The trials to detect the cerebral ischemia during the brain surgery have been continued since last three decades. The intraoperative Xenon isotope cerebral blood flow(CBF) measurement and EEG monitoring were proven to be useful techniques for this purpose. But these techniques have several drawbacks and are not easily applicable in most institutions. Authors, therefore, developed a intraoperative cerebral ischemia monitoring system which applied the digital electroencephalography(EEG) and compressed spectral array(CSA) technique. Technical details of our system and the examples of clinical applications are described.
Brain ; Brain Ischemia* ; Electroencephalography ; Xenon

BACKGROUND: Solar furnaces are used worldwide to conduct experiments to demonstrate the feasibility of solar–chemical processes with the aid of concentrated sunlight, or to qualify high temperature-resistant components. In recent years, high-flux solar simulators (HFSSs) based on short-arc xenon lamps are more frequently used. The emitted spectrum is very similar to natural sunlight but with dangerous portions of ultraviolet light as well. Due to special benefits of solar simulators the increase of construction activity for HFSS can be observed worldwide. Hence, it is quite important to protect employees against serious injuries caused by ultraviolet radiation (UVR) in a range of 100 nm to 400 nm. METHODS: The UV measurements were made at the German Aerospace Center (DLR), Cologne and Paul-Scherrer-Institute (PSI), Switzerland, during normal operations of the HFSS, with a high-precision UV-A/B radiometer using different experiment setups at different power levels. Thus, the measurement results represent UV emissions which are typical when operating a HFSS. Therefore, the biological effects on people exposed to UVR was investigated systematically to identify the existing hazard potential. RESULTS: It should be noted that the permissible workplace exposure limits for UV emissions significantly exceeded after a few seconds. One critical value was strongly exceeded by a factor of 770. CONCLUSION: The prevention of emissions must first and foremost be carried out by structural measures. Furthermore, unambiguous protocols have to be defined and compliance must be monitored. For short-term activities in the hazard area, measures for the protection of eyes and skin must be taken.
Compliance ; Skin ; Sunlight ; Switzerland ; Ultraviolet Rays ; Xenon*

Using Xenon inhalation method, the authers measured the rCBF's within 24 hours before and after the operation of 4 AVM patients. We found the obliteration of the cerebral steal syndrome in all cases and the loss of initial shunt peak in 2 cases after excision of AVM. We discussed these hemodynamic changes in AVM and reviewed the literatures.
Hemodynamics ; Humans ; Inhalation ; Intracranial Arteriovenous Malformations* ; Xenon

The purpose of this study was to evaluate the color changes of the composite resin resulting from xenon lamp exposure in different environments. Composite resin (Z 250 ; shade A1, A2, A3, A3.5, and A4) were applied in a cylindrical metal mold. Seventy five specimens according to environments of exposure were made as follows; Group I: aluminum foiling of the specimens in the air at 37degrees C for 1 day and 7 days. Group II: exposure of xenon lamp to the specimens in the air at 37degrees C for 1 day and 7 days. Group III: exposure of xenon lamp to the specimens in distilled water at 37degrees C for 1 day and 7 days. The color characteristics (L*,a*,b*) of the specimens before and after exposure of xenon lamp were measured by spectrophotometer and the total color differences (DeltaE*) were computed. The results obtained were as follows: 1. In all groups except A1 shade of group III, the DeltaE* values presented below 2.0, and group III showed the highest DeltaE* values followed by group II and group I in a decreasing order(p<0.05). 2. In all shades and groups, the more the exposure time of xenon lamp and the lighter the shade were, the higher the tendency for discoloration (p<0.05). 3. The composite resins which was exposed to xenon lamp in the distilled water was more discolored than those in the air (p<0.05). 4. The major changes of composite resins which were exposed to xenon lamp in the air were an increase in yellowness through a positive shift of the b* value, and those in the distilled water were an increase in darkness and yellowness through a negative shift of the L* value and a positive shift of the b* value.
Aluminum ; Composite Resins* ; Darkness ; Fungi ; Water ; Xenon*

A non-invasive technique for measuring regional cerebral blood flow by xenon-enhanced CT has been developed with advent of computed tomography and reported extensively in recent years. Inhaled non-radioactive xenon gas can make tissue contrast enhancement on CT scan. Attenuation change from time dependent xenon concentration in brain CT slice are used to derive both parition coefficient and rCBF. In spite of its limited slice, it appears to be a useful and potentially widely available technique for clinical examination of rCBF in cerebrovascular disease, and it provides blood flow information with relatively high degree of spatial resolution and anatomical correlation. In this report, we present four clinical cases of various conditions and discuss methodology.
Brain ; Tomography, X-Ray Computed ; Xenon

With Xenon gas inhalation method, the authors measured the rCBF from 14 AVM patients who were checked into the Neurosurgical Department of Kyung Hee Medical College. In nine of them, we detected the rCBF within 24 hours after operation ; in comparison with the clinical progress, we got the results as follows; 1) The amount of rCBF before operation was 62.9+/-12.7 in adjacent regions around the AVM, and 67.8+/-14.7 in the contralateral hemisphere. These values were lower than normal rCBF, undoubtedly demonstrating the development of cerebral steal phenomenon. 2) After total excision of AVM, the amount of rCBF was 77.5+/-20.7(11.6+/-21.5% increase) in adjacent regions around AVM, and 79.6+/-16.3(8.9+/-17.0% increase) in the contralateral hemisphere. As the cerebral steal phenomenon was disappeared, 80% of clinical symptoms and signs were restored, which showed the interrelation between the rCBF and clinical progress. 3) The measurement of rCBF by Xenon gas inhalation method does no harm to human body, and can be carried out with ease and safety. 4) It is thought that in the case if AVM patient, the measurement of rCBF by Xenon gas inhalation method is a good parameter for diagnosis and follow up of AVM's patients.
Arteriovenous Malformations* ; Diagnosis ; Hemodynamics* ; Human Body ; Humans ; Inhalation ; Xenon

BACKGROUND: Recently, the 2nd generation IPL with a filtered xenon flash lamp has been widely used in the dermatologic field. In disagreement with the manufacturer's intent, for Asian skin, there were some reports that the best results for vascular lesions were obtained with the PR applicator, while the best results for pigmented lesions were obtained with the VL applicator. OBJECTIVE: The purpose of this study is to compare the efficacy and safety of two different (530~750 nm PR applicator and the 555~950 nm VL applicator) wavelength bands of 2nd generation IPL in Korean photo-rejuvenation. In addition, we compared the improvement of telangiectasia, irregular pigmentation, and overall patient' satisfaction for both settings. METHODS: Twenty-two patients with signs of photoaging skin including irregular pigmentation and telangiectasia were treated with 2nd generation IPL (Ellipse-Flex(R), DDD, Denmark) using a split-face comparative method, comparing both sides with respect to improvement of telangiectasia, irregular pigmentation, and overall patient satisfaction. RESULTS: Comparison of the efficacy and safety between the VL and PR applicators revealed that the VL applicator was not specific for vascular lesions and that the PR applicator was not specific for pigmented lesions. Additionally, VL is not better than PR for vascular lesions (p=0.80, McNemar test) and PR is not better than VL for pigmented lesions (p=0.80, McNemar test). Finally, improvements in skin texture were not significantly different between VL and PR (p=0.80, McNemar test). CONCLUSION: The two IPL wavelength bands were found to be effective in the treatment of photo-damaged facial skin. The difference between the two treatment procedures with regard to clinical efficacy and safety was not significant.
Asian Continental Ancestry Group ; Dichlorodiphenyldichloroethane ; Humans ; Pigmentation ; Skin ; Telangiectasis ; Xenon

In cerebrovascular disease, the measurement of cerebral blood flow(CBF) is an important indicator of a patient's clinical status, treatment and prognosis. The main advantage of Stable Xenon CT is that it noninvasively provides three-dimensional, high resolution, quantitative local cerebral blood flow information coupled to anatomic exposition. Using this modality, we measured postoperative CBF in 50 patients with subarachnoid hemorrhage from a ruptured intracranial aneurysm. The results were as follows : 1) There was a negative relationship between age and CBF. 2) Among postoperative disability patients, global and regional CBF were markedly diminished. 3) CBF on the ipsilateral side of a craniotomy site was markedly lower than on the contralateral side. Xenon CT is a very useful method for the evaluation of postoperative CBF in intracranial aneurysm patients.
Craniotomy ; Humans ; Intracranial Aneurysm* ; Prognosis ; Subarachnoid Hemorrhage ; Xenon*

STATEMENT OF PROBLEM: The discoloration of anterior teeth restoration is one of the material problems demanding retreatment. OBJECTIVES: To evaluate the color stability and affecting factors on esthetic restorative materials when subjected to accelerated aging. MATERIAL AND METHODS: This study was conducted using porcelain disks (IPS Empress 2-glazed, IPS Empress 2-polished), direct restorative resin disks (SYNERGY Duo) and indirect restorative resin disks (Sinfony, TESCERA ATL). Accelerated aging was done by precipitating the specimens in 38 degrees C distilled water and irradiating with xenon light, and the total irradiation was 397.98 KJ/mm. Color and microhardness change of the specimens were measured before accelerated aging and after 100 hours, 200 hours and 300 hours of accelerated aging, and Surface of the specimens were examined with SEM before and after 300 hours of accelerated aging. RESULTS: 1. After 300 hours' accelerated aging, a delta E value was 3.3 or lower in IPS Empress 2-glazed, IPS Empress 2-polished and Sinfony. 2. After 300 hours' accelerated aging, gloss was lost and surface changes including microcracks were observed in TESCERA ATL and SYNERGY Duo, and color changes of them ranged between 3.58 and 6.40 delta E units. 3. During 300 hours' accelerated aging, the microhardness of surface was increased by 3.21 - 19.64 percent in all kinds of composites resin. CONCLUSION: After 300 hours' accelerated aging, SEM images IPS Empress 2-glazed, IPS Empress 2-polished and Sinfony showed little morphological change and their color changes were considered to be clinically acceptable. And there was significant correlation between microhardness changes and color changes of composites (P < .05).
Aging ; Composite Resins ; Dental Porcelain ; Light ; Retreatment ; Tooth ; Water ; Xenon

BACKGROUND: Incohorenet lamps or pulsed/continuous wave lasers have effectively been used for photodynamic therapy (PDT). OBJECTIVE: To assess the safety and efficacy of the various light sources, such as halogen, xenon arc, and the 585nm pulsed dye laser, in photodynamic therapy for treatment of actinic keratosis. METHODS: PDT, using 5-aminolaevulinic acid (5-ALA), was used on 18 patients who had been diagnosed with actinic keratoses. A single treatment consisting of a topical application of 20% 5-aminolaevulinic acid for 4 hours, followed by halogen, xenon arch lamp and the 585nm pulsed dye laser was administered. RESULTS: Of the 227 lesions, 95/106 (89.6%), 68/77 (88.3%), and 39/44 (88.6%) lesions showed complete response to the halogen lamp, xenon arc lamp, and 595nm dye laser respectively, and 10/106 (9.4%), 9/77 (11.7%), and 5/44 (11.4%) lesions showed partial response to the above, respectively. Only one lesion (1.0%) showed no response to the halogen lamp. In all cases, cosmetic outcome was excellent, and anatomical function was preserved. Topical 5-ALA based PDT is an effective and useful treatment modality for various premalignant diseases, to the halogen lamp, xenon arc lamp, or 585nm pulsed dye laser were used. CONCLUSIONS: Treatment of actinic keratosis with various light sources, following topical application of 5-ALA is effective. However, advantages of the laser treatment may include recovery times, excellent postreatment cosmesis, and high efficacy rate.
Actins* ; Humans ; Keratosis, Actinic* ; Lasers, Dye* ; Photochemotherapy* ; Xenon