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1.
J Speech Lang Hear Res ; : 1-20, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38754039

RESUMO

PURPOSE: Cross-language studies suggest more similarities than differences in how dysarthria affects the speech of people with Parkinson's disease (PwPD) who speak different languages. In this study, we aimed to identify the relative contribution of acoustic variables to distinguish PwPD from controls who spoke varieties of two Romance languages, French and Portuguese. METHOD: This bi-national, cross-sectional, and case-controlled study included 129 PwPD and 124 healthy controls who spoke French or Portuguese. All participants underwent the same clinical examinations, voice/speech recordings, and self-assessment questionnaires. PwPD were evaluated off and on optimal medication. Inferential analyses included Disease (controls vs. PwPD) and Language (French vs. Portuguese) as factors, and random decision forest algorithms identified relevant acoustic variables able to distinguish participants: (a) by language (French vs. Portuguese) and (b) by clinical status (PwPD on and off medication vs. controls). RESULTS: French-speaking and Portuguese-speaking individuals were distinguished from each other with over 90% accuracy by five acoustic variables (the mean fundamental frequency and the shimmer of the sustained vowel /a/ production, the oral diadochokinesis performance index, the relative sound level pressure and the relative sound pressure level standard deviation of the text reading). A distinct set of parameters discriminated between controls and PwPD: for men, maximum phonation time and the oral diadochokinesis speech proportion were the most significant variables; for women, variables calculated from the oral diadochokinesis were the most discriminative. CONCLUSIONS: Acoustic variables related to phonation and voice quality distinguished between speakers of the two languages. Variables related to pneumophonic coordination and articulation rate were the more effective in distinguishing PwPD from controls. Thus, our research findings support that respiration and diadochokinesis tasks appear to be the most appropriate to pinpoint signs of dysarthria, which are largely homogeneous and language-universal. In contrast, identifying language-specific variables with the speech tasks and acoustic variables studied was less conclusive.

2.
J Chem Inf Model ; 64(10): 4218-4230, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38684937

RESUMO

Due to its detrimental impact on human health and the environment, regulations demand ultralow sulfur levels on fossil fuels, in particular in diesel. However, current desulfurization techniques are expensive and cannot efficiently remove heteroaromatic sulfur compounds, which are abundant in crude oil and concentrate in the diesel fraction after distillation. Biodesulfurization via the four enzymes of the metabolic 4S pathway of the bacterium Rhodococcus erythropolis (DszA-D) is a possible solution. However, the 4S pathway needs to operate at least 500 times faster for industrial applicability, a goal currently pursued through enzyme engineering. In this work, we unveil the catalytic mechanism of the flavin monooxygenase DszA. Surprisingly, we found that this enzyme follows a recently proposed atypical mechanism that passes through the formation of an N5OOH intermediate at the re side of the cofactor, aided by a well-defined, predominantly hydrophobic O2 pocket. Besides clarifying the unusual chemical mechanism of the complex DszA enzyme, with obvious implications for understanding the puzzling chemistry of flavin-mediated catalysis, the result is crucial for the rational engineering of DszA, contributing to making biodesulfurization attractive for the oil refining industry.


Assuntos
Biocatálise , Rhodococcus , Rhodococcus/enzimologia , Rhodococcus/metabolismo , Modelos Moleculares , Enxofre/metabolismo , Enxofre/química , Oxigenases de Função Mista/metabolismo , Oxigenases de Função Mista/química , Carbono/química , Carbono/metabolismo
3.
CoDAS ; 36(2): e20230055, 2024. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1520737

RESUMO

ABSTRACT Purpose To compare the speech and voice patterns of myasthenia gravis (MG) patients over four years, and correlate the results with clinical aspects of the disease. Methods Data was collected for 4 years. The clinical assessment tools included the Quantitative Myasthenia Gravis (QMG) score, the Myasthenia Gravis Foundation of America (MGFA) clinical classification, and the Myasthenia Gravis Quality of Life 15-item Scale (MG-QoL). To assess speech, the recorded speaking tasks were analyzed acoustically and given auditory-perceptual ratings. Sex (equal distribution) and age (p=0.949) were used as matching criteria in the final sample, which consisted of 10 individuals in the MG group (MGG) and 10 individuals in the control group (CG). Results After 4 years, the MG participants presented stable health status, increased mild and moderate dysarthria (from 40% to 90% of the subjects), and a significant deterioration in the respiration, phonation, and articulation subsystems. The acoustic analysis showed a decline in articulatory patterns (speech rate p=0.047, articulation rate p=0.007, mean syllable duration p=0.007) and vocal quality (increased jitter p=0.022). In the follow-up comparison, there was a significant difference between the phonation variables (shimmer and harmonic-to-noise ratio) of the MGG and CG. Conclusion The MG patients presented a decline in speech over four years and an increase in mild and moderate dysarthria. Despite presenting stable health status, their respiratory, phonatory, and articulatory subsystems worsened. There was no correlation between speech patterns and clinical characteristics of the disease (severity and motor scale).


RESUMO Objetivo Comparar o padrão de fala e voz de indivíduos com Miastenia Gravis (MG) em um intervalo de quatro anos e correlacionar com aspectos clínicos da doença. Método A coleta de dados foi realizada ao longo de 4 anos. A avaliação clínica foi composta pelo Quantitative Myasthenia Gravis Score (QMGS), pela Myasthenia Gravis Foundation of America Classification (MGFA) e pela escala de qualidade de vida para Miastenia Gravis (MG-QOL). A avaliação da fala foi composta por gravação de tarefas, análise perceptivo-auditiva e análise acústica. A amostra final foi composta por 10 indivíduos em MG e 10 indivíduos no grupo controle (GC), pareados por sexo (distribuição igualitária) e idade (p=0,949). Resultados Após 4 anos, os indivíduos com MG apresentaram estabilidade clínica, aumento do diagnóstico de disartria leve e moderada (de 40% para 90% dos sujeitos) e diminuição significativa no desempenho dos subsistemas da fala: respiração, fonação e articulação. Na análise acústica, houve declínio do padrão articulatório (taxa de fala p=0,047, taxa de articulação p=0,007, duração média das sílabas p=0,007) e qualidade vocal (jitter aumentado p=0,022). Houve diferença significativa nas variáveis fonatórias (shimmer e harmonic-to-noise ratio) entre os grupos MG e GC na comparação do seguimento. Conclusão Indivíduos com MG apresentaram declínio no padrão de fala em um intervalo de quatro anos, com aumento no número de disártricos (leve e moderado). Mesmo com a estabilidade da doença, houve piora dos subsistemas respiratório, fonatório e articulatório. Não houve correlação entre o padrão de fala e as características clínicas da doença (gravidade e escala motora).

4.
Mol Cancer ; 22(1): 181, 2023 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-37957606

RESUMO

The limited sensitivity of circulating tumor cell (CTC) detection in pancreatic adenocarcinoma (PDAC) stems from their extremely low concentration in the whole circulating blood, necessitating enhanced detection methodologies. This study sought to amplify assay-sensitivity by employing diagnostic leukapheresis (DLA) to screen large blood volumes. Sixty patients were subjected to DLA, with a median processed blood volume of ~ 2.8 L and approximately 5% of the resulting DLA-product analyzed using CellSearch (CS). Notably, DLA significantly increased CS-CTC detection to 44% in M0-patients and 74% in M1-patients, yielding a 60-fold increase in CS-CTC enumeration. DLA also provided sufficient CS-CTCs for genomic profiling, thereby delivering additional genomic information compared to tissue biopsy samples. DLA CS-CTCs exhibited a pronounced negative prognostic impact on overall survival (OS), evidenced by a reduction in OS from 28.6 to 8.5 months (univariate: p = 0.002; multivariable: p = 0.043). Additionally, a marked enhancement in sensitivity was achieved (by around 3-4-times) compared to peripheral blood (PB) samples, with positive predictive values for OS being preserved at around 90%. Prognostic relevance of CS-CTCs in PDAC was further validated in PB-samples from 228 PDAC patients, consolidating the established association between CTC-presence and reduced OS (8.5 vs. 19.0 months, p < 0.001). In conclusion, DLA-derived CS-CTCs may serve as a viable tool for identifying high-risk PDAC-patients and aiding the optimization of multimodal treatment strategies. Moreover, DLA enables comprehensive diagnostic profiling by providing ample CTC material, reinforcing its utility as a reliable liquid-biopsy approach. This high-volume liquid-biopsy strategy presents a potential pathway for enhancing clinical management in this malignancy.


Assuntos
Adenocarcinoma , Células Neoplásicas Circulantes , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/diagnóstico , Adenocarcinoma/diagnóstico , Células Neoplásicas Circulantes/patologia , Biópsia Líquida/métodos , Biomarcadores Tumorais , Volume Sanguíneo , Neoplasias Pancreáticas
5.
Front Neurol ; 14: 1075736, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37384284

RESUMO

Background: Dysarthria is one of the most frequent communication disorders in patients with Multiple Sclerosis (MS), with an estimated prevalence of around 50%. However, it is unclear if there is a relationship between dysarthria and the severity or duration of the disease. Objective: Describe the speech pattern in MS, correlate with clinical data, and compare with controls. Methods: A group of MS patients (n = 73) matched to healthy controls (n = 37) by sex and age. Individuals with neurological and/or systemic conditions that could interfere with speech were excluded. MS group clinical data were obtained through the analysis of medical records. The speech assessment consisted of auditory-perceptual and speech acoustic analysis, from recording the following speech tasks: phonation and breathing (sustained vowel/a/); prosody (sentences with different intonation patterns) and articulation (diadochokinesis; spontaneous speech; diphthong/iu/repeatedly). Results: In MS, 72.6% of the individuals presented mild dysarthria, with alterations in speech subsystems: phonation, breathing, resonance, and articulation. In the acoustic analysis, individuals with MS were significantly worse than the control group (CG) in the variables: standard deviation of the fundamental frequency (p = 0.001) and maximum phonation time (p = 0.041). In diadochokinesis, individuals with MS had a lower number of syllables, duration, and phonation time, but larger pauses per seconds, and in spontaneous speech, a high number of pauses were evidenced as compared to CG. Correlations were found between phonation time in spontaneous speech and the Expanded Disability Status Scale (EDSS) (r = - 0.238, p = 0.043) and phonation ratio in spontaneous speech and EDSS (r = -0.265, p = 0.023), which indicates a correlation between the number of pauses during spontaneous speech and the severity of the disease. Conclusion: The speech profile in MS patients was mild dysarthria, with a decline in the phonatory, respiratory, resonant, and articulatory subsystems of speech, respectively, in order of prevalence. The increased number of pauses during speech and lower rates of phonation ratio can reflect the severity of MS.

6.
Front Neurol ; 14: 1179287, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37213898

RESUMO

Background: The basal ganglia and cerebellum both have a role in speech production although the effect of isolated involvement of these structures on speech fluency remains unclear. Objective: The study aimed to assess the differences in the articulatory pattern in patients with cerebellar vs. basal ganglia disorders. Methods: A total of 20 individuals with Parkinson's disease (PD), 20 with spinocerebellar ataxia type 3 (SCA3), and 40 controls (control group, CG) were included. Diadochokinesis (DDK) and monolog tasks were collected. Results: The only variable that distinguished SCA3 carriers from the CG was the number of syllables in the monolog, with SCA3 patients of a significantly lower number. For patients with PD, the number of syllables, phonation time, DDK, and monolog were significantly lower than for CG. Patients with PD were significantly worse compared to patients with SCA3 in the number of syllables and phonation time in DDK, and phonation time in monolog. Additionally, there was a significant correlation between the number of syllables in the monolog and the MDS-UPDRS III for participants with PD, and the Friedreich Ataxia Rating Scale for participants with SCA3 suggesting a relationship between speech and general motor functioning. Conclusion: The monolog task is better at discriminating individuals with cerebellar vs. Parkinson's diseases as well as differentiating healthy control and was related to the severity of the disease.

7.
PLoS Biol ; 21(3): e3002021, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36913435

RESUMO

Morphogenetic gradients specify distinct cell populations within tissues. Originally, morphogens were conceived as substances that act on a static field of cells, yet cells usually move during development. Thus, the way cell fates are defined in moving cells remains a significant and largely unsolved problem. Here, we investigated this issue using spatial referencing of cells and 3D spatial statistics in the Drosophila blastoderm to reveal how cell density responds to morphogenetic activity. We show that the morphogen decapentaplegic (DPP) attracts cells towards its peak levels in the dorsal midline, whereas dorsal (DL) stalls them ventrally. We identified frazzled and GUK-holder as the downstream effectors regulated by these morphogens that constrict cells and provide the mechanical force necessary to draw cells dorsally. Surprisingly, GUKH and FRA modulate the DL and DPP gradient levels and this regulation creates a very precise mechanism of coordinating cell movement and fate specification.


Assuntos
Proteínas de Drosophila , Drosophila , Animais , Diferenciação Celular , Drosophila/genética , Drosophila melanogaster/genética , Proteínas de Drosophila/genética , Morfogênese/genética
8.
Clinics (Sao Paulo) ; 78: 100128, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36473366

RESUMO

OBJECTIVE: To describe the speech pattern of patients with hereditary Spastic Paraplegia type 4 (SPG4) and correlated it with their clinical data. METHODS: Cross-sectional study was carried out in two university hospitals in Brazil. Two groups participated in the study: the case group (n = 28) with a confirmed genetic diagnosis for SPG4 and a control group (n = 17) matched for sex and age. The speech assessment of both groups included: speech task recording, acoustic analysis, and auditory-perceptual analysis. In addition, disease severity was assessed with the Spastic Paraplegia Rating Scale (SPRS). RESULTS: In the auditory-perceptual analysis, 53.5% (n = 15) of individuals with SPG4 were dysarthric, with mild to moderate changes in the subsystems of phonation and articulation. On acoustic analysis, SPG4 subjects' performances were worse in measurements related to breathing (maximum phonation time) and articulation (speech rate, articulation rate). The articulation variables (speech rate, articulation rate) are related to the age of onset of the first motor symptom. CONCLUSION: Dysarthria in SPG4 is frequent and mild, and it did not evolve in conjunction with more advanced motor diseases. This data suggest that diagnosed patients should be screened and referred for speech therapy evaluation and those pathophysiological mechanisms of speech involvement may differ from the length-dependent degeneration of the corticospinal tract.


Assuntos
Paraplegia Espástica Hereditária , Humanos , Paraplegia Espástica Hereditária/genética , Disartria , Estudos Transversais , Paraplegia
9.
J Chem Inf Model ; 63(1): 20-26, 2023 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-36534708

RESUMO

We describe an approach to identify enzyme mutants with increased turnover using the enzyme DszC as a case study. Our approach is based on recalculating the barriers of alanine mutants through single-point energy calculations at the hybrid QM/MM level in the wild-type reactant and transition state geometries. We analyze the difference in the electron density between the reactant and transition state to identify sites/residues where electrostatic interactions stabilize the transition state over the reactants. We also assess the insertion of a unit probe charge to identify positions in which the introduction of charged residues lowers the barrier.


Assuntos
Catálise
10.
Med Genet ; 35(4): 237-250, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38835741

RESUMO

This narrative review aims to provide a comprehensive overview of the current state of circulating tumor cell (CTC) analysis and its clinical significance in patients with epithelial cancers. The review explores the advancements in CTC detection methods, their clinical applications, and the challenges that lie ahead. By examining the important research findings in this field, this review offers the reader a solid foundation to understand the evolving landscape of CTC analysis and its potential implications for clinical practice. The comprehensive analysis of CTCs provides valuable insights into tumor biology, treatment response, minimal residual disease detection, and prognostic evaluation. Furthermore, the review highlights the potential of CTCs as a non-invasive biomarker for personalized medicine and the monitoring of treatment efficacy. Despite the progress made in CTC research, several challenges such as standardization, validation, and integration into routine clinical practice remain. The review concludes by discussing future directions and the potential impact of CTC analysis on improving patient outcomes and guiding therapeutic decision-making in epithelial cancers.

11.
Clinics ; 78: 100128, 2023. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1421267

RESUMO

Abstract Objective: To describe the speech pattern of patients with hereditary Spastic Paraplegia type 4 (SPG4) and correlated it with their clinical data. Methods: Cross-sectional study was carried out in two university hospitals in Brazil. Two groups participated in the study: the case group (n = 28) with a confirmed genetic diagnosis for SPG4 and a control group (n = 17) matched for sex and age. The speech assessment of both groups included: speech task recording, acoustic analysis, and auditory-perceptual analysis. In addition, disease severity was assessed with the Spastic Paraplegia Rating Scale (SPRS). Results: In the auditory-perceptual analysis, 53.5% (n = 15) of individuals with SPG4 were dysarthric, with mild to moderate changes in the subsystems of phonation and articulation. On acoustic analysis, SPG4 subjects' performances were worse in measurements related to breathing (maximum phonation time) and articulation (speech rate, articulation rate). The articulation variables (speech rate, articulation rate) are related to the age of onset of the first motor symptom. Conclusion: Dysarthria in SPG4 is frequent and mild, and it did not evolve in conjunction with more advanced motor diseases. This data suggest that diagnosed patients should be screened and referred for speech therapy evaluation and those pathophysiological mechanisms of speech involvement may differ from the length-dependent degeneration of the corticospinal tract.

12.
Motrivivência (Florianópolis) ; 35(66): 1-13, 2023.
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1509770

RESUMO

As Provas de Aferição em Educação Física (PAEF) integram um processo de avaliação externa dos alunos e do currículo da Educação Física (EF) na escola do 1º Ciclo do Ensino Básico (1º CEB) em Portugal. Assim, a opinião dos pais e encarregados de educação (PEE) sobre as PAEF pode ser um fator relevante. Analisaram-se as perceções globais de 127 PEE dos alunos do 2º ano de escolaridade, recolhidas através de um questionário, com os dados tratados através de análise de conteúdo (categorias emergentes) e estatística. Os resultados evidenciaram que os PEE têm uma dispersão de perceções sobre as PAEF, que vão desde uma posição contrária e negativa até à sua apreciação positiva e fundamentada. Identificam também que estas podem ter um impacte futuro expressivo, monitorização da aprendizagem, do currículo e papel de avaliação formativa. Há necessidade de ampliar o conhecimento sobre a natureza e objetivos das PAEF e sua influência na valorização da área de EF na escola do 1º CEB.


The Assessment Tests in Physical Education (ATPE) are part of an external assessment process of students and the Physical Education (PE) curriculum in the Elementary School (ES) in Portugal. Thus, the opinion of parents and guardians (PG) about the ATPE can be a relevant factor. The global perceptions of 127 PEE of 2nd year students were analyzed, collected through a questionnaire, with the data processed through content analysis (emerging categories) and statistics. The results showed that the PG have a dispersion of perceptions about the ATPE, ranging from a contrary and negative position to a positive and reasoned assessment. They also identify that these can have a significant future impact, monitoring learning, the curriculum and the role of formative assessment. There is a need to expand knowledge about the nature and objectives of ATPE and its influence on valuing the PE area in the ES


Las Pruebas de Evaluación en Educación Física (PAEF) forman parte de un proceso de evaluación externa de los alumnos y del currículo de Educación Física (EF) en Escuela Primária en Portugal. Así, la opinión de los padres y tutores (PT) sobre el PAEF puede ser un factor relevante. Se analizaron las percepciones globales de 127 PT de alumnos de 2º año, recogidas a través de un cuestionario, siendo los datos procesados mediante análisis de contenido (categorías emergentes) y estadística. Los resultados mostraron que los PT tienen una dispersión de percepciones sobre el PAEF, que van desde una posición contraria y negativa hasta una valoración positiva y razonada. También identifican que estos pueden tener un impacto futuro significativo, monitoreando el aprendizaje, el currículo y el rol de la evaluación formativa. Existe la necesidad de ampliar el conocimiento sobre la naturaleza y objetivos del PAEF y su influencia en la valorización del área de EF en la Escuela Primária.

14.
Chemphyschem ; 23(20): e202200269, 2022 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-35925549

RESUMO

Hydrolysis of lignocellulosic biomass, composed of a lignin-carbohydrate-complex (LCC) matrix, is critical for producing bioethanol from glucose. However, current methods for LCC processing require costly and polluting processes. The fungal Thermothelomyces thermophila glucuronoyl esterase (TtGE) is a promising thermophilic enzyme that hydrolyses LCC ester bonds. This study describes the TtGE catalytic mechanism using QM/MM methods. Two nearly-degenerate rate-determining transition states were found, with barriers of 16 and 17 kcal ⋅ mol-1 , both with a zwitterionic nature that results from a proton interplay from His346 to either the Ser213-hydroxyl or the lignin leaving group and the rehybridisation of the ester moiety of the substrate to an alkoxide. An oxyanion hole, characteristic of esterases, was provided by the conserved Arg214 through its backbone and sidechain. Our work further suggests that a mutation of Glu267 to a non-negative residue will decrease the energetic barrier in ca. -5 kcal ⋅ mol-1 , improving the catalytic rate of TtGE.


Assuntos
Esterases , Lignina , Esterases/química , Lignina/química , Biomassa , Ácido Glucurônico/química , Prótons , Hidrólise , Carboidratos/química , Ésteres/química , Glucose
15.
J Chem Inf Model ; 62(15): 3638-3650, 2022 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-35880954

RESUMO

We assessed enzyme:substrate conformational dynamics and the rate-limiting glycosylation step of a human pancreatic α-amylase:maltopentose complex. Microsecond molecular dynamics simulations suggested that the distance of the catalytic Asp197 nucleophile to the anomeric carbon of the buried glucoside is responsible for most of the enzyme active site fluctuations and that both Asp197 and Asp300 interact the most with the buried glucoside unit. The buried glucoside binds either in a 4C1 chair or 2SO skew conformations, both of which can change to TS-like conformations characteristic of retaining glucosidases. Starting from four distinct enzyme:substrate complexes, umbrella sampling quantum mechanics/molecular mechanics simulations (converged within less than 1 kcal·mol-1 within a total simulation time of 1.6 ns) indicated that the reaction occurrs with a Gibbs barrier of 13.9 kcal·mol -1, in one asynchronous concerted step encompassing an acid-base reaction with Glu233 followed by a loose SN2-like nucleophilic substitution by the Asp197. The transition state is characterized by a 2H3 half-chair conformation of the buried glucoside that quickly changes to the E3 envelope conformation preceding the attack of the anomeric carbon by the Asp197 nucleophile. Thermodynamic analysis of the reaction supported that a water molecule tightly hydrogen bonded to the glycosidic oxygen of the substrate at the reactant state (∼1.6 Å) forms a short hydrogen bond with Glu233 at the transition state (∼1.7 Å) and lowers the Gibbs barrier in over 5 kcal·mol-1. The resulting Asp197-glycosyl was mostly found in the 4C1 conformation, although the more endergonic B3,O conformation was also observed. Altogether, the combination of short distances for the acid-base reaction with the Glu233 and for the nucleophilic attack by the Asp197 nucleophile and the availability of water within hydrogen bonding distance of the glycosidic oxygen provides a reliable criteria to identify reactive conformations of α-amylase complexes.


Assuntos
Simulação de Dinâmica Molecular , alfa-Amilases , Carbono , Catálise , Domínio Catalítico , Glucosídeos , Humanos , Oxigênio , Teoria Quântica , Água , alfa-Amilases/química
16.
Chemistry ; 28(42): e202201066, 2022 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-35686565

RESUMO

The influence of the dynamical flexibility of enzymes on reaction mechanisms is a cornerstone in biological sciences. In this study, we aim to 1) study the convergence of the activation free energy by using the first step of the reaction catalysed by HIV-1 protease as a case study, and 2) provide further evidence for a mechanistic divergence in this enzyme, as two different reaction pathways were seen to contribute to this step. We used quantum mechanics/molecular mechanics molecular dynamics simulations, on four different initial conformations that led to different barriers in a previous study. Despite the sampling, the four activation free energies still spanned a range of 5.0 kcal ⋅ mol-1 . Furthermore, the new simulations did confirm the occurrence of an unusual mechanistic divergence, with two different mechanistic pathways displaying equivalent barriers. An active-site water molecule is proposed to influence the mechanistic pathway.


Assuntos
Protease de HIV , Domínio Catalítico , Protease de HIV/metabolismo , Simulação de Dinâmica Molecular , Teoria Quântica , Termodinâmica
17.
Chemphyschem ; 23(13): e202200159, 2022 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35499146

RESUMO

We employed QM/MM molecular dynamics (MD) simulations to characterize the rate-limiting step of the glycosylation reaction of pancreatic α-amylase with combined DFT/molecular dynamics methods (PBE/def2-SVP : AMBER). Upon careful choice of four starting active site conformations based on thorough reactivity criteria, Gibbs energy profiles were calculated with umbrella sampling simulations within a statistical convergence of 1-2 kcal ⋅ mol-1 . Nevertheless, Gibbs activation barriers and reaction energies still varied from 11.0 to 16.8 kcal ⋅ mol-1 and -6.3 to +3.8 kcal ⋅ mol-1 depending on the starting conformations, showing that despite significant state-of-the-art QM/MM MD sampling (0.5 ns/profile) the result still depends on the starting structure. The results supported the one step dissociative mechanism of Asp197 glycosylation preceded by an acid-base reaction by the Glu233, which are qualitatively similar to those from multi-PES QM/MM studies, and thus support the use of the latter to determine enzyme reaction mechanisms.


Assuntos
Simulação de Dinâmica Molecular , Teoria Quântica , Domínio Catalítico , Termodinâmica
18.
Front Psychiatry ; 13: 824919, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35432028

RESUMO

Guidance about treatment-resistant depression (TRD) in Portugal is very limited, even though depression prevalence is among the highest in European countries. A questionnaire was conducted, followed by two advisory boards with seven Portuguese psychiatry experts, to characterize and discuss MDD and TRD epidemiology, diagnosis, patient journey, treatment options, and unmet clinical needs. Consensus was reached on the main issues. In daily practice, TRD can be defined as moderate to severe MDD episodes with insufficient clinical improvement after two antidepressant treatments, taken in adequate doses and duration. TRD diagnosis and treatment are mostly decided by psychiatrists at public hospitals. Treatment type and duration must be adjusted to characteristics of the patient and the depressive episode, including symptoms, number of previous episodes, comorbidities, and previous treatment response and side effects. The most relevant objectives of TRD treatment are reaching response and remission, prevention of suicide, and improvement of quality of life, functionality, and wellbeing. Regarding pharmacotherapy, antidepressant switch occurs more frequently with non-response, while optimization, combination, and augmentation are considered for patients with partial response. Psychotherapy should be considered in parallel to pharmacological treatment. Brain stimulation techniques are underused. Lifelong treatment is required for recurrent or more chronic TRD episodes, but patient adherence is also poorer in these cases. In Portugal, TRD management is limited by lack of access to specialist care and to many treatment options. These aspects highlight that conventional pharmacotherapy does not lead to remission in many patients and that optimization strategies are frequently necessary to achieve satisfactory treatment outcomes.

19.
Sci Data ; 9(1): 13, 2022 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-35058477

RESUMO

Several global high-resolution built-up surface products have emerged over the last five years, taking full advantage of open sources of satellite data such as Landsat and Sentinel. However, these data sets require validation that is independent of the producers of these products. To fill this gap, we designed a validation sample set of 50 K locations using a stratified sampling approach independent of any existing global built-up surface products. We launched a crowdsourcing campaign using Geo-Wiki ( https://www.geo-wiki.org/ ) to visually interpret this sample set for built-up surfaces using very high-resolution satellite images as a source of reference data for labelling the samples, with a minimum of five validations per sample location. Data were collected for 10 m sub-pixels in an 80 × 80 m grid to allow for geo-registration errors as well as the application of different validation modes including exact pixel matching to majority or percentage agreement. The data set presented in this paper is suitable for the validation and inter-comparison of multiple products of built-up areas.

20.
Mol Oncol ; 16(2): 333-346, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34719102

RESUMO

Considering the limited information on the biology and molecular characteristics of disseminated tumor cells (DTCs) in head and neck squamous cell carcinoma (HNSCC), we examined the genomic alterations in DTCs from HNSCCs and their potential clinical relevance. To analyze both the lymphatic and hematogenous routes of tumor cell dissemination, we investigated samples from lymph nodes (LNs) and bone marrow (BM) of 49 patients using immunofluorescence double staining for epithelial cells expressing cytokeratin 18 (KRT18) and/or epithelial cell adhesion molecules (EpCAM, CD326). The identified marker-positive cells were isolated by micromanipulation followed by single-cell whole-genome amplification and metaphase-based comparative genomic hybridization (mCGH) to determine genome-wide copy number alterations. The findings were correlated with clinical parameters and follow-up data. We detected chromosomal aberrations in KRT18- and EpCAM-positive cells from both compartments; BM-derived cells showed a significantly higher percentage of aberrant genome (PAG) per cell than cells detected in LNs. No significant association was found between DTC data and clinical follow-up. Genomic profiling of BM-DTCs revealed genomic alterations typical for HNSCC, suggesting hematogenous dissemination of subclones around the time of surgery. In contrast, DTC data in LNs revealed that several marker-positive cells were not of malignant origin, indicating the presence of epithelial glandular inclusions in parts of the processed neck LN samples. Therefore, DTC detection of LNs in the neck based only on epithelial markers is not advisable and requires detection of chromosomal instability (CIN), gene mutations, or additional markers, which have yet to be identified. Nevertheless, our investigation paves the way for larger studies to focus on HNSCC BM-DTCs with high-resolution methods to gain deeper insights into the biology of hematogenous metastasis in this cancer.


Assuntos
Medula Óssea/patologia , Linfonodos/patologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Biomarcadores Tumorais/metabolismo , Medula Óssea/metabolismo , Mapeamento Cromossômico , Hibridização Genômica Comparativa , Feminino , Humanos , Linfonodos/metabolismo , Masculino , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo
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