bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rate process model for arterial tissue thermal damage: Implications on vessel photocoagulation
Authors: Agah Ramtin , Pearce John A. , Welch Ashley J. , Motamedi Massoud 
Published: March 2007

AbstractA numerical model for thermal damage to human arterial tissue is presented, based on protein denaturation kinetics. The model involves determination of coefficients of rate processes A & δE, which are tissue type‐dependent (arterial tissue in this study), and definition of threshold damage. A feedback‐controlled constant surface temperature device was used to induce 80 coagulative lesions of arterial human tissue ranging in temperature from 66°C to 76°C and in duration from 15 to 1,500 seconds. The measured coefficients were determined to be A = 5.6 × 1063s−1and δE = 430 KJ mole−1. These numerical values closely approximate the coefficients of the rate process for denaturation of collagen molecules. These and other histological observations strongly suggest collagen to be the primary coagulating component of arterial tissue at the onset of thermal coagulative damage. The ability of this model to predict onset of tissue coagulation during laser coagulation was studied using 10 postmortem human arterial samples exposed to argon laser irradiation. © 1994 Wiley‐Liss, Inc.
Characterization of tissue effects produced by the Prolase II lateral‐firing neodymm:YAG laser fiber in the canine prostate
Authors: Gill Harcharan S. , Kabalin John N. , Mikus Paul W. 
Published: March 2007

AbstractThe immediate and long term‐effects of neodymium:YAG laser treatment with the ProLase II lateral‐firing laser fiber in the canine prostate were evaluated. Fourteen male dogs, aged 3 years and older with established benign prostatic hyperplasia, underwent endoscopic ablation of the prostate using the ProLase II fiber. Subjects were treated at laser power settings of 60 watts (6 dogs), 75 watts (4 dogs), or 90 watts (3 dogs), with a mean total energy delivery of 15,000 joules. One dog underwent a sham procedure and served as a normal control. Prostates were examined grossly and histologically at 48 hours, 2 weeks, 4 weeks, or 8 weeks post‐treatment. The cross‐sectional diameter and volume of tissue ablation were measured in each prostate. Histological studies of the extent of thermal injury to the prostatic tissue and the course of healing of the prostatic urethra were performed.The mean cross‐sectional diameter of tissue ablation was 28.6 ± 4.7 mm and mean volume of tissue ablation was 8.2 ± 5.1 cc. No statistically significant difference in diameter or volume of tissue ablation was noted between varying power settings. Histological studies showed extensive tissue necrosis with hemorrhage and an acute inflammatory cell infiltrate at 48 hours. By 8 weeks, total resolution of both necrosis and inflammatory changes with complete re‐epithelialization of the prostatic urethra was observed. © 1994 Wiley‐Liss, Inc.
Clinical applications of lasers in otolaryngology—head and neck surgery
Authors: Ossoff Robert H. , Coleman Jack A. , Courey Mark S. , Duncavage James A. , Werkhaven Jay A. , Reinisch Lou 
Published: March 2007

AbstractThe use of lasers in Otolaryngology—head and neck surgery is described from the invention of the laser in 1960, through the current uses of the laser, and concludes with a summary for the future directions of laser surgery. The various lasers, including the argon, the KTP, and the carbon dioxide lasers used in otolaryngology, are briefly described. The applications of lasers in the larynx, sinuses, and the ear are separately covered, as well as pediatric Otolaryngology. In addition to a brief description of the procedure, the complications and limitations are given. Anesthetic considerations are also covered. © 1994 Wiley‐Liss, Inc.
Experimental study of co2 laser myringotomy with a hand‐held otoscope and fiberoptic delivery system
Authors: Derowe Ari , Ophir Dov , Katzir Abraham 
Published: March 2007

AbstractCO2 laser myringotomy has previously been proven effective in patients with serous otitis media for short‐term aeration of the middle ear. However, the system based on a microscope and a coaxially aligned laser is cumbersome and expensive. The advantage of CO2 laser energy is the high absorption coefficient in biological tissue, meaning minimal damage surrounding the desired lesion. The disadvantage is that conventional optical fibers do not transmit CO2 laser energy (A = 10.6 μm). We have developed a silver halide optical fiber of diameter 0.9 mm and lengths of several meters, with high transmission at 10.6 μm. Using a hand‐held otoscope coupled to a fiberoptic delivery system, CO2laser myringotomies were performed in guinea pigs. In the animal model the feasibility of the procedure was proven. Different irradiation parameters were studied and a “dose‐dependent” relationship was found between the total energy used and the duration of a patent myringotomy. However, conventional histological studies failed to show a difference in circumferential damage with different energy parameters. CO2 laser myringotomy utilizing a hand‐held otoscope coupled to an optical fiber capable of transmitting CO2 laser energy may prove simple and effective. The relationship between energy parameters and myringotomy patency may be instrumental in deciding on the optimal duration of aeration of the middle ear in secretory otitis media. © 1994 Wiley‐Liss, Inc.
New device for visual neodymium:YAG laser prostate ablation: Acute and chronic canine evaluation
Authors: Kopchok George E. , Back Martin , White Rodney A. , Cavaye Douglas M. , Peng Shi‐Kaung , Moriel Evyatar , Rajfer Jacob 
Published: March 2007

AbstractThis canine study (n = 6) evaluated the acute and chronic effects of Nd:YAG laser prostatectomy using a Prolase II fiber. The Prolase II device consists of a 1,000 μm quartz fiber which directs a cone of Nd:YAG laser energy, at 45° to the axis of the fiber, into the prostatic urethra under direct visual guidance [visual laser ablation of prostate, (VLAP)]. Under visual guidance and saline irrigation, 60 seconds of 60 watts of laser power was delivered at 3, 6, 9, and 12 o'clock positions (14,400 J). One canine was instrumented but received no laser energy (control). One prostate was harvested acutely. The remaining four laser‐treated dogs were evaluated at 6 to 16 weeks. The histopathology of acute laser effects shows areas of necrosis with loss of glandular structures and stromal edema. Surrounding this area was a zone of degenerative glandular structures extending up to 12.6 mm into the prostate. Two of the four dogs developed urinary retention at 6.5 and 9 weeks. On examination, both were found to have fibrotic strictures at the distal prostatic urethra with markedly dilated proximal prostatic urethral lumens (1.98 and 2.8 cm). Two other dogs showed no signs of urinary retention at sacrifice. Histopathology, both the 6 and 16 week laser‐treated animals without urinary retention demonstrated dilated prostatic urethras with maximum cross‐sectional diameters of 1.52 and 1.50 cm, respectively. However, the 16 week dog demonstrated mild distal urethral narrowing by urethrogram. The control dog demonstrated normal histology of the prostate at 16 weeks. This study demonstrates the safety and initial results of a delivery device for trans‐urethral laser prostate ablation in a canine model. Further studies are needed to evaluate the cause of the fibrotic urethral strictures in this model and determine its clinical relevance. © 1994 Wiley‐Liss, Inc.
308 nm Excimer laser ablation of cartilage
Authors: Prodoehl John A. , Rhodes Anthony L. B. , Cummings Robert S. , Meller Menachem M. , Sherk Henry H. 
Published: March 2007

AbstractThis article reports the investigation of the XeCl excimer laser as a cutting‐ablating tool for human fibrocartilage and hyaline cartilage. Quantitative measurements were made of tissue ablation rates as a function of fluence in meniscal fibrocartilage and articular hyaline cartilage. A force of 1.47 Newtons was applied to an 800‐μm fiber with the laser delivering a range of fluences (40‐190 mJ/mm2) firing at a frequency of 5 Hz. To assess the effect of repetition rate on depth per pulse, a set of measurements was made at a constant fluence of 60 mJ/mm2, with the repetition rate varying from 10 to 40 Hz. Histologic and morphometric analysis of preserved specimens was performed using light microscopy. The results of these studies revealed that the ablation rate was directly proportional to fluence over the range tested. Fibrocartilage was ablated at a rate 2.56 times faster than hyaline cartilage. Repetition rate had no effect on the penetration per pulse. Adjacent tissue damage was noted to be minimal (10–70 μm). The excimer laser achieved ablation rates adequate for arthroscopic applications. © 1994 Wiley‐Liss, Inc.
Histological studies on the rheumatoid synovial membrane irradiated with a low energy laser
Authors: Amano A. , Miyagi K. , Azuma T. , Ishihara Y. , Katsube S. , Aoyama I. , Saito I. 
Published: March 2007

AbstractThe beneficial effects of low energy laser irradiation on rheumatoid arthritis (RA) joints have been reported, but the mechanisms of action of low energy lasers in RA are unclear. The synovial membrane in cases of RA was studied histologically to observe the effects of low energy laser irradiation. Fourteen knee joints of RA cases, which had been scheduled for arthroplasty, were irradiated with a gallium‐aluminium‐arsenide (Ga‐Al‐As) laser (790 nm in wavelength and 10 mW of output power) prior to the surgical operation, at six points of the external aspect of the knee joint for 80 seconds at each points once a day for 6 days. On the day following the last irradiation, pieces of synovial membrane from the lateral irradiated area and from the median nonirradiated area as a control were resected during the arthroplasty. The histological findings of the irradiated synovial membrane showed flattening of epithelial cells, decreased villous proliferation, narrowed vascular lumen, and less infiltration of inflammatory cells compared with those of nonirradiated synovia. The evaluation of slides was done in a blinded manner, and significant differences was seen by Wilcoxon's t‐test (P < 0.01). Histological findings suggested that the low energy laser irradiation induced suppression of inflammation in the synovial membrane of RA. © 1994 Wiley‐Liss, Inc.
Tumor cell‐enhanced sensitivity of vascular endothelial cells to photodynamic therapy
Authors: Yang Zhengang , Lu Xiaochen , Frazier Donita L. , Panjehpour Masoud , Breider Mike A. 
Published: March 2007

AbstractEffective antitumor photodynamic therapy (PDT) may be related to damage of vasculature within the tumor. The purpose of this study was to determine if tumor cells secrete factors that stimulate proliferation of human umbilical vein endothelial cells (HUVEC) and result in enhanced sensitivity of HUVEC to aluminum‐sulfonated phthalocyanine (AISPc)‐PDT. Three human tumor cell lines—pharyngeal squamous carcinoma, colonic carcinoma, and mammary carcinoma—were used in this study. Co‐culture of HUVEC and either squamous carcinoma or colonic carcinoma, but not mammary carcinoma, significantly increased HUVEC proliferation and AlSPc‐PDT mediated cell damage. In addition, supernatant from squamous carcinoma and colonic carcinoma cultures also stimulated HUVEC proliferation and sensitivity to AISPc‐PDT. Both supernatant and cell lysate from squamous carcinoma cells contained angiogenic factors consistent with basic and acidic fibroblast growth factors, as evidenced by Western blot analysis and BALB/c 3T3 fibroblast cell proliferation assays. Collectively, these results suggest that selected tumor cell lines produce angiogenic factors that induce HUVEC proliferation and subsequently enhance sensitivity to AISPc‐PDT. © 1994 Wiley‐Liss, Inc.
Er:YAG laser ablation of prairie dog gallbladder epithelium for the prevention of gallstones
Authors: Visuri Steven R. , Prystowsky Jay B. , Walsh Joseph T. 
Published: March 2007

AbstractWe hypothesized that laser ablation of gallbladder epithelium would prevent gallstone formation in prairie dogs. An Er:YAG laser (λ = 2.94 μm) was used to ablate the gallbladder epithelium of 24 prairie dogs; 20 sham‐irradiated and 12 non‐operated prairie dogs served as controls. Prairie dogs were sacrificed at time periods of 4 days, 2 weeks, and 8–12 weeks and evaluated for the presence of gallstones and cholesterol crystals. Laser‐irradiated gallbladders demonstrated a lower rate of gallstone formation at 8–12 weeks than the sham‐irradiated gallbladders (39% vs. 79%: P <.02). Crystal formation, however, was not different between laser‐irradiated (88%) and sham‐irradiated (100%) animals. The laser‐irradiated group had less epithelium than the non‐operated group at all time periods (P ≤.002) and compared to the sham‐irradiated group at 4 days and 8–12 weeks (P ≤.001). These data suggest that laser ablation of gallbladder epithelium can reduce the rate of gallstone formation although this effect may be temporary. © 1994 Wiley‐Liss, Inc.
Clinical, histologic, and ultrastructural evaluation of tattoos treated with three laser systems
Authors: Zelickson Brian D. , Mehregan David A. , Zarrin Ali A. , Coles Charlotte , Hartwig Patricia , Olson Susan , Leaf‐Davis Janette 
Published: March 2007

AbstractWe examined the response of tattoo pigments treated with three commercially available lasers: Q‐switched ruby, Q‐Switched neodynium:yttrium, aluminum, garnet (Nd:YAG), and the alexandrite. Tattoos applied to hairless guinea pigs and treated with the aforementioned lasers were evaluated clinically, histologically, and ultrastructurally. Clinical evaluation showed red brown, dark brown, and orange pigment responded best to the Nd:YAG laser (1064 nm). The alexandrite laser was most effective for removing blue and green pigment, the Q‐switched ruby laser was most effective for removing purple and violet pigment, and the NdYAG laser (532 nm) removed red pigment the best. Black pig ment was lightened equally with the Nd:YAG laser (1064 nm) and (532 nm) and the alexandrite laser (755 nm). No clinical scarring was observed; however, some colors turned black after treatment. Histologic and ultrastructural examination showed epidermal and dermal damage to be most evident after treatment with the Nd:YAG laser. Our study shows that certain tattoo pigments respond better to different laser systems. © 1994 WiIey‐Liss, Inc.
Comparative study of the thermal effects of four semiconductor lasers on the enamel and pulp chamber of a human tooth
Authors: Arrastia Anna Marie A. , Machida Takashi , Smith Petra Wilder , Matsumoto Koukichi 
Published: March 2007

AbstractAn in vitro thermometric study was conducted on various GaAlAs semiconductor lasers emitting at wavelengths between 750 nm and 905 nm, to verify whether these lasers produce significant heating during application to tooth structure. Measurements were conducted in vitro, using a thermal camera and a thermocouple during a 60, 120, and 180 s laser exposure at energy densities between 1.5 and 2,400 J/cm2. Mean temperature changes on surface enamel were statistically significant in all groups at P ≤.05 and P ≤.01. The higher the energy density applied to a surface area, the greater the temperature rise observed using the same spot size, operation mode, and wavelength. Intrspulpal temperature elevations measured ≥37°C. An in vivo study was also conducted to determine whether perceptible stimuli are experienced by patients during this time of laser treatment and to verify results of the in vitro study. The results did not conform well with the in vitro study because of uncontrollable variables. None of the patients who received irradiation treatment described any perceptible stimuli. © 1994 WiIey‐Liss, Inc.
In vivo cancer diagnosis of the esophagus using differential normalized fluorescence (DNF) indices
Authors: Vo‐Dinh Tuan , Panjehpour Masoud , Overholt Begein F. , Farris Christie , Buckley F. Paul , Sneed Rick 
Published: March 2007

AbstractBackground and Objective: We report the use of new diagnostic parameters based on the differential normalized fluorescence (DNF) signals for malignant tumor diagnosis.Study Design/Materials and Methods: Over 200 measurements of endogenous fluorescence from normal and malignant esophageal tissues were performed during routine endoscopy in 48 patients. A pulsed nitrogen‐pumped dye laser was used to provide in situ excitation at 410 nm. Direct collection of the fluorescence signal emitted by the tissue was achieved using an intensified photodiode array detector equipped with a fiberoptic probe.Results: The fluorescence signals were normalized with respect to the total fluorescence signal area. The cancer diagnosis indices were defined by the difference between the normalized fluorescence signal of a tumor and the mean value of a reference set of normal tissues. The results of the DNF approach were compared with endoscopic examinations and histopathology interpretations of the biopsy samples. Excellent correlation in the classification of normal and malignant tumors for the samples was found.Conclusion: The data indicated that the DNF approach has a significant potential to provide a direct, real‐time, and in‐situtechnique for cancer diagnosis of the esophagus without requiring biopsy of the tumors and time‐consuming histopathology tests. © 1995 Wiley‐Liss, Inc.
Natural fluorescence of normal and neoplastic human colon: A comprehensive “ex vivo” study
Authors: Bottiroli Giovanni , Croce Anna C. , Locatelli Donata , Marchesini Renato , Pignoli Emanuele , Tomatis Stefano , Cuzzoni Carolina , Di Palma Silvana , Dalfante Marco , Spinelli Pasquale 
Published: March 2007

AbstractBackground and Objective : A microspectrofluorometric analysis on “ex vivo” samples from normal tissue and adenocarcinoma of the human colon has been performed to characterize the histological, biochemical, and biophysical bases of the autofluorescence.Study Design/Materials and Methods: Differences between normal and tumor tissues are found that concern both the intensity distribution and spectral shape of the autofluorescence emission. The different pattern of the fluorescence intensity can be related to the histological organization of the tissue, and involves mainly the arrangement of the submucosa, the most fluorescent layer.Results: The most evident differences in the spectral shape found in the 480–580 nm range involve the stromal compartment, seem to be due to the presence of different fluorochromes, and are possibly related to the host response to the tumor.Conclusion: The nature and the extent of the autofluorescence modification between normal and tumor tissue in sections explain at least partly the evidence of the “in vivo” analysis and highlight the importance of excitation for full exploitation of the potentials of autofluorescence in diagnosis. © 1995 Wiley‐Liss, Inc.
Effect of midinfrared holmium:YAG laser angioplasty with and without balloon angioplasty on acute outcome and restenosis in atherosclerotic femoral arteries in rabbits
Authors: Ragosta Michael , Gertz S. David , Sarembock Ian J. , Deckelbaum Lawrence I. , Haber Howard L. , Powers Eric R. , Gimple Lawrence W. 
Published: March 2007

AbstractBackground and Objective: Pulsed laser may lessen vascular damage and reduce restenosis. This study examined the acute and chronic effects of midinfrared laser angioplasty with and without balloon angioplasty in atherosclerotic femoral arteries in rabbits.Study Design/Materials and Methods: Atherosclerosis was induced in arteries by air desiccation and cholesterol feeding. Arteries were assigned to one of four groups: (1) laser angioplasty with a Thullium/Holmium/Chromium:YAG infrared laser (Eclipse), (2) balloon angioplasty, (3) laser followed by balloon angioplasty and (4) no intervention. Arteries were examined angiographically and histologically at 2 hours and 28 days.Results: Intervention groups had significant initial gain, but this gain was less with laser alone than after balloon or after laser plus balloon. At 2 hours, laser alone caused greater arterial damage and thrombosis compared to controls. At 28 days, arteries treated with laser plus balloon had greater narrowing compared with arteries treated with balloon angioplasty. By multivariate regression analysis, the severity of the pre‐intervention stenosis (P = 0.001) and intervention with laser plus balloon (P = 0.01) correlated independently with the severity of luminal narrowing at 28 days.Conclusion: Midinfrared Ho:YAG laser angioplasty resulted in substantial acute damage with increased frequency of thrombus formation in this rabbit model. Arteries treated with laser alone had suboptimal initial gain and more obstruction by plaque at 28 days compared to nonintervened arteries. The adjunctive use of balloon angioplasty improved initial gain, but correlated with smaller luminal diameters and more severe narrowing by plaque at 28 days. © 1995 Wiley‐Liss, Inc.
Immediate changes in subcellular structures of transplanted tumors following photodynamic and laser hyperthermic therapy
Authors: Hotta Soichi , Kashimura Hiromasa , Hirai Shinji , Nakahara Akira , Fukutomi Hisayuki , Osuga Toshiaki , Uchiyama Yasuo 
Published: March 2007

AbstractBackground and Objective: To further understand the precise process of the tumor cell degeneration after photodynamic therapy (PDT), laser hyperthermic therapy (LH), and combined treatments using an Nd:YAG laser. It is important to examine initial morphological alteration of tumor cells after these treatments.Study Design/Materials and Methods: In this study, nude mice bearing HeLa cell tumors were treated with PDT, LH, and combined treatments of the two. Tumor tissues obtained immediately after these treatments were analyzed using electron microscopy and morphometry.Results: In the combined treatments, which produced more severe effects on tumor cells, morphological features of apoptosis such as cytoplasmic condensation, blebs, and apoptotic bodies appeared in the cells, although the typical alteration in the nuclear chromatin was not seen.Conclusion: Cytoplasmic alterations may proceed more rapidly than nuclear alterations in the cellular degeneration induced by the single or combined treatments of PDT and LH.
Carbon dioxide laser therapy of a widespread epidermal nevus
Authors: Hohenleutner U. , Wlotzke U. , Konz B. , Landthaler M. 
Published: March 2007

AbstractBackground and Objective: The treatment of epidermal nevi is difficult and often unsatisfactory. Many therapeutic approaches have been tried, of which the surgical methods including lasers aim to avoid recurrences and hypertrophic scarring. Here we report the case of a widespread, life‐impairing epidermal nevus, summarize the available treatment modalities, and discuss CO2 laser therapy with respect to the clinically soft variants of these developmental defects.Study Design/Patients and Methods: A patient with a widespread, recurrent, biopsy‐proven epidermal nevus was treated with a 10,600‐nm CO2 laser. After test treatments in local anaesthesia, four sessions were performed under general anaesthesia each with a follow‐up time of 4 years to date.Results: CO2 laser vaporization resulted in complete removal of the treated nevus without any obvious scarring. The patient is free of recurrence 4 years postoperatively.Conclusion. CO2 laser treatment of epidermal nevi is a useful modality in selected variants. © 1995 Wiley‐Liss, Inc.