate care of LVAD patients under conditions of precipitous clinical deterioration. In summary, the Joint British Societies and Transplant Centres LVAD Working Group present the UK guideline on management of emergencies in implantable LVAD recipients for use in advanced heart failure centres. These recommendations have been made with a UK resuscitation focus but are widely applicable to professionals regularly managing patients with implantable LVADs.


Assuntos
Deterioração Clínica , Insuficiência Cardíaca , Transplante de Coração , Coração Auxiliar , Humanos , Emergências , Insuficiência Cardíaca/terapia
10.
Sensors (Basel) ; 13(11): 15549-81, 2013 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-24240598

RESUMO

In this paper, a multimodal user-emotion detection system for social robots is presented. This system is intended to be used during human-robot interaction, and it is integrated as part of the overall interaction system of the robot: the Robotics Dialog System (RDS). Two modes are used to detect emotions: the voice and face expression analysis. In order to analyze the voice of the user, a new component has been developed: Gender and Emotion Voice Analysis (GEVA), which is written using the Chuck language. For emotion detection in facial expressions, the system, Gender and Emotion Facial Analysis (GEFA), has been also developed. This last system integrates two third-party solutions: Sophisticated High-speed Object Recognition Engine (SHORE) and Computer Expression Recognition Toolbox (CERT). Once these new components (GEVA and GEFA) give their results, a decision rule is applied in order to combine the information given by both of them. The result of this rule, the detected emotion, is integrated into the dialog system through communicative acts. Hence, each communicative act gives, among other things, the detected emotion of the user to the RDS so it can adapt its strategy in order to get a greater satisfaction degree during the human-robot dialog. Each of the new components, GEVA and GEFA, can also be used individually. Moreover, they are integrated with the robotic control platform ROS (Robot Operating System). Several experiments with real users were performed to determine the accuracy of each component and to set the final decision rule. The results obtained from applying this decision rule in these experiments show a high success rate in automatic user emotion recognition, improving the results given by the two information channels (audio and visual) separately.


Assuntos
Emoções/fisiologia , Robótica , Expressão Facial , Humanos
11.
PeerJ Comput Sci ; 9: e1550, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38077605

RESUMO

This article proposes an adaptable path tracking control system, based on reinforcement learning (RL), for autonomous cars. A four-parameter controller shapes the behaviour of the vehicle to navigate lane changes and roundabouts. The tuning of the tracker uses an 'educated' Q-Learning algorithm to minimize the lateral and steering trajectory errors, this being a key contribution of this article. The CARLA (CAR Learning to Act) simulator was used both for training and testing. The results show the vehicle is able to adapt its behaviour to the different types of reference trajectories, navigating safely with low tracking errors. The use of a robot operating system (ROS) bridge between CARLA and the tracker (i) results in a realistic system, and (ii) simplifies the replacement of CARLA by a real vehicle, as in a hardware-in-the-loop system. Another contribution of this article is the framework for the dependability of the overall architecture based on stability results of non-smooth systems, presented at the end of this article.

12.
PeerJ Comput Sci ; 9: e1563, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38192445

RESUMO

Devices such as canes and wheelchairs, used to assist locomotion, have remained mostly unchanged for centuries. Recent advances in robotics have the potential to develop smart versions of these devices that can offer better support and living conditions to their users. This is the underlying objective of this project. The existing devices, used during recovery and rehabilitation phases where gait stability is key, are often bulky and cannot be easily migrated from hospital to domestic environments, where maneuvering space tends to be restricted. This article discusses a compact, lightweight and minimally invasive, robotic cane to assist locomotion. The device can assist users with mild locomotion disabilities, e.g., in the final stages of rehabilitation, to maintain and recover their balance in standing and walking situations. This extends previous experiments with alternative control strategies, merged with indicators (based on the Gini index) able to recognize differences between users. Several experiments, with a range of users possessing different mobility impairments, confirm the viability of the robotic cane, with users comfortably using the cane after three minutes, on average, proving its ease of use and low intrusiveness, and with constant support offered during the whole movement. Furthermore, the real-time tuning of the controller gains, via the Gini inequality index, enables adjustment to the user's movement.

13.
Int J Artif Organs ; 46(10-11): 589-591, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37278015

RESUMO

Patients with implantable left ventricular assist devices (LVAD) are at risk of ventricular arrhythmias but these may be hemodynamically tolerated. An electrocardiogram (ECG) is essential to determine whether an LVAD-supported patient is experiencing a ventricular arrhythmia. Access to 12 lead ECG is predominantly in healthcare facilities. Implantable LVAD also cause significant electromagnetic interference leading to artefacts on ECG. We report a patient on Heartmate 3 LVAD with a diagnostic quality 6 lead ECG obtained with an AliveCor device during an episode of sustained palpitations. The AliveCor device may be used for remote identification of ventricular arrhythmias in LVAD patients.


Assuntos
Insuficiência Cardíaca , Coração Auxiliar , Humanos , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/terapia , Smartphone , Arritmias Cardíacas , Coração Auxiliar/efeitos adversos , Eletrocardiografia
14.
Mult Scler Relat Disord ; 70: 104490, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36621160

RESUMO

BACKGROUND: Strategies recommended to decrease the risk of infection associated with the use of multiple sclerosis disease-modifying treatments include screening and immunization against common viral infections such as varicella-zoster (VZV) and hepatitis B (HBV). However, the data concerning the durability of those vaccine responses and the need for re-test is scarce. OBJECTIVES: We aimed to evaluate HBV and VZV seroprotection loss in MS patients under DMT. METHODS: We conducted a cohort study including patients with basal seroprotective titers against HBV/VZV viruses and a subsequent serology performed at least 3 months apart. We evaluated predictors of seroprotection loss through a binary regression. RESULTS: HBV seroprotection loss occurred in one-fifth of patients in a median interval of 21.3 months. Anti-CD20 treatment (OR 8.559 95%CI 3.467- 21.130, p < 000.1), age at last serology higher or equal to 55 years (OR 7.506, 95% CI 2.473-22.786, p < 0.001) and basal HBsAb titer (OR 0.992, 95%CI 0.987 -0.996, p=0.001) increase the risk of seroprotection loss. VZV seroprotection loss occurred rarely in a median interval of 21.3 months. We could not identify any factor associated with an increased risk of VZV seroprotection loss. CONCLUSIONS: Anti-CD20 drugs are associated with a loss of seroprotection against HBV in a short-interval follow-up.


Assuntos
Vírus da Hepatite B , Hepatite B , Humanos , Vacinas contra Hepatite B/uso terapêutico , Estudos de Coortes , Hepatite B/tratamento farmacológico , Hepatite B/prevenção & controle , Anticorpos Anti-Hepatite B
15.
J Med Chem ; 66(20): 14080-14094, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37616241

RESUMO

The search for more effective and selective drugs to overcome cancer multidrug resistance is urgent. As such, a new series of ruthenium-cyclopentadienyl ("RuCp") compounds with the general formula [Ru(η5-C5H4R)(4,4'-R'-2,2'-bipy)(PPh3)] were prepared and fully characterized. All compounds were evaluated toward non-small cell lung cancer cells with different degrees of cisplatin sensitivity (A549, NCI-H2228, Calu-3, and NCI-H1975), showing better cytotoxicity than the first-line chemotherapeutic drug cisplatin. Compounds 2 and 3 (R' = -OCH3; R = CHO (2) or CH2OH (3)) further inhibited the activity of P-gp and MRP1 efflux pumps by impairing their catalytic activity. Molecular docking calculations identified the R-site P-gp pocket as the preferred one, which was further validated using site-directed mutagenesis experiments in P-gp. Altogether, our results unveil the first direct evidence of the interaction between P-gp and "RuCp" compounds in the modulation of P-gp activity and establish them as valuable candidates to circumvent cancer MDR.


Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Rutênio , Humanos , Antineoplásicos/farmacologia , Rutênio/farmacologia , Cisplatino/farmacologia , Simulação de Acoplamento Molecular , Compostos de Rutênio/farmacologia , Linhagem Celular Tumoral , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos
16.
Clin Neuropharmacol ; 46(3): 105-111, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37191564

RESUMO

OBJECTIVES: Cladribine is a selective and oral immunological reconstitution treatment, approved in Europe for very active multiple sclerosis (MS) with relapses. Aims were to assess the safety and effectiveness of cladribine in real-world setting, during treatment follow-up. METHODS: This was a multicentric, longitudinal, observational study with retrospective and prospective data collection of clinical, laboratory, and imaging data. This interim analysis reports data from July 1, 2018 (study onset), to March 31, 2021. RESULTS: A total of 182 patients were enrolled: 68.7% were female; mean age at onset was 30.1 ± 10.0 years, and mean age at first cycle of cladribine treatment was 41.1 ± 12.1; 88.5% were diagnosed with relapse-remitting MS and 11.5% with secondary progressive MS. Mean disease duration at cladribine start was 8.9 ± 7.7 years. Most patients (86.1%) were not naive, and median number of previous disease-modifying therapies was 2 (interquartile range, 1-3). At 12 months, we observed no significant Expanded Disability Status Scale score worsening ( P = 0.843, Mann-Whitney U test) and a significantly lower annualized relapse rate (0.9 at baseline to 0.2; 78% reduction). Cladribine treatment discontinuation was registered in 8% of patients, mainly (69.2%) due to disease activity persistence. Most frequent adverse reactions were lymphocytopenia (55%), infections (25.2%), and fatigue (10.7%). Serious adverse effects were reported in 3.3%. No patient has discontinued cladribine treatment because of adverse effects. CONCLUSION: Our study confirms the clinical efficacy and the safety profile of cladribine for treating MS patients with a long-term active disease in the real-world setting. Our data contribute to the body of knowledge of the clinical management of MS patients and the improvement of related clinical outcomes.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Humanos , Feminino , Masculino , Cladribina/efeitos adversos , Esclerose Múltipla/tratamento farmacológico , Imunossupressores/efeitos adversos , Portugal/epidemiologia , Estudos Retrospectivos , Centros de Atenção Terciária , Recidiva , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico
17.
Comput Struct Biotechnol J ; 20: 1798-1810, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35495109

RESUMO

Omics and meta-omics technologies are powerful approaches to explore microorganisms' functions, but the sheer size and complexity of omics datasets often turn the analysis into a challenging task. Software developed for omics and meta-omics analyses, together with knowledgebases encompassing information on genes, proteins, taxonomic and functional annotation, among other types of information, are valuable resources for analyzing omics data. Although several bioinformatics resources are available for meta-omics analyses, many require significant computational expertise. Web interfaces are more user-friendly, but often struggle to handle large data files, such as those obtained in metagenomics, metatranscriptomics, or metaproteomics experiments. In this work, we present three novel bioinformatics tools, which are available through user-friendly command-line interfaces, can be run sequentially or stand-alone, and combine popular resources for functional annotation. UPIMAPI performs sequence homology-based annotation and obtains data from UniProtKB (e.g., protein names, EC numbers, Gene Ontology, Taxonomy, cross-references to external databases). reCOGnizer performs multithreaded domain homology-based annotation of protein sequences with several functional databases (i.e., CDD, NCBIfam, Pfam, Protein Clusters, SMART, TIGRFAM, COG and KOG) and in addition, obtains information on domain names and descriptions and EC numbers. KEGGCharter represents omics results, including differential gene expression, in KEGG metabolic pathways. In addition, it shows the taxonomic assignment of the enzymes represented, which is particularly useful in metagenomics studies in which several microorganisms are present. reCOGnizer, UPIMAPI and KEGGCharter together provide a comprehensive and complete functional characterization of large datasets, facilitating the interpretation of microbial activities in nature and in biotechnological processes.

18.
J Phys Chem B ; 126(40): 7870-7882, 2022 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-36190807

RESUMO

The impact of pH on proteins is significant but often neglected in molecular dynamics simulations. Constant-pH Molecular Dynamics (CpHMD) is the state-of-the-art methodology to deal with these effects. However, it still lacks widespread adoption by the scientific community. The stochastic titration CpHMD is one of such methods that, until now, only supported the GROMOS force field family. Here, we extend this method's implementation to include the CHARMM36m force field available in the GROMACS software package. We test this new implementation with a diverse group of proteins, namely, lysozyme, Staphylococcal nuclease, and human and E. coli thioredoxins. All proteins were conformationally stable in the simulations, even at extreme pH values. The RMSE values (pKa prediction vs experimental) obtained were very encouraging, in particular for lysozyme and human thioredoxin. We have also identified a few residues that challenged the CpHMD simulations, highlighting scenarios where the method still needs improvement independently of the force field. The CHARMM36m all-atom implementation was more computationally efficient when compared with the GROMOS 54A7, taking advantage of a shorter nonbonded interaction cutoff and a less frequent neighboring list update. The new extension will allow the study of pH effects in many systems for which this force field is particularly suited, i.e., proteins, membrane proteins, lipid bilayers, and nucleic acids.


Assuntos
Simulação de Dinâmica Molecular , Ácidos Nucleicos , Escherichia coli , Humanos , Concentração de Íons de Hidrogênio , Bicamadas Lipídicas , Proteínas de Membrana , Nuclease do Micrococo/química , Muramidase , Tiorredoxinas
19.
J Integr Bioinform ; 19(3)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36054839

RESUMO

Genome-scale metabolic models (GEMs) are essential tools for in silico phenotype prediction and strain optimisation. The most straightforward GEMs reconstruction approach uses published models as templates to generate the initial draft, requiring further curation. Such an approach is used by BiGG Integration Tool (BIT), available for merlin users. This tool uses models from BiGG Models database as templates for the draft models. Moreover, BIT allows the selection between different template combinations. The main objective of this study is to assess the draft models generated using this tool and compare them BIT, comparing these to CarveMe models, both of which use the BiGG database, and curated models. For this, three organisms were selected, namely Streptococcus thermophilus, Xylella fastidiosa and Mycobacterium tuberculosis. The models' variability was assessed using reactions and genes' metabolic functions. This study concluded that models generated with BIT for each organism were differentiated, despite sharing a significant portion of metabolic functions. Furthermore, the template seems to influence the content of the models, though to a lower extent. When comparing each draft with curated models, BIT had better performances than CarveMe in all metrics. Hence, BIT can be considered a fast and reliable alternative for draft reconstruction for bacteria models.


Assuntos
Redes e Vias Metabólicas , Neurofibromina 2 , Bases de Dados Factuais , Genoma , Redes e Vias Metabólicas/genética , Modelos Biológicos
20.
J Clin Neuromuscul Dis ; 22(3): 155-159, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33595999

RESUMO

ABSTRACT: We present the case of a 24-year-old man with a 3-day history of limb weakness and flaccid tetraparesis, hyporreflexia, and gait difficulties (Hughes grade 3) in the examination. Electromyography at presentation revealed severe amplitude reduction in distal compound muscle action potentials of several nerves without features of demyelination, fulfilling electrodiagnostic criteria for acute axonal motor neuropathy. The patient was treated with immunoglobulin and recovered completely 21 days after symptom onset. Electromyography at this timepoint showed normalization of compound muscle action potentials without increased temporal dispersion. The electroclinical recovery profile in this patient is consistent with reversible conduction failure in distal nerve segments in detriment of axonal degeneration. Thus, it is an "axonal motor neuropathy" where axonopathy is unlikely, giving strength to the concept of "nodopathies/paranodopathies."


Assuntos
Axônios/fisiologia , Síndrome de Guillain-Barré/diagnóstico , Potenciais de Ação , Eletromiografia , Humanos , Masculino , Condução Nervosa , Adulto Jovem
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