bluuebunny/crossref_metadata_2025_split huggingface dataset:
CO2 laser urethroplasty in the rabbit: A preclinical model
Authors: Choma Theodore J. , Poppas Dix P. , Presberg Harry J. , Cundiff Maria , Schlossberg Steven M. 
Published: March 2007

AbstractOur previous work has shown that the CO2 laser can be successfully used in urethral reconstruction in a rat model. This new experiment investigates the use of the CO2 laser to perform a patch graft urethroplasty in the rabbit, as a preclinical model to its use in the repair of hypospadias in humans. Using sterile technique, a patch graft of preputial skin was welded in the repair of a standardized urethral defect in 10 rabbits. In another cohort, the same urethral defect was repaired using standard microsuture technique. In a control group the patch graft was placed with microsuture in a nonwatertight fashion. All animals were followed for 3 weeks. Histologic and radiologic analyses were done in a blinded fashion. Our study showed that CO2 laser repair, when compared to microsuture in urethral reconstruction, required 40% less operative time and produced better graft healing and less intraluminal scarring. © 1992 Wiley‐Liss, Inc.
Quantification of phthalocyanine concentration in rat tissue using laser–induced fluorescence spectroscopy
Authors: Panjehpour Masoud , Sneed Rick E. , Frazier Donita L. , Barnhill Mary Ann , O'Brien Sherrie F. , Harb William , Overholt Bergein F. 
Published: March 2007

AbstractQuantification of photosensitizer concentration in tissue should improve planning and outcome of photodynamic therapy. laser–induced fluorescence (LIF) can be used to measure in vivo fluorescence of photosensitizers in tissue. This study was designed to determine if in vivo fluorescence intensity of chloroaluminum phthalocyanine tetrasulfonate correlates with its concentration in different rat tissues. Following LIF measurements, the animals were humanely euthanized and the concentration of phthalocyanine in different tissues was determined using chemical extraction technique. The correlation of phthalocyanine fluorescence intensity and its concentration was determined for each tissue using Pearson product‐moment correlation analysis. A strong correlation between in vivo phthalocyanine fluorescence intensity and its concentration was found for spleen, kidney, liver, and chemically induced mammary adenocarcinoma. Low correlation was found for thigh skin and planum of nose. No correlation was found for thigh muscle and tongue. © 1993 Wiley‐Liss, Inc.
Comparison of magnetic resonance images and the histopathological findings of lesions induced by interstitial laser photocoagulation in the brain
Authors: Tracz Robert A. , Wyman Douglas R. , Little Peter B. , Towner Rheal A. , Stewart Wendy A. , Schatz Stanley W. , Wilson Brian C. , Pennock Paul W. , Janzen Edward G. 
Published: March 2007

AbstractInterest has developed in using magnetic resonance (MR) imaging to monitor the volume of tissue destroyed by interstitial laser photocoagulation (ILP). In these experiments, ILP was induced in the normal brains of 9 anesthetized cats by delivering 1.5 W of continuous‐wave Nd:YAG laser energy (1,064 nm) from a single 400‐μm core optical fiber for 1,000 s. The irradiations were monitored using proton spin‐echo MR imaging during and immediately after ILP and at postirradiation survival times of 2, 5, and 14 days. At 2 days postirradiation, the necrotic thermal lesion consisted of a central cavity surrounded by 2 concentric zones of coagulative necrosis, one dense and the other dispersed. The lesion shrank and the zonal appearance became less obvious over the 14 day survival period. An enhancing halo on contrast‐enhanced T1‐weighted images acquired immediately postirradiation best approximated the total lesion diameter at 2 days. These images also indicated that the volume of tissue destroyed during ILP corresponded better to the necrotic volume determined at 2 days than at 5 days and 14 days postirradiation. T2‐weighted images acquired during and immediately after ILP consistently underestimated the total lesion diameter at 2 days. © 1993 Wiley‐Liss, Inc.
Rationale for automatic scanners in laser treatment of port wine stains
Authors: Mordon Serge , Rotteleur Guy , Brunetaud Jean Marc , Apfelberg David B. 
Published: March 2007

AbstractLaser therapy of port wine stains (PWS) is well established. However, the application of lasers to PWS treatment over the last decade has resulted in the use of many laser systems. The goal of this study is to describe the different laser parameters, treatment techniques, and delivery systems. Two methods, coagulation and microvaporization, are used to destroy the abnormal blood vessels. The coagulation method results in excellent treatment, but it requires careful control of laser parameters during the treatment process. Scanning devices can be utilized for this purpose. The microvaporization method, obtained with a pulsed dye laser, is restricted to PWS composed of small vessels since it is difficult to obtain a pulse longer than 450 microseconds. In addition, numerous retreatments are needed with the pulsed dye method. The initial assessment of the patient should contribute to an improvement in the choice of laser parameters and the outcome of treatment. © 1993 Wiley‐Liss, Inc.
Assessing Photofrin® uptake in atherosclerosis with a fluorescent probe: Comparison with photography and tissue measurements
Authors: Hsiang York , Stonefield Michael , Bower Robert D. , Fragoso Miguel , Tsang Vincent , Crespo M. Teresa , Lundkvist Anna 
Published: March 2007

AbstractThe purpose of this study was to assess Photofrin® porfimer sodium (P*) concentration in atherosclerotic plaque (ASP) using a fluorescence detector (Fluoroprobe) compared with fluorescent photography and chemical extraction of P*. ASP was created in the aortoiliac segments of Yucatan miniswine by a combination of balloon endothelial injury and 2% cholesterol and 15% lard diet for 7 weeks. At that time, swine were given P* I.V. in one of the following single dosages: Group I, 2.5; Group II, 1.0; or Group III, 0.5 mg/kg. Swine were sacrificed 24 hours later and aortoiliac and control carotid artery segments removed. Fluorescence was determined from these segments using photographic techniques, the Fluoroprobe, and a spectrofluorometer after chemical extraction. ASP were identified in all swine using photography and the Fluoroprobe. The intensity of fluorescence measured with the Fluoroprobe for Groups I to III was 1,098 ± 524, 471 ± 337, and 295 ± 173 units, respectively (P < 0.01). The tissue concentration of P* in ASP from each group was 130.4 ± 82.7, 10.0 ± 1.2, and 9.1 ± 0.6 ng/g, respectively (P < 0.01). There was a linear correlation between the fluorescence intensity measured with the Fluoroprobe and the extracted tissue concentration (r = 0.88, P < 0.0001). This study showed that a fluorescent detector such as the Fluoroprobe accurately detects the uptake of P* into atherosclerotic plaque. © 1993 Wiley‐Liss, Inc.
Evaluation of changes in oxygen tension as indicators of RIF‐1 tumor response to Nd:YAG laser heating
Authors: Fahy Alice K. , Waldow Stephen M. 
Published: March 2007

AbstractHeat‐induced oxygen tension changes in RIF‐1 tumors in C3H male mice were analyzed in an attempt to correlate these changes with tumor response to Nd:YAG laser heating. A low power, microprocessor‐controlled Nd:YAG laser was used to superficially heat 250–300 mm3 tumors to base temperatures of 44, 45, 46, or 48°C for 30 minutes via a flexible 600 μm quartz fiberoptic with a terminating microlens. A glass, Clark‐style microelectrode was inserted into the center of each tumor allowing real time measurement of the tumor's oxygenation status before, during, and after heating. Results showed that heating at 44°C caused a greater than 2‐fold increase in oxygen tension during heating, while a temperature of 48°C caused a brief initial increase in oxygen tension followed by a decrease to below pretreatment values. There was a significant correlation (P<0.05) between relative tumor oxygen tension during and post‐heating and tumor growth delay. A significant correlation (P<0.05) was also seen between tumor base temperature during heating and tumor growth delay. It appears from our initial data that single point oxygen tension measurements in small RIF‐1 tumors may be useful indicators of this model's response to Nd:YAG laser heating. This result may allow for modification of heating parameters (temperature/time) during treatment to optimize thermal response. © 1993 Wiley‐Liss, Inc.
Fluorospectral study of the rat brain and glioma in vivo
Authors: Tsai Jui‐Chang , Kao Ming‐Chien , Hsiao Yi‐Yun 
Published: March 2007

AbstractAn animal model of cerebral glioma was utilized by implanting C6 glioma cells into the brains of adult Wistar rats. Once tumors developed to 7–12 mm in diameter, we conducted continuous fluorimetry monitoring of glioma up to 24 hours using a fibre‐optic system connected to an intensified multichannel photodetector after an intravenous injection of hematoporphyrin derivative (HPD) into the rats. The intensity of the fluorescence in normal brain reached a plateau 6 hours after intravenous injection of HPD while that in glioma reached a plateau 80 minutes after injection. These fluorescence intensities of glioma, brain adjacent to tumor (BAT), and surrounding normal brain were measured in vivo 24 hours after intravenous administration of 5 mg/kg of HPD. The ratio of fluorescence intensities between glioma and brain was 6.1 while the ratio between BAT and brain was 3.9. There were no obvious differences in shapes between the spectra of the natural fluorescence (autofluorescence) of rat glioma and brain but the intensity of autofluorescence was much weaker in glioma. There are many problems in spectroscopic studies of biological tissues in vivo. It cannot be overemphasized that very strict criteria must be applied in order to get accurate data. Fluorescence from HPD administration may be used to discriminate tumor tissue from surrounding normal brain tissue during operation if the measuring conditions could be kept constant. It is important to understand the photospectral properties of glioma and brain tissue in order to get the most benefits in clinical application of light‐induced fluorescence or photoradiation therapy. © 1993 Wiley‐Liss, Inc.
Water‐jet‐cooled Nd:YAG laser coagulation of experimental liver metastases: Correlation between ultrasonography and histology
Authors: van Hillegersberg Richard , de Witte Marcel T. , Kort Will J. , Terpstra Onno T. 
Published: March 2007

AbstractTo establish the value of ultrasonography in imaging laser coagulation of tumor and surrounding tissue, the relation between measurements on ultrasound and histology was determined in a rat tumor model. A piece of colon carcinoma CC531 was implanted in the liver of 21 Wag/Rij rats; 20 days later, tumors (mean diameter 5.3 mm) were treated with a water‐jet‐cooled Nd:YAG laser at 10 W and either 150 J, 300 J, 600 J, 1,200 J, 1,700 J, or 2,400 J. Ultrasonography was done just pre‐ and immediately post‐laser treatment. The animals were sacrificed and livers removed for light microscopical evaluation. Depth and width of coagulation were measured directly on ultrasound, and on histological samples by computer‐assisted image analysis. Laser treatment did not change the echogenic aspect of the tumor on ultrasound. However, liver damage appeared hypoechoic compared to normal liver. A significant correlation was found between the total size of the lesion on ultrasound and histology (P = 0.015, r = 0.57 for depth; P = 0.012, r = 0.58 for width), suggesting that laser induced tumor destruction may be derived from the amount of surrounding hepatic damage on ultrasound. © 1993 Wiley‐Liss, Inc.
Comparison of the flashlamp pulsed dye laser with the argon tunable dye laser with robotized handpiece for facial telangiectasia
Authors: Ross Maria , Watcher Melissa A. , Goodman Matthew M. 
Published: March 2007

AbstractThis prospective study compares the efficacy, side effects, and patient acceptance of the flashlamp pulsed dye laser (FPDL) with the argon tunable dye laser with robotized handpiece (ATDL/H) for facial telangiectasias. Seventeen adult patients with bilaterally symmetric facial telangiectasias were enrolled. The right cheek on each patient was treated in one session with the FPDL at a fluence of 6.0–6.75 J/cm2 and a spot size of 5 mm. The left cheek was treated at the same session with the ATDL/H at a power of 1 W, a fluence of 26–27 J/cm2, and a hexagonal treatment area of 13 mm (127 individual 1 mm spots grouped mechanically by the handpiece). Patients were evaluated subjectively and by the investigators at 2, 4, and 6 weeks for blistering, swelling, bruising, changes in pigment, scarring, overall efficacy, and patient preference. Average treatment times were 5.4 minutes for FPDL and 9.4 minutes for ATDL/H. Blistering, crusting, and discomfort were completely resolved on both sides by week 2 in all patients. Bruising occurred in all patients with FPDL but had resolved in 62.5% of patients at 2 weeks and 100% at 4 weeks. There was no bruising with ATDL/H. Postinflammatory hyper‐pigmentation was much more prominent with FPDL but had resolved in 88% of cases by week 6. As rated by the investigators 100% of the FPDL treated areas showed excellent clearing of telangiectasias, compared with 47% of ATDL/H treated areas. Despite better efficacy of the FPDL in clearing facial telangiectasias in one treatment, of the 15 patients with a preference 47% preferred the ATDL/H due to the marked bruising experienced with the FPDL. In conclusion, although the FPDL showed greater objective efficacy, the acceptable efficacy combined with the lack of bruising led almost half of the patients to prefer treatment with the ATDL/H. © 1993 Wiley‐Liss, Inc.
β‐Carotene enhances plaque detection by fluorescence attenuation in an atherosclerotic rabbit model
Authors: Ye Biqing , Abela George S. 
Published: March 2007

AbstractImproved detection of plaque during cardiovascular procedures could enhance the outcome of diagnosis and therapy. We evaluated a new method to stain plaque using a special intravenous preparation of β‐carotene (β‐C) in an in vivo model. β‐C was used to enhance the absorption coefficient of plaque and decrease the laser–induced fluorescence emission. Using this approach the difference in fluorescence emission was accentuated between normal artery and atherosclerotic plaque. Twenty‐nine NZW rabbits were divided into five groups, each receiving a different intervention. This included the administration of β‐C to rabbits on a normal or a high cholesterol diet, with or without endothelial debridement. Aortae were examined grossly, by histology, and relative total fluorescence was detected at 886 sites using 488 nm or 514 nm laser excitation. At 488 nm excitation, unstained plaque attenuated total fluorescence twice as much as normal controls (7.55± 1.46 vs. 15.06 ± 3.12; P<0.0001); β‐C stained plaque attenuated total fluorescence 17 times more than normal controls (0.89 ± 0.29 vs. 15.06 ± 3.12; P<0.0001). Total fluorescence from unstained plaque was eight times greater than plaque stained with β‐C (7.55 ± 1.46 vs. 0.89 ± 0.29; P<0.0001). Results obtained using 514 nm excitation were similar. The attenuation effect persisted up to 8 weeks following β‐C administration. Thus, β‐C stained plaque displayed fluorescence attenuation, which suggests that pretreatment with β‐C may greatly enhance plaque detection. This may be useful as a guide during‐plaque removal procedures. © 1993 Wiley‐Liss, Inc.
Acute response of the arterial wall to pulsed laser irradiation
Authors: Nakamura Fumitaka , Kvasnicka Jan , Levame Micheline , Lange Françoise , Bousbaa Hassan , Geschwind Herbert J. 
Published: March 2007

AbstractThis study was designed to examine the acute response of normal arterial wall to pulsed laser irradiation. Irradiation with an Excimer or a Holmium YAG laser was performed in 15 normal iliac sites of 8 male New Zealand white rabbits. The excimer laser was operated at 308 nm, 25 Hz, 50 mj/mm2/pulse, and 135 nsec/pulse and the Ho:YAG laser was operated at 2.1 μm, 3.5 Hz, 400 mj/ pulse, 250 μsec/pulse. The excimer and Ho:YAG laser were coupled into a multifiber wire‐guided catheter of 1.4 and 1.5 mm diameter, respectively. The mean luminal diameter increased similarly from 2.01 ± 0.29 to 2.46 ± 0.27 mm (P < 0.0005) and from 2.09 ± 0.53 to 2.45 ± 0.30 mm (P < 0.005) after excimer and Ho:YAG laser irradiation, respectively. Perforation occurred in 3 of 15 Ho:YAG irradiated sites and 0 of 15 excimer laser irradiated sites. The sites irradiated with excimer or Ho:YAG laser had similar histologic features, consisting of shedding of the endothelium, disorganization of internal elastic lamina, localized necrosis of vascular smooth muscle cells, and fissures in the medial layer. However, the sites irradiated with excimer laser had lower grading scores than those irradiated with the Ho:YAG laser (P<0.05). Irradiation with excimer or Ho:YAG laser of normal arteries results in: (1) vasodilation of the irradiated artery; (2) localized mechanical vascular injury, and (3) Ho:YAG laser induces more severe damage to the arterial wall than excimer. © 1993 Wiley‐Liss, Inc.
Tumor specific response to photodynamic therapy
Authors: Stern Scott J. , Craig Jock , Flock Stephen , Montague Donna , Waner Milton , Jacques Steven 
Published: March 2007

AbstractThe exact mechanism by which photodynamic therapy (PDT) causes tumor destruction has not been elucidated. Early reports indicated that PDT causes direct cellular effects probably mediated by unstable oxygen species, resulting in cellular oxidation and death. More recently, PDT effects on tumor blood flow have been implicated, and there are questions as to whether the PDT response is specific to tumor tissue.Rats were implanted with a window chamber containing either a mammary adenocarcinoma or a piece of inert surgical sponge. After growth of the tumor was ascertained, all rats were given 5 mg/kg Photofrin intraperitoneally, and then were irradiated with 630 nm light 24 hours post‐injection. Caliper thickness and reflectance measurements were performed before and after irradiation; all animals were sacrificed 72 hours post‐PDT and the chambers submitted for histologic analysis.Animals implanted with tumors demonstrated marked edema of the chamber with an associated decrease in reflectance. No edema response was noted in the chambers containing inert sponge, or in any controls. Nonselective PDT effects (characterized by a marked foreign body response) in chambers containing sponge was not seen. Histologic analysis of treated specimens corroborate the above data. © 1993 Wiley‐Liss, Inc.
Effects of pulse width on erbium: YAG laser photothermal trabecular ablation (LTA)
Authors: Hill Richard A. , Stern David , Lesiecki Michael L. , Hsia James , Berns Michael W. 
Published: March 2007

AbstractAn erbium (Er):YAG laser can remove trabecular meshwork (TM) by photothermal ablation with minimal contiguous thermal damage. A variable pulse width Er:YAG laser was used to investigate the effect of varying pulse width on ablation of human TM. Trabecular photothermal ablation was performed on tissue obtained from eye bank eyes at pulse widths of 50, 150, and 250μs, with energy held constant at 4 mJ. At this energy, a single laser pulse was sufficient for full‐thickness ablation of TM. Laser energy was delivered through a 200‐μm diameter optical fiber held in apposition to the tissue sample, which was immersed in physiologic saline. High‐speed photography of the resultant steam bubbles also was performed. Light microscopy and scanning electron microscopy of TM ablated at 50 μs revealed the greatest variability in size (0–140 μm) of the full‐thickness ablated areas and demonstrated blast effects, tissue shredding and ⩽10 μm thermal damage. At 150 μs, the full‐thickness ablated areas were more consistent in size (115–120 μm), showed no blast effects and 10 to 20 μm thermal damage. At 250 μs, the largest ablations were found (180–220 μm) and showed no blast damage; however, a significant amount of thermal damage (⩽50 μm) was evident. The steam bubbles produced by the laser energy were largest at 50 μs and did not begin to collapse until well over twice the original pulse interval. At 150 and 250 μs, the steam bubbles were successively smaller and dissipated at the end of the laser pulse. In single pulse Er:YAG photothermal laser trabecular ablation, a pulse width (total energy of 4 mJ) around 150 μs appears to be optimal. The resultant acoustic shock wave from steam bubble formation is smaller, its duration does not exceed the laser pulse width and tissue thermal damage is minimal. © 1993 Wiley‐Liss, Inc.
Slit lamp laser doppler interferometer
Authors: Fercher Adolf F. , Li Hai C. , Hitzenberger Christoph K. 
Published: March 2007

AbstractA slit lamp laser interferometer is described for clinical in vivo eye length measurements. The basic components are a laser Doppler interferometer, a slit lamp attachment, and a commercial slit lamp. First measurements of the axial length of the eye yielded a standard deviation of 0.04 mm and less. © 1993 Wiley‐Liss, Inc.
Low‐level CO2 laser–induced release of 51chromium from canine 2C5 gliosarcoma cells
Authors: Van Kooten David W. , Maciunas Robert J. , Carver Robert S. 
Published: March 2007

AbstractRecently, interest has grown in the area of low‐power laser effects upon tissues. We used a 51Cr cell labeling technique with glioma tissue to better understand these effects. Canine 2C5 gliosarcoma cells with intracellular 51Cr were exposed to CO2 laser in the range of 0.2 to 3.0 J/cm2. Correlative analysis of the data indicated that there is a strong direct relationship between laser fluence and the percent of total intracellular 51Cr released from the glioma cells with a coefficient of correlation (r) of +0.93. The calculated standard error of the correlation coefficient was ± 0.06 and the coefficient of determination (r2) was 0.86. These results indicate that the 51Cr cell labeling technique is a useful method for quantifying the low‐power laser effects on the integrity of the cell membrane of gliosarcoma cells in vitro. However, further investigation is needed to clarify the specific mechanisms by which the CO2 laser induces changes upon these cells. © 1993 Wiley‐Liss, Inc. © 1993 Wiley‐Liss, Inc.
Clinical exacerbation of systemic lupus erythematosus after photodynamic therapy of laryngotracheal papillomatosis
Authors: Abramson Allan L. , Alvi Aijaz , Mullooly Virginia M. 
Published: March 2007

AbstractPhotodynamic therapy was used to treat a patient with recurrent laryngotracheal papillomatosis who had a history of systemic lupus erythematosus (SLE). At the time of photoactivation, the patient's SLE was in remission for 2 years. Postoperatively, the patient was not compliant in avoiding sunlight exposure and developed photosensitive skin reactions of his face and hands. In addition, he had clinical activation of his SLE following that exposure. © 1993 Wiley‐Liss, Inc.
Fundus laser coagulation using a video system of scanning laser ophthalmoscope
Authors: Peyman Gholam A. , Khoobehi Bahram , Shamsnia Saeed , Navarro Greta C. 
Published: March 2007

AbstractWe modified a scanning laser ophthalmoscope for simultaneous photocoagulation of the retina and video recording. Using a diode laser (810 nm wavelength), we produced fundus lesions that scarred within 14 days. © 1993 Wiley‐Liss, Inc.