Prof. Tiina I. Karu Profile

Prof. Tiina I. Karu

at Institute on Laser and Information Part Technologies'

SPIE Involvement:

Author

Proceedings Article | 22 September 2003 Paper

Cellular mechanisms of low-power laser therapy

Tiina Karu

Proceedings Volume 5149, (2003) https://doi.org/10.1117/12.518686

KEYWORDS: Light emitting diodes, Tissues, Laser therapeutics, Absorption, Molecules, Aluminum, Oxygen, Acquisition tracking and pointing, Mode conditioning cables, Semiconductor lasers

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Proceedings Article | 2 November 2001 Paper

Changes in absorbance of monolayer of living cells induced by laser radiation at 633, 670, and 820 nm

Tiina Karu, Natalia Afanasyeva, Sergei Kolyakov, Ludmila Pyatibrat, Leslie Welser

Proceedings Volume 4431, (2001) https://doi.org/10.1117/12.447438

KEYWORDS: Absorption, Absorbance, Laser therapeutics, Chromophores, Mode conditioning cables, In vivo imaging, Optical testing, Molecules, In vitro testing, Modulation

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Proceedings Article | 26 October 2001 Paper

Irradiation with a diode at 820 nm induces changes in circular dichroism spectra (250-780 nm) of living cells

Tiina Karu, Sergei Kolyakov, Ludmila Pyatibrat, Evgenii Mikhailov, Oleg Kompanets

Proceedings Volume 4433, (2001) https://doi.org/10.1117/12.446508

KEYWORDS: Dichroic materials, Absorption, Visible radiation, Circular dichroism spectroscopy, Chromophores, Ultraviolet radiation, Spectroscopy, Diodes, Laser therapeutics, Oxidation

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Proceedings Article | 3 November 2000 Paper

Mechanisms of low-power laser light action on cellular level

Tiina Karu

Proceedings Volume 4159, (2000) https://doi.org/10.1117/12.405918

KEYWORDS: Absorption, Molecules, Chromophores, Oxygen, Laser therapeutics, Visible radiation, Electrons, Tissues, Modulation, Acquisition tracking and pointing

Proceedings Article | 14 July 1999 Paper

Primary mechanisms of action of low-intensity laser light on cells

Tiina Karu

Proceedings Volume 3829, (1999) https://doi.org/10.1117/12.353128

KEYWORDS: Absorption, Chromophores, Oxygen, Copper, Molecules, Proteins, Transition metals, Iron, Acquisition tracking and pointing, Oxidation

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Proceedings Article | 5 February 1999 Paper

Can a mechanism based on changes in redox properties of cytochrome c oxidase be crucial in explaining low-power laser effects?

Tiina Karu

Proceedings Volume 3732, (1999) https://doi.org/10.1117/12.340012

KEYWORDS: Absorption, Chromophores, Oxygen, Molecules, Proteins, Copper, Transition metals, Iron, Metals, Oxidation

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Proceedings Article | 29 December 1998 Paper

Activation of chromatin in T-lymphocytes under He-Ne laser radiation

Valentina Manteifel, Tiina Karu

Proceedings Volume 3569, (1998) https://doi.org/10.1117/12.334394

KEYWORDS: Helium neon lasers, Luminescence, Blood, Adaptive optics, Beam controllers, Radiation effects, Microscopes, Laser therapeutics, Scanning electron microscopy, Laser applications

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Proceedings Article | 29 December 1998 Paper

Introductory remarks: blood irradiation as a new (renewed) phototherapeutic modality

Tiina Karu

Proceedings Volume 3569, (1998) https://doi.org/10.1117/12.334381

KEYWORDS: Blood, Ultraviolet radiation, Radiation effects, Laser therapeutics, Semiconductor lasers, Fiber coupled lasers, Radiotherapy, Laser applications, Medicine, Helium neon lasers

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Proceedings Article | 22 December 1997 Paper

He-Ne laser radiation influence on single-channel ionic currents through cell membranes: a patch-clamp study

Tiina Karu, A. Kurchikov, Vladilen Letokhov, V. Mokh

Proceedings Volume 3198, (1997) https://doi.org/10.1117/12.298001

KEYWORDS: Helium neon lasers, Neurons, Glucose, Spinal cord, Glia, Potassium, Arteries, Plasma, Brain, Laser irradiation

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Proceedings Article | 22 December 1997 Paper

Changes in absorption (lambda=500-860 nm) of cell monolayer under irradiation with semiconductor laser at 670 or 820 nm

Tiina Karu, Natalia Afanasyeva, Sergei Kolyakov, Ludmila Pyatibrat

Proceedings Volume 3198, (1997) https://doi.org/10.1117/12.297985

KEYWORDS: Absorption, Chromophores, Copper, Oxygen, Molecules, Semiconductor lasers, Transition metals, Iron, Metals, Oxidation

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Proceedings Article | 25 November 1996 Paper

Different sensitivity of cells from tumor-bearing organisms to continuous-wave and pulsed laser radiation (lambda = 632.8 nm) evaluated by chemiluminescence test

Tiina Karu, T. Ryabykh, Sergei Antonov, Vladilen Letokhov

Proceedings Volume 2929, (1996) https://doi.org/10.1117/12.259981

KEYWORDS: Blood, Pulsed laser operation, Organisms, Chemiluminescence, Continuous wave operation, Tumors, Radiation effects, Cancer, Colorectal cancer, Helium neon lasers

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Proceedings Article | 25 November 1996 Paper

Irradiation with HeNe laser can influence the cytotoxic response of HeLa cells to ionizing radiation

Tiina Karu, Ludmila Pyatibrat, G. Kalendo

Proceedings Volume 2929, (1996) https://doi.org/10.1117/12.260004

KEYWORDS: Helium neon lasers, Ionizing radiation, Radiation effects, Visible radiation, Laser irradiation, Plating, Laser therapeutics, Scintillation, Scanning electron microscopy, Genetics

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Proceedings Article | 25 November 1996 Paper

Ultrastructural changes in chondriome of human lymphocytes after irradiation with HeNe laser: appearance of giant mitochondria

Valentina Manteifel, L. Bakeeva, Tiina Karu

Proceedings Volume 2929, (1996) https://doi.org/10.1117/12.260002

KEYWORDS: Helium neon lasers, Electron microscopy, Blood, Statistical analysis, Electron microscopes, Photography, Data processing, Visualization, Photomicroscopy, Light

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Proceedings Article | 10 June 1996 Paper

Biophysical basis of low-power-laser effects

Tiina Karu

Proceedings Volume 2802, (1996) https://doi.org/10.1117/12.242159

KEYWORDS: Molecules, Tissues, Visible radiation, Chromophores, Helium neon lasers, Oxygen, Collagen, Absorption, Proteins, Inflammation

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Biological responses of cells to visible and near IR (laser) radiation occur due to physical and/or chemical changes in photoacceptor molecules, components of respiratory chains (cyt a/a₃ in mitochondria). As a result of the photoexcitation of electronic states, the following physical and/or chemical changes can occur: alteration of redox properties and acceleration of electron transfer, changes in biochemical activity due to local transient heating of chromophores, one-electron auto-oxidation and O₂^- production, and photodynamic action and ¹O₂ production. Different reaction channels can be activated to achieve the photobiological macroeffect. The primary physical and/or chemical changes induced by light in photoacceptor molecules are followed by a cascade of biochemical reactions in the cell that do not need further light activation and occur in the dark (photosignal transduction and amplification chains). These actions are connected with changes in cellular homeostasis parameters. The crucial step here is thought to be an alteration of the cellular redox state: a shift towards oxidation is associated with stimulation of cellular vitality, and a shift towards reduction is linked to inhibition. Cells with a lower than normal pH, where the redox state is shifted in the reduced direction, are considered to be more sensitive to the stimulative action of light than those with the respective parameters being optimal or near optimal. This circumstance explains the possible variations in observed magnitudes of low-power laser effects. Light action on the redox state of a cell via the respiratory chain also explains the diversity of low-power laser effects. Beside explaining many controversies in the field of low-power laser effects (i.e., the diversity of effects, the variable magnitude or absence of effects in certain studies), the proposed redox-regulation mechanism may be a fundamental explanation for some clinical effects of irradiation, for example the positive results achieved in treating wounds, chronic inflammation, and ischemia, all characterized by acidosis and hypoxia.

Proceedings Article | 15 January 1996 Paper

Action of pulsed visible and near-IR laser radiation on oxidative metabolism of cells evaluated by chemiluminescence measurement

T. Ryabykh, Tiina Karu

Proceedings Volume 2630, (1996) https://doi.org/10.1117/12.230024

KEYWORDS: Blood, Chemiluminescence, Radiation effects, Pulsed laser operation, Virtual colonoscopy, Colorectal cancer, Mode conditioning cables, Cancer, Continuous wave operation, Leukemia

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Proceedings Article | 15 January 1996 Paper

Mechanisms of interaction of monochromatic visible light with cells

Tiina Karu

Proceedings Volume 2630, (1996) https://doi.org/10.1117/12.230023

KEYWORDS: Visible radiation, Molecules, Chromophores, Oxygen, Absorption, Proteins, Industrial chemicals, Continuous wave operation, Femtosecond phenomena, Chemiluminescence

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Biological responses of cells to visible and near IR (laser) radiation occur due to physical and/or chemical changes in photoacceptor molecules, components of respiratory chains (cyt a/a₃ in mitochondria). As a result of the photoexcitation of electronic states, the following physical and/or chemical changes can occur: alteration of redox properties and acceleration of electron transfer, changes in biochemical activity due to local transient heating of chromophores, one-electron auto-oxidation and O'₂- production, and photodynamic action and ¹O₂ production. Different reaction channels can be activated to achieve the photobiological macroeffect. The primary physical and/or chemical changes induced by light in photoacceptor molecules are followed by a cascade of biochemical reactions in the cell that do not need further light activation and occur in the dark (photosignal transduction and amplification chains). These reactions are connected with changes in cellular homeostasis parameters. The crucial step here is thought to be an alteration of the cellular redox state: a shift towards oxidation is associated with stimulation of cellular vitality, and a shift towards reduction is linked to inhibition. Cells with a lower than normal pH, where the redox state is shifted in the reduced direction, are considered to be more sensitive to the stimulative action of light than those with the respective parameters being optimal or near optimal. This circumstance explains the possible variations in observed magnitudes of low- power laser effects. Light action on the redox state of a cell via the respiratory chain also explains the diversity of low-power laser effects. Besides explaining many controversies in the field of low-power laser effects (i.e., the diversity of effects, the variable magnitude or absence of effects in certain studies), the proposed redox-regulation mechanism may be a fundamental explanation for some clinical effects of irradiation, for example the positive results achieved in treating wounds, chronic inflammation, and ischemia, all characterized by acidosis and hypoxia.

Proceedings Article | 22 May 1995 Paper

Interactions of monochromatic visible light and near-IR radiation with cells: currently discussed mechanisms

Tiina Karu

Proceedings Volume 2391, (1995) https://doi.org/10.1117/12.209921

KEYWORDS: Visible radiation, Molecules, Tissues, Chromophores, Oxygen, Inflammation, Hypoxia, Absorption, Proteins, Helium neon lasers

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Biological responses of cells to visible and near IR (laser) radiation occur due to physical and/or chemical changes in photoacceptor molecules, components of respiratory chains (cyt a/a₃ in mitochondria, and cyt d in E. coli). As a result of the photoexcitation of electronic states, the following physical and/or chemical changes can occur: alteration of redox properties and acceleration of electron transfer, changes in biochemical activity due to local transient heating of chromophores, one-electron auto-oxidation and O₂^- production, and photodynamic action and ¹O₂ production. Different reaction channels can be activated to achieve the photobiological macroeffect. The primary physical and/or chemical changes induced by light in photoacceptor molecules are followed by a cascade of biochemical reactions in the cell that do not need further light activation and occur in the dark (photosignal transduction and amplification chains). These reactions are connected with changes in cellular homeostasis parameters. The crucial step here is thought to be an alteration of the cellular redox state: a shift towards oxidation is associated with stimulation of cellular vitality, and a shift towards reduction is linked to inhibition. Cells with a lower than normal pH, where the redox state is shifted in the reduced direction, are considered to be more sensitive to the stimulative action of light than those with the respective parameters being optimal or near optimal. This circumstance explains the possible variations in observed magnitudes of low-power laser effects. Light action on the redox state of a cell via the respiratory chain also explains the diversity of low-power laser effects. Beside explaining many controversies in the field of low-power laser effects (i.e., the diversity of effects, the variable magnitude or absence of effects in certain studies), the proposed redox-regulation mechanism may be a fundamental explanation of some clinical effects of irradiation, for example the positive results achieved in treating wounds, chronic inflammation, and ischemia, all characterized by acidosis and hypoxia.

Proceedings Article | 1 September 1990 Paper

Regulation of cellular metabolism with low-intensity monochromic visible light

Tiina Karu, Olgo Tiphlova

Proceedings Volume 1353, (1990) https://doi.org/10.1117/12.23743

KEYWORDS: Visible radiation, Bacteria, Mode conditioning cables, Medicine, Chemical oxygen iodine lasers, Absorption, Organisms, Laser therapeutics, Chromophores, Glucose

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