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Portable Paper-Based Immunoassay Combined with Smartphone Application for Colorimetric and Quantitative Detection of Dengue NS1 Antigen

Dengue virus (DENV) infection, which is transmitted by Aedes mosquitoes, is a major public health concern in tropical and subtropical countries. With an ...

Phramongkutklao Hospital and College of Medicine

Upper airway diseases including allergic rhinitis, chronic rhinosinusitis with or without polyps, and cystic fibrosis are characterized by substantially different inflammatory profiles. Traditionally, studies on the association of specific bacterial patterns with inflammatory profiles of diseases had been dependent on bacterial culturing. In the past 30 years, molecular biology methods have allowed bacterial culture free studies of microbial communities, revealing microbiota much more diverse than previously recognized including those found in the upper airway. At presence, the study of the pathophysiology of upper airway diseases is necessary to establish the relationship between the microbiome and inflammatory patterns to find their clinical reflections and also their possible causal relationships. Such investigations may elucidate the path to therapeutic approaches in correcting an imbalanced microbiome. In the review we summarized techniques used and the current knowledge on the microbiome of upper airway diseases, the limitations and pitfalls, and identified areas of interest for further research.

The microbiome of the upper airways: focus on chronic rhinosinusitis.

Chronic rhinosinusitis is a multifactorial process disease in which bacterial infection or colonization may play an important role in the initiation or persistence of inflammatory response. The association between mucosal bacteria presence and inflammatory patterns has only been partially explored.

Association of Mucosal Organisms with Patterns of Inflammation in Chronic Rhinosinusitis.

Chronic rhinosinusitis with nasal polyp (CRSwNP) patients are often characterized by asthma comorbidity and a type-2 inflammation of the sinonasal mucosa. The mucosal microbiota has been suggested to be implicated in the persistence of inflammation, but associations have not been well defined. To compare the bacterial communities of healthy subjects with CRSwNP patients, we collected nasal swabs from 17 healthy subjects, 21 CRSwNP patients without asthma (CRSwNP-A), and 20 CRSwNP patients with co-morbid asthma (CRSwNP+A). We analysed the microbiota using high-throughput sequencing of the bacterial 16S rRNA. Bacterial communities were different between the three groups. Haemophilus influenzae was significantly enriched in CRSwNP patients, Propionibacterium acnes in the healthy group; Staphylococcus aureus was abundant in the CRSwNP-A group, even though present in 57% of patients. Escherichia coli was found in high amounts in CRSwNP+A patients. Nasal tissues of CRSwNP+A patients expressed significantly higher concentrations of IgE, SE-IgE, and IL-5 compared to those of CRSwNP-A patients. Co-cultivation demonstrated that P. acnes growth was inhibited by H. influenzae, E. coli and S. aureus. The nasal microbiota of healthy subjects are different from those of CRSwNP-A and CRSwNP+A patients. However, the most abundant species in healthy status could not inhibit those in CRSwNP disease.

Chronic rhinosinusitis with nasal polyps is characterized by dysbacteriosis of the nasal microbiota.

We report a new highly selective detection platform for human albumin (HA) in urine based on aptamer-functionalised magnetic particles. Magnetic separation and re-dispersion was utilised to expose the HA-bound particles to a methylene blue solution. A second magnetic collection step was then used to allow the methylene blue supernatant to be reduced at an unmodified screen-printed electrode. Since methylene blue adsorbs to HA, the reduction current fell in proportion to HA concentration. There was no interference from compounds such as dopamine, epinephrine, vanillylmandelic acid, normetanephrine, metanephrine and creatinine in artificial urine at the concentrations at which they would be expected to appear. A calibration equation was derived to allow for the effect of pH on the response. This enabled measurement to be made directly in clinical urine samples of varying pH. After optimisation of experimental parameters, the total assay time was 40 min and the limit of detection was between 0.93 and 1.16 μg mL, depending on the pH used. HA could be detected up to 400 μg mL, covering the range from normoalbuminuria to macroalbuminuria. Analysis of urine samples of patients, with diabatic nephropathy, type I & II diabetes mellitus and chronic kidney disease, from a local hospital showed good agreement with the standard urinary human albumin detection method.

Aptamer-functionalised magnetic particles for highly selective detection of urinary albumin in clinical samples of diabetic nephropathy and other kidney tract disease.

This study aimed to evaluate a microfluidic paper-based analytical device (DEN-NS1-PAD) based on a rapid NS1 antigen test for diagnosing dengue at the point of care.

Clinical evaluation of a developed paper-based Dengue NS1 rapid diagnostic test for febrile illness patients.

Diabetic nephropathy (DN) is a serious diabetic complication, usually developed from type II diabetes mellitus (T2DM) and known as type II DN (T2DN). New emerging biomarkers for T2DN are microRNAs (miRNAs) which have been studied for the noninvasive early-stage detection of the disease. In this work, a nucleic acid amplification-free miRNA-124 sensor based on target-induced strand displacement on magnetic beads, and by using methylene blue-loaded silica particles as a label was developed. Measurement methods can be either visual observation, spectrophotometry, or electrochemistry. After incubation and separation of the magnetic particles, a blue-violet solution (564 nm) appeared, depending on the concentration of miRNA displaced. For electrochemical detection, methylene blue on the silica served as a redox mediator for the coupled reaction with ferricyanide in the solution phase. At the electrode surface, ferricyanide was re-reduced to ferrocyanide, and was thus available for further reaction with methylene blue, forming an amplification cycle. After optimization, the total assay time was 60 min, and limits of detection were 1 pM, 6 fM, and 0.65 fM, by the naked eye, spectrophotometry and electrochemistry, respectively. The miRNAs in 42 suspected urine samples from patients suffering from either diabetic nephropathy, diabetes mellitus, or chronic kidney disease were validated by comparing with the droplet digital polymerase chain reaction (ddPCR).

Thanit Chalermwatanachai

Department of Otolaryngology

Phramongkutklao Hospital and College of Medicine

Portable Paper-Based Immunoassay Combined with Smartphone Application for Colorimetric and Quantitative Detection of Dengue NS1 Antigen

Thanit Chalermwatanachai

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Otolaryngology

Phramongkutklao Hospital and College of Medicine

Portable Paper-Based Immunoassay Combined with Smartphone Application for Colorimetric and Quantitative Detection of Dengue NS1 Antigen

Department of Otolaryngology