Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.005
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
EMBO J ; 43(15): 3240-3255, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38886582

RESUMO

Mutational patterns caused by APOBEC3 cytidine deaminase activity are evident throughout human cancer genomes. In particular, the APOBEC3A family member is a potent genotoxin that causes substantial DNA damage in experimental systems and human tumors. However, the mechanisms that ensure genome stability in cells with active APOBEC3A are unknown. Through an unbiased genome-wide screen, we define the Structural Maintenance of Chromosomes 5/6 (SMC5/6) complex as essential for cell viability when APOBEC3A is active. We observe an absence of APOBEC3A mutagenesis in human tumors with SMC5/6 dysfunction, consistent with synthetic lethality. Cancer cells depleted of SMC5/6 incur substantial genome damage from APOBEC3A activity during DNA replication. Further, APOBEC3A activity results in replication tract lengthening which is dependent on PrimPol, consistent with re-initiation of DNA synthesis downstream of APOBEC3A-induced lesions. Loss of SMC5/6 abrogates elongated replication tracts and increases DNA breaks upon APOBEC3A activity. Our findings indicate that replication fork lengthening reflects a DNA damage response to APOBEC3A activity that promotes genome stability in an SMC5/6-dependent manner. Therefore, SMC5/6 presents a potential therapeutic vulnerability in tumors with active APOBEC3A.


Assuntos
Proteínas de Ciclo Celular , Proteínas Cromossômicas não Histona , Citidina Desaminase , Dano ao DNA , Replicação do DNA , Humanos , Citidina Desaminase/metabolismo , Citidina Desaminase/genética , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas Cromossômicas não Histona/genética , Instabilidade Genômica , Linhagem Celular Tumoral , Proteínas
2.
Plant Cell ; 36(10): 4637-4657, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39158598

RESUMO

Duplicated genes are thought to follow one of three evolutionary trajectories that resolve their redundancy: neofunctionalization, subfunctionalization, or pseudogenization. Differences in expression patterns have been documented for many duplicated gene pairs and interpreted as evidence of subfunctionalization and a loss of redundancy. However, little is known about the functional impact of such differences and about their molecular basis. Here, we investigate the genetic and molecular basis for the partial loss of redundancy between the two BLADE-ON-PETIOLE genes BOP1 and BOP2 in red shepherd's purse (Capsella rubella) compared to Arabidopsis (Arabidopsis thaliana). While both genes remain almost fully redundant in A. thaliana, BOP1 in C. rubella can no longer ensure wild-type floral organ numbers and suppress bract formation, due to an altered expression pattern in the region of the cryptic bract primordium. We use two complementary approaches, transgenic rescue of A. thaliana atbop1 atbop2 double mutants and deletions in the endogenous AtBOP1 promoter, to demonstrate that several BOP1 promoter regions containing conserved noncoding sequences interact in a nonadditive manner to control BOP1 expression in the bract primordium and that changes in these interactions underlie the evolutionary divergence between C. rubella and A. thaliana BOP1 expression and activity. Similarly, altered interactions between cis-regulatory regions underlie the divergence in functional promoter architecture related to the control of floral organ abscission by BOP1. These findings highlight the complexity of promoter architecture in plants and suggest that changes in the interactions between cis-regulatory elements are key drivers for evolutionary divergence in gene expression and the loss of redundancy.


Assuntos
Arabidopsis , Capsella , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Regiões Promotoras Genéticas , Capsella/genética , Arabidopsis/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética , Plantas Geneticamente Modificadas , Flores/genética , Flores/crescimento & desenvolvimento , Genes de Plantas , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Sequências Reguladoras de Ácido Nucleico/genética , Duplicação Gênica , Genes Duplicados/genética
3.
Nature ; 592(7852): 122-127, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33636719

RESUMO

During the evolution of SARS-CoV-2 in humans, a D614G substitution in the spike glycoprotein (S) has emerged; virus containing this substitution has become the predominant circulating variant in the COVID-19 pandemic1. However, whether the increasing prevalence of this variant reflects a fitness advantage that improves replication and/or transmission in humans or is merely due to founder effects remains unknown. Here we use isogenic SARS-CoV-2 variants to demonstrate that the variant that contains S(D614G) has enhanced binding to the human cell-surface receptor angiotensin-converting enzyme 2 (ACE2), increased replication in primary human bronchial and nasal airway epithelial cultures as well as in a human ACE2 knock-in mouse model, and markedly increased replication and transmissibility in hamster and ferret models of SARS-CoV-2 infection. Our data show that the D614G substitution in S results in subtle increases in binding and replication in vitro, and provides a real competitive advantage in vivo-particularly during the transmission bottleneck. Our data therefore provide an explanation for the global predominance of the variant that contains S(D614G) among the SARS-CoV-2 viruses that are currently circulating.


Assuntos
COVID-19/transmissão , COVID-19/virologia , Mutação , SARS-CoV-2/genética , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/genética , Replicação Viral/genética , Enzima de Conversão de Angiotensina 2/genética , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Brônquios/citologia , Brônquios/virologia , COVID-19/epidemiologia , Linhagem Celular , Células Cultivadas , Cricetinae , Modelos Animais de Doenças , Células Epiteliais/virologia , Feminino , Furões/virologia , Efeito Fundador , Técnicas de Introdução de Genes , Aptidão Genética , Humanos , Masculino , Mesocricetus , Camundongos , Mucosa Nasal/citologia , Mucosa Nasal/virologia , Ligação Proteica , RNA Viral/análise , Receptores de Coronavírus/metabolismo , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidade
4.
J Biol Chem ; 300(5): 107280, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38588810

RESUMO

Evolutionarily conserved structural folds can give rise to diverse biological functions, yet predicting atomic-scale interactions that contribute to the emergence of novel activities within such folds remains challenging. Pancreatic-type ribonucleases illustrate this complexity, sharing a core structure that has evolved to accommodate varied functions. In this study, we used ancestral sequence reconstruction to probe evolutionary and molecular determinants that distinguish biological activities within eosinophil members of the RNase 2/3 subfamily. Our investigation unveils functional, structural, and dynamical behaviors that differentiate the evolved ancestral ribonuclease (AncRNase) from its contemporary eosinophil RNase orthologs. Leveraging the potential of ancestral reconstruction for protein engineering, we used AncRNase predictions to design a minimal 4-residue variant that transforms human RNase 2 into a chimeric enzyme endowed with the antimicrobial and cytotoxic activities of RNase 3 members. This work provides unique insights into mutational and evolutionary pathways governing structure, function, and conformational states within the eosinophil RNase subfamily, offering potential for targeted modulation of RNase-associated functions.


Assuntos
Eosinófilos , Humanos , Sequência de Aminoácidos , Eosinófilos/metabolismo , Eosinófilos/enzimologia , Evolução Molecular , Ribonucleases/metabolismo , Ribonucleases/química , Ribonucleases/genética , Animais , Macaca fascicularis , Filogenia , Modelos Moleculares , Estrutura Terciária de Proteína
5.
PLoS Biol ; 20(11): e3001871, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36383605

RESUMO

Epidemiological data demonstrate that Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) Alpha and Delta are more transmissible, infectious, and pathogenic than previous variants. Phenotypic properties of VOC remain understudied. Here, we provide an extensive functional study of VOC Alpha replication and cell entry phenotypes assisted by reverse genetics, mutational mapping of spike in lentiviral pseudotypes, viral and cellular gene expression studies, and infectivity stability assays in an enhanced range of cell and epithelial culture models. In almost all models, VOC Alpha spread less or equally efficiently as ancestral (B.1) SARS-CoV-2. B.1. and VOC Alpha shared similar susceptibility to serum neutralization. Despite increased relative abundance of specific sgRNAs in the context of VOC Alpha infection, immune gene expression in infected cells did not differ between VOC Alpha and B.1. However, inferior spreading and entry efficiencies of VOC Alpha corresponded to lower abundance of proteolytically cleaved spike products presumably linked to the T716I mutation. In addition, we identified a bronchial cell line, NCI-H1299, which supported 24-fold increased growth of VOC Alpha and is to our knowledge the only cell line to recapitulate the fitness advantage of VOC Alpha compared to B.1. Interestingly, also VOC Delta showed a strong (595-fold) fitness advantage over B.1 in these cells. Comparative analysis of chimeric viruses expressing VOC Alpha spike in the backbone of B.1, and vice versa, showed that the specific replication phenotype of VOC Alpha in NCI-H1299 cells is largely determined by its spike protein. Despite undetectable ACE2 protein expression in NCI-H1299 cells, CRISPR/Cas9 knock-out and antibody-mediated blocking experiments revealed that multicycle spread of B.1 and VOC Alpha required ACE2 expression. Interestingly, entry of VOC Alpha, as opposed to B.1 virions, was largely unaffected by treatment with exogenous trypsin or saliva prior to infection, suggesting enhanced resistance of VOC Alpha spike to premature proteolytic cleavage in the extracellular environment of the human respiratory tract. This property may result in delayed degradation of VOC Alpha particle infectivity in conditions typical of mucosal fluids of the upper respiratory tract that may be recapitulated in NCI-H1299 cells closer than in highly ACE2-expressing cell lines and models. Our study highlights the importance of cell model evaluation and comparison for in-depth characterization of virus variant-specific phenotypes and uncovers a fine-tuned interrelationship between VOC Alpha- and host cell-specific determinants that may underlie the increased and prolonged virus shedding detected in patients infected with VOC Alpha.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Enzima de Conversão de Angiotensina 2/genética , Eliminação de Partículas Virais , Anticorpos Bloqueadores
6.
Chem Rev ; 123(5): 2311-2348, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36354420

RESUMO

The development of efficient and sustainable electrochemical systems able to provide clean-energy fuels and chemicals is one of the main current challenges of materials science and engineering. Over the last decades, significant advances have been made in the development of robust electrocatalysts for different reactions, with fundamental insights from both computational and experimental work. Some of the most promising systems in the literature are based on expensive and scarce platinum-group metals; however, natural enzymes show the highest per-site catalytic activities, while their active sites are based exclusively on earth-abundant metals. Additionally, natural biomass provides a valuable feedstock for producing advanced carbonaceous materials with porous hierarchical structures. Utilizing resources and design inspiration from nature can help create more sustainable and cost-effective strategies for manufacturing cost-effective, sustainable, and robust electrochemical materials and devices. This review spans from materials to device engineering; we initially discuss the design of carbon-based materials with bioinspired features (such as enzyme active sites), the utilization of biomass resources to construct tailored carbon materials, and their activity in aqueous electrocatalysis for water splitting, oxygen reduction, and CO2 reduction. We then delve in the applicability of bioinspired features in electrochemical devices, such as the engineering of bioinspired mass transport and electrode interfaces. Finally, we address remaining challenges, such as the stability of bioinspired active sites or the activity of metal-free carbon materials, and discuss new potential research directions that can open the gates to the implementation of bioinspired sustainable materials in electrochemical devices.

7.
Methods ; 2024 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-39447942

RESUMO

Protein ubiquitination is a critical post-translational modification (PTM) involved in diverse biological processes and plays a pivotal role in regulating physiological mechanisms and disease states. Despite various efforts to develop ubiquitination site prediction tools across species, these tools mainly rely on predefined sequence features and machine learning algorithms, with species-specific variations in ubiquitination patterns remaining poorly understood. This study introduces a novel approach for predicting Arabidopsis thaliana ubiquitination sites using a neural network model based on knowledge distillation and natural language processing (NLP) of protein sequences. Our framework employs a multi-species "Teacher model" to guide a more compact, species-specific "Student model", with the "Teacher" generating pseudo-labels that enhance the "Student" learning and prediction robustness. Cross-validation results demonstrate that our model achieves superior performance, with an accuracy of 86.3 % and an area under the curve (AUC) of 0.926, while independent testing confirmed these results with an accuracy of 86.3 % and an AUC of 0.923. Comparative analysis with established predictors further highlights the model's superiority, emphasizing the effectiveness of integrating knowledge distillation and NLP in ubiquitination prediction tasks. This study presents a promising and efficient approach for ubiquitination site prediction, offering valuable insights for researchers in related fields. The code and resources are available on GitHub: https://github.com/nuinvtnu/KD_ArapUbi.

8.
Nature ; 569(7758): 663-671, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31142858

RESUMO

Type 2 diabetes mellitus (T2D) is a growing health problem, but little is known about its early disease stages, its effects on biological processes or the transition to clinical T2D. To understand the earliest stages of T2D better, we obtained samples from 106 healthy individuals and individuals with prediabetes over approximately four years and performed deep profiling of transcriptomes, metabolomes, cytokines, and proteomes, as well as changes in the microbiome. This rich longitudinal data set revealed many insights: first, healthy profiles are distinct among individuals while displaying diverse patterns of intra- and/or inter-personal variability. Second, extensive host and microbial changes occur during respiratory viral infections and immunization, and immunization triggers potentially protective responses that are distinct from responses to respiratory viral infections. Moreover, during respiratory viral infections, insulin-resistant participants respond differently than insulin-sensitive participants. Third, global co-association analyses among the thousands of profiled molecules reveal specific host-microbe interactions that differ between insulin-resistant and insulin-sensitive individuals. Last, we identified early personal molecular signatures in one individual that preceded the onset of T2D, including the inflammation markers interleukin-1 receptor agonist (IL-1RA) and high-sensitivity C-reactive protein (CRP) paired with xenobiotic-induced immune signalling. Our study reveals insights into pathways and responses that differ between glucose-dysregulated and healthy individuals during health and disease and provides an open-access data resource to enable further research into healthy, prediabetic and T2D states.


Assuntos
Biomarcadores/metabolismo , Biologia Computacional , Diabetes Mellitus Tipo 2/microbiologia , Microbioma Gastrointestinal , Interações entre Hospedeiro e Microrganismos/genética , Estado Pré-Diabético/microbiologia , Proteoma/metabolismo , Transcriptoma , Adulto , Idoso , Antibacterianos/administração & dosagem , Biomarcadores/análise , Estudos de Coortes , Conjuntos de Dados como Assunto , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Glucose/metabolismo , Voluntários Saudáveis , Humanos , Inflamação/metabolismo , Vacinas contra Influenza/imunologia , Insulina/metabolismo , Resistência à Insulina , Estudos Longitudinais , Masculino , Microbiota/fisiologia , Pessoa de Meia-Idade , Estado Pré-Diabético/genética , Estado Pré-Diabético/metabolismo , Infecções Respiratórias/genética , Infecções Respiratórias/metabolismo , Infecções Respiratórias/microbiologia , Infecções Respiratórias/virologia , Estresse Fisiológico , Vacinação/estatística & dados numéricos
9.
J Am Chem Soc ; 146(30): 20972-20981, 2024 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-39041456

RESUMO

Catalyst-free and reversible step-growth Diels-Alder (DA) polymerization has a wide range of applications in polymer synthesis and is a promising method for fabricating recyclable thermoplastics. The effectiveness of polymerization and depolymerization relies on the chemical building blocks, often utilizing furan as the diene and maleimide as the dienophile. Compared to the traditional diene-dienophile or two-component approach that requires precise stoichiometry, cyclopentadiene (Cp) can serve dual roles via self-dimerization. This internally balanced platform offers a route to access high-molecular-weight polymers and a dynamic handle for polymer recycling, which has yet to be explored. Herein, through a reactivity investigation of different telechelic Cp derivatives, the uncontrolled cross-linking of Cp was addressed, revealing the first successful DA homopolymerization. To demonstrate the generality of our methodology, we synthesized and characterized six Cp homopolymers with backbones derived from common thermoplastics, such as poly(dimethylsiloxane), hydrogenated polybutadiene, and ethylene phthalate. Among these materials, the hydrogenated polybutadiene-Cp analog can be thermally depolymerized (Mn = 68 to 23 kDa) and repolymerized to the parent polymer (Mn = 68 kDa) under solvent- and catalyst-free conditions. This process was repeated over three cycles without intermediate purification, confirming the efficient thermo-selective recyclability. The varied degradable properties of the other four Cp-incorporated thermoplastics were also examined. Overall, this work provides a general methodology for accessing a new class of reversible homopolymers, potentially expanding the design and construction of sustainable thermoplastics.

10.
Cancer ; 130(8): 1303-1315, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38103206

RESUMO

BACKGROUND: Understanding cancer treatment-related cardiovascular (CV) events is important for cancer care; however, comprehensive evaluation of CV events in patients with lung cancer is limited. This study aimed to assess the cumulative incidence and associated risks of various CV event types in patients with non-small cell lung cancer (NSCLC). METHODS: A total of 7868 individuals aged 40 years and older, recently diagnosed with NSCLC (2007-2018), were assessed with data obtained from the National Cancer Center, Korea. This study included nine types of CV events. A 2-year cumulative incidence function (CIF) of CV events was estimated, with death as a competing event. The associated risks were assessed by subdistribution hazard ratio (sHR) in the Fine-Gray competing risks model. RESULTS: CV events were observed in 7.8% of patients with NSCLC, with the most frequently observed types being atrial fibrillation and flutter (AF) (2.7%), venous thromboembolic disease (2.0%), and cerebrovascular disease (CeVD) (1.5%). Overall, all CV events were highest in the group treated with systemic therapy (CIF, 10.6%; 95% confidence interval [CI], 9.5%-11.8%), followed by those treated with surgery (CIF, 10.0%; 95% CI, 8.6%-11.6%); the incidence of AF (CIF, 5.7%; 95% CI, 4.6%-7.0%) was highest in patients treated with surgery. Individuals treated with systemic therapy were found to exhibit a higher CeVD risk than those treated with surgery (sHR, 4.12; 95% CI, 1.66-10.23). Among the patients who underwent surgery, those with lobectomy and pneumonectomy had a higher AF risk (vs. wedge resection/segmentectomy; sHR, 7.79; 95% CI, 1.87-32.42; sHR, 8.10; 95% CI, 1.60-40.89). CONCLUSIONS: These findings revealed treatment-related CV event risks in patients with NSCLC, which suggests that the risk of AF in surgery and CeVD in systemic therapy should be paid more attention to achieve a better prognosis and improve cancer survivorship outcomes. PLAIN LANGUAGE SUMMARY: Atrial fibrillation and flutter (AF) is the most common cardiovascular event, particularly at a high risk in patients with non-small cell lung cancer (NSCLC) undergoing surgery. Patients receiving surgery with poor performance status, diagnosed with regional stage, and undergoing lobectomy or pneumonectomy are at a high risk of AF. Systemic/radiotherapy is associated with cerebrovascular and ischemic heart disease in patients with NSCLC.


Assuntos
Fibrilação Atrial , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Adulto , Pessoa de Meia-Idade , Carcinoma Pulmonar de Células não Pequenas/terapia , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/radioterapia , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/cirurgia , Prognóstico , Incidência , Pneumonectomia
11.
Br J Cancer ; 2024 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-39375531

RESUMO

BACKGROUND: Taller women are at an increased risk of breast cancer; however, evidence regarding this in younger women is limited. This study investigated the association between body height and breast cancer risk in premenopausal Korean women aged <40 years. METHODS: Premenopausal women aged <40 years enroled in the Kangbuk Samsung Health Study (KSHS) and National Health Insurance Service-National Health Information Database (NHIS-NHID) were included in the analysis. Trained staff members performed anthropometry, including height measurements. Breast cancer incidence was followed up until December 2019. Cox regression model and restricted cubic- spline regression were applied. RESULTS: The mean (standard deviation [SD]) age was 33.3 (3.6) years and 32.9 (4.2) in KSHS and NHIS-NHID cohorts, respectively. After adjusting for age at baseline and other confounders, every 10 cm of height was associated with a 1.44-fold increased risk of developing breast cancer (adjusted hazard ratio [aHR], 1.44; 95% confidence interval [CI], 1.17-1.78) in the KSHS. The restricted cubic spline regression showed an almost linear association between height and breast cancer risk. Compared to women with height <155 cm, aHRs (95% CI) among those with height 160-165 cm, 165-170 cm, and ≥170 cm were 1.67 (1.07-2.60), 1.75 (1.09-2.81), and 2.31 (1.18-3.86), respectively (P = 0.009). Results were similar in the NHIS-NHID cohort (aHR, 1.20 [95% CI, 1.10-1.31] per 10-cm increase in height). CONCLUSION: In young Korean women, greater body height was associated with increased breast cancer risk.

12.
J Clin Microbiol ; 62(4): e0128723, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38466092

RESUMO

Mortality from tuberculous meningitis (TBM) remains around 30%, with most deaths occurring within 2 months of starting treatment. Mortality from drug-resistant strains is higher still, making early detection of drug resistance (DR) essential. Targeted next-generation sequencing (tNGS) produces high read depths, allowing the detection of DR-associated alleles with low frequencies. We applied Deeplex Myc-TB-a tNGS assay-to cerebrospinal fluid (CSF) samples from 72 adults with microbiologically confirmed TBM and compared its genomic drug susceptibility predictions to a composite reference standard of phenotypic susceptibility testing (pDST) and whole genome sequencing, as well as to clinical outcomes. Deeplex detected Mycobacterium tuberculosis complex DNA in 24/72 (33.3%) CSF samples and generated full DR reports for 22/24 (91.7%). The read depth generated by Deeplex correlated with semi-quantitative results from MTB/RIF Xpert. Alleles with <20% frequency were seen at canonical loci associated with first-line DR. Disregarding these low-frequency alleles, Deeplex had 100% concordance with the composite reference standard for all drugs except pyrazinamide and streptomycin. Three patients had positive CSF cultures after 30 days of treatment; reference tests and Deeplex identified isoniazid resistance in two, and Deeplex alone identified low-frequency rifampin resistance alleles in one. Five patients died, of whom one had pDST-identified pyrazinamide resistance. tNGS on CSF can rapidly and accurately detect drug-resistant TBM, but its application is limited to those with higher bacterial loads. In those with lower bacterial burdens, alternative approaches need to be developed for both diagnosis and resistance detection.


Assuntos
Mycobacterium tuberculosis , Tuberculose Meníngea , Tuberculose Resistente a Múltiplos Medicamentos , Adulto , Humanos , Tuberculose Meníngea/diagnóstico , Tuberculose Meníngea/tratamento farmacológico , Tuberculose Meníngea/líquido cefalorraquidiano , Mycobacterium tuberculosis/genética , Pirazinamida , Sensibilidade e Especificidade , Rifampina/farmacologia , Rifampina/uso terapêutico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Líquido Cefalorraquidiano , Testes de Sensibilidade Microbiana
13.
J Transl Med ; 22(1): 498, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796431

RESUMO

OBJECTIVE: The aim of the present pilot study was to assess the effectiveness of the platelet-rich fibrin (PRF) apical barrier for the placement of MTA for the treatment of teeth with periapical lesions and open apices. METHODS: A total of thirty teeth on twenty-eight patients with open apices and periapical periodontitis were enrolled and divided into two groups in the present pilot study. In the PRF group (fourteen teeth in thirteen patients), nonsurgical endodontic treatment was performed using PRF as an apical matrix, after which the apical plug of the MTA was created. For the non-PRF group (fourteen teeth in fourteen patients), nonsurgical endodontic therapy was performed using only the MTA for an apical plug with no further periapical intervention. Clinical findings and periapical digital radiographs were used for evaluating the healing progress after periodic follow-ups of 1, 3, 6, and 9 months. The horizontal dimension of the periapical lesion was gauged, and the changes in the dimensions were recorded each time. The Friedman test, Dunn-Bonferroni post hoc correction, and Mann-Whitney U test were used for statistical analysis, with P < 0.05 serving as the threshold for determining statistical significance. RESULTS: All patients in both groups in the present pilot study had no clinical symptoms after 1 month, with a significant reduction in the periapical lesion after periodic appointments. The lesion width of the PRF group was significantly smaller than that of the non-PRF group in the sixth and ninth month after treatment. CONCLUSIONS: PRF is a promising apical barrier matrix when combined with MTA for the treatment of teeth with open apices and periapical periodontitis. Small number of study subjects and the short time of follow-up period limit the generalizability of these results. TRIAL REGISTRATION: TCTR, TCTR20221109006. Registered 09 November 2022 - Retrospectively registered, https://www.thaiclinicaltrials.org/show/TCTR20221109006 .


Assuntos
Compostos de Alumínio , Compostos de Cálcio , Fibrina Rica em Plaquetas , Silicatos , Ápice Dentário , Humanos , Projetos Piloto , Fibrina Rica em Plaquetas/metabolismo , Feminino , Masculino , Compostos de Alumínio/uso terapêutico , Silicatos/uso terapêutico , Compostos de Cálcio/uso terapêutico , Adulto , Ápice Dentário/patologia , Ápice Dentário/diagnóstico por imagem , Combinação de Medicamentos , Pessoa de Meia-Idade , Óxidos/uso terapêutico , Periodontite Periapical/terapia , Periodontite Periapical/diagnóstico por imagem
14.
BMC Microbiol ; 24(1): 85, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38468236

RESUMO

Antimicrobial peptides, such as bacteriocin, produced by probiotics have become a promising novel class of therapeutic agents for treating infectious diseases. Selected lactic acid bacteria (LAB) isolated from fermented foods with probiotic potential were evaluated for various tests, including exopolysaccharide production, antibiotic susceptibility, acid and bile tolerance, antibacterial activity, and cell adhesion and cytotoxicity to gastric cell lines. Six selected LAB strains maintained their high viability under gastrointestinal conditions, produced high exopolysaccharides, showed no or less cytotoxicity, and adhered successfully to gastric cells. Furthermore, three strains, Weissella confusa CYLB30, Lactiplantibacillus plantarum CYLB47, and Limosilactobacillus fermentum CYLB55, demonstrated a strong antibacterial effect against drug-resistant Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica serovar Choleraesuis, Enterococcus faecium, and Staphylococcus aureus. Whole genome sequencing was performed on these three strains using the Nanopore platform; then, the results showed that all three strains did not harbor genes related to toxins, superantigens, and acquired antimicrobial resistance, in their genome. The bacteriocin gene cluster was found in CYLB47 genome, but not in CYLB30 and CYLB55 genomes. In SDS-PAGE, the extract of CYLB30 and CYLB47 bacteriocin-like inhibitory substance (BLIS) yielded a single band with a size of less than 10 kDa. These BLIS inhibited the growth and biofilm formation of drug-resistant P. aeruginosa and methicillin-resistant S. aureus (MRSA), causing membrane disruption and inhibiting adhesion ability to human skin HaCaT cells. Moreover, CYLB30 and CYLB47 BLIS rescued the larvae after being infected with P. aeruginosa and MRSA infections. In conclusion, CYLB30 and CYLB47 BLIS may be potential alternative treatment for multidrug-resistant bacteria infections.


Assuntos
Bacteriocinas , Alimentos Fermentados , Lactobacillales , Staphylococcus aureus Resistente à Meticilina , Probióticos , Humanos , Bacteriocinas/metabolismo , Staphylococcus aureus Resistente à Meticilina/metabolismo , Antibacterianos/farmacologia , Antibacterianos/metabolismo , Probióticos/metabolismo
15.
Epilepsia ; 65(8): 2280-2294, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38780375

RESUMO

OBJECTIVE: This study was undertaken to develop and evaluate a machine learning-based algorithm for the detection of focal to bilateral tonic-clonic seizures (FBTCS) using a novel multimodal connected shirt. METHODS: We prospectively recruited patients with epilepsy admitted to our epilepsy monitoring unit and asked them to wear the connected shirt while under simultaneous video-electroencephalographic monitoring. Electrocardiographic (ECG) and accelerometric (ACC) signals recorded with the connected shirt were used for the development of the seizure detection algorithm. First, we used a sliding window to extract linear and nonlinear features from both ECG and ACC signals. Then, we trained an extreme gradient boosting algorithm (XGBoost) to detect FBTCS according to seizure onset and offset annotated by three board-certified epileptologists. Finally, we applied a postprocessing step to regularize the classification output. A patientwise nested cross-validation was implemented to evaluate the performances in terms of sensitivity, false alarm rate (FAR), time in false warning (TiW), detection latency, and receiver operating characteristic area under the curve (ROC-AUC). RESULTS: We recorded 66 FBTCS from 42 patients who wore the connected shirt for a total of 8067 continuous hours. The XGBoost algorithm reached a sensitivity of 84.8% (56/66 seizures), with a median FAR of .55/24 h and a median TiW of 10 s/alarm. ROC-AUC was .90 (95% confidence interval = .88-.91). Median detection latency from the time of progression to the bilateral tonic-clonic phase was 25.5 s. SIGNIFICANCE: The novel connected shirt allowed accurate detection of FBTCS with a low false alarm rate in a hospital setting. Prospective studies in a residential setting with a real-time and online seizure detection algorithm are required to validate the performance and usability of this device.


Assuntos
Algoritmos , Eletroencefalografia , Convulsões , Dispositivos Eletrônicos Vestíveis , Humanos , Masculino , Feminino , Adulto , Eletroencefalografia/métodos , Convulsões/diagnóstico , Convulsões/fisiopatologia , Pessoa de Meia-Idade , Adulto Jovem , Eletrocardiografia/métodos , Estudos Prospectivos , Adolescente , Aprendizado de Máquina , Acelerometria/métodos , Acelerometria/instrumentação , Epilepsia Tônico-Clônica/diagnóstico , Epilepsia Tônico-Clônica/fisiopatologia
16.
Arch Microbiol ; 206(11): 423, 2024 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-39361043

RESUMO

Minor ginsenosides produced by ß-glucosidase are interesting biologically and pharmacologically. In this study, new ginsenoside-hydrolyzing glycosidase from Furfurilactobacillus rossiae DCYL3 was cloned and expressed in Escherichia coli strain BL21. The enzyme converted Rb1 and Gyp XVII into Rd and compound K following the pathways: Rb1→Rd and Gyp XVII→F2→CK, respectively at optimal condition: 40 °C, 15 min, and pH 6.0. Furthermore, we examined the cytotoxicity, NO production, ROS generation, and gene expression of Gynostemma extract (GE) and bioconverted Gynostemma extract (BGE) in vitro against A549 cell lines for human lung cancer and macrophage RAW 264.7 cells for antiinflammation, respectively. As a result, BGE demonstrated significantly greater toxicity than GE against lung cancer at a dose of 500 µg/mL but in normal cells showed lower toxicity. Then, we indicated an enhanced generation of ROS, which may be boosting cancer cell toxicity. By blocking the intrinsic way, BGE increased p53, Bax, Caspase 3, 9, and while Bcl2 is decreased. At 500 µg/mL, the BGE sample was less toxic in normal cells and decreased the LPS-treated NO and ROS level to reduce inflammation. In addition, BGE inhibited the expression of pro-inflammatory genes COX-2, iNOS, IL-6, and IL-8 in RAW 264.7 cells than the sample of GE. In conclusion, FrBGL3 has considerable downstream applications for high-yield, low-cost, effective manufacture of minor ginsenosides. Moreover, the study's findings imply that BGE would be potential materials for anti-cancer and anti-inflammatory agent after consideration of future studies.


•The first time ß-glucosidase (FrBGL3) from Furfurilactobacillus rossiae was identified and characterized.•FrBGL3 activity in ginsenoside and gypenoside bioconversion were found and confirmed.•Application in Gynostemma extract bioconversion by FrBGL3 boosts anti-inflammatory and anti-cancer activities.


Assuntos
beta-Glucosidase , Camundongos , Animais , Humanos , Células RAW 264.7 , Células A549 , beta-Glucosidase/genética , beta-Glucosidase/metabolismo , beta-Glucosidase/química , Clonagem Molecular , Ginsenosídeos/metabolismo , Ginsenosídeos/farmacologia , Escherichia coli/genética , Escherichia coli/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Macrófagos/efeitos dos fármacos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Óxido Nítrico/metabolismo , Clostridiales/genética , Clostridiales/enzimologia , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/metabolismo
17.
Med Mycol ; 62(8)2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39174488

RESUMO

The Trichophyton mentagrophytes complex comprises a group of dermatophyte fungi responsible for various dermatological infections. The increasing drug resistance of this species complex, especially terbinafine resistance of Trichophyton indotineae, is a major concern in dermatologist practice. This study provides a comprehensive analysis of T. mentagrophytes complex strains isolated from patients in Hue City, Vietnam, focusing on their phenotypic and genetic characteristics, antifungal susceptibility profiles, and molecular epidemiology. Keratinophilic fungi from dermatophytosis culture samples were identified morphologically and phenotypically, with species and genotypes confirmed by internal transcribed spacer sequencing and phylogenetic analysis. Antifungal susceptibility testing was carried out to evaluate their susceptibility to itraconazole, voriconazole, and terbinafine. The 24% (n = 27/114) of superficial mycoses were phenotypically attributed to T. mentagrophytes complex isolates. Trichophyton interdigitale, mainly genotype II*, was predominant (44.4%), followed by T. mentagrophytes genotype III* (22.2%), T. indotineae (14.8%), T. tonsurans (11.2%), and T. mentagrophytes (7.4%). While all isolates were susceptible to itraconazole and voriconazole, half of T. indotineae isolates exhibited resistance to terbinafine, linked to the Phe397Leu mutation in the SQLE protein. This study highlighted the presence of terbinafine-resistant T. indotineae isolates in Vietnam, emphasizing the need to investigate dermatophyte drug resistance and implement effective measures in clinical practice.


Species diversity within the Trichophyton mentagrophytes complex isolated from dermatophytosis in Hue City, Vietnam, was observed. Terbinafine-resistant T. indotineae isolates were detected for the first time in Vietnam, emphasizing the importance of implementing antifungal susceptibility testing to effectively manage and prevent the spread of resistant isolates.


Assuntos
Antifúngicos , Farmacorresistência Fúngica , Genótipo , Testes de Sensibilidade Microbiana , Filogenia , Terbinafina , Tinha , Humanos , Vietnã , Antifúngicos/farmacologia , Terbinafina/farmacologia , Tinha/microbiologia , Arthrodermataceae/efeitos dos fármacos , Arthrodermataceae/genética , Arthrodermataceae/classificação , Arthrodermataceae/isolamento & purificação , Masculino , Análise de Sequência de DNA , Itraconazol/farmacologia , DNA Espaçador Ribossômico/genética , Feminino , Pessoa de Meia-Idade , DNA Fúngico/genética , Epidemiologia Molecular , Adulto , Trichophyton
18.
BMC Infect Dis ; 24(1): 622, 2024 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-38910264

RESUMO

BACKGROUND: Respiratory infections have long been recognized as a primary cause of acute exacerbation of chronic obstructive pulmonary disease (AE-COPD). Additionally, the emergence of antimicrobial resistance has led to an urgent and critical situation in developing countries, including Vietnam. This study aimed to investigate the distribution and antimicrobial resistance of bacteria in patients with AE-COPD using both conventional culture and multiplex real-time PCR. Additionally, associations between clinical characteristics and indicators of pneumonia in these patients were examined. METHODS: This cross-sectional prospective study included 92 AE-COPD patients with pneumonia and 46 without pneumonia. Sputum specimens were cultured and examined for bacterial identification, and antimicrobial susceptibility was determined for each isolate. Multiplex real-time PCR was also performed to detect ten bacteria and seven viruses. RESULTS: The detection rates of pathogens in AE-COPD patients with pneumonia were 92.39%, compared to 86.96% in those without pneumonia. A total of 26 pathogenic species were identified, showing no significant difference in distribution between the two groups. The predominant bacteria included Klebsiella pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae, followed by Acinetobacter baumannii and Streptococcus mitis. There was a slight difference in antibiotic resistance between bacteria isolated from two groups. The frequency of H. influenzae was notably greater in AE-COPD patients who experienced respiratory failure (21.92%) than in those who did not (9.23%). S. pneumoniae was more common in patients with stage I (44.44%) or IV (36.36%) COPD than in patients with stage II (17.39%) or III (9.72%) disease. ROC curve analysis revealed that C-reactive protein (CRP) levels could distinguish patients with AE-COPD with and without pneumonia (AUC = 0.78). CONCLUSION: Gram-negative bacteria still play a key role in the etiology of AE-COPD patients, regardless of the presence of pneumonia. This study provides updated evidence for the epidemiology of AE-COPD pathogens and the appropriate selection of antimicrobial agents in Vietnam.


Assuntos
Antibacterianos , Bactérias , Farmacorresistência Bacteriana , Doença Pulmonar Obstrutiva Crônica , Humanos , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/microbiologia , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Estudos Transversais , Vietnã/epidemiologia , Estudos Prospectivos , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias/isolamento & purificação , Bactérias/efeitos dos fármacos , Bactérias/classificação , Bactérias/genética , Pneumonia Bacteriana/microbiologia , Pneumonia Bacteriana/tratamento farmacológico , Pneumonia Bacteriana/epidemiologia , Testes de Sensibilidade Microbiana , Escarro/microbiologia , Idoso de 80 Anos ou mais , Pneumonia/microbiologia , Pneumonia/tratamento farmacológico , Pneumonia/epidemiologia
19.
BMC Infect Dis ; 24(1): 164, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38326753

RESUMO

BACKGROUND: Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, Streptococcus pneumoniae and Staphylococcus aureus are major bacterial causes of lower respiratory tract infections (LRTIs) globally, leading to substantial morbidity and mortality. The rapid increase of antimicrobial resistance (AMR) in these pathogens poses significant challenges for their effective antibiotic therapy. In low-resourced settings, patients with LRTIs are prescribed antibiotics empirically while awaiting several days for culture results. Rapid pathogen and AMR gene detection could prompt optimal antibiotic use and improve outcomes. METHODS: Here, we developed multiplex quantitative real-time PCR using EvaGreen dye and melting curve analysis to rapidly identify six major pathogens and fourteen AMR genes directly from respiratory samples. The reproducibility, linearity, limit of detection (LOD) of real-time PCR assays for pathogen detection were evaluated using DNA control mixes and spiked tracheal aspirate. The performance of RT-PCR assays was subsequently compared with the gold standard, conventional culture on 50 tracheal aspirate and sputum specimens of ICU patients. RESULTS: The sensitivity of RT-PCR assays was 100% for K. pneumoniae, A. baumannii, P. aeruginosa, E. coli and 63.6% for S. aureus and the specificity ranged from 87.5% to 97.6%. The kappa correlation values of all pathogens between the two methods varied from 0.63 to 0.95. The limit of detection of target bacteria was 1600 CFU/ml. The quantitative results from the PCR assays demonstrated 100% concordance with quantitative culture of tracheal aspirates. Compared to culture, PCR assays exhibited higher sensitivity in detecting mixed infections and S. pneumoniae. There was a high level of concordance between the detection of AMR gene and AMR phenotype in single infections. CONCLUSIONS: Our multiplex quantitative RT-PCR assays are fast and simple, but sensitive and specific in detecting six bacterial pathogens of LRTIs and their antimicrobial resistance genes and should be further evaluated for clinical utility.


Assuntos
Antibacterianos , Infecções Respiratórias , Humanos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Escherichia coli/genética , Staphylococcus aureus/genética , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Multiplex/métodos , Farmacorresistência Bacteriana , Bactérias/genética , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/microbiologia , Streptococcus pneumoniae/genética , Klebsiella pneumoniae/genética
20.
J Pept Sci ; 30(6): e3570, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38317283

RESUMO

Chemical pesticides remain the predominant method for pest management in numerous countries. Given the current landscape of agriculture, the development of biopesticides has become increasingly crucial. The strategy empowers farmers to efficiently manage pests and diseases, while prioritizing minimal adverse effects on the environment and human health, hence fostering sustainable management. In recent years, there has been a growing interest and optimism surrounding the utilization of peptide biopesticides for crop protection. These sustainable and environmentally friendly substances have been recognized as viable alternatives to synthetic pesticides due to their outstanding environmental compatibility and efficacy. Numerous studies have been conducted to synthesize and identify peptides that exhibit activity against significant plant pathogens. One of the peptide classes is cyclotides, which are cyclic cysteine-rich peptides renowned for their wide range of sequences and functions. In this review, we conducted a comprehensive analysis of cyclotides, focusing on their structural attributes, developmental history, significant biological functions in crop protection, techniques for identification and investigation, and the application of biotechnology to enhance cyclotide synthesis. The objective is to emphasize the considerable potential of cyclotides as the next generation of plant protection agents on the global scale.


Assuntos
Agricultura , Ciclotídeos , Ciclotídeos/química , Agricultura/métodos , Agentes de Controle Biológico/química , Praguicidas/química , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA