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1.
J Clin Microbiol ; 62(2): e0012023, 2024 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-38284761

RESUMEN

Rapid phenotypic detection assays, including Carba NP and its variants, are widely applied for clinical diagnosis of carbapenemase-producing Enterobacterales (CPE). However, these tests are based on the acidification of the pH indicator during carbapenem hydrolysis, which limits test sensitivity and speed, especially for the detection of CPE producing low-activity carbapenem (e.g., OXA-48 variants). Herein, we developed a novel rapid and sensitive CPE detection method (Carba PBP) that could measure substrate (meropenem) consumption based on penicillin-binding protein (PBP). Meropenem-specific PBP was used to develop a competitive lateral flow assay (LFA) for meropenem identification. For the detection of carbapenemase activity, meropenem concentration was optimized using a checkerboard assay. The performance of Carba PBP was evaluated and compared with that of Carba NP using a panel of 94 clinical strains characterized by whole-genome sequencing and carbapenem susceptibility test. The limit of detection of PBP-based LFA for meropenem identification was 7 ng mL-1. Using 10 ng mL-1 meropenem as the substrate, Carba PBP and Carba NP could detect 10 ng mL-1 carbapenemase within 25 min and 1,280 ng mL-1 CPE in 2 h, respectively. The sensitivity and specificity were 100% (75/75) and 100% (19/19) for Carba PBP and 85.3% (64/75) and 100% (19/19) for Carba NP, respectively. When compared with Carba NP, Carba PBP showed superior performance in detecting all the tested CPE strains (including OXA-48-like variants) within 25 min and presented two orders of magnitude higher analytical sensitivity, demonstrating potential for clinical diagnosis of CPE. IMPORTANCE This study successfully achieved the goal of carbapenemase activity detection with both high sensitivity and convenience, offering a convenient lateral flow assay for clinical diagnosis of carbapenemase-producing Enterobacterales.


Asunto(s)
Proteínas Bacterianas , beta-Lactamasas , Humanos , Proteínas de Unión a las Penicilinas/genética , Meropenem/farmacología , Pruebas de Sensibilidad Microbiana , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , beta-Lactamasas/metabolismo , Carbapenémicos/farmacología , Sensibilidad y Especificidad
2.
Biomed Microdevices ; 26(3): 30, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38913209

RESUMEN

Flexible electronics offer a versatile, rapid, cost-effective and portable solution to monitor water contamination, which poses serious threat to the environment and human health. This review paper presents a comprehensive exploration of the versatile platforms of flexible electronics in the context of heavy metal ion detection in water systems. The review overviews of the fundamental principles of heavy metal ion detection, surveys the state-of-the-art materials and fabrication techniques for flexible sensors, analyses key performance metrics and limitations, and discusses future opportunities and challenges. By highlighting recent advances in nanomaterials, polymers, wireless integration, and sustainability, this review aims to serve as an essential resource for researchers, engineers, and policy makers seeking to address the critical challenge of heavy metal contamination in water resources. The versatile promise of flexible electronics is thoroughly elucidated to inspire continued innovation in this emerging technology arena.


Asunto(s)
Metales Pesados , Metales Pesados/análisis , Agua/química , Electrónica , Contaminantes Químicos del Agua/análisis , Iones/química , Iones/análisis
3.
Anal Chem ; 95(39): 14665-14674, 2023 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-37679861

RESUMEN

A sandwich immunoassay theoretically exhibits higher sensitivity and specificity compared to a competitive counterpart; however, it is extremely difficult to obtain a pair of antibodies that can bind to a small molecule simultaneously, which is always thought to be a single epitope. In the present study, abamectin (ABM) was selected to prove the effect of hapten design and antibody recognition properties on the development of a sandwich immunoassay for small molecules. First, the epitopes of ABM were roughly located, and epitope distances were determined. Then, two haptens were designed by introducing spacer arms at the C4″-OH and C5-OH of ABM, respectively, aiming to provide the longest epitope distances. A total of seven rabbit polyclonal antibodies (pAbs) and 21 mouse monoclonal antibodies (mAbs) with various recognition properties were obtained. Extensive combinatorial associations of antibody pairs for simultaneously binding to ABM were performed, and only two mAb-mAb pairs were observed to achieve a sandwich immunoassay for ABM with a total success rate of 0.27%. The best mAb pair for sandwich immunoassay was confirmed by surface plasmon resonance, used to develop a sandwich immunoassay, and then evaluated by cross-reactivities and molecular docking with structurally similar analogues and abamectin. Altogether, the study provided a theoretical foundation as well as practical experience and demonstrated the importance of careful hapten design and extensive antibody screening to successfully establish the sandwich immunoassay for small molecules.


Asunto(s)
Anticuerpos Monoclonales , Haptenos , Animales , Ratones , Conejos , Simulación del Acoplamiento Molecular , Anticuerpos Monoclonales/química , Inmunoensayo , Epítopos , Ensayo de Inmunoadsorción Enzimática
4.
Anal Chem ; 95(12): 5223-5231, 2023 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-36920169

RESUMEN

Aggregation-induced emission luminogens (AIEgens) are promising candidates for bacterial imaging and detection because they can "Light-Up" pathogenic bacteria without complicated labeling or washing steps. However, there have been few in-depth analyses of the intrinsic mechanism underlying their utility as fluorescence probes for targeting bacteria. Therefore, using large-scale molecular dynamics simulations, we investigated the mechanism of their bacterial "Light-Up" behavior with N,N-diphenyl-4-(7-(pyridin-4-yl)benzo[c][1,2,5]thiadiazol-4-yl) aniline functionalized with 1-bromoethane (TBP-1). We propose that the triphenylamine motif of TBP-1, rather than the positively charged pyridine group, first contacts the cell membrane. After TBP-1 completely inserts into the cell membrane, the hydrophobic triphenylamine motif localizes in the hydrophobic core of the cell membrane, restricting the molecular variation of TBP-1, which induces the fluorescent "turn-on" and bacterial "Light-Up." On this basis, we established a heterogeneous lateral flow immunoassay (LFIA) for the detection of foodborne pathogens. The LFIA system showed improved sensitivity with a limit of detection as low as 103 CFU mL-1 and strong specificity. Our protocol opened an effective shortcut to the design of more efficient AIEgens and novel AIEgens-based immunoassays.


Asunto(s)
Técnicas Biosensibles , Colorantes Fluorescentes/química , Inmunoensayo , Diagnóstico por Imagen , Bacterias
5.
Nucleic Acids Res ; 49(3): 1235-1246, 2021 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-33398344

RESUMEN

We have identified chemical probes that simultaneously inhibit cancer cell progression and an immune checkpoint. Using the computational Site Identification by Ligand Competitive Saturation (SILCS) technology, structural biology and cell-based assays, we identify small molecules that directly and selectively bind to the RNA Recognition Motif (RRM) of hnRNP A18, a regulator of protein translation in cancer cells. hnRNP A18 recognizes a specific RNA signature motif in the 3'UTR of transcripts associated with cancer cell progression (Trx, VEGF, RPA) and, as shown here, a tumor immune checkpoint (CTLA-4). Post-transcriptional regulation of immune checkpoints is a potential therapeutic strategy that remains to be exploited. The probes target hnRNP A18 RRM in vitro and in cells as evaluated by cellular target engagement. As single agents, the probes specifically disrupt hnRNP A18-RNA interactions, downregulate Trx and CTLA-4 protein levels and inhibit proliferation of several cancer cell lines without affecting the viability of normal epithelial cells. These first-in-class chemical probes will greatly facilitate the elucidation of the underexplored biological function of RNA Binding Proteins (RBPs) in cancer cells, including their effects on proliferation and immune checkpoint activation.


Asunto(s)
Antineoplásicos/farmacología , Proteínas de Unión al ARN/antagonistas & inhibidores , Animales , Antineoplásicos/uso terapéutico , Antígeno CTLA-4/genética , Antígeno CTLA-4/metabolismo , Línea Celular Tumoral , Humanos , Ligandos , Ratones , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Resonancia Magnética Nuclear Biomolecular , Biosíntesis de Proteínas , ARN/metabolismo , Motivo de Reconocimiento de ARN , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/metabolismo
6.
Proc Natl Acad Sci U S A ; 117(48): 30687-30698, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-33184176

RESUMEN

The SARS-CoV-2 pandemic has made it clear that we have a desperate need for antivirals. We present work that the mammalian SKI complex is a broad-spectrum, host-directed, antiviral drug target. Yeast suppressor screening was utilized to find a functional genetic interaction between proteins from influenza A virus (IAV) and Middle East respiratory syndrome coronavirus (MERS-CoV) with eukaryotic proteins that may be potential host factors involved in replication. This screening identified the SKI complex as a potential host factor for both viruses. In mammalian systems siRNA-mediated knockdown of SKI genes inhibited replication of IAV and MERS-CoV. In silico modeling and database screening identified a binding pocket on the SKI complex and compounds predicted to bind. Experimental assays of those compounds identified three chemical structures that were antiviral against IAV and MERS-CoV along with the filoviruses Ebola and Marburg and two further coronaviruses, SARS-CoV and SARS-CoV-2. The mechanism of antiviral activity is through inhibition of viral RNA production. This work defines the mammalian SKI complex as a broad-spectrum antiviral drug target and identifies lead compounds for further development.


Asunto(s)
Antivirales/farmacología , Coronavirus/efectos de los fármacos , Filoviridae/efectos de los fármacos , Interacciones Huésped-Patógeno/efectos de los fármacos , Complejos Multiproteicos/metabolismo , Orthomyxoviridae/efectos de los fármacos , Línea Celular , Genes Supresores , Modelos Moleculares , Terapia Molecular Dirigida , Unión Proteica , ARN Interferente Pequeño/metabolismo , ARN Viral/genética , ARN Viral/metabolismo , Saccharomyces cerevisiae/genética , Proteínas Virales/metabolismo , Replicación Viral/efectos de los fármacos
7.
Proc Natl Acad Sci U S A ; 117(2): 1049-1058, 2020 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-31896582

RESUMEN

Targeting Clostridium difficile infection is challenging because treatment options are limited, and high recurrence rates are common. One reason for this is that hypervirulent C. difficile strains often have a binary toxin termed the C. difficile toxin, in addition to the enterotoxins TsdA and TsdB. The C. difficile toxin has an enzymatic component, termed CDTa, and a pore-forming or delivery subunit termed CDTb. CDTb was characterized here using a combination of single-particle cryoelectron microscopy, X-ray crystallography, NMR, and other biophysical methods. In the absence of CDTa, 2 di-heptamer structures for activated CDTb (1.0 MDa) were solved at atomic resolution, including a symmetric (SymCDTb; 3.14 Å) and an asymmetric form (AsymCDTb; 2.84 Å). Roles played by 2 receptor-binding domains of activated CDTb were of particular interest since the receptor-binding domain 1 lacks sequence homology to any other known toxin, and the receptor-binding domain 2 is completely absent in other well-studied heptameric toxins (i.e., anthrax). For AsymCDTb, a Ca2+ binding site was discovered in the first receptor-binding domain that is important for its stability, and the second receptor-binding domain was found to be critical for host cell toxicity and the di-heptamer fold for both forms of activated CDTb. Together, these studies represent a starting point for developing structure-based drug-design strategies to target the most severe strains of C. difficile.


Asunto(s)
ADP Ribosa Transferasas/química , ADP Ribosa Transferasas/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Clostridioides difficile/metabolismo , Enterotoxinas/química , Enterotoxinas/metabolismo , ADP Ribosa Transferasas/genética , Animales , Proteínas Bacterianas/genética , Sitios de Unión , Fenómenos Biofísicos , Chlorocebus aethiops , Microscopía por Crioelectrón , Cristalografía por Rayos X , Modelos Moleculares , Resonancia Magnética Nuclear Biomolecular , Conformación Proteica , Dominios Proteicos , Células Vero
8.
Int J Lang Commun Disord ; 58(6): 1927-1938, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37260193

RESUMEN

BACKGROUND: Weak theory of mind (ToM) ability is a core deficit in children with autism. A growing body of work has found that there is a close relation between complement syntax and ToM in autistic children. However, researchers have not yet investigated whether other linguistic components may explain the difficulties in ToM reasoning in autistic children. AIMS: To determine whether verb factuality (i.e., mental and action verbs) is related to ToM ability, as measured by a false belief understanding (FBU) task after controlling the effect of complement syntax for Mandarin-speaking autistic children. METHODS & PROCEDURES: Participants were verbal autistic children, aged 4-7 years. Their IQ performance (verbal, performance and total IQ) and the comprehension of complement syntax were evaluated. A total of 38 children scoring over 9 points in complement syntax test and 90 points in the verbal IQ test were selected to complete verb factuality and FBU task. The χ2 tests and correlation analyses were carried out on two relations: (1) ToM ability and understanding of verb factuality; and (2) ToM ability and comprehension of complement syntax. OUTCOMES & RESULTS: A total of 11 autistic children completed the action verb factuality task, while 14 completed the mental verb factuality task and 13 completed both tasks. Participants performed well on the verb factuality task, and their ToM performance appeared to be related to their linguistic ability, regardless of the type of verb (i.e., action or mental verb). However, complement syntax scores did not significantly predict the success of the FBU task for the autistic children. CONCLUSIONS & IMPLICATIONS: The results of this study link weaker ToM ability with the understanding of verb factuality among autistic children aged 4-7 and provide new evidence for the view that the development of language facilitates improvement of ToM skills. The findings shed new light on how language affects or determines social interactions. WHAT THIS PAPER ADDS: What is already known on the subject ToM ability is crucial for social interaction. It has been claimed that mental verb factuality (e.g., think, had thought) may play a role in the development of ToM reasoning in typically developing children, but whether there is a link between the mastery of verb factuality and ToM skills in autistic children is still unclear. What this study adds to existing knowledge Correlational analysis revealed links between verbal ToM measured by unexpected location task and factuality test of mental verbs as well as action verbs. More importantly, this study confirmed the extra role of verb factuality in explaining ToM ability after excluding the influence of the complement syntax. What are the potential or actual clinical implications of this work? This study suggests that the factuality of verbs could serve as a tool for autistic children to infer the mental states of others. Thus, training on this linguistic structure could be taken into consideration when improving the social skills of autistic children.


Asunto(s)
Trastorno Autístico , Teoría de la Mente , Humanos , Niño , Lenguaje , Pruebas del Lenguaje
9.
Sensors (Basel) ; 23(18)2023 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-37765880

RESUMEN

A multi-exposure imaging approach proposed in earlier studies is used to increase star sensors' attitude update rate by N times. Unfortunately, serious noises are also introduced in the star image due to multiple exposures. Therefore, a star centroid extraction method based on Kalman Filter is proposed in this paper. Firstly, star point prediction windows are generated based on centroids' kinematic model. Secondly, the classic centroid method is used to calculate the coarse centroids of the star points within the prediction windows. Lastly, the coarse centroids are, respectively, processed by each Kalman Filter to filter image noises, and thus fine centroids are obtained. Simulations are conducted to verify the Kalman-Filter-based estimation model. Under noises with zero mean and ±0.4, ±1.0, and ±2.5 pixel maximum deviations, the coordinate errors after filtering are reduced to about 37.5%, 26.3%, and 20.7% of the original ones, respectively. In addition, experiments are conducted to verify the star point prediction windows. Among 100 star images, the average proportion of the number of effective star point objects obtained by the star point prediction windows in the total object number of each star image is calculated as only 0.95%. Both the simulated and experimental results demonstrate the feasibility and effectiveness of the proposed method.

10.
Molecules ; 28(9)2023 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-37175227

RESUMEN

TMAO is a new risk biomarker for cardiovascular disease. With trimethylammonium as its main chemical skeleton, TMAO is structurally similar to many endogenous metabolites, such as acetylcholine, carnitine, phosphorylcholine, etc. The mechanism of TMAO on the pathological process of CVD is still unclear. In this study, the quantitative analysis of plasma TMAO is conducted, and the contribution of Cathepsin B and NLRP3 inflammasome during the process of TMAO-induced endothelial injury was proposed and investigated at animal and cellular levels. Immunofluorescence assay was applied to represent the protein expression of Cathepsin B and NLRP3 inflammasome located at endothelial cells. The results showed that TMAO could disrupt endothelial cells permeability to induce endothelial injury, meanwhile, TMAO could increase NLRP3 inflammasome activation and promote the activity and expression of Cathepsin B in vitro and in vivo, whereas inhibition of NLRP3 inflammasome activation by MCC950 could protect the endothelial cells from TMAO associated endothelial injury via Cathepsin B. The study reveals that TMAO can cause endothelial injury via Cathepsin B-dependent NLRP3 inflammasome, and inhibition of Cathepsin B and NLRP3 inflammasome can reduce the TMAO-induced damage. The results provide new insight into the role of TMAO in CVD, which can be a potential therapeutic target for disease treatment and drug design.


Asunto(s)
Enfermedades Cardiovasculares , Inflamasomas , Animales , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Células Endoteliales/metabolismo , Células Cultivadas , Catepsina B/metabolismo , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Espectrometría de Masas en Tándem , Enfermedades Cardiovasculares/metabolismo
11.
Molecules ; 28(18)2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37764423

RESUMEN

(1) Background: Solanum nigrum L. is a plant of the genus Solanum in the family Solanaceae and is commonly used to treat tumors. Solasonin (SS) is a steroidal alkaloid extracted from Solanum nigrum L. that has anti-colorectal cancer (CRC) activity. (2) Methods: Column chromatography, semi-preparative HPLC and cellular activity screening were used to isolate potential anti-CRC active compounds in Solanum nigrum L., and structure identification using 1H-NMR and 13C-NMR techniques. Expression levels of HDAC in CRC were mined in the UALCAN database. The in vitro effects of SS on SW620 cell line and its mechanism were examined via Western blot, EdU staining, flow cytometry and immunofluorescence. CRC xenograft model and IHC staining were mainly used to evaluate the role of SS in vivo. (3) Results: The results showed that SS was the most potent anti-CRC component in Solanum nigrum L., which induced apoptosis and cell cycle arrest in the SW620 cell line. HDAC was highly expressed in CRC. The treatment of SW620 cell line with SS resulted in a significant downregulation of HDAC, an increase in the level of P53 acetylation and a subsequent increase in the level of P21. The in vivo validation results showed that SS could effectively inhibit CRC growth, which was associated with the downregulation of HDAC. (4) Conclusions: SS treatment for CRC mainly works through the induction of apoptosis and cycle arrest, and its mechanism of action is mainly related to HDAC-induced P53 acetylation, and the HDAC/P53 signaling pathway may be a potential pathway for the treatment of CRC.


Asunto(s)
Neoplasias , Solanum nigrum , Solanum , Humanos , Acetilación , Proteína p53 Supresora de Tumor/genética , Regulación hacia Abajo
12.
Int Wound J ; 20(9): 3491-3497, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37165731

RESUMEN

A meta-analysis investigation was executed to measurethe wound complications (WCs) frequency in heart transplant (HT) recipients on mammalian target of rapamycin inhibitors (MTRIs). A comprehensive literature investigation till February 2023 was applied and 978 interrelated investigations were reviewed. The 10 chosen investigations enclosed 2173 individuals with HT were in the chosen investigations' starting point, 1164 of them were utilising MTRIs, and 1009 were utilising control. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were utilised to compute the value of the WCs frequency in HT recipients on MTRIs by the dichotomous approaches and a fixed or random model. MTRIs had significantly higher WCs (OR, 1.53; 95% CI, 1.19-1.98, P = .001) compared with those with control in individuals with HT. MTRIs had significantly higher WCs compared with those with control in individuals with HT. However, care must be exercised when dealing with its values because of the low number of the nominated investigations and the low sample size of some of the nominated investigations for the meta-analysis.


Asunto(s)
Trasplante de Corazón , Inmunosupresores , Humanos , Inmunosupresores/efectos adversos , Serina-Treonina Quinasas TOR , Trasplante de Corazón/efectos adversos
13.
Int Wound J ; 20(9): 3794-3801, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37350616

RESUMEN

A meta-analysis research was executed to appraise the effect of platelet-rich plasma (PRP) on sternal wound healing (SWH). Inclusive literature research till April 2023 was done and 1098 interconnected researches were revised. The 11 picked researches, enclosed 8961 cardiac surgery (CS) persons were in the utilised researchers' starting point, 3663 of them were utilising PRP, and 5298 were control. Odds ratio (OR) and 95% confidence intervals (CIs) were utilised to appraise the effect of PRP on the SWH by the dichotomous approach and a fixed or random model. PRP had significantly lower sternal wound infection (SWI) (OR, 0.11; 95% CI, 0.03-0.34, p < 0.001), deep SWI (OR, 0.29; 95% CI, 0.16-0.51, p < 0.001), and superficial SWI (OR, 0.20; 95% CI, 0.13-0.33, p < 0.001), compared to control in CS persons. PRP had significantly lower SWI, deep SWI, and superficial SWI, compared to control in CS persons. However, caution must be taken when interacting with its values since there was a low sample size of some of the nominated research found for the comparisons in the meta-analysis.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Plasma Rico en Plaquetas , Humanos , Infección de la Herida Quirúrgica/terapia , Cicatrización de Heridas , Esternón/cirugía
14.
Int Wound J ; 2023 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-37740672

RESUMEN

We examined whether small incision aortic root replacement could reduce the amount of blood transfusion during operation and the risk of postoperative complications. An extensive e-review of the 4 main databases (PubMed, Cochrane, Web of Science and EMBASE) was carried out to determine all the published trials by July 2023. The search terms used were associated with partial versus full sternotomy and aortic root. This analysis only included the study articles that compared partial and full sternotomy. After excluding articles based on titles or abstracts, selected full-text articles had reference lists searched for any potential further articles. We analysed a total of 2167 subjects from 10 comparable trials. The minimally invasive aortic root graft in breastbone decreased the duration of hospitalization (MD, -2.58; 95% CI, -3.15, -2.01, p < 0.0001) and intraoperative red blood cell transfusion (MD, -1.27; 95% CI, -2.34, -0.19, p = 0.02). However, there were no significant differences in wound infection (OR, 0.88; 95% CI, 0.16, 4.93, p = 0.88), re-exploration for bleeding (OR, 0.96; 95% CI, 0.60, 1.53, p = 0.86), intraoperative blood loss (MD, -259.19; 95% CI, -615.11, 96.73, p = 0.15) and operative time (MD, -7.39; 95% CI, -19.10, 4.32, p = 0.22); the results showed that the microsternotomy did not differ significantly from that of the routine approach. Small sternotomy may be an effective and safe substitute for the treatment of the aorta root. Nevertheless, the wide variety of data indicates that larger, well-designed studies are required to back up the current limited literature evidence showing a benefit in terms of complications like postoperative wound infections or the volume of intraoperative red blood cell transfusion.

15.
Anal Chem ; 94(51): 17843-17852, 2022 12 27.
Artículo en Inglés | MEDLINE | ID: mdl-36519948

RESUMEN

The pursuit of the limit between dimensionalities is a scientific goal with high applicability. Sandwich immunoassay, usually based on two antibodies binding two epitopes, is one of the most popular mainstay tools in both academic and industrial fields. Herein, we determined and evaluated the minimum distance of two epitopes in sandwich immunoassays for small molecules. Briefly, nine model analytes comprising two hapten epitopes, that is, melamine (MEL) and p-nitroaniline (NIA), were designed by increasing the linear chain linkers brick by brick. Two groups of monoclonal antibodies (mAbs) were produced with different recognition properties toward MEL and NIA using 12 new haptens with different spacer arms. The results indicated that two epitopes of the analyte with a distance of only 2.4 Å could be simultaneously bound by two mAbs, which is the known limit of epitope distance in sandwich immunoassays thus far. We further found that an epitope distance of below 8.8 Å for the analyte generally induces noticeable steric hindrance of antibodies, preventing a sandwich immunoassay with high probability. These observations were investigated and evaluated by molecular docking, molecular dynamics, and surface plasmon resonance and using model and real analytes. Altogether, we determined the minimum distance of two epitopes and explored the molecular mechanism of the antibody-analyte-antibody ternary complex in sandwich immunoassays, providing a theoretical basis for hapten design, antibody discovery and development, and sandwich immunoassay establishment for small molecules.


Asunto(s)
Anticuerpos Monoclonales , Haptenos , Epítopos , Simulación del Acoplamiento Molecular , Inmunoensayo/métodos , Anticuerpos Monoclonales/química
16.
Anal Chem ; 94(6): 2996-3004, 2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-35107983

RESUMEN

Antibiotics abuse has caused various problems threatening human health and ecological environment. Monitoring antibiotics residual levels is of great significance, yet still challenging for quantitative point-of-need testing with high-sensitivity and visual capability. Here we developed a competitive lateral flow immunoassay (CLFIA) platform with flexible readout for enrofloxacin (ENR), a regularly added antibiotic. To overcome the limitation of low sensitivity of traditional colloidal gold-based CLFIA, the three-dimensionally assembled gold nanoparticles (AuNPs) within dendritic silica scaffold were fabricated as signal reporters. The assembly structure effectively retained the intrinsic absorption features of hydrophobic AuNPs and greatly enhanced the light extinction ability of a single label for signal amplification. The obtained CLFIA strips can not only achieve qualitative screening of ENR at a very low concentration by naked eye (cutoff value: 0.125 ng/mL), but also enable ultrasensitive quantification of ENR by an optical scanner (limit of detection: 0.00195 ng/mL) or a smartphone (limit of detection: 0.0078 ng/mL). Moreover, to elaborate the visual inspection degree of CLFIA against traditional yes/no interpretation, a novel multirange gradient CLFIA strip was prepared for visually semiquantitative identification of ENR with four concentration ranges. The novel CLFIA platform demonstrated sensitive, specific, and reliable determination of ENR with flexible signal readout and provides a potential and invigorating pathway to point-of-need immunoassay of antibiotics.


Asunto(s)
Oro , Nanopartículas del Metal , Enrofloxacina , Oro Coloide/química , Humanos , Inmunoensayo , Límite de Detección , Nanopartículas del Metal/química
17.
Analyst ; 147(13): 2942-2952, 2022 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-35674177

RESUMEN

A rare antibody that is able to tolerate physio-chemical factors is preferred and highly demanded in diagnosis and therapy. Rabbit monoclonal antibodies (RmAbs) are distinguished owing to their high affinity and stability. However, the efficiency and availability of traditional methods for RmAb discovery are limited, particularly for small molecules. Here, we present an indirect competitive screening method in nanowells, named CSMN, for single rabbit antibody-secreting cells (ASCs) selection with 20.6 h and propose an efficient platform for RmAb production against small molecules within 5.8 days for the first time. Chloramphenicol (CAP) as an antibacterial agent poses a great threat to public health. We applied CSMN to select CAP-specific ASCs and produced one high-affinity RmAb, surprisingly showed extremely halophilic properties with an IC50 of 0.08 ng mL-1 in the saturated salt solution, which has not yet been seen for other antibodies. The molecular dynamic simulation showed that the negatively charged surface improved the stability of the RmAb structure with additional disulfide bonds compared with mouse antibodies. Moreover, the reduced solvent accessible surface area of the binding pocket increased the interactions of RmAb with CAP in a saturated salt solution. Furthermore, RmAb was used to develop an immunoassay for the detection of CAP in real biological samples with simple pretreatment, shorter assay time, and higher sensitivity. The results demonstrated that the practical and efficient CSMN is suitable for rare RmAb discovery against small molecules.


Asunto(s)
Anticuerpos Monoclonales , Haptenos , Animales , Células Productoras de Anticuerpos , Inmunoensayo , Ratones
18.
Brain ; 144(2): 601-614, 2021 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-33374016

RESUMEN

Oculopharyngodistal myopathy is a late-onset degenerative muscle disorder characterized by ptosis and weakness of the facial, pharyngeal, and distal limb muscles. A recent report suggested a non-coding trinucleotide repeat expansion in LRP12 to be associated with the disease. Here we report a genetic study in a Chinese cohort of 41 patients with the clinical diagnosis of oculopharyngodistal myopathy (21 cases from seven families and 20 sporadic cases). In a large family with 12 affected individuals, combined haplotype and linkage analysis revealed a maximum two-point logarithm of the odds (LOD) score of 3.3 in chromosomal region chr19p13.11-p13.2 and narrowed the candidate region to an interval of 4.5 Mb. Using a comprehensive strategy combining whole-exome sequencing, long-read sequencing, repeat-primed polymerase chain reaction and GC-rich polymerase chain reaction, we identified an abnormal CGG repeat expansion in the 5' UTR of the GIPC1 gene that co-segregated with disease. Overall, the repeat expansion in GIPC1 was identified in 51.9% independent pedigrees (4/7 families and 10/20 sporadic cases), while the repeat expansion in LRP12 was only identified in one sporadic case (3.7%) in our cohort. The number of CGG repeats was <30 in controls but >60 in affected individuals. There was a slight correlation between repeat size and the age at onset. Both repeat expansion and retraction were observed during transmission but somatic instability was not evident. These results further support that non-coding CGG repeat expansion plays an essential role in the pathogenesis of oculopharyngodistal myopathy.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Distrofias Musculares/genética , Expansión de Repetición de Trinucleótido , Regiones no Traducidas 5' , Adulto , Anciano , Anciano de 80 o más Años , Pueblo Asiatico/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/patología , Distrofias Musculares/patología , Mutación , Linaje , Polimorfismo de Nucleótido Simple , Secuenciación del Exoma
19.
Environ Res ; 214(Pt 3): 114032, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35952741

RESUMEN

Here the role of microplastic size on dissolved organic matter, leaching compounds and microbial community during anaerobic sludge digestion was evaluated. Compared to that without the addition of polyvinyl chloride (PVC), during the 30 days' incubation, the anaerobic sludge digestion by adding PVC at the size of 75 µm and the concentration of 2.4 g/g volatile solids (VS) showed a 8.5% lower cumulative methane production, while a 17.9% higher cumulative methane production was noted by adding PVC at the size of 3000 µm and the concentration of 2.4 g/g VS. A long-term fed-batch laboratory-scale fermenter test for 147 days further testified, that higher removal efficiencies of total solids, volatile solids, and total chemical oxygen demand, and higher methane production were noted by adding PVC (2.4 g/g VS, 3000 µm) into the fermenter. More interestingly, higher concentrations of proteins, polysaccharides, volatile fatty acids, and soluble microbial by-products component were noted in the liquid phase of sludge drawn from the fermenter added with PVC since the biomass therein showed higher efficiencies of solubilization, hydrolysis, acidification, and methanogenesis. Moreover, as identified from the fermenter added with PVC, dibutyl phthalate (DBP) was the most predominant leaching phthalates compound, although the biomass therein showed a 93.4% anaerobic biodegradability of DBP. The leaching of DBP drove the predominance of microbial community towards Synergistota and Methanosaeta. More irregular elliptical shallow dimples were noted on the PVC surface after 147 days' incubation, accompanied with abundances of Proteobacteria, Actinobacteriota, Chloroflexi, Methanosaeta and Methanobacterium. The results from this study showed that the size of microplastic was a crucial factor in evaluating its impact on anaerobic sludge digestion.


Asunto(s)
Microbiota , Aguas del Alcantarillado , Anaerobiosis , Reactores Biológicos , Digestión , Materia Orgánica Disuelta , Metano , Microplásticos , Plásticos , Cloruro de Polivinilo , Aguas del Alcantarillado/química
20.
Environ Res ; 203: 111825, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34364865

RESUMEN

Deep dewatering of sewage sludge pretreated with advanced oxidation processes (AOPs) is a strategy for efficient sludge reduction and subsequent disposal. The pretreatment and dewatering performance of sludge conditioned with three types of AOPs (Fe2+/H2O2, Fe2+/Ca(ClO)2, and Fe2+/Na2S2O8), compared with sludge conditioned with traditional conditioner (Fe3+/CaO), were investigated in both bench and pilot-scale tests. All of those conditioner systems could reduce the water content of dewatered sludge cake to below 60 wt% in bench-scale (about 16 kg raw sludge per round) and pilot-scale (approximate 800 kg raw sludge per round) diaphragm filter press dewatering. Compared with raw sludge, the deep-dewatering filtrate after different conditioning and dewatering processes had higher ammonia nitrogen (NH4+-N) and chemical oxygen demand (COD) contents due to the degradation of organic matter, and much lower total phosphorus (TP) content due to the formation of iron phosphate precipitate. A better biodegradability (i.e. higher BOD5/COD ratio) was found in the deep-dewatering filtrate of sludge conditioned with Fe2+/H2O2 (25.2 %) and Fe2+/Ca(ClO)2 (17.4 %). Most of the heavy metals (Cr, Cu, Ni, and Pb) (>79 wt%) have remained in the dewatered sludge cake, and most of the Cl element (>90 wt%) in the sludge pretreated by Fe2+/Ca(ClO)2 and Fe3+/CaO was kept in the filtrate, rather than the dewatered sludge cake. Based on the pilot-scale experimental results, if all the filtrate in the deep-dewatering process returned to the influent of WWTP, the loading ratios of TP, NH4+-N, COD in the four conditioner systems were less than 3 wt%. The above results proved that the AOPs conditioned sludge could achieve deep-dewatering in pilot-scale and the direct recirculation of deep-dewatering filtrate to the influent of wastewater treatment plant was feasible.


Asunto(s)
Aguas del Alcantarillado , Purificación del Agua , Peróxido de Hidrógeno , Eliminación de Residuos Líquidos , Agua
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