Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.451
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 184(9): 2412-2429.e16, 2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-33852913

RESUMO

Cellular versatility depends on accurate trafficking of diverse proteins to their organellar destinations. For the secretory pathway (followed by approximately 30% of all proteins), the physical nature of the vessel conducting the first portage (endoplasmic reticulum [ER] to Golgi apparatus) is unclear. We provide a dynamic 3D view of early secretory compartments in mammalian cells with isotropic resolution and precise protein localization using whole-cell, focused ion beam scanning electron microscopy with cryo-structured illumination microscopy and live-cell synchronized cargo release approaches. Rather than vesicles alone, the ER spawns an elaborate, interwoven tubular network of contiguous lipid bilayers (ER exit site) for protein export. This receptacle is capable of extending microns along microtubules while still connected to the ER by a thin neck. COPII localizes to this neck region and dynamically regulates cargo entry from the ER, while COPI acts more distally, escorting the detached, accelerating tubular entity on its way to joining the Golgi apparatus through microtubule-directed movement.


Assuntos
Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Microtúbulos/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Transporte Biológico Ativo , Células HeLa , Humanos , Transporte Proteico
2.
Cell ; 177(6): 1522-1535.e14, 2019 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-31130380

RESUMO

Metabolic coordination between neurons and astrocytes is critical for the health of the brain. However, neuron-astrocyte coupling of lipid metabolism, particularly in response to neural activity, remains largely uncharacterized. Here, we demonstrate that toxic fatty acids (FAs) produced in hyperactive neurons are transferred to astrocytic lipid droplets by ApoE-positive lipid particles. Astrocytes consume the FAs stored in lipid droplets via mitochondrial ß-oxidation in response to neuronal activity and turn on a detoxification gene expression program. Our findings reveal that FA metabolism is coupled in neurons and astrocytes to protect neurons from FA toxicity during periods of enhanced activity. This coordinated mechanism for metabolizing FAs could underlie both homeostasis and a variety of disease states of the brain.


Assuntos
Astrócitos/metabolismo , Ácidos Graxos/metabolismo , Neurônios/metabolismo , Animais , Apolipoproteínas E/metabolismo , Apolipoproteínas E/fisiologia , Astrócitos/fisiologia , Encéfalo/metabolismo , Ácidos Graxos/toxicidade , Homeostase , Gotículas Lipídicas/metabolismo , Metabolismo dos Lipídeos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Oxirredução , Ratos , Ratos Sprague-Dawley
3.
Mol Cell ; 84(7): 1338-1353.e8, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38503284

RESUMO

MCL-1 is essential for promoting the survival of many normal cell lineages and confers survival and chemoresistance in cancer. Beyond apoptosis regulation, MCL-1 has been linked to modulating mitochondrial metabolism, but the mechanism(s) by which it does so are unclear. Here, we show in tissues and cells that MCL-1 supports essential steps in long-chain (but not short-chain) fatty acid ß-oxidation (FAO) through its binding to specific long-chain acyl-coenzyme A (CoA) synthetases of the ACSL family. ACSL1 binds to the BH3-binding hydrophobic groove of MCL-1 through a non-conventional BH3-domain. Perturbation of this interaction, via genetic loss of Mcl1, mutagenesis, or use of selective BH3-mimetic MCL-1 inhibitors, represses long-chain FAO in cells and in mouse livers and hearts. Our findings reveal how anti-apoptotic MCL-1 facilitates mitochondrial metabolism and indicate that disruption of this function may be associated with unanticipated cardiac toxicities of MCL-1 inhibitors in clinical trials.


Assuntos
Ácidos Graxos , Mitocôndrias , Animais , Camundongos , Apoptose , Coenzima A Ligases/genética , Ácidos Graxos/metabolismo , Mitocôndrias/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Oxirredução
4.
Cell ; 160(4): 595-606, 2015 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-25640239

RESUMO

Functional micropeptides can be concealed within RNAs that appear to be noncoding. We discovered a conserved micropeptide, which we named myoregulin (MLN), encoded by a skeletal muscle-specific RNA annotated as a putative long noncoding RNA. MLN shares structural and functional similarity with phospholamban (PLN) and sarcolipin (SLN), which inhibit SERCA, the membrane pump that controls muscle relaxation by regulating Ca(2+) uptake into the sarcoplasmic reticulum (SR). MLN interacts directly with SERCA and impedes Ca(2+) uptake into the SR. In contrast to PLN and SLN, which are expressed in cardiac and slow skeletal muscle in mice, MLN is robustly expressed in all skeletal muscle. Genetic deletion of MLN in mice enhances Ca(2+) handling in skeletal muscle and improves exercise performance. These findings identify MLN as an important regulator of skeletal muscle physiology and highlight the possibility that additional micropeptides are encoded in the many RNAs currently annotated as noncoding.


Assuntos
Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , RNA Longo não Codificante/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Humanos , Masculino , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Proteínas Musculares/química , Músculo Esquelético/citologia , Miocárdio/metabolismo , Estrutura Secundária de Proteína , Proteolipídeos/metabolismo , RNA Longo não Codificante/metabolismo , Retículo Sarcoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Alinhamento de Sequência
5.
Nature ; 623(7989): 1086-1092, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37914936

RESUMO

Monoamine neurotransmitters such as dopamine and serotonin control important brain pathways, including movement, sleep, reward and mood1. Dysfunction of monoaminergic circuits has been implicated in various neurodegenerative and neuropsychiatric disorders2. Vesicular monoamine transporters (VMATs) pack monoamines into vesicles for synaptic release and are essential to neurotransmission3-5. VMATs are also therapeutic drug targets for a number of different conditions6-9. Despite the importance of these transporters, the mechanisms of substrate transport and drug inhibition of VMATs have remained elusive. Here we report cryo-electron microscopy structures of the human vesicular monoamine transporter VMAT2 in complex with the antichorea drug tetrabenazine, the antihypertensive drug reserpine or the substrate serotonin. Remarkably, the two drugs use completely distinct inhibition mechanisms. Tetrabenazine binds VMAT2 in a lumen-facing conformation, locking the luminal gating lid in an occluded state to arrest the transport cycle. By contrast, reserpine binds in a cytoplasm-facing conformation, expanding the vestibule and blocking substrate access. Structural analyses of VMAT2 also reveal the conformational changes following transporter isomerization that drive substrate transport into the vesicle. These findings provide a structural framework for understanding the physiology and pharmacology of neurotransmitter packaging by synaptic vesicular transporters.


Assuntos
Neurotransmissores , Reserpina , Serotonina , Tetrabenazina , Proteínas Vesiculares de Transporte de Monoamina , Humanos , Inibidores da Captação Adrenérgica/química , Inibidores da Captação Adrenérgica/farmacologia , Transporte Biológico/efeitos dos fármacos , Microscopia Crioeletrônica , Neurotransmissores/química , Neurotransmissores/farmacologia , Reserpina/química , Reserpina/farmacologia , Serotonina/metabolismo , Transmissão Sináptica , Tetrabenazina/química , Tetrabenazina/farmacologia , Proteínas Vesiculares de Transporte de Monoamina/antagonistas & inibidores , Proteínas Vesiculares de Transporte de Monoamina/química , Proteínas Vesiculares de Transporte de Monoamina/metabolismo , Proteínas Vesiculares de Transporte de Monoamina/ultraestrutura , Especificidade por Substrato/efeitos dos fármacos
6.
Cell ; 148(4): 690-701, 2012 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-22341442

RESUMO

Lengthy trinucleotide repeats encoding polyglutamine (polyQ) stretches characterize the variant proteins of Huntington's disease and certain other inherited neurological disorders. Using a phenotypic screen to identify events that restore functionality to polyQ proteins in S. cerevisiae, we discovered that transcription elongation factor Spt4 is required to transcribe long trinucleotide repeats located either in ORFs or nonprotein-coding regions of DNA templates. Mutation of SPT4 selectively decreased synthesis of and restored enzymatic activity to expanded polyQ protein without affecting protein lacking long-polyQ stretches. RNA-seq analysis revealed limited effects of Spt4 on overall gene expression. Inhibition of Supt4h, the mammalian ortholog of Spt4, reduced mutant huntingtin protein in neuronal cells and decreased its aggregation and toxicity while not altering overall cellular mRNA synthesis. Our findings identify a cellular mechanism for transcription through repeated trinucleotides and a potential target for countermeasures against neurological disorders attributable to expanded trinucleotide regions.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Neurônios/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Transcrição Gênica , Fatores de Elongação da Transcrição/metabolismo , Repetições de Trinucleotídeos , Animais , Linhagem Celular , Expressão Gênica , Técnicas de Introdução de Genes , Humanos , Proteína Huntingtina , Doença de Huntington/metabolismo , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Peptídeos/genética , Peptídeos/metabolismo , Ratos
7.
Nucleic Acids Res ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38989613

RESUMO

Non-CpG methylation is associated with several cellular processes, especially neuronal development and cancer, while its effect on DNA structure remains unclear. We have determined the crystal structures of DNA duplexes containing -CGCCG- regions as CCG repeat motifs that comprise a non-CpG site with or without cytosine methylation. Crystal structure analyses have revealed that the mC:G base-pair can simultaneously form two alternative conformations arising from non-CpG methylation, including a unique water-mediated cis Watson-Crick/Hoogsteen, (w)cWH, and Watson-Crick (WC) geometries, with partial occupancies of 0.1 and 0.9, respectively. NMR studies showed that an alternative conformation of methylated mC:G base-pair at non-CpG step exhibits characteristics of cWH with a syn-guanosine conformation in solution. DNA duplexes complexed with the DNA binding drug echinomycin result in increased occupancy of the (w)cWH geometry in the methylated base-pair (from 0.1 to 0.3). Our structural results demonstrated that cytosine methylation at a non-CpG step leads to an anti→syntransition of its complementary guanosine residue toward the (w)cWH geometry as a partial population of WC, in both drug-bound and naked mC:G base pairs. This particular geometry is specific to non-CpG methylated dinucleotide sites in B-form DNA. Overall, the current study provides new insights into DNA conformation during epigenetic regulation.

8.
J Biol Chem ; 300(5): 107230, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38537699

RESUMO

Arsenite-induced stress granule (SG) formation can be cleared by the ubiquitin-proteasome system aided by the ATP-dependent unfoldase p97. ZFAND1 participates in this pathway by recruiting p97 to trigger SG clearance. ZFAND1 contains two An1-type zinc finger domains (ZF1 and ZF2), followed by a ubiquitin-like domain (UBL); but their structures are not experimentally determined. To shed light on the structural basis of the ZFAND1-p97 interaction, we determined the atomic structures of the individual domains of ZFAND1 by solution-state NMR spectroscopy and X-ray crystallography. We further characterized the interaction between ZFAND1 and p97 by methyl NMR spectroscopy and cryo-EM. 15N spin relaxation dynamics analysis indicated independent domain motions for ZF1, ZF2, and UBL. The crystal structure and NMR structure of UBL showed a conserved ß-grasp fold homologous to ubiquitin and other UBLs. Nevertheless, the UBL of ZFAND1 contains an additional N-terminal helix that adopts different conformations in the crystalline and solution states. ZFAND1 uses the C-terminal UBL to bind to p97, evidenced by the pronounced line-broadening of the UBL domain during the p97 titration monitored by methyl NMR spectroscopy. ZFAND1 binding induces pronounced conformational heterogeneity in the N-terminal domain of p97, leading to a partial loss of the cryo-EM density of the N-terminal domain of p97. In conclusion, this work paved the way for a better understanding of the interplay between p97 and ZFAND1 in the context of SG clearance.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular , Modelos Moleculares , Grânulos de Estresse , Proteína com Valosina , Humanos , Arsenitos/metabolismo , Arsenitos/química , Cristalografia por Raios X , Ligação Proteica , Domínios Proteicos , Grânulos de Estresse/metabolismo , Ubiquitina/metabolismo , Proteína com Valosina/metabolismo , Proteína com Valosina/química , Proteína com Valosina/genética , Dedos de Zinco , Dobramento de Proteína , Imageamento por Ressonância Magnética , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo
9.
Am J Gastroenterol ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38775310

RESUMO

INTRODUCTION: Concerns regarding bleeding remain in cold snare polypectomy (CSP) for small pedunculated (0-Ip) polyps. The aim of this study was to compare the risk of CSP and hot snare polypectomy (HSP) for such lesions. METHODS: Data on 0-Ip colorectal polyps ≤10 mm were extracted from a large, pragmatic, randomized trial. Immediate postpolypectomy bleeding (IPPB), defined as the perioperative use of a clip for bleeding, was evaluated through polyp-level analysis. Delayed postpolypectomy bleeding (DPPB), defined as bleeding occurring within 2 weeks postoperatively, was assessed at the patient-level among patients whose polyps were all ≤10 mm, including at least one 0-Ip polyp. RESULTS: A total of 647 0-Ip polyps (CSP: 306; HSP: 341) were included for IPPB analysis and 386 patients (CSP: 192; HSP: 194) for DPPB analysis. CSP was associated with a higher incidence of IPPB (10.8% vs 3.2%, P < 0.001) but no adverse clinical events. The procedure time of all polypectomies was shorter for CSP than for HSP (123.0 ± 117.8 vs 166.0 ± 237.7 seconds, P = 0.003), while the procedure time of polypectomies with IPPB were similar (249.8 ± 140.2 vs 227.4 ± 125.9 seconds, P = 0.64). DPPB was observed in 3 patients (1.5%) in the HSP group, including one patient (0.5%) with severe bleeding, but not in the CSP group. DISCUSSION: Despite CSP being associated with more IPPB events, it could be timely treated without adverse outcomes. Notably, no delayed bleeding occurred in the CSP group. Our findings support the use of CSP for 0-Ip polyps ≤ 10 mm.

10.
Small ; : e2401966, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38733223

RESUMO

While research on organic thermoelectric polymers is making significant progress in recent years, realization of a single polymer material possessing both thermoelectric properties and stretchability for the next generation of self-powered wearable electronics is a challenging task and remains an area yet to be explored. A new molecular engineering concept of "conjugated breaker" is employed to impart stretchability to a highly crystalline diketopyrrolepyrrole (DPP)-based polymer. A hexacyclic diindenothieno[2,3-b]thiophene (DITT) unit, with two 4-octyloxyphenyl groups substituted at the tetrahedral sp3-carbon bridges, is selected to function as the conjugated breaker that can sterically hinder intermolecular packing to reduce polymers' crystallinity. A series of donor-acceptor random copolymers is thus developed via polymerizing the crystalline DPP units with the DITT conjugated breakers. By controlling the monomeric DPP/DITT ratios, DITT30 reaches the optimal balance of crystalline/amorphous regions, exhibiting an exceptional power factor (PF) value up to 12.5 µW m-1 K-2 after FeCl3-doping; while, simultaneously displaying the capability to withstand strains exceeding 100%. More significantly, the doped DITT30 film possesses excellent mechanical endurance, retaining 80% of its initial PF value after 200 cycles of stretching/releasing at a strain of 50%. This research marks a pioneering achievement in creating intrinsically stretchable polymers with exceptional thermoelectric properties.

11.
Opt Express ; 32(7): 12228-12242, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38571052

RESUMO

Highly collimated and directional backlights are essential for realizing advanced display technologies such as autostereoscopic 3D displays. Previously reported collimated backlights, either edge-lit or direct-lit, in general still suffer unsatisfactory form factors, directivity, uniformity, or crosstalk etc. In this work, we report a simple stacking architecture for the highly collimated and uniform backlights, by combining linear light source arrays and carefully designed cylindrical lens arrays. Experiments were conducted to validate the design and simulation, using the conventional edge-lit backlight or the direct-lit mini-LED (mLED) arrays as light sources, the NiFe (stainless steel) barrier sheets, and cylindrical lens arrays fabricated by molding. Highly collimated backlights with small angular divergence of ±1.45°âˆ¼±2.61°, decent uniformity of 93-96%, and minimal larger-angle sidelobes in emission patterns were achieved with controlled divergence of the light source and optimization of lens designs. The architecture reported here provides a convenient way to convert available backlight sources into a highly collimated backlight, and the use of optically reflective barrier also helps recycle light energy and enhance the luminance. The results of this work are believed to provide a facile approach for display technologies requiring highly collimated backlights.

12.
J Biomed Sci ; 31(1): 21, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38350919

RESUMO

BACKGROUND: Cancer susceptibility germline mutations are associated with pancreatic ductal adenocarcinoma (PDAC). However, the hereditary status of PDAC and its impact on survival is largely unknown in the Asian population. METHODS: Exome sequencing was performed on 527 blood samples from PDAC individuals and analyzed for mutations in 80 oncogenic genes. Pathogenic and likely pathogenic (P/LP) germline variants were diagnosed according to the ACMG variant classification categories. The association between germline homologous recombination gene mutations (gHRmut, including BAP1, BRCA1, BRCA2, PALB2, ATM, BLM, BRIP1, CHEK2, NBN, MUTYH, FANCA and FANCC) and the treatment outcomes was explored in patients with stage III/IV diseases treated with first-line (1L) platinum-based versus platinum-free chemotherapy. RESULTS: Overall, 104 of 527 (19.7%) patients carried germline P/LP variants. The most common mutated genes were BRCA2 (3.60%), followed by ATR (2.66%) and ATM (1.9%). After a median follow-up duration of 38.3-months (95% confidence interval, 95% CI 35.0-43.7), the median overall survival (OS) was not significantly different among patients with gHRmut, non-HR germline mutations, or no mutation (P = 0.43). Among the 320 patients with stage III/IV disease who received 1L combination chemotherapy, 32 (10%) had gHRmut. Of them, patients receiving 1L platinum-based chemotherapy exhibited a significantly longer median OS compared to those with platinum-free chemotherapy, 26.1 months (95% CI 12.7-33.7) versus 9.6 months (95% CI 5.9-17.6), P = 0.001. However, the median OS of patients without gHRmut was 14.5 months (95% CI 13.2-16.9) and 12.6 months (95% CI 10.8-14.7) for patients receiving 1L platinum-based and platinum-free chemotherapy, respectively (P = 0.22). These results were consistent after adjusting for potential confounding factors including age, tumor stage, performance status, and baseline CA 19.9 in the multivariate Cox regression analysis. CONCLUSIONS: Our study showed that nearly 20% of Taiwanese PDAC patients carried germline P/LP variants. The longer survival observed in gHRmut patients treated with 1L platinum-based chemotherapy highlights the importance of germline testing for all patients with advanced PDAC at diagnosis.


Assuntos
Mutação em Linhagem Germinativa , Neoplasias Pancreáticas , Humanos , Taiwan , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Recombinação Homóloga , Genes BRCA2 , Proteína BRCA1/genética , Proteína BRCA2/genética
13.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33593904

RESUMO

Single-nucleotide variants (SNVs), pertinent to aging and disease, occur sporadically in the human genome, hence necessitating single-cell measurements. However, detection of single-cell SNVs suffers from false positives (FPs) due to intracellular single-stranded DNA damage and the process of whole-genome amplification (WGA). Here, we report a single-cell WGA method termed multiplexed end-tagging amplification of complementary strands (META-CS), which eliminates nearly all FPs by virtue of DNA complementarity, and achieved the highest accuracy thus far. We validated META-CS by sequencing kindred cells and human sperm, and applied it to other human tissues. Investigation of mature single human neurons revealed increasing SNVs with age and potentially unrepaired strand-specific oxidative guanine damage. We determined SNV frequencies along the genome in differentiated single human blood cells, and identified cell type-dependent mutational patterns for major types of lymphocytes.


Assuntos
Variações do Número de Cópias de DNA , Leucócitos Mononucleares/citologia , Neurônios/citologia , Análise de Célula Única/métodos , Espermatozoides/citologia , Adulto , Idoso , Feminino , Genoma Humano , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Leucócitos Mononucleares/fisiologia , Masculino , Mutação , Neurônios/fisiologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Reprodutibilidade dos Testes
14.
Ann Intern Med ; 176(3): 311-319, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36802753

RESUMO

BACKGROUND: Although cold snare polypectomy (CSP) is considered effective in reducing delayed postpolypectomy bleeding risk, direct evidence supporting its safety in the general population remains lacking. OBJECTIVE: To clarify whether CSP would reduce delayed bleeding risk after polypectomy compared with hot snare polypectomy (HSP) in the general population. DESIGN: Multicenter randomized controlled study. (ClinicalTrials.gov: NCT03373136). SETTING: 6 sites in Taiwan, July 2018 through July 2020. PARTICIPANTS: Participants aged 40 years or older with polyps of 4 to 10 mm. INTERVENTION: CSP or HSP to remove polyps of 4 to 10 mm. MEASUREMENTS: The primary outcome was the delayed bleeding rate within 14 days after polypectomy. Severe bleeding was defined as a decrease in hemoglobin concentration of 20 g/L or more, requiring transfusion or hemostasis. Secondary outcomes included mean polypectomy time, successful tissue retrieval, en bloc resection, complete histologic resection, and emergency service visits. RESULTS: A total of 4270 participants were randomly assigned (2137 to CSP and 2133 to HSP). Eight patients (0.4%) in the CSP group and 31 (1.5%) in the HSP group had delayed bleeding (risk difference, -1.1% [95% CI, -1.7% to -0.5%]). Severe delayed bleeding was also lower in the CSP group (1 [0.05%] vs. 8 [0.4%] events; risk difference, -0.3% [CI, -0.6% to -0.05%]). Mean polypectomy time (119.0 vs. 162.9 seconds; difference in mean, -44.0 seconds [CI, -53.1 to -34.9 seconds]) was shorter in the CSP group, although successful tissue retrieval, en bloc resection, and complete histologic resection did not differ. The CSP group had fewer emergency service visits than the HSP group (4 [0.2%] vs. 13 [0.6%] visits; risk difference, -0.4% [CI, -0.8% to -0.04%]). LIMITATION: An open-label, single-blind trial. CONCLUSION: Compared with HSP, CSP for small colorectal polyps significantly reduces the risk for delayed postpolypectomy bleeding, including severe events. PRIMARY FUNDING SOURCE: Boston Scientific Corporation.


Assuntos
Pólipos do Colo , Humanos , Pólipos do Colo/cirurgia , Pólipos do Colo/patologia , Colonoscopia/efeitos adversos , Método Simples-Cego , Microcirurgia , Hemorragia Pós-Operatória/epidemiologia
15.
J Neuroeng Rehabil ; 21(1): 49, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38589875

RESUMO

BACKGROUND: Non-invasive techniques such as central intermittent theta burst stimulation (iTBS) and repetitive peripheral magnetic stimulation (rPMS) have shown promise in improving motor function for patients with stroke. However, the combined efficacy of rPMS and central iTBS has not been extensively studied. This randomized controlled trial aimed to investigate the synergistic effects of rPMS and central iTBS in patients with stroke. METHOD: In this study, 28 stroke patients were randomly allocated to receive either 1200 pulses of real or sham rPMS on the radial nerve of the affected limb, followed by 1200 pulses of central iTBS on the ipsilesional hemisphere. The patients received the intervention for 10 sessions over two weeks. The primary outcome measures were the Fugl-Meyer Assessment-Upper Extremity (FMA-UE) and the Action Research Arm Test (ARAT). Secondary outcomes for activities and participation included the Functional Independence Measure-Selfcare (FIM-Selfcare) and the Stroke Impact Scale (SIS). The outcome measures were assessed before and after the intervention. RESULTS: Both groups showed significant improvement in FMA-UE and FIM-Selfcare after the intervention (p < 0.05). Only the rPMS + iTBS group had significant improvement in ARAT-Grasp and SIS-Strength and activity of daily living (p < 0.05). However, the change scores in all outcome measures did not differ between two groups. CONCLUSIONS: Overall, the study's findings suggest that rPMS may have a synergistic effect on central iTBS to improve grasp function and participation. In conclusion, these findings highlight the potential of rPMS as an adjuvant therapy for central iTBS in stroke rehabilitation. Further large-scale studies are needed to fully explore the synergistic effects of rPMS on central iTBS. TRIAL REGISTRATION: This trial was registered under ClinicalTrials.gov ID No.NCT04265365, retrospectively registered, on February 11, 2020.


Assuntos
Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Humanos , Fenômenos Magnéticos , Reabilitação do Acidente Vascular Cerebral/métodos , Estimulação Magnética Transcraniana/métodos , Resultado do Tratamento , Extremidade Superior , Método Duplo-Cego
16.
Immunopharmacol Immunotoxicol ; : 1-11, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38800857

RESUMO

OBJECTIVE: Microglia in the central nervous system regulate neuroinflammation that leads to a wide range of neuropathological alterations. The present study investigated the anti-neuroinflammatory properties of nobiletin (Nob) derivative, 5-acetoxy-6,7,8,3',4'-pentamethoxyflavone (5-Ac-Nob), in lipopolysaccharide (LPS)-activated BV2 microglia. MATERIALS AND METHODS: By using the MTT assay, Griess method, flow cytometry, and enzyme-linked immunosorbent assay (ELISA), we determined the cell viability, the levels of nitric oxide (NO), reactive oxygen species (ROS), and pro-inflammatory factors (interleukin 1 beta; IL-1ß, interleukin 6; IL-6, tumor necrosis factor alpha; TNF-α and prostaglandin E2; PGE2) in LPS-stimulated BV2 microglia. Toll-like receptor 4 (TLR4)-mediated myeloid differentiation primary response gene 88 (MyD88)/nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK) signaling pathway and signal transducer and activator of transcription 3 (STAT3) were measured by western blotting. Analysis of NO generation and mRNA of pro-inflammatory cytokines was confirmed in the zebrafish model. RESULTS: 5-Ac-Nob reduced cell death, the levels of NO, ROS, inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), and pro-inflammatory factors in LPS-activated BV-2 microglial cells. TLR4-mediated MyD88/NF-κB and MAPK pathway (p38, ERK and JNK) after exposure to 5-Ac-Nob was also suppressed. Moreover, 5-Ac-Nob inhibited phosphorylated STAT3 proteins expression in LPS-induced BV-2 microglial cells. Furthermore, we confirmed that 5-Ac-Nob decreased LPS-induced NO generation and mRNA of pro-inflammatory cytokines in the zebrafish model. CONCLUSIONS: Our findings suggest that 5-Ac-Nob represses neuroinflammatory responses by inhibiting TLR4-mediated signaling pathway and STAT3. As a result of these findings, 5-Ac-Nob has potential as an anti-inflammatory agent against microglia-mediated neuroinflammatory disorders.

17.
J Formos Med Assoc ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38653676

RESUMO

BACKGROUND: /Purpose: The Pediatric Eating Assessment Tool-10 (Pedi-EAT-10) is a caregiver-administrated subjective questionnaire for evaluating swallowing and feeding disorders among children. This study translated the Pedi-EAT-10 into Traditional Chinese and tested the translated version's reliability and validity. METHODS: Pedi-EAT-10 was translated into Traditional Chinese by experts and finalized after discussion and testing. A total of 168 participants, consisting of 32 children with dysphagia from a tertiary medical center and 136 healthy controls from its Children Care Center for Employees, were recruited. All participants were assessed by an otolaryngologist and speech-language pathologist. The reliability, validity, and efficacy of the translated Pedi-EAT-10 were analyzed to ensure it could be used to identify pediatric dysphagia and feeding problems. RESULTS: The Traditional Chinese version of the Pedi-EAT-10 had significant clinical discriminative validity between the dysphagia group and the control group (total score = 9.6 vs. 2.6, P < 0.001), acceptable test-retest reliability (intraclass correlation = 0.63), and excellent internal consistency (Cronbach's α = 0.91 for the entire cohort). The overall performance of the test for distinguishing children with dysphagia from normal controls was acceptable, and the area under the curve was 74.8% (sensitivity = 71.9%; specificity = 69.9%). The optimal cutoff score was ≥3 on the Youdex index. CONCLUSIONS: The Traditional Chinese version of the Pedi-EAT-10 has fair reliability and validity and can be quickly and easily completed by caregivers. The translated Ped-EAT-10 can be used as a first-line tool for assessing the need for further referral and instrumental examination.

18.
Sensors (Basel) ; 24(12)2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38931733

RESUMO

Current challenges in visible and infrared image fusion include color information distortion, texture detail loss, and target edge blur. To address these issues, a fusion algorithm based on double-domain transform filter and nonlinear contrast transform feature extraction (DDCTFuse) is proposed. First, for the problem of incomplete detail extraction that exists in the traditional transform domain image decomposition, an adaptive high-pass filter is proposed to decompose images into high-frequency and low-frequency portions. Second, in order to address the issue of fuzzy fusion target caused by contrast loss during the fusion process, a novel feature extraction algorithm is devised based on a novel nonlinear transform function. Finally, the fusion results are optimized and color-corrected by our proposed spatial-domain logical filter, in order to solve the color loss and edge blur generated in the fusion process. To validate the benefits of the proposed algorithm, nine classical algorithms are compared on the LLVIP, MSRS, INO, and Roadscene datasets. The results of these experiments indicate that the proposed fusion algorithm exhibits distinct targets, provides comprehensive scene information, and offers significant image contrast.

19.
Telemed J E Health ; 30(6): e1705-e1712, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38512470

RESUMO

Background: The scarcity of medical resources and personnel has worsened due to COVID-19. Telemedicine faces challenges in assessing wounds without physical examination. Evaluating pressure injuries is time consuming, energy intensive, and inconsistent. Most of today's telemedicine platforms utilize graphical user interfaces with complex operational procedures and limited channels for information dissemination. The study aims to establish a smart telemedicine diagnosis system based on YOLOv7 and large language model. Methods: The YOLOv7 model is trained using a clinical data set, with data augmentation techniques employed to enhance the data set to identify six types of pressure injury images. The established system features a front-end interface that includes responsive web design and a chatbot with ChatGPT, and it is integrated with a database for personal information management. Results: This research provides a practical pressure injury staging classification model with an average F1 score of 0.9238. The system remotely provides real-time accurate diagnoses and prescriptions, guiding patients to seek various medical help levels based on symptom severity. Conclusions: This study establishes a smart telemedicine auxiliary diagnosis system based on the YOLOv7 model, which possesses capabilities for classification and real-time detection. During teleconsultations, it provides immediate and accurate diagnostic information and prescription recommendations and seeks various medical assistance based on the severity of symptoms. Through the setup of a chatbot with ChatGPT, different users can quickly achieve their respective objectives.


Assuntos
COVID-19 , Úlcera por Pressão , Telemedicina , Humanos , Úlcera por Pressão/diagnóstico , COVID-19/diagnóstico , SARS-CoV-2
20.
Int J Mol Sci ; 25(4)2024 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-38396862

RESUMO

Atrial fibrillation (AF), characterized by structural remodeling involving atrial myocardial degradation and fibrosis, is linked with obesity and transforming growth factor beta 1 (TGF-ß1). Aldehyde dehydrogenase 2 (ALDH2) deficiency, highly prevalent in East Asian people, is paradoxically associated with a lower AF risk. This study investigated the impact of ALDH2 deficiency on diet-induced obesity and AF vulnerability in mice, exploring potential compensatory upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme-oxygenase 1 (HO-1). Wild-type (WT) and ALDH2*2 knock-in (KI) mice were administered a high-fat diet (HFD) for 16 weeks. Despite heightened levels of reactive oxygen species (ROS) post HFD, the ALDH2*2 KI mice did not exhibit a greater propensity for AF compared to the WT controls. The ALDH2*2 KI mice showed equivalent myofibril degradation in cardiomyocytes compared to WT after chronic HFD consumption, indicating suppressed ALDH2 production in the WT mice. Atrial fibrosis did not proportionally increase with TGF-ß1 expression in ALDH2*2 KI mice, suggesting compensatory upregulation of the Nrf2 and HO-1 pathway, attenuating fibrosis. In summary, ALDH2 deficiency did not heighten AF susceptibility in obesity, highlighting Nrf2/HO-1 pathway activation as an adaptive mechanism. Despite limitations, these findings reveal a complex molecular interplay, providing insights into the paradoxical AF-ALDH2 relationship in the setting of obesity.


Assuntos
Aldeído-Desidrogenase Mitocondrial , Fibrilação Atrial , Animais , Camundongos , Aldeído Desidrogenase , Aldeído-Desidrogenase Mitocondrial/genética , Aldeído-Desidrogenase Mitocondrial/metabolismo , Fibrilação Atrial/genética , Fibrilação Atrial/complicações , Fibrose , Fator 2 Relacionado a NF-E2 , Obesidade/complicações , Obesidade/genética , Fator de Crescimento Transformador beta1/genética
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa