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1.
Cell ; 186(19): 4172-4188.e18, 2023 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-37633267

RESUMO

Selective clearance of organelles, including endoplasmic reticulum (ER) and mitochondria, by autophagy plays an important role in cell health. Here, we describe a developmentally programmed selective ER clearance by autophagy. We show that Parkinson's disease-associated PINK1, as well as Atl, Rtnl1, and Trp1 receptors, regulate ER clearance by autophagy. The E3 ubiquitin ligase Parkin functions downstream of PINK1 and is required for mitochondrial clearance while having the opposite function in ER clearance. By contrast, Keap1 and the E3 ubiquitin ligase Cullin3 function downstream of PINK1 to regulate ER clearance by influencing Rtnl1 and Atl. PINK1 regulates a change in Keap1 localization and Keap1-dependent ubiquitylation of the ER-phagy receptor Rtnl1 to facilitate ER clearance. Thus, PINK1 regulates the selective clearance of ER and mitochondria by influencing the balance of Keap1- and Parkin-dependent ubiquitylation of substrates that determine which organelle is removed by autophagy.


Assuntos
Retículo Endoplasmático , Fator 2 Relacionado a NF-E2 , Retículo Endoplasmático/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch , Proteínas Quinases , Ubiquitina-Proteína Ligases , Drosophila melanogaster , Animais
2.
Nature ; 586(7827): 145-150, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32968273

RESUMO

Natural products serve as chemical blueprints for most antibiotics in clinical use. The evolutionary process by which these molecules arise is inherently accompanied by the co-evolution of resistance mechanisms that shorten the clinical lifetime of any given class of antibiotics1. Virginiamycin acetyltransferase (Vat) enzymes are resistance proteins that provide protection against streptogramins2, potent antibiotics against Gram-positive bacteria that inhibit the bacterial ribosome3. Owing to the challenge of selectively modifying the chemically complex, 23-membered macrocyclic scaffold of group A streptogramins, analogues that overcome the resistance conferred by Vat enzymes have not been previously developed2. Here we report the design, synthesis, and antibacterial evaluation of group A streptogramin antibiotics with extensive structural variability. Using cryo-electron microscopy and forcefield-based refinement, we characterize the binding of eight analogues to the bacterial ribosome at high resolution, revealing binding interactions that extend into the peptidyl tRNA-binding site and towards synergistic binders that occupy the nascent peptide exit tunnel. One of these analogues has excellent activity against several streptogramin-resistant strains of Staphylococcus aureus, exhibits decreased rates of acetylation in vitro, and is effective at lowering bacterial load in a mouse model of infection. Our results demonstrate that the combination of rational design and modular chemical synthesis can revitalize classes of antibiotics that are limited by naturally arising resistance mechanisms.


Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Desenho de Fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Estreptogramina Grupo A/síntese química , Estreptogramina Grupo A/farmacologia , Acetilação/efeitos dos fármacos , Acetiltransferases/genética , Acetiltransferases/metabolismo , Animais , Antibacterianos/classificação , Carga Bacteriana/efeitos dos fármacos , Sítios de Ligação , Microscopia Crioeletrônica , Feminino , Técnicas In Vitro , Camundongos , Testes de Sensibilidade Microbiana , Modelos Moleculares , RNA de Transferência/metabolismo , Ribossomos/efeitos dos fármacos , Ribossomos/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo , Estreptogramina Grupo A/química , Estreptogramina Grupo A/classificação , Virginiamicina/análogos & derivados , Virginiamicina/química , Virginiamicina/metabolismo
3.
Lancet ; 403(10435): 1460-1471, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38554725

RESUMO

BACKGROUND: Afamitresgene autoleucel (afami-cel) showed acceptable safety and promising efficacy in a phase 1 trial (NCT03132922). The aim of this study was to further evaluate the efficacy of afami-cel for the treatment of patients with HLA-A*02 and MAGE-A4-expressing advanced synovial sarcoma or myxoid round cell liposarcoma. METHODS: SPEARHEAD-1 was an open-label, non-randomised, phase 2 trial done across 23 sites in Canada, the USA, and Europe. The trial included three cohorts, of which the main investigational cohort (cohort 1) is reported here. Cohort 1 included patients with HLA-A*02, aged 16-75 years, with metastatic or unresectable synovial sarcoma or myxoid round cell liposarcoma (confirmed by cytogenetics) expressing MAGE-A4, and who had received at least one previous line of anthracycline-containing or ifosfamide-containing chemotherapy. Patients received a single intravenous dose of afami-cel (transduced dose range 1·0 × 109-10·0 × 109 T cells) after lymphodepletion. The primary endpoint was overall response rate in cohort 1, assessed by a masked independent review committee using Response Evaluation Criteria in Solid Tumours (version 1.1) in the modified intention-to-treat population (all patients who received afami-cel). Adverse events, including those of special interest (cytokine release syndrome, prolonged cytopenia, and neurotoxicity), were monitored and are reported for the modified intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT04044768; recruitment is closed and follow-up is ongoing for cohorts 1 and 2, and recruitment is open for cohort 3. FINDINGS: Between Dec 17, 2019, and July 27, 2021, 52 patients with cytogenetically confirmed synovial sarcoma (n=44) and myxoid round cell liposarcoma (n=8) were enrolled and received afami-cel in cohort 1. Patients were heavily pre-treated (median three [IQR two to four] previous lines of systemic therapy). Median follow-up time was 32·6 months (IQR 29·4-36·1). Overall response rate was 37% (19 of 52; 95% CI 24-51) overall, 39% (17 of 44; 24-55) for patients with synovial sarcoma, and 25% (two of eight; 3-65) for patients with myxoid round cell liposarcoma. Cytokine release syndrome occurred in 37 (71%) of 52 of patients (one grade 3 event). Cytopenias were the most common grade 3 or worse adverse events (lymphopenia in 50 [96%], neutropenia 44 [85%], leukopenia 42 [81%] of 52 patients). No treatment-related deaths occurred. INTERPRETATION: Afami-cel treatment resulted in durable responses in heavily pre-treated patients with HLA-A*02 and MAGE-A4-expressing synovial sarcoma. This study shows that T-cell receptor therapy can be used to effectively target solid tumours and provides rationale to expand this approach to other solid malignancies. FUNDING: Adaptimmune.


Assuntos
Anemia , Lipossarcoma Mixoide , Sarcoma Sinovial , Trombocitopenia , Adulto , Humanos , Sarcoma Sinovial/tratamento farmacológico , Sarcoma Sinovial/genética , Lipossarcoma Mixoide/etiologia , Síndrome da Liberação de Citocina/etiologia , Ifosfamida , Trombocitopenia/etiologia , Anemia/etiologia , Antígenos HLA-A , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
4.
J Biol Chem ; 299(11): 105308, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37778730

RESUMO

Nuclear factor kappa B (NF-κB) activity is regulated by various posttranslational modifications, of which Ser276 phosphorylation of RelA/p65 is particularly impacted by reactive oxygen species (ROS). This modification is responsible for selective upregulation of a subset of NF-κB targets; however, the precise mechanism remains elusive. ROS have the ability to modify cellular molecules including DNA. One of the most common oxidation products is 8-oxo-7,8-dihydroguanine (8-oxoGua), which is repaired by the 8-oxoguanine DNA glycosylase1 (OGG1)-initiated base excision repair pathway. Recently, a new function of OGG1 has been uncovered. OGG1 binds to 8-oxoGua, facilitating the occupancy of NF-κB at promoters and enhancing transcription of pro-inflammatory cytokines and chemokines. In the present study, we demonstrated that an interaction between DNA-bound OGG1 and mitogen-and stress-activated kinase 1 is crucial for RelA/p65 Ser276 phosphorylation. ROS scavenging or OGG1 depletion/inhibition hindered the interaction between mitogen-and stress-activated kinase 1 and RelA/p65, thereby decreasing the level of phospho-Ser276 and leading to significantly lowered expression of ROS-responsive cytokine/chemokine genes, but not that of Nfkbis. Blockade of OGG1 binding to DNA also prevented promoter recruitment of RelA/p65, Pol II, and p-RNAP II in a gene-specific manner. Collectively, the data presented offer new insights into how ROS signaling dictates NF-κB phosphorylation codes and how the promoter-situated substrate-bound OGG1 is exploited by aerobic mammalian cells for timely transcriptional activation of ROS-responsive genes.


Assuntos
DNA Glicosilases , NF-kappa B , Animais , DNA/metabolismo , DNA Glicosilases/genética , DNA Glicosilases/metabolismo , Mamíferos/metabolismo , Mitógenos , NF-kappa B/metabolismo , Fosforilação , Espécies Reativas de Oxigênio/metabolismo , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo , Humanos , Camundongos , Linhagem Celular , Camundongos Knockout
5.
J Cell Physiol ; 239(1): 3-19, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38032002

RESUMO

Meiosis is a specialized cell division that occurs in sexually reproducing organisms, generating haploid gametes containing half the chromosome number through two rounds of cell division. Homologous chromosomes pair and prepare for their proper segregation in subsequent divisions. How homologous chromosomes recognize each other and achieve pairing is an important question. Early studies showed that in most organisms, homologous pairing relies on homologous recombination. However, pairing mechanisms differ across species. Evidence indicates that chromosomes are dynamic and move during early meiotic stages, facilitating pairing. Recent studies in various model organisms suggest conserved mechanisms and key regulators of homologous chromosome pairing. This review summarizes these findings and compare similarities and differences in homologous chromosome pairing mechanisms across species.


Assuntos
Pareamento Cromossômico , Segregação de Cromossomos , Meiose , Pareamento Cromossômico/genética , Segregação de Cromossomos/genética , Cromossomos , Recombinação Homóloga , Meiose/genética
6.
J Cell Physiol ; 239(8): e31327, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38801120

RESUMO

Aging leads to an accumulation of cellular mutations and damage, increasing the risk of senescence, apoptosis, and malignant transformation. Cellular senescence, which is pivotal in aging, acts as both a guard against cellular transformation and as a check against cancer progression. It is marked by stable cell cycle arrest, widespread macromolecular changes, a pro-inflammatory profile, and altered gene expression. However, it remains to be determined whether these differing subsets of senescent cells result from unique intrinsic programs or are influenced by their environmental contexts. Multiple transcription regulators and chromatin modifiers contribute to these alterations. Special AT-rich sequence-binding protein 1 (SATB1) stands out as a crucial regulator in this process, orchestrating gene expression by structuring chromatin into loop domains and anchoring DNA elements. This review provides an overview of cellular senescence and delves into the role of SATB1 in senescence-related diseases. It highlights SATB1's potential in developing antiaging and anticancer strategies, potentially contributing to improved quality of life and addressing aging-related diseases.


Assuntos
Senescência Celular , Proteínas de Ligação à Região de Interação com a Matriz , Humanos , Senescência Celular/genética , Proteínas de Ligação à Região de Interação com a Matriz/metabolismo , Proteínas de Ligação à Região de Interação com a Matriz/genética , Envelhecimento/genética , Envelhecimento/patologia , Envelhecimento/metabolismo , Animais , Neoplasias/genética , Neoplasias/patologia , Neoplasias/metabolismo , Cromatina/metabolismo , Cromatina/genética
7.
Anal Chem ; 96(40): 16036-16044, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39342508

RESUMO

Engineering an elaborate nanotheranostic platform that can achieve spatiotemporally selective microRNA (miRNA) imaging and imaging-guided therapy in time is critical for precise cancer diagnosis and efficient treatment, yet remains a challenge. Herein, we present an on-site-activatable nanotheranostic platform (Ti3C2-NEDR) that engineers a photothermal-activated entropy-driven strand displacement reaction (NEDR) module on a photothermal conversion module (Ti3C2) for achieving spatiotemporally controlled miRNA-21 imaging in vivo and imaging-guided photothermal therapy only by varying the power of the near-infrared (NIR) laser. The upstream NIR photothermal conversion module, Ti3C2, can act not only as a DNA circuit carrier to deliver the NEDR module but also as a photothermal agent to activate the downstream NEDR module in low-power NIR laser irradiation. Once the NEDR module is activated by the NIR laser, the entropy-driven strand displacement reaction can be innated by intracellular miRNA-21 to generate an amplified fluorescence signal for the spatiotemporally selective imaging of miRNA-21 in vivo. Thereafter, the imaging-guided in vivo photothermal therapy can be achieved in time only by switching to the high-power NIR laser. It is envisioned that this strategy of NIR light-activated spatiotemporally selective miRNA imaging and imaging-guided on-demand therapy may expand the nanotheranostic platform for precise cancer diagnosis and personalized therapy in time, providing a remarkable prospect in biomedical diagnosis and therapy.


Assuntos
DNA , Entropia , MicroRNAs , Terapia Fototérmica , Titânio , MicroRNAs/metabolismo , MicroRNAs/genética , Animais , Humanos , Camundongos , Titânio/química , DNA/química , Camundongos Nus , Imagem Óptica , Raios Infravermelhos , Camundongos Endogâmicos BALB C , Nanomedicina Teranóstica , Feminino , Nanopartículas/química
8.
Small ; 20(19): e2309230, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38112271

RESUMO

Bone infection poses a major clinical challenge that can hinder patient recovery and exacerbate postoperative complications. This study has developed a bioactive composite scaffold through the co-assembly and intrafibrillar mineralization of collagen fibrils and zinc oxide (ZnO) nanowires (IMC/ZnO). The IMC/ZnO exhibits bone-like hierarchical structures and enhances capabilities for osteogenesis, antibacterial activity, and bacteria-infected bone healing. During co-cultivation with human bone marrow mesenchymal stem cells (BMMSCs), the IMC/ZnO improves BMMSC adhesion, proliferation, and osteogenic differentiation even under inflammatory conditions. Moreover, it suppresses the activity of Gram-negative Porphyromonas gingivalis and Gram-positive Streptococcus mutans by releasing zinc ions within the acidic infectious microenvironment. In vivo, the IMC/ZnO enables near-complete healing of infected bone defects within the intricate oral bacterial milieu, which is attributed to IMC/ZnO orchestrating M2 macrophage polarization, and fostering an osteogenic and anti-inflammatory microenvironment. Overall, these findings demonstrate the promise of the bioactive scaffold IMC/ZnO for treating bacteria-infected bone defects.


Assuntos
Regeneração Óssea , Colágeno , Células-Tronco Mesenquimais , Nanofios , Osteogênese , Alicerces Teciduais , Óxido de Zinco , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Nanofios/química , Regeneração Óssea/efeitos dos fármacos , Alicerces Teciduais/química , Humanos , Colágeno/química , Células-Tronco Mesenquimais/citologia , Osteogênese/efeitos dos fármacos , Animais , Porphyromonas gingivalis/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Streptococcus mutans/fisiologia , Streptococcus mutans/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos
9.
Opt Lett ; 49(11): 3066-3069, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38824329

RESUMO

We present a space-angle dual multiplexing holographic recording system for realizing single-exposure multi-wavelength optical diffraction tomographic (ODT) imaging. This system is achieved by combining the principle of single-exposure multi-wavelength holographic imaging technique based on angle-division multiplexing with the principle of single-exposure ODT imaging technique based on microlens array multi-angle illuminations and space-division multiplexing. Compared with the existing multi-wavelength ODT imaging methods, it enables the holographic recording of all the diffraction tomography information of a measured specimen at multiple illumination wavelengths in a single camera exposure without any scan mechanism. Using our proposed data processing method, the multi-wavelength three-dimensional (3D) refractive index tomograms of a specimen can be eventually reconstructed from single recorded multiplexing hologram. Experimental results of a static polystyrene bead and a living C. elegans worm demonstrate the feasibility of this system.

10.
J Org Chem ; 89(20): 14650-14657, 2024 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-38720168

RESUMO

Tracking carboxylesterases (CESs) through noninvasive and dynamic imaging is of great significance for diagnosing and treating CES-related metabolic diseases. Herein, three BODIPY-based fluorescent probes with a pyridine unit quaternarized via an acetoxybenzyl group were designed and synthesized to detect CESs based on the photoinduced electron transfer process. Notably, among these probes, BDPN2-CES exhibited a remarkable 182-fold fluorescence enhancement for CESs within 10 min. Moreover, BDPN2-CES successfully enabled real-time imaging of endogenous CES variations in living cells. Using BDPN2-CES, a visual high-throughput screening method for CES inhibitors was established, culminating in the discovery of an efficient inhibitor, WZU-13, sourced from a chemical library. These findings suggest that BDPN2-CES could provide a new avenue for diagnosing CES-related diseases, and WZU-13 emerges as a promising therapeutic candidate for CES-overexpression pathological processes.


Assuntos
Compostos de Boro , Carboxilesterase , Inibidores Enzimáticos , Corantes Fluorescentes , Ensaios de Triagem em Larga Escala , Humanos , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Ensaios de Triagem em Larga Escala/métodos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/síntese química , Compostos de Boro/química , Compostos de Boro/farmacologia , Carboxilesterase/antagonistas & inibidores , Carboxilesterase/metabolismo , Carboxilesterase/análise , Desenho de Fármacos , Estrutura Molecular
11.
Physiol Plant ; 176(4): e14407, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38973613

RESUMO

Despite the abundance of species with transcriptomic data, a significant number of species still lack sequenced genomes, making it difficult to study gene function and expression in these organisms. While de novo transcriptome assembly can be used to assemble protein-coding transcripts from RNA-sequencing (RNA-seq) data, the datasets used often only feature samples of arbitrarily selected or similar experimental conditions, which might fail to capture condition-specific transcripts. We developed the Large-Scale Transcriptome Assembly Pipeline for de novo assembled transcripts (LSTrAP-denovo) to automatically generate transcriptome atlases of eukaryotic species. Specifically, given an NCBI TaxID, LSTrAP-denovo can (1) filter undesirable RNA-seq accessions based on read data, (2) select RNA-seq accessions via unsupervised machine learning to construct a sample-balanced dataset for download, (3) assemble transcripts via over-assembly, (4) functionally annotate coding sequences (CDS) from assembled transcripts and (5) generate transcriptome atlases in the form of expression matrices for downstream transcriptomic analyses. LSTrAP-denovo is easy to implement, written in Python, and is freely available at https://github.com/pengkenlim/LSTrAP-denovo/.


Assuntos
Eucariotos , Transcriptoma , Transcriptoma/genética , Eucariotos/genética , Software , Perfilação da Expressão Gênica/métodos , Análise de Sequência de RNA/métodos
12.
Ecotoxicol Environ Saf ; 286: 117237, 2024 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-39447297

RESUMO

Micro/nanoplastics (MNPs) and heavy metals (HMs) coexist worldwide. Existing studies have reported different or even contradictory toxic effects of co-exposure to MNPs and HMs on plants, which may be related to various influencing factors. In this study, existing publications were searched and analyzed using CiteSpace, meta-analysis, and machine learning. CiteSpace analysis showed that this research field was still in the nascent stage, and hotspots in this field included accumulation, cadmium (Cd), growth, and combined toxicity. Meta-analysis revealed the differential association of seven influencing factors (MNP size, pollutant treatment duration, cultivation media, plant species, MNP type, HM concentration, and MNP concentration) and 8 physiological parameters receiving the most attention. Co-exposure of the two contaminants had stronger toxic effects than HM treatment alone, and phytotoxicity was generally enhanced with increasing concentrations and longer exposure durations, especially when using nanoparticles, hydroponic medium, dicotyledons producing stronger toxic effects than microplastics, soil-based medium, and monocotyledons. Dry and fresh weight analysis showed that co-exposure to MNPs and Cd resulted in significant phytotoxicity in all classifications. Concerning the MNP types, polyolefins partially attenuated plant toxicity, but both modified polystyrene (PS) and biodegradable polymers exacerbated joint phytotoxicity. Finally, machine learning was used to fit and predict plant HM concentrations, showing five classifications with an accuracy over 80 %, implying that the polynomial regression model could be used to predict HM content in plants under complex pollution conditions. Overall, this study identifies current knowledge gaps and provides guidance for future research.

13.
Ecotoxicol Environ Saf ; 271: 116002, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38277972

RESUMO

Propylene glycol (PG) and vegetable glycerin (VG) are the most common solvents used in electronic cigarette liquids. No long-term inhalation toxicity assessments have been performed combining conventional and multi-omics approaches on the potential respiratory effects of the solvents in vivo. In this study, the systemic toxicity of aerosol generated from a ceramic heating coil-based e-cigarette was evaluated. First, the aerosol properties were characterized, including carbonyl emissions, the particle size distribution, and aerosol temperatures. To determine toxicological effects, rats were exposed, through their nose only, to filtered air or a propylene glycol (PG)/ glycerin (VG) (50:50, %W/W) aerosol mixture at the target concentration of 3 mg/L for six hours daily over a continuous 28-day period. Compared with the air group, female rats in the PG/VG group exhibited significantly lower body weights during both the exposure period and recovery period, and this was linked to a reduced food intake. Male rats in the PG/VG group also experienced a significant decline in body weight during the exposure period. Importantly, rats exposed to the PG/VG aerosol showed only minimal biological effects compared to those with only air exposure, with no signs of toxicity. Moreover, the transcriptomic, proteomic, and metabolomic analyses of the rat lung tissues following aerosol exposure revealed a series of candidate pathways linking aerosol inhalation to altered lung functions, especially the inflammatory response and disease. Dysregulated pathways of arachidonic acids, the neuroactive ligand-receptor interaction, and the hematopoietic cell lineage were revealed through integrated multi-omics analysis. Therefore, our integrated multi-omics approach offers novel systemic insights and early evidence of environmental-related health hazards associated with an e-cigarette aerosol using two carrier solvents in a rat model.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Glicerol , Masculino , Feminino , Ratos , Animais , Glicerol/toxicidade , Glicerol/análise , Verduras , Multiômica , Proteômica , Propilenoglicol/toxicidade , Propilenoglicol/análise , Solventes , Aerossóis/análise
14.
J Appl Clin Med Phys ; 25(8): e14376, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38695849

RESUMO

PURPOSE: To propose a straightforward and time-efficient quality assurance (QA) approach of beam time delay for respiratory-gated radiotherapy and validate the proposed method on typical respiratory gating systems, Catalyst™ and AlignRT™. METHODS: The QA apparatus was composed of a motion platform and a Winston-Lutz cube phantom (WL3) embedded with metal balls. The apparatus was first scanned in CT-Sim and two types of QA plans specific for beam on and beam off time delay, respectively, were designed. Static reference images and motion testing images of the WL3 cube were acquired with EPID. By comparing the position differences of the embedded metal balls in the motion and reference images, beam time delays were determined. The proposed approach was validated on three linacs with either Catalyst™ or AlignRT™ respiratory gating systems. To investigate the impact of energy and dose rate on beam time delay, a range of QA plans with Eclipse (V15.7) were devised with varying energy and dose rates. RESULTS: For all energies, the beam on time delays in AlignRT™ V6.3.226, AlignRT™ V7.1.1, and Catalyst™ were 92.13 ± $ \pm $ 5.79 ms, 123.11 ± $ \pm $ 6.44 ms, and 303.44 ± $ \pm $ 4.28 ms, respectively. The beam off time delays in AlignRT™ V6.3.226, AlignRT™ V7.1.1, and Catalyst™ were 121.87 ± $ \pm $ 1.34 ms, 119.33 ± $ \pm $ 0.75 ms, and 97.69 ± $ \pm $ 2.02 ms, respectively. Furthermore, the beam on delays decreased slightly as dose rates increased for all gating systems, whereas the beam off delays remained unaffected. CONCLUSIONS: The validation results demonstrate the proposed QA approach of beam time delay for respiratory-gated radiotherapy was both reproducible and time-efficient to practice for institutions to customize accordingly.


Assuntos
Imagens de Fantasmas , Garantia da Qualidade dos Cuidados de Saúde , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada , Humanos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Garantia da Qualidade dos Cuidados de Saúde/normas , Aceleradores de Partículas/instrumentação , Respiração , Técnicas de Imagem de Sincronização Respiratória/métodos , Neoplasias/radioterapia , Fatores de Tempo
15.
J Appl Clin Med Phys ; : e14552, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39406255

RESUMO

PURPOSE: To develop and implement a fully automatic iterative planning (AIP) system in the clinical practice, generating volumetric-modulated arc therapy plans combined with simultaneous integrated boost technique VMAT (SIB-VMAT) for locally advanced rectal cancer (LARC) patients. METHOD: The designed AIP system aimed to automate the entire planning process through a web-based service, including auxiliary structure generation, plan creation, field configuration, plan optimization, dose calculation, and plan assessment. The system was implemented based on the Eclipse scripting application programming interface and an efficient iterative optimization algorithm was proposed to reduce the required iterations in the optimization process. To verify the performance of the implemented AIP system, we retrospectively selected a total of 106 patients and performed dosimetric comparisons between the automatic plans (APs) and the manual plans (MPs), in terms of dose-volume histogram (DVH) metrics, homogeneity index (HI), and conformity index (CI) for different volumes of interest. RESULT: The AIP system has successfully created 106 APs within clinically acceptable timeframes. The average planning time per case was 36.8 ± 6.5 min, with an average iteration number of 6.8 (±1.1) in plan optimization. Compared to MPs, APs exhibited better performance in the planning target volume conformity and hotspot control ( p < 0.001 $p < 0.001$ ). The organs at risk (OARs) sparing was significantly improved in APs, with mean dose reductions in the femoral heads, the bone marrow, and the SmallBowel-Avoid of 0.53 Gy, 1.18 Gy, and 1.00 Gy, respectively ( p < 0.001 $p < 0.001$ ). Slight improvement was also observed in the urinary bladder V 40 Gy ${{V}_{40{\mathrm{\ Gy}}}}$ and the small bowel D 2 cc ( p < 0.001 ) ${{D}_{2{\mathrm{\ cc}}}}\ (p < 0.001)$ . Additionally, quality variation between plans from different planners was observed in DVH metrics while the APs represented better plan quality consistency. CONCLUSION: An AIP system has been implemented and integrated into the clinical treatment planning workflow. The AIP-generated SIB-VMAT plans for LARC have demonstrated superior plan quality and consistency compared with the manual counterparts. In the meantime, the planning time has been reduced by the AIP approach. Based on the reported results, the implemented AIP framework has been proven to improve plan quality and planning efficiency, liberating planners from the laborious parameter-tuning in the optimization phase.

16.
Can Fam Physician ; 70(10): e156-e168, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39406418

RESUMO

OBJECTIVE: To describe family physicians who primarily practise in a walk-in clinic setting and compare them with family physicians who provide longitudinal care. DESIGN: A cross-sectional study that linked results from a 2019 physician survey to provincial administrative health care data in Ontario. The characteristics, practice patterns, and patients of physicians primarily working in a walk-in clinic setting were compared with those of family physicians providing longitudinal care. SETTING: Ontario. PARTICIPANTS: Physicians who primarily worked in a walk-in clinic setting in 2019, as indicated by an annual physician survey. MAIN OUTCOME MEASURES: Physician demographic and practice characteristics, as well as their patients' demographic and health care utilization characteristics, were reported according to whether the physician was a walk-in clinic physician or a family physician who provided longitudinal care. RESULTS: Compared with the 9137 family physicians providing longitudinal care, the 597 physicians who self-identified as practising primarily in walk-in clinics were more frequently male (67% vs 49%) and more likely to speak a language other than English or French (43% vs 32%). Walk-in clinic physicians tended to have more encounters with patients who were younger (mean 37 vs 47 years), who had lower levels of prior health care utilization (15% vs 19% in highest band), who resided in large urban areas (87% vs 77%), and who lived in highly ethnically diverse neighbourhoods (45% vs 35%). Walk-in clinic physicians tended to have more encounters with unattached patients (33% vs 17%) and with patients attached to another physician outside their group (54% vs 18%). CONCLUSION: Physicians who primarily work in walk-in clinics saw many patients from historically underserved groups and many patients who were attached to another family physician.


Assuntos
Médicos de Família , Humanos , Ontário , Estudos Transversais , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Médicos de Família/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Instituições de Assistência Ambulatorial/estatística & dados numéricos , Medicina de Família e Comunidade/estatística & dados numéricos , Inquéritos e Questionários , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos
17.
J Cell Physiol ; 238(9): 2147-2160, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37475648

RESUMO

Repair of orthodontic external root resorption and periodontal tissue dysfunction induced by mechanical force remains a clinical challenge. Cementoblasts are vital in cementum mineralization, a process important for restoring damaged cementum. Despite autophagy plays a role in mineralization under various environmental stimuli, the underlying mechanism of autophagy in mediating cementoblast mineralization remains unclear. Here we verified that murine cementoblasts exhibit compromised mineralization under compressive force. Autophagy was indispensable for cementoblast mineralization, and autophagic activation markedly reversed cementoblast mineralization and prevented cementum damage in mice during tooth movement. Subsequently, messenger RNA sequencing analyses identified periostin (Postn) as a mediator of autophagy and mineralization in cementoblasts. Cementoblast mineralization was significantly inhibited following the knockdown of Postn. Furthermore, Postn silencing suppressed Wnt signaling by modulating the stability of ß-catenin. Together our results highlight the role of autophagy in cementoblast mineralization via Postn/ß-catenin signaling under compressive force and may provide a new strategy for the remineralization of cementum and regeneration of periodontal tissue.


Assuntos
Autofagia , Calcificação Fisiológica , Moléculas de Adesão Celular , Cemento Dentário , beta Catenina , Animais , Camundongos , beta Catenina/metabolismo , Diferenciação Celular , Linhagem Celular , Cemento Dentário/fisiologia , Via de Sinalização Wnt , Moléculas de Adesão Celular/metabolismo , Força Compressiva
18.
EMBO Rep ; 22(8): e52032, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34105235

RESUMO

The immune system plays a major role in the protection against cancer. Identifying and characterizing the pathways mediating this immune surveillance are thus critical for understanding how cancer cells are recognized and eliminated. Aneuploidy is a hallmark of cancer, and we previously found that untransformed cells that had undergone senescence due to highly abnormal karyotypes are eliminated by natural killer (NK) cells in vitro. However, the mechanisms underlying this process remained elusive. Here, using an in vitro NK cell killing system, we show that non-cell-autonomous mechanisms in aneuploid cells predominantly mediate their clearance by NK cells. Our data indicate that in untransformed aneuploid cells, NF-κB signaling upregulation is central to elicit this immune response. Inactivating NF-κB abolishes NK cell-mediated clearance of untransformed aneuploid cells. In cancer cell lines, NF-κB upregulation also correlates with the degree of aneuploidy. However, such upregulation in cancer cells is not sufficient to trigger NK cell-mediated clearance, suggesting that additional mechanisms might be at play during cancer evolution to counteract NF-κB-mediated immunogenicity.


Assuntos
Células Matadoras Naturais , NF-kappa B , Aneuploidia , Senescência Celular/genética , Humanos , NF-kappa B/genética , NF-kappa B/metabolismo , Transdução de Sinais
19.
Cell Mol Life Sci ; 79(1): 60, 2022 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-35000037

RESUMO

Parthanatos is a form of regulated cell death involved in the pathogenesis of many diseases, particularly neurodegenerative disorders, such as Parkinson's disease, Alzheimer's disease, Huntington's disease, and amyotrophic lateral sclerosis. Parthanatos is a multistep cell death pathway cascade that involves poly (ADP-ribose) polymerase 1 (PARP-1) overactivation, PAR accumulation, PAR binding to apoptosis-inducing factor (AIF), AIF release from the mitochondria, nuclear translocation of the AIF/macrophage migration inhibitory factor (MIF) complex, and MIF-mediated large-scale DNA fragmentation. All the key players in the parthanatos pathway are pleiotropic proteins with diverse functions. An in-depth understanding of the structure-based activity of the key factors, and the biochemical mechanisms of parthanatos, is crucial for the development of drugs and therapeutic strategies. In this review, we delve into the key players of the parthanatos pathway and reveal the multiple levels of therapeutic opportunities for treating parthanatos-based pathogenesis.


Assuntos
Fragmentação do DNA , Oxirredutases Intramoleculares/metabolismo , Fatores Inibidores da Migração de Macrófagos/metabolismo , Doenças Neurodegenerativas/patologia , Parthanatos/fisiologia , Poli(ADP-Ribose) Polimerase-1/metabolismo , Transporte Ativo do Núcleo Celular/fisiologia , Fator de Indução de Apoptose/metabolismo , Humanos , Mitocôndrias/metabolismo , Doenças Neurodegenerativas/tratamento farmacológico , Poli Adenosina Difosfato Ribose/metabolismo
20.
Sensors (Basel) ; 23(3)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36772143

RESUMO

Graph neural networks have been widely used by multivariate time series-based anomaly detection algorithms to model the dependencies of system sensors. Previous studies have focused on learning the fixed dependency patterns between sensors. However, they ignore that the inter-sensor and temporal dependencies of time series are highly nonlinear and dynamic, leading to inevitable false alarms. In this paper, we propose a novel disentangled dynamic deviation transformer network (D3TN) for anomaly detection of multivariate time series, which jointly exploits multiscale dynamic inter-sensor dependencies and long-term temporal dependencies to improve the accuracy of multivariate time series prediction. Specifically, to disentangle the multiscale graph convolution, we design a novel disentangled multiscale aggregation scheme to better represent the hidden dependencies between sensors to learn fixed inter-sensor dependencies based on static topology. To capture dynamic inter-sensor dependencies determined by real-time monitoring situations and unexpected anomalies, we introduce a self-attention mechanism to model dynamic directed interactions in various potential subspaces influenced by various factors. In addition, complex temporal correlations across multiple time steps are simulated by processing the time series in parallel. Experiments on three real datasets show that the proposed D3TN significantly outperforms the state-of-the-art methods.

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