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1.
Antimicrob Resist Infect Control ; 13(1): 12, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38273403

RESUMO

BACKGROUND: Vietnam is among 11 countries in the Western Pacific region that has developed a National Action Plan for Antimicrobial Resistance (NAPCA). METHODS: This scoping review characterises health system barriers to the implementation of the Vietnam NAPCA, with reference to the WHO Health Systems Framework. RESULTS: Over 7 years, between 2013 and 2020, the Ministry of Health (MOH) of Vietnam has been implementing activities to achieve the six NAPCA objectives. They include revision of regulations needed for antimicrobial resistance (AMR) prevention programs; formation and operation of national management bodies; improvement of antimicrobial stewardship (AMS) in hospitals; maintenance of surveillance systems for AMR; provision of trainings on AMR and antibiotics use to doctors and pharmacists; and organization of nation-wide educational campaigns. Limited cooperation between MOH management bodies, shortages of human resource at all health system levels, a low degree of agreement between national and hospital guidelines on antibiotic use, low capability in the domestic supply of standardised drugs, and unequal training opportunities for lower-level health professionals present ongoing challenges. Actions suggested for the next period of the NAPCA include a final review of what has been achieved by the plan so far and evaluating the effectiveness of the different components of the plan. Different options on how to improve coordination across sectors in the development of a new NAPCA should be put forward. CONCLUSIONS: The 6-year implementation of the Vietnam NAPCA has yielded valuable lessons for AMS in Vietnam, guiding the development of future national plans, with a central focus on scaling up AMS in hospitals and promoting community AMS programs to combat AMR.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Humanos , Antibacterianos/uso terapêutico , Vietnã , Pessoal de Saúde , Farmacêuticos
2.
Biosensors (Basel) ; 13(8)2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37622895

RESUMO

Alzheimer's disease has taken the spotlight as a neurodegenerative disease which has caused crucial issues to both society and the economy. Specifically, aging populations in developed countries face an increasingly serious problem due to the increasing budget for patient care and an inadequate labor force, and therefore a solution is urgently needed. Recently, diverse techniques for the detection of Alzheimer's biomarkers have been researched and developed to support early diagnosis and treatment. Among them, electrochemical biosensors and electrode modification proved their effectiveness in the detection of the Aß biomarker at appropriately low concentrations for practice and point-of-care application. This review discusses the production and detection ability of amyloid beta, an Alzheimer's biomarker, by electrochemical biosensors with SAM support for antibody conjugation. In addition, future perspectives on SAM for the improvement of electrochemical biosensors are also proposed and discussed.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Humanos , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides , Anticorpos , Biomarcadores
3.
Anal Chim Acta ; 1273: 341535, 2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37423666

RESUMO

Plasma phosphorylated-tau threonine 181 (p-tau181) is a promising biomarker for predicting Alzheimer's disease (AD) and mild cognitive impairment (MCI), which is the symptomatic pre-dementia stage of AD. To date, there are limitations in the current diagnosis and classification of the two stages of MCI and AD in clinical practice remain a dilemma. In this study, we aimed to discriminate and diagnose patients with MCI, AD, and healthy participants based on the accurate, label-free, and ultrasensitive detection of p-tau181 levels in human clinical plasma samples using our developed electrochemical impedance-based biosensor, which allows to detect p-tau181 at a very low concentration of 0.92 fg mL-1. Human plasma samples were collected from 20 patients with AD, 20 patients with MCI, and 20 individuals with healthy control. The change in charge-transfer resistance of the developed impedance-based biosensor caused by capturing p-tau181 in plasma samples was recorded to evaluate the determination of plasma p-tau181 levels in human clinical samples for discrimination and diagnosis of AD, MCI, and healthy control individuals, respectively. Receiver operating characteristic (ROC) curve, a standard analysis to judge the clinically diagnostic capability of our biosensor platform based on the estimated levels of plasma p-tau181, resulted a sensitivity of 95%, a specificity of 85%, the area under the ROC curve (AUC) value of 0.94 of the accuracy for discriminating AD patients from healthy controls; a sensitivity of 70%, a specificity of 70%, the AUC of 0.75 to discriminate MCI patients from healthy controls. Statistical analysis (one-way analysis of variance (ANOVA)) was used to compare the estimated plasma p-tau181 levels in clinical samples, indicated significantly higher for AD patients with healthy controls (***p ≤ 0.001), AD with MCI patients (***p ≤ 0.001), and MCI patients with healthy controls (*p ≤ 0.05), respectively. In addition, we compared our sensor to the global cognitive function scales and discovered that it performed noticeably improvement in diagnosing the stages of AD. These results demonstrated the good application of our developed electrochemical impedance-based biosensor in the identification of clinical disease stages. Moreover, in this study, a small dissociation constant (KD) of 0.533 pM was first determined to evaluate the high binding affinity between the p-tau181 biomarker and its antibody, providing a reference parameter for future studies of the p-tau181 biomarker and AD.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/diagnóstico , Proteínas tau , Impedância Elétrica , Peptídeos beta-Amiloides , Disfunção Cognitiva/diagnóstico , Biomarcadores
4.
Micromachines (Basel) ; 14(5)2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37241556

RESUMO

Advancing low-cost and user-friendly innovations to benefit public health is an important task of scientific and engineering research. According to the World Health Organization (WHO), electrochemical sensors are being developed for low-cost SARS-CoV-2 diagnosis, particularly in resource-limited settings. Nanostructures with sizes ranging from 10 nm to a few micrometers could deliver optimum electrochemical behavior (e.g., quick response, compact size, sensitivity and selectivity, and portability), providing an excellent alternative to the existing techniques. Therefore, nanostructures, such as metal, 1D, and 2D materials, have been successfully applied in in vitro and in vivo detection of a wide range of infectious diseases, particularly SARS-CoV-2. Electrochemical detection methods reduce the cost of electrodes, provide analytical ability to detect targets with a wide variety of nanomaterials, and are an essential strategy in biomarker sensing as they can rapidly, sensitively, and selectively detect SARS-CoV-2. The current studies in this area provide fundamental knowledge of electrochemical techniques for future applications.

5.
PLoS One ; 17(9): e0275347, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36178928

RESUMO

BACKGROUND: Sediment scour at downstream of hydraulic structures is one of the main reasons threatening its stability. Several soil properties and initial input data have been studied to investigate its influence on scour hole geometry by both physical and numerical models. However, parameters of resistance affecting sedimentation and erosion phenomena have not been carried out in the literature. Besides, the auxiliary-like wing walls prevalently used in many real applications have been rarely addressed for their effect on morphological change. RESULTS: In this study, a 3D Computational Fluid Dynamics model is utilized to calibrate the hydraulic characteristics of steady flow going through the culvert by comparison with experimental data, showing good agreement between water depth, velocity, and pressure profiles at the bottom of the boxed culvert. The results show that a grid cell of 0.015 m gave minimum NRMSE and MAE values in test cases. Another approach is numerical testing sediment scour at a meander flume outlet with a variety of roughness/d50 ratio (cs) and diversion wall types. The findings include the following: cs = 2.5 indicates the close agreement between the numerical and analytical results of maximum scour depth after the culvert; the influence of four types of wing wall on the geometrical deformation including erosion at the concave bank and deposition at the convex bank of the meander flume outlet; and two short headwalls represent the best solution that accounts for small morphological changes. CONCLUSIONS: The influence of the roughness parameter of soil material and headwall types on sediment scour at the meander exit channel of hydraulic structure can be estimated by the numerical model.


Assuntos
Sedimentos Geológicos , Movimentos da Água , Animais , Hidrodinâmica , Solo , Água
6.
Sensors (Basel) ; 22(7)2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35408401

RESUMO

Miniaturization and wireless continuous glucose monitoring are key factors for the successful management of diabetes. Electrochemical sensors are very versatile and can be easily miniaturized for wireless glucose monitoring. The authors report a microneedle-based enzyme-free electrochemical wireless sensor for painless and continuous glucose monitoring. The microneedles (MNs) fabricated consist of a 3 × 5 sharp and stainless-steel electrode array configuration. Each MN in the 3 × 5 array has 575 µm × 150 µm in height and width, respectively. A glucose-catalyzing layer, porous platinum black, was electrochemically deposited on the tips of the MNs by applying a fixed cathodic current of 2.5 mA cm-2 for a period of 200 s. For the non-interference glucose sensing, the platinum (Pt)-black-coated MN was carefully packaged into a biocompatible ionomer, nafion. The surface morphologies of the bare and modified MNs were studied using field-emission scanning electron microscopy (FESEM) and energy-dispersive X-ray analysis (EDX). The wireless glucose sensor displayed a broad linear range of glucose (1→30 mM), a good sensitivity and higher detection limit of 145.33 µA mM-1 cm-2 and 480 µM, respectively, with bare AuMN as a counter electrode. However, the wireless device showed an improved sensitivity and enhanced detection limit of 445.75, 165.83 µA mM-1 cm-2 and 268 µM, respectively, with the Pt-black-modified MN as a counter electrode. The sensor also exhibited a very good response time (2 s) and a limited interference effect on the detection of glucose in the presence of other electroactive oxidizing species, indicating a very fast and interference-free chronoamperometric response.


Assuntos
Técnicas Biossensoriais , Glucose , Glicemia , Automonitorização da Glicemia , Técnicas Eletroquímicas , Eletrodos , Glucose/análise , Platina
7.
Materials (Basel) ; 15(6)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35329670

RESUMO

The self-assembled monolayer (SAM) is the most common organic assembly utilized for the formation of the monolayers of alkane-thiolates on gold electrode, resulting in a wide range of applications for the modified SAM on gold in various research areas. This study examined the desorption of a SAM that was developed on the gold surface of an interdigitated chain-shaped electrode (the ICE, a unique electrode design, was fabricated by our group) with the goal of determining the most efficient strategy of SAM removal for the ICE to be re-used. A simple and proficient solution-based cleaning procedure was applied for the removal of a SAM on the gold surface of the ICE by using a sodium borohydride solution within short-term treatment, resulting in efficiency for the recovery of the originally electrochemical characteristic of ICE of 90.3%. The re-use of ICE after the removal process was confirmed by the successful re-deposition of a SAM onto the electrode surface, resulting in the high efficiency percentage of 90.1% for the reusability of ICE with the SAM modification. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used as tools to investigate the changes in the electrode interface at each stage of the SAM removal and the electrode recycling. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy were employed, being powerful spectrum techniques, for the characterization of the bonding structure and chemical state of the bare ICE and the modified ICE at each treatment step. Based on the comprehensive discussion of analytical chemistry from the obtained EIS and CV data in this study, we confirmed and proved the effectiveness of this promising method for the removal of a SAM from the ICE and the re-use of ICE in the field of material deposition, with the aims of saving money, improving experimental handling, and protecting the environment.

8.
Emerg Infect Dis ; 28(3): 684-692, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35202526

RESUMO

We evaluated the effects of the coronavirus disease pandemic on diagnosis of and treatment for tuberculosis (TB) in Vietnam. We obtained quarterly notifications for TB and multidrug-resistant/rifampin-resistant (MDR/RR) TB from 2015-2020 and evaluated changes in monthly TB case notifications. We used an interrupted time series to assess the change in notifications and treatment outcomes. Overall, TB case notifications were 8% lower in 2020 than in 2019; MDR/RR TB notifications were 1% lower. TB case notifications decreased by 364 (95% CI -1,236 to 508) notifications per quarter and MDR/RR TB by 1 (95% CI -129 to 132) notification per quarter. The proportion of successful TB treatment outcomes decreased by 0.1% per quarter (95% CI -1.1% to 0.8%) in 2020 compared with previous years. Our study suggests that Vietnam was able to maintain its TB response in 2020, despite the pandemic.


Assuntos
COVID-19 , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose , Antituberculosos/uso terapêutico , COVID-19/epidemiologia , Humanos , Pandemias , Estudos Retrospectivos , SARS-CoV-2 , Tuberculose/diagnóstico , Tuberculose/tratamento farmacológico , Tuberculose/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Vietnã/epidemiologia
9.
J Minim Invasive Gynecol ; 29(2): 284-290, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34433103

RESUMO

STUDY OBJECTIVE: To compare the recurrence rate, post-treatment American Fertility Society (AFS) score, ongoing pregnancy rate, and endometrial thickness of 3 secondary prevention therapies in preventing recurrent intrauterine adhesions (IUAs) and increasing pregnancy rates in infertile women after hysteroscopic adhesiolysis. DESIGN: A retrospective study. SETTING: A private fertility hospital. PATIENTS: A total of 200 consecutive infertile women, with the desire to have a baby and were diagnosed as having IUAs detected by hysterosalpingogram, who underwent hysteroscopic adhesiolysis for IUAs from January, 2018 to May, 2020. INTERVENTIONS: Women who underwent hysteroscopic adhesiolysis received hormone therapy, and one of the 3 secondary preventions: hyaluronic acid (HA) gel alone, intrauterine devices (IUDs) alone, or HA gel + IUD. MEASUREMENTS AND MAIN RESULTS: Of the 200 women included in the final analysis, 121 received HA alone, 59 were treated with IUD alone, and 20 received HA gel + IUD combination. The mean post-treatment AFS score for IUAs was significantly lower in the HA gel + IUD group than the HA alone or the IUD alone groups (adjusted p = .01 and p = .02, respectively). Multivariable analysis revealed a significantly lower recurrence rate in the women after treatment with HA gel + IUD than HA alone (adjusted odds ratio, 0.19; 95% credible interval [CreI], 0.03-0.88). Women treated with HA gel + IUD also had reduced post-treatment AFS scores compared with HA alone (ß coefficients, -0.83; 95% CreI, -1.64 to -0.01). For ongoing pregnancy rates after in vitro fertilization, the adjusted odds ratio for HA gel + IUD vs HA alone was 2.03 (95% CreI, 0.44-11.00) and for IUD alone vs HA alone was 1.13 (95% CreI, 0.41-3.29), indicating nonsignificant differences. There were no differences observed in endometrial thickness on the day of embryo transfer among the 3 groups. CONCLUSION: The investigation of the primary outcome in reducing the recurrence rate IUA after treatment demonstrated that a combination of HA gel + IUD provides greater prevention of recurrent IUAs and may decrease post-treatment AFS scores for infertile women undergoing hysteroscopic adhesiolysis. However, for the secondary outcome of increasing pregnancy rates, there was no improvement in the ongoing pregnancy rates after in vitro fertilization.


Assuntos
Infertilidade Feminina , Dispositivos Intrauterinos , Doenças Uterinas , Feminino , Humanos , Ácido Hialurônico/uso terapêutico , Histeroscopia/efeitos adversos , Infertilidade Feminina/etiologia , Infertilidade Feminina/prevenção & controle , Infertilidade Feminina/cirurgia , Dispositivos Intrauterinos/efeitos adversos , Gravidez , Estudos Retrospectivos , Aderências Teciduais/etiologia , Aderências Teciduais/prevenção & controle , Aderências Teciduais/cirurgia , Doenças Uterinas/cirurgia
10.
Talanta ; 237: 122907, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34736644

RESUMO

In this paper, we developed a new ultrasensitive capacitance sensor for detection of amyloid beta 1-40 (aß40) protein (one of Alzheimer's disease core biomarkers) in human serum based on the high supramolecular recognition of the ß-cyclodextrin/reduced graphene oxide (ß-CD/RGO) nanohybrid toward the anti-aß40 antibody molecule. The sensor was established by immobilizing specific anti-aß40 antibody onto the ß-CD/RGO nanohybrid functionalized on indium tin oxide micro-disk electrode (anti-aß40/ß-CD/RGO/ITO). Detection of aß40 in the human serum (HS) using the sensor anti-aß40/ß-CD/RGO/ITO is carried out by capacitance measurement without a redox probe to prevent protein denaturation, serving as a convenient strategy for point-of-care diagnosis. In comparison with other studies, the sensor shows a very low limit of detection of 0.69 fg mL-1 in HS, demonstrating its ability for the ultrasensitive detection of aß40. Using this sensor, the dissociation constant KD of the binding interaction between anti-aß40 and aß40 in HS is found to be 2.9 × 10-7 nM, indicating the high binding affinity of antibody-antigen and the suitability of the anti-aß40/ß-CD/RGO/ITO sensor for aß40 protein detection. The good selectivity of the anti-aß40/ß-CD/RGO/ITO sensor in the presence of differential analytes was also performed in this paper.


Assuntos
Técnicas Biossensoriais , Grafite , beta-Ciclodextrinas , Peptídeos beta-Amiloides , Técnicas Eletroquímicas , Eletrodos , Humanos
11.
Phytochemistry ; 190: 112863, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34242970

RESUMO

Lepidium meyenii Walp., known as Peruvian ginseng, is widely used in ethnomedicine. To date, L. meyenii is cultivated worldwide at high-altitude and is commonly used as a food supplement. However, its medicinal value is still controversial and its mechanism of action remains unknown, due to limited knowledge about the phytochemical constituents of this plant species. In this study, a multidisciplinary approach comprising conventional NMR- and HRMS-based structure elucidation, quantum mechanical calculation of NMR chemical shifts and UPLC-MS/MS feature-based molecular networking was applied to analyse the phytochemical profile of L. meyenii. In the current work, three previously undescribed imidazole alkaloids were identified using extensive spectroscopic techniques (HRMS, NMR), for which the names lepidiline E, F and G were adopted. In addition, two amidine alkaloids were reported, representing an undescribed class of alkaloids in L. meyenii, and 1,2,3,4-tetrahydro-ß-carboline-3-carboxylic acid, a well-known ß-carboline alkaloid, was also isolated from L. meyenii for the first time. Molecular networks of imidazole, amidine and ß-carboline alkaloids in L. meyenii were constructed by the Global Natural Products Social Molecular Networking (GNPS) web platform, resulting in the tentative identification of three undescribed analogues. In addition, the structure of a previously reported compound named 'macaridine' was revised as macapyrrolin C based on density functional theory (DFT) calculations and comprehensive comparison of NMR data.


Assuntos
Alcaloides , Lepidium , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Extratos Vegetais , Piridinas , Espectrometria de Massas em Tandem
12.
Expert Rev Mol Diagn ; 21(2): 175-193, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33560154

RESUMO

INTRODUCTION: Alzheimer's disease (AD), a heterogeneous pathological process representing the most common causes of dementia worldwide, has required early and accurate diagnostic tools. Neuropathological hallmarks of AD involve the aberrant accumulation of Amyloid beta (Aß) into Amyloid plaques and hyperphosphorylated Tau into neurofibrillary tangles, occurring long before the onset of brain dysfunction.Areas covered:Considering the significance of Aß and Tau in AD pathogenesis, these proteins have been adopted as core biomarkers of AD, and their quantification has provided precise diagnostic information to develop next-generation AD therapeutic approaches. However, conventional diagnostic methods may not suffice to achieve clinical criteria that are acceptable for proper diagnosis and treatment. The advantages of nanomaterial-based biosensors including facile miniaturization, mass fabrication, ultra-sensitivity, make them useful to be promising tools to measure Aß and Tau simultaneously for accurate validation of low-abundance yet potentially informative biomarkers of AD.. EXPERT OPINION: The study has identified the potential application of advanced biosensors as standardized clinical diagnostic tools for AD, evolving the way for new and efficient AD control with minimum economic and social burden. After clinical trial, nanobiosensors for measuring Aß and Tau simultaneously possess innovative diagnosis of AD to provide significant contributions to primary Alzheimer's care intervention.


Assuntos
Doença de Alzheimer , Técnicas Biossensoriais , Nanoestruturas , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides , Diagnóstico Precoce , Humanos , Proteínas tau/metabolismo
13.
Sensors (Basel) ; 21(3)2021 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-33503934

RESUMO

Aggregation of amyloid-ß (aß) peptides into toxic oligomers, fibrils, and plaques is central in the molecular pathogenesis of Alzheimer's disease (AD) and is the primary focus of AD diagnostics. Disaggregation or elimination of toxic aß aggregates in patients is important for delaying the progression of neurodegenerative disorders in AD. Recently, 4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid (EPPS) was introduced as a chemical agent that binds with toxic aß aggregates and transforms them into monomers to reduce the negative effects of aß aggregates in the brain. However, the mechanism of aß disaggregation by EPPS has not yet been completely clarified. In this study, an electrochemical impedimetric immunosensor for aß diagnostics was developed by immobilizing a specific anti-amyloid-ß (aß) antibody onto a self-assembled monolayer functionalized with a new interdigitated chain-shaped electrode (anti-aß/SAM/ICE). To investigate the ability of EPPS in recognizing AD by extricating aß aggregation, commercially available aß aggregates (aßagg) were used. Electrochemical impedance spectroscopy was used to probe the changes in charge transfer resistance (Rct) of the immunosensor after the specific binding of biosensor with aßagg. The subsequent incubation of the aßagg complex with a specific concentration of EPPS at different time intervals divulged AD progression. The decline in the Rct of the immunosensor started at 10 min of EPPS incubation and continued to decrease gradually from 20 min, indicating that the accumulation of aßagg on the surface of the anti-aß/SAM/ICE sensor has been extricated. Here, the kinetic disaggregation rate k value of aßagg was found to be 0.038. This innovative study using electrochemical measurement to investigate the mechanism of aßagg disaggregation by EPPS could provide a new perspective in monitoring the disaggregation periods of aßagg from oligomeric to monomeric form, and then support for the prediction and handling AD symptoms at different stages after treatment by a drug, EPPS.


Assuntos
Doença de Alzheimer , Técnicas Biossensoriais , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides , Espectroscopia Dielétrica , Humanos , Imunoensaio
14.
Biomedicines ; 10(1)2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-35052691

RESUMO

The development of an electrochemical biosensor for the detection of phosphorylated-tau threonine 231 (p-tau231), a biomarker of Alzheimer's disease (AD), has yet to be achieved. Therefore, in this study, we developed a simple, small size, cheap, and sensitive electrochemical biosensor based on an interdigitated wave-shaped electrode via an activated self-assembled monolayer to preserve a specific anti-p-tau231 antibody (IWE/SAM/EDC-NHS/anti-p-tau231). Detection of p-tau231 in human serum (HS) using the biosensor was undertaken using electrochemical impedance spectroscopy (EIS). The change in charge-transfer resistance (Rct) in the EIS analysis of the biosensor indicated the detection of p-tau231 in HS within a wide linear range of detection (10-4-101 ng mL-1), and a low limit of detection (140 pg mL-1). This lower limit is less than the detection level of p-tau231 in cerebrospinal fluid (CSF) (700 pg mL-1) of AD patients and the level of CSF p-tau231 of patients with mild cognitive impairment (501 pg mL-1), demonstrating the possibility of using the biosensor in detection of p-tau231 at early stage AD. A high binding affinity and low dissociation constant (Kd) between anti-p-tau231 and p-tau231 in HS was demonstrated by using a biosensor and Kd was 7.6 pM, demonstrating the high specific detection of p-tau231 by the biosensor. The good selectivity of the biosensor for the detection of p-tau231 with differential analytes was also examined in this study.

15.
Nanomaterials (Basel) ; 10(9)2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32825146

RESUMO

Hydrogen peroxide (H2O2) is a partially reduced metabolite of oxygen that exerts a diverse array of physiological and pathological activities in living organisms. Therefore, the accurate quantitative determination of H2O2 is crucial in clinical diagnostics, the food industry, and environmental monitoring. Herein we report the electrosynthesis of silver nanoflowers (AgNFs) on indium tin oxide (ITO) electrodes for direct electron transfer of hemoglobin (Hb) toward the selective quantification of H2O2. After well-ordered and fully-grown AgNFs were created on an ITO substrate by electrodeposition, their morphological and optical properties were analyzed with scanning electron microscopy and UV-Vis spectroscopy. Hb was immobilized on 3-mercaptopropionic acid-coated AgNFs through carbodiimide cross-linking to form an Hb/AgNF/ITO biosensor. Electrochemical measurement and analysis demonstrated that Hb retained its direct electron transfer and electrocatalytic properties and acted as a H2O2 sensor with a detection limit of 0.12 µM and a linear detection range of 0.2 to 3.4 mM in phosphate-buffered saline (PBS). The sensitivity, detection limit, and detection range of the Hb/AgNF/ITO biosensor toward detection H2O2 in human serum was also found to be 0.730 mA mM-1 cm-2, 90 µM, and 0.2 to 2.6 mM, indicating the clinical application for the H2O2 detection of the Hb/AgNF/ITO biosensor. Moreover, interference experiments revealed that the Hb/AgNF/ITO sensor displayed excellent selectivity for H2O2.

16.
Micromachines (Basel) ; 11(9)2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32825726

RESUMO

Amyloid beta (aß) 1-42, a peptide that is 1-42 amino acids long, is a major component of senile plaques in the brains of patients with Alzheimer's disease. Aß detection has become an essential antecedence to predict the declining mental abilities of patients. In this paper, a probeless capacitive biosensor for the non-Faradaic detection of aß 1-42 peptide was developed by immobilizing a specific anti-aß antibody onto a self-assembled monolayer functionalized interdigitated chain-shaped electrode (anti-aß/SAM/ICE). The novelty and difference of this article from previous studies is the direct detection of aß peptide with no redox probe ((Fe(CN)6)3-/4-), which can avoid the denaturation of the protein caused by the metallization (binding of aß to metal ion Fe which is presented in the redox couple). The direct detection of aß with no redox probe is performed by non-Faradaic capacitive measurement, which is greatly different from the Faradaic measurement of the charge transfer resistance of the redox probe. The detection of various aß 1-42 peptide concentrations in human serum (HS) was performed by measuring the relative change in electrode interfacial capacitance due to the specific antibody-aß binding. Capacitance change in the anti-aß/SAM/ICE biosensor showed a linear detection range between 10 pg mL-1 and 104 pg mL-1, and a detection limit of 7.5 pg mL-1 in HS, which was much lower than the limit of detection for CSF aß 1-42 (~500 pg mL-1) and other biosensors. The small dissociation constant Kd of the antibody-antigen interaction was also found to be 0.016 nM in HS, indicating the high binding affinity of the anti-aß/SAM/ICE biosensor in the recognizing of aß 1-42. Thus, the developed sensor can be used for label-free and direct measurement of aß 1-42 peptide and for point-of-care diagnosis of Alzheimer's disease without redox probe.

17.
Biosens Bioelectron ; 144: 111694, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31539720

RESUMO

In this study, we developed a small size, low cost, highly sensitive electrochemical biosensor with a low limit of detection by immobilizing specific anti-amyloid-ß (aß) antibody onto a self-assembled monolayer functionalized interdigitated chain-shaped electrode (anti-aß/EDC-NHS/SAM/ICE). The anti-aß/EDC-NHS/SAM/ICE specifically detects aß 1-42 peptide (a peptide 1-42 amino acids long), which is one of main biomarkers of Alzheimer's disease in human serum (HS). Electrochemical impedance spectroscopy (EIS) was used to characterize the impedance change of the anti-aß/EDC-NHS/SAM/ICE biosensor for aß 1-42 detection, which provided a wide linear range of detection from 10-3-103 ng mL-1, and a low limit of detection of aß in HS (100 pg mL-1) much lower than the limit of detection of CSF aß 1-42 (∼500 pg mL-1), and other biosensors. Therefore, the developed biosensor is sensitive enough to be used for the diagnosis of early stage Alzheimer's disease.


Assuntos
Doença de Alzheimer/sangue , Peptídeos beta-Amiloides/sangue , Técnicas Biossensoriais , Fragmentos de Peptídeos/isolamento & purificação , Peptídeos beta-Amiloides/química , Biomarcadores/sangue , Biomarcadores/química , Técnicas Eletroquímicas , Eletrodos , Ouro/química , Humanos , Fragmentos de Peptídeos/química
18.
Int J Genomics ; 2016: 5078796, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28097123

RESUMO

Genome editing with engineered nucleases enabling site-directed sequence modifications bears a great potential for advanced plant breeding and crop protection. Remarkably, the RNA-guided endonuclease technology (RGEN) based on the clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) is an extremely powerful and easy tool that revolutionizes both basic research and plant breeding. Here, we review the major technical advances and recent applications of the CRISPR-Cas9 system for manipulation of model and crop plant genomes. We also discuss the future prospects of this technology in molecular plant breeding.

19.
J Emerg Med ; 42(6): e129-31, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19615847

RESUMO

BACKGROUND: We describe the case of a 53-year-old woman with hip pain secondary to an obturator hernia. Obturator hernia is uncommon, and the most lethal of all abdominal hernias. The high mortality rate of this disease requires an acute clinical awareness to facilitate rapid diagnosis and surgical intervention for improved prognosis. OBJECTIVES: This case highlights a vitally important diagnosis that is rarely discussed in the emergency medicine literature. CASE REPORT: Our patient presented without symptoms typical of a bowel obstruction, although a computed tomography scan of her pelvis revealed an incarcerated obturator hernia and a small bowel obstruction. CONCLUSIONS: Early diagnosis and expeditious surgical management resulted in a good outcome.


Assuntos
Hérnia do Obturador/complicações , Articulação do Quadril , Obstrução Intestinal/etiologia , Dor/etiologia , Feminino , Humanos , Pessoa de Meia-Idade
20.
J Biol Chem ; 278(23): 21136-45, 2003 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-12665522

RESUMO

3,3'-Diindolylmethane (DIM) is a major digestive product of indole-3-carbinol, a potential anticancer component of cruciferous vegetables. Our results indicate that DIM exhibits potent antiproliferative and antiandrogenic properties in androgen-dependent human prostate cancer cells. DIM suppresses cell proliferation of LNCaP cells and inhibits dihydrotestosterone (DHT) stimulation of DNA synthesis. These activities were not produced in androgen-independent PC-3 cells. Moreover, DIM inhibited endogenous PSA transcription and reduced intracellular and secreted PSA protein levels induced by DHT in LNCaP cells. Also, DIM inhibited, in a concentration-dependent manner, the DHT-induced expression of a prostate-specific antigen promoter-regulated reporter gene construct in transiently transfected LNCaP cells. Similar effects of DIM were observed in PC-3 cells only when these cells were co-transfected with a wild-type androgen receptor expression plasmid. Using fluorescence imaging with green fluorescent protein androgen receptor and Western blot analysis, we demonstrated that DIM inhibited androgen-induced androgen receptor (AR) translocation into the nucleus. Results of receptor binding assays indicated further that DIM is a strong competitive inhibitor of DHT binding to the AR. Results of structural modeling studies showed that DIM is remarkably similar in conformational geometry and surface charge distribution to an established synthetic AR antagonist, although the atomic compositions of the two substances are quite different. Taken together with our published reports of the estrogen agonist activities of DIM, the present results establish DIM as a unique bifunctional hormone disrupter. To our knowledge, DIM is the first example of a pure androgen receptor antagonist from plants.


Assuntos
Adenocarcinoma , Antagonistas de Androgênios/farmacologia , Anticarcinógenos/farmacologia , Indóis/farmacologia , Neoplasias da Próstata , Antagonistas de Androgênios/metabolismo , Anilidas/química , Anilidas/metabolismo , Anilidas/farmacologia , Animais , Anticarcinógenos/química , Anticarcinógenos/metabolismo , Ligação Competitiva , Divisão Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Citoplasma/metabolismo , DNA/biossíntese , Di-Hidrotestosterona/metabolismo , Di-Hidrotestosterona/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Indóis/química , Indóis/metabolismo , Masculino , Metribolona/metabolismo , Metribolona/farmacologia , Nitrilas , Antígeno Prostático Específico/genética , RNA Mensageiro/análise , Receptores Androgênicos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Congêneres da Testosterona/metabolismo , Congêneres da Testosterona/farmacologia , Compostos de Tosil , Transcrição Gênica/efeitos dos fármacos , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/fisiologia , Verduras/química
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