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1.
Hepatol Commun ; 7(7)2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-37314737

RESUMEN

BACKGROUND AIMS: Early-stage HCC can be treated with thermal ablation or stereotactic body radiation therapy (SBRT). We retrospectively compared local progression, mortality, and toxicity among patients with HCC treated with ablation or SBRT in a multicenter, US cohort. APPROACH RESULTS: We included adult patients with treatment-naïve HCC lesions without vascular invasion treated with thermal ablation or SBRT per individual physician or institutional preference from January 2012 to December 2018. Outcomes included local progression after a 3-month landmark period assessed at the lesion level and overall survival at the patient level. Inverse probability of treatment weighting was used to account for imbalances in treatment groups. The Cox proportional hazard modeling was used to compare progression and overall survival, and logistic regression was used for toxicity. There were 642 patients with 786 lesions (median size: 2.1 cm) treated with ablation or SBRT. In adjusted analyses, SBRT was associated with a reduced risk of local progression compared to ablation (aHR 0.30, 95% CI: 0.15-0.60). However, SBRT-treated patients had an increased risk of liver dysfunction at 3 months (absolute difference 5.5%, aOR 2.31, 95% CI: 1.13-4.73) and death (aHR 2.04, 95% CI: 1.44-2.88, p < 0.0001). CONCLUSIONS: In this multicenter study of patients with HCC, SBRT was associated with a lower risk of local progression compared to thermal ablation but higher all-cause mortality. Survival differences may be attributable to residual confounding, patient selection, or downstream treatments. These retrospective real-world data help guide treatment decisions while demonstrating the need for a prospective clinical trial.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Radiocirugia , Adulto , Humanos , Carcinoma Hepatocelular/radioterapia , Estudios Retrospectivos , Radiocirugia/efectos adversos , Neoplasias Hepáticas/radioterapia , Selección de Paciente
2.
Viruses ; 15(3)2023 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-36992515

RESUMEN

The sandwich format immunoassay is generally more sensitive and specific than more common assay formats, including direct, indirect, or competitive. A sandwich assay, however, requires two receptors to bind non-competitively to the target analyte. Typically, pairs of antibodies (Abs) or antibody fragments (Fabs) that are capable of forming a sandwiching with the target are identified through a slow, guess-and-check method with panels of candidate binding partners. Additionally, sandwich assays that are reliant on commercial antibodies can suffer from changes to reagent quality outside the researchers' control. This report presents a reimagined and simplified phage display selection protocol that directly identifies sandwich binding peptides and Fabs. The approach yielded two sandwich pairs, one peptide-peptide and one Fab-peptide sandwich for the cancer and Parkinson's disease biomarker DJ-1. Requiring just a few weeks to identify, the sandwich pairs delivered apparent affinity that is comparable to other commercial peptide and antibody sandwiches. The results reported here could expand the availability of sandwich binding partners for a wide range of clinical biomarker assays.


Asunto(s)
Bacteriófagos , Biblioteca de Péptidos , Ensayo de Inmunoadsorción Enzimática/métodos , Bacteriófagos/metabolismo , Anticuerpos , Péptidos/metabolismo , Biomarcadores
3.
PLoS One ; 17(8): e0272163, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36001626

RESUMEN

A previous report demonstrated the strong association between the presence of antibodies binding to an epitope region from SARS-CoV-2 nucleocapsid, termed Ep9, and COVID-19 disease severity. Patients with anti-Ep9 antibodies (Abs) had hallmarks of antigenic interference (AIN), including early IgG upregulation and cytokine-associated injury. Thus, the immunological memory of a prior infection was hypothesized to drive formation of suboptimal anti-Ep9 Abs in severe COVID-19 infections. This study identifies a putative primary antigen capable of stimulating production of cross-reactive, anti-Ep9 Abs. Binding assays with patient blood samples directly show cross-reactivity between Abs binding to Ep9 and only one bioinformatics-derived, homologous putative antigen, a sequence derived from the neuraminidase protein of H3N2 influenza A virus. This cross-reactive binding is highly influenza strain specific and sensitive to even single amino acid changes in epitope sequence. The neuraminidase protein is not present in the influenza vaccine, and the anti-Ep9 Abs likely resulted from the widespread influenza infection in 2014. Therefore, AIN from a previous infection could underlie some cases of COVID-19 disease severity.


Asunto(s)
COVID-19 , Vacunas contra la Influenza , Gripe Humana , Anticuerpos Antivirales , Epítopos , Humanos , Subtipo H3N2 del Virus de la Influenza A , Gripe Humana/prevención & control , Neuraminidasa , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus
4.
Angew Chem Int Ed Engl ; 61(23): e202202021, 2022 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-35333430

RESUMEN

Unlocking the potential of personalized medicine in point-of-care settings requires a new generation of biomarker and proteomic assays. Ideally, assays could inexpensively perform hundreds of quantitative protein measurements in parallel at the bedsides of patients. This goal greatly exceeds current capabilities. Furthermore, biomarker assays are often challenging to translate from benchtop to clinic due to difficulties achieving and assessing the necessary selectivity, sensitivity, and reproducibility. To address these challenges, we developed an efficient (<5 min), robust (comparatively lower CVs), and inexpensive (decreasing reagent use and cost by >70 %) immunoassay method. Specifically, the immunoblot membrane is dotted with the sample and then developed in a vortex fluidic device (VFD) reactor. All assay steps-blocking, binding, and washing-leverage the unique thin-film microfluidics of the VFD. The approach can accelerate direct, indirect, and sandwich immunoblot assays. The applications demonstrated include assays relevant to both the laboratory and the clinic.


Asunto(s)
Microfluídica , Proteómica , Aceleración , Humanos , Inmunoensayo , Reproducibilidad de los Resultados
5.
Artículo en Inglés | MEDLINE | ID: mdl-35162711

RESUMEN

The prevalence rate of Cigar, Little Cigar, and Cigarillo (CLCC) use among youth rose above the rate of cigarettes for the first time in 2019, and Black and Hispanic youth remain disproportionately more susceptible and likely to use these products compared to White youth. Addressing this disparity through education requires a clearer understanding of the ways youth refer to, and group, CLCCs. Twenty-eight virtual focus groups with youth ages 13-17 (n = 105) were conducted across the U.S. Groups were split by race/ethnicity, with 14 Black and 14 Hispanic groups, and further divided by CLCC experimenters and susceptible users. Youth participants discussed CLCC use behaviors, harm and risk perceptions, and knowledge, attitudes, and beliefs about CLCC products. When shown photos of CLCC products during focus groups, youth across groups identified and labeled these products into four subcategories. Large cigars were universally labeled "cigars". Little cigars were unfamiliar and guessed to be cigarettes. Tipped cigarillos were synonymous with the brand Black and Mild and considered tobacco. Untipped cigarillos were most referred to as "blunts" and used with marijuana. Understanding the nuances of language and use patterns of CLCCs is critical to ensuring the accuracy of measurement and impact of public health communications.


Asunto(s)
Cannabis , Productos de Tabaco , Adolescente , Hispánicos o Latinos , Humanos , Nicotiana , Uso de Tabaco
6.
Tob Control ; 2022 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-36601779

RESUMEN

INTRODUCTION: Studies show that tobacco use among sexual and gender minority (SGM) populations is disproportionately higher than heterosexual or cisgender populations. However, few studies have examined tobacco use among SGM subgroups by race/ethnicity or associations between SGM-specific discrimination and connection to SGM identity and tobacco use. METHODS: This study analysed survey data from 11 313 SGM (gay, lesbian, bisexual, other sexual minority or gender minority) young adults in the USA and reported current cigarette, e-cigarette, other tobacco (cigar, smokeless tobacco, hookah) and polytobacco use. We used multinomial logistic regression to estimate associations between (a) SGM subgroup, race/ethnicity, SGM-specific discrimination and SGM identity connection and (b) each tobacco use outcome (vs never use of tobacco). We conducted postestimation testing to assess predicted probabilities of tobacco use against the sample average. RESULTS: Lesbian females (particularly black lesbian females) had higher-than-average probability of polytobacco use. White bisexual and lesbian participants had higher-than-average probability of cigarette and e-cigarette use, respectively. Higher levels of discrimination were associated with polytobacco use. Higher levels of identity connectedness were protective against certain tobacco use behaviours among gender minority participants and participants with high levels of discrimination experience. CONCLUSIONS: We found variations in tobacco use by SGM subgroups overall and by race/ethnicity. Discrimination may be a risk factor for certain tobacco use behaviours. However, SGM identity connectedness may be protective against tobacco use among gender minority individuals and individuals experiencing SGM-specific discrimination. These findings can inform targeted approaches to reach SGM subgroups at greater risk of tobacco use.

7.
Anal Chem ; 93(32): 11259-11267, 2021 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-34347442

RESUMEN

The Virus BioResistor (VBR) is a biosensor capable of rapid and sensitive detection of small protein disease markers using a simple dip-and-read modality. For example, the bladder cancer-associated protein DJ-1 (22 kDa) can be detected in human urine within 1.0 min with a limit of detection (LOD) of 10 pM. The VBR uses engineered virus particles as receptors to recognize and selectively bind the protein of interest. These virus particles are entrained in a conductive poly(3,4-ethylenedioxythiophene) or PEDOT channel. The electrical impedance of the channel increases when the target protein is bound by the virus particles. But VBRs exhibit a sensitivity that is inversely related to the molecular weight of the protein target. Thus, large proteins, such as IgG antibodies (150 kDa), can be undetectable even at high concentrations. We demonstrate that the electrochemical overoxidation of the VBR's PEDOT channel increases its electrical impedance, conferring enhanced sensitivity for both small and large proteins. Overoxidation makes possible the detection of two antibodies, undetectable at a normal VBR, with a limit of detection of 40 ng/mL (250 pM), and a dynamic range for quantitation extending to 600 ng/mL.


Asunto(s)
Técnicas Biosensibles , Compuestos Bicíclicos Heterocíclicos con Puentes , Humanos , Inmunoglobulina G , Límite de Detección , Polímeros
8.
bioRxiv ; 2021 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-34127968

RESUMEN

A previous report demonstrated the strong association between the presence of antibodies binding to an epitope region from SARS-CoV-2 nucleocapsid, termed Ep9, and COVID-19 disease severity. Patients with anti-Ep9 antibodies (Abs) had hallmarks of antigenic imprinting (AIM), including early IgG upregulation and cytokine-associated injury. Thus, the immunological memory of a previous infection was hypothesized to drive formation of suboptimal anti-Ep9 Abs in severe COVID-19 infections. This study identifies a putative primary antigen capable of stimulating production of cross-reactive, anti-Ep9 Abs. Binding assays with patient blood samples directly show cross-reactivity between Abs binding to Ep9 and only one bioinformatics-derived, homologous potential antigen, a sequence derived from the neuraminidase protein of H3N2 Influenza A virus. This cross-reactive binding is highly influenza strain specific and sensitive to even single amino acid changes in epitope sequence. The neuraminidase protein is not present in the influenza vaccine, and the anti-Ep9 Abs likely resulted from the widespread influenza infection in 2014. Therefore, AIM from a previous infection could underlie some cases of COVID-19 disease severity. IMPORTANCE: Infections with SARS-COV-2 result in diverse disease outcomes, ranging from asymptomatic to fatal. The mechanisms underlying different disease outcomes remain largely unexplained. Previously, our laboratory identified a strong association between the presence of an antibody and increased disease severity in a subset of COVID-19 patients. Here, we report that this severity-associated antibody cross-reacts with viral proteins from an influenza A viral strain from 2014. Therefore, we speculate that antibodies generated against previous infections, like the 2014 influenza A, play a significant role in directing some peoples’ immune responses against SARS-COV-2. Such understanding of the sources and drivers of COVID-19 disease severity can help early identification and pre-emptive treatment.

9.
Chronic Obstr Pulm Dis ; 8(3): 371-381, 2021 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-34044475

RESUMEN

INTRODUCTION: Cathelicidin is a vitamin D-regulated, antimicrobial peptide involved in the innate immune response of the airways. Reduced plasma cathelicidin concentrations are independently associated with worse pulmonary outcomes in current and former smokers. This study aimed to determine whether oral vitamin D supplementation in vitamin D-deficient current smokers increases plasma and bronchoalveolar lavage (BAL) cathelicidin levels. METHODS: Vitamin D-deficient (25-hydroxy vitamin D [25-OH vitamin D] <20 ng/ml) smokers (n=17) underwent collection of plasma and BAL for cathelicidin and 25-OH vitamin D measurements before and after 8 weeks of oral supplementation with 50,000 IU vitamin D3 weekly. Differences between baseline and 8-week levels of cathelicidin and 25-OH vitamin D in blood and BAL were assessed along with correlations between serum 25-OH vitamin D, plasma cathelicidin, and BAL cathelicidin. RESULTS: At baseline, there was no correlation between BAL and plasma cathelicidin. There was a significant increase in 25-OH vitamin D (median 17.0 to 43.3 ng/mL, p<0.001) after 8 weeks of vitamin D supplementation. There was no change in plasma cathelicidin (p=0.86), BAL cathelicidin (p=0.31), or BAL 25-OH vitamin D (p=0.89). There was no correlation between serum 25-OH vitamin D and either BAL or plasma cathelicidin post-supplementation. CONCLUSIONS: Oral vitamin D supplementation, while increasing serum 25-OH vitamin D levels, does not increase plasma or BAL cathelicidin levels in vitamin D-deficient, active smokers. The lack of increased BAL cathelicidin may be explained by multiple factors related to dosing, smoking effects, or putative mechanisms of engagement. Future studies are needed to determine the effects of vitamin D supplementation on lung and blood functional activity.

10.
mSphere ; 6(2)2021 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-33910993

RESUMEN

Effective methods for predicting COVID-19 disease trajectories are urgently needed. Here, enzyme-linked immunosorbent assay (ELISA) and coronavirus antigen microarray (COVAM) analysis mapped antibody epitopes in the plasma of COVID-19 patients (n = 86) experiencing a wide range of disease states. The experiments identified antibodies to a 21-residue epitope from nucleocapsid (termed Ep9) associated with severe disease, including admission to the intensive care unit (ICU), requirement for ventilators, or death. Importantly, anti-Ep9 antibodies can be detected within 6 days post-symptom onset and sometimes within 1 day. Furthermore, anti-Ep9 antibodies correlate with various comorbidities and hallmarks of immune hyperactivity. We introduce a simple-to-calculate, disease risk factor score to quantitate each patient's comorbidities and age. For patients with anti-Ep9 antibodies, scores above 3.0 predict more severe disease outcomes with a 13.42 likelihood ratio (96.7% specificity). The results lay the groundwork for a new type of COVID-19 prognostic to allow early identification and triage of high-risk patients. Such information could guide more effective therapeutic intervention.IMPORTANCE The COVID-19 pandemic has resulted in over two million deaths worldwide. Despite efforts to fight the virus, the disease continues to overwhelm hospitals with severely ill patients. Diagnosis of COVID-19 is readily accomplished through a multitude of reliable testing platforms; however, prognostic prediction remains elusive. To this end, we identified a short epitope from the SARS-CoV-2 nucleocapsid protein and also a disease risk factor score based upon comorbidities and age. The presence of antibodies specifically binding to this epitope plus a score cutoff can predict severe COVID-19 outcomes with 96.7% specificity.


Asunto(s)
Anticuerpos Antivirales/sangre , COVID-19/diagnóstico , Proteínas de la Nucleocápside de Coronavirus/inmunología , SARS-CoV-2/inmunología , Índice de Severidad de la Enfermedad , COVID-19/patología , Técnicas de Visualización de Superficie Celular , Ensayo de Inmunoadsorción Enzimática , Epítopos/sangre , Epítopos/inmunología , Humanos , Nucleocápside/inmunología , Fosfoproteínas/inmunología , Pronóstico , Factores de Riesgo
11.
bioRxiv ; 2021 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-33083803

RESUMEN

Effective methods for predicting COVID-19 disease trajectories are urgently needed. Here, ELISA and coronavirus antigen microarray (COVAM) analysis mapped antibody epitopes in the plasma of COVID-19 patients (n = 86) experiencing a wide-range of disease states. The experiments identified antibodies to a 21-residue epitope from nucleocapsid (termed Ep9) associated with severe disease, including admission to the ICU, requirement for ventilators, or death. Importantly, anti-Ep9 antibodies can be detected within six days post-symptom onset and sometimes within one day. Furthermore, anti-Ep9 antibodies correlate with various comorbidities and hallmarks of immune hyperactivity. We introduce a simple-to-calculate, disease risk factor score to quantitate each patients comorbidities and age. For patients with anti-Ep9 antibodies, scores above 3.0 predict more severe disease outcomes with a 13.42 Likelihood Ratio (96.7% specificity). The results lay the groundwork for a new type of COVID-19 prognostic to allow early identification and triage of high-risk patients. Such information could guide more effective therapeutic intervention.

12.
Acc Chem Res ; 53(10): 2384-2394, 2020 10 20.
Artículo en Inglés | MEDLINE | ID: mdl-33001632

RESUMEN

The 2018 Nobel Prize in Chemistry recognized in vitro evolution, including the development by George Smith and Gregory Winter of phage display, a technology for engineering the functional capabilities of antibodies into viruses. Such bacteriophages solve inherent problems with antibodies, including their high cost, thermal lability, and propensity to aggregate. While phage display accelerated the discovery of peptide and protein motifs for recognition and binding to proteins in a variety of applications, the development of biosensors using intact phage particles was largely unexplored in the early 2000s. Virus particles, 16.5 MDa in size and assembled from thousands of proteins, could not simply be substituted for antibodies in any existing biosensor architectures.Incorporating viruses into biosensors required us to answer several questions: What process will allow the incorporation of viruses into a functional bioaffinity layer? How can the binding of a protein disease marker to a virus particle be electrically transduced to produce a signal? Will the variable salt concentration of a bodily fluid interfere with electrical transduction? A completely new biosensor architecture and a new scheme for electrical transduction of the binding of molecules to viruses were required.This Account describes the highlights of a research program launched in 2006 that answered these questions. These efforts culminated in 2018 in the invention of a biosensor specifically designed to interface with virus particles: the Virus BioResistor (VBR). The VBR is a resistor consisting of a conductive polymer matrix in which M13 virus particles are entrained. The electrical impedance of this resistor, measured across 4 orders of magnitude in frequency, simultaneously measures the concentration of a target protein and the ionic conductivity of the medium in which the resistor is immersed. Large signal amplitudes coupled with the inherent simplicity of the VBR sensor design result in high signal-to-noise ratio (S/N > 100) and excellent sensor-to-sensor reproducibility. Using this new device, we have measured the urinary bladder cancer biomarker nucleic acid deglycase (DJ-1) in urine samples. This optimized VBR is characterized by extremely low sensor-to-sensor coefficients of variation in the range of 3-7% across the DJ-1 binding curve down to a limit of quantitation of 30 pM, encompassing 4 orders of magnitude in concentration.


Asunto(s)
Bacteriófago M13/aislamiento & purificación , Técnicas Biosensibles/métodos , Anticuerpos/inmunología , Bacteriófago M13/química , Bacteriófago M13/inmunología , Bacteriófago M13/metabolismo , Biomarcadores de Tumor/orina , Técnicas Biosensibles/instrumentación , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Electrodos , Humanos , Límite de Detección , Nanocables/química , Neoplasias/diagnóstico , Biblioteca de Péptidos , Polímeros/química , Proteína Desglicasa DJ-1/orina , Tecnicas de Microbalanza del Cristal de Cuarzo , Reproducibilidad de los Resultados , Relación Señal-Ruido
14.
Anal Chem ; 92(9): 6654-6666, 2020 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-32252524

RESUMEN

DJ-1, a 20.7 kDa protein, is overexpressed in people who have bladder cancer (BC). Its elevated concentration in urine allows it to serve as a marker for BC. However, no biosensor for the detection of DJ-1 has been demonstrated. Here, we describe a virus bioresistor (VBR) capable of detecting DJ-1 in urine at a concentration of 10 pM in 1 min. The VBR consists of a pair of millimeter-scale gold electrodes that measure the electrical impedance of an ultrathin (≈ 150-200 nm), two-layer polymeric channel. The top layer of this channel (90-105 nm in thickness) consists of an electrodeposited virus-PEDOT (PEDOT is poly(3,4-ethylenedioxythiophene)) composite containing embedded M13 virus particles that are engineered to recognize and bind to the target protein of interest, DJ-1. The bottom layer consists of spin-coated PEDOT-PSS (poly(styrenesulfonate)). Together, these two layers constitute a current divider. We demonstrate here that reducing the thickness of the bottom PEDOT-PSS layer increases its resistance and concentrates the resistance drop of the channel in the top virus-PEDOT layer, thereby increasing the sensitivity of the VBR and enabling the detection of DJ-1. Large signal amplitudes coupled with the inherent simplicity of the VBR sensor design result in high signal-to-noise (S/N > 100) and excellent sensor-to-sensor reproducibility characterized by coefficients of variation in the range of 3-7% across the DJ-1 binding curve down to a concentration of 30 pM, near the 10 pM limit of detection (LOD), encompassing four orders of magnitude in concentration.


Asunto(s)
Bacteriófago M13/química , Biomarcadores de Tumor/orina , Técnicas Biosensibles , Proteína Desglicasa DJ-1/orina , Neoplasias de la Vejiga Urinaria/orina , Humanos , Factores de Tiempo
15.
J Pediatr Surg ; 54(5): 949-954, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30782443

RESUMEN

PURPOSE: Limited data exists for longitudinal growth outcomes in neonates with a history of necrotizing enterocolitis (NEC). We aimed to study 20-year growth outcomes in NEC survivors. METHODS: A retrospective matched cohort study included neonates diagnosed with NEC and control subjects matched for birth year, birth weight, and gestational age who had at least one post-discharge follow-up. The primary outcome was growth, measured by length and weight until 20 years. Logistic regression was used to test the change in growth from birth until most recent encounter. RESULTS: Five hundred twenty-seven neonates were included: 294 with NEC, and 233 controls. Sixty-eight percent of NEC cases were Bell's stage I, 25% were stage II, and 7% were stage III. Median gestational age was 29 weeks, and median birth weight was 1237 g. Infants with NEC had a longer NICU stay (p < 0.0001) and increased number of comorbidities (p < 0.0001). Compared to overall and sex-matched controls, infants with NEC had a significantly slower growth rate in terms of weight (p < 0.0068) but not length (p = 0.09). Neither group exhibited failure to thrive. CONCLUSIONS: These results suggest that non-surgical NEC may have a more profound impact on long-term growth than previously considered. TYPE OF STUDY: Retrospective Cohort-Matched Study. LEVEL OF EVIDENCE: Level III.


Asunto(s)
Estatura , Peso Corporal , Desarrollo Infantil , Enterocolitis Necrotizante/fisiopatología , Enfermedades del Prematuro/fisiopatología , Adolescente , Estudios de Casos y Controles , Niño , Preescolar , Comorbilidad , Femenino , Edad Gestacional , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Masculino , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Factores de Tiempo , Adulto Joven
16.
ACS Appl Mater Interfaces ; 11(5): 4757-4765, 2019 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-30668098

RESUMEN

A polymer-based electrode capable of specific detection of human serum albumin, and its glycated derivatives, is described. The sensor is constructed from a glass microscope slide coated with a synthesized, polythiophene film bearing a protected, iminodiacetic acid motif. The electrode surface is then further elaborated to a functional biosensor through deprotection of the iminodiacetic acid, followed by metal-affinity immobilization of a specific and high-affinity, albumin ligand. Albumin was then quantified in buffer and synthetic urine via electrochemical impedance spectroscopy. Glycated albumin was next bound to a boronic acid-modified, single-cysteine dihydrofolate reductase variant to quantify glycation ratios by square-wave voltammetry. The platform offers high sensitivity, specificity, and reproducibility in an inexpensive arrangement. The detection limits exceed the requirements for intermediate-term glycemic control monitoring in diabetes patients at 5 and 1 nM for albumin and its glycated forms, respectively.


Asunto(s)
Técnicas Biosensibles/métodos , Técnicas Electroquímicas/métodos , Albúmina Sérica Humana/orina , Albúmina Sérica/análisis , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Diseño de Equipo , Productos Finales de Glicación Avanzada , Humanos , Modelos Biológicos , Tetrahidrofolato Deshidrogenasa/química , Tetrahidrofolato Deshidrogenasa/metabolismo , Albúmina Sérica Glicada
17.
Angew Chem Int Ed Engl ; 57(35): 11208-11212, 2018 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-29992680

RESUMEN

Mechano-activated chemistry is a powerful tool for remodeling of synthetic polymeric materials, however, few reactions are currently available. Here we show that using piezochemical reduction of a CuII -based pre-catalyst, a step-growth polymerization occurs via the copper catalyzed azide-alkyne cycloaddition (CuAAC) reaction to form a linear polytriazole. Furthermore, we show that a linear polymer can be crosslinked mechanochemically using the same chemistry to form a solid organogel. We envision that this chemistry can be used to harness mechanical energy for constructive purposes in polymeric materials.

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