bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laser Raman spectrum of calcified human aorta
Authors: Klug Dennis D. , Singleton Donald L. , Walley Virginia M. 
Published: March 2007

AbstractRaman spectra of highly calcified areas of areas of human aorta were obtained using long wavelength excitation at 740 nm minimize background fluorescence interference. Raman spectra resembling that of hydroxyapatite were obtained for segments of highly calcified aorta that were thawed frozen samples, from which the surface layer had been removed, or were dired. These are the first reported spectra obtained in air or in normal saline solution showing the hydroxyapatite peak in calcified plaque for samples which were untreated except for freezing, which is encouraging for the application of Raman spectroscopy as a method of detection of plaque during laser angioplasty. Spectra obtained from calcified aorta using excitation at 514.5 nm did not show evidence of the hydroxykapatite band because of the severe interference by background fluorescence generated at this wave length.
Detection of calcified atherosclerotic plaque by laser‐induced plasma emission
Authors: Deckelbaum Lawrence I. , Scott John J. , Stetz Mark L. , O'Brien Kenneth M. , Baker Glenn 
Published: March 2007

AbstractThe use of fluorescence spectroscopy to discriminate atherosclerotic from normal tissue is limited by a lower sensitivity for calcified than noncalcified atherosclerotic plaque (65% vs. 93%, respectively). To evaluate plasma emission as a means to detect calcified plaque, 325 normal and atherosclerotic cadaveric aortic sites were irradiated through a 100‐μm silica fiber in blood by a pulsed holmium laser (λ = 2.1 μm, fluence =4 J/mm2). A photo‐diode positioned near the proximal end of the fiber detected plasma emission during a laser pulse. Plasma emission was detected at 0% (0/110) of normal, 0% (0/107) of noncalcified atherosclerotic tissue, and 91% (98/108) of calcified atherosclerotic sites. Spectroscopic analysis confirmed the presence of calcium lines in the plasma emission from calcified atherosclerotic plaque. Although ablative fluences (> 3 J/mm2) were required for plasma generation, a single laser pulse ablated only to a depth of 67 ± 16 μm in normal tissue. In an additional 10 calcified atherosclerotic sites, laser ablation was continued as long as plasma emission was detected. In all cases, plaque ablation was terminated before arterial perforation. Furthermore, the adjunctive use of plasma detection improved the accuracy of fluorescence spectroscopic classification of normal and atherosclerotic tissue. In conclusion, plasma detection has a high sensitivity (91%) and specificity (100%) for calcified atherosclerotic plaque and may be a useful adjunct for laser angioplasty guidance. Furthermore, plasma detection can be implemented both simply and inexpensively.
Comparative study of laser and scalpel nerve transections
Authors: Fligny Isabelle , Wu Justin S. , Samonte Bernadette R. , Fried Marvin P. 
Published: March 2007

AbstractThis investigation was designed to compare standard scalpel transections of the tibial branch of the rat sciatic nerve with those performed using either a milliwatt carbon dioxide (CO2) or a potassium titanyl phosphate (KTP/532) laser. Four transection groups consisted of nerves sectioned with (1) scalpel (control), (2) milliwatt CO2 laser, (3) KTP/532 with microscope attachment, and (4) KTP/532 laser with 400‐n‐m bare fiber. Each laser was used with the same parameters: 10 watts, 0.4‐mm spot size, and continuous‐wave mode. Horseradish peroxidase (HRP) was applied to the proximal stump for 30 min, and the animals were sacrificed 24 h later. Horseradish peroxidase (HRP)‐labeled motoneuron cell bodies in the lumbar spinal cord were then counted. The average numbers of labeled neurons in each group were as follows: group I (n = 14) 518, group II (n = 8) 424, group III (n = 8) 351, and group IV (n = 8) 283. The standard deviations were quite large, however.When all laser transections were pooled and compared with paired scalpel transections, we found a significant difference, both by the paired t‐test (P = 0.016) and by the Wilcoxon matched‐paired test (P = 0.02). We conclude that laser transection significantly diminishes the number of neurons labeled by the retrograde transport of HRP.
Holmium:YAG laser ablation of human intervertebral disc: Preliminary evaluation
Authors: Gottlob Charles , Kopchok George E. , Peng Shi‐Kaung , Tabbara Marwan , Cavaye Douglas , White Rodney A. 
Published: March 2007

AbstractPercutaneous discetomy has become a viable alternative in the treatment of herniated intervertebral disc. This study determined the effectiveness of holmium:YAG laser for ablation of human disc tissue. Human cadaveric intervertebral disc was harvested and stored in cold saline‐soaked gauze for evaluation within 24 hr of removal. Using a specially designed apparatus, a 600 μm diameter fiber was advanced perpendicular through the annulus fibrosis at a controlled force of 0.098 Newtons (10 g). Samples were lased in air (n = 17) and in room temperature saline (n = 32). The laser energy was delivered at 5 Hz, 250 μsec pulsewidth, and from 50 mJ/mm2 to 1,100 mJ/mm2 fluence. Three to six holes were lased using identical parameters in each tissue specimen and were evaluated histologically and by morphometric analysis. The maximum zone of thermal necrosis and thermal denaturation occurred at 700–1,100 mJ/mm2; 140 μm and 590μm in air and 80 μm and 730μm in saline, respectively. At fluences between 200 and 700 mJ/mm2, the thermal necrosis ranged from 20 to 60 μm in air and from 10 to 50μm in saline, the zone of denaturation also being less. The holes created with the 600μm fiber were circular in shape, with a mean diameter of 500 μm (n = 3). The etch rates (penetration/pulse) appeared to increase with increasing fluences. In saline, the etch rate ranged from 7 to 53 μm/pulse (r = 0.57, P ≤ 0.10), and, in air, the values ranged from 7 to 65 μm/pulse (r = 0.79, P ≤ 0.03). No tissue ablation occurred at 50 mJ/mm2, suggesting that the ablation threshold lies between 50 and 200 mJ/mm2. This study demonstrates that controlled ablation of human disc tissue can be accomplished with the hol‐mium:YAG laser, the degree of thermal injury being related to the amount of energy delivered.
Correlation between photodynamic efficacy of differing porphyrins and membrane partitioning behavior
Authors: Okunaka Tetsuya , Eckhauser Mark L. , Kato Harubumi , Bomaminio Anthony , Yamamoto Hideki , Aizawa Katsuo , Sarasua Martha M. , Koehler Karl A. 
Published: March 2007

AbstractThe ability of a photosensitizer to partition into membrane is determined by its structure and physical properties. Partitioning behavior can be quantitated as the partition coefficient (Kp) for a particular drug. This property may be an important determinant of cytocidal efficacy in photodynamic therapy. The Kp of five photoactive drugs—13,17‐ditetraammonium protoporphyrin (PH1008), photofrin II (PII), hematoporphyrin (Hp), benzopor‐phyrin derivative monoacid (BPD‐MA), coproporphyrin (Cp), and uroporphyrin (Up)—was determined using a simple liposome system composed of sonicated egg phosphatidylcholine single bi‐layer vesicles. The cytocidal efficacy of each drug was compared by determining the concentration of drug resulting in 50% maximal lysis (C50) obtained by measuring the hemoglobin absor‐bance at 414 nm released from lysed human red blood cells. The percentage lysis at 1 μM final drug concentration was also determined. An argon‐dye laser was used to administer light of 630‐nm wavelength for a total exposure of 5 J/cm2. Porphyrins with a greater tendency to partition into phosphocholine bilayer membranes demonstrated a greater lytic efficacy in the rbc system utilized. The comparison of physical properties with lytic ability may be useful in understanding the mechanism by which PDT exerts its effects and in predicting the clinical efficacy of different drugs.
Magnetic resonance imaging of interstitial laser photocoagulation in brain
Authors: Tracz Robert A. , Wyman Douglas R. , Little Peter B. , Towner Rheal A. , Stewart Wendy A. , Schatz Stanley W. , Pennock Paul W. , Wilson Brian C. 
Published: March 2007

AbstractMagnetic resonance (MR) imaging can be used to monitor the development of thermal lesions induced in tissue using interstitial laser photocoagulation (ILP). A potential application for ILP is the treatment of surgically inaccessible brain tumors. For the successful clinical application of MR‐monitored ILP, it is necessary to relate MR images of ILP lesions to the actual induced lesions. In this preliminary study we performed ILP in the normal brains of anesthetized cats by delivering interstitially 1.0, 1.5, and 2.0 W of continuous‐wave Nd:YAG laser energy (1,064 nm) for 1,000 s via a plane‐cut 400 p,m core optical fiber. At 48 h post‐irradiation the lesions consisted of four sharply demarcated concentric zones of thermal damage. Lesion diameter increased linearly with delivered power. T2‐weighted proton spin‐echo images acquired during ILP showed a region of complete or near signal loss that underestimated the actual lesion at 48 h. Gadolinium‐enhanced T1‐weighted spin‐echo images acquired immediately post‐irradiation showed the actual lesion precisely. © 1992 Wiley‐Liss, Inc.
Nd:YAG laser bipolar dissector—preliminary results
Authors: Nishiwaki Yoshiro , Daikuzono Norio , Joffe Stephen N. 
Published: March 2007

AbstractWe have developed a laser bipolar dissector (LBD) which uses the 1,064 nm Nd:YAG wavelength. The laser emits from the inner surface of the distal 7 mm of each probe made of synthetic sapphire. With low laser power (15–25 W), the bipolar provides hemostatic cutting of larger blood vessels. Animal experiments were carried out using New Zealand white rabbits. The LED he‐mostatically cut through veins up to 5 mm and arteries up to 2 mm in diameter. Rebleeding did not occur. Transection of parenchymal organs such as liver and lung was easily performed with complete hemostasis. In chronic experiments a partial hepatectomy with splenectomy and left nephrectomy was performed using the LBD alone without any ligation. Up to 3 weeks postoperatively there were no direct complications related to using the LBD. In conclusion the LBD could perform a hemostatic transection of large vessels and might have clinical application in the dissection of vascular parenchymal organs. © 1992 Wiley‐Liss, Inc.
Nd:YAG laser treatment of colorectal malignancies: An experience of 4 ½ years
Authors: Dittrich K. , Armbruster C. , Hotter F. , Tuchmann A. , Dinstl K. 
Published: March 2007

AbstractBetween 1985 and 1990, 517 patients were treated for colorectal malignancies at our department of surgery. Nd:YAG laser therapy was used in 37 cases (7.1%). The mean age of these 22 men and 15 women was 71.4 years (range: 22–96 years). One hundred‐twenty‐nine Nd:YAG laser treatments were performed. Indications for laser treatment were (1) palliative tumor reduction (n = 21), (2) preresectional laser recanalization for obstructing carcinoma (n = 6), and (3) curative treatment (n = 10). Laser related complications included one perforation of the rectum and one rectovaginal fistula. One fatal pulmonary embolism occurred. After palliative treatment, five patients died because of tumor progression (mean survival time: 16 months), two because of other reasons. All patients with obstructing tumors could be recanalized successfully. After curative treatment, eight patients are still alive without tumor recurrence (mean survival time: 25.5 months), and two died of other causes. Palliative Nd:YAG laser treatment of colorectal malignancies is a competitive alternative to conventional surgery. Recanalization of obstructing tumors is an excellent treatment for large bowel obstruction, making one‐stage resections possible. Curative treatment should be reserved for special cases only. © 1992 Wiley‐Liss, Inc.
Thermal effects in tissues from combined simultaneous coaxial CO2 and Nd:YAG laser beams
Authors: Judy Millard M. , Matthews J. Lester , Goodson J. Rush , Hults Donald F. , Viherkoski Esa , Aronoff Billie L. 
Published: March 2007

AbstractThis study examines the depth of thermal coagulation and charring in swine liver, kidney cortex, tongue (inferior surface), skeletal muscle, inflated lung, and skin resulting from in vivo incision with simultaneous coaxial CO2 and Nd:YAG (1.064 μM) laser beams. At values of 20 w and 40 w, respectively, and at values of 30 w and 60 w, respectively, of combined CO2 and Nd:YAG laser radiation, coagulation depths determined histologically in liver were significantly greater (P<0.01) than in the other tissues and were significantly less in inflated lung (P<0.05) than in other tissues for the larger laser power settings employed. Coagulation depths achieved at 10 w and 20 w, respectively, and at 20 w and 40 w, respectively, of CO2 and Nd:YAG laser power were comparable to those obtained by other workers in liver and other relatively vascular tissues using a contact Nd:YAG laser tip. Charring depths obtained at power settings of 30 w (CO2) and 60 w (Nd:YAG) were greater in liver (P<0.001) than in all other tissues examined. Hemostasis during incision was achieved only for values of the ratio of CO2 to Nd:YAG laser power in the range 2–3 in the more vascular tissues, liver and kidney cortex, whereas hemostasis was achieved also in the lesser vascular tissues at higher values. These results strongly suggest the usefulness of combined simultaneous CO2 and Nd:YAG laser beams in surgery of the more vascular organs and tissues. © 1992 Wiley‐Liss, Inc.
Pathologic changes occurring in the prostate following transurethral laser prostatectomy
Authors: Johnson Douglas E. , Price Roger E. , Cromeens Douglas M. 
Published: March 2007

AbstractSerial gross and histopathologic examinations of the prostate following transurethral laser prostatectomy in the canine model demonstrated an immediate well‐demarcated sphere of thermal necrosis measuring 2.7 cm in diameter, which, within 24 hours, had begun liquefaction and was showing multiple areas of cavitation. By the end of the 1st week, the areas of cavitation had coalesced to form a central cavity lined by a narrow layer of necrotic tissue clinging to the thin surviving peripheral belt of prostatic glandular parenchyma. At 3 weeks, the bluish‐black discoloration resulting from breakdown of blood in the necrotic tissue had subsided, leaving masses of coagulonecrotic tissue within the central cavity. Within 5 weeks, the ectatic central cavity was lined by transitional epithelium. These postmortem pathologic observations confirm our surgical and clinical impressions of being able to satisfactorily perform an effective transurethral prostatectomy using neodymium:YAG (Nd:YAG) laser photoirradiation. © 1992 Wiley‐Liss, Inc.
Laser endoscopic sympathectomy for palmar hyperhidrosis
Authors: Kao Ming‐Chien 
Published: March 2007

AbstractHyperhidrosis palmaris is a common disorder among the Orientals. Despite numerous therapeutic modalities in practice, none has proved entirely satisfactory. With the introduction of video‐endoscopic surgery, we combined this system with a fiber optic Nd‐YAG laser unit, electrocautery, and a laser Doppler flowme‐ter to design a new and promising therapeutic technique for palmar hyperhidrosis.General anesthesia with alternating one‐lung ventilation is essential for a safe and smooth endoscopic sympathectomy. An operating endoscope was introduced into thoracic cavity via the second intercostal space and then attached to a CCD camera video system, which provided clear visibility of the sympathetic trunk in most cases. The proper level of the sympathetic trunk was further confirmed with the aid of vasomotor response of the palmar skin resulting from electric stimulation on the related sympathetic trunk. Finally, the confirmed target was precisely vaporized with a low power Nd‐YAG laser through an endoscope.Twenty patients underwent bilateral symapthectomy, mostly on T2 and its adjacent trunk. This technique did not cause any injury to the lung or bleeding. No Horner's syndrome was produced. It provided a precise ganglionectomy on a confirmed target under clear magnified vision. Consequently, a definite and long‐lasting therapeutic effect seemed warranted. It was considered to be a relative minor and safe procedure causing minimal discomfort and an almost invisible scar without producing serious complications. It also shortened the operation time and hospital stay remarkably in comparison with other open sympathectomy procedures. © 1992 Wiley‐Liss, Inc.
Augmentation of the systemic host anti‐tumor response through laser excision
Authors: Brien Thomas P. , Lanzafame Raymond J. , Nairn John O. , Rogers David W. , Wang Mian Jing , Hinshaw J. Raymond 
Published: March 2007

AbstractThis study examines whether primary laser excision results in augmentation of the systemic host anti‐tumor response to tumor rechallenge. Single R3230AC mammary tumor implants, (0.5 × 0.5 × 1.0 mm), were grown in 112 female Fisher 344 rats. The animals were randomized. Group S tumors were excised by scalpel. Group E was excised with a Surgistat electrocautery (Valley Labs, Boulder, CO). Group CS was excised with a Sharplan 1100 CO2 laser (Sharplan, Allendale, NJ) at 25 watts (W) continuous wave (C W) (0.2 mm spot size) and the wound was “sterilized” with a 5‐mm spot size by gently heating the tissue without blanching. Group K was excised with a KTP/532 laser (Laserscope, San Jose, CA) at 17 W CW using a 400 μ fiber. Group Y was excised with a Sharplan 2100 Nd:YAG laser set at 15W CW using a 0.2 mm clear sapphire tip. A second tumor implant, (0.5 × 0.5 × 1.0 mm), was placed at a remote site 14 days postoperatively. An unoperated control group was implanted. Secondary tumor volumes were measured for 36 days and the mean tumor volumes (MTV) were statistically compared. The MTV in groups CS, K, Y, and E was less than control (P < 0.01). The MTV in groups CS, K, Y, and E was less than group S, although this was not statistically different. Lasers and cautery appear to increase the host response against subsequent tumor challenge. This study corroborates earlier studies of other modalities. Further studies to determine whether this host sensitization is an immune response and to elucidate the mechanisms of this effect are warranted. © 1992 Wiley‐Liss, Inc.
Global status of clinical photodynamic therapy: The registration process for a new therapy
Authors: Marcus Stuart L. , Dugan Margaret H. 
Published: March 2007

AbstractThe clinical use of photodynamic therapy (PDT) has been ongoing for over a decade. However, attempts to apply for approval of the therapy from boards of health for general use began only in 1989. The unique nature of PDT and the resultant changes in the normal drug registration process, as well as steps which are being taken to approve PDT for the treatment of endobronchial lung cancer, superficial bladder cancer and esophageal cancer are described. The current clinical status of PDT in these indications is also reviewed. © 1992 Wiley‐Liss, Inc.
Effect of tissue pressure on contact laser insults
Authors: Wyman Andrew , Sweetland Helen M. , Rogers Kenneth 
Published: March 2007

AbstractThe effect of variations in tissue pressure transmitted through contact laser probes during tissue ablation has been investigated. Weights of 10 and 50 g were transmitted through the tip of the probes onto the gastric and colorectal wall. At all laser energies the depth of tissue vaporization was significantly greater at the higher tissue pressure with perforation of the viscus occurring at laser energies above 10 J. The lateral zones of thermal tissue necrosis were not influenced by tissue pressure. Deformation of the wall of the viscus under the pressure of the probe was identified as a sign of excessive tissue pressure likely to result in perforation of any tissue of similar thickness to the normal gastric or colorectal wall. © 1992 Wiley‐Liss, Inc.
He‐Ne laser irradiation of single identified neurons
Authors: Balaban Pavel , Esenaliev Rinat , Karu Tiina , Kutomkina Elena , Letokhov Vladilen , Oraevsky Alexander , Ovcharenko Nikolay 
Published: March 2007

AbstractSilent (LPa2 and LPa3) and spontaneously active (V3, V5, V17) neurons of subesophageal ganglia of Helix pomatia were irradiated via a 125‐mm fiber probe with a 10‐mW He‐Ne laser (λ = 632.8 nm), and the rate of membrane depolarization, duration of latent period, and probability of spike activity were measured as the functions of light intensity. It was found that silent neurons can not be activated by He‐Ne laser irradiation. When the spontaneously active neurons generating spikes every 7–10 min were irradiated in between their spontaneous spikes, the depolarization of membrane and generation of action potentials occurred as a function of light intensity, I. The probability of spike generation increased until the intensity reached 1 W/cm2, and when 1 = 4 W/cm2 was equal to 1. The depolarization of the membrane had a threshold at I = 0.1 W/cm2, then increased with increasing the intensity, and reached a plateau at I = 0.7 W/cm2 (depolarization rate 0.18 mV/s). Duration of the latent period decreased from 28 s to 17 s when the intensity was increased from 0.05 to 0.3 W/cm2. Further increase of the light intensity, from 0.3 to 1.5 W/cm2, caused a less pronounced change in the duration of the latent period (e.g., latent period equal to 11 s at I = 1.5 W/cm2). © 1992 Wiley‐Liss, Inc.
Neodymium:YAG laser treatment of bladder neck contracture following prostatectomy
Authors: Silber Nahum , Servadio Giro 
Published: March 2007

AbstractA total of 21 patients with postprostatectomy bladder neck contracture underwent treatment with Nd:YAG laser irradiation. A new 800‐μm hemispherical optical quarz fiber was used in contact technique to produce linear incisions in the scarred tissue. Within 11.2 months, median of follow‐up, there was improvement in the obstructive voiding symptoms in all the patients. Two patients who had still mild contracture in the first follow‐up cystoscopy were managed successfully with a second treatment. Endoscopic application of laser energy in the contact mode enables the immediate vaporization and disintegration of the fibrous area and secondary reepithelization of the bladder neck without scarring. © 1992 Wiley‐Liss, Inc.
Demonstration of synergistic effects of hyperthermia and photodynamic therapy using the chick chorioallantoic membrane model
Authors: Kimel S. , Svaasand L. O. , Hammer‐Wilson M. , Gottfried V. , Cheng S. , Svaasand E. , Berns M. W. 
Published: March 2007

AbstractThe chick chorioallantoic membrane (CAM) model was used to study vascular effects of photodynamic therapy (PDT) and hyperthermia (HPT) and the synergism of these modalities. The CAM is a convenient medium for monitoring the modifications of the vasculature. It is possible to view the CAM and to examine structural changes of individual blood vessels in real tune. Moreover, the CAM is a closed system which lends itself to mathematical modeling of the temporal and spatial temperature profile and in which HPT can be performed quantitatively and to a selected depth, using different lasers. A porphyrin‐type photosensitizer solution was applied to areas of the CAM, defined by teflon O‐rings placed on the surface. Uptake dynamics of the sensitizer into the CAM was determined by analyzing its fluorescence in vivo. The CAM area was irradiated with a dual‐wavelength laser system composed of a dye laser at 644 nm (to induce PDT) and a CO2 laser at 10.6 μm (to bring about HPT). Damage to the CAM vasculature, due to combined PDT + HPT, was compared to the outcome of the separate modalities, and a synergistic effect of about 40% was observed. © 1992 Wiley‐Liss, Inc.