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Sukon N, Choopong P, Tungsattayathitthan U, Tesavibul N, Sanpan W, Boonsopon S. Association between advanced glycation end products and uveitis/scleritis activity in patients with active immune-mediated ocular inflammatory diseases. Int Ophthalmol 2024; 44:33. [PMID: 38329659 PMCID: PMC10853306 DOI: 10.1007/s10792-024-02980-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/29/2023] [Indexed: 02/09/2024]
Abstract
PURPOSE To investigate for association between skin autofluorescence (SAF) advanced glycation end products (AGEs) and uveitis/scleritis activity in systemic inflammatory disease-related active non-infectious uveitis/scleritis patients. METHODS This cross-sectional study was conducted at Siriraj Hospital during October 2019 to March 2020. AGEs were measured by SAF method in systemic immune-related disease patients with active uveitis/scleritis, and those results were compared with those of healthy age-matched controls. RESULTS Thirty-one active non-infectious uveitis/scleritis patients and 31 age-matched controls were enrolled. The mean age of patients was 40.0 ± 12.8 years, and most were female (55.0%). The most common associated systemic immune-related disease was Vogt-Koyanagi-Harada disease (n = 14). Mean SAF AGE level in the study group compared to the control group was 2.38 ± 0.66 arbitrary units (AU) versus 2.58 ± 0.56 AU, respectively (p = 0.20). Multivariate analysis showed decreased SAF AGE level to be significantly associated with active ocular inflammation, (odds ratio: 0.01, 95% confidence interval: 0.00004-0.81; p = 0.04). CONCLUSIONS SAF AGE level was not so far found to be a reliable biomarker for indicating uveitis/scleritis activity in systemic immune-related disease patients with active ocular inflammation. CLINICAL TRIAL REGISTRATION Thai Clinical Trials Registry, https://www.thaiclinicaltrials.org/ . (Reg. No. TCTR20200114004, registered date 01/01/2020, beginning date of the trial 10/01/2019).
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Affiliation(s)
- Nutchaya Sukon
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Pitipol Choopong
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Usanee Tungsattayathitthan
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Nattaporn Tesavibul
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Wilawan Sanpan
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Sutasinee Boonsopon
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
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Du T, Brandl B, Hauner H, Skurk T. Skin Autofluorescence Mirrors Surrogate Parameters of Vascular Aging: An Enable Study. Nutrients 2023; 15:nu15071597. [PMID: 37049440 PMCID: PMC10096848 DOI: 10.3390/nu15071597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/10/2023] [Accepted: 03/23/2023] [Indexed: 03/28/2023] Open
Abstract
Advanced glycation end-products (AGEs) are implicated in vascular aging due to their pro-inflammatory properties. Skin autofluorescence (SAF) is a measure to estimate their deposition. It is an easily quantifiable marker that has been shown to correlate with cardiovascular risk and parameters of metabolic diseases. Herein, we compared skin autofluorescence with other techniques indicating increased cardiovascular diseases, namely, pulse wave velocity (PWVao) and intima–media thickness (IMT). We also studied the impacts of other parameters in deeply phenotyped cohorts of young, middle-aged, and older individuals. SAF, aortic PWVao, and IMT proved to be significantly correlated with each other and with age. However, based on a moderator analysis, we could not show that these associations were affected by age. Some specific parameters such as creatinine and CRP were found to be significantly associated with skin AGE values after adjusting for confounding variables. In conclusion, SAF is a simple screening tool for vascular health with comparable power to more elaborated technical tests.
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Giovannacci I, Meleti M, Garbarino F, Cesinaro AM, Mataca E, Pedrazzi G, Reggiani C, Paganelli A, Truzzi A, Elia F, Giacomelli L, Magnoni C. Correlation between Autofluorescence Intensity and Histopathological Features in Non-Melanoma Skin Cancer: An Ex Vivo Study. Cancers (Basel) 2021; 13:cancers13163974. [PMID: 34439130 PMCID: PMC8393486 DOI: 10.3390/cancers13163974] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/24/2021] [Accepted: 07/29/2021] [Indexed: 12/18/2022] Open
Abstract
Simple Summary Non-melanoma skin cancers (NMSC) are the most prevalent neoplasms worldwide, especially in the Caucasian population. Radical surgical excision is considered the therapeutic gold standard, while incomplete tumor removal is invariably associated with recurrence and the need for reintervention. Autofluorescence (AF) spectroscopy has recently been investigated for early diagnosis of NMSC and assessment of tumor margins. Understanding changes in AF intensity in association with peculiar histological features could improve the diagnostic accuracy of skin fluorescence spectroscopy. The main goal of our work was to investigate the correlation between the intensity of cutaneous AF and the histopathological features of NMSC. The intensity of fluorescence emission in tissues obtained from NMSC samples was approximately 4 times lower than that in healthy conditions. In fact, mean AF intensity for BCC group was 4.5 and 4.4 for SCCs, with further variability being recorded according to histopathologic subtypes. Histopathological features such as hyperkeratosis, neoangiogenesis, fibrosis and elastosis are statistically associated with a decrease in AF intensity. Our data suggest that such tissue alterations could be responsible for the difference in AF emission between neoplastic and healthy tissue. These results support the potential application of AF as a useful non-invasive diagnostic tool for NMSCs. Abstract Non-melanoma skin cancer (NMSC) is the most common malignant tumor affecting fair-skinned people. Increasing incidence rates of NMSC have been reported worldwide, which is an important challenge in terms of public health management. Surgical excision with pre-operatively identified margins is one of the most common and effective treatment strategies. Incomplete tumor removal is associated with a very high risk of recurrence and re-excision. Biological tissues can absorb and re-emit specific light wave-lengths, detectable through spectrophotometric devices. Such a phenomenon is known as autofluorescence (AF). AF spectroscopy has been widely explored for non-invasive, early detection of NMSC as well as for evaluation of surgical margins before excision. Fluorescence-aided diagnosis is based on differences in spectral characteristics between healthy and neoplastic skin. Understanding the biological basis of such differences and correlating AF intensity to histological features could improve the diagnostic accuracy of skin fluorescence spectroscopy. The primary objective of the present pre-clinical ex vivo study is to investigate the correlation between the intensity of cutaneous AF and the histopathological features of NMSC. Ninety-eight lesions suggestive for NMSCs were radically excised from 75 patients (46 M; 29 F; mean age: 79 years). After removal, 115 specific reference points on lesions (“cases”; 59 on BBC, 53 on SCC and 3 on other lesions) and on peri-lesional healthy skin (controls; 115 healthy skin) were identified and marked through suture stitches. Such reference points were irradiated at 400–430 nm wavelength, and resulting emission AF spectra were acquired through spectrophotometry. For each case, AFIR (autofluorescence intensity ratio) was measured as the ratio between the number of photons emitted at a wavelength ranging between 450 and 700 nm (peak: 500 nm) in the healthy skin and that was captured in the pathological tissue. At the histological level, hyperkeratosis, neoangiogenesis, cellular atypia, epithelial thickening, fibrosis and elastosis were quantified by light microscopy and were assessed through a previously validated grading system. Statistical correlation between histologic variables and AFIR was calculated through linear regression. Spectrometric evaluation was performed on 230 (115 cases + 115 controls) reference points. The mean AFIR for BCC group was 4.5, while the mean AFIR for SCC group was 4.4 and the fluorescence peaks at 500 nm were approximately 4 times lower (hypo-fluorescent) in BCCs and in SCCs than in healthy skin. Histological variables significantly associated with alteration of AFIR were fibrosis and elastosis (p < 0.05), neoangiogenesis, hyperkeratosis and epithelial thickening. Cellular atypia was not significantly associated with alteration of AFIR. The intensity of fluorescence emission in neoplastic tissues was approximately 4 times lower than that in healthy tissues. Histopathological features such as hyperkeratosis, neoangiogenesis, fibrosis and elastosis are statistically associated with the decrease in AFIR. We hypothesize that such tissue alterations are among the possible biophysical and biochemical bases of difference in emission AF between neoplastic and healthy tissue. The results of the present evaluation highlighted the possible usefulness of autofluorescence as diagnostic, non-invasive and real-time tool for NMSCs.
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Affiliation(s)
- Ilaria Giovannacci
- Department of Dermatology, Surgical, Medical and Dental Department of Morphological Sciences Related to Transplant, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy; (I.G.); (F.G.); (C.R.); (A.P.)
| | - Marco Meleti
- Centro Universitario di Odontoiatria, Department of Medicine and Surgery, University of Parma, 43121 Parma, Italy;
| | - Federico Garbarino
- Department of Dermatology, Surgical, Medical and Dental Department of Morphological Sciences Related to Transplant, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy; (I.G.); (F.G.); (C.R.); (A.P.)
- PhD Program in Clinical and Experimental Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy
| | - Anna Maria Cesinaro
- Department of Anatomic Pathology, University of Modena and Reggio Emilia, 41124 Modena, Italy; (A.M.C.); (E.M.)
| | - Ema Mataca
- Department of Anatomic Pathology, University of Modena and Reggio Emilia, 41124 Modena, Italy; (A.M.C.); (E.M.)
| | - Giuseppe Pedrazzi
- Department of Medicine and Surgery and Robust Statistics Academy, University of Parma, 43121 Parma, Italy;
| | - Camilla Reggiani
- Department of Dermatology, Surgical, Medical and Dental Department of Morphological Sciences Related to Transplant, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy; (I.G.); (F.G.); (C.R.); (A.P.)
- PhD Program in Clinical and Experimental Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy
| | - Alessia Paganelli
- Department of Dermatology, Surgical, Medical and Dental Department of Morphological Sciences Related to Transplant, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy; (I.G.); (F.G.); (C.R.); (A.P.)
- PhD Program in Clinical and Experimental Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy
| | - Arianna Truzzi
- School of Dentistry, University of Modena and Reggio Emilia, 41124 Modena, Italy; (A.T.); (F.E.)
| | - Federica Elia
- School of Dentistry, University of Modena and Reggio Emilia, 41124 Modena, Italy; (A.T.); (F.E.)
| | | | - Cristina Magnoni
- Department of Dermatology, Surgical, Medical and Dental Department of Morphological Sciences Related to Transplant, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, 41124 Modena, Italy; (I.G.); (F.G.); (C.R.); (A.P.)
- Correspondence: ; Tel.: +39-059-422-2464; Fax: +39-059-422-4271
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Sandhu A, Badal D, Sheokand R, Tyagi S, Singh V. Specific collagens maintain the cuticle permeability barrier in Caenorhabditis elegans. Genetics 2021; 217:iyaa047. [PMID: 33789349 PMCID: PMC8045729 DOI: 10.1093/genetics/iyaa047] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 12/05/2020] [Indexed: 01/01/2023] Open
Abstract
Collagen-enriched cuticle forms the outermost layer of skin in nematode Caenorhabditis elegans. The nematode's genome encodes 177 collagens, but little is known about their role in maintaining the structure or barrier function of the cuticle. In this study, we found six permeability determining (PD) collagens. Loss of any of these PD collagens-DPY-2, DPY-3, DPY-7, DPY-8, DPY-9, and DPY-10-led to enhanced susceptibility of nematodes to paraquat (PQ) and antihelminthic drugs- levamisole and ivermectin. Upon exposure to PQ, PD collagen mutants accumulated more PQ and incurred more damage and death despite the robust activation of antioxidant machinery. We find that BLMP-1, a zinc finger transcription factor, maintains the barrier function of the cuticle by regulating the expression of PD collagens. We show that the permeability barrier maintained by PD collagens acts in parallel to FOXO transcription factor DAF-16 to enhance survival of insulin-like receptor mutant, daf-2. In all, this study shows that PD collagens regulate cuticle permeability by maintaining the structure of C. elegans cuticle and thus provide protection against exogenous toxins.
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Affiliation(s)
- Anjali Sandhu
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560012, India
| | - Divakar Badal
- Center for Biosystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Riya Sheokand
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560012, India
| | - Shalini Tyagi
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560012, India
| | - Varsha Singh
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560012, India
- Center for Biosystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India
- Lead contact
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5
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The AGE Reader: A non-invasive method to assess long-term tissue damage. Methods 2021; 203:533-541. [PMID: 33636313 DOI: 10.1016/j.ymeth.2021.02.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/16/2020] [Accepted: 02/21/2021] [Indexed: 12/11/2022] Open
Abstract
AIMS Advanced glycation endproducts (AGEs) are sugar-modified adducts which arise during non-enzymatic glycoxidative stress. These compounds may become systemically elevated in disease states, and accumulate in tissue, especially on long-lived proteins. AGEs have been implicated in various acute, and chronic diseases, stressing the need for reliable and comprehensive measuring techniques. Measurement of AGEs in tissue such as skin requires invasive skin biopsies. The AGE Reader has been developed to assess skin autofluorescence (SAF) non-invasively using the fluorescent properties of several AGEs. RESULTS/CONCLUSION Various studies have shown that SAF is a useful marker of disease processes associated with oxidative stress. It is prospectively associated with the development of cardiovascular events in patients with diabetes, renal or cardiovascular disease, and it predicts diabetes, cardiovascular disease, and mortality in the general population. However, when measuring SAF in individual subjects, several factors may limit the reliability of the measurement. These include endogenous factors present in the skin that absorb emission light such as melanin in dark-skinned subjects, but also factors that lead to temporal changes in SAF such as acute diseases and strenuous physical exercise associated with glycoxidative stress. Also, exogenous factors could potentially influence SAF levels inadvertently such as nutrition, and for example the application of skin care products. This review will address the AGE Reader functionality and the endogenous, and exogenous factors which potentially influence the SAF assessment in individual subjects.
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6
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Ali SM. In vivo confocal Raman spectroscopic imaging of the human skin extracellular matrix degradation due to accumulated intrinsic and extrinsic aging. PHOTODERMATOLOGY PHOTOIMMUNOLOGY & PHOTOMEDICINE 2020; 37:140-152. [DOI: 10.1111/phpp.12623] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/07/2020] [Accepted: 10/19/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Syed Mehmood Ali
- Department of Biomedical Engineering College of Engineering Imam Abdulrahman Bin Faisal University Dammam Saudi Arabia
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Wouters HJ, van der Klauw MM, Wolffenbuttel BH, Huls G, van Zeventer IA. The Association Between Anemia and Skin Autofluorescence, a Marker for Advanced Glycation End Product Accumulation. Hemasphere 2020; 4:e470. [PMID: 33134864 PMCID: PMC7593064 DOI: 10.1097/hs9.0000000000000470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 07/20/2020] [Indexed: 11/28/2022] Open
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Narayanamurthy V, Padmapriya P, Noorasafrin A, Pooja B, Hema K, Firus Khan AY, Nithyakalyani K, Samsuri F. Skin cancer detection using non-invasive techniques. RSC Adv 2018; 8:28095-28130. [PMID: 35542700 PMCID: PMC9084287 DOI: 10.1039/c8ra04164d] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 07/22/2018] [Indexed: 12/22/2022] Open
Abstract
Skin cancer is the most common form of cancer and is globally rising. Historically, the diagnosis of skin cancers has depended on various conventional techniques which are of an invasive manner. A variety of commercial diagnostic tools and auxiliary techniques are available to detect skin cancer. This article explains in detail the principles and approaches involved for non-invasive skin cancer diagnostic methods such as photography, dermoscopy, sonography, confocal microscopy, Raman spectroscopy, fluorescence spectroscopy, terahertz spectroscopy, optical coherence tomography, the multispectral imaging technique, thermography, electrical bio-impedance, tape stripping and computer-aided analysis. The characteristics of an ideal screening test are outlined, and the authors pose several points for clinicians and scientists to consider in the evaluation of current and future studies of skin cancer detection and diagnosis. This comprehensive review critically analyses the literature associated with the field and summarises the recent updates along with their merits and demerits.
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Affiliation(s)
- Vigneswaran Narayanamurthy
- InnoFuTech No: 42/12, 7th Street, Vallalar Nagar, Pattabiram Chennai Tamil Nadu 600072 India
- Faculty of Electrical and Electronics Engineering, University Malaysia Pahang Pekan 26600 Malaysia
| | - P Padmapriya
- Department of Biomedical Engineering, Veltech Multitech Dr. RR & Dr. SR Engineering College Chennai 600 062 India
| | - A Noorasafrin
- Department of Biomedical Engineering, Veltech Multitech Dr. RR & Dr. SR Engineering College Chennai 600 062 India
| | - B Pooja
- Department of Biomedical Engineering, Veltech Multitech Dr. RR & Dr. SR Engineering College Chennai 600 062 India
| | - K Hema
- Department of Biomedical Engineering, Veltech Multitech Dr. RR & Dr. SR Engineering College Chennai 600 062 India
| | - Al'aina Yuhainis Firus Khan
- Department of Biomedical Science, Faculty of Allied Health Sciences, International Islamic University Malaysia 25200 Kuantan Pahang Malaysia
| | - K Nithyakalyani
- Department of Biomedical Engineering, Veltech Multitech Dr. RR & Dr. SR Engineering College Chennai 600 062 India
| | - Fahmi Samsuri
- Faculty of Electrical and Electronics Engineering, University Malaysia Pahang Pekan 26600 Malaysia
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Ghazaryan A, Omar M, Tserevelakis GJ, Ntziachristos V. Optoacoustic detection of tissue glycation. BIOMEDICAL OPTICS EXPRESS 2015; 6:3149-56. [PMID: 26417487 PMCID: PMC4574643 DOI: 10.1364/boe.6.003149] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 06/19/2015] [Accepted: 06/26/2015] [Indexed: 05/18/2023]
Abstract
Oxidative-based diseases including diabetes, chronic renal failure, cardiovascular diseases and neurological disorders are accompanied by accumulation of advanced glycation endproducts (AGE). Therefore, AGE-associated changes in tissue optical properties could yield a viable pathological indicator for disease diagnostics and monitoring. We investigated whether skin glycation could be detected based on absorption changes associated with AGE accumulation using spectral optoacoustic measurements and interrogated the optimal spectral band for skin glycation determination. Glycated and non-glycated skin was optoacoustically measured at multiple wavelengths in the visible region. The detected signals were spectrally processed and compared to measurements of skin auto-fluorescence and to second harmonic generation multiphoton microscopy images. Optoacoustic measurements are shown to be capable of detecting skin glycolysis based on AGE detection. A linear dependence was observed between optoacoustic intensity and the progression of skin glycation. The findings where corroborated by autofluorescence observations. Detection sensitivity is enhanced by observing normalised tissue spectra. This result points to a ratiometric method for skin glycation detection, specifically at 540 nm and 620 nm. We demonstrate that optoacoustic spectroscopy could be employed to detect AGE accumulation, and possibly can be employed as a non-invasive quick method for monitoring tissue glycation.
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Affiliation(s)
- Ara Ghazaryan
- Institute for Biological and Medical Imaging, Technische Universität München, Munich, Germany
| | - Murad Omar
- Institute for Biological and Medical Imaging, Technische Universität München, Munich, Germany
| | - George J. Tserevelakis
- Institute for Biological and Medical Imaging, Technische Universität München, Munich, Germany
| | - Vasilis Ntziachristos
- Institute for Biological and Medical Imaging, Technische Universität München, Munich, Germany
- Helmholtz Zentrum München, Munich, Germany
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Correction for tissue optical properties enables quantitative skin fluorescence measurements using multi-diameter single fiber reflectance spectroscopy. J Dermatol Sci 2015; 79:64-73. [PMID: 25911633 DOI: 10.1016/j.jdermsci.2015.03.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 02/18/2015] [Accepted: 03/23/2015] [Indexed: 11/21/2022]
Abstract
BACKGROUND AND OBJECTIVE Fluorescence measurements in the skin are very much affected by absorption and scattering but existing methods to correct for this are not applicable to superficial skin measurements. STUDY DESIGN/MATERIALS AND METHODS The first use of multiple-diameter single fiber reflectance (MDSFR) and single fiber fluorescence (SFF) spectroscopy in human skin was investigated. MDSFR spectroscopy allows a quantification of the full optical properties in superficial skin (μa, μs' and γ), which can next be used to retrieve the corrected - intrinsic - fluorescence of a fluorophore Qμa,x(f). Our goal was to investigate the importance of such correction for individual patients. We studied this in 22 patients undergoing photodynamic therapy (PDT) for actinic keratosis. RESULTS The magnitude of correction of fluorescence was around 4 (for both autofluorescence and protoporphyrin IX). Moreover, it was variable between patients, but also within patients over the course of fractionated aminolevulinic acid PDT (range 2.7-7.5). Patients also varied in the amount of protoporphyrin IX synthesis, photobleaching percentages and resynthesis (>100× difference between the lowest and highest PpIX synthesis). The autofluorescence was lower in actinic keratosis than contralateral normal skin (0.0032 versus 0.0052; P<0.0005). CONCLUSIONS Our results clearly demonstrate the importance of correcting the measured fluorescence for optical properties, because these vary considerably between individual patients and also during PDT. Protoporphyrin IX synthesis and photobleaching kinetics allow monitoring clinical PDT which facilitates individual-based PDT dosing and improvement of clinical treatment protocols. Furthermore, the skin autofluorescence can be relevant for diagnostic use in the skin, but it may also be interesting because of its association with several internal diseases.
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Rajan SAP, Towe BC. Non-invasive method to detect the changes of glucose concentration in whole blood using photometric technique. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:4034-7. [PMID: 25570877 DOI: 10.1109/embc.2014.6944509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A non-invasive method is developed to monitor rapid changes in blood glucose levels in diabetic patients. The system depends on an optical cell built with a LED that emits light of wavelength 535nm, which is a peak absorbance of hemoglobin. As the glucose concentration in blood decreases, its osmolarity also decreases and the Red Blood Cells (RBCs) swell and decrease the path length absorption coefficient. Decreasing absorption coefficient increases the transmission of light through the whole blood. The system was tested with a constructed optical cell that held whole blood in a capillary tube. As expected the light transmitted to the photodiode increases with decreasing glucose concentration. The average response time of the system was between 30-40 seconds.
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12
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Zeković I, Dramićanin T, Lenhardt L, Bandić J, Dramićanin MD. Discrimination among melanoma, nevi, and normal skin by using synchronous luminescence spectroscopy. APPLIED SPECTROSCOPY 2014; 68:823-830. [PMID: 25061783 DOI: 10.1366/13-07153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Novel optical spectroscopy and imaging methods may be valuable in the early detection of cancer. This paper reports differences in the luminescence responses of pigmented skin lesions (melanomas and nevi) and apparently normal non-pigmented human skin, based on analyses of synchronous luminescence spectroscopy measurements. Measurements were performed in the excitation range of 330-545 nm, with synchronous intervals varying from 30-120 nm. Normal skin, nevi, and melanomas differ in the way they fluoresce, and these differences are more distinct in the synchronous fluorescence spectra than in the conventional emission and excitation spectra. The differences in the fluorescence characteristics of pigmented and normal skin samples were ascribed to differences in concentrations of endogenous fluorophores and chromophores. Principal component and linear discriminant analysis of the synchronous spectra measured at different synchronous intervals showed that the greatest variance among the sample groups was at the 70 nm interval spectra. These spectra were then used to create partial least squares discriminant analysis-based classification models. Evaluation of the quality of these models from the receiver operating characteristic curves showed they performed well, with a maximum value of 1 for the area under the curve for melanoma detection. Hence, synchronous luminescence spectroscopy coupled with statistical methods may be advantageous in the early detection of skin cancer.
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Affiliation(s)
- Ivana Zeković
- Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade, Serbia
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13
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Chen Y, Chen ZP, Yang J, Jin JW, Zhang J, Yu RQ. Quantitative Fluorescence Spectroscopy in Turbid Media: A Practical Solution to the Problem of Scattering and Absorption. Anal Chem 2013; 85:2015-20. [DOI: 10.1021/ac302815e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yao Chen
- State Key Laboratory
of Chemo/Biosensing and Chemometrics,
College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, PR China
| | - Zeng-Ping Chen
- State Key Laboratory
of Chemo/Biosensing and Chemometrics,
College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, PR China
| | - Jing Yang
- State Key Laboratory
of Chemo/Biosensing and Chemometrics,
College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, PR China
| | - Jing-Wen Jin
- State Key Laboratory
of Chemo/Biosensing and Chemometrics,
College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, PR China
| | - Juan Zhang
- State Key Laboratory
of Chemo/Biosensing and Chemometrics,
College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, PR China
| | - Ru-Qin Yu
- State Key Laboratory
of Chemo/Biosensing and Chemometrics,
College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, PR China
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14
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Pollefliet C, Corstjens H, González S, Hellemans L, Declercq L, Yarosh D. Morphological characterization of solar lentigines byin vivoreflectance confocal microscopy: a longitudinal approach. Int J Cosmet Sci 2012; 35:149-55. [DOI: 10.1111/ics.12016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 10/08/2012] [Indexed: 10/27/2022]
Affiliation(s)
- C. Pollefliet
- Estée Lauder Companies; Biological Research Department; Oevel; Belgium
| | - H. Corstjens
- Estée Lauder Companies; Biological Research Department; Oevel; Belgium
| | - S. González
- Memorial Sloan-Kettering Cancer Center; Faculty of Dermatology Service; New York; NY; U.S.A
| | - L. Hellemans
- Estée Lauder Companies; Biological Research Department; Oevel; Belgium
| | - L. Declercq
- Estée Lauder Companies; Biological Research Department; Oevel; Belgium
| | - D. Yarosh
- Estée Lauder Companies; Research Park; Melville; NY; U.S.A
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15
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Choi JW, Na SY, Chung MY, Na JI, Huh CH, Youn SW, Kang HY, Park KC. Pigmentation above the constitutive level: an indicator of excimer laser radiation-induced erythema in Koreans. J Dermatol 2012; 39:608-12. [PMID: 22506614 DOI: 10.1111/j.1346-8138.2012.01557.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ultraviolet (UV) irradiation induces skin erythema, but it is not clear which factors have the greatest effects on UV sensitivity. Six healthy Korean adult men were enrolled and their melanin index (MI) and increment of erythema index (ΔEI) were measured. In each individual, 12 different sites were selected and 36 spots were irradiated with a single shot of monochromatic excimer laser with a dose of 350 mJ/cm(2) . The sites were categorized into three groups based on the cumulative sun exposure: UZ, unexposed zones; FEZ, frequently exposed zones; and IEZ, intermittently exposed zones. The sun exposure indexes (SEI) were also calculated based on previously described methods. ΔEI, MI and SEI were measured and calculated. The ΔEI of UZ was significantly higher than that of FEZ, but lower than that of IEZ. In general, there was a significant relationship between ΔEI and MI (R(2) = 0.135). However, IEZ did not show significant results. In contrast, there was a stronger relationship between ΔEI and SEI (R(2) = 0.344). Overall, the values were significantly higher for the SEI (0.541 [UZ], 0.281 [IEZ] and 0.228 [FEZ]) than for MI (0.311 [UZ], 0.011 [IEZ] and 0.073 [FEZ]). There were significant site variations in UV sensitivity along with skin pigmentation. In addition, significant differences were observed according to the exposure frequency. The SEI was found to be strongly correlated with UV sensitivity. These results suggest that the induced level of pigmentation above the constitutive level will be a better indicator for UV sensitivity than baseline MI.
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Affiliation(s)
- Jee-Woong Choi
- Department of Dermatology, Seoul National University Bundang Hospital, Seongnam-si, Korea
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16
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Vashist SK. Non-invasive glucose monitoring technology in diabetes management: a review. Anal Chim Acta 2012; 750:16-27. [PMID: 23062426 DOI: 10.1016/j.aca.2012.03.043] [Citation(s) in RCA: 223] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Revised: 03/23/2012] [Accepted: 03/23/2012] [Indexed: 12/19/2022]
Abstract
The frequent monitoring of glucose is an essential part of diabetes management. Despite the fact that almost all the commercially successful blood glucose monitoring devices are invasive, there is an immense need to develop non-invasive glucose monitoring (NGM) devices that will alleviate the pain and suffering of diabetics associated with the frequent pricking of skin for taking the blood sample for glucose testing. There have been numerous developments in the field of NGM during the last decade, which stress the need for a critical review. This manuscript aims to review the various NGM techniques and devices. The challenges and future trends in NGM are also discussed.
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Affiliation(s)
- Sandeep Kumar Vashist
- NUS Nanosience and Nanotechnology Initiative NanoCore, National University of Singapore, T-Lab Level 11, 5A Engineering Drive 1, Singapore 117580, Singapore.
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17
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Koetsier M, Nur E, Chunmao H, Lutgers HL, Links TP, Smit AJ, Rakhorst G, Graaff R. Skin color independent assessment of aging using skin autofluorescence. OPTICS EXPRESS 2010; 18:14416-14429. [PMID: 20639927 DOI: 10.1364/oe.18.014416] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Skin autofluorescence (AF) for the non-invasive assessment of the amount of accumulated tissue Advanced Glycation Endproducts (AGEs) increases with aging. In subjects with darker skin colors, measurements typically result in lower AF values than in subjects with fair skin colors, e.g. due to selective absorption by skin compounds. Our aim was to provide a new method for calculating skin AF, yielding values that are independent of skin color. The deviation of skin AF of healthy subjects with various darker skin types (N = 99) compared to reference values from Caucasians showed to be a function of various parameters that were derived from reflectance and emission spectra in the UV and visible range (adjusted R(2) = 80%). Validation of the new algorithm, based on these findings, in a separate dataset (N = 141) showed that results of skin AF can now be obtained to assess skin AGEs independently of skin color.
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Affiliation(s)
- M Koetsier
- Department of BioMedical Engineering, University Medical Center Groningen and University of Groningen, Groningen, The Netherlands
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18
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Corstjens H, Dicanio D, Muizzuddin N, Neven A, Sparacio R, Declercq L, Maes D. Glycation associated skin autofluorescence and skin elasticity are related to chronological age and body mass index of healthy subjects. Exp Gerontol 2008; 43:663-667. [DOI: 10.1016/j.exger.2008.01.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 01/29/2008] [Accepted: 01/31/2008] [Indexed: 10/22/2022]
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19
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Lieber CA, Majumder SK, Billheimer D, Ellis DL, Mahadevan-Jansen A. Raman microspectroscopy for skin cancer detection in vitro. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:024013. [PMID: 18465976 DOI: 10.1117/1.2899155] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We investigate the potential of near-infrared Raman microspectroscopy to differentiate between normal and malignant skin lesions. Thirty-nine skin tissue samples consisting of normal, basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma from 39 patients were investigated. Raman spectra were recorded at the surface and at 20-microm intervals below the surface for each sample, down to a depth of at least 100 microm. Data reduction algorithms based on the nonlinear maximum representation and discrimination feature (MRDF) and discriminant algorithms using sparse multinomial logistic regression (SMLR) were developed for classification of the Raman spectra relative to histopathology. The tissue Raman spectra were classified into pathological states with a maximal overall sensitivity and specificity for disease of 100%. These results indicate the potential of using Raman microspectroscopy for skin cancer detection and provide a clear rationale for future clinical studies.
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Affiliation(s)
- Chad A Lieber
- Vanderbilt University, Department of Biomedical Engineering, Nashville, Tennessee 37235, USA.
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20
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Tura A, Maran A, Pacini G. Non-invasive glucose monitoring: assessment of technologies and devices according to quantitative criteria. Diabetes Res Clin Pract 2007; 77:16-40. [PMID: 17141349 DOI: 10.1016/j.diabres.2006.10.027] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Accepted: 10/25/2006] [Indexed: 10/23/2022]
Abstract
Aim of this review was to describe the main technologies for non-invasive glucose monitoring and the corresponding most relevant devices. The review tries to overcome the limitations of previous reviews on this topic, such as the lack of objective criteria for inclusion or exclusion of technologies or devices, and the poor organization of the information, which often does not allow easy comparison between technologies and devices. In this review, the information is concise and organized into specific categories, and hence it becomes easy to compare advantages and disadvantages of the different technologies and devices. For technologies, the categories of information considered are the technology name, the underlying physical principle, the technology limitations and the measurement sites on the human body. For devices, the categories of information are the device name, its approval condition (FDA Approval and/or CE Mark), the technology on which it is based, a device general description, the tests performed on the device, the corresponding results, safety information, aspects affecting usability, current status of the device and the manufacturer, an Internet reference for the device. A total of 14 technologies and 16 devices are included. Conclusions of the review were that, despite some interesting and promising technologies and devices, a satisfactory solution to the non-invasive glucose monitoring problem still requires further efforts.
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21
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Tajaddini A, Scoffone HM, Botek G, Davis BL. Laser-induced auto-fluorescence (LIAF) as a method for assessing skin stiffness preceding diabetic ulcer formation. J Biomech 2007; 40:736-41. [PMID: 17123538 DOI: 10.1016/j.jbiomech.2006.10.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2006] [Accepted: 10/13/2006] [Indexed: 11/19/2022]
Abstract
Recurrent foot ulceration is a major cause of morbidity in diabetic patients. Discrepancy between the stiffness of the plantar skin and underlying soft tissues may influence the likelihood of ulceration. Tissue properties change with diabetes primarily due to high blood glucose which promotes intermolecular cross-linking of structural proteins thus leading to altered structure and function of these structural fibers. This study utilizes a non-invasive method for indirectly assessing skin tissue in the context of plantar ulcer formation in diabetic patients' feet. Control (C, n=13), and diabetic subjects with a history of ulceration (n=16) were matched based on gender, age (42-81years old) and BMI. Six subjects re-ulcerated (U) during their 1-year follow-up. At every visit, each subject's plantar skin was excited with a weak laser light (337nm) to induce tissue fluorescence at three locations on each foot. The spectral area under the curve (AUC) was calculated after background subtraction and normalization. The mean AUC was significantly higher for diabetics compared to control subjects, (mean AUC: 145.6+/-7.2, C=112.6+/-8.3, respectively, p=0.006). For those who re-ulcerated (U, n=6), skin site was not a significant factor, but AUC was diminished at the time of re-ulceration (p<0.05). The alteration of intermolecular bonds in diabetic subjects and thinning of skin prior to ulceration could account for these observations. The decrease in AUC prior to an ulcer formation suggests its potential as a marker of tissue changes, which precede ulceration in the diabetic foot.
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Affiliation(s)
- Azita Tajaddini
- Department of Biomedical Engineering (ND20), The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
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22
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Gambichler T, Matip R, Moussa G, Altmeyer P, Hoffmann K. In vivo data of epidermal thickness evaluated by optical coherence tomography: effects of age, gender, skin type, and anatomic site. J Dermatol Sci 2006; 44:145-52. [PMID: 17071059 DOI: 10.1016/j.jdermsci.2006.09.008] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Revised: 09/21/2006] [Accepted: 09/22/2006] [Indexed: 11/20/2022]
Abstract
BACKGROUND The knowledge of epidermal thickness (ET) is of great significance in many areas of medical and biological research. OBJECTIVES We aimed to assess optical coherence tomography (OCT) in terms of precision, and to investigate the influence of several constitutional factors, such as age, gender, skin type, and anatomic site, on the mean ET using OCT in vivo. METHODS Eighty-three subjects were studied using OCT in vivo. Intra- and inter-day repeatability measurements were performed. The mean ET was assessed in six different body sites of young (20-40 years old) and old (60-80 years old) Caucasians, respectively. An ethnic group was included into the study. RESULTS OCT proved to be a precise technique in terms of repeatability and reproducibility as expressed in low coefficients of variation. Comparison of young and old Caucasians demonstrated a significant decrease of ET with age in all anatomic sites investigated. ET assessed in males and females did not significantly differ, except for forehead skin which is significantly thinner in old females than in males. ET observed in Caucasians did not significantly differ from ET measured in ethnic individuals. Anatomic sites insignificantly influenced ET on an inter-individual level. However, differences of ET between body sites on an intra-individual level are significant. CONCLUSIONS This was the first systematic in vivo study on ET investigating several influencing parameters of the epidermal dimension in a reasonable study sample by means of OCT. The results presented here may serve as ET reference data in a variety of clinical and experimental matters.
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Affiliation(s)
- Thilo Gambichler
- Department of Dermatology, Ruhr-University Bochum, Gudrunstr. 56, 44791 Bochum, Germany.
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23
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Mulder DJ, Water TVD, Lutgers HL, Graaff R, Gans RO, Zijlstra F, Smit AJ. Skin autofluorescence, a novel marker for glycemic and oxidative stress-derived advanced glycation endproducts: an overview of current clinical studies, evidence, and limitations. Diabetes Technol Ther 2006; 8:523-35. [PMID: 17037967 DOI: 10.1089/dia.2006.8.523] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Advanced glycation endproducts (AGEs) predict long-term complications in agerelated diseases. However, there are no clinically applicable markers for measuring AGEs in vivo. METHODS We have recently introduced the AGE-Reader (DiagnOptics B.V., Groningen, The Netherlands) to noninvasively measure AGE accumulation in the human skin of the forearm, making use of the characteristic autofluorescence (AF) pattern that AGEs encompass. Skin AF is calculated as a ratio of mean intensities detected from the skin between 420-600 nm and 300-420 nm. It correlates with collagen-linked fluorescence and specific skin AGE levels from skin biopsies in diabetes, renal failure, and control subjects. Skin AF levels are increased in patients with diabetes and renal failure and are associated with the presence of vascular complications. Additionally, skin AF is strongly related to the progression of coronary heart disease and mortality, independently of traditional risk factors. Since skin pigmentation might influence skin AF, we have investigated the relation of relative skin reflectance (R%) to skin AF in subjects with varying skin phototypes (SPT). RESULTS The data presented in this article suggest that only in subjects with an SPT of V and VI or R% <12%, no reliable measurement can be performed. Therefore, the current prototype of the AGE-Reader is suitable for subjects with SPT I-IV or R% >12%, and more research is needed for a broader application. CONCLUSION The AGE-Reader is useful as a noninvasive clinical tool for assessment of risk for long-term vascular complications in diabetes and in other conditions associated with AGE accumulation.
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Affiliation(s)
- Douwe J Mulder
- Department of Internal Medicine, University Medical Center Groningen, Groningen, The Netherlands.
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24
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Bradley RS, Thorniley MS. A review of attenuation correction techniques for tissue fluorescence. J R Soc Interface 2006; 3:1-13. [PMID: 16849213 PMCID: PMC1618480 DOI: 10.1098/rsif.2005.0066] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Fluorescence intensity measurements have the potential to facilitate the diagnoses of many pathological conditions. However, accurate interpretation of the measurements is complicated by the distorting effects of tissue scattering and absorption. Consequently, different techniques have been developed to attempt to compensate for these effects. This paper reviews currently available correction techniques with emphasis on clinical application and consideration given to the intrinsic accuracy and limitations of each technique.
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Affiliation(s)
- Robert S Bradley
- The University of Manchester School of Chemical Engineering and Analytical Science, The University of Manchester, M60 1QD, UK.
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25
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Stamatas GN, Estanislao RB, Suero M, Rivera ZS, Li J, Khaiat A, Kollias N. Facial skin fluorescence as a marker of the skin's response to chronic environmental insults and its dependence on age. Br J Dermatol 2006; 154:125-32. [PMID: 16403105 DOI: 10.1111/j.1365-2133.2005.06949.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Throughout life facial skin is exposed to a variety of adverse environmental conditions and is constantly required to repair itself. The rate of epidermal cell proliferation is indicative of the skin's repair rate and can be monitored noninvasively in vivo using skin intrinsic fluorescence markers. OBJECTIVES The goal of the present study was to assess the effects of ageing, geographical region, ethnic origin and season on the ability of facial skin to repair itself in the presence of chronic environmental insults using in vivo fluorescence spectroscopy. METHODS Skin fluorescence emission was measured on the cheeks of 522 individuals in winter and repeated in summer in five different geographical locations in the Asia-Pacific region. Fluorescence emission was also measured from 80 caucasians of fair complexion in the United States (New Jersey area) on the face and on a relatively protected area (upper inner arm). The age range of the participants was 14-75 years. RESULTS We found that epidermal proliferation rates decrease monotonically with age, while the fluorescence of collagen and elastin cross-links increases with age indicating accumulation of advanced glycation end-products. These trends were independent of geographical region, ethnic origin and season of measurement. Epidermal proliferation rates of facial skin were higher than those of unexposed sites; they may be 10 times higher in younger (second decade) than in older (seventh decade) individuals, and they decrease with age at rates 10 times faster compared with those of unexposed sites. CONCLUSIONS This is the first time that epidermal proliferation and its dependence on ageing have been measured noninvasively on the human face. The higher tryptophan fluorescence values on the face vs. the protected site are indicative of accelerated rates of epidermal proliferation in the presence of chronic environmental insults. The repair potential of facial skin, i.e. its ability to maintain high proliferation rates, is maximal in younger populations and gradually decreases with age.
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Affiliation(s)
- G N Stamatas
- Johnson & Johnson Consumer Products Worldwide, Skillman, NJ, USA.
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26
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Diagaradjane P, Yaseen MA, Yu J, Wong MS, Anvari B. Synchronous fluorescence spectroscopic characterization of DMBA-TPA-induced squamous cell carcinoma in mice. JOURNAL OF BIOMEDICAL OPTICS 2006; 11:014012. [PMID: 16526889 DOI: 10.1117/1.2167933] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
While initially confined to the epidermis, squamous cell carcinoma can eventually penetrate into the underlying tissue if not diagnosed early and treated. The noninvasive early detection of the carcinoma is important to achieve a complete treatment of the disease. Of the various non-invasive optical techniques, the synchronous fluorescence (SF) technique is considered to provide a simplified spectral profile with more sharp spectral signatures of the endogenous fluorophores in complex systems. The potential use of the SF technique in the characterization of the sequential tissue transformation in 7,12-dimethylbenz(a)anthracene-12-O-tetradecanoylphorbol-13-acetate (DMBA-TPA)-induced mouse skin tumor model in conjunction with simple statistical analysis is explored. The SF spectra show distinct differences during the earlier weeks of the tumor-induction period. Intensity ratio variables are calculated and used in three discriminant analyses. All the discriminant analyses show better classification results with accuracy greater than 80%. From the observed differences in the spectral characteristics and the ratio variables that resulted in better classification between groups, it is concluded that tryptophan, collagen, and NADH are the key fluorophores that undergo changes during tissue transformation process and hence they can be targeted as tumor markers to diagnose normal from abnormal tissues using the SF technique.
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Affiliation(s)
- Parmeswaran Diagaradjane
- Rice University, Department of Bioengineering, MS-142, P.O. Box 1892,, Houston, Texas 77251, USA
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27
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Khalil OS. Non-invasive glucose measurement technologies: an update from 1999 to the dawn of the new millennium. Diabetes Technol Ther 2004; 6:660-97. [PMID: 15628820 DOI: 10.1089/dia.2004.6.660] [Citation(s) in RCA: 177] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
There are three main issues in non-invasive (NI) glucose measurements: namely, specificity, compartmentalization of glucose values, and calibration. There has been progress in the use of near-infrared and mid-infrared spectroscopy. Recently new glucose measurement methods have been developed, exploiting the effect of glucose on erythrocyte scattering, new photoacoustic phenomenon, optical coherence tomography, thermo-optical studies on human skin, Raman spectroscopy studies, fluorescence measurements, and use of photonic crystals. In addition to optical methods, in vivo electrical impedance results have been reported. Some of these methods measure intrinsic properties of glucose; others deal with its effect on tissue or blood properties. Recent studies on skin from individuals with diabetes and its response to stimuli, skin thermo-optical response, peripheral blood flow, and red blood cell rheology in diabetes shed new light on physical and physiological changes resulting from the disease that can affect NI glucose measurements. There have been advances in understanding compartmentalization of glucose values by targeting certain regions of human tissue. Calibration of NI measurements and devices is still an open question. More studies are needed to understand the specific glucose signals and signals that are due to the effect of glucose on blood and tissue properties. These studies should be performed under normal physiological conditions and in the presence of other co-morbidities.
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Affiliation(s)
- Omar S Khalil
- Diagnostics Division, Abbott Laboratories, Abbott Park, Illinois 60064, USA.
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