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1.
J Virol Methods ; : 114983, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38901646

RESUMO

Hand foot and mouth disease (HFMD) is a common childhood infectious disease which is caused by human enterovirus. The objective of this study was to develop a rapid, sensitive, and accurate method for detecting severe HFMD caused by coxsackievirus A16 (CV-A16). A closed-tube sensitive multiplex one-step reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was applied to detect CV-A16 in the early stage of severe HFMD. This assay targeted the CV-A16 structure protein VP1 to distinguish CV-A16 from other coxsackieviruses The 5'UTR region of enteric viruses was used for detecting the enterovirus and ribonuclease P (RNaseP) was adopted as the internal reference gene. The multiplex MGB probe assay system was used to detect PCR amplicons with different fluorescence reporters in the same system. The limit of detection (LOD) of the RT-qPCR assay for the CV-A16 VP1 gene was 125.893 copies/µl, for the 5' UTR was 50.1187 copies/µl and for the RNaseP gene was 158.49 copies/µl. Furthermore, specificity analysis showed that the multiplex RT-PCR had no cross-reactivity with the influenza virus, herpangina virus and SARS-COV-2. In correlation analysis, the sensitivity of the multiplex RT-qPCR assay for CV-A16 detection was 100% (288/288) and the specificity of the multiplex RT-qPCR assay was 99.94% (3395/3397). The overall agreement between the multiplex RT-qPCR and the results of clinical diagnosis was 99.95% (3683/3685) and kappa value was 0.996 (p<0.001). The entire procedure, from specimen processing to result reporting, could be completed within 1.5hours. The one-step multiplex RT-qPCR assay for detecting CV-A16 developed in this study is a good laboratory diagnostic tool for rapid and reliable distinguished detection of CV-A16, especially for severe HFMD patients at an early stage in the disease with low virus load of CV-A16.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38861392

RESUMO

Dielectric ceramic capacitors are prospective energy-storage devices for pulsed-power systems owing to their ultrafast charge-discharge speed. However, low energy-storage density makes them difficult to commercialize for high-pulse-power technology applications. Herein, we presented a structurally regulated design strategy to disrupt a long-range ferroelectric order, refined grains, and eventually achieve excellent comprehensive energy-storage performance in (1 - x) (0.7Bi0.5Na0.5TiO3-0.3SrTiO3)-x Sm(Zn2/3Nb1/3)O3 eco-friendly ceramics. A large Wrec of ∼7.43 ± 0.05 J/cm3 and a high η of ∼85 ± 0.5% of 0.96 (0.7Bi0.5Na0.5TiO3-0.3SrTiO3)-0.04 Sm(Zn2/3Nb1/3)O3 were obtained at a low electric field of 290 kV cm-1 with good energy-storage temperature (25-120 °C), frequency (1-100 Hz) stability, and charge-discharge properties (PD ∼ 74 ± 1 MW/cm3 and τ0.9 ∼ 159 ± 2 ns). This strategy inspires rational structurally regulated designs and aims to promote the development of eco-friendly 0.7Bi0.5Na0.5TiO3-based ceramics with excellent energy-storage characteristics.

3.
J Clin Gastroenterol ; 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38896424

RESUMO

OBJECTIVE: The diagnosis of RGERD in patients typically involves 24-hour esophageal pH monitoring, but due to its invasiveness and low patient compliance, new screening methods are needed. In this study, a lactulose breath test (LBT) was conducted to detect the growth of small intestine bacteria (SIBO) and explore the potential relationship between LBT and RGERD to identify a new treatment method for RGERD. METHODS: A total of 178 patients with gastroesophageal reflux were enrolled from June 2020 to December 2022 in the Gastroenterology Department, Building 3, the First Affiliated Hospital of Kunming Medical University; these patients included 96 patients with nonrefractory GERD (NRGERD) and 82 patients with RGERD. The Gerd Q score, reflux symptom index (RSI) score, gastroscopy results, clinical symptoms, and other related indicators were collected. Statistical methods were used to analyze the gathered data. RESULTS: The incidence of acid reflux and heartburn in patients with RGERD was significantly greater than that in patients with NRGERD (67.10% vs. 42.70%, P<0.01 and 65.00% vs. 34.40%, P<0.01). The CH4 values of patients with RGERD were significantly greater than those of patients with NRGERD at each time point, and there was a correlation between the CH4 values at 60 min and RGERD (P<0.05). For patients with RGERD, the incidence of abdominal pain, acid regurgitation, and heartburn was greater in the CH4-positive group than in the CH4-negative group (61.90% vs. 57.50%, 69.05% vs. 65.00%, 69.05% vs. 57.50%, P>0.05). The incidence of nausea was also greater in the CH4-positive group than in the CH4-negative group (61.90% vs. 35.00%, P<0.05). CONCLUSION: Increased CH4 levels are correlated with RGERD. In addition, patients with RGERD may develop SIBO after long-term use of PPIs, and interventions involving SIBO could provide new ideas for the treatment of RGERD.

4.
Front Microbiol ; 15: 1399123, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38765685

RESUMO

Introduction: Pseudorabies (PR) is a multi-animal comorbid disease caused by pseudorabies virus (PRV), which are naturally found in pigs. At the end of 2011, the emergence of PRV variant strains in many provinces in China had caused huge economic losses to pig farms. Rapid detection diagnosis of pigs infected with the PRV variant helps prevent outbreaks of PR. The immunochromatography test strip with colloidal gold nanoparticles is often used in clinical testing due to its low cost and high throughput. Methods: This study was designed to produce monoclonal antibodies targeting PRV through immunization of mice using the eukaryotic system to express the gE glycoprotein. Subsequently, paired monoclonal antibodies were screened based on their sensitivity and specificity for use in the preparation of test strips. Results and discussion: The strip prepared in this study was highly specific, only PRV was detected, and there was no cross-reactivity with glycoprotein gB, glycoprotein gC, glycoprotein gD, and glycoprotein gE of herpes simplex virus and varicellazoster virus, porcine epidemic diarrhea virus, Senecavirus A, classical swine fever virus, porcine reproductive and respiratory syndrome virus, and porcine parvovirus. Moreover, it demonstrated high sensitivity with a detection limit of 1.336 × 103 copies/µL (the number of viral genome copies per microliter); the coincidence rate with the RT-PCR detection method was 96.4%. The strip developed by our laboratory provides an effective method for monitoring PRV infection and controlling of PR vaccine quality.

5.
Mar Drugs ; 22(4)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38667798

RESUMO

Three pairs of enantiomers (1-3)-the new 12R-aloesol (1a) and two new fatty acids (2 and 3)-and one new natural product (4) together three known compounds (5-7) were isolated from a coral-reef-derived Streptomyces sp. SCSIO 66814. Their structures were determined through extensive spectroscopic analysis, chiral analysis, and single-crystal X-ray diffraction data. Compounds 2 and 3 were presumed to be intermediates for further generating homononactic acid (5) and nonactic acid, and the latter two molecules were able to act as precursors to form macrotetrolides with remarkable biological activity. The isolation of related precursors, compounds 2-5, provided more evidence to support the proposal of a plausible biosynthetic pathway for nonactic acid and its homologs. Additionally, (+)-1 exhibited a weak activity against DPPH radicals.


Assuntos
Antozoários , Cromonas , Streptomyces , Streptomyces/metabolismo , Streptomyces/química , Cromonas/química , Cromonas/isolamento & purificação , Cromonas/farmacologia , Estereoisomerismo , Antozoários/química , Animais , Cristalografia por Raios X , Ácidos Graxos/química , Ácidos Graxos/isolamento & purificação , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Produtos Biológicos/isolamento & purificação , Estrutura Molecular
6.
Mar Drugs ; 22(4)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38667794

RESUMO

An ethyl acetate extract of a marine actinomycete strain, Nocardiopsis mentallicus SCSIO 53858, isolated from a deep-sea sediment sample in the South China Sea, exhibited anti-quorum-sensing (QS) activity against Chromobacterium violaceum CV026. Guided by the anti-QS activity, a novel active compound was isolated and purified from the extract and was identified as 2,3-dimethoxycinnamic acid (2,3-DCA) through spectral data analysis. At a concentration of 150 µg/mL, 2,3-DCA exhibited robust inhibitory effects on three QS-regulated traits of C. violaceum CV026: violacein production, swarming motility, and biofilm formation, with inhibition rates of 73.9%, 65.9%, and 37.8%, respectively. The quantitative reverse transcription polymerase chain reaction results indicated that 2,3-DCA can disrupt the QS system in C. violaceum CV026 by effectively suppressing the expression of QS-related genes, including cviR, vioA, vioB, and vioE. Molecular docking analysis revealed that 2,3-DCA hinders the QS system by competitively binding to the same binding pocket on the CviR receptor as the natural signal molecule N-hexanoyl-L-homoserine lactone. Collectively, these findings suggest that 2,3-DCA exhibits promising potential as an inhibitor of QS systems, providing a potential solution to the emerging problem of bacterial resistance.


Assuntos
Antibacterianos , Chromobacterium , Indóis , Simulação de Acoplamento Molecular , Percepção de Quorum , Percepção de Quorum/efeitos dos fármacos , Chromobacterium/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/isolamento & purificação , Antibacterianos/química , Actinobacteria/química , Cinamatos/farmacologia , Cinamatos/isolamento & purificação , Cinamatos/química , Biofilmes/efeitos dos fármacos , Sedimentos Geológicos/microbiologia , Organismos Aquáticos , China
7.
Phytochemistry ; 222: 114101, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38636687

RESUMO

Bafilomycins are macrocyclic polyketides with intriguing structures and therapeutic value. Genomic analysis of Streptomyces sp. SCSIO 66814 revealed a type I polyketide synthase biosynthetic gene cluster (BGC), namely blm, which encoded bafilomycins and featured rich post-modification genes. The One strain many compounds (OSMAC) strategy led to the discovery of six compounds related to the blm BGC from the strain, including two previously undescribed 6,6-spiroketal polyketides, streptospirodienoic acids D (1) and E (2), and four known bafilomycins, bafilomycins P (3), Q (4), D (5), and G (6). The structures of 1 and 2 were determined by extensive spectroscopic analysis, quantum calculation, and biosynthetic analysis. Additionally, the absolute configurations of the 6/5/5 tricyclic ring moiety containing six consecutive chiral carbons in the putative structures of 3 and 4 were corrected through NOE analysis, DP4+ calculation, and single-crystal X-ray diffraction data. Bioinformatic analysis uncovered a plausible biosynthetic pathway for compounds 1-6, indicating that both streptospirodienoic acids and bafilomycins were derived from the same blm BGC. Additionally, sequence analysis revealed that the KR domains of module 2 from blm BGC was B1-type, further supporting the configurations of 1-4. Notably, compounds 3 and 4 displayed significant cytotoxic activities against A-549 human non-small cell lung cancer cells and HCT-116 human colon cancer cells.


Assuntos
Policetídeos , Streptomyces , Streptomyces/química , Streptomyces/metabolismo , Streptomyces/genética , Policetídeos/química , Policetídeos/farmacologia , Policetídeos/isolamento & purificação , Humanos , Estereoisomerismo , Ensaios de Seleção de Medicamentos Antitumorais , Estrutura Molecular , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Macrolídeos/química , Macrolídeos/farmacologia , Macrolídeos/isolamento & purificação , Macrolídeos/metabolismo , Proliferação de Células/efeitos dos fármacos , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Compostos de Espiro/isolamento & purificação , Relação Estrutura-Atividade , Policetídeo Sintases/metabolismo , Policetídeo Sintases/genética , Linhagem Celular Tumoral , Genoma Bacteriano , Família Multigênica
8.
Biosens Bioelectron ; 250: 116087, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38295583

RESUMO

Dopamine (DA), a catecholamine neurotransmitter, is crucial in brain signal transmission. Monitoring cytoplasmic DA levels can reflect changes in metabolic factors and provide valuable information for researching the mechanisms involved in neurodegenerative diseases. However, the in-situ detection of intracellular DA is constrained by its low contents in small-sized single cells. In this work, we report that noble metal (Au, Pt)-modified carbon fiber micro-nanoelectrodes are capable of real-time detection of DA in single cells with excellent sensitivity, selectivity, and anti-contamination capabilities. Notably, noble metals can be modified on the electrode surface through electrochemical deposition to enhance the conductivity of the electrode and the oxidation current of DA by 50 %. The nanosensors can work stably and continuously in rat adrenal pheochromocytoma cells (PC12) to monitor changes in DA levels upon K+ stimulation. The functionalized carbon fibers based nanosensors will provide excellent prospects for DA analysis in the brains of living animals.


Assuntos
Técnicas Biossensoriais , Dopamina , Ratos , Animais , Dopamina/química , Fibra de Carbono/química , Técnicas Eletroquímicas , Eletrodos , Metais , Carbono/química
9.
Front Microbiol ; 14: 1297843, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38098670

RESUMO

Background: Quorum sensing is bacteria's ability to communicate and regulate their behavior based on population density. Anti-quorum sensing agents (anti-QSA) is promising strategy to treat resistant infections, as well as reduce selective pressure that leads to antibiotic resistance of clinically relevant pathogens. This study analyzes the output, hotspots, and trends of research in the field of anti-QSA against clinically relevant pathogens. Methods: The literature on anti-QSA from the Web of Science Core Collection database was retrieved and analyzed. Tools such as CiteSpace and Alluvial Generator were used to visualize and interpret the data. Results: From 1998 to 2023, the number of publications related to anti-QAS research increased rapidly, with a total of 1,743 articles and reviews published in 558 journals. The United States was the largest contributor and the most influential country, with an H-index of 88, higher than other countries. Williams was the most productive author, and Hoiby N was the most cited author. Frontiers in Microbiology was the most prolific and the most cited journal. Burst detection indicated that the main frontier disciplines shifted from MICROBIOLOGY, CLINICAL, MOLECULAR BIOLOGY, and other biomedicine-related fields to FOOD, MATERIALS, NATURAL PRODUCTS, and MULTIDISCIPLINARY. In the whole research history, the strongest burst keyword was cystic-fibrosis patients, and the strongest burst reference was Lee and Zhang (2015). In the latest period (burst until 2023), the strongest burst keyword was silver nanoparticle, and the strongest burst reference was Whiteley et al. (2017). The co-citation network revealed that the most important interest and research direction was anti-biofilm/anti-virulence drug development, and timeline analysis suggested that this direction is also the most active. The key concepts alluvial flow visualization revealed seven terms with the longest time span and lasting until now, namely Escherichia coli, virulence, Pseudomonas aeruginosa, virulence factor, bacterial biofilm, gene expression, quorum sensing. Comprehensive analysis shows that nanomaterials, marine natural products, and artificial intelligence (AI) may become hotspots in the future. Conclusion: This bibliometric study reveals the current status and trends of anti-QSA research and may assist researchers in identifying hot topics and exploring new research directions.

10.
Anal Chem ; 95(37): 14101-14110, 2023 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-37674256

RESUMO

Intracellular dynamic assembly of DNA structures may be beneficial for the development of multifunctional nanoplatforms for the regulation of cell behaviors, providing new strategies for disease diagnosis and intervention. Herein, we propose the dynamic assembly of DNA coacervates in living cells triggered by miRNA-21 and K+, which can be used for both miRNA imaging and mitochondrial intervention. The rationale is that miRNA-21 can trigger the hybridization chain reaction to generate G-quadruplex precursors, and K+ can mediate the assembly of G-quadruplex-based coacervates, allowing the colorimetric detection of miRNA-21 ranging from 10 pM to 10 µM. Moreover, the as-formed DNA coacervates can specifically target mitochondria in MCF-7 breast cancer cells using the MCF-7 cell membrane as delivery carriers, which further act as an anionic shielding to inhibit communication between mitochondria and environments, with a significant inhibitory effect on ATP production and cellular migration behaviors. This work provides an ideal multifunctional nanoplatform for rationally interfering with cellular metabolism and migration behaviors through the dynamic assembly of DNA coacervates mediated by endogenous molecules, which has a large number of potential applications in the biomedical field, especially theranostics for cancer metastasis.


Assuntos
DNA , MicroRNAs , Replicação do DNA , Diagnóstico por Imagem , MicroRNAs/genética , Mitocôndrias
11.
Biomaterials ; 296: 122094, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36933458

RESUMO

Since the hypoxia tumor microenvironment (TME) will not only limit the treatment effect but also cause tumor recurrence and metastasis, intratumoral aggravated hypoxia level induced by vascular embolization is one of the major challenges in tumor therapy. The chemotherapeutic effect of hypoxia-activated prodrugs (HAPs) could be enhanced by the intensified hypoxia, the combination of tumor embolization and HAP-based chemotherapy exhibits a promising strategy for cancer therapy. Herein, an acidity-responsive nanoplatform (TACC NP) with multiple pathways to benefit the hypoxia-activated chemotherapy is constructed by loading the photosensitizer Chlorin e6 (Ce6), thrombin (Thr), and AQ4N within the calcium phosphate nanocarrier via a simple one-pot method. In the acidic TME, TACC NPs could be degraded to release Thr and Ce6, resulting in the destruction of tumor vessels and consumption of intratumoral oxygen under laser irradiation. Therefore, the intratumoral hypoxia level could be significantly aggravated, further leading to the enhanced chemotherapeutic effect of AQ4N. With the guidance of in vivo fluorescence imaging, the TACC NPs exhibited excellent tumor embolization/photodynamic/prodrug synergistic therapeutic effects with good biosafety.


Assuntos
Nanopartículas , Fotoquimioterapia , Pró-Fármacos , Humanos , Fotoquimioterapia/métodos , Hipóxia Tumoral , Recidiva Local de Neoplasia , Fármacos Fotossensibilizantes/farmacologia , Pró-Fármacos/farmacologia , Hipóxia , Linhagem Celular Tumoral , Microambiente Tumoral
12.
Acta Odontol Scand ; 81(5): 374-395, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36538375

RESUMO

OBJECTIVE: Oral hygiene has been suspected to contribute to the aetiology of head and neck cancer (HNC). Based on the meta-analysis, we evaluated the impact of oral hygiene on head and neck cancer (HNC) and its survival. MATERIALS AND METHODS: Relevant case-control and cohort studies reporting survival data, oral hygiene data were searched via PubMed, Embase, Cochrane Library, and Web of Science databases. The odds ratios (ORs), hazard ratios (HRs), and 95% confidence intervals (CIs) were used. Subgroup analysis was performed. RESULTS: Oral hygiene was associated with HNC. Tooth brushing ≥2 a day, dental floss use, denture wearing, caries ≥3, and dental visit ≥1 reduced the risk of oral cavity cancer while mouth wash use, missing teeth >5, gum bleeding, and periodontal disease increased the risk of oral cavity cancer. For oropharynx cancer, tooth brushing ≥2 and caries ≥3 were associated with reduced risk of it. Tooth brushing ≥2 and dental visits ≥1 decreased the risk of pharynx cancer risk and larynx cancer risk, however, missing teeth >5 increased both of them. CONCLUSION: Oral hygiene was associated with HNC and its sub sites. Oral hygiene should be strengthened, a dental floss use and dentist's visits can be recommended.


Assuntos
Cárie Dentária , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Doenças Periodontais , Humanos , Higiene Bucal , Neoplasias de Cabeça e Pescoço/etiologia , Escovação Dentária , Neoplasias Bucais/etiologia
13.
Front Vet Sci ; 9: 986619, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36532346

RESUMO

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can be transmitted from human to companion animals. The national wide serological surveillance against SARS-CoV-2 was conducted among pet animals, mainly in cats and dogs, 1 year after the first outbreak of COVID-19 in China. All sera were tested for SARS-CoV-2 IgG antibodies using an indirect enzyme linked immunosorbent assay (ELISA) based on the receptor binding domain (RBD) of spike protein. This late survey takes advantage of the short duration of the serological response in these animals to track recent episode of transmission. A total of 20,592 blood samples were obtained from 25 provinces across 7 geographical regions. The overall seroprevalence of SARS-CoV-2 infections in cats was 0.015% (2/13397; 95% confidence intervals (CI): 0.0, 0.1). The virus infections in cats were only detected in Central (Hubei, 0.375%) and Eastern China (Zhejiang, 0.087%) with a seroprevalence estimated at 0.090 and 0.020%, respectively. In dogs, the seroprevalence of SARS-CoV-2 infections was 0.014% (1/7159; 95% CI: 0.0, 0.1) in the entire nation, seropositive samples were limited to Beijing (0.070%) of Northern China with a prevalence of 0.054%. No seropositive cases were discovered in other geographic regions, nor in other companion animals analyzed in this study. These data reveal the circulation of SARS-CoV-2 in companion animals, although transmission of the virus to domestic cats and dogs is low in China, continuous monitoring is helpful for the better understand of the virus transmission status and the effect on animals.

14.
Microbiol Spectr ; 10(5): e0142922, 2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-36154153

RESUMO

Bluetongue (BT) is a severe noncontagious infectious disease that occurs in sheep and wild ruminants but occasionally also in cattle and camels. The worldwide BT pandemic has had a significant impact on global livestock production. Rapid detection helps prevent outbreaks of bluetongue disease. Fluorescence-linked immunosorbent assay (FLISA) labeled with quantum dots (QDs) is typically used for detection due to its high sensitivity. There has been no reported detection of BT virus (BTV) using QD-based fluorescence immunoassays. In this study, monoclonal antibodies (MAbs) against BT were prepared by immunizing BALB/c mice with recombinant VP7 protein. Two MAbs with high sensitivity and specificity were selected as the detection antibody (2F11) and capture antibody (11B7). Then, the detection antibody was coupled with QDs to prepare QD-MAb fluorescence probes. Fluorescence-linked immunosorbent assay is highly specific, detecting only VP7 protein/BTV, and did not show any nonspecific reactions with other reoviruses. The detection limit of VP7 protein was 3.91 ng/mL using fluorescence-linked immunosorbent assay, with a coefficient of variation (CV) of less than 15%. The establishment of rapid, sensitive direct FLISA has potential for bluetongue virus detection and control of BT vaccine quality. IMPORTANCE Bluetongue virus causes the severe infectious disease BT. BTV has many serotypes, and there is no cross-protection among different serotypes. BT is listed as a notifiable animal infectious disease by the World Organisation for Animal Health (OIE) and occurs throughout the world, causing significant economic losses. The establishment of a fast and effective detection method is the key to controlling and preventing this disease. Current methods for detecting BTV mainly include reverse transcription-PCR (RT-PCR), enzyme-linked immunosorbent assays (ELISA), and immunochromatographic strips that are based on antigen-antibody recognition. Immunoassays are most commonly used because of their low cost, high specificity, and fast analysis, making them particularly useful for routine monitoring. These conventional detection strategies for BTV have some drawbacks. Recently, FLISA has been drawing attention due to its sensitivity, which is higher than traditional immunoassays. Fluorescence-linked immunosorbent assays (FLISA) using fluorescent materials as labels overcome ELISA's disadvantage of being time-consuming.


Assuntos
Vírus Bluetongue , Bluetongue , Bovinos , Camundongos , Animais , Ovinos , Bluetongue/diagnóstico , Imunoadsorventes , Anticorpos Antivirais , Ruminantes , Anticorpos Monoclonais
15.
Emerg Microbes Infect ; 11(1): 2120-2131, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35916768

RESUMO

Spike (S) glycoprotein is the most significant structural protein of SARS-CoV-2 and a key target for neutralizing antibodies. In light of the on-going SARS-CoV-2 pandemic, identification and screening of epitopes of spike glycoproteins will provide vital progress in the development of sensitive and specific diagnostic tools. In the present study, NTD, RBD, and S2 genes were inserted into the pcDNA3.1(+) vector and designed with N-terminal 6× His-tag for fusion expression in HEK293F cells by transient transfection. Six monoclonal antibodies (4G, 9E, 4B, 7D, 8F, and 3D) were prepared using the expressed proteins by cell fusion technique. The characterization of mAbs was performed by indirect -ELISA, western blot, and IFA. We designed 49 overlapping synthesized peptides that cover the extracellular region of S protein in which 6 amino acid residues were offset between adjacent (S1-S49). Peptides S12, S19, and S49 were identified as the immunodominant epitope regions by the mAbs. These regions were further truncated and the peptides S12.2 286TDAVDCALDPLS297, S19.2 464FERDISTEIYQA475, and S49.4 1202ELGKYEQYIKWP1213 were identified as B- cell linear epitopes for the first time. Alanine scans showed that the D467, I468, E471, Q474, and A475 of the epitope S19.2 and K1205, Q1208, and Y1209 of the epitope S49.4 were the core sites involved in the mAbs binding. The multiple sequence alignment analysis showed that these three epitopes were highly conserved among the variants of concern (VOCs) and variants of interest (VOIs). Taken together, the findings provide a potential material for rapid diagnosis methods of COVID-19.


Assuntos
Epitopos de Linfócito B , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Sequência de Aminoácidos , Anticorpos Monoclonais , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19 , Epitopos de Linfócito B/genética , Humanos , Glicoproteínas de Membrana/genética , Peptídeos , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Proteínas do Envelope Viral
16.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 38(6): 553-558, 2022 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-35732612

RESUMO

Objective The major capsid protein L1 of human papillomavirus type 58 (HPV58 L1) was obtained and identified by prokaryotic expression. Methods The recombinant expression strain pE-SUMO-58 L1 (BL21) was induced by IPTG. The recombinant protein SUMO-58 L1 was expressed in E.coli and identified by SDS-PAGE and Western blot analysis. Then the recombinant protein SUMO-58 L1 was purified by Ni-column and the SUMO-tag was removed by ubiquitin-like protease 1 (ULP1) digestion. Subsequently, the bioactivity of recombinant protein HPV58 L1 was verified by hemagglutination assay (HA). BALB/c mice were immunized with HPV58 L1, and the antibody titers in sera of the immunized mice were detected by ELISA. And then the reaction between the immune serum and the HPV58 L1 protein transiently expressed by HEK293T cells was detected by indirect immunofluorescence assay (IFA). Results The soluble expression of the recombinant protein SUMO-58 L1 was identified by SDS-PAGE and Western blot analysis, with yields of soluble protein SUMO-58 L1 being about 50% of total soluble bacterial proteins. The relative molecular mass (Mr) of SUMO-58 L1 was about 72 000. After Ni-NTA affinity was purified and the SUMO-tag was removed by ULP1 digestion, Mr of recombinant protein HPV58 L1 reached about 58 000. The recombinant protein HPV58 L1 showed hemagglutination activity similar to that of natural HPV, with hemagglutination value of 1:16. After immunizing BALB/c mice, the titer of immune serum observed was about 1:10 240 by ELISA; and the sera of the immunized mice reacted specifically with HPV58 L1 proteins which were transiently expressed in HEK293T cells by IFA. Conclusion The recombinant protein HPV58 L1 also has hemagglutination activity, which can be successfully obtained from E. coli. The sera of the HPV58 L1 protein immunized mice can be used for immunocytochemical detection of HPV58 L1 protein expressed in eukaryotic cells.


Assuntos
Alphapapillomavirus , Infecções por Papillomavirus , Animais , Proteínas do Capsídeo/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Células HEK293 , Humanos , Soros Imunes , Camundongos , Camundongos Endogâmicos BALB C , Papillomaviridae , Proteínas Recombinantes de Fusão , Proteínas Recombinantes
17.
Membranes (Basel) ; 12(6)2022 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-35736299

RESUMO

Polyimide membranes have excellent physiochemical properties which make them valuable materials for optical area. However, common aromatic polyimide membrane trend to show low transmittance in visible region because of the charge-transfer complex (CTC) in molecular structures. Moreover, it's trending to show high moisture uptakes because of the hydrophilic imide rings in molecular structure. In this work, a polyimide composite membrane with SiO2 antireflective membrane on both sides was prepared. High transmittance (93% within 500~800 nm) and surface hydrophobicity was realized simultaneously. The polyimide composite membrane showed great optical homogeneity. The SiO2 antireflective membranes on polyimide substrate were prepared through a simple and efficient sol-gel method. The surface roughness of polyimide membrane substrate on each side has been improved to 1.56 nm and 3.14 nm, respectively. Moreover, the excellent thermal stability and mechanical property of polyimide membrane has been preserved, which greatly improves the range of applications for the composite membrane. It is a good candidate for light weight optical system.

18.
Small ; 17(52): e2105033, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34729905

RESUMO

The specific coagulation in the tumor vasculature has the potential for the ablation of solid tumors by cutting off the blood supply. However, the safe delivery of effective vessel occluding agents in the tumor-specific embolization therapy remains challenging. Herein, it is reported that the photothermal responsive tumor-specific embolization therapy based on thrombin (Thr) is delivered by intravenous injection via the phase-change materials (PCM)-based nanoparticles. The wax sealing profile of PCM enables safe delivery and prevents the preleakage of Thr in the blood circulation. While in the tumor site, the thermal effect induced by IR780 triggers the melting of PCM and rapidly releases Thr to generate coagulation in the tumor blood vessels. Based on the safe delivery and controllable release of Thr, thermal responsive tumor-specific embolization therapy could be achieved with high efficiency and no significant damage to normal organs and tissues. The safe administration of Thr to induce vascular infarction in tumors based on PCM nanoparticles in this work shows a promising strategy for improving the therapeutic specificity and efficacy of coagulation-based tumor therapy.


Assuntos
Hipertermia Induzida , Nanopartículas , Neoplasias , Animais , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias/tratamento farmacológico , Fototerapia , Trombina
19.
Polymers (Basel) ; 13(7)2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33805213

RESUMO

Polyimide diffractive membrane lens can be used in space optical telescope to reduce the size and mass of an imaging system. However, traditional commercial aromatic polyimide membrane is hard to meet the challenging requirements of dimensional stability and optical homogeneity for optical use. Based on molecular structure design and the optimization of fabrication process, the prepared copolyamide-imide membrane achieved the desired performance of membrane as an optical material. It showed a very low coefficient of thermal expansion (CTE), which is 0.95 ppm/°C over a temperature range of -150-100 °C and relatively low coefficient of moisture expansion (CME), which is only 13.30 ppm/% RH (0~90% RH). For the optical use, the prepared copolyamide-imide membrane (φ200 mm) achieved good thickness uniformity with wave-front error smaller than λ/30 (λ = 632 nm) in RMS (root mean square). Besides, it simultaneously meets the optical, thermal, and mechanical requirements for space telescope use. Copolyamide-imide membranes in this research with good comprehensive performance can be used as large aperture membrane optical system architectures.

20.
PeerJ ; 9: e10543, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33505791

RESUMO

BACKGROUND: The VP2 on the surface of the virus particle is the main structural protein of BTV, which can induce the host to produce neutralizing antibodies and play an important role in the antiviral immunity process. This study aimed to obtain the soluble VP2 and analyze its immunogenicity. METHODS: The gene encoding the full-length VP2 of BTV1 was amplified by PCR. The products from restriction enzyme digestion and ligase reaction between VP2 and vector pET-28a were transformed into E.coli DH5α. After PCR and sequencing detection, the positive plasmid PET28a-VP2 was transformed into E.coli BL21(DE3) and Rosetta(DE3) competent cells, expression induced by IPTG. The fusion protein was expressed in the optimized conditions with the induction of IPTG, purified by affinity chromatography and identified by SDS-PAGE and Western blotting. A total of 5 Balb/c mice aged 6-8 weeks were immunized with the fusion protein at a dose of 30 µg per mouse. Each mouse was immunized three times at an interval of 3 weeks. RESULTS: The recombinant plasmid PET28a-VP2 was successfully constructed. The expression strains were induced by 0.4 mmol/L IPTG at 16 °C for 10 h, and BTV1 VP2 was expressed in a soluble form. The purity of the recombinant VP2 protein (∼109 kDa) was about 90% in the concentration at 0.2 mg/ml afterpurification. The purified VP2 had good immunoreactivity with BTV1 positive serum. Taken together, thisstudy offered a route for producing soluble BTV VP2, which retains activity and immunogenicity, to bebeneficial to the research on developing BTV vaccine, and lay the foundation for further research on BTV.

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