Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Phys Chem B ; 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38940335

RESUMO

Microbial rhodopsin, a pivotal photoreceptor protein, has garnered widespread application in diverse fields such as optogenetics, biotechnology, biodevices, etc. However, current microbial rhodopsins are all transmembrane proteins, which both complicates the investigation on the photoreaction mechanism and limits their further applications. Therefore, a specific mimic for microbial rhodopsin can not only provide a better model for understanding the mechanism but also can extend the applications. The human protein CRABPII turns out to be a good template for design mimics on rhodopsin due to the convenience in synthesis and the stability after mutations. Recently, Geiger et al. designed a new CRABPII-based mimic M1-L121E on microbial rhodopsin with the 13-cis, syn (13C) isomerization after irradiation. However, it still remains a question as to how similar it is compared with the natural microbial rhodopsin, in particular, in the aspect of the photoreaction dynamics. In this article, we investigate the excited-state dynamics of this mimic by measuring its transient absorption spectra. Our results reveal that there are two components in the solution of mimic M1-L121E at pH 8, known as protonated Schiff base (PSB) and unprotonated Schiff base (USB) states. In both states, the photoreaction process from 13-cis, syn(13C) to all-trans,anti (AT) is faster than that from the inverse direction. In addition, the photoreaction process in the PSB state is faster than that in the USB state. We compared the isomerization time of the PSB state to that of microbial rhodopsin. Our findings indicate that M1-L121E exhibits behaviors similar to those of microbial rhodopsins in the general pattern of PSB isomerization, where the isomerization from 13C to AT is much faster than its inverse direction. However, our results also reveal significant differences in the excited-state dynamics of the mimic relative to the native microbial rhodopsin, including the slower PSB isomerization rates as well as the unusual USB photoreaction dynamics at pH = 8. By elucidating the distinctive characteristics of mimics M1-L121E, this study enhances our understanding of microbial rhodopsin mimics and their potential applications.

2.
Comput Biol Med ; 173: 108311, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38513395

RESUMO

COVID-19 is a global pandemic that has caused significant global, social, and economic disruption. To effectively assist in screening and monitoring diagnosed cases, it is crucial to accurately segment lesions from Computer Tomography (CT) scans. Due to the lack of labeled data and the presence of redundant parameters in 3D CT, there are still significant challenges in diagnosing COVID-19 in related fields. To address the problem, we have developed a new model called the Cascaded 3D Dilated convolutional neural network (CD-Net) for directly processing CT volume data. To reduce memory consumption when cutting volume data into small patches, we initially design a cascade architecture in CD-Net to preserve global information. Then, we construct a Multi-scale Parallel Dilated Convolution (MPDC) block to aggregate features of different sizes and simultaneously reduce the parameters. Moreover, to alleviate the shortage of labeled data, we employ classical transfer learning, which requires only a small amount of data while achieving better performance. Experimental results conducted on the different public-available datasets verify that the proposed CD-Net has reduced the negative-positive ratio and outperformed other existing segmentation methods while requiring less data.


Assuntos
COVID-19 , Pneumonia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Redes Neurais de Computação , Tomografia Computadorizada por Raios X , COVID-19/diagnóstico por imagem
3.
J Ethnopharmacol ; 321: 117480, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37995823

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Heng-Gu-Gu-Shang-Yu-He-Ji (Osteoking, OK) is a well-known formula for fracture therapy. In clinic, OK is effective in treating fractures while alleviating osteoporosis (OP) symptoms. However, active components of OK and the associated molecular mechanisms remain not fully elucidated. AIM OF THE STUDY: This study aims to systematically evaluate the anti-osteoporosis efficacy of OK and for the first time combine network pharmacology with high-throughput whole gene transcriptome sequencing to study its underlying mechanism. MATERIALS AND METHODS: In this study, the osteoporosis model was established by the castration of both ovaries. The level of serum bone turnover factor was detected by enzyme-linked immunosorbent assay. Micro-CT and HE staining were used to observe the changes of bone histopathology, and nano-indentation technique was used to detect the biomechanical properties of rat bone. The main active Chemical components of OK were identified using UPLC-DAD. Efficacy verification and mechanism exploration were conducted by network pharmacology, molecular docking, whole gene transcriptomics and in vivo experiments. RESULTS: In our study, OK significantly improved bone microarchitecture and bone biomechanical parameters in OVX rats, reduced osteoclast indexes such as C-telopeptide of type I collage (CTX-I) and increased Osteoprotegerin (OPG)/Receptor activator of NF-κB ligand (RANKL) levels. Mechanistically, PI3K/AKT pathway was a common pathway for genome enrichment analysis (KEGG) of both network pharmacology and RNA-seq studies. G protein-ß-like protein (GßL), Ribosomal-protein S6 kinase homolog 2 (S6K2), and Phosphoinositide 3-kinase (PI3K) appeared differentially expression in the PI3K-AKT signaling pathway. These results were also confirmed by qRT-PCR and immunohistochemistry. CONCLUSIONS: OK may be used to treat osteoporosis, at least partly by activating PI3K/AKT/mTORC1 signaling pathway.


Assuntos
Medicamentos de Ervas Chinesas , Osteoporose , Ratos , Animais , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Farmacologia em Rede , Simulação de Acoplamento Molecular , Ratos Sprague-Dawley , Osteoprotegerina/genética , Osteoprotegerina/metabolismo , Osteoporose/metabolismo , Perfilação da Expressão Gênica , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico
4.
Front Med (Lausanne) ; 10: 1022584, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36910484

RESUMO

Purpose: What constitutes the optimal surgical plan for femoral neck fractures (FNFs) in elderly patients is controversial. The European quality of life 5-Dimension Questionnaire (EU-5Q) is an international scale used to measure the health-related quality of life (HRQoL) after surgery. We aim to verify the hip arthroplasty effect in elderly patients by analyzing HRQoL scores in the EU-5Q scale. Methods: We searched the EBSCO, Embase, PubMed, Ovid, Cochrane Library, and Web of Science databases using strict searching from established to 30 November 2022; used the Cochrane Library's Risk of Bias Assessment Tool and the Newcastle-Ottawa Scale to evaluate the literature; and used RevMan5.4.1 software to perform a meta-analysis. All the included studies used the EU-5Q scale to validate the overall outcomes for elderly hip arthroplasty. Results: The final included literature is composed of four RCTs, two cohort studies, three case-control trials, and three cross-sectional surveys. This study compared HRQoL scores measured by the EU-5Q scale, including 328 elderly patients with total hip arthroplasty (THA) and 323 elderly patients with hemiarthroplasty, which is statistically significant (OR = 0.05; 95% CI, 0.02~0.08; P = 0.002). The subgroups were as follows: unipolar vs. bipolar and cemented vs. uncemented hemiarthroplasty (OR = 0.06; 95% CI, 0.03~0.08; P < 0.001), follow-up time and age arthroplasty (OR = 0.16; 95% CI, 0.11~0.22; P < 0.001), molecular exercise and enhanced recovery after surgery (ERAS) (OR = 0.02; 95% CI,-0.03~0.07; P = 0.38), and analysis of hemiarthroplasty with cognitive dysfunction vs. the normal group (OR = 0.17; 95% CI, 0.08~0.26; P < 0.001). The outcome analysis was consistent with the included studies, and HRQoL of the EU-5Q scale is sensitive to surgical outcomes between THA and hemiarthroplasty. Conclusion: Surgeons still need to further evaluate and verify whether the hip arthroplasty surgical program or effect in elderly patients is optimal. Hemiarthroplasty operations in elderly patients have pointed toward a new direction for clinical treatment, and HRQoL scores measured by the EU-5Q can sensitively reflect the rehabilitation status after hip arthroplasty surgery. Moreover, the extensive correlation between surgical outcomes and perioperative neurocognitive function should be further investigated.

5.
Appl Ergon ; 104: 103804, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35635940

RESUMO

Visuospatial attention during walking has been associated with pedestrian safety and fall risks. However, visuospatial attention measures during walking remained under-explored. Current studies introduced a newly-developed Standing and Walking Visual Attention Field (SWAVF) task to assess visuospatial attention during walking and examined its reliability, validity, and stability. Thirty young adults completed a traditional computerized Attention Visual Field (AVF) task while sitting, and the SWAVF task under walking and standing settings. Nine participants also performed the SWAVF task under additional distraction conditions. Results showed good split-half reliability during standing (r = 0.70) and walking (r = 0.69), moderate concurrent validity with the sitting AVF task (r = 0.42), moderate convergent validity between the standing and walking settings (r = 0.69), good construct validity, and moderate rank-order stability (r = 0.53). Overall, the SWAVF task showed good psychometric properties. Potential applications to the evaluation of prosthetic and other exoskeleton devices, smart glasses, and ground-level traffic lights or signs were discussed.


Assuntos
Campos Visuais , Caminhada , Humanos , Reprodutibilidade dos Testes , Postura Sentada , Posição Ortostática , Adulto Jovem
6.
Comput Math Methods Med ; 2021: 3859338, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34868339

RESUMO

PURPOSE: Heart failure (HF) is a clinical syndrome caused by ventricular insufficiency. In order to further explore the biomarkers related to HF, we apply the high-throughput database. MATERIALS AND METHODS: The GSE21610 was applied for the differentially expressed gene (DEG) analysis. The Database for Annotation, Visualization, and Integrated Discovery (DAVID) was performed to assess Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The Gene Set Enrichment Analysis (GSEA) was used for gene expression profile GSE21610. The Protein-Protein Interaction (PPI) network and modules were also constructed for research. These hub gene function pathways were estimated in HF progression. RESULT: We have identified 434 DEGs in total, including 304 downregulated DEGs and 130 upregulated DEGs. GO and KEGG illustrated that DEGs in HF were significantly enriched in G protein-coupled receptor binding, peroxisome, and cAMP signaling pathway. GSEA results showed gene set GSE21610 was gathered in lipid digestion, defense response to fungus, and intestinal lipid absorption. Finally, through analyzing the PPI network, we screened hub genes CDH1, TFRC, CCL2, BUB1B, and CD19 by the Cytoscape software. CONCLUSION: This study uses a series of bioinformatics technologies to obtain hug genes and key pathways related to HF. These analysis results provide us with new ideas for finding biomarkers and treatment methods for HF.


Assuntos
Redes Reguladoras de Genes , Marcadores Genéticos , Insuficiência Cardíaca/genética , Biologia Computacional/métodos , Bases de Dados Genéticas , Progressão da Doença , Regulação para Baixo , Perfilação da Expressão Gênica , Ontologia Genética , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/metabolismo , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Mapas de Interação de Proteínas/genética , Transdução de Sinais/genética , Regulação para Cima
7.
Opt Express ; 29(22): 36567-36580, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34809065

RESUMO

High-order harmonics generated from Xe driven by counter-rotating two-color driving fields are studied in the frame of a quantum-field scattering theory, and the spin angular momentum transfer is discussed. The driving field is composed by a circularly polarized (CP) mode and an elliptically polarized (EP) mode. We treat the EP mode as a compostition of counter-rotating CP fields of unequal intensity. We use a pair of phased generalized Bessel functions to describe the harmonic generation amplitude, and the conservation of the spin angular momentum during harmonic generation in the two-color field is derived in a solid base and in a straightforward way. The experimentally observed V-type and Λ-type distributions of the harmonic spectra with ellipticity are recovered theoretically. Balance pattern of the spin angular momentum is disclosed substantially.

8.
Bioengineered ; 12(1): 6674-6686, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34632932

RESUMO

The purpose of this work is to probe into the potential role of long non-coding RNA growth arrest specific transcript 5 (lncGAS5)/ microRNA (miR)-188-5p/SMAD2 axis in MIRI. Through ligating the left anterior descending (LAD) coronary artery, MIRI animal model and hypoxia/reoxygenation (H/R) myocardial injury model in vitro were established. Via adenovirus or plasmid transfection, lncGAS5/MiR-188-5p/SMAD2 expression was up-regulated or down-regulated in the study. RT-qPCR was applied to check LncGAS5/MiR-188-5p/SMAD2 mRNA expression, HE staining for histopathological staining, TUNEL staining and flow cytometry to examine cardiomyocyte apoptotic rate, CCK-8 to check cell viability, ELISA to detect inflammatory factor levels, Western blot to examine Bax, Bcl-2, cleaved caspase-3, NF-κB and SMAD2 expression, and dual luciferase reporter experiment to examine the targeting relationship of miR-188-5p with LncGAS5 and SMAD2. The results indicated that LncGAS5 and SMAD2 were highly expressed in MIRI and miR-188-5p was under-expressed. Silencing LncGAS5 and SMAD2 or overexpressing miR-188-5p could reduce MIRI in myocardial tissue, cardiomyocyte apoptosis, inhibit Bax, cleaved caspase-3 and NF-κB expressions and promote Bcl-2 expression, while reducing inflammatory factors TNF -α, IL-1ß and IL-6 levels. Overexpressing LncGAS5 promoted MIRI. Additionally, the impact of silencing LncGAS5 on MIRI could be reversed through inhibiting miR-188-5p. LncGAS5 acted as a sponge of miR-188-5p to target SMAD2 expression. In conclusion, Silencing LncGAS5 is available to improve MIRI through regulating miR-188-5p/SMAD2 axis, and may be used as a potential target for treating MIRI in the future.


Assuntos
MicroRNAs/genética , Traumatismo por Reperfusão Miocárdica , RNA Nucleolar Pequeno/genética , Proteína Smad2/genética , Animais , Células Cultivadas , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Miócitos Cardíacos/metabolismo , RNA Nucleolar Pequeno/metabolismo , Proteína Smad2/metabolismo
9.
Biochem Biophys Res Commun ; 583: 35-42, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34717123

RESUMO

Atherosclerosis in diabetes is a leading cause of cardiovascular complications. Intermedin (IMD) is a calcitonin peptide that is known to inhibit macrophage phagocytosis in atherosclerosis, but the exact mechanism is unclear. We investigate genes that are differentially expressed in response to IMD in hyperglycemic conditions and determine whether they delay the progression of atherosclerosis. An atherosclerotic and diabetic-murine model was generated in 8-week-old male ApoE-/- mice receiving streptozotocin and a high-fat diet. The mouse model was treated with IMD and the expression levels of NF-κB, Dnm3os, miR-27b-3p, and SLAMF7 were detected in plaque tissue and macrophages cultured with high glucose concentrations. Phagocytosis was determined by oxidized-low-density lipoprotein (Ox-LDL) uptake and the interactions among Dnm3os, SLAMF7 and miR-27b-3p were assessed by dual-luciferase reporter assays. The expression of NF-κB, Dnm3os, and SLAMF7 was enhanced in atherosclerotic plaques but decreased by IMD. The suppression of Dnm3os reduced plaque formation in IMD-treated mice even further whereas increased by miR-27b-3p. Dnm3os and SLAMF7 were competitively bind to miR-27b-3p in vivo. In vitro, ox-LDL uptake is elevated in macrophages cultured in hyperglycemic conditions but reduced by IMD. Dual-luciferase assays indicate that Dnm3os positively regulates SLAMF7 through miR-27b-3p expression. In conclusion, Dnm3os is involved in macrophage phagocytosis through the competitive binding of SLAMF7 with miR-27b-3p. IMD induces the suppression of Dnm3os to inhibit macrophage phagocytosis and alleviate atherosclerosis in diabetes.

10.
Front Genet ; 12: 632164, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33841499

RESUMO

Circular RNAs (circRNAs) are novel non-coding RNAs, which show abnormal expression in several diseases, such as atherosclerosis (AS). The purpose of the present study was to reveal the association between hsa_circ_0004543 and AS. In the present study, hsa_circ_0004543 was overexpressed in human umbilical vein endothelial cells (HUVECs) induced by oxidized low-density lipoprotein (oxLDL). Inhibition of hsa_circ_0004543 expression facilitated the proliferation, migration, and invasion of HUVECs and significantly reduced their apoptotic rate following treatment with oxLDL. Furthermore, silencing of hsa_circ_0004543 activated the PI3K/AKT/NOS3 pathway in oxLDL-induced HUVECs. Collectively, these results demonstrated that hsa_circ_0004543 may play a vital role in the development of AS and affect the proliferation of HUVECs, providing a potential target for treating endothelial cell damage in AS.

11.
J Theor Biol ; 473: 44-51, 2019 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-30917919

RESUMO

The Bac2A (RLARIVVIRVAR-NH2) is a linearized counterpart of cationic cyclic peptide Bactenecin-one of the smallest naturally occurring antimicrobial peptides (AMPs), which, however, generally exhibits a low or moderate antibacterial potency against gram-positive bacteria. Here, it is found that the Bac2A and its linear derivates cannot spontaneously fold into a well-defined helical conformation in solution, thus impairing the peptide amphipathicity and antibacterial activity. Hydrocarbon stapling is rationally designed to constrain the helical conformation of these linear peptides. Atomistic dynamics simulations reveal that the membrane-penetrating course of linear and stapled peptides include four distinct phases, during which the stapled peptides can maintain in an ordered helical conformation, while linear peptides are structured from intrinsic disorder in water solution to partially helical state in membrane interior, indicating that lipid environment can help the linear peptide refolding into amphipathic helix, although the refolding process would incur a large configurational entropy penalty. The antibacterial activities of the most potent stapled peptide are determined as MIC = 7.6 and 16 µg/ml against two gram-positive Staphylococcus aureus clinical strains isolated from pyemia. The activity values are improved by 7.1-fold and 5-fold as compared to that of native Bac2A peptide with MIC = 54 and 80 µg/ml, respectively.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Penetradores de Células/química , Peptídeos Penetradores de Células/farmacologia , Desenho de Fármacos , Sepse/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Sequência de Aminoácidos , Entropia , Humanos , Hidrocarbonetos/química , Testes de Sensibilidade Microbiana , Simulação de Dinâmica Molecular , Conformação Proteica
12.
Med Sci Monit ; 24: 5008-5014, 2018 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-30022020

RESUMO

BACKGROUND Cardiac infarction frequently leads to arrhythmia and ischemia/reperfusion (I/R) aggravates cardiac injury. Pinocembrin can resist cerebral ischemia and decrease cardiac infarction area. This study thus generated a rat myocardial I/R model to assess the effect on ventricular rhythm and expression of gap junction connexin (Cx43). MATERIAL AND METHODS Male SD rats were randomly assigned into sham, model, and pinocembrin (30 mg/kg) pretreatment groups (N=15 each). The I/R model was generated by ligation of the left anterior descending coronary artery for 30 min. The pinocembrin group received intravenous injection 10 min before surgery. Heart rate (HR), mean artery pressure (MAP), rate pressure product (RPP), and arrhythmia were observed at 10 min before ischemia, 30 min after ischemia, and at 30, 60, and 120 min after reperfusion. ELISA was used to assess serum CK-MB and cTnI levels. Na+-K+ATPase and Ca+-Mg2+ATPase levels were quantified by spectrometry, followed by HE staining, IHC approach for Cx43 expression, and Western blot for Kir2.1 protein expression. RESULTS Model rats had significantly lower HR, MAP, and RPP than in the sham group, and the pinocembrin pretreatment group had higher serum indexes. Arrhythmia index, CK-MB, and cTnI were higher in the model and pinocembrin groups, while Na+-K+ATPase, Ca+-Mg2+ATPase, Cx43, and Kir2.1 proteins were lower (p<0.05). CONCLUSIONS Pinocembrin alleviated ventricular arrhythmia in I/R rats via enhancing Na+-K+ATPase and Ca+-Mg2+ATPase activity and upregulating Cx43 and Kir2.1 protein expression.


Assuntos
Conexina 43/biossíntese , Flavanonas/farmacologia , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/metabolismo , Animais , Arritmias Cardíacas/tratamento farmacológico , Arritmias Cardíacas/metabolismo , Modelos Animais de Doenças , Masculino , Infarto do Miocárdio/metabolismo , Isquemia Miocárdica/tratamento farmacológico , Isquemia Miocárdica/metabolismo , Ratos , Ratos Sprague-Dawley , Regulação para Cima/efeitos dos fármacos
13.
PLoS One ; 9(1): e72181, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24475014

RESUMO

HERG K(+) channel, the genetic counterpart of rapid delayed rectifier K(+) current in cardiac cells, is responsible for many cases of inherited and drug-induced long QT syndromes. HERG has unusual biophysical properties distinct from those of other K(+) channels. While the conventional pulse protocols in patch-clamp studies have helped us elucidate these properties, their limitations in assessing HERG function have also been progressively noticed. We employed AP-clamp techniques using physiological action potential waveforms recorded from various regions of canine heart to study HERG function in HEK293 cells and identified several novel aspects of HERG function. We showed that under AP-clamp IHERG increased gradually with membrane repolarization, peaked at potentials around 20-30 mV more negative than revealed by pulse protocols and at action potential duration (APD) to 60%-70% full repolarization, and fell rapidly at the terminal phase of repolarization. We found that the rising phase of IHERG was conferred by removal of inactivation and the decaying phase resulted from a fall in driving force, which were all determined by the rate of membrane repolarization. We identified regional heterogeneity and transmural gradient of IHERG when quantified with the area covered by IHERG trace. In addition, we observed regional and transmural differences of IHERG in response to dofetilide blockade. Finally, we characterized the influence of HERG function by selective inhibition of other ion currents. Based on our results, we conclude that the distinct biophysical properties of HERG reported by AP-clamp confer its unique function in cardiac repolarization thereby in antiarrhythmia and arrhythmogenesis.


Assuntos
Potenciais de Ação/fisiologia , Canais de Potássio Éter-A-Go-Go/metabolismo , Sistema de Condução Cardíaco/fisiologia , Miócitos Cardíacos/metabolismo , Animais , Cães , Canal de Potássio ERG1 , Células HEK293 , Humanos , Análise dos Mínimos Quadrados , Masculino , Técnicas de Patch-Clamp , Fenetilaminas , Sulfonamidas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...