The ability oflow-energy laser radiation (LLR) to counteract the detrimental effects of gamma radiation was studied with a murine model. Three control and two experimental groups of mice were used. Control group I consisted of animals unexposed to either gamma or laser irradiation. Group II consisted of mice exposed solely to gamma radiation. Control group III consisted of mice exposed solely to LLR. Experimental group I included mice exposed to gamma radiation initially, followed by LLR for three days. In experimental group II, LLR was applied each of three days prior to gamma irradiation.Gamma radiation was produced by 137 Cs with a total dose of 8.75 Gr (0.02 GrImm). The source of laser radiation was He-Ne (632.8 nm), and a power density of 0.5 Wt/cm2. Irradiation was performed once every three days for 15 sec. In an additional set of experiments, the effect of LLR in various doses on survival of gamma-irradiated mice was examined. The effects of laser exposure prior to and after gamma radiation, percent survival, changes in lipid peroxithtion in serum and liver, the concentration of S-H groups in serum, and catalase activity in erythrocytes were obtained.LLR reduced average lethality. Successful results were achieved in all sets of experiments and were dependent mostiy on the dose of LLR. The biochemical tests exhibited the ability of LLR to modifies the dalTiaging effects of gamma radiation when laser is applied prior to or after gamma radiation. However, the protective effect of LLR was greater in the group with exposure before gamma radiation.
Open surgeiy for the removal of renal and ureteric calculi has been rendered almost obsolete in the last ten years. The development ofthe extracorporeal and the intiOCOTpOTeaI lithotripters has permitted many patients to have their stones treated without operation.Several kinds ofalternative disintegration methods such as electrohydraulic lithotripsy, ultrasound lithotiipsy, stone disintegration by laser irradiation, electric drill disintegration, microexplosion lithotripsy and extracorporeal shock wave lithotripsy have contributed to this advancement.However, these methods are not without some problems, such as effect and technique. Shock wave lithotripsy is the cornerstone ofthe nxxlern management ofurinary calculi and is the preferred treatment for nxst small renal stones. However, in cases oflarge renal or impacted ureter calculi this approach can be combined intracorporeal lithotripsy or percutaneous nephrolithotripsy treatment in the staged management of complex upper urinary tract calculous disease.Ultrasound lithotriptors (USL)and electrohydraulic lithotriptors (EHL)are representative lithotriptors forendoscopic elimination of upper urinary tract stones. However, they have some disadvantages. For example, USL can not be used with flexible scopes and EHL can cause unexpected tissue injury.L.aser4nduced shockwave lithotripsy appears to be a very promising solution to this problem. Laser lithotripsy is the only technique that uses a flexible transmission system, results in the fine fragmentation ofcalculi, and is free of serious side effects on tissue, i.e. does not lead to perforation of the wall of the ureter.Today there are two laser system, which use as lithotripter in patients. But the problem of suitable energy transfer and conversion for intraUreteral lithotripsy has not yet been solved satisftctorily.Lotracorporeal lithotripsy using the Q-switched Nd:YAG laser generating a shockwave on the metallic surface of an optomechanic coupler needs a large diameter probe.The pulsed dyelaser was used widly and succesfully, because it can be transmitted through a thin, flexible quartz fiber a small caliber ureteroscope and flexible ureterorenoscope are applicable. But a dye laser operating at a wavelength of 504 am, which can damage tissue, especially in region of hemorrhage. So this method neels good visual observation.To overcome these problems, the Ruby laser lithotriptor was developed. This device generates a 694-nm wavelength red light beam, transmitted by flexible 400 micron quartz fiber. The maximum output energy is 130 mJ/pulse at the fiber tip and the pulse duration is 1.0 microsecond. The pulse rate can be varied from 1 to 5 Hz. Moreover, the 100
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