RESUMO
Apolipoprotein E containing high-density lipoprotein (apoE-HDL) and apoE-HDL cholesterol (apoE-HDL-C) are recently recognized as potential biomarkers for coronary heart disease (CHD). We herein developed a two-stage, enzyme-assisted, dual-signal aptasensor that enables a useful electrochemical sensing platform for simultaneous determination of apoE-HDL, apoE-HDL-C, and total HDL-C presented in the sample. The detection scheme consists of two subsystems. In subsystem (I), the level of apoE-HDL is evaluated upon the binding of apoE-specific aptamer and subsequently methylene blue (MB)-labeled DNA displacement occurs on the electrode surface, resulting in electrochemical reduction of methylene blue. In subsystem (II), two kinds of cholesterol levels (apoE-HDL-C and total HDL-C) can be measured. For apoE-HDL-C, the amount of cholesterol in apoE-HDL captured by the aptamer in the first step can be further determined with the aid of surfactant, cholesterol esterase, cholesterol oxidase, and p-aminophenol-mediated electrochemical signal amplification. As for total HDL-C, the amount of cholesterol is determined by the same approach as that used for apoE-HDL-C determination, but without washing (separation). The linear dynamic range for apoE-HDL determination is from 1 to 100 mg/dL (R2 = 1.00). For cholesterol standards, the linear dynamic range is determined to be 0-250 mg/dL (R2 = 0.98). Finally, serial dilutions of purified human HDL preparations were examined using the newly developed aptasensor; the percentage of apoE-HDL-C to HDL-C was found to be ~10%, which correlated well with previously reported values. In conclusion, we successfully developed an electrochemical aptasensor that allows concurrent quantification of apoE-HDL, apoE-HDL-C, and HDL-C on the same platform, offering an efficient, convenient, and purification-free sensing strategy for predictive CHD biomarkers.
Assuntos
Apolipoproteínas E , HDL-Colesterol , Doença das Coronárias , Fatores de Risco de Doenças Cardíacas , Doença das Coronárias/diagnóstico , Humanos , Azul de MetilenoRESUMO
BACKGROUND: Early detection of dysphagia is important for preventing aspiration pneumonia. Although videofluoroscopy is currently the primary diagnostic tool for dysphagia, access to this tool may be limited because of radiation exposure risk, high cost, and other factors. PURPOSE: In this study, a meta-analysis was used to determine the strength of the correlation between dysphagia detection outcomes obtained using subjective questionnaires and videofluoroscopy. METHODS: The PubMed and Embase databases were searched for original articles up to December 2022. Studies published in English that used cross-sectional designs to assess the correlation between subjective questionnaires and videofluoroscopy were considered eligible for inclusion. The search terms used included "dysphagia," "questionnaire," and "videofluoroscopy." Two reviewers critically appraised and extracted the correlation coefficient r values. In addition, a random-effects meta-analysis was conducted. The Q statistic was used to assess the heterogeneity among the included studies. Publication bias was checked using the funnel plot and Egger's tests. Multilevel analysis was used to determine sensitivity to consider within-study correlations. In addition, subgroup analyses were conducted based on type of questionnaire, head and neck cancer, and English-speaking regions. RESULTS: The meta-analysis included five studies and 856 patients using the Eating Assessment Tool-10 and one study and 27 patients using the Sydney Swallow Questionnaire. The results of the random-effects meta-analysis showed a moderate relationship between the subjective questionnaires and videofluoroscopy ( r = .35, 95% CI [0.20, 0.48]). Similar results were also obtained using multilevel analysis ( r = .34, 95% CI [0.25, 0.42]). No publication bias was found for any of the studies ( p = .88). In the subgroup analyses, a moderate relationship between Eating Assessment Tool-10 and videofluoroscopy ( r = .31, 95% CI [0.19, 0.42]) and an ultrahigh relationship between Sydney Swallow Questionnaire and video-fluoroscopy ( r = .74, 95% CI [0.50, 0.87]) were found. Furthermore, moderate associations were observed within each head and neck cancer and English-speaking regions subgroup. However, no significant differences were found between these two subgroups. CONCLUSIONS: These results indicate the subjective questionnaires considered in this study share a moderate relationship with videofluoroscopy. Subjective questionnaires may be used as an auxiliary tool by nurses and homecare givers for the early assessment of dysphagia risk in patients.
Assuntos
Transtornos de Deglutição , Neoplasias de Cabeça e Pescoço , Humanos , Transtornos de Deglutição/diagnóstico por imagem , Inquéritos e QuestionáriosRESUMO
A flow-injection analytical (FIA) system was developed for the determination of cholesterol concentrations based on enzymatic reactions that occurred in a cholesterol oxidase (CHOx)-immobilized, fused-silica capillary followed by electrochemical detection. The production of hydrogen peroxide from cholesterol in an enzymatic reaction catalyzed by CHOx was subsequently oxidized electrochemically at an electrode. Our FlA system demonstrated its cost-effectiveness and utility at an applied potential of 0.6 V (vs. Ag/AgCl), a flow rate of 100 µL/min and, under optimal conditions, the resulting signal demonstrated a linear dynamic range from 50 µM to 1.0 mM with a limit of detection (LOD) of 12.4 µM, limit of quantification (LOQ) of 44.9 µM, and the coefficient of variation of 5.17%. In addition, validation of our proposed system using a reference HDL-cholesterol kit used for clinical diagnosis suggested our FIA system was comparable to commercial kits for the determination of the cholesterol incorporation amount in various aqueous liposomal suspensions. These good analytical features achieved by FIA could make the implementation of this methodology possible for on-line monitoring of cholesterol in various types of samples.