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Volume 19, Issue 4
Displaying 1-11 of 11 articles from this issue
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Hitoshi NAKANO, Daisuke AKITA, Takeyoshi NAKAYAMA1998 Volume 19 Issue 4 Pages 191-195
Published: 1998
Released on J-STAGE: September 24, 2012
JOURNAL FREE ACCESSWhen performing ultraviolet (UV) laser surgery, certain problems, such as genetic damage, must be considered because photochemical damage to living tissue is caused without exception during UV laser irradiation. In the present paper, changes in the structure of soft tissue caused by UV laser irradiation are discussed. A lipid was adopted as a soft tissue model. The UV and IR absorption spectra of the lipid were measured before and after each irradiation either an ArF or a KrF excimer laser. A remarkable difference in UV absorption spectra was found between KrF and ArF excimer laser irradiation. This difference was clearly identified using the resultant IR absorption spectra of the lipid.View full abstractDownload PDF (383K) -
Akihiko SHIBATA, Masanori NASU, Takashi YOSUE1998 Volume 19 Issue 4 Pages 197-204
Published: 1998
Released on J-STAGE: September 24, 2012
JOURNAL FREE ACCESSThe study of forecasting the continuation of nerve blocks by laser, and the effects on peripheral nerves irradiated by various doses was biochemically and histologically investigated.
Using a probe with the lens focusing from a distance of 8mm, the Nd-YAG laser was irradiated on the extracted sciatic nerves of rats at 10W (1,208J/cm2), 20W (2,117J/cm2) and 30W (2,702J/cm2). The procedure was also done from a distance of 18 mm at 10W (856J/cm2), 20W (1,378J/cm2) and 30W (1,791J/cm2).
The irradiated nerves were analysed for protein composition by SDS-PAGE and the histological changes were observed by light and by electron microscope.
The results were as follows.
The irradiation group were observed to have in the compositions of the cytoskeletons in axon and myelin. As the laser doses increased, the protein quantity tended to decrease. The ablation of myelin and the destroyed basement membrane were observed to significantly increase to 2,117J/cm2 and 2,702J/cm2.
From the above results, it was suggested that the nerve regeneration might be strongly obstructed at a dose over 2,117J/cm2 for nerve block treatment.View full abstractDownload PDF (1612K) -
[in Japanese]1998 Volume 19 Issue 4 Pages 205-206
Published: 1998
Released on J-STAGE: September 24, 2012
JOURNAL FREE ACCESSDownload PDF (228K) -
Mika HAKOZAKI, Seiichiro KOBAYASHI1998 Volume 19 Issue 4 Pages 207-216
Published: 1998
Released on J-STAGE: September 24, 2012
JOURNAL FREE ACCESSA Q-switched alexandrite laser was used at wavelength of 755nm, a pulse duration of 100ns and a spot size of 3mm. The laser was operated at a repetition rate of 1Hz with an energy fluence of 4.5-8J/cm2. The Q-switched alexandrite laser irradiation is widely used for benign cutaneous pigmented lesions and tattoos. The Q-switched alexandrite laser can remove nevus of Ota, tattoos, traumatic tattoos, senile pigmentations and seborrheic keratosis with a minimal number of treatment and without significant side-effects.
Using light and electron microscopes, we investigated the alterations in melanocytes and recovery of injured tissue of the nevus of Ota by Q-switched alexandrite laser irradiation. Q-switched alexandrite laser is highly selective and highly absorbed by melanosomes. Other cells and tissue components of the dermis remained almost intact. Following irradiation macrophages infiltrated the irradiated areas and scavenged degenerated melanosomes and cellular debris. Thus, discoloration of the skin was markedly reduced.View full abstractDownload PDF (3072K) -
Taro KONO, Sung-Ghi KWON, Kenji SASAKI, Motohiro NOZAKI1998 Volume 19 Issue 4 Pages 217-220
Published: 1998
Released on J-STAGE: September 24, 2012
JOURNAL FREE ACCESSIt has been generally accepted that LASER therapy is not suitable for patients with pigmented nevus, due to the existence of the nest formation. We considered that the epidermal ablation prior to the LASER therapy might be effective in these cases. We ablated epidermal layer using normal mode ruby LASER (20J), thereafter applied Q-switched ruby LASER (7J), sequentially. This combined method lead to satisfactory results without unfavorable complications.View full abstractDownload PDF (738K) -
Tohru TATESHITA, Ichiro ONO1998 Volume 19 Issue 4 Pages 221-229
Published: 1998
Released on J-STAGE: September 24, 2012
JOURNAL FREE ACCESSNevus spilus is known to have a high recurrence rate against the various treatments.
To minimize recurrence rate of the nevus, treatment was performed using a normal-pulsed ruby laser system (dual pulse width: 240μsec.~1msec.) as well as a Q-switched ruby laser system (pulse width: 30 nsec.). We treated the patients with nevus spilus using our protocol as indicated below.
After the epidermis on the treated area had been completely removed using long pulse of normal-pulsed ruby laser, the additional irradiation of short pulse with normal-pulsed ruby laser was performed and additional treatment with Q-switched ruby laser treatment to whom the recurrence rate seems to be high. The protocol was further improved with additional laser treatment using short pulse of 10J/cm2 and Q-switched ruby laser treatment of 4-7J/cm2, 3 weeks after the first treatment even there is no visible recurrence on the treated area. We consider that at least 2 sessions of the treatment with our protocol are needed for establishing good results. The efficacy of ruby laser treatment on nevus spilus was judged as excellent of good in 69 out of 97 cases (71.1%), and which has tendency to be improved as increasing treatment sessions. The side effects such as darkening of the lesion, ulceration, scar formation, or longstanding depigmentation were not observed.View full abstractDownload PDF (1961K) -
Yasumasa IWASAKI, Shinji OKANO, Hisakazu DAIKOKU, Kenji MORITA, Shoso ...1998 Volume 19 Issue 4 Pages 231-240
Published: 1998
Released on J-STAGE: September 24, 2012
JOURNAL FREE ACCESSThe dye laser with a wavelength of 585nm pulsed at 450μsec selectively reacts with red boold cells, resulting in impairment of ectatic blood vessels in dermis. It, thus, diminishes numbers and luminal diameters of abnormal blood vessels in hemangioma with minimum side effects, such as scarformation. In theory, the light of dye laser penetrates into 1,400μm depth of the human skin. However, histological examination in clinical trials have revealed that blood vessels in deep dermis reopened and circulate blood after treatments, while those at less than 600μm depth from the skin surface were completely destroyed. Clinically, substantial decrease of lesions has been achieved by the first treatments with this laser in most cases of port-wine stains, possiblly follwed by some additional improvements in the next 3 to 4 treatments, with only little efficacy thereafter. For strawberry mark, complete disapperance or satisfactory improvement of the thin flat lesions has been achieved, but the tumor type lesions remained as atrophic and redundant skin lesions or even unaffected, indicating importance of the treatments in an early stage this tumor.View full abstractDownload PDF (2098K) -
Toru HASHIMOTO1998 Volume 19 Issue 4 Pages 241-247
Published: 1998
Released on J-STAGE: September 24, 2012
JOURNAL FREE ACCESSThe carbon dioxide (CO2) laser has an emission wavelength of 10,600nm, which is absorbed by biologic tissue regardless of pigmentation or vascularity because its target of interaction water. The CO, laser can be used either incise or vaporise tissue. Currently, the CO2 laser is most frequently used in the defocused mode to vaporize tissue. The CO2 laser is used successfully and excellent cosmetic results in the treatment of syringomas and xanthelasma. It is also quite useful in the treatment of pyogenic granulomas. The CO2 laser is quite effective in the treatment of other tumors, including seborrhic keratosis, cutaneous neurofibromas, mucous cysts, and venouus lakes. In the treatment of lower labial melanosis, the CO2 laser seems to provide a slightly less treatment response than Q-switched ruby laser.View full abstractDownload PDF (2299K) -
Shinichi WATANABE1998 Volume 19 Issue 4 Pages 249-258
Published: 1998
Released on J-STAGE: September 24, 2012
JOURNAL FREE ACCESSMany biomedical applications of lasers have been developed. In many cases, however, selection of a particular laser has been based largely on availability, and treatment protocols have often been developed by an empirical approach. Selective photothermolysis (SP) has been proposed as a construct which may be useful in designing laser systems for biomedical applications, especially for the treatment of pigmentary dermatoses. The necessary conditions are (1) tissue structures which preferentially absorb a wavelength of light more than the surrounding tissue, (2) a pulse of light sufficiently short and energetic to produce localized high temperatures in the absorbing structures, and (3) a predominantly thermal mode of initiation of tissue damage. The concept of selective photothermolysis was confirmed by our experimental observations. The lasers, with a pulse of light sufficiently short and energetic to produce localized high temperatures in the targets, were demonstrated to be useful for treatment of some pigmented and vascular lesions which showed no significant response to previous therapies. Furthermore, SP of hair follicles can also be applied for removal of excess hair growth in unwanted areas. Photoablation by using CO2 or excimer lasers is used for microsurgery of the skin, especially skin resurfacing.View full abstractDownload PDF (1981K) -
1998 Volume 19 Issue 4 Pages 259-260
Published: 1998
Released on J-STAGE: September 24, 2012
JOURNAL FREE ACCESSDownload PDF (235K) -
1998 Volume 19 Issue 4 Pages 261-267
Published: 1998
Released on J-STAGE: September 24, 2012
JOURNAL FREE ACCESSDownload PDF (913K)
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