bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endometrial laser ablation in rabbits: A comparative study of three laser types
Authors: Rosenberg Carlos , Tadir Yona , Braslavsky Diana , Fisch Benjamin , Karni Ziv , Ovadia Jardena 
Published: March 2007

AbstractEndometrial laser ablation is one of the alternatives to hysterectomy in cases of intractable uterine bleeding. It is currently performed using the Nd:YAG laser at 1.06 μm. The aim of this study was to compare the tissue effect of three types of laser irradiation (Nd:YAG laser at 1.06 and 1.32 μm and holmium laser at 2.12 μm) on the rabbit endometrium. Crater formation, coagulation necrosis, and muscle necrosis were evaluated at the time of ablation, as well as at 1 week and 4 weeks postablation. The results were assessed by determining the depth and width of the affected portion in the uterine wall (lumen to serosa). It was shown that Nd:YAG laser at 1.32 μm caused more generalized and extended effects as compared with the other laser types examined. Endometrial regeneration was faster after ablation by the Nd:YAG laser at 1.06 μm and the holmium laser than by the Nd:YAG laser at 1.32 μm. The widest range of “ablation energy” (defined as that causing ablation without muscle damage) was achieved by applying the holmium laser. Further evaluation of the holmium laser for this indication is recommended.
Effects of Nd:YAG laser coagulation of myocardium on coronary vessels
Authors: Weber Helmut , Enders Susanne , Coppenrath Klaus , Murray A. Beatrice , Schad Hubert , Mendler Nikolaus 
Published: March 2007

AbstractLaser coagulation of arrhythmogenic myocardium proved to be an effective surgical therapy for refractory arrhythmias. To determine the influence of NdYAG laser coagulation of myocardium on coronary vessels, a total of 48 transcatheter laser impacts (10 W, 10 sec, 7 W mm2) were directed to the left ventricular free wall via endocardial (24 lesions in 2 dogs) or epicardial (24 lesions in 2 dogs) approach. In 8 of 24 endomyocardial lesions (2 and 6 months old) coronary vessels with a diameter of > 50 μm were found within the coagulation zones. The volume of these lesions was significantly (P < 0.0l) smaller (139 ± 43 mm3) than those (n = 16) with coronary vessels measuring <50 μm (311 ± 87 mm3). Volumes of epimyocardial lesions (1‐2 hours old) produced by transcoronary irradiation with normal coronary blood flow were significantly (P < 0.01) smaller (31 ± 17 mm3) than with reduced (73 ± 22) or interrupted (119 ± 34 mm3) blood flow (n = 8, each). Both directly irradiated coronary vessels and those found within the coagulation zones and scars appeared histologically normal through all layers with an intact intima without fibrosis or thrombosis. The ultrastructure of irradiated arteries, even with total interruption of blood flow, was no different from that of non‐irradiated controls. Thus, coronary artery blood flow significantly reduces the volume of coagulated myocardium, whereas the vessels themselves appear to remain undamaged by laser irradiation as used for myocardial coagulation.
Early and late arterial healing response to catheter‐Induced laser, thermal, and mechanical wall damage in the rabbit
Authors: Oornen Antonius , Van Erven Lieselotte , Vandenbroucke Walda V. A. , Verdaasdonk Rudolf M. , Slager Cornelius J. , Thornsen Sharon L. , Borst Cornelius 
Published: March 2007

AbstractPulsed lasers are being promoted for laser angioplasty because of their capacity to ablate obstructions without producing adjacent thermal tissue injury. The implicit assumption that thermal injury to the artery is to be avoided was tested. Thermal lesions were produced in the iliac arteries and aorta of normal rabbits by a) electrical spark erosion, b) the metal laser probe, and c) continuous wave neodymium‐yttrium aluminum garnet (Nd‐YAG) laser energy through the sapphire contact probe. High‐energy doses were used to induce substantial damage without perforating the vessel wall. Thermal lesions (n=77) were compared with mechanical lesions (n=22) induced by oversized balloon dilation. Medial necrosis was induced by all four injury methods. Provided no extravascular contrast was observed after the injury, all damaged segments were patent after 1 to 56 days. The progression of healing with myointimal proliferation was remarkably similar for all injuries. At 56 days, the neointima measured up to 370 μm. In conclusion, provided no perforation with contrast extravasation occurred, the normal rabbit artery recovered well from transmural thermal injury. The wall healing response is largely nonspecific.
Carbon dioxide laser‐assisted thyroarytenoid myomectomy
Authors: Woo Peak 
Published: March 2007

AbstractCO2 laser‐assisted myomectomy of the thyroarytenoid muscle (TA) was carried out through a thyroplasty approach in ten la‐ryngeal specimens and the TA was examined histologically. Using the CO2 laser at super‐pulsed mode, the TA can be cut or resected using 3–5 W of laser power. There is good control of the depth and extent of TA resection. Histologically, there is little evidence of collateral injury, with sparing of vital surrounding vocal structures. The use of CO2 laser for TA resection offers better access and surgical hemostasis in an otherwise difficult surgical field. Laser‐assisted myomectomy may be a feasible alternative to current methods to treat spasmodic dysphonia.
Scanning electron microscopic study of laser‐induced morphologic changes of a coated enamel surface
Authors: Hess John A. 
Published: March 2007

AbstractA low‐energy Nd:YAG laser was used to irradiate extracted human teeth coated with a black energy‐absorbent laser initiator in a study to determine the extent of the morphologic changes produced in the enamel surface. The laser initiator was applied to a cleaned enamel surface and irradiated at an energy output of 30 mJ or 75 mJ. Both energy levels produced morphologic changes of the surface. There was a sharp line of demarcation between the coated, irradiated area and the surrounding noncoated enamel surface. The scanning electron microscope view at the lower energy level showed that the surface had melted and reformed with numerous small, bubble‐like inclusions. The 75 mJ energy level showed individual impact craters with shallow centers and raised edges containing numerous pores and large, bubble‐like inclusions. Etching is a dental procedure in which an acid is normally used to remove a thin outer layer of the tooth structure. This is necessary to create a roughened, irregular surface in order to provide mechanical retention for dental restorative materials. The changes produced by the laser in this study suggest a simple, effective, and controlled method of etching the enamel surface of a tooth by altering its surface characteristics.
Cutaneous phototoxic occurrences in patients receiving Photofrin®
Authors: Dougherty Thomas J. , Cooper Michele T. , Mang Thomas S. 
Published: March 2007

AbstractIncidence of cutaneous phototoxic reactions induced by intravenous injection of Photofrin polyporphyrin was assessed in a series of 180 patients (266 injections) undergoing photodynamic therapy (PDT) at Roswell Park Cancer Institute during the period 1986–1989. In addition to the usual verbal questions regarding phototoxic reactions solicited at follow‐up, forty‐two patients in this group also responded to a written questionnaire designed to solicit answers to specific questions. Photofrin doses ranged from 0.5 to 2.0 mg/kg. Overall, 20‐40% of patients reported some type of phototoxic response.
Effect of blood upon the selective ablation of atherosclerotic plaque witha pulsed dye laser
Authors: Gregory Kenton W. , Prince Martin R. , Lamuraglia Gleen M. , Flotte Thomas J. , Buckley Lisa , Tobin Jill M. , Ziskind Andrew A. , Caplin John , Anderson R. Rox 
Published: March 2007

AbstractLaser angioplasty systems with laser energy preferentially absorbed by atherosclerotic plaque may offer a safe method of plaque removal. This study evaluated the effect of blood upon selective energy absorption using a pulsed dye lasser at 480 nm. Intra‐arterial laser irradiation of normal rabbit femoral arteries demonstrated a perforation threshold energy with blood perfusion of 13.1 mJ per pulse compared to 87.9 mJ with saline (P < .0001), indicating a deleterious effect in the presence of blood. An adverse effect upon arterial healingt at 3 days was noted in sheep following intra‐arterial irradiation during blood but not saline nerfusion. Normal and atherosclerotic human aorta ablation thresholds differed significantly (P < .0002) under saline (plaque: 20 mJ and normal: 20 mJ) was not significant. We conclude that absorption of laser energy by blood can reduce the effect of differential absorption by endogenous chromophores in normal and pathologic vascular tissues and, therefore, removal of blood may be a prerequisite for selective ablation of atherosclerotic plaques.
Presence of human immunodeficiency virus DNA in laser smoke
Authors: Baggish Michael S. , Polesz Bernard J. , Joret Dale , Williamson Patrick , Refai Ashraf 
Published: March 2007

AbstractConcentrated tissue culture pellets infected with human immunodeficiency virus (HIV) containing 1 ± 107 cells/ml were vaporized by means of a carbon dioxide laser. The vaporous debris resulting from the laser's impact were evacuated through sterile silastic tubing, then bubbled through sterile culture medium (RPMI) positioned in series with a commercial smoke evacuator. No HIV DNA was detected in the culture medium flask. Tissue culture studies of the silastic collection tubing revealed p24 HIV gag antigen in 3 of 12 tube segments at the end of 1 week and in 1 of 12 tube segments at 2 weeks. No sustained infection of HIV cultured cells was observed at the 28th day. Polymerase chain reaction (PCR) analysis of particulate debris obtained from the silastic collection tubing was positive from proviral HIV DNA in both immediately sampled and day 14 cultured material.
Wavelength dependence of pulsed laser ablation of calcified tissue
Authors: Izatt Joseph A. , Albagli Douglas , Britton Matthew , Jubas Jay M. , Itzkan Irving , Feld Michael S. 
Published: March 2007

AbstractPulsed laser ablation of calcified biological tissue was studied at several wavelengths in the near‐ultraviolet, visible, near‐ and mid‐infrared regions of the spectrum. The primary tissue model was bovine shank bone, while human arterial calcified plaque and normal human artery wall were also studied at selected wavelengths for comparison. Laser irradiances were on the order of MW/mm2, fluences ranged up to 1000 mJ/mm2, and repetition rates varied between 0.3–10 Hz. Spot sizes on the tissue surface ranged from 150 to 850 μm. Laser craters made with wavelengths between λ=295 nm and λ=375 nm and in the λ =3 pm region exhibited the highest quality ablation with clean, sharp cuts following closely the spatial contour of the incident beam. Craters drilled with visible wavelengths between λ =450 nm and λ =590 nm were generally larger than the incident laser beam spot, irregular in shape and often surrounded by large flakes of tissue debris. Ablation fluence thresholds increased with wavelength through the visible wavelengths and into the mid‐infrared, but dropped to their lowest values near λ=3 pm. Fluence thresholds obtained with the tissue under a 1 mm depth of saline were approximately twice air thresholds. Ablation yields also varied with wavelength, probably due to increased scattering in the visible region, and were the same under saline as in air.
Excimer laser ablation of fibrocartilage: An in vitro and in vivo study
Authors: Buchelt Martin , Papaioannou Thanassis , Fishbein Mike , Peters Werner , Beeder Clain , Grundfest Warren S. 
Published: March 2007

AbstractTo date, lasers have found only limited applications in orthopedics. We employed a 308 nm XeCl excimer laser for ablation of fibrocartilage, in order to investigate the feasibility of excimer laser assisted meniscectomy.Experiments were conducted both in vitro and in vivo. For the in vitro study, human menisci, obtained during surgery and autopsy, were irradiated via a 600μm core fiber at radiant exposures ranging between 20 mj/mm2 and 80 mj/mm2, at 20 Hz. Ablation rate measurements and histological analysis of the samples were performed. The ablation rates were found to range from 3 μm/pulse to 100 μm/pulse depending on the radiant exposure and/or the applied pressure on the fiber delivery system. Thermographic analysis was also performed during pulsed excimer as well as CW Nd:Yag and CW Co2 laser irradiation. Temperatures were lower for excimer laser (Tmax <65°) than CW ND:Yag (Tmax <210°) or CW Co2 (Tmax <202°) laser.For the in vitro study, medial meniscectomy was performed in 15 rabbits with the excimer laser and a CW Nd:Yag laser in the right and left knee respectively. Excimer laser irradiation was performed at 70 mj/mm2. Nd:Yag irradiation was performed via a 600 μm core fiber at power outputs between 20 to 40 W for 10 and 20 seconds duration.The healing response to injury was investigated by histological analysis of the menisci after 1 day, 1, 2, 4, and 8 weeks following the laser procedure. Excimer laser treated menisci showed less inflammatory reaction and noticeable repair with minimal inflammatory response. Carbonization, induced in the Nd:Yag treated menisci remained up to 8 weeks and only minimal healing was observed. The results suggest that, with the development of an appropriate delivery system, excimer laser ablation may be useful in arthroscopic meniscectomy.
Dependence of subcellular damage on various laser beam parameters
Authors: Oyog Shirley S. , Smith Michael J. , van de Merwe Willem P. 
Published: March 2007

AbstractA cw argon laser operating at the multiline UV TEM00 mode was used to create lesions in the nucleoli of fibroblast cells. Laser powers emitted through the objective were varied from 5–8 mW and laser pulse durations ranged from 50 to 600 ms. Our study showed lesion diameters ranging from 0.7 μm to 2.9 μm and an average lesion diameter of 1.77 μm. All cells were exposed to at most a laser spotsize of 2.2 μm diameter and for a laser spotsize of this diameter, we calculated that the central 18.3% of the total energy was in the central area of 0.7 μm diameter. We also found that as little as 0.3 mJ of energy could produce a lesion. No absolute threshold correlation was found between the size or type of lesion and the laser parameters used.
Endoscopic palliation of malignancies of the upper gastrointestinal tract using Nd:YAG laser: Results and survival in 308 treated patients
Authors: Spinelli Pasquale , Fante Marco Dal , Mancini Andrea 
Published: March 2007

AbstractThree hundred eight patients with obstructing malignant tumors of the gastrointestinal tract were submitted to endoscopic Nd:YAG laser palliation. The number of sessions as well as the number of days and total energy required for initial recanalization of the stenosis were related to tumor length. Luminal patency was obtained in 94% of patients, but improved swallowing was achieved in 74% of patients. The technical success rate did not depend on tumor site, whereas functional positive results are related to the location of the stenosis, with worst results for tumors involving the upper third of the esophagus. Life‐table analysis revealed that 1‐year survival was 23% when a luminal patency was achieved and 7%when treatment failed.
Contact Nd:YAG laser potentiates the tumor cell killing effect of hyperthermia
Authors: Castrén‐Persons M. , Schröder T. , Rämö O. J. , Puolakkainen P. , Lehtonen E. 
Published: March 2007

AbstractThis study was carried out to investigate the effects of Nd:YAG laser‐induced hyperthermia on murine F9 embryonal carcinoma cells in vitro using various power settings, temperatures, and exposure times. F9 cells were plated on gelatin‐coated dishes, treated on the following day, and cultured overnight. The following day the killing efficiency of the treatments was estimated by staining the dishes or by labeling the cells with 3H‐thymidine. A contact Nd:YAG laser with a frosted‐end probe was used. After laser treatments at 39°C, no significant changes were observed in the viability of the cells. Laser treatment at 43°C killed F9 cells, and the effect was related to the power setting used. Using 6 W, the quantity of viable cells progressively decreased after 1‐, 2‐, and 5‐min treatments, and no viable cells were found after a 10‐min treatment. Using 10 W, approximately 10% of the cells survived a 1‐min laser treatment, but all cells were killed after a 2‐min treatment. In the control wells, heated in a water bath for up to 40 min, all cells regularly survived at 43°C. There were much less viable cells in those laser‐treated wells where the temperature exceeded 44°C than in those where the temperature was kept at 44°C. In conclusion, the tumoricidic effect of hyperthermia can be potentiated by the use of the contact Nd:YAG laser. At a set temperature the cell killing effect of laser treatment is dependent on the power used and the duration of the treatment. This suggests that laser irradiation effects tumor cells in vitro by a mechanism not solely dependent on heating.
Ultraviolet laser‐induced fluorescence of colonic tissue: Basic biology and diagnostic potential
Authors: Schomacker Kevin T. , Frisoli Joan K. , Compton Carolyn C. , Flotte Thomas J. , Richter James M. , Nishioka Norman S. , Deutsch Thomas F. 
Published: March 2007

AbstractLaser‐induced fluorescence (LIF) of colonic tissue was examined both in vitro and in vivo to assess the ability of the technique to distinguish neoplastic from hyperplastic and normal tissue and to relate the LIF spectra to specific constituents of the colon. Spectra from 86 normal colonic sites, 35 hyperplastic polyps, 49 adenomatous polyps, and 7 adenocarcinomas were recorded both in vivo and in vitro. With 337‐nm excitation, the fluorescence spectra all had peaks at 390 and 460 nm, believed to arise from collagen and NADH, and a minimum at 425 nm, consistent with absorption attributable to hemoglobin. The spectra of colonic tissue recorded both in vivo and in vitro are different, primarily in the NADH fluorescence component, which decays exponentially with time after resection. When normal colonic tissue is compared to hyperplastic or adenomatous polyps, the predominant changes in the fluorescence spectra are a decrease in collagen fluorescence and a slight increase in hemoglobin reabsorption. A multivariate linear regression (MVLR) analysis was used to distinguish neoplastic tissue from non‐neoplastic tissue with a sensitivity, specificity, predictive value positive, and predictive value negative toward neoplastic tissue of 80%, 92%, 82%, and 91%, respectively. When the MVLR technique was used to distinguish neoplastic polyps from non‐neoplastic polyps, values of 86%, 77%, 86%, and 77% respectively, were obtained. The data suggest that the LIF measurements sense changes in polyp morphology, rather than changes in fluorophores specific to polyps, and it is this change in morphology that leads indirectly to discrimination of polyps.
Nd:YAG laser ablation of the prostate as a treatment for benign prostatic hypertrophy
Authors: Costello Anthony J. , Johnson Douglas E. , Bolton Damien M. 
Published: March 2007

AbstractMany techniques have been used to relieve obstructive symptoms associated with benign prostatic hypertrophy. Transurethral resection of the prostate (TURP) with an electrocautery loop is the most commonly performed operation to relieve bladder neck and urethral obstruction caused by prostatic adenoma. There is increased interest in alternative therapies to reduce prostatic size for symptom relief in this condition. We describe a technique using the neodymium:YAG (Nd:YAG) laser and a 600‐μm laser quartz fibre with an attached terminal gold‐plated metal alloy reflector to provide reliable deep penetration into prostatic tissue for prostatic adenoma ablation. We report the first use of this technique in three patients with benign prostatic obstruction and one with localised adenocarcinoma of the prostate. © 1992 Wiley‐Liss, Inc.
Preliminary observations of Holmium:YAG laser tissue interaction using human uterus
Authors: Duffy Sean , Davis Mike , Sharp Frank , Stamp John , Ginsberg Robert 
Published: March 2007

AbstractPreliminary observations of a pulsed HorYAG laser on human uterine tissue in‐vitro are presented. The tissue effect on the uterine myometrium was demonstrated using fresh uteri which had been subjected to laser energy. The laser crater and surrounding zone of thermal necrosis (ZTN) was quantified. Measurements demonstrated a consistent narrow ZTN (0.8–1.8 mm) irrespective of power or pulse frequency used. The percentage forward transmission of laser energy through 1 mm of myometrium was investigated using a pyroelectric detector and found to be 0.41%. Finally, a visible and measurable photoacoustic component to the Ho:YAG laser was demonstrated using a water bath and needle hydrophone. © 1992 Wiley‐Liss, Inc.
Dye‐mediated bactericidal effect of He‐Ne laser irradiation on oral microorganisms
Authors: Okamoto Hayato , Iwase Tatsuo , Morioka Toshio 
Published: March 2007

AbstractLittle attention has been given to the bactericidal effect of laser irradiation, particularly using low‐power energy lasers. It has been demonstrated that He‐Ne laser light has an inhibitory action on dental plaque.The purpose of this study was to investigate the bactericidal effect of He‐Ne laser irradiation on cariogenic microorganisms. The bactericidal effect was determined by the formation of a growth‐inhibitory zone or by the counting of viable bacterial colonies. Streptococcus sobrinus AHT that is a Gram‐positive microorganism was sensitive to He‐Ne laser light, but Escherichia coli, a Gram‐negative microorganism, was resistant. The effect of several dyes necessary to instigate a bactericidal action was also examined. A growth‐inhibitory zone was observed using 10 kinds of blue, purple, or green dyes, which were mainly phenylmethane dyes. The leakage of potassium from S. sobrinus AHT following laser irradiation was determined using an atomic absorption spectrophotometer. The leakage began to increase following irradiation for 2 min, and reached a plateau following irradiation for 30–60 min.Moreover, to examine some changes in the dye itself following laser irradiation in the absence of bacteria, ultraviolet‐visible absorption spectra and 1H NMR spectra were recorded.In this study, it was indicated that the bactericidal effect on cariogenic bacteria by He‐Ne laser irradiation was efficient only in the presence of specific dyes. It is suggested that this laser may be suitable for clinical applications in preventive dentistry. © 1992 Wiley‐Liss, Inc.
Pulsed dye laser treatment of benign cutaneous pigmented lesions
Authors: Tan O. T. , Morelli J. G. , Kurban A. K. 
Published: March 2007

AbstractSuperficial benign cutaneous pigmented lesions that commonly present to the dermatologists and plastic surgeons have been treated by many conventional modalities such as dermabrasion, depigmenting creams as well as several types of lasers. Many of these treatment modalities lack specificity of injury, which has meant that normally pigmented and even non‐pigment containing structures such as collagen as well as the hyperpigmented lesion itself have all been indiscriminately destroyed. This has resulted variously in hypopigmentation, hyperpigmentation, in addition to scar formation in some cases.A coaxial 504 nm laser with a pulse duration of 300 nsec was used to treat fifty two patients with superficial benign cutaneous pigmented lesions. Although the number of treatments required to clear the lesion varied according to the type of lesions being treated, on average, between 2 and 4 treatments were required to completely eradicate the superficial benign cutaneous pigmented lesions using 504 nm pulsed dye laser. The skin at the site successfully cleared of the pigmented lesion remained normal in skin color, texture, markings, and mobility. © 1992 Wiley‐Liss, Inc.