bluuebunny/crossref_metadata_2025 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

A 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

The 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

The 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

CO2 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

This 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

This 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

The 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

Effective 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

We 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

We 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

An 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

Background 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

Background 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

Background 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

Background 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

Background 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.
Lasers in urology
Authors: Bhatta Krishna M.
Published: March 2007

Ever since Mulvany first described use of Ruby laser for lithotripsy, urologists have been exploiting every possible application of this technology. Laser lithotripsy in the 1980s and now laser prostatectomy in the 1990s have dominated laser usage in urology. Applications of lasers for superficial lesions (e.g., condylomata acuminata and carcinoma of penis) have found an established role. Interests in laser welding, photodynamic therapy and fluorescence continues to grow and evolve. The laser industry at the same time is striving to provide more efficient lasers. High power lasers (Hohmium:YAG, KTP:YAG) and laser machines combining double wavelengths (Nd:YAG and KTP, Ho: YAG and Nd:YAG) are commercially available. Diode lasers with their portability and reliability qualities can now provide high output powers in various wavelengths. Here, we have reviewed different lasers, laser tissue interaction and clinical laser applications relevent to urology. © 1995 Wiley‐Liss, Inc.
Effect of N‐acetylcysteïne on photofrin‐induced skin photosensitivity in patients
Authors: Baas Paul , van Mansom Inge , van Tinteren Harm , Stewart Fiona A. , van Zandwijk Nico
Published: March 2007

Background and Objective: One of the major side effects of photodynamic therapy (PDT) employing Photofrin as the sensitizer is enhanced photosensitivity of the skin. The basic mechanism in PDT damage is believed to be the formation of singlet oxygen and radical species. N‐acetylcysteïne (NAC) increases glutathione levels and is known to prevent pathology elicited by radicals and reactive species.

Study Design/Materials and Methods: NAC was tested in a randomized, open label study for its protective effect on skin photosensitivity. Twenty‐seven patients treated with PDT for central obstructive lung cancer or esophageal cancer received either “early” or “delayed” NAC, starting 5 or 10 days after Photofrin, in a dose of 3 × 600 mg per day for 5 days. Light, obtained from a halogen lamp (fluence rate 200 mW·cm−2) was used to illuminate skin patches of 2.5 cm2 on the back (10, 25, and 50 J·cm−2). Skin response was measured by using a visual scoring system and by measuring the redness using a reflectance meter.

Results: Skin responses varied from no changes at 10 J·cm−2 to redness with edema at energies of 50 J·cm−2. In the absence of edema, measurements with the reflectance meter appeared to be more sensitive than visual scoring.

Conclusion: In a limited number of patients, there was a trend for decreased sensitivity after NAC, but statistical analysis failed to show any significant protective effect of this short course of NAC. © 1995 Wiley‐Liss, Inc.
High‐powered CO2 laser cystoscope for endoscopic bladder surgery
Authors: Fournier George R. , Kung Andrew H. , Trost David
Published: March 2007

Background and Objective: The CO2 laser is potentially useful for the surgical treatment of superficial bladder tumors. High water absorption of the CO2 laser beam and the lack of a flexible fiber delivery system has hindered development of cystoscopes designed to evaporate bladder tumors. This report describes a cystoscope capable of delivering a high‐power CO2 laser beam to all parts of the urinary bladder.

Study Design/Materials and Methods: A rigid 24 Fr. cystoscope transmitting 80 Watts of power via an articulated arm and infrared waveguide was built. Beam manipulation is by reflection using a movable mirror. Smoke and urine are evacuated by continuous flow of CO2 purge gas. An isotopic laser delivering an 11.1 μm wavelength beam prevents resonant absorption. Conventional 30–70° telescopes are used. Scope performance and lesion morphology were tested in four female pigs.

Results: A total of 80–85% of the incident energy is delivered to the mucosa. All areas of the bladder mucosa can be evaporated. All components tolerate wetting. Mucosa and lamina propria are evaporated with 30 Joules of delivered energy. Perforation occurs after 120–160 Joules are delivered to a single spot.

Conclusion: The limitations of power, beam transmission, beam manipulation within a small cavity, and resistance to wetting have been overcome. © 1995 Wiley‐Liss, Inc.
Automated lesion placement in the rabbit eye
Authors: Barrett Steven F. , Jerath Maya R. , Rylander H. Grady , Welch Ashley J.
Published: March 2007

Background and Objective: The objective of this research was to build a prototype feedback control system to precisely place argon laser lesions on the retina for treatment of retinal disorders.

Study Design/Materials, and Methods: The prototype feedback control system was tested by placing lesions at specific locations on the retina of pigmented rabbits to simulate the treatment of diabetic retinopathy, retinal breaks or tears, and a pre‐programmed, two‐dimensional array of lesions was placed at a specific site.

Results: Results of feedback‐controlled lesion placement performed in vivo on pigmented rabbits are presented. The ability to place lesions with automated feedback control is demonstrated.

Conclusion: Automated feedback control placement of argon laser lesions is possible at a reasonable cost and has numerous therapeutic and safety benefits over current ballistic delivery.
Laser tissue welding: A comprehensive review of current and future
Authors: Bass Lawrence S. , Treat Michael R.
Published: March 2007

Laser techniques for joining tissue, in combination with other surgical technologies, will be a hallmark of surgery in the next century. At present, there are many clinical applications of tissue welding and soldering which are beginning to achieve wide spread acceptance. These exciting clinical developments are the result of many advances which have been made in the past few years in our understanding of the mechanism of laser tissue welding. Also contributing to this progress are many important technical refinements such as tissue solders and feedback control of the laser device. In this article, we describe in depth the history and development of laser tissue welding including key theoretical concepts as well as crucial experiments which have added to our insight into this phenomenon. We also review the evolving concepts of its clinical application and indicate clinical applications which are likely to become more important in the future. © 1995 Wiley‐Liss, Inc.
Spectroscopic diagnosis of bladder cancer with elastic light scattering
Authors: Mourant Judith R. , Bigio Irving J. , Boyer James , Conn Richard L. , Johnson Tamara , Shimada Tsutomu
Published: March 2007

Background and Objectives: Recently, significant progress has been made toward the development of optical, noninvasive medical diagnostics. The goal of this study was to evaluate elastic scatter measurements as a tool for diagnosing bladder cancer. Study Design/Materials and Methods: In vivo measurements on 10 patients with suspected bladder cancer were made with the optical biopsy system (OBS) developed at Los Alamos National Laboratory. Elastic‐scatter spectra over the wavelength range 250–800 nm were obtained using a fiber‐optic probe through one of the lumens of a urological cystoscope. Measurements were made on putatively normal areas and areas of uncertain abnormality, as well as those suspected to be cancerous. After measurements were made with the OBS, biopsy samples were taken at the measurement sites. Comparisons of the histopathology and the optical spectra were then made.

Results and Conclusions: A diagnostic algorithm for distinguishing malignant from nonmalignant tissue based on the values of the slopes over the wavelength range 330–370 nm has a sensitivity of 100% and specificity of 97% for the limited number of patients in this Study.
Study on superabsorbent composite. XV. Effects of ion‐exchanged attapulgite on water absorbency of superabsorbent composites
Authors: Zhang Junping , Chen Hao , Wang Aiqin
Published: March 2007

A series of superabsorbent composite, polyacrylamide/attapulgite, from acrylamide (AM) and ion‐exchanged attapulgite (APT) was prepared by aqueous polymerization, using N,N′‐methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as an initiator. The effects of ion‐exchanged APT on water absorbency of superabsorbent composites in distilled water and in 0.9 wt% NaCl solution were studied. The result indicates that higher cation‐exchange capacity (CEC) and lower specific surface area (SSA) of APT treated with various anions are of benefit for improving water absorbency in distilled water. The effects of AlCl3 solution concentration and Al3+‐exchanged APT content on water absorbency of the composite were also investigated. The concentration of AlCl3 solution has a great influence on water absorbency of the superabsorbent composite. Al3+‐exchange of APT could also enhance reswelling ability of the corresponding composite, which indicates that Al3+‐exchange of APT could improve gel strength and gives a direct evidence for its acting as an inorganic assistant crosslinker in the polymeric network. POLYM. COMPOS., 28:208–213, 2007. © 2007 Society of Plastics Engineers
Peri‐ and paracentric inversions in chromosome 12: Prenatal diagnosis and family study
Authors: Poulsen Hanne , Mikkelsen Margareta , Holmgren Gösta
Published: March 2007

Three different types of chromosome 12 inversion were seen in 15 individuals out of 44 individuals examined in one 8 generation family. Type 1: a pericentric inversion inv(12) (p112; q131) was found in 7 individuals and twice at prenatal diagnosis. Type 2: a paracentric inversion inv(12) (p123; p131) was seen in two individuals. Two individuals carried both inversion chromosomes, namely type 1 and type 2. The two inversion chromosomes were transmitted from each of the parents. Type 3: a double pericentric and paracentric inversion (type 3) inv(12) (p123; p131) (p112; q131) was observed in the daughter of one of the carriers of type 1 and 2 inversions and again at prenatal diagnosis in her son. The double inversion most likely arose through crossing‐over in between the two inversion loops. A balanced translocation t(7; 13) and the inversion type 1 was observed in one individual, who transmitted the translocation only to an offspring.

The frequency of inversions in amniotic fluid cells observed in our laboratory was 1·9 per cent. The clinical implications of these findings are discussed.
A case of a paracentric inversion inv(7)(q11q22). Prenatal detection and counselling
Authors: Ridler Michael A. C. , Sutton Simon D.
Published: March 2007

A paracentric inversion in the long arm of a number 7 chromosome was detected in an amniotic cell culture from a 41 year old woman, screened because of maternal age. The karyotype was 46, XX, inv(7) (q11q22). Her husband carried an identical inversion. The parents were advised that the pregnancy should continue and a healthy infant was born at term. Prenatal diagnosis and counselling for paracentric inversion heterozygotes are discussed in the light of published and unpublished cases.
Menkes X‐linked disease: Prenatal diagnosis of hemizygous males and heterozygous females
Authors: Horn Nina
Published: March 2007

Menkes X‐linked disease, a copper disturbance syndrome, is detectable in cell cultures.

Prenatal findings in two at‐risk foetuses suggested that prenatal diagnosis was also feasible. In this study, we report substantial evidence that therapeutic abortion can be limited to hemizygous males.

Forty‐two at‐risk pregnancies from 21 European families and 1 Canadian family were monitored with 64Cu‐uptake into cultured amniotic fluid cells. In 10 pregnancies with a male karyotype an affected foetus was predicted on the basis of the copper studies. The pregnancies were terminated and the diagnosis was in each case confirmed by a markedly increased placenta copper content.

Fourteen male foetuses were predicted to be unaffected and none of them has developed signs of Menkes disease after birth. In 6 of these cases the diagnosis was checked in the newborn boy by placenta copper measurements, and they all had copper concentrations within normal limits.

Eighteen pregnancies with a female karyotype were also studied. 9 females could be identified as carriers on the basis of the tissue culture studies or raised placenta copper values.
Correct prenatal diagnosis of a hurler fetus where amniotic fluid cell cultures were of maternal origin
Authors: Mossman Jean , Patrick A. D. , Fensom A. H. , Tansley Linda R. , Benson P. F. , Der Kaloustian V. M. , Dudin Gertrud
Published: March 2007

Contamination of amniotic fluid cell cultures by maternal cells can be expected to lead to misdiagnosis of fetal genotype in 0·1 to 0·5/100 cultures, when assays are carried out directly on cultured cells. Chemical analysis of the cell‐free amniotic fluid supernatant may overcome this source of error and has the added advantages of speed and independence from amniotic cell culture failure. We describe a pregnancy at risk for Hurler's disease where amniotic cells cultured at amniocentesis had a female karyotype and an α‐iduronidase activity towards both phenyl and 4‐methylumbelliferyl substrates at the lower end of the normal range, suggesting a heterozygous fetus. An affected fetus was predicted, however, because of a high concentration of dermatan sulphate in the amniotic fluid. The discrepancy between these findings was shown to be due to maternal cell contamination of amniotic fluid cell cultures by the birth of a male infant with Hurler's disease.
Risk of amniocentesis and laboratory findings in a series of 1500 prenatal diagnoses
Authors: Verjaal Marianne , Leschot Nico J. , Treffers Pieter E.
Published: March 2007

The experiences with 1500 midtrimester prenatal diagnoses are reported. Abnormal findings of amniotic fluid investigations led to 43 therapeutic abortions. In ± 30 percent of the chromosome anomalies diagnosed, the significance of the effect on fetal development was inconclusive. The outcomes of all pregnancies except one are known. Fetal loss and perinatal mortality involved 69 cases, 23 (33 percent) of which occurred within three weeks after amniocentesis. In these 23 cases there appeared to be a relationship between the degree of experience of the gynaecologist and fetal loss: 3·7 percent when this experience was limited to a maximum of 10 punctures diminishing to 0·3 percent with an experience of more than 50 punctures. It is concluded that the risk of an abortion due to amniocentesis decreases as the gynaecologist becomes more experienced with the puncture technique.
Maple syrup urine disease: α‐Ketoisocaproate decarboxylation activity in different types of cultured amniotic fluid cells
Authors: Wendel U. , Gamm G. , Claussen U.
Published: March 2007

Three different cell types of primary amniotic fluid cultures (AF‐, F‐, and E‐cells according to Hoehn et al., 1974) were analysed for α‐ketoisocaproate decarboxylation activity by microtechnique. This reaction using L‐[1‐14C] leucine as initial substrate is applied for prenatal diagnosis of maple syrup urine disease. Activities of α‐ketoisocaproate decarboxylation did not differ significantly for the respective cell types and comparatively small numbers of cells from any primary amniotic fluid culture can be used for the biochemical assay irrespective of the prevailing cell type.
The characterization of hCG regulation in cultured human amniotic fluid cells
Authors: Laundon Caroline H. , Priest Jean H. , Priest Robert E.
Published: March 2007

The media from primary cultures and subcultures of second trimester human amniotic fluid (AF) cells were assayed by radioimmunoassay to quantitate production of human chorionic gonadotropin (hCG). Primary AF cultures produce more hCG per cell than do the corresponding subcultures. Sodium butyrate (2 mM) stimulates AF subcultures to produce 5‐13 times more hCG per cell or per mg of cellular protein than do untreated subcultures. This stimulatory effect of sodium butyrate is dose dependent between 0 and 5 mM.

Addition of sodium butyrate 24 hours after subculture, while stimulating production of hCG during the subsequent 3 days, also results in fewer cells and less protein per culture. This effect on cell growth is also dose‐dependent.

Previous investigators have proposed that the stimulation of hCG by sodium butyrate in other types of cell cultures is due to an effect of that agent on culture growth. Therefore, in these studies AF cells are allowed to grow to confluency before sodium butyrate was added. Production of hCG was stimulated by sodium butyrate about four‐fold during the next 5 days although no significant changes were observed either in number of cells or amount of cellular protein per culture. These results suggest that stimulation of hCG by sodium butyrate is not dependent on its effect on growth of the cultures.
Stimulation of human amniotic fluid cell proliferation and colony formation by cell plating on a naturally produced extracellular matrix
Authors: Vlodavsky I. , Voss R. , Yarkoni S. , Fuks Z.
Published: March 2007

Human amniotic fluid cells exhibit a higher cloning efficiency and rate of cell proliferation when maintained on dishes coated with a naturally produced extracellular matrix (ECM) in comparison with the regular tissue culture plastic. In 22 out of 31 amniotic fluid samples there was by plating the cells on ECM a 2–6 fold increase in number and size of colonies and in the cell density per colony as detected by actual staining and viewing of each colony. These effects yielded, in 21 of 41 additional samples, a reduction ranging from 2–8 days, in the culture time elapsing between amniocentesis and the first harvesting of cells for chromosomal analysis. An even greater effect was obtained with primary cells that failed to attach to plastic surfaces and stayed floating in the medium but did attach and proliferate when seeded on ECM. Cells that were left firmly attached to ECM after the first trypsinization and harvesting of cells for chromosomal analysis yielded colonies ready for second karyotyping in less than half the time required for cells maintained on plastic. Studies with secondary cultures of human amniotic fluid cells have demonstrated a 5–10 fold decrease in serum requirement of cells cultured on ECM as compared with plastic. Addition of fibroblast growth factor (FGF) to the cultures further potentiated the effects of ECM. The ECM induced stimulation of cell attachment and proliferation was not associated with any chromosomal anomalies, nor did it interfere with the handling procedure. ECM coated dishes may be useful to reduce the time interval between amniocentesis and diagnosis, in particular when the amniotic cells exhibit an exceedingly slow rate of proliferation on plastic or when large quantities of cells are required for enzymatic studies.
Prenatal diagnosis of morquio's disease type a (n‐acetylgalactosamine 6‐sulphate sulphatase deficiency)
Authors: Von Figura Kurt , Van De Kamp J. J. , Niermeijer Martinus F.
Published: March 2007

Prenatal monitoring of three pregnancies at risk of Morquio's disease type A by determination of N‐acetylgalactosamine 6‐sulphate sulphatase activity in cultured amniotic cells is reported. In one pregnancy prenatal diagnosis of one affected fetus was made. Enzyme determinations in tissues of the aborted fetus confirmed the prenatal diagnosis.
Prenatal diagnosis of intestinal obstruction in the third trimester using amniotic fluid bile acid analysis
Authors: Legge M. , Rippon P.
Published: March 2007

Total bile acid concentration in third trimester amniotic fluid was determined using an enzymatic technique and fluorometry. The technique was successfully applied to the prenatal diagnosis of intestinal obstruction in a 33‐week fetus from a pregnancy presenting with polyhydramnios.
Prenatal testing for inherited immune deficiencies by fetal blood sampling
Authors: Durandy A. , Oury C. , Griscelli C. , Dumez Y. , Oury J. F. , Henrion R.
Published: March 2007

We attempted to develop a prenatal diagnosis in fetuses at risk for immunodeficiency by fetal blood sampling performed under fetoscopy at 18–22 weeks of gestation. In order to obtain normal values, we first investigated thirty‐five control fetuses whose blood punctures were undertaken for the diagnosis of haemoglobinopathies. Surface markers and in vitro mitogen‐induced proliferation of the fetal lymphocytes were studied using micromethods. We then examined two fetuses at risk for two different types of severe combined immunodeficiency and established their immunological integrity, hence avoiding an unjustified termination of pregnancy. This immunological integrity was confirmed after birth.
Unexpected structural chromosome rearrangements in prenatal diagnosis
Authors: Boué J. , Girard S. , Thépot F. , Choiset A. , Boué A.
Published: March 2007

Among 5315 prenatal diagnoses performed for various indications (maternal age, neural tube defect, metabolic diseases, X‐linked diseases, pathologic pregnancies) 29 unexpected structural chromosome rearrangements were found in fetal cells.

Fourteen were de novo chromosome rearrangements, six unbalanced, and eight balanced. Fifteen were inherited and balanced rearrangements. This high frequency of structural anomalies is discussed.
Chemical and biochemical studies in fetuses affected with nieman‐pick disease type A
Authors: Schoenfeld Alex , Ovadia Jardena , Neri Alex , Abramovici Armand , Klibanski Chaya
Published: March 2007

Chemical and biochemical studies were performed on two unrelated fetuses affected with Niemann‐Pick disease type A, following abortion at about the 19th week of gestation. Abortion was performed as a consequence of previous findings, in amniotic fluid cell cultures, that sphingomyelinase activity was completely absent. Phospholipid analyses of various organs of the fetuses, spleen and liver were the organs mostly affected. Interestingly enough considerable accumulation of sphingomyelin was found in the placenta. The brain was the only organ in which sphingomyeiin storage could not be proved. In addition to sphingomyelin a slight accumulation of cholesterol was noticed. Deficiency of sphingomyelinase activity measured at pH 5·0 was the general characteristic of the affected tissues.

It is concluded that the accumulation of sphingomyelin in various organs throughout the body of fetuses affected with Niemann‐Pick disease is suggestive of the essential role of the enzyme sphingomyelinase and its biochemical maturation, even during the early stages of gestation.
Phenotypic analysis of fetal blood leucocytes: Potential for prenatal diagnosis of immunodeficiency disorders
Authors: Linch David C. , Beverley Peter C. L. , Levinsky Roland J. , Rodeck Charles H.
Published: March 2007

Recent technological advances allow the detection and quantitation of subsets of leucocytes using monoclonal antibodies. We have taken advantage of this to study the ontogeny of fetal blood leucocytes, using very small blood samples obtained at fetoscopy. By 14 weeks gestation T cells represent 35 per cent or more of fetal leucocytes and the distribution of the helper/inducer and suppressor/cytotoxic subsets is similar to that of adults. B lymphocytes before 161/2 weeks are low (4–20 per cent), but rise to a mean of 28 per cent in 17–26 week fetuses. Granulocytic cells, many of which are phenotypically immature, represent 18–34 per cent of total leucocytes. The methodology employed is very reliable and offers the opportunity for the prenatal diagnosis of some immunodeficiency disorders, since using the same reagents we have diagnosed children with severe combined immunodeficiency shortly after birth.
Prenatal ultrasound detection of humero‐radial synostosis in a case of antley‐bixler syndrome
Authors: Savoldelli G. , Schinzel A.
Published: March 2007

The Antley‐Bixler syndrome is characterized by multiple skeletal fusions including humero‐radial synostosis, anterior bowing of the femora, cardiac and renal malformations and a high incidence of early postnatal lethality. In the pregnancy of a mother who had previously given birth to a child with the Antley‐Bixler syndrome, prenatal ultrasound diagnosis was performed at 17 and 20 weeks. Fixed flexion of about 80° in both elbows was seen together with humero‐radial synostosis and bowing of the ulnae. The fetus performed jerky cranio‐caudal movements in its shoulders, but did not, during five hours of real‐time observation, move at all in the elbows. Mild anterior bowing of the femora was also observed. The pregnancy was terminated at 21 weeks, and radiological examination of the female fetus confirmed the above mentioned findings including complete bilateral humero‐radial synostosis. She also had cardiac and renal malformations. An ultrasound diagnosis of syndromes which have humero‐radial synostosis as one feature is possible. Immobility and flexion in the elbows during a long period is probably the essential diagnostic finding.