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Sample records for holmium laser enucleation

  1. Laser Prostatectomy: Holmium Laser Enucleation and Photoselective Laser Vaporization of the Prostate

    PubMed Central

    Bostanci, Yakup; Kazzazi, Amir; Djavan, Bob

    2013-01-01

    Historically, transurethral resection of the prostate has been the gold standard for the treatment of benign prostatic hyperplasia (BPH). Laser technology has been used to treat BPH for > 15 years. Over the past decade, it has gained wide acceptance by experienced urologists. This review provides an evidence-based update on laser surgery for BPH with a focus on photoselective laser vaporization and holmium laser enucleation of the prostate surgeries and assesses the safety, efficacy, and durability of these techniques. PMID:23671400

  2. The Learning Curve for Holmium Laser Enucleation of the Prostate: A Single-Center Experience

    PubMed Central

    Bae, Jungbum; Oh, Seung-June

    2010-01-01

    Purpose Holmium laser enucleation of the prostate (HoLEP) is known to have a steep learning curve and, as a result, its clinical usage has limitations. The purpose of this study was to analyze the learning curve and early complications following the HoLEP procedure. Materials and Methods A retrospective analysis was performed on 161 patients who had undergone the HoLEP procedure for lower urinary tract symptoms suggestive of benign prostatic hyperplasia (BPH) from July 2008 to September 2009. The procedure was done by two surgeons. Perioperatively, enucleated tissue weight, enucleation time, morcellation time, enucleation ratio (enucleation weight/transitional zone volume), and enucleation efficiency (enucleated weight/enucleation time) were analyzed, and early complications were assessed. Results Mean enucleation time, morcellation time, and enucleation ratio were 61.3 min (range, 10-180 min), 12.3 min (range, 2-60 min), and 0.66 (range, 0.07-2.51), respectively. In terms of efficiency, enucleation efficiency was 0.32 g/min (range, 0.02-1.25 g/min) and morcellation efficiency was 1.73 g/min (range, 0.1-7.7 g/min). Concerning the learning curve, enucleation efficiency was stationary after 30 cases (p<0.001), morcellation efficiency reached a learning curve at 20 cases (p=0.032), and enucleation ratio had no learning curve in this study. There were several cases of surgery-related complications, including bladder mucosal injury by the morcellator (13%), capsular injury during enucleation (7%), and conversion to a conventional resectoscopy procedure (15%), which showed a reduction in incidence with time. Conclusions The learning curve of HoLEP is steep; however, it can be overcome gradually. Further study is necessary with respect to long-term postoperative follow-up. PMID:21031088

  3. Holmium laser enucleation of the prostate: a review of the clinical trial evidence

    PubMed Central

    2014-01-01

    Transurethral resection of the prostate (TURP) has remained the procedure of choice for the surgical treatment of bladder outflow obstruction for almost five decades, but holmium laser enucleation of the prostate (HoLEP) is now emerging as a challenger as the gold standard procedure. This review summarizes the evidence base for HoLEP, with particular reference to randomized, controlled (level 1) evidence. PMID:24688602

  4. Holmium laser enucleation of the prostate: a review of the clinical trial evidence.

    PubMed

    Cynk, Mark

    2014-04-01

    Transurethral resection of the prostate (TURP) has remained the procedure of choice for the surgical treatment of bladder outflow obstruction for almost five decades, but holmium laser enucleation of the prostate (HoLEP) is now emerging as a challenger as the gold standard procedure. This review summarizes the evidence base for HoLEP, with particular reference to randomized, controlled (level 1) evidence. PMID:24688602

  5. Holmium Laser Enucleation of the Prostate (HoLEP): A Technical Update

    PubMed Central

    Kuo, Ramsay L; Paterson, Ryan F; Kim, Samuel C; Siqueira Jr, Tibrio M; Elhilali, Mostafa M; Lingeman, James E

    2003-01-01

    Introduction Holmium laser enucleation of the prostate (HoLEP) combined with mechanical morcellation represents the latest refinement of holmium:YAG surgical treatment for benign prostatic hyperplasia (BPH). Utilizing this technique, even the largest of glands can be effectively treated with minimal morbidity. The learning curve remains an obstacle, preventing more widespread adoption of this procedure. This paper provides an outline of the HoLEP technique as is currently used at two centers in hopes of easing the initial learning curve. Technical considerations Detailed descriptions of the major steps of the HoLEP procedure are provided with attention to critical steps such as identification of the surgical capsule, median and lateral lobe enucleation, and morcellation of enucleated tissue. Conclusions HoLEP is a promising alternative for the surgical treatment of BPH which allows complete removal of intact lobes of the prostate. Obstruction is relieved immediately with superior hemostasis, no risk of TUR syndrome, and a minimal hospital stay. PMID:12818001

  6. Technical Aspects of Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia

    PubMed Central

    Kim, Myong; Lee, Hahn-Ey

    2013-01-01

    Holmium laser enucleation of the prostate (HoLEP) is a minimally invasive procedure and a size-independent treatment for benign prostatic hyperplasia with excellent long-term surgical outcome. HoLEP has become an alternative to conventional transurethral resection of the prostate or open prostatectomy owing to its efficacy and safety. Although HoLEP is known to have a steep learning curve, very few articles have addressed the technical aspects of HoLEP. Herein, we described detailed techniques and tips for HoLEP as performed at Seoul National University Hospital in a step-by-step manner with extensive review of the literature. PMID:24044089

  7. Holmium Laser Enucleation of the Prostate and Iatrogenic Arteriovenous Fistula Treated by Superselective Arterial Embolization

    PubMed Central

    Dutto, Lorenzo; Preziosi, Paolo; Spera, Enrico; Micali, Francesco; De Carolis, Andrea; Iorio, Beniamino

    2016-01-01

    Iatrogenic pelvic pseudoaneurysm with concomitant arteriovenous fistula has been described as a rare and challenging complication, which may occur during transurethral resection of the prostate. We provide the first report of this complication after holmium laser enucleation of the prostate for the treatment of benign prostatic hyperplasia. The attempt to control the bleeding by conversion to open surgery and placement of haemostatic stitches into the prostatic fossa failed. Angiography with superselective arterial embolization proved to be a modern, quick, safe, and efficient treatment of this uncommon complication.

  8. Holmium Laser Enucleation of the Prostate and Iatrogenic Arteriovenous Fistula Treated by Superselective Arterial Embolization.

    PubMed

    Asimakopoulos, Anastasios D; Dutto, Lorenzo; Preziosi, Paolo; Spera, Enrico; Micali, Francesco; De Carolis, Andrea; Iorio, Beniamino

    2016-01-01

    Iatrogenic pelvic pseudoaneurysm with concomitant arteriovenous fistula has been described as a rare and challenging complication, which may occur during transurethral resection of the prostate. We provide the first report of this complication after holmium laser enucleation of the prostate for the treatment of benign prostatic hyperplasia. The attempt to control the bleeding by conversion to open surgery and placement of haemostatic stitches into the prostatic fossa failed. Angiography with superselective arterial embolization proved to be a modern, quick, safe, and efficient treatment of this uncommon complication. PMID:27022498

  9. Acute abdominal compartment syndrome as a complication of Holmium laser enucleation of the prostate: a case report

    PubMed Central

    2014-01-01

    Background In 1996, Holmium laser enucleation of the prostate was introduced and has been shown to be safe and highly effective. Case presentation We report a case of a rare complication that resulted in intra-abdominal compartment syndrome with prolonged intubation and intensive care, involving an 74-year-old male after holmium laser enucleation of prostate, with a massive irrigant fluid leakage into the retroperitoneal space. The elevated abdominal pressure was reduced by forced diuresis. The tracheal tube was removed 18hours after the patients transfer to the ICU. The patient was discharged to home one week after the operation. Conclusion In rare cases when no obvious ruptures of the prostate capsule or the bladder occur during laser enucleation of prostate, knowledge regarding possible emersion of massive amounts of irrigant fluid into the retroperitoneal space leading to intra-abdominal compartment syndrome aids in the diagnosis and subsequent successful therapy of intra-abdominal hypertension. PMID:24910537

  10. Holmium Laser Enucleation of Prostate for Benign Prostatic Hyperplasia: Seoul National University Hospital Experience

    PubMed Central

    Bae, Jungbum; Choo, Minsoo; Park, Ji Hyun; Oh, Jin Kyu; Paick, Jae-Seung

    2011-01-01

    Purpose The objective of this study was to report the experience acquired at the Seoul National University Hospital with Holmium Laser Enucleation of Prostate (HoLEP), combined with mechanical morcellation for symptomatic benign prostatic hyperplasia (BPH). Methods A retrospective review was performed on the clinical data of 309 consecutive patients who underwent HoLEP at our institution between July 2008 and June 2010. All patients were evaluated preoperatively for prostate volume by transrectal ultrasound, maximum urinary flow rate (Qmax), International Prostate Symptoms Score (IPSS) and quality of life (QoL) score. Peri- and postoperative parameters were evaluated and patients were followed-up at 1-, 3-, 6-, and 12- months with the aforementioned investigations. Results The patients' mean age was 68.3 (6.5) years and mean prostate volume was 55.6 (23.6) mL. Mean enucleation time was 56.2 (25.1) minutes, mean morcellation time was 11.3 (9.5) minutes, and the mean resected weight of the prostate was 20.8 (16.9) g. The mean catheter indwelling period was 1.9 (1.7) days and mean hospital stay was 2.9 (1.5) days. Significant improvement was noted in Qmax, IPSS, and QoL at the 1-year follow-up compared with baseline (P<0.01). At 1 month 17.2% of patients complained of irritative urinary symptoms, which were typically self-limiting within 3 months. Transient stress incontinence was reported in 15.2% of patients. No patient experienced persistent obstructive symptoms that required reoperation. Conclusions Our study showed that HoLEP is a safe and effective therapeutic modality for BPH. PMID:21468284

  11. An Improved Morcellation Procedure for Holmium Laser Enucleation of the Prostate

    PubMed Central

    Chen, Qi; Chen, Yan-Bo; Zheng, Da-Chao; Cai, Zhi-Kang; Li, Wen-Ji; Zhou, Juan

    2012-01-01

    Abstract Purpose We modified the conventional morcellation procedure for holmium laser enucleation of the prostate (HoLEP), and its outcomes are presented in this article. Materials and Methods As 395 patients were included, the conventional morcellation procedure was performed in the first 100 cases (group 1, cases 1100), and an improved procedure was used in the last 100 cases (group 2, cases 296395). The improved morcellation process has three steps to execute. The morcellation time, collected tissue weight, morcellation rate, and associated complications were recorded. Results The tissue-resected weight was similar between group 1 (60.733.9?g) and group 2 (62.436.8?g). The mean morcellation time in group 1 was greater than that in group 2 (11.37.1 and 8.34.1 minutes, respectively), and the mean morcellation rate was better in group 2 than in group 1 (5.751.7?g/minutes in group 1 v 7.31.1?g/minutes in group 2). Complications, such as bladder injury, were similar in both groups. Conclusion The improved morcellation procedure described in this article can be used in various situations of suction and can be performed in a more fluent manner and with better efficiency. PMID:22788738

  12. Efficacy of Holmium Laser Enucleation of the Prostate Based on Patient Preoperative Characteristics

    PubMed Central

    Suh, Yoon Seok; Kim, Tae Heon; Sung, Hyun Hwan; Jeong, Jeongyun

    2015-01-01

    Purpose: To evaluate the efficacy of holmium laser enucleation of the prostate (HoLEP) in relation to prostate size and urodynamic parameters, including bladder outlet obstruction index (BOOI), presence of detrusor overactivity, and detrusor contractility, and to investigate factors predictive of HoLEP success. Methods: This retrospective analysis of prospective data included 174 consecutive patients treated with HoLEP at Samsung Medical Center from 2009 to 2013. Prostate-specific antigen, prostate size, urodynamic parameters, and International Prostate Symptom Score (IPSS)/quality of life (QoL) were evaluated preoperatively, while prostate-specific antigen, uroflowmetry/postvoid residual (PVR) urine, and IPSS were measured six months after HoLEP. Two definitions of treatment success were established based on the following three variables: IPSS, maximum flow rate (Qmax), and QoL index. Factors predictive of HoLEP success were identified using multiple logistic regression analysis. Results: IPSS/QoL, Qmax, and PVR improved significantly following HoLEP. Improvements in IPSS and PVR were more significant in the BOOI≥40 group compared to the BOOI<40 group, with overall success rates of 93.7% and 73.6%, respectively. Thus, the BOOI≥40 group had a significantly higher success rate, and BOOI≥40 was a significant predictor of HoLEP success based on the multivariate analyses. Conclusions: We found good surgical outcomes after HoLEP, and specifically patients with a higher BOOI had a greater chance of surgical success. PMID:26739183

  13. Holmium Laser Enucleation of the Prostate: Modified Morcellation Technique and Results

    PubMed Central

    Lee, Su Hyung; Choi, Jong In; Moon, Kyung Young; Na, Woong

    2012-01-01

    Purpose We developed an inverse technique for tissue morcellation by modifying the conventional upward technique and then examined its safety and efficiency. Materials and Methods From July 2008 to December 2010, a total of 389 consecutive patients treated with holmium laser enucleation of the prostate (HoLEP) were enrolled in this study. For tissue morcellation, we used an upward technique for an initial series of 84 patients and an inverse technique for a consecutive series of 305 patients. We compared efficiency and safety between the inverse technique and the upward technique. Results There were no significant differences in mean age or prostate volume between the two groups. The mean morcellation efficiency was higher in the inverse technique group. The incidence of severe bladder injury was significantly higher in the upward technique group. Regarding the site of bladder injury, 7 and 4 cases of bladder injury occurred in the bladder dome and posterior wall, respectively, in the upward technique group. In the inverse technique group, however, the site of bladder injury was limited to the trigone. We divided our clinical series of patients into the upward technique group and three inverse technique groups on the basis of the timing. The mean morcellation efficiency was significantly higher in all three inverse technique groups than in the upward technique group. However, there was no significant difference in mean morcellation efficiency between the three inverse technique groups. Conclusions In conclusion, the inverse technique might be a more effective, safer, and more excellent method of morcellation than the conventional upward technique. PMID:23185670

  14. Risk Factors for Transient Urinary Incontinence after Holmium Laser Enucleation of the Prostate

    PubMed Central

    Nam, Jong Kil; Kim, Hyeon Woo; Lee, Dong Hoon; Han, Ji-Yeon; Lee, Jeong Zoo

    2015-01-01

    Purpose To investigate the factors associated with the occurrence of and recovery from transient urinary incontinence (TUI) after holmium laser enucleation of the prostate (HoLEP). Materials and Methods From March 2009 to December 2012, 391 consecutive patients treated with HoLEP for benign prostatic hyperplasia were enrolled. Information regarding age, prostate volume, International Prostate Symptom Score, Overactive Bladder Symptom Score, peak urinary flow rate, postvoid residual urine, and operation time was collected. TUI was defined as a patient complaint of urine leakage, regardless of type. Logistic regression was used to investigate the factors associated with the occurrence of TUI, and the Kaplan-Meier test was used to analyze the TUI recovery period. Results TUI after HoLEP occurred in 65 patients (16.6%), 52 patients of whom (80.0%) showed recovery within three months. Stress and urge urinary incontinence and postvoid dribbling occurred in 16 patients (4.1%), 29 patients (7.4%), and 33 patients (8.4%), respectively. Age (odds ratio [OR]=3.494; 95% confidence interval [CI]=1.565~7.803; p=0.002) and total operation time (OR=3.849; 95% CI=1.613~9.185; p=0.002) were factors that significantly affected the occurrence of TUI. Conclusions TUI, defined as any type of urine leakage, occurred after HoLEP in some patients, most of whom recovered within three months. Stress urinary incontinence occurred in only 4% of patients after HoLEP. Age and total operation time were associated with the occurrence of postoperative TUI. PMID:26331125

  15. Clinical and Pathological Characteristics of Hard Nodules Resistant to Morcellation During Holmium Laser Enucleation of the Prostate

    PubMed Central

    Piao, Songzhe; Choo, Min Soo; Wang, Yue; Lee, Young Ju; Bae, Jungbum; Oh, Seung-June

    2015-01-01

    Purpose: To identify the clinical and pathological characteristics of hard nodules resistant to morcellation (HNRM) during holmium laser enucleation of the prostate (HoLEP) for benign prostatic hyperplasia (BPH). Methods: Between July 2008 and October 2011, 246 patients underwent HoLEP for symptomatic BPH. The first 30 patients were excluded from the analysis due to the learning curve of the procedure. The remaining patients were divided into HNRM (n=29) and non-HNRM groups (n=187), and comparative analysis of the clinical parameters of the two groups was performed. International prostate symptom score analysis and urodynamic studies were performed preoperatively. Histological analysis was performed after hematoxylin and eosin staining and Masson trichrome staining of the HNRM specimens. Results: Twenty-nine patients (13.4%) had HNRM. The patients in the HNRM group had significantly higher proportions of advanced age (?65 years, P=0.029), total prostate volume ?65 mL (P<0.001), transition zone volume ?35 mL (P<0.001), serum prostate-specific antigen levels ?10 ng/mL (P=0.007), and functional urethral length ?70 mm (P=0.009); larger enucleation weight (P<0.001); longer operation (P=0.001), enucleation (P=0.042), and morcellation times (P<0.001); and higher enucleation ratio (P=0.028) and enucleation efficacy (P=0.001). After adjusting for confounding factors, multivariate logistic regression analysis revealed that age ?65 years and total prostate volume ?65 mL were independent risk factors for HNRM. Pathological examination did not reveal any malignant cells, with mainly dense fibrous tissue found in the HNRM. Conclusions: HNRM can make morcellation cumbersome and time-consuming, and older patients with larger prostates have a higher incidence of HNRM. However, the histopathology of HNRM revealed mainly fibrotic tissue. PMID:26126438

  16. The Impact of Increased Bladder Blood Flow on Storage Symptoms after Holmium Laser Enucleation of the Prostate.

    PubMed

    Saito, Keisuke; Hisasue, Shin-ichi; Ide, Hisamitsu; Aoki, Hiroaki; Muto, Satoru; Yamaguchi, Raizo; Tsujimura, Akira; Horie, Shigeo

    2015-01-01

    In order to investigate how holmium laser enucleation of the prostate (HoLEP) improves urinary storage symptoms, we assessed blood flow in the urinary bladder mucosa of patients with benign prostatic hyperplasia (BPH) before and after laser surgery. Seventy-four consecutive patients with BPH (median age 69 years, range; 53-88) underwent HoLEP at our institution and are included in this study. We prospectively assessed the International Prostate Symptom Score (IPSS), IPSS-QOL Score, the Overactive Bladder Symptom Score (OABSS), uroflowmetry, and blood flow in the urinary bladder, before and after surgery. Blood flow in the bladder mucosa was measured using the OMEGA FLOW (OMEGAWAVE, Tokyo, Japan) laser Doppler flowmeter. The median volume of the enucleated adenomas was 45.0 g (range: 25.0 to 83.2). The median IPSS improved significantly from 20 (range: 6-35) to 3 (0-22) (p < 0.001; Wilcoxon signed-rank test), as did the storage symptoms score, which decreased from 13 (2-20) to 3 (1-8) (p < 0.001). Median bladder blood flow increased at the trigone from 9.57 0.83 ml/sec to 17.60 1.08 ml/sec. Multiple regression analysis for the improved storage symptom score eliminated all explanatory variables except increased bladder perfusion. The data suggest that HoLEP improves blood flow in the bladder mucosa, which independently leads to the improvement of storage symptoms. PMID:26090819

  17. The Impact of Increased Bladder Blood Flow on Storage Symptoms after Holmium Laser Enucleation of the Prostate

    PubMed Central

    Ide, Hisamitsu; Aoki, Hiroaki; Muto, Satoru; Yamaguchi, Raizo; Tsujimura, Akira; Horie, Shigeo

    2015-01-01

    In order to investigate how holmium laser enucleation of the prostate (HoLEP) improves urinary storage symptoms, we assessed blood flow in the urinary bladder mucosa of patients with benign prostatic hyperplasia (BPH) before and after laser surgery. Seventy-four consecutive patients with BPH (median age 69 years, range; 5388) underwent HoLEP at our institution and are included in this study. We prospectively assessed the International Prostate Symptom Score (IPSS), IPSS-QOL Score, the Overactive Bladder Symptom Score (OABSS), uroflowmetry, and blood flow in the urinary bladder, before and after surgery. Blood flow in the bladder mucosa was measured using the OMEGA FLOW (OMEGAWAVE, Tokyo, Japan) laser Doppler flowmeter. The median volume of the enucleated adenomas was 45.0 g (range: 25.0 to 83.2). The median IPSS improved significantly from 20 (range: 635) to 3 (022) (p<0.001; Wilcoxon signed-rank test), as did the storage symptoms score, which decreased from 13 (220) to 3 (18) (p<0.001). Median bladder blood flow increased at the trigone from 9.570.83 ml/sec to 17.601.08 ml/sec. Multiple regression analysis for the improved storage symptom score eliminated all explanatory variables except increased bladder perfusion. The data suggest that HoLEP improves blood flow in the bladder mucosa, which independently leads to the improvement of storage symptoms. PMID:26090819

  18. Transurethral Surgical Anatomy of the Arterial Bleeder in the Enucleated Capsular Plane of Enlarged Prostates During Holmium Laser Enucleation of the Prostate

    PubMed Central

    Choo, Min Soo; Lee, Hahn-Ey; Bae, Jungbum; Cho, Sung Yong

    2014-01-01

    Purpose To identify the endoscopic vascular anatomy of the prostate during Holmium laser enucleation of the prostate (HoLEP), and analyze the clinical risk factors associated with significant arterial bleeding. Methods We identified 107 consecutive patients with benign prostatic hyperplasia who underwent HoLEP between September 2009 and August 2010, performed by a single surgeon (S.J.O.). Two independent reviewers reviewed the surgery video database and completed a prespecified form. The location of bleeding arteries was marked at the level of the bladder neck, proximal prostate, distal prostate, and verumontanum. Arterial bleeding was classified into one of three grades according to bleeding severity (grades 2 and 3 indicate significant bleeding). Results The mean prostate volume was 65.131.5 mL, and the mean prostate-specific antigen (PSA) level was 3.693.58 ng/mL. During the HoLEP procedure, the most common locations of significant bleeders were the 2-5 and 7-10 o'clock positions in the proximal prostate. The average number of bleeding arteries was 12.17.9 per procedure, and 1.931.20 per 10 mL of prostate volume. Multivariate analysis revealed that prostate volume and serum PSA were significant parameters for estimating the number of bleeding vessels. Conclusions During the HoLEP procedure, the most common locations of significant bleeders were the 2-5 and 7-10 o'clock positions in the proximal prostate. Prostate volume was associated with the number of bleeders. A careful approach to the capsular plane of the proximal prostate facilitates early hemostasis during the HoLEP procedure, especially with larger adenomas. PMID:25279241

  19. Preoperative Factors Affecting Postoperative Early Quality of Life During the Learning Curve of Holmium Laser Enucleation of the Prostate

    PubMed Central

    Cho, Kang Jun; Kim, Hyo Sin; Koh, Jun Sung; Han, Seung Bum; Kim, Sang Hoon; Kim, Hyun Woo; Cho, Su Yeon

    2013-01-01

    Purpose The aim of this study was to investigate the preoperative factors related to early quality of life (QoL) in patients with benign prostatic hyperplasia after holmium laser enucleation of the prostate (HoLEP) during the surgeon's learning curve. Methods The medical records of 82 patients with a follow-up period of at least 3 months who were treated with HoLEP during the time of a surgeon's learning curve were analyzed retrospectively. We divided the patients into two groups on the basis of the QoL component of the International Prostate Symptom Score (IPSS) 3 months after HoLEP: the high QoL group (IPSS/QoL?3) and the low QoL group (IPSS/QoL?4). Preoperative factors in each group were compared, including prostate volume, prostate-specific antigen, history of acute urinary retention (AUR), urgency incontinence, IPSS, and urodynamic parameters. Detrusor underactivity was defined as a bladder contractility index less than 100 on urodynamic study. Results A total of 61 patients (74.3%) had a high QoL, whereas 21 (25.7%) had a low QoL. A history of AUR, detrusor pressure on maximal flow (PdetQmax), bladder outlet obstruction grade, bladder contractility index, and detrusor underactivity were associated with postoperative QoL in the univariate analysis. In the multivariate analysis, a history of AUR and PdetQmax were independent factors affecting postoperative QoL. Conclusions A history of AUR and bladder contractility affect early QoL, and preoperative urodynamic study plays an important role in the proper selection of patients during the HoLEP learning curve. PMID:23869273

  20. Holmium Laser Enucleation of the Prostate: Comparison of Immediate Postoperative Outcomes in Patients with and without Antithrombotic Therapy

    PubMed Central

    Bishop, Conrad V.; Liddell, Heath; Ischia, Joseph; Paul, Eldho; Appu, Sree; Frydenberg, Mark; Pham, Trung

    2013-01-01

    Objective To compare the immediate postoperative outcomes of patients with benign prostatic hyperplasia undergoing Holmium laser enucleation of the prostate (HOLEP) with and without full anticoagulation or antiplatelet therapy at the time of surgery. Materials and Methods A retrospective review was performed on a series of consecutive patients undergoing HOLEP at our institution by a single surgeon from February 2004 to September 2010. Demographic, surgical, pathological and outcome data were collected. Two cohorts were identified on the basis of antithrombotic therapy at the time of surgery. Patients who continued on aspirin, aspirin/dipyridamole, clopidogrel and warfarin throughout the surgery were included in the antithrombotic cohort. Univariate analysis was performed to determine differences in outcomes between the 2 cohorts. Results Total 125 consecutive patients underwent HOLEP with 52 patients on antithrombotic therapy at the time of surgery and 73 patients were not on antithrombotic therapy during surgery. Patients in the antithrombotic group were older (75.1 7.5 vs. 71.7 8.3 years; p = 0.02) and had a higher median ASA physical status (3 (3-3) vs. 2 (2-3), p < 0.0001). The mean operating time and median specimen volume were not significantly different between the 2 cohorts. The median length of stay (2 (1-3) vs. 1 (1-2) d, p = 0.014) was longer in the antithrombotic cohort. The transfusion rate (7.7 vs. 0%, p = 0.028) was predictably higher in the antithrombotic cohort. No patients required re-operation for bleeding. Conclusions The use of HOLEP in patients on antithrombotic therapy is safe despite the higher surgical risk profile of that particular patient population and the potential increased risk for significant bleeding. PMID:24917753

  1. Postoperative Infectious Complications in Our Early Experience With Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia

    PubMed Central

    Tanaka, Kazushi; Haraguchi, Takahiro; Yamamichi, Fukashi; Muramaki, Mototsugu; Miyake, Hideaki; Fujisawa, Masato

    2013-01-01

    Purpose The objective of this study was to retrospectively investigate postoperative infectious complications (PICs) in our early experience with holmium laser enucleation of the prostate (HoLEP) followed by mechanical morcellation for symptomatic benign prostatic hyperplasia. Materials and Methods A retrospective review was performed of the clinical data for 90 consecutive patients who underwent HoLEP at our institution between February 2008 and March 2011. All patients were evaluated for the emergence of PICs, including prophylactic antibiotic administration (PAA) and the influence of the kind or duration of PAA on PIC. The details of cases with PICs were also examined. Results The patients' mean age was 71 years (range, 50 to 95 years), and their mean prostate volume was 60 mL (range, 2 to 250 mL). There were 7 cases (7.78%) with PICs; in detail, 3 patients were diagnosed with prostatitis, 2 with pyelonephritis, and 2 with epididymitis. Three patients had positive urine cultures: 1 had Serratia marcescens/Proteus mirabilis, 1 had S. marcescens, and 1 had Klebsiella pneumonia; only one case had urological sepsis. Our statistical data showed no significant differences between 2 or fewer days and 3 or more days of PAA and PIC occurrence. There was also no significant effect on PIC occurrence of sulbactam/ampicillin compared with other antibiotics. Conclusions The results of this retrospective study showed that PIC occurrence did not depend on the duration or the kind of PAA. Further prospective study is necessary for the evaluation and establishment of prophylactic measures for PICs. PMID:23526729

  2. Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia: Effectiveness, Safety, and Overcoming of the Learning Curve

    PubMed Central

    Hwang, Jin Chul; Park, Sang Myung

    2010-01-01

    Purpose To examine the efficacy and safety of holmium laser enucleation of the prostate (HoLEP) for the surgical treatment of benign prostatic hyperplasia and to estimate the time to overcome the learning curve. Materials and Methods From May 2008 to October 2009, 164 consecutive patients treated with HoLEP were enrolled in this study. International Prostate Symptom Score (IPSS), peak urinary flow rate (Qmax), and postvoid residual urine (PVR) were documented preoperatively and at 6 weeks and 3, 6, 12, and 18 months postoperatively. The 164 study subjects were divided into 3 groups (group 1 the first 50 patients treated, group 2 the second 50, and group 3 the third 64), and perioperative data and complications were analyzed in these groups to determine the learning curve. In addition, the inverse and upward techniques were compared in terms of the effects and the stability of morcellation. Results The mean patient age was 69 years, and the average operation time was 62 minutes (range, 20-208 minutes). Mean prostate volume was 54.2 ml and mean resected tissue weight was 18.6 g. Postoperatively, IPSS and PVR decreased and Qmax increased significantly. Postoperative complications were transient incontinence (8.5%), urinary retention (4.3%), hematuria (3.0%), urinary tract infection (1.2%), and urethral stricture (0.6%), and intraoperative complications were minor capsular perforation (4%) and bladder injury (8%). Conclusions HoLEP was found to be effective and safe regardless of prostate size. We recommend that a systematic educational program be established to reduce the learning curve. PMID:20856646

  3. Relationship of Postoperative Recatheterization and Intraoperative Bladder Distention Volume in Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia

    PubMed Central

    Kim, Hyeon Jun; Lee, Han Yi; Song, Sang Hun

    2013-01-01

    Purpose The purpose of this study was to identify the risk factors for recatheterization after holmium laser enucleation of the prostate (HoLEP). Materials and Methods A total of 166 consecutive patients treated with HoLEP by a single surgeon from January 2010 to June 2011 were enrolled in this study. We collected data on preoperative and intraoperative parameters, including intraoperative bladder distention volume. The patients were divided into two groups. Group 1 included patients who voided successfully after removal of the catheter, and group 2 included patients who required recatheterization. Analysis and comparison of the perioperative parameters of both groups was performed for identification of risk factors for recatheterization. Results Recatheterization was required in 9 of 166 (5.4%) patients. No significant differences in age or preoperative parameters, including prostate-specific antigen, prostate volume, International Prostate Symptom Score, peak flow rate, postvoid residual urine, maximal bladder capacity, and Abrahams Griffiths number, were observed between the two groups. Of the intraoperative parameters, intraoperative bladder distention volume was significantly smaller in group 1 than in group 2 (700.65 mL vs. 897.78 mL, p<0.001). In the multivariate logistic regression analysis, after adjustment for other variables, intraoperative bladder distention volume was found to be a statistically significant risk factor for postoperative recatheterization (hazard ratio, 1.006; confidence interval, 1.002 to 1.010; p=0.002). Conclusions Nine of 166 (5.4%) patients failed to void after HoLEP and required catheterization. Intraoperative bladder distention volume was found to be a statistically significant risk factor for recatheterization in this patient group. PMID:23549294

  4. Holmium Laser Enucleation of the Prostate With Percutaneous Nephrostomy Into the Transplanted Kidney in Patient With Severe Benign Prostatic Hyperplasia With Vesicoureteral Reflux - A Case Report.

    PubMed

    Nohara, Takahiro; Matsuyama, Satoko; Shima, Takashi; Kawaguchi, Shohei; Seto, Chikashi

    2016-01-01

    A 66-year-old male, who had received renal transplantation 10years before, was admitted to our hospital with urinary retention. The prostate volume was 169.2ml. Furthermore, grade 5 vesicoureteral reflux (VUR) was shown in the cystography. Holmium laser enucleation of prostate (HoLEP) was performed, and percutaneous nephrostomy to the transplanted kidney was performed simultaneously to prevent from severe perioperative infection. After that, renal graft function improved and no urinary retention reoccurred, although surgical repair against VUR was necessary 10months after HoLEP. We conclude that surgical treatment for BPH after kidney transplantation should be strongly considered with care for infections. PMID:26793574

  5. Holmium Laser Enucleation of the Prostate With Percutaneous Nephrostomy Into the Transplanted Kidney in Patient With Severe Benign Prostatic Hyperplasia With Vesicoureteral Reflux A Case Report

    PubMed Central

    Nohara, Takahiro; Matsuyama, Satoko; Shima, Takashi; Kawaguchi, Shohei; Seto, Chikashi

    2015-01-01

    A 66-year-old male, who had received renal transplantation 10years before, was admitted to our hospital with urinary retention. The prostate volume was 169.2ml. Furthermore, grade 5 vesicoureteral reflux (VUR) was shown in the cystography. Holmium laser enucleation of prostate (HoLEP) was performed, and percutaneous nephrostomy to the transplanted kidney was performed simultaneously to prevent from severe perioperative infection. After that, renal graft function improved and no urinary retention reoccurred, although surgical repair against VUR was necessary 10months after HoLEP. We conclude that surgical treatment for BPH after kidney transplantation should be strongly considered with care for infections. PMID:26793574

  6. Towards optimizing prostate tissue retrieval following holmium laser enucleation of the prostate (HoLEP): Assessment of two morcellators and review of literature

    PubMed Central

    Elshal, Ahmed M.; Mekkawy, Ramy; Laymon, Mahmoud; El-Assmy, Ahmed; El-Nahas, Ahmed R.

    2015-01-01

    Introduction: We assess different approaches to retrieve the enucleated adenoma after transurethral enucleation of the prostate, particularly using the holmium laser. Methods: A retrospective review through our prospectively maintained database was performed looking for safety and efficacy of two morcellators. The enucleation phase of the holmium laser enucleation of the prostate (HoLEP) was classically performed followed by retrieval of the intravesical adenoma using either the Piranha (Wolf Inc., Knittlingen, Germany) or VersaCut (Lumenis) morcellator. A PubMed-MEDLINE search was conducted for all transurethral enucleation procedures and relevant data regarding methods of prostate tissue retrieval were extracted. Results: Strictly limiting the study to 3 reusable blades with each morcellator, we performed 67 and 55 consecutive procedures with Piranha and VersaCut, respectively. There was no significant difference between the two morcellators regarding perioperative complications, apart from 5 bladder mucosal injuries with the VersaCut (9%). Furthermore, there were similar retrieved tissue weight, mechanical problems-rate, catheter-time and hospital-stay in both morcellators. However, the Piranha morcellator needed significantly less morcellation-time, needed to use cold loop to remove non-morcellated pieces and to score the adenoma by laser for better bite of the adenoma, and had a higher median morcellation-rate 6.2 (rate: 2.812) g/min. Despite little reporting on morcellation, we had data on the tissue retrieval rate (2.6 to 6.5 g/min with Piranha and 1.9 to 11 g/min with VersaCut. Furthermore, bladder mucosal injury was reported in 1.4% and 0.7 to 5.7% with Piranha and VersaCut, respectively; bladder perforation with VersaCut was experienced in about 0.1 to 1.5% of patients. Our study is limited by its non-randomization. Conclusion: The Piranha morcellator was the most efficient and safe way to retrieve tissue after a transurethral enucleation of a prostate adenoma. PMID:26425224

  7. Holmium laser enucleation versus simple prostatectomy for treating large prostates: Results of a systematic review and meta-analysis

    PubMed Central

    Jones, Patrick; Alzweri, Laith; Rai, Bhavan Prasad; Somani, Bhaskar K.; Bates, Chris; Aboumarzouk, Omar M.

    2015-01-01

    Objective To compare and evaluate the safety and efficacy of holmium laser enucleation of the prostate (HoLEP) and simple prostatectomy for large prostate burdens, as discussion and debate continue about the optimal surgical intervention for this common pathology. Materials and methods A systematic search was conducted for studies comparing HoLEP with simple prostatectomy [open (OP), robot-assisted, laparoscopic] using a sensitive strategy and in accordance with Cochrane collaboration guidelines. Primary parameters of interest were objective measurements including maximum urinary flow rate (Qmax) and post-void residual urine volume (PVR), and subjective outcomes including International Prostate Symptom Score (IPSS) and quality of life (QoL). Secondary outcomes of interest included volume of tissue retrieved, catheterisation time, hospital stay, blood loss and serum sodium decrease. Data on baseline characteristics and complications were also collected. Where possible, comparable data were combined and meta-analysis was conducted. Results In all, 310 articles were identified and after screening abstracts (114) and full manuscripts (14), three randomised studies (263 patients) were included, which met our pre-defined inclusion criteria. All these compared HoLEP with OP. The mean transrectal ultrasonography (TRUS) volume was 113.9 mL in the HoLEP group and 119.4 mL in the OP group. There was no statistically significant difference in Qmax, PVR, IPSS and QoL at 12 and 24 months between the two interventions. OP was associated with a significantly shorter operative time (P = 0.01) and greater tissue retrieved (P < 0.001). However, with HoLEP there was significantly less blood loss (P < 0.001), patients had a shorter hospital stay (P = 0.03), and were catheterised for significantly fewer hours (P = 0.01). There were no significant differences in the total number of complications recorded amongst HoLEP and OP (P = 0.80). Conclusion The results of the meta-analysis have shown that HoLEP and OP possess similar overall efficacy profiles for both objective and subjective disease status outcome measures. This review shows these improvements persist to at least the 24 month follow-up point. Further randomised studies are warranted to fully determine the optimal surgical intervention for large prostate burdens. PMID:26966594

  8. Transurethral holmium laser enucleation of prostates (HoLEP) larger than 80 g

    NASA Astrophysics Data System (ADS)

    Kuntz, Rainer M.; Lehrich, Karin; Fayad, Amr

    2001-05-01

    In this prospective study, the efficiency of HoLEP inpatients with prostates larger than 80 grams was to be evaluated. 64 urodynamically obstructed patients with prostate glands of 103 (80-230) grams of weight underwent HoLEP (80 W, 2.0 J, 40 Hz, 550 nm bare laser fibers). The resected weight was 70 (50-200) grams, the resection time was 120.5 (83-170) min., the average resection weight was 0.7 gm/min. The postoperative catheter time was 1.3 (1-3) days. The postoperative hospital stay was 2.5 (1-7) days. HoLEP induced a significant, pronounced and immediate improvement of lower urinary tract symptoms and micturition. The symptom score decreased from 22.3 preoperatively to 5.7 one week and 2.8 one year postoperatively. The peak urinary flow rate of 4.3 ml/sec preoperatively increased to 22 ml/sec one week and 32 ml/sec one year postoperatively. The residual urine dropped from 267 ml preoperatively to 11.5 ml one week and 5.0 ml one year postoperatively. There was one incident of postoperative arterial bleeding, one patient developed urethral stricture and two patients needed a second HoLEP. HoLEP appeared to be a highly effective treatment for prostates larger than 80 grams, with excellent functional results, minor blood loss, low complication rate and very short catheter time and hospital stay.

  9. Efficacy and safety of holmium laser enucleation of the prostate for extremely large prostatic adenoma in patients with benign prostatic hyperplasia

    PubMed Central

    Kim, Myong; Piao, Songzhe; Lee, Hahn-Ey; Kim, Sung Han

    2015-01-01

    Purpose To evaluate the efficacy and safety of holmium laser enucleation of the prostate (HoLEP) for extremely large prostates. Materials and Methods Patients undergoing HoLEP between July 2008 and December 2013 from the Seoul National University Hospital Benign Prostatic Hyperplasia Database Registry were retrospectively analyzed. The patients were divided into three groups according to their total prostate volume (TPV): group A (TPV<100 mL), group B (100 mL?TPV<200 mL), and group C (TPV?200 mL); the clinical data of the three groups were compared. All patients were followed up 2 weeks, 3 months, and 6 months after surgery. Results A total of 502 patients (group A, 426; group B, 70; group C, 6) with a mean age of 69.0 (standard deviation, 7.3) years were included in our analysis. The mean prostate volume and prostate-specific antigen level were 68.736.9 mL and 4.154.24 ng/mL, respectively. The enucleation and morcellation times were longer in group C (p<0.001), and the enucleation efficacy was higher in this group (p<0.001, R2=0.399). Moreover, the mean postoperative catheterization and hospitalization periods were significantly longer in group C (p=0.004 and p=0.011, respectively). However, there were no significant differences between the groups in any other postoperative events, including recatheterization, reoperation, urinary tract infection, clot retention, and bladder neck contracture (p range, 0.516-0.913). One patient in group C experienced recurrence of the urethral stricture. Conclusions HoLEP in patients with an extremely large prostate can be performed efficiently and safely. PMID:25763126

  10. Application of the Modified Clavien Classification System to 402 Cases of Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia

    PubMed Central

    Choi, Jong In; Moon, Kyung Young; Yoon, Jong Hyun; Na, Woong

    2014-01-01

    Purpose We attempted to evaluate the perioperative complications of holmium laser enucleation of the prostate (HoLEP) for benign prostatic hyperplasia by using the modified Clavien classification system (MCCS). Materials and Methods Targeting 402 patients who underwent HoLEP for benign prostatic hyperplasia performed by a single surgeon between July 2008 and January 2011, we investigated complications that occurred during and within 1 month after surgery and classified them into grade I to grade V on the basis of the MCCS. If two or more complications occurred in one patient, each complication was graded and counted. Results The mean age, prostate volume, operation time, hospital stay, and average follow-up period of 402 patients who underwent HoLEP were 68.8 years (range, 52-84 years), 53.2 g (range, 23-228 g), 58.2 minutes (range, 20-230 minutes), 4.5 days (range, 2-7 days), and 9 months (range, 4-27 months), respectively; 78 complications occurred in 71 of the patients (morbidity rate, 17.6%). In MCCS grade I, complications occurred in 54 cases (69.2%); in grade II, complications occurred in 19 cases (24.3%); in grade III, complications occurred in 4 cases (5.1%); and in grade IV, 1 patient required intensive care unit care because of cerebral infarction (1.2%). There were no grade V complications. Conclusions The HoLEP-based MCCS complications classification was performed very quickly. However, MCCS, when compared with other measures of endoscopic prostate surgery experiences, including HoLEP, exposed the lack of accuracy in low grade classification and the inability to include late complications. PMID:24648872

  11. Holmium quasi-two level laser

    NASA Astrophysics Data System (ADS)

    Bowman, Steven R.; Feldman, Barry J.

    1994-02-01

    The directly pumped holmium (Ho) quasi-two level laser of the invention comprises a directly pumped holmium laser having a host material doped with an amount of holmium ions sufficient to produce an output laser emission at a wavelength of about 2.1 micrometer when the holmium laser is pumped by a pump beam at a wavelength of about 2 Jim and a pumping laser for producing the pump beam. In an exemplary embodiment, the pumping laser comprises a Cr,Tm:YAG laser pumped by a flashlamp.

  12. Novel endourologic applications for holmium laser.

    PubMed

    Lane, Brian R; Singh, Dinesh; Meraney, Anoop; Streem, Stevan B

    2005-05-01

    The holmium laser is used routinely during endoscopic procedures to treat stones, strictures, and tumors of the urinary tract. We report two successful novel endourologic applications of a holmium laser: division and removal of a synthetic urethral sling mesh in one patient and fragmentation of a tempered stainless steel surgical needle in another. PMID:15882739

  13. Holmium laser for treatment of benign prostatic hyperplasia: old wine in a new bottle?

    NASA Astrophysics Data System (ADS)

    Nelius, Thomas; de Riese, Werner T. W.

    2003-06-01

    Urinary tract symptoms related to benign prostatic hyperplasia affect 70% of men older than 70 years. Complications are common problems and a significant cause of morbidity in this population, placing a considerable burden on health services. In the early 1990s laser treatment of benign prostatic hyperplasia became widely used after the introduction of the side-firing neodym: YAG laser. However, because of technical limitations and inferior results compared to classical transurethral resection of the prostate many Urologists became desinterested in this device. With the introduction of the holmium: YAG laser a new laser generation became available for use in Urology. Beside several other applications the holmium: YAG laser can be used for incision, ablation, resection, and more recently enucleation of the prostate. In this paper we reviewed the current literature regarding the holmium: YAG laser resection and enucleation of the prostate compared to transurethral resection of the prostate and open prostatectomy. The holmium: YAG laser technique is an effective and durable surgical alternative to standard transurethral resection of the prostate. Interestingly, enucleation of the prostate with this device seems to be a safe and effective procedure for large prostatic adenomas, it may become an attractive alternative to open prostatectomy.

  14. Semiconductor disk laser-pumped subpicosecond holmium fibre laser

    SciTech Connect

    Chamorovskiy, A Yu; Marakulin, A V; Leinonen, T; Kurkov, Andrei S; Okhotnikov, Oleg G

    2012-01-31

    The first passively mode-locked holmium fibre laser has been demonstrated, with a semiconductor saturable absorber mirror (SESAM) as a mode locker. Semiconductor disk lasers have been used for the first time to pump holmium fibre lasers. We obtained 830-fs pulses at a repetition rate of 34 MHz with an average output power of 6.6 mW.

  15. [A Case of Holmium: YAG Laser Resection of Superficial Bladder Tumor (HoLRBT)].

    PubMed

    Sugita, Yoshiko; Shitara, Toshiya; Hirayama, Takahiro; Fujita, Tetsuo; Yoshida, Kazunari; Kubo, Seiichi; Iwamura, Masatsugu

    2015-10-01

    We present a case of holmium : YAG laser resection of superficial bladder tumor (HoLRBT). A 73-year-old male was referred to our hospital with elevated prostatic specific antigen. Due to difficulty of urination, holmium : YAG laser enucleation of the prostate was performed under the diagnosis of benign prostatic hyperplasia. During the surgery, superficial bladder tumor was incidentally identified, and HoLRBT was performed. After the operation, histopathological examination revealed urothelial carcinoma, G2 ? G1, pTa. The patient has been subsequently followed up for 9 months, and there areno evidence of recurrence. Changing the holmium : YAG laser energy setting can potentially be effective and safe to approach a superficial bladder tumor. PMID:26563623

  16. Urological applications of the holmium laser

    NASA Astrophysics Data System (ADS)

    Beaghler, Marc A.; Poon, Michael W.; Ruckle, Herbert C.; Stewart, Steven C.; Weil, Dane

    1998-07-01

    While the role of endoscopy was initially diagnostic, the advent of improved endoscopes and working instruments have increased its therapeutic applications. One of the most recent advances is the holmium laser. It has a broad range of urological applications due to its ability to fragment all urinary calculi and its soft tissue effects. This laser is based on laser energy delivered in a pulsatile fashion at 2100 nm. The purpose of this study is to report our experience with the holmium laser. A retrospective study of patients undergoing endourological procedures with the holmium laser was performed. One hundred and forty patients underwent 157 procedures. The holmium laser was used for the treatment of urinary calculi in 122 patients. Stone location included 61 renal, 64 ureteral, and 17 bladder stones. Renal stone burden was 17 mm (range 3-50), ureteral stone size averaged 10 mm (range 3 - 35), and mean bladder stone size was 31 mm (range 10 - 60). Other uses included treatment of transitional cell carcinoma of the renal pelvis, ureter, and bladder, incision of ureteral strictures, ureterocele, and prostate, and ablation of renal hemangiomas. Intraoperative and post operative complications were noted. Follow-up for calculi consisted of a plain film of the abdomen at one week and an ultrasound or intravenous pyelogram at six to eight weeks post procedure. No ureteral perforations or strictures occurred. The Holmium laser was capable of fragmenting all urinary calculi in this study. No complications were directly attributable to the Holmium laser. In our initial experience, the Holmium laser is safe and effective in the treatment of urinary pathology. It is the most effective lithotrite available and is able to incise and coagulate soft tissue as well. This combination allows the urologist to treat a variety of urinary pathology using a single modality. Its main limitation is the ability to access lower pole lesions in the upper urinary tract due to the fiber's stiffness. Use of laser fibers larger than 200 microns occasionally limit deflection into a lower pole or dependent calyx.

  17. Fluoride and Oxide Holmium Doped Lasers

    NASA Astrophysics Data System (ADS)

    Kalisky, Yehoshua

    1989-12-01

    Laser holmium belongs to a family of rare earth doped ions emitting in the near or mid-IR spectral range. Its 2.1 ?m laser emission has potential applications in many fields as will be discussed below. In this review we will concentrate on the following topics: A. General characteristics of Ho3+ laser and hosts. B. Significant milestones in holmium laser development. C. Mechanism of basic processes. D. Engineering considerations E. Applications F. Trends and future. A. General Characteristics The main characteristics of holmium laser are as follows: 1-A. Its emission wavelength originates from the 517-->518 transition (?2.1 ?m) 2-A. The main laser hosts used are: oxide crystals such as YAG (Y3Al5O12), YAlO3 or fluorides such as YLF (YLiF4) or HoBaYb28. 3-A. Energy sensitizers such as Cr3+, Tm3+, Er3+ are used in order to increase the laser efficiency and to better utilize the lamp emission spectrum. 4-A. Holmium laser needs liquid nitrogen cooling for efficient operation. At ambient temperature it behaves as a quasi three-level system with high lasing threshold and low slope efficiency. 5-A. The laser can be operated both in CW or pulsed modes. 6-A. It has high gain cross section and a long lifetime of 5I7 level which results in an efficient Q-switched operation. 7-A. Applications: Medical Free space communication Eye-safe range finders or Target illuminators Remote sensing Tunable operational amplifier The most popular hosts for holmium laser are the aPHo:YAG (erbium-thulium-sensitized Ho:YAG) and aPHo:YLF. Tables 1 and 2 summarize the mechanical and optical properties of YLF, YAG and GSGG (gadolinium scandium galium garnet), respectively. The mechanical and thermal properties of YAG are better than those of GSGG and superior relative to YLF - see Table 1. From Table 2 it is inferred that YLF has a negative derivative of its refraction index with temperature, implying that YLF may show a lower thermal lensing effect than YAG in spite of its lower thermal conductivity. YLF does not exhibit uv induced damage (solarization) as is the case in YAG, and has lower multiphonon rates.

  18. Holmium fibre laser with record quantum efficiency

    SciTech Connect

    Kurkov, Andrei S; Sholokhov, E M; Tsvetkov, V B; Marakulin, A V; Minashina, L A; Medvedkov, O I; Kosolapov, A F

    2011-06-30

    We report holmium-doped fibre lasers with a Ho{sup 3+} concentration of 1.6 x 10{sup 19} cm{sup -3} and lasing wavelengths of 2.02, 2.05, 2.07 and 2.1 {mu}m at a pump wavelength of 1.15 {mu}m. The slope efficiency of the lasers has been measured. The maximum efficiency, 0.455, has been obtained at a lasing wavelength of 2.05 {mu}m. The laser efficiency is influenced by both the optical loss in the wing of a vibrational absorption band of silica and active-ion clustering. (lasers)

  19. Perspectives of holmium laser resection of the prostate: cutting effects with the holmium:YAG laser

    NASA Astrophysics Data System (ADS)

    Eichenauer, Rolf H.; Droege, Gerit; Brinkmann, Ralf; Neuss, Malte; Gafumbegete, Evariste; Jocham, Dieter

    1998-07-01

    Laser prostatectomy shows an improvement in peak urinary flow rates, in post-void residual urine volumes and also a symptomatic improvement when compared to the transurethral resection of the prostate (TUR-P). Time to achieve symptomatic improvement is delayed with many established laser procedures compared to standard resection. However, this disadvantage can be solved with a new resection technique using a pulsed holmium laser. Nevertheless, this advanced technique shows a few problems in a first clinical trial. Besides this clinical study, in vitro experiments were carried out in order to determine the optimal irradiation parameters with respect to resection rate, incision/ablation quality and handling. Prostate tissue of radical prostatectomies and chicken breast as model were irradiated with a pulsed holmium-laser in vitro with different laser parameters using a bare fiber in contact to tissue. The incision quality (depths and coagulation/vaporization effects) was analyzed with regard to pulse energy (speed of incision, angle of incision) and fiber diameter. Fast flash photography was performed to analyze thermo-mechanical side-effects. Fast flash photography reveals cavitation bubble up to 7 mm length in water and dissections in tissue. The ablation rate increases proportional to the laser pulse energy. The Holmium Laser Resection of the Prostate (HOLRP) in humans with available instrumentation right now shows equieffective results compared to the transurethral resection, no need for transfusion, no transurethral resection syndrome, short time for catheterization. Further technical approvement may significantly improve holmium laser prostate resection. We present a new application system for the laser resection.

  20. Percutaneous laser disc decompression with the holmium: YAG laser.

    PubMed

    Casper, G D; Hartman, V L; Mullins, L L

    1995-06-01

    This article discusses the evolution of the percutaneous laser disc decompression (PLDD) method using a holmium:YAG laser. Advantages of using this wavelength and several techniques for its use in PLDD are reviewed. The article also discusses the current devices and delivery systems available for this application. PMID:10150646

  1. New application system for the holmium laser resection of the prostate

    NASA Astrophysics Data System (ADS)

    Eichenauer, Rolf H.; Doehn, Christian; Droege, Gerit; Brinkmann, Ralf; Salamon, Manfred; Jocham, Dieter

    1999-06-01

    The clinical outcome of the holmium laser resection of the prostate (HoLRP) shows similar results when compared to the transurethral resection of the prostate (TURP). Our efforts had ben to solve certain problems in the clinical application, e.g. the angle fiber/tissue in the apex area of the prostate and the movements of the shaft during the resection. The authors present a new application system for the laser resection and review their own experience in the development and clinical application system for the laser resection and review their own experience in the development and clinical application of Holmium:YAG laser technology for prostatectomy. Between 3/97 and 12/98, 79 patients were treated with the holmium laser resection of the prostate. The laser resections with the specially designed laser-resectoscope were performed from 5/98-12/98 (n-28 patients). With the new resectoscope a proper instrumentation became available. A ceramic tip mounted lever provided a deflection at an angle of 20 of the fiber without any damage of the applicator during the laser application. The manipulation of the fiber within the shaft in all three directions makes an enucleation of the prostate possible. The mean operating time was 63 minutes. There were no acute perioperative complications. The mean postoperative AUA symptom score was 9.1 compared to 22.5 preoperatively. The mean postoperative peak flow rate was 19.1 ml/s compared to 7 ml/s preoperatively. The new technical device improves holmium laser prostate resection and a combination of techniques provides an effective method with minimal complications and morbidity.

  2. Holmium:YAG laser stapedotomy: preliminary evaluation

    NASA Astrophysics Data System (ADS)

    Stubig, Ingrid M.; Reder, Paul A.; Facer, G. W.; Rylander, Henry G.; Welch, Ashley J.

    1993-07-01

    This study investigated the use of a pulsed Holmium:YAG ((lambda) equals 2.09 micrometers ) laser- fiber microsurgical system for laser stapedotomy. This system ablates human stapes bones effectively with minimal thermal damage. The study was designed to determine the effectiveness of the Ho:YAG laser (Schwartz Electro Optics, Inc., Orlando, FL) for stapedotomy and to evaluate temperature changes within the cochlea during the ablation process. Human cadaveric temporal bones were obtained and the stapes portion of the ossicular chain was removed. A 200 micrometers diameter low OH quartz fiber was used to irradiate these stapes bones in an air environment. The laser was pulsed at 2 Hz, 250 microsecond(s) ec pulse width and an irradiance range of 100 - 240 J/cm2 was used to ablate holes in the stapes footplate. The resultant stapedotomies created had smooth 300 micrometers diameter holes with a minimum of circumferential charring. Animal studies in-vivo were carried out in chinchillas to determine the caloric spread within the cochlea. A 0.075 mm Type T thermocouple was placed in the round window. Average temperature change during irradiation of the stapes footplate recorded in the round window was 3.6 degree(s)C. The data suggest that stapedotomy using the Ho:YAG laser can result in a controlled ablation of the stapes footplate with minimal thermal damage to the surrounding stapes. Optical coupling using fiberoptic silica fibers is an ideal method for delivering laser energy to the stapes during stapedotomy.

  3. Spectral performance of monolithic holmium and thulium lasers

    NASA Technical Reports Server (NTRS)

    Storm, Mark E.

    1991-01-01

    Fabry-Perot resonators have been used to demonstrate single-mode lasing of holmium and neodymium YAG. The previous demonstration in the holmium laser required TE cooling the crystal to -15 C in order to achieve threshold. The present study extends that result, demonstrating +25 C operation in a 1-mm thick plano/plano resonator. The experimental configuration of lasing both the holmium and thulium lasers used a 500-mW diode laser which was collimated, circularized, and focused into a beam radius of 60 microns. The single-frequency lasing spectrum of the holmium laser is shown. By adjusting the mirror reflectivity, the ability to control the laser's wavelength is demonstrated. This laser operated with 11 mW of optical power, a 57-percent slope efficiency, and 120-mW threshold vs absorbed diode power laser for the 60-micron beam radius. The thulium laser operated very efficiently at room temperature, but on seven longitudinal modes. The Tm:TAG laser exhibits typical characteristics of spatial hole burning not seen in the Ho:Tm:YAG for flat/flat resonators.

  4. Holmium:YAG laser coronary angioplasty in acute myocardial infarction

    NASA Astrophysics Data System (ADS)

    Topaz, On; Luxenberg, Michael; Schumacher, Audrey

    1994-07-01

    Patients who sustain complicated acute myocardial infarction in whom thrombolytic agents either fail or are contraindicated often need mechanical revascularization other than PTCA. In 24 patients with acute infarction complicated by continuous chest pain and ischemia who either received lytics or with contraindication to lytics, a holmium:YAG laser (Eclipse Surgical Technologies, Palo Alto, CA) was utilized for thrombolysis and plaque ablation. Clinical success was achieved in 23/24 patients, with 23 patients (94%) surviving the acute infarction. Holmium:YAG laser is very effective and safe in thrombolysis and revascularization in this complicated clinical setting.

  5. Intracorporeal lithotripsy with the holmium:YAG laser

    NASA Astrophysics Data System (ADS)

    Denstedt, John D.; Razvi, Hassan A.; Chun, Samuel S.; Sales, Jack L.

    1995-05-01

    A variety of devices are currently available for intracorporeal stone fragmentation. Recently a new wavelength of laser, the Holmium:YAG, has demonstrated a variety of potential urologic applications including ablation of soft tissue lesions as well as stone fragmentation. This laser has a wavelength of 2100 nm and operates in a pulsed mode. Energy is delivered through a 400 um quartz end-firing fiber. In this presentation we review our clinical experience with the Holmium:YAG laser for the treatment of renal and ureteral calculi. Over a 23 month period, 63 patients underwent 67 procedures. Seven procedures consisted of percutaneous nephrolithotripsy for large or staghorn renal calculi. Sixty procedures were performed for ureteral stones. Procedures for proximal ureteral stones (6) employed a retrograde approach using flexible ureteroscopes (8.5 or 9.8). Stones in the mid ureter (12) and distal ureter (42) were approached transurethrally using a 6.9 rigid ureteroscope. Complete stone fragmentation without the need for additional procedures was achieved in 82% of cases. Treatment failures included 1 stone migration into the renal pelvis during laser activation, 6 patients who had incomplete fragmentation and 3 patients in which laser malfunction precluded complete fragmentation. Stone analysis available in 23 patients revealed calcium oxalate monohydrate (15), calcium oxalate dihydrate (2), cystine (2), uric acid (3) and calcium phosphate (1). A single complication of ureteral perforation occurred when the laser was fired without direct visual guidance. Radiographic follow-up at an average of 16 weeks is available in 22 patients and has identified 2 patients with ureteral strictures that are not believed to be related to laser lithotripsy. In summary, we have found the Holmium:YAG laser to be a reliable and versatile device for intracorporeal lithotripsy. Its safety and efficacy make it a suitable alternative for performing intracorporeal lithotripsy of urinary calculi.

  6. Holmium:YAG laser angioplasty: treatment of acute myocardial infarction

    NASA Astrophysics Data System (ADS)

    Topaz, On

    1993-06-01

    We report our clinical experience with a group of 14 patients who presented with acute myocardial infarction. A holmium:YAG laser was applied to the infarct-related artery. This laser emits 250 - 600 mJ per pulse, with a pulse length of 250 microseconds and repetition rate of 5 Hz. Potential benefits of acute thrombolysis by lasers include the absence of systemic lytic state; a shortened thrombus clearing time relative to using thrombolytics; safe removal of the intracoronary thrombus and facilitation of adjunct balloon angioplasty. Potential clinical difficulties include targeting the obstructive clot and plaque, creation of debris and distal emboli and laser-tissue damage. It is conceivable that holmium:YAG laser can be a successful thrombolytic device as its wave length (2.1 microns) coincides with strong water absorption peaks. Since it is common to find an atherosclerotic plaque located under or distal to the thrombotic occlusion, this laser can also be applied for plaque ablation, and the patient presenting with acute myocardial infarction can clearly benefit from the combined function of this laser system.

  7. Dynamics of pulsed holmium:YAG laser photocoagulation of albumen

    NASA Astrophysics Data System (ADS)

    Pfefer, T. Joshua; Foong Chan, Kin; Hammer, Daniel X.; Welch, A. J.

    2000-05-01

    The pulsed holmium:YAG laser (? = 2.12 m, ?p = 250 s) has been investigated as a method for inducing localized coagulation for medical procedures, yet the dynamics of this process are not well understood. In this study, photocoagulation of albumen (egg white) was analysed experimentally and results compared with optical-thermal simulations to investigate a rate process approach to thermal damage and the role of heat conduction and dynamic changes in absorption. The coagulation threshold was determined using probit analysis, and coagulum dynamics were documented with fast flash photography. The nonlinear computational model, which included a Beer's law optical component, a finite difference heat transfer component and an Arrhenius equation-based damage calculation, was verified against data from the literature. Moderate discrepancies between simulation results and our experimental data probably resulted from the use of a laser beam with an irregular spatial profile. This profile produced a lower than expected coagulation threshold and an irregular damage distribution within a millisecond after laser onset. After 1 ms, heat conduction led to smoothing of the coagulum. Simulations indicated that dynamic changes in absorption led to a reduction in surface temperatures. The Arrhenius equation was shown to be effective for simulating transient albumen coagulation during pulsed holmium:YAG laser irradiation. Greater understanding of pulsed laser-tissue interactions may lead to improved treatment outcome and optimization of laser parameters for a variety of medical procedures.

  8. Acoustic transient generation in pulsed holmium laser ablation under water

    NASA Astrophysics Data System (ADS)

    Asshauer, Thomas; Rink, Klaus; Delacretaz, Guy P.; Salathe, Rene-Paul; Gerber, Bruno E.; Frenz, Martin; Pratisto, Hans; Ith, Michael; Romano, Valerio; Weber, Heinz P.

    1994-08-01

    In this study the role of acoustical transients during pulsed holmium laser ablation is addressed. For this the collapse of cavitation bubbles generated by 2.12 micrometers Cr:Tm:Ho:YAG laser pulses delivered via a fiber in water is investigated. Multiple consecutive collapses of a single bubble generating acoustic transients are documented. Pulse durations are varied from 130 - 230 microsecond(s) and pulse energies from 20 - 800 mJ. Fiber diameters of 400 and 600 micrometers are used. The bubble collapse behavior is observed by time resolved fast flash photography with 1 microsecond(s) strobe lamp or 5 ns 1064 nm Nd:YAG laser illumination. A PVDF needle probe transducer is used to observe acoustic transients and measure their pressure amplitudes. Under certain conditions, at the end of the collapse phase the bubbles emit spherical acoustic transients of up to several hundred bars amplitude. After the first collapse up to two rebounds leading to further acoustic transient emissions are observed. Bubbles generated near a solid surface under water are attracted towards the surface during their development. The final phase of the collapse generating the acoustic transients takes place directly on the surface, exposing it to maximum pressure amplitudes. Our results indicate a possible mechanism of unwanted tissue damage during holmium laser application in a liquid environment as in arthroscopy or angioplasty that may set limits to the choice of laser pulse duration and energies.

  9. [Holmium:YAG infrared laser and UV-Excimer. Laser effects on oral mucosa].

    PubMed

    Kautzky, M; Susani, M; Schenk, P

    1992-07-01

    The in-vivo tissue ablation characteristics of a pulsed infrared laser (Holmium:YAG, lambda = 1980) and a pulsed excimer laser (XeCl, lambda = 308 nm) were studied. The holmium laser energy was coupled into nylon fibres. The excimer laser energy was coupled into quartz fibers. Laser incisions were made on white rats at different sites of the tongue. Power settings of 400 mJ per 2.5 microseconds pulse at 5 pulses per second for the holmium:YAG laser and 250 mJ per 1 microsecond pulse at 20 pulses per second for the excimer laser were used. Thermal gradients following laser application were measured. Excellent control of depth of tissue ablation was noted for both types of lasers. The tissue response was examined by light microscopy. Histological studies revealed tissue defects with clean contours. The coagulative necrosis zone for the 400 mJ holmium:YAG injuries measured from 370 microns to 640 microns, compared with 40 microns to 160 microns with the 250 mJ UV-excimer injuries. Wound healing was studied over a six-week period. Histologically, wound closure was completed after four weeks showing re-epithelialization without scar formation for both types of laser. The in-vivo tissue ablation characteristics and the operation reliability of the two lasers were compared. PMID:1497766

  10. A 2. mu. m holmium laser

    SciTech Connect

    Lotem, H.; Kalisky, Y.; Kagan, J.; Sagie, D.

    1988-06-01

    A comparison of the CW laser performance of the /sup 5/I/sub 7/-/sup 5/I/sub 8/ transition at 2 ..mu..m erbium-thulium-sensitized Ho:YLF and Ho:YAG (..cap alpha..BETAHo:YLF and ..cap alpha..BETAHo:YAG) crystals at liquid nitrogen temperature is reported. Multimode laser output power above 60 W was obtained with two compositions of ..cap alpha..BETAHo:YLF (with a rod size of 5 mm in diameter and 75 mm in length) with 4.1 percent efficiency and 4.75 percent slope efficiency. Thermal load measurements on ..cap alpha..BETAHo:YLF and ..cap alpha..BETAHo:YAG laser rods and effects of the pumping lamp on the laser yield are also presented. Preliminary results on single-pulse operation of both ..cap alpha..BETAHo:YLF and ..cap alpha..BETAHo:YAG lasers in the free-running mode in the temperature range of 83-230 K are also reported. The laser threshold in both YLF and YAG is constant up to 110 K and increases with temperature above 110 K. The laser slope efficiency in YAG is quite constant up to 150 K, above which to decreases with temperature, while in the YLF the slope efficiency has a broad maximum around 150 K. The net result in YLF is a broad maximum of the laser output power around 130 K at high pumping levels.

  11. Combination of erbium and holmium laser radiation for tissue ablation

    NASA Astrophysics Data System (ADS)

    Pratisto, Hans S.; Frenz, Martin; Koenz, Flurin; Altermatt, Hans J.; Weber, Heinz P.

    1996-05-01

    Erbium lasers emitting at 2.94 micrometers and holmium lasers emitting at 2.1 micrometers are interesting tools for cutting, drilling, smoothing and welding of water containing tissues. The high absorption coefficient of water at these wavelengths leads to their good ablation efficiency with controlled thermally altered zones around the ablation sites. Combination of pulses with both wavelengths transmitted through one fiber were used to perform incisions in soft tissue and impacts in bone disks. Histological results and scanning electron microscope evaluations reveal the strong influence of the absorption coefficient on tissue effects, especially on the ablation efficiency and the zone of thermally damaged tissue. It is demonstrated that the combination of high ablation rates and deep coagulation zones can be achieved. The results indicate that this laser system can be considered as a first step towards a multi-functional medical instrument.

  12. Effect of active-ion concentration on holmium fibre laser efficiency

    SciTech Connect

    Kurkov, Andrei S; Sholokhov, E M; Marakulin, A V; Minashina, L A

    2010-08-03

    We have measured the fraction of holmium ions that relax nonradiatively to the ground level as a result of interaction at a metastable level in optical fibres with a silica-based core doped with holmium ions to 2 x 10{sup 19} - 2 x 10{sup 20} cm{sup -3}. The percentage of such ions has been shown to depend on the absolute active-ion concentration. The fibres have been used to make a number of 2.05-{mu}m lasers, and their slope efficiency has been measured. The laser efficiency decreases with increasing holmium concentration in the fibres (lasers)

  13. Effect of the active-ion concentration on the lasing dynamics of holmium fibre lasers

    SciTech Connect

    Kurkov, Andrei S; Sholokhov, E M; Marakulin, A V; Minashina, L A

    2010-12-09

    The lasing dynamics of fibre lasers with a core based on quartz glass doped with holmium ions to concentrations in the range of 10{sup 19}-10{sup 20} cm{sup -3} is investigated. It is shown that fibre lasers with a high concentration of active holmium ions generate pulses, but a decrease in the holmium concentration changes the lasing from pulsed to cw regime. At the same time, a decrease in the active-ion concentration and the corresponding increase in the fibre length in the cavity reduce the lasing efficiency. (lasers)

  14. Femtosecond laser based enucleation of porcine oocytes for somatic cell nuclear transfer

    NASA Astrophysics Data System (ADS)

    Ktemeyer, K.; Lucas-Hahn, A.; Petersen, B.; Hassel, P.; Lemme, E.; Niemann, H.; Heisterkamp, A.

    2009-07-01

    Cloning of several mammalian species has been achieved by somatic cell nuclear transfer (SCNT) in recent years. However, this method still results in very low efficiencies around 1% which originate from suboptimal culture conditions and highly invasive techniques for oocyte enucleation and injection of the donor cell using micromanipulators. In this paper, we present a new minimal invasive method for oocyte imaging and enucleation based on the application of femtosecond (fs) laser pulses. After imaging of the oocyte with multiphoton microscopy, ultrashort pulses are focused onto the metaphase plate of MII-oocytes in order to ablate the DNA molecules. We show that fs laser based enucleation of porcine oocytes completely inhibits the first mitotic cleavage after parthenogenetic activation while maintaining intact oocyte morphology in most cases. In contrast, control groups without previous irradiation of the metaphase plate are able to develop to the blastocyst stage. Further experiments have to clarify the suitability of fs laser based enucleated oocytes for SCNT.

  15. Comparison of holmium:YAG and thulium fiber lasers for lithotripsy

    NASA Astrophysics Data System (ADS)

    Blackmon, Richard L.; Irby, Pierce B.; Fried, Nathaniel M.

    2010-02-01

    The Holmium:YAG laser is currently the most common laser lithotripter. However, recent experimental studies have demonstrated that the Thulium fiber laser is also capable of vaporizing urinary stones. The high-temperature water absorption coefficient for the Thulium wavelength (?a = 160 cm-1 at ? = 1908 nm) is significantly greater than for the Holmium wavelength (?a = 28 cm-1 at ? = 2120 nm). We hypothesize that this should translate into more efficient laser lithotripsy using the Thulium fiber laser. This study directly compares stone vaporization rates for Holmium and Thulium fiber lasers. Holmium laser radiation pulsed at 3 Hz with 70 mJ pulse energy and 220 ?s pulse duration was delivered through a 100-?m-core silica fiber to human uric acid (UA) and calcium oxalate monohydrate (COM) stones, ex vivo (n = 10 each). Thulium fiber laser radiation pulsed at 10 Hz with 70 mJ pulse energy and 1 ms pulse duration was also delivered through a 100-?m fiber for the same sets of 10 stones. For same number of pulses and total energy (126 J) delivered to each stone, mass loss averaged 2.4 +/- 0.6 mg (UA) and 0.7 +/- 0.2 mg (COM) for Holmium laser and 12.6 +/- 2.5 mg (UA) and 6.8 +/- 1.7 (COM) for Thulium fiber laser. UA and COM stone vaporization rates for Thulium fiber laser averaged 5-10 times higher than for Holmium laser at 70 mJ pulse energies. With further development, the Thulium fiber laser may represent an alternative to the conventional Holmium laser for more efficient laser lithotripsy.

  16. Excimer and holmium:YAG laser coronary angioplasty

    NASA Astrophysics Data System (ADS)

    Geschwind, Herbert J.; Nakamura, Fumitaka; Kvasnicka, Jan; Dubois-Rande, Jean Luc

    1992-08-01

    Recently, access to the coronary arteries became available to laser angioplasty based upon a new concept which utilizes a pulsed laser source and multifiber, `over-the-wire' guided catheters. The aim of this study was to evaluate the early and long-term results and the side effects of coronary angioplasty using an excimer or a Holmium:YAG laser. Forty consecutive patients were treated with the Holmium:YAG laser (group I) and 46 consecutive patients were treated with the excimer laser (group II). The primary laser angioplasty success rate was 55% and 71.7% for group I and II, respectively. It was similar in calcified and in non-calcified lesions and in total occlusions and stenoses. Laser stand-alone therapy was obtained in 5.0% of group I patients versus 21.7% in group II patients (p < 0.05). Failures were due to the inability for the laser catheter tip to reach the lesion, to cross the obstruction, or to obtain a significant reduction in stenosis. They were more frequent in group I than in group II patients (45% versus 28.3%). Complications included acute closure in 7.5% of group I and 17.1% of group II patients and spasm in 10.0% and 13.0% of group I and group II patients, respectively. Dissection occurred more frequently in group II than in group I patients (28.3% versus 7.5%, p < 0.04). The angiographic patency rate at 6 month follow up was 33% and 29% for group I and group II patients, respectively. Multifiber, wire-guided catheters provide an easy access to the coronary arteries. Excimer laser angioplasty using large, densely packed catheters is effective but induces a high rate of dissections. Technical improvements are required to ablate more tissue to possibly reduce the restenosis rate. Further studies ar needed to elucidate the mechanism of side effects to reduce their impact on restenosis rate.

  17. Excising multiple ureteral cysts endoscopically utilizing the OmniPlus-Max 80 W holmium laser

    PubMed Central

    Blewniewski, Mariusz; R?a?ski, Waldemar

    2015-01-01

    We present a rare case of ureteral cysts in the left ureter treated by an endoscopic holmium laser. These cysts caused asymptomatic hydronephrosis in the left kidney. Complete cyst removal was performed by a ureteroscopically applied holmium laser. Six months post-procedure, the patient had no recurrence, which suggests that endoscopic excision is an optimal treatment for this disorder. Periodic ureteroscopic examination is indicated for further observation. PMID:25624968

  18. Acoustic transient generation by holmium-laser-induced cavitation bubbles

    NASA Astrophysics Data System (ADS)

    Asshauer, T.; Rink, K.; Delacretaz, G.

    1994-11-01

    The acoustic effects of free-running 2.12 micron Cr:Tm:Ho:YAG laser pulses delivered in water are studied. Laser pulses of 10 to 1200 mJ energy and 230 microsecs duration (full width at half-maximum) are used. Delivery fiber diameters of 200 - 600 microns are investigated. Combined fast flash video imaging and needle probe hydrophone pressure sensing are used. The experimental results show that the laser-induced water vapor bubbles can generate strong acoustic transients at the bubble collapse several hundreds of microsecs after the start of the laser pulse. Pressures of up to 3600 bar are measured. Above a laser fluence threshold of 40 J/sq cm the pressure amplitude increases sharply, reaching a maximum value between 100 and 200 J/sq cm. At higher fluences up to more than 1000 J/sq cm, the pressure amplitude is found to decrease again. A two-phase mechanism is proposed to describe the complex bubble dynamics generated by the free-running pulses: The isotropic expansion of an initially superheated water volume is followed by a continuous ablation phase. The results suggest a mechanism of possible unwanted acoustic damage during Holmium laser medical applications in a liquid environment.

  19. The pulsed holmium: yttrium-aluminum-garnet laser. Applications to ankle arthroscopy.

    PubMed

    Janis, L R; Kravitz, R D; Wagner, S S

    1994-07-01

    The holmium:YAG laser has many advantages over conventional surgical instrumentation and techniques in ankle arthroscopy. These include minimal mechanical damage to surrounding tissue structures, better access to tight recesses, and the ability to coagulate, smooth, ablate, and weld tissues. The laser also offers improved contouring of damaged articular surfaces, all with a single instrument. The holmium:YAG laser uses a wavelength of 2.1 microns, which is strongly absorbed by water, the major component of tissue. This wavelength allows the laser to deliver a consistent tissue effect to both pigmented and nonpigmented tissues. It currently may transmit up to 60 watts of power to tissue in high-energy, short-duration pulses. The holmium:YAG laser also operates in a fluid medium, which provides a near physiologic environment and maintains continual irrigation. The holmium:YAG laser beam is transmitted through a flexible fiberoptic handpiece, which greatly increases maneuverability. A variety of angled laser tips are available, depending on the pathology type and location. Different tissue effects can be created by varying the tip to target distance. All these qualities provide precise control without significant thermal damage and make the laser ideal for application to articular structures of the ankle joint. The holmium:YAG laser is a safe and effective arthroscopic instrument with a promising future. We have used it, along with traditional shavers and abraders, to effectively treat numerous pathologies of the ankle joint. The laser's versatility in cutting, ablation, and coagulation has been uniformly successful. Patients surveyed postoperatively have reported less overall symptoms and faster healing. They have reported a decrease in ecchymosis, edema, and postoperative pain. Patients' return to full activity has appeared to be quicker with the use of holmium:YAG laser therapy. Although our results have thus far been very encouraging, further research and clinical applications in the use of the holmium:YAG laser need to be continued. PMID:7954213

  20. Efficient holmium:yttrium lithium fluoride laser longitudinally pumped by a semiconductor laser array

    NASA Technical Reports Server (NTRS)

    Hemmati, H.

    1987-01-01

    Optical pumping of a holmium:yttrium lithium floride (Ho:YLF) crystal with a 790-nm continuous-wave diode-laser array has generated 56 mW of 2.1-micron laser radiation with an optical-to-optical conversion slope efficiency of 33 percent while the crystal temperature is held at 77 K. The lasing threshold occurs at 7 mW of input power, and laser operation continues up to a crystal temperature of 124 K.

  1. Holmium:YAG laser in dentistry: photoconditioning of dentinal surfaces

    NASA Astrophysics Data System (ADS)

    Holt, Raleigh A.; Nordquist, Robert E.

    1994-09-01

    This in vitro study was undertaken to determine energy levels necessary to produce tubule closure and surface smoothing on dentinal surfaces of human teeth and their resultant temperature increases within the pulpal canals with the Holmium:YAG laser. An optimal working spot size and even absorption pattern were produced by defocusing the laser beam and evaluated by images produced on light exposed and developed photographic paper. The surface effects on dentin were examined by scanning electron microscopy. A thermocouple was positioned in the canals of fresh dissected dog jaws and attached to a recorder which produced a graph of the temperature changes. The in vitro research model for intrapulpal temperatures changes was verified by comparing premortem and postmortem temperature readings. The same protocol was used to evaluate temperature changes in fresh human extracted teeth. In vivo histological studies were conducted to evaluate the effects of HO:YAG laser energy on pulpal tissues. The results of these studies indicate the HO:YAG laser at a wavelength of 2.12 microns can be safely and effectively used for photoconditioning of the dentinal surfaces of teeth in clinical conditions.

  2. Use of the holmium:YAG laser in urology

    NASA Astrophysics Data System (ADS)

    Johnson, Douglas E.; Cromeens, Douglas M.; Price, Roger E.

    1992-06-01

    The Holmium:YAG (Ho:YAG) laser operating at a wavelength of 2.1 micrometers with a maximum power of 15 watts (W) and 10 different pulse-energy settings was systematically evaluated on kidney, bladder, prostate, ureteral, and vasal tissue, and was used to perform various urologic surgical procedures (partial nephrectomy, transurethral laser incision of the prostate, and laser-assisted vasovasostomy) in the dog. By using the SurgiTomeTM 3- inch straight delivery system with an energy-pulse setting of 0.5 joules (J) at 20 Hz (10 W), partial nephrectomies required slightly longer operating times (15 minutes) than when similar procedures were performed using the Neodymium:YAG (Nd:YAG) laser and a free GI fiber at 59 to 83 W (4 - 7 minutes); however, the total energy required was considerably less. Hemostasis was excellent and no sutures were required to control bleeding. Transurethral incisions of the prostate using TV monitoring were made at the 4 and 8 o'clock positions extending from the colliculus seminalis through the vesical neck with an energy/pulse setting of 1.0 J at 15 Hz (15 W). Attempts at laser-assisted vasovasostomies were unsuccessful due to excessive thermal affect. The LaparoTomeTM Delivery System proved helpful in performing laparoscopic pelvic lymphadenectomy in the pig. Our investigations showed that the Ho:YAG laser possesses both excellent cutting and adequate hemostatic abilities even in a fluid medium. Although these results are preliminary, we believe that the Ho:YAG laser is well suited for urologic surgery and may well become the 'urologist's laser of the future.'

  3. Combined multiphoton imaging and automated functional enucleation of porcine oocytes using femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Kuetemeyer, Kai; Lucas-Hahn, Andrea; Petersen, Bjoern; Lemme, Erika; Hassel, Petra; Niemann, Heiner; Heisterkamp, Alexander

    2010-07-01

    Since the birth of ``Dolly'' as the first mammal cloned from a differentiated cell, somatic cell cloning has been successful in several mammalian species, albeit at low success rates. The highly invasive mechanical enucleation step of a cloning protocol requires sophisticated, expensive equipment and considerable micromanipulation skill. We present a novel noninvasive method for combined oocyte imaging and automated functional enucleation using femtosecond (fs) laser pulses. After three-dimensional imaging of Hoechst-labeled porcine oocytes by multiphoton microscopy, our self-developed software automatically identified the metaphase plate. Subsequent irradiation of the metaphase chromosomes with the very same laser at higher pulse energies in the low-density-plasma regime was used for metaphase plate ablation (functional enucleation). We show that fs laser-based functional enucleation of porcine oocytes completely inhibited the parthenogenetic development without affecting the oocyte morphology. In contrast, nonirradiated oocytes were able to develop parthenogenetically to the blastocyst stage without significant differences to controls. Our results indicate that fs laser systems have great potential for oocyte imaging and functional enucleation and may improve the efficiency of somatic cell cloning.

  4. Laser angioplasty with lensed fibers and a holmium:YAG laser in iliac artery occlusions

    NASA Astrophysics Data System (ADS)

    White, Christopher J.; Ramee, Stephen R.; Mesa, Juan E.; Collins, Tyrone J.; Kotmel, Robert; Godfrey, Maureen A.

    1991-05-01

    Holmium-YAG (2.1 (mu) ) laser recanalization was attempted in 10 totally occluded miniature swine iliac arteries using a lensed fiber delivery system. The iliac artery occlusions were created in a Yucatan miniature swine model of atherosclerosis by means of a high cholesterol diet and balloon endothelial denudation. In order to increase the spot size, a spherical silica lens was attached to the distal end of a 300 micrometers core diameter silica optical fiber. The holmium-YAG laser was operated in the free-running mode with 250 microsecond(s) ec pulses at 4 Hz. The energy delivered was 225 mJ per pulse for the 1.0 mm lensed fiber and 200 mJ per pulse for the 1.3 mm lensed fiber. Laser energy was delivered in 2 to 5 second bursts. Successful recanalization was achieved in all 10 arteries attempted without perforation of the arterial wall. The average length of the occlusions was 5.0 +/- 1.8 cm. Following successful laser recanalization significant stenoses (>50%) remained in all of the arteries as judged by angiography. In conclusion, the lensed fibers coupled to the pulsed holmium-YAG laser were safe and effective in recanalizing these difficult lesions in relatively straight iliac arteries. There is potential clinical utility for this system as an adjunct to balloon angioplasty in patients with lesions which are unable to be crossed with guidewires.

  5. Safety and efficacy of holmium:YAG laser lithotripsy in patients with bleeding diatheses

    NASA Astrophysics Data System (ADS)

    Watterson, James D.; Girvan, Andrew R.; Cook, Anthony J.; Beiko, Darren T.; Nott, Linda; Auge, Brian K.; Preminger, Glenn M.; Denstedt, John D.

    2003-06-01

    Purpose: To assess the safety and efficacy of ureteroscopy and holmium:YAG (yttrium-aluminum-garnet) laser lithotripsy in the treatment of upper urinary tract calculi in patients with known and uncorrected bleeding diatheses. Materials and Methods: A retrospective chart review from 2 tertiary stone centers was performed to identify patients with known bleeding diatheses who were treated with holmium:YAG laser lithotripsy for upper urinary tract calculi. Twenty-five patients with 29 upper urinary tract calculi were treated with ureteroscopic holmium laser lithotripsy. Bleeding diatheses identified were coumadin administration for various conditions (17), liver dysfunction (3), thrombocytopenia (4), and von Willebrand's disease (1). Mean international normalized ratio (INR), platelet count and bleeding time were 2.3, 50 x 109/L, and > 16 minutes, for patients receiving coumadin or with liver dysfunction, thrombocytopenia, or von Willebrand's disease, respectively. Results: Overall, the stone-free rate was 96% (27/28) and 29 of 30 procedures were completed successfully without significant complication. One patient who was treated concomitantly with electrohydraulic lithotripsy (EHL) had a significant retroperitoneal hemorrhage that required blood transfusion. Conclusions: Treatment of upper tract urinary calculi in patients with uncorrected bleeding diatheses can be safely performed using contemporary small caliber ureteroscopes and holmium laser as the sole modality of lithotripsy. Ureteroscopic holmium laser lithotripsy without preoperative correction of hemostatic parameters limits the risk of thromboembolic complications and costs associated with an extended hospital stay. Avoidance of the use of EHL is crucial in reducing bleeding complications in this cohort of patients.

  6. Office Hysteroscopic Laser Enucleation of Submucous Myomas without Mass Extraction: A Case Series Study

    PubMed Central

    Haimovich, Sergio; López-Yarto, Maite; Urresta Ávila, Julio; Saavedra Tascón, Alejandro; Hernández, José L.; Carreras Collado, Ramón

    2015-01-01

    Background and Objectives. A new two-step hysteroscopic myomectomy carried out in the office setting and without anesthesia was feasible for the excision of submucous myomas. The objective of this study was to assess whether removal of submucous myomas from the uterine cavity after hysteroscopic laser enucleation is necessary. Methods. Between June 2009 and April 2013, all outpatients with symptomatic myomatosis (bleeding, pelvic pain, and infertility) assessed ultrasonographically were eligible to participate in a prospective study. All patients underwent office hysteroscopic enucleation of submucous myomas. Enucleated myomas were left in the uterine cavity. Neither anesthesia nor antibiotic prophylaxis was used. Results. Sixty-one women (mean age: 47.3 years) were included. Regardless of hysteroscopic localization and grading, all myomas were enucleated. The mean (standard deviation, SD) diameter of the myoma as measured by the ultrasound scan was 22.6 (8.5) mm. In 29 cases (47.5%), the diameter of the resected myoma was >20 mm and in 10 cases (16.4%) >30 mm. After a mean follow-up of 68.2 (16.5) days, none of the patients showed a residual myoma inside the uterine cavity. Conclusions. The present results indicate that leaving laser-enucleated submucous myoma in the uterine cavity is a feasible and safe therapeutic option. PMID:26090457

  7. Holmium:YAG and erbium:YAG laser interaction with hard and soft tissue

    NASA Astrophysics Data System (ADS)

    Charlton, Andrew; Dickinson, Mark R.; King, Terence A.; Freemont, Anthony J.

    1991-06-01

    The holmium YAG and erbium YAG lasers operating at 2.1 micrometers and 2.9 micrometers respectively, are the subject of great interest for various medical applications. The interaction of both these pulsed lasers with biological tissue involves absorption of the radiation by water leading to rapid heating and ablation, however the different absorption coefficients at these two wavelengths give rise to different ablation efficiencies and haemostatic properties for the two lasers. It is this cut/seal ratio that determines for which medical applications each of these lasers is most suited. The lasers were used to produce incisions in various tissues by translating the tissue at fixed speed beneath a focused laser beam. The laser energy density was varied between 100 and 500 J/cm2 and the lasers were operated at 2 Hz. After irradiation the tissues were fixed in formalin, processed routinely into paraffin wax, sectioned at 5 micrometers and stained with haemotoxylin and eosin. This allowed the dimensions of the incisions to be measured, as well as the depth of coagulative denatured tissue surrounding each incision. In this way the cut/seal ratio was determined for both the holmium YAG and erbium YAG laser in a range of hard and soft tissues. Results show that the latent heat of ablation for the holmium YAG laser interacting with soft tissue varies between 20-50 kJ/cm3, almost an order of magnitude larger than with the erbium YAG laser. Furthermore, the depth of coagulative necrosis with holmium YAG extends 100-400 micrometers , compared with 10-30 micrometers for erbium YAG. The two interactions clearly lead to vastly different results suggesting that the holmium YAG laser is suitable for producing lesions in highly vascular tissue where haemostasis is important, whereas the erbium YAG laser is better suited to avascular tissue requiring large depths of incision.

  8. Histological evaluation of coagulation foci produced in the human lens with a holmium laser

    NASA Astrophysics Data System (ADS)

    Kecik, Dariusz; Kecik, Tadeusz; Pratnicki, Antoni; Kasprzak, Jan; Kecik, Mariusz

    1997-10-01

    We present the results of histological evaluation of human lenses treated with the holmium laser. The lenses, extracted at the time of extracapsular surgery for cataract, were placed in containers filled with Ringer's solution. After treatment with laser-emitted radiation they were histologically evaluated. The formation of crater-like defects was found in the material studied.

  9. Functional enucleation of porcine oocytes for somatic cell nuclear transfer using femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Kuetemeyer, K.; Lucas-Hahn, A.; Petersen, B.; Hassel, P.; Lemme, E.; Niemann, H.; Heisterkamp, A.

    2010-02-01

    Cloning of several mammalian species has been achieved by somatic cell nuclear transfer over the last decade. However, this method still results in very low efficiencies originating from biological and technical aspects. The highly-invasive mechanical enucleation belongs to the technical aspects and requires considerable micromanipulation skill. In this paper, we present a novel non-invasive method for combined oocyte imaging and automated functional enucleation using femtosecond (fs) laser pulses. After three-dimensional imaging of Hoechst-labeled porcine oocytes by multiphoton microscopy, our self-developed software automatically determined the metaphase plate position and shape. Subsequent irradiation of this volume with the very same laser at higher pulse energies in the low-density-plasma regime was used for metaphase plate ablation. We show that functional fs laser-based enucleation of porcine oocytes completely inhibited further embryonic development while maintaining intact oocyte morphology. In contrast, non-irradiated oocytes were able to develop to the blastocyst stage without significant differences to control oocytes. Our results indicate that fs laser systems offer great potential for oocyte imaging and enucleation as a fast, easy to use and reliable tool which may improve the efficiency of somatic cell clone production.

  10. Ureteroscopic holmium laser cutting for inadvertently sutured drainage tube (report of five cases).

    PubMed

    Gao, Xu; Lu, Xin; Ren, Shancheng; Xu, Chuanliang; Sun, Yinghao

    2008-07-01

    The aim of this paper is to report a simple solution for inadvertently sutured drainage tube after urological surgery and discuss the different managements according to different types of this embarrassing complication. From September 2001 to January 2007, five inadvertently sutured drainage tubes were treated with ureteroscopic holmium laser cutting for the suture. All drainage tubes were removed after the operation without other complications. Holmium laser cutting via ureteroscope is a simple solution for the embarrassing problem of inadvertently sutured drainage tube. It can save the patient from undergoing another open surgery. PMID:17713824

  11. Thulium laser enucleation of the prostate is a safe and a highly effective modality for the treatment of benign prostatic hyperplasia - Our experience of 236 patients

    PubMed Central

    Ketan, P. Vartak; Prashant, H. Salvi

    2016-01-01

    Context: Thulium LASER is fast emerging as a safe and effective modality for benign prostatic hyperplasia (BPH). Still, compared to holmium laser transurethral enucleation of the prostate (HoLEP) the number of institutes all over the world using Thulium LASER are limited. This is our effort to bring the statistical facts about the safety and effectivity of Thulium LASER. Aims: To study the efficacy of thulium laser enucleation of the prostate (ThuLEP). Settings and Design: All patients in the stipulated period were documented for all parameters and were evaluated. The results were tabulated. Subjects and Materials: (1) Two hundred and thirty-six patients with symptomatic BPH were treated with ThuLEP between March 2010 and September 2014 at our institute by a single surgeon. (2) The inclusion criteria were maximum urinary flow rate (Qmax) <15 ml/s, International Prostate Symptoms Score (IPSS) >15 or acute retention of urine with the failure of catheter trial or Acute retention of urine with prior history of severe bladder outlet obstruction. (3) Patients evaluated by: Digital rectal examination, uroflowmetry, IPSS, prostate-specific antigen (PSA), blood and urine routine tests, abdominal usage with trains rectal ultrasonography (TRUS), TRUS guided biopsies. Statistical Analysis Used: Not used. Results: (1) ThuLEP was a highly effective procedure as compared to all other procedures like HOLEP, TURP in terms of catheterization time, hospital stay, and drop in hemoglobin (Hb). (2) Catheterization time: 25.22 h (224 patients within 24 h and 12 patients within 48 h). (3) Hospital stay: 24–36 h 218 patients (92.3%), 36–48 h 18 patients (7.6%). (4) Drop in Hb: 0.8 ± 0.42 g/dl. (5) Average operative time: 56.91 min. Conclusions: Thulium LASER is a safe and highly effective LASER in terms of blood loss, speed of tissue resection, drop in serum PSA, and versatility of prostatic resection. PMID:26834407

  12. Combination of fiber-guided pulsed erbium and holmium laser radiation for tissue ablation under water

    NASA Astrophysics Data System (ADS)

    Pratisto, Hans; Frenz, Martin; Ith, Michael; Altermatt, Hans J.; Jansen, E. Duco; Weber, Heinz P.

    1996-07-01

    Because of the high absorption of near-infrared laser radiation in biological tissue, erbium lasers and holmium lasers emitting at 3 and 2 mu m, respectively, have been proven to have optimal qualities for cutting or welding and coagulating tissue. To combine the advantages of both wavelengths, we realized a multiwavelength laser system by simultaneously guiding erbium and holmium laser radiation by means of a single zirconium fluoride (ZrF4) fiber. Laser-induced channel formation in water and poly(acrylamide) gel was investigated by the use of a time-resolved flash-photography setup, while pressure transients were recorded simultaneously with a needle hydrophone. The shapes and depths of vapor channels produced in water and in a submerged gel after single erbium and after combination erbium-holmium radiation delivered by means of a 400- mu m ZrF4 fiber were measured. Transmission measurements were performed to determine the amount of pulse energy available for tissue ablation. The effects of laser wavelength and the delay time between pulses of different wavelengths on the photomechanical and photothermal responses of meniscal tissue were evaluated in vitro by the use of histology. It was observed that the use of a short (200- mu s, 100-mJ) holmium laser pulse as a prepulse to generate a vapor bubble through which the ablating erbium laser pulse can be transmitted (delay time, 100 mu s) increases the cutting depth in meniscus from 450 to 1120 mu m as compared with the depth following a single erbium pulse. The results indicate that a combination of erbium and holmium laser radiation precisely and efficiently cuts tissue under water with 20-50- mu m collateral tissue damage. wave, cavitation, channel formation, infrared-fiber-delivery system, tissue damage, cartilage.

  13. Tissue treatment under water with simultaneously fiber-guided erbium and holmium laser radiation

    NASA Astrophysics Data System (ADS)

    Pratisto, Hans S.; Frenz, Martin; Koenz, Flurin; Ith, Michael; Weber, Heinz P.; Altermatt, Hans J.

    1996-01-01

    Non-contact fiber guided IR-tissue treatment under water requires the formation of a water vapor channel at the fiber tip to bridge the water layer between the fiber and the tissue surface and to allow transmission of the radiation. The formation of the channel, however, consumes most of the initial pulse energy which strongly restricts the ablation efficiency. The goal of this study was to determine optimum laser parameters which guarantee a high ablation efficiency and a high cutting precision. A multi-wavelength-laser system was realized by simultaneously guiding erbium and holmium laser radiation via a single ZrF4 fiber. Both lasers were operated in free-running mode at pulse durations adjustable between 100 microsecond(s) and 1 ms. Pressure measurements and video flash photography were performed to study the channel formation process as a function of laser wavelength, pulse duration and delay time between laser pulses at different wavelengths. The tissue response of human meniscus after laser impact was histologically investigated. The efficiency of erbium laser tissue ablation under water increases from 25% up to 80% by using a multi-wavelength system emitting 2.1 micrometers and 2.79 micrometers radiation. This is achieved when a 200 microsecond(s) long holmium laser pulse of low energy is used to open a water vapor channel through which the ablating erbium laser radiation can be transmitted. The induced thermal tissue damage is essentially determined by the holmium laser parameters and the delay time between both pulses. The combination of erbium and holmium laser radiation offers the surgeon the possibility for efficient and precise cutting of tissue under water. Moreover, it represents an universal medical instrument for cutting and/or coagulation just by changing the laser parameters without changing the instrument.

  14. Holmium:YAG laser coronary angioplasty: quantitative angiography and clinical results in a large experience of a single medical center

    NASA Astrophysics Data System (ADS)

    Topaz, On; Luxenberg, Michael; Schumacher, Audrey

    1994-07-01

    Clinical experience with the mid IR holmium:YAG laser in a single medical center (St. Paul Ramsey Medical Center, University of Minnesota Medical School, St. Paul, MN) includes 112 patients who underwent holmium laser coronary angioplasty. Utilizing a unique lasing technique; `pulse and retreat,' we applied this laser to thrombotic and nonthrombotic lesions in patients presenting with unstable angina, stable angina, and acute myocardial infarction. A very high clinical success and very low complication rates were achieved. Holmium:YAG laser is effective and safe therapy for patients with symptomatic coronary artery disease. Unlike excimer lasers, the clinical success, efficacy and safety of holmium laser angioplasty is not compromised when thrombus is present.

  15. Mathematical modelling of dispersion-managed thulium/holmium fibre lasers

    SciTech Connect

    Yarutkina, I A; Shtyrina, O V

    2013-11-30

    The mathematical model of a dispersion-managed thulium/holmium fibre laser is described; the results of numerical calculations and their comparison with the experimental data are presented. Qualitative agreement of the results of the mathematical modelling with those of the experiment is obtained. Using the methods of mathematical modelling, the variation in the characteristics of the optical pulses due to the change in the average cavity dispersion is analysed. (control of laser radiation parameters)

  16. Effects of the holmium:YAG and erbium:YAG lasers on endotracheal tubes.

    PubMed

    Kautzky, M; Fitzgerald, R; Dechtyar, I; Schenk, P

    1993-01-01

    Endotracheal tube (ET) fire is the most frequent complication arising with laser surgery in the upper aerodigestive tract. No data are available about the safety of commonly used ETs when used with recently developed high-energy pulsed lasers, working with only a minimal thermal component but mainly photoablative. A comparative in vitro study was performed with three types of endotracheal tubes to assess their resistance to wall and cuff damage by the laser beams of two pulsed infrared solid-state lasers. ET perforation was attempted with the erbium:YAG (lambda = 2,930 nm) and holmium:YAG (lambda = 2,120 nm) lasers. For all experiments, a repetition rate of 5 Hz was used. The 2.5-microseconds holmium:YAG pulses were coupled into a nylon fibre of 400 microns diameter. The 2.0-microseconds erbium:YAG laser pulses were applied to ETs through a lens system providing a spot size diameter of 200 microns. Polyvinyl chloride and silicon ET segments were exposed to laser pulse energies from 97 to 500 mJ in the presence of different anaesthetic gas mixtures. The time from the onset of exposure to tube perforation was recorded. Thermal gradients following laser application were measured. Laser exposure was continued for up to 90 s, unless tube ignition occurred. At all energy levels tested, the photo-ablative mechanism of laser-tube interaction, with few thermal components, led to laser-induced tube ignition if an FiO2 > 21% for the holmium:YAG and 34% for the erbium:YAG laser was established. With increasing pulse energies, ET segments ignited sooner. MLT tubes performed best in the present safety test. PMID:8446385

  17. Transurethral holmium laser vaporization to the urethral tumour through a ureteroscope

    PubMed Central

    Li, Aihua; Fang, Wei; Zuo, Xiaoming; Zhang, Feng; Li, Weiwu; Lu, Honghai; Liu, Sikuan; Wang, Hui; Zhang, Binghui

    2014-01-01

    We present 2 cases of urethral cancers: one is recurrent bladder transitional cell carcinoma accompanied by urethral metastatic carcinoma located on the right side of verumontanum, and the other is primary bladder and metastatic urethral adenocarcinoma. The urethral tumour was treated by transurethral holmium laser vaporization to the urethral tumour through a ureteroscope and the bladder tumour was treated with transurethral resection and degeneration of the bladder tumour (TURD-Bt). After the second or third therapy, patients were free of urethral or bladder tumour recurrence; they also did not experience urethral stricture or urinary incontinence during the 24- to 36-month follow-up. Transurethral holmium laser vaporization and TURD-Bt could be performed to treat non-invasive urethral cancer accompanied with bladder cancer and preserve the urethra and bladder. PMID:25553166

  18. Are Histological Findings of Thulium Laser Vapo-Enucleation Versus Transurethral Resection of the Prostate Comparable?

    PubMed

    Carmignani, Luca; Macchi, Alberto; Ratti, Dario; Finkelberg, Elisabetta; Casellato, Stefano; Bozzini, Giorgio; Maruccia, Serena; Marenghi, Carlo; Picozzi, Stefano

    2015-09-01

    We investigated if an adequate histological diagnosis can be made from tissue after Thulium laser vapo-enucleation of the prostate (ThuVEP) and whether it is comparable to transurethral prostate resection (TURP) tissue findings in patients with symptomatic benign prostatic hyperplasia. We analyzed 350 ThuLEP and 100 matched TURP tissue specimens from patients who underwent one of the two procedures between January 2009 and June 2014. Thulium Laser Enucleation of Prostate (ThuVEP) was combined with mechanical morcellation of the resected lobe. Each histological specimen was reviewed by two pathologists. Preoperative prostate ultrasound volume, total serum prostatic specific antigen and postoperative tissue weight were evaluated. Microscopic histological diagnosis was assessed by standard histological techniques and immunohistochemical evaluation. Patients were comparable in terms of age and preoperative total serum prostate specific antigen. Incidental adenocarcinoma and high grade PIN of the prostate were diagnosed in a comparable percent of specimens in the 2 groups (2.5 % in the ThuVEP group versus 3 % in the TURP group). Tissue thermal artifacts induced by the Thulium laser are mostly due to coagulation as that of the conventional monopolar diathermy in TURP. Tissue quality was maintained in the ThuVEP histological specimens. Tissue maintain histological characteristics and proprieties without modification for successive immunoistochemical analysis. The pathologist ability to detect incidental prostate cancer and PIN was maintained even if there is a quoted of vaporized tissue. PMID:25862670

  19. Ureteroscopy and holmium:YAG laser lithotripsy: an emerging definitive management strategy for symptomatic ureteral calculi in pregnancy

    NASA Astrophysics Data System (ADS)

    Watterson, James D.; Girvan, Andrew R.; Beiko, Darren T.; Nott, Linda; Wollin, Timothy A.; Razvi, Hassan A.; Denstedt, John D.

    2003-06-01

    Objectives: Symptomatic urolithiasis in pregnancy that does not respond to conservative measures has traditionally been managed with ureteral stent insertion or percutaneous nephrostomy (PCN). Holmium:yttrium-aluminum-garnet (YAG) laser lithotripsy using state-of-the-art ureteroscopes represents an emerging strategy for definitive stone management in pregnancy. The purpose of this study was to review the results of holmium laser lithotripsy in a cohort of patients who presented with symptomatic urolithiasis in pregnancy. Methods: A retrospective analysis was conducted at 2 tertiary stone centers from January 1996 to August 2001 to identify pregnant patients who were treated with ureteroscopic holmium laser lithotripsy for symptomatic urolithiasis or encrusted stents. Eight patients with a total of 10 symptomatic ureteral calculi and 2 encrusted ureteral stents were treated. Mean gestational age at presentation was 22 weeks. Mean stone size was 8.1 mm. Stones were located in the proximal ureter/ureteropelvic junction (UPJ) (3), mid ureter (1), and distal ureter (6). Results: Complete stone fragmentation and/or removal of encrusted ureteral stents were achieved in all patients using the holmium:YAG laser. The overall procedural success rate was 91%. The overall stone-free rate was 89%. No obstetrical or urological complications were encountered. Conclusions: Ureteroscopy and holmium laser lithotripsy can be performed safely in all stages of pregnancy providing definitive management of symptomatic ureteral calculi. The procedure can be done with minimal or no fluoroscopy and avoids the undesirable features of stents or nephrostomy tubes.

  20. Holmium-doped 2.1 ?m waveguide chip laser with an output power > 1 W.

    PubMed

    Lancaster, D G; Stevens, V J; Michaud-Belleau, V; Gross, S; Fuerbach, A; Monro, T M

    2015-12-14

    We demonstrate the increasing applicability of compact ultra-fast laser inscribed glass guided-wave lasers and report the highest-power glass waveguide laser with over 1.1 W of output power in monolithic operation in the short-infrared near 2070 nm achieved (51% incident slope efficiency). The holmium doped ZBLAN chip laser is in-band pumped by a 1945 nm thulium fiber laser. When operated in an extended-cavity configuration, over 1 W of output power is realized in a linearly polarized beam. Broad and continuous tunability of the extended-cavity laser is demonstrated from 2004 nm to 2099 nm. Considering its excellent beam quality of M2 = 1.08, this laser shows potential as a flexible master oscillator for single frequency and mode-locking applications. PMID:26699055

  1. Endoscopic laser fragmentation of ureteral calculi using the holmium:YAG

    NASA Astrophysics Data System (ADS)

    Sayer, Jeanie; Johnson, Douglas E.; Price, Roger E.; Cromeens, Douglas M.

    1993-05-01

    We used the holmium:YAG (Ho:YAG) laser successfully to fragment human urinary calculi of various sizes and compositions. At an energy level of 0.5 J/pulse and a frequency of 5 Hz, lithotripsy resulted in minimal ureteral-wall injury that was limited to superficial coagulative necrosis of the submucosa. Increasing the amount of energy or the frequency level, however, often resulted in significant damage to deeper ureteral tissue. When performed at low power settings with care to avoid direct ureteral-wall contact, Ho:YAG laser lithotripsy is safe and effective.

  2. [Critical evaluation of indications for the holmium:YAG laser and the neodymium:YAG laser in orthopedic surgery based on an in vitro study].

    PubMed

    Anders, J O; Pietsch, S; Staupendahl, G

    1999-04-01

    This is an in vitro study of the biophysical effects of holmium:YAG and neodymium-YAG lasers that was prompted by the poor clinical results obtained with lumbar percutaneous laser discus decompression (PLDD). In the absence of adequate cooling, ablation of tissue with the holmium:YAG laser causes thermal damage to the surrounding tissues. Utilizing the immediate colour-independent laser coupling effect, the holmium:YAG laser removes soft and hard tissue immediately. The low tissue penetrating power (max. 0.32 mm), together with the use of irrigation, avoids thermal problems, and this laser type with its high pulse energy and frequency is to be recommended for arthroscopic surgery. In contrast, the effects of the neodymium:YAG laser are highly dependent on tissue colour. Using this laser on light-coloured tissue only diffuse warming but no ablation of soft tissue was often seen. The depth of tissue penetration seen in our study was 0.58 mm, but is greatly dependent on the duration of application, and is much larger with long application times. In conclusion, we believe that the neodymium:YAG laser is more suitable for percutaneous intradiscal procedures than the holmium:YAG laser. For arthroscopic surgery, the holmium:YAG laser will be the better choice. The effect of each type of laser depends not only on its physical properties, but also on tissue properties (light or dark-coloured, thermal conductivity) and duration of application. PMID:10379068

  3. Optimization of dosimetry and safety using the holmium laser for urology

    NASA Astrophysics Data System (ADS)

    van Swol, Christiaan F. P.; Verdaasdonck, Rudolf M.; Zeijlemaker, Bram Y. W.; Grimbergen, Matthijs C. M.; Boon, Tom A.

    1998-07-01

    The holmium laser has become accepted as a versatile instrument for urological applications, such as prostate resection, urethrotomy, tumor coagulation and lithotripsy. Presently, more powerful lasers have become available generating pulses up to 4 J at 80 W. The necessity of these high power systems in urology is ambiguous. In this study, the dosimetry as to efficacy and especially safety was investigated for various applications. The holmium laser ((lambda) equals 2.1 micrometer) emits its energy in 350 microsecond pulses which instantly turn water into vapor. Using high-speed photography explosive vapor bubbles with diameters over 10 mm were captured. The mechanical force of these bubbles, effectively fragments stones but may dilate and rupture a small lumen like the ureter. After implosion of the bubble, the energy of vaporization turns into heat. Depending on pulse energy and pulse repetition rate, tissue can be thermally affected up to 5 mm. For soft tissue applications, e.g., urethrotomy, prostatectomy or tumor coagulation, pulse energies of 0.5 - 1.5 J were applied at a high repetition rate (20 - 40 Hz) to provide sufficient coagulative and hemostatic effects. At higher pulse energies, the fiber tip was vibrating vigorously and the tissue was ripped to pieces decreasing hemostasis and visibility. For hard tissue applications, bursts of 0.5 J pulses at 5 Hz, proved to be sufficient to fragment all types of stones (including cystine) in the ureter and the bladder without mechanical or thermal damage to surrounding tissue. At higher settings, targeting the stone was less controlled and effective due to 'jumping' of the fiber tip with resulting mechanical and thermal trauma to the surrounding tissue. The holmium laser can be used effectively to coagulate and cut soft tissue and fragment stones at relatively low energy and power settings, thus minimizing the risk of complications.

  4. Cavitation effect of holmium laser pulse applied to ablation of hard tissue underwater

    NASA Astrophysics Data System (ADS)

    Lü, Tao; Xiao, Qing; Xia, Danqing; Ruan, Kai; Li, Zhengjia

    2010-07-01

    To overcome the inconsecutive drawback of shadow and schlieren photography, the complete dynamics of cavitation bubble oscillation or ablation products induced by a single holmium laser pulse [2.12 μm, 300 μs (FWHM)] transmitted in different core diameter (200, 400, and 600 μm) fibers is recorded by means of high-speed photography. Consecutive images from high-speed cameras can stand for the true and complete process of laser-water or laser-tissue interaction. Both laser pulse energy and fiber diameter determine cavitation bubble size, which further determines acoustic transient amplitudes. Based on the pictures taken by high-speed camera and scanned by an optical coherent microscopy (OCM) system, it is easily seen that the liquid layer at the distal end of the fiber plays an important role during the process of laser-tissue interaction, which can increase ablation efficiency, decrease heat side effects, and reduce cost.

  5. Cavitation effect of holmium laser pulse applied to ablation of hard tissue underwater.

    PubMed

    Lü, Tao; Xiao, Qing; Xia, Danqing; Ruan, Kai; Li, Zhengjia

    2010-01-01

    To overcome the inconsecutive drawback of shadow and schlieren photography, the complete dynamics of cavitation bubble oscillation or ablation products induced by a single holmium laser pulse [2.12 microm, 300 micros (FWHM)] transmitted in different core diameter (200, 400, and 600 microm) fibers is recorded by means of high-speed photography. Consecutive images from high-speed cameras can stand for the true and complete process of laser-water or laser-tissue interaction. Both laser pulse energy and fiber diameter determine cavitation bubble size, which further determines acoustic transient amplitudes. Based on the pictures taken by high-speed camera and scanned by an optical coherent microscopy (OCM) system, it is easily seen that the liquid layer at the distal end of the fiber plays an important role during the process of laser-tissue interaction, which can increase ablation efficiency, decrease heat side effects, and reduce cost. PMID:20799845

  6. Acute and chronic response of meniscal fibrocartilage to holmium:YAG laser irradiation

    NASA Astrophysics Data System (ADS)

    Horan, Patrick J.; Popovic, Neven A.; Islinger, Richard B.; Kuklo, Timothy R.; Dick, Edward J.

    1997-05-01

    The acute and chronic (10 week) histological effects of the holmium:YAG laser during partial meniscectomy in an in vivo rabbit model were investigated. Twenty-four adult male New Zealand rabbits underwent bilateral parapatellar medial knee arthrotomies. In the right knee, a partial medial meniscectomy was done through the avascular zone using a standard surgical blade. In the left knee, an anatomically similar partial medial meniscectomy was performed using a Ho:YAG laser (Coherent, USA). This study indicates that the laser creates two zones of damage in the meniscal fibrocartilage and that the zone of thermal change may act as a barrier to healing. The zone of thermal change which is eventually debrided was thought at the time of surgery to be viable. In the laser cut menisci, the synovium appears to have greater inflammation early and to be equivalent with the scalpel cut after three weeks. At all time periods there appeared more cellular damage in the laser specimens.

  7. AB093. Treatment of upper ureteral calculi with trans-ureteroscopic holmium laser lithotripsy

    PubMed Central

    Liu, Wei-Guang

    2015-01-01

    Objective To study the clinical effects of using ureteroscopic holmium laser lithotripsy to treat patients with upper urinary tract calculi. Methods We analysis the clinical materials of 260 cases patients in our hospital using ureteroscopic holmium laser lithotripsy to treat patients with upper ureteral stones in 2014. Results The overall successful rate of fragmentation for all ureteral stones in a single procedure achieved 93.1% (242/260). Ten cases were fragmented successfully by ESWL, four cases were fragmented successfully by flexible ureteroscope, two cases were fragmented successfully by mPCNL, two cases were fragmented successfully by laparoscopic. Operation time ranged 36 min (mean 36.47.9 min), and duration of hospitalization after operation was 3-7 d, with an average 4.5 d. There were 15 patients with urinary tract infection and suffered fever. One patient with ureteral perforation, and no one with ureteral avulsion or long term complications such as ureteral stricture. The stone-free rate was 98.3% (238/242) in a month postoperation. Conclusions Trauma patients are small, quick recovery and fewer complications. It is an ideal methods treatment of urinary calculi, especially in some complex upper urinary tract stones, such as patients failed from ESWL or with stone wrapped by hyperplasia tissues. Correct and skilled ureteroscopic holmium laser management may decrease the complication. Breaking the stones gradually, and using small power and slow lavage can prevent stones from translocating efficiently. To treat stones which combined with polyps or wrapped by hyperplasia tissues, it is not necessary to clear the polyps or hyperplasia tissues absolutely, but the stones must be removed absolutely.

  8. Percutaneous Endoscopic Holmium Laser Lithotripsy for Management of Complicated Biliary Calculi

    PubMed Central

    Healy, Kelly; Chamsuddin, Abbas; Spivey, James; Martin, Louis; Nieh, Peter

    2009-01-01

    Background and Objectives: Advances in endoscopic techniques have transformed the management of urolithiasis. We sought to evaluate the role of such urological interventions for the treatment of complex biliary calculi. Methods: We conducted a retrospective review of all patients (n=9) undergoing percutaneous holmium laser lithotripsy for complicated biliary calculi over a 4-year period (12/2003 to 12/2007). All previously failed standard techniques include ERCP with sphincterotomy (n=6), PTHC (n=7), or both of these. Access to the biliary system was obtained via an existing percutaneous transhepatic catheter or T-tube tracts. Endoscopic holmium laser lithotripsy was performed via a flexible cystoscope or ureteroscope. Stone clearance was confirmed intra- and postoperatively. A percutaneous transhepatic drain was left indwelling for follow-up imaging. Results: Mean patient age was 65.6 years (range, 38 to 92). Total stone burden ranged from 1.7 cm to 5 cm. All 9 patients had stones located in the CBD, with 2 patients also having additional stones within the hepatic ducts. All 9 patients (100%) were visually stone-free after one endoscopic procedure. No major perioperative complications occurred. Mean length of stay was 2.4 days. At a mean radiological follow-up of 5.4 months (range, 0.5 to 21), no stone recurrence was noted. Conclusions: Percutaneous endoscopic holmium laser lithotripsy is a minimally invasive alternative to open salvage surgery for complex biliary calculi refractory to standard approaches. This treatment is both safe and efficacious. Success depends on a multidisciplinary approach. PMID:19660213

  9. Zebra guidewire damage by Holmium: YAG laser and management of removal

    PubMed Central

    Huang, Zhichao; Fu, Fajun; Zhong, Zhaohui; Xu, Ran; Zhang, Lei; Deng, Guangcheng; Zhao, Xiaokun

    2015-01-01

    The zebra guidewire is widely used in endoscopic surgery. Because of its central mental core, it is not easy to break or shear off within the urinary tract. We report a case about the breakage of zebra guidewire in ureteroscopy (URS) with Holmium: YAG laser lithotripsy. It is easily to be managed by percutaneous access or open surgery. For the purpose of minimal invasiveness and risk, we performed a retrograde flexible ureteroscopy and extracted it successfully without any complication. To our knowledge, this is the first case report on flexible ureteroscopy to remove the residual tip of damaged guidewire in renal. PMID:26550405

  10. In vivo treatment of proliferations in the vitreous body with a holmium: YAG laser

    NASA Astrophysics Data System (ADS)

    Schruender, Stephan; Foerster, Michael; Mueller-Stolzenburg, Norbert; Sola, Steffen; Schmitt, Isabella; Mueller, Gerhard J.

    1995-01-01

    A Holmium:YAG (Ho:YAG) laser assisted vitrectomy system has been developed. In vitro studies on porcine cadaver eyes were performed to determine optimal laser settings taking into account mechanical effects such as bubble formation and collapse and tissue displacements. Optimal laser settings were 60 - 80 mJ at a pulse length of 150 microsecond(s) . Measurements of induced shockwaves and associated effects led to the construction of a specially designed laser vitrectomy endoprobe that incorporates the distal end of a flexible fiber with 365 micrometers core diameter. Intraocular membranes and strands in the vitreous body of five rabbits were induced by injection of mouse fibroblasts. An additional five rabbits without alterations were treated as a control group. Cutting of membranes was possible and efficient at distances larger than 1.5 mm from the retina. Smaller distances partly led to injuries like retinal holes or ruptures that were induced by mechanical effects of the radiation.

  11. Noncontact tissue ablation by holmium:YSGG laser pulses in blood.

    PubMed

    van Leeuwen, T G; van der Veen, M J; Verdaasdonk, R M; Borst, C

    1991-01-01

    To assess the feasibility of intra-arterial tissue ablation by Holmium:YSGG laser pulses (2.1 microns) in a noncontact mode, the transmission of the laser pulses through saline and blood was measured. The temporal interaction between the 500 microseconds laser pulse and saline at the fiber tip was investigated with time-resolved flash photography. The penetration depth in blood, and saline depended on the fiber output energy. In blood at 37 degrees C, the penetration depth varied from 1.2 to 2.1 mm for intensities of 3.1 to 12.4 J/mm2 per pulse, respectively, whereas its theoretical value for water is 0.33 mm, which is based on the measured absorption coefficient of 3.0 +/- 0.1/mm. The large penetration depth was due to the development of a transparent vapour cavity around the fiber tip. In saline, its maximum length was 4.7 mm. Its maximum width was 2.8 mm. The lifetime of the cavity was 450 microseconds. In blood, ablation of porcine aorta was feasible at a distance of 3 mm. Large fissures observed in adjacent tissue are likely to be caused by the expansion of the vapour cavity. We conclude that, due to a "Moses effect in the microsecond region," Holmium:YSGG tissue ablation is possible through at least 2.7 mm of blood. PMID:1997777

  12. A novel one lobe technique of thulium laser enucleation of the prostate: 'All-in-One' technique

    PubMed Central

    Kim, Yeon Joo; Lee, Yoon Hyung; Kwon, Joon Beom; Cho, Sung Ryong

    2015-01-01

    Purpose The thulium laser is the most recently introduced technology for the surgical treatment of benign prostatic hyperplasia (BPH). Until recently, most thulium laser enucleation of the prostate (ThuLEP) was performed by use of the three-lobe technique. We introduce a novel one-lobe enucleation technique for ThuLEP called the "All-in-One" technique. We report our initial experiences here. Materials and Methods From June 2013 to May 2014, a total of 47 patients underwent the All-in-One technique of ThuLEP for symptomatic BPH performed by a single surgeon. All patients were assessed with the International Prostate Symptom Score (IPSS), transrectal ultrasonography, serum prostate-specific antigen (PSA), maximal urine flow rate (Qmax), and postvoid residual urine volume (PVR) before and 1 month after surgery. We reassessed IPSS, Qmax, and PVR 3 months after surgery. To assess the efficacy of the All-in-One technique, we checked the PSA reduction ratio, transitional zone volume reduction ratio, and enucleation failure rate. Results The mean operative time was 82.1±33.3 minutes. The mean enucleation time and morcellation time were 52.7±21.7 minutes and 8.2±7.0 minutes, respectively. The mean resected tissue weight and decrease in hemoglobin were 36.9±24.6 g and 0.4±0.8 g/dL, respectively. All perioperative parameters showed significant improvement (p<0.05). No major complications were observed. The PSA reduction ratio, transitional zone volume reduction ratio, and enucleation failure rate were 0.81, 0.92, and 4.3%, respectively. Conclusions The All-in-One technique of ThuLEP showed efficacy and effectiveness comparable to that of other techniques. We expect that this new technique could reduce the operation time and the bleeding and improve the effectiveness of enucleation. PMID:26568795

  13. Characteristics of shock waves induced by pulsed lasers and their effects on arterial tissue: comparison of excimer, pulse dye, and holmium YAG lasers.

    PubMed

    Tomaru, T; Geschwind, H J; Boussignac, G; Lange, F; Tahk, S J

    1992-04-01

    Shock waves were investigated using an excimer laser at 308 nm with 18.9 mjoules/pulse, a pulsed dye laser at 480 nm with 100 mjoules/pulse, and a holmium YAG (yttrium-aluminum-garnet) laser at 2.1 microns with 420 mjoules/pulse. At a distance from the target tissue, excimer lasing resulted in no shock waves in saline, while the other lasers produced smaller shock waves than those recorded when the laser was in contact with tissue (0.22 versus 2.0 mm Hg with the pulsed dye laser, 0 versus 0.23 mm Hg with the excimer laser, and 0.44 versus 6.9 mm Hg with the holmium YAG laser; p less than 0.001, respectively). In blood, excimer laser irradiation at a distance from the tissue produced shock waves as great as those produced when the laser was in contact with the tissue (0.19 versus 0.24 mm Hg with the excimer laser, 1.8 versus 3.0 mm Hg with the pulsed dye laser, and 3.1 versus 5.9 mm Hg with the holmium YAG laser; p less than 0.001 with the pulsed dye and holmium YAG lasers, respectively). When lasing was done at 60 mjoules/mm2, the pulsed dye and excimer lasers produced similar shock waves when the lasers were in contact with tissue; however, the holmium YAG laser did not produce shock waves. Thus pulsed lasers can produce shock waves of different characteristics according to the laser source. PMID:1549997

  14. Operation of the nose using Nd-YAG and holmium laser

    NASA Astrophysics Data System (ADS)

    Kukwa, Andrzej; Tulibacki, Marek P.; Zajac, Andrzej; Dudziec, Katarzyna

    2000-06-01

    During more than 5 years Nd:YAG and Holmium laser has been used in our ENT Department for the treatment of varies pathological changes. Most of our cases were previously treated many times because of recurrences of the nasal polyps. As a rule the treatment was given in one to three sessions. Each patient was very closely monitored. The time period between the session was 2-4 weeks. The consequent application of laser was dependent on healing process. All adults' patients were treated in local anesthesia using 1,5 percent of Cocaine and 10 percent Xylocaine applied in a spray; no other anesthetics were needed, although in some patients 10 mg Valium was administered before first session of laser application. We do not observe a severe bleeding needed sponge or a nose package. Among advantages we have to concentrate on two: the recurrences of nasal polyps are definitely much rare and patient may appear at work at the same day.

  15. High power operation of cladding pumped holmium-doped silica fibre lasers.

    PubMed

    Hemming, Alexander; Bennetts, Shayne; Simakov, Nikita; Davidson, Alan; Haub, John; Carter, Adrian

    2013-02-25

    We report the highest power operation of a resonantly cladding-pumped, holmium-doped silica fibre laser. The cladding pumped all-glass fibre utilises a fluorine doped glass layer to provide low loss cladding guidance of the 1.95 m pump radiation. The operation of both single mode and large-mode area fibre lasers was demonstrated, with up to 140 W of output power achieved. A slope efficiency of 59% versus launched pump power was demonstrated. The free running emission was measured to be 2.12-2.15 m demonstrating the potential of this architecture to address the long wavelength operation of silica based fibre lasers with high efficiency. PMID:23481989

  16. Experience with endoscopic holmium laser in the pediatric population

    NASA Astrophysics Data System (ADS)

    Merguerian, Paul A.; Reddy, Pramod P.; Barrieras, Diego; Bagli, Darius J.; McLorie, Gordon A.; Khoury, Antoine E.

    1999-06-01

    Introduction: Due to the unavailability of suitable endoscopic instruments, pediatric patients have not benefited fully from the technological advances in the endoscopic management of the upper urinary tract. This limitation may be overcome with the Holmuim:Yttrium-Aluminum-Garnet(Ho:YAG) laser delivered via small instruments. To date, there is no published report on the use of this modality in children. Purpose: We evaluated the indications, efficacy, and complications of endourological Ho:YAG laser surgery in the treatment of pediatric urolithiasis, posterior urethral valves, ureterocele and ureteropelvic junction obstruction. Methods: The patient population included 10 children with renal, ureteral and bladder calculi, 2 children with posterior urethral valves, 2 children with obstructing ureteroceles, 2 children with ureteropelvic junction obstruction and 1 child with a urethral stricture. Access to the lesions was either antegrade via a percutaneous nephrostomy tract or retrograde via the urethra. A solid state Ho:YAG laser with maximum output of 30 watts (New Star lasers, Auburn, CA) was utilized as the energy source. Results: A total of 10 patients underwent laser lithotripsy. The means age of the patients was 9 yrs (5-13 yrs). The average surface area of the calculi as 425.2 mm2 (92-1645 mm2). 8 of the patients required one procedure to render them stone free, one patient had a staghorn calculus filling every calyx of a solitary kidney requiring multiple treatments and one other patient with a staghorn calculus required 2 treatments. There were no complications related to the laser lithotripsy. Two newborn underwent successful ablation of po sterious urethral valves. Two infants underwent incision of obstructing ureteroceles with decompression of the ureterocele on postoperative ultrasound. Two children underwent endypyelotomy for ureteropelvic junction obstruction. One was successful an done required an open procedure to correct the obstruction. One child underwent successful direct visual urethrotomy for a urethral sticture. Conclusions: The Ho:YAGs ability to pulverize urinary calculi make it an obvious choice for lithotripsy in children. The advantages of this technology are the ability to precisely apply the laser using small fibers, and the laser's ability to pulverize calculi with minimal trauma to surrounding tissue. The Ho-YAG laser is also superior to other modalities in the treatment of secondary ureteropelvic junction obstruction. We do not feel the Ho:YAG laser is superior to the curren treatment methods for the treatment of posterior urethral valves and obstructed ureteroceles.

  17. Erbium:YAG laser photothermal retinal ablation in enucleated rabbit eyes.

    PubMed

    D'Amico, D J; Moulton, R S; Theodossiadis, P G; Yarborough, J M

    1994-06-15

    The erbium:YAG laser has been shown to produce precise tissue ablation because of the high water absorption of the 2.94-microns wave-length emitted by this laser. We used an experimental system to create lesions of various depths in the surface of the rabbit retina in enucleated eyes in vitro to examine the potential application to maneuvers such as retinotomy and the removal of epiretinal membranes in vitrectomy. With an air/retinal interface, single pulses produced discrete craters in the retinal surface with a depth proportional to fluence, ranging from 30 microns for a pulse of 1.3 J/cm2 to a full-thickness retinotomy at 3.9 J/cm2. An adjacent zone of coagulated tissue ranging in size from 15 to 40 microns was noted. Multiple pulses had an additive effect. With a fluid/retinal interface, 20 pulses of 3.6 J/cm2 produced a full-thickness retinotomy, with an adjacent zone of damaged tissue up to 1 mm, caused by effects of volatilization of intervening fluid. The erbium:YAG laser may have a role in vitreoretinal surgery. PMID:8198163

  18. Metals fact sheet: Holmium/thulium

    SciTech Connect

    1996-02-01

    This article discusses the geology, exploitation, market, and applications of holmium and thulium. Holmium and thulium are important part in the development of specific laser technologies, x-ray film and high-temperature superconductors.

  19. Holmium laser ablation of cartilage: effects of cavitation bubbles

    NASA Astrophysics Data System (ADS)

    Asshauer, Thomas; Jansen, Thomas; Oberthur, Thorsten; Delacretaz, Guy P.; Gerber, Bruno E.

    1995-05-01

    The ablation of fresh harvested porcine femur patellar groove cartilage by a 2.12 micrometers Cr:Tm:Ho:YAG laser in clinically used irradiation conditions was studied. Laser pulses were delivered via a 600 micrometers diameter fiber in isotonic saline. Ablation was investigated as a function of the angle of incidence of the delivery fiber with respect to the cartilage surface (0-90 degrees) and of radiant exposure. Laser pulses with energies of 0.5, 1.0 and 1.5 J and a duration of 250 microseconds were used. A constant fiber tip-tissue distance of 1 mm was maintained for all experiments. The dynamics of the induced vapor bubble and of the ablation process was monitored by time resolved flash videography with a 1 microseconds illumination. Acoustic transients were measured with a piezoelectric PVDF needle probe hydrophone. Bubble attachment to the cartilage surface during the collapse phase, leading to the direct exposition of the cartilage surface to the maximal pressure generated, was observed in all investigated irradiation conditions. Maximal pressure transients of up to 200 bars (at 1 mm distance from the collapse center) were measured at the bubble collapse at irradiation angles >= 60 degrees. No significant pressure variation was observed in perpendicular irradiation conditions as a function of radiant exposure. A significant reduction of the induced pressure for irradiation angles

  20. Evaluation of holmium laser versus cold knife in optical internal urethrotomy for the management of short segment urethral stricture

    PubMed Central

    Jain, Sudhir Kumar; Kaza, Ram Chandra Murthy; Singh, Bipin Kumar

    2014-01-01

    Objectives: Sachse cold knife is conventionally used for optical internal urethrotomy intended to manage urethral strictures and Ho: YAG laser is an alternative to it. The aim of this study was to evaluate the role of urethral stricture treatment outcomes, efficacy, and complications using cold knife and Ho: YAG (Holmium laser) for optical internal urethrotomy Materials and Methods: In this prospective study included, 90 male patients age >18 years, with diagnosis of urethral stricture admitted for internal optical urethrotomy during April 2010 to March 2012. The patients were randomized into two groups containing 45 patients each using computer generated random number. In group A (Holmium group), internal urethrotomy was done with Holmium laser and in group B (Cold knife group) Sachse cold knife was used. Patients were followed up for 6 months after surgery in Out Patient Department on 15, 30 and 180 post-operative days. At each follow up visit physical examination, and uroflowmetry was performed along with noting complaints, if any. Results: The peak flow rates (PFR) were compared between the two groups on each follow up. At 180 days (6 month interval) the difference between mean of PFR for Holmium and Cold knife group was statistically highly significant (P < 0.001). Complications were seen in 12.22% of cases. Conclusion: Both modalities are effective in providing immediate relief to patients with single and short segment (<2 cm long) urethral strictures but more sustained response was attained with Cold knife urethrotomy. PMID:25371611

  1. Application of 2-um wavelength holmium lasers for treatment of skin diseases

    NASA Astrophysics Data System (ADS)

    Shcherbakov, Ivan A.; Klimov, Igor V.; Tsvetkov, Vladimir B.; Nerobeev, Alexander I.; Sadovnikova, Lija B.; Eliseenko, Vladimir I.

    1994-09-01

    Theoretical and experimental analysis of the efficiency of application of 2 micrometers pulsed holmium laser for cosmetic and plastic surgery and dermatology is carried out. Preliminary experiments were carried out on rats. Solid state 2 micrometers pulsed laser was allowed to operate in free running mode with pulse energy up to 1.5 J and pulse repetition rate up to 5 Hz. To deliver emission to the object a flexible quartz fiber without further focusing of 2.5 m in length and 400 micrometers of the core diameter was used. The effect of the different power density emission on the skin was studied. The second stage was the study of the influence of 2 micrometers emission on human skin. The results of the removal of hemangioma, papilloma, telangiectasia, nevus, nevus acantholytic, xanthelasma palpebral, verruca, chloasma, pigmental spots, tattoos, etc. are presented. Precision, simplicity, efficiency, and the high cosmetic effect of these operations is noted.

  2. Tissue ablation by holmium:YSGG laser pulses through saline and blood

    NASA Astrophysics Data System (ADS)

    van Leeuwen, Ton G. J. M.; van der Veen, Maurits J.; Verdaasdonck, Rudolf M.; Borst, Cornelius

    1991-06-01

    The use of 2.09 micrometers Ho-YSGG laser pulses for intra-vascular non- contact ablation of tissue has been investigated. Therefore the transmission and the temporal shape of the laser pulse transmitted through saline was measured. Also the interaction between the laser pulses (200 microsecond(s) FWHM) and saline was studied by time resolved flash photography. Finally, porcine aorta was ablated (in vitro) through either blood or saline. The lesions and adjacent tissue were examined histologically. The penetration depth (the depth for a decrease to 1/e of the transmitted energy) of the laser pulses in saline depended on the power density (0.01 to 12.4 J/mm2) and varied from 0.33 to 2.2 mm, respectively. The photography showed the development of a transparent water vapor cavity around the fiber tip (320 micrometers ) during the laser pulse. The maximum dimensions of the cavity varied as function of the intensity. Within the vapor cavity the laser pulse was undisturbed. Due to this 'Moses effect in the microsecond region' porcine aorta could be ablated through up to 3 mm of saline and blood. Especially after successive laser pulses, histology showed large fissures in adjacent tissue, presumably due to the expanding vapor cavity and the layered structure of the aorta. In conclusion, the formation of a vapor cavity during Holmium laser irradiation in physiological media enables non- contact tissue ablation and induces fissures into adjacent tissue, that may be undesirable.

  3. Q-switching of a thulium-doped fibre laser using a holmium-doped fibre saturable absorber

    SciTech Connect

    Sadovnikova, Ya E; Kamynin, V A; Kurkov, A S; Medvedkov, O I; Marakulin, A V; Minashina, L A

    2014-01-31

    We have proposed and demonstrated a new passively Q-switched thulium-doped fibre laser configuration. A distinctive feature of this configuration is the use of a heavily holmium-doped fibre for Q-switching. Lasing was obtained at 1.96 ?m, with a pulse energy of 3 ?J and pulse duration of 600 ns. The highest pulse repetition rate was 80 kHz. (control of laser radiation parameters)

  4. Correlation of thermal and mechanical effects of the holmium laser for various clinical applications

    NASA Astrophysics Data System (ADS)

    Grimbergen, Matthijs C. M.; Verdaasdonck, Rudolf M.; van Swol, Christiaan F. P.

    1998-05-01

    The Holmium laser has become established in orthopedic surgery and urology due to its unique combination of mechanical and thermal properties induced by explosive vapor bubbles. In a specialized setup, real-time high-speed and thermal images of dynamic vapor bubbles and thermal relaxation at a water tissue interface were obtained simultaneously. The thermal effects in the tissue model were correlated to the characteristics of the bubbles dependent on pulse energy (0.2 - 4 J), pulse repetition frequency (5 - 40 Hz), distance and angle of fiber delivery system (diameter 365 micrometer) to the tissue surface. Up to a fiber-to-tissue distance of 50% of the radius of the bubble, only a superficial tissue layer was heated. During bubble implosion, the tissue surface was attracted to the fiber, ripping of irregularities, and was effectively cooled by turbulence. In case of hard tissues, the bubble detached from the fiber imploding towards the hard surface. At closer distances (less than 50% of bubble radius), the tissue itself was vaporized resulting in mechanical damage and thermal relaxation into the tissue, especially above repetition rates of 5 Hz. There is a strong correlation between the path length of the free beam within the bubble and the degree of mechanical and thermal damage in the tissue directly irradiated by this beam. During clinical applications the surgeon should be aware of the size of the vapor bubble in relation to the distance and angle with the tissue for safe optimal use of the mechanical and thermal properties of the Holmium laser.

  5. Percutaneous Transhepatic Endoscopic Holmium Laser Lithotripsy for Intrahepatic and Choledochal Biliary Stones

    SciTech Connect

    Rimon, Uri; Kleinmann, Nir; Bensaid, Paul; Golan, Gil; Garniek, Alexander; Khaitovich, Boris; Winkler, Harry

    2011-12-15

    Purpose: To report our approach for treating complicated biliary calculi by percutaneous transhepatic endoscopic biliary holmium laser lithotripsy (PTBL). Patients and Methods: Twenty-two symptomatic patients (11 men and 11 women, age range 51 to 88 years) with intrahepatic or common bile duct calculi underwent PTBL. Nine patients had undergone previous gastrectomy and small-bowel anastomosis, thus precluding endoscopic retrograde cholangiopancreatography. In the other 13 patients, stone removal attempts by ERCP failed due to failed access or very large calculi. We used a 7.5F flexible ureteroscope and a 200-{mu}m holmium laser fiber by way of a percutaneous transhepatic tract, with graded fluoroscopy, to fragment the calculi with direct vision. Balloon dilatation was added when a stricture was seen. The procedure was performed with the patient under general anaesthesia. A biliary drainage tube was left at the end of the procedure. Results: All stones were completely fragmented and flushed into the small bowel under direct vision except for one patient in whom the procedure was aborted. In 18 patients, 1 session sufficed, and in 3 patients, 2 sessions were needed. In 7 patients, balloon dilatation was performed for benign stricture after Whipple operation (n = 3), for choledochalenteric anastomosis (n = 3), and for recurrent cholangitis (n = 1). Adjunctive 'balloon push' (n = 4) and 'rendezvous' (n = 1) procedures were needed to completely clean the biliary tree. None of these patients needed surgery. Conclusion: Complicated or large biliary calculi can be treated successfully using PTBL. We suggest that this approach should become the first choice of treatment before laparoscopic or open surgery is considered.

  6. Risk factors of infectious complications following flexible ureteroscope with a holmium laser: a retrospective study

    PubMed Central

    Fan, Song; Gong, Binbin; Hao, Zongyao; Zhang, Li; Zhou, Jun; Zhang, Yifei; Liang, Chaozhao

    2015-01-01

    Purpose: We aimed to evaluate the effectiveness of flexible ureteroscope for treating kidney stones and the risk factors for infectious complications following flexible ureteroscope (FURS) with a holmium laser. Methods: We retrospectively reviewed the data of 227 patients with kidney stones who underwent flexible ureteroscope with a holmium laser at our hospital from January 2012 to September 2014, including gender, age, comorbidity, urine analysis results, urine culture results, blood test results, stone size, operative duration, and residual stones. Patients with and without infectious complications were assigned to groups A and B, respectively. The dependent variables were postoperative infectious complications, and the risk factors for infectious complications following FURS were assessed using Chi-square tests and multivariate logistic regression analyses. Results: All the surgeries were successfully completed. The total stone-free rate was 81.9% (n = 186), and the incidence of infectious complications after FURS was 8.37% (n = 19). Fifteen patients (6.61%) developed fever postoperatively, 10 patients (4.41%) developed systemic inflammatory response syndrome (SIRS), 6 patients with fever were considered to have SIRS (2.64%), and 2 patients had sepsis (0.88%). Univariate analyses of groups A and B indicated that pyuria, stone size, operative duration, and infectious stones were risk factors for infectious complications after FURS (P < 0.05). Multivariate logistic regression analyses indicated that pyuria (P = 0.017), operative duration (P = 0.026), and infectious stones (P = 0.030) were independently related to infectious complications. Conclusion: Pyuria, operative duration, and infectious stones were risk factors for infectious complications following FURS. Hence, routine urinalysis findings should be carefully considered, particularly the finding of pyuria. PMID:26379932

  7. Holmium:YAG laser treatment of ureteral calculi: A 5-year experience.

    PubMed

    Farkas, A; Pteri, L; Lorincz, L; Salah, M A; Flask, T; Varga, A; Tth, Cs

    2006-09-01

    The purpose of this study was to provide an account of the 5-year experience we have gained using holmium:yttrium-aluminium-garnet (Ho:YAG) lasertripsy in the treatment of ureteral stones. One-hundred thirty-seven transurethral ureterolithotripsies were performed in 131 patients. A Ho:YAG laser device, fibres with diameters of 360 and 550 mum, a video camera as well as semi-rigid and flexible ureterorenoscopes were used. Results showed that the direct success rates-which meant stone-free ureters on the first post-operative day-in the upper, middle and lower ureters were 84.6, 88.7 and 94.8%, respectively. The final success rates--which meant stone-free ureters 4 weeks after the operation without a second intervention--were 84.6, 96.7 and 96.7%, respectively. The pulsatile Ho:YAG laser beam fragmented all kinds of stones easily. No ureteral stricture or reflux was identified during the follow-up period. The advantages of Ho lasertripsy outweighed its disadvantages. Based on our experience, the Ho:YAG laser is one of the most effective and safest energy sources in the treatment of ureteral calculi. PMID:16897107

  8. Clinical experience with percutaneous holmium:YAG laser discectomy in dogs

    NASA Astrophysics Data System (ADS)

    Henry, George A.; Bartels, Kenneth E.; Dickey, D. Thomas

    1995-05-01

    Thirty-five clinical cases received laser disc ablation utilizing a uniplanar fluoroscopically guided percutaneous technique over a three year period. With the dog in right lateral recumbency, uniplanar fluoroscopy was utilized to guide the placement of 20-gauge, 2.5 inch spinal needles percutaneously through the left epaxial soft tissues into the nucleus pulposus with the dog in right lateral recumbency. The needle was advanced in increments following palpation and brief fluoroscopic observations to insure avoidance of the spinal cord and other vital structures. Entrance into the intervertebral disc was identified by a characteristic `gritty' feel of the needle passing through the annulus fibrosus. The dog was then placed in sternal recumbency, and the needles adjusted to place the tip approximately one-third of the distance into the disc. The laser fiber was then placed through the needle into the nucleus pulposus to ablate the nucleus with holmium laser energy. No detrimental side effects of this technique have been identified with the exception of one case. This single exception suggests that this procedure should not be performed on dogs with acute disc herniation. The technique appears safe given adherence to careful placement of the spinal needles and proper clinical criteria for patient selection.

  9. Sexual outcome of patients undergoing thulium laser enucleation of the prostate for benign prostatic hyperplasia

    PubMed Central

    Carmignani, Luca; Bozzini, Giorgio; Macchi, Alberto; Maruccia, Serena; Picozzi, Stefano; Casellato, Stefano

    2015-01-01

    Treatment of patients with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) may affect the quality of sexual function and ejaculation. The effect of new surgical procedures, which are currently available to treat BPH, on erection and ejaculation, has been poorly studied. This study aimed to assess the effect of thulium laser enucleation of the prostate (ThuLEP) on sexual function and retrograde ejaculation in patients with LUTS secondary to BPH. We performed a prospective study in 110 consecutive patients who had undergone ThuLEP to analyze changes in sexual function and urinary symptoms. To evaluate changes in erection and ejaculation, and the effect of urinary symptoms on the quality of life (QoL), five validated questionnaires were used: the ICIQ-MLUTSsex, MSHQ-EjD, International Index of Erectile Function 5, International Prognostic Scoring System (IPSS) questionnaire, and QoL index of the intraclass correlation coefficients. Patients also underwent IPSS and flowmetry to assess the outcome of flow. Patients were evaluated before surgery and 36 months after ThuLEP, whereas those with previous abdominal surgery were excluded. The patients mean age was 67.83 years. Postoperative urinary symptoms improved after surgery. No significant differences in erectile function before and after surgery were observed. As compared with other techniques described in the literature, the percentage of patients with conserved ejaculation increased by 52.7% after ThuLEP. ThuLEP positively affects urinary symptoms and their effect on the QoL of patients as assessed by questionnaire scores. While endoscopic management of BPH (e.g. transurethral resection of the prostate) causes retrograde ejaculation in most patients, those who undergo ThuLEP have conserved ejaculation and erectile function. PMID:25652616

  10. Sexual outcome of patients undergoing thulium laser enucleation of the prostate for benign prostatic hyperplasia.

    PubMed

    Carmignani, Luca; Bozzini, Giorgio; Macchi, Alberto; Maruccia, Serena; Picozzi, Stefano; Casellato, Stefano

    2015-01-01

    Treatment of patients with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) may affect the quality of sexual function and ejaculation. The effect of new surgical procedures, which are currently available to treat BPH, on erection and ejaculation, has been poorly studied. This study aimed to assess the effect of thulium laser enucleation of the prostate (ThuLEP) on sexual function and retrograde ejaculation in patients with LUTS secondary to BPH. We performed a prospective study in 110 consecutive patients who had undergone ThuLEP to analyze changes in sexual function and urinary symptoms. To evaluate changes in erection and ejaculation, and the effect of urinary symptoms on the quality of life (QoL), five validated questionnaires were used: the ICIQ-MLUTSsex, MSHQ-EjD, International Index of Erectile Function 5, International Prognostic Scoring System (IPSS) questionnaire, and QoL index of the intraclass correlation coefficients. Patients also underwent IPSS and flowmetry to assess the outcome of flow. Patients were evaluated before surgery and 3-6 months after ThuLEP, whereas those with previous abdominal surgery were excluded. The patients' mean age was 67.83 years. Postoperative urinary symptoms improved after surgery. No significant differences in erectile function before and after surgery were observed. As compared with other techniques described in the literature, the percentage of patients with conserved ejaculation increased by 52.7% after ThuLEP. ThuLEP positively affects urinary symptoms and their effect on the QoL of patients as assessed by questionnaire scores. While endoscopic management of BPH (e.g. transurethral resection of the prostate) causes retrograde ejaculation in most patients, those who undergo ThuLEP have conserved ejaculation and erectile function. PMID:25652616

  11. Acoustic transients in pulsed holmium laser ablation: effects of pulse duration

    NASA Astrophysics Data System (ADS)

    Asshauer, Thomas; Delacretaz, Guy P.; Jansen, E. Duco; Welch, Ashley J.; Frenz, Martin

    1995-01-01

    The goal of this work was to study the influence of pulse duration on acoustic transient generation in holmium laser ablation. For this, the generation and collapse of cavitation bubbles induced by Q-switched and free-running laser pulses delivered under water were investigated. Polyacrylamide gel of 84% water content served as a model for soft tissue. This gel is a more realistic tissue phantom than water because it mimics not only the optical properties but also the mechanical properties of tissue. The dynamics of bubble formation inside the clear gel were observed by 1 ns time resolved flash videography. A polyvinylidenefluoride (PVDF) needle probe transducer measured absolute values of pressure amplitudes. Pressure wave generation by cavitation bubble collapse was observed in all phantoms used. Maximum pressures of more than 180 bars at 1 mm from the collapse center were observed in water and high water-contents gels with a pulse energy of 200 mJ and a 400 micrometers fiber. A strong dependency of the bubble collapse pressure on the pulse duration for constant pulse energy was observed in gel as well as in water. For pulse durations longer than 400 microsecond(s) a 90% reduction of pressure amplitudes relative to 100 microsecond(s) pulses was found. This suggests that optimization of pulse duration offers a degree of freedom allowing us to minimize the risk of acoustical damage in medical applications like arthroscopy and angioplasty.

  12. The evaluation of tissue mass loss in the incision line of prostate with benign hyperplasia performed using holmium laser and cutting electrode

    PubMed Central

    Szewczyk, Mariusz; JesionekKupnicka, Dorota; Lipinski, Piotr; R?a?ski, Waldemar

    2014-01-01

    Introduction The aim of this study is to compare the changes in the incision line of prostatic adenoma using a monopolar cutting electrode and holmium laser, as well as the assessment of associated tissue mass and volume loss of benign prostatic hyperplasia (BPH). Material and methods The material used in this study consisted of 74 preparations of prostatic adenoma obtained via open retropubic adenomectomy, with an average volume of 120.7 ml. The material obtained cut in vitro before fixation in formaldehyde. One lobe was cut using holmium laser, the other using a monopolar cutting electrode. After the incision was made, tissue mass and volume loss were evaluated. Thermocoagulation changes in the incision line were examinedunder light microscope. Results In the case of the holmium laser incision, the average tissue mass loss was 1.73 g, tissue volume loss 3.57 ml and the depth of thermocoagulation was 1.17 mm. When the monopolar cutting electrode was used average tissue mass loss was 0.807 g, tissue volume loss 2.48 ml and the depth of thermocoagulation was 0.19 mm. Conclusions Where holmium laser was used, it was observed that the layer of tissue with thermocoagulation changes was deeper than in the case of the monopolar cutting electrode. Moreover, it was noticed that holmium laser caused bigger tissue mass and volume loss than the cutting electrode. PMID:25247088

  13. Kidney stone ablation times and peak saline temperatures during Holmium:YAG and Thulium fiber laser lithotripsy, in vitro, in a ureteral model

    NASA Astrophysics Data System (ADS)

    Hardy, Luke A.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

    2015-02-01

    Using a validated in vitro ureter model for laser lithotripsy, the performance of an experimental Thulium fiber laser (TFL) was studied and compared to clinical gold standard Holmium:YAG laser. The Holmium laser (? = 2120 nm) was operated with standard parameters of 600 mJ, 350 ?s, 6 Hz, and 270-?m-core optical fiber. TFL (? = 1908 nm) was operated with 35 mJ, 500 ?s, 150-500 Hz, and 100-?m-core fiber. Urinary stones (60% calcium oxalate monohydrate / 40% calcium phosphate), of uniform mass and diameter (4-5 mm) were laser ablated with fibers through a flexible video-ureteroscope under saline irrigation with flow rates of 22.7 ml/min and 13.7 ml/min for the TFL and Holmium laser, respectively. The temperature 3 mm from tube's center and 1 mm above mesh sieve was measured by a thermocouple and recorded during experiments. Total laser and operation times were recorded once all stone fragments passed through a 1.5-mm sieve. Holmium laser time measured 167 +/- 41 s (n = 12). TFL times measured 111 +/- 49 s, 39 +/- 11 s, and 23 +/- 4 s, for pulse rates of 150, 300, and 500 Hz (n = 12 each). Mean peak saline irrigation temperatures reached 24 +/- 1 C for Holmium, and 33 +/- 3 C, 33 +/- 7 C, and 39 +/- 6 C, for TFL at pulse rates of 150, 300, and 500 Hz. To avoid thermal buildup and provide a sufficient safety margin, TFL lithotripsy should be performed with pulse rates below 500 Hz and/or increased saline irrigation rates. The TFL rapidly fragmented kidney stones due in part to its high pulse rate, high power density, high average power, and reduced stone retropulsion, and may provide a clinical alternative to the conventional Holmium laser for lithotripsy.

  14. Management of calcular anuria in adults caused by ureteric stones: By using of ureteroscopy and holmium laser

    PubMed Central

    Abdel-Kader, Mohammad S.

    2011-01-01

    Purpose To present our clinical outcomes in the management of anuria in adult patients caused by ureteral calculi by using of ureteroscopy and holmium laser. Materials and methods Nineteen patients presented with calcular anuria with ages between 19 and 48years. The presentation was anuria with serum creatinine levels of 25.5mg% (mean 3.5) and hyperkalemia in nine patients (5.26.1mmol/L). There were bilateral ureteric stones in 14 (73.7%) and unilateral in five (26.3%) with single functioning kidney. Thirty-three ureteroscopic procedures were performed for 19 patients including bilateral ureteroscopy in 14. Laser lithotripsy was delivered using holmium laser via 356?m laser fibre, with energy (11.2J) and pulse rate (10Hz). Post-operatively, monitoring of urine output, serum creatinine and K levels was done until normal values were obtained. Results Ureteroscopy was performed for all 19 patients (33 procedures), but laser lithotripsy was done successfully in 30 procedures. The operative time was 46min (2570). The successful fragmentation rate was (100%). The stone-free rate was 90.9%. There were mucosal abrasions in 6 (31.5%), and mild to moderate haematuria in 9 (47.4%), and high fever in two patients (10.5%). Serum creatinine and potassium levels returned to normal within 710days. Urine output gradually reached normal level within a week. Conclusions Ureteroscopy and holmium laser lithotripsy represent an effective and safe modality for the treatment of anuria caused by ureteral calculi. PMID:26579292

  15. Laser dynamics of a mode-locked thulium/holmium fiber laser in the solitonic and the stretched pulse regimes

    NASA Astrophysics Data System (ADS)

    Kadel, Rajesh

    Mode-locked lasers that produce short optical pulses in the mid-infrared wavelength region have been sought out for a wide range of applications such as free space communication, molecular spectroscopy, medical diagnostics, and remote sensing. Here, a thulium and holmium (Tm/Ho) co-doped fiber laser that mode-locks in both the solitonic and stretched-pulse regimes is used to produce ultra-short pulses in the 2 mum region. Nonlinear polarization rotation technique is used where fiber nonlinearity is responsible to mode-lock the laser. The anomalous group velocity dispersion of both the single mode and gain fibers used limit the laser operation in the solitonic regime where spectral bandwidth is 10 nm and hence the pulse duration is limited to 996 fs. In order to increase the spectral bandwidth and hence get the shorter pulses the anomalous dispersion of these fibers has to compensate using normal group velocity dispersion fiber in the laser cavity. High numerical aperture fibers, which have normal group velocity dispersion around 2 mum due to its large and positive waveguide dispersion, can be used to compensate the anomalous dispersion of the gain and single mode fibers. We used a high numerical aperture fiber called UHNA4 in the laser cavity in order to compensate the anomalous dispersion of other fibers and mode-locked the laser in stretched pulse regime. The spectral bandwidth of the laser increased to 31 nm with corresponding pulse duration of 450 fs measured from the interferometric autocorrelation. The laser dynamics of the Tm/Ho co-doped fiber laser is also studied while going from the stretched-pulse to solitonic regime by fiber cut-back measurements of normal dispersion fiber. It was clearly observed that both the spectral bandwidth and the pulse duration changed significantly going from one region to the other.

  16. Use of the holmium:YAG laser for percutaneous photothermal ablation of cervical invertebral disks in dogs

    NASA Astrophysics Data System (ADS)

    Rochat, Mark; Henry, George A.; Campbell, Gregory A.; Stair, Ernest L.; Bartels, Kenneth E.; Dickey, Tom

    1999-06-01

    Holmium:YAG laser ablation of thoracolumbar disks in dogs has been shown to be an effective alternative to standard surgical fenestration techniques. Our hypothesis was the Holmium:YAG laser could be equally effective and safe when used to ablate cervical intervertebral disks. Six normal chondrodystrophoid breed dogs were used. A sterile, cleaved, 320 micrometers , low-OH quartz optical fiber was inserted into each needle and the laser activated for 40 s at 2 W mean power and a 15 Hz pulse repetition rate for a total of 80 J. Dogs were observed in pain, neurological deficits, or other complications for 24 weeks. At 24 weeks, dogs were euthanatized and cervical disks collected and placed in 10 percent neutral buffered formalin. Disks were decalcified, sectioned at 5 micrometers , and stained with H and E. No problems were encountered during the procedure except occasional difficulties passing the needle by the shoulder to enter the C6-7 disk space. No complications, including neurologic deficits or pain were observe during the 24 weeks. Histologic examination revealed varying degrees of necrosis and defects created in the nucleus pulposus by laser irradiation. In some instances there was evidence of mild adjacent annular and bony thermal injury. On the basis of these result, the Ho:YAG laser appears to be a safe and efficacious method for ablation of canine cervical disks.

  17. Stretched-pulse and solitonic operation of an all-fiber thulium/holmium-doped fiber laser.

    PubMed

    Kadel, Rajesh; Washburn, Brian R

    2015-02-01

    Stretched-pulse operation of a mode-locked thulium/holmium-doped fiber laser has been demonstrated using a high numerical aperture (NA) fiber inside the laser cavity for intracavity dispersion compensation. The high NA fiber exhibits normal group-velocity dispersion allowing for the net-cavity dispersion to be positive. We experimentally investigate the laser dynamics as a function of the net-cavity dispersion, observing the transition from stretched-pulse to solitonic operation as the length of high NA fiber was reduced. In the stretched-pulse regime the laser produced pulses with a bandwidth of 30nm and duration of 450fs. Methods for compensating the third-order dispersion using high NA fibers are proposed. PMID:25967783

  18. Comparison of the pulsed dye and holmium lasers for stone fragmentation: in-vitro studies and clinical experience

    NASA Astrophysics Data System (ADS)

    Watson, Graham M.; Smith, Neil

    1993-05-01

    The pulsed dye laser used with a 1 microsecond pulse duration at 504 nm delivered via a 320 micron core fiber is designed specifically for ureteric calculi. The threshold for stone fragmentation is in the region of 40 to 50 mJ for the majority of stones. Fragmentation is efficient in the 60 to 70 mJ range but for some stones 100 mJ is required. The Candela MDL 2000 (Candela Corporation) is capable of delivering 140 mJ. This laser has minimal effect on tissue. The holmium laser delivers 300 microsecond pulses of 2.1 microns wavelength (Sunrise Technologies and Coherent Ltd). A maximum of 1 J per pulse at 5 Hz is usually recommended because of the significant action on tissue. Even using this regimen significant damage can be inflicted on the ureter. In this paper the action of these two laser regimens on stones is contrasted.

  19. A review of thulium laser vapo-enucleation of the prostate: A novel laser-based strategy for benign prostate enlargement

    PubMed Central

    Jones, Patrick; Rai, Bhavan Prasad; Somani, Bhaskar K.; Aboumarzouk, Omar M.

    2015-01-01

    Thulium laser vapo-enucleation of the prostate is the latest addition to the arsenal of minimally invasive therapies available for the surgical treatment of lower urinary tract symptoms secondary to benign prostate hyperplasia. The potential advantages include smoother vaporisation, a clearer visual field and the option of both continuous-wave and pulsed modes, which also potentiate the haemostatic properties of this endoscopic method. Short-term results show that it yields significant improvements in both subjective and objective outcomes, with a strong safety profile. Large-scale randomised studies with a longer follow-up are warranted to determine the durability of this laser procedure. PMID:26413349

  20. A review of thulium laser vapo-enucleation of the prostate: A novel laser-based strategy for benign prostate enlargement.

    PubMed

    Jones, Patrick; Rai, Bhavan Prasad; Somani, Bhaskar K; Aboumarzouk, Omar M

    2015-09-01

    Thulium laser vapo-enucleation of the prostate is the latest addition to the arsenal of minimally invasive therapies available for the surgical treatment of lower urinary tract symptoms secondary to benign prostate hyperplasia. The potential advantages include smoother vaporisation, a clearer visual field and the option of both continuous-wave and pulsed modes, which also potentiate the haemostatic properties of this endoscopic method. Short-term results show that it yields significant improvements in both subjective and objective outcomes, with a strong safety profile. Large-scale randomised studies with a longer follow-up are warranted to determine the durability of this laser procedure. PMID:26413349

  1. AB131. Novel green-light KTP laser en bloc enucleation for nonmuscle-invasive bladder cancer: technique and initial clinical experience

    PubMed Central

    He, Dalin; Fan, Jinhai; Wu, Kaijie; Wang, Xinyang; Wu, Dapeng; Li, Lei; Li, Xudong; Liu, Lixia; Cao, Peilong; Cao, Jianwei; Chang, Luke S.

    2014-01-01

    Background and purpose The standard procedure for staging and treating nonmuscle-invasive bladder cancer (NMIBC) is still transurethral resection of bladder tumor (TURBT) via a wire loop. However, TURBT is associated with serious disadvantages that facilitate tumor recurrence. Recently, lasers have been explored as treatment tools for bladder tumors. Here, we report a novel tumor en bloc enucleation using a front-firing green-light potassium-titanyl-phosphate laser and its initial clinical application. Patients and methods From March through June 2013, 45 patients with NMIBC received modified transurethral resection using a front-firing green-light laser. En bloc enucleation was performed on all tumors. Preoperative and intraoperative data were retrospectively collected. Results All patients successfully went through a session of treatment with front-firing green-light laser enucleation of the bladder tumor. Complications such as bladder hemorrhage, vesicle perforation, and obturator nerve reflex were not encountered during the treatment. The tumor diameter ranges from 0.3 to 3.0?cm with a mean value of 1.8?cm. Mean operative time and enucleation time were 21 [12-38] and 12 [4-23] minutes, respectively. Serum hemoglobin decreased 1.1 (0.1-2.4) mg/dL averagely. Mean catheter time was 2.0 (1.0-3.0) days, and mean postoperative hospital stay was 2.5 (1.5-4.0) days. The stages of bladder cancer included 27 Ta, 15 T1, and 3 T2a. No tumor recurrence was observed at the initial 6-month follow-up. Conclusions The modified technique using a front-firing green-light laser to en bloc enucleate bladder tumors is effective and safe for treatment of NMIBC. Moreover, it may improve the accurate valuation of tumor stage and prediction of postoperative prognosis, although long-term outcomes and prospective clinical trials are needed.

  2. Holmium YLF amplifier performance and the prospects for multi-Joule energies using diode-laser pumping

    NASA Technical Reports Server (NTRS)

    Storm, Mark E.

    1993-01-01

    Laser studies were performed to examine the amplifier characteristics of holmium-doped yttrium lithium fluoride (YLF) at 300 K. An inversion ratio of 0.37 was reached resulting in a measured small-signal gain coefficient of 0.50/cm. In a flashlamp pumping experiment, an output energy of 240 mJ was achieved for 38.5 mJ of input energy resulting in a large gain of 6.2. An amplifier model was developed for diode laser pumping and adapted to consider this flashlamp-pumped case. There is good agreement between the theory and experiment. Multipass amplifier calculations using the model suggest that the Ho: Tm: YLF laser crystal can support a 12 percent electrical to optical efficiency at 300 K even in the presence of upconversion.

  3. Holmium YLF amplifier performance and the prospects for multi-Joule energies using diode-laser pumping

    SciTech Connect

    Storm, M.E. )

    1993-02-01

    Laser studies were performed that examined the amplifier characteristics of holmium-doped yttrium lithium fluoride (YLF) at 300 K. An inversion ratio n[sup 5]I[sub 7]/n[sub H0] of 0.37 was reached resulting in a measured small-signal gain coefficient of 0.50 cm[sub [minus]1]. In a flashlamp pumping experiment, an output energy of 240 mJ was achieved for 38.5 Mj of input energy resulting in a large gain of 6.2. An amplifier model was developed for diode laser pumping and adapted to consider this flashlamp-pumped case. There is good agreement between the theory and experiment. Multipass amplifier calculations using the model suggest that the Ho:Tm:YLF laser crystal can support a 12% electrical to optical efficiency at 300 K even in the presence of upconversion.

  4. Subcapsular renal hematoma after ureteroscopy with holmium:yttrium-aluminum-garnet laser lithotripsy.

    PubMed

    Tao, Wei; Cai, Chun Jie; Sun, Chuan Yang; Xue, Bo Xin; Shan, Yu Xi

    2015-07-01

    Subcapsular renal hematoma (SRH) after ureteroscopic lithotripsy (URSL) using holmium:yttrium-aluminum-garnet (Ho:YAG) laser to treat ureteric stones is a rare complication. We aimed to review our unit's experience of post-URSL subcapsular renal hematoma. From 2006 to 2012, 2059 URSLs using F9.5 rigid ureteroscope were performed in our unit. Patients with post-URSL symptomatic renal hematoma were reviewed. Perioperative information on patients' renal function, stone characteristics, and degree of renal hydronephrosis were reviewed. Operative data, postoperative information such as clinical manifestation, changes in blood parameters, CT findings, and subsequent treatment were documented. Of the 2059 patients treated with URSL and Ho:YAG laser, three patients were diagnosed as subcapsular renal hematoma after surgery; the age is 57, 61, and 63years old, respectively. Preoperative imaging examination showed that two patients and one patient had obstructing middle and proximal ureteral stones ranging in size from 0.8 to 1.6cm, and three patients had thin renal cortices. The double-J ureteral stents were inserted in all cases regularly. All three subcapsular renal hematoma patients had the loin pain of the operation side and fever, and one patient had significant hemoglobin drop (from 111 to 61g/L) who need to transfusion. Two patients presented within 24h of URSL, and one patient presented on day 10. One patient was treated conservatively for 3weeks and recovered with bed rest, antibiotics, hemostasis, and analgesia with no intervention or drain. The other two patients underwent ultrasonography-guided drainage of the hematoma. Two-month follow-up CT scans or ultrasonography confirmed the resolution of the hematoma in all three cases. Renal subcapsular hematoma after URSL is a rare and one of serious complications. Subcapsular renal hematoma should be considered when patients have the symptoms of significant loin pain after URSL for obstructing ureteral stones with thin renal cortices. The treatment of post-URSL renal subcapsular hematomas needs to be customized for each patient. PMID:25943289

  5. Thulium/holmium-doped fiber laser passively mode locked by black phosphorus nanoplatelets-based saturable absorber.

    PubMed

    Yu, Hao; Zheng, Xin; Yin, Ke; Cheng, Xiang'ai; Jiang, Tian

    2015-12-01

    By coupling black phosphorus (BP) nanoplatelets (NPs) with a fiber-taper evanescent light field, a saturable absorber (SA) based on the BP NPs has been successfully fabricated and used in a thulium/holmium-doped fiber laser as the mode locker. The SA had a modulation depth of ?9.8% measured at 1.93?m. A stable mode-locking operation at 1898nm was achieved with a pulse width of 1.58ps and a fundamental mode-lock repetition rate of 19.2MHz. By increasing the pump intensity, phenomena of multi-pulsing operations, including harmonic mode-locked states and soliton bunches, were obtained in the experiment, showing that the BP NPs possess an ultrafast optical response time. This work suggests that the BP NPs-based SA is potentially useful for ultrashort, pulsed laser operations in the eye-safe region of 2?m. PMID:26836690

  6. Thulium laser enucleation of the prostate (TmLEP) vs. transurethral resection of the prostate (TURP): evaluation of early results

    PubMed Central

    St?pie?, Stanis?aw; Dudzic, Waldemar; K?sy, Stanis?aw; Blewniewski, Mariusz; R?a?ski, Waldemar

    2012-01-01

    Introduction The first decade of XXI century it is a time of the thulium laser implementation to a benign prostatic hyperplasia treatment. Objective The objective of this paper is a comparative assessment of early results thulium laser enucleation of the prostate (TmLEP) versus transurethral resection of the prostate (TURP) in 3-months observation. Materials and methods Patients were randomized to BPH surgical treatment: research group (TmLEP 54 men) or control group (TURP 52 men). Between 02.2007-09.2009 non-consecutive patients were examined before, one month, and 3-months after surgery. Perioperative data (age, PV, time of surgery, use of laser, morcellation, catheterization, hospitalization, used energy, Hgb loss and removed tissue weight) were assessed. Before and after surgery IPSS, QoL, Qmax and PVR were controlled. Results Hemoglobin loss was twice lower during TmLEP than TURP [0.95 0.77 (0-3.2) vs. 1.81 0.97 (0.1-4.7) g/dl, p <0.0001]. Surgery time TmLEP was longer than TURP [102.2 38.7 (25-210) vs. 74.5 22.8 (25-140) min. p <0.0001]. Without morcellation time [28.1 17.9 (5-80) min.], surgery time of both procedures was comparable. Weight of resected tissue was lower in TmLEP than TURP [24.8 14.8 (2-65) vs. 34.8 14.1 (12-68)g]. without consideration of vaporized tissue. In both groups we noticed a distinct improvement in all parameters: IPSS, QoL, Qmax and PVR, but without any statistically significant differences between them. Complications after surgery were similar in TmLEP and TURP group. Conclusions The thulium laser enucleation of the prostate is safe and efficient BPH treatment method, comparable to the transurethral electroresection in 3-months observation. Lack of long-term research does not allow to form wider conclusions. PMID:24578948

  7. Holmium: YAG laser lithotripsy versus pneumatic lithotripsy for treatment of distal ureteral calculi: a meta-analysis.

    PubMed

    Yin, Xiangrui; Tang, Ziwei; Yu, Bei; Wang, Yarong; Li, Yuehua; Yang, Qi; Tang, Wei

    2013-04-01

    The objective of this study was to estimate the treatment effect of Pneumatic Lithotripsy (PL) versus holmium: YAG laser lithotripsy (LL) in the treatment of distal ureteric calculi. A bibliographic search covering the period from 1990 to April 2012 was conducted using search engines such as MEDLINE, EMBASE, and Cochrane library. Data were extracted and analyzed with RevMan5.1 software. A total of 47 studies were scant, and 4 independent studies were finally recruited. Holmium: YAG LL conveyed significant benefits compared with PL in terms of early stone-free rate [odds ratio (OR)=4.42, 95% confidence interval (CI) (1.14, 17.16), p=0.03], delayed stone-free rate [OR=4.42, 95%CI (1.58, 12.37), p=0.005], mean operative time [WMD=-16.86, 95%CI (-21.33, -12.39), p<0.00001], retaining double-J catheter rate [OR=0.44, 95%CI (0.25, 0.78), p=0.004], and stone migration incidence [OR=0.26, 95%CI (0.11, 0.62), p=0.003], but not yet in the postoperative hematuria rate and the ureteral perforation rate according to this meta-analysis. Precise estimates on larger sample size and trials of high quality may provide more uncovered outcomes in the future. PMID:23016622

  8. Ex vivo pyelotomy, nephroscopy and holmium laser lithotripsy of a staghorn stone in a donor kidney prior to renal transplant

    PubMed Central

    Janczak, Dariusz; Bolanowska, Barbara; Jankowski, Pawe?; Dorobisz, Tadeusz; Dorobisz, Karolina; Chabowski, Mariusz; Janczak, Dawid

    2015-01-01

    This case report presents the diagnostic and treatment procedures of stone removal from the kidney of a 67-year-old donor, the transplantation of the kidney to a 65-year-old recipient, and the postoperative course until the end of hospitalization. Computed tomography performed before collecting the organ showed a staghorn stone in the renal pelvis and lower calyces in the right donor kidney. The stones were removed ex-vivo using a rigid ureteroscope and a holmium laser prior to transplantation. Then the organ was transplanted to the left iliac fossa of a 65-year-old man with end-stage renal failure. The authors think there is a possibility of increasing the kidney pool, by using organs containing large calculi. In such cases stones should be removed before the operation and the patient should be monitored regularly, especially in the first months after the transplant. PMID:26240630

  9. Sudden onset of a huge subcapsular renal hematoma following minimally invasive ureteroscopic holmium laser lithotripsy: A case report

    PubMed Central

    ZHANG, PENG; HU, WAN-LI

    2015-01-01

    The postoperative complication rate of ureteroscopic lithotripsy (URSL) is low, and the most frequent complication is fever. Thus, urological surgeons often neglect or are unaware of subcapsular renal hematoma (SRH) as a rare complication following URSL. Although a SRH after undergoing URSL is uncommon, the occurrence may be fatal. The current study reports on a rare life-threatening case that occurred recently at Zhongnan Hospital (Wuhan, China). A 24-year-old male patient presented with a large SRH (111411 cm) after undergoing a failed, but minimally invasive URSL with a holmium laser. The presence of the large SRH was confirmed by computerized tomography imaging. The patient underwent conservative management, which prevented hematoma enlargement, and no further treatment was conducted. In conclusion, SRH, although rare following URSL, should be noted by the urological surgeon. PMID:26170958

  10. [New perspectives for laser therapy].

    PubMed

    Amn Sesmero, Jos H

    2008-11-01

    We review the current trends and new perspectives of the use of laser in urology, analyzing different fields in which this energy has been used. In lithotripsy, the laser has modified the therapeutic algorithms for ureteral lithiasis. Moreover, the possibility of using laser with flexible ureteroscopes is enabling the performance of intracorporeal in situ renal lithotripsy. New lasers such as Erbium:yag, more effective and more innocuous than holmium are currently under development. The research in new fibers, more flexible, economic and long-lasting is the next challenge in this field. In BPH, although the KTP laser has obtained and extraordinary diffusion for a certain type of prostate volume, new lasers such as thulium and diode, are in competition with holmium laser in the field of prostatic enucleation due to their precise cut. The application of laser in photodynamic therapy for urological cancers and tissue welding are currently new promising objectives of research. PMID:19140601

  11. Holmium:YAG laser lithotripsy for the management of urolithiasis in small ruminants and pot-bellied pigs

    NASA Astrophysics Data System (ADS)

    Halland, Spring K.; House, John K.; George, Lisle

    2001-05-01

    Obstructive urolithiasis is a common problem in small ruminants and pot-bellied pigs. The most common site of urinary tract obstruction in these species is the urethra. Surgical procedures developed to relieve obstructions, in our experience have been effective in approximately 75% of cases. Urethral stricture is a common complication if the mucosa of the urethra is disrupted. The objective of this project was to evaluate endoscopy guided laser lithotripsy as a therapeutic modality to relieve urethral obstructions in small ruminants and pot-bellied pigs. The study population consisted of patients presented to the Veterinary Medical Teaching Hospital at the University of California Davis with obstructive urolithiasis. Lithotripsy was performed using a Holmium:YAG laser via a 200-micron low water quartz fiber passed through a flexible mini-endoscope. Two types of urinary calculi were managed with this technique, calcium carbonate and calcium hydroxyphosphate. Laser lithotripsy was effective at relieving obstructions caused by both types of calculi when conventional methods had failed. Laser lithotripsy performed via urethral endoscopy is a safe and effective therapeutic modality for management of obstructive urolithiasis in small ruminants and pot-bellied pigs and reduces the risk of post procedural urethral stricture.

  12. Imaging of laser-induced strain in biological tissue: pulsed holmium laser ablation of bovine cornea

    NASA Astrophysics Data System (ADS)

    Delacretaz, Guy P.; Walsh, Joseph T., Jr.; Beghuin, Didier

    1998-01-01

    Laser ablation of tissue can be accompanied by deleterious training. A polaroscopic technique was used to image induced strain. In a bovine cornea model, we demonstrate that strain induced by a cavitation bubble occurs over an area larger than the bubble. Further, although the bubble lifetime is only about 400 microseconds and the cornea tissue is strained greatly by the expanding and collapsing bubble, there is substantial strain for several milliseconds after the bubble collapse. The results indicate the utility of polaroscopic imaging as well as the magnitude and spatial extent of mechanical events at times long after the initiating mechanical insult.

  13. High power resonantly pumped holmium-doped fibre sources

    NASA Astrophysics Data System (ADS)

    Hemming, Alexander; Simakov, Nikita; Haub, John; Carter, Adrian

    2014-03-01

    Holmium-doped fibres provide a power scalable gain-medium capable of operation at wavelengths beyond 2.05 ?m. We discuss and review our approach to the power scaling of pulsed and CW laser sources at 2.1 ?m using holmium-doped fibres. This paper outlines experiments which demonstrate the wavelength region accessible using holmium-doped silica fibres, as well as a linearly polarised pulsed master-oscillator power amplifier and high average power CW laser and amplifier systems. These devices demonstrate the applicability of holmium fibre lasers to a range of scientific, medical, industrial and defence applications.

  14. Impact of holmium fibre laser radiation (λ = 2.1 μm) on the spinal cord dura mater and adipose tissue

    NASA Astrophysics Data System (ADS)

    Filatova, S. A.; Kamynin, V. A.; Ryabova, A. V.; Loshchenov, V. B.; Zelenkov, P. V.; Zolotovskii, I. O.; Tsvetkov, V. B.; Kurkov, A. S.

    2015-08-01

    The impact of holmium fibre laser radiation on the samples of biologic tissues (dura mater of spinal cord and adipose tissue with interlayers of muscle) is studied. The experimental results are evaluated by the size of carbonisation and coagulation necrosis zones. The experiment shows that in the case of irradiation of the spinal cord dura mater samples the size of carbonisation and coagulation necrosis zones is insignificant. In the adipose tissue the carbonisation zone is also insignificant, but the region of cellular structure disturbance is large. In the muscle tissue the situation is opposite. The cw laser operation provides clinically acceptable degree of destruction in tissue samples with a minimal carbonisation zone.

  15. A comparison of efficacies of holmium YAG laser, and pneumatic lithotripsy in the endoscopic treatment of ureteral stones

    PubMed Central

    Akdeniz, Ekrem; ?rk?lata, Lokman; Demirel, Hseyin Cihan; Sayl?k, Acun; Bolat, Mustafa Suat; ?ahinkaya, Necmettin; Zengin, Mehmet; Atilla, Mustafa Kemal

    2014-01-01

    Objective: We aimed to compare the effectiveness of holmium YAG laser and pneumatic lithotripsy in the treatment of ureteral stones. Material and methods: A total of 216 patients who had established indications of ureteroscopy between November 2011 and June 2012 were included in this study. Patients files were retrospectively reviewed by dividing cases as groups that underwent pneumatic (PL) or laser lithotripsy (LL) procedures. Age, sex, stone burden and localization, duration of follow-up, operative times were evaluated. Stone-free rates were evaluated by ureteroscopical examination, postoperative scout films and ultrasonography. Results: Group PL consisted of 109 and group LL of 107 patients. Median age was 43.9315.94 years in Group PL and 46.1514.54 years in Group LL. Male to female ratio, stone burden and localization were similar for both groups. Overall success rate was 89.9% in Group PL and 87.9% in Group LL, respectively (p<0.791). With the aid of additional procedures, success rate was 100% for both groups at the end of the first month. Groups were not different as for operative time, rate of insertion of an ureteral catheter and its removal time. Hospitalization period was apparently somewhat shorter in Group LL (p=0.00). Conclusion: Pneumatic lithotripsy can be as efficacious as laser lithotripsy and be used safely in the endoscopic management of ureteral stone. In comparison of both methods, we detected no differences as to operative time, success of operation and the time to removal of the catheter, however, hospitalization period was shorter in Group LL. PMID:26328167

  16. Use of the holmium: yttrium aluminum garnet (Ho:YAG) laser for cranial nerve decompression: an in vivo study using the rabbit model.

    PubMed

    Qadir, R; Kennedy, D

    1993-06-01

    A study was designed to evaluate the utility and safety of the holmium:yttrium aluminum garnet (Ho:YAG) laser for precise bony decompression of neural canals. In vivo rabbit studies were performed to measure temperature changes and nerve degeneration which occurred when the facial canal was decompressed with the laser as compared to the diamond burr. Marked temperature elevations were noted with the laser (n = 4), but not with the burr (n = 4). Seven of nine nerves decompressed with the laser revealed moderate to severe degeneration, whereas two control nerves decompressed with the drill demonstrated only minimal degeneration. It is concluded that this laser should not be used for nerve decompression unless better control of temperature elevation can be achieved. PMID:8502097

  17. Sialendoscopy with holmium:YAG laser treatment for multiple large sialolithiases of the Wharton duct: a case report and literature review.

    PubMed

    Sun, Yu-Ting; Lee, Kuo-Sheng; Hung, Shih-Han; Su, Chin-Hui

    2014-12-01

    Sialolithiasis is defined as calcified stone(s) in the salivary duct or glands. Submandibular gland sialolithiasis is the most common (80 to 90%), followed by parotid gland sialolithiasis (5 to 15%). The typical clinical presentation is salivary gland swelling after eating. As the swelling persists, symptoms owing to local inflammation, such as pain and trismus, emerge. In severe cases, cellulitis and even abscess formation occur and subsequently lead to salivary gland atrophy or fistula formation if the sialolithiasis remains untreated. The most common treatment is complete excision of the affected gland together with the stone(s). In some cases, intraoral sialolithotomy is performed when the stone is solitary and easily palpable through the oral cavity. Sialendoscopy is increasingly performed because of its minimal invasiveness. The major limitation of endoscopic laser lithotripsy of the salivary glands is the size of the stone. Often, for a stone larger than 4 mm, multiple fragmentations of the stone into small pieces is necessary before the pieces can be removed by wire basket or grasping forceps. Recently, the holmium:YAG laser has been reported as quite effective in removing larger salivary gland stones. However, sialoendoscopic laser lithotripsy is a very time-consuming procedure and in most cases, when there are multiple large stones in a single gland, entire gland excision is recommended. This report describes a male patient diagnosed with multiple large stones in his left submandibular gland who was successfully treated under sialendoscopy with holmium:YAG laser lithotripsy. PMID:25216563

  18. Enucleation Procedure Manual.

    ERIC Educational Resources Information Center

    Davis, Kevin; Poston, George

    This manual provides information on the enucleation procedure (removal of the eyes for organ banks). An introductory section focuses on the anatomy of the eye and defines each of the parts. Diagrams of the eye are provided. A list of enucleation materials follows. Other sections present outlines of (1) a sterile procedure; (2) preparation for eye

  19. Transcranial excision of massive pituitary tumor with low-energy holmium laser

    NASA Astrophysics Data System (ADS)

    Xiong, Wen-Hao; Luo, Qi-Zhong; Li, Shan-Quan; Li, Xiao-Xiong; Dai, Jun; Zhu, Jing; Zhang, Mei-Jue

    1998-11-01

    From May, 1994 to September, 1996 we have operated on 64 cases of brain tumor with Homium Laser, 18 cases of massive pituitary tumor with low energy laser were included. The result are satisfying. Now, we report it to the congress.

  20. Photothermal ablation is the primary mechanism in holmium:YAG laser lithotripsy of urinary calculi

    NASA Astrophysics Data System (ADS)

    Glickman, Randolph D.; Teichman, Joel M. H.; Corbin, Nicole S.; Vassar, George J.; Weintraub, Susan T.; Chan, Kin Foong; Welch, Ashley J.

    1999-09-01

    Because of the >= 250 microsecond(s) pulsewidth emitted by the Ho:YAG laser used in clinical lithotripsy, it is unlikely that stress confinement occurs within the irradiated stones. Experimental data supports a thermal mechanism for Ho:YAG laser stone ablation. Previous work has shown that stone fragmentation occurs soon after the onset of the laser pulse, is uncorrelated to cavitation bubble formation or collapse, and is associated with low pressures. Moreover, lithotripsy proceeds fastest with desiccated stones in air (data based on laser ablation of calcium oxalate monohydrate stones), indicating that direct absorption of the laser radiation by the stone material is required for the most efficient ablation. Lowering the initial temperature of calculi reduces the stone mass-loss following 20 J of delivered laser energy: 2.2 +/- 1.1 mg vs 5.2 +/- 1.6 mg for calcium oxalate monohydrate (COM) stones (-80 vs 23 degree(s)C), and 0.8 +/- 0.4 mg vs 2.2 +/- 1.1 mg for cystine stones (-80 vs 23 degree(s)C), p laser lithotripsy.

  1. Electron-impact excitation of holmium atoms

    SciTech Connect

    Smirnov, Yu M

    2000-06-30

    The electron-impact excitation of holmium atoms was studied by the method of extended crossing beams. The cross sections and the optical excitation functions were obtained for odd levels of Ho I, including the 22014 cm{sup -1} laser level. Over 99% of the atoms were shown to reside in the ground level prior to collisions with electrons. Also measured were the excitation cross sections for six even levels, which presumably participate in the formation of inversion population in a gas-discharge holmium vapour laser. (laser applications and other topics in quantum electronics)

  2. Chemical decomposition of urinary stones during holmium-laser lithotripsy: II. Evidence for photothermal breakdown

    NASA Astrophysics Data System (ADS)

    Glickman, Randolph D.; Teichman, Joel M. H.; Vassar, George J.; Weintraub, Susan T.; Chan, Kin Foong; Pfefer, T. Joshua; Welch, Ashley J.

    1999-06-01

    Because of the greater than or equal to 250 microsecond pulsewidth emitted by the Ho:YAG laser used in clinical lithotripsy, it is unlikely that stress confinement occurs within the irradiated stones. Experimental data supports a thermal mechanism for Ho:YAG laser stone ablation. Stone fragmentation occurs soon after the onset of the laser pulse, is uncorrelated to cavitation bubble formation or collapse, and is associated with low pressures (cf. part I). The mass- loss of desiccated calcium oxalate monohydrate (COM) stones exposed to 150 J from the Ho:YAG laser in air was 40 plus or minus 12 mg (mean plus or minus 1 s.d.); for hydrated stones in air was 25 plus or minus 9 mg; and for hydrated stones in water was 17 plus or minus 3 mg, p less than .001. These differences indicate that direct absorption of the laser radiation by the stone is required for the most efficient ablation. Lowering the initial temperature of COM or cystine stones also reduced the stone mass-loss following 20 J of delivered laser energy: 2.2 plus or minus 1.1 mg vs 5.2 plus or minus 1.6 mg for COM stones (-80 vs 23 degrees Celsius), and 0.8 plus or minus 0.4 mg vs 2.2 plus or minus 1.1 mg for cystine stones (-80 vs 23 degrees Celsius), p less than or equal to .05. Finally, chemical analysis of the laser-induced stone fragments revealed the presence of thermal breakdown products: CaCO3 from COM; free sulfur and cysteine from cystine; Ca2O7P2 from calcium hydorgen phosphate dihydrate, and cyanide from uric acid.

  3. Different lasers in the treatment of benign prostatic hyperplasia: a network meta-analysis.

    PubMed

    Zhang, Xingming; Shen, Pengfei; He, Qiying; Yin, Xiaoxue; Chen, Zhibin; Gui, Haojun; Shu, Kunpeng; Tang, Qidun; Yang, Yaojing; Pan, Xiuyi; Wang, Jia; Chen, Ni; Zeng, Hao

    2016-01-01

    All available surgical treatments for benign prostatic hyperplasia (BPH) have their individual advantages or disadvantages. However, the lack of head-to-head studies comparing different surgeries makes it unavailable to conduct direct analysis. To compare the efficacy and safety among different lasers and transurethral resection of prostate (TURP) for BPH, randomized controlled trials were searched in MEDLINE, EMBASE, Cochrane library, WHO International Clinical Trial Registration Platform, and Clinical Trial.gov by 2015.5; and the effectiveness-, perioperation- and complication-related outcomes were assessed by network meta-analysis. 36 studies involving 3831 patients were included. Holmium laser through resection and enucleation had the best efficacy in maximum flow rate. Thulium laser through vapo-resection was superior in improving international prostate symptom score and holmium laser through enucleation was the best for post-voiding residual volume improvement. Diode laser through vaporization was the rapidest in removing postoperative indwelling catheter, while TURP was the longest. TURP required the longest hospitalization and thulium laser through vapo-resection was relatively shorter. Holmium and thulium lasers seem to be relatively better in surgical efficacy and safety, so that these two lasers might be preferred in selection of optimal laser surgery. Actually, more large-scale and high quality head-to-head RCTs are suggested to validate the conclusions. PMID:27009501

  4. Different lasers in the treatment of benign prostatic hyperplasia: a network meta-analysis

    PubMed Central

    Zhang, Xingming; Shen, Pengfei; He, Qiying; Yin, Xiaoxue; Chen, Zhibin; Gui, Haojun; Shu, Kunpeng; Tang, Qidun; Yang, Yaojing; Pan, Xiuyi; Wang, Jia; Chen, Ni; Zeng, Hao

    2016-01-01

    All available surgical treatments for benign prostatic hyperplasia (BPH) have their individual advantages or disadvantages. However, the lack of head-to-head studies comparing different surgeries makes it unavailable to conduct direct analysis. To compare the efficacy and safety among different lasers and transurethral resection of prostate (TURP) for BPH, randomized controlled trials were searched in MEDLINE, EMBASE, Cochrane library, WHO International Clinical Trial Registration Platform, and Clinical Trial.gov by 2015.5; and the effectiveness-, perioperation- and complication-related outcomes were assessed by network meta-analysis. 36 studies involving 3831 patients were included. Holmium laser through resection and enucleation had the best efficacy in maximum flow rate. Thulium laser through vapo-resection was superior in improving international prostate symptom score and holmium laser through enucleation was the best for post-voiding residual volume improvement. Diode laser through vaporization was the rapidest in removing postoperative indwelling catheter, while TURP was the longest. TURP required the longest hospitalization and thulium laser through vapo-resection was relatively shorter. Holmium and thulium lasers seem to be relatively better in surgical efficacy and safety, so that these two lasers might be preferred in selection of optimal laser surgery. Actually, more large-scale and high quality head-to-head RCTs are suggested to validate the conclusions. PMID:27009501

  5. In-fiber resonantly pumped Q-switched holmium fiber laser.

    PubMed

    Lancaster, David G; Jackson, Stuart D

    2009-11-01

    We demonstrate a double-clad fiber laser that incorporates a pump-light absorbing coaxially located Tm(3+)-doped outer core that reaches threshold and resonantly pumps an Ho(3+)-doped inner core. Under cw diode pumping, the output from the laser displays a pulse modulated behavior at wavelengths corresponding to the Tm(3+) transition and short gain switched pulses from the Ho(3+) core that have mode-locked characteristics. The Ho(3+) and Tm(3+) fiber lasers simultaneously produced 1.5 W across 2040-2140 nm and operate at a pulse repetition frequency of approximately 80 kHz and at pulse widths as short as 330 ns. PMID:19881611

  6. Acoustic measurements during holmium:YAG laser ablation of cadaveric human temporal bone: preliminary observations

    NASA Astrophysics Data System (ADS)

    Wong, Brian J.; Gibbs, Lisa; Neev, Joseph; Shanks, Janet

    1997-05-01

    Pulsed IR and UV lasers have been suggested for use in middle ear surgery due to decreased thermal trauma, precise ablation characteristics, and potential fiberoptic delivery. While there has been much focus on the thermal and photoacoustic events that occur during pulsed laser ablation of hard tissue, there are few studies that look at the acoustic energy generated from these devices from an audiologic standpoint. In this study, the mastoid cavities of cadaveric human temporal bones were irradiated with a Ho:YAG laser (lambda equals 2.12 micrometer) with the following parameters: 5, 10, and 15 Hz pulse repetition rate and 1, 2, 4, 6, 8, and 10 W average power. During ablation, acoustic measurements were made using a sound level meter held 5 cm away from the target site. With each set of laser parameters, the sound intensity (dB SPL) exceeded 85 dB. Peak intensity measurements of 125 dB were measured, and a saturation effect was noted above 4 W or 500 mJ/pulse. The clinical significance of these findings is discussed and the acoustical aspects of middle ear function and noise trauma are reviewed.

  7. Thulium:YAG VapoEnucleation of the prostate in large glands: a prospective comparison using 70- and 120-W 2-m lasers

    PubMed Central

    Netsch, Christopher; Bach, Thorsten; Herrmann, Thomas RW; Gross, Andreas J

    2012-01-01

    This study compared the efficacy of 70- and 120-w 2-m thulium:YAG VapoEnucleation of the prostate (ThuVEP) for patients with benign prostatic obstruction (BPO). A prospective analysis of 84 patients with symptomatic BPO and prostatic enlargement (?60ml) who underwent either 70-w (n=44) or 120-w ThuVEP (n=40) non-randomly was carried out. Patient demographics and perioperative and 12-month follow-up data were analysed. The mean prostate volume was 79.9027.49ml in patients who had received 70-w ThuVEP, which was less than in those who had received 120-w ThuVEP (88.5325.10; P=0.033). The mean enucleation (resected weight/laser time, 2.161.21g min?1 vs. 1.230.60g min?1; P=0.013), operation efficiency (resected weight/total operation time, 0.760.35g min?1 vs. 0.420.27g min?1; P=0.000) and percentage of resected tissue (66.93%22.79% vs. 45.41%23.33% P=0.000) were higher with 120-w treatment compared to 70-w ThuVEP. One patient (1.2% of total patients) (in the 120-w group) required a blood transfusion postoperatively. Sixty-one patients (73%) were available for review at the 12-month follow-up time point. The quality of life (QoL), International Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax), postvoiding residual urine (PVR) and prostate volume improved significantly after treatment (P?0.035) and were not significantly different between those treated with the different devices (70- and 120-w). The median prostate volume reduction was 81.70% and 82.19% with 70- and 120-w ThuVEP, respectively. The incidence of complications was low and did not differ between groups treated with the different devices. Two patients (2.4%) (one per group) had a bladder neck contracture at the follow-up. ThuVEP is a safe and efficacious procedure for the treatment of symptomatic BPO. The incidence of complications was low with both devices. The 120-w thulium:YAG device enhances the effectiveness of ThuVEP with regard to the percentage of resected tissue and the enucleation/operation efficiency. PMID:22231295

  8. Holmium laser ablation of cartilage: effects of delivery fiber angle of incidence

    NASA Astrophysics Data System (ADS)

    Asshauer, Thomas; Oberthur, Thorsten; Jansen, Thomas; Gerber, Bruno E.; Delacretaz, Guy P.

    1996-01-01

    The effects of 2.12 micrometers Cr:Tm:Ho:YAG laser pulses delivered in isotonic saline solution via an optical fiber system on fresh porcine femur patellar groove cartilage were studied in vitro. Various irradiation geometry, corresponding to angles of 0 - 90 degree(s) of the delivering fiber with respect to the cartilage surface, have been investigated. A laser pulse energies of 1.0 J with a pulse duration of 250 microsecond(s) (FWHM) was used. The dynamics of the induced transient vapor bubbles and the ablation process were monitored by time resolved flash videography techniques. Acoustic transients of up to 200 bars induced by bubble collapses were measured by a calibrated piezoelectric needle probe hydrophone. Histological assessment of the irradiated cartilage samples was performed using azan and Safranin-O stains. The extent of the area of altered cartilage cells is larger than the zone of tissue matrix damage. The predominant mechanism of tissue damage is thermal rather than acousto-mechanical. Cartilage treatment at an angle of incidence of 30 degree(s) reduces significantly the overall damage as compared to 60 degree(s) or 90 degree(s) irradiation.

  9. Combined electrohydraulic and holmium: YAG laser ureteroscopic nephrolithotripsy of large (>2 cm) renal calculi

    PubMed Central

    Mariani, Albert J.

    2008-01-01

    Percutaneous nephrolithotripsy (PCL) is a standard treatment for renal calculi >2 cm. Modern flexible ureteroscopes and accessories employing the complementary effects of electrohydraulic lithotripsy (EHL) and Ho:YAG laser lithotrites can treat these renal calculi in a minimally invasive fashion with similar or superior results. Objective: To assess the safety and efficacy of ureteroscopic nephrolithotripsy monotherapy for the management of >2 cm renal calculi in the community setting. Materials and Methods: Fifty nine patients with 63 renal calculi ranging from 20 to 97 mm (mean 44 mm) in length and 175 to 3300 mm2 (mean 728 mm2) area underwent staged ureteroscopic nephrolithotripsy monotherapy. Obesity (BMI > 30) was present in 54% and 19% were morbidly obese (BMI > 40). An infectious etiology was present in 49% and hard stone components in 89%. All patients presented with hematuria, pain, and/or recurrent urinary tract infection (UTI). Lithotripsy was performed with a single deflection flexible ureteroscope and predominantly EHL. Laser drilling was employed (n = 6) to weaken very hard stones prior to EHL. Low intrarenal pressure was maintained by continuous bladder drainage and placement of a stiff safety wire. Visibility was maintained using manual pulsatile irrigation. Results: All patients were rendered pain and infection-free. No patient required a blood transfusion and there was no change in serum creatinine. Mobile stone-free status was achieved in 60/63 (95%) with a mean of 1.7 nephrolithotripsy stages and 0.38 secondary or ancillary procedures. Outpatient management was sufficient for 121/131 (92%) of the procedures. Operative time averaged 46 min/stage and 79 min/calculus. Complications included endotoxic shock (3), fever (5), ureteral fragments requiring treatment (11), delayed extubation (2), delayed pneumonia (1), and urinary retention (1). Conclusion: Staged ureteroscopic nephrolithotripsy of large renal calculi is feasible with low morbidity and stone clearance rates that compare favorably with PCL. It has largely replaced PCL at this institution. PMID:19468511

  10. Modular flexible ureteroscopy and holmium laser lithotripsy for the treatment of renal and proximal ureteral calculi: A single-surgeon experience of 382 cases

    PubMed Central

    YAN, ZEJUN; XIE, GUOHAI; YUAN, HESHENG; CHENG, YUE

    2015-01-01

    To determine the safety and efficacy of modular flexible ureteroscopy and holmium laser lithotripsy for the treatment of renal and proximal ureteral calculi, a retrospective chart review of a single surgeon's 3-year modular flexible ureteroscopy experience was performed. All of the patients were treated with modular flexible ureteroscopy and holmium laser lithotripsy by a single surgeon. Stone-free status was defined as no fragments or a single fragment ?4 mm in diameter at the 3-month follow-up. The procedure number, operative time, stone-free rates, repeat usage of the multilumen catheter, and perioperative complications were documented. The present study included 215 male patients and 167 female patients, with an average age of 48.513.7 years (range, 1784 years). The mean stone size was 11.54.1 mm (range, 428 mm), and the mean total stone burden was 17.55.7 mm (range 1546 mm). A total of 305 patients (79.8%) had a stone burden ?20 mm, and 77 patients (20.2%) had a stone burden >20 mm. The mean number of primary procedures was 1.30.2 (range, 13). The stone-free rate following the first and the second procedure was 73.4 and 86.9%, respectively. The mean postoperative hospital stay was 3.11.2 days (range, 26 days). The highest clearance rates were observed for proximal ureteral stones (100%) and renal pelvic stones (88.7%), whereas the lowest clearance rates were observed for lower calyx stones (76.7%) and multiple calyx stones (77.8%). The higher the initial stone burden, the lower the postoperative stone-free rate (?20 vs. >20 mm; 89.8 vs. 75.3%). The overall complication rate was 8.1%. The results of the present study suggest that modular flexible ureteroscopy with holmium laser lithotripsy may be considered the primary method for the treatment of renal and proximal ureteral calculi in select patients, due to its acceptable efficacy, low morbidity, and relatively low maintenance costs. PMID:26622508

  11. Low-power holmium:YAG laser urethrotomy for urethral stricture disease: comparison of outcomes with the cold-knife technique.

    PubMed

    Atak, Mustafa; Tokgz, Hsn; Akduman, Blent; Erol, Blent; Dnmez, Ibrahim; Hanc?, Volkan; Trksoy, Ozlem; Mungan, Necmettin Ayd?n

    2011-11-01

    In this prospective randomized clinical trial, we aimed to evaluate the safety and efficacy of endourethrotomy with holmium:yttrium-aluminium-garnet (HO:YAG) laser and compare the outcomes with the conventional cold-knife urethrotomy. Fifty-one male patients with single, iatrogenic, annular strictures of the urethra were randomly divided into two groups; 21 patients who underwent direct-vision endoscopic urethrotomy with Ho:YAG laser (15 W; 1,200-1,400 mJ; 8-12 Hz) at 12 o'clock position (laser group) and 30 patients who underwent direct-vision endoscopic urethrotomy with cold-knife incision at 12 o'clock position (cold-knife group). The results obtained were analyzed and compared at 3 months, 6 months, 9 months, and 12 months postoperatively by clinical evaluation, uroflowmetry, and retrograde urethrographies. Variables were compared among groups using Fisher's exact and Mann Whitney U tests. There were no differences between two groups in terms of patient age, preoperative Qmax value, stricture location, and length. Operative time was shorter in laser group (16.4 8.04 minutes) when compared with cold-knife group (23.8 5.47 minutes) (p<0.001). Recurrence-free rate at 3 months was similar between two groups (p=0.122). However, recurrence-free rates at 6 months, 9 months, and 12 months were significantly higher in laser group when compared with cold-knife group (p values were 0.045, 0.027, and 0.04, respectively). No intra- or postoperative complications were encountered. Use of Ho:YAG laser in the management of urethral stricture disease is a safe and effective method. In addition, it provides shorter operative time and lower recurrence rate when compared with the conventional technique. PMID:22005159

  12. Efficacy of holmium laser urethrotomy and intralesional injection of Santosh PGI tetra-inject (Triamcinolone, Mitomycin C, Hyaluronidase and N-acetyl cysteine) on the outcome of urethral strictures

    PubMed Central

    Kishore, Lalit; Sharma, Aditya Prakash; Garg, Nitin; Singh, Shrawan Kumar

    2015-01-01

    Introduction To study the efficacy of holmium laser urethrotomy with intralesional injection of Santosh PGI tetra-inject (Triamcinolone, Mitomycin C, Hyaluronidase and N-acetyl cysteine) in the treatment of urethral strictures. Material and methods A total of 50 patients with symptomatic urethral stricture were evaluated by clinical history, physical examination, uroflowmetry and retrograde urethrogram preoperatively. All patients were treated with holmium laser urethrotomy, followed by injection of tetra-inject at the urethrotomy site. Tetra-inject was prepared by diluting acombination of 40 mg Triamcinolone, 2 mg Mitomycin, 3000 UHyaluronidase and 600 mg N-acetyl cysteine in 5–10 ml of saline, according to the stricture length. An indwelling 18 Fr silicone catheter was left in place for 7–10 days.All patients were followed-up for 6-18 months postoperatively by history, uroflowmetry, and if required, retrograde urethrogram and micturating urethrogram every 3 months. Results 41 (82%) patients had asuccessful outcome,whereas 9 (18%) had recurrences during a follow-up ranging from 6–18 months. In <1 cm length strictures, the success rate was 100%, while in 1–3 cm and >3 cm lengthsthe success rates were 81.2% and 66.7% respectively. This modality, thus, has an encouraging success rate, especially in those with short segment urethral strictures (<3 cm). Conclusions Holmium laser urethrotomy with intralesional injection ofSantosh PGI tetra-inject (Triamcinolone, Mitomycin C, Hyaluronidase, N-acetyl cysteine) is a safe and effective minimally-invasive therapeutic modality for short segment urethral strictures. PMID:26855803

  13. New techniques for laser prostatectomy: an update

    PubMed Central

    Chung, Doreen E.; Te, Alexis E.

    2009-01-01

    Traditionally, the gold standard for treatment of BPH has been the electrocautery-based TransUrethral Resection of the Prostate (TURP). However, the number of laser techniques being performed is rapidly increasing. Potential advantages of laser therapy over traditional TURP include decreased morbidity and shorter hospital stay. There are several techniques for laser prostatectomy that continue to evolve. The main competing techniques are currently the Holmium Laser Enucleation of the Prostate (HoLEP) and the 80W 532nm laser prostatectomy. The HoLEP, using the Holmium:YAG laser, has been shown to have clinical results similar to TURP and is suitable for patients on anticoagulation as well as those with large prostates. Disadvantages of this technique are the high learning curve and requirement of a morcellator. When used to treat BPH, studies have demonstrated that, like the HoLEP, the 80W KTP laser is safe and effective in patients with large prostates and in those taking oral anticoagulation. Several studies have compared these two techniques to TURP. Frequently reported advantages of the HoLEP over the 80W laser prostatectomy are the availability after the procedure of a pathology specimen and ability to remove a higher percentage of prostate tissue during resection. However, the transurethral laser enucleation of the prostate addresses these concerns and has shown to have durable outcomes at 2-year follow-up. Two new laser systems and techniques, the thulium laser and the 980nm laser, have emerged recently. However, clinical data from these procedures are in their infancy and large long-term studies are required. PMID:21789057

  14. A comparative study to analyze the efficacy and safety of flexible ureteroscopy combined with holmium laser lithotripsy for residual calculi after percutaneous nephrolithotripsy

    PubMed Central

    Xu, Gang; Wen, Jiaming; Li, Zhongyi; Zhang, Zhewei; Gong, Xiuqing; Chen, Jimin; Du, Chuanjun

    2015-01-01

    A certain proportion of patients with initial Percutaneous nephrolithotripsy (PCNL) management require ancillary procedures to increase the stone-free rate. In this study, we aim to analyze the efficacy and safety of flexible ureteroscopy combined with holmium laser lithotripsy (F-UL) for treatment of residual calculi after PCNL by comparison with extracorporeal shockwave lithotripsy (SWL). Total of 96 patients with residual renal calculi (4 mm to 20 mm) after PCNL was enrolled from May 2010 to March 2013. They were randomly divided into two groups: US Group: patients were treated with F-UL; SWL Group: patients were treated with SWL. Follow-up was made one month and three months after treatment. The mean residual stone size after PCNL was 12.4 4.3 mm in US group compared with 11.9 4.5 in SWL group. The stone-free rate was 84.7% one month after surgical procedure in US group, this rate increased to 91.3% in the third months, while the stone-free rate in SWL group is 64.6% one month after treatment and 72.9% in the third month. For residual stone in lower calyx, the stone-free rate three month after treatment was 90.4% in US group compared to 65.2% in SWL group (P < 0.05). The overall complication rate was low in both groups, no severe complication was found. Both F-UL and SWL are safe and effective methods for residual calculi after PCNL, without severe complications. F-UL provided significantly higher stone-free rate compared with SWL, especially for low-pole calculi. PMID:26064375

  15. A comparative study to analyze the efficacy and safety of flexible ureteroscopy combined with holmium laser lithotripsy for residual calculi after percutaneous nephrolithotripsy.

    PubMed

    Xu, Gang; Wen, Jiaming; Li, Zhongyi; Zhang, Zhewei; Gong, Xiuqing; Chen, Jimin; Du, Chuanjun

    2015-01-01

    A certain proportion of patients with initial Percutaneous nephrolithotripsy (PCNL) management require ancillary procedures to increase the stone-free rate. In this study, we aim to analyze the efficacy and safety of flexible ureteroscopy combined with holmium laser lithotripsy (F-UL) for treatment of residual calculi after PCNL by comparison with extracorporeal shockwave lithotripsy (SWL). Total of 96 patients with residual renal calculi (4 mm to 20 mm) after PCNL was enrolled from May 2010 to March 2013. They were randomly divided into two groups: US Group: patients were treated with F-UL; SWL Group: patients were treated with SWL. Follow-up was made one month and three months after treatment. The mean residual stone size after PCNL was 12.4 4.3 mm in US group compared with 11.9 4.5 in SWL group. The stone-free rate was 84.7% one month after surgical procedure in US group, this rate increased to 91.3% in the third months, while the stone-free rate in SWL group is 64.6% one month after treatment and 72.9% in the third month. For residual stone in lower calyx, the stone-free rate three month after treatment was 90.4% in US group compared to 65.2% in SWL group (P < 0.05). The overall complication rate was low in both groups, no severe complication was found. Both F-UL and SWL are safe and effective methods for residual calculi after PCNL, without severe complications. F-UL provided significantly higher stone-free rate compared with SWL, especially for low-pole calculi. PMID:26064375

  16. Efficacy and safety profile of a novel technique, ThuLEP (Thulium laser enucleation of the prostate) for the treatment of benign prostate hypertrophy. Our experience on 148 patients

    PubMed Central

    2012-01-01

    Background Over the past years laser technology has played a predominant role in prostate surgery, for the treatment of benign prostate hypertrophy (BPH). Various laser devices have been introduced in clinical practice, showing good results in terms of complications and urodynamic outcomes efficacy compared with TURP and Open Prostatectomy. In this study we describe the efficacy and the safety profile of a novel laser technique, ThuLEP (Thulium Laser Enucleation of Prostate) that permits a complete anatomical endoscopic enucleation of prostatic adenoma independently to prostate size. Methods 148 patients with a mean age of 68.2 years were enrolled between September 2009 and March 2012 (36 months), and treated for BPH with ThuLEP. Every patient was evaluated at base line according to: Digital Rectal Examination (DRE), prostate volume, Post-Voided volume (PVR), International Prostate Symptoms Score (I-PSS), International Index of Erectile Function-5 (IIEF-5), Quality of Life (QoL), PSA values, urine analysis and urine culture, uroflowmetry. The same evaluation was conducted after a 12 month follow-up. ThuLEP was performed by 2 expert surgeons. Results Our data showed a better post-operative outcome in terms of catheter removal, blood loss, TURP syndrome, clot retention and residual tissue compared to large series of TURP and OP. Only 1.3% of patients had bladder wall injury during morcellation. I-PSS, Qmax, Prostate Volume, QoL and PVR showed a highly significant improvement at 12 month follow-up in comparison to preoperative assessment. Conclusion ThuLEP represent an innovative option in patients with BPH. It is a size independent surgical endoscopic technique and it can be considered the real alternative, at this time, to TURP and even more to Open Prostatectomy for large prostate, with a complete removal of adenoma and with a low complication rate. PMID:23173611

  17. High-power frequency comb in the range of 2-2.15???m based on a holmium fiber amplifier seeded by wavelength-shifted Raman solitons from an erbium-fiber laser.

    PubMed

    Coluccelli, Nicola; Cassinerio, Marco; Gambetta, Alessio; Laporta, Paolo; Galzerano, Gianluca

    2014-03-15

    We demonstrate a room-temperature high-power frequency comb source covering the spectral region from 2 to 2.15?m. The source is based on a femtosecond erbium-fiber laser operating at 1.55?m with a repetition rate of 250MHz, wavelength-shifted up to 2.06?m by the solitonic Raman effect, seeding a large-mode-area holmium (Ho) fiber amplifier pumped by a thulium (Tm) fiber laser emitting at 1.94?m. The frequency comb has an integrated power of 2W, with overall power fluctuations as low as 0.3%. The beatnote between the comb and a high-spectral-purity, single-frequency Tm-Ho laser has a linewidth of 32kHz over 1ms observation time, with a signal-to-noise ratio in excess of 30dB. PMID:24690863

  18. Holmium-doped fibre amplifier operating at 2.1 μm

    SciTech Connect

    Kamynin, V A; Antipov, S O; Kurkov, A S; Baranikov, A V

    2014-02-28

    A small-signal holmium-doped fibre amplifier is demonstrated. The seed source is a cw holmium-doped fibre laser whose output power is modulated by an electro-optical modulator. The maximum gain reached (wavelength, 2.1 μm; power, 0.25 mW; pulse duration, 100 ns; pulse repetition rate, 1 μs) is 28.5 dB. (lasers)

  19. Effects of holmium:YAG laser on equine articular cartilage and subchondral bone adjacent to traumatic lesions

    NASA Astrophysics Data System (ADS)

    Collier, Michael A.; Haugland, L. Mark; Bellamy, Janine; Johnson, Lanny L.; Rohrer, Michael D.; Walls, Robert C.; Bartels, Kenneth E.

    1994-09-01

    The effects of Ho:YAG laser energy on articular cartilage and subchondral bone adjacent to traumatically created cartilage lesions in a continuous weight-bearing model were investigated. The 2.1 micrometers wavelength was delivered in hand-controlled contact and near-contact hard tissue arthroscopic surgery in a saline medium. Bilateral arthroscopy was performed on normal antebrachiocarpal and intercarpal joints of four adult horses. One-hundred twenty traumatic lesions were created on three weight-bearing articular surfaces with a knife, curette, or a motorized burr. Depths of the lesions were partial and full thickness. Configurations of the lesions were lacerations, scrapes, and craters. Left limbs were used as controls. Right limb lesions were treated with various intensities of laser energy. Animals were sacrificed at intervals of 1, 3, and 8 weeks. Gross microscopic anatomy was documented, and tissue sections were subjected to blind review by a pathologist. Mankin grading for cellularity and proteoglycan content was used to qualitatively evaluate cartilage response. Cartilage adjacent to all lesions exposed to laser energy had better cellularity and proteoglycan content than corresponding controls by Mankin grading.

  20. A prospective, randomized comparison of a 1940 nm and a 2013 nm thulium: yttriumaluminumgarnet laser device for Thulium VapoEnucleation of the prostate (ThuVEP): First results

    PubMed Central

    Tiburtius, Christian; Gross, Andreas J.; Netsch, Christopher

    2015-01-01

    Introduction: We report the early postoperative results of the first prospective, randomized comparison of two commercially available thulium lasers with different wavelengths for the treatment of benign prostatic obstruction (BPO). Materials and Methods: From January to June 2013, 80 consecutive patients were randomized for Thulium VapoEnucleation of the prostate (ThuVEP) with a 2013 nm (RevoLix) (n = 39) or a 1940 nm (VelaXL) (n = 41) thulium laser. Preoperative status, surgical details and the immediate outcome were recorded for each patient. The perioperative complications were assessed and classified according to the modified Clavien classification system. Results: Median operation time, resected tissue, percentage of resected tissue, catheter time, overall operation efficiency and Hb loss differed nonsignificantly between both devices (P > 0.05). At discharge, the median maximum urinary flow rate and postvoiding residual (PVR) urine improved significantly in both groups (P < 0.001). The PVR was lower in the 1940 nm ThuVEP group (P ? 0.034). Perioperative complications occurred in 18 (22.5%) patients (Clavien 1: 12.5%; Clavien 2: 5%, Clavien 3b: 2.5%, Clavien 4a: 2.5%), with no differences between the groups (P = 0.5). Conclusions: The 1940 nm and the 2013 nm thulium lasers are both safe and effective for the treatment of BPO with ThuVEP. Both lasers give equivalent and satisfactory immediate micturition improvement with low perioperative morbidity. PMID:25624576

  1. Clinical effectiveness of the PolyScope endoscope system combined with holmium laser lithotripsy in the treatment of upper urinary calculi with a diameter of less than 2 cm

    PubMed Central

    GU, SI-PING; HUANG, YUN-TENG; YOU, ZHI-YUAN; ZHOU, XIAOMING; LU, YI-JIN; HE, CAO-HUI; QI, JUAN

    2013-01-01

    The aim of this study was to evaluate the clinical value of the PolyScope endoscope system in the treatment of upper urinary calculi with a diameter of <2 cm. A total of 86 patients hospitalized with upper urinary tract calculi were included. The patients were placed under general or spinal anesthesia and in a lithotomy position. Following the dilation of the ureter, a guide wire was inserted under the direct vision of an F8/9.8 rigid ureteroscope, and an F12/14 flexible ureteral access sheath was positioned along the guide wire. Holmium laser lithotripsy was subsequently performed, using an F8.0 PolyScope modular flexible ureteroscope. Plain film of the kidney-ureter-bladder (KUB) was performed 1 day subsequent to the surgery, in order to determine the result of the lithotripsy and the position of the double-J stent which was inserted after after holmium laser lithotripsy. In addition, in certain patients, KUB radiography was performed 24 weeks subsequent to the surgery, and extracorporeal shockwave lithotripsy (ESWL) was performed if the diameter of the residual stones was >6 mm. Lithotripsy was successful in 77 patients and the duration of the surgery ranged between 25 and 80 min (mean duration, 42 min). Little bleeding was observed. Three patients presented with a slight fever following the surgery; however, no ureteral perforation, high fever or septicemia was observed among the patients following anti-inflammatory treatment. The stone-free rate (SFR) of the single-pass lithotripsy was 89.5% (77/86) and the SFR with ESWL was 96.5% (83/86). The study demonstrated that the F8 modular flexible ureteroscope was safe, convenient and effective for the lithotripsy of upper-tract calculi. PMID:24137232

  2. New advances in benign prostatic hyperplasia: laser therapy.

    PubMed

    Mandeville, Jessica; Gnessin, Ehud; Lingeman, James E

    2011-02-01

    Throughout the past decade, numerous techniques for the treatment of benign prostatic hyperplasia have emerged. Laser therapy, in particular, has gained widespread popularity among urologists. Since its inception in 1996, holmium laser enucleation of the prostate (HoLEP) has been evaluated rigorously in the treatment of glands of all sizes. HoLEP has produced superior relief of bladder outlet obstruction as compared to transurethral resection of the prostate based on urodynamics, and has proved equally as effective as open prostatectomy, for the management of very large glands (>100 cc), with lower morbidity. In addition to HoLEP, several newer but less well-studied laser techniques currently are available. These include photoselective laser vaporization utilizing the potassium-titanyl-phosphate (KTP or "green light") laser, thulium laser enucleation, and high-power diode laser vaporization. This report reviews the most current literature on laser therapies utilized in the treatment of benign prostatic hyperplasia with regards to safety, outcome, efficiency, and long-term durability. PMID:21088938

  3. Evaluation of six holmium:YAG optical fibers for ureteroscopy: What's new in 2009?

    NASA Astrophysics Data System (ADS)

    Knudsen, Bodo E.; Teichman, Joel M. H.

    2010-02-01

    The holmium:yttrium aluminum garnet (YAG) laser is the gold standard laser for intracorporeal lithotripsy.1 Optical fibers are utilized to transmit laser energy to the surface of a stone for fragmentation via a predominant photothermal mechanism.2 Previous work has demonstrated that performance characteristics of holmium:YAG optical fibers used for laser lithotripsy varies. Performance may difference not only between fibers made by different manufacturers but also between individual fibers produced by the same manufacturer.3,4 Fiber failure with bending, such as during lower pole ureterorenoscopy, can lead to catastrophic endoscope damage resulting in costly repair. Manufacturers continue to develop new holmium:YAG optical fibers. In this study we evaluate a series of newly commercially available fibers using a previously designed testing protocol. This study was designed to determine the performance and threshold for failure of six newly available holmium:YAG laser fibers from Cook Medical and Fibertech Gmbh. We hypothesize that fiber performance will continue to vary amongst different holmium:YAG optical fibers.

  4. Calcium Signaling Is Required for Erythroid Enucleation

    PubMed Central

    Russell, Sarah M.; Humbert, Patrick O.

    2016-01-01

    Although erythroid enucleation, the property of erythroblasts to expel their nucleus, has been known for 7ore than a century, surprisingly little is known regarding the molecular mechanisms governing this unique developmental process. Here we show that similar to cytokinesis, nuclear extrusion requires intracellular calcium signaling and signal transduction through the calmodulin (CaM) pathway. However, in contrast to cytokinesis we found that orthochromatic erythroblasts require uptake of extracellular calcium to enucleate. Together these functional studies highlight a critical role for calcium signaling in the regulation of erythroid enucleation. PMID:26731108

  5. Calcium Signaling Is Required for Erythroid Enucleation.

    PubMed

    Wölwer, Christina B; Pase, Luke B; Russell, Sarah M; Humbert, Patrick O

    2016-01-01

    Although erythroid enucleation, the property of erythroblasts to expel their nucleus, has been known for 7ore than a century, surprisingly little is known regarding the molecular mechanisms governing this unique developmental process. Here we show that similar to cytokinesis, nuclear extrusion requires intracellular calcium signaling and signal transduction through the calmodulin (CaM) pathway. However, in contrast to cytokinesis we found that orthochromatic erythroblasts require uptake of extracellular calcium to enucleate. Together these functional studies highlight a critical role for calcium signaling in the regulation of erythroid enucleation. PMID:26731108

  6. Best laser for prostatectomy in the year 2013.

    PubMed

    Maheshwari, Pankaj N; Joshi, Nitin; Maheshwari, Reeta P

    2013-07-01

    Lasers have come a long way in the management of benign prostatic hyperplasia. Over last nearly two decades, various different lasers have been utilized for prostatectomy. Neodymium: yttrium-aluminum-garnet laser that started this journey, is no longer used for prostatectomy. Holmium laser can achieve transurethral enucleation of the prostatic adenoma producing a fossa that can be compared with the fossa after Freyer's prostatectomy. Green light laser has a short learning curve, is nearly blood-less with good immediate results. Thulium laser is a faster cutting laser while diode laser is a portable laser device. Often laser prostatectomy is considered as a replacement for the standard transurethral resection of prostate (TURP). To be comparable, laser should reduce or avoid the immediate and long-term complications of TURP, especially bleeding and need for blood transfusion. It should also be safe in the ever increasing patient population on antiplatelet and anticoagulant drugs. We need to take stock of the situation and identify, which among the present day lasers has stood the test of time. A review of the literature was performed to see if any of these lasers could be called the "best laser for prostatectomy in 2013." PMID:24082446

  7. Evaluation of eyes enucleated for scleritis.

    PubMed

    Fraunfelder, F T; Watson, P G

    1976-03-01

    A series of 30 enucleated eyes, all of which had a primary histological diagnosis of scleritis, was analysed. The average age of patients at enucleation was 68 years; many of these patients had had the disease for more than 30 years. In 40 per cent the diagnosis of scleritis was unsuspected and was often masked by multiple complications. Scleritis with uveitis and glaucoma was the most common combination to come to enucleation. In 82 per cent, pain was the reason for enucleation, which suggests that some patients were on inadequate levels of steroid treatment or were unable to tolerate them. In the series, 37 per cent of the eyes perforated. Perforation occurred in those patients who were having steriods but not in those who were not, but the data are inconclusive as to which method of steroid administration was most likely to cause ocular perforation. PMID:1268181

  8. The role of lasers in modern urology

    PubMed Central

    Dołowy, Łukasz; Dembowski, Janusz; Zdrojowy, Romuald; Kołodziej, Anna

    2015-01-01

    Introduction The functioning of modern urological departments and the high level of service they provide is possible through, among other things, the use of modern laser techniques. Material and methods Open operations have been replaced by minimally invasive procedures, and classical surgical tools by advanced lasers. The search for new applications with lasers began as technology developed. Among many devices available, holmium, diode and thulium lasers are currently the most popular. Results Depending on the wavelength, the absorption by water and hemoglobin and the depth of penetration, lasers can be used for coagulation, vaporization and enucleation. In many centres, after all the possibilities of pharmacological treatment have been exhausted, lasers are used as the primary treatment for patients with benign prostatic hyperplasia, with therapeutic results that are better than those obtained through open or endoscopic operations. The use of lasers in the treatment of urolithiasis, urinary strictures and bladder tumours has made treatment of older patients with multiple comorbidities safe, without further necessity to modify the anticoagulant drug treatment. Laser procedures are additionally less invasive, reduce hospitalization time and enable a shorter bladder catheterization time, sometimes even eliminating the need for bladder catherterization completely. Such procedures are also characterized by more stable outcomes and a lower number of reoperations. Conclusions There are also indications that with the increased competition among laser manufacturers, decreased purchase and maintenance costs, and increased operational safety, laser equipment will become mandatory and indispensable asset in all urology wards. PMID:26251737

  9. Gain and energy storage in holmium YLF

    NASA Technical Reports Server (NTRS)

    Storm, Mark E.; Deyst, John P.

    1991-01-01

    It is demonstrated that Q-switched holmium lasers are capable of high-gain and high-energy operation at 300 K. Small-signal gain coefficients of 0.50 and 0.12/cm have been measured in YLF and YAG, respectively. Small-signal gains of 0.50/cm are comparable to those achievable in Nd:YAG and are not typical of low-gain materials. This large gain in the Ho:YLF material is made possible by operating the amplifier in the ground state depletion mode. The amplifier performance data and associated analysis presented demonstrate that efficient energy storage is possible with very high excited state ion densities of the Ho 5I7 upper laser level. This is an important result since upconversion can limit the 5I7 population. Although upconversion was still present in this experiment, it was possible to achieve efficient energy storage, demonstrating that the problem is manageable even at high excitation densities in YLF.

  10. Gain and energy storage in holmium YLF

    NASA Astrophysics Data System (ADS)

    Storm, Mark E.; Deyst, John P.

    1991-11-01

    It is demonstrated that Q-switched holmium lasers are capable of high-gain and high-energy operation at 300 K. Small-signal gain coefficients of 0.50 and 0.12/cm have been measured in YLF and YAG, respectively. Small-signal gains of 0.50/cm are comparable to those achievable in Nd:YAG and are not typical of low-gain materials. This large gain in the Ho:YLF material is made possible by operating the amplifier in the ground state depletion mode. The amplifier performance data and associated analysis presented demonstrate that efficient energy storage is possible with very high excited state ion densities of the Ho 5I7 upper laser level. This is an important result since upconversion can limit the 5I7 population. Although upconversion was still present in this experiment, it was possible to achieve efficient energy storage, demonstrating that the problem is manageable even at high excitation densities in YLF.

  11. Radioactive phosphorus-uptake-testing variables before and after enucleation

    SciTech Connect

    Goldstein, B.G.; Robertson, D.M.

    1981-03-01

    Values for radioactive phosphorus uptake from 23 eyes with malignant melanomas of the choroid were compared before and after enucleation. In 11 but two eyes, the percentage increase in 32P uptake was higher immediately after enucleation than before enucleation. In eleven eyes, the variation was more than 100%. In one eye, the percentage increase of 32P uptake was 68% before enucleation and 137% after enucleation. The clinical importance of our findings is that pressure on the globe by the detector probe before enucleation may locally decrease choroidal blood volume thereby causing an increase in the calculated 32P uptake.

  12. Effects of simultaneously fiber transmitted erbium and holmium radiation on the interaction with highly absorbing media

    NASA Astrophysics Data System (ADS)

    Frenz, Martin; Pratisto, Hans S.; Ith, Michael; Koenz, Flurin; Weber, Heinz P.

    1995-05-01

    Erbium and Holmium lasers have both been shown to be suitable for orthopedic surgery performed under water. Erbium lasers emitting in the 3 micrometers wavelength region corresponding to the maximum water absorption peak effectively ablated biological tissues with high precision and minimal thermal damage. Holmium laser radiation at 2 micrometers , due to a lower absorption coefficient, is characterized by a greater extent of thermal damage leading to hemostasis. To combine the special advantages of each system we simultaneously coupled their radiation into a zirconium fluoride fiber (ZrF4) which was protected with a quartz fiber tip. Pressure measurements performed in the liquid using a piezo electrical transducer, transmission measurements and video flash lamp schlieren imaging of the laser induced vapor bubble were used in order to determine optimum laser parameters. The cutting efficiency of the Erbium laser is drastically improved when a low energy Holmium laser pulse is additionally used which is just able to open a vapor channel through which the Erbium laser pulse can be transmitted. The dynamics of the channel formation, geometry and life time are measured as a function of the delay time between the two different laser pulses and the pulse energy applied. The combination of 2 micrometers and 3 micrometers radiation seems to be an ideal instrument for tissue treatment.

  13. Enucleation versus plaque irradiation for choroidal melanoma

    SciTech Connect

    Straatsma, B.R.; Fine, S.L.; Earle, J.D.; Hawkins, B.S.; Diener-West, M.; McLaughlin, J.A.

    1988-07-01

    The Collaborative Ocular Melanoma Study (COMS) is an international, multicenter-controlled study. The organization includes an Executive Committee, Steering Committee, 6 Central Units, 32 Clinical Centers, and a Data and Safety Monitoring Committee. Scientifically, the COMS consists of (1) a randomized trial of patients with medium choroidal melanoma treated with enucleation versus iodine-125 plaque irradiation, (2) a randomized trial of patients with large choroidal melanoma treated with enucleation versus preenucleation external beam irradiation and enucleation, and (3) a prospective observational study of patients with small choroidal melanoma to determine whether a randomized trial of treatment is appropriate. In design and conduct of the COMS, special consideration is given to biostatistics and sample size considerations, iodine-125 plaque irradiation of choroidal melanoma, and coordinated ocular melanoma research. Recruitment is in progress. However, the pool of eligible patients is limited and the COMS needs the continued support and cooperation of ophthalmologists throughout the United States and Canada.

  14. Mandibular buccal bifurcation cyst: enucleation without extraction.

    PubMed

    Shohat, I; Buchner, A; Taicher, S

    2003-12-01

    The mandibular buccal bifurcation cyst (MBBC) is a cystic lesion, which occurs on the buccal surface of the permanent mandibular first molar in children around 6-8 years old. Treatment of the cyst has been controversial: extraction of the involved tooth and enucleation of the cyst, or only enucleation, without extraction. The aim of this article is to familiarize oral and maxillofacial surgeons with this entity and the appropriate treatment approach. The diagnostic features of MBBC are described and the treatment approach in five patients with a total of seven cysts is presented. Two cases were identified in identical twins. Enucleation of the cyst without extraction of the involved tooth is the treatment of choice when the available data and experience in treating MBBC are considered. PMID:14636611

  15. The influence of enucleation on the ultrastructure of in vitro matured and enucleated cattle oocytes.

    PubMed

    Greising, T; Jonas, L

    1999-07-15

    The enucleation of recipient oocytes in nuclear transfer experiments is generally carried out by aspirating one third of the ooplasm adjacent to the first polar body. It was supposed that this enucleation step affects the ultrastructure of the remaining cytoplast, resulting in a decline or destruction of its cellular compartments. Even if the transferred nucleus had the potential to support the development of a single-cell nucleus transfer embryo to the blastocyst stage, meiotic division could be stopped at any stage if the destruction of the ultrastructure of host cytoplasm resulted in a limited metabolism. The present study was conducted to investigate the influence of the enucleation procedure on the ultrastructure of the remaining ooplast. In vitro matured oocytes; in vitro matured and enucleated oocytes; and in vitro matured and enucleated oocytes that were subsequently cultivated in vitro for additional 4 h were prepared for transmission electron microscopy (TEM). An examination of ultra-thin sections showed that the arrangement of organelles in all matured oocytes was in accordance with that already described for normal oocyte development. Immediately after enucleation no major differences in the arrangement of cortical granules, mitochondria, smooth endoplasmic reticulum (SER), lipid droplets and vacuoles were found compared with nonmanipulated oocytes. After enucleation and 4 h of culture, 24- and 36-h matured oocytes differed from each other in the arrangement of large aggregates of SER surrounded by a wall of mitochondria and lipid droplets. These complexes were still found in the 24-h but not in 36-h matured, enucleated and cultivated oocytes. Clusters of SER, mitochondria and lipid droplets were described by different authors as having metabolic activity. The results of this study in connection with results from nuclear transfer experiments suggest that these aggregates and their metabolic activity can be transferred with cytoplasm from 24- but not 36-h matured oocytes. Only cytoplasm from the 24-h matured oocytes showed a development-supporting effect when fused to enucleated recipient cells before nuclear transfer. PMID:10734396

  16. Current Laser Treatments for Benign Prostatic Hyperplasia

    PubMed Central

    Son, Hwancheol; Song, Sang Hoon

    2010-01-01

    The latest technical improvements in the surgical armamentarium are remarkable. In particular, advancements in the urologic field are so exceptional that we could observe the flare-up of robot-assisted laparoscopic radical prostatectomy for prostate cancer and laser prostatectomy for benign prostatic hyperplasia (BPH). Photoselective vaporization of the prostate (PVP) and holmium laser prostatectomy are the most generalized options for laser surgery of BPH, and both modalities have shown good postoperative results. In comparison to transurethral prostatectomy (TURP), they showed similar efficacy and a much lower complication rate in randomized prospective clinical trials. Even in cases of large prostates, laser prostatectomy showed comparable efficacy and safety profiles compared to open prostatectomy. From a technical point of view, PVP is considered to be an easier technique for the urologist to master. Furthermore, patients can be safely followed up in an outpatient clinic. Holmium laser enucleation of the prostate (HoLEP) mimics open prostatectomy because the adenomatous tissue is peeled off the surgical capsule in both procedures. Therefore, HoLEP shows notable volume reduction of the prostate similar to open prostatectomy with fewer blood transfusions, shorter hospital stay, and cost reduction regardless of prostate size. Outcomes of laser prostatectomy for BPH are encouraging but sometimes are unbalanced because safety and feasibility studies were reported mainly for PVP, whereas long-term data are mostly available for HoLEP. We need longer-term randomized clinical data to identify the reoperation rate of PVP and to determine which procedure is the ideal alternative to TURP and open prostatectomy for each patient. PMID:21165192

  17. Holmium-doped Lu2O3, Y2O3, and Sc2O3 for lasers above 2.1 ?m.

    PubMed

    Koopmann, Philipp; Lamrini, Samir; Scholle, Karsten; Schfer, Michael; Fuhrberg, Peter; Huber, Gnter

    2013-02-11

    Efficient room-temperature laser operation was obtained in the wavelength range from 2117 nm to 2134 nm with Ho:Lu(2)O(3) and Ho:Y(2)O(3) as the active materials. With an FBG-stabilized Tm-doped fiber laser as the pump source, the maximum slope efficiency and output power of the Ho:Y(2)O(3) laser were 63% and 18.8 W, respectively. With Ho:Lu(2)O(3) the respective values were 76% and 25.2 W. With Ho:Sc(2)O(3) as the active material the accessible wavelength range could be expanded to 2158 nm in a diode-pumped setup. PMID:23481849

  18. Enucleation for Treating Rodent Ocular Disease

    PubMed Central

    Wilding, Laura A; Uchihashi, Mayu; Bergin, Ingrid L; Nowland, Megan H

    2015-01-01

    Our standard of care for rodent corneal lesions previously included treatment of the primary lesion, application of topical NSAIDs, and systemic NSAIDs in severe cases. When intensive medical management was unsuccessful, animals were euthanized, leading to premature loss of valuable genetically modified animals and those on long-term studies. We investigated enucleation surgery as a treatment for 15 cases of rodent corneal disease that did not respond to medical management. Enucleation was performed under isoflurane anesthesia and involved removal of the globe, extensive hemostasis, and packing the orbital space with absorbable gelatin sponge. The lid margins were closed by tarsorrhaphy and tissue glue. Analgesia was provided by using buprenorphine preoperatively and carprofen chew tabs postoperatively. To date, we have a 100% success rate with this procedure (n = 20; 15 clinically affected rodents [2 rats, 13 mice], 5 healthy controls), which included a 60-d follow-up period. The single complication involved dehiscence of the tarsorrhaphy site and was repaired by trimming the lid margins to provide fresh tissue for closure. Histologic examination at both 1 and 3 mo after surgery revealed no evidence of infection of the enucleation site. Enucleation in rodents is a straightforward procedure that represents a refinement to our current standard of care for rodents, does not cause significant inflammation of remaining periocular structures, and has reduced the number of animals euthanized prior to study endpoint because of severe ocular lesions. PMID:26045460

  19. [Traumatic enucleation. Accident or self-mutilation?].

    PubMed

    Straburger, P; Vradi, G

    2013-05-01

    A 52-year-old woman was admitted for emergency treatment after traumatic enucleation. Because of the position of the avulsed eye and the acute mental condition of the patient a trauma caused by self-mutilation could not be excluded. There was even the suspicion of self-enucleation in a second case and in both cases a psychiatrist was consulted but ultimately a disastrous accident was clearly verified for both patients. Nevertheless, an interdisciplinary evaluation should be initiated in cases of patients with a suspicious traumatic injury as in cases of self-mutilation the danger of relapse is high in the first hours and weeks after the primary event. PMID:23179946

  20. Energy upconversion in holmium doped lead-germano-tellurite glass

    SciTech Connect

    Kamma, Indumathi; Reddy, B. Rami

    2010-06-15

    Holmium doped lead-germano-tellurite glass was prepared by the melt quenching technique. The Judd-Ofelt intensity parameters were estimated as {Omega}{sub 2}=7.6x10{sup -20}, {Omega}{sub 4}=12.9x10{sup -20}, and {Omega}{sub 6}=2.5x10{sup -20} cm{sup 2}. Radiative transition probabilities and lifetimes were also determined for some of the levels. Room temperature upconversion emissions have been observed from Ho{sup 3+} at 497 nm under 532 nm laser excitation, and at 557 and 668 nm under 762 nm laser excitation. The upconversion emission mechanisms were found to be due to a step wise excitation process. Upconversion emission intensity enhanced in a heat treated glass.

  1. Video-thoracoscopic enucleation of esophageal leiomyoma

    PubMed Central

    2012-01-01

    Background Leiomyoma is the most common benign tumor of the esophagus. Surgical enucleation is indicated in case of symptoms or an unclear diagnosis, and open thoracotomy has long been the standard approach for this procedure. However, enucleation through video assisted thoracoscopic surgery (VATS) has been developed as a preferred approach for most lesions in recent years. Method Herein we report our twelve patients (seven men and five women, with median age of 42 years) from 2001 to 2009, who underwent enucleation through VATS for esophageal leiomyomas, with a size from 1 to 8 cm in diameter (median: 5), and at different locations, from the thoracic outlet to near the diaphragmatic level of the thoracic esophagus. Intraoperative fiberoptic esophagoscopy was performed in two patients for localization by illumination. A right-sided approach was performed in eight cases (upper two thirds of esophagus) and the left-sided in another four cases (lower third of esophagus). Result The median operative time was 95 minutes (70 to 230 minutes). Four of them required small utility incisions (4-6 cm) for better exploration and manipulation. There were no major complications, such as death or empyema due to leaks from mucosal tears, and the presenting symptoms were improved during the follow-up period, from 12 to 98 months. Conclusion VATS can be considered as an initial approach for most patients with esophageal leiomyomas, even large in size, irregular in shape, or at unfavorable location. It is a safe, minimally invasive, and effective treatment. However, conversion to open thoracotomy should be required for the sake of clinical or technical concern. PMID:22420503

  2. New, efficient, room temperature mid-infrared laser at 3.9 mu m in holmium:barium yttrium fluoride and visible praseodymium:lithium yttrium fluoride laser for holography

    NASA Astrophysics Data System (ADS)

    Tabirian, Anna Murazian

    This dissertation describes a series of experiments and theoretical studies, which led to the development of two new solid state laser systems: efficient, room temperature mid-infrared solid state laser at 3.9 ?m in Ho 3+ doped BaY2F8 and visible Pr:LiYF4 laser at 640 mn for holography. The 3.9 ?m laser wavelength matches the peak of mid-IR atmospheric transmission window, which makes it very important for multiple applications such as remote sensing, imaging, IR countermeasures, eye-safe lidars and environmental agent detection. We present the results of spectroscopic evaluations and numerical modeling of energy transfer processes between rare earth ions of Ho3+ doped in two host laser materials: BaY2F8 and LiYF 4. The 3.9 ?m laser is based on transition with upper laser lifetime considerably shorter than lower level lifetime, which in general leads to self-terminating laser action in the cw mode or at high repetition rates. Therefore, three different pumping and lasing schemes, that could allow overcoming these limitations have been suggested and studied. First, cascade laser action at 1.4 ?m and 3.9 ?m was achieved with low thresholds and near-theoretical quantum efficiency in Ho3+ doped BaY2F8 pumped at 532 nm by a Q- switched frequency doubled Nd:YAG laser. Next, the feasibility of achieving 3.9 ?m laser with cw resonant cascade pumping at 750 mn by a Ti:Sapphire laser was studied. New energy transfer process, such as upconversion from terminal level of the 3.9 ?m laser was observed in high concentration Ho3+ doped BaY2F 8. Finally, we proposed to use high-energy flashlamp pumped tunable Cr:LiSAF laser operating in long pulse regime for the direct pumping of the upper level of the 3.9 ?m laser. Pulsed laser oscillation at 3.9 ?m is demonstrated in Ho3+ doped BaY2F8 with low threshold of 3 mJ and a slope efficiency of 14.5% with maximal energy of 30 mJ. The second part of the thesis describes the design and the development of the visible Pr:LiYF4 laser for holography at 640 nm resonantly pumped by the frequency-doubled flashlamp pumped tunable Cr:LiSAF laser at 444 nm.

  3. Erythroblast enucleation is a dynein-dependent process.

    PubMed

    Kobayashi, Isuzu; Ubukawa, Kumi; Sugawara, Kotomi; Asanuma, Ken; Guo, Yong-Mei; Yamashita, Junsuke; Takahashi, Naoto; Sawada, Kenichi; Nunomura, Wataru

    2016-04-01

    Mammalian erythroblasts undergo enucleation through a process thought to be similar to cytokinesis. Microtubule-organizing centers (MTOCs) mediate organization of the mitotic spindle apparatus that separates the chromosomes during mitosis and are known to be crucial for proper cytokinesis. However, the role of MTOCs in erythroblast enucleation remains unknown. We therefore investigated the effect of various MTOC inhibitors on cytokinesis and enucleation using human colony-forming units-erythroid (CFU-Es) and mature erythroblasts generated from purified CD34(+) cells. We found that erythro-9-[3-(2-hydroxynonyl)]adenine (EHNA), a dynein inhibitor, and monastrol, a kinesin Eg5 inhibitor, as well as various inhibitors of MTOC regulators, including ON-01910 (Plk-1), MLN8237 (aurora A), hesperadin (aurora B), and LY294002 (PI3K), all inhibited CFU-E cytokinesis. Among these inhibitors, however, only EHNA blocked enucleation. Moreover, terminally differentiated erythroblasts expressed only dynein; little or none of the other tested proteins was detected. Over the course of the terminal differentiation of human erythroblasts, the fraction of cells with nuclei at the cell center declined, whereas the fraction of polarized cells, with nuclei shifted to a position near the plasma membrane, increased. Dynein inhibition impaired nuclear polarization, thereby blocking enucleation. These data indicate that dynein plays an essential role not only in cytokinesis but also in enucleation. We therefore conclude that human erythroblast enucleation is a process largely independent of MTOCs, but dependent on dynein. PMID:26724640

  4. Spherulitic crystallization of holmium tartrates in silica gels

    NASA Astrophysics Data System (ADS)

    Want, Basharat

    2011-09-01

    Spherulites of holmium tartrate trihydrate and holmium nitro-tartrate monohydrate have been grown in silica gel medium by making holmium nitrate to react with tartaric acid at high supersaturations. The mechanism of spherulitic growth of holmium tartrates is discussed. The spherulitic crystallization is shown to be due to heterogeneous nucleation. In the early stages of growth an amorphous spherical mass gets nucleated inside the gel. Crystal fibers diverge radially from the surface of the spherical mass giving rise to a spherical polycrystalline holmium tartrate. Thermal stability of the two types of spherulites grown in the silica gel shows that the holmium tartrate trihydrate is more stable than holmium nitro-tartrate monohydrate. The surface morphology and internal structure of the spherulites of holmium tartrates have been studied by using scanning electron microscopy. The results on growth kinetics are given by studying the variation of radius of spherulites as a function of time. A non-linear time-size relations under several conditions of growth have been observed, which suggests a non-uniform solute concentration at the crystal surface.

  5. SELF-ENUCLEATION IN DEPRESSION: A CASE REPORT

    PubMed Central

    Rao, K.N.; Begum, Shamshad

    1996-01-01

    Self- enucleation is a rare and an extreme form of self - mutilation, most commonly reported in schizophrenia. Many forms of self - injuries have been described in depression. However severe form of self- mutilation without suicidal intention, especially self- enucleation is rarely reported. In the present case self- enucleation is described as an expression of aggression in a depressive patient threatened with inter-personal loss. Aggression turned inwards is one of the major psychodynamic explanations in depression. In depressive syndrome self- mutilation, whether mild or severe is an expression of loss of affective (aggression) control. PMID:21584146

  6. The sorting of blood group active proteins during enucleation

    PubMed Central

    Satchwell, Timothy J.; Bell, Amanda J.; Toye, Ashley M.

    2015-01-01

    Enucleation represents the critical stage during red blood cell development when the nucleus is extruded from an orthochromatic erythroblast in order to generate a nascent immature reticulocyte. Extrusion of the nucleus results in loss of a proportion of the erythroblast plasma membrane, which surrounds the nucleus, the bulk of the endoplasmic reticulum and a small region of cytoplasm. For this reason enucleation provides an important point in erythroblast differentiation at which proteins not required for the function of the erythrocyte can be lost, whilst those that are important for the structure-function properties of the mature erythrocyte must be efficiently retained in the reticulocyte plasma membrane. Disturbances in protein distribution during enucleation are envisaged to occur during human diseases such as Hereditary Spherocytosis. This article will discuss the current knowledge of erythroblast enucleation in the context of retention and loss of proteins that display antigenic blood group sites and that exist within multiprotein complexes within the erythrocyte membrane. PMID:26640516

  7. Topical autologous serum promotes enucleation wound healing in retinoblastoma patients.

    PubMed

    Kwok, Madeline K; Yam, Jason C S; Yu, Christopher B O; Lau, Flora H S

    2015-08-01

    Two retinoblastoma patients underwent uneventful enucleations while undergoing perioperative chemotherapy. In both cases the postoperative course was complicated by poor conjunctival wound healing. Administration of topical autologous serum was associated with wound healing and conjunctivalization of these wounds. PMID:26210027

  8. Unsuccessful Self-Enucleation in a Schizophrenic Patient

    PubMed Central

    Noy Achiron, Romi; Paul, Michael; Achiron, Asaf

    2014-01-01

    Self-enucleation is a very unusual form of self-mutilation directly linked to mental illness. In this case we present a 26-year-old schizophrenic patient who attempted to enucleate his eye with a rollerball pen. Antipsychotic therapy and emergency surgery saved the patient eye and emphasize the importance of quick response and good collaboration between psychiatric and ophthalmic teams. PMID:25328735

  9. Unsuccessful self-enucleation in a schizophrenic patient.

    PubMed

    Bar-Yaakov, Noam; Noy Achiron, Romi; Paul, Michael; Achiron, Asaf

    2014-01-01

    Self-enucleation is a very unusual form of self-mutilation directly linked to mental illness. In this case we present a 26-year-old schizophrenic patient who attempted to enucleate his eye with a rollerball pen. Antipsychotic therapy and emergency surgery saved the patient eye and emphasize the importance of quick response and good collaboration between psychiatric and ophthalmic teams. PMID:25328735

  10. On-chip enucleation of an oocyte by untethered microrobots

    NASA Astrophysics Data System (ADS)

    Ichikawa, Akihiko; Sakuma, Shinya; Sugita, Masakuni; Shoda, Tatsuro; Tamakoshi, Takahiro; Akagi, Satoshi; Arai, Fumihito

    2014-09-01

    We propose a novel on-chip enucleation of an oocyte with zona pellucida by using a combination of untethered microrobots. To achieve enucleation within the closed space of a microfluidic chip, two microrobots, a microknife and a microgripper were integrated into the microfluidic chip. These microrobots were actuated by an external magnetic force produced by permanent magnets placed on the robotic stage. The tip of the microknife was designed by considering the biological geometric feature of an oocyte, i.e. the oocyte has a polar body in maturation stage II. Moreover, the microknife was fabricated by using grayscale lithography, which allows fabrication of three-dimensional microstructures. The microgripper has a gripping function that is independent of the driving mechanism. On-chip enucleation was demonstrated, and the enucleated oocytes are spherical, indicating that the cell membrane of the oocytes remained intact. To confirm successful enucleation using this method, we investigated the viability of oocytes after enucleation. The results show that the production rate, i.e. the ratio between the number of oocytes that reach the blastocyst stage and the number of bovine oocytes after nucleus transfer, is 100%. The technique will contribute to complex cell manipulation such as cell surgery in lab-on-a-chip devices.

  11. A simplified approach for oocyte enucleation in mammalian cloning.

    PubMed

    Iuso, Domenico; Czernik, Marta; Zacchini, Federica; Ptak, Grazyna; Loi, Pasqualino

    2013-12-01

    Despite its success in almost all farm and laboratory animals, somatic cell nuclear transfer (SCNT) is still a low-efficiency technique. In this investigation, we determined the impact of each enucleation step on oocyte viability (assessed by parthenogenetic activation): Hoechst (HO) staining, cytochalasin B, ultraviolet (UV) exposure, and demecolcine. Our data showed that of all the factors analyzed, UV exposure impaired oocyte development (cleavage, 59% for untreated oocytes vs. 8% UV exposed; blastocyst stage, 32% untreated vs. 0% UV exposed). A minor toxicity was detected following demecolcine treatment (cleavage, 62%; blastocyst stage, 13%). Next, we compared HO/UV (canonical) and demecolcine-assisted enucleation (DAE), with a straight removal of metaphase chromosomes without any chemical or physical aid (straight enucleation). DAE improved the preimplantation development of sheep cloned embryos compared to HO/UV enucleation (cleavage, 38% vs. 19%; blastocysts, 17% vs. 4%), yet straight enucleation resulted in the highest cleavage and blastocysts rates (61% and 30%, respectively). We concluded that: (1) UV exposure harms sheep oocyte and embryo development; (2) DAE may represent an alternative approach, especially for unskilled operators; and (3) straight enucleation remains, in our estimation, the most reliable and least harmful protocol for SCNT. PMID:24219576

  12. Pulsed holmium:YAG-induced thermal damage in albumen

    NASA Astrophysics Data System (ADS)

    Pfefer, T. Joshua; Chan, Kin Foong; Hammer, Daniel X.; Welch, Ashley J.

    1998-05-01

    The development of thermal damage during pulsed Holmium:YAG ((lambda) equals 2.12 micrometer, (tau) p equals 250 microseconds) irradiation of albumen was analyzed experimentally and numerically with the intent of validating the Arrhenius integral and investigating the influence of beam profile and dynamic changes in absorption. Fast flash videography was performed to document the transient development of coagulation during and after the laser pulse. A two-dimensional dynamic optical-thermal model was developed. The optical component involved a discretized Beer's law method in which absorption is a function of temperature. The thermal component was comprised of (1) a cylindrical coordinate (r,z) finite difference formulation of the heat conduction equation in which the output from the optical model was used as the source term and (2) a routine for calculating thermal damage using the Arrhenius relation. At the end of each time step, the temperature distribution was used to recalculate the absorption coefficient array, which in turn is used in the optical component. The model showed good agreement with experimental data and the literature. The Arrhenius integral was shown to be valid for the sub-vaporization pulsed laser regime. Experimental and numerical results indicated that spatial beam profile has a significant impact on thermal damage. Simulations predicted that at higher radiant exposures dynamic changes in absorption become more significant, accounting for a 10% increase in coagulation depth.

  13. Influence of holmium:YSGG intensity on bubble formation in saline and in tissue

    NASA Astrophysics Data System (ADS)

    van Leeuwen, Ton G. J. M.; Verdaasdonck, Rudolf M.; Borst, Cornelius

    1992-08-01

    Previous studies of mid-infrared ablation of tissue showed blast damage to adjacent tissue in the form of large fissures extending from the crater wall. We hypothesized that these fissures are due to the forceful expansion of a water vapor bubble within tissue. Time resolved flash photography documented an expanding vapor bubble within the tissue by the elevation of the tissue surface. The aim of this study was to determine the relation between the intensity of holmium:YSGG laser irradiation and bubble dimension in saline and in tissue. The influence of the spatial distribution of the intensity was determined by delivering 200 to 500 mJ laser pulses through a 320 micrometers and 600 micrometers diameter bare fiber, which was in light contact with porcine aorta. A holmium:YSGG laser pulse is a superposition (500 microsecond(s) long) of microsecond pulses. The first part of the laser pulse contains the most intense spikes. To determine the influence of the high peak power spikes on bubble formation, the first part of a 650 mJ laser pulse was absorbed. The modified laser pulse (400 mJ) was smoother and 75 microsecond(s) shorter than the original 400 mJ laser pulse. Increasing the fiber tip area by a factor of 3.5 (600 micrometers vs. 320 micrometers diameter) resulted in a decrease in the diameter of tissue elevation by only a factor of 1.25, indicating that the delivered energy determined the extent of tissue elevation. Elimination of the high peak power of the first part of the laser pulse did not decrease the dimension of the bubble in saline and of the tissue elevation. Therefore we anticipate that the extent of the blast damage in tissue cannot be reduced substantially by either reducing the fluence or by quenching high peak power spikes of the laser pulse.

  14. Molecular signature of erythroblast enucleation in human embryonic stem cells.

    PubMed

    Rouzbeh, Shaghayegh; Kobari, Ladan; Cambot, Marie; Mazurier, Christelle; Hebert, Nicolas; Faussat, Anne-Marie; Durand, Charles; Douay, Luc; Lapillonne, Hlne

    2015-08-01

    While enucleation is a critical step in the terminal differentiation of human red blood cells, the molecular mechanisms underlying this unique process remain unclear. To investigate erythroblast enucleation, we studied the erythroid differentiation of human embryonic stem cells (hESCs), which provide a unique model for deeper understanding of the development and differentiation of multiple cell types. First, using a two-step protocol, we demonstrated that terminal erythroid differentiation from hESCs is directly dependent on the age of the embryoid bodies. Second, by choosing hESCs in two extreme conditions of erythroid culture, we obtained an original differentiation model which allows one to study the mechanisms underlying the enucleation of erythroid cells by analyzing the gene and miRNA (miR) expression profiles of cells from these two culture conditions. Third, using an integrated analysis of mRNA and miR expression profiles, we identified five miRs potentially involved in erythroblast enucleation. Finally, by selective knockdown of these five miRs we found miR-30a to be a regulator of erythroblast enucleation in hESCs. PMID:25850942

  15. Enucleation and evisceration: indications, complications and clinicopathological correlations

    PubMed Central

    Kord Valeshabad, Ali; Naseripour, Masood; Asghari, Rajab; Parhizgar, Seyed Hamid; Parhizgar, Seyed Ehsan; Taghvaei, Mohammad; Miri, Shahin

    2014-01-01

    AIM To assess main indications, postoperative complications and clinicopathological correlation of ocular enucleation-evisceration. METHODS A total of 107 subjects who underwent enucleation and/or evisceration and received hydroxyapatite implants (Scleral wrap or mesh) were assessed. For each patient clinicopathological data was collected which included demographic information, clinical history, primary clinical diagnosis, main cause of ophthalmic surgery (traumatic, non-traumatic), type of surgical procedure (enucleation, evisceration) and pathological report. Patients' postoperative clinical visits were checked for procedure-related complications during first year after surgery. RESULTS One hundred and seven patients (male: 65.4%; mean age: 26y) underwent enucleation (n=100) or evisceration (n=7) due to traumatic (n=41) and non-traumatic (n=66) causes. Disfiguring painful blind eye was the most common indication of surgery (66.4%), followed by leukocoria (19.6%) and endophthalmitis (4.7%). The main types of injury included firecracker, traffic and work accidents, and sharp object perforating injury. In 53 (80.3%) subjects in non-traumatic group the initial clinical diagnosis matched the histopathological results. Malignant tumors (retinoblastoma: 47.5%, malignant melanoma: 27.3%) were the most common pathological diagnoses followed by phthisis bulbi (25.8%). The most common procedure-related complications were major eye discharge (39.6%), and implant exposure and discharge (20.8%). CONCLUSION Trauma and malignant tumors are the leading causes of enucleation-evisceration. Despite developing new techniques and materials, enucleation is still associated with considerable postoperative complications. PMID:25161942

  16. Tumor Enucleation of Renal Cell Carcinoma in a Solitary Kidney

    PubMed Central

    Farber, NJ; Faiena, I; Parihar, JS; Singer, EA

    2015-01-01

    We describe the case of a 57 year old man with a solitary kidney after undergoing resection of a Wilm's tumor as a child and a recent left partial colectomy who presents with an incidentally found clinical T1b renal mass. The patient underwent tumor enucleation and had no change in his renal function twelve days after surgery as compared to his preoperative baseline, highlighting the additional nephron-sparing associated with tumor enucleation as compared to partial nephrectomy that includes a gross margin of normal parenchyma. PMID:26380382

  17. Simple Enucleation for Renal Tumors: Indications, Techniques, and Results.

    PubMed

    Garca, Adolfo Garca; Len, Tania Gonzlez

    2016-01-01

    Kidney cancer is the 13th most common malignancy worldwide with significant increase in Stage I renal cell cancer (RCC). Surgical excision by nephron sparing surgery (NSS) remains the treatment of choice for small renal masses (SRMs). One of the variants of partial nephrectomy is simple enucleation (SE) or tumor enucleation (TE). The present review comments on the indications and technical aspects of SE as well as its outcomes. SE/TE has shown both perioperative and oncologic satisfactory results, comparable to partial nephrectomy (PN). It is a valid technique for SRMs and achieves maximum renal parenchymal preservation with an insignificant impact on renal function. PMID:26728315

  18. Clinicopathological review of 1146 enucleations (1980-90).

    PubMed Central

    de Gottrau, P; Holbach, L M; Naumann, G O

    1994-01-01

    The clinicopathological data of 1146 enucleated eyes obtained from 1146 patients (485 females and 661 males; mean age 57.4 (SD 21.6) years) between 1980 and 1990 were reviewed. The most common underlying diseases included trauma (37.4%), malignant tumours (19.6%), systemic diseases (diabetes, vascular diseases) (17.1%), surgical diseases (retinal detachment, glaucoma, cataract, corneal dystrophy) (14.1%), infection and inflammation (7%). The most frequent indications for enucleation were secondary angle closure glaucoma (34.9%), ocular malignant tumours (21.7%), atrophia or phthisis bulbi (18.7%), ocular infectious or inflammatory disease (14.7%), and recent trauma (enucleation was performed within the first month after trauma) (11.2%). Histopathologically, diagnoses included secondary angle closure (691 eyes or 60.3%), rubeosis iridis (550 or 48%), endothelialisation of the iridocorneal angle (198 or 17.3%), and retrocorneal membrane (143 or 12.5%). These data indicate that rubeosis iridis, often followed by irreversible secondary angle closure, represents the most common pathogenetic reason for enucleating eyes. Management procedures must be directed towards the prevention or consequent therapy of rubeosis iridis. PMID:8199109

  19. Holmium-doped fluorotellurite microstructured fibers for 2.1 ?m lasing.

    PubMed

    Yao, Chuanfei; He, Chunfeng; Jia, Zhixu; Wang, Shunbin; Qin, Guanshi; Ohishi, Yasutake; Qin, Weiping

    2015-10-15

    Holmium (Ho3+)-doped fluorotellurite microstructured fibers based on TeO2-BaF2-Y2O3 glasses are fabricated by using a rod-in-tube method. By using a 1.992 ?m fiber laser as the pump source, lasing at 2.077 ?m is obtained from a 27 cm long Ho3+-doped fluorotellurite microstructured fiber. The maximum unsaturated power is about 161 mW and the corresponding slope efficiency is up to 67.4%. The influence of fiber length on lasing at 2.1 ?m is also investigated. Our results show that Ho3+-doped fluorotellurite microstructured fibers are promising gain media for 2.1 ?m laser applications. PMID:26469597

  20. Laser tissue interaction in direct myocardial revascularization.

    PubMed

    Shehada, R E; Mansour, H N; Grundfest, W S

    2000-06-01

    This investigation examines the various laser choices used for transmyocardial laser revascularization (TMLR) with emphasis on the laser-tissue interaction. A series of in vivo (porcine model, n=27) and in vitro experiments were performed to study the effects of CO(2), holmium:YAG, and XeCl excimer lasers on the histological outcome of TMR channels. Computerized histopathological analysis has revealed that the CO(2) and holmium:YAG lasers produce substantial unpredictable thermal damage and differ predominantly in the amount of the mechanical injury or tissue shredding. In comparison, the excimer laser appears to produce the most uniform tissue ablation with the least thermal and shockwave damage. PMID:10867762

  1. Enucleation of a Giant Hemangioma of Liver: Old School Revisited.

    PubMed

    ChandraBose, Karpagavel; Ramanujam, A; Muthu, Yega

    2015-01-01

    Hemangiomas are the most frequent benign hepatic tumours and are usually found in patients aged between 40 and 60 years, more frequently in women. In 30-35% of patients, the lesions are multiple. If the lesions are larger than 4-10?cm, they are coined as "giant" hemangioma. Here, we present a case of giant hemangioma treated with enucleation of the lesion and the advantages of the procedure. PMID:26844001

  2. Enucleation of a Giant Hemangioma of Liver: Old School Revisited

    PubMed Central

    ChandraBose, Karpagavel; Ramanujam, A.; Muthu, Yega

    2015-01-01

    Hemangiomas are the most frequent benign hepatic tumours and are usually found in patients aged between 40 and 60 years, more frequently in women. In 3035% of patients, the lesions are multiple. If the lesions are larger than 410?cm, they are coined as giant hemangioma. Here, we present a case of giant hemangioma treated with enucleation of the lesion and the advantages of the procedure. PMID:26844001

  3. Cobalt-60 plaque radiotherapy vs enucleation for posterior uveal melanoma

    SciTech Connect

    Augsburger, J.J.; Gamel, J.W.; Lauritzen, K.; Brady, L.W. )

    1990-05-15

    We compared the survival of 302 patients with a primary choroidal or ciliary body melanoma treated by cobalt-60 plaque radiotherapy between 1976 and 1982 with the survival of 134 patients treated by enucleation during the same period. Tumor size, location of the anterior margin of the tumor, and patient age at the time of treatment were identified as simultaneous significant clinical variables for predicting melanoma-specific mortality by multivariate Cox proportional hazards modeling. We computed a prognostic index for each patient based on this model and found that patients in the enucleation group had slightly higher values of this index than did patients in the cobalt-60 plaque radiotherapy group. Risk ratios for the treatment effect computed from a Cox model incorporating prognostic index and the treatment variable were found to be approximately equal to 1, both for analysis of melanoma-specific mortality and total mortality. These results indicate that when one controls for differences in prognostic index between the groups, cobalt-60 plaque therapy and enucleation are essentially equivalent in their effect on survival.

  4. The risk of enucleation after proton beam irradiation of uveal melanoma

    SciTech Connect

    Egan, K.M.; Gragoudas, E.S.; Seddon, J.M.; Glynn, R.J.; Munzenreider, J.E.; Goitein, M.; Verhey, L.; Urie, M.; Koehler, A. )

    1989-09-01

    Enucleation after proton beam irradiation of uveal melanomas occurred in 64 (6.4%) of 994 eyes with a median follow-up time of 2.7 years. The median time between irradiation and enucleation in the 64 enucleated eyes was 13 months. The probability of retaining the eye was 95 and 90%, 2 and 5 years postirradiation, respectively. Three percent of eyes were enucleated during posttreatment year 1, and the yearly rate was 1% by the fourth year. No patient had enucleation later than 5 1/2 years posttreatment. The complication most likely to result in enucleation was neovascular glaucoma although this was frequently managed without enucleation. Other common reasons for enucleation were documented or suspected tumor growth and complete retinal detachment with associated loss of vision. The leading risk factors for enucleation were anterior tumor margin involving the ciliary body, tumor height greater than 8 mm, and proximity of the tumor to the fovea. Based on the presence or absence of these factors, 5-year eye retention rates were 99, 92, and 76% for low-, moderate-, and high-risk groups, respectively. Thus, the probability of eye retention after proton beam irradiation is high even among those at greatest risk of enucleation.

  5. Discovery of dysprosium, holmium, erbium, thulium, and ytterbium isotopes

    SciTech Connect

    Fry, C.; Thoennessen, M.

    2013-09-15

    Currently, thirty-one dysprosium, thirty-two holmium, thirty-two erbium, thirty-three thulium, and thirty-one ytterbium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  6. Sub-100 fs passively mode-locked holmium-doped fiber oscillator operating at 2.06 ?m

    NASA Astrophysics Data System (ADS)

    Li, Peng; Ruehl, Axel; Grosse-Wortmann, Uwe; Hartl, Ingmar

    2015-03-01

    We demonstrate a simple and compact Holmium-doped fiber (HDF) femtosecond oscillator with 35 MHz repetition rate. The oscillator is pumped by a Tm-doped fiber laser. A dispersion compensating fiber was utilized to set the net-intracavity dispersion to zero at 2.06 ?m. The output pulses had an maximum average power of 40 mW and 160 fs FWHM pulse duration. To further shorten the pulse duration, we implemented a nonlinear compressor consisting of a solid core highly nonlinear fiber (HNLF) for SPM broadening and single mode fiber (SMF) for pulse compression. Sub-100 fs pulses were achieved.

  7. A Chemical Screening Approach to Identify Novel Key Mediators of Erythroid Enucleation.

    PubMed

    Wölwer, Christina B; Pase, Luke B; Pearson, Helen B; Gödde, Nathan J; Lackovic, Kurt; Huang, David C S; Russell, Sarah M; Humbert, Patrick O

    2015-01-01

    Erythroid enucleation is critical for terminal differentiation of red blood cells, and involves extrusion of the nucleus by orthochromatic erythroblasts to produce reticulocytes. Due to the difficulty of synchronizing erythroblasts, the molecular mechanisms underlying the enucleation process remain poorly understood. To elucidate the cellular program governing enucleation, we utilized a novel chemical screening approach whereby orthochromatic cells primed for enucleation were enriched ex vivo and subjected to a functional drug screen using a 324 compound library consisting of structurally diverse, medicinally active and cell permeable drugs. Using this approach, we have confirmed the role of HDACs, proteasomal regulators and MAPK in erythroid enucleation and introduce a new role for Cyclin-dependent kinases, in particular CDK9, in this process. Importantly, we demonstrate that when coupled with imaging analysis, this approach provides a powerful means to identify and characterize rate limiting steps involved in the erythroid enucleation process. PMID:26569102

  8. A Chemical Screening Approach to Identify Novel Key Mediators of Erythroid Enucleation

    PubMed Central

    Wölwer, Christina B.; Pase, Luke B.; Pearson, Helen B.; Gödde, Nathan J.; Lackovic, Kurt; Huang, David C. S.; Russell, Sarah M.; Humbert, Patrick O.

    2015-01-01

    Erythroid enucleation is critical for terminal differentiation of red blood cells, and involves extrusion of the nucleus by orthochromatic erythroblasts to produce reticulocytes. Due to the difficulty of synchronizing erythroblasts, the molecular mechanisms underlying the enucleation process remain poorly understood. To elucidate the cellular program governing enucleation, we utilized a novel chemical screening approach whereby orthochromatic cells primed for enucleation were enriched ex vivo and subjected to a functional drug screen using a 324 compound library consisting of structurally diverse, medicinally active and cell permeable drugs. Using this approach, we have confirmed the role of HDACs, proteasomal regulators and MAPK in erythroid enucleation and introduce a new role for Cyclin-dependent kinases, in particular CDK9, in this process. Importantly, we demonstrate that when coupled with imaging analysis, this approach provides a powerful means to identify and characterize rate limiting steps involved in the erythroid enucleation process. PMID:26569102

  9. Compact Ho:YLF Laser

    NASA Technical Reports Server (NTRS)

    Hemmati, H.

    1988-01-01

    Longitudinal pumping by laser diodes increases efficiency. Improved holmium:yttrium lithium fluoride laser radiates as much as 56 mW of power at wavelength of 2.1 micrometer. New Ho:YLF laser more compact and efficient than older, more powerful devices of this type. Compact, efficient Ho:YLF laser based on recent successes in use of diode lasers to pump other types of solid-state lasers.

  10. Fifteen-year trends in indications for enucleation from a tertiary care center in South India

    PubMed Central

    Sengupta, Sabyasachi; Krishnakumar, Subramanian; Biswas, Jyotirmay; Gopal, Lingam; Khetan, Vikas

    2012-01-01

    Aim: To analyze the trends in clinicopathologic indications for enucleations over a 15-year period. Materials and Methods: Clinicopathologic details of all eyes that underwent enucleation from January 1996 to December 2010 were drawn up from a computerized database. The study was divided into three periods of 5 years each and comparison tables for each cause of enucleation during these periods were generated. Chi-square test was used to compare proportions. Results: Out of a total 1467 enucleations performed during the study period, 693 (46%) were attributable to retinoblastoma, 189 (12.5%) to uveal melanoma, 228 (15%) to trauma, and 149 (10%) to phthisis bulbi. Intraocular tumors accounted for more than 63% of all enucleations performed. Over the three time periods, proportion of enucleations secondary to retinoblastoma increased from 38% in the 1st period to 58% in the 3rd period (P < 0.001). Enucleations for trauma showed statistically significant reduction in trends over the three periods (24% in the 1st period vs. 4.4% in the 3rd period, P < 0.001). Similar trends were also seen in the proportion of enucleations due to intractable glaucoma and chronic uveitis. The absolute number of enucleations secondary to retinoblastoma out of the total cases seen during the study period did not change over the three periods (range 51–60%). Conclusion: Intraocular tumors were the commonest indications for enucleation in our patient population despite the availability of globe-conserving treatments such as chemotherapy and radioactive plaques. We observed increasing trends in the proportion of enucleations due to retinoblastoma and reduction of enucleations secondary to trauma, chronic uveitis, and glaucoma. PMID:22569377

  11. Review of enucleation methods and procedures used in animal cloning: state of the art.

    PubMed

    Li, Guang-Peng; White, Kenneth L; Bunch, Thomas D

    2004-01-01

    Enucleation of a recipient oocyte is a crucially important process for nuclear transfer efficiency. Several procedures have been developed and used in the production of nuclear transfer embryos. Although the use of excitable fluorochromes and ultraviolet (UV) light are commonly used for complete enucleation, they also pose the risk of damaging the maternal cytoplast. Telophase and chemically assisted enucleation have also been used for cloning, but the quality and quantity of the recipient cytoplasm varies with the procedure used. This paper reviews various methods used for enucleation, and discusses their benefits and limitations with respect to cloning efficiency. PMID:15107241

  12. Replication of somatic micronuclei in bovine enucleated oocytes

    PubMed Central

    2012-01-01

    Background Microcell-mediated chromosome transfer (MMCT) was developed to introduce a low number of chromosomes into a host cell. We have designed a novel technique combining part of MMCT with somatic cell nuclear transfer, which consists of injecting a somatic micronucleus into an enucleated oocyte, and inducing its cellular machinery to replicate such micronucleus. It would allow the isolation and manipulation of a single or a low number of somatic chromosomes. Methods Micronuclei from adult bovine fibroblasts were produced by incubation in 0.05 ?g/ml demecolcine for 46 h followed by 2 mg/ml mitomycin for 2 h. Cells were finally treated with 10 ?g/ml cytochalasin B for 1 h. In vitro matured bovine oocytes were mechanically enucleated and intracytoplasmatically injected with one somatic micronucleus, which had been previously exposed [Micronucleus- injected (+)] or not [Micronucleus- injected (?)] to a transgene (50 ng/?l pCX-EGFP) during 5 min. Enucleated oocytes [Enucleated (+)] and parthenogenetic [Parthenogenetic (+)] controls were injected into the cytoplasm with less than 10 pl of PVP containing 50 ng/?l pCX-EGFP. A non-injected parthenogenetic control [Parthenogenetic (?)] was also included. Two hours after injection, oocytes and reconstituted embryos were activated by incubation in 5 ?M ionomycin for 4 min + 1.9 mM 6-DMAP for 3 h. Cleavage stage and egfp expression were evaluated. DNA replication was confirmed by DAPI staining. On day 2, Micronucleus- injected (?), Parthenogenetic (?) and in vitro fertilized (IVF) embryos were karyotyped. Differences among treatments were determined by Fisher?s exact test (p?0.05). Results All the experimental groups underwent the first cell divisions. Interestingly, a low number of Micronucleus-injected embryos showed egfp expression. DAPI staining confirmed replication of micronuclei in most of the evaluated embryos. Karyotype analysis revealed that all Micronucleus-injected embryos had fewer than 15 chromosomes per blastomere (from 1 to 13), while none of the IVF and Parthenogenetic controls showed less than 30 chromosomes per spread. Conclusions We have developed a new method to replicate somatic micronuclei, by using the replication machinery of the oocyte. This could be a useful tool for making chromosome transfer, which could be previously targeted for transgenesis. PMID:23173571

  13. Pathological findings in enucleated eyes after intravitreal melphalan injection.

    PubMed

    Ghassemi, Fariba; Amoli, Fahimeh Asadi

    2014-06-01

    The aim of this study is to evaluate the pathological findings of the eye after intravitreal melphalan for viable vitreous seeding from retinoblastoma. All enucleated eyes receiving an intravitreal injection of melphalan (10-50 ?g in 0.05 cc) were evaluated for histological changes. Of 25 treated cases, 8 eyes needed enucleation because of phthisis, parent request, or new tumor development. One of the cases was excluded from the study because of a history of intra-arterial chemotherapy with melphalan. There was no case of needle-site scleral involvement by retinoblastoma cells. In two eyes receiving 50 ?g melphalan, no viable retinoblastoma cell was detectable in the eye. Severe gliosis, vascular occlusion, retinal necrosis, hemorrhage and neovascularization were seen. Histologically, intravitreal melphalan for recalcitrant or recurrent vitreous seeds from retinoblastoma appears to provide acceptable vitreous seed control. It seems that higher doses could be destructive causing ischemic necrosis in the retina, severe gliosis and secondary neovascular changes as well as having a destructive effect on retinoblastoma cells. PMID:24043335

  14. The construction of cloned Sika deer embryos (Cervus nippon hortulorum) by demecolcine auxiliary enucleation.

    PubMed

    Yin, Y; Mei, M; Zhang, D; Zhang, S; Fan, A; Zhou, H; Li, Z

    2014-02-01

    The objective of our study was to establish the feasibility of experimental protocols for cloning sika deer. We performed auxiliary enucleation to improve the efficiency of nuclear transfer operation by optimizing the demecolcine concentration to induce cytoplasmic protrusions in the sika deer oocytes. In the present study,we had studied the impact of different demecolcine concentrations on cytoplasmic protrusions and enucleation rates. We determined that 95.9% of the sika deer oocytes formed cytoplasmic protrusions when treated for 1h with 0.8?g/ml demecolcine. The lowest observed rate of protrusion was 19.3% after overnight treatment with demecolcine. When the oocytes aged or had a poor cumulus expansion, they exhibited a significant decrease in the ability to form cytoplasmic protrusions. The rates of enucleation (94.9% vs 85.8%, p<0.05), cell fusion (84.6% vs 70.1%, p<0.05) and blastocyst formation (15.4% vs 10.9%, p<0.05) using demecolcine auxiliary enucleation were significantly higher than those after blind enucleation. These results demonstrated that sika deer oocytes could be enucleated quickly and effectively using demecolcine auxiliary enucleation, which could enhance the enucleation rate, cell fusion rate and blastocyst rate of cloned embryos in vitro. PMID:24138424

  15. Hard and fragile holmium-based bulk metallic glasses

    SciTech Connect

    Luo, Q.; Zhao, D.Q.; Pan, M.X.; Wang, R.J.; Wang, W.H.

    2006-05-01

    A family of holmium-based bulk metallic glasses (BMGs) with high glass-forming ability is obtained. The Ho-based BMGs exhibit much larger elastic moduli and high thermal stability in contrast to other known rare-earth (RE)-based BMGs. In particular, the BMGs show a large value of fragility. It is expected that the hard RE-based glasses with high glass-forming ability and fragile behaviors make them the appropriate candidate for glass transition study.

  16. Rydberg Spectroscopy and imaging of single Holmium atoms

    NASA Astrophysics Data System (ADS)

    Hostetter, James; Pritchard, Jonathan; Saffman, Mark

    2015-05-01

    Neutral holmium with its large number of hyperfine ground states provides a promising approach for collective encoding of a multi-qubit register. Collective encoding relies on the use of Rydberg blockade to create a one-to-one correspondence between singly excited states of the atomic ensemble and logical register states. As a step towards collective encoding with Rydberg blockade in holmium we have precisely measured the energy of ns and nd Rydberg states from n = 41-101 using MOT depletion spectroscopy. These measurements have resulted in a precise determination of the first ionization potential as well as the quantum defects of the singlet ns and nd series. The strong 410.5 nm cooling transition with ~ 33 MHz linewidth coupled with the large hyperfine splitting in the electronically excited state are predicted to enable fast, loss-free, and state sensitive measurements which are a prerequisite for collective encoding experiments. We report on progress towards single-atom trapping and state sensitive detection of holmium in a far off-resonant optical dipole trap. Work supported by NSF award PHY-1404357.

  17. The structure of rare earth thin films: holmium and gadolinium on yttrium

    NASA Astrophysics Data System (ADS)

    Bentall, M. J.; Cowley, R. A.; Ward, R. C. C.; Wells, M. R.; Stunault, A.

    2003-11-01

    Single-crystal holmium and gadolinium layers have been grown on yttrium substrates using the molecular beam epitaxy technique and their structures investigated using high resolution x-ray scattering. The experiments were performed using a Philips MRD diffractometer in Oxford, and with the XMaS facility at the ESRF. Holmium layers with a thickness below T_{\\mathrm {c}}'=115\

  18. Endometrial laser ablation in rabbits: A comparative study of three laser types

    SciTech Connect

    Rosenberg, C.; Tadir, Y.; Braslavsky, D.; Fisch, B.; Karni, Z.; Ovadia, J. )

    1990-01-01

    Endometrial laser ablation is one of the alternatives to hysterectomy in cases of intractable uterine bleeding. It is currently performed using the Nd:YAG laser at 1.06 microns. The aim of this study was to compare the tissue effect of three types of laser irradiation (Nd:YAG laser at 1.06 and 1.32 microns and holmium laser at 2.12 microns) on the rabbit endometrium. Crater formation, coagulation necrosis, and muscle necrosis were evaluated at the time of ablation, as well as at 1 week and 4 weeks postablation. The results were assessed by determining the depth and width of the affected portion in the uterine wall (lumen to serosa). It was shown that Nd:YAG laser at 1.32 microns caused more generalized and extended effects as compared with the other laser types examined. Endometrial regeneration was faster after ablation by the Nd:YAG laser at 1.06 microns and the holmium laser than by the Nd:YAG laser at 1.32 microns. The widest range of ablation energy (defined as that causing ablation without muscle damage) was achieved by applying the holmium laser. Further evaluation of the holmium laser for this indication is recommended.

  19. The eyeball killer: serial killings with postmortem globe enucleation.

    PubMed

    Coyle, Julie; Ross, Karen F; Barnard, Jeffrey J; Peacock, Elizabeth; Linch, Charles A; Prahlow, Joseph A

    2015-05-01

    Although serial killings are relatively rare, they can be the cause of a great deal of anxiety while the killer remains at-large. Despite the fact that the motivations for serial killings are typically quite complex, the psychological analysis of a serial killer can provide valuable insight into how and why certain individuals become serial killers. Such knowledge may be instrumental in preventing future serial killings or in solving ongoing cases. In certain serial killings, the various incidents have a variety of similar features. Identification of similarities between separate homicidal incidents is necessary to recognize that a serial killer may be actively killing. In this report, the authors present a group of serial killings involving three prostitutes who were shot to death over a 3-month period. Scene and autopsy findings, including the unusual finding of postmortem enucleation of the eyes, led investigators to recognize the serial nature of the homicides. PMID:25682709

  20. Laser division of intraluminal sutures.

    PubMed

    Bagley, D H; Schultz, E; Conlin, M J

    1998-08-01

    Neodymium:YAG and holmium:YAG lasers were used to remove intraluminal sutures from three patients. In two, the suture was in the bladder and had served as a nidus for stone formation. In the other, the suture was in the ureter. An in vitro study showed that the Nd:YAG laser could divide all types of suture readily, whereas the Ho:YAG laser could divide all materials except Gortex. These cases illustrate another application for lasers. PMID:9726402

  1. Attempted auto-enucleation in two incarcerated young men with psychosis

    PubMed Central

    Reichstein, David; Esmaili, Neda; Wells, Timothy; Kim, Judy E.

    2014-01-01

    Auto-enucleation is a sign of untreated psychosis. We describe two patients who presented with attempted auto-enucleation while being incarcerated. This is an observation two-case series of two young men who suffered untreated psychosis while being incarcerated. These young men showed severe self-inflicted ocular trauma during episodes of untreated psychosis. Injuries included orbital bone fracture and dehiscence of the lateral rectus in one patient and severe retinal hemorrhage and partial optic nerve avulsion in the second patient. Auto-enucleation is a severe symptom of untreated psychosis. This urgent finding can occur in a jail setting in which psychiatric care may be minimal. PMID:25892940

  2. Attempted auto-enucleation in two incarcerated young men with psychosis.

    PubMed

    Reichstein, David; Esmaili, Neda; Wells, Timothy; Kim, Judy E

    2015-01-01

    Auto-enucleation is a sign of untreated psychosis. We describe two patients who presented with attempted auto-enucleation while being incarcerated. This is an observation two-case series of two young men who suffered untreated psychosis while being incarcerated. These young men showed severe self-inflicted ocular trauma during episodes of untreated psychosis. Injuries included orbital bone fracture and dehiscence of the lateral rectus in one patient and severe retinal hemorrhage and partial optic nerve avulsion in the second patient. Auto-enucleation is a severe symptom of untreated psychosis. This urgent finding can occur in a jail setting in which psychiatric care may be minimal. PMID:25892940

  3. Energetics of holmium adsorption on Mo(1 1 2) surface

    NASA Astrophysics Data System (ADS)

    Szcze?niak, Micha?; Oleksy, Czes?aw; ?liwi?ski, Jakub; Szukiewicz, Rafa?; Wiejak, Marcin; Ko?aczkiewicz, Jan

    2015-03-01

    Adsorption and formation of ordered structures of Ho atoms on Mo(1 1 2) surface are studied by LEED, work function measurement and first-principle calculations. It is found that the most favorable energetically periodic structure is (3 2) structure at coverage of ? = 2/3, in which separation of Ho atoms is very close to metallic diameter of holmium. LEED measurements and the ground state analysis have revealed that structures (4 1) with ? = 3/4 and (5 1) with ? = 4/5 are also favorable. There are no ordered structures at low coverages although the long-range indirect interaction between adatoms is present.

  4. Role of temperature in the theoretical analysis of holmium pnictides

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Purvee; Singh, Sadhna

    2016-01-01

    The high-pressure structural phase transition and associated properties of holmium pnictides (HoX; X = P, As, Sb and Bi) have been investigated in the present work. The Realistic Interaction Potential Approach (RIPA) including the effect of temperature has been applied. The occurrence of first order phase transition is evidenced from a sudden collapse in volume. These compounds transform from B1 to B2 structure under high pressure. The high temperature and pressure behaviour of elastic constants and bulk modulus are also reported. Our results are in general in good agreement with experimental and other theoretical results where available, and provide predictions where they are unavailable.

  5. Mouse model of brachytherapy in consort with enucleation for treatment of malignant intraocular melanoma

    SciTech Connect

    Niederkorn, J.; Sanborn, G.E.; Scarbrough, E.E. )

    1990-06-01

    The efficacy of brachytherapy in the treatment and prevention of metastasis of intraocular melanoma was investigated in a mouse model. A highly metastatic subline of B16 melanoma was transplanted into the anterior segment of C57BL/6 mice and allowed to grow. Brachytherapy was delivered by means of miniature iodine 125 seeds implanted in shallow subcutaneous pockets of the upper eyelid margin of these mice, and 25 Gy of radiation was delivered between days 12 and 14. This brachytherapy reduced both the tumor volume and the number of mitotic figures per high-power field compared with irradiated controls. In a second experiment, 25 Gy of brachytherapy was delivered before enucleation, straddling enucleation, and after enucleation; there was a significant reduction in metastasis when radiation was delivered prior to enucleation. This model may be useful in conducting further studies involving brachytherapy with 125I plaque implants.

  6. Simple, fast, and efficient method of manual oocyte enucleation using a pulled Pasteur pipette.

    PubMed

    Hosseini, S M; Moulavi, F; Asgari, V; Shirazi, A; Abazari-Kia, A H; Ghanaei, H R; Nasr-Esfahani, M H

    2013-09-01

    Cloning mammals by somatic cell nuclear transfer entails the replacement of oocyte chromosomes with the nucleus of a somatic cell. A major step in this technique is to efficiently produce large batches of enucleated oocytes, a process that requires considerable micromanipulation skills and expensive equipments. Here, a simple, fast, and efficient method of manual oocyte enucleation was introduced that can be adopted in every laboratory with the minimum equipments. Common laboratory glass pipettes were pulled on the flame of a burner and then used for manual bisection or enucleation of sheep and goat zona-free oocytes by passing them through the discontinuous cutting border of culture medium and mineral oil. The described techniques showed a certain efficiency to conveniently bisect or enucleate large batches of sheep, and goat oocytes being pre-treated with demecolcine. The method may be straightforward for simple manipulation of oocytes of other species and for development of automated cloning methods as well. PMID:23824953

  7. Efficiency of disc ablation with lasers of various wavelengths.

    PubMed

    Choy, D S; Altman, P; Trokel, S L

    1995-06-01

    In testing the CO2 lasers in CW and pulse mode, the erbium:YAG, the Nd:YAG 1318 microns and 1064 microns, the argon, the holmium:YAG, and the excimer, we found the greatest efficiency in the CO2 CW and pulse mode, and the lowest efficiency in the argon. Data with the holmium:YAG were unreliable because of the early generation laser tested. The Nd:YAG was second only to the CO2 laser, and because the latter has no waveguide, we deemed the Nd:YAG the laser of choice for PLDD. PMID:10150639

  8. Holmium Nitrate Complexation with Tri-n-butyl Phosphate in Supercritical Carbon Dioxide

    SciTech Connect

    Robert V. Fox; R. Duane Ball; Peter de B. Harrington; Harry W. Rollins; Chien M. Wai

    2005-12-01

    Holmium nitrate pentahydrate was reacted with tri-n-butyl phosphate in supercritical carbon dioxide at 308 K. The products of the complexation reaction were measured under supercritical fluid conditions using UV-vis spectroscopy. The solubility of the metal complexes in the supercritical fluid phase was measured. The mole-ratio titration method was used to determine the stoichiometry of the soluble complexes. Conditional extraction coefficients were calculated from spectral data using least-squares regression and hard-equilibria models. Data indicate that the holmium nitrate-tributyl phosphate system forms 1:2 and 1:4 holmium-tributyl phosphate complexes.

  9. Enucleation by centrifugation of in vitro-matured bovine oocytes for use in nuclear transfer.

    PubMed

    Tatham, B G; Dowsing, A T; Trounson, A O

    1995-11-01

    Nuclear transfer has the potential to produce large numbers of identical progeny. Current limitations of the technique are associated with the use of micromanipulation for the demanding enucleation and reconstitution procedure. With the overcoming of this limitation, increased numbers of nuclear transfer embryos could be produced. Centrifugation of bovine oocytes at 15,000 x g for 2 min resulted in the stratification of organelles within the cytoplasm which positioned the metaphase II spindle for enucleation. After removal of the zona pellucida with Pronase, the oocytes were centrifuged in a Percoll density gradient so that the oocytes were stretched apart to form cytoplasts and the metaphase II spindle was separated from the majority of oocytes. Enucleation by centrifugation efficiently produced a consistent population of enucleated cytoplasts from bovine in vitro-matured oocytes. The population of enucleated cytoplasts was enriched by exclusion of the cytoplasts that exhibited an extrusion cone containing metaphase II chromosomes 6 h after centrifugation. The enucleated oocyte cytoplasts were aggregated with blastomeres isolated from in vivo-collected morulae. The aggregated embryonic cells were electrofused to obtain nuclear transfer embryos that were placed into a sodium alginate false zona and were capable of cleavage and development in vitro. The development of nuclear transfer embryos produced through use of centrifugation and aggregation techniques was comparable with that of nuclear transfer embryos produced by micromanipulation techniques. PMID:8527512

  10. Artificial orbit system for experimental surgery with enucleated globes.

    PubMed

    Lowery, J A; Parel, J M; Roussel, T J; Simon, G; Lee, W; Nose, I

    1990-07-01

    A portable system for holding, accurately positioning, and restoring the physiologic integrity of enucleated globes during experimental anterior segment procedures and pars plana vitrectomy is described. A 0 to 500-mm Hg vacuum fixation ring and positioning apparatus mechanically locks globes into known spatial position while they are supported in a 2 to 6-mm Hg pressurized, pliable socket designed to match the size and pressure of a natural orbit. A gravity infusion system and an implantable piezoelectric pressure sensor in conjunction with a syringe and stopcock assembly allow for controlled inflation of globes to intraocular pressure (IOP) levels from 0 to 70 mm Hg, and to over 300 mm Hg. The fixation vacuum level, and intraocular and extraocular pressures are simultaneously monitored on 3-digit LED displays, and permanent records of each can be generated by routing data to storage devices. The anterior segment remains accessible at all times for surgical procedures and diagnostic measurements. The entire system is portable, allowing globes to be transported to multiple experimental stations, while all pressure settings and the position of the globe are maintained. To demonstrate applications of the artificial orbit system, we describe experiments using it to calibrate applanation tonometers, and to study the relationship between IOP and corneal curvature as well as the effect of trephination procedures and limbal vacuum fixation on IOP. PMID:2399003

  11. Tunable frequency stabilized diode-laser-pumped Tm,Ho:YLiF4 laser at room temperature

    NASA Technical Reports Server (NTRS)

    Mcguckin, Brendan T.; Menzies, Robert T.; Esproles, Carlos

    1993-01-01

    A diode-laser-pumped single-frequency thulium holmium yttrium lithium fluoride laser that exhibits a closed-loop stability of a few megahertz and a continuous single-mode tuning range of 800 MHz is described. The laser output power is 25 mW, and is tunable over about 8/cm at 25 C.

  12. Thulium fiber laser lithotripsy in an in vitro ureter model

    NASA Astrophysics Data System (ADS)

    Hardy, Luke A.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

    2014-12-01

    Using a validated in vitro ureter model for laser lithotripsy, the performance of an experimental thulium fiber laser (TFL) was studied and compared to the clinical gold standard holmium:YAG laser. The holmium laser (?=2120 nm) was operated with standard parameters of 600 mJ, 350 ?s, 6 Hz, and 270-?m-core optical fiber. The TFL (?=1908 nm) was operated with 35 mJ, 500 ?s, 150 to 500 Hz, and a 100-?m-core fiber. Urinary stones (60% calcium oxalate monohydrate/40% calcium phosphate) of uniform mass and diameter (4 to 5 mm) were laser ablated with fibers through a flexible video-ureteroscope under saline irrigation with flow rates of 22.7 and 13.7 ml/min for the TFL and holmium laser, respectively. The temperature 3 mm from the tube's center and 1 mm above the mesh sieve was measured by a thermocouple and recorded throughout each experiment for both lasers. Total laser and operation times were recorded once all stone fragments passed through a 1.5-mm sieve. The holmium laser time measured 16741 s (n=12). TFL times measured 11149, 3911, and 234 s, for pulse rates of 150, 300, and 500 Hz, respectively (n=12 each). Mean peak saline irrigation temperatures reached 241C for holmium, and 333C, 337C, and 396C, for TFL at pulse rates of 150, 300, and 500 Hz, respectively. To avoid thermal buildup and provide a sufficient safety margin, TFL lithotripsy should be performed with pulse rates below 500 Hz and/or increased saline irrigation rates. The TFL rapidly fragmented kidney stones due in part to its high pulse rate, high power density, high average power, and observation of reduced stone retropulsion and may provide a clinical alternative to the conventional holmium laser for lithotripsy.

  13. Optical materials for space based laser systems

    NASA Technical Reports Server (NTRS)

    Buoncristiani, A. M.; Armagan, G.; Byvik, C. E.; Albin, S.

    1989-01-01

    The design features and performance characteristics of a sensitized holmium laser applicable to differential lidar and Doppler windshear measurements are presented, giving attention to the optimal choice of sensitizing/activating dopant ions. This development of a 2-micron region eye-safe laser, where holmium is sensitized by either hulium or erbium, has called for interionic energy transfer processes whose rate will not result in gain-switched pulses that are excessively long for atmospheric lidar and Doppler windshear detection. The application of diamond films for optical component hardening is noted.

  14. Sub-100??fs passively mode-locked holmium-doped fiber oscillator operating at 2.06???m.

    PubMed

    Li, Peng; Ruehl, Axel; Grosse-Wortmann, Uwe; Hartl, Ingmar

    2014-12-15

    We demonstrate a simple and compact Holmium-doped fiber femtosecond oscillator, in-band pumped by a commercial Tm-doped fiber laser. The oscillator operates in the dispersion managed soliton regime at net zero intracavity dispersion and delivers >1??nJ pulse energy at 35MHz repetition rate. The pulse duration directly at the oscillator output is 160fs FWHM, close to the Fourier-limit of 145fs FWHM. Using an additional nonlinear compressor stage, sub-100fs FWHM pulse durations could be achieved. The nonlinear fiber compressor is implemented by a solid core highly nonlinear fiber for spectral broadening and a single mode fiber for pulse compression. PMID:25503015

  15. Composition and method of treatment of arthritis and related diseases with holmium-166 radionuclides

    SciTech Connect

    Lieberman, E.; Bordoni, M.E.; Thornton, A.K.

    1991-10-29

    This patent describes a radioactive composition for the treatment of arthritis. It comprises a suspension containing particles having a minimum size of one micron, the suspension including particles containing holmium-166.

  16. Re3+ : YAG laser ceramics: synthesis, optical properties and laser characteristics

    NASA Astrophysics Data System (ADS)

    Bagayev, S. N.; Osipov, V. V.; Vatnik, S. M.; Shitov, V. A.; Shteinberg, I. Sh; Vedin, I. A.; Kurbatov, P. F.; Luk'yashin, K. E.; Maksimov, R. N.; Solomonov, V. I.; Tverdokhleb, P. E.

    2015-05-01

    Highly transparent yttrium aluminium garnet ceramics doped with holmium or ytterbium or neodymium are synthesised. The ceramics were made of a mixture of nanopowders synthesised by laser ablation. The structural and spectral characteristics of ceramics are studied. In the samples with holmium Ho3+ and neodymium Nd3+ ions, lasing was achieved with a slope efficiency of 40% and 35.3%, respectively; the maximum laser power exceeded 4 W. The internal absorption and scattering losses for 1% Nd : YAG ceramics are estimated to be 1.6 10-2 cm-1.

  17. Unilateral eye enucleation in adult rats causes neuronal loss in the contralateral superior colliculus

    PubMed Central

    SMITH, S. A.; BEDI, K. S.

    1997-01-01

    Several studies have reported the morphological changes induced by unilateral enucleation during early neonatal life on the developing visual system. This study has examined cellular changes in the superior colliculi by removal of a single eye in adult rats. Anaesthetised male hooded rats aged 90 d had their right eyes removed. Groups of nonenucleated control and enucleated rats were killed when aged either 150 or 390 d. The brains were removed and both the right and left superior colliculi dissected out. The volume of the stratum griseum superficiale (SGS) within these colliculi was estimated stereologically by light microscopy, as well as the numerical density and total number of neurons within this cell layer. The volume of the cell layer was reduced by about 40% on the side contralateral to the enucleated eye but not on the ipsilateral side at both survival periods examined. The numerical density of neurons within the SGS was unaffected by the enucleation so that the colliculi contralateral to the enucleated eye showed a substantial loss of neurons within this cell layer. This study demonstrates the importance of the retinal ganglion cell input, even in adult animals, for maintaining the viability of neurons in the SGS layer of the superior colliculus. PMID:9183672

  18. Increased cortical surface area and gyrification following long-term survival from early monocular enucleation

    PubMed Central

    Kelly, Krista R.; DeSimone, Kevin D.; Gallie, Brenda L.; Steeves, Jennifer K.E.

    2014-01-01

    Purpose Retinoblastoma is typically diagnosed before 5years of age and is often treated by enucleation (surgical removal) of the cancerous eye. Here, we sought to characterize morphological changes of the cortex following long-term survival from early monocular enucleation. Methods Nine adults with early right-eye enucleation (?48months of age) due to retinoblastoma were compared to 18 binocularly intact controls. Surface area, cortical thickness, and gyrification estimates were obtained from T1 weighted images and group differences were examined. Results Early monocular enucleation was associated with increased surface area and/or gyrification in visual (i.e., V1, inferior temporal), auditory (i.e., supramarginal), and multisensory (i.e., superior temporal, inferior parietal, superior parietal) cortices compared with controls. Visual cortex increases were restricted to the right hemisphere contralateral to the remaining eye, consistent with previous subcortical data showing asymmetrical lateral geniculate nucleus volume following early monocular enucleation. Conclusions Altered morphological development of visual, auditory, and multisensory regions occurs subsequent to long-time survival from early eye loss. PMID:25610793

  19. Lasers in the management of calcified urinary tract stents

    NASA Astrophysics Data System (ADS)

    Nseyo, Unyime O.; Tunuguntla, Hari S. G. R.; Crone, Michael

    2003-06-01

    Indwelling double J ureteral stents are used for internal urinary diversion for ureteral obstruction and post-surgical drainage of the upper urinary tract. Stent calcification is a serious complication especially in those with forgotten stents. In a retrospective review of 16 patients (10 male and 6 female) we found holmium laser to be highly effective in the management of calcified stents. Encrustations/calcifications were noted on the distal end of the sent in 6 patiens (37.5%), middle and distal portions in 2 patients (12.5%), along the entire length of the stent in 3 patients (18.75%), lower portion of the stent in 4 patients (25%) and at the upper and lower ends of the stent in one patient (6.25%). Cystolitholapaxy, retrograde ureteroscopy (URS) with holmium: YAG (yttrium-aluminum-garnet) laser intracorporeal lithotripsy, percutaneous nephrostolithotomy (PNL) and antegrade URS with holmium: YAG laser intracorporeal lithotripsy were effectively performed without intraoperative complications. Lithotripsy became necessary before stent removal in 11 patients (68.75%). Holmium laser lithotripsy was useful in managing 7 patients (43.75%), and shockwave lithotripsy (SWL) in 6 patients (37.5%). In two patients (12.5%) both holmium and SWL were used before the stent can be removed.

  20. Video Assisted Thoracoscopic Surgical Enucleation of a Giant Esophageal Leiomyoma Presenting with Persistent Cough

    PubMed Central

    Mujawar, Parvez; Pawar, Tushar; Chavan, Rahulkumar Narayan

    2016-01-01

    Esophageal leiomyoma is a relatively rare tumor of esophagus but it is the most common benign neoplasm of the esophagus. Small esophageal leiomyoma can be observed but larger ones and those producing symptoms should be excised. As observed for other esophageal tumors, dysphagia is its main symptom. Traditionally, open thoracotomy and enucleation are its main treatment but in the last few years video assisted thoracoscopic surgical (VATS) enucleation is gaining recognition with proven advantages of minimally invasive surgery. Herein we present our experience with patient presenting with cough rather than dysphagia as a main symptom, who was diagnosed to be having giant esophageal leiomyoma. VATS guided enucleation was accomplished successfully. Size of lesion was 16 × 4 × 3 cm. Postoperative recovery was uneventful and patient is not having any signs of recurrence, after three years during follow-up period. PMID:26977331

  1. Enucleation vs cobalt plaque radiotherapy for malignant melanomas of the choroid and ciliary body

    SciTech Connect

    Augsburger, J.J.; Gamel, J.W.; Sardi, V.F.; Greenberg, R.A.; Shields, J.A.; Brady, L.W.

    1986-05-01

    Clinical risk factors were assessed prospectively in a nonrandomized concurrent observational study of 237 patients with posterior uveal malignant melanoma. One hundred forty of these patients were treated with enucleation, and 97 underwent cobalt plaque radiotherapy. Tumor size and location of the anterior tumor margin proved to be the most significant clinical risk factors for death from metastatic melanoma. When Cox proportional hazards modeling was used to adjust for recognized intergroup differences in risk factors, the effect of therapy (enucleation vs cobalt plaque radiotherapy) on survival time was not statistically significant. We discuss the implications of this study for a randomized clinical trial of enucleation vs cobalt plaque therapy or comparable forms of irradiation.

  2. Comparison of prognosis after enucleation vs cobalt 60 irradiation of melanomas

    SciTech Connect

    Gass, J.D.

    1985-07-01

    Between December 1962 and May 1979, growth of choroidal and ciliary body melanomas was documented in 34 patients prior to enucleation. Twenty-seven of the 34 patients underwent enucleation during the same time period (1967 through 1976), when primary treatment with a cobalt 60 episcleral plaque was employed in a nonrandomized fashion in 21 patients with similar-sized melanomas. Comparison of these two groups of patients, none of whom was unavailable for follow-up and all of whom were followed up for a minimum of 66 months, showed that the probability of dying of metastatic melanoma within five years after cobalt 60 therapy was 50% compared with 16% after enucleation. Factors of potential importance in explaining this difference included nonrandomization, small number of patients in both groups, and greater frequency of anterior location of tumors in the cobalt 60 group (76% vs 22%). A randomized, controlled clinical trial is required to determine the relative safety of treatment for uveal melanomas.

  3. Rapid Changes in Cortical and Subcortical Brain Regions after Early Bilateral Enucleation in the Mouse

    PubMed Central

    Huffman, Kelly J.

    2015-01-01

    Functional sensory and motor areas in the developing mammalian neocortex are formed through a complex interaction of cortically intrinsic mechanisms, such as gene expression, and cortically extrinsic mechanisms such as those mediated by thalamic input from the senses. Both intrinsic and extrinsic mechanisms are believed to be involved in cortical patterning and the establishment of areal boundaries in early development; however, the nature of the interaction between intrinsic and extrinsic processes is not well understood. In a previous study, we used a perinatal bilateral enucleation mouse model to test some aspects of this interaction by reweighting sensory input to the developing cortex. Visual deprivation at birth resulted in a shift of intraneocortical connections (INCs) that aligned with ectopic ephrin A5 expression in the same location ten days later at postnatal day (P) 10. A prevailing question remained: Does visual deprivation first induce a change in gene expression, followed by a shift in INCs, or vice versa? In the present study, we address this question by investigating the neuroanatomy and patterns of gene expression in post-natal day (P) 1 and 4 mice following bilateral enucleation at birth. Our results demonstrate a rapid reduction in dorsal lateral geniculate nucleus (dLGN) size and ephrin A5 gene expression 24-hours post-enucleation, with more profound effects apparent at P4. The reduced nuclear size and diminished gene expression mirrors subtle changes in ephrin A5 expression evident in P1 and P4 enucleated neocortex, 11 and 8 days prior to natural eye opening, respectively. Somatosensory and visual INCs were indistinguishable between P1 and P4 mice bilaterally enucleated at birth, indicating that perinatal bilateral enucleation initiates a rapid change in gene expression (within one day) followed by an alteration of sensory INCs later on (second postnatal week). With these results, we gain a deeper understanding of how gene expression and sensory input together regulate cortical arealization and plasticity during early development. PMID:26452243

  4. The effects of chemical enucleation combined with whole cell intracytoplasmic injection on panda-rabbit interspecies nuclear transfer.

    PubMed

    Jiang, Man-Xi; Yang, Cai-Xia; Zhang, Li-Sheng; Zheng, Yue-Liang; Liu, Shu-Zhen; Sun, Qing-Yuan; Chen, Da-Yuan

    2004-11-01

    Conventional methods of somatic cell nuclear transfer either by electrofusion or direct nucleus injection have very low efficiency in animal cloning, especially interspecies cloning. To increase the efficiency of interspecies somatic cell nuclear transfer, in the present study we introduced a method of whole cell intracytoplasmic injection (WCICI) combined with chemical enucleation into panda-rabbit nuclear transfer and assessed the effects of this method on the enucleation rate of rabbit oocytes and the in vitro development and spindle structures of giant panda-rabbit reconstructed embryos. Our results demonstrated that chemical enucleation can be used in rabbit oocytes and the optimal enucleation result can be obtained. When we compared the rates of cleavage and blastocyst formation of subzonal injection (SUZI) and WCICI using chemically enucleated rabbit oocytes as cytoplasm recipients, the rates in the WCICI group were higher than those in the SUZI group, but there was no statistically siginificant difference (p > 0.05) between the two methods. The microtubule structures of rabbit oocytes enucleated by chemicals and giant panda-rabbit embryos reconstructed by WCICI combined with chemical enucleation were normal. Therefore the present study suggests that WCICI combined with chemical enucleation can provide an efficient and less labor-intensive protocol of interspecies somatic cell nuclear transfer for producing giant panda cloned embryos. PMID:15751540

  5. Comparison of survival rates for patients with uveal melanoma after treatment with proton beam irradiation or enucleation

    SciTech Connect

    Seddon, J.M.; Gragoudas, E.S.; Albert, D.M.; Hsieh, C.C.; Polivogianis, L.; Friedenberg, G.R.

    1985-03-15

    A comparison was made of survival experiences for three groups with uveal melanoma: (1) 120 patients treated by proton beam irradiation from 1975 to 1981; (2) 235 patients treated by enucleation from 1953 to 1973 (enucleation group 1); and (3) 161 patients treated by enucleation from 1975 to 1981 (enucleation group 2). The following variables were predictive of melanoma-related deaths. Treatment: rate ratio (ratio of the rate of death for one category of the variable relative to the rate of death for another category) of 6.32 (95% confidence interval 1.70 to 23.51) for enucleation group 1 vs proton beam, 3.06 (0.81 to 11.54) for enucleation group 2 vs proton beam, and 2.07 (1.05 to 4.07) for enucleation group 1 vs enucleation group 2. Size: rate ratio of 3.61 (1.51 to 8.64) for large (16+ mm) vs small (less than 11 mm) tumors. Location: rate ratio of 3.19 (1.56 to 6.53) for tumors anterior vs posterior to the equator. When death from all causes was evaluated as the outcome, the estimated rate ratios were similar. When melanoma metastasis was evaluated as the outcome, the estimated rate ratios were reduced in magnitude.

  6. Uveal Melanoma Recurrence After Fractionated Proton Beam Therapy: Comparison of Survival in Patients Treated With Reirradiation or With Enucleation

    SciTech Connect

    Marucci, Laura; Ancukiewicz, Marek; Lane, Anne Marie; Collier, John M.; Gragoudas, Evangelos S.; Munzenrider, John E.

    2011-03-01

    Purpose: To retrospectively compare survival in recurrent uveal melanoma, between patients treated by enucleation or by a second course of fractionated proton beam therapy (PBT). Methods and Materials: Tumor recurrence was documented in 73 patients treated with PBT for uveal melanoma. Of the patients, 31 received a second course of PBT and 42 underwent enucleation. The mean patient age was 56 and 61 years for those undergoing enucleation and those undergoing reirradiation, respectively. Both primary and recurrent tumors were larger in patients undergoing enucleation. Tumor location and the presence or absence of ciliary body involvement did not differ significantly between the groups. The median follow-up after enucleation and after re-treatment was 79 and 59 months, respectively. Cumulative rates of outcomes and differences in rates between the reirradiated and enucleation groups were calculated by the Cox proportional hazards model and the log-rank test, respectively. Results: The median survival duration in the enucleated and reirradiated groups was 42 and 90 months, respectively. The median time free of metastases was 38 months in enucleated patients and 97 months in reirradiated patients. At 5 years after enucleation and after reirradiation, the probability of overall survival was 36% and 63%, respectively (p = 0.040, log-rank test); the probability of freedom from metastases was 31% and 66%, respectively (p = 0.028, log-rank test). These differences persisted after adjustment for recurrent tumor largest diameter and volume at the time of reirradiation or enucleation. Conclusions: This retrospective analysis suggests that survival in reirradiated patients is not compromised by administration of a second course of PBT for recurrent uveal melanoma.

  7. A reliable, noninvasive technique for spindle imaging and enucleation of mammalian oocytes.

    PubMed

    Liu, L; Oldenbourg, R; Trimarchi, J R; Keefe, D L

    2000-02-01

    Factors affecting the efficiency of animal cloning remain to be elucidated. Enucleation of recipient oocytes is a critical step in cloning procedures and typically is performed by aspirating a portion of the cytoplasm underlying the first polar body. Enucleation is evaluated using epifluorescence after Hoechst staining for DNA, which may disrupt functions of the cytoplast, especially mitochondria. Mitochondrial DNA in Dolly and other cloned sheep has been shown to derive exclusively from recipient oocytes. Not only might evaluation of the aspirated karyoplast portion inadequately reflect the state of the cytoplast, it is also time consuming. Here we report a reliable, noninvasive technique for spindle imaging and enucleation of oocytes using a new microscope, the Pol-Scope. The efficiency of enucleation was 100%, and only 5.5% of the oocytes' mitochondria entered the karyoplast upon Pol-Scope-directed removal of the spindle. Moreover, Pol-Scope imaging of spindles and micromanipulation did not compromise the developmental competence of reconstituted oocytes and cytoplasts. PMID:10657133

  8. Chromatin Condensation and Enucleation in Red Blood Cells: An Open Question.

    PubMed

    Baron, Margaret H; Barminko, Jeffrey

    2016-03-01

    Differentiating erythroid cells undergo dramatic changes in morphology, with reduction in cell size, chromatin and nuclear condensation, and enucleation. In this issue of Developmental Cell,Zhao etal. (2016) show that these events are associated with the formation of transient, recurring nuclear openings and selective histone release mediated by caspase-3. PMID:26954541

  9. Two stage enucleation and deflation of a large unicystic ameloblastoma with mural invasion in mandible.

    PubMed

    Sasaki, Ryo; Watanabe, Yorikatsu; Ando, Tomohiro; Akizuki, Tanetaka

    2014-06-01

    A treatment for strategy of unicystic ameloblastoma (UA) should be decided by its pathology type including luminal or mural type. Luminal type of UA can be treated only by enucleation alone, but UA with mural invasion should be treated aggressively like conventional ameloblastomas. However, it is difficult to diagnose the subtype of UA by an initial biopsy. There is a possibility that the lesion is an ordinary cyst or keratocystic odontogenic tumor, leading to a possible overtreatment. Therefore, this study performed the enucleation of the cyst wall and deflation at first, and the pathological finding confirmed mural invasion into the cystic wall, leading to the second surgery. The second surgery enucleated scar tissue, bone curettage, and deflation, and was able to contribute to the reduction of the recurrence rate by removing tumor nest in scar tissue or new bone, enhancing new bone formation, and shrinking the mandibular expanding by fenestration. In this study, a large UA with mural invasion including condyle was treated by "two-stage enucleation and deflation" in a 20-year-old patient. PMID:25050148

  10. Evidence for spin mixing in holmium thin film and crystal samples

    NASA Astrophysics Data System (ADS)

    Usman, I. T. M.; Yates, K. A.; Moore, J. D.; Morrison, K.; Pecharsky, V. K.; Gschneidner, K. A.; Verhagen, T.; Aarts, J.; Zverev, V. I.; Robinson, J. W. A.; Witt, J. D. S.; Blamire, M. G.; Cohen, L. F.

    2011-04-01

    In a number of recent experiments, holmium has been shown to promote spin-triplet pairing when in proximity to a spin-singlet superconductor. The condition for the support of spin-triplet pairing is that the ferromagnet should have an inhomogeneous magnetic state at the interface with the superconductor. Here we use Andreev reflection spectroscopy to study the properties of single ferromagnet/superconductor interfaces formed of holmium and niobium, as a function of the contact resistance of the junction between them. We find that both single-crystal and c-axis-oriented thin-film holmium show unusual behavior for low junction contact resistance, characteristic of spin-mixing-type properties, which are thought necessary to underpin spin-triplet formation. We also explore whether this signature is observed when the junction is formed of Ni0.19Pd0.81 and niobium.

  11. Single crystal growth and characterization of holmium tartrate trihydrate

    NASA Astrophysics Data System (ADS)

    Want, Basharat; Ahmad, Farooq; Kotru, P. N.

    2007-02-01

    The growth of holmium tartrate trihydrate (HTT) single crystals is achieved in organic (agar-agar) as well as in inorganic (silica) gels by single gel diffusion method. Results of the study on nucleation kinetics of crystals grown in silica gel are described. The crystals exhibit the morphological form of a tetragonal dipyramidal class with {0 0 1} and {1 1 1} as dominant faces. Elemental and thermogravimetric analysis (TGA) supplemented by energy dispersive analysis of X-rays (EDAX) support the suggested chemical formula of the grown crystals to be [Ho (C 4H 4O 6) (C 4H 5O 6)3H 2O]. Single crystal X-ray diffraction (XRD) studies indicate that the crystals belong to tetragonal system with the cell parameters a=5.97 , c=36.09 , bearing the space group P4 1. Fourier transform infrared (FT-IR) spectroscopic study indicates the presence of tartrate ligands and suggests that one of the tartrate ions is singly ionized. TGA suggests that the material is thermally stable up to 220 C.

  12. Thulium fiber laser damage to Nitinol stone baskets

    NASA Astrophysics Data System (ADS)

    Wilson, Christopher R.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

    2015-02-01

    Our laboratory is studying the experimental Thulium fiber laser (TFL) as an alternative lithotripter to clinical gold standard Holmium:YAG laser. Safety studies characterizing undesirable Holmium laser-induced damage to Nitinol stone baskets have been previously reported. Similarly, this study characterizes TFL induced stone basket damage. A TFL beam with pulse energy of 35 mJ, pulse duration of 500 ?s, and pulse rates of 50-500 Hz was delivered through 100-?m-core optical fibers, to a standard 1.9-Fr Nitinol stone basket wire. Stone basket damage was graded as a function of pulse rate, number of pulses, and working distance. Nitinol wire damage decreased with working distance and was non-existent at distances greater than 1.0 mm. In contact mode, 500 pulses delivered at pulse rates >= 200 Hz (<= 2.5 s) were sufficient to cut Nitinol wires. The Thulium fiber laser, operated in low pulse energy and high pulse rate mode, may provide a greater safety margin than standard Holmium laser for lithotripsy, as evidenced by shorter non-contact working distances for stone basket damage than previously reported with Holmium laser.

  13. Identification of a Murine Erythroblast Subpopulation Enriched in Enucleating Events by Multi-spectral Imaging Flow Cytometry

    PubMed Central

    Konstantinidis, Diamantis G.; Pushkaran, Suvarnamala; Giger, Katie; Manganaris, Stefanos; Zheng, Yi; Kalfa, Theodosia A.

    2015-01-01

    Erythropoiesis in mammals concludes with the dramatic process of enucleation that results in reticulocyte formation. The mechanism of enucleation has not yet been fully elucidated. A common problem encountered when studying the localization of key proteins and structures within enucleating erythroblasts by microscopy is the difficulty to observe a sufficient number of cells undergoing enucleation. We have developed a novel analysis protocol using multiparameter high-speed cell imaging in flow (Multi-Spectral Imaging Flow Cytometry), a method that combines immunofluorescent microscopy with flow cytometry, in order to identify efficiently a significant number of enucleating events, that allows to obtain measurements and perform statistical analysis. We first describe here two in vitro erythropoiesis culture methods used in order to synchronize murine erythroblasts and increase the probability of capturing enucleation at the time of evaluation. Then, we describe in detail the staining of erythroblasts after fixation and permeabilization in order to study the localization of intracellular proteins or lipid rafts during enucleation by multi-spectral imaging flow cytometry. Along with size and DNA/Ter119 staining which are used to identify the orthochromatic erythroblasts, we utilize the parameters aspect ratio of a cell in the bright-field channel that aids in the recognition of elongated cells and delta centroid XY Ter119/Draq5 that allows the identification of cellular events in which the center of Ter119 staining (nascent reticulocyte) is far apart from the center of Draq5 staining (nucleus undergoing extrusion), thus indicating a cell about to enucleate. The subset of the orthochromatic erythroblast population with high delta centroid and low aspect ratio is highly enriched in enucleating cells. PMID:24962543

  14. Efficient 2.9 ?m fluorozirconate glass waveguide chip laser.

    PubMed

    Lancaster, David G; Gross, Simon; Ebendorff-Heidepriem, Heike; Withford, Michael J; Monro, Tanya M; Jackson, Stuart D

    2013-07-15

    We report a large mode-area holmium-doped ZBLAN waveguide laser operating at 2.9 ?m, which was pumped by a 1150 nm diode laser. The laser is based on ultrafast laser inscribed depressed cladding waveguides fabricated in uniformly rare-earth-doped bulk glass. It has a threshold of 28 mW and produced up to 27 mW of output power at an internal slope efficiency of approximately 20%. PMID:23939120

  15. Characterization of a Ho:Tm:Cr:YAG laser with a Cr:GSAG laser as pumping source

    NASA Technical Reports Server (NTRS)

    Henderson, George W.

    1989-01-01

    Rare earth lasers were in existance since the first laser was developed. The primary lasing elements for the class of lasers in the infrared was neodymium and chromium. However, the need for eye safe lasers in the mid-infrared range has prompted an enormous amount of research to the use of other elements. Holmium was investigated extensively as the source of infrared radiation for atmospheric research as well as medical research. The results and procedure are briefly discussed.

  16. Fundamental laser-tissue interactions.

    PubMed

    van Leeuwen, T G; Borst, C

    1996-06-01

    Pulsed xenon chloride excimer and holmium laser-tissue interaction is primarily based on tissue water vaporization. Consequently, each ablative laser pulse produces a rapidly expanding and imploding vapour bubble in blood or the target tissue. In experimental studies, explosive water vaporization is the major mechanical cause of observed tissue dissections. By reduction of the induced bubble volume, a reduction in experimentally and clinically observed dissections after coronary excimer laser angioplasty is to be expected. This reduction of mechanical damage, however, in combination with efficient and substantial plaque debulking is the major challenge in the development of laser angioplasty. PMID:9552502

  17. Effect of Young's modulus on bubble formation and pressure waves during pulsed holmium ablation of tissue phantoms

    NASA Astrophysics Data System (ADS)

    Jansen, E. Duco; Asshauer, Thomas; Frenz, Martin; Delacretaz, Guy P.; Motamedi, Massoud; Welch, Ashley J.

    1995-05-01

    Mechanical injury during pulsed laser ablation of tissue is caused by rapid bubble expansions and collapse or by laser-induced pressure waves. In this study the effect of material elasticity on the ablation process has been investigated. Polyacrylamide tissue phantoms with various water concentrations (75-95%) were made. The Young's moduli of the gels were determined by measuring the stress-strain relationship. An optical fiber (200 or 400 micrometers ) was translated into the clear gel and one pulse of holmium:YAG laser radiation was given. The laser was operated in either the Q-switched mode (tau) p equals 500 ns, Qp equals 14 +/- 1 mJ, 200 micrometers fiber, Ho equals 446 mJ/mm2) or the free-running mode ((tau) p equals 100 microsecond(s) , Qp equals 200 +/- 5 mJ, 400 micrometers fiber, Ho equals 1592 mJ/mm2). Bubble formation inside the gels was recorded using a fast flash photography setup while simultaneously recording pressures with a PVDP needle hydrophone (40 ns risetime) positioned in the gel, approximately 2 mm away from the fibertip. A thermo-elastic expansion wave was measured only during Q-switched pulse delivery. The amplitude of this wave (approximately equals 40 bar at 1 mm from the fiber) did not vary significantly in any of the phantoms investigated. Rapid bubble formation and collapse was observed inside the clear gels. Upon bubble collapse, a pressure transient was emitted; the amplitude of this transient depended strongly on bubble size and geometry. It was found that (1) the bubble was almost spherical for the Q-switched pulse and became more elongated for the free-running pulse, and (2) the maximum bubble size and thus the collapse amplitude decreased with an increase in Young's modulus (from 68 +/- 11 bar at 1 mm in 95% water gel to 25 +/- 10 bar at 1 mm in 75% water gel).

  18. Enucleation after Embolization of Liver Failure-Causing Giant Liver Hemangioma

    PubMed Central

    Sharma, Amit; Kaspar, Matthew; Siddiqui, Mohammad; Kim, Joohyun

    2015-01-01

    Patient: Female, 73 Final Diagnosis: Giant liver hemangioma Symptoms: Abdominal discomfort • abdominal enlargement • Icterus Medication: — Clinical Procedure: Enucleation after embolization of liver failure-causing giant liver Specialty: Surgery Objective: Unusual clinical course Background: Hepatic hemangioma is a congenital tumor of the mesenchymal tissues of the liver. While typically benign, these tumors can occasionally grow to sufficient size to cause a number of symptoms, including pain, severe hepatic dysfunction, or, rarely, consumptive coagulopathy. In such instances, surgical treatment may be warranted. Case Report: We present a case of a symptomatic giant hepatic hemangioma in an elderly patient who presented with impending liver failure. She was successfully treated with a combination of surgical enucleation and liver resection after preoperative arterial embolization. We also provide a brief discussion of current treatment options for giant hepatic hemangiomas. Conclusions: Early referral to experienced surgical centers before the onset of dire complications such as severe hepatic dysfunction and liver failure is recommended. PMID:26301888

  19. Ki-67 immunostaining in uveal melanoma. The effect of pre-enucleation radiotherapy

    SciTech Connect

    Mooy, C.M.; de Jong, P.T.; Van der Kwast, T.H.; Mulder, P.G.; Jager, M.J.; Ruiter, D.J. )

    1990-10-01

    The reactivity of 33 choroidal and ciliary body melanomas with monoclonal antibody Ki-67, which recognizes a proliferation associated nuclear antigen, has been assessed and compared with clinicopathologic parameters. In 23 cases, 8 Gy irradiation was given 2 days before enucleation. Nonirradiated melanomas had a significantly higher proliferation rate as defined by staining with monoclonal antibody Ki-67 as compared with irradiated tumors (P = 0.007). Similarly, a strong relationship was found between pre-enucleation irradiation and low mitotic activity (P = 0.001). There was no significant correlation between the presence of Ki-67-positive nuclei and histologic classification, largest tumor diameter, localization of the tumor, age, sex, scleral invasion, pigmentation, and lymphocytic infiltration. The relevance of Ki-67 immunohistochemistry for the assessment of the life prognosis of patients with uveal melanoma has to be studied prospectively.

  20. Transendoscopic soft-tissue laser ablation in the equine upper respiratory tract

    NASA Astrophysics Data System (ADS)

    Bartels, K. E.; MacAllister, C. G.; Dickey, D. T.; Schafer, S. A.; Nordquist, R. E.

    1997-05-01

    Transendoscopic application of Nd:YAG laser energy for treatment of partial upper respiratory obstruction in the horse has been practiced for the last 12 years in both contact and non-contact modes. Endoscopic laser ablation has been limited to wavelengths transmitted through flexible optical fibers. Devices used for this purpose have been primarily the Nd:YAG (1064 nm), KTP (532 nm), holmium (2100 nm), and diode (805 nm) lasers. Few investigations have focused on use of the holmium or diode lasers. Objectives of this study were to evaluate use of fiber-deliverable laser wavelengths provided by newer, more portable, user-friendly, solid-state diode and holmium lasers for ablation of laryngeal tissues of the equine upper respiratory tract. In addition, information on efficacy and dosimetry for both the contact and non-contact modes was obtained using an in vitro cadaveric model. Preliminary conclusions based on histologic evaluation and scanning electron microscopy revealed that diode laser energy has the ability to penetrate laryngeal tissue easily and deeply with minimal collateral coagulation, but is sensitive to tissue color. Holmium laser energy can be used to incise laryngeal tissue easily in contact mode with moderate collateral damage, and absorption does not seem dependent on tissue color.

  1. Nuclear Transfer of Embryonic Cell Nuclei to Non-enucleated Eggs in Zebrafish, Danio rerio

    PubMed Central

    Hattori, Manabu; Hashimoto, Hisashi; Bubenshchikova, Ekaterina; Wakamatsu, Yuko

    2011-01-01

    We previously established a novel method for nuclear transfer in medaka (Oryzias latipes) using non-enucleated, diploidized eggs as recipients for adult somatic cell nuclei. Here we report the first attempt to apply this method to another fish species. To examine suitability of using non-enucleated eggs as recipients for nuclear transfer in the zebrafish (Danio rerio), we transferred blastula cell nuclei from a wild-type donor strain to non-enucleated, unfertilized eggs from a golden recipient strain. As a result, 31 of 184 (16.8%) operated eggs developed normally and reached the adult stage. Twenty-eight (15.2%) of these transplants showed wild-type phenotype and the remaining three (1.6%) were golden. Except for one individual that exhibited diploid/tetraploid mosaicism, all of the wild-type nuclear transplants were either triploid or diploid. While all of 19 triploid transplants were infertile, a total of six transplants (21.4%) were fertile (five of the eight diploid transplants and one transplant exhibiting ploidy mosaicism). Except for one diploid individual, all of the fertile transplants transferred both the wild-type golden gene allele (slc24a5) as well as the phenotype, the wild-type body color, to their F1 and F2 progeny in a typical Mendelian fashion. PCR analysis of slc24a5 suggested that triploidy originated from a fused nucleus in the diploid donor and haploid recipient nuclei, and that the sole origin of diploidy was the diploid donor nucleus. The results of the present study demonstrated the suitability of using non-enucleated eggs as recipients for nuclear transfer experiments in zebrafish. PMID:21547063

  2. Bilateral self-enucleation in acute transient psychotic disorder: the influence of sociocultural factors on psychopathology.

    PubMed

    Harish, Thippeswamy; Chawan, Namdev; Rajkumar, Ravi Philip; Chaturvedi, Santosh Kumar

    2012-07-01

    Self-inflicted eye injuries are rare but a devastating consequence of a serious mental disorder. Bilateral self-enucleation also known as oedipism has been documented in ancient texts and myths. Various biologic, psychologic, and social theories have been put forward to explain this rare phenomenon. In this report, we describe a case of oedipism, which highlights the influence of sociocultural factors on the psychopathology in acute transient psychotic disorder. PMID:21864835

  3. Three histopathological types of retinoblastoma and their relation to heredity and age of enucleation.

    PubMed Central

    Moll, A C; Koten, J W; Lindenmayer, D A; Everse, L A; Tan, K E; Hamburg, A; Faber, J A; Den Otter, W

    1996-01-01

    The histopathology of 61 eyes was studied with special attention to the morphology of the retina adjacent to the main tumour. Three retinal types were distinguished. Retina type 1 (RT-1, 28 specimens) contained a single tumour that was sharply demarcated from surrounding normal retina. In retina type 2 (RT-2, 29 specimens) large parts of the retina were affected and the main tumour mass gradually blended with the adjacent pathological retina. Retina type 3 (RT-3, four specimens) was characterised by a retina almost entirely affected by diffuse tumour growth. RT-1 correlated significantly with early enucleation (0-3 years) both in hereditary and non-hereditary cases. RT-2 was seen in eyes enucleated later (2-5 years). The progressing tumour may release growth factors in the intraocular space that stimulate the cells of the adjacent retina and lead to multiple new primary tumours in the adjacent retinal area. RT-3 was only present in non-hereditary cases with late enucleation (at 2-5 years). Hereditary retinoblastoma cases are usually detected early. Therefore in hereditary cases RT-1 is significantly more common than RT-2. In 25 eyes of the 44 patients with unilateral sporadic retinoblastoma, multifocal tumours of the retina were observed. Such cases should not mistakenly be classified as hereditary cases on the basis of the histological pattern of multifocality of the tumour process. Images PMID:8950672

  4. Spontaneous Bone Healing after Cysts Enucleation without Bone Grafting Materials: A Randomized Clinical Study.

    PubMed

    Rubio, Eduardo Daniel; Mombr, Carlos Mariano

    2015-03-01

    The aim of this study was to evaluate spontaneous bone regeneration after cysts enucleation of the jaws without the use of bone grafting materials. We included 18 patients at random (11 men and 7 women) with a mean age of 31.8 years, with jaw cysts treated by enucleation, without the use of grafting materials. A method of measurements to assess the percentage of reduction of the bone cavities was used to objectify the results. The patients were evaluated before and at least 6 months after surgery, with radiographic scans based on linear measures with a computerized method using Nemoceph program (Nemotec, NemoCeph Software, Madrid, Espaa). The analysis of the sample shows an average of 85.59% decrease in horizontal measures, 89.53% in the vertical, and 88.98 and 89.81% in the diagonal left and right, respectively. The total average reduction was 88.47%. It showed a greater decrease in vertical and diagonal measurements with respect to horizontal. Regeneration in 12 patients was 100% and in 6 patients was higher at 50.4%. Bone density increased in the postoperative radiographs. The results suggest that in some cases, spontaneous bone regeneration can be achieved by cysts enucleation without bone grafting materials. PMID:25709749

  5. Quantitative Monte Carlo-based holmium-166 SPECT reconstruction

    SciTech Connect

    Elschot, Mattijs; Smits, Maarten L. J.; Nijsen, Johannes F. W.; Lam, Marnix G. E. H.; Zonnenberg, Bernard A.; Bosch, Maurice A. A. J. van den; Jong, Hugo W. A. M. de; Viergever, Max A.

    2013-11-15

    Purpose: Quantitative imaging of the radionuclide distribution is of increasing interest for microsphere radioembolization (RE) of liver malignancies, to aid treatment planning and dosimetry. For this purpose, holmium-166 ({sup 166}Ho) microspheres have been developed, which can be visualized with a gamma camera. The objective of this work is to develop and evaluate a new reconstruction method for quantitative {sup 166}Ho SPECT, including Monte Carlo-based modeling of photon contributions from the full energy spectrum.Methods: A fast Monte Carlo (MC) simulator was developed for simulation of {sup 166}Ho projection images and incorporated in a statistical reconstruction algorithm (SPECT-fMC). Photon scatter and attenuation for all photons sampled from the full {sup 166}Ho energy spectrum were modeled during reconstruction by Monte Carlo simulations. The energy- and distance-dependent collimator-detector response was modeled using precalculated convolution kernels. Phantom experiments were performed to quantitatively evaluate image contrast, image noise, count errors, and activity recovery coefficients (ARCs) of SPECT-fMC in comparison with those of an energy window-based method for correction of down-scattered high-energy photons (SPECT-DSW) and a previously presented hybrid method that combines MC simulation of photopeak scatter with energy window-based estimation of down-scattered high-energy contributions (SPECT-ppMC+DSW). Additionally, the impact of SPECT-fMC on whole-body recovered activities (A{sup est}) and estimated radiation absorbed doses was evaluated using clinical SPECT data of six {sup 166}Ho RE patients.Results: At the same noise level, SPECT-fMC images showed substantially higher contrast than SPECT-DSW and SPECT-ppMC+DSW in spheres ?17 mm in diameter. The count error was reduced from 29% (SPECT-DSW) and 25% (SPECT-ppMC+DSW) to 12% (SPECT-fMC). ARCs in five spherical volumes of 1.96106.21 ml were improved from 32%63% (SPECT-DSW) and 50%80% (SPECT-ppMC+DSW) to 76%103% (SPECT-fMC). Furthermore, SPECT-fMC recovered whole-body activities were most accurate (A{sup est}= 1.06 A ? 5.90 MBq, R{sup 2}= 0.97) and SPECT-fMC tumor absorbed doses were significantly higher than with SPECT-DSW (p = 0.031) and SPECT-ppMC+DSW (p = 0.031).Conclusions: The quantitative accuracy of {sup 166}Ho SPECT is improved by Monte Carlo-based modeling of the image degrading factors. Consequently, the proposed reconstruction method enables accurate estimation of the radiation absorbed dose in clinical practice.

  6. Bilateral enucleation alters gene expression and intraneocortical connections in the mouse

    PubMed Central

    2012-01-01

    Background Anatomically and functionally distinct sensory and motor neocortical areas form during mammalian development through a process called arealization. This process is believed to be reliant on both activity-dependent and activity-independent mechanisms. Although both mechanisms are thought to function concurrently during arealization, the nature of their interaction is not understood. To examine the potential interplay of extrinsic activity-dependent mechanisms, such as sensory input, and intrinsic activity-independent mechanisms, including gene expression in mouse neocortical development, we performed bilateral enucleations in newborn mice and conducted anatomical and molecular analyses 10 days later. In this study, by surgically removing the eyes of the newborn mouse, we examined whether early enucleation would impact normal gene expression and the development of basic anatomical features such as intraneocortical connections and cortical area boundaries in the first 10 days of life, before natural eye opening. We examined the acute effects of bilateral enucleation on the lateral geniculate nucleus of the thalamus and the neocortical somatosensory-visual area boundary through detailed analyses of intraneocortical connections and gene expression of six developmentally regulated genes at postnatal day 10. Results Our results demonstrate short-term plasticity on postnatal day 10 resulting from the removal of the eyes at birth, with changes in nuclear size and gene expression within the lateral geniculate nucleus as well as a shift in intraneocortical connections and ephrin A5 expression at the somatosensory-visual boundary. In this report, we highlight the correlation between positional shifts in ephrin A5 expression and improper refinement of intraneocortical connections observed at the somatosensory-visual boundary in enucleates on postnatal day 10. Conclusions Bilateral enucleation induces a positional shift of both ephrin A5 expression and intraneocortical projections at the somatosensory-visual border in only 10 days. These changes occur prior to natural eye opening, suggesting a possible role of spontaneous retinal activity in area border formation within the neocortex. Through these analyses, we gain a deeper understanding of how extrinsic activity-dependent mechanisms, particularly input from sensory organs, are integrated with intrinsic activity-independent mechanisms to regulate neocortical arealization and plasticity. PMID:22289655

  7. Wilbrand's knee of the primate optic chiasm is an artefact of monocular enucleation.

    PubMed Central

    Horton, J C

    1997-01-01

    PURPOSE: The anterior chiasmal syndrome consists of a temporal hemianopia or complete visual field loss in one eye, plus a superior temporal hemianopia in the other eye. The superior temporal hemianopia in the other eye is thought to result from injury to Wilbrand's Knee of the optic chiasm. Wilbrand's Knee is a loop of decussating fibers which detours into the contralateral optic nerve before entering the optic tract. I studied the organization of fibers in the optic chiasm of monkeys and humans to verify the existence of Wilbrand's Knee and to elucidate further the pattern of visual field loss seen from lesions of the sellar region. METHODS: The primary optic pathway was labelled in monkeys by injection of [3H] proline into one eye, followed by autoradiography. There were 8 intact Rhesus monkeys and 3 intact squirrel monkeys. In addition, the optic pathway was studied in the Rhesus monkey 6 months and 4 years after monocular enucleation. The optic chiasm was also examined using myelin stains in specimens obtained post-mortem from 3 patients. The patients had lost 1 eye 5 months, 2 years, and 28 years prior to their deaths. Finally, clinical observations were recorded in 3 patients with the anterior chiasmal syndrome. RESULTS: In normal Rhesus and squirrel monkeys, optic nerve fibers crossed the optic chiasm without entering the contralateral optic nerve. After short-term monocular enucleation, fibers from the normal optic nerve were drawn closer to the entry zone of the degenerating optic nerve, but Wilbrand's Knee was still absent. After long-term enucleation, a typical Wilbrand's Knee was induced to form. In the human, Wilbrand's Knee was absent 5 months after monocular enucleation, but emerged in the two cases involving long-term enucleation, in a fashion analogous to the monkey. The case reports describe 3 patients with variants of the anterior chiasmal syndrome from parasellar tumors. CONCLUSIONS: Wilbrand's Knee does not exist in the normal primate optic chiasm. It forms gradually over a period of years following monocular enucleation, presumably from shrinkage of the optic chiasm caused by atrophy of fibers from the enucleated eye. Therefore, the superior temporal hemianopia in the "other eye" seen in the anterior chiasmal syndrome cannot be due to compression of Wilbrand's Knee. I propose that it occurs from combined compression of the optic chiasm and one (or both) optic nerves. Images FIGURE 2 FIGURE 5A FIGURE 5B FIGURE 6 FIGURE 7 A FIGURE 7 B FIGURE 7 C FIGURE 7 D FIGURE 7 E FIGURE 7 F FIGURE 7 G FIGURE 7 H FIGURE 8A FIGURE 8B FIGURE 9A FIGURE 9B FIGURE 10 FIGURE 11A FIGURE 11B FIGURE 12 FIGURE 13 FIGURE 14 FIGURE 16 FIGURE 18 FIGURE 20 PMID:9440188

  8. Stress relaxation and cartilage shaping under laser radiation

    NASA Astrophysics Data System (ADS)

    Sobol, Emil N.; Sviridov, Alexander P.; Bagratashvili, Victor N.; Omelchenko, Alexander I.; Ovchinnikov, Yuriy M.; Shekhter, Anatoliy B.; Downes, S.; Howdle, Steven; Jones, Nicholas; Lowe, J.

    1996-05-01

    The problem of a purposeful change of the shape of cartilage is of great importance for otolaryngology, orthopaedics, and plastic surgery. In 1992 we have found a possibility of controlled shaping of cartilage under moderate laser heating. This paper presents new results in studies of that phenomenon. We have measured temperature and stress in a tissue undergoing to irradiation with a Holmium laser. Study of cartilage structure allowed us to find conditions for laser shaping without pronounced alterations in the structure of matrix.

  9. Lasers.

    ERIC Educational Resources Information Center

    Schewe, Phillip F.

    1981-01-01

    Examines the nature of laser light. Topics include: (1) production and characteristics of laser light; (2) nine types of lasers; (3) five laser techniques including holography; (4) laser spectroscopy; and (5) laser fusion and other applications. (SK)

  10. Advanced Unilateral Retinoblastoma: The Impact of Ophthalmic Artery Chemosurgery on Enucleation Rate and Patient Survival at MSKCC

    PubMed Central

    Abramson, David H.; Fabius, Armida W. M.; Issa, Reda; Francis, Jasmine H.; Marr, Brian P.; Dunkel, Ira J.; Gobin, Y. Pierre

    2015-01-01

    Purpose To report on the influence of ophthalmic artery chemosurgery (OAC) on enucleation rates, ocular and patient survival from metastasis and impact on practice patterns at Memorial Sloan Kettering for children with advanced intraocular unilateral retinoblastoma. Patients and Methods Single-center retrospective review of all unilateral retinoblastoma patients with advanced intraocular retinoblastoma treated at MSKCC between our introduction of OAC (May 2006) and December 2014. End points were ocular survival, patient survival from metastases and enucleation rates. Results 156 eyes of 156 retinoblastoma patients were included. Primary enucleation rates have progressively decreased from a rate of >95% before OAC to 66.7% in the first year of OAC use to the present rate of 7.4%. The percent of patients receiving OAC has progressively increased from 33.3% in 2006 to 92.6% in 2014. Overall, ocular survival was significantly better in eyes treated with OAC in the years 20102014 compared to 20062009 (p = 0.023, 92.7% vs 68.0% ocular survival at 48 months). There have been no metastatic deaths in the OAC group but two patients treated with primary enucleation have died of metastatic disease. Conclusion OAC was introduced in 2006 and its impact on patient management is profound. Enucleation rates have decreased from over 95% to less than 10%. Our ocular survival rate has also significantly and progressively improved since May 2006. Despite treating more advanced eyes rather then enucleating them patient survival has not been compromised (there have been no metastatic deaths in the OAC group). In our institution, enucleation is no longer the most common treatment for advanced unilateral retinoblastoma. PMID:26709699

  11. Bubble formation during pulsed laser ablation: mechanism and implications

    NASA Astrophysics Data System (ADS)

    van Leeuwen, Ton G. J. M.; Jansen, E. Duco; Motamedi, Massoud; Welch, Ashley J.; Borst, Cornelius

    1993-07-01

    Holmium ((lambda) equals 2.09 micrometers ) and excimer ((lambda) equals 308 nm) lasers are used for ablation of tissue. In a previous study it was demonstrated that both excimer and holmium laser pulses produce fast expanding and collapsing vapor bubbles. To investigate whether the excimer induced bubble is caused by vaporization of water, the threshold fluence for bubble formation at a bare fiber tip in water was compared between the excimer laser (pulse length 115 ns) and the Q-switched and free-running holmium lasers (pulse length 1 microsecond(s) to 250 microsecond(s) , respectively). To induce bubble formation by excimer laser light in water, the absorber oxybuprocaine-hydrochloride (OBP-HCl) was added to the water. Fast flash photography was used to measure the threshold fluence as a function of the water temperature (6 - 90 degree(s)C) at environmental pressure. The ultraviolet excimer laser light is strongly absorbed by blood. Therefore, to document the implications of bubble formation at fluences above the tissue ablation threshold, excimer laser pulses were delivered in vitro in hemoglobin solution and in vivo in the femoral artery of the rabbit. We conclude that the principal content of the fast bubble induced by a 308 nm excimer laser pulse is water vapor. Therefore, delivery of excimer laser pulses in a water or blood environment will cause fast expanding water vapor bubbles, which may induce mechanical damage to adjacent tissue.

  12. Laser purification of ultradispersed diamond in aqueous solution

    SciTech Connect

    Dolgaev, Sergei I; Kirichenko, N A; Lubnin, Evgenii N; Simakin, Aleksandr V; Shafeev, Georgii A; Kulevskii, L A

    2004-09-30

    The effect of pulsed radiation from a 2.92-{mu}m, 130-ns Cr{sup 3+}:Yb{sup 3+}:Ho{sup 3+}:YSGG holmium laser and a 510-nm, 20-ns copper vapour laser on an aqueous suspension of ultradispersed diamond is studied. X-ray photoelectron spectroscopy and electron energy loss spectroscopy revealed that exposure of the suspension to holmium laser radiation reduces the concentration of nondiamond carbon impurity in it. This is due to the dissolution of carbon impurity in supercritical aqueous solution, caused by radiation absorption. Dissolution of the nondiamond fraction may serve as an indicator of the solution being in the supercritical state as a result of laser irradiation of liquids. This process can be used for efficient purification of ultradispersed diamonds. (laser applications and other topics in quantum electronics)

  13. Medium-energy ion-scattering study of strained holmium silicide nanoislands grown on silicon (100)

    NASA Astrophysics Data System (ADS)

    Wood, T. J.; Eames, C.; Bonet, C.; Reakes, M. B.; Noakes, T. C. Q.; Bailey, P.; Tear, S. P.

    2008-07-01

    We have used medium-energy ion scattering (MEIS) to quantitatively analyze the structure of holmium silicide islands grown on the Si(100) surface. Structure fitting to the experimental data unambiguously shows that the tetragonal silicide phase is present and not the hexagonal phase, which is associated with the growth of nanowires at submonolayer coverages. Islands formed with a lower holmium coverage of 3 ML are also shown to be tetragonal, which suggests that the hexagonal structure is not a low coverage precursor to the growth of the tetragonal phase. MEIS simulations of large nanoislands, which include the effects of lateral strain relief, have been performed and these compare well with the experimental data.

  14. Helicity of magnetic domains in holmium studied with circularly polarized x rays

    SciTech Connect

    Sutter, C.; Gruebel, G.; Vettier, C.; de Bergevin, F.; Stunault, A.; Gibbs, D.; Giles, C.

    1997-01-01

    We have studied the helicity of magnetic domains in antiferromagnetic holmium using circularly polarized x rays. The spiral magnetic structure of holmium gives rise to pairs of magnetic satellites split symmetrically around each of the main charge Bragg reflections. For circularly polarized light the nonresonant scattering amplitudes at these satellites depend upon the helicity of the spiral, and thereby yield information about the distribution of magnetic domains with opposite helicity in the sample. The high degree of circular polarization (96{percent}) in the incident beam was obtained by transforming a linearly polarized undulator beam with the help of a diamond quarter-wave plate. The data reveal that domains with opposite helicity were nearly equally distributed in the crystal under investigation. {copyright} {ital 1997} {ital The American Physical Society}

  15. Thermal properties of holmium-implanted gold films for a neutrino mass experiment with cryogenic microcalorimeters

    SciTech Connect

    Prasai, K.; Yanardag, S. Basak; Galeazzi, M.; Uprety, Y.; Alves, E.; Rocha, J.; Bagliani, D.; Biasotti, M.; Gatti, F.; Gomes, M. Ribeiro

    2013-08-15

    In a microcalorimetric neutrino mass experiment using the radioactive decay of {sup 163}Ho, the radioactive material must be fully embedded in the microcalorimeter absorber. One option that is being investigated is to implant the radioactive isotope into a gold absorber, as gold is successfully used in other applications. However, knowing the thermal properties at the working temperature of microcalorimeters is critical for choosing the absorber material and for optimizing the detector performance. In particular, it is paramount to understand if implanting the radioactive material in gold changes its heat capacity. We used a bolometric technique to measure the heat capacity of gold films, implanted with various concentrations of holmium and erbium (a byproduct of the {sup 163}Ho fabrication), in the temperature range 70 mK–300 mK. Our results show that the specific heat capacity of the gold films is not affected by the implant, making this a viable option for a future microcalorimeter holmium experiment.

  16. Magnetic X-ray and neutron scattering from holmium and terbium

    NASA Astrophysics Data System (ADS)

    Tang, C. C.; Stirling, W. G.; Jones, D. L.; Wilson, C. C.; Haycock, P. W.; Rollason, A. J.; Thomas, A. H.; Fort, D.

    1992-01-01

    We report complementary magnetic X-ray and neutron diffraction measurements on the rare earth metals, holmium and terbium, using the 9.4 diffractometer at the Synchrotron Radiation Source (Daresbury Laboratory) and the white-beam SXD diffractometer at the ISIS pulsed neutron source (Rutherford Appleton Laboratory). Holmium, which has been studied extensively in previous X-ray and neutron investigations, was employed in preliminary measurements to develop the necessary experimental techniques. New X-ray results on terbium are described, of the temperature variation of the modulation wavevector and of the resonant enhancement at the L III absorption edge. The neutron and X-ray results are compared for the two samples studied.

  17. Effects of dexmedetomidine for retrobulbar anesthesia in orbital ball implants after enucleation surgery

    PubMed Central

    Ye, Weidi; Hu, Zhiyong; Jin, Xiuming; Wang, Pei

    2015-01-01

    Background: Dexmedetomidine (DEX) can prolong the duration of local anesthetics, but the use of retrobulbar DEX has not been fully elucidated. This study was designed to determine the effects of adding DEX to lidocaine-bupivacaine for retrobulbar block in orbital ball implants after enucleation surgery. Materials and Methods: A total of 200 patients of both sexes aged 3060 years of American Society of Anesthesiologists I and II, scheduled for orbital ball implants after enucleation surgery, were enrolled for the study. Patients were randomly assigned into one of the two groups: Control (n = 100) received lidocaine-bupivacaine retrobulbar block, DEX (n = 100) received lidocaine-bupivacaine plus 1 ug/kg DEX retrobulbar block. Hemodynamic data, duration of motor and sensory blocks, pain by visual analog scale, bispectral index (BIS), side effects, consumption of dezocine as a rescue analgesic, patient and surgeon satisfaction were recorded. Results: Duration of analgesia was prolonged in the DEX, compared with the control group ([258.35 66.82 min] as [130.75 29.52 min], [P < 0.05]). The median number of postoperative analgesic requests per patient during the first 24 h was decreased in the DEX group (P < 0.05). In the first 24 postoperative hours, DEX group consumed significantly less dezocine (P < 0.05). BIS values and mean arterial pressure remained lower in the DEX group, but within the safe range (P < 0.05). The side effect profile was similar between the two groups. Patients and surgeon satisfaction were higher in the DEX group (P < 0.05). Demographic characteristics were comparable in both groups (P > 0.05). Conclusion: Retrobulbar DEX reduces consumption of rescue analgesic, prolonged the duration of retrobulbar block, improved postoperative pain, provided better sedation effects, and increased patient and surgeon satisfaction after orbital ball implants after enucleation surgery. PMID:26632125

  18. Chemically induced enucleation of activated bovine oocytes: chromatin and microtubule organization and production of viable cytoplasts.

    PubMed

    Saraiva, Naiara Zoccal; Oliveira, Clara Slade; Leal, Cláudia Lima Verde; de Lima, Marina Ragagnin; Del Collado, Maite; Vantini, Roberta; Monteiro, Fabio Morato; Niciura, Simone Cristina Méo; Garcia, Joaquim Mansano

    2015-12-01

    As the standard enucleation method in mammalian nuclear transfer is invasive and damaging to cytoplast spatial organization, alternative procedures have been developed over recent years. Among these techniques, chemically induced enucleation (IE) is especially interesting because it does not employ ultraviolet light and reduces the amount of cytoplasm eliminated during the procedure. The objective of this study was to optimize the culture conditions with demecolcine of pre-activated bovine oocytes for chemically IE, and to evaluate nuclear and microtubule organization in cytoplasts obtained by this technique and their viability. In the first experiment, a negative effect on oocyte activation was verified when demecolcine was added at the beginning of the process, reducing activation rates by approximately 30%. This effect was not observed when demecolcine was added to the medium after 1.5 h of activation. In the second experiment, although a reduction in the number of microtubules was observed in most oocytes, these structures did not disappear completely during assessment. Approximately 50% of treated oocytes presented microtubule reduction at the end of the evaluation period, while 23% of oocytes were observed to exhibit the complete disappearance of these structures and 28% exhibited visible microtubules. These findings indicated the lack of immediate microtubule repolymerization after culture in demecolcine-free medium, a fact that may negatively influence embryonic development. However, cleavage rates of 63.6-70.0% and blastocyst yield of 15.5-24.2% were obtained in the final experiment, without significant differences between techniques, indicating that chemically induced enucleation produces normal embryos. PMID:25318529

  19. Thulium fiber laser damage to the ureter

    NASA Astrophysics Data System (ADS)

    Wilson, Christopher R.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

    2015-07-01

    Our laboratory is studying experimental thulium fiber laser (TFL) as a potential alternative lithotripter to the clinical gold standard Holmium:YAG laser. Safety studies characterizing undesirable Holmium laser-induced damage to ureter tissue have been previously reported. Similarly, this study characterizes TFL induced ureter and stone basket damage. A TFL beam with pulse energy of 35 mJ, pulse duration of 500 ?s, and pulse rates of 150-500 Hz was delivered through a 100-?m-core, low-OH, silica optical fiber to the porcine ureter wall, in vitro. Ureter perforation times were measured and gross, histological, and optical coherence tomography images of the ablation zone were acquired. TFL operation at 150, 300, and 500 Hz produced mean ureter perforation times of 7.9, 3.8, and 1.8 s, respectively. Collateral damage averaged 510, 370, and 310 ?m. TFL mean perforation time exceeded 1 s at each setting, which is a greater safety margin than previously reported during Holmium laser ureter perforation studies.

  20. Selective determination of the holmium in rare earth mixtures by second derivative spectrophotometry with 2-isobutylformyl-1,3-dione-indan and octylphenol poly-(ethyleneglycol)ether

    SciTech Connect

    Wang Naixing; Si Zhikun; Jiang Wei

    1996-09-01

    In this paper the absorption spectra of 4f electron transitions of the system of holmium with 2-isobutylformyl-1,3-dione-indan and TX-100 have been studied by normal and derivative spectrophotometry. The molar absorptivities are 98 (at 450 nm) and 21 (at 460 nm) 1 {center_dot} mol{sup -1} {center_dot} cm{sup -1}, respectively. The use of the second derivative spectra, eliminates the interference by other lanthanides and improves the sensitivity for holmium determination. The derivative molar absorptivity is 558 1 {center_dot} mol{sup -1} {center_dot} cm{sup -1}. The calibration graph was linear up to 25{mu}g/ml of holmium. The relative standard deviation evaluated from ten independent determinations of 8.0 {mu}g/ml holmium is 1.0%. The detection limit, obtained from the sensitivity of the calibration graph and for 3 S{sub b} (S{sub b} = standard deviation of a blank without holmium, n = 11), was found to be 0.31 {mu}g/ml of holmium. The quantification limit, obtained for 10 S{sub b}, was 1.0 {mu}g/ml of holmium. A method has been developed for determining holmium in a mixture of lanthanides by means of the second derivative spectra and the analytical results obtained are satisfactory.

  1. A technique for evisceration as an alternative to enucleation in birds of prey: 19 cases.

    PubMed

    Murray, Maureen; Pizzirani, Stefano; Tseng, Florina

    2013-06-01

    Ocular trauma is common in birds of prey presented to wildlife clinics and rehabilitation centers. Enucleation is the procedure most commonly described for treatment of end-stage ocular disease or chronically painful eyes in birds; however, there are several disadvantages and risks to this procedure. While evisceration has been suggested as an alternative, it has not been described for multiple cases or with long-term follow-up data in birds of prey. This report details an evisceration technique performed in 5 captive birds of prey of 4 different species (1 eastern screech owl [Megascops asio], 1 great horned owl [Bubo virginianus], 2 red-tailed hawks [Buteo jamaicensis], and 1 bald eagle [Haliaeetus leucocephalus]) with long-term follow-up information. In addition, this report describes 14 cases of free-living owls of 3 different species (1 great horned owl, 4 barred owls [Strix varia], and 9 eastern screech owls) on which this technique was performed from 2004 to 2011 and which were subsequently released to the wild. Because of the limited risk of complications and the less-severe disruption of facial symmetry, which may be particularly important in owls that are candidates for release to the wild, evisceration should be considered over enucleation in birds of prey that require surgical intervention for the management of severe sequelae to ocular trauma. PMID:23971220

  2. Plexiform unicystic ameloblastoma. A variant of ameloblastoma with a low-recurrence rate after enucleation.

    PubMed

    Gardner, D G; Corio, R L

    1984-04-15

    The term, plexiform unicystic ameloblastoma, refers to a pattern of epithelial proliferation that has been described in dentigerous cysts, primarily in persons in the second and third decades of life and predominantly in the posterior part of the mandible. This article provides the first study on the biologic behavior of these lesions. Of 28 examples treated by enucleation/curettage, and for which adequate follow-up information was obtained, only three recurred. This figure (10.7%) compares very favorably with the 55% to 90% recurrence rate quoted for ameloblastomas of all types that have been treated by curettage and is similar to that found in other types of unicystic ameloblastoma. The plexiform unicystic ameloblastoma is concluded from this study to be an undifferentiated histologic variant of unicystic ameloblastoma and not a separate entity. Enucleation with long-term follow-up information is adequate for tumors that have proliferated into the lumen of the cyst, but more extensive surgery is recommended for those that involve the periphery of its fibrous connective wall. This study has also shown that plexiform unicystic ameloblastomas are not always associated with unerupted teeth, in which case they probably occur over a wider age range than those resembling dentigerous cysts. PMID:6697311

  3. Hereditary Spherocytosis and Hereditary Elliptocytosis: Aberrant Protein Sorting during Erythroblast Enucleation

    SciTech Connect

    Salomao, Marcela; Chen, Ke; Villalobos, Jonathan; Mohandas, Narla; An, Xiuli; Chasis, Joel Anne

    2010-02-08

    During erythroblast enucleation, membrane proteins distribute between extruded nuclei and reticulocytes. In hereditary spherocytosis (HS) and hereditary elliptocytosis (HE), deficiencies of membrane proteins, in addition to those encoded by the mutant gene, occur. Elliptocytes, resulting from protein 4.1R gene mutations, lack not only 4.1R but also glycophorin C, which links the cytoskeleton and bilayer. In HS resulting from ankyrin-1 mutations, band 3, Rh-associated antigen, and glycophorin A are deficient. The current study was undertaken to explore whether aberrant protein sorting, during enucleation, creates these membrane-spanning protein deficiencies. We found that although glycophorin C sorts to reticulocytes normally, it distributes to nuclei in 4.1R-deficient HE cells. Further, glycophorin A and Rh-associated antigen, which normally partition predominantly to reticulocytes, distribute to both nuclei and reticulocytes in an ankyrin-1-deficient murine model of HS. We conclude that aberrant protein sorting is one mechanistic basis for protein deficiencies in HE and HS.

  4. Transient cavitation and acoustic emission produced by different laser lithotripters.

    PubMed

    Zhong, P; Tong, H L; Cocks, F H; Pearle, M S; Preminger, G M

    1998-08-01

    Transient cavitation and shockwave generation produced by pulsed-dye and holmium:YAG laser lithotripters were studied using high-speed photography and acoustic emission measurements. In addition, stone phantoms were used to compare the fragmentation efficiency of various laser and electrohydraulic lithotripters. The pulsed-dye laser, with a wavelength (504 nm) strongly absorbed by most stone materials but not by water, and a short pulse duration of approximately 1 microsec, induces plasma formation on the surface of the target calculi. Subsequently, the rapid expansion of the plasma forms a cavitation bubble, which expands spherically to a maximum size and then collapses violently, leading to strong shockwave generation and microjet impingement, which comprises the primary mechanism for stone fragmentation with short-pulse lasers. In contrast, the holmium laser, with a wavelength (2100 nm) most strongly absorbed by water as well as by all stone materials and a long pulse duration of 250 to 350 microsec, produces an elongated, pear-shaped cavitation bubble at the tip of the optical fiber that forms a vapor channel to conduct the ensuing laser energy to the target stone (Moss effect). The expansion and subsequent collapse of the elongated bubble is asymmetric, resulting in weak shockwave generation and microjet impingement. Thus, stone fragmentation in holmium laser lithotripsy is caused primarily by thermal ablation (drilling effect). PMID:9726407

  5. A simple technique for hemostasis control after enucleation of deep located liver tumors or after liver trauma

    PubMed Central

    Machado, Marcel A.; Surjan, Rodrigo C.; Basseres, Tiago; Makdissi, Fbio F.

    2016-01-01

    Modern liver techniques allowed the development of segment-based anatomical liver resections. Nevertheless, there is still a place for nonanatomical liver resections. However, in some cases, there is a need for enucleation of deep located liver tumors. The main problem with enucleation of a liver tumor deeply located in the middle of the liver is the control of bleeding resulting from the rupture of small or medium vessels. The authors describe a simple way to control the bleeding without the use of any special instrument or material. This technique can also be used to control bleeding from penetrating liver injury. PMID:26846270

  6. Percutaneous laser discectomy of cervical discs: preliminary clinical results.

    PubMed

    Siebert, W

    1995-06-01

    Thirty-one patients with herniated cervical discs were treated with PLDD from 1991 to 1993. In 1990, a few of these patients were treated with the Nd:YAG laser with no complications. Since 1991 we have used the holmium:YAG laser; 28 of the 31 patients experienced pain relief in a 6-week follow-up. PLDD for the cervical discs is a viable therapy. PMID:10150647

  7. Ureteropyeloscopy and homium: YAG laser lithotripsy for treatment of ureteral calculi (report of 356 cases)

    NASA Astrophysics Data System (ADS)

    Wu, Zhong; Din, Qiang; Jiang, Hao-wen; Zen, Jing-cun; Yu, Jiang; Zhang, Yuanfang

    2005-07-01

    Objective: To evaluate the efficacy and safety of holmium YAG laser lithotripsy for the treatment of ureteral calculi. Methods: A total of 356 patients underwent ureteropyeloscopic lithotripsy using holmium YAG laser with a semirigid uretesopyeloscope, 93 upper, 135 middle, and 128 lower ureteral stones were treated. Results: The overall successful fragmentation rate for all ureteral stones in a single session achieved 98% (349/356). The successful fragmentation rate stratified by stone location was 95% 88/93 in the upper ureter, 99% (134/135) in the mid ureter , and 99%(127/128) in the distal ureter. 12 cases with bilateral ureteral stones which caused acute renal failure and anuria were treated rapidly and effectively by the holmium YAG laser lithotripsy. No complications such as perforation and severe trauma were encountered during the operations. 2 weeks 17months (with an average of 6.8 month ) follow up postoperatively revealed that the overall stone-free rate was 98%(343/349) and no ureteral stenosis was found. Conclusions Holmium YAG laser lithotripsy is a highly effective, minimally invasive and safe therapy for ureteral calculi. It is indicated as a first choice of treatment for patients with ureteral calculi, especially for the ones with mid- lower levels of ureteral calculi.

  8. High frequency AC response, DC resistivity and magnetic studies of holmium substituted Ni-ferrite: A novel electromagnetic material

    NASA Astrophysics Data System (ADS)

    Pervaiz, Erum; Gul, I. H.

    2014-01-01

    Nanoparticles of holmium substituted nickel ferrites (NiHoxFe2-xO4) with x ranging from 0.0 to 0.15 have been prepared by the sol-gel auto-combustion method. Structural and morphology studies have been performed by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). XRD patterns revealed the formation of pure spinel phase ferrites without any impurity phase. Lattice parameter increases along with a decrease in crystallite size with increasing the concentration of Ho3+ in the parent nickel ferrite due to large ionic radius of Ho3+ (0.901 ) as compared to Fe3+ (0.67 ). SEM shows the spherical, uniformly distributed homogenous nanoparticles grown by controlled reaction parameters of the sol-gel method. Complex permittivity (?*) and complex electric modulus (M*) have been studied for the present nanoferrites in the frequency ranges of 1 MHz-1 GHz. Frequency dependent dielectric parameters (relative permittivity (?'), dielectric loss (??), dielectric loss tangent (tan ?)) decreases due to holmium substitution in nickel ferrites, showing the electrical conduction is decreasing in the nickel holmium ferrites with increase in the concentration of holmium. Complex modulus plots shows the poorly resolved semi circles and relaxation of nanoferrite is studied in the high frequency region. Also the relaxation time increases due to increase in x (0.0-0.15). DC electrical resistivity increases (107 ?-cm-1010 ?-cm) due to holmium ions substitution in nickel ferrites. Magnetic behavior was also characterized using a Vibrating Sample Magnetometer (VSM) under an applied magnetic field of 10 kOe and shows that magnetization decreases with increase in composition of holmium in nickel ferrites. High frequency behavior, low losses and very high DC electrical resistivity made the material a novel one for electromagnetic devices.

  9. HO:LULF and HO:LULF Laser Materials

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P. (Inventor); Morrison, Clyde A. (Inventor); Filer, Elizabeth D. (Inventor); Jani, Mahendra G. (Inventor); Murray, Keith E. (Inventor); Lockard, George E. (Inventor)

    1998-01-01

    A laser host material LULF (LuLiF4) is doped with holmium (Ho) and thulium (Tm) to produce a new laser material that is capable of laser light production in the vicinity of 2 microns. The material provides an advantage in efficiency over conventional Ho lasers because the LULF host material allows for decreased threshold and upconversion over such hosts as YAG and YLF. The addition of Tm allows for pumping by commonly available GaAlAs laser diodes. For use with flashlamp pumping, erbium (Er) may be added as an additional dopant. For further upconversion reduction, the Tm can be eliminated and the Ho can be directly pumped.

  10. A case of a benign cementoblastoma treated by enucleation and apicoectomy.

    PubMed

    Gulses, Aydin; Bayar, Gurkan Rasit; Aydin, Cumhur; Sencimen, Metin

    2012-01-01

    Cementoblastoma is a rare, benign, odontogenic neoplasm of ectomesenchymal origin, representing less than 6% of all odontogenic tumors. Despite its well-known typical features, there are still controversies regarding the management of the condition. This article presents the case of a benign cementoblastoma in a 17-year-old girl. The lesion was typical and associated with the mandibular right first molar. Endodontic treatment of the involved tooth, enucleation of the cementoblastoma, and apicoectomy of the affected roots were performed. Removal of the tumor while preserving the associated tooth resulted in normal osseous healing and no evidence of recurrence after one year. Based on the findings of the current report, it can be suggested that, in properly selected cases, it is possible to remove cementoblastomas that affect molars without extracting the involved teeth. PMID:23220315

  11. Visual system plasticity in mammals: the story of monocular enucleation-induced vision loss

    PubMed Central

    Nys, Julie; Scheyltjens, Isabelle; Arckens, Lutgarde

    2015-01-01

    The groundbreaking work of Hubel and Wiesel in the 1960’s on ocular dominance plasticity instigated many studies of the visual system of mammals, enriching our understanding of how the development of its structure and function depends on high quality visual input through both eyes. These studies have mainly employed lid suturing, dark rearing and eye patching applied to different species to reduce or impair visual input, and have created extensive knowledge on binocular vision. However, not all aspects and types of plasticity in the visual cortex have been covered in full detail. In that regard, a more drastic deprivation method like enucleation, leading to complete vision loss appears useful as it has more widespread effects on the afferent visual pathway and even on non-visual brain regions. One-eyed vision due to monocular enucleation (ME) profoundly affects the contralateral retinorecipient subcortical and cortical structures thereby creating a powerful means to investigate cortical plasticity phenomena in which binocular competition has no vote.In this review, we will present current knowledge about the specific application of ME as an experimental tool to study visual and cross-modal brain plasticity and compare early postnatal stages up into adulthood. The structural and physiological consequences of this type of extensive sensory loss as documented and studied in several animal species and human patients will be discussed. We will summarize how ME studies have been instrumental to our current understanding of the differentiation of sensory systems and how the structure and function of cortical circuits in mammals are shaped in response to such an extensive alteration in experience. In conclusion, we will highlight future perspectives and the clinical relevance of adding ME to the list of more longstanding deprivation models in visual system research. PMID:25972788

  12. Early development of cloned bovine embryos produced from oocytes enucleated by fluorescence metaphase II imaging using a conventional halogen-lamp microscope.

    PubMed

    Iwamoto, Daisaku; Yamagata, Kazuo; Kishi, Masao; Hayashi-Takanaka, Yoko; Kimura, Hiroshi; Wakayama, Teruhiko; Saeki, Kazuhiro

    2015-04-01

    Enucleation of a recipient oocyte is one of the key processes in the procedure of somatic cell nuclear transfer (SCNT). However, especially in bovine species, lipid droplets spreading in the ooplasm hamper identification and enucleation of metaphase II (MII) chromosomes, and thereby the success rate of the cloning remains low. In this study we used a new experimental system that enables fluorescent observation of chromosomes in living oocytes without any damage. We succeeded in visualizing and removing the MII chromosome in matured bovine oocytes. This experimental system consists of injecting fluorescence-labeled antibody conjugates that bind to chromosomes and fluorescent observation using a conventional halogen-lamp microscope. The cleavage rates and blastocyst rates of bovine embryos following in vitro fertilization (IVF) decreased as the concentration of the antibody increased (p<0.05). The enucleation rate of the conventional method (blind enucleation) was 86%, whereas all oocytes injected with the antibody conjugates were enucleated successfully. Fusion rates and developmental rates of SCNT embryos produced with the enucleated oocytes were the same as those of the blind enucleation group (p>0.05). For the production of SCNT embryos, the new system can be used as a reliable predictor of the location of metaphase plates in opaque oocytes, such as those in ruminant animals. PMID:25826723

  13. Intracorporeal laser lithotripsy

    PubMed Central

    Papatsoris, Athanasios G.; Skolarikos, Andreas; Buchholz, Noor

    2012-01-01

    Objectives To review the current literature on intracorporeal laser lithotripsy. Methods We searched PubMed for relevant reports up to January 2012, using the keywords laser, lithotripsy and intracorporeal. Results We studied 125 relevant reports of studies with various levels of evidence. Efficient lithotripsy depends on the laser variables (wavelength, pulse duration and pulse energy) and the physical properties of the stones (optical, mechanical and chemical). The most efficient laser for stones in all locations and of all mineral compositions is the holmium yttriumaluminiumgarnet laser (Ho:YAG). The frequency-doubled double-pulse Nd:YAG laser functions through the generation of a plasma bubble. New laser systems, such as the erbium:YAG and the thulium laser, are under evaluation. Laser protection systems have also been developed for the novel digital flexible ureteroscopes. Although complications are rare, a high relevant clinical suspicion is necessary. Conclusions Laser lithotripsy technology is continuously developing, while the Ho:YAG laser remains the reference standard for intracorporeal lithotripsy. PMID:26558041

  14. Frequency Swept Diode-pumped Single Frequency TM,Ho:YLiF Laser for spaceborne Doppler Lidar

    NASA Technical Reports Server (NTRS)

    McGuckin, B. T.; Menzies, R. T.; Esproles, C.

    1993-01-01

    Optical heterodyne experiments involving the photomixing of two single frequency, deode-pumped thulium holmium yttrium lithium flouride lasers are described. Operated in external frquency stabilization loops, the lasers exhibit 1MHz short term stability, and are photomixed and offset-locked at 140 MHz. Summation of sine wave modulation onto the PZT control voltage on one laser results in frequency swept operation over a continuous tuning range of 160 MHz.

  15. Efficient energy extraction from a diode-pumped Q-switched Tm,Ho:YLiF4 laser

    NASA Technical Reports Server (NTRS)

    Mcguckin, B. T.; Menzies, R. T.; Hemmati, H.

    1991-01-01

    The operation of a diode-laser pumped thulium, holmium yttrium-lithium-fluoride laser (Tm,Ho:YLF) in Q-switched mode is reported. Output energies of 200 microjoules in pulses of 22 ns duration are recorded at Q-switch frequencies commensurate with an effective upper laser level lifetime of 6 ms. This lifetime is appreciably longer than that observed in other hosts permitting stored energy extraction of 64 percent, close to the projected maximum performance from these materials.

  16. Scleral indentation height after laser scleral buckling

    NASA Astrophysics Data System (ADS)

    Kang, Se W.; Parel, Jean-Marie A.; Manns, Fabrice; Lee, Jawheung; Smiddy, William E.

    1998-06-01

    Laser scleral buckling (LSB) and scleral buckling are methods of inducing scleral indentation, a necessary objective in standard retinal reattachment surgery. The purpose of this study was to compare the height of scleral indentation produced by both modalities. Twenty (4 columns, 5 rows) overlapping spots of pulsed Holmium:YAG or Thulium:YAG laser were applied at the equatorial sclera in 20 human cadaver eyes (LSB group). The diameter of each laser spot was set to 2.5 mm using a custom-made laser probe. Total energy of Holmium:YAG and Thulium:YAG applied to each laser spot were 1285 mJ and 815 mJ, respectively. Scleral shrinkage and change in scleral thickness were measured. A radially oriented 5 mm silicone band was placed at the equator in 10 human cadaver eyes (explant group). The intraocular pressure (IOP) was adjusted to 4 mm Hg preoperatively, and to 16 mm Hg postoperatively in all eyes and monitored during the procedure. Scleral indentation height, assessed in frozen sections made along the eyeball equator, produced by Holmium:YAG (1.07 mm) and Thulium:YAG (1.30 mm) was less than that of explant group (3.12 mm) (p less than 0.05). Each application of a laser spot elevated the IOP by 4.9 mm Hg and the IOP decreased into a quarter of its elevation after 3.64 seconds. LSB with Thulium:YAG laser is potentially useful in retinal detachments when combined with vitrectomy for creating a shallow and broad buckling effect (i.e. in proliferative vitreoretinopathy cases).

  17. Improving Lifetime of Quasi-CW Laser Diode Arrays for Pumping 2-Micron Solid State Lasers

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Meadows, Byron L.; Baker, Nathaniel R.; Barnes, Bruce W.; Singh, Upendra N.; Kavaya, Michael J.

    2007-01-01

    Operating high power laser diode arrays in long pulse regime of about 1 msec, which is required for pumping 2-micron thulium and holmium-based lasers, greatly limits their useful lifetime. This paper describes performance of laser diode arrays operating in long pulse mode and presents experimental data on the active region temperature and pulse-to-pulse thermal cycling that are the primary cause of their premature failure and rapid degradation. This paper will then offer a viable approach for determining the optimum design and operational parameters leading to the maximum attainable lifetime.

  18. Malignant melanoma of the eye: treatment of posterior uveal lesions by Co-60 plaque radiotherapy versus enucleation

    SciTech Connect

    Markoe, A.M.; Brady, L.W. Jr.; Shields, J.A.; Augsburger, J.J.; Micaily, B.; Damsker, J.I.; Day, J.L.; Gamel, J.W.

    1985-09-01

    Survival rates and visual acuity of 100 patients treated for posterior uveal malignant melanoma by cobalt-60 plaque radiotherapy were compared with 150 patients treated by enucleation for the same disease. Life-table comparisons of the entire group showed significant differences in survival rates, with plaque radiotherapy patients appearing to fare better. However, when patients with small or medium tumors were compared, only slight differences were seen, implying that criteria used to select patients for treatment may affect interpretation. The two groups were also compared using the Cox proportional hazards model, which predicts survival based on the impact of clinical variables. In this analysis, the survival rates of the plaque radiotherapy group were no worse than those of the enucleation group. The advantage of conservative therapy lies in the potential to preserve useful vision over a considerable time.

  19. Enucleation of large keratocystic odontogenic tumor at mandible via unilateral sagittal split osteotomy: a report of three cases.

    PubMed

    Lee, Hyeong-Geun; Rhee, Seung-Hyun; Noh, Chung-Ah; Shin, Sang-Hun

    2015-08-01

    Keratocystic odontogenic tumor (KCOT) is a common benign tumor of osseous lesions in dental and maxillofacial practice. We describe three cases of large KCOT located in the posterior part of the mandible extending to the angle and ramus region, which were enucleated via sagittal split osteotomy (SSO) of the mandible. There are cases in which a conventional enucleation procedure does not ensure complete excision of the entire lesion without damage to vital structures like the inferior alveolar nerve. In such cases, a SSO approach could be a better choice than conventional methods. The purpose of this article is to describe our experience using unilateral mandibular SSO for removal of a KCOT from the mandible. PMID:26339581

  20. Enucleation of large keratocystic odontogenic tumor at mandible via unilateral sagittal split osteotomy: a report of three cases

    PubMed Central

    Lee, Hyeong-Geun; Rhee, Seung-Hyun; Noh, Chung-Ah

    2015-01-01

    Keratocystic odontogenic tumor (KCOT) is a common benign tumor of osseous lesions in dental and maxillofacial practice. We describe three cases of large KCOT located in the posterior part of the mandible extending to the angle and ramus region, which were enucleated via sagittal split osteotomy (SSO) of the mandible. There are cases in which a conventional enucleation procedure does not ensure complete excision of the entire lesion without damage to vital structures like the inferior alveolar nerve. In such cases, a SSO approach could be a better choice than conventional methods. The purpose of this article is to describe our experience using unilateral mandibular SSO for removal of a KCOT from the mandible. PMID:26339581

  1. Shifts in Developmental Timing, and Not Increased Levels of Experience-Dependent Neuronal Activity, Promote Barrel Expansion in the Primary Somatosensory Cortex of Rats Enucleated at Birth

    PubMed Central

    Fetter-Pruneda, Ingrid; Ibarrarn-Viniegra, Ana Sofa; Martnez-Martnez, Eduardo; Sandoval-Velasco, Marcela; Uribe-Figueroa, Laura; Padilla-Corts, Patricia; Mercado-Clis, Gabriela; Gutirrez-Ospina, Gabriel

    2013-01-01

    Birth-enucleated rodents display enlarged representations of whiskers (i.e., barrels of the posteromedial subfield) in the primary somatosensory cortex. Although the historical view maintains that barrel expansion is due to incremental increases in neuronal activity along the trigeminal pathway during postnatal development, recent evidence obtained in experimental models of intramodal plasticity challenges this view. Here, we re-evaluate the role of experience-dependent neuronal activity on barrel expansion in birth-enucleated rats by combining various anatomical methods and sensory deprivation paradigms. We show that barrels in birth-enucleated rats were already enlarged by the end of the first week of life and had levels of metabolic activity comparable to those in control rats at different ages. Dewhiskering after the postnatal period of barrel formation did not prevent barrel expansion in adult, birth-enucleated rats. Further, dark rearing and enucleation after barrel formation did not lead to expanded barrels in adult brains. Because incremental increases of somatosensory experience did not promote barrel expansion in birth-enucleated rats, we explored whether shifts of the developmental timing could better explain barrel expansion during the first week of life. Accordingly, birth-enucleated rats show earlier formation of barrels, accelerated growth of somatosensory thalamocortical afferents, and an earlier H4 deacetylation. Interestingly, when H4 deacetylation was prevented with a histone deacetylases inhibitor (valproic acid), barrel specification timing returned to normal and barrel expansion did not occur. Thus, we provide evidence supporting that shifts in developmental timing modulated through epigenetic mechanisms, and not increased levels of experience dependent neuronal activity, promote barrel expansion in the primary somatosensory cortex of rats enucleated at birth. PMID:23372796

  2. [Experimental and morphological results of using carbon foam in the formation of the locomotor stump after enucleation].

    PubMed

    Gundarova, R A; Khoroshilopva-Maslova, I P; Bykov, V P; Kataev, M G; Filatova, I A; Ilatovskaia, L V; Frolov-Bagreev, M N

    1997-01-01

    Syntactic carbon foam implants were used for the formation of the stump after unilateral enucleation in 24 rabbits. Clinical follow-up of the experimental animals demonstrated positive results of using syntactic carbon foam for plastic ophthalmosurgery. No complications, such as migration, infection, denudation, or rejection were observed in the immediate or late periods after surgery. Results of morphologic examinations of tissues adjacent to implants, carried out at different terms, are presented. PMID:9133035

  3. In vivo cerebral incorporation of radiolabeled fatty acids after acute unilateral orbital enucleation in adult hooded Long-Evans rats

    SciTech Connect

    Wakabayashi, S.; Freed, L.M.; Bell, J.M.; Rapoport, S.I.

    1994-03-01

    We examined effects of acute unilateral enucleation on incorporation from blood of intravenously injected unsaturated [1-{sup 14}C]arachidonic acid ([{sup 14}C]AA) and [1-{sup 14}C]docosahexaenoic acid ([{sup 14}C]DHA), and of saturated [9,10-{sup 3}H]palmitic acid ([{sup 3}H]PA), into visual and nonvisual brain areas of awake adult Long-Evans hooded rats. Regional cerebral metabolic rate for glucose (rCMR{sub glc}) values also were assessed with 2-deoxy-D-[1-{sup 14}C]glucose ([{sup 14}C]DG). One day after unilateral enucleation, an awake rat was placed in a brightly lit visual stimulation box with black and white striped walls, and a radiolabeled fatty acid was infused for 5 min or [{sup 14}C]DG was injected as a bolus. [{sup 14}C]DG also was injected in a group of rats kept in the dark for 4 h. Fifteen minutes after starting an infusion of a radiolabeled fatty acid, or 45 min after injecting [{sup 14}C]DG, the rat was killed and the brain was prepared for quantitative autoradiography. Incorporation coefficients k* of fatty acids, or rCMR{sub glc} values, were calculated in homologous brain regions contralateral and ipsilateral to enucleation. As compared with ipsilateral regions, rCMR{sub glc} was reduced significantly (by as much as -39%) in contralateral visual areas, including the superior colliculus, lateral geniculate body, and layers I, IV, and V of the primary (striate) and secondary (association, extrastriate) visual cortices. These results indicate that enucleation acutely reduces neuronal activity in contralateral visual areas of the awake rat and that the reductions are coupled to reduced incorporation of unsaturated fatty acids into sn-2 regions of phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine. Reduced fatty acid incorporation likely reflects reduced activity of phospholipases A{sub 2} and/or phospholipase C. 65 refs., 5 figs., 5 tabs.

  4. A unique case of facial burn superinfected with Dermatobia Hominis larvae resulting in a bilateral enucleation of the eyes.

    PubMed

    Pinos, Victor Hugo; Ortiz-Prado, Esteban; Bermeo, Carlos; Len, Juan; Armijos, Luciana; Almeida, Estibaliz

    2014-10-01

    We present a case of a female Ecuadorian patient who presented a deep facial burn injury complicated with a severe infestation of Dermatobia Hominis larvae. The burn injury was complicated by severe myiasis attributable to the poor management of the wound received at home, using tropical plants, which caused a secondary infection and severe necrosis of the tissue involving the forehead, cheeks, chin, scalp, nose, mouth and the eyes resulting in a bilateral enucleation and long inpatient hospital care. PMID:24728977

  5. Chloroplast-like organelles were found in enucleate sieve elements of transgenic plants overexpressing a proteinase inhibitor.

    PubMed

    Xie, Jun; Ouyang, Xue-Zhi; Xia, Kuai-Fei; Huang, Yu-Feng; Pan, Wen-Bi; Cai, Ying-Peng; Xu, Xinping; Li, Baojian; Xu, Zeng-Fu

    2007-11-01

    SaPIN2a, a plant proteinase inhibitor from nightshade (Solanum americanum), was located to the enucleate sieve elements (SEs) of phloem. The expressed SaPIN2a in transgenic lettuce showed inhibition of plant endogenous trypsin- and chymotrypsin-like activities, suggesting that SaPIN2a can regulate proteolysis in plant cells. To further investigate the physiological role of SaPIN2a, we produced transgenic nightshade and lettuce plants overexpressing SaPIN2a from the cauliflower mosaic virus (CaMV) 35S promoter using Agrobacterium-mediated transformation. Overexpression of SaPIN2a in transgenic plants was demonstrated by northern blot and western blot analysis. SaPIN2a-overexpressing transgenic nightshade plants showed significantly lower height than wild-type plants. Transmission electron microscopy analysis showed that chloroplast-like organelles with thylakoids, which are not present in enucleate SEs of wild-type plants, were present in the enucleate SEs of SaPIN2a-overexpressing transgenic plants. This finding is discussed in terms of the possible role played by SaPIN2a in the regulation of proteolysis in SEs. PMID:17986772

  6. Unimpaired terminal erythroid differentiation and preserved enucleation capacity in myelodysplastic 5q(del) clones: a single cell study

    PubMed Central

    Garderet, Laurent; Kobari, Ladan; Mazurier, Christelle; De Witte, Caroline; Giarratana, Marie-Catherine; Prot, Christine; Gorin, Norbert Claude; Lapillonne, Hlne; Douay, Luc

    2010-01-01

    Background Anemia is a characteristic of myelodysplastic syndromes, such as the rare 5q- syndrome, but its mechanism remains unclear. In particular, data are lacking on the terminal phase of differentiation of erythroid cells (enucleation) in myelodysplastic syndromes. Design and Methods We used a previously published culture model to generate mature red blood cells in vitro from human hematopoietic progenitor cells in order to study the pathophysiology of the 5q- syndrome. Our model enables analysis of cell proliferation and differentiation at a single cell level and determination of the enucleation capacity of erythroid precursors. Results The erythroid commitment of 5q(del) clones was not altered and their terminal differentiation capacity was preserved since they achieved final erythroid maturation (enucleation stage). The drop in red blood cell production was secondary to the decrease in the erythroid progenitor cell pool and to impaired proliferative capacity. RPS14 gene haploinsufficiency was related to defective erythroid proliferation but not to differentiation capacity. Conclusions The 5q- syndrome should be considered a quantitative rather than qualitative bone marrow defect. This observation might open the way to new therapeutic concepts. PMID:19815832

  7. Ankyrin and band 3 differentially affect expression of membrane glycoproteins but are not required for erythroblast enucleation

    SciTech Connect

    Ji, Peng; Whitehead Institute for Biomedical Research, Cambridge, MA 02142 ; Lodish, Harvey F.; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer Ankyrin and band 3 are not required for erythroblasts enucleation. Black-Right-Pointing-Pointer Loss of ankyrin does not affect erythroid membrane glycoprotein expression. Black-Right-Pointing-Pointer Loss of band 3 influences erythroid membrane glycoprotein expression. -- Abstract: During late stages of mammalian erythropoiesis the nucleus undergoes chromatin condensation, migration to the plasma membrane, and extrusion from the cytoplasm surrounded by a segment of plasma membrane. Since nuclear condensation occurs in all vertebrates, mammalian erythroid membrane and cytoskeleton proteins were implicated as playing important roles in mediating the movement and extrusion of the nucleus. Here we use erythroid ankyrin deficient and band 3 knockout mouse models to show that band 3, but not ankyrin, plays an important role in regulating the level of erythroid cell membrane proteins, as evidenced by decreased cell surface expression of glycophorin A in band 3 knockout mice. However, neither band 3 nor ankyrin are required for enucleation. These results demonstrate that mammalian erythroblast enucleation does not depend on the membrane integrity generated by the ankyrin-band 3 complex.

  8. STM and ab initio study of holmium nanowires on a Ge(111) surface

    NASA Astrophysics Data System (ADS)

    Eames, C.; Bonet, C.; Probert, M. I. J.; Tear, S. P.; Perkins, E. W.

    2006-11-01

    A nanorod structure has been observed on the Ho/Ge(111) surface using scanning tunneling microscopy (STM). The rods do not require patterning of the surface or defects such as step edges in order to grow as is the case for nanorods on Si(111). At low holmium coverage the nanorods exist as isolated nanostructures while at high coverage they form a periodic 51 structure. We propose a structural model for the 51 unit cell and show using an ab initio calculation that the STM profile of our model structure compares favorably to that obtained experimentally for both filled and empty states sampling. The calculated local density of states shows that the nanorod is metallic in character.

  9. Fibre laser component technology for 2-micron laser systems

    NASA Astrophysics Data System (ADS)

    Stevens, G.; Robertson, A.

    2014-05-01

    We report on recent developments in fibre laser component technology for use in 2-micron laser systems. A range of `building block' components has been built to allow novel fibre laser architectures that exploit the advantages of fibre lasers based on Thulium and Holmium active fibres. Fibre lasers operating around 2-microns are becoming widely used in an increasing number of applications, which is driving the need for components that can operate reliably at high powers and also integrate easily with other components. To that end, we have designed and built a range of fused fibre, acousto-optic and magneto-optic devices that can be readily integrated into a range of novel fibre laser systems. Research has been carried out into improving fused fibre technology for components operating at 2um wavelengths. Side-coupled feed through combiners have been developed with signal losses as low as 0.02dB and kilowatt level end-coupled pump couplers. Alongside this a range of taps, splitters and WDMs have been developed which allows for the implementation of a variety of laser architectures. Optical isolators based on new Faraday materials have been developed, providing over 30dB isolation, low insertion loss and 30W power handling in a fibre-in, fibre-out version. New cell designs and materials for Acousto-Optic devices have been researched leading to the development of fibre-coupled Acousto-Optic Modulators (AOM) and allows for the realisation of all fibre Thulium and Holmium Q-switched and pulsed fibre lasers. Novel Acousto-Optic Tunable Filters (AOTF) designs have been realised to produce narrow resolution AOTFs and zero-shift AOTFs.

  10. Thulium fiber laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Scott, Nicholas J.; Cilip, Christopher M.; Fried, Nathaniel M.

    2009-02-01

    Complications during laser lithotripsy include optical fiber bending failure resulting in endoscope damage and low irrigation rates leading to poor visibility. Both problems are related to fiber diameter and limited by the Holmium:YAG laser (? = 2120 nm) multimode beam profile. This study exploits the Thulium fiber laser (? = 1908 nm) beam profile for higher power transmission through smaller fibers. Thulium fiber laser radiation with 1-ms pulse duration, pulse rates of 10-30 Hz, and 70-?m-diameter spot was coupled into silica fibers with 100, 150, and 200 ?m core diameters. Fiber transmission, bending, and endoscope irrigation tests were performed. Damage thresholds for 100, 150, 200 ?m fibers averaged 40 W, 60 W, and > 80 W. Irrigation rates measured 35, 26, and 15 ml/min for no fiber, 100, and 200 ?m fibers. Thulium fiber laser energy of 70-mJ delivered at 20 Hz through a 100 ?m fiber resulted in vaporization and fragmentation rates of 10 and 60 mg/min for uric acid stones. The Thulium fiber laser beam profile provides higher laser power through smaller fibers than the Ho:YAG laser, potentially reducing fiber failure and endoscope damage and allowing greater irrigation rates for improved visibility.

  11. AB050. Laparoscopic transperitoneal enucleation of the prostate for benigh prostatic hyperplasia >80 mL

    PubMed Central

    Feng, Ning-Han

    2015-01-01

    Background Most laparoscopic enucleation of the prostate (LEP) procedures are performed via the extraperitoneal approach for large benign prostatic hyperplasia (prostate volume >80 mL). Therefore, we evaluate the feasibility of LEP via the transperitoneal approach with a 2-year follow-up. Methods LEP was performed on seven patients from December 2010 to July 2012. Surgery on all patients was performed using the transperitoneal method. The International Prostate Symptom Score (IPSS), and quality of life (QoL) questionnaire scores, maximum urinary flow rate (Qmax), postvoid residual urine volume (PVR) and other data were recorded pre- and post-operatively. All patients were followed up at least for 2 years. Results The mean prostate volume, PVR and Qmax were 95.6315.06 mL, 108.5771.46 mL and 8.141.99 mL/s respectively. The mean operation time was 240.7188.05 min. The mean catheterization time and duration of post-operative hospitalization was 9.291.98 and 11.002.77 d, respectively. In addition, significant improvements were observed in IPSS, QoL and Qmax at the 3-month follow-up. At the 6-, 12-, and 24-month follow-ups, the IPSS, QoL and Qmax remained stable. Only two patients required blood transfusions and two patients complained of urinary tract infection at the 3-month follow-up. None of the patients required recatheterization or repeated surgery. All patients were satisfied with the outcome of the operation. Conclusions LEP via the transperitoneal approach is a feasible, safe and effective minimally invasive operation for large prostate patients, particularly in cases with coexistent bladder calculi or diverticula. In the future, prospective randomized control trials with larger numbers of patients are warranted to confirm this conclusion.

  12. Retrograde endopyelotomy: a comparison between laser and Acucise balloon cutting catheter.

    PubMed

    el-Nahas, Ahmed R

    2007-03-01

    Endopyelotomy and laparoscopic pyeloplasty are the preferred modalities for treatment of ureteropelvic junction obstruction because of their minimally invasive nature. There are continuous efforts for improving endopyelotomy techniques and outcome. Retrograde access represents the natural evolution of endopyelotomy. The Acucise cutting balloon catheter (Applied Medical Resources Corp., Laguna Hills, CA) and ureteroscopic endopyelotomy using holmium laser are the most widely accepted techniques. The Acucise catheter was developed to simplify retrograde endopyelotomy and made it possible for all urologists, regardless of their endourologic skills. The Acucise catheter depends on incision and dilatation of the ureteropelvic junction under fluoroscopic guidance, whereas ureteroscopy allows visual control of the site, depth, and extent of the incision; the holmium laser is a perfect method for a clean precise incision. Review of the English literature showed that the Acucise technique was more widely performed, though laser had better (but not statistically significant) safety and efficacy profiles. PMID:17303017

  13. Chiral Holmium Complex-Catalyzed Synthesis of Hydrocarbazole from Siloxyvinylindole and Its Application to the Enantioselective Total Synthesis of (-)-Minovincine.

    PubMed

    Morikawa, Takahiro; Harada, Shinji; Nishida, Atsushi

    2015-09-01

    The catalytic and enantioselective total synthesis of (-)-minovincine has been accomplished. The key highly substituted hydrocarbazole derivative was obtained by an asymmetric Diels-Alder reaction of siloxyvinylindole catalyzed by 0.5 mol % of a chiral holmium complex. The Diels-Alder adduct was converted to a tetracyclic intermediate in a one-pot procedure. No waste stereoisomers were produced throughout the entire total synthesis. PMID:26247095

  14. Depolarization of neutrons in ferromagnetic holmium by means of enhanced nuclear parity violation in sup 139 La

    SciTech Connect

    Haase, D.G.; Bowman, J.D.; Delheij, P.P.J.; Frankle, C.M.; Gould, C.R.; Knudson, J.N.; Koster, J.E.; Mitchell, G.E.; Penttilae, S.; Postma, H.; Roberson, N.R.; Seestrom, S.J.; Yoo, S.H.; Yuan, V.W. Triangle Universities Nuclear Laboratory, Durham, North Carolina 27706 Los Alamos National Laboratory, Los Alamos, New Mexico 87545 TRIUMF, Vancouver, British Colombia, V6T 2A3 Physics Department, Duke University, Durham, North Carolina 27706 Triangle Universities Nuclear Laboratory, Durham, North Carolina 27706 University of Technology, P.O. Box 5046, 2600 GA Delft )

    1992-11-01

    The depolarization of epithermal neutrons in a thick single crystal of ferromagnetic holmium has been measured and analyzed with a model of neutron precession through a highly correlated array of magnetic domains. The large parity violation in the 0.734-eV {ital p}-wave resonance in {sup 139}La was used to analyze the neutron polarization, and represents an application of parity violation in nuclear resonances to a measurement in condensed-matter physics.

  15. Carprofen provides better post-operative analgesia than tramadol in dogs after enucleation: A randomized, masked clinical trial

    PubMed Central

    Delgado, Cherlene; Bentley, Ellison; Hetzel, Scott; Smith, Lesley J

    2015-01-01

    Objective To compare analgesia provided by carprofen or tramadol in dogs after enucleation. Design Randomized, masked trial Animals Forty-three dogs Procedures Client-owned dogs admitted for routine enucleation were randomly assigned to receive either carprofen or tramadol orally 2 hours prior to surgery and 12 hours after the first dose. Dogs were scored for pain at baseline, and postoperatively at 0.25, 0.5, 1, 2, 4, 6, 8, 24, and 30 hours after extubation. Dogs received identical premedication and inhalation anesthesia regimens, including premedication with hydromorphone. If the total pain score was ≥9, if there was a score ≥ 3 in any one category, or if the visual analog scale score (VAS) was ≥35 combined with a palpation score of >0, rescue analgesia (hydromorphone) was administered and treatment failure was recorded. Characteristics between groups were compared with a Student’s t-test and Fisher’s exact test. The incidence of rescue was compared between groups using a log rank test. Pain scores and VAS scores between groups were compared using repeated measures ANOVA. Results There was no difference in age (p=0.493), gender (p=0.366) or baseline pain scores (p=0.288) between groups. Significantly more dogs receiving tramadol required rescue analgesia (6/21) compared to dogs receiving carprofen (1/22; p=0.035). Pain and VAS scores decreased linearly over time (p=0.038, p<0.001, respectively). There were no significant differences in pain (p=0.915) or VAS scores (p=0.372) between groups at any time point (dogs were excluded from analysis after rescue). Conclusions and Clinical Relevance This study suggests that carprofen, with opioid premedication, provides more effective post-operative analgesia than tramadol in dogs undergoing enucleation. PMID:25459482

  16. Spontaneous Bone Regeneration After Enucleation of Large Jaw Cysts: A Digital Radiographic Analysis of 44 Consecutive Cases

    PubMed Central

    Chacko, Rabin; Paul, Arun; Arvind

    2015-01-01

    Purpose This study evaluated the healing in cystic defect of the jaw to substantiate our understanding of spontaneous bone healing after enucleation of jaw cysts subjectively and with analysis of digital postoperative panoramic radiographs. Materials and Methods Fourty four consecutive patients reporting to the Department of Dental and Oral Surgery, during the period between 2008-2012 having maxillary and mandibular cysts treated by either surgical enucleation or by marsupialization followed by enucleation were evaluated for subsequent bone formation at the site of cystectomy defect by subjective clinical examination along with digital radiographic examination. Postoperative clinical and radiographic examinations were performed at 6,9,12, and 24 months. Bone regeneration was evaluated by reduction of the size of residual cavities at the cystectomy defect using digital orthopantomogram. Results Out of 44 patients 15 patients completed two years of follow-up with all the patients having 6 months follow-up. The maximum size of the cystic pathology was 150.40mm and minimum of 14.73mm at the time of presentation (average size of 58.16mm). Twenty patients were diagnosed with odontogenic keratocyst, with one patient having multiple OKC associated with Gorlin Goltz Syndrome, 17 patients had dentigerous cyst, 5 had Radicular cyst; solitary bone cyst and globulomaxillary cyst formed one each. Uneventful healing and spontaneous filling of the residual cavities were obtained in all cases. The digital analysis of the postoperative radiographs showed mean values of reduction in size of the residual cavity of 25.85% after 6 months, 57.13% after 9 months, 81.03% after one year and 100% after two year. Conclusion Spontaneous bone regeneration can occur after surgical removal of jaw cysts without the aid of any graft materials even in large cystic cavity sufficiently surrounded by enough bony walls. This simplifies the surgical procedure, decreases the overall cost of surgery, and reduces the risk of postoperative complications associated with grafting. PMID:26501020

  17. Laparoscopic Non-clamping Tumor Enucleation of Renal Hilum Schwannoma in a Single Kidney: A Case Report

    PubMed Central

    Hanashima, Fuminari; Yanaihara, Hitoshi; Hayashi, Taiki; Kaguyama, Hirofumi; Teranishi, Yu; Sakamoto, Hirofumi; Nakahira, Yoko; Asakura, Hirotaka

    2015-01-01

    A 56-year-old woman underwent laparoscopic right nephrectomy due to pyonephrosis associated with right ureteral stones. Moreover, the patient developed a brain stem hemorrhage and became bedridden. At the time of nephrectomy, a renal tumor, with a size of 24נ24נ20mm, was observed in the left renal hilum; the tumor did not show contrast enhancement on computed tomography. After 3years, the tumor gradually grew to a size of 45נ35נ34mm, and therefore, laparoscopic non-clamping tumor enucleation was performed. Pathological examination confirmed a diagnosis of renal schwannoma.

  18. Fertility and Pregnancy Outcome after Myoma Enucleation by Minilaparotomy under Microsurgical Conditions in Pronounced Uterus Myomatosus

    PubMed Central

    Floss, K.; Garcia-Rocha, G.-J.; Kundu, S.; von Kaisenberg, C. S.; Hillemanns, P.; Schippert, C.

    2015-01-01

    Introduction: Besides the typical complaints and symptoms, myomas can cause sterility, infertility and complications during pregnancy. Laparoscopic interventions reach their limits with regard to organ preservation and the simultaneous desire to have children in the removal of multiple and larger intramural myoma nodes. The aim of this study is to examine fertility status and pregnancy outcome after myoma removal by minilaparotomy (skin incision maximal 8 cm) in women with pronounced uterus myomatosus. Materials and Methods: This retrospective study makes use of the data from 160 patients with an average age of 34.6 years. Factors analysed include number, size and localisation of the myomas, complaints due to the myoma, pre- and postoperative gravidity, mode of delivery, and complications of birth. Results: Indications for organ-sparing myoma enucleation were the desire to have children (72.5 %), bleeding disorders (60 %) and pressure discomfort (36.5 %). On average 4.95 (SD ± 0.41), maximally 46 myomas were removed. The largest myoma had a diameter of 6.64 cm (SD ± 2.74). 82.5 % of the patients had transmural myomas, in 17.5 % the uterine cavity was inadvertently opened. On average the operating time was 163 minutes (SD ± 45.47), the blood loss 1.59 g/dL (SD ± 0.955). 60.3 % of the patients with the desire to have children became pregnant postoperatively. 75.3 % of the pregnancies were on average carried through to the 38th week (28.4 % vaginal deliveries, 71.6 % Caesarean sections). In the postoperative period there was one case of uterine rupture in the vicinity of a previous scar. Discussion: By means of the microsurgical “mini-laparotomy” even extensive myomatous uterine changes can, in the majority of cases, be operated in an organ-sparing manner with retention of the ability to conceive and to carry a pregnancy through to maturity of the infant. The risk for a postoperative uterine rupture in a subsequent pregnancy and during delivery is minimal. PMID:25684787

  19. Single-Frequency Narrow Linewidth 2 Micron Fiber Laser

    NASA Technical Reports Server (NTRS)

    Jiang, Shibin (Inventor); Spiegelberg, Christine (Inventor); Luo, Tao (Inventor)

    2006-01-01

    A compact single frequency, single-mode 2 .mu.m fiber laser with narrow linewidth, <100 kHz and preferably <100 kHz, is formed with a low phonon energy glass doped with triply ionized rare-earth thulium and/or holmium oxide and fiber gratings formed in sections of passive silica fiber and fused thereto. Formation of the gratings in passive silica fiber both facilitates splicing to other optical components and reduces noise thus improving linewidth. An increased doping concentration of 0.5 to 15 wt. % for thulium, holmium or mixtures thereof produces adequate gain, hence output power levels for fiber lengths less than 5 cm and preferably less than 3 cm to enable single-frequency operation.

  20. Moderate-power cw fibre lasers

    SciTech Connect

    Kurkov, Andrei S; Dianov, Evgenii M

    2004-10-31

    A review of the development and investigation of moderate-power (10{sup -1}-10{sup 2} W) cw fibre lasers is presented. The properties of optical fibres doped with rare-earth ions and methods for fabricating double-clad fibres are considered. The methods for fabrication of fibre Bragg gratings used as selective reflectors are discussed and the grating properties are analysed. The main pump schemes for double-clad fibre lasers are described. The properties of fibre lasers doped with neodymium, ytterbium, erbium, thulium, and holmium ions are also considered. The principles of fabrication of Raman converters of laser radiation based on optical fibres of different compositions are discussed and the main results of their studies are presented. It is concluded that fibre lasers described in the review can produce moderate-power radiation at any wavelength in the spectral range from 0.9 to 2 {mu}m. (review)

  1. Aggressive Central Giant Cell Granuloma of the Mandible Treated With Conservative Surgical Enucleation and Interferon-?-2a: Complete Remission With Long-Term Follow-Up.

    PubMed

    Tarsitano, Achille; Del Corso, Giacomo; Pizzigallo, Angelo; Marchetti, Claudio

    2015-11-01

    Central giant cell granuloma (CGCG) is a benign tumor of the jaws. Aggressive lesions present a strong tendency toward recurrence after surgical enucleation; thus, en bloc resection and microvascular bone free flap transfer are usually performed. However, in young patients, aggressive surgical treatment is a not always suitable solution. This report describes the case of a young female patient who developed an aggressive recurrence of CGCG after its diagnosis and enucleation from the mandible. Surgical enucleation with subcutaneous injection of interferon-?-2a was performed. The patient was evaluated every 6weeks, and after 6months radiographic evidence of complete bone regeneration was obtained. No sign of recurrence was seen after 8years of follow-up. A review of the literature proved that interferon treatment is an effective strategy to avoid extensive surgery in patients with aggressive CGCG. PMID:25985764

  2. Development of inter-family nuclear transplant embryos by transplanting the nuclei from the loach blastulae into the non-enucleated zebrafish eggs

    NASA Astrophysics Data System (ADS)

    Li, Li; Zhang, Shicui; Yuan, Jinduo; Li, Hongyan

    2003-03-01

    The developmental fate of the pronuclei in recombined embryos obtained by transplanting the donor nuclei into the non-enucleated eggs remains controversial in the case of fish. In the present study, the nuclei from the loach blastulae were transplanted into non-enucleated zebrafish eggs, the resulting 9 inter-family nuclear transplant embryos developed to larval stages. Although the development timing of the nuclear transplants resembled that of zebrafish, chromosome examination revealed that most of the recombined embryos were diploids with karyotype characteristic of loach, which was also proved by RAPD analysis. Moreover, 3 out of the 9 larval fish formed barb rudiments specific to loach. It was therefore concluded that the nuclear transplant larval fish were inter-family nucleo-cytoplasmic hybrids; and that only the donor nuclei were involved in the development of the nuclear transplant embryos, while the pronuclei in the non-enucleated eggs were likely automatically eliminated during the development.

  3. Recovery of cell nuclei from 15,000 years old mammoth tissues and its injection into mouse enucleated matured oocytes.

    PubMed

    Kato, Hiromi; Anzai, Masayuki; Mitani, Tasuku; Morita, Masahiro; Nishiyama, Yui; Nakao, Akemi; Kondo, Kenji; Lazarev, Petr A; Ohtani, Tsuyoshi; Shibata, Yasuyuki; Iritani, Akira

    2009-01-01

    Here, we report the recovery of cell nuclei from 14,000-15,000 years old mammoth tissues and the injection of those nuclei into mouse enucleated matured oocytes by somatic cell nuclear transfer (SCNT). From both skin and muscle tissues, cell nucleus-like structures were successfully recovered. Those nuclei were then injected into enucleated oocytes and more than half of the oocytes were able to survive. Injected nuclei were not taken apart and remained its nuclear structure. Those oocytes did not show disappearance of nuclear membrane or premature chromosome condensation (PCC) at 1 hour after injection and did not form pronuclear-like structures at 7 hours after injection. As half of the oocytes injected with nuclei derived from frozen-thawed mouse bone marrow cells were able to form pronuclear-like structures, it might be possible to promote the cell cycle of nuclei from ancient animal tissues by suitable pre-treatment in SCNT. This is the first report of SCNT with nuclei derived from mammoth tissues. PMID:19644224

  4. Enucleation in equids with and without the use of an orbital suture meshwork implant: a retrospective study of 37 cases.

    PubMed

    Maninchedda, U; Nottrott, K; Gangl, M

    2015-10-10

    This retrospective study on 37 horses was conducted to assess long-term complications, scarring, cosmetic appearance and owner satisfaction of horses that underwent transpalpebral enucleation with (n=26) or without (n=11) non-absorbable sutured meshwork prosthesis between 2006 and 2013. Postoperative complications related to the surgery were wound infection, discharge and dehiscence, and no significant difference between groups was found. In one horse, the meshwork had to be removed in order to treat a chronic fistula. Horses with infection or inflammation before surgery were more likely to encounter postoperative complications, whether or not a meshwork was used. Most owners were satisfied by the surgical technique for scarring, but contrary to the present hypothesis, most horses with a meshwork implant had a poor sunken-in appearance, and 26 per cent of owners would like to attempt other techniques to improve the cosmetic result. Also, a further 44 per cent of owners would prefer a better cosmetic result if the technique does not increase complication risk or cost. Meshwork implant prosthesis after transpalpebral enucleation was safe. However, in order to achieve a better cosmetic result, further improvements of the technique will be required. PMID:26442527

  5. Minimization of thermomechanical side effects and increase of ablation efficiency in IR ablation by use of multiply Q-switched laser pulses

    NASA Astrophysics Data System (ADS)

    Vogel, Alfred; Schmidt, Peter; Flucke, Barbara

    2002-06-01

    Large thermal damage zones have been observed after application of free-running holmium laser pulses inside the human body as, for example, for arthroscopic surgery. The aim of our study is to reduce thermal damage by increasing the ablation efficiency, and to achieve a smooth surface of the ablated tissue. For that purpose we use a multiply Q- switched thulium laser ((lambda) equals 2.0 micrometers , acousto- optical QS) that emits pulse series consisting of a pre- pulse of 40 mJ energy and up to 6 ablation pulses of 100 mJ each, separated by time intervals of 60 microsecond(s) . Q-switched laser pulses explosively ablate the target material. In a liquid environment, this leads to the formation of cavitation bubbles and to mechanical damage of the surrounding tissue. The pre-pulse of 40 mJ serves to minimize the cavitation effects, as it produces a small cavity that is then filled by the ablation products created by the burst of 100-mJ pulses. The pre-pulse creates, furthermore, a channel between fiber tip and target that reduces absorption losses in the liquid. Reduction of cavitation effects and channel formation are demonstrated by time-resolved photography. The use of a thulium laser instead of a holmium laser contributed to the desired reduction of thermal damage, because the penetration depth of the thulium laser light in cartilage (approximately 170 micrometers ) is only half as large as with the holmium laser.

  6. Is there a niche for arthroscopic laser surgery of the temporomandibular joint?

    NASA Astrophysics Data System (ADS)

    Nuebler-Moritz, Michael; Hering, Peter; Bachmaier, Uli; Schiessl, Robert; Rueschoff, Josef; Meister, Joerg

    1996-04-01

    The purpose of this in vitro study was to investigate and compare effects of currently available laser systems at different wavelengths (XeCl excimer laser, Holmium:YAG laser, Erbium:YAG laser) on porcine articulating facets, capsule and meniscus of the temporomandibular joint via photomacroscopy, light and scanning electron microscopy. From a critical review of the relevant literature and the preliminary observations of this investigation, it appears that the Neodymium:YAG laser is inappropriate for TMJ arthroscopic surgery with regard to the huge thermal injury caused to the remaining tissue. The Holmium:YAG laser suffers from remarkable photomechanical and photothermal side effects, whereas the Erbium:YAG laser ablates temporomandibular joint tissue efficiently with minimal adjacent damage--similar to the XeCl excimer laser, without entailing the risk of potential mutagenity. To sum up, it can be concluded that there is a clinical need for laser- assisted arthroscopic surgery of the craniomandibular articulation. Nevertheless, at present none of the available laser systems meet the medical demands completely. Currently, the Erbium:YAG laser seems to be the most suitable for TMJ arthroscopic surgery.

  7. Histological analysis of a cornea following experimental femtosecond laser ablation.

    PubMed

    Sumioka, Takayoshi; Miyamoto, Takeshi; Takatsuki, Reiko; Okada, Yuka; Yamanaka, Osamu; Saika, Shizuya

    2014-11-01

    Corneal photorefractive surgery is currently performed by ablation of corneal stroma under the stromal flap. A stromal flap is created using a femtosecond (FS) laser or mechanical microkeratome, although the FS laser procedure is considered safer and more accurate. This review assesses and compares the use of FS laser versus mechanical microkeratome ablation for corneal stromal characteristics mainly examined by histology and cellular biological responses. Supporting data from our studies, using corneas of enucleated porcine eye globes, are included in this review. Histological analysis and experimental studies of cellular/tissue responses to FS laser irradiation should be further investigated, and the equipment used to perform these techniques should be improved. PMID:25289720

  8. Tm-Ho co-doped fiber-based high repetition rate passive Q-switching of an Er-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Tao, Mengmeng; Ye, Xisheng; Wang, Zhenbao; Yang, Pengling; Feng, Guobin

    2014-01-01

    An all-fiber Q-switched Er-doped laser is built with a ring cavity. Stable Q-switching is demonstrated with a Tm-Ho co-doped fiber saturable absorber. The maximum repetition rate of the laser system reaches 42 kHz, which is much larger than that with Tm singly doped fiber saturable absorbers. Analysis shows that interaction between thulium and holmium ions is the main reason for this high repetition rate operation.

  9. Encrusted Ureteral Stent Retrieval Using Flexible Ureteroscopy with a Ho: YAG Laser.

    PubMed

    Kawahara, Takashi; Ito, Hiroki; Terao, Hideyuki; Ogawa, Takehiko; Uemura, Hiroji; Kubota, Yoshinobu; Matsuzaki, Junichi

    2012-01-01

    A 23-year-old female had bilateral ureteral stents placed due to bilateral renal stones and hydronephrosis. The bilateral ureteral stents were changed every 3 months. A kidney ureter bladder (KUB) film showed left encrustation along the ureteral stent thus necessitating removal; however, the ureteral stent could not be removed cystoscopically. The ureteral stent was, therefore, extracted using flexible ureteroscopy (URS) with a holmium (Ho): yttrium aluminum garnet (YAG) laser. PMID:22548081

  10. Endoscopic Ho laser interstitial therapy for pharyngolaryngeal venous malformations in adults.

    PubMed

    Xiuwen, Jiang; Jianguo, Tang

    2015-04-01

    Many methods have been used to treat venous malformations, including sclerotherapy, laser therapy, and surgery. Nowadays, endoscopic laser surgery has become a popular therapeutic modality for most of pharyngolaryngeal venous malformations. There are various kinds of lasers that have been applied, but Holmium:YAG laser (Ho laser) has not been reported yet. Ho laser is produced by a kind of iraser which is made of yttrium aluminum garnet mixed with holmium, chromium and thulium. Aim of the current work is to evaluate the efficacy and safety of Ho laser interstitial therapy in pharyngolaryngeal venous malformations in adults. The clinical data of 42 patients with pharyngolaryngeal venous malformation treated with endoscopic Ho laser interstitial therapy over a 12-year period were retrospectively reviewed and analyzed. The wave length of Ho laser was 2.1m and the diameter of optical fiber was 550m. The pulse energy was 0.5J and the time of duration was 600s. The highest output power was 100W. Outcomes were graded as cure (complete resolution), considerable reduction (>60-80% reduction), and no obvious change (<50% reduction). The lesions were well controlled without severe complications. Complete resolution of the lesion was observed in 95.1% of the patients, while 4.9% patients showed considerable reduction of the swelling. Complications occurred in 4.8% of patients. No respiratory troubles or other severe complications occurred. Endoscopic Ho laser interstitial therapy is an effective and safe treatment modality for pharyngolaryngeal venous malformations in adults. PMID:25534288

  11. Expression of selected genes involved in steroidogenesis in the course of enucleation-induced rat adrenal regeneration.

    PubMed

    Tyczewska, Marianna; Rucinski, Marcin; Ziolkowska, Agnieszka; Trejter, Marcin; Szyszka, Marta; Malendowicz, Ludwik K

    2014-03-01

    The enucleation-induced (EI) rapid proliferation of adrenocortical cells is followed by their differentiation, the degree of which may be characterized by the expression of genes directly and indirectly involved in steroid hormone biosynthesis. In this study, out of 30,000 transcripts of genes identified by means of Affymetrix Rat Gene 1.1 ST Array, we aimed to select genes (either up- or downregulated) involved in steroidogenesis in the course of enucleation-induced adrenal regeneration. On day 1, we found 32 genes with altered expression levels, 15 were upregulated and 17 were downregulated [i.e., 3?-hydroxysteroid dehydrogenase (Hsd3?), nuclear receptor subfamily 0, group B, member 1 (Nr0b1), cytochrome P450 aldosterone synthase (Cyp11b2) and sterol O-acyltransferase 1 (Soat1)]. On day 15, the expression of only 2 genes was increased and that of 3 was decreased. The investigated genes were clustered according to an hierarchical clustering algorithm and 4 clusters were obtained. Quantitative PCR (qPCR) confirmed the much lower mRNA expression levels of steroidogenic acute regulatory protein (StAR) during the regeneration process compared to the control, while the cholesterol side-chain cleavage enzyme (cholesterol desmolase; Cyp11a1) and Hsd3? genes presented similar expression profiles throughout the entire regeneration process. Cyp11b2 mRNA levels remained very low during the whole regeneration period. Fatty acid binding protein 6 (Fabp6) was markedly upregulated, whereas hormone-sensitive lipase (Lipe) was downregulated. The expression of Soat1 was lowest on regeneration day 1 and, subsequently, its expression increased from there on, reaching levels higher than the control. Dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 (Dax-1) mRNA levels were lowest on day 1 of the experiment; however, throughout the entire experimental period, there were no statistically significant differences observed. After the initial decrease in steroidogenic factor 1 (Sf-1) mRNA levels observed on the 1st day of the experiment, a marked upregulation in its expression was observed from there on. Data from the current study strongly suggest the role of Fabp6, Lipe and Soat1 in supplying substrates of regenerating adrenocortical cells for steroid synthesis. Our results indicate that during the first days of adrenal regeneration, intense synthesis of cholesterol may occur, which is then followed by its conversion into cholesteryl esters. Moreover, our data demonstrated that in enucleation-induced regeneration, the restoration of genes involved in glucocorticoid synthesis is notably shorter than that of those involved in aldosterone synthesis. PMID:24366092

  12. Modified endoscopic submucosal dissection with enucleation for treatment of gastric subepithelial tumors originating from the muscularis propria layer

    PubMed Central

    2012-01-01

    Background Gastric subepithelial tumors are usually asymptomatic and observed incidentally during endoscopic examination. Although most of these tumors are considered benign, some have a potential for malignant transformation, particularly those originating from the muscularis propria layer. For this type of tumor, surgical resection is the standard treatment of choice. With recent advent of endoscopic resection techniques and devices, endoscopic submucosal dissection (ESD) has been considered as an alternative way of treatment. The aim of this study is to demonstrate the feasibility of a modified ESD technique with enucleation for removal of gastric subepithelial tumors originating from the muscularis propria layer, and to evaluate its efficacy and safety. Methods From November 2009 to May 2011, a total of 16 patients received a modified ESD with enucleation for their subepithelial tumors. All tumors were smaller than 5?cm and originated from the muscularis propria layer of the stomach, as shown by endoscopic ultrasonography (EUS). The procedure was conducted with an insulated-tip knife 2. Patients demographics, tumor size and pathological diagnosis, procedure time, procedure-related complication, and treatment outcome were reviewed. Results Fifteen of the sixteen tumors were successful complete resection. The mean tumor size measured by EUS was 26.1?mm (range: 2042?mm). The mean procedure time was 52?minutes (range: 30120?minutes). Endoscopic features of the 4 tumors were pedunculated and 12 were sessile. Their immunohistochemical diagnosis was c-kit (+) stromal tumor in 14 patients and leiomyoma in 2 patients. There was no procedure-related perforation or overt bleeding. During a mean follow up duration of 14.8?months (range: 622?months), there was no tumor recurrence or metastasis. Conclusions Using a modified ESD with enucleation for treatment of gastric subepithelial tumors originating from the muscularis propria layer and larger than 2?cm, complete resection can be successfully performed without serious complication. It is a safe and effective alternative to surgical therapy for these tumors of 2 to 5?cm in size. PMID:22978826

  13. Enucleated eyes after failed intra-arterial infusion of chemotherapy for unilateral retinoblastoma: histopathologic evaluation of vitreous seeding

    PubMed Central

    Kim, Jonathan; Do, Huy; Egbert, Peter

    2011-01-01

    Selective intra-arterial chemotherapy (IAC) has been adopted by many ocular oncology centers to treat advanced intraocular retinoblastoma. In this report, we describe two patients with unilateral intraocular retinoblastoma and persistent vitreous seeding, who were treated with IAC after failed systemic chemotherapy. Despite multiple sessions and increasing dosage of drug delivery, vitreous seeding in these cases failed to respond to IAC, and ultimately both eyes were enucleated for tumor control. Based on the histopathologic findings in these two cases, IAC appears to have limitations in treating persistent vitreous seeding in eyes which have failed systemic chemotherapy. Possible causes for failure of IAC to treat persistent vitreous seeding include poor vitreous penetration, inactive state of tumor seeds within the avascular vitreous cavity, and chemotherapeutic drug resistance. PMID:22174572

  14. Qualification Testing of Laser Diode Pump Arrays for a Space-Based 2-micron Coherent Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Meadows, Byron L.; Baker, Nathaniel R.; Barnes, Bruce W.; Singh, Upendra N.; Kavaya, Michael J.

    2007-01-01

    The 2-micron thulium and holmium-based lasers being considered as the transmitter source for space-based coherent Doppler lidar require high power laser diode pump arrays operating in a long pulse regime of about 1 msec. Operating laser diode arrays over such long pulses drastically impact their useful lifetime due to the excessive localized heating and substantial pulse-to-pulse thermal cycling of their active regions. This paper describes the long pulse performance of laser diode arrays and their critical thermal characteristics. A viable approach is then offered that allows for determining the optimum operational parameters leading to the maximum attainable lifetime.

  15. Outflow facility efficacy of five drugs in enucleated porcine eyes by a method of constant-pressure perfusion.

    PubMed

    Li, Ning; Shi, Hui-Min; Cong, Lin; Lu, Zhao-Zeng; Ye, Wen; Zhang, Yu-Yan

    2015-01-01

    This study aimed to characterize a technique that assesses the outflow facility (C) efficacy of five kinds of IOP-lowering drugs commonly used clinically in enucleated porcine Eyes. Eyes were perfused at 15 mmHg with GPBS first to establish the baseline outflow facility (C0). Then the anterior chamber contents were exchanged for GPBS with corresponding concentration eye drops (4.910(3) nM Brimonidine, 41.1 nM Latanoprost, 3.410(3) nM Levobunolol, 3.010(3) nM Brinzolamide, 8.310(3) nM Pilocarpine) in five groups (n = 6 each), while 6 eyes received GPBS alone as control. The mean stable facility obtained after drug administration (C1) was continuously recorded. The changes between C0 and C1 (?C = C1-C0) were analyzed. Finally, for drugs among the five experiment groups with statistical significance, the concentration was reduced 3 times, otherwise the drugs' concentration was increased to 10 times to confirm its effectiveness further using the same methods (n = 6 each). We found that the average baseline outflow facility was 0.240.01 ?lmin(-1)mmHg(-1). C increased significantly in Brimonidine and Latanoprost groups, even the concentration of Brimonidine and Latanoprost was decreased 3 times (P < 0.05). However, there was no significantly increase in Levobunolol, Brinzolamide, Pilocarpine and control group (P > 0.05), but when drugs' concentration was increased to 10 times, the C value of Pilocarpine decreased significantly (P = 0.04). No significant washout effects in porcine eyes were observed. To conclude, outflow facility efficacy of five drugs in enucleated porcine eyes may provide a reference for clinical medicine. A constant-pressure perfusion technique should be useful to evaluate effect of pharmacologic agents or surgical manipulations on aqueous humor dynamics. PMID:26221257

  16. Outflow facility efficacy of five drugs in enucleated porcine eyes by a method of constant-pressure perfusion

    PubMed Central

    Li, Ning; Shi, Hui-Min; Cong, Lin; Lu, Zhao-Zeng; Ye, Wen; Zhang, Yu-Yan

    2015-01-01

    This study aimed to characterize a technique that assesses the outflow facility (C) efficacy of five kinds of IOP-lowering drugs commonly used clinically in enucleated porcine Eyes. Eyes were perfused at 15 mmHg with GPBS first to establish the baseline outflow facility (C0). Then the anterior chamber contents were exchanged for GPBS with corresponding concentration eye drops (4.9103 nM Brimonidine, 41.1 nM Latanoprost, 3.4103 nM Levobunolol, 3.0103 nM Brinzolamide, 8.3103 nM Pilocarpine) in five groups (n = 6 each), while 6 eyes received GPBS alone as control. The mean stable facility obtained after drug administration (C1) was continuously recorded. The changes between C0 and C1 (?C = C1-C0) were analyzed. Finally, for drugs among the five experiment groups with statistical significance, the concentration was reduced 3 times, otherwise the drugs concentration was increased to 10 times to confirm its effectiveness further using the same methods (n = 6 each). We found that the average baseline outflow facility was 0.240.01 ?lmin-1mmHg-1. C increased significantly in Brimonidine and Latanoprost groups, even the concentration of Brimonidine and Latanoprost was decreased 3 times (P < 0.05). However, there was no significantly increase in Levobunolol, Brinzolamide, Pilocarpine and control group (P > 0.05), but when drugs concentration was increased to 10 times, the C value of Pilocarpine decreased significantly (P = 0.04). No significant washout effects in porcine eyes were observed. To conclude, outflow facility efficacy of five drugs in enucleated porcine eyes may provide a reference for clinical medicine. A constant-pressure perfusion technique should be useful to evaluate effect of pharmacologic agents or surgical manipulations on aqueous humor dynamics. PMID:26221257

  17. Improving Reliability of High Power Quasi-CW Laser Diode Arrays Operating in Long Pulse Mode

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Meadows, Byron L.; Barnes, Bruce W.; Lockard, George E.; Singh, Upendra N.; Kavaya, Michael J.; Baker, Nathaniel R.

    2006-01-01

    Operating high power laser diode arrays in long pulse regime of about 1 msec, which is required for pumping 2-micron thulium and holmium-based lasers, greatly limits their useful lifetime. This paper describes performance of laser diode arrays operating in long pulse mode and presents experimental data of the active region temperature and pulse-to-pulse thermal cycling that are the primary cause of their premature failure and rapid degradation. This paper will then offer a viable approach for determining the optimum design and operational parameters leading to the maximum attainable lifetime.

  18. Percutaneous laser disc decompression.

    PubMed

    Choy, D S

    1995-06-01

    Herniated disc disease has an incidence of 1.7% in the U.S. Heretofore, open operative procedures were the rule for this condition when conservative measures were ineffective. Choy and Ascher introduced this new technique in February 1986 using a Nd:YAG laser introduced into the disc through an optical fiber in a needle. Percutaneous laser disc decompression is based on the principle that in an enclosed hydraulic space, such as an intact disc, a small reduction in volume is associated with a disproportionate fall in pressure. In the disc, this partial vacuum causes the herniated portion to move away from the nerve root back toward the center of the disc. This technique has been taught worldwide and is being performed in most of Europe, Japan, the United States, and Korea. In this special issue devoted to percutaneous laser disc decompression (PLDD), we will set forth the basic science of PLDD, patient selection, use of the holmium:YAG, and the Nd:YAG lasers, operative technique, and results. PMID:10150634

  19. Could titanium oxide coating from a solgel process make stone baskets more resistant to laser radiation at 2.1 ?m?

    PubMed Central

    2012-01-01

    Background Stone baskets could be easily destroyed by Holmium:YAG-laser at an endourologic treatment, with respect to this, we try to improve the resistance by coating them with a titanium oxide layer. The layer was established by a solgel-process. Materials and methods Six new baskets (Equadus, Opi Med, Ettlingen, Germany) were used: 1.8 Ch. with 4 wires (diameter 0.127 mm). Three baskets were coated with a layer of titanium oxide established by a solgel process at the BioCerEntwicklungs GmbH in Bayreuth (~100 nanometres thickness). The lithotripter was a Holmium:YAG laser (Auriga XL, Starmedtec, Starnberg, Germany). 10 uncoated and 10 coated wires were tested with 610 mJ (the minimal clinical setting) and 2 uncoated and 2 coated wires were tested with 110 mJ. The wires were locked in a special holding instrument under water and the laser incident angle was 90. The endpoint was gross visible damage to the wire and loss of electric conduction. Results Only two coated wires resisted two pulses (one in the 610 mJ and one in the 110 mJ setting). All other wires were destroyed after one pulse. Conclusion This was the first attempt at making stone baskets more resistant to a Holmium:YAG laser beam. Titanium oxide deposited by a solgel-process on a titanium-nickel alloy did not result in better resistance to laser injuries PMID:23083224

  20. Laser therapy in intraocular tumors

    NASA Astrophysics Data System (ADS)

    Carstocea, Benone D.; Gafencu, Otilia L.; Apostol, Silvia

    1995-01-01

    Intraocular tumors present special problems of diagnosis and treatment. Diagnostic methods include, in addition to systemic and ophthalmological examinations, ancillary examinations such as transillumination, fluorescein angiography, ultrasonography, radioactive phosphorus uptake test, radiology, computerized tomography, and fine-needle aspiration biopsy with cytological analyses. Previously, enucleation of the involved eye was generally accepted as management of malignant tumors. Improved therapeutic methods such as photocoagulation and better surgical techniques now provide a variety of therapeutical alternatives. This study consists of 21 cases of intraocular tumors that were managed by Argon laser photocoagulation. Four cases were intraocular metastasis and 17 cases were primitive intraocular tumors. Argon laser therapy proved to be totally ineffective for the intraocular metastasis and a very adequate therapy for the primitive tumors. Tumor extirpations (choroidal, cillary body, or iris tumors) using laser lancet proved to be more suitable than classic surgery.

  1. Partial orbital rim resection, mesh skin expansion, and second intention healing combined with enucleation or exenteration for extensive periocular tumors in horses.

    PubMed

    Beard, W L; Wilkie, D A

    2002-03-01

    Ocular and periorbital sarcoids and squamous cell carcinoma are common in equine practice. Extensive involvement of periorbital tissues often necessitates removal of the globe if the function of the eyelids can not be maintained with tumor removal alone. This report describes a modification of the standard enucleation or exenteration technique for cases in which there is insufficient skin to achieve primary closure following complete surgical excision. The caudal portion of the dorsal orbital rim is protuberant; partial excision with an osteotome facilitates skin closure by decreasing the size of the wound. Mesh expansion of skin via multiple rows or parallel stab incisions can also be used as an adjunct to facilitate closure. Four horses underwent enucleation or exenteration using the orbital rim resection and mesh skin expansion techniques for extensive periocular tumors that were unresponsive to prior treatments. Follow-up intervals ranged from 6 to 42 months and no horses had tumor regrowth. PMID:11940244

  2. Review of Current Laser Therapies for the Treatment of Benign Prostatic Hyperplasia

    PubMed Central

    Choi, Benjamin B.

    2013-01-01

    The gold standard for symptomatic relief of bladder outlet obstruction secondary to benign prostatic hyperplasia has traditionally been a transurethral resection of the prostate (TURP). Over the past decade, however, novel laser technologies that rival the conventional TURP have multiplied. As part of the ongoing quest to minimize complications, shorten hospitalization, improve resection time, and most importantly reduce mortality, laser prostatectomy has continually evolved. Today, there are more variations of laser prostatectomy, each with several differing surgical techniques. Although abundant data are available confirming the safety and feasibility of the various laser systems, future randomized-controlled trials will be necessary to verify which technique is superior. In this review, we describe the most common modalities used to perform a laser prostatectomy, mainly, the holmium laser and the potassium-titanyl-phosphate lasers. We also highlight the physical and clinical characteristics of each technology with a review of the most current and highest-quality literature. PMID:23789041

  3. Vision-Related Quality of Life and Appearance Concerns Are Associated with Anxiety and Depression after Eye Enucleation: A Cross-Sectional Study

    PubMed Central

    Ye, Juan; Lou, Lixia; Jin, Kai; Xu, Yufeng; Ye, Xin; Moss, Timothy; McBain, Hayley

    2015-01-01

    Aims To investigate the association of demographic, clinical and psychosocial variables with levels of anxiety and depression in participants wearing an ocular prosthesis after eye enucleation. Methods This cross-sectional study included 195 participants with an enucleated eye who were attending an ophthalmic clinic for prosthetic rehabilitation between July and November 2014. Demographic and clinical data, and self-reported feelings of shame, sadness and anger were collected. Participants also completed the National Eye Institute Visual Function Questionnaire, the Facial Appearance subscale of the Negative Physical Self Scale, and the Hospital Anxiety and Depression Scale. Regression models were used to identify the factors associated with anxiety and depression. Results The proportion of participants with clinical anxiety was 11.8% and clinical depression 13.8%. More anxiety and depression were associated with poorer vision-related quality of life and greater levels of appearance concerns. Younger age was related to greater levels of anxiety. Less educated participants and those feeling more angry about losing an eye are more prone to experience depression. Clinical variables were unrelated to anxiety or depression. Conclusions Anxiety and depression are more prevalent in eye-enucleated patients than the general population, which brings up the issues of psychiatric support in these patients. Psychosocial rather than clinical characteristics were associated with anxiety and depression. Longitudinal studies need to be conducted to further elucidate the direction of causality before interventions to improve mood states are developed. PMID:26317860

  4. Maturation and enucleation of primitive erythroblasts during mouse embryogenesis is accompanied by changes in cell-surface antigen expression

    PubMed Central

    Fraser, Stuart T.; Isern, Joan; Baron, Margaret H.

    2007-01-01

    Primitive erythroblasts (EryPs) are the first hematopoietic cell type to form during mammalian embryogenesis and emerge within the blood islands of the yolk sac. Large, nucleated EryPs begin to circulate around midgestation, when connections between yolk sac and embryonic vasculature mature. Two to 3 days later, small cells of the definitive erythroid lineage (EryD) begin to differentiate within the fetal liver and rapidly outnumber EryPs in the circulation. The development and maturation of EryPs remain poorly defined. Our analysis of embryonic blood at different stages reveals a stepwise developmental progression within the EryP lineage from E9.5 to E12.5. Thereafter, EryDs are also present in the bloodstream, and the 2 lineages are not easily distinguished. We have generated a transgenic mouse line in which the human ?-globin gene promoter drives expression of green fluorescent protein exclusively within the EryP lineage. Here, we have used this line to characterize changes in cell morphology and surface-marker expression as EryPs mature and to track EryP numbers and enucleation throughout gestation. This study identifies previously unrecognized synchronous developmental stages leading to the maturation of EryPs in the mouse embryo. Unexpectedly, we find that EryPs are a stable cell population that persists through the end of gestation. PMID:16940424

  5. Production of cloned sei whale (Balaenoptera borealis) embryos by interspecies somatic cell nuclear transfer using enucleated pig oocytes

    PubMed Central

    Lee, Eunsong; Bhuiyan, Mohammad Musharraf Uddin; Watanabe, Hiroyuki; Matsuoka, Kohji; Fujise, Yoshihiro; Ishikawa, Hajime

    2009-01-01

    In this study, we examined the feasibility of using subzonal cell injection with electrofusion for interspecies somatic cell nuclear transfer (iSCNT) to produce sei whale embryos and to improve their developmental capacity by investigating the effect of osmolarity and macromolecules in the culture medium on the in vitro developmental capacity. Hybrid embryos produced by the electrofusion of fetal whale fibroblasts with enucleated porcine oocytes were cultured in modified porcine zygote medium-3 to examine the effects of osmolarity and fetal serum on their in vitro developmental capacity. More than 66% of the whale somatic cells successfully fused with the porcine oocytes following electrofusion. A portion (60~81%) of the iSCNT whale embryos developed to the two- to four-cell stages, but no embryos were able to reach the blastocyst stage. This developmental arrest was not overcome by increasing the osmolarity of the medium to 360 mOsm or by the addition of fetal bovine or fetal whale serum. Our results demonstrate that sei whale-porcine hybrid embryos may be produced by SCNT using subzonal injection and electrofusion. The pig oocytes partly supported the remodeling and reprogramming of the sei whale somatic cell nuclei, but they were unable to support the development of iSCNT whale embryos to the blastocyst stage. PMID:19934592

  6. Inhibition of secondary cartilage of the intermaxillary suture in Sprague-Dawley rats following the enucleation of maxillary molars

    SciTech Connect

    Forbes, D.P.; Al-Bareedi, S.

    1986-01-01

    A single craniofacial suture can undergo several morphologic transformations during its development. From 3 to 7 weeks of age, the intermaxillary suture of the rat is synchondrotic in character, featuring secondary cartilage; at later times, this suture is syndesmotic in character, featuring a fibrous tissue interface. Since intermittent mechanical stimulation has been reported to initiate secondary cartilage formation, a study was done to determine if the functioning dentition were responsible for secondary cartilage formation in the intermaxillary suture of the rat. Twenty-two female Sprague-Dawley rats were used. At 3 weeks of age, prior to eruption, the maxillary molars were enucleated from nine animals. Body weights were recorded weekly. Animals were sacrificed weekly from 4 to 7 weeks of age. One hour prior to sacrifice, each rat was injected with (/sup 35/S)sulfate at a dosage of 2 microCi/g body weight. The tissues were evaluated by light microscopy and autoradiography. In the experimental group, the midpalatal suture did not undergo the normal synchondrotic transformation. Instead, this suture remained fibrous with negligible metachromatic staining. In the control animals, the peak period of (/sup 35/S)sulfate incorporation was 4 weeks of age and was five times greater than in the experimental group. The primary stimulus for the initiation of secondary cartilage formation in the midpalatal suture of the rat was molar function. Also, functioning molars were found to be important in the maintenance of the palatal bone.

  7. Effect of Intraocular Lens Diameter Implanted in Enucleated Porcine Eye on Intraocular Pressure Induced by Scleral Depression

    PubMed Central

    Terauchi, Gaku; Matsumoto, Celso Soiti; Matsumoto, Harue

    2014-01-01

    The effect of the diameter of an intraocular lens (IOL) implanted in enucleated porcine eyes on the intraocular pressure induced by scleral depression was investigated. Two IOLs of 6 mm and 7 mm optic diameter were implanted. The intraocular pressure (IOP) was monitored during scleral depression by a transducer placed in the midvitreous through a sclerotomy at 6 o'clock. The area under the curve (AUC) of the IOP changes from the beginning of the indentation to the point when the peripheral retinal surface was observed through the IOL optics was measured. The AUC was significantly larger in eyes with a 6 mm IOL than in eyes with a 7 mm IOL (p < 0.05). The IOP elevation at the endpoint was higher in eyes with the 6 mm IOL than in eyes with the 7 mm IOL. We conclude that the AUC may represent the degree of stress induced by scleral depression. The higher AUC value with the X-60 may be because of the longer distance from the peripheral retina to the edge of the IOL optics. PMID:24795886

  8. Studies on the sorption of praseodymium (III), holmium (III) and cobalt (II) from nitrate medium using TVEX-PHOR resin.

    PubMed

    El-Dessouky, S I; El-Sofany, E A; Daoud, J A

    2007-05-01

    The use of TVEX-PHOR resin for the sorption of praseodymium (III), holmium (III) and cobalt (II) from nitrate medium was carried out using batch and column techniques. Various parameters affecting the uptake of these metal ions such as v/m ratio, pH and the metal ion concentration were separately studied. Effect of temperature on the equilibrium distribution values has been studied to evaluate the changes in standard thermodynamic quantities. Experimental results of the investigated metal ions were found to fit to Freundlich isotherm model over the entire studied concentration range. Selectivity sequence of the resin for these metals is Ho>Pr>Co. The recovery of the investigated metals from the loaded resin is preformed with 0.1M sulphuric acid. PMID:17034940

  9. Study of the line intensity in the optical and magnetooptical spectra in holmium-containing paramagnetic garnets

    NASA Astrophysics Data System (ADS)

    Valiev, Uygun V.; Gruber, John B.; Burdick, Gary W.; Pelenovich, Vasiliy O.; Fu, Dejun; Dzhuraev, Davron R.

    2016-01-01

    Studies of line intensity in the optical and magneto-optical spectra in the holmium-containing paramagnetic garnet Ho3+:YAG were carried out within the visible spectrum at T = 85 K. Detailed investigation of the magnetic circularly polarized luminescence spectra at 85 and 300 K on 5S2 ? 5I8 emission transition in Ho3+:YAG was carried out. A quasi-doublet state in the energy spectrum of the Ho3+ ions was observed, characterized by a significant magneto-optical activity, which is caused by a large Zeeman splitting of the quasi-doublet. The measurement of the magnetic circular polarized luminescence spectrum carried out within one of the emission lines of the luminescence band 5S2 ? 5I8 in Ho3+:YAG at 85 K shows significant magneto-optical effects of the intensity change of the emitted light, compared to that measured for the other emission lines in the same luminescent band.

  10. Neutron diffraction and electrical transport studies on the incommensurate magnetic phase transition in holmium at high pressures

    SciTech Connect

    Thomas, Sarah; Uhoya, Walter; Tsoi, Georgiy; Wenger, Lowell E; Vohra, Yogesh; Chesnut, Gary Neal; Weir, S. T.; Tulk, Christopher A; Moreira Dos Santos, Antonio F

    2012-01-01

    Neutron diffraction and electrical transport measurements have been made on the heavy rare earth metal holmium at high pressures and low temperatures in order to elucidate its transition from a paramagnetic (PM) to a helical antiferromagnetic (AFM) ordered phase as a function of pressure. The electrical resistance measurements show a change in the resistance slope as the temperature is lowered through the antiferromagnetic Neel temperature. The temperature of this antiferromagnetic transition decreases from approximately 122 K at ambient pressure at a rate of -4.9 K GPa(-1) up to a pressure of 9 GPa, whereupon the PM-to-AFM transition vanishes for higher pressures. Neutron diffraction measurements as a function of pressure at 89 and 110 K confirm the incommensurate nature of the phase transition associated with the antiferromagnetic ordering of the magnetic moments in a helical arrangement and that the ordering occurs at similar pressures as determined from the resistance results for these temperatures.

  11. Temporal model of an optically pumped co-doped solid state laser

    NASA Technical Reports Server (NTRS)

    Wangler, T. G.; Swetits, J. J.; Buoncristiani, A. M.

    1993-01-01

    Currently, research is being conducted on the optical properties of materials associated with the development of solid state lasers in the two micron region. In support of this effort, a mathematical model describing the energy transfer in a holmium laser sensitized with thulium is developed. In this paper, we establish some qualitative properties of the solution of the model, such as non-negativity, boundedness, and integrability. A local stability analysis is then performed from which conditions for asymptotic stability are attained. Finally, we report on our numerical analysis of the system and how it compares with experimental results.

  12. Percutaneous laser disc decompression (PLDD) update: focus on device and procedure advances.

    PubMed

    Choy, D S

    1993-08-01

    This discussion is an update on the U.S. advances in percutaneous laser disc decompression (PLDD). This report summarizes the knowledge that has been gained about the procedure, advances in technique, and increased information about the three lasers currently in use for PLDD: KTP, Nd:YAG, and holmium. A new surgical approach to the L5-S1 disc is described. It is concluded that PLDD has become an established procedure that will be more widely used because it is simple, effective, and reasonably safe. PMID:10146384

  13. Intraocular applications of the Ho:YAG laser

    NASA Astrophysics Data System (ADS)

    Boiko, Ernest V.; Danilichev, Vladimir F.; Shishkin, Michael M.; Berezin, Yuri D.; Smirnov, Nicolay N.; Lazo, Victor V.

    1995-05-01

    Despite advances in mechanical vitrectomy, cutting dense membranes and fibrovascular strands remains a technical challenge. Widespread acceptance of carbon dioxide and Er:YAG lasers, which cutting potential and coagulative properties were highly evaluated by experimentators, now is limited because of insufficiently convenient fiberoptic delivery systems. We investigated the use of Ho:YAG laser emitting at 2.09 micrometers to cut experimental vitreous membranes in rabbits. Radiation at 2.09 micrometers is enough strongly absorbed by water (absorption length 385 micrometers ) and can be transmitted through silica fiberoptic delivery system practically without attenuation. At first, the dependence of retinal damage thresholds and wet field thermal effects from distance `endolaser tip--target', energy, pulse rates and number of pulses were determined. With the help of multiple regression analysis models of these processes were constructed. Coagulative and cutting properties of holmium endolaser were assessed on the created transvitreal membranes. Optimal parameters for cutting and coagulation were determined. Based on own experimental studies we also used Ho:YAG endolaser in vitrectomies for diabetes and traumas. The advantages and disadvantages of the 2.09 micrometers infrared wavelength of holmium laser photoincision and photocoagulation in vitreous are discussed.

  14. AB100. Modified techniques and clinical results of high power green laser in the treatment of benign prostatic hyperplasia

    PubMed Central

    Ge, Yong-Chao; Feng, Jin-Shun; Duan, Kun; Chen, Shi-Lin; Zhang, Li; Qin, Fen; Chang, Bao-Dong; Yuan, Zhi-Hao

    2015-01-01

    Objective To investigate the safety and clinical efficacy of high power green laser in the treatment of benign prostatic hyperplasia (BPH). Methods Thirty cases of BPH patients accepted the lateral jet type high power green laser enucleation of prostate leaf drawing block chopped. The time of operation, bleeding volume, hemoglobin (Hb) before and after surgery, indwelling catheter time, perioperative complications, changes of IPSS, Qmax and PVR 1 month after operation were assessed. Results All the operations were successfully. The average operative time was (59+16.1) min, amount of bleeding during operation was (36.3+18.5) mL, catheter time was (35.1+20.6) h. IPSS, Qmax and PVR compared with preoperative were statistically better with statistic significant (P<0.01). Conclusions High power green laser enucleation of prostate leaf drawing block chopped technology is safe and reliable, the effect is satisfied.

  15. The Evolution of Laser Therapy in the Treatment of Benign Prostatic Hyperplasia

    PubMed Central

    Issa, Muta M

    2005-01-01

    The 2 basic principles of laser therapy for benign prostatic hyperplasia (BPH), based on the final tissue effect, are laser vaporization and laser coagulation. In laser vaporization techniques, higher-density laser thermal energy is used; effects range from complete tissue vaporization to incision, resection, or enucleation of the obstructing prostatic tissue. Interstitial laser coagulation (ILC) requires lower therapeutic temperatures. The urethral preservation and lack of tissue evaporation/resection with ILC make this treatment different from conventional transurethral free-beam laser prostatectomy. The Indigo Optima Laser treatment system is the most widely used ILC system. Unlike other BPH laser therapies, Indigo ILC can be satisfactorily performed using pure local anesthesia in an office or outpatient setting. Favorable treatment outcomes are seen in a large percentage of patients, with minimal adverse events. Such favorable results depend on proper surgical technique and operator experience. PMID:16985899

  16. Laser assisted vascular anastomosis (LAVA): a promising nonsuture technique for surgery

    NASA Astrophysics Data System (ADS)

    Chen, Chen; Peng, Fei; Xu, Dahai; Cheng, Qinghua

    2009-08-01

    The first successful experiment of laser vascular welding was reported in 1979. Laser assisted vascular anastomosis (LAVA) is looked as a particularly promising non-suture method in future. We performed a Medline literature search on laser vessel welding combined with cross-referencing. According to the former experimental animal studies, CO2-, argon-, diode-, KTP-, Holmium:YAG-, and Nd:YAG-lasers have been used for LAVA. Almost all lasers have been used in combination with stay suture and/or solders in order to improve the strength on anastomosis site. Advantages of LAVA are minimal vessel damage, faster operation and the potential for minimally invasive application. However, the clinical application of LAVA is still seldom employed because of aneurysm formation. In conclusion of the literature study, the diode laser is the most popular, but long-term evaluation is required.

  17. Laser irradiation reduces vasoreactivity of coronary artery: implication for prevention of coronary spasm

    NASA Astrophysics Data System (ADS)

    Tomaru, Takanobu; Nakamura, Fumitaka; Miwa, Atsuko; Fujimori, Yoshiharu; Uchida, Yasumi

    1993-06-01

    Vasoreactivity of laser-treated coronary artery was investigated in canine left circumflex coronary artery (LCx). Excimer laser (XeCl 308 nm, 50 mJ/mm2), holmium YAG laser (2.1 micrometers , 150 mJ/pulse), or argon laser (488 nm, 3 W), were used through a single optical fiber. Two 3-mm long segments were obtained from the treated segments and controls in Krebs-bicarbonate buffer. Contraction of LCx was induced with KCl at 30 mM or 3,4 DAP and expressed as developed tension (gram; g). Eighteen dogs were used. Reduction of vasocontactility was observed in excimer treated vessels (0.17 +/- 0.24 g with KCl and 0.34 +/- 0.55 g with 3,4 DAP vs 2.13 +/- 0.85 with KCl and 3.1 +/- 1.9 with 3,4 DAP in control, P < 0.001 respectively), holmium YAG treated vessels (0.43 +/- 0.48 g with KCl and 0.46 +/- 0.24 with 3,4 DAP vs 2.42 +/- 0.49 g with KCl and 3.2 +/- 0.46 with 3,4 DAP in control, P < 0.001 respectively) and argon treated vessels (0.48 +/- 0.79 g vs 4.4 +/- 0.88 in control, P < 0.001). Either pulsed or argon laser irradiation results in loss of vasoreactivity to either constrictive or relaxation agent.

  18. Alternative infrared lasers for endoscopic surgery

    NASA Astrophysics Data System (ADS)

    Bass, Lawrence S.; Font, David E.; Oz, Mehmet C.; Trokel, Stephen L.; Treat, Michael R.

    1990-06-01

    There are substantial technical problems attendant to the removal of sessile polyps from the lumen of thin walled gastrointestinal organs such as the colon. A laser system which is capable of precise and circumscribed mucosal tissue vaporization would be useful for this task. Because of technical shortcomings of existing medical laser systems, we investigated the possibilities of mid-infrared lasers which could take advantage of large water absorption peaks in the 2 micron region to produce precise vaporization while retaining fiberoptic transmissibility. In addition to a high absorption wavelength, pulsed energy delivery contributes to precise vaporizing capabilities. The laser system that best fits our criteria is the 2.15 micron thulium-holmium- chromium:YAG which produces 200 microsecond pulses of energies up to 1 joule at firing rates up to 6 Hz. The laser output is transmitted efficiently via low hydroxyl quartz fibers. Ablative efficiency, defined here as the slope of the vaporization depth versus energy, reveals that the THC:YAG produces approximately 3 times greater depth of vaporization per joule than the cw Nd:YAG. On average, the Nd:YAG produced 1.5 times the amount of thermal damage as the THC:YAG for a given depth of vaporization. The THC:YAG laser should have an important clinical role since its use could reduce the risk of perforation in endoscopic laser procedures such as the removal of sessile polyps.

  19. Laser therapy in ocular tumors

    NASA Astrophysics Data System (ADS)

    Carstocea, Benone D.; Gafencu, Otilia L.; Apostol, Silvia; Ionita, Marcel A.; Moroseanu, A.; Dascalu, Traian; Lupei, Voicu; Ionita-Manzatu, V.

    1998-07-01

    The medical laser equipments made at NILPRP have been exploited intensively for more than 10 years at CMH. The availability and reliability of the first like-on equipment have increased, following improvements in optical delivery system and cooling circuit. This paper shows the impact of technical advances on the development of ophthalmologic laser therapy. Intraocular tumors pose special problems of diagnosis and treatment. Diagnostic methods include addition to systemic and ophthalmologic examinations, ancillary examinations, such as transillumination, fluorescence angiography, ultrasonography, radioactive phosphorus uptake tests, radiology, computerized tomography and fine-needle aspiration biopsy with cytological analyses. The enucleation of the involved eye used to be a generally accepted management of malignant tumors. Improved therapeutic methods such as photocoagulation and better surgical techniques now provide a variety of therapeutic alternatives. This study covers 31 cases of intraocular tumors that were managed either by Argon Laser photocoagulation and/or by Nd:YAG laser surgical treatment. Four cases were intraocular metastasse and 17 cases were primitive intraocular tumors. Argon laser therapy proved to be totally ineffective for intraocular metastasse but very adequate therapy for primitive tumors. Tumor extirpations (choroidal, cillary body or iris tumors) using Nd:YAG laser lancet proved to be more suitable than classic surgery.

  20. Laser radar technology for airborne theater missile defense

    NASA Astrophysics Data System (ADS)

    Cassady, Philip E.; Murata, Ronald N.; McKenna, Sean; Yoder, M. John; Keicher, William E.; Blumenau, Philip M.; Leslie, Daniel H.; Youmans, Douglas G.

    1995-06-01

    Range information from a laser radar can be used to rapidly converge target track files for theater missile defense from an airborne sensor platform. This paper examines the application of laser radar technology to this mission. Eyesafe lasers including carbon dioxide, holmium/thulium, and YAG shifted by optical parametric oscillators or Raman cells are considered. Performance analyses include the effects of wavelength dependent target cross sections, atmospheric attenuation and background radiation, and either direct or heterodyne detection processes on the received signal to noise ratio. Signal processing analyses include the effects of noise statistics, target fading for either direct or heterodyne detection, and the optical wavelength dependent effects of atmospheric turbulence on system false alarm and detection probabilities.

  1. Preliminary experiences on diode laser welding in corneal transplantation

    NASA Astrophysics Data System (ADS)

    Menabuoni, Luca; Dragoni, B.; Pini, Roberto

    1996-12-01

    An experimental study on the applicability of diode laser welding to assist corneal transplantation is presented. Fusion of corneal tissue was accomplished by low power laser irradiation at 810 nm in association with Indocyanine Green (ICG) as the photoenhancing chromophore. Twenty freshly enucleated eyes obtained from young goats were used. In the preliminary experimental phase we examined the effects of laser welding on cuts produced by the scalpel on the cornea. Then we tried to design and test a novel diode laser- assisted corneal transplantation procedure. Our experimental results indicate that this procedure is affordable, but some technical aspects, as the application of ICG to the cut as well as the control of laser action are very critical issues.

  2. Endoscopic Enucleation versus Open Prostatectomy for Treating Large Benign Prostatic Hyperplasia: A Meta-Analysis of Randomized Controlled Trials

    PubMed Central

    Hou, Qi; Wang, Dejuan; Huang, Wentao; Hu, Cheng; Li, Ke; Gao, Xin

    2015-01-01

    Objectives To evaluate the overall efficacy and safety of endoscopic enucleation of the prostate (EP) vs open prostatectomy (OP) for large benign prostatic hyperplasia (BPH). Methods We conducted an electronic search of PubMed/Medline, EMBASE, The Cochrane Library, and Web of Science to detect all relevant randomized controlled trials (RCTs) comparing EP with OP. A meta-analysis was performed using Review Manager 5.3. Results Seven RCTs (735 patients) were included. At the 3-, 6- and 12-month follow-up, there were no significant differences in the International Prostate Symptom Score (IPSS), maximum flow rate (Qmax), quality of life (QoL) score and post-void residual urine volume (PVR) between EP and OP. The International Index of Erectile Function (IIEF-5) was higher with EP (weighted mean difference [WMD]: 1.00, 95% confidence interval [CI]: 0.21 to 1.78, p=0.01) at the 12-month follow-up. The catheterization time (WMD: 3.80 d, 95%CI: -5.11 to -2.48, P<0.00001) and hospital stay (WMD: 4.93 d, 95%CI: -5.96 to -3.89, P<0.00001) were shorter with EP. The duration of operation was longer for EP compared with OP (WMD: 16.21 min, 95%CI: 3.72 to 28.70, P=0.01). The resected tissue weight (WMD: -9.63 g, 95%CI: -14.46 to -4.81, P<0.0001) and decrease in hemoglobin (WMD: -1.14 g/dL, 95%CI: -1.81 to -0.47, P=0.0008) were less with EP. EP was associated with fewer blood transfusions (risk ratio: 0.22, 95%CI: 0.10 to 0.47, P=0.0001). There were no significant differences between EP and OP when comparing other complications. Conclusions Although only a limited number of RCTs with relatively limited follow-up are available, EP is shown to have a similar postoperative profile and comparable safety to OP. By contrast, EP may have a more desirable perioperative profile. EP appears to be an effective and safe minimally invasive option for treating large prostates that requires only brief convalescence. PMID:25826453

  3. The determination of energy transfer rates in the Ho:Tm:Cr:YAG laser material

    NASA Technical Reports Server (NTRS)

    Koker, Edmond B.

    1988-01-01

    Energy transfer processes occurring between atomic, ionic, or molecular systems are very widespread in nature. The applications of such processes range form radiation physics and chemistry to biology. In the field of laser physics, energy transfer processes have been used to extend the lasing range, increase the output efficiency, and influence the spectral and temporal characteristics of the output pulses of energy transfer dye lasers or solid-state laser materials. Thus in the development of solid state lasers, it is important to investigate the basic energy transfer (ET) mechanisms and processes in order to gain detailed knowledge so that successful technical utilization can be achieved. The aim of the present research is to measure the ET rate from a given manifold associated with the chromium sensitizer atom to a given manifold in the holmium activator atom via the thulium transfer atom, in the Ho:Cr:YAG laser material.

  4. Laser reshaping of nasal septum cartilage: clinical results for 40 patients

    NASA Astrophysics Data System (ADS)

    Sobol, Emil N.; Sviridov, Alexander P.; Bagratashvili, Victor N.; Omelchenko, Alexander I.; Ovchinnikov, Yuriy M.; Shekhter, Anatoliy B.; Svistushkin, Valeriy M.; Shinaev, Alexander N.

    2000-05-01

    Clinical results on sparing laser reshaping of nasal septum cartilage are reported for the first time. Forty patients have been treated with holmium laser to correct a deformed cartilage. The laser reshaping is a bloodless, painless procedure which takes few minutes to straighten nasal septum. The stability of the new shape and possible side effects have been examined during twelve months. The headache and other negative symptoms have disappeared, as a result of laser treatment for the most of patients. Rhinoscopic examination show an excellent long-term reshaping effects for nasal septum of 23 patients, and, also, good results for other 12 patients. For 5 patients only a little effect takes place. Our rhinomanometric examinations demonstrate a pronounced improvement of the breathing for 35 patients. No visible undesirable side effects were observed for all patients underwent to laser reshaping procedure.

  5. Comparison of in situ Corneoscleral Disc Excision versus Whole Globe Enucleation in Cornea Donors Regarding Microbial Contamination in Organ Culture Medium a Prospective Monocentric Study over 9 Years

    PubMed Central

    Schroeter, Jan; Wilkemeyer, Ina; Herrlinger, Frithjof; Pruss, Axel

    2012-01-01

    Summary Background Corneas needed for keratoplasty can be harvested using two techniques: whole globe enucleation and in situ excision of the corneoscleral disc. This study evaluates the rate of microbial contamination of the donor cornea organ culture medium according to the method of retrieval. Methods All donor corneas of our cornea bank received between January 1, 2001 and December 31, 2009 put into organ culture and microbio-logically tested were prospectively analyzed for microbial contamination of the organ culture medium. Results 2,805 donor corneas could be included in this study in total. 975 of them were retrieved by whole globe enucleation (group 1) and 1,830 by in situ corneoscleral disc excision (group 2). 15 corneas of group 1 (1.5%) and 46 corneas of group 2 (2.5%) showed a contamination of the organ culture medium. The difference was shown not to be statistically significant (p = 0.082). Conclusion The rate of microbial contamination in organ-cultured donor corneas does not seem to be dependent on the method of their retrieval. PMID:23801381

  6. Application of erbium: YAG laser in ocular ablation.

    PubMed

    Tsubota, K

    1990-01-01

    Recent developments in lasers have provided us the possibility of laser ocular surgery. The xenon, argon, neodymium:YAG and dye lasers have been successfully used in out-patient clinics. The excimer laser has been attracting researchers' interest in the new application of laser to cornea and lens. The erbium:YAG laser emits a 2.94-microns beam that can ablate the transparent ocular tissues such as lenses and corneas. The author has applied this laser to the cornea, lens, vitreous and other ocular tissues. The erbium:YAG laser beam was directed through a 1.5-meter-long, 200-microns-diameter fiberoptic guide. The radiant energy measured about 50 mJ at the end of the probe. The laser was emitted as a 400-microsecond pulse. Freshly enucleated rabbit eyes were used in this study. Laser burns were applied to the tissue surface at various energy settings. At minimal power, the tissues were coagulated by the erbium:YAG laser application. At a power of more than 636-954 mJ/mm2, tissue began to evaporate; the tissue loss was observed under a surgical light microscope. Corneal photoablation, lens ablation, iridotomy, trabeculotomy, cutting of the vitreous and retinal ablation were easily performed. Like the excimer laser, the erbium:YAG laser is a potential tool for ocular surgery. PMID:2345625

  7. Development of mid-infrared solid state lasers for spaceborne lidar

    NASA Technical Reports Server (NTRS)

    Whitney, Donald A.; Kim, Kyong H.

    1989-01-01

    Laser performance of Ho(3+):Tm(3+):Cr(3+):YAG crystals was investigated under both Cr:GSAG laser and flashlamp pumping. A flashlamp pumped Cr:GSAG laser was built to simulate high power quasi-CW laser diode pumping of a 2.1 micrometer holmium laser. The 2.1 micrometer output laser energy exceeded more than 14 mJ, the highest value reported to date under laser pumping near 785 nm. This was obtained in a pulse length of nearly 650 microsec from a 3 x 3 mm Ho:Tm:Cr:YAG rod by using the flashlamp-pumped Cr:CSAG laser as a pumping source at the diode laser wavelength, 785 micrometers. In addition, Ho:Tm:Cr:YAG crystals with various Tm(3+) concentrations were evaluated for flashlamp-pumped normal mode and Q-switched 2.1 micrometer laser operations under a wide variety of experimental conditions in order to understand internal dynamic processes among the ions and to determine an optimum lasing condition. An increase of the laser slope efficiency was observed with the increase of the Tm(3+) concentration from 2.5 to 4.5 atomic percent. The thermal dependence of the laser performance was also investigated. Q-switched laser output energies corresponding to nearly 100 percent of the normal-mode laser energies were obtained in a strong single spike of 200 ns pulse length by optimizing the opening time of a lithium niobate Q-switch.

  8. Laser welding of corneal tissue: preliminary experiences using 810-nm and 1950-nm diode lasers

    NASA Astrophysics Data System (ADS)

    Trabucchi, Giuseppe; Gobbi, Pier Giorgio; Brancato, Rosario; Carones, Francesco; Resti, Antonio G.; Jansen, Anita; Pini, Roberto

    1996-01-01

    Laser welding of corneal incisions was performed using two different diode laser wavelengths. Tissue fusion was attempted both with direct absorption of radiation at 1950 nm radiation and with ICG dye-enhanced technique at 810 nm. Thirty deep (not full thickness) corneal incisions of 15 fresh-enucleated porcine eyes were treated. Semiconductor diode lasers emitting in continuous wave at 1950 nm and at 810 nm were used. Both were coupled to an optic fiber handpiece. Wound samples were explanted on day 0 after treatment for histological evaluation. The group of corneal wounds treated with the ICG-enhanced technique revealed tissue welding in 70% of treated wounds. Using 1950 nm tissue fusion was observed in 50% of treated wounds. Macroscopic evaluation revealed a pronounced thermal damage of the epithelium in the samples treated with 1950 nm radiation. Wound closures obtained using 1950 nm were characterized by superficial welding of corneal layers. (Abstract truncated.)

  9. Laser photoacoustic spectroscopy for trace level detection of actinides in groundwater

    SciTech Connect

    Doxtader, M.M.; Maroni, V.A.; Beitz, J.V.; Heaven, M.

    1986-01-01

    In this paper we examine the utility of the laser photoacoustic spectroscopy (LPAS) technique for elucidating the chemical behavior of species present in the near-field environment of the Basalt Waste Isolation Project (BWIP) repository. We briefly review the existing basis for interpreting actinide spectra at low concentrations, and describe our initial experiments. These experiments include development and demonstration of the methodology under optimum conditions, e.g., stable, well-characterized solutions of holmium; and application of the technique to conditions relevant to the repository, including studies performed with uranium in synthetic groundwater and at elevated temperatures.

  10. Semiempirical Quantum Chemistry Model for the Lanthanides: RM1 (Recife Model 1) Parameters for Dysprosium, Holmium and Erbium

    PubMed Central

    Filho, Manoel A. M.; Dutra, Jos Diogo L.; Rocha, Gerd B.; Simas, Alfredo M.; Freire, Ricardo O.

    2014-01-01

    Complexes of dysprosium, holmium, and erbium find many applications as single-molecule magnets, as contrast agents for magnetic resonance imaging, as anti-cancer agents, in optical telecommunications, etc. Therefore, the development of tools that can be proven helpful to complex design is presently an active area of research. In this article, we advance a major improvement to the semiempirical description of lanthanide complexes: the Recife Model 1, RM1, model for the lanthanides, parameterized for the trications of Dy, Ho, and Er. By representing such lanthanide in the RM1 calculation as a three-electron atom with a set of 5 d, 6 s, and 6 p semiempirical orbitals, the accuracy of the previous sparkle models, mainly concentrated on lanthanide-oxygen and lanthanide-nitrogen distances, is extended to other types of bonds in the trication complexes coordination polyhedra, such as lanthanide-carbon, lanthanide-chlorine, etc. This is even more important as, for example, lanthanide-carbon atom distances in the coordination polyhedra of the complexes comprise about 30% of all distances for all complexes of Dy, Ho, and Er considered. Our results indicate that the average unsigned mean error for the lanthanide-carbon distances dropped from an average of 0.30 , for the sparkle models, to 0.04 for the RM1 model for the lanthanides; for a total of 509 such distances for the set of all Dy, Ho, and Er complexes considered. A similar behavior took place for the other distances as well, such as lanthanide-chlorine, lanthanide-bromine, lanthanide, phosphorus and lanthanide-sulfur. Thus, the RM1 model for the lanthanides, being advanced in this article, broadens the range of application of semiempirical models to lanthanide complexes by including comprehensively many other types of bonds not adequately described by the previous models. PMID:24497945

  11. Expanding rare-earth oxidation state chemistry to molecular complexes of holmium(II) and erbium(II).

    PubMed

    MacDonald, Matthew R; Bates, Jefferson E; Fieser, Megan E; Ziller, Joseph W; Furche, Filipp; Evans, William J

    2012-05-23

    The first molecular complexes of holmium and erbium in the +2 oxidation state have been generated by reducing Cp'(3)Ln [Cp' = C(5)H(4)SiMe(3); Ln = Ho (1), Er (2)] with KC(8) in the presence of 18-crown-6 in Et(2)O at -35 C under argon. Purification and crystallization below -35 C gave isomorphous [(18-crown-6)K][Cp'(3)Ln] [Ln = Ho (3), Er (4)]. The three Cp' ring centroids define a trigonal-planar geometry around each metal ion that is not perturbed by the location of the potassium crown cation near one ring with K-C(Cp') distances of 3.053(8)-3.078(2) . The metrical parameters of the three rings are indistinguishable within the error limits. In contrast to Ln(2+) complexes of Eu, Yb, Sm, Tm, Dy, and Nd, 3 and 4 have average Ln-(Cp' ring centroid) distances only 0.029 and 0.021 longer than those of the Ln(3+) analogues 1 and 2, a result similar to that previously reported for the 4d(1) Y(2+) complex [(18-crown-6)K][Cp'(3)Y] (5) and the 5d(1) La(2+) complex [K(18-crown-6)(Et(2)O)][Cp?(3)La] [Cp? = 1,3-(Me(3)Si)(2)C(5)H(3)]. Surprisingly, the UV-vis spectra of 3 and 4 are also very similar to that of 5 with two broad absorptions in the visible region, suggesting that 3-5 have similar electron configurations. Density functional theory calculations on the Ho(2+) and Er(2+) species yielded HOMOs that are largely 5d(z(2)) in character and supportive of 4f(10)5d(1) and 4f(11)5d(1) ground-state configurations, respectively. PMID:22583320

  12. Effect of nonablative laser energy on joint capsular properties: an in-vitro study using a rabbit model

    NASA Astrophysics Data System (ADS)

    Hayashi, Kei; Markel, Mark D.; Thabit, George, III; Bogdanske, John J.; Thielke, Robert J.; Cooley, A. J.; Vailas, Arthur C.; Mascio, Laura N.; Vanderby, Ray, Jr.

    1996-05-01

    Recent scientific studies evaluating laser energy for tissue welding and thermokeratoplasty have demonstrated that the application of laser energy at non-ablative levels can alter collagen's structural and biochemical properties. A recent pilot study has demonstrated that the non-ablative application of holmium: yttrium-aluminum-garnet (Ho:YAG) laser energy to the joint capsule of patients with glenohumeral instability shrank the joint capsule, stabilizing the shoulder in the majority of the patients treated. Based on the collective findings of these studies, we hypothesized that thermal modification of dense collagenous tissues such as joint capsule, ligament, and tendon can be achieved by applying non-ablative laser energy. The purpose of this study was to evaluate the effect of laser energy at non-ablative levels on joint capsular mechanical, biochemical, histological, and ultrastructural properties in an in vitro rabbit model.

  13. YAG lasers in restorative dentistry: a histological investigation

    NASA Astrophysics Data System (ADS)

    Koort, Hans J.; Frentzen, Matthias

    1992-06-01

    An important indicator to prove the effectiveness of laser radiation and to control the side effects are histological studies of dental hard tissues. In our study, different pulsed, rare earth doped YAG-laser systems in the range from 1 micrometers to 3 micrometers were investigated. An improved plastic embedding technique based on a penetrating uv-activated PMMA-medium was developed to cut undecalcified sections of 15 micrometers thickness. The Nd:YAG laser showed wide zones of necrosis but little carbonization. The radiation of Holmium and Thullium-doped YAG lasers causes strong but well-defined zones of carbonization comparable to those of pulsed (ms) CO2 lasers. The Erbium-doped YAG-laser was the most effective system. As predominant side effects, residual zones of debris and microcracks were observed. In deeper cavities, the zones of damages increase. The side effects of the pulsed infrared laser types seem to be mainly influenced by the physical or chemical properties of the dental tissues and not by the selected laser parameters.

  14. A new technique for the closure of the lens capsule by laser welding.

    PubMed

    Pini, Roberto; Rossi, Francesca; Menabuoni, Luca; Lenzetti, Ivo; Yoo, Sonia; Parel, Jean-Marie

    2008-01-01

    A new method is presented for the closure of the lens capsule based on laser welding of suitably prepared patches of anterior capsular tissue. Experiments were performed in freshly enucleated porcine eyes. The patches were previously stained with a solution of indocyanine green in sterile water and then welded on the recipient capsule by means of diode laser radiation at 810 nm. The welded tissue revealed mechanical properties comparable to those of healthy tissue. This technique is proposed to repair capsular breaks and to provide the closure of the capsulorhexis in lens refilling procedures. PMID:18556957

  15. A COMPARISON OF IMPLANT EXTRUSION RATES AND POSTOPERATIVE PAIN AFTER EVISCERATION WITH IMMEDIATE OR DELAYED IMPLANTS AND AFTER ENUCLEATION WITH IMPLANTS

    PubMed Central

    Liu, Don

    2005-01-01

    Purpose To examine implant extrusion rates after evisceration with immediate or delayed implants in patients with culture-proven endophthalmitis. To compare postevisceration and postenucleation pain. Methods This prospective, nonrandomized interventional case series included four groups of patients: group 1, 25 endophthalmitis patients undergoing evisceration with immediate implants; group 2, 15 endophthalmitis patients undergoing evisceration with delayed implants; group 3, 31 patients without endophthalmitis undergoing evisceration with immediate implants; and group 4, eight patients undergoing enucleations with implants. Standardized techniques and follow-up schedules were used. Postoperative pain was assessed by weighted frequency of pain medications used during two 48-hour periods. Statistical analysis was performed. Retrospective review of two series of patients undergoing evisceration was performed. Results No cases of implant extrusion occurred during an average follow-up of 37.9 months. Average implant size was 19.0 mm. Conjunctival dehiscence occurred in one patient. Average total pain scores were 20.8 in endophthalmitis patients with immediate implants; 22.1 in endophthalmitis patients with delayed implants; 20.3 in patients without endophthalmitis and with immediate implants; and 23.1 in patients with enucleations and immediate implant insertions. Retrospective review suggested possible causes of implant extrusion. Conclusion Both immediate and delayed implant techniques appear safe in patients with endophthalmitis, with the former being simpler, more cost-effective, and perhaps less painful. Prolonged antibiotic therapy and smaller implants may render a false sense of security against implant extrusion; good surgical technique and meticulous postoperative wound care are essential. Postenucleation pain appears more severe than postevisceration pain. PMID:17057818

  16. Effect of pulse duration on photomechanical response of soft tissue during Ho:YAG laser ablation

    NASA Astrophysics Data System (ADS)

    Jansen, E. Duco; Motamedi, Massoud; Pfefer, T. Joshua; Asshauer, Thomas; Frenz, Martin; Delacretaz, Guy P.; Abela, George S.; Welch, Ashley J.

    1995-05-01

    Mechanical injury during pulsed holmium laser ablation of tissue is caused by rapid bubble expansion and collapse or by laser-induced pressure waves. In this study the effect of pulse duration on the photomechanical response of soft tissue during holmium:YAG laser ablation has been investigated. The dynamics of laser-induced bubble formation was documented in water and in transparent polyacrylamide tissue phantoms with a water concentration of 84%. Holmium:YAG laser radiation ((lambda) equals 2.12 micrometers ) was delivered in water or tissue phantoms via an optical fiber (200 or 400 micrometers ). The laser was operated in either the Q- switched mode ((tau) p equals 500 ns, Qp equals 14 +/- 1 mJ, 200 micrometers fiber, Ho equals 446 mJ/mm2) or the free-running mode ((tau) p equals 100 - 1100 microsecond(s) , Qp equals 200 +/- 5 mJ, 400 micrometers fiber, Ho equals 1592 mJ/mm2). Bubble formation was documented using a fast flash photography setup while simultaneously a PVDP needle hydrophone (40 ns risetime), recorded pressures. The effect of the pulse duration on the photomechanical response of soft biological tissue was evaluated by delivering 5 pulses of 800 mJ to the intimal side of porcine aorta in vitro, followed by histologic evaluation. It was observed that, as the pulse duration was increased the bubble shape changed from almost spherical for Q-switched pulses to a more elongated, cylindrical shape for the longer pulse durations. The bubble expansion velocity was larger for shorter pulse durations. A thermo- elastic expansion wave was measured only during Q-switched pulse delivery. All pulses that induced bubble formation generated pressure waves upon collapse of the bubble in water as well as in the gel. The amplitude of the pressure wave depended strongly on the size and geometry of the laser-induced bubble. The important findings of this study were (1) the magnitude of collapse pressure wave decreased as laser pulse duration increased, and (2) mechanical tissue damage is reduced significantly by using longer pulse durations (> 460 microsecond(s) , for the pulse energy used).

  17. Development of mid-infrared solid state lasers for spaceborne lidar. Final report, 13 April 1988-15 October 1989

    SciTech Connect

    Whitney, D.A.; Kim, K.H.

    1989-10-01

    Laser performance of Ho(3+):Tm(3+):Cr(3+):YAG crystals was investigated under both Cr:GSAG laser and flashlamp pumping. A flashlamp pumped Cr:GSAG laser was built to simulate high power quasi-CW laser diode pumping of a 2.1 micrometer holmium laser. The 2.1 micrometer output laser energy exceeded more than 14 mJ, the highest value reported to date under laser pumping near 785 nm. This was obtained in a pulse length of nearly 650 microsec from a 3 x 3 mm Ho:Tm:Cr:YAG rod by using the flashlamp-pumped Cr:CSAG laser as a pumping source at the diode laser wavelength, 785 micrometers. In addition, Ho:Tm:Cr:YAG crystals with various Tm(3+) concentrations were evaluated for flashlamp-pumped normal mode and Q-switched 2.1 micrometer laser operations under a wide variety of experimental conditions in order to understand internal dynamic processes among the ions and to determine an optimum lasing condition. An increase of the laser slope efficiency was observed with the increase of the Tm(3+) concentration from 2.5 to 4.5 atomic percent. The thermal dependence of the laser performance was also investigated. Q-switched laser output energies corresponding to nearly 100 percent of the normal-mode laser energies were obtained in a strong single spike of 200 ns pulse length by optimizing the opening time of a lithium niobate Q-switch.

  18. Lasers in clinical urology: state of the art and new horizons.

    PubMed

    Marks, Andrew J; Teichman, Joel M H

    2007-06-01

    We present an overview of current and emerging lasers for Urology. We begin with an overview of the Holmium:YAG laser. The Ho:YAG laser is the gold standard lithotripsy modality for endoscopic lithotripsy, and compares favorably to standard electrocautery transurethral resection of the prostate for benign prostatic hyperplasia (BPH). Available laser technologies currently being studied include the frequency doubled double-pulse Nd:Yag (FREDDY) and high-powered potassium-titanyl-phosphate (KTP) lasers. The FREDDY laser presents an affordable and safe option for intracorporeal lithotripsy, but it does not fragment all stone compositions, and does not have soft tissue applications. The high power KTP laser shows promise in the ablative treatment of BPH. Initial experiments with the Erbium:YAG laser show it has improved efficiency of lithotripsy and more precise ablative and incisional properties compared to Ho:YAG, but the lack of adequate optical fibers limits its use in Urology. Thulium:YAG fiber lasers have also demonstrated tissue ablative and incision properties comparable to Ho:YAG. Lastly, compact size, portability, and low maintenance schedules of fiber lasers may allow them to shape the way lasers are used by urologists in the future. PMID:17393172

  19. Treatment of Hemorrhagic Vocal Polyps by Pulsed Dye Laser-Assisted Laryngomicrosurgery

    PubMed Central

    Byeon, Hyung Kwon; Han, Ji Hyuk; Choi, Byeong Il; Hwang, Hye Jin; Kim, Ji-Hoon; Choi, Hong-Shik

    2015-01-01

    Objective. Conventional surgical techniques of laryngomicrosurgery (LMS) on hemorrhagic vocal polyps are often difficult due to obscuration of the surgical field by inadvertent bleeding from the lesion, and there are often significant amounts of mucosal epithelium loss. Here, we introduce our surgical technique using pulsed dye laser (PDL), which can effectively resect the polyp with vocal fold mucosa preservation. Methods. Patients who were diagnosed with hemorrhagic vocal polyp and who were surgically managed using PDL from March 2013 to October 2014 were retrospectively reviewed. Preoperative and postoperative clinical outcomes and surgical findings were evaluated. Results. A total of 39 patients were treated with PDL-assisted enucleation LMS. The average age was 43.7 years (range 20–73), and there were 20 males and 19 females (17 professional voice users). In all cases, the hemorrhagic polyp was successfully enucleated after application of PDL, thereby preserving the overlying epithelium. Postoperative voice outcomes were favorable with clear preservation of the vocal fold mucosal wave. Conclusion. PDL-assisted enucleation LMS for the treatment of hemorrhagic vocal polyps can be a safe and effective surgical technique. It can be considered a promising treatment option for hemorrhagic vocal polyps. PMID:26557700

  20. Thulium fiber laser ablation of kidney stones using a 50-?m-core silica optical fiber

    NASA Astrophysics Data System (ADS)

    Blackmon, Richard L.; Hutchens, Thomas C.; Hardy, Luke A.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

    2015-01-01

    Our laboratory is currently studying the experimental thulium fiber laser (TFL) as a potential alternative laser lithotripter to the gold standard, clinical Holmium:YAG laser. We have previously demonstrated the efficient coupling of TFL energy into fibers as small as 100-?m-core-diameter without damage to the proximal end. Although smaller fibers have a greater tendency to degrade at the distal tip during lithotripsy, fiber diameters (?200 ?m) have been shown to increase the saline irrigation rates through the working channel of a flexible ureteroscope, to maximize the ureteroscope deflection, and to reduce the stone retropulsion during laser lithotripsy. In this study, a 50-?m-core-diameter, 85-?m-outer-diameter, low-OH silica fiber is characterized for TFL ablation of human calcium oxalate monohydrate urinary stones, ex vivo. The 50-?m-core fiber consumes approximately 30 times less cross-sectional area inside the single working channel of a ureteroscope than the standard 270-?m-core fiber currently used in the clinic. The ureteroscope working channel flow rate, including the 50-?m fiber, decreased by only 10% with no impairment of ureteroscope deflection. The fiber delivered up to 15.45.9 W under extreme bending (5-mm-radius) conditions. The stone ablation rate measured 7022 ?g/s for 35-mJ-pulse-energy, 500-?s-pulse-duration, and 50-Hz-pulse-rate. Stone retropulsion and fiber burnback averaged 201336 and 30002600 ?m, respectively, after 2 min. With further development, thulium fiber laser lithotripsy using ultra-small, 50-?m-core fibers may introduce new integration and miniaturization possibilities and potentially provide an alternative to conventional Holmium:YAG laser lithotripsy using larger fibers.

  1. Establishment of pregnancy after the transfer of nuclear transfer embryos produced from the fusion of argali (Ovis ammon) nuclei into domestic sheep (Ovis aries) enucleated oocytes.

    PubMed

    White, K L; Bunch, T D; Mitalipov, S; Reed, W A

    1999-01-01

    Cloning mammalian species from cell lines of adult animals has been demonstrated. Aside from its importance for cloning multiple copies of genetically valuable livestock, cloning now has the potential to salvage endangered or even extinct species. The aim of this study was to investigate the effect of the bovine and domestic (Ovis aries) ovine oocyte cytoplasm on the nucleus of an established cell line from an endangered argali wild sheep (Ovis ammon) after nuclear transplantation. A fibroblast cell line was established from skin biopsies from an adult argali ram from the People's Republic of China. Early karyotype analysis of cells between 3-6 passages revealed a normal diploid chromosome number of 56. The argali karyotype consisted of 2 pairs of biarmed and 25 pairs of acrocentric autosomes, a large acrocentric and minute biarmed Y. Bovine ovaries were collected from a local abattoir, oocytes aspirated, and immediately placed in maturation medium consisting of M-199 containing 10% fetal bovine serum, 100 IU/mL penicillin, 100 microg/mL streptomycin, 0.5 microg/mL follicle-stimulating hormone (FSH), 5.0 microg/mL luetinizing hormone (LH) and 1.0 microg/mL estradiol. Ovine (O. aries) oocytes were collected at surgery 25 hours postonset of estrus from the oviducts of superovulated donor animals. All cultures were carried out at 39 degrees C in a humidified atmosphere of 5% CO2 and air. In vitro matured MII bovine oocytes were enucleated 16-20 hours after onset of maturation and ovine oocytes within 2-3 hours after collection. Enucleation was confirmed using Hoechst 33342 and UV light. The donor argali cells were synchronized in G0-G1 phase by culturing in Dulbecco's modified Eagle's medium (DMEM) plus 0.5% fetal bovine serum for 5-10 days. Fusion of nuclear donor cell to an enucleated oocyte (cytoplast) to produce nuclear transfer (NT) embryos was induced by 2 electric pulses of 1.4 kV/cm for 30 microsc. Fused NT embryos were activated after 24 hours of maturation by exposure to ionomycin (5 microM, 4 minutes) followed by incubation in 6-dimethylaminopurine (0.2 mM, 4 hours) and cultured in microdrops of CR1aa medium. From a total of 166 constructed nuclear donor cell-bovine cytoplasm NT couples, 128 (77%) successfully fused, 100 (78%) developed to 8-16 cell stage, and 2 (1.56%) developed to the blastocyst stage. The presence of argali nuclei in 8-16 cell stage embryo clones was confirmed after observation of Hoechst 33342 stained embryos under UV light and chromosome analysis of metaphase spreads from blastomeres. A total of 127 constructed nuclear donor cell-ovine cytoplasm NT couples were produced, 101 (80%) successfully fused, 81 (80% of fused) developed to the 16- to 32-cell stage. A total of 28 hybrid (argali-sheep) and 21 sheep-sheep NT embryos were transferred into 6 recipients and 4 recipients, respectively. Two of these recipients, 1 carrying argali-sheep and 1 sheep-sheep, were confirmed pregnant at 49 days by ultrasound, but both pregnancies terminated by 59 days. The results of this study demonstrate the possibility of using xenogenic oocytes to produce early-stage embryos and pregnancies from an established fibroblast cell line of an endangered species. PMID:16218829

  2. Structural properties of a holmium iron carbide interstitial compound, Ho[sub 2]Fe[sub 17]C[sub 3-x

    SciTech Connect

    Bocelli, G.; Calestani, G. ); Leccabue, F.; Watts, B.E. ); Sanchez, J.L. )

    1993-01-01

    X-ray diffractometric studies were performed on a single-crystalline specimen of the Ho[sub 2]Fe[sub 17]C[sub 3-x] intermetallic alloy. Its crystal data (for x > 2) are a = 8.521 (2), c = 8.309 (2) [angstrom], V = 522.5 [angstrom][sup 3], hexagonal space group P6[sub 3]/mmc. The crystal structure, solved by direct methods, was refined to a final agreement factor R of 0.045. The atoms are distributed in two layers perpendicular to the z axis: while one is composed only of iron atoms forming regular hexagonal nets, the insertion of carbons in the second layer deforms the hexagonal nets which contain holmium atoms in their centers. 19 refs., 3 figs., 2 tabs.

  3. Enhanced cathodoluminescence from an amorphous AlN:holmium phosphor by co-doped Gd{sup +3} for optical devices applications

    SciTech Connect

    Maqbool, Muhammad; Kordesch, Martin E.; Kayani, A.

    2009-05-15

    Sputter-deposited thin films of amorphous AlN:Ho (1 at. %) emits in the green (549 nm) region of the visible spectrum under electron excitation. The addition of Gd (1 at. %) in the film enhances the green emission linearly after thermal activation at 900 deg. C for 40 min in a nitrogen atmosphere. The luminescence enhancement saturates when the gadolinium concentration reaches four times the holmium concentration. The optical bandgap of amorphous AlN is about 210 nm, so that the film is transparent in the ultraviolet, allowing us to observe the ultraviolet emission at 313 nm from Gd. No significant quenching of the Gd emission is observed. Energy dispersive x-ray (EDX) spectra confirm the increasing concentration of Gd. X-ray diffraction (XRD) analysis shows no peaks other than those arising from the Si (111) substrate, confirming that the films are amorphous. The enhanced luminescence can be used to make high-efficiency optical devices.

  4. Development of 166Holmium-1,2 Propylene Di-amino Tetra (Methy1enephosphonicacid) as a Possible Bone Palliation Agent

    PubMed Central

    Zolghadri, Samaneh; Jalilian, Amir Reza; Yousefnia, Hassan; Bahrami-Samani, Ali; Ghannadi-Maragheh, Mohammad

    2014-01-01

    166Holmium-1,2-propylene di-amino tetra (methy1enephosphonicacid) (166 Ho-PDTMP) complex was prepared successfully using an in-house synthesized PDTMP ligand and 166 HoCl 3 . Ho-166 chloride was obtained by thermal neutron irradiation (1 10 13 n/cm 2 /s) of natural Ho (NO 3 ) 3 samples (specific activity = 3-5 GBq/mg), dissolved in acidic media. Radiochemical purity of 166 Ho-PDTMP was checked by instant thin layer chromatography (>99%). Stability studies of the complex in the final preparation and in the presence of human serum were performed up to 72 h. The biodistribution of 166 Ho-PDTMP and 166 HoCl 3 in wild-type rats was checked in animal tissues up to 48 h. The produced 166 Ho-PDTMP properties suggest a possible new bone palliative therapeutic to overcome the metastatic bone pains. PMID:25191109

  5. Safety of cornea and iris in ocular surgery with 355-nm lasers.

    PubMed

    Wang, Jenny; Chung, Jae Lim; Schuele, Georg; Vankov, Alexander; Dalal, Roopa; Wiltberger, Michael; Palanker, Daniel

    2015-09-01

    A recent study showed that 355-nm nanosecond lasers cut cornea with similar precision to infrared femtosecond lasers. However, use of ultraviolet wavelength requires precise assessment of ocular safety to determine the range of possible ophthalmic applications. In this study, the 355-nm nanosecond laser was evaluated for corneal and iris damage in rabbit, porcine, and human donor eyes as determined by minimum visible lesion (MVL) observation, live/dead staining of the endothelium, and apoptosis assay. Single-pulse damage to the iris was evaluated on porcine eyes using live/dead staining. In live rabbits, the cumulative median effective dose (ED50) for corneal damage was 231 J/cm2, as seen by lesion observation. Appearance of endothelial damage in live/dead staining or apoptosis occurred at higher radiant exposure of 287 J/cm2. On enucleated rabbit and porcine corneas, ED50 was 87 and 52 J/cm2, respectively, by MVL, and 241 and 160 J/cm2 for endothelial damage. In human eyes, ED50 for MVL was 110 J/cm2 and endothelial damage at 453 J/cm2. Single-pulse iris damage occurred at ED 50 of 208 mJ/cm2. These values determine the energy permitted for surgical patterns and can guide development of ophthalmic laser systems. Lower damage threshold in corneas of enucleated eyes versus live rabbits is noted for future safety evaluation. PMID:26359809

  6. Safety of cornea and iris in ocular surgery with 355-nm lasers

    NASA Astrophysics Data System (ADS)

    Wang, Jenny; Chung, Jae Lim; Schuele, Georg; Vankov, Alexander; Dalal, Roopa; Wiltberger, Michael; Palanker, Daniel

    2015-09-01

    A recent study showed that 355-nm nanosecond lasers cut cornea with similar precision to infrared femtosecond lasers. However, use of ultraviolet wavelength requires precise assessment of ocular safety to determine the range of possible ophthalmic applications. In this study, the 355-nm nanosecond laser was evaluated for corneal and iris damage in rabbit, porcine, and human donor eyes as determined by minimum visible lesion (MVL) observation, live/dead staining of the endothelium, and apoptosis assay. Single-pulse damage to the iris was evaluated on porcine eyes using live/dead staining. In live rabbits, the cumulative median effective dose (ED50) for corneal damage was 231 J/cm2, as seen by lesion observation. Appearance of endothelial damage in live/dead staining or apoptosis occurred at higher radiant exposure of 287 J/cm2. On enucleated rabbit and porcine corneas, ED50 was 87 and 52 J/cm2, respectively, by MVL, and 241 and 160 J/cm2 for endothelial damage. In human eyes, ED50 for MVL was 110 J/cm2 and endothelial damage at 453 J/cm2. Single-pulse iris damage occurred at ED50 of 208 mJ/cm2. These values determine the energy permitted for surgical patterns and can guide development of ophthalmic laser systems. Lower damage threshold in corneas of enucleated eyes versus live rabbits is noted for future safety evaluation.

  7. Effects of pulsed lasers on agar model simulation of the arterial wall.

    PubMed

    Asada, M; Kvasnicka, J; Geschwind, H J

    1993-01-01

    Coronary laser angioplasty is limited by a high rate of dissection and the occurrence of abrupt closure and perforation. The aim of this study was to visualize the mechanical effects of pulsed lasers on two chamber in vitro models. These models consisted of 1 or 2 agar layers and calcium carbonate inclusions (1-layer model) or lipid (2-layer model) simulating lipid or calcified tissue. The inclusions were irradiated with a holmium-yttrium-aluminum-garnet (Ho-YAG) laser or a xenon chloride excimer laser. The Ho-YAG laser demonstrated dissection-like expansions of the target and perforation-like cracks. The size of dissection was obtained using an the empirical formula of energy (E) and the maximal expansion distance (Dmax) of the targets, Dmax = 0.15E0,87-1,17. The excimer laser showed rare and short perforation-like cracks and little dissection-like expansion of the gaseous products originating from the ablation of material. Ho-YAG laser ablation is likely to induce target tissue dissections and/or perforations. Excimer laser-ablates targets with less traumatic effects than Ho-YAG laser. PMID:8366739

  8. Five years follow-up of a keratocyst odontogenic tumor treated by marsupialization and enucleation: A case report and literature review

    PubMed Central

    de Molon, Rafael Scaf; Verzola, Mario H.; Pires, Luana C.; Mascarenhas, Vinicius I.; da Silva, Rodrigo B.; Cirelli, Joni A.; Barbeiro, Roberto H.

    2015-01-01

    Odontogenic cysts are considered as nonneoplasic benign lesions. Among the cysts, keratocyst odontogenic tumor (KCOT) is an intra-osseous tumor characterized by parakeratinized stratified squamous epithelium and a potential for aggressive, infiltrative behavior, and for the possibility to develop carcinomas in the lesion wall. Thus, the aim of this study was to describe a clinical case of KCOT in a young patient and discuss the treatment alternatives to solve this case. A 15-year-old male was referred for treatment of a giant lesion in his left side of the mandible. After the biopsy, a diagnostic of KCOT was made, and the following procedures were planned for KCOT treatment. Marsupialization was performed for lesion decompression and consequent lesion size reduction. Afterward, enucleation for complete KCOT removal was performed followed by third mandibular molar extraction. After 5 years, no signs of recurrence were observed. The treatment proposed was efficient in removing the KCOT with minimal surgical morbidity and optimal healing process, and the first and second mandibular molars were preserved with pulp vitality. In conclusion, this treatment protocol was an effective and conservative approach for the management of the KCOT, enabling the reduction of the initial lesion, the preservation of anatomical structures and teeth, allowing quicker return to function. No signs of recurrence after 5 years were observed. PMID:25821360

  9. Detection of rare earth elements in Powder River Basin sub-bituminous coal ash using laser-induced breakdown spectroscopy (LIBS)

    SciTech Connect

    Tran, Phuoc

    2015-10-01

    We reported our preliminary results on the use of laser-induced breakdown spectroscopy to analyze the rare earth elements contained in ash samples from Powder River Basin sub-bituminous coal (PRB-coal). We have identified many elements in the lanthanide series (cerium, europium, holmium, lanthanum, lutetium, praseodymium, promethium, samarium, terbium, ytterbium) and some elements in the actinide series (actinium, thorium, uranium, plutonium, berkelium, californium) in the ash samples. In addition, various metals were also seen to present in the ash samples

  10. Two-dimensional micro-displacement measurement for laser coagulation using optical coherence tomography

    PubMed Central

    Kurokawa, Kazuhiro; Makita, Shuichi; Hong, Young-Joo; Yasuno, Yoshiaki

    2014-01-01

    To improve the reproducibility of photocoagulation, the ability to quantitatively monitor the thermal change of laser-irradiated retinal tissue is required. Recently, optical coherence tomography has enabled non-invasive and non-contact monitoring of the tissue structural changes during laser irradiation. To further improve the capability of this technique, a method is proposed to measure tissue displacement by simultaneously using Doppler phase shifts and correlation coefficients. The theoretical approach for this method is described, and its performance is experimentally confirmed and evaluated. Finally, lateral and axial displacements in the laser-irradiated retinal tissues of an enucleated porcine eye are observed. The proposed method is found to be useful for further understanding the direct thermal response of laser-irradiated retinal tissue. PMID:25657885

  11. MR Evaluation of Radiation Synovectomy of the Knee by Means of Intra-articular Injection of Holmium-166-Chitosan Complex in Patients with Rheumatoid Arthritis: Results at 4-month Follow-up

    PubMed Central

    Lee, Sang Hoon; Kim, Ho Seok; Lee, Jong Doo; Song, Jungsik; Lee, Soo Kon

    2003-01-01

    Objective To determine whether MRI is able to demonstrate the effect of radiation synovectomy after the intra-articular injection of holmium-166-chitosan complex for the treatment of rheumatoid arthritis of the knee. Materials and Methods Fourteen patients aged 36-59 years were treated with 10-20 mCi of holmium-166-chitosan complex. A criterion for inclusion in this study was the absence of observable improvement after 3- or more months of treatment of the knee with disease-modifying anti-rheumatic drugs. MR images were acquired both prior to and 4-months after treatment. Clinical evaluation included the use of visual analog scales to assess pain, and the circumference of the knee and its range of motion were also determined. MR evaluation included measurement of the volume of synovial enhancement and wall thickness, the amount of joint effusion, and quantifiable scoring of bone erosion, bone edema and lymph nodes. Results Visual analog scale readings decreased significantly after radiation synovectomy (p < 0.05). MRI showed that joint effusion decreased significantly (p < 0.05), and that the volume of synovial enhancement tended to decrease, but to an insignificant extent (p = 0.107). Conclusion The decreased joint effusion noted at 4-month follow-up resulted from radiation synovectomy of the rheumatoid knee by means of intra-articular injection of holmium-166-chitosan complex. PMID:14530646

  12. Single-frequency Ho(3+)-doped ZBLAN fiber laser at 1200 nm.

    PubMed

    Zhu, Xiushan; Zong, Jie; Miller, Andy; Wiersma, Kort; Norwood, R A; Prasad, Narasimha S; Chavez-Pirson, Arturo; Peyghambarian, N

    2012-10-15

    A single-frequency (SF) fiber laser at 1200 nm was developed with a distributed Bragg reflector (DBR) configuration by splicing a 22 mm long highly holmium-doped ZBLAN (ZrF(4)-BaF(2)-LaF(3)-AlF(3)-NaF) fiber with a pair of silica fiber Bragg gratings. The linewidth was estimated to be less than 100 kHz based on the measured frequency noise. The relative intensity noise was measured to be <110 dB/Hz at the relaxation oscillation peak and the polarization extinction ratio was measured to be >19 dB. Our results highlight the exciting prospect that wavelength coverage of SF DBR fiber lasers can be expanded significantly by using rare-earth-doped ZBLAN fibers. PMID:23073405

  13. Chemically Assisted Enucleation Results in Higher G6PD Expression in Early Bovine Female Embryos Obtained by Somatic Cell Nuclear Transfer

    PubMed Central

    Oliveira, Clara Slade; Tetzner, Tatiane Almeida Drummond; de Lima, Marina Ragagnin; de Melo, Danilas Salinet; Niciura, Simone Cristina Mo; Garcia, Joaquim Mansano

    2012-01-01

    Abstract Despite extensive efforts, low efficiency is still an issue in bovine somatic cell nuclear transfer (SCNT). The hypothesis of our study was that the use of cytoplasts produced by chemically assisted enucleation (EN) would improve nuclear reprogramming in nuclear transfer (NT)derived embryos because it results in lower damage and higher cytoplasm content than conventional EN. For that purpose, we investigated the expression of two X-linked genes: X inactive-specific transcript (XIST) and glucose 6-phosphate dehydrogenase (G6PD). In the first experiment, gene expression was assessed in day-7 female blastocysts from embryonic cell NT (ECNT) groups [conventional, ECNT conv; chemically assisted, ECNT deme (demecolcine)]. Whereas in the ECNT conv group, only one embryo (25%; n=4) expressed XIST transcripts, most embryos showed XIST expression (75%; n=4) in the ECNT deme group. However, no significant differences in transcript abundance of XIST and G6PD were found when comparing the embryos from all groups. In a second experiment using somatic cells as nuclear donors, we evaluated gene expression profiles in female SCNT-derived embryos. No significant differences in relative abundance (RA) of XIST transcripts were observed among the groups. Nonetheless, higher (p<0.05) levels of G6PD were observed in SCNT deme and in vitroderived groups in comparison to SCNT conv. To know whether higher G6PD expression in embryos derived from SCNT chemically assisted EN indicates higher metabolism in embryos considered of superior quality or if the presence of higher reactive oxygen species (ROS) levels generated by the increased oxygen consumption triggers G6PD activation, the expression of genes related to stress response should be investigated in embryos produced by that technique. PMID:22908977

  14. Pseudocapsule of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion: a clue for tumor enucleation?

    PubMed Central

    Cheng, Xiangming; He, Jian; Gan, Weidong; Fan, Xiangshan; Yang, Jun; Zhu, Bin; Guo, Hongqian

    2015-01-01

    Objectives: To evaluate the feasibility and efficacy of tumor enucleation (TE) for patients with small renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2 RCC) by analyzing the pseudocapsule characteristics of Xp11.2 RCCs comparing with that of clear cell renal cell carcinoma (ccRCC). Methods: From June 2007 to February 2014, 22 patients with Xp11.2 RCC who were diagnosed by fluorescence in-situ hybridization polyclonal (FISH) assay and 32 patients with ccRCC treated in our institution were comparatively studied. 12 patients with ccRCC underwent radical nephrectomy (RN) and 20 received TE. Among 22 patients with Xp11.2 RCC, 19 were treated by RN and 3 by TE (1 by radiofrequency ablation assisted TE). Pseudocapsule and other clinicopathological characteristics of the two subtypes of RCC were compared. Survival of patients treated with different surgical methods was evaluated and compared. Results: Pseudocapsule incidence of Xp11.2 RCC (14/22, 63.6%) was lower than that of ccRCC (32/32, 100%, P<0.001). However, pseudocapsule integrity rate of Xp11.2 RCC (10/14, 71.4%) was comparable with that of ccRCC (23/32, 71.9%, P=1.000). The 5-year overall survival of patients with ccRCC treated with RN and TE was 86% and 81%, respectively (P=0.845). Three patients with small Xp11.2 RCC performed well after TE. Conclusions: Over half Xp11.2 RCC had pseudocapsules, whose integrity rate was comparable to that of ccRCC. Treatment effectives of TE and RN were comparable in ccRCC. A preliminary attempt to treat small Xp11.2 RCC with intact pseudocapsule by using TE produced a favorable treatment outcome. PMID:26191243

  15. Development of mid-infrared solid state lasers for spaceborne lidar

    NASA Technical Reports Server (NTRS)

    Whitney, Donald A.

    1990-01-01

    Researchers investigated laser performance of Ho(3+):Tm(3+):Cr(3+):YAG crystals under both Cr:GSAG laser and flashlamp pumping. A flashlamp pumped Cr:GSAG laser was built to simulate high power quasi-CW laser diode pumping of a 2.1 micron holmium laser. The 2.1 micron output laser energy exceeded more than 14 mJ, the highest value reported to date under laser pumping near 785 nm. This was obtained in a pulse length of nearly 650 microns from a 3 x 3 mm Ho:Tm:Cr:YAG rod by using the flashlamp-pumped Cr:GSAG laser as a pumping source at the diode laser wavelength, 785 microns. In addition, Ho:Tm:Cr:YAG crystals with various Tm(3+) concentrations have been evaluated for flashlamp-pumped normal mode and Q-switched 2.1 micron laser operations under a wide variety of experimental conditions in order to understand internal dynamic processes among the ions and to determine an optimum lasing condition. An increase of the laser slope efficiency was observed with the increase of the Tm(3+) concentration from 2.5 atomic percent to 4.5 atomic percent. The thermal dependence of the laser performance was also investigated. Q-switched laser output energies corresponding to nearly 100 percent of the normal-mode laser energies were obtained in a strong single spike of 200 ns pulse length by optimizing the opening time of a lithium niobate Q-switch.

  16. AB051. Technical improvement of HoLEP and prevention strategies of postoperative incontinence

    PubMed Central

    Ding, Mingxia; Wang, Jiansong; Zuo, Yigang; Chen, Jian; Wang, Haifeng; Li, Ning; Liu, Jingyu; Wang, Wei; Li, Haihao

    2015-01-01

    Objective To improve HoLEP surgical techniques of finding envelope, enucleation, hemostatic and comminution, and to treate the incontinence reason predictably, so as to reduce the complications of HoLEP surgery. Methods Technical improvements were performed in 272 patients who underwent HoLEP during January 2014 to December 2014. (I) The gland was enucleated in three lobes, not overall enucleation; (II) start with both sides of verumontanum to find envelope, the three-lobe technique involves 5- and 7-o'clock position incisions with enucleation of the middle lobe and subsequent enucleation of one lateral lobe followed by the other lateral lobe; (III) we only lift the glands gently by lens body, using holmium laser blasting to peel glands, and abandon conventional mirror peeling method; (IV) if bleeding is encountered, the laser fibre can be defocused slightly from the bleeding point to achieve haemostasis; (V) we crushed glands vacantly with the status of bladder filling. The reason why postoperative urinary incontinence occurs may be thermal burns sphincter, mucosal retention inadequate, sphincter weiss at around 12:00, and sphincter injury caused by mirror body elevation, etc. Some precautions during the operation were as follows: (I) reducing laser ablation; (II) separation off the reserved side lobe mucosa before peeling; (III) avoid 12:00 distal mucosal tear; (IV) using blasting holmium laser energy not lens body to peel glands, which can avoid sphincter injury by mirror body elevation force. Results We identified 272 patients who underwent HoLEP. The median volume of enucleated adenomas was 9224 g. The median IPSS before surgery was 23.36.1. Average (range) operation time was 8621 minutes. Amount of bleeding was 5614 mL. Postoperative patients of hospital stay was 325 h, average time of indwelling catheter time was 226 h. Patients were followed up for 6-28 months time, an average of 12.4 months. Postoperative patients with international prostate symptom score progressive declined. The quality of life score was 6.72.6. The maximum urinary flow rate also improved (P<0.05). Postoperative complication included urge urinary incontinence (36 cases, 13.2%), 31 of which did not occur in the first 5 days, 2 of which lasted for 2 days. However, there was no real urinary incontinence case. Conclusions By improving HoLEP technology and treating the incontinence reason predictably, HoLEP proved to be a safe and effective therapy, with fewer surgical complications, and it may be potential to become a new gold standard for treating BPH.

  17. Acute light and electron microscopic study of ultraviolet 193-nm excimer laser corneal incisions

    SciTech Connect

    Berns, M.W.; Liaw, L.H.; Oliva, A.; Andrews, J.J.; Rasmussen, R.E.; Kimel, S.

    1988-10-01

    The 193-nm ultraviolet beam from an argon fluoride excimer laser was focused on the corneas of rabbits to produce incisions of the type necessary for radial keratotomy. The energy densities used were in two ranges, 1.0 to 2.1 J/cm2 per pulse and 200 to 700 mJ/cm2 per pulse. The eyes were enucleated and fixed for histologic and electron microscopic examination immediately after exposure. Structural analysis of the higher energy density exposures showed ridging on the surface of the cornea, micro-pitting on the stromal surface inside the cut, and denudation of the endothelium under the ablation zone. The lower energy density incisions did not exhibit significant surface ridging or endothelial cell loss but did exhibit significant stromal swelling during the laser exposure thus making it difficult to produce incisions of a precisely controlled depth. Beam profile measurements and infrared thermal measurements of the cornea surface during laser exposure were made.

  18. Quantitative and ultrastructural studies of excimer laser ablation of the cornea at 193 and 248 nanometers

    SciTech Connect

    Puliafito, C.A.; Wong, K.; Steinert, R.F.

    1987-01-01

    Excimer laser radiation at 193 nm and 248 nm was used to create linear etch perforations of enucleated calf corneas. The etch depth per pulse was determined for various exposures, and specimens were examined by light and transmission electron microscopy. Compared to 248 nm, excimer laser ablation at 193 nm was found to have a lower threshold for onset of ablation, less increase in etch depth per pulse at increasing fluences, and less structural alteration in adjacent cornea. For 193 nm, structural alterations were minimal, confined to an area less than 0.3 micron wide, and did not increase with increasing fluence. These studies suggest that clinical strategies for excimer laser refractive surgery will employ the 193-nm wavelength, with fluence chosen depending on surgical strategy. Ablation exposures above 600 mJ/cm2 at 193 nm may give the most repeatable etch depth.

  19. Holmium(III)-selective fluorimetric optode based on N,N-bis(salicylidene)-naphthylene-1,8-diamine as a neutral fluorogenic ionophore.

    PubMed

    Ganjali, Mohammad Reza; Hosseini, Morteza; Karimi, Anahita; Haji-Hashemi, Hedieh; Salavati-Niasari, Masoud; Norouzi, Parviz

    2014-01-01

    For the first time a highly sensitive and selective fluorimetric optode for determination of trace amounts of Ho(3+) ions was prepared. The sensing system was prepared by incorporating of N,N-bis(salicylidene)-naphthylene-1,8-diamine (L) as a neutral Ho(3+)-selective fluoroionophore, in a plasticized PVC membrane containing sodium tetraphenyl borate as a lipophilic anionic additive. The response of the sensor is based on the strong fluorescence quenching of L by Ho(3+) ions. At pH 5.4, the proposed sensor displays a calibration curve over a wide concentration range of 1.010(-10)-1.010(-3)M, with a relatively fast response time of less than 1 min. In addition to high stability, high reproducibility and a relatively long working lifetime, the sensor shows a good selectivity towards Ho(3+) ion with respect to common coexisting cations. The fluorescence optode was applied to determination of holmium ion contents of water samples. PMID:24247094

  20. Utility and Limitation of Cumulative Stone Diameter in Predicting Urinary Stone Burden at Flexible Ureteroscopy with Holmium Laser Lithotripsy: A Single-Center Experience

    PubMed Central

    Ito, Hiroki; Kawahara, Takashi; Terao, Hideyuki; Ogawa, Takehiko; Yao, Masahiro; Kubota, Yoshinobu; Matsuzaki, Junichi

    2013-01-01

    Purpose To retrospectively assess the clinical utility in ureteroscopy (URS) planning of cumulative stone diameter (CSD), which does not account for stone width or depth, as a predictor of URS outcome and compare it with stone volume. Materials and Methods Patients with renal stones treated at a single institute by flexible URS were retrospectively evaluated. To assess the clinical utility of CSD, relationships between stone-free (SF) status and stone burden (CSD and volume) were analyzed using the area under the receiver operating characteristics (AUROC) curve. To identify stone number impact on CSD, the AUROC of CSD divided by stone number was evaluated. Correlation coefficients of CSD and stone volume were also calculated for groups by stone number. Results In cases with CSD <20.0 mm, CSD and stone volume revealed equal ability to predict SF status. In cases with CSD ?20.0 mm, stone volume showed higher predictive ability. The ROC curves for cases with ?4 stones showed that CSD was less predictive of SF status than stone volume. The correlation coefficients of CSD and stone volume by stone number were 0.922 for 1 stone, 0.900 for 23 stones, and 0.661 for ?4 stones. Conclusions In cases with CSD ?20.0 mm or ?4 stones, we should evaluate stone volume for a more predictive stone burden, and pretreatment non-contrast CT seems sufficient. In cases with CSD <20.0 mm or 13 stones, CSD was as valid a predictor of preoperative stone burden as stone volume, so preoperative kidney-ureter-bladder (KUB) films may be sufficient. PMID:23750229

  1. Perioperative care of patients undergoing holmium laser resection of the prostate (HoLRP) compared with transurethral resection of the prostate (TURP)

    NASA Astrophysics Data System (ADS)

    Gilling, Peter J.; Mackey, Michael; Cresswell, Michael D.; Kennett, Katie M.; Cass, Carol B.; Fraundorfer, Mark R.; Kabalin, John N.

    1998-07-01

    HoLRP is a technique which produces a defect in the prostatic fossa analogous to TURP but does so with significantly less blood loss. The perioperative outcome was assessed in a randomized clinical trial. The patients in the HoLRP arm (61 patients) had a longer resection time when compared to the TURP group (59 patients) but had less nursing contact time, shorter catheter time and a shorter hospital stay. Four patients in the TURP arm (6.8%) required blood transfusion compared to none in the HoLRP arm. Postoperative dysuria was similar in the two groups. Overall, the perioperative morbidity of HoLRP is less than that of TURP.

  2. Improved efficiency of microsurgical enucleated tripronuclear zygotes development and embryonic stem cell derivation by supplementing epidermal growth factor, brain-derived neurotrophic factor, and insulin-like growth factor-1.

    PubMed

    Fan, Yong; Li, Rong; Huang, Jin; Zhao, Hong-Cui; Ding, Ting; Sun, Xiaofang; Yu, Yang; Qiao, Jie

    2014-03-15

    Human embryonic stem cells (hESCs) hold great promise for future clinical cell therapies because of their unique potential to differentiate into all human cell types. However, the destruction of normal fertilized embryos and the derivation of hESCs for research has resulted in polarized ethical debates, with most of the controversy centered on embryo destruction. Therefore, due to less ethical controversy surrounding them, abnormal fertilized zygotes that are usually discarded are a potential feasible resource for the derivation of hESCs. Microsurgery on human polyspermic zygotes can contribute to the derivation of hESCs, but the efficiency is much lower. Here, we reported a culture system to enhance the developmental competence of such microsurgical human polyspermic zygotes by EGF-BDNF-IGF-1 combination, which eventually resulted in the increased derivation efficiency of hESCs from them. We found that the developmental efficiency of microsurgical enucleated tripronuclear (3PN) embryos cultured with the EGF-BDNF-IGF-1 combination was significantly increased compared with the control group. More importantly, when the microsurgical enucleated 3PN embryos were cultured in medium supplemented with EGF-BDNF-IGF-1, the frequency ratio of chromosome abnormality was reduced. Our present study will facilitate the development of hESC line derivation in subsequent studies and also provide an additional choice for infertile couples. PMID:24261581

  3. Improved Efficiency of Microsurgical Enucleated Tripronuclear Zygotes Development and Embryonic Stem Cell Derivation by Supplementing Epidermal Growth Factor, Brain-Derived Neurotrophic Factor, and Insulin-Like Growth Factor-1

    PubMed Central

    Fan, Yong; Li, Rong; Huang, Jin; Zhao, Hong-Cui; Ding, Ting; Sun, Xiaofang

    2014-01-01

    Human embryonic stem cells (hESCs) hold great promise for future clinical cell therapies because of their unique potential to differentiate into all human cell types. However, the destruction of normal fertilized embryos and the derivation of hESCs for research has resulted in polarized ethical debates, with most of the controversy centered on embryo destruction. Therefore, due to less ethical controversy surrounding them, abnormal fertilized zygotes that are usually discarded are a potential feasible resource for the derivation of hESCs. Microsurgery on human polyspermic zygotes can contribute to the derivation of hESCs, but the efficiency is much lower. Here, we reported a culture system to enhance the developmental competence of such microsurgical human polyspermic zygotes by EGFBDNFIGF-1 combination, which eventually resulted in the increased derivation efficiency of hESCs from them. We found that the developmental efficiency of microsurgical enucleated tripronuclear (3PN) embryos cultured with the EGFBDNFIGF-1 combination was significantly increased compared with the control group. More importantly, when the microsurgical enucleated 3PN embryos were cultured in medium supplemented with EGFBDNFIGF-1, the frequency ratio of chromosome abnormality was reduced. Our present study will facilitate the development of hESC line derivation in subsequent studies and also provide an additional choice for infertile couples. PMID:24261581

  4. In vitro study of pulsed Ho:YAG laser meniscectomy

    NASA Astrophysics Data System (ADS)

    Jacques, Steven L.; Schwartz, Jon A.; Gofstein, Gary; Vangsness, C. Thomas

    1994-09-01

    The ablation of ex vivo human samples of meniscus using the pulsed holmium:YAG (Ho:YAG) laser was studied. Delivery was by optical fiber in contact with the tissue. The rate of ablation was determined as (mm/pulse) for a range of pulse energies. Ablation with tissue in air versus under saline yielded similar rates of ablation, with the under-saline rate slightly higher. Experiments with two optical fiber sizes (200 micrometers and 600 micrometers ) suggested that total pulse energy [J/pulse] rather than radiant exposure [J/cm2/pulse] may be the better predictor for ablation rate. For comparison, results of a study of continuous Nd:YAG laser ablation of chicken breast using two beam sizes are also presented which suggest that total beam power [W] rather than irradiance [W/cm2] may be the better predictor for ablation rate. Comparison with the efficiency of simple boiling water indicates that laser ablation (both pulsed and continuous) is only about 10% as efficient as boiling water.

  5. Development of mid-infrared solid state lasers for spaceborne lidar. Final report, 13 April 1988-31 January 1990

    SciTech Connect

    Whitney, D.A.

    1990-01-01

    Researchers investigated laser performance of Ho(3+):Tm(3+):Cr(3+):YAG crystals under both Cr:GSAG laser and flashlamp pumping. A flashlamp pumped Cr:GSAG laser was built to simulate high power quasi-CW laser diode pumping of a 2.1 micron holmium laser. The 2.1 micron output laser energy exceeded more than 14 mJ, the highest value reported to date under laser pumping near 785 nm. This was obtained in a pulse length of nearly 650 microns from a 3 x 3 mm Ho:Tm:Cr:YAG rod by using the flashlamp-pumped Cr:GSAG laser as a pumping source at the diode laser wavelength, 785 microns. In addition, Ho:Tm:Cr:YAG crystals with various Tm(3+) concentrations have been evaluated for flashlamp-pumped normal mode and Q-switched 2.1 micron laser operations under a wide variety of experimental conditions in order to understand internal dynamic processes among the ions and to determine an optimum lasing condition. An increase of the laser slope efficiency was observed with the increase of the Tm(3+) concentration from 2.5 atomic percent to 4.5 atomic percent. The thermal dependence of the laser performance was also investigated. Q-switched laser output energies corresponding to nearly 100 percent of the normal-mode laser energies were obtained in a strong single spike of 200 ns pulse length by optimizing the opening time of a lithium niobate Q-switch.

  6. Imaging laser-induced thermal fields and effects

    NASA Astrophysics Data System (ADS)

    Verdaasdonck, Rudolf M.

    1995-05-01

    Laser light interaction with biological tissues is a combination of optical, thermal and mechanical effects depending on the energy applied per unit of volume per unit of time. Visualization of the phenomena with a high temporal and spatial resolution, contributes to a better understanding of the mechanism of action, especially when pulsed lasers are involved. For this goal, setups were developed based on Schlieren techniques to image the interaction of pulsed (CO2, Holmium and Excimer) and CW (CO2, Nd:YAG, Cu-vapor) lasers with physiological media and biological tissues. In a 'fast' Schlieren setup, images of shock waves and fast expanding and imploding vapor bubbles were captured using very short light flashes (10 ns-10 microseconds). These recordings suggest that these explosive vapor bubbles seem to be the main dynamism for tissue ablation. In a 'color' Schlieren setup, very small changes in optical density of the media induced by temperature gradients, were color coded. Calibration of the color images to absolute temperatures were performed by using calculated temperature distributions and by thermocouple measurements. Cameras with high speed shutters (0.1-50 ms) enabled the recording of dynamic images of the thermal relaxation and heat diffusion in tissues during variation of pulse length and repetition rate. Despite pulse lengths < ms, heat generation in tissue was considerable already at pulse repetition rates above a few Hz. Similar Schlieren techniques were applied to study the thermal characteristics of laser probes, e.g. for the treatment of Benign Prostatic Hyperplasia (BPH). In combination with thermal modeling an optimal therapy might be predicted. Schlieren techniques, generating high-speed and 'thermal' images, can provide a good understanding of the ablation mechanism and the thermo-dynamics during laser-tissue interaction with continuous wave and pulse lasers.

  7. Understanding lasers

    SciTech Connect

    Gibilisco, S.

    1989-01-01

    Covering all different types of laser applications-Gibilisco offers an overview of this fascinating phenomenon of light. Here he describes what lasers are and how they work and examines in detail the different kinds of lasers in use today. Topics of particular interest include: the way lasers work; the different kinds of lasers; infrared, ultraviolet and x-ray lasers; use of lasers in industry and manufacturing; use of lasers for long-distance communications; fiberoptic communications; the way laser shows work; the reality of Star Wars; lasers in surgical and medical applications; and holography and the future of laser technology.

  8. Hyperplasia suppression by Ho:YAG laser intravascular irradiation in rabbit.

    PubMed

    Nakatani, Eriko; Arai, Tsunenori

    2006-07-01

    The proliferation of smooth muscle cells (SMCs) was suppressed in denudated rabbit aorta by holmium-yttrium-aluminum-garnet (Ho:YAG) laser intravascular irradiation. This study was dedicated to determine the applicability of the Ho:YAG laser irradiation on chronic restenosis after balloon angioplasty. The proliferation of SMCs in denudated rabbit aortas was suppressed in vivo 6 weeks after the laser irradiation of 20 pulses with 60 mJ per pulse. To investigate the mechanisms of this in vivo effect, the death of SMCs by the Ho:YAG laser-induced bubble collapse pressure was studied in vitro. No significant cell death attributed to this pressure was found. We conclude that the suppression of the proliferation of SMCs in vivo might not be caused by a reduction in density of SMCs induced by the collapse in pressure. We submit that the suppression of SMC proliferation in vivo could be caused by the bubble expansion pressure and/or heat induced by the laser irradiation. PMID:16673055

  9. Laser resistance and clinical practicability of a new compound endotracheal tube

    NASA Astrophysics Data System (ADS)

    Foth, Hans-Jochen; Hoermann, Karl

    1994-12-01

    The danger of ignition of ventilation tubes during CO2-laser surgery in the larynx region has been described several times in the literature. It was found that tubes of polymers, like PVC, have a low ignition threshold and, even worse, evaporate toxic gases when they were irradiated accidentally by the laser beam. So far, a pure metal tube was described as the safest endotracheal tube. A newly developed compound tube built up by a rubber tube surrounded by an ondulated silver foil and a layer of white MerocelR-foam, was tested for its laser stability against various types of lasers, like CO2 Holmium:YAG, Nd:YAG, Ar+ and excimer laser. The damage threshold of this tube at approximately 3 (DOT) 106 W/cm2 is significantly higher than the damage threshold of the metal tube and far above the power density used for coagulation or ablation of tissue. Beside these experimental results, this contribution describes the experiences which have been obtained with this tube in the clinical routine.

  10. Laser balloon vascular welding using a dye-enhanced albumin solder

    NASA Astrophysics Data System (ADS)

    Ott, Beat; Zueger, Benno J.; Erni, Dominique; Banic, Andrej; Schaffner, Thomas; Weber, Heinz P.; Frenz, Martin

    2001-05-01

    Porcine posterior tibial arteries (n equals 50) and saphenous veins (n equals 32) have been welded end-to-end using an 808 nm diode laser combined with an indocyanine green enhanced albumin solder. For comparison, the same welding procedure has been performed with a Holmium:YAG laser without solder. Both lasers were running in continuous wave (cw) regime at a power limited below 1.2 W. The vascular stumps were approached to each other over a coronary dilatation catheter in order to obtain a precise alignment. The balloon catheter simplified vessel handling and the tight vessel positioning prevented a solder penetration into the lumen. Standard histology revealed for both welding techniques a lateral tissue damage between 2 and 3 mm. The vessels welded with the 808 nm diode laser using albumin solder showed considerably higher tensile strength (1 N compared to 0.3 N) than vessels welded exclusively by Ho:YAG laser radiation. In contrast, leaking pressure (350 +/- 200 mmHg) and bursting pressure 457 +/- 200 mmHg) were independent of the welding technique used.

  11. Using transurethral Ho:YAG-laser resection to treat urethral stricture and bladder neck contracture

    NASA Astrophysics Data System (ADS)

    Bo, Juanjie; Dai, Shengguo; Huang, Xuyuan; Zhu, Jing; Zhang, Huiguo; Shi, Hongmin

    2005-07-01

    Objective: Ho:YAG laser had been used to treat the common diseases of urinary system such as bladder cancer and benign prostatic hyperplasia in our hospital. This study is to assess the efficacy and safety of transurethral Ho:YAG-laser resection to treat the urethral stricture and bladder neck contracture. Methods: From May 1997 to August 2004, 26 cases of urethral stricture and 33 cases of bladder neck contracture were treated by transurethral Ho:YAG-laser resection. These patients were followed up at regular intervals after operation. The uroflow rate of these patients was detected before and one-month after operation. The blood loss and the energy consumption of holmium-laser during the operation as well as the complications and curative effect after operation were observed. Results: The therapeutic effects were considered successful, with less bleeding and no severe complications. The Qmax of one month postoperation increased obviously than that of preoperation. Of the 59 cases, restenosis appeared in 11 cases (19%) with the symptoms of dysuria and weak urinary stream in 3-24 months respectively. Conclusions: The Ho:YAG-laser demonstrated good effect to treat the obstructive diseases of lower urinary tract such as urethral stricture and bladder neck contracture. It was safe, minimal invasive and easy to operate.

  12. Mid - infrared solid state lasers for spectroscopic applications

    NASA Astrophysics Data System (ADS)

    Terekhov, Yuri

    This work is devoted to study of novel high power middle-infrared (Mid-IR) laser sources enabling development of portable platform for sensing of organic molecules with the use of recently discovered Quartz Enhanced Photo Acoustic Spectroscopy (QEPAS). The ability to detect small concentrations is beneficial to monitor atmosphere pollution as well for biomedical applications such as analysis of human breath to detect earlier stages of cancer or virus activities. A QEPAS technique using a quartz tuning fork (QTF) as a detector enables a strong enhancement of measured signal when pump laser is modulated with a frequency coinciding with a natural frequency of a QTF. It is known that the detectability of acousto-optics based sensors is proportional to the square root of the laser intensity used for detection of analyte. That is the reason why commercially available semiconductor Mid-IR lasers having small output power limit sensitivity of modern QEPAS based sensors. The lack of high power broadly tunable lasers operating with a modulation frequency of quartz forks (~ 32.768 kHz) is the major motivation of this study. Commercially available Mid-IR (2-3.3 microm), single frequency, continuous wave (CW) fiber pumped lasers based on transition metal doped chalcogenides (e.g. Cr:ZnSe) prove to be efficient laser sources for organic molecules detection. However, their direct modulation is limited to several kHz, and cannot be directly used in combination with QEPAS. Hence, one objective of this work is to study and develop fiber laser pumped Ho:YAG (Er:YAG)/Cr:ZnSe tandem laser system/s. Ho (Holmium) and/or Er (Erbium) ions having long radiation lifetime (~ 10 ms) can effectively accumulate population inversion under CW fiber laser excitation. Utilization of acousto-optic (AO) modulators in the cavity of Ho:YAG (Er:YAG) laser will enable effective Q-Switching with repetition rate easily reaching the resonance frequency of a QTF. It is expected that utilization of Ho:YAG (Er:YAG)/Cr:ZnSe tandem will further result in effective conversion of monochromatic radiation of Ho/Er lasers in a broadly tunable Mid-IR radiation compatible with QEPAS detection.

  13. High-Resolution In Vivo Imaging of Regimes of Laser Damage to the Primate Retina

    PubMed Central

    Pocock, Ginger M.; Oliver, Jeffrey W.; Specht, Charles S.; Estep, J. Scot; Noojin, Gary D.; Schuster, Kurt; Rockwell, Benjamin A.

    2014-01-01

    Purpose. To investigate fundamental mechanisms of regimes of laser induced damage to the retina and the morphological changes associated with the damage response. Methods. Varying grades of photothermal, photochemical, and photomechanical retinal laser damage were produced in eyes of eight cynomolgus monkeys. An adaptive optics confocal scanning laser ophthalmoscope and spectral domain optical coherence tomographer were combined to simultaneously collect complementary in vivo images of retinal laser damage during and following exposure. Baseline color fundus photography was performed to complement high-resolution imaging. Monkeys were perfused with 10% buffered formalin and eyes were enucleated for histological analysis. Results. Laser energies for visible retinal damage in this study were consistent with previously reported damage thresholds. Lesions were identified in OCT images that were not visible in direct ophthalmoscopic examination or fundus photos. Unique diagnostic characteristics, specific to each damage regime, were identified and associated with shape and localization of lesions to specific retinal layers. Previously undocumented retinal healing response to blue continuous wave laser exposure was recorded through a novel experimental methodology. Conclusion. This study revealed increased sensitivity of lesion detection and improved specificity to the laser of origin utilizing high-resolution imaging when compared to traditional ophthalmic imaging techniques in the retina. PMID:24891943

  14. High-resolution in vivo imaging of regimes of laser damage to the primate retina.

    PubMed

    Pocock, Ginger M; Oliver, Jeffrey W; Specht, Charles S; Estep, J Scot; Noojin, Gary D; Schuster, Kurt; Rockwell, Benjamin A

    2014-01-01

    Purpose. To investigate fundamental mechanisms of regimes of laser induced damage to the retina and the morphological changes associated with the damage response. Methods. Varying grades of photothermal, photochemical, and photomechanical retinal laser damage were produced in eyes of eight cynomolgus monkeys. An adaptive optics confocal scanning laser ophthalmoscope and spectral domain optical coherence tomographer were combined to simultaneously collect complementary in vivo images of retinal laser damage during and following exposure. Baseline color fundus photography was performed to complement high-resolution imaging. Monkeys were perfused with 10% buffered formalin and eyes were enucleated for histological analysis. Results. Laser energies for visible retinal damage in this study were consistent with previously reported damage thresholds. Lesions were identified in OCT images that were not visible in direct ophthalmoscopic examination or fundus photos. Unique diagnostic characteristics, specific to each damage regime, were identified and associated with shape and localization of lesions to specific retinal layers. Previously undocumented retinal healing response to blue continuous wave laser exposure was recorded through a novel experimental methodology. Conclusion. This study revealed increased sensitivity of lesion detection and improved specificity to the laser of origin utilizing high-resolution imaging when compared to traditional ophthalmic imaging techniques in the retina. PMID:24891943

  15. A tapered distal fiber tip for thulium fiber laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Blackmon, Richard L.; Irby, Pierce B.; Fried, Nathaniel M.

    2010-02-01

    The Thulium fiber laser has recently been tested as a potential alternative to the Holmium:YAG laser for lithotripsy. This study explores use of a short taper for expanding the Thulium fiber laser beam at the distal tip of a small-core fiber. Thulium fiber laser radiation with a wavelength of 1908 nm, 10 Hz pulse rate, 70 mJ pulse energy, and 1-ms pulse duration was delivered through a 2-m-length fiber with 150-?m-input-end, 300-?m-output-end, and 5-mmlength taper, in contact with human uric acid (UA) and calcium oxalate monohydrate (COM) stones, ex vivo (n=10 each). Stone mass loss, stone crater depths, fiber transmission losses, fiber burn-back, irrigation rates, and deflection through a flexible ureteroscope were measured for the above tapered fiber and compared with conventional fibers. After delivery of 1800 pulses through the tapered fiber, mass loss measured 12.7 +/- 2.6 mg for UA and 7.2 +/- 0.8 mg COM stones, comparable to conventional 100-?m-core fibers (12.6 +/- 2.5 mg for UA and 6.8 +/- 1.7 mg for COM stones). No transmission losses or burn-back occurred for the tapered fiber after 36,000 pulses, while a conventional 150-?m fiber experienced significant tip degradation after only 1800 pulses. High irrigation rates were measured with the tapered fiber inserted through the working port of an ureteroscope, without hindering ureteroscope deflection, mimicking that of conventional 150 m fibers. The short tapered distal fiber tip allows expansion of the laser beam, resulting in decreased fiber tip damage compared to conventional small-core fibers, without compromising fiber bending, stone vaporization efficiency, or irrigation rates.

  16. Corneal photoablation in vivo with the erbium:YAG laser: first report

    NASA Astrophysics Data System (ADS)

    Jean, Benedikt J.; Bende, Thomas; Matallana, Michael; Kriegerowski, Martin

    1995-05-01

    As an alternative to far-UV lasers for corneal refractive surgery, the Erbium:YAG laser may be used in TEM00 mode. The resulting gaussian beam profile leads to a certain amount of myopic correction per laser pulse. Although animal data suggest that the clinical outcome should be comparable to the UV-lasers, no human data were available until now. We performed Erbium:YAG laser areal ablation in 5 blind human eyes. In TEM00 mode, the laser parameters were: effective diameter of laser spot equals 3.4 mm, fluence equals 380 mJ/cm2, pulse duration equals 250 microsecond(s) , Repetition rate equals 4 Hz, Number of applied laser pulses equals 15. Four patients with no light perception, one with intact light projection on one eye (some of them scheduled for enucleation) were treated under topical anaesthesia. Patient selection and informed consent were agreed to by the University's independent Ethics Committee. Prior to laser irradiation, corneal epithelium was removed. A postoperative silicone cast of the cornea was analyzed with a confocal laser micro-topometer for the ablation profile. The eyes were treated with antibiotic ointment until the epithelium was closed. Clinical appearance and, where possible, profilometry of the ablated area was observed. The ablation profile in cornea was gaussian shaped with a maximal depth of 30 micrometers . During laser treatment, the corneal surface becomes opaque, clearing in a matter of seconds. Epithelial healing and clinical appearance was similar to excimer laser treatment. However, during the first week, the irradiated area shows subepithelial irregularities, resembling small bubbles, disappearing thereafter.

  17. Pulsed infrared laser irradiation of biological tissue: effect of pulse duration and repetition rate

    NASA Astrophysics Data System (ADS)

    Jansen, E. Duco; Chundru, Ravi K.; Samanani, Salim A.; Tibbetts, Todd A.; Welch, Ashley J.

    1993-07-01

    Pulsed laser ablation is a trade off between minimizing thermal damage (for relatively long pulses) and mechanical damage (for relatively short pulses) to tissue adjacent to the ablation crater. Often it is not known what the optimal laser parameters are for a specific application, since clinically used parameters have at least partially been dictated by physical limitations of the laser devices. We recently obtained a novel type of cryogenic continuous wave holmium:YAG laser ((lambda) equals 2.09 micrometers ) with a galvanometric drive outcouple mirror that acts as a Q-switch. This unique device provides pulse repetition rates from a few Hz up to kHz and the pulse length is variable from microsecond(s) to ms. The effect of pulse duration and repetition rate on the thermal response of chicken breast is documented using temperature measurements with a thermal camera. We varied the pulse width from 10 microsecond(s) to 5 ms and fond that these pulse durations can be considered impulses of thermalized optical energy. In this paper some theoretical considerations of the pulse length will be described that support the experimental data. It was also found that even at 1 pulse per second thermal superposition occurs, indicating a much longer thermal relaxation time than predicted by a simple time constant model.

  18. The effect of nonablative laser energy on joint capsular properties. An in vitro histologic and biochemical study using a rabbit model

    NASA Technical Reports Server (NTRS)

    Hayashi, K.; Thabit, G. 3rd; Vailas, A. C.; Bogdanske, J. J.; Cooley, A. J.; Markel, M. D.

    1996-01-01

    The purpose of this study was to evaluate the effect of laser energy at nonablative levels on joint capsular histologic and biochemical properties in an in vitro rabbit model. The medial and lateral portions of the femoropatellar joint capsule from both stifles of 12 mature New Zealand White rabbits were used. Specimens were divided into three treatment groups (5 watts, 10 watts, and 15 watt) and one control group using a randomized block design. Specimens were placed in a 37 degrees bath of lactated Ringer's solution and laser energy was applied using a holmium:yttrium-aluminum-garnet laser in four transverse passes across the tissue at a velocity of 2 mm/sec with the handpiece set 1.5 mm from the synovial surface. Histologic analysis revealed thermal alteration of collagen (fusion) and fibroblasts (pyknosis) at all energy densities, with higher laser energy causing significantly greater morphologic changes over a larger area (P < 0.05). Application of laser energy did not significantly alter the biochemical parameters evaluated, including type I collagen content and nonreducible crosslinks (P > 0.05). This study demonstrated that nonablative laser energy caused significant thermal damage to the joint capsular tissue in an energy-dependent fashion, but type I collagen content and nonreducible crosslinks (P > 0.05). This study demonstrated that nonablative laser energy caused significant thermal damage to the joint capsular tissue in an energy-dependent fashion, but type I Collagen content and nonreducible corsslinks were not significantly altered.

  19. Delivery of Erbium:YAG laser radiation through side-firing germanium oxide optical fibers

    NASA Astrophysics Data System (ADS)

    Ngo, Anthony K.; Fried, Nathaniel M.

    2006-02-01

    The Erbium:YAG laser is currently being tested experimentally for endoscopic applications in urology, including more efficient laser lithotripsy and more precise incision of urethral strictures than the Holmium:YAG laser. While side-firing silica fibers are available for use with the Ho:YAG laser in urology, no such fibers exist for use with the Er:YAG laser. These applications may benefit from the availability of a side-firing, mid-infrared optical fiber capable of delivering the laser radiation at a 90-degree angle to the tissue. The objective of this study is to describe the simple construction and characterization of a side-firing germanium oxide fiber for potential use in endoscopic laser surgery. Side-firing fibers were constructed from 450-micron-core germanium oxide fibers of 1.45-m-length by polishing the distal tip at a 45-degree angle and placing a 1-cm-long protective quartz cap over the fiber tip. Er:YAG laser radiation with a wavelength of 2.94 microns, pulse duration of 300 microseconds, pulse repetition rate of 3 Hz, and pulse energies of from 5 to 550 mJ was coupled into the fibers. The fiber transmission rate and damage threshold measured 48 +/- 4 % and 149 +/- 37 mJ, respectively (n = 6 fibers). By comparison, fiber transmission through normal germanium oxide trunk fibers measured 66 +/- 3 %, with no observed damage (n = 5 fibers). Sufficient pulse energies were transmitted through the side-firing fibers for contact tissue ablation. Although these initial tests are promising, further studies will need to be conducted, focusing on assembly of more flexible, smaller diameter fibers, fiber bending transmission tests, long-term fiber reliability tests, and improvement of the fiber output spatial beam profile.

  20. Preliminary report: Laser welding and fibrinogen soldering are superior to sutured cholecyctostomy closure in a canine model

    NASA Astrophysics Data System (ADS)

    Oz, Mehmet C.; Treat, Michael R.; Libutti, Steven K.; Popp, Howard W.; Bass, Lawrence S.; Popilskis, Sulli

    1990-06-01

    Percutaneous endoscopic techniques for biliary surgery would be facilitated by methods of welding biliary tissue. To further investigate laser methods for fusing biliary tissue, we compared the time 0 bursting strength of two variations of near-infrared laser closure against polyglycolic acid suture controls. These time 0 studies were performed with a gallium-aluminum-arsenide semiconductor diode laser with a major ,iavelength output of 808 -F 1 nm and an energy density of 4.8 J/cm'. Using the 808 nm laser and indocyanine green dye to enhance laser energy uptake, closure of gallbladder incisions was accomplished with and without addition of fibrinogen to the target site prior to laser exposure. Without fibrinogen, the laser welds burst at 77 mm Hg, while fibrinogen soldering yielded a bursting pressure of 194 mm Hg. Sutured welds leaked at 215 mm Hg. Survival studies were performed with a mid-infrared 2.15 micron thulium-holmium--chromium:YAG laser producing 200 microsecond 300 millijoule pulses at 3 Hz (peak power .75 megawatts/sq cm, fluence 150 joules per square centimeter). The healing of midinfrared and polyglycolic suture closures of gallbladder incisions were compared at 1,2,3, and 4 weeks. All closures healed without evidence of leakage or infection. Laser welded cholecystostomy sites were completely ingrown with fibrous tissue by 2 weeks post- operatively and re-epithelialized by 3 weeks after operation. Suture closed wounds were still without complete epithelization 4 weeks after the procedure. Laser welding, particularly with fibrinogen reinforcement, may be a useful technique in future developments in percutaneous endoscopic biliary surgery.

  1. High-pressure synthesis and single-crystal structure refinement of gadolinium holmium silicate hydroxyapatite Gd{sub 4.33}Ho{sub 4.33}(SiO{sub 4}){sub 6}(OH){sub 2}

    SciTech Connect

    Wang Chao; Liu Xiaoyang . E-mail: liuxy@jlu.edu.cn; Fleet, M.E.; Feng, Shouhua; Xu Ruren

    2006-07-15

    Single crystals of gadolinium holmium silicate hydroxyapatite Gd{sub 4.33}Ho{sub 4.33}(SiO{sub 4}){sub 6}(OH){sub 2} have been synthesized at 2.0GPa and 1450 deg. C using a piston-cylinder-type high-pressure apparatus. The crystal symmetry by single-crystal X-ray diffraction analysis is hexagonal, space group P6{sub 3}/m (No. 176), with a=9.3142(5)A, c=6.7010(4)A, Z=1. Gadolinium and Ho are disordered over the two large cation positions, A(1) and A(2), and charge balance in this silicate apatite is maintained by cation vacancies in A(1). Two other apatite-structure crystals investigated have P3-bar and Imma symmetry, and represent either partially ordered Gd-Ho distributions or crystal strain induced during quenching.

  2. Dye lasers

    SciTech Connect

    Schafer, F.P. )

    1990-01-01

    This book includes chapters on continuous-wave dye lasers and properties of dye lasers and a chapter on continuous-wave dye lasers. There is also a chapter on wavemeters. This book provides an introduction to dye lasers and contains information for scientists and engineers who deal with their applications.

  3. Laser clock

    NASA Astrophysics Data System (ADS)

    Facklam, R. L.

    1984-11-01

    A laser clock includes a linear laser in one embodiment of the clock and a ring laser gyro in the other embodiment. The linear laser is frequency stabilized and utilizes a single active medium in the form of a low pressure gas, such as He-Ne, with a Doppler broadened gain curve. The ring laser gyro is a four frequency laser with a Faraday rotor. Detector and electronic circuitry associated with the laser of each embodiment detect a beat frequency and coverts it to a clock signal.

  4. High power diode pumped solid state laser development at Lawrence Livermore National Laboratory

    SciTech Connect

    Solarz, R.; Albrecht, G.; Hackel, L.

    1994-03-01

    The authors recent developments in high powered diode pumped solid state lasers at Lawrence Livermore National Laboratory. Over the past year the authors have made continued improvements to semiconductor pump array technology which includes the development of higher average power and lower cost pump modules. They report the performance of high power AlGaAs, InGaAs, and AlGaInP arrays. They also report on improvement to the integrated micro-optics designs in conjunction with lensing duct technology which gives rise to very high performance end pumping designs for solid state lasers which have major advantages which they detail. Substantial progress on beam quality improvements to near the diffraction limit at very high power have also been made and will be reported. They also will discuss recent experiments on high power non-linear materials for q-switches, harmonic converters, and parametric oscillators. Advances in diode pumped devices at LLNL which include tunable Cr:LiSrAlF{sub 6}, mid-IR Er:YAG, holmium based lasers and other developments will also be outlined. Concepts for delivering up to 30 kilowatts of average power from a DPSSL oscillator will be described.

  5. A Miniaturized, 1.9F Integrated Optical Fiber and Stone Basket for Use in Thulium Fiber Laser Lithotripsy.

    PubMed

    Wilson, Christopher R; Hutchens, Thomas C; Hardy, Luke A; Irby, Pierce B; Fried, Nathaniel M

    2015-10-01

    The thulium fiber laser (TFL) is being explored as an alternative laser lithotripter to the standard holmium:yttrium-aluminum-garnet laser. The more uniform beam profile of the TFL enables higher power transmission through smaller fibers. In this study, a 100-?m core, 140-?m outer-diameter (OD) silica fiber with 5-mm length hollow steel tip was integrated with 1.3F (0.433-mm OD) nitinol wire basket to form a 1.9F (0.633-mm OD) device. TFL energy of 30?mJ, 500??s pulse duration, and 500?Hz pulse rate was delivered to human uric acid stones, ex vivo. Stone ablation rates measured 1.5 0.2?mg/s, comparable to 1.7 0.3?mg/s using bare fiber tips separately with stone basket. With further development, this device may minimize stone retropulsion, allowing more efficient TFL lithotripsy at higher pulse rates. It may also provide increased flexibility, higher saline irrigation rates through the ureteroscope working channel, reduce fiber degradation compared with separate fiber and basket manipulation, and reduce laser-induced nitinol wire damage. PMID:26167738

  6. Laser ignition

    DOEpatents

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    2002-01-01

    In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. The beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being recombined with the first portion after a delay before injection into the ignitor laser. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones.

  7. Laser Analyzer

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Dopant level analysis is important to the laser system designer because it allows him to model the laser's performance. It also allows the end user to determine what went wrong when a laser fails to perform as expected. Under a Small Business Innovation Research (SBIR) contract, Scientific Materials Corporation has developed a process for producing uniform laser rods in which the amount of water trapped in the crystal during growth is reduced. This research led to the formation of a subsidiary company, Montana Analytical Services, which conducts analysis of laser rods for dopant ion concentrations. This is a significant advance in laser technology.

  8. A pilot study to determine medical laser generated air contaminant emission rates for a simulated surgical procedure.

    PubMed

    Lippert, Julia F; Lacey, Steven E; Lopez, Ramon; Franke, John; Conroy, Lorraine; Breskey, John; Esmen, Nurtan; Liu, Li

    2014-01-01

    The U.S. Occupational Safety and Health Administration (OSHA) estimates that half a million health-care workers are exposed to laser surgical smoke each year. The purpose of this study was to establish a methodology to (1) estimate emission rates of laser-generated air contaminants (LGACs) using an emission chamber, and to (2) perform a screening study to differentiate the effects of three laser operational parameters. An emission chamber was designed, fabricated, and assessed for performance to estimate the emission rates of gases and particles associated with LGACs during a simulated surgical procedure. Two medical lasers (Holmium Yttrium Aluminum Garnet [Ho:YAG] and carbon dioxide [CO2]) were set to a range of plausible medical laser operational parameters in a simulated surgery to pyrolyze porcine skin generating plume in the emission chamber. Power, pulse repetition frequency (PRF), and beam diameter were evaluated to determine the effect of each operational parameter on emission rate using a fractional factorial design. The plume was sampled for particulate matter and seven gas phase combustion byproduct contaminants (benzene, ethylbenzene, toluene, formaldehyde, hydrogen cyanide, carbon dioxide, and carbon monoxide): the gas phase emission results are presented here. Most of the measured concentrations of gas phase contaminants were below their limit of detection (LOD), but detectable measurements enabled us to determine laser operation parameter influence on CO2 emissions. Confined to the experimental conditions of this screening study, results indicated that beam diameter was statistically significantly influential and power was marginally statistically significant to emission rates of CO2 when using the Ho:YAG laser but not with the carbon dioxide laser; PRF was not influential vis-a-vis emission rates of these gas phase contaminants. PMID:24498966

  9. Influence of Saline on Temperature Profile of Laser Lithotripsy Activation

    PubMed Central

    Silva, Igor N.; Donalisio da Silva, Rodrigo; Gustafson, Diedra; Sehrt, David; Kim, Fernando J.

    2015-01-01

    Abstract Purpose: We established an ex vivo model to evaluate the temperature profile of the ureter during laser lithotripsy, the influence of irrigation on temperature, and thermal spread during lithotripsy with the holmium:yttrium-aluminum-garnet (Ho:YAG) laser. Materials and Methods: Two ex vivo models of Ovis aries urinary tract and human calcium oxalate calculi were used. The Open Ureteral Model was opened longitudinally to measure the thermal profile of the urothelium. On the Clinical Model, anterograde ureteroscopy was performed in an intact urinary system. Temperatures were measured on the external portion of the ureter and the urothelium during lithotripsy and intentional perforation. The lithotripsy group (n=20) was divided into irrigated (n=10) and nonirrigated (n=10), which were compared for thermal spread length and values during laser activation. The intentional perforation group (n=10) was evaluated under saline flow. The Ho:YAG laser with a 365 μm laser fiber and power at 10W was used (1J/Pulse at 10 Hz). Infrared Fluke Ti55 Thermal Imager was used for evaluation. Maximum temperature values were recorded and compared. Results: On the Clinical Model, the external ureteral wall obtained a temperature of 37.4°C±2.5° and 49.5°C±2.3° (P=0.003) and in the Open Ureteral Model, 49.7°C and 112.4°C with and without irrigation, respectively (P<0.05). The thermal spread along the external ureter wall was not statically significant with or without irrigation (P=0.065). During intentional perforation, differences in temperatures were found between groups (opened with and without irrigation): 81.8°±8.8° and 145.0°±15.0°, respectively (P<0.005). Conclusion: There is an increase in the external ureteral temperature during laser activation, but ureteral thermal values decreased when saline flow was applied. Ureter thermal spread showed no difference between irrigated and nonirrigated subgroups. This is the first laser lithotripsy thermography study establishing the framework to evaluate the temperature profile in the future. PMID:25154455

  10. Continuous-wave and high repetition rate Q-switched operation of Ho:YLF laser in-band pumped by a linearly polarized Tm:fiber laser

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, Jacek; Zendzian, Waldemar; Jabczynski, Jan Karol; Swiderski, Jacek

    2014-11-01

    A study of Ho:YLF laser in continuous-wave (CW) and Q-switched operation, single-pass end-pumped by a Tm:fiber laser is presented. The research was made for two crystals of the same length and with different Ho dopant concentrations (0.5 at%, 3330 mm3 and 1.0 at%, 5530 mm3). The lasers operated on ?-polarization. The lasers based on both crystals were examined under the same experimental circumstances. At room temperature, for an output coupling transmission of 40%, the maximum CW output powers of 11.5 W (0.5 at%) and 14.5 W (1.0 at%) were achieved, corresponding to slope efficiencies of 40.9% and 53.4% and optical-to-optical efficiencies of 35.4% and 44.6% with respect to the incident pump power, respectively. For a Q-switched operation, in a CW pumping regime, the pulse repetition frequency (PRF) was changed from 1 to 10 kHz. For this case, the maximum average output power of 14.2 W at the PRF of 10 kHz was obtained for a higher holmium-doping concentration crystal. For 1 kHz PRF, pulse energies of 5.7 mJ with a 11 ns FWHM pulse width corresponding to almost 520 kW peak power were recorded. The laser operated at the wavelength of 2050.08 nm with the FWHM line width of 0.86 nm delivering a near-diffraction-limited beam with M2 values of 1.05 and 1.09 in the horizontal and vertical directions, respectively.

  11. Lasers of All Sizes

    NASA Astrophysics Data System (ADS)

    Balcou, Philippe; Forget, Sébastien Robert-Philip, Isabelle

    2015-10-01

    * Introduction * The Laser in All Its Forms * Gas lasers * Dye lasers * Solid-state lasers * Lasers for Every Taste * The rise of lasers * Lasers of all sizes * The colors of the rainbow... and beyond * Shorter and shorter lasers * Increasingly powerful lasers * Lasers: A Universal Tool? * Cutting, welding, and cleaning * Communicating * Treating illnesses * Measuring * Supplying energy? * Entertaining * Understanding * Conclusion

  12. AB016. Which laser works best for benign prostatic hyperplasia?

    PubMed Central

    Kim, Sae Woong

    2015-01-01

    For decades, transurethral resection of the prostate (TUR-P) has been considered the gold standard surgical procedure for men with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH). The GreenLight (GL) laser has a wavelength of 532 nm the range of visible green light. The emitted energy is mostly absorbed by hemoglobin, thus heating the intracellular fluid in the well vascularized prostatic tissue which leads to vaporization. Since about half of men over the age of 60 often have lower LUTS due to BPH with prolonged life expectancy worldwide, more symptomatic BPH patients will require surgical interventions. The incidence of cardiovascular, stroke, and lung diseases also increases with age, the number of BPH patients at high risk for these diseases will increase accordingly. Gu et al. concluded that age has little effect on the efficacy and safety of GL HPS laser. Series of a total of 188 BPH patients at high cardiovascular risk and on long-term anticoagulation underwent 120-W GL laser vaporization of the BPH showed that no patient required blood transfusion, and none revealed any evidence of intraoperative fluid absorption leading to serum electrolyte abnormalities. Severe intraoperative and postoperative complications were not occurred. Disadvantage of previous KTP laser is limited volume reduction in large size prostate and may be insufficient to maintain long-lasting good functional results. Brunken et al. reported that GL laser enucleation of the prostate volume ?50 cc. The results showed that all patients were able to void properly and during follow-up, none of the patients needed further interventions or hospital treatment. A multicenter randomized controlled trial at Europe compared GL laser with monopolar TUR-P with a total of randomized 139 patients. The results for IPSS variation were not different between two group in prostate volume ?70 cc. The authors concluded that GL laser seems an acceptable alternative to TUR-P with close results on LUTS improvement in the short term and GL laser is associated with a reduced hospital stay with less postoperative irrigation and hematuria. Based on recently reported series, GL laser were not influenced by the size of prostate, the use of anticoagulant, the intake of 5-ARI for BPH management, a history of AUR. GL laser can be applied to the patients of large size of prostate, or difficult to stop the use of anticoagulant.

  13. Removal of vitreous body by IR laser radiation

    NASA Astrophysics Data System (ADS)

    Steeb, Diana; Foth, Hans-Jochen; Krause, M.; Weindler, J.

    1998-01-01

    The common method to remove the vitreous body of the eye (vitrectomy) is based on mechanical cutting and pulling of the tissue. Since this involves the risk of mechanical violation it can not be performed in close contact to the retina. This limitation should not exist for erbium laser radiation due to its short penetration depth. A flashlamp pumped, pulsed free- running erbium:YAG laser was used at a wavelength of 2.94 micrometer. Three different pulse length were used. The measurements were performed at freshly enucleated porcine vitreous bodies stored in cooled saline water. The ablation rate was taken by a high precision scale. The same experiments were performed with saline water replacing the vitreous body. Pulse energies under 25 mJ were ignored. The ablation rates did hardly differ here from the results measuring the evaporation of water. Energies above 125 mJ per pulse caused a visible movement of the surface. Therefore this energy range was not included in the experiment. The ablation rate was observed to increase linear with higher pulse energies and shorter pulse lengths. The ablation energy per mass decreases linear with increasing pulse energy for all pulse length. The results show that it is possible to ablate the vitreous body. It should be possible to perform the ablation process in less than half an hour.

  14. Laser microphone

    DOEpatents

    Veligdan, James T. (Manorville, NY)

    2000-11-14

    A microphone for detecting sound pressure waves includes a laser resonator having a laser gain material aligned coaxially between a pair of first and second mirrors for producing a laser beam. A reference cell is disposed between the laser material and one of the mirrors for transmitting a reference portion of the laser beam between the mirrors. A sensing cell is disposed between the laser material and one of the mirrors, and is laterally displaced from the reference cell for transmitting a signal portion of the laser beam, with the sensing cell being open for receiving the sound waves. A photodetector is disposed in optical communication with the first mirror for receiving the laser beam, and produces an acoustic signal therefrom for the sound waves.

  15. Histopathologic observations on human eyes following neodymium: YAG laser cyclophotocoagulation for glaucoma.

    PubMed Central

    Ferry, A P; King, M H; Richards, D W

    1995-01-01

    PURPOSE: Although Nd:YAG laser cyclophotocoagulation has been extensively used for nearly a decade in treatment of severe glaucoma, there have been remarkably few reports (each of them extremely brief) of histopathological examination of glancomatous human eyes that had been so treated. We undertook this study to provide further details regarding the nature of the lesions produced in this type of ciliary ablation. METHODS: We chose three representative cases in which a glaucomatous human eye had been subjected to Nd: YAG cyclophotocoagulation, and was subsequently enucleated. To better understand the temporal evolution of the lesions, we selected eyes that were enucleated 1 day, 20 days, and 3 months, respectively, after they had been treated with noncontact Nd: YAG laser cyclophotocoagulation. RESULTS AND CONCLUSIONS: (1) energy levels ranging from 4.4 Joules to 5.6 Joules were effective in producing appropriate lesions; (2) direction of the laser beam 1 to 1.5 mm behind the limbus caused severe destructive lesions of the pars plicata: (3) toward the periphery of the individual treatment sites, the stroma and ciliary muscle continued to exhibit severe degeneration, as did the epithelium lining the valleys between the crests of the ciliary processes; but in those peripheral zones of individual treatment sites, the epithelium lining the crests of the ciliary processes survived and appears normal; (4) bleb-like separations of the ciliary epithelium from the adjacent stroma, particularly along the posterior aspect of the ciliary body lesions, are a prominent early feature of Nd:YAG cyclophotocoagulation; (5) the pigmented epithelium is more vulnerable to laser energy than is the nonpigmented epithelium of the ciliary body; (6) the destruction of the ciliary epithelium is permanent; (7) deeply pigmented persons have more melanocytes in the ciliary body muscle and stroma than do more lightly pigmented individuals, a circumstance that renders the tissues more vulnerable to laser energy; (8) the ciliary muscle was always severely damaged; (9) no scleral injury was observed other than evanescent, focal areas of edema of the deep sclera; and (10) except in the episclera, inflammatory cells were strikingly few in number, a circumstance providing support for the clinical observation that eyes treated with laser cyclophotocoagulation exhibit less of an inflammatory response than do those treated with cyclocryotherapy. Images FIGURE 1 FIGURE 2 FIGURE 3 A FIGURE 3 B FIGURE 3 C FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 9 p336-a PMID:8719684

  16. Laser ignition

    DOEpatents

    Early, James W.; Lester, Charles S.

    2004-01-13

    Sequenced pulses of light from an excitation laser with at least two resonator cavities with separate output couplers are directed through a light modulator and a first polarzing analyzer. A portion of the light not rejected by the first polarizing analyzer is transported through a first optical fiber into a first ignitor laser rod in an ignitor laser. Another portion of the light is rejected by the first polarizing analyzer and directed through a halfwave plate into a second polarization analyzer. A first portion of the output of the second polarization analyzer passes through the second polarization analyzer to a second, oscillator, laser rod in the ignitor laser. A second portion of the output of the second polarization analyzer is redirected by the second polarization analyzer to a second optical fiber which delays the beam before the beam is combined with output of the first ignitor laser rod. Output of the second laser rod in the ignitor laser is directed into the first ignitor laser rod which was energized by light passing through the first polarizing analyzer. Combined output of the first ignitor laser rod and output of the second optical fiber is focused into a combustible fuel where the first short duration, high peak power pulse from the ignitor laser ignites the fuel and the second long duration, low peak power pulse directly from the excitation laser sustains the combustion.

  17. Laser sampling

    NASA Astrophysics Data System (ADS)

    Gorbatenko, A. A.; Revina, E. I.

    2015-10-01

    The review is devoted to the major advances in laser sampling. The advantages and drawbacks of the technique are considered. Specific features of combinations of laser sampling with various instrumental analytical methods, primarily inductively coupled plasma mass spectrometry, are discussed. Examples of practical implementation of hybrid methods involving laser sampling as well as corresponding analytical characteristics are presented. The bibliography includes 78 references.

  18. Novel fiber optic tip designs and devices for laser surgery

    NASA Astrophysics Data System (ADS)

    Hutchens, Thomas Clifton

    Fiber optic delivery of laser energy has been used for years in various types of surgical procedures in the human body. Optical energy provides several benefits over electrical or mechanical surgery, including the ability to selectively target specific tissue types while preserving others. Specialty fiber optic tips have also been introduced to further customize delivery of laser energy to the tissue. Recent evolution in lasers and miniaturization has opened up opportunities for many novel surgical techniques. Currently, ophthalmic surgeons use relatively invasive mechanical tools to dissect retinal deposits which occur in proliferative diabetic retinopathy. By using the tight focusing properties of microspheres combined with the short optical penetration depth of the Erbium:YAG laser and mid-IR fiber delivery, a precise laser scalpel can be constructed as an alternative, less invasive and more precise approach to this surgery. Chains of microspheres may allow for a self limiting ablation depth of approximately 10 microm based on the defocusing of paraxial rays. The microsphere laser scalpel may also be integrated with other surgical instruments to reduce the total number of handpieces for the surgeon. In current clinical laser lithotripsy procedures, poor input coupling of the Holmium:YAG laser energy frequently damages and requires discarding of the optical fiber. However, recent stone ablation studies with the Thulium fiber laser have provided comparable results to the Ho:YAG laser. The improved spatial beam profile of the Thulium fiber laser can also be efficiently coupled into a fiber approximately one third the diameter and reduces the risk of damaging the fiber input. For this reason, the trunk optical fiber minus the distal fiber tip can be preserved between procedures. The distal fiber tip, which degrades during stone ablation, could be made detachable and disposable. A novel, low-profile, twist-locking, detachable distal fiber tip interface was designed, assembled, and tested for use in Thulium fiber laser lithotripsy. A 1.00-mm-outer-diameter detachable fiber tip interface was designed, constructed, and tested ex vivo on urinary stones in the laboratory. Similar stone ablation rates between the previously studied tapered distal fiber tip and the detachable fiber tip were measured. For urologists desiring faster TFL lithotripsy procedures, the incorporation of detachable distal fiber tips allows for rapid replacement of damaged fiber tips without concern about the laser to trunk fiber connection. This method for preserving the trunk fiber could be a motivation for integrating a dedicated laser fiber into the ureteroscope, with detachable distal tips, thus freeing the working channel for the use of other surgical instruments. During laser lithotripsy, distal fiber tip degradation increases as the fiber core diameter decreases. However, smaller fiber diameters (≤ 200 microm) are more desirable because of increased saline irrigation rates in the single working channel of the ureteroscope and less impact on ureteroscope deflection. A hollow fiber cap is proposed to reduced fiber tip degradation in small diameter fibers, without compromising stone ablation rates. The disadvantage of the hollow fiber tip observed in the study is the increase in stone retropulsion. However, integrating the hollow fiber tip with a clinically used stone basket may allow for a robust stone ablation instrument that also minimizes retropulsion. These surgical approaches involving novel specialty fiber optic tip designs are discussed in this thesis.

  19. Preliminary study on the closure of the lens capsule by laser welding

    NASA Astrophysics Data System (ADS)

    Pini, Roberto; Rossi, Francesca; Menabuoni, Luca; Lenzetti, Ivo; Rossi, Giacomo; Parel, Jean-Marie

    2006-02-01

    We present a preliminary study of a new method, based on the laser welding of suitably prepared patches of capsular tissue for the closure of capsulorhexes in the lens capsule. This technique is proposed for the repair capsular breaks or tears caused by accidental traumas or ones produced intraoperatively during standard IOL implantation. Experiments were carried out ex vivo on freshly enucleated porcine eyes. Patches of anterior capsular tissue, collected from donor eyes, were stained with a solution of Indocyanine Green (ICG) in sterile water. Closure tests on a capsulorhexis were performed by welding a stained patch onto the recipient capsule, using diode laser radiation at 810 nm, which greatly absorbed by the ICG-stained tissue. Laser radiation was delivered by means of a 200-micron-core-fiber, the tip of which was gently pressed onto the patch surface (contact welding technique) so as to produce effective tissue welding in underwater conditions. Laser-welded capsular tissue was found to have good resistance to mechanical load, comparable in fact to that of healthy tissue.

  20. Effect of laser microbeam irradiation of the nucleus on the cleavage of mouse eggs in culture

    SciTech Connect

    Lin, T.P.; Chan, J.Y.

    1984-06-01

    Two-cell mouse eggs were irradiated by a helium-cadmium laser on a spot of about 4 ..mu..m/sup 2/ in one or both nuclei either continuously or repeatedly at 0.36 erg ..mu..m/sup -2/ sec/sup -1/ and then cultured to observe cellular development. After exposing one nucleus to the microbeam to five or seven 1-sec pulses, about 45% developed to the 3-cell stage in 24 hr of culture. In overnight cultures of the 2-cell eggs in which both nuclei were irradiated for 9 or 20 sec continuously, 40 (9 sec) and 50% (20 sec) of the eggs remained at the 2-cell stage, while 45 (9 sec) and 25% (20 sec) developed to the 4-cell stage. When both nuclei were each irradiated by a 9-sec continuous laser beam (totaling 13 ergs), about 40% of the embryos of the 2-cell stage did not divide. The effect of seven pulses on the blastomere cleavage of 2-cell mouse eggs appeared to be comparable to that of continuous 9-sec laser irradiation. Both pulse and continuous laser microirradiation methods may be developed for inactivation of the nucleus as a nonpipetting, less injurious method for enucleation of mammalian eggs.

  1. Morphologic evaluations of Q-switched Nd:YAG laser injury of human retina

    NASA Astrophysics Data System (ADS)

    Scales, David K.; Schuschereba, Steven T.; Lund, David J.; Stuck, Bruce E.

    1997-05-01

    Depiction of the cellular and immune responses in the human model is critical to design rational therapies preventing/limiting cellular destruction and ultimately functional visual loss following acute laser injuries. We report the light and electron microscopy histologic findings in a controlled ocular human laser exposure. Following informed consent, the normal eye of a patient scheduled to undergo exenteration for invasive carcinoma of the orbit was exposed to both continuous wave and Q-switched lasers. Four hours prior to exenteration, argon G lesions were placed in the superior/temporal quadrant and Nd:YAG lesions were placed in the inferior/temporal quadrant. After enucleation, the retina was prepared for routine light and transmission electron microscopy. Histology of the argon G lesions showed primarily photoreceptor and RPE photocoagulation damage. Neutrophil adhesion was limited within the choroid and no neutrophils were observed in the subretinal space. In contrast, the 4 hr Nd:YAG lesions showed extensive retinal disruption, hemorrhage within subretinal and intraretinal spaces, neutrophil accumulation in the retina, and an extensive neutrophil chemotaxic and emigration response in the choroid. Severe laser injuries elicit a significant neutrophil response by 4 hr, suggesting that neutrophils should be an early stage therapeutic target.

  2. Laser welding of chitosan-GNRs films for the closure of a capsulorhexis

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Matteini, Paolo; Ratto, Fulvio; Menabuoni, Luca; Lenzetti, Ivo; Pini, Roberto

    2011-03-01

    In this work we present the first attempt to close the anterior lens capsule bag by the use of chitosan patches, where Gold Nanorods (GNRs) are embedded. GNRs exhibit intense localized plasmon resonances at optical frequencies in the near infrared (NIR): upon excitation with a NIR laser, a strong photothermal effect is produced, which can be exploited to develop minimally invasive therapies. Here we use the chitosan-GNRs films as a novel NIR sensitive nanocomposite for the photothermal conversion of NIR laser light during surgical interventions of tissue welding. Chitosan is an attractive biomaterial due to its biodegradability, biocompatibility, antimicrobial and wound healing-promoting activity. Colloidal GNRs were embedded in chitosan based, highly stabilized, flexible and easy-to-handle films, which were stored in water until the time of surgery. In these preliminary tests, a capsulorhexis was performed in freshly enucleated porcine eyes. The lens was aspired, then the patch was put onto the capsule bag and welded: a diode laser (810 nm) was used to deliver single spots (200 ?m core diameter optical fiber) of local capsule/patch adhesion. Then the bag was refilled with silicon oil. The result is an immediate closure of the capsular tissue, with high mechanical strength. The laser welded chitosan- GNRs films are an innovative and highly stable solution to be exploited for the treatment of capsular breaks and for the implementation of a lens refilling procedure.

  3. CW laser pumped emerald laser

    SciTech Connect

    Shand, M.L.; Lai, S.T.

    1984-02-01

    A CW laser-pumped emerald laser is reported. A 34 percent output power slope efficiency is observed with longitudinal pumping by a krypton laser in a nearly concentric cavity. The laser has been tuned from 728.8 to 809.0 nm. Losses in emerald are larger than those of alexandrite determined in a similar cavity. The present data also indicate that the excited state absorption minimum is shifted from that of alexandrite. 13 references.

  4. Laser device

    DOEpatents

    Scott, Jill R.; Tremblay, Paul L.

    2007-07-10

    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  5. Laser device

    DOEpatents

    Scott, Jill R.; Tremblay, Paul L.

    2004-11-23

    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  6. Laser ignition

    DOEpatents

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    2003-01-01

    In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In a third embodiment, alternating short and long pulses of light from the excitation light source are directed into the ignitor laser. Each of the embodiments of the invention can be multiplexed so as to provide laser light energy sequentially to more than one ignitor laser.

  7. Laser thruster

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.

    1989-01-01

    Laser propulsion can reduce fuel by 57 t to 105 t over chemical propulsion for a 144 t Lunar base, with no significant increase in trip time. Laser propulsion reduces trip time by a factor of 40 to 120 over nuclear electric propulsion and time in radiation belts by a factor of 100 to 1700. Either solar or nuclear driven laser diode arrays could produce multimegawatt beams, typically 3,700 t for a 235 MW laser system. Laser diode arrays have high payoff due to short wavelength (850 nm) and high diode efficiency (70 percent). A dry laser OTV of 8790 kg and 60 percent efficiency can transport a 144 t lunar base. Laser propulsion could carry both personnel and cargo safely to the lunar base.

  8. Percutaneous yttrium aluminum garnet-laser lithotripsy of intrahepatic stones and casts after liver transplantation.

    PubMed

    Schlesinger, Nis Hallundbaek; Svenningsen, Peter; Frevert, Susanne; Wettergren, Andr; Hillings, Jens

    2015-06-01

    Bile duct stones and casts (BDSs) contribute importantly to morbidity after liver transplantation (LT). The purpose of this study was to estimate the clinical efficacy, safety, and long-term results of percutaneous transhepatic cholangioscopic lithotripsy (PTCSL) in transplant recipients and to discuss underlying factors affecting the outcome. A retrospective chart review revealed 18 recipients with BDSs treated by PTCSL laser lithotripsy with a holmium-yttrium aluminum garnet laser probe at 365 to 550 m. They were analyzed in a median follow-up time of 55 months. In all but 1 patient (17/18 or 94%), it was technically feasible to clear all BDSs with a mean of 1.3 sessions. PTCSL was unsuccessful in 1 patient because of multiple stones impacting the bile ducts bilaterally; 17% had early complications (Clavien II). All biliary casts were successfully cleared; 39% had total remission; 61% needed additional interventions in the form of percutaneous transhepatic cholangiography and dilation (17%), re-PTCSL (11%), self-expandable metallic stents (22%), or hepaticojejunostomy (6%); and 22% eventually underwent retransplantation. The overall liver graft survival rate was 78%. Two patients died during follow-up for reasons not related to their BDS. Nonanastomotic strictures (NASs) were significantly associated with treatment failure. We conclude that PTCSL in LT patients is safe and feasible. NASs significantly increased the risk of relapse. Repeated minimally invasive treatments, however, prevented graft failure in 78% of the cases. PMID:25821134

  9. Highly efficient high power CW and Q-switched Ho:YLF laser

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, J.

    2015-06-01

    An efficient operation of a Ho:YLF laser pumped by a Tm-doped fibre laser is reported. The research in a continuous-wave (CW) operation was done for two crystals of the same 0.5 at.%Ho dopant concentration and with different lengths (3330 mm3 and 3350 mm3). For an output coupling transmission of 20% and a crystal length of 50 mm, the maximum CWoutput power of 38.9 W for 81.4 W of incident pump power, corresponding to the slope efficiency of 52.3% and optical-to-optical conversion efficiency of 47.8% (determined with respect to the incident pump power) was achieved. The highest opti- cal-to-optical conversion efficiency of 70.2% with respect to the absorbed pump power was obtained. The influence of a heat-sink cooling water temperature on theCWlaser performance was studied. For a Q-switched operation the pulse repe- tition frequency (PRF) was changed from 2 to 10 kHz. The maximum average output power of 34.1 W at the PRF of 10 kHz was obtained for a 50 mm holmium crystal length. For 2 kHz PRF and 71.9 W of incident pump power, pulse energies of 13.7 mJ with a 21 ns FWHM pulse width corresponding to 652 kW peak power were recorded.

  10. Chemically assisted somatic cell nuclear transfer without micromanipulator in the goat: effects of demecolcine, cytochalasin-B, and MG-132 on the efficiency of a manual method of oocyte enucleation using a pulled Pasteur pipette.

    PubMed

    Hosseini, S M; Hajian, M; Forouzanfar, M; Ostadhosseini, S; Moulavi, F; Ghanaei, H R; Gourbai, H; Shahverdi, A H; Vosough, A D; Nasr-Esfahani, M H

    2015-07-01

    The present study aimed to facilitate widespread application of a previously described manual method of somatic cell nuclear transfer (SCNT) by investigating the effects of demecolcine (a microtubule-depolymerizing chemical), cytochalasin-B (a microfilament-depolymerizing chemical: 2.5?g/ml for 15min) and MG-132 (a proteasome inhibitor chemical) on the (i) incidence of cytoplasmic protrusion of MII chromosomes, (ii) improvement of manual oocyte enucleation, and (iii) in vitro and in vivo developmental competence of SCNT embryos in the goat. Following in vitro maturation, around 65% of goat oocytes contained a characteristic cytoplasmic protrusion of MII-chromosomes. Treatment with demecolcine (0.4?g/ml for 30min) significantly increased this rate to 92.24.5%. Treatment with MG-132 (2?M for 30min) could not improve this rate when used alone (61.411.5%), but when combined with demecolcine (86.48.1%). Treatment with cytochalasin-B completely suppressed this rate whenever used, either alone (7.75.1%) or in combination with demecolcine (3.91.3%). In a direct comparison, there was no significant difference in quantity and quality of embryos propagated by the manual vs. micromanipulation-based methods of SCNT (cleavage: 85.34.5 vs. 89.58.9%, blastocyst: 19.54.3 vs. 24.34.4%, grade 1 and 2 blastocyst: 33.87.1 vs. 29.56.3%, total cell count: 12511.1 vs. 12210.5, respectively). Furthermore, development to live kids at term was not significant between the two SCNT methods. From both technical and economical points of view, the overall in vitro and in vivo efficiency of this manual method of SCNT proved it a simple, fast and efficient alternative for large scale production of cloned goats. PMID:25956201

  11. A pulsed, high repetition rate 2-micron laser transmitter for coherent CO2 DIAL

    NASA Astrophysics Data System (ADS)

    Yu, J.; Bai, Y.; Petzar, P.; Petros, M.; Chen, S.; Trieu, B.; Koch, G. J.; Kavaya, M. J.; Singh, U. N.

    2009-12-01

    A Holmium solid-state 2-m pulsed laser, end-pumped by a Thulium fiber laser, is being developed for coherent CO2 Differential Absorption Lidar (DIAL). It combines the advantages of high efficient fiber laser technology with the mature high energy solid state laser technology to produce desired energy levels at a high repetition rate. To obtain high beam quality that is required by coherent detection technique, the effect of spatial hole burning in the laser gain medium must be prevented. This is achieved by the use of ring cavity configuration in which the laser light is forced to travel in one direction, so that no standing waves are formed. The pump beam and laser beam are mode-matched in the laser crystals to improve the laser efficiency. At the pumping power of 13.25W, optical-to-optical efficiency of 52% was obtained with the pulse repetition rate of 1.25 kHz, which gives the energy per pulse of ~5.5mJ. The pulse energy can be scaled by increasing the pump power or by reducing the pulse repetition rate. The pulse length of this laser is at ~50ns. The wavelengths of the Ho pulse laser are tunable over several characteristic absorption lines of CO2. The exact wavelengths of the Ho pulse laser are controlled by well-controlled continuous wave (CW) seed lasers to provide the required sequential, on-and-off line wavelength pulses for DIAL applications. Three CW lasers were used to provide the accurate on-and-off wavelengths. The first CW laser is locked to the center of a characteristic CO2 absorption line through a CO2 cell by the frequency modulation technique. The frequency of the second CW laser was shifted related to the first CW laser by a few GHz to the wing of the CO2 absorption line, and used as the on-line frequency of the CO2 DIAL. This frequency shift is necessary to obtain a better weighting function for the CO2 measurement. The standard deviation of the CW on-line frequency can be controlled within 250 KHz. The third CW laser provides the off-line frequency. The on-line and off-line CW laser beams are fed through a fiber optical switch, which provides the sequential seed light to the Ho pulse laser. The Ho pulse laser was injection seeded by the well-controlled CW seed laser. The injection seeding is based on a modified ramp-and-fire technique, which has been successfully applied to operational coherent wind lidars. This paper will describe the 2-m laser transmitter that will be integrated into a pulsed coherent heterodyne DIAL system and expected to make precise, accurate, high-resolution atmospheric CO2 measurements.

  12. High repetition rate, Q-switched Ho:YAG laser resonantly pumped by a 20 W linearly polarized Tm: fiber laser

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, J.; Jabczynski, J. K.; Zendzian, W.; Gorajek, L.; Kaskow, M.

    2014-03-01

    We describe an efficient, low-threshold, continuous-wave (CW) and Q-switched operation of a Ho:YAG laser resonantly, single-pass pumped by a 20 W linearly polarized narrow line width Tm: fiber laser at the wavelength of 1,908 nm. At room temperature for an output coupler of 30 % transmission, a maximum continuous-wave output power of 13.3 W for 18.9 W of absorbed pump power was achieved, corresponding to a slope efficiency of 73 %. In a quasi continuous-wave pumping regime, for several output couplers slope efficiencies of almost 82 % were observed. For a Q-switched operation, a Brewster-cut acousto-optic modulator was used. In a CW pumping regime, the pulse repetition frequency (PRF) was changed from 4 to 15 kHz. Under a Q-switched operation, the maximum output power of 12.25 W in relation to 15 kHz PRF was obtained; however, the maximum peak power of almost 250 kW at the PRF of 4 kHz was demonstrated. In the best case, for 4 kHz PRF, pulse energies of 2.18 mJ with a 8.8 ns FWHM pulse width (one of the shortest pulse durations observed in holmium-doped Q-switched lasers) were achieved. The laser operated at the wavelength of 2,090.23 nm with the FWHM line width of 0.95 nm. The beam quality factor of M 2 was measured to be below 1.42 in both X and Y axis.

  13. Rapid vaporization of kidney stones, ex vivo, using a Thulium fiber laser at pulse rates up to 500 Hz with a stone basket

    NASA Astrophysics Data System (ADS)

    Hardy, Luke A.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

    2014-03-01

    The Holmium:YAG laser (? = 2120 nm) is currently the preferred laser for fragmenting kidney stones in the clinic. However, this laser has some limitations, including operation at low pulse rates and a multimode spatial beam profile which prohibits its use with smaller, more flexible optical fibers. Our laboratory is studying the Thulium fiber laser (? = 1908 nm) as an alternative lithotripter. The TFL has several advantages, including lower stone ablation thresholds, use with smaller and more flexible fibers, and operation at arbitrary pulse lengths and pulse rates. Previous studies have reported increased stone ablation rates with TFL operation at higher pulse rates, however, stone retropulsion remains an obstacle to even more efficient stone ablation. This study explores TFL operation at high pulse rates in combination with a stone stabilization device (e.g. stone basket) for improved efficiency. A TFL beam with pulse energy of 35 mJ, pulse duration of 500-?s, and pulse rates of 10-500 Hz was coupled into 100-?m-core, low-OH, silica fibers, in contact mode with uric acid and calcium oxalate monohydrate stones, ex vivo. TFL operation at 500 Hz produced UA and COM stone ablation rates up to 5.0 mg/s and 1.3 mg/s, respectively. High TFL pulse rates produced increased stone ablation rates sufficient for use in the clinic.

  14. Evaluation of Color-Changing Effect and Complications After Nd: YAG Laser Application On Iris Surface.

    PubMed

    Yildirim, Yildiray; Duzgun, Eyup; Kar, Taner; Sonmez, Murat; Kucukodaci, Zafer; Ersanli, Dilaver; Basoglu, Ayhan

    2016-01-01

    BACKGROUND The aim of this study was to evaluate the color-changing effect and adverse effects after Nd: YAG laser application on the iris surface of rabbit eyes. MATERIAL AND METHODS The study was performed on right eyes of 12 pigmented rabbits. A laser device that produces frequency doubled 532 nm wavelength Nd: YAG laser with 900 ?m spot diameter was used. The laser was applied in 3 sessions at 2-week intervals, at energy levels of 0.8 mJ in Group A and 1.5 mJ in Group B. Slit-lamp examinations and measurements of intraocular pressure (IOP) using a Tono-Pen were performed before and 1 day after each laser session. Iris thickness (IT) was measured at the beginning and the end using an ultrasonic biomicroscope. The eyes were enucleated for histopathologic examination on day 60. RESULTS On the first day after each laser session, maximum grade 1 anterior chamber flare and cells were observed in both groups. In all eyes, flare and cells disappeared at the end of the first week. There was no significant difference in the IOP and IT values between measurements performed prior to and after laser sessions during the study (p>0.05). None of the eyes showed complications such as corneal edema, hypopyon, posterior synechia, transillumination defect, or pupillary defect. In histopathological examinations, reduction in pigment density was more profound in Group B compared to Group A, which was statistically significant (p<0.019). CONCLUSIONS There were no serious complications apart from mild transient inflammatory signs. Change in iris color was more evident at the end of the second month. PMID:26751845

  15. Evaluation of Color-Changing Effect and Complications After Nd: YAG Laser Application On Iris Surface

    PubMed Central

    Yildirim, Yildiray; Duzgun, Eyup; Kar, Taner; Sonmez, Murat; Kucukodaci, Zafer; Ersanli, Dilaver; Basoglu, Ayhan

    2016-01-01

    Background The aim of this study was to evaluate the color-changing effect and adverse effects after Nd: YAG laser application on the iris surface of rabbit eyes. Material/Methods The study was performed on right eyes of 12 pigmented rabbits. A laser device that produces frequency doubled 532 nm wavelength Nd: YAG laser with 900 μm spot diameter was used. The laser was applied in 3 sessions at 2-week intervals, at energy levels of 0.8 mJ in Group A and 1.5 mJ in Group B. Slit-lamp examinations and measurements of intraocular pressure (IOP) using a Tono-Pen were performed before and 1 day after each laser session. Iris thickness (IT) was measured at the beginning and the end using an ultrasonic biomicroscope. The eyes were enucleated for histopathologic examination on day 60. Results On the first day after each laser session, maximum grade 1 anterior chamber flare and cells were observed in both groups. In all eyes, flare and cells disappeared at the end of the first week. There was no significant difference in the IOP and IT values between measurements performed prior to and after laser sessions during the study (p>0.05). None of the eyes showed complications such as corneal edema, hypopyon, posterior synechia, transillumination defect, or pupillary defect. In histopathological examinations, reduction in pigment density was more profound in Group B compared to Group A, which was statistically significant (p<0.019). Conclusions There were no serious complications apart from mild transient inflammatory signs. Change in iris color was more evident at the end of the second month. PMID:26751845

  16. Laser propulsion

    NASA Technical Reports Server (NTRS)

    Kemp, N. H.; Rosen, D. I.

    1984-01-01

    An introduction to thermal laser propulsion is presented. This form of rocket propulsion uses a laser beam from a remotely-located laser to heat a propellant gas, which is then expanded in a conventional way to produce thrust. This propulsion scheme has the potential for producing high specific impulse (greater than 1000 s) at moderate to high thrust (1000 lbs). Laser propulsion can thus fill a niche in propulsion for spaceflight missions which can be filled by no other practical scheme. The system analyses and some of the experimental and theoretical studies which have been performed are briefly reviewed. Production of thrust by a pulsed laser has been demonstrated on a laboratory scale at an Isp of 1000 s in hydrogen. While more work is needed, it seems apparent that laser propulsion has an important and unique capability which should be pursued, and should be considered for space missions in the 1990's and beyond.

  17. Laser ignition

    DOEpatents

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    2002-01-01

    In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In the embodiment of the invention claimed herein, the beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being combined with either the first portion after a delay before injection into the ignitor laser.

  18. Laser perforator

    NASA Astrophysics Data System (ADS)

    Kiyanitsa, Sergey N.; Bezrodny, Yury E.; Kononov, Sergey B.; Ivanova, Vita V.

    2000-02-01

    Laser equipment for the perforation of documents and securities is presented. This laser perforator (LP) differs by extended precision of perforation, high processing velocity, perfected automatic control. LP's operation is based on the preliminary theoretical and experimental research of laser irradiation and paper or/and organic tissue interaction. The results of CO2-laser irradiation action upon different materials and samples of documents allowed to determine system requirements to LP. Developed LP is destined for perforation of paper documents with jackets with total thickness from 0.5 to 4 mm. Processing document, LP makes more than 100 conical perforation holes that improve protection rate of document. LP guarantees perforation time less than 3 sec, document's blank positioning precision plus or minus 0.2 mm, laser beam positioning precision plus or minus 0.01 mm. Due to the system parameters optimization it became possible to eliminate a singeing of hole edge, that improved perforation quality. Developed LP consists of laser-module, technological module, laser cooling module and automatic control system. Laser module includes continuous Q-switched CO2-laser, scanner, power supply, controller, chopper. Technological module has X- Y-table, conveyer for blanks of documents, pneumatic block. Automatic control system, which includes two video cameras, illuminators, controller, PC, gives a possibility to control holes disposition in a matrix and to identify perforated number.

  19. Laser apparatus

    DOEpatents

    Lewis, Owen (Fairport, NY); Stogran, Edmund M. (North Syracuse, NY)

    1980-01-01

    Laser apparatus is described wherein an active laser element, such as the disc of a face-pumped laser, is mounted in a housing such that the weight of the element is supported by glass spheres which fill a chamber defined in the housing between the walls of the housing and the edges of the laser element. The uniform support provided by the spheres enable the chamber and the pump side of the laser element to be sealed without affecting the alignment or other optical properties of the laser element. Cooling fluid may be circulated through the sealed region by way of the interstices between the spheres. The spheres, and if desired also the cooling fluid may contain material which absorbs radiation at the wavelength of parasitic emissions from the laser element. These parasitic emissions enter the spheres through the interface along the edge surface of the laser element and it is desirable that the index of refraction of the spheres and cooling fluid be near the index of refraction of the laser element. Thus support, cooling, and parasitic suppression functions are all accomplished through the use of the arrangement.

  20. Laser ignition

    DOEpatents

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    2002-01-01

    In the apparatus of the invention, a first excitation laser or other excitation light source capable of producing alternating beams of light having different wavelengths is used in tandem with one or more ignitor lasers to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using the single remote excitation light source for pumping one or more small lasers located proximate to one or more fuel combustion zones with alternating wavelengths of light.

  1. Satellite Laser

    NASA Astrophysics Data System (ADS)

    Ibrahim, Makram; Hanna, Y. S.; Samwel, S. W.; Hegazy, Maroof A.

    2015-06-01

    The paper concerns on the satellite laser ranging (SLR) in Egypt. The three generations which can be loosely defined by their single shot root mean square precision, are discussed. The laser generators used at the Helwan half automatic and full automatic stations are described. The equipments used for the operation of the satellite laser ranging and their upgrading are presented. The observations carried out from Helwan-SLR stations are mentioned. The importance of the satellite laser ranging from Egypt and their contributions to the SLR network are explained. The modification requested for increasing the performance of the Helwan-SLR station is given.

  2. Biocavity Lasers

    SciTech Connect

    Gourley, P.L.; Gourley, M.F.

    2000-10-05

    Laser technology has advanced dramatically and is an integral part of today's healthcare delivery system. Lasers are used in the laboratory analysis of human blood samples and serve as surgical tools that kill, burn or cut tissue. Recent semiconductor microtechnology has reduced the size o f a laser to the size of a biological cell or even a virus particle. By integrating these ultra small lasers with biological systems, it is possible to create micro-electrical mechanical systems that may revolutionize health care delivery.

  3. Heterodyne laser spectroscopy system

    DOEpatents

    Wyeth, Richard W. (Livermore, CA); Paisner, Jeffrey A. (San Ramon, CA); Story, Thomas (Antioch, CA)

    1989-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency and the like, and provides spectral analysis of a laser beam.

  4. Heterodyne laser spectroscopy system

    DOEpatents

    Wyeth, Richard W. (Livermore, CA); Paisner, Jeffrey A. (San Ramon, CA); Story, Thomas (Antioch, CA)

    1990-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency, and provides spectral analysis of a laser beam.

  5. Lasers in Cancer Treatment

    MedlinePLUS

    ... Cancer Treatment On This Page What is laser light? What is laser therapy, and how is it ... future hold for laser therapy? What is laser light? The term “ laser ” stands for light amplification by ...

  6. First application of laser welding in clinical transplantation of the cornea

    NASA Astrophysics Data System (ADS)

    Pini, Roberto; Menabuoni, Luca; Starnotti, Lorenzo

    2001-05-01

    After a 4-year-long pre-clinical experimentation carried out at first on enucleated eyes and then on animal models, we applied a new procedure of laser welding of the cornea on voluntary patients. The welding technique is based on controlled irradiation of the cornea by diode laser radiation (805 nm) operating at low power (60-90 mW) in association with a photoenhancing chromophore applied locally. The welding effect is very effective and selective, because it takes place only in the cut where chromophore is present, while the contiguous tissue remains completely untouched. In the clinical phase, this technique was firstly tested in corneal cuts of increasing length on 25 patients subjected to facoemulsification of the cataract, by both sclero-corneal and corneal tunnels, and to extracapsular cataract extraction by sclero-corneal and corneal cuts. As previously confirmed by histological analysis performed on animal samples, we observed in humans too an early and effective healing process, with a sensible reduction of the post-operatory astigmatism. Based on these positive results, we finally arrived at the first application of diode laser- assisted corneal welding to penetrating keratoplasty (corneal transplantation), where this technique has been employed as far as now in 3 cases to substitute the application of the continuous suture.

  7. Laser Crystal

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Lightning Optical Corporation, under an SBIR (Small Business Innovative Research) agreement with Langley Research Center, manufactures oxide and fluoride laser gain crystals, as well as various nonlinear materials. The ultimate result of this research program is the commercial availability in the marketplace of a reliable source of high-quality, damage resistant laser material, primarily for diode-pumping applications.

  8. Laser device

    DOEpatents

    Scott, Jill R. (Idaho Falls, ID); Tremblay, Paul L. (Idaho Falls, ID)

    2008-08-19

    A laser device includes a virtual source configured to aim laser energy that originates from a true source. The virtual source has a vertical rotational axis during vertical motion of the virtual source and the vertical axis passes through an exit point from which the laser energy emanates independent of virtual source position. The emanating laser energy is collinear with an orientation line. The laser device includes a virtual source manipulation mechanism that positions the virtual source. The manipulation mechanism has a center of lateral pivot approximately coincident with a lateral index and a center of vertical pivot approximately coincident with a vertical index. The vertical index and lateral index intersect at an index origin. The virtual source and manipulation mechanism auto align the orientation line through the index origin during virtual source motion.

  9. Dye lasers

    SciTech Connect

    Stone, J.

    1984-04-03

    A dye laser (FIG. 1, 5 or 6) includes a pumping laser source (e.g. 11), an optical resonator (e.g. 13-15), and a dye solution or dye cell (e.g. 12) disposed in the path of the pumping laser light in the resonator. The dye cell disclosed herein comprises a pair of closely spaced transparent discs (21). A motor (26) serves to spin the discs at a high rate of speed. The pumping laser light in the resonator is focused on the discs at a predetermined angle (i.e. the Brewster angle). New, unbleached dye is injected axially with respect to the discs so that the spin force causes a radial flow of the dye solution between the spinning discs and, of course, past the pumping laser light spot.

  10. Human excimer laser lamellar keratectomy. A clinical study

    SciTech Connect

    Taylor, D.M.; L'Esperance, F.A. Jr.; Del Pero, R.A.; Roberts, A.D.; Gigstad, J.E.; Klintworth, G.; Martin, C.A.; Warner, J.

    1989-05-01

    The first ten blind human eyes in the United States to receive excimer laser (ArFl 193 nm) lamellar keratectomy (reprofiling) are presented. Seven of these patients were followed 6 to 12 months after ablation. All eyes are grossly clear in the region of ablation. Results of slit-lamp examination of all flattened ablated areas show mild superficial haze at the epithelial/stromal interface. This haze might not interfere significantly with vision in patients 7 to 10. Serial pachymetry and keratometry measurements, refraction, and digital keratoscopy show a progressive filling in of the excavated area by approximately two thirds but a loss of initial diopteric correction of only one third. Histopathologic analysis was obtained for four eyes. Transmission electron microscopy of three eyes enucleated 3 to 12 days after ablation shows 40-microns ablation depths through Bowman's layer and superficial stroma with minimal adjacent tissue damage and no inflammatory cells. The epithelium is increased in thickness by 50%, and firmly attached to the underlying stroma. A 4-month postablation specimen shows keratocyte activation with increased protein synthesis (presumed collagen and ground substance).

  11. Laser propulsion

    NASA Technical Reports Server (NTRS)

    Rom, F. E.; Putre, H. A.

    1972-01-01

    The use of an earth-based high-power laser beam to provide energy for earth-launched rocket vehicle is investigated. The laser beam energy is absorbed in an opaque propellant gas and is converted to high-specific-impulse thrust by expanding the heated propellant to space by means of a nozzle. This laser propulsion scheme can produce specific impulses of several thousand seconds. Payload to gross-weight fractions about an order of magnitude higher than those for conventional chemical earth-launched vehicles appear possible. There is a potential for a significant reduction in cost per payload mass in earth orbit.

  12. Laser goniometer

    DOEpatents

    Fairer, George M. (Boulder, CO); Boernge, James M. (Lakewood, CO); Harris, David W. (Lakewood, CO); Campbell, DeWayne A. (Littleton, CO); Tuttle, Gene E. (Littleton, CO); McKeown, Mark H. (Golden, CO); Beason, Steven C. (Lakewood, CO)

    1993-01-01

    The laser goniometer is an apparatus which permits an operator to sight along a geologic feature and orient a collimated lamer beam to match the attitude of the feature directly. The horizontal orientation (strike) and the angle from horizontal (dip), are detected by rotary incremental encoders attached to the laser goniometer which provide a digital readout of the azimuth and tilt of the collimated laser beam. A microprocessor then translates the square wave signal encoder outputs into an ASCII signal for use by data recording equipment.

  13. A femtosecond pulse fiber laser at 1935 nm using a bulk-structured Bi2Te3 topological insulator.

    PubMed

    Jung, Minwan; Lee, Junsu; Koo, Joonhoi; Park, Jaehyun; Song, Yong-Won; Lee, Kwanil; Lee, Sangbae; Lee, Ju Han

    2014-04-01

    We experimentally demonstrate a femtosecond mode-locked, all-fiberized laser that operates in the 2 ?m region and that incorporates a saturable absorber based on a bulk-structured bismuth telluride (Bi(2)Te(3)) topological insulator (TI). Our fiberized saturable absorber was prepared by depositing a mechanically exfoliated, ~30 ?m-thick Bi(2)Te(3) TI layer on a side-polished optical fiber platform. The bulk crystalline structure of the prepared Bi(2)Te(3) layer was confirmed by Raman and X-ray photoelectron spectroscopy measurements. The modulation depth of the prepared saturable absorber was measured to be ~20.6%. Using the saturable absorber, it is shown that stable, ultrafast pulses with a temporal width of ~795 fs could readily be generated at a wavelength of 1935 nm from a thulium/holmium co-doped fiber ring cavity. This experimental demonstration confirms that bulk structured, TI-based saturable absorbers can readily be used as an ultra-fast mode-locker for 2 ?m lasers. PMID:24718162

  14. Investigations of a Q-switched Ho:YAG laser intracavity-pumped by a diode-pumped Tm:YLF laser

    NASA Astrophysics Data System (ADS)

    Kieleck, Christelle; Hirth, Antoine

    2004-09-01

    Q-switched and diode-pumped 2 ?m solid state lasers are becoming of increasing interest for efficient pumping of mid-infrared emitting optical parametric oscillators (OPOs). In particular, Thulium and Holmium rare earths seem to be most suited for systems with high efficiency due to their long upper state lifetime. In addition, the Ho:YAG emission around 2.1 ?m is not in the strong absorption spectral band of water and it is a suitable wavelength for non linear crystal pumping, such as ZnGeP2. Several works on Ho:YAG laser end-pumped by diode-pumped Tm:YLF laser have demonstrated high power operations1. To simplify the set-ups, experiments with Tm-Ho intracavity lasers have been done; they demonstrated a 36.5% slope efficiency2. Unfortunately these set-ups3 did not allow Q-switched operations and the thermal lens in the rods led to relatively poor beam quality (M2~5-6). We designed an original intracavity configuration with a dichroic polarizing beamsplitter to decouple Tm:YLF and Ho:YAG cavities. This solution was to improve the beam quality and allow Q-switched operations. 1.9 W of 2.09 ?m at the 17.3 W diodes pump level were obtained. The slope efficiency of the diode-pump to the Ho laser output and the optical-to-optical conversion efficiency achieved were respectively ~ 21.4 % and ~ 11 %. As anticipated 4, a shift of Tm:YLF emission was experimentally scaled from 1.908 to 1.953 ?m which led to an efficiency decrease for the Tm laser. Unfortunately, in this intracavity geometry, Ho:YAG acted as a saturable absorber. Instead of a cw operation in free running, random Tm:YLF laser pulses of ~ 2.5 ?s were observed that each resulted in an Ho pulse (~ 200-250 ns). When the acousto-optic modulator (AOM) worked, the Ho pulses did not follow the Q-switched frequency. In fact Ho emission depends on the Tm:YLF pump energy accumulated between two gates of the AOM. Some possible ways to optimize the efficiency and to avoid the passive Q-switching behaviour of Ho:YAG are tested and first results are presented in this paper.

  15. Biophysical mechanisms responsible for pulsed low-level laser excitation of neural tissue

    NASA Astrophysics Data System (ADS)

    Wells, Jonathon; Kao, Chris; Konrad, Peter; Mahadevan-Jansen, Anita; Jansen, E. Duco

    2006-02-01

    Background/Objective: The traditional method of stimulating neural activity has been based on electrical methods and remains the gold standard to date despite inherent limitations. We have previously shown a new paradigm to in vivo neural activation based on pulsed infrared light, which provides a contact-free, spatially selective, artifact-free method without incurring tissue damage that may have significant advantages over electrical stimulation in a variety of diagnostic and therapeutic applications. The goal of this study was to investigate the physical mechanism of this phenomenon, which we propose is a photo-thermal effect from transient tissue temperature changes resulting in direct or indirect activation of transmembrane ion channels causing propagation of the action potential. Methods: Rat sciatic nerve preparation was stimulated in vivo with the Holmium:YAG laser (2.12μm), Free Electron Laser (2.1μm), Alexandrite laser (690nm), and the prototype for a solid state commercial laser nerve stimulator built by Aculight (1.87μm) to determine contributions of photobiological responses from laser tissue interactions, including temperature, pressure, electric field, and photochemistry, underlying the biophysical mechanism of stimulation. Single point temperature measurements were made with a microthermocouple adjacent to the excitation site, while an infrared camera was used for 2-D radiometry of the irradiated surface. Displacement from laser-induced pressure waves or thermoelastic expansion was measured using a PS-OCT system. Results: Results exclude a direct photochemical, electric field, or pressure wave effect as the mechanism of optical stimulation. Measurements show relative small contributions from thermoelastic expansion (300 nm) with the laser parameters used for nerve stimulation. The maximum change in tissue temperature is about 9°C (average increase of 3.66 °C) at stimulation threshold radiant exposures. Conclusion: Neural activation with pulsed laser-light occurs by a transient thermally induced mechanism. Future experiments will reveal if this effect is through direct membrane interaction or facilitated through an indirect effect leading to membrane depolarization.

  16. Laser endoscopy.

    PubMed

    McElvein, R B

    1981-11-01

    A carbon dioxide laser operating in the invisible infrared range (10.6 mu) generates a beam of energy that is almost completely absorbed by biological tissue with release of intense heat and rapid destruction. A laser attached to a rigid bronchoscope has been used in 18 patients ranging in age from 21 to 62 years to treat a variety of causes of airway obstruction. These include tracheal stenosis and granulation tissue (6 patients), adenoma (1), web (2), and carcinoma (9). The results were good in 15 and poor in 3 patients. However, all patients had an improved airway after laser treatment with the best results occurring in patients with benign, inflammatory disease. The advantages of the laser are a lack of bleeding, minimal edema after treatment, and minimal scar formation. The disadvantages are the expense of the machine, and the need for general anesthesia and direct visualization of the lesion. PMID:6796011

  17. Laser fusion

    SciTech Connect

    Smit, W.A.; Boskma, P.

    1980-12-01

    Unrestricted laser fusion offers nations an opportunity to circumvent arms control agreements and develop thermonuclear weapons. Early laser weapons research sought a clean radiation-free bomb to replace the fission bomb, but this was deceptive because a fission bomb was needed to trigger the fusion reaction and additional radioactivity was induced by generating fast neutrons. As laser-implosion experiments focused on weapons physics, simulating weapons effects, and applications for new weapons, the military interest shifted from developing a laser-ignited hydrogen bomb to more sophisticated weapons and civilian applications for power generation. Civilian and military research now overlap, making it possible for several countries to continue weapons activities and permitting proliferation of nuclear weapons. These countries are reluctant to include inertial confinement fusion research in the Non-Proliferation Treaty. 16 references. (DCK)

  18. Laser therapy

    MedlinePLUS

    ... Avram MM, Anderson RR. Lasers and other energy technologies: principles and skin interactions. In: Bolognia JL, Jorizzo JL, Schaffer JV, eds. Dermatology . 3rd ed. Philadelphia, PA: Elsevier Saunders; 2012:chap ...

  19. Laser barometer

    SciTech Connect

    Abercrombie, K.R.; Shiels, D.; Rash, T.

    1998-04-01

    This paper describes an invention of a pressure measuring instrument which uses laser radiation to sense the pressure in an enclosed environment by means of measuring the change in refractive index of a gas - which is pressure dependent.

  20. Laser Research

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Eastman Kodak Company, Rochester, New York is a broad-based firm which produces photographic apparatus and supplies, fibers, chemicals and vitamin concentrates. Much of the company's research and development effort is devoted to photographic science and imaging technology, including laser technology. Eastman Kodak is using a COSMIC computer program called LACOMA in the analysis of laser optical systems and camera design studies. The company reports that use of the program has provided development time savings and reduced computer service fees.

  1. Laser bronchoscopy.

    PubMed

    Duhamel, D R; Harrell, J H

    2001-11-01

    Because the lung cancer epidemic shows no signs of abating, little doubt exists that the need for interventional bronchoscopists will persist for many years to come. The Nd:YAG laser and the rigid bronchoscope remain crucial weapons in the fight against lung cancer. With more than 4000 published interventions pertaining to it, this combination is ideal for treating central airways obstruction. The safety and efficacy of laser bronchoscopy has been well established, and the reported incidence of complications is impressively low. If complications were to arise, a skilled bronchoscopist can manage them easily by using the beneficial attributes of the rigid bronchoscope. Many complications can be avoided by implementing the established safety procedures and techniques. A solid understanding of laser physics and tissue interactions is a necessity to anyone performing laser surgery. The team approach, relying on communication among the bronchoscopist, anesthesiologist, laser technician, and nurses, leads to a safer and more successful procedure. It is important to remember, however, that this is typically a palliative procedure, and therefore the focus should be on alleviating symptoms and improving quality of life. Unfortunately, because not every patient is a candidate for laser bronchoscopy, there are specific characteristics of endobronchial lesions that make them more or less amenable to resection. Each year a promising new technology is being developed, such as argon plasma coagulation, cryotherapy, and endobronchial electrosurgery. Although it is unclear what role these technologies will have, prospective controlled studies must be done to help clarify this question. The future may lay in combining these various technologies along with Nd:YAG laser bronchoscopy to maximize the therapeutic, palliative, and possibly even curative effect. As the experience of the medical community with Nd:YAG laser bronchoscopy continues to grow and as more health-care professionals are made aware of its therapeutic capability, fewer patients with cancer will need to suffer and die from the complications of airway obstruction. PMID:11780295

  2. Semiconductor laser

    SciTech Connect

    Mori, Y.; Matsuda, O.

    1985-03-05

    A new laser structure having self-aligned junction stripe geometry grown by the MO CVD process is disclosed. The laser is grown on a groove-etched substrate and has a DH structure with a small V-shaped active region. A current path in the V-shaped region is formed using anomalous zinc diffusion during growth, which allows a broad area metal contact for both sides of the wafer.

  3. Laser Technology

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Amoco Laser Company, a subsidiary of Amoco Corporation, has developed microlasers for the commercial market based on a JPL concept for optical communications over interplanetary distances. Lasers emit narrow, intense beams of light or other radiation. The beams transmit communication signals, drill, cut or melt materials or remove diseased body tissue. The microlasers cover a broad portion of the spectrum, and performance is improved significantly. Current applications include medical instrumentation, color separation equipment, telecommunications, etc.

  4. Laser Angioplasty

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The principal method of dealing with coronary artery blockage is bypass surgery. A non-surgical alternative available to some patients is balloon angioplasty. For several years, medical researchers have been exploring another alternative that would help a wider circle of patients than the balloon treatment and entail less risk than bypass surgery. A research group is on the verge of an exciting development: laser angioplasty with a 'cool' type of laser, called an excimer laser, that does not damage blood vessel walls and offers non-surgical cleansing of clogged arteries with extraordinary precision. The system is the Dymer 200+ Excimer Laser Angioplasty System, developed by Advanced Intraventional Systems. Used in human clinical tests since 1987, the system is the first fully integrated 'cool' laser capable of generating the requisite laser energy and delivering the energy to target arteries. Thirteen research hospitals in the U.S. have purchased Dymer 200+ systems and used them in clinical trials in 121 peripheral and 555 coronary artery cases. The success rate in opening blocked coronary arteries is 85 percent, with fewer complications than in balloon angioplasty. Food and Drug Administration approval for the system is hoped for in the latter part of 1990. * Advanced Intraventional Systems became Spectranetics in 1994 and discontinued the product.

  5. Laser optomechanics

    NASA Astrophysics Data System (ADS)

    Yang, Weijian; Adair Gerke, Stephen; Wei Ng, Kar; Rao, Yi; Chase, Christopher; Chang-Hasnain, Connie J.

    2015-09-01

    Cavity optomechanics explores the interaction between optical field and mechanical motion. So far, this interaction has relied on the detuning between a passive optical resonator and an external pump laser. Here, we report a new scheme with mutual coupling between a mechanical oscillator supporting the mirror of a laser and the optical field generated by the laser itself. The optically active cavity greatly enhances the light-matter energy transfer. In this work, we use an electrically-pumped vertical-cavity surface-emitting laser (VCSEL) with an ultra-light-weight (130 pg) high-contrast-grating (HCG) mirror, whose reflectivity spectrum is designed to facilitate strong optomechanical coupling, to demonstrate optomechanically-induced regenerative oscillation of the laser optomechanical cavity. We observe >550?nm self-oscillation amplitude of the micromechanical oscillator, two to three orders of magnitude larger than typical, and correspondingly a 23?nm laser wavelength sweep. In addition to its immediate applications as a high-speed wavelength-swept source, this scheme also offers a new approach for integrated on-chip sensors.

  6. Laser optomechanics

    PubMed Central

    Yang, Weijian; Adair Gerke, Stephen; Wei Ng, Kar; Rao, Yi; Chase, Christopher; Chang-Hasnain, Connie J.

    2015-01-01

    Cavity optomechanics explores the interaction between optical field and mechanical motion. So far, this interaction has relied on the detuning between a passive optical resonator and an external pump laser. Here, we report a new scheme with mutual coupling between a mechanical oscillator supporting the mirror of a laser and the optical field generated by the laser itself. The optically active cavity greatly enhances the light-matter energy transfer. In this work, we use an electrically-pumped vertical-cavity surface-emitting laser (VCSEL) with an ultra-light-weight (130 pg) high-contrast-grating (HCG) mirror, whose reflectivity spectrum is designed to facilitate strong optomechanical coupling, to demonstrate optomechanically-induced regenerative oscillation of the laser optomechanical cavity. We observe >550 nm self-oscillation amplitude of the micromechanical oscillator, two to three orders of magnitude larger than typical, and correspondingly a 23 nm laser wavelength sweep. In addition to its immediate applications as a high-speed wavelength-swept source, this scheme also offers a new approach for integrated on-chip sensors. PMID:26333804

  7. Influence of holmium impurities on photoelectric properties of As{sub 2}Se{sub 3} and (As{sub 2}S{sub 3}){sub 0.3}(As{sub 2}Se{sub 3}){sub 0.7}

    SciTech Connect

    Burdiyan, I. I.; Senokosov, E. A.; Kosyuk, V. V. Pynzar', R. A.

    2006-10-15

    The influence of a holmium impurity on the photoelectric properties of bulk and film As{sub 2}Se{sub 3} and (As{sub 2}S{sub 3}){sub 0.3}(As{sub 2}Se{sub 3}){sub 0.7} samples is studied. Measurements of the relative photoconductivity of bulk samples and the spectral distribution of the persistent photoconductivity in film samples showed an increase in the photoconductivity of materials doped with holmium to concentrations equivalent to 0.010-0.015 at %. The spectral distribution of the persistent photoconductivity and optical absorption showed that the band gap monotonically decreases from 1.88 to 1.85 eV for As{sub 2}Se{sub 3} and from 2.05 to 2.00 eV for (As{sub 2}S{sub 3}){sub 0.3}(As{sub 2}Se{sub 3}){sub 0.7} as Ho concentration increases to 0.015 at %, and then weakly increases to the values in initial pure materials.

  8. An integrated fiber and stone basket device for use in Thulium fiber laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Wilson, Christopher R.; Hutchens, Thomas C.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

    2014-03-01

    The Thulium fiber laser (TFL) is being explored as an alternative laser lithotripter to the Holmium:YAG laser. The TFL's superior near-single mode beam profile enables higher power transmission through smaller fibers with reduced proximal fiber tip damage. Recent studies have also reported that attaching hollow steel tubing to the distal fiber tip decreases fiber degradation and burn-back without compromising stone ablation rates. However, significant stone retropulsion was observed, which increased with pulse rate. In this study, the hollow steel tip fiber design was integrated with a stone basket to minimize stone retropulsion during ablation. A device was constructed consisting of a 100-?m-core, 140-?m-OD silica fiber outfitted with 5-mm-long stainless steel tubing at the distal tip, and integrated with a 1.3-Fr (0.433-mm-OD) disposable nitinol wire basket, to form an overall 1.9-Fr (0.633-mm- OD) integrated device. This compact design may provide several potential advantages including increased flexibility, higher saline irrigation rates through the ureteroscope working channel, and reduced fiber tip degradation compared to separate fiber and stone basket manipulation. TFL pulse energy of 31.5 mJ with 500 ?s pulse duration and pulse rate of 500 Hz was delivered through the integrated fiber/basket device in contact with human uric acid stones, ex vivo. TFL stone ablation rates measured 1.5 +/- 0.2 mg/s, comparable to 1.7 +/- 0.3 mg/s (P > 0.05) using standard bare fiber tips separately with a stone basket. With further development, this device may be useful for minimizing stone retropulsion, thus enabling more efficient TFL lithotripsy at higher pulse rates.

  9. Differentiation of tissue and kidney stones for laser lithotripsy using different spectroscopic approaches

    NASA Astrophysics Data System (ADS)

    Lange, Birgit; Cordes, Jens; Brinkmann, Ralf

    2015-07-01

    Holmium lasers are nowadays the gold standard for endoscopic laser lithotripsy. However, there is a risk of damaging or perforating the ureter or kidney tissue when the vision is poor. An automatic tissue/stone differentiation would improve the handling and safety of the procedure. To achieve this objective, an easy and robust real-time discrimination method has to be found which can be used to realize a feedback loop to control the laser system. Two possible approaches have been evaluated: White light reflectance and fluorescence spectroscopy. In both cases, we use the treatment fiber for detection and evaluate the possibility to decide whether the fiber is placed in front of tissue or calculus by the signal that is delivered by the surface in front of it. White light reflectance spectroscopy uses the standard light source for endourologic surgeries: Radiation of a Xenon light source is coupled to the ureteroscope via a liquid light guide. The part of the white light that is reflected back into the fiber is spectroscopically analyzed. In a clinical proof of concept study reflection signals were measured in vivo in 8 patients. For differentiation of stone and tissue via autofluorescence, excitation as well as detection was done via the treatment fiber. A suitable excitation wavelength was chosen with in vitro measurements (UV / visible) on several human renal calculi and porcine tissues. For verification of the positive results with green excitation in a clinical proof of concept study, a measurement set-up was realized which allows the recording of fluorescence signals during an endourological intervention.

  10. Laser beam monitoring system

    DOEpatents

    Weil, Bradley S. (Knoxville, TN); Wetherington, Jr., Grady R. (Harriman, TN)

    1985-01-01

    Laser beam monitoring systems include laser-transparent plates set at an angle to the laser beam passing therethrough and light sensor for detecting light reflected from an object on which the laser beam impinges.

  11. Laser Physics and Laser-Tissue Interaction

    PubMed Central

    Welch, A. J.; Torres, Jorge H.; Cheong, Wai-Fung

    1989-01-01

    Within the last few years, lasers have gained increasing use in the management of cardiovascular disease, and laser angioplasty has become a widely performed procedure. For this reason, a basic knowledge of lasers and their applications is essential to vascular surgeons, cardiologists, and interventional radiologists. To elucidate some fundamental concepts regarding laser physics, we describe how laser light is generated and review the properties that make lasers useful in medicine. We also discuss beam profile and spotsize, as well as dosimetric specifications for laser angioplasty. After considering laser-tissue interaction and light propagation in tissue, we explain how the aforementioned concepts apply to direct laser angioplasty and laser-balloon angioplasty. An understanding of these issues should prove useful not only in performing laser angioplasty but in comparing the reported results of various laser applications. (Texas Heart Institute Journal 1989;16:141-9) PMID:15227198

  12. Tunable solid state lasers

    SciTech Connect

    Hammerling, R.; Budgor, A.B.; Pinto, A.

    1985-01-01

    This book presents the papers given at a conference on solid state lasers. Topics considered at the conference included transition-metal-doped lasers, line-narrowed alexandrite lasers, NASA specification, meteorological lidars, laser materials spectroscopy, laser pumped single pass gain, vibronic laser materials growth, crystal growth methods, vibronic laser theory, cross-fertilization through interdisciplinary fields, and laser action of color centers in diamonds.

  13. Immunohistochemical and electronmicroscopic effects of a new 2.1 microns Ho:YAG laser on the rat brain.

    PubMed

    Ludwig, H C; Bauer, C; Behnke, J; Fuhrberg, P; Teichmann, H P; Markakis, E

    1994-01-01

    Using an experimental animal model, the thermal single-pulse lesion derived from a mid-infrared 1.0 Joule 300 microns fibre-conducted Holmium: Yttrium-Aluminum-Garnet (Ho:YAG) laser was examined, with special emphasis on the orientation and depth of the tissue reaction. Performing biparietal craniotomy in Sprague-Dawley rats weighing 250-300 g, both hemispheres were targeted by different radiant exposures from 20 to 140 J/cm2 derived from a 600-800 microsecond single pulse. After survival periods of one to 30 days, the animals were sacrificed and both hemispheres were processed for light- and electronmicroscopic investigations. To resolve the depth and orientation of the tissue reaction regarding the localization of reactive astrocytes, we looked for the expression of glial proteins like glial fibrillary acidic protein (GFAP), Vimentin and S 100 with a three-step biotin-avidin immunoperoxidase method. Neuronal and secondary axonal damage was investigated by labelling Neurofilament and Synaptophysin. The tissue reaction beneath the ablated material, consisting of a vacuolation and coagulation zone resulting from heat diffusion, was further elucidated by localization of the heat shock protein (HSP 72 kilo Dalton). Revealing the extension of reactive astrocytes and the degree of the electronmicroscopically depicted glial oedema, the depth of the tissue damage was estimated to reach about 700 microns beneath laser excision. Since McKenzie predicted the depth of tissue damage beneath CO2 and YAG laser excisions in a theoretical mathematical model, the authors were able to develop a sensitive model for testing new laser systems and as a promising instrument for neurosurgery. PMID:8185264

  14. Laser Resonator

    NASA Technical Reports Server (NTRS)

    Harper, L. L. (inventor)

    1983-01-01

    An optical resonator cavity configuration has a unitary mirror with oppositely directed convex and concave reflective surfaces disposed into one fold and concertedly reversing both ends of a beam propagating from a laser rod disposed between two total internal reflection prisms. The optical components are rigidly positioned with perpendicularly crossed virtual rooflines by a compact optical bed. The rooflines of the internal reflection prisms, are arranged perpendicularly to the axis of the laser beam and to the optical axes of the optical resonator components.

  15. Laser theory

    SciTech Connect

    Haken, H.

    1983-01-01

    This book first appeared as v. XXX/2c of the 1970 Encyclopedia of Physics. It still remains a useful and classic introduction to the subject. Laser resonators, the quantum theory of coherence and the quantization of electromagnetic fields are thoroughly covered and with some rigor. A knowledge of quantum and wave theory is presumed. Full bibliographic footnotes. Contents abridged: Optical resonators. Fully quantum mechanical solutions of the laser equations. The semiclassical approach and its applications. Rate equations and their applications. Rate equations and their applications. Further methods for dealing with quantum systems far from thermal equilibrium.

  16. Gas laser

    SciTech Connect

    Hayakawa, S.; Kubota, S.; Kurousu, A.

    1981-02-10

    A gas laser is disclosed, in which one end surface of a plasma tube of a gas laser envelope is worked to be perpendicular to the axis of the plasma tube, a cap covers, a mirror and the end surface of the plasma tube so as to make the mirror abut against the worked end surface, the cap is fixed at its open end to the plasma tube by frit material, and a bore is formed through the plasma tube which is covered by the cap.

  17. Excimer lasers

    NASA Technical Reports Server (NTRS)

    Palmer, A. J.; Hess, L. D.; Stephens, R. R.

    1976-01-01

    A theoretical and experimental investigation into the possibility of achieving CW discharge pumped excimer laser oscillation is reported. Detailed theoretical modeling of capillary discharge pumping of the XeF and KXe and K2 excimer systems was carried out which predicted the required discharge parameters for reaching laser threshold on these systems. Capillary discharge pumping of the XeF excimer system was investigated experimentally. The experiments revealed a lower excimer level population density than predicted theoretically by about an order of magnitude. The experiments also revealed a fluorine consumption problem in the discharge in agreement with theory.

  18. Laser barometer

    DOEpatents

    Abercrombie, Kevin R.; Shiels, David; Rash, Tim

    2001-02-06

    A pressure measuring instrument that utilizes the change of the refractive index of a gas as a function of pressure and the coherent nature of a laser light to determine the barometric pressure within an environment. As the gas pressure in a closed environment varies, the index of refraction of the gas changes. The amount of change is a function of the gas pressure. By illuminating the gas with a laser light source, causing the wavelength of the light to change, pressure can be quantified by measuring the shift in fringes (alternating light and dark bands produced when coherent light is mixed) in an interferometer.

  19. Histological aspects of retinal damage following exposure to pulsed Nd:YAG laser radiation in rabbits: indication for mechanism

    NASA Astrophysics Data System (ADS)

    Kadar, T.; Peri, D.; Turetz, J.; Fishbine, E.; Sahar, R.; Egoz, I.; Sapiens, N.; Brandeis, R.

    2007-02-01

    The severity and characteristics of retinal injury following laser radiation derived from laser and tissue related factors. We have previously shown that retinal damage following Nd:YAG Q-switched laser radiation in rabbits was related to physical parameters, i.e. energy levels and number of pulses. Yet, an extremely large variability in the severity of the damage was found under similar exposure paradigms, even within the same retina. This emphasizes the role of the biological variables in the pathological mechanism of laser-induced retinal damage. The aim of the present study was to further study histological parameters of the injury in relation to retinal site and to elucidate their role in the initiation and characteristics of the damage, following various energy levels (10-50 ?J) and number of pulses (1-4). Pigmented rabbits were exposed to Nd:YAG laser radiation (532nm, pulse duration: 20ns). Exposures were conducted in retina tissue, adjacent to the optic nerve, with a total of 20 exposures per retina. Animals were sacrificed 15 min or 24 hours post exposure, eyes enucleated and processed for paraffin embedding. 4?m thick serial sections, stained with hematoxylin and eosin, were examined under light microscopy. Two major types of retinal damage were observed: focal edema confined to the pigmented epithelium and the photoreceptor cells, and hemorrhages, associated with destruction of retinal tissue. While focal edema associated with slight elevation of the photoreceptor layer seems to depend on the pigmented epithelium, hemorrhages were related also to the choroid vasculature at the site of radiation. It is suggested that a thermo-mechanical mechanism is involved in laser induced retinal hemorrhages at energies above 10-30?J (2-1 pulses, respectively).

  20. Dye laser principles, with applications

    SciTech Connect

    Duarte, F.J. . Dept. of Physics); Hillman, L.W. . Dept. of Physics)

    1990-01-01

    This book contains papers which explain dye laser principles. Topics covered include: laser dynamics, femtosecond dye lasers, CW dye lasers, technology of pulsed dye lases, photochemistry of laser dyes, and laser applications.