bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of nimodipine and dexamethasone on low‐level co2 laser‐induced release of 51chromium from canine 2c5 gliosarcoma cells
Authors: van Kooten David W. , Maciunas Robert J. , Carver Robert S. 
Published: March 2007

AbstractLow‐energy penumbral irradiation of surgical lasers may produce undesirable effects on surrounding tissues. This study used a 51Cr cell labeling technique to determine if gliosarcoma cells could be therapeutically protected prior to their exposure to low‐power laser irradiation. Canine 2C5 gliosarcoma cells with intra‐cellular 51Cr were treated with nimodipine and/or dexamethasone and then exposed to low‐power levels of CO2 laser. The 51Cr was released from the cells in a dose‐dependent fashion following exposure to laser energy. Correlative analysis of the data indicated that a strong direct relationship between laser fluence and 51Cr release did exist for controls and drug‐treated groups with coefficients of correlation r ≥ +0.90 and coefficients of determination r2 ≥ 0.82. However, comparison of the data from the drug‐treated and control groups found that there was no significant difference between them (P >.05). Therefore, no protective or detrimental effects were observed with the use of nimodipine and/or dexamethasone on the gliosarcoma cells as tested in this system. Further investigation is necessary in order to define the mechanisms by which low‐power level lasers affect these cells. These effects do not appear to be mediated through localization of mechanisms to the cell membranes or their constituent Ca2+channels. © 1994 Wiley‐Liss, Inc.
Pulsed Ho:YAG laser meniscectomy: Effect of pulsewidth on tissue penetration rate and lateral thermal damage
Authors: Vangsness C. Thomas , Watson Troy , Saadatmanesh Vahid , Moran Kevin 
Published: March 2007

AbstractBackground and Objective: Studies need to define the optimal parameters under which the holmium laser should operate for arthroscopic meniscectomy. This study was designed to analyze the effect of various Holmium wavelength pulsewidths on human meniscal tissue penetration rates and lateral thermal injury.Study Design/Materials and Methods: Using a pulsed Holmium: YAG laser at a wavelength of 2.1μm, the effect of various pulsewidths on tissue penetration rates as well as the degree of accompanying thermal damage in human meniscal tissue was evaluated in a specially designed jig. Holding the energy constant at 500 mJ per pulse, the pulsewidth was varied between 100 and 600 microseconds.Results: Fiber penetration of meniscal tissue was found to be fastest at a pulsewidth of 250 microseconds. As the pulsewidth was increased or decreased around this number, the observed penetration time decreased, although no statistical difference was found. The size of the hole created was inversely related to the penetration time. Microscopic examination revealed zones of lateral thermal effect extending 800 μm from the ablation site.Conclusion: No relationship between the pulsewidth and the lateral thermal effect could be found. © 1995 Wiley‐Liss, Inc.
Characteristics of Nd:YAG sculptured contact probes after prolonged laser application
Authors: Barroso Eduardo G. , Haklin Michael F. , Staren Edgar D. 
Published: March 2007

AbstractThis study analyzed the functional and structural characteristics of cone, hemisphere, and modified sculptured contact fibers (1,000 μm) after 1 hour of continuous Nd:YAG laser application. Continuous laser application was performed on live porcine tissue using 20 watts of power. The fiber's appearance under a microscope as well as the power output was recorded after 0, 5, 10, 20, 30, 45, and 60 minutes of continuous laser application. (N = 3 for each fiber). At time 0, all fibers transmitted from 49 to 56% of the initial 20 watts (W); power transmission decreased to less than 9% relative power transmission after 20 minutes and then plateaued. The fibers exhibited severe distortion and carbonization of the surface where laser had been applied with evidence of quartz melting and shattering after only 10 minutes. By 30 minutes of laser application, all three fibers were fractured and essentially indistinguishable from one another; moreover, the fibers exhibited similar power transmission, and cutting and coagulation activity, as determined by a panel of independent, double‐blinded surgeons. These data lead us to conclude that 1) Nd:YAG contact laser effects result from thermal heating of the fiber tip with subsequent tissue injury, 2) the unique structural configuration of the fiber's sculptured tip are lost after several minutes of laser application without appreciable change in functional integrity, and 3) fibers may be manually fractured allowing for multiple uses without significant sacrifice of power transmission or surgical utility. © 1995 Wiley‐Liss, Inc.
Fragmentation process of current laser lithotriptors
Authors: Rink Klaus , Delacrétaz Guy , Salathé René P. 
Published: March 2007

AbstractBackground and Objective: Flashlamp pumped dye (FPDL), Q‐switched Nd:YAG, and alexandrite lasers are the most clinically used laser lithotriptors. Although calculi are fragmented by laser induced mechanical stresses for all lithotriptors, different fragment sizes and fragmentation efficiencies have been reported. In this work the effect of the pulse duration and pulse shape on the fragmentation processes is studied.Material and Methods: Fragmentation processes are characterized on model stones and on sensing target fibers. Stone fragmentation and cavitation bubble generation are observed by video flash photography. Shock wave occurrence and strength are monitored with an hydrophone.Results: For the FPDL, stone fragmentation is induced by the collapse of the large cavitation bubble formed. For the Q‐switched Nd:YAG, fragmentation is already observed during the laser pulse, at the plasma onset, although further fragmentation can occur at the bubble collapse. For pulse durations corresponding to the alexandrite, an intermediate fragmentation regime is observed.Conclusion: For the first time the physical basis of the observed differences in the fragmentation efficiencies of current laser lithotriptors is described. For nanosecond durations the fragmentation processes are governed by plasma induced shock waves. On the contrary, for microsecond durations fragmentation is governed by cavitation. The high fragmentation efficiency of microsecond lasers is due to a high laser energy transfer into cavitation. © 1995 Wiley‐Liss, Inc.
Optical properties of human articular tissue as implication for a selective laser application in arthroscopic surgery
Authors: Raunest Juergen , Schwarzmaier Hans‐Joachim 
Published: March 2007

AbstractBackground and Objective: Optical density of normal and pathological hyaline cartilage, meniscus, and synovium is determined using native and laser‐irradiated tissue samples in order to examine potentials for a selective laser ablation.Study Design/Materials and Methods: One hundred forty‐four autopsy specimens were irradiated in a direct contact mode using a XeCl excimer laser (λ = 308 nm; 20 ns; 40 Hz; 40 ± 2.1 J/mm2; 800 μm fused silica fiber) and a continuous‐wave Nd:YAG laser (λ = 1,064 nm; 1 s; 124 ± 5.4 W/mm2; 600 μm fused silica fiber). Transmission spectra were obtained by microspectrophotometry in a spectral range from 250 to 770 nm.Results: In the ultraviolet spectrum analyzed, optical density (OD) is calculated to 0.81 ± 0.05 for native hyaline cartilage, to 1.0 ± 0.07 for meniscal tissue, and to 0.68 ± 0.04 for synovium. With increasing wavelength the OD steadily decreases reaching mean values of 0.06 ± 0.01, 0.13 ± 0.03, and 0.15 ± 0.04 at 750 nm. Compared to normal tissue degeneration of cartilage and meniscus lead to a significant increase in OD with a maximum relative OD of 4.39 and 1.26, respectively (P <.001 and P <.01). In synovitis the OD increases with a maximum ratio of 1.45:1 (P <.01). Following Nd:YAG laser exposition the OD of the coagulated zone exceeded the value of native tissue by a factor of 9.71 for cartilage, 4.71 for meniscus, and 3.04 for synovium (P <.001). Excimer irradiation leads to a 3.38‐fold increase in OD for cartilage, 2.23‐fold for meniscal tissue, and 1.6‐fold for synovium (P <.01).Conclusion: The results presented indicate that a preferential ablation of pathological tissue structures in articular surgery is possible by selecting laser systems with an appropriate spectral emission range. However, thermal laser tissue interaction may lead to severe alterations in optical properties reducing potentials of a preferential or selective laser application. © 1995 Wiley‐Liss, Inc.
Laparoscopic surgery of chronic hyperandrogenic anovulation
Authors: Kaaijk Eugenie M. , Beek Johan F. , van der Veen Fulco 
Published: March 2007

AbstractThe review describes briefly the clinical and endocrinological characteristics of chronic hyperandrogenic anovulation (CHA), as well as ovulation induction by hormone therapy (therapy of first choice) and by classical wedge resection. The main purpose of this study, however, is to compare different laparoscopic treatments of CHA, with emphasis on laser treatments by argon, CO2, Nd:YAG, and frequency‐doubled Nd:YAG laser. The overall results of laparoscopic treatments in hormone‐therapy–resistant patients with CHA are encouraging and the results are comparable. In the studies considered in this review, ovulation was induced for longer or shorter periods in 21 out of 31 patients (68%) after ovarian biopsy, in 57 out of 73 patients (78%) after electro‐surgery, and in 82 out of 118 patients (70%) after laser treatment. Subsequent conception occurred in 44%, 40%, and in 41% of the patients, respectively. Of interest is the fact that some hormone‐therapy–resistant patients become sensitive to Clomiphene after laparoscopic treatment, giving an overall percentage of ovulation and an overall pregnancy rate of 89% and 54%, respectively, for electrosurgery, and of 88% and 50%, respectively, for laser treatment. Unfortunately, adhesion formation, a serious complication of surgical treatment of the ovaries, is still a drawback using laparoscopic surgical techniques. © 1995 Wiley‐Liss, Inc.
Role of the alexandrite laser for removal of tattoos
Authors: Stafford Timothy J. , Lizek Robert , Tan Oon Tian 
Published: March 2007

AbstractBackground and Objective: The development of the Alexandrite laser for the removal of blue‐black tattoos is described.Study Design/Materials and Methods: The responses of an animal study, using professionally tattooed skin and a human study involving 22 (professional and nonprofessional) blue‐black tattoos, to the Alexandrite laser are reported.Results: Histopathologic evaluation of tattooed pig skin biopsies demonstrated the method of removal of dermal tattoo pigment. An average 11.6 treatments were required to remove completely the ten human blue‐black professional tattoos compared to an average of 10.3 treatments to reach the same endpoint in six subjects with nonprofessional tattoos.Conclusion: Of significance was the fact that unlike the Q‐switched Ruby and Nd: YAG lasers where punctate bleeding and tissue splattering have been reported to occur during laser tattoo removal, epidermal integrity was maintained during exposure of tattooed skin to the Q‐switched Alexandrite laser at therapeutic fluences used. © 1995 Wiley‐Liss, Inc.
Superior nerve anastomosis using a low‐output CO2 laser on fibrin membrane
Authors: Ochi Mitsuo , Osedo Masashi , Ikuta Yoshikazu 
Published: March 2007

AbstractBackground and Objective: To date, no procedure of laser‐aided nerve anastomosis has yet proved to be consistently superior to suture nerve repair. This study examines a new method for nerve repair using a low output CO2 laser and fibrin membrane to ascertain the efficacy of this method for nerve regeneration in comparison with the suture method.Study Design/Materials and Methods: Both sciatic nerves of 42 Wister rats were used. The left sciatic nerves were cut and reconnected using 70 mW of irradiation on fibrin membrane bridging the nerve stumps, whereas the right sciatic nerves were repaired with two stitches of epineuro‐fascicular sutures.Results: No deleterious effect of the irradiation on nerve regeneration was demonstrated at any time after surgery. The number of myelinated axons larger than 5 μm in diameter and the mean diameter of mylinated axons 8 weeks after surgery were significantly larger in the laser group than those in the suture group (P < 0.05).Conclusion: The results suggest this new method may be useful and effective for clinical nerve repair. © 1995 Wiley‐Liss, Inc.
Spot size reduction in coupling of laser to micromanipulator in laser microsurgery by fiberoptic link
Authors: Logunov Stephan L. , Lemberg Vladimir G. 
Published: March 2007

AbstractBackground and Objective: In coupling laser with micromanipulator through fiberoptics, the resulting diameter of the spot is limited by the laws of geometrical optics, because of the high numerical aperture (N.A.) of fiberoptic radiation. A new method for the reduction of spot size diameter is suggested.Study Design/Materials and Methods: The output of a 2 mW He‐Ne laser was couped via fiberoptic link, the fiberoptic output light collected by a single lens collimator and directed to the input of the micromanipulator.Results: The spot size can be considerably reduced by the introduction of an aperture which reduces the numerical aperture (N.A.) of the fiberoptic. The resulting reduction in total power has little effect on the power density.Conclusion: This approach to the collimator design permits reduction in spot size without any significant changes in power density, thus avoiding damage to the tissue and obtaining optimum performance from the micromanipulator. © 1995 Wiley‐Liss, Inc.
Transurethral Balloon Laser Prostatectomy in the Canine: Medium‐Term, Follow‐Up Results
Authors: Suzuki Takanori , Kurokawa Kohei , Suzuki Kazuhiro , Yamanaka Hidetoshi 
Published: March 2007

AbstractBackground and Objective: To demonstrate surgical complications in transurethral balloon laser prostatectomy by medium‐term, follow‐up observation.Study Design/Materials and Methods: Three dogs were treated with transurethral laser irradiation using 15 watts for 20 minutes at 60°C at a 5 mm depth of the prostate, one dog was for 5 minutes with same parameters, and one dog was with only laser balloon probe as a control. All animals were followed for 24 weeks.Results: A large cavity in the prostatic urethra was formed in laser‐treated animals 4 weeks later, whereas the cavity in the balloon‐treated animals was not shown. Cavity volume did not significantly change for 6 months, and there was no bladder neck stricture or urethral stenosis observed in any case. An increase in collagen fibers in the periurethral tissue was barely observed by Mallory staining.Conclusion: The risk of bladder neck stricture and urethral stenosis was estimated to be low for transurethral balloon laser prostatectomy. © 1995 Wiley‐Liss, Inc.
Transurethral Nd:YAG laser prostatectomy with a laterally firing fiber: Local effects on tissue associated with erectile dysfunction
Authors: Breza Jan , Aboseif Sherif , Zvara Peter , Bolton Damien , Tewari Ashutosh , Narayan Perinchery 
Published: March 2007

AbstractBackground and Objectives: Transurethral laser prostatectomy is anticipated to become a recognized alternative to conventional transurethral resection of the prostate. However, the effects of this procedure on the nerves of the pelvic plexus and erectile dysfunction remain unaddressed. The objective of this study was to evaluate the effects of laser energy on extent of prostatic damage as well as injury to periprostatic cavernosal nerves and erectile dysfunction in a canine model.Study Design/Materials and Methods: Six adult male mongrel dogs underwent transurethral laser prostatectomy at 30 (n = 3) and 40 (n = 3) watt power settings. Total laser energy delivered varied between 6,000 and 13,800 joules. Erectile function was evaluated by pelvic nerve stimulation at 2, 4, and 8 weeks. Animals were then sacrificed to assess histopathology of the prostate at each time point.Results: Histopathologic changes were noted in the prostate in a dose‐dependent manner and did not vary with different laser power settings. In dogs that received ˜10,000 J, substantial prostate ablation confined within the capsule was achieved in every prostate gland. Adequate erectile responses were noted in five of six animals; all received < 10,000 J. In one animal that received a total dose of 13,800 J, an erectile response was not obtained, and histology revealed both prostatic capsule perforation in close proximity to the cavernous nerves and thermal neural damage.Conclusions: We conclude that cavernous nerve damage may result from excessive doses of laser energy during transurethral laser treatment of the prostate gland. In canines, the upper limit for periprostatic injury is between 10 and 14,000 joules. © 1995 Wiley‐Liss, Inc.
First vaginal delivery at an older age: Does it carry an extra risk for the development of stress urinary incontinence?
Authors: Groutz Asnat , Helpman Limor , Gold Ronen , Pauzner David , Lessing Joseph B. , Gordon David 
Published: March 2007

AbstractAimsFirst delivery at an older age is not an uncommon event in modern obstetric practice. The present study was undertaken to compare the prevalence of postpartum stress urinary incontinence (SUI) according to maternal age and mode of delivery.MethodsFifty two consecutive elderly primiparae (mean age 40.0 ± 1.8) who underwent spontaneous vaginal delivery, 42 consecutive elderly primiparae (mean age 40.7 ± 3.6) who underwent elective cesarean section, and 92 consecutive young primiparae (mean age 26.2 ± 2.5) who underwent spontaneous vaginal delivery were interviewed 1–2 years postpartum about the symptom of SUI. Women who had SUI before pregnancy were not enrolled. Obstetric data were collected from computerized hospital records.ResultsThe prevalence of SUI 1–2 years after spontaneous vaginal delivery was significantly higher in elderly compared with younger primiparae (38.5% vs. 9.8%, respectively). Elderly primiparae who underwent elective cesarean section had a significantly lower prevalence of postpartum SUI than those delivered vaginally (16.7% vs. 38.5%, respectively). Further comparison of stress‐incontinent versus continent elderly primiparae failed to reveal significant demographic or obstetric differences, except for increased prevalence of SUI during pregnancy among incontinent patients (45% vs. 19%, respectively).ConclusionsFirst vaginal delivery at an older age carries an increased risk for postpartum SUI. Stress‐incontinent women also had higher prevalence of SUI during pregnancy. This finding implies that the pathophysiologic process of SUI begins during pregnancy, prior to active labor and delivery. Nonetheless, elective cesarean section in these women has a protective effect and lowers the risk of developing postpartum SUI. Neurourol. Urodynam. 26:779–782, 2007. © 2007 Wiley‐Liss, Inc.
Alphafetoprotein, cholinesterases and rapidly adhering cells in the prenatal diagnosis of neural tube defects
Authors: Seller Mary J. , Cole Kathleen J. , Merritt Bernadette L. 
Published: March 2007

AbstractAmniotic fluid cholinesterases tested on polyacrylamide gel and rapidly adhering cell analysis were compared in their efficiency at diagnosing fetal neural tube defects in three cases where the alphafetoprotein results were equivocal. While rapidly adhering cells were also equivocal, the cholinesterases consistently gave a clear indication of fetal abnormality.
Prenatal diagnosis of congenital enzymopenic methaemoglobinaemia with mental retardation due to generalized cytochrome b5 reductase deficiency: First report of two cases
Authors: Junien C. , Leroux A. , Lostanlen D. , Reghis A. , Boue J. , Nicolas H. , Boue A. , Kaplan J. C. 
Published: March 2007

AbstractPrenatal diagnosis of congenital enzymopenic methaemoglobinaemia (CEM) with mental retardation was performed in two fetuses at risk for generalized NADH‐cytochrome b5 reductase deficiency. In the first case the enzyme activity of cultured amniotic cells was in the heterozygous to normal range. The mother delivered a normal baby with normal enzyme activity in cord blood cells. In the second case, the amniotic cells were almost completely enzyme deficient. The pregnancy was terminated, and the diagnosis of homozygous NADH‐cytochrome b5 reductase deficiency was confirmed in cord blood cells, in several different tissues and in cultured fibroblasts from the aborted fetus.
The effect of the introduction of prenatal diagnosis on the reproductive history of women at increased risk from neural tube defects
Authors: Laurence K. M. , Morris Jenny 
Published: March 2007

AbstractThe reproductive history of 45 couples at increased risk for neural tube defect (NTD) who came for genetic counselling in 1970 and 1971 were compared with a similar number counselled in 1975 and 1976, when prenatal diagnostic tests were freely offered. They were subsequently interviewed in their homes and had their reproductive history recorded to the end of 1973 and 1978 respectively. Nearly all had a previous child with an NTD and none of the women were pregnant at the time of counselling.The effect of prenatal diagnosis was to speed somewhat the decision about further pregnancies, but the number of couples deciding on no further children and on having further pregnancies were almost identical in the two groups. The average number of pregnancies was 2·8 per family, with only 1·2 surviving children. The pregnancy outcomes are discussed as are the reasons for not attempting further pregnancies in both groups, which included very high risk of recurrence, a surviving spina bifida child, inability to accept the tests or its implications. Ninety per cent of the second group had tests. Their reactions to the tests were favourable but all complained of the waiting time between amniocentesis and obtaining the results. They all would have tests again in any future pregnancy. The reason for women not having prenatal diagnostic tests included inability to accept termination. It is concluded that couples in South Wales decide either to have no more children or to have further pregnancies regardless of tests. but tests speed a decision and enable the women to enjoy the pregnancy after obtaining the results, and that an NTD greatly reduces the number of children per family. A termination for an NTD is much more acceptable to most than an NTD at term. The reasons for this are discussed.
Detection and isolation of fetal cells from maternal blood using the flourescence‐activated cell sorter (FACS)
Authors: Iverson G. Michael , Bianchi Diana W. , Cann Howard M. , Herzenberg Leonard A. 
Published: March 2007

AbstractThe presence of fetal cells in the maternal circulation during pregnancy has been suggested by repeated observations of small numbers of cells containing Y chromatin or a Y chromosome in the blood of pregnant women. With the fluorescence‐activitated cell sorter (FACS), we have used antibodies to a paternal cell surface (HLA) antigen, not present in the mother, to select fetal cells from the lymphocyte fractions of a series of maternal blood samples, collected as early as 15 weeks of gestation. These sorted cells have been examined for a second paternal genetic marker, Y chromatin. Y chromatin‐containing cells were found among the sorted cells from prenatal maternal blood specimens in 8 pregnancies subsequently producing male infants whose lymphocytes reacted with the same antibodies to paternal antigen used for sorting with the FACS. In each of 17 pregnancies resulting in male infants who failed to inherit the antigen detected by the antibodies used for cell sorting, Y chromatin‐containing cells were not found prenatally. The use of two paternal genetic markers, a cell surface antigen and nuclear Y chromatin, to identify fetal cells in maternal blood permits us to conclude that these cells are present in the mother's circulation, as early as 15 weeks gestation. Further development of the techniques reported here could lead to widespread screening of maternal blood samples during pregnancy for detection of fetal genetic abnormalities.