bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dye‐enhanced laser welding for skin closure
Authors: DeCoste Susan D. , Farinelli William , Flotte Thomas , Anderson R. Rox 
Published: March 2007

AbstractThe use of a laser to weld tissue in combination with a topical photosensitizing dye permits selective delivery of energy to the target tissue. A combination of indocyanine green (IG), absorption peak 780 nm, and the near‐infrared (IR) alexandrite laser was studied with albino guinea pig skin. IG was shown to bind to the outer 25 μm of guinea pig dermis and appeared to be bound to collagen. The optical transmittance of full‐thickness guinea pig skin in the near IR was 40% indicating that the alexandrite laser should provide adequate tissue penetration. Laser “welding” of skin in vivo was achieved at various concentrations of IG from 0.03 to 3 mg/cc using the alexandrite at 780 nm, 250‐μsec pulse duration, 8 Hz, and a 4‐mm spot size. A spectrum of welds was obtained from 1‐ to 20‐W/cm average irradiance. Weak welds occurred with no thermal damage obtained at lower irradiances: stronger welds with thermal damage confined to the weld site occurred at higher irradiances. At still higher irradiances, local vaporization occurred with failure to “weld.” Thus, there was an optimal range of irradiances for “welding,” which varied inversely with dye concentration. Histology confirmed the thermal damage results that were evident clinically. IG dye‐enhanced laser welding is possible in skin and with further optimization may have practical application.
Bone ablation with Er:YAG and CO2 laser: Study of thermal and acoustic effects
Authors: Li Zhao‐Zhang , Reinisch Lou , Van de Merwe Willem P. 
Published: March 2007

AbstractA pulsed Er:YAG laser at 2.94 μm and a superpulsed CO2 laser at 10.6 μm are used to investigate bone ablation applications in otolaryngology. Quantitative measurements of mass removal and the ablation depth of cat skull bone and rat femur are presented with the Er:YAG laser at fluences of 9–117 J/cm2. Histological results show that the minimal thermal injury zone from the edge of the lesion is 5–10 μm. Comparison of the photoacoustic and thermal effects during the ablation process indicates that the temperature rise from the 10.6–μm light was higher than that from the 2.94–μm light but that the photoacoustic wave amplitude produced with the Er:YAG laser was higher than that with the CO2 laser. The fluence used for the efficient ablation of bone tissues produces a photoacoustic wave ranging from 100 to 120 dB. The ear can tolerate this level for a short time period. Results of this study suggest that the Er:YAG laser can be an important surgical tool in otolaryngology.
Complications of laparoscopic cholecystectomy: A prospective review of an initial 100 consecutive cases
Authors: Graber John N. , Schultz Leonard S. , Pietrafitta Joseph J. , Hickok David F. 
Published: March 2007

AbstractIn order to identify problems in concept or technique with lap‐aroscopic cholecystectomy, a prospective analysis of the initial consecutive 100 procedures was accomplished. Ongoing review of the results led to modifications in order to improve operative outcome. Minor complications such as nausea for more than 12 h (20%) and right shoulder pain (29%) were self‐limiting. There were no deaths, two bile duct injuries, two abscesses, two retained common duct stones, and one case requiring transfusion, totaling a 7% major complication rate. In the subsequent 200 laparoscopic cholecystectomies, there was a 1.5% rate of major complications. Specific measures and modifications in technique that account for this improvement are detailed. Complications of laparoscopic cholecystectomy are more frequent in initial cases but can be minimized by observing specific intraoperative principles.
Tissue response following CO2 laser application in apical surgery: Light microscopic assessment in dogs
Authors: Friedman Shimon , Rotstein Ilan , Bab Itai 
Published: March 2007

AbstractThe potential advantages of CO2 laser in apical surgery have not been established histologically. Therefore, the long‐term effects of CO2 laser on the apical and periapical tissues were examined histologically in dogs 6 months after apical surgery. Lased specimens and unlased controls showed periapical inflammatory and osteogenic reactions. Lased root surfaces revealed craters with a superficial charred layer closely associated with new cementum‐like matrix. The subjacent dentin appeared tubule‐free and eosinophylic. Lased bone trabeculae showed a charred layer with a deeper osteocyte‐free zone. The charred layer was covered by new bone. Detached charred segments in the marrow space and periapical inflammatory infiltrate were intimately associated with multinucleated giant cells, some containing minute char particles. Such cells were absent from the root and trabecular char linings. In addition, the charred surfaces were free of hard tissue resorption. These results suggest that CO2 laser does not hinder healing when applied in apical surgery.
Mechanical effects of erbium:YAG laser bone ablation
Authors: Hibst Raimund 
Published: March 2007

AbstractWhen intending to use pulsed erbium:YAG laser radiation for the ablation of small bones, e.g., the ossicular chain or footplate, not only temperature and thermal damage, but also mechanical side effects become important. In studies on desiccated bone the total recoil momentum caused by laser ablation was measured using a sensitive pendulum. The momentum depends linearly on the radiant energy of the laser pulse with a slope of 10−4 kg m s−1/J. The temporal course of the recoil force during ablation observed by means of a piezoelectric transducer is nearly proportional to the laser pulse intensity. By evaluating recoil momentum and mass loss data, the average initial velocity of the plume was calculated to be 230 to 280 m s−1. The kinetic energy is approximately 1% of the input energy. The measurements support to the hypothesis of a thermally induced explosive process. © 1992 Wiley‐Liss, Inc.
Some morphologic changes induced by Nd:YAG laser on the noncoated enamel surface: A scanning electron microscopy study
Authors: Quintana Eugenio , Márquez Francisco , Roca Inmaculada , Torres Vicente , Salgado Jesús 
Published: March 2007

AbstractThe enamel surface layer of some human teeth was treated with the low‐energy Nd:YAG laser at 8 mJ pulse energy. These samples were previously etched with 0.05 M orthophosphoric acid to reduce the surface reflection. The treated samples, as well as the control samples, were widely studied by scanning electron microscopy, and, in the lased group, significant morphologic changes affecting the enamel surface were observed. Those changes reveal principally the loss of the typical surface structure of the acid‐etched enamel. The hydroxyapatite prisms were not discernible, and there was a decrease in the roughness of the lased surface enamel. These laser‐induced structural changes may be related to the increased resistance to the calcification reported by many authors. © 1992 Wiley‐Liss, Inc.
Effect of steroids or tissue preceding on edema and tissue thermal coagulation after CO2 laser impact
Authors: Sheppard LisaMarie , Werkhaven Jay , Mickelson Samuel , Crissman John D. , Peterson Edward , Jacobsen Gordon 
Published: March 2007

AbstractThe carbon dioxide laser is frequently used in laryngeal microsurgery. Some surgeons have empirically used preoperative steroids or precooling with ice prior to laser impact to limit the resultant tissue thermal coagulation and/or edema. An animal model was designed to quantitatively test these effects. Depillated areas of rat skin were exposed to a CO2 beam of 1 mm diameter at 15 W for 0.1 sec after either administration of Decadron (0.25 mg/kg) immediately prior to impact or precooling more than 10oC below basal body temperature. Measurement of edema was quantitated as extravasation of Evan's blue dye that had been injected intravenously. Tissue thermal coagulation was measured on hematoxylin and eosin stained histologic sections. In comparison to controls, statistically significant reduction in edema was seen only at the 24 hour time period after laser exposure for the steroid group (P<.002) but not for the precooling group. Tissue thermal coagulation was significantly smaller for both the steroid and the ice group (P < .006 and P < .001, respectively) when compared to controls. © 1992 Wiley‐Liss, Inc.
Relation between polyporphyrin distribution and blood brain barrier changes in the rat glioma model
Authors: Ji Ying , Walstad Diana L. , Brown J. Tony , Powers Stephen K. 
Published: March 2007

AbstractPhotofrin™ (a polyporphyrin mixture) distribution in a rat glioma model was studied in relation to changes in the blood brain barrier (BBB). At selected intervals after intraperitoneal injection of Photofrin™, the concentration of polyporphyrins (PP) and Evans Blue Dye, an indicator of BBB permeability, were determined for tumor, brain adjacent to tumor (BAT), and normal brain tissue. Contrary to earlier reports of maximal accumulation at 4–24 hours, tumor levels of PP increased throughout the 96 hour measurement period. During the early stages of tumor development, PP uptake by tumor appeared to be less correlated to BBB disruption. We conclude that passive diffusion through an incompetent BBB does not completely explain PP accumulation in tumor tissue. © 1992 Wiley‐Liss, Inc.
Comparison of a pulsed dye laser and electrohydraulic lithotripsy on porcine gallbladder and common bile duct in vitro
Authors: Birkett Desmond H. , Lamont Jeffrey S. , O'Keane J. Conor , Babayan Richard K. 
Published: March 2007

AbstractWith the advent of minimal access biliary procedures there is a need for a safe intracorporal lithotripsy technique that can be used through small flexible endoscopes. Currently, the two techniques available are electrohydraulic lithotripsy and laser induced shock wave lithotripsy. In this study we compare the effect of a 504 nm coumarin pulsed dye laser and electrohydraulic lithotripsy on in vitro porcine gallbladder and common bile duct. Electrohydraulic lithotripsy at the lowest energy the generator would deliver caused perforation of both tissues in only a few pulses when a 1.9‐F probe was placed in direct contact with the tissue. Energy from a 504 nm coumarin pulsed dye laser delivered through a 320‐μ fiber placed in light contact with the tissue caused an energy dependent perforation after 50 pulses in from none to 44% of tissues. It was also found that there was a higher incidence of perforation in more vascular than non‐vascular tissue. When the EHL probe and the laser fiber were held 1–2 mm from the tissue surface, discharge of each resulted in no perforation. On histological examination of the tissues, the perforations were found to be very small with laser lithotripsy and considerably larger with the electrohydraulic lithotripsy. It was felt that laser lithotripsy in the clinical situation was likely to be much safer than electrohydraulic lithotripsy. © 1992 Wiley‐Liss, Inc.
Mid‐Infrared laser ablation of the cornea: A comparative study
Authors: Ren Qiushi , Venugopalan Vasan , Schomacker Kevin , Deutsch Thomas F. , Flotte Thomas J. , Puliafito Carmen A. , Birngruber Reginald 
Published: March 2007

AbstractThe ablation thresholds and patterns of collateral damage in cornea produced by Er:YAG (2.94 μm) and Er:YSGG (2.79 μm) lasers were measured. Two different pulse durations, 200 μs (normal spiking mode) and 100 ns (Q–switched mode), were used at both wavelengths. In the normal spiking mode, damage zones of 16 ± 2 μm and 39 ± 7 μm and ablation thresholds of 250 ± 20 mJ/cm2 and 420 ± 35 mJ/cm2 were measured at 2.94 μm and 2.79 μm, respectively. In the Q–switched mode, damage zones of 4 ± 2 μm and ablation thresholds of 150 ± 10 mJ/cm2 were found irrespective of the laser used. The similarity between the results using the Er:YAG and Er:YSGG lasers in the Q–switched mode suggest that either laser can be used with equal effectiveness for corneal trephination. © 1992 Wiley‐Liss, Inc.
Reduced tumor cell transfer with contact neodymlum‐yttrium‐aluminium
Authors: Maker Vijay K. , Elseth Kim M. , Radosevich James A. 
Published: March 2007

AbstractThe local recurrence of tumor growth after surgery is thought, in part, to be a consequence of seeding of tumor cells from the primary lesion. This study was directed at determining if the contact Nd:YAG laser provides any advantage over the use of traditional scalpel disection for tumor resection. Five human tumor tissue culture cell lines were studied in this report. They included MCF‐7 (breast), HeLa (cervical), SW‐780 (bladder), HT29 (colon), and A549 (lung). Using a scalpel blade or contact laser scalpel (with or without laser energy), the ability to transfer viable cells from dense cell stocks to new tissue culture wells was tested. Using the A549 cell line, the extent that these instruments were able to “seed” tumor cells was also assessed in a soft agar, in vitro, “incision” model. Results from these studies suggest that the contact laser scalpel has a significantly lower potential to transmit tumor cells, when compared to traditional scalpel blades. © 1992 Wiley‐Liss, Inc.
Holmium‐laser synovectomy of immune synovitis in rabbits
Authors: Möller Karl O. , Lind Barbara M. , Schramm Uda , Trautmann Christoph , Hohlbach Gerd 
Published: March 2007

AbstractHolmium‐laser synovectomy was carried out to remove allergically inflamed synovial membranes in rabbit knee joints. The healing process was then investigated at different periods. Left knee joints of 12 rabbits were exposed to Ho:YAG‐laser radiation at a wavelength of 2.1 μm, pulse energy of 600 mJ, pulse length of 1 ms, and repetition rate of 3 Hz. Twelve others were treated conventionally and 12 served as controls. After 1 day, 1 week, and 1 and 3 months, respectively, 3 animals from each group were sacrificed and the synovialis grossly and microscopically examined. Coagulation necrosis, inflammation, and edema resulted following laser therapy. After 1 week, the synovial layer consisted of a scarlike formation of fibers and within 1 month, its surface appeared smooth. The mechanical abrasion caused hemorrhage and necrosis. Fibrosis developed in the capsular layers, and after 3 months, the surface appeared coarse and villous. Based on these preliminary findings, holmium‐laser synovectomy may offer an alternative method to existing therapeutic techniques. © 1992 Wiley‐Liss, Inc.
Laser etching of teeth for orthodontic bracket placement: A preliminary clinical study
Authors: Roberts‐Harry Dai P. 
Published: March 2007

AbstractCurrent interest in the use of layers in clinical dentistry has suggested that this technique may be applicable to enamel etching in orthodontics. A pulsed Nd:YAG laser was used to etch the enamel surfaces of teeth in vivo prior to the bonding of orthodontic brackets with composite resin. Overall laser bonding took considerably longer, was less reliable in terms of bond strength, and produced more discomfort than conventional acid etching. The use of the ND:YAG laser for etching teeth prior to bonding orthodontic brackets is not recommended. © 1992 Wiley‐Liss, Inc.
Endoscopic laser therapy of the watermelon stomach
Authors: Bjorkman David J. , Buchi Kenneth N. 
Published: March 2007

AbstractEndoscopic laser therapy has been used in the treatment of vascular lesions throughout the gastrointestinal tract. The “watermelon stomach” is a pattern of vascular ectasia in the gastric antrum that results in chronic gastrointestinal blood loss and iron deficiency anemia.We have treated 7 transfusion dependent patients with a watermelon stomach using endoscopic laser therapy. Four of these patients were treated with the argon laser and 3 with the Nd:YAG laser. Patient age and prior transfusion requirements were similar in both groups. The mean number of treatments to obliterate vascular lesions and eliminate the need for transfusions was 5.75 ± 0.89 (SEM) for the argon laser and 2.33 ± 0.27 for the Nd:YAG laser (P < 0.05). Lesions recurred and required retreatment in 1 patient treated with the NdrYAG laser and 3 patients treated with the argon laser (mean follow‐up of 35 months). We conclude that endoscopic laser therapy with either the argon or Nd:YAG laser is an effective treatment modality for antral vascular ectasia (watermelon stomach). The Nd:YAG laser requires fewer treatment sessions than the argon laser to obliterate the lesions without increased risk of complications. © 1992 Wiley‐Liss, Inc.
Optical properties of intralipid: A phantom medium for light propagation studies
Authors: Flock Stephen T. , Jacques Steven L. , Wilson Brian C. , Star Willem M. , van Gemert Martin J. C. 
Published: March 2007

AbstractIntralipid™ is an intravenous nutrient consisting of an emulsion of phospholipid micelles and water. Because Intralipid is turbid and has no strong absorption bands in the visible region of the electromagnetic spectrum, and is readily available and relatively inexpensive, it is often used as a tissue simulating phantom medium in light dosimetry experiments. In order to assist investigators requiring a controllable medium that over a finite range of wavelengths is optically equivalent to tissue, we have compiled previously published values of the optical interaction coefficients of Intralipid, most of which were measured at a wavelength of 633 nm. We have extended the measurements of the absorption and reduced scattering coefficients from 460 to 690 nm and the total attenuation coefficient from 500 to 890 nm. These measurements show that, for stock 10% Intralipid, the absorption coefficient varies from 0.015 to 0.001 cm−1 between 460 and 690 nm, the reduced scattering coefficient varies from 92 to 50 cm−1 between 460 and 690 nm, the total attenuation coefficient varies from 575 to 150 cm−1 between 500 and 890 nm, and the average cosine of scatter varies from 0.87 to 0.82 between 460 and 690 nm. With these data, we discuss the design of an optically tissue‐equivalent phantom consisting of Intralipid and black India ink. © 1992 Wiley‐Liss, Inc.
Cornea epithelial damage thresholds in rabbits exposed to Tm:YAG laser radiation at 2.02 μm
Authors: McCally Russell L. , Farrell Richard A. , Bargeron C. Brent 
Published: March 2007

AbstractWe have determined exposure conditions for minimal damage to the corneal epithelium in rabbit using a continuous wave Tm: YAG laser operating in the TEMoo mode at incident powers between 80 and 450 mW. The 1/e beam diameter was 0.94 mm and exposure durations for threshold damage ranged from 4.3 to 0.08 sec. Calculated temperature increases on the beam axis 10 μm beneath the surface at the measured thresholds were essentially constant and averaged 44°C. This is basically the same temperature increase found for threshold CO2 laser damage and suggests that the critical temperature damage model, which correlates CO2 laser damage, can predict damage thresholds for mid‐infrared laser radiation. We also showed that reliable thresholds can be determined in freshly enucleated eyes, thus opening up the possibility of using available laser sources in laboratories not equipped and approved for animal experiments to determine damage thresholds. © 1992 Wiley‐Liss, Inc.
Percutaneous laser discectomy with the Ho:YAG laser
Authors: Quigley Matthew R. , Shih Tommy , Elrifai Amr , Maroon Joseph C. , Lesiecki Michael L. 
Published: March 2007

AbstractA prototype Ho:YAG (2.15 μm) laser operating at 2‐J/pulse, 3 Hz through a 600‐μm fiber was employed to perform laser discectomies at the L3–4 disc through an 18G needle in five juvenile pigs. No temperature elevations were recorded in the posterior longitudinal ligament at the disc level and all animals recovered fully with no adverse sequelae, even immediately upon awakening from anesthesia. Pathologic examination demonstrated a wide swath of coagulation necrosis confined to the disc space. The Ho:YAG laser, owing to its close approximation to the intense 2.0 μm absorption band of water, appears to be a viable candidate for clinical trials of laser discectomy. © 1992 Wiley‐Liss, Inc.
Er:YAG laser ablation of enamel and dentin of human teeth: Determination of ablation rates at various fluences and pulse repetition rates
Authors: Li Zhao‐Zhang , Code James E. , Van de Merwe Willem P. 
Published: March 2007

AbstractA pulsed Er:YAG laser (2.94 μm) was used to determine ablation depths per pulse of laser energy at 2 Hz and 5 Hz in human teeth cross sections of enamel and dentin. Ablation depths per pulse at 2 Hz in enamel of intact human teeth were measured and compared to ablation depths per pulse determined in enamel cross sections at 2 Hz. Close correlation was observed for ablation depths per pulse of laser energy between teeth cross sections and intact teeth for enamel. Photographs of lased holes at 2 Hz and 5 Hz indicated minimal thermal effects in enamel at fluences below 80 J/cm2. Minimal thermal effects in dentin were noted below 74 J/cm2. Scanning Electron Microscopy (SEM) pictures of lased dentin showed an irregular serrated surface. Results of this study suggest that the Er:YAG laser can effectively ablate enamel and dentin with minimal thermal effects at 2 Hz and 5 Hz. © 1992 Wiley‐Liss, Inc.
Centering balloon to improve esophageal photodynamic therapy
Authors: Panjehpour Masoud , Overholt Bergein F. , Denovo Robert C. , Sneed Rick E. , Petersen Mark G. 
Published: March 2007

AbstractA cylindrical balloon was developed to improve delivery of circumferential light for photodynamic therapy (PDT) of esophageal carcinoma. The balloon consisted of a 36‐mm‐long clear cylindrical membrane and a central tube to hold a cylindrical diffuser in the center of the lumen. Three isotropic probes were placed on the outside of the balloon to allow measurement of delivered light dose to the esophageal mucosa. The balloon was tested in the normal esophagus of 8 dogs that were injected with 4.0 mg/kg of PHOTOFRINR. Endoscopy was performed 48 hours following the injection, and under endoscopic observation the balloon assembly was passed, fixed in place, and inflated. A 1‐cm cylindrical diffuser was passed into the central tube and 150,300, and 600 Joules/cm of 630 nm laser light was delivered at 25 cm, 15 cm, and 5 cm proximal to the gastroesophageal junction. One control dog was illuminated using the cylindrical diffuser alone at doses of 300 and 600 Joules/cm of diffuser. Complete circumferential tissue response was obtained when the balloon was used. Relatively uniform light intensities were measured around the lumen. In contrast, noncircumferential and unpredictable PDT responses were generated when the cylindrical diffuser was used without the balloon. © 1992 Wiley‐Liss, Inc.
Locomotory characteristics of fibroblasts within a three‐dimensional collagen lattice: Modulation by a helium/neon soft laser
Authors: Noble Peter B. , Shields Edward D. , Blecher Peter D. M. , Bentley Kenneth C. 
Published: March 2007

AbstractIt has been postulated that low energy (soft) lasers can enhance wound healing. Considering the importance of cell locomotion in the wound healing process, we have studied the effects of a helium/neon laser upon the locomotory behaviour of a population of fibroblasts migrating within a three‐dimensional hydrated collagen lattice. Statistical methods were used to quantify cell three‐dimensional trajectories obtained using a computer‐assisted tracking system. A two‐minute exposure of embryonic fibroblasts to soft laser light decreased the speed and increased the frequency and duration of stops compared to controls. The locomotory phenotype induced in embryonic fibroblasts by the laser light resembled that of the developmentally older c20 fibroblasts, which are known to express a more mature locomotory phenotype. The relevance of these results to wound healing is discussed. © 1992 Wiley‐Liss, Inc.