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1.
Healthcare (Basel) ; 11(4)2023 Feb 14.
Article in English | MEDLINE | ID: mdl-36833097

ABSTRACT

As the number of elderly drivers rapidly increases worldwide, interest in the dangers of driving is growing as accidents rise. The purpose of this study was to conduct a statistical analysis of the driving risk factors of elderly drivers. In this analysis, data from the government organization's open data were used for the secondary processing of 10,097 people. Of the 9990 respondents, 2168 were current drivers, 1552 were past drivers but were not driving presently, and 6270 did not have a driver's license; the participants were divided into groups accordingly. The elderly drivers who were current drivers had a better subjective health status than those who were not. Visual and hearing aids were used in the current driving group, and their depression symptoms reduced as they drove. The elderly who were current drivers experienced difficulties while driving in terms of decreased vision, hearing loss, reduced arm/leg reaction speed, decreased judgment of the road conditions such as signals and intersections, and a decreased sense of speed. The results suggest that elderly drivers are unaware of the medical conditions that can negatively affect their driving. This study contributes to the safety management of elderly drivers by understanding their mental and physical status.

2.
Healthcare (Basel) ; 10(10)2022 Sep 27.
Article in English | MEDLINE | ID: mdl-36292328

ABSTRACT

This study used raw data obtained from the Adolescents' Health Behavior Survey by government-affiliated agency open data. A total of 109,796 students were sampled. A comparative analysis was performed based on the year 2020 and when the COVID-19 pandemic occurred, in which we analyzed changes in adolescents' depression and panic anxiety perception and dietary habits, physical factors, physical activity, and handwashing habits. There was no weight control in the second year compared to the first year of the COVID-19 pandemic, and obesity also increased. The continuation of the non-contact situation caused by COVID-19 led to a worsening of subjective health awareness, and the experience of generalized anxiety disorder, depression, sadness and hopelessness, and suicidal thoughts and attempts increased. The frequency of washing hands with soap before meals and after using the toilet at school or at home was reduced. As a result of this analysis, we believe that there needs to be a system of support in place to address the academic gaps and deficiencies in learning caused by COVID-19, and that psychological and emotional support needs to be strengthened at this time, as well as the issues to be supported after the end of the non-contact situation.

3.
Exp Dermatol ; 27(2): 199-201, 2018 02.
Article in English | MEDLINE | ID: mdl-29197132

ABSTRACT

The purpose of this study was to establish a small-animal model for molecular imaging and to acquire basic data on assessing the efficacy of candidate melanoma drugs using small-animal PET imaging analysis with [18 F]FHBG for herpes simplex virus 1-thymidine kinase (HSV1-tk) gene expression in a melanoma mouse model. The B16 melanoma cell line was transduced with a recombinant lentiviral vector containing the HSV1-tk gene and inoculated into the back skin of C57BL/6J mice. [18 F]FHBG PET imaging showed better contrast for HSV1-tk(+) melanomas compared to brain, heart, gall bladder, intestine and kidney than did [18 F]FDG PET imaging.


Subject(s)
Gene Expression Regulation, Neoplastic , Melanoma/diagnostic imaging , Positron-Emission Tomography , Skin Neoplasms/diagnostic imaging , Animals , Fluorodeoxyglucose F18 , Gene Expression Profiling , Genes, Reporter , Genetic Therapy , Guanine/analogs & derivatives , HEK293 Cells , Herpesvirus 1, Human , Humans , Male , Melanoma/metabolism , Melanoma, Experimental , Mice , Mice, Inbred C57BL , Mice, Nude , Skin Neoplasms/metabolism , Thymidine Kinase , Tissue Distribution
4.
Skin Res Technol ; 23(4): 563-572, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28543966

ABSTRACT

BACKGROUND/PURPOSE: The visual scoring method has been used as a subjective evaluation of pigmentary skin disorders. Severity of pigmentary skin disease, especially melasma, is evaluated using a visual scoring method, the MASI (melasma area severity index). This study differentiates between epidermal and dermal pigmented disease. The study was undertaken to determine methods to quantitatively measure the severity of pigmentary skin disorders under ultraviolet illumination. METHODS: The optical imaging system consists of illumination (white LED, UV-A lamp) and image acquisition (DSLR camera, air cooling CMOS CCD camera). Each camera is equipped with a polarizing filter to remove glare. To analyze images of visible and UV light, images are divided into frontal, cheek, and chin regions of melasma patients. Each image must undergo image processing. To reduce the curvature error in facial contours, a gradient mask is used. RESULTS: The new method of segmentation of front and lateral facial images is more objective for face-area-measurement than the MASI score. Image analysis of darkness and homogeneity is adequate to quantify the conventional MASI score. Under visible light, active lesion margins appear in both epidermal and dermal melanin, whereas melanin is found in the epidermis under UV light. CONCLUSION: This study objectively analyzes severity of melasma and attempts to develop new methods of image analysis with ultraviolet optical imaging equipment. Based on the results of this study, our optical imaging system could be used as a valuable tool to assess the severity of pigmentary skin disease.


Subject(s)
Melanosis/diagnostic imaging , Equipment Design , Face , Humans , Optical Imaging/instrumentation , Optical Imaging/methods , Skin Pigmentation/physiology , Ultraviolet Rays
5.
J Fluoresc ; 27(1): 13-20, 2017 01.
Article in English | MEDLINE | ID: mdl-27633372

ABSTRACT

Early diagnosis is one of the most important factors that increase the therapeutic potential of the disease. Diagnoses conducted by conventional equipment are expensive, time-consuming, burdensome to patients, and do not have high success rates. Diagnostic methods have also been investigated using nanoparticles. However, there have been no significant improvements in the early diagnosis of disease. The diagnosis technique proposed in this paper consumes less time, is more cost-effective, and more accurate. It uses a new concept-a low-intensity fluorescence molecular imaging system with a lock-in technique. This study applied the lock-in technique to basic research in contrast enhancement and optimization. This improved fluorescence distribution analysis, resulting in increased resolution of optical molecular imaging for early diagnosis of disease. An experimental lock-in fluorescence imaging system, which used a variety of fluorescent dyes, achieved signal amplification 100 times greater than that of a conventional fluorescence imaging system. The results of this study demonstrate that the lock-in technique could significantly improve optical molecular imaging technology, making it possible to achieve early diagnosis of disease.


Subject(s)
Fluorescent Dyes , Molecular Imaging , Nanoparticles , Humans , Light , Optical Imaging
6.
J Invest Dermatol ; 136(1): 161-172, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26763436

ABSTRACT

Psoriasis is present in all racial groups, but in varying frequencies and severity. Considering that small plaque psoriasis is specific to the Asian population and severe psoriasis is more predominant in the Western population, we defined Asian small and intermediate plaque psoriasis as psoriasis subtypes and compared their molecular signatures with the classic subtype of Western large plaque psoriasis. Two different characteristics of psoriatic spreading-vertical growth and radial expansion-were contrasted between subtypes, and genomic data were correlated to histologic and clinical measurements. Compared with Western large plaque psoriasis, Asian small plaque psoriasis revealed limited psoriasis spreading, but IL-17A and IL-17-regulated proinflammatory cytokines were highly expressed. Paradoxically, IL-17A and IL-17-regulated proinflammatory cytokines were lower in Western large plaque psoriasis, whereas T cells and dendritic cells in total psoriatic skin area were exponentially increased. Negative immune regulators, such as CD69 and FAS, were decreased in both Western large plaque psoriasis and psoriasis with accompanying arthritis or obesity, and their expression was correlated with psoriasis severity index. Based on the disease subtype comparisons, we propose that dysregulation of T-cell expansion enabled by downregulation of immune negative regulators is the main mechanism for development of large plaque psoriasis subtypes.


Subject(s)
Gene Expression Regulation , Genes, Regulator , Interleukin-17/genetics , Psoriasis/ethnology , Psoriasis/genetics , Asian People/genetics , Biopsy, Needle , Cohort Studies , Disease Progression , Female , Humans , Immunohistochemistry , Male , Phenotype , Psoriasis/pathology , Risk Assessment , Sampling Studies , Severity of Illness Index , Signal Transduction , White People/genetics
7.
Med Biol Eng Comput ; 54(10): 1469-79, 2016 Oct.
Article in English | MEDLINE | ID: mdl-26589318

ABSTRACT

In the last decade, the application of nanotechnology techniques has expanded within diverse areas such as pharmacology, medicine, and optical science. Despite such wide-ranging possibilities for implementation into practice, the mechanisms behind nanoparticle skin absorption remain unknown. Moreover, the main mode of investigation has been qualitative analysis. Using interactive segmentation, this study suggests a method of objectively and quantitatively analyzing the mechanisms underlying the skin absorption of nanoparticles. Silica nanoparticles (SNPs) were assessed using transmission electron microscopy and applied to the human skin equivalent model. Captured fluorescence images of this model were used to evaluate degrees of skin penetration. These images underwent interactive segmentation and image processing in addition to statistical quantitative analyses of calculated image parameters including the mean, integrated density, skewness, kurtosis, and area fraction. In images from both groups, the distribution area and intensity of fluorescent silica gradually increased in proportion to time. Since statistical significance was achieved after 2 days in the negative charge group and after 4 days in the positive charge group, there is a periodic difference. Furthermore, the quantity of silica per unit area showed a dramatic change after 6 days in the negative charge group. Although this quantitative result is identical to results obtained by qualitative assessment, it is meaningful in that it was proven by statistical analysis with quantitation by using image processing. The present study suggests that the surface charge of SNPs could play an important role in the percutaneous absorption of NPs. These findings can help achieve a better understanding of the percutaneous transport of NPs. In addition, these results provide important guidance for the design of NPs for biomedical applications.


Subject(s)
Nanoparticles , Skin/metabolism , Humans , Microscopy, Electron, Transmission , Microscopy, Fluorescence , Silicon Dioxide
8.
Exp Dermatol ; 22(12): 842-4, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24171727

ABSTRACT

Oregonin has been reported to act as a mediator of antibiosis, a liver-protective agent, an antioxidant, an anti-inflammatory agent, and to prevent cancer outbreaks. B16 melanoma cells were separated with trypsin-ethylenediaminetetraacetic acid, resuspended in 50 µl of phosphate-buffered saline and transplanted into the backs of 6- to 8-week-old male Balb/c nude mice through subcutaneous injection. Treatment doses of oregonin were administered three times weekly, for 30 days from the 11th day after transplantation of the melanoma cells, in each group. The study consisted of a control group, a dacarbazine group, an oregonin group and a dacarbazine + oregonin group. Measurements were taken before treatment and on the 5th, 7th, 10th and 15th days after treatment for each group. Based on survival rates after transplantation, the control group showed less than 50% survival after 20 days, while the treatment groups showed at least 50% survival up to the 41st day.


Subject(s)
Diarylheptanoids/therapeutic use , Melanoma, Experimental/drug therapy , Animals , Antineoplastic Agents/therapeutic use , Antioxidants/chemistry , Dacarbazine/chemistry , Fluorodeoxyglucose F18/chemistry , Mice , Mice, Inbred BALB C , Mice, Nude , Multimodal Imaging , Neoplasm Transplantation , Neoplasms, Experimental/drug therapy , Plant Extracts/therapeutic use , Positron-Emission Tomography , Tomography, X-Ray Computed
9.
Melanoma Res ; 23(5): 349-59, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23839076

ABSTRACT

In small-animal studies, calipers are the standard method used for measurement of external tumor size. However, as tumors are not usually prolate spheroids, this may lead to inaccuracies in the data. Also, correlations vary according to the kind and size of tumors. Tumors were generated by transplanting B16 mouse melanoma cells into the back of Balb/c nude mice. True volumes were measured by calipers, an in-vivo stereo imaging system, and as a standard uptake value (SUV) by (18)F-fluorodeoxyglucose ([(18)F]FDG)-PET. Correlations between measurements were analyzed. Correlation with the true volume was higher for measurements using the in-vivo stereo imaging system (r = 0.876) than with calipers (r = 0.744). Measurement of melanoma volume has a larger measuring error when performed using a caliper compared with measurements performed by stereo imaging when the volume of the melanoma is small. Correlation of the volume and PET-SUV by a caliper is low as the size of the melanoma increases. This same relationship exists with the comparison of stereo imaging and PET-SUV. The correlation between the SUV of [(18)F]FDG-PET and tumor volume with the melanoma is expected to be important in related future studies.


Subject(s)
Melanoma, Experimental/diagnosis , Multimodal Imaging/methods , Positron-Emission Tomography , Tomography, X-Ray Computed , Animals , Cell Line, Tumor , Cell Proliferation , Fluorodeoxyglucose F18 , Male , Melanoma, Experimental/diagnostic imaging , Melanoma, Experimental/pathology , Mice, Inbred BALB C , Mice, Nude , Neoplasm Transplantation , Predictive Value of Tests , Radiopharmaceuticals , Reproducibility of Results , Tumor Burden
10.
Skin Res Technol ; 19(1): e390-6, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23293910

ABSTRACT

BACKGROUND/PURPOSE: The skin plays an important role as a protective barrier against toxic environments and also is a route of drug administration. In spite of evidence for and interest in the skin penetration of nanoparticles, no study has examined the effect of nanoparticle surface charge on percutaneous absorption. In this study, we investigated the effect of surface charges of gold nanorods (GNs) on skin penetration. METHODS: Using transmission electron microscopy (TEM) and image analysis, we quantitatively measured the ability of GNs to penetrate the skin. RESULTS: Our results showed that the area density of the electron-dense dots of GNs, which penetrated into the stratum corneum, significantly increased for negatively charged GNs compared to those with a positive charge (P < 0.01). To investigate the percutanoues absorption of charged GNs, in vitro skin permeation studies were carried out using a Franz-type diffusion cell (FDC). The penetration of GNs through the skin was quantified by inductively coupled plasma mass spectrometry. Consistent with TEM observations, our penetration study using an FDC also revealed that negative particles were frequently detected in samples of receptor fluid at 48 h after exposure (P < 0.01). CONCLUSION: Together our results showed that anionic GNs penetrate skin better than cationic GNs.


Subject(s)
Epidermis/drug effects , Epidermis/metabolism , Gold/pharmacokinetics , Nanotubes/chemistry , Skin Absorption/drug effects , Skin Absorption/physiology , Administration, Cutaneous , Animals , Anions/chemistry , Anions/pharmacokinetics , Cations/chemistry , Cations/pharmacokinetics , Diffusion , Epidermis/ultrastructure , Female , Gold/chemistry , Humans , Metal Nanoparticles/chemistry , Mice , Mice, Hairless , Microscopy, Electron, Transmission , Surface Properties
11.
Skin Res Technol ; 18(4): 462-70, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22272727

ABSTRACT

BACKGROUND: Dermoscopy is a non-invasive in vivo skin imaging technique that assists dermatologists in diagnosing melanoma. However, the use of dermoscopy for diagnosis requires extensive training since this approach often provides extremely complex and subjective information. The presence of an imperceptible color difference in dermoscopy images is one of the serious problems associated with the use of this technique. This imperceptible color difference leads to inaccurate lesion extraction at the borders and hinders the assessment of lesion features. Therefore, objective and quantitative assessment based on perceptible color differences is important for the diagnosis of melanoma using dermoscopy. METHODS: In this study, we developed a method for assessing colors in a lesion. Twenty-seven perceptible color regions based on the multi-thresholding method in each color channel were constructed, and dominant color region (DCR), bluish dominant region (BDR), and the number of colors were assessed as three diagnostic parameters from these perceptible color regions on 150 dermoscopy images. RESULTS/CONCLUSION: Diagnostic accuracy was calculated by combination of three diagnostic parameters derived from DCR, BDR, and the number of colors. Diagnostic accuracy with 73.33% sensitivity and 90.67% specificity was obtained in case of positive features in more than two parameters.


Subject(s)
Color , Colorimetry/methods , Dermoscopy/methods , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Melanoma/pathology , Skin Neoplasms/pathology , Algorithms , Humans , Reproducibility of Results , Sensitivity and Specificity
12.
Skin Res Technol ; 17(1): 11-9, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20923459

ABSTRACT

BACKGROUND/PURPOSE: The aim of this study was to establish a scientific assessment method to evaluate the severity of atopic dermatitis (AD) by calibrating part of a previously described stereo-image optical topometer (SOT). METHODS: The old SOT was created using a non-convergence model. However, this study utilizes a convergence model. Camera calibration and rectification were performed using images obtained from stereo cameras. We attempted to verify the efficacy of AD treatment by objectively measuring the improvement in a group of subjects. Twenty AD patients with a variety of disease types were divided into a control group and a treatment group. RESULTS: The scoring of the AD (SCORAD) index did not show any improvements in the treated patients. However, when comparing the advanced SOT and the old SOT, we observed a decreased variation for five parameters, indicating that the treated patients experienced improved outcomes compared with controls. Most notably, we found that the coefficient of variation of the advanced SOT was lower than that of the old SOT. CONCLUSION: We conclude that the advanced SOT may be useful for evaluating AD. The use of an advanced stereo image system may yield more reliable results than the old SOT system.


Subject(s)
Dermatitis, Atopic/diagnosis , Dermoscopy/methods , Dermoscopy/standards , Photography/methods , Photography/standards , Calibration , Dermoscopy/instrumentation , Female , Humans , Male , Models, Theoretical , Photography/instrumentation , Reproducibility of Results , Severity of Illness Index
13.
Microsc Res Tech ; 73(12): 1110-4, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20981756

ABSTRACT

Onychomycosis, or fungal infection of the nail, is a disease seen frequently in clinical settings. However, the rates of positive identification using potassium hydroxide preparations or fungal cultures are relatively low. Precise diagnosis is possible via histopathologic examination to monitor the existence of fungus and performance of a fungal culture for confirmation. Phase-contrast hard X-ray microscopy using synchrotron radiation provides 70-nm spatial resolution and enables imaging of minute internal cellular structures. This study confirms the feasibility of diagnosing onychomycosis using a phase-contrast hard X-ray microscope developed at 1B2 beam line using a Pohang light source.


Subject(s)
Microscopy, Phase-Contrast/methods , Nails , Onychomycosis/diagnosis , Radiography/methods , Synchrotrons , Histocytochemistry , Humans , Keratinocytes/microbiology , Keratinocytes/pathology , Nails/microbiology , Nails/pathology
14.
Skin Res Technol ; 15(2): 200-13, 2009 May.
Article in English | MEDLINE | ID: mdl-19416467

ABSTRACT

BACKGROUND/AIMS: The objective and quantitative assessment of the skin is important in medical and cosmeceutical research. Assessment of color is an important element for analyzing the surface of the skin, which is usually determined subjectively by a doctor or using color analysis devices. These devices, however, cannot provide correct color information because color is construed from the mean value of the observation region, and analysis of color distribution is impossible. The purpose of this paper is to develop an objective analysis method to permit skin color measurement of each pixel unit of an image and analyze the distribution of skin surface color. METHODS: The Skin Color Distribution Analyzer (SCDA) is an analysis method newly developed at the Research Institute for Skin Image at Korea University. The SCDA system presented in this paper performed a novel form of quantitative and objective analysis of skin color distribution using each pixel color model parameter found in image wavelength information. In this paper, distribution analysis was conducted on normal skin and skin lesions and skin affected by artificially induced irritant contact dermatitis and pigmented nevous. The method selected a grade using a color model parameter. Twenty healthy Korean males participated in this study. A comparative study of the eight anatomical areas was performed, including the exposure and non-exposure parts and the medial aspect and the lateral aspect of the forearm. A reliability test for the SCDA system was also conducted with a spectrometer (SPEC) using the color analysis method. RESULTS: Each skin lesion was precisely segmented by grade and each parameter had a different statistical significance for results of analysis of distribution in pigmented nevous and the artificially induced irritant contact dermatitis. Parameters L(*), b(*), a(*), and EI showed salient traits. Showed resemble measured result in the SCDA system and the SPEC of normal skin. The exposed site, in comparison with the non-exposed site, showed a notable difference in the L(*) parameter and a significant statistical difference in the x and z parameters, except b(*). The comparison of the medial and lateral aspects of the forearm showed a notable difference in the L(*) parameter and a significant statistical difference in the parameters except y and b(*). In the reliability test result using the SCDA system and the SPEC, the SCDA system was highly reliable in terms of the CV value in all color model parameters. CONCLUSIONS: The color distribution analysis method using the SCDA system has revealed an aspect that the existent method of medical research has not shown, and is considered to be more reliable than other methods. This method can provide better study findings because it can be applied to other fields in addition to the medical science field and the ripple effect is thought to be bigger in other science field too.


Subject(s)
Colorimetry/instrumentation , Colorimetry/methods , Dermoscopy/instrumentation , Dermoscopy/methods , Skin Physiological Phenomena , Skin/cytology , Adult , Equipment Design , Equipment Failure Analysis , Humans , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity
16.
J Invest Dermatol ; 128(10): 2429-41, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18463684

ABSTRACT

Keloids are benign skin tumors characterized by collagen accumulation and hyperproliferation of fibroblasts. To find an effective therapy for keloids, we explored the pharmacological potential of (-)-epigallocatechin-3-gallate (EGCG), a widely investigated tumor-preventive agent. When applied to normal and keloid fibroblasts (KFs) in vitro, proliferation and migration of KFs were more strongly suppressed by EGCG than normal fibroblast proliferation and migration (IC(50): 54.4 microM (keloid fibroblast (KF)) versus 63.0 microM (NF)). The level of Smad2/3, signal transducer and activator of transcription-3 (STAT3), and p38 phosphorylation is more enhanced in KFs, and EGCG inhibited phosphorylation of phosphatidylinositol-3-kinase (PI3K), extracellular signal-regulated protein kinase 1/2 (ERK1/2), and STAT3 (Tyr705 and Ser727). To evaluate the contribution of these pathways to keloid pathology, we treated KFs with specific inhibitors for PI3K, ERK1/2, or STAT3. Although a PI3K inhibitor significantly suppressed proliferation, PI3K and MEK/ERK inhibitors had a minor effect on migration and collagen production. However, a JAK2/STAT3 inhibitor and a STAT3 siRNA strongly suppressed proliferation, migration, and collagen production by KFs. We also found that treatment with EGCG suppressed growth and collagen production in the in vivo keloid model. This study demonstrates that EGCG suppresses the pathological characteristics of keloids through inhibition of the STAT3-signaling pathway. We propose that EGCG has potential in the treatment and prevention of keloids.


Subject(s)
Catechin/analogs & derivatives , Collagen/antagonists & inhibitors , Keloid/metabolism , Keloid/pathology , STAT3 Transcription Factor/metabolism , Signal Transduction/drug effects , Animals , Catechin/pharmacology , Cell Cycle/drug effects , Cell Movement/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Collagen/biosynthesis , Fibroblasts/metabolism , Fibroblasts/pathology , Flavonoids/pharmacology , Humans , Keloid/physiopathology , Mice , Mice, Nude , Mitogen-Activated Protein Kinase Kinases/metabolism , Phenols/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Polyphenols , Protein Kinase Inhibitors/pharmacology , RNA, Small Interfering/pharmacology , STAT3 Transcription Factor/antagonists & inhibitors , STAT3 Transcription Factor/genetics , Tea/chemistry , Triterpenes/pharmacology , Wound Healing/drug effects
17.
Anal Sci ; 23(4): 401-5, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17420542

ABSTRACT

A rapid DNA analysis has been developed based on a fluorescence intensity change of a molecular beacon in a PDMS microfluidic channel. Recently, we reported a new analytical method of DNA hybridization involving a PDMS microfluidic sensor using fluorescence energy transfer (FRET). However, there are some limitations in its application to real DNA samples because the target DNA must be labelled with a suitable fluorescent dye. To resolve this problem, we have developed a new DNA microfluidic sensor using a molecular beacon. By monitoring the change in the restored fluorescence intensity along the channel length, it is possible to rapidly detect any hybridization of the molecular beacon to the target DNA. In this case, the target DNA does not need to be labelled. Our experimental results demonstrate that this microfluidic sensor using a molecular beacon is a promising diagnostic tool for rapid DNA hybridization analysis.


Subject(s)
DNA Probes/chemistry , Microfluidics/methods , Oligonucleotides/chemistry , Fluorescent Dyes/chemistry , Microfluidics/instrumentation , Nucleic Acid Hybridization/methods
18.
Anal Bioanal Chem ; 387(8): 2609-15, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17318519

ABSTRACT

A new DNA hybridization analytical method using a microfluidic channel and a molecular beacon-based probe (MB-probe) is described. A stem-loop DNA oligonucleotide labeled with two fluorophores at the 5' and 3' termini (a donor dye, TET, and an acceptor dye, TAMRA, respectively) was used to carry out a fast and sensitive DNA analysis. The MB-probe utilized the specificity and selectivity of the DNA hairpin-type probe DNA to detect a specific target DNA of interest. The quenching of the fluorescence resonance energy transfer (FRET) signal between the two fluorophores, caused by the sequence-specific hybridization of the MB-probe and the target DNA, was used to detect a DNA hybridization reaction in a poly(dimethylsiloxane) (PDMS) microfluidic channel. The azoospermia gene, DYS 209, was used as the target DNA to demonstrate the applicability of the method. A simple syringe pumping system was used for quick and accurate analysis. The laminar flow along the channel could be easily controlled by the 3-D channel structure and flow speed. By injecting the MB-probe and target DNA solutions into a zigzag-shaped PDMS microfluidic channel, it was possible to detect their sequence-specific hybridization. Surface-enhanced Raman spectroscopy (SERS) was also used to provide complementary evidence of the DNA hybridization. Our data show that this technique is a promising real-time detection method for label-free DNA targets in the solution phase. Figure FRET-based DNA hybridization detection using a molecular beacon in a zigzag-shaped PDMS microfluidic channel.


Subject(s)
DNA/analysis , Microfluidics/instrumentation , Base Sequence , DNA Probes , Fluorescence Resonance Energy Transfer , Sensitivity and Specificity , Spectrometry, Fluorescence , Spectrum Analysis, Raman
20.
Biopolymers ; 77(5): 264-72, 2005 Apr 05.
Article in English | MEDLINE | ID: mdl-15657894

ABSTRACT

Raman spectroscopy has strong potential for providing noninvasive dermatological diagnosis of skin cancer. In this study, confocal Raman microscopy was applied to the dermatological diagnosis for one of the most common skin cancers, basal cell carcinoma (BCC). BCC tissues were obtained from 10 BCC patients using a routine biopsy and used for confocal Raman measurements. Autofluorescence signals from tissues, which interfere with the Raman signals, were greatly reduced using a confocal slit adjustment. Distinct Raman band differences between normal and BCC tissues for the amide I mode and the PO2- symmetric stretching mode showed that this technique has strong potential for use as a dermatological diagnostic tool without the need for statistical treatment of spectral data. It was also possible to precisely differentiate BCC tissue from surrounding noncancerous tissue using the confocal Raman depth profiling technique. We propose that confocal Raman microscopy provides a novel method for dermatological diagnosis since direct observations of spectral differences between normal and BCC tissues are possible.


Subject(s)
Carcinoma, Basal Cell/pathology , Skin Neoplasms/pathology , Skin/cytology , Skin/pathology , Spectrum Analysis, Raman , Humans , Reproducibility of Results , Sensitivity and Specificity
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