Penetration of laser light through red blood cell ghosts

Šikurová, L; Balis, P.; Zvarík, Milan

doi:10.1016/j.jphotobiol.2011.03.015

Cited by 12 publications

(8 citation statements)

References 23 publications

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“…than other organs. 9 HbO and HbR are the primary absorbers in biological tissues in the visible wavelength region, 10 whereas the dominant absorbers in the NIR wavelength region are lipids, water, and collagen. In the present study, we demonstrate the characterization of the light scattering and absorption properties of in vivo liver tissue based on diffuse reflectance spectroscopy (DRS).…”

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confidence: 99%

Evaluation of light scattering and absorption properties ofin vivorat liver using a single-reflectance fiber probe during preischemia, ischemia–reperfusion, and postmortem

et al. 2015

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Diffuse reflectance spectroscopy (DRS) has been extensively used for characterization of biological tissues as a noninvasive optical technique to evaluate the optical properties of tissue. We investigated a method for evaluating the reduced scattering coefficient μ(s)', the absorption coefficient μ(a), the tissue oxygen saturation StO₂, and the reduction of heme aa3 in cytochrome c oxidase CcO of in vivo liver tissue using a single-reflectance fiber probe with two source-collector geometries. We performed in vivo recordings of diffuse reflectance spectra for exposed rat liver during the ischemia-reperfusion induced by the hepatic portal (hepatic artery, portal vein, and bile duct) occlusion. The time courses of μ a at 500, 530, 570, and 584 nm indicated the hemodynamic change in liver tissue as well as StO₂. Significant increase in μ(a)(605)/μ(a)(620) during ischemia and after euthanasia induced by nitrogen breathing was observed, which indicates the reduction of heme aa3, representing a sign of mitochondrial energy failure. The time courses of μ(s)' at 500, 530, 570, and 584 nm were well correlated with those of μ(a), which also reflect the scattering by red blood cells. On the other hand, at 700 and 800 nm, a temporary increase in μ(s)' and an irreversible decrease in μ(s)' were observed during ischemia-reperfusion and after euthanasia induced by nitrogen breathing, respectively. The change in μ(s)' in the near-infrared wavelength region during ischemia is indicative of the morphological changes in the cellular and subcellular structures induced by the ischemia, whereas that after euthanasia implies the hepatocyte vacuolation. The results of the present study indicate the potential application of the current DRS system for evaluating the pathophysiological conditions of in vivo liver tissue.

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confidence: 99%

Evaluation of light scattering and absorption properties ofin vivorat liver using a single-reflectance fiber probe during preischemia, ischemia–reperfusion, and postmortem

et al. 2015

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“…Any studies relating photochemical action to direct intervention with platelets or other blood components, has to take their optical properties into account [57]. Likewise, photochemolysis of Human red blood cells can occur and the resulting release of hemoglobin will affect the penetration depth of the activating laser light [58].…”

Section: Direct Light Effects On Plateletsmentioning

confidence: 99%

Platelets, photosensitizers, and PDT

Senge

Radomski

2013

Photodiagnosis and Photodynamic Therapy

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SummaryPhotodynamic therapy (PDT) has both direct cell and indirect vascular effects. Both are well established and the latter has given rise to specifically target angiogenesis in PDT treatments. While the vascular effects are well understood, further advances in antiangiogenesis require a detailed understanding of PDT effects at the microvasculature level. Although some of the earliest investigations of PDT noted effects on platelet aggregation the importance of their interaction with endothelial cells and the crucial role of various signaling pathways is only now emerging. This review aims to give a general overview of PDT related studies on platelets, vascular effects, and their interaction with endothelial cells to indicate the potential for studies in this area.Abbreviations: ALA --aminolevulinic acid; AMD -age-related macular degeneration; ANET -anti-neovascular therapy; BGF -basic fibroblast growth factor; DHEdihaematoporphyrin ether; EDRF -endothelium-derived relaxing factor; epithelial growth factor -EGF; HIF-1 -hypoxia-inducible factor 1; HpD -haematoporphyrin derivative; IL -interleukin; PAF -platelet activating factor; PDT -photodynamic therapy; PS -photosensitizer; transforming growth factor 1 -TGF-1; TNF -tumor necrosis factor.

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“…The absorption coefficient of each chromophore is directly linked to the concentration of this chromophore in the tissue that can be precisely measured from the reflected light spectrum. 17 Both oxygenated and deoxygenated hemoglobin are the principal absorbers in biological tissues of the visible spectrum of light, 18 while the principal absorbers in the near infrared spectrum of light are lipid, water and collagen. 19 Moreover, the scattering coefficient is intrinsically dependent on both structural and functional changes in tissues, and is sensitive to several physical parameters such as size, shape, density and refractive index relative to that of the surrounding medium 20 ; thus, it can be altered by changes in tissue such as cell death and the proliferation of cells.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Medical applications of reflectance spectroscopy in the diffusive and sub-diffusive regimes

Akter

Hossain

Nishidate

et al. 2018

Journal of Near Infrared Spectroscopy

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Diffuse reflectance spectroscopy is a widely used technique for medical applications that may analyze the optical characteristics of biological tissues. By using diffuse reflectance spectroscopy, different tissue types can be distinguished based on specific changes on reflected light spectrum that are a result of differences on a molecular level between compared tissues. Identification of the structural features of tissue can be performed by applying diffuse reflectance spectroscopy, and the spectra obtained from this technique could provide important diagnostic information about the tissue morphology and physiology. Moreover, different tissue types can be classified using diffuse reflectance spectroscopy, during surgery on the basis of their optical properties that are related to the tissue morphology and constituents. In recent years, several research groups have been shown the feasibility of diffuse reflectance spectroscopy in discriminating benign and malignant tissue, and thus making it a good competitor for margin assessment. Therefore, the diffuse reflectance spectroscopy has the possibility to become an important optical means for disease diagnosis, treatment and prognosis monitoring. This review represents a summary of the literature on diffuse reflectance spectroscopy and its important clinical applications.

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Penetration of laser light through red blood cell ghosts

Cited by 12 publications

References 23 publications

Evaluation of light scattering and absorption properties ofin vivorat liver using a single-reflectance fiber probe during preischemia, ischemia–reperfusion, and postmortem

Evaluation of light scattering and absorption properties ofin vivorat liver using a single-reflectance fiber probe during preischemia, ischemia–reperfusion, and postmortem

Platelets, photosensitizers, and PDT

Medical applications of reflectance spectroscopy in the diffusive and sub-diffusive regimes

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