In photodynamic therapy, availability of water-soluble zinc tetrasulfophthalocyanine (Zn-TSPc) was investigated, and it was found that Zn-TSPc was easily incorporated in tumor cells (HeLa cells). Though the detection of fluorescence of Zn-TSPc is difficult in aqueous solution, Zn-TSPc incorporated in tumor cells showed strong fluorescence. This will be a great help for the detection of very small tumor, and laser light irradiation damaged the tumor incorporated with Zn-TSPc.

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The effect of irradiation with two kinds of low-energy lasers, semiconductor laser (wavelength: 900nm, output power: 1.5mW)and He-Ne Laser (wavelength: 632.8nm, output power: 5mW), on the mitogenesis of human lymphocytes was compared in vitro. Peripheral blood lymphocytes (PBL) isolated from healthy subjects. PBL were stimulated by mitogens such as lectins following laser irradiation, and then were incubated for 96hr in serum-supplemented medium. After incubation, these lymphocytes were measured by using a flow cytometry. The ability of lymphocytes blastoid transformation was shown by three analyses, that is, stimulation index (SI), growth rate (Gr) and DNA synthetic phase ratio.
The semiconductor laser has shown the ability to accelerate the mitogenesis of human lymphocytes at a low dose of irradiation, and He-Ne laser produces stimulative effect on these lymphocytes only at 0.1J/cm² of irradiation.

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In order to clarify the effects of SOFT LASER at the cellular level in vitro, we constructed a trial production of diode laser irradiation system to irradiate indevidual cells. This apparatus is composed of seven components: microscope, laser optical system, laser device, pin-hole system, light guide, TV monitor and eye safety system. The laser device, manufactured by SEDATELEC (FRANCE), emits short-infrared rays (wave length: 904nm) and has seven serial pulse modes (A-F). The apparatus was adapted with pin-hole system, light guide and objective lens of 100 magnifications to irradiate selectively the target cell. The apparatus was fitted with eye safety system for comfortable and safe use.
In consequence of the preliminary experiment with this apparatus, it was proved that SOFT LASER can be used for selective and precise irradiation which produces measure able effects at the microlevel.
This apparatus is very useful in the elucidation of the direct biological effects of SOFT LASER in vitro.

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Recently SOFT LASER has been used over a wide range. The clinical effects of SOFT LASER include wound healing effect in trauma, sedation and activation. However, the mechanism of SOFT LASER has not yet been elucidated. And then, in order to clarify the effects of SOFT LASER under the cell culture in vitro, we constructed a trial production of diode laser irradiation system to irradiate individual cells. We used the apparatus to investigate the proliferative function and morphological changes of MC3T3-E1 osteogenic cells.
As compared with the non-irradiated group, the irradiated group well proliferated. Proliferation in the irradiated group of 3 times was significantly greater than that in the other groups. Especially, F mode irradiated group showed significantly great values, and cells irradiated in F mode for 4 min x 3 times/day multiplied by cell division twenty-four hours later. Irradiation of SOFT LASER accelerated cell proliferation.
These results suggest that the biological and direct effects were clarified by SOFT LASER.

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We compared bactericidal effect on Streptococcus sobrinus between He-Ne laser (wavelength: 632.8nm, output power: 6mW) and ordinary red light. The red light was 632.0±3.0nm of wavelength and 5mW of output power, which was produced through four color filter glasses using 2kW xenon short arch lamp, Besides, we examined the bactericidal effect by the laser under an anaerobic atmosphere. The bactericidal effect of the lights was determined by the formation of a growth inhibitory zone on the mitis-salivarius agar plate.
As the results, the bactericidal effect on S. sobrinus was observed by He-Ne laser and the red light. However, the bactericidal effect by the laser was not found under the anaerobic condition. The mechanism of the bactericidal effect by He-Ne laser is photodynamic action by light, dye and oxygen, which is same in the case of the ordinary red light.

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We evaluated the effects of acupuncture and skin-contact type semiconductor low energy laser with irradiation signal sounds (Ga-Al-As, wavelength, 780nm, output, 10 mW, continuous waves) on peripheral circulation in the upper limbs using acupuncture points in oriental medicine along the arrangement of arteries and nerves as stimulatiom sites. The sites of irradiation and acupuncture were the point near the spinal process of T1 (Ex-B2 Jiaji), that along the brachial artery in the elbow joint (Cx3 Chutse), and that along the medial nerve in the central area of the volar wrist (Cx7 Taling). A placebo group was studied in comparison with laser irradiation group.
As parameters of peripheral circulation in the upper limbs, index finger blood flow and skin temperatures on the dorsal surface of the hand and that of the foot were recorded. After a 5minute control period without stimulation, laser irradiation and acupuncture (in situ needle technique) were continuously performed for 5minutes. Blood flow and changes in skin temperature during the 25minute period after stimulation were observed. The placebo group heard only irradiation signal sounds, and each parameter was measured. Measurements were done in the sitting position.
Low energy semiconductor laser irradiation of the site near Tl(Ex-B2 Jiaji) significantly increased index finger blood flow, associated with an increase in the skin temperature on the dorsal surface of the hand. Acupuncture of the point near Tl (Ex-B2 Jiaji) or that along the brachial artery (Cx3 Chutse) significantly increased index finger blood flow, associated with an increase in skin temperature on the dorsal surface of the hand. In the placebo group, no marked changes were observed in index finger blood flow or skin temperature after stimulation of any site.

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