1
|
Khramov RN, Kreslavski VD, Svidchenko EA, Surin NM, Kosobryukhov AA. Influence of photoluminophore-modified agro textile spunbond on growth and photosynthesis of cabbage and lettuce plants. OPTICS EXPRESS 2019; 27:31967-31977. [PMID: 31684418 DOI: 10.1364/oe.27.031967] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 10/07/2019] [Indexed: 06/10/2023]
Abstract
Light-converting polypropylene spunbond was first used in the study of the key physiological parameters of plants. A comparative study of the functioning of the photosynthetic apparatus and the dynamics of growth in late cabbage plants (Olga variety) and leaf lettuce (Emerald variety) was conducted using the ordinary nonwoven polypropylene fabric (spunbond) (density 30 g·m-2) and the spunbond containing a photoluminophore (PL) (1.6% yttrium oxysulfide doped with europium). The plants were grown in a glass greenhouse without spunbond and under the spunbond containing and not containing the PL that transforms a part of UV-radiation into red light radiation. The use of the spunbond led to a decrease in the rate of photosynthesis, activity of the photosystem 2, and the accumulation of plant biomass and to an increase in the stomatal conductance. By contrast to unmodified spunbond, the application of the spunbond containing the PL led to an increase in the rate of photosynthesis, the water-use efficiency (WUE), and the accumulation of the total biomass of plants by 30-50% but to a decrease in the transpiration rate and the stomatal conductance. It is assumed that the positive effect of the PL is associated with an increase in the fraction of fluorescent red light, which enhances photosynthetic activity and accelerates plant growth.
Collapse
|
2
|
Skin adhesive low-level light therapy for dysmenorrhoea: a randomized, double-blind, placebo-controlled, pilot trial. Arch Gynecol Obstet 2012; 286:947-52. [PMID: 22648444 DOI: 10.1007/s00404-012-2380-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Accepted: 05/08/2012] [Indexed: 10/28/2022]
Abstract
PURPOSE The cause of dysmenorrhoea is an abnormal function of smooth muscles in the uterus due to long-term deficient blood supply into smooth muscle tissue. The purpose of this study was to evaluate the effectiveness of skin adhesive low-level light therapy (LLLT) in participants with dysmenorrhoea. METHODS Thirty-one women were included in this randomized, double-blind, placebo-controlled, pilot trial. Twenty-one women were treated with active LLLT and ten women were treated with placebo one. The therapy was performed in a laboratory room for 20 min a day over a period of 5 days prior to the expected onset of menstruation. The outcome was measured using a visual analog scale (VAS) for each participant's dysmenorrhoeal pain severity. VAS of each subject was measured every month for 6 months. RESULTS In the active LLLT group, 16 women reported successful results during their first menstrual cycle just after active LLLT and 5 women had successful results from the second menstrual cycle after active LLLT. The pain reduction rate was 83 % in the active LLLT group, whereas there was only a slight and temporary reduction in pain in the placebo LLLT group. Changes of VAS within 6 months of LLLT showed statistical significance (p = 0.001) over placebo control. CONCLUSIONS Our study suggests that skin adhesive LLLT on acupuncture points might be an effective, simple and safe non-pharmacological treatment for dysmenorrhoea.
Collapse
|
3
|
Lim JH, Lee J, Choi J, Hong J, Jhun H, Han J, Kim S. The Effects of Light-Emitting Diode Irradiation at 610 nm and 710 nm on Murine T-Cell Subset Populations. Photomed Laser Surg 2009; 27:813-8. [DOI: 10.1089/pho.2008.2375] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Jeong H. Lim
- Department of Rehabilitation Medicine, Konkuk University Medical Center, Seoul, South Korea
| | - Jongmin Lee
- Department of Rehabilitation Medicine, Konkuk University Medical Center, Seoul, South Korea
| | - Jida Choi
- Department of Biomedical Science and Technology, Konkuk University, Seoul, South Korea
| | - Jaewoo Hong
- Department of Biomedical Science and Technology, Konkuk University, Seoul, South Korea
| | - Hyunjhung Jhun
- Department of Biomedical Science and Technology, Konkuk University, Seoul, South Korea
| | - Jinsoo Han
- College of Veterinary Medicine, Konkuk University, Seoul, South Korea
| | - Soohyun Kim
- Department of Biomedical Science and Technology, Konkuk University, Seoul, South Korea
| |
Collapse
|
4
|
Lim JH, Lee J, Lee IS, Kim YJ, Song EY, Choi YS, Yun YM. The effects of daily irradiation with polychromatic visible polarized light on human lymphocyte populations. Photomed Laser Surg 2008; 26:361-6. [PMID: 18647093 DOI: 10.1089/pho.2007.2175] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE The goal of this randomized, placebo controlled, double-blind study was to investigate the effects of transcutaneous irradiation with polychromatic visible polarized light (540-780 nm; 68% polarization; power density 3.0 E-10 W/cm(2)) on a subset population of human lymphocytes using flow cytometry. BACKGROUND DATA The biomodulation and therapeutic effects of visible light of different wavelengths are well known, but the immunological effects of polychromatic visible polarized light have not been investigated sufficiently. METHODS Before and after 28 consecutive days of irradiation, blood samples were collected from the subjects and the population count of the lymphocyte subset was measured. RESULTS The absolute count of total lymphocytes, CD3(+) lymphocytes, and CD3(+)CD4(+) lymphocytes increased by 7% (p = 0.023), 9% (p = 0.058), and 13% (p = 0.021), respectively. Yet the absolute count of WBCs, CD3(+)CD8(+), CD19(+), and CD16(+)56(+) lymphocytes did not change significantly. CONCLUSION The application of polychromatic visible polarized light with the aforementioned features increases the CD3(+)CD4(+) lymphocyte population. It is suggested that this regimen may be useful for the promotion of natural defenses in cell-mediated immunity.
Collapse
Affiliation(s)
- Jeong H Lim
- Department of Rehabilitation Medicine, Konkuk University School of Medicine, Seoul, South Korea
| | | | | | | | | | | | | |
Collapse
|
5
|
Montagnoli G, Podestà A, Bonaretti S. Photomodulated Azoaldolase: A Model for Light Intervention in Biological Systems? Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2000)0720727paamfl2.0.co2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
6
|
Montagnoli G, Podestà A, Bonaretti S. Photomodulated azoaldolase: a model for light intervention in biological systems? Photochem Photobiol 2000; 72:727-30. [PMID: 11140259 DOI: 10.1562/0031-8655(2000)072<0727:paamfl>2.0.co;2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Azoaldolase is obtained from rabbit muscle aldolase by adding an azo chromophore to a cysteine side chain in each of the four enzyme subunits. The enzyme becomes photosensitive whereas both its catalytic activity and the michaelian kinetics are retained. Chromophore excitation causes E to Z isomerization of the azo bond, and mutually influences the protein-substrate equilibria. The various isomerization and substrate binding equilibria have been investigated under the hypothesis of a cyclic process described by four linked equilibrium constants. The mechanism of the light effect is a continuous adaptation of the specific parameters of the active protein, that is substrate recognition and rate of the catalyzed process. Absorbed light allows the rapid modification of the concentrations of various related molecules, depending on the used frequencies. At present such a mechanism has not been described in photobiology; so azoaldolase can be taken as a model for a possible new mechanism of light regulation of a biological system, based on changes in the molecular recognition by an active protein against its substrate.
Collapse
Affiliation(s)
- G Montagnoli
- Department of Veterinary Anatomy, Biochemistry and Physiology, University of Pisa, Pisa, Italy.
| | | | | |
Collapse
|
7
|
Lage C, Teixeira PC, Leitão AC. Non-coherent visible and infrared radiation increase survival to UV (254 nm) in Escherichia coli K12. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2000; 54:155-61. [PMID: 10836546 DOI: 10.1016/s1011-1344(00)00010-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Interactions between visible or infrared (IR) and ultraviolet (UV, 254 nm) radiation have been studied in E. coli. Pre-illumination with non-coherent monochromatic 446, 466, 570 and 685 nm radiation, as well as with polychromatic red and IR radiation at room temperature, leads to increased cell survival after a subsequent irradiation with UV light. In the thermic range of the spectrum (red and IR), IR but not red light pre-treatment is able to increase cell survival to a subsequent lethal heat (51 degrees C) challenge, suggesting that increased UV survival may be due to IR-induced heat-shock response. On the other hand, visible-light-induced resistance may be due to a different mechanism, possibly involved with unknown bacterial light receptors.
Collapse
Affiliation(s)
- C Lage
- Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, UFRJ, Rio de Janeiro, RJ, Brazil.
| | | | | |
Collapse
|
8
|
Sroka R, Schaffer M, Fuchs C, Pongratz T, Schrader-Reichard U, Busch M, Schaffer PM, Dühmke E, Baumgartner R. Effects on the mitosis of normal and tumor cells induced by light treatment of different wavelengths. Lasers Surg Med 1999; 25:263-71. [PMID: 10495304 DOI: 10.1002/(sici)1096-9101(1999)25:3<263::aid-lsm11>3.0.co;2-t] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Although the background of laser therapy by means of low level energy and power is still only partially understood, there are nevertheless promising reports from clinical studies concerning pain treatment, the acceleration of wound healing, and the modulation of cell functions. In order to contribute to the understanding of such a phototherapeutic procedure cell experiments were performed. MATERIALS AND METHODS The influence of light (lambda = 410, 488, 630, 635, 640, 805, and 1,064 nm and broad band white light) on the proliferation of cells was investigated on skeletal myotubes (C2), normal urothelial cells (HCV29), human squamous carcinoma cells of the gingival mucosa (ZMK1), urothelial carcinoma cells (J82), glioblastoma cells (U373MG), and mamma adenocarcinoma cells (MCF7) in a computer-controlled light treatment chamber. The cellular response was tested by way of the following methods: The rate of mitosis was determined by counting the single cells after Orcein-staining. The proliferation index measurements were based on the BrdU incorporation during the DNA synthesis. Statistics were performed using unpaired Student's t-test procedures, stating P < 0. 05 to be significant and P>0.05 not to be significant. RESULTS Twenty-four hours after light treatment, a significant increase in the mitotic rate of J82 and HCV29 cells was determined when illuminated with lambda = 410 nm, lambda = 635 nm and lambda = 805 nm, respectively. C2 cells showed an increase only after lambda = 635 nm illumination. In all three cell lines, a maximum mitotic rate was determined after an irradiation between 4 and 8 J/cm(2), while a reduced mitotic rate was measured at 20 J/cm(2). MCF7, U373MG, and ZMK1 cells showed a slight decrease in the mitotic rate with increasing irradiation independent of the wavelength used. When an irradiation of 20 J/cm(2) was applied, all cell lines showed a slight decrease compared to the controls independent to the wavelength used. White light as well as lambda = 1,064 nm does not affect the mitotic rate in this irradiation range. No significant differences in the effects could be determined when the irradiance changed between 10 and 150 mW/cm(2) at certain irradiation values. The BrdU test did not show any significant alterations with respect to possible light induced processes compared to the controls. CONCLUSIONS Dependent upon the irradiation parameter, light of a defined wavelength does affect the mitotic rate of both normal as well as tumor cells. It could be hypothesized that the action spectra of the cellular response indicate the participation of endogenous porphyrins and cytochromes as primary photoreceptors. Taking into account all light induced processes, the term biomodulation should preferably be used.
Collapse
Affiliation(s)
- R Sroka
- Laser-Research Laboratory, Ludwig-Maximilians-University, Munich, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Schaffer M, Sroka R, Fuchs C, Schrader-Reichardt U, Schaffer PM, Busch M, Dühmke E. Biomodulative effects induced by 805 nm laser light irradiation of normal and tumor cells. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1997; 40:253-7. [PMID: 9372613 DOI: 10.1016/s1011-1344(97)00065-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The influence of light emitted from a diode laser centred at lambda = 805 nm was investigated on murine skeletal myotubes (C2), normal urothelial cells (HCV29), human squamous carcinoma cells of the gingival mucosa (ZMK) and urothelial carcinoma cells (J82) in a computer-controlled irradiation chamber. Cells were treated with varying fluences between 0 and 20 J cm-2. The response was tested by analysis of the mitotic index using single cell counting after Orcein staining and proliferation index based on BrdU incorporation during DNA synthesis. While the mitotic index of C2, HCV29 and J82 cells increased at a fluence of 4 J cm-2, irradiation with fluences of 20 J cm-2 resulted in a slight decrease. ZMK tumor cells showed a decrease of the mitotic index with both fluences. No significant differences could be determined when using irradiances between 10 mW cm-2 and 150 mW cm-2. The BrdU test after irradiation showed no significant effects compared to the controls in each cell line.
Collapse
Affiliation(s)
- M Schaffer
- Department of Radiotherapy and Radiation Oncology, Ludwig-Maximilians-University, Munich, Germany
| | | | | | | | | | | | | |
Collapse
|
10
|
Sachdeva R, Bhagwanani NS, Chitnis DS. INVESTIGATION INTO THE WAVELENGTH-DEPENDENT EFFECT OF LOW INCIDENT LEVELS OF LASER RADIATION ON THE GROWTH OF MICROBIAL CELLS. Laser Ther 1997. [DOI: 10.5978/islsm.9.19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
11
|
Daniels LL, Quickenden TI. Does low-intensity He-Ne laser radiation produce a photobiological growth response in Escherichia coli? Photochem Photobiol 1994; 60:481-5. [PMID: 7800719 DOI: 10.1111/j.1751-1097.1994.tb05138.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A photobiological study was carried out on the bacterium Escherichia coli in order to determine whether stimulation of growth occurred after irradiation of an inoculum with coherent red light. No enhancement or inhibition of growth was observed for cultures of the bacterium following irradiation of inocula with a Helium-neon laser (continuous wave, lambda = 632.8 nm) at irradiances of 7.7 x 10(15) and 1.8 x 10(16) photons cm-2 s-1 using fluences of 4.5 x 10(-1) and 4.5 J cm-2 at each irradiance. Bacterial growth in irradiated and control cultures was monitored during a growth period of ca 2 h using a viable count technique after inocula in the early exponential phase had been diluted with fresh growth medium. These results do not provide support for the work of Karu et al. (1983, Nuov. Cim. 2D, 1138-1144), and Tiphlova and Karu (1988, Photochem. Photobiol. 48, 467-471), which appear to show substantial enhancement of E. coli growth under these conditions.
Collapse
Affiliation(s)
- L L Daniels
- Department of Chemistry, University of Western Australia, Nedlands
| | | |
Collapse
|
12
|
Karu T, Tiphlova O, Esenaliev R, Letokhov V. Two different mechanisms of low-intensity laser photobiological effects on Escherichia coli. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1994; 24:155-61. [PMID: 7965412 DOI: 10.1016/1011-1344(94)07016-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Bacterial suspensions in a phosphate buffer were irradiated at wavelengths lambda of 632.8, 1066 and 1286 nm, incubated in Hottinguer broth for 60 min and assayed for viability by the standard surface-plating technique. The difference between the number of viable cells in the irradiated culture and the control was termed growth stimulation. Irradiation of the bacteria with an He-Ne laser (632.8 nm) or semiconductor lasers at 1066 and 1286 nm at various intensities and irradiation times produced two maxima in the growth stimulation vs. dose curve. The first maximum, in all cases, occurred near 50 J m-2, and the reciprocity law was obeyed. The second maximum occurred at an irradiation time of 100 s irrespective of the particular radiation intensity, and the reciprocity law was not obeyed. It is assumed that two different mechanisms are responsible for these two maxima in the growth stimulation vs. dose curve.
Collapse
Affiliation(s)
- T Karu
- Laser Technology Centre of the Academy of Sciences, Moscow Region, Troitzk, Russian Federation
| | | | | | | |
Collapse
|
13
|
Bertoloni G, Sacchetto R, Baro E, Ceccherelli F, Jori G. Biochemical and morphological changes in Escherichia coli irradiated by coherent and non-coherent 632.8 nm light. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1993; 18:191-6. [PMID: 8350186 DOI: 10.1016/1011-1344(93)80062-e] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Irradiation of Escherichia coli cells with either coherent or non-coherent 632.8 nm light (4 J cm-2) causes a transient acceleration of cell proliferation, which is maximal about 60 min after the end of the phototreatment. The stimulatory effect is dose dependent and is especially evident in the case of defective E. coli strains which are in the logarithmic phase of growth, while it becomes less important when cells are exposed to non-coherent 600-700 nm light. Stimulated cells exhibit biochemical and morphological changes, such as an intensified synthesis of cytoplasmic membrane proteins, increased cell volume and ribosomal content, which are suggestive of an enhanced cell metabolism.
Collapse
Affiliation(s)
- G Bertoloni
- Institute of Microbiology, University of Padova, Italy
| | | | | | | | | |
Collapse
|
14
|
Quickenden TI, Daniels LL. Attempted biostimulation of division in Saccharomyces cerevisiae using red coherent light. Photochem Photobiol 1993; 57:272-8. [PMID: 8451289 DOI: 10.1111/j.1751-1097.1993.tb02286.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Replicate cultures of the yeast Saccharomyces cerevisiae were irradiated with 632.8 nm coherent light from He-Ne lasers at irradiances of 6.5 x 10(15) and 1.0 x 10(16) photons s-1 cm-2. Irradiation periods ranged from 0 to 652 min, and cultures were grown until well into the exponential phase. Unirradiated control cultures were grown alongside the irradiated cultures under otherwise identical conditions. The extents of growth in the control and irradiated cultures were compared spectrophotometrically at the end of each experiment. Contrary to the expectations of Karu et al. (e.g. Karu, 1988, Lasers Life Sci. 2, 53-74) no growth enhancement was found in the irradiated cultures, but a mild inhibitory effect was observed.
Collapse
Affiliation(s)
- T I Quickenden
- Department of Chemistry, University of Western Australia, Nedlands
| | | |
Collapse
|
15
|
Abstract
Green light (510-565 nm) constitutes a significant portion of the visible spectrum impinging on biological systems. It plays many different roles in the biochemistry, physiology and structure of plants and animals. In only a relatively small number of responses to green light is the photoreceptor known with certainty or even provisionally and in even fewer systems has the chain of events leading from perception to response been examined experimentally. This review provides a detailed view of those biological systems shown to respond to green light, an evaluation of possible photoreceptors and a review of the known and postulated mechanisms leading to the responses.
Collapse
Affiliation(s)
- R M Klein
- Botany Department, University of Vermont, Burlington 05405
| |
Collapse
|
16
|
Tribble J, Kozub J, Aly A, Ossoff R, Edwards G. Role of immersion refractometry for investigating laser-induced effects in cells. Lasers Surg Med 1992; 12:459-63. [PMID: 1495374 DOI: 10.1002/lsm.1900120416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The broad background of scattered light observed in spectra of cell suspensions is reduced by factors of up to 20 by immersion refractometry allowing for improved spectroscopic determination of the absorption properties of cells in the 325-820 nm range. Refractive-index matched spectra of E. coli C1a exhibit a set of resonant features near 422, 561, and 582 nm. Exposure wavelengths are chosen based on this spectrum and cell viability is investigated in E. coli suspensions exposed to 350, 400, 422, 440, and 700 nm radiation delivered in nanosecond pulses with total doses from 500 millijoules to 60 Joules. We observe a loss in cell viability for doses greater than 1 Joule at 422 nm and for all doses at other wavelengths; exposures of less than 1 Joule at 422 nm enhance growth. Excluding exposures at wavelengths within the resonant feature, longer wavelengths are less effective at reducing the viability of E. coli C1a. This indicates the occurrence of at least two absorption processes.
Collapse
Affiliation(s)
- J Tribble
- Department of Otolaryngology, Vanderbilt University, Nashville, Tennessee 37232-2559
| | | | | | | | | |
Collapse
|
17
|
Karu TI, Tiphlova OA, Matveyets YuA, Yartsev AP, Letokhov VS. Comparison of the effects of visible femtosecond laser pulses and continuous wave laser radiation of low average intensity on the clonogenicity of Escherichia coli. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1991; 10:339-44. [PMID: 1791489 DOI: 10.1016/1011-1344(91)80019-e] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To evaluate the contribution of local pulsed heating of light-absorbing microregions to biochemical activity, irradiation of Escherichia coli was carried out using femtosecond laser pulses (lambda = 620 nm, tau p = 3 x 10(-13) S, fp = 0.5 Hz, Ep = 1.1 x 10(-3) J cm-2, Iav = 5.5 x 10(-4) W cm-2, Ip = 10(9) W cm-2) and continuous wave (CW) laser radiation (lambda = 632.8 nm, I = 1.3 W cm-2). The irradiation dose required to produce a similar biological effect (a 160%-190% increase in the clonogenic activity of the irradiated cells compared with the non-irradiated controls) is a factor of about 10(3) lower for pulsed radiation than for CW radiation (3.3 X 10(-1) and 7.8 X 10(2) J cm-2 respectively). The minimum size of the microregions transiently heated on irradiation with femtosecond laser pulses is estimated to be about 10 A, which corresponds to the size of the chromophores of hypothetical primary photoacceptors--respiratory chain components.
Collapse
Affiliation(s)
- T I Karu
- Research Centre for Laser Technology, U.S.S.R. Academy of Sciences, Moscow
| | | | | | | | | |
Collapse
|
18
|
Abstract
The photomodulation of enzymes involves the activation and inactivation of enzyme reactions by UV and visible light. Enzymes or their reactions may be affected directly or indirectly. Direct effects involve photoproduction of a substrate, photodissociation of an inhibitor, photochemistry of protein amino acids, irradiation of a chromophore and irradiation of an enzyme substrate. Indirect effects involve gene expression, phytochrome and other photoreceptors which are not part of the enzyme, protein synthesis, membranes and photosynthesis. Photoactivation of enzymes is related to photocarcinogenesis, photomorphogenesis of plants, primary effects or side effects of phototherapy, deoxyribose nucleic acid (DNA) repair and many other aspects of biology and medicine. Model systems may contribute to the knowledge of protein chemistry and medicinal chemistry.
Collapse
Affiliation(s)
- D H Hug
- Infectious Disease Division, Department of Veterans Affairs Medical Center, Iowa City, IA
| | | |
Collapse
|
19
|
Tiphlova O. Does bacterial response to irradiation with monochromatic visible light reflect the pH dependence of genetic processes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1989; 3:640-1. [PMID: 2507764 DOI: 10.1016/1011-1344(89)80089-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
20
|
Tiphlova O, Karu T. Role of primary photoacceptors in low-power laser effects: action of He-Ne laser radiation on bacteriophage T4-Escherichia coli interaction. Lasers Surg Med Suppl 1989; 9:67-9. [PMID: 2648092 DOI: 10.1002/lsm.1900090114] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The effect of He-Ne laser radiation (lambda = 632.8 nm) on bacteriophage T4-Escherichia coli WP2 interactions was studied. Irradiation of bacteria having respiratory chain components as primary photoacceptors accelerated their division in a dose-dependent manner, but irradiation had no effect on the properties of the phage (measured as its ability to infect host cells). At the same time, exposure of bacteria to stimulating doses of He-Ne laser radiation (from 10(3) to 6 x 10(4) J/m2) increased their ability to promote the growth of unexposed phages. These results clearly indicate that low-power laser effects require primary photoacceptors (phage contains no chromophores for red light).
Collapse
Affiliation(s)
- O Tiphlova
- Laboratory of Laser Biology and Medicine, USSR Academy of Sciences, Moscow Region, Troitzk
| | | |
Collapse
|