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Sample records for par implants permanents

  1. Lens implant surgery in pars planitis.

    PubMed

    Michelson, J B; Friedlaender, M H; Nozik, R A

    1990-08-01

    Intraocular lens (IOL) implantation is usually contraindicated in eyes with active inflammation, but patients with "burned-out" pars planitis also may be considered as candidates. Fifteen of 16 eyes in eight patients underwent extracapsular cataract extraction (ECCE) with posterior chamber IOL (PC IOL) implantation combined with pars plana vitrectomy for both cataracts and chronic cystoid macular edema (CME); 60% achieved visual acuity of 20/40 or better. Even with "low-grade" inflammation in these patients, however, a persistent veil of debris accumulated over the posterior and anterior surface of the IOL. One patient (patient 2) required 27 YAG procedures for two eyes, and another required 11 YAG procedures and eventual removal of the IOL. Another patient required surgical "brushing-off" of the IOL and vitrectomy. Even in eyes with "burned-out" uveitis, a continual low-grade inflammation may complicate the use of IOL implantation. PMID:2402411

  2. [Permanent pacemaker implantation. Indications and results].

    PubMed

    Gutiérrez, A; Iturralde, P; Gutiérrez Fuster, E; Martínez Ríos, N; Martínez Ríos, M A; Romero, L; Hernández, D; González Hermosillo, J A

    1990-01-01

    Clinical, laboratory and electrocardiographic data from 608 patients with permanent pacemakers implanted over a period of 8 years, were evaluated retrospectively. The number of implants was greater in males (56.5%) and in patients over 60 years of age (77.5%). Atherosclerosis was the most common disease found in this group (50%). Syncope occurred in 96.2% of the cases; and complete AV block was the most common electrocardiographic alteration (50.5%). Electrode displacement occurred in 32 patients (5.2%) and was the most commonly found early complication. Among the late complications, 10.3% of the patients had infections in the area of the generator. The total mortality was 7.7% due to the heart disease rather than pacemaker-related complication. PMID:2344227

  3. Temporary inhibition of permanently implanted demand pacemakers.

    PubMed

    Latif, P; Ewy, G A

    1977-01-01

    Temporary inhibition of permanently implanted demand pacemakers has been previously described. Demand pacemakers may be inhibited by waving a magnet over the region of the pacemaker generator or by chest wall stimulation. The former may not inhibit most of the bipolar pacemakers, whereas the latter may be time consuming and may casue patient discomfort. Another method is described which utilized a commercially available Cordis Omnicor Programmer, Model 166-B, to temporarily inhibit bipolar and unipolar pacemakers. By placing the programmer over the skin where the pacemaker generator is implanted and/or over the area of the subcutaneous pervenous lead and activating the programmer multiple times at a rate faster then the pacing rate, the demand pacemakers are inhibited. After testing the efficacy in vitro, the method was successfully tried on 45 patients. Fifteen of these patients had unipolar pacemakers. Pacemakers marketed by Medtronic, Cordis, Starr-Edwards, C.P.I., and Arco were tested. Temporary inhibition of permanent demand pacemakers is desirable under various clinical situations. The method herein described has the advantages of being simple, quick, painless, and is effective for both unipolar and bipolar pacemakers. PMID:830215

  4. Permanent Breast Seed Implant Dosimetry Quality Assurance

    SciTech Connect

    Keller, Brian M.; Ravi, Ananth; Sankreacha, Raxa; Pignol, Jean-Philippe

    2012-05-01

    Purpose: A permanent breast seed implant is a novel method of accelerated partial breast irradiation for women with early-stage breast cancer. This article presents pre- and post-implant dosimetric data, relates these data to clinical outcomes, and makes recommendations for those interested in starting a program. Methods and Materials: A total of 95 consecutive patients were accrued into one of three clinical trials after breast-conserving surgery: a Phase I/II trial (67 patients with infiltrating ductal carcinoma); a Phase II registry trial (25 patients with infiltrating ductal carcinoma); or a multi-center Phase II trial for patients with ductal carcinoma in situ (3 patients). Contouring of the planning target volume (PTV) was done on a Pinnacle workstation and dosimetry calculations, including dose-volume histograms, were done using a Variseed planning computer. Results: The mean pre-implant PTV coverage for the V{sub 90}, V{sub 100}, V{sub 150}, and V{sub 200} were as follows: 98.8% {+-} 1.2% (range, 94.5-100%); 97.3% {+-} 2.1% (range, 90.3-99.9%), 68.8% {+-} 14.3% (range, 32.7-91.5%); and 27.8% {+-} 8.6% (range, 15.1-62.3%). The effect of seed motion was characterized by post-implant dosimetry performed immediately after the implantation (same day) and at 2 months after the implantation. The mean V{sub 100} changed from 85.6% to 88.4% (p = 0.004) and the mean V{sub 200} changed from 36.2% to 48.3% (p < 0.001). Skin toxicity was associated with maximum skin dose (p = 0.014). Conclusions: Preplanning dosimetry should aim for a V{sub 90} of approximately 100%, a V{sub 100} between 95% and 100%, and a V{sub 200} between 20% and 30%, as these numbers are associated with no local recurrences to date and good patient tolerance. In general, the target volume coverage improved over the duration of the seed therapy. The maximum skin dose, defined as the average dose over the hottest 1 Multiplication-Sign 1-cm{sup 2} surface area, should be limited to 90% of the

  5. Prescription dose in permanent {sup 131}Cs seed prostate implants

    SciTech Connect

    Yue Ning; Heron, Dwight E.; Komanduri, Krishna; Huq, M. Saiful

    2005-08-15

    Recently, {sup 131}Cs seeds have been introduced for prostate permanent seed implants. This type of seed has a relatively short half-life of 9.7 days and has its most prominent emitted photon energy peaks in the 29-34 keV region. Traditionally, 145 and 125 Gy have been prescribed for {sup 125}I and {sup 103}Pd seed prostate implants, respectively. Since both the half-life and dosimetry characteristics of {sup 131}Cs seed are quite different from those of {sup 125}I and {sup 103}Pd, the appropriate prescription dose for {sup 131}Cs seed prostate implant may well be different. This study was designed to use a linear quadratic radiobiological model to determine an appropriate dose prescription scheme for permanent {sup 131}Cs seed prostate implants. In this model, prostate edema was taken into consideration. Calculations were also performed for tumors of different doubling times and for other related radiobiological parameters of different values. As expected, the derived prescription dose values were dependent on type of tumors and types of edema. However, for prostate cancers in which tumor cells are relatively slow growing and are reported to have a mean potential doubling time of around 40 days, the appropriate prescription dose for permanent {sup 131}Cs seed prostate implants was determined to be: 127{sub -12}{sup +5}Gy if the experiences of {sup 125}I seed implants were followed and 121{sub -3}{sup +0}Gy if the experiences of {sup 103}Pd seed implants were followed.

  6. Permanent and removable implants for the brachytherapy of brain tumors

    SciTech Connect

    Gutin, P.H.; Phillips, T.L.; Hosobuchi, Y.

    1981-10-01

    Thirty-seven patients harboring primary or metastatic brain tumors were treated with 40 implantations of radioactive sources (/sup 192/Ir, /sup 198/Au, or /sup 125/I) using stereotactic neurosurgical techniques. Most tumors had recurred after surgery, whole brain irradiation, and treatment with all feasible chemotherapeutic agents. Sixteen of the 40 implants were pregnant; 24 were mounted in plastic catheters for removal after the desired dose had been delivered. One or more sources were placed in each tumor to deliver 3500-7350 rad to the tumor's periphery for /sup 198/Au, 4,000-12,000 rad for /sup 192/Ir, and 3,000-20,000 rad for /sup 125/I. Three of the six patients treated with /sup 192/Ir had objective responses for 2, 4, and 12 months, and two stabilized for 8 and 11 months. Seven of the 11 patients treated with /sup 198/Au were evaluable: three responded for 3, 5, and 37 + months, one deteriorating patient with a recurrent tumor stabilized for 6 months, and two deteriorated despite treatment. One patient received an interstitial ''boost'' dose with /sup 198/Au after whole brain irradiation and stabilized for 15 months before developing spinal metastases. Six patients received permanent implants with low activity /sup 125/I. Three of these patients had blioblastomas or anaplastic astrocytomas; all continued to deteriorate despite the interstitial irradiation, presumably because the dose rat was too low. One patient with a low-grade astrocytoma (optic chiasm) responded dramatically to permanent, low activity /sup 125/I implants (11 + months). Another (hypothalamic glioma) had a permanent /sup 125/I implant, responded, as was stable at 9 months when external irradiation was administered. One patient with a suprasellar ''teratoid'' tumor stabilized for 10 months.

  7. Dual-chamber implantable cardioverter-defibrillator. Is it useful in patient with permanent atrial fibrillation?

    PubMed

    Porres-Aracama, José M; Cerezuela, José Luis; García-Urra, Francisco; Luque-Lezcano, Oscar; Herrero, Vicente

    2016-08-01

    In patients with permanent atrial fibrillation (AF) and implantable cardioverter-defibrillator (ICD) implant indication, a single-chamber device is the choice because AF does not provide interesting information for the treatment. It is very unusual to find patients with permanent AF that coexist with atrial tachycardia with various degree of Atrioventricular block. PMID:27525075

  8. Versatile permanent planar implant technique utilizing Iodine-125 seeds imbedded in gelfoam

    SciTech Connect

    Marchese, M.J.; Nori, D.; Anderson, L.L.; Hilaris, B.S.

    1984-05-01

    Tumors attached or adjacent to critical structures can often not be completely resected or resected with adequate surgical margins. Sites involving major blood vessels, the vertebral column or the brain with small residual tumors or suspicious margins often present technical difficulties for standard I-125 or Ir-192 implants. A relatively simple, accurate and inexpensive implant method is decribed using I-125 seeds imbedded in gelfoam to implant permanently into small residual tumors or suspicious margins where standard implant techniques may be unsatisfactory. A method for planning the treatment dose for such an implant is described. Cases involving paraspinal and brain tumors are reported to illustrate the technique.

  9. [Intraoperative and post-implant dosimetry in patients treated with permanent prostate implant brachytherapy].

    PubMed

    Herein, András; Ágoston, Péter; Szabó, Zoltán; Jorgo, Kliton; Markgruber, Balázs; Pesznyák, Csilla; Polgár, Csaba; Major, Tibor

    2015-06-01

    The purpose of our work was to compare intraoperative and four-week post-implant dosimetry for loose and stranded seed implants for permanent prostate implant brachytherapy. In our institute low-dose-rate (LDR) prostate brachytherapy is performed with encapsulated I-125 isotopes (seeds) using transrectal ultrasound guidance and metal needles. The SPOT PRO 3.1 (Elekta, Sweden) system is used for treatment planning. In this study the first 79 patients were treated with loose seed (LS) technique, the consecutive patients were treated with stranded seed (SS) technique. During intraoperative planning the dose constraints were the same for both techniques. All LSs were placed inside the prostate capsule, while with SS a 2 mm margin around the prostate was allowed for seed positioning. The prescribed dose for the prostate was 145 Gy. This study investigated prostate dose coverage in 30-30 randomly selected patients with LS and SS. Four weeks after the implantation native CT and MRI were done and CT/MRI image fusion was performed. The target was contoured on MRI and the plan was prepared on CT data. To assess the treatment plan dose-volume histograms were used. For the target coverage V100, V90, D90, D100, for the dose inhomogeneity V150, V200, and the dose-homogeneity index (DHI), for dose conformality the conformal index (COIN) were calculated. Intraoperative and postimplant plans were compared. The mean V100 values decreased at four-week plan for SS (97% vs. 84%) and for LS (96% vs. 80%) technique, as well. Decrease was observed for all parameters except for the DHI value. The DHI increased for SS (0.38 vs. 0.41) and for LS (0.38 vs. 0.47) technique, as well. The COIN decreased for both techniques at four-week plan (SS: 0.63 vs. 0.57; LS: 0.67 vs. 0.50). All differences were significant except for the DHI value at SS technique. The percentage changes were not significant, except the COIN value. The dose coverage of the target decreased significantly at four-week plans

  10. Monte Carlo calculated doses to treatment volumes and organs at risk for permanent implant lung brachytherapy

    NASA Astrophysics Data System (ADS)

    Sutherland, J. G. H.; Furutani, K. M.; Thomson, R. M.

    2013-10-01

    Iodine-125 (125I) and Caesium-131 (131Cs) brachytherapy have been used with sublobar resection to treat stage I non-small cell lung cancer and other radionuclides, 169Yb and 103Pd, are considered for these treatments. This work investigates the dosimetry of permanent implant lung brachytherapy for a range of source energies and various implant sites in the lung. Monte Carlo calculated doses are calculated in a patient CT-derived computational phantom using the EGsnrc user-code BrachyDose. Calculations are performed for 103Pd, 125I, 131Cs seeds and 50 and 100 keV point sources for 17 implant positions. Doses to treatment volumes, ipsilateral lung, aorta, and heart are determined and compared to those determined using the TG-43 approach. Considerable variation with source energy and differences between model-based and TG-43 doses are found for both treatment volumes and organs. Doses to the heart and aorta generally increase with increasing source energy. TG-43 underestimates the dose to the heart and aorta for all implants except those nearest to these organs where the dose is overestimated. Results suggest that model-based dose calculations are crucial for selecting prescription doses, comparing clinical endpoints, and studying radiobiological effects for permanent implant lung brachytherapy.

  11. Percutaneous permanent pacemaker implantation via the azygous vein in a patient with superior vena cava occlusion.

    PubMed

    Kamdar, Ravindu Hasmukh; Schilling, Richard John

    2008-03-01

    Occlusion of the superior vena cava (SVCO) makes implantation of permanent pacemakers challenging and difficult. We describe an extended application of a Medtronic Attain (Medtronic Inc., Minneapolis, MN, USA) guide catheter (a tool designed for delivery of left ventricular pacing leads into the coronary sinus) for delivery of a right ventricular pacing lead via the azygous vein in a 72-year-old woman with SVCO secondary to long-term central venous hemodialysis catheters. This approach allowed the use of an endocardial pacing lead, implantation under local anesthesia, and conventional positioning of the pacemaker generator in the pectoral region in a patient with SVCO. PMID:18307638

  12. Determination of prescription dose for Cs-131 permanent implants using the BED formalism including resensitization correction

    SciTech Connect

    Luo, Wei Molloy, Janelle; Aryal, Prakash; Feddock, Jonathan; Randall, Marcus

    2014-02-15

    Purpose: The current widely used biological equivalent dose (BED) formalism for permanent implants is based on the linear-quadratic model that includes cell repair and repopulation but not resensitization (redistribution and reoxygenation). The authors propose a BED formalism that includes all the four biological effects (4Rs), and the authors propose how it can be used to calculate appropriate prescription doses for permanent implants with Cs-131. Methods: A resensitization correction was added to the BED calculation for permanent implants to account for 4Rs. Using the same BED, the prescription doses with Au-198, I-125, and Pd-103 were converted to the isoeffective Cs-131 prescription doses. The conversion factor F, ratio of the Cs-131 dose to the equivalent dose with the other reference isotope (F{sub r}: with resensitization, F{sub n}: without resensitization), was thus derived and used for actual prescription. Different values of biological parameters such as α, β, and relative biological effectiveness for different types of tumors were used for the calculation. Results: Prescription doses with I-125, Pd-103, and Au-198 ranging from 10 to 160 Gy were converted into prescription doses with Cs-131. The difference in dose conversion factors with (F{sub r}) and without (F{sub n}) resensitization was significant but varied with different isotopes and different types of tumors. The conversion factors also varied with different doses. For I-125, the average values of F{sub r}/F{sub n} were 0.51/0.46, for fast growing tumors, and 0.88/0.77 for slow growing tumors. For Pd-103, the average values of F{sub r}/F{sub n} were 1.25/1.15 for fast growing tumors, and 1.28/1.22 for slow growing tumors. For Au-198, the average values of F{sub r}/F{sub n} were 1.08/1.25 for fast growing tumors, and 1.00/1.06 for slow growing tumors. Using the biological parameters for the HeLa/C4-I cells, the averaged value of F{sub r} was 1.07/1.11 (rounded to 1.1), and the averaged value of F

  13. Adverse reactions after cosmetic lip augmentation with permanent biologically inert implant materials.

    PubMed

    Hoffmann, C; Schuller-Petrovic, S; Soyer, H P; Kerl, H

    1999-01-01

    Augmentation of lips is a common aesthetic procedure that is mostly performed with alloplastic materials or autologous tissue. Various alloplastic injectable implants have been developed for soft tissue augmentation without surgery. Most biologic materials are resorbed within a few months, fluid silicone may migrate, and autologous fat is not ideal for fine contouring of the lips. The search for a biocompatible, permanent, nontoxic, and biologically inert filler material led to the development of some new materials for subdermal or intradermal implantation. Recently Bioplastique, Artecoll, and Gore-Tex have been well established and recommended by many authors. Although these materials meet most of the characteristics that constitute an ideal injectable prosthetic material, we describe 3 examples of adverse reactions after their implantation into lips. PMID:9922021

  14. Adjuvant stereotactic permanent seed breast implant: A boost series in view of partial breast irradiation

    SciTech Connect

    Jansen, Nicolas . E-mail: nicolas.jansen@chu.ulg.ac.be; Deneufbourg, Jean-Marie; Nickers, Philippe

    2007-03-15

    Purpose: The aim of this study was to use permanent seed implants in the breast and describe our experience with 15 cases, using iodine seed implants as a tumor bed boost. Methods and Materials: Breasts were fixed with a thermoplastic sheet, a template bridge applied, the thorax scanned and the images rotated to be perpendicular to the implant axis. Skin, heart, and lung were delineated. A preplan was made, prescribing 50 Gy to the clinical target volume (CTV), consisting in this boost series of nearly a quadrant. Iodine (125) seeds were stereotactically implanted through the template, and results were checked with a postplan computed tomographic (CT) scan. Results: The breast was immobilized reproducibly. Simulation, scanning, and implant were performed without difficulties. Preplan CTV D90% (the dose delivered to 90% of the CTV) was 66 Gy, and postoperative fluoroscopic or CT scan checks were satisfactory. Pre- and postplan dose-volume histogram showed good organ sparing: mean postplan skin, heart, and lung V30 Gy (the organ volume receiving a dose of 30 Gy) of 2 {+-} 2.2 mL, 0.24 {+-} 0.34 mL, and 3.5 {+-} 5 mL, respectively. No short-term toxicity above Grade 1 was noted, except for transient Grade 3 neuropathy in 1 patient. Conclusions: Seeds remained in the right place, as assessed by fluoroscopy, absence of significant pre- to postplan dose-volume histogram change for critical organs, and total irradiated breast volume. The method could be proposed as a boost when high dosimetric selectivity is required (young patients after cardiotoxic chemotherapy for left-sided cancer). This boost series was a preliminary step before testing partial breast irradiation by permanent seed implant in a prospective trial.

  15. An automated, fast and accurate registration method to link stranded seeds in permanent prostate implants.

    PubMed

    Westendorp, Hendrik; Nuver, Tonnis T; Moerland, Marinus A; Minken, André W

    2015-10-21

    The geometry of a permanent prostate implant varies over time. Seeds can migrate and edema of the prostate affects the position of seeds. Seed movements directly influence dosimetry which relates to treatment quality. We present a method that tracks all individual seeds over time allowing quantification of seed movements. This linking procedure was tested on transrectal ultrasound (TRUS) and cone-beam CT (CBCT) datasets of 699 patients. These datasets were acquired intraoperatively during a dynamic implantation procedure, that combines both imaging modalities. The procedure was subdivided in four automatic linking steps. (I) The Hungarian Algorithm was applied to initially link seeds in CBCT and the corresponding TRUS datasets. (II) Strands were identified and optimized based on curvature and linefits: non optimal links were removed. (III) The positions of unlinked seeds were reviewed and were linked to incomplete strands if within curvature- and distance-thresholds. (IV) Finally, seeds close to strands were linked, also if the curvature-threshold was violated. After linking the seeds an affine transformation was applied. The procedure was repeated until the results were stable or the 6th iteration ended. All results were visually reviewed for mismatches and uncertainties. Eleven implants showed a mismatch and in 12 cases an uncertainty was identified. On average the linking procedure took 42 ms per case. This accurate and fast method has the potential to be used for other time spans, like Day 30, and other imaging modalities. It can potentially be used during a dynamic implantation procedure to faster and better evaluate the quality of the permanent prostate implant. PMID:26439900

  16. Prostatic edema in {sup 125}I permanent prostate implants: Dynamical dosimetry taking volume changes into account

    SciTech Connect

    Leclerc, Ghyslain; Lavallee, Marie-Claude; Roy, Rene; Vigneault, Eric; Beaulieu, Luc

    2006-03-15

    The purpose of this study is to determine the impact of edema on the dose delivered to the target volume. An evaluation of the edema characteristics was first made, and then a dynamical dosimetry algorithm was developed and used to compare its results to a standard clinical (static) dosimetry. Source positions and prostate contours extracted from 66 clinical cases on images taken at different points in time (planning, implant day, post-implant evaluation) were used, via the mean interseed distance, to characterize edema [initial increase ({delta}r{sub 0}), half-life ({tau})]. An algorithm was developed to take into account the edema by summing a time series of dose-volume histograms (DVHs) with a weight based on the fraction of the dose delivered during the time interval considered. The algorithm was then used to evaluate the impact of edema on the dosimetry of permanent implants by comparing its results to those of a standard clinical dosimetry. The volumetric study yielded results as follows: the initial prostate volume increase was found to be 1.58 (ranging from 1.15 to 2.48) and the edema half-life, approximately 30 days (range: 3 to 170 days). The dosimetric differences in D{sub 90} observed between the dynamic dosimetry and the clinical one for a single case were up to 15 Gy and depended on the edema half-life and the initial volume increase. The average edema half-life, 30 days, is about 3 times longer than the previously reported 9 days. Dosimetric differences up to 10% of the prescription dose are observed, which can lead to differences in the quality assertion of an implant. The study of individual patient edema resorption with time might be necessary to extract meaningful clinical correlation or biological parameters in permanent implants.

  17. An automated, fast and accurate registration method to link stranded seeds in permanent prostate implants

    NASA Astrophysics Data System (ADS)

    Westendorp, Hendrik; Nuver, Tonnis T.; Moerland, Marinus A.; Minken, André W.

    2015-10-01

    The geometry of a permanent prostate implant varies over time. Seeds can migrate and edema of the prostate affects the position of seeds. Seed movements directly influence dosimetry which relates to treatment quality. We present a method that tracks all individual seeds over time allowing quantification of seed movements. This linking procedure was tested on transrectal ultrasound (TRUS) and cone-beam CT (CBCT) datasets of 699 patients. These datasets were acquired intraoperatively during a dynamic implantation procedure, that combines both imaging modalities. The procedure was subdivided in four automatic linking steps. (I) The Hungarian Algorithm was applied to initially link seeds in CBCT and the corresponding TRUS datasets. (II) Strands were identified and optimized based on curvature and linefits: non optimal links were removed. (III) The positions of unlinked seeds were reviewed and were linked to incomplete strands if within curvature- and distance-thresholds. (IV) Finally, seeds close to strands were linked, also if the curvature-threshold was violated. After linking the seeds an affine transformation was applied. The procedure was repeated until the results were stable or the 6th iteration ended. All results were visually reviewed for mismatches and uncertainties. Eleven implants showed a mismatch and in 12 cases an uncertainty was identified. On average the linking procedure took 42 ms per case. This accurate and fast method has the potential to be used for other time spans, like Day 30, and other imaging modalities. It can potentially be used during a dynamic implantation procedure to faster and better evaluate the quality of the permanent prostate implant.

  18. Dose calculation for permanent prostate implants incorporating spatially anisotropic linearly time-resolving edema

    SciTech Connect

    Monajemi, T. T.; Clements, Charles M.; Sloboda, Ron S.

    2011-04-15

    Purpose: The objectives of this study were (i) to develop a dose calculation method for permanent prostate implants that incorporates a clinically motivated model for edema and (ii) to illustrate the use of the method by calculating the preimplant dosimetry error for a reference configuration of {sup 125}I, {sup 103}Pd, and {sup 137}Cs seeds subject to edema-induced motions corresponding to a variety of model parameters. Methods: A model for spatially anisotropic edema that resolves linearly with time was developed based on serial magnetic resonance imaging measurements made previously at our center to characterize the edema for a group of n=40 prostate implant patients [R. S. Sloboda et al., ''Time course of prostatic edema post permanent seed implant determined by magnetic resonance imaging,'' Brachytherapy 9, 354-361 (2010)]. Model parameters consisted of edema magnitude, {Delta}, and period, T. The TG-43 dose calculation formalism for a point source was extended to incorporate the edema model, thus enabling calculation via numerical integration of the cumulative dose around an individual seed in the presence of edema. Using an even power piecewise-continuous polynomial representation for the radial dose function, the cumulative dose was also expressed in closed analytical form. Application of the method was illustrated by calculating the preimplant dosimetry error, RE{sub preplan}, in a 5x5x5 cm{sup 3} volume for {sup 125}I (Oncura 6711), {sup 103}Pd (Theragenics 200), and {sup 131}Cs (IsoRay CS-1) seeds arranged in the Radiological Physics Center test case 2 configuration for a range of edema relative magnitudes ({Delta}=[0.1,0.2,0.4,0.6,1.0]) and periods (T=[28,56,84] d). Results were compared to preimplant dosimetry errors calculated using a variation of the isotropic edema model developed by Chen et al. [''Dosimetric effects of edema in permanent prostate seed implants: A rigorous solution,'' Int. J. Radiat. Oncol., Biol., Phys. 47, 1405-1419 (2000

  19. Stereotactic iodine-125 brachytherapy for brain tumors: temporary versus permanent implantation.

    PubMed

    Ruge, Maximilian I; Kickingereder, Philipp; Grau, Stefan; Treuer, Harald; Sturm, Volker; Voges, Juergen

    2012-01-01

    Stereotactic brachytherapy (SBT) has been described in several publications as an effective, minimal invasive and safe highly focal treatment option in selected patients with well circumscribed brain tumors <4 cm. However, a still ongoing discussion about indications and technique is hindering the definition of a clear legitimation of SBT in modern brain tumor treatment. These controversies encompass the question of how intense the irradiation should be delivered into the target volume (dose rate). For instance, reports about the use of high does rate (HDR) implantation schemes (>40 cGy/h) in combination with adjuvant external beam radiation and/or chemotherapy for the treatment of malignant gliomas and metastases resulted in increased rates of radiation induced adverse tissue changes requiring surgical intervention. Vice versa, such effects have been only minimally observed in numerous studies applying low dose rate (LDR) regiments (3-8 cGy/h) for low grade gliomas, metastases and other rare indications. Besides these observations, there are, however, no data available directly comparing the long term incidences of tissue changes after HDR and LDR and there is, furthermore, no evidence regarding a difference between temporary or permanent LDR implantation schemes. Thus, recommendations for effective and safe implantation schemes have to be investigated and compared in future studies. PMID:22713629

  20. Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants.

    PubMed

    Thompson, S A; Fung, A Y C; Zaider, M

    2002-08-21

    One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with 1-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results. PMID:12222865

  1. NOTE: Optimal needle arrangement for intraoperative planning in permanent I-125 prostate implants

    NASA Astrophysics Data System (ADS)

    Thompson, S. A.; Fung, A. Y. C.; Zaider, M.

    2002-08-01

    One limitation of intraoperative planning of permanent prostate implants is that needles must already be in the gland before planning images are acquired. Improperly placed needles often restrict the capability of generating optimal seed placement. We developed guiding principles for the proper layout of needles within the treatment volume. The Memorial Sloan-Kettering Cancer Center planning system employs a genetic algorithm to find the optimal seed implantation pattern consistent with pre-assigned constraints (needle geometry, uniformity, conformity and the avoidance of high doses to urethra and rectum). Ultrasound volumes for twelve patients with I-125 implants were used to generate six plans per patient (total 72 plans) with different needle arrangements. The plans were evaluated in terms of V100 (percentage prostate volume receiving at least the prescription dose), U135 (percentage urethra volume receiving at least 135% of prescription dose), and CI (conformity index, the ratio of treatment volume to prescription dose volume.) The method termed POSTCTR, in which needles were placed on the periphery of the largest ultrasound slice and posterior central needles were placed as needed, consistently gave superior results for all prostate sizes. Another arrangement, labelled POSTLAT, where the needles were placed peripherally with additional needles in the posterior lateral lobes, also gave satisfactory results. We advocate two needle arrangements, POSTCTR and POSTLAT, with the former giving better results.

  2. Caractérisation des effets de l'implantation ionique dans les alliages super-élastiques nickel titane par diffraction des rayons X

    NASA Astrophysics Data System (ADS)

    Pelletier, H.; Muller, D.; Grob, J. J.; Mille, P.; Cornet, A.

    2002-07-01

    the specific properties (shape memory effect and super-elasticity) of NiTi alloys have provided the enabling technology for many groundbreaking applications in the medical and dentistry industries. These applications include everything from the surgical tools to permanent implants. Super-elastic NiTi alloys take advantage of a stress induced martensitic transformation to achieve incredible amounts of flexibility. This last property represents the most interesting aspect of such alloys for restoration procedures. However, recent instrumentation tests have shown brittle rupture of endodontic instruments inside the tooth during preparation of dental root channels.To improve the mechanical properties of NiTi endodontic instruments, argon, nitrogen and boron implantations at different energies and at fixed dose (1.10^{17} at.cm^{-2}) have been used. In this paper, we have investigated the effects on NiTi microstructure, especially the crystalline to amorphous transition induced by ion bombardment, using Grazing Incidence X-ray Diffraction (GIXRD). Nano-indentation tests have also been performed to determine hardness H and elastic modulus E of implanted surfaces as a function of ion species and energy. Le but de cette d'étude est de caractériser les effets de l'implantation ionique sur la microstructure d'un alliage Nickel Titane à l'aide de la diffraction des rayons X en incidence rasante. Nous avons réalisé différents types d'implantation en faisant varier l'espèce implantée (bore, azote, argon) ainsi que l'énergie d'implantation, pour des doses d'implantation de l'ordre de 1.10^{17} at.cm^{-2}. Les résultats des mesures de diffraction sous différents angles d'incidence (0{,}5^circ leq α_ileq 6^circ) ont été corrélés avec les différents profils d'implantation simulés. Des tests de nanoindentation ainsi que des mesures de RBS ont été également réalisés. Après implantation, on observe la formation d'une couche amorphe, conduisant à une

  3. Bypassing the learning curve in permanent seed implants using state-of-the-art technology

    SciTech Connect

    Beaulieu, Luc . E-mail: beaulieu@phy.ulaval.ca; Evans, Dee-Ann Radford; Aubin, Sylviane; Angyalfi, Steven; Husain, Siraj; Kay, Ian; Martin, Andre-Guy; Varfalvy, Nicolas; Vigneault, Eric; Dunscombe, Peter

    2007-01-01

    Purpose: The aim of this study was to demonstrate, based on clinical postplan dose distributions, that technology can be used efficiently to eliminate the learning curve associated with permanent seed implant planning and delivery. Methods and Materials: Dose distributions evaluated 30 days after the implant of the initial 22 consecutive patients treated with permanent seed implants at two institutions were studied. Institution 1 (I1) consisted of a new team, whereas institution 2 (I2) had performed more than 740 preplanned implantations over a 9-year period before the study. Both teams had adopted similar integrated systems based on three-dimensional (3D) transrectal ultrasonography, intraoperative dosimetry, and an automated seed delivery and needle retraction system (FIRST, Nucletron). Procedure time and dose volume histogram parameters such as D90, V100, V150, V200, and others were collected in the operating room and at 30 days postplan. Results: The average target coverage from the intraoperative plan (V100) was 99.4% for I1 and 99.9% for I2. D90, V150, and V200 were 191.4 Gy (196.3 Gy), 75.3% (73.0%), and 37.5% (34.1%) for I1 (I2) respectively. None of these parameters shows a significant difference between institutions. The postplan D90 was 151.2 Gy for I1 and 167.3 Gy for I2, well above the 140 Gy from the Stock et al. analysis, taking into account differences at planning, results in a p value of 0.0676. The procedure time required on average 174.4 min for I1 and 89 min for I2. The time was found to decrease with the increasing number of patients. Conclusion: State-of-the-art technology enables a new brachytherapy team to obtain excellent postplan dose distributions, similar to those achieved by an experienced team with proven long-term clinical results. The cost for bypassing the usual dosimetry learning curve is time, with increasing team experience resulting in shorter treatment times.

  4. 125I Seed Permanent Implantation as a Palliative Treatment for Stage III and IV Hypopharyngeal Carcinoma

    PubMed Central

    Li, Lei; Yang, Jie; Li, Xiaojiang; Wang, Xiaoli; Ren, Yanxin; Fei, Jimin; Xi, Yan; Sun, Ruimei; Ma, Jing

    2016-01-01

    Objectives. The aim of this study was to investigate the feasibility and safety of percutaneous 125I seed permanent implantation for advanced hypopharyngeal carcinoma from toxicity, tumor response, and short-term outcome. Methods. 125I seeds implant procedures were performed under computed tomography for 34 patients with advanced hypopharyngeal carcinoma. We observed the local control rate, overall survival, and acute or late toxicity rate. Results. In the 34 patients (stage III, n=6; stage IV, n=28), the sites of origin were pyriform sinus (n=29) and postcricoid area (n=5). All patients also received one to four cycles of chemotherapy after seed implantation. The post-plan showed that the actuarial D90 of 125I seeds ranged from 90 to 158 Gy (median, 127 Gy). The mean follow-up was 12.3 months (range, 3.4 to 43.2 months). The local control was 2.1–31.0 months with a median of 17.7 months (95% confidence interval [CI], 13.4 to 22.0 months). The 1-, 2-, and 3-year local controls were 65.3%, 28.6%, and 9.5% respectively. Twelve patients (35%) died of local recurrence, fourteen patients (41%) died of distant metastases, and three patients (9%) died of recurrence and metastases at the same time. Five patients (15%) still survived to follow-up. At the time of analysis, the median survival time was 12.5 months (95% CI, 9.5 to 15.4 months). The 1-, 2-, and 3-year overall survival rates were 55.2%, 20.3%, and 10.9%, respectively. Five patients (15%) experienced grade 3 toxic events and nine patients (26%) have experienced grade 2 toxic events. Conclusion. This review shows relatively low toxicity for interstitial 125I seed implantation in the patients with advanced stage hypopharyngeal cancer. The high local control results suggest that 125I seed brachytherapy implant as a salvage or palliative treatment for advanced hypopharyngeal carcinoma merit further investigation. PMID:27440132

  5. [Permanent endocardiac electrostimulation. Considerations on 511 implantations and reimplantations in 7 years of practice].

    PubMed

    Mangiameli, S; Circo, A; Vanaria, D; Lombardo, D; Scalisi, A; Genovese, G; Galassi, A

    1977-06-30

    Permanent pacemakers were implanted and reimplanted in a total of 511 patients (mostly men) during a period of about 7 yr. Mean age was 67.9 yr. The cephalic route was used in nearly every case, with subclavicular implantation of the generator. Mean hospital stay was 7.6 days. Ventricular inhibition pacemakers were used in over 84% and fixed-frequency models in 7%. Mean pacemaker life was 24.1 months, with longer periods in the last months of the period of observation. The evaluation of battery run-down and recent and long-term complications is discussed, together with a particular type of decubitus of electrolytic origin. Hospital mortality was 2%. Survival was 91% at 1 yr and 54% at 6 yr. Emphasis is placed on the fact that subjects continue to be heart patients. Their well-being depends on psychological and general medical care, together with help from their, families and society, quite apart from cardiological attention. PMID:876509

  6. Essure Permanent Birth Control

    MedlinePlus

    ... Implants and Prosthetics Essure Permanent Birth Control Essure Permanent Birth Control Share Tweet Linkedin Pin it More sharing options ... evaluation of the Essure System Essure is a permanent birth control method for women (female sterilization). Implantation of Essure ...

  7. In Vivo Dosimetry With a Linear MOSFET Array to Evaluate the Urethra Dose During Permanent Implant Brachytherapy Using Iodine-125

    SciTech Connect

    Bloemen-van Gurp, Esther J.; Haanstra, Bjoerk K.C.; Murrer, Lars H.P.; Gils, Francis C.J.M. van; Dekker, Andre L.A.J.; Mijnheer, Ben J.; Lambin, Philippe

    2009-11-15

    Purpose: To develop a technique to monitor the dose rate in the urethra during permanent implant brachytherapy using a linear MOSFET array, with sufficient accuracy and without significantly extending the implantation time. Methods and Materials: Phantom measurements were performed to determine the optimal conditions for clinical measurements. In vivo measurements were performed in 5 patients during the {sup 125}I brachytherapy implant procedure. To evaluate if the urethra dose obtained in the operating room with the ultrasound transducer in the rectum and the patient in treatment position is a reference for the total accumulated dose; additional measurements were performed after the implantation procedure, in the recovery room. Results: In vivo measurements during and after the implantation procedure agree very well, illustrating that the ultrasound transducer in the rectum and patient positioning do not influence the measured dose in the urethra. In vivo dose values obtained during the implantation are therefore representative for the total accumulated dose in the urethra. In 5 patients, the dose rates during and after the implantation were below the maximum dose rate of the urethra, using the planned seed distribution. Conclusion: In vivo dosimetry during the implantation, using a MOSFET array, is a feasible technique to evaluate the dose in the urethra during the implantation of {sup 125}I seeds for prostate brachytherapy.

  8. [Syncope of unknown origin in patients with permanent auriculoventricular block with an implanted pacemaker. Usefulness of the tilt table test].

    PubMed

    Márquez, Manlio F; Encarnación-Roa, Carmen F; Hermosillo, Antonio G; Benítez-Pinto, William J; Cárdenas, Manuel

    2002-04-01

    Four female patients aged 26 to 71 years, with permanent complete AV heart block and an implanted pacemaker had syncope or presyncope after the pacemaker implantation. As part of the study protocol the tilt table test was done. Neurological disease, arrhythmias, pacemaker syndrome or dysfunction of the stimulation system were ruled out. A head up tilt was performed, isosorbide was used as pharmacological challenge, since the basal test was negative. In three patients this test was positive: in one patient possibly caused by postural orthostatic tachycardia syndrome, and two with neurally mediated syncope. In one patient it was not possible a diagnosis. The head-up tilt test is a useful procedure to identify the etiology of the appearance of syncope or presyncope after a pacemaker implantation in patients with complete and permanent AV block. PMID:11975909

  9. Class solution for inversely planned permanent prostate implants to mimic an experienced dosimetrist

    SciTech Connect

    Lessard, Etienne; Kwa, Stefan L. S.; Pickett, Barby; Roach, Mach III; Pouliot, Jean

    2006-08-15

    The purpose of this paper is to present a method for the selection of inverse planning parameters and to establish a set of inverse planning parameters (class solution) for the inverse planning included in a commercial permanent prostate implant treatment planning system. The manual planning of more than 750 patients since 1996 led to the establishment of general treatment planning rules. A class solution is tuned to fulfill the treatment planning rules and generate equivalent implants. For ten patients, the inverse planning is compared with manual planning performed by our experienced physicist. The prostate volumes ranged from 17 to 51 cc and are implanted with low activity I-125 seeds. Dosimetric indices are calculated for comparison. The inverse planning needed about 15 s for each optimization (400 000 iterations on a 2.5 GHz PC). In comparison, the physicist needed about 20 min to perform each manual plan. A class solution is found that consistently produces dosimetric indices equivalent or better than the manual planning. Moreover, even with strict seed placement rules, the inverse planning can produce adequate prostate dose coverage and organ at risk protection. The inverse planning avoids implant with seeds outside of the prostate and too close to the urethra. It also avoids needles with only one seed and needles with three consecutive seeds. This reduces the risk of complication due to seed misplacement and edema. The inverse planning also uses a smaller number of needles, reducing the cause of trauma. The quality of the treatment plans is independent of the gland size and shape. A class solution is established that consistently and rapidly produces equivalent dosimetric indices as manual planning while respecting severe seed placement rules. The class solution can be used as a starting point for every patient, dramatically reducing the time needed to plan individual patient treatments. The class solution works with inverse preplanning, intraoperative

  10. Long-term outcome in patients receiving permanent pacemaker implantation for atrioventricular block

    PubMed Central

    Liao, Jo-Nan; Chao, Tze-Fan; Tuan, Ta-Chuan; Kong, Chi-Woon; Chen, Shih-Ann

    2016-01-01

    Abstract A permanent pacemaker (PPM) with dual chamber pacing (DDD) offers atrioventricular synchronization for patients with atrioventricular block (AVB). Single lead atrial synchronous ventricular pacing mode (VDD) is an alternative, but there are concerns about its efficacy and risk of atrial undersensing. Whether VDD can be a good alternative in patients with AVB remains unknown. The aim of the present study was to compare the long-term risk of mortality of VDD with DDD pacing. A total of 207 patients undergoing PPM implantations for AVB with VDD mode were enrolled from 2000 to 2013. Another 828 age- and sex-matched patients undergoing DDD implantations during the same period of time were selected as the control group in a 1 to 4 ratio. The study endpoint was mortality. A total of 1035 patients (64.3% male) were followed up for 46.5 ± 43.2 months. The mean ages were 75.0 years for VDD, and 74.9 years for DDD. The Kaplan–Meier survival analysis showed no significant difference in long-term survival between the VDD and DDD groups (log-rank P = 0.313). After adjustment for baseline characteristics, the VDD and DDD groups had a similar long-term prognosis with an adjusted hazard ratio of 0.875 (P = 0.445). Further analyses for the risk of cardiovascular and noncardiovascular deaths also showed no significant differences between the 2 groups. The long-term prognosis of VDD mode is comparable to that of DDD mode. Single lead VDD can be considered as an alternative choice in patients with AVB without sinus nodal dysfunction. PMID:27583889

  11. The selection criteria of temporary or permanent luting agents in implant-supported prostheses: in vitro study

    PubMed Central

    Gonzalez-Gonzalez, Ignacio; Brizuela-Velasco, Aritza; Ellacuria-Echebarria, Joseba

    2016-01-01

    PURPOSE The use of temporary or permanent cements in fixed implant-supported prostheses is under discussion. The objective was to compare the retentiveness of one temporary and two permanent cements after cyclic compressive loading. MATERIALS AND METHODS The working model was five solid abutments screwed to five implant analogs. Thirty Cr-Ni alloy copings were randomized and cemented to the abutments with one temporary (resin urethane-based) or two permanent (resin-modified glass ionomer, resin-composite) cements. The retention strength was measured twice: once after the copings were cemented and again after a compressive cyclic loading of 100 N at 0.72 Hz (100,000 cycles). RESULTS Before loading, the retention strength of resin composite was 75% higher than the resin-modified glass ionomer and 2.5 times higher than resin urethanebased cement. After loading, the retentiveness of the three cements decreased in a non-uniform manner. The greatest percentage of retention loss was shown by the temporary cement and the lowest by the permanent resin composite. However, the two permanent cements consistently show high retention values. CONCLUSION The higher the initial retention of each cement, the lower the percentage of retention loss after compressive cyclic loading. After loading, the resin urethane-based cement was the most favourable cement for retrieving the crowns and resin composite was the most favourable cement to keep them in place. PMID:27141259

  12. Postimplantation Analysis Enables Improvement of Dose-Volume Histograms and Reduction of Toxicity for Permanent Seed Implantation

    SciTech Connect

    Wust, Peter Postrach, Johanna; Kahmann, Frank; Henkel, Thomas; Graf, Reinhold; Cho, Chie Hee; Budach, Volker; Boehmer, Dirk

    2008-05-01

    Purpose: To demonstrate how postimplantation analysis is useful for improving permanent seed implantation and reducing toxicity. Patients and Methods: We evaluated 197 questionnaires completed by patients after permanent seed implantation (monotherapy between 1999 and 2003). For 70% of these patients, a computed tomography was available to perform postimplantation analysis. The index doses and volumes of the dose-volume histograms (DVHs) were determined and categorized with respect to the date of implantation. Differences in symptom scores relative to pretherapeutic status were analyzed with regard to follow-up times and DVH descriptors. Acute and subacute toxicities in a control group of 117 patients from an earlier study (June 1999 to September 2001) by Wust et al. (2004) were compared with a matched subgroup from this study equaling 110 patients treated between October 2001 and August 2003. Results: Improved performance, identifying a characteristic time dependency of DVH parameters (after implantation) and toxicity scores, was demonstrated. Although coverage (volume covered by 100% of the prescription dose of the prostate) increased slightly, high-dose regions decreased with the growing experience of the users. Improvement in the DVH and a reduction of toxicities were found in the patient group implanted in the later period. A decline in symptoms with follow-up time counteracts this gain of experience and must be considered. Urinary and sexual discomfort was enhanced by dose heterogeneities (e.g., dose covering 10% of the prostate volume, volume covered by 200% of prescription dose). In contrast, rectal toxicities correlated with exposed rectal volumes, especially the rectal volume covered by 100% of the prescription dose. Conclusion: The typical side effects occurring after permanent seed implantation can be reduced by improving the dose distributions. An improvement in dose distributions and a reduction of toxicities were identified with elapsed time between

  13. Poster — Thur Eve — 41: Considerations for Patients with Permanently Implant Radioactive Sources Requiring Unrelated Surgery

    SciTech Connect

    Basran, P. S; Beckham, WA; Baxter, P

    2014-08-15

    Permanent implant of sealed radioactive sources is an effective technique for treating cancer. Typically, the radioactive sources are implanted in and near the disease, depositing dose locally over several months. There may be instances where these patients must undergo unrelated surgical procedures when the radioactive material remains active enough to pose risks. This work explores these risks, discusses strategies to mitigate those risks, and describes a case study for a permanent I-125 prostate brachytherapy implant patient who developed colo-rectal cancer and required surgery 6 months after brachytherapy. The first consideration is identifying the risk from unwarranted radiation to the patient and staff before, during, and after the surgical procedure. The second is identifying the risk the surgical procedure may have on the efficacy of the brachytherapy implant. Finally, there are considerations for controlling for radioactive substances from a regulatory perspective. After these risks are defined, strategies to mitigate those risks are considered. These strategies may include applying the concepts of ALARA, the use of protective equipment and developing a best practice strategy with the operating room team. We summarize this experience with some guidelines: If the surgical procedure is near (ex: 5 cm) of the implant; and, the surgical intervention may dislodge radioisotopes enough to compromise treatment or introduces radiation safety risks; and, the radioisotope has not sufficiently decayed to background levels; and, the surgery cannot be postponed, then a detailed analysis of risk is advised.

  14. Combined pars plana vitrectomy and Baerveldt glaucoma implant placement for refractory glaucoma

    PubMed Central

    Campagnoli, Thalmon R.; Kim, Sung Soo; Smiddy, William E.; Gedde, Steve J.; Budenz, Donald L.; Parrish, Richard K.; Palmberg, Paul F.; Feuer, William; Shi, Wei

    2015-01-01

    AIM To evaluate outcomes of combined pars plana vitrectomy and Baerveldt glaucoma implant (PPV-BGI) placement for refractory glaucoma. METHODS The medical records of 92 eyes (89 patients) that underwent PPV-BGI were retrospectively reviewed, including 43 eyes with neovascular glaucoma (NVG) and 49 eyes with other types of glaucoma (non-NVG). RESULTS Outcome measures were visual acuity (VA), intraocular pressure (IOP), glaucoma medical therapy, complications, and success [VA>hand motions (HM), IOP≥6 mm Hg and ≤21 mm Hg, no subsequent glaucoma surgery]. Cumulative success rates for the non-NVG group and NVG group were 79% and 40% at 1y, respectively (P=0.038). No difference in the rates of surgical success were found between pars plana and anterior chamber tube placement. Preoperative IOP (mean±SD) was 30.3±11.7 mm Hg in the Non-NVG group and 40.0±10.6 mm Hg in the NVG group, and IOP was reduced to 15±9.5 mm Hg in the non-NVG group and 15±10.5 mm Hg in the NVG at 1y. Number of glaucoma medications (mean±SD) decreased from 2.7±1.3 in the non-NVG group and 2.8±1.3 in the NVG group preoperatively to 0.76±1.18 in the non-NVG group and 0.51±1.00 in the NVG group at 1y. Improvement in VA of ≥2 Snellen lines was observed in 25 (27%) eyes, although only 33% of non-NVG eyes and 2.3% of NVG eyes maintained VA better than 20/200 at 1y. Nonclearing vitreous hemorrhage was the most common postoperative complication occurring in 16 (17%) eyes, and postoperative suprachoroidal hemorrhages developed in 5 (5.4%) eyes. CONCLUSION PPV-BGI is a viable surgical option for eyes with refractory glaucoma, but visual outcomes are frequently poor because of ocular comorbidities, especially in eyes with NVG. The location of tube placement does not influence surgical outcome and should be left to the discretion of the surgeon. PMID:26558201

  15. Comparison between Limbal and Pars Plana Approaches Using Microincision Vitrectomy for Removal of Congenital Cataracts with Primary Intraocular Lens Implantation

    PubMed Central

    Liu, Xin; Zheng, Tianyu; Zhou, Xingtao; Lu, Yi; Zhou, Peng; Fan, Fan; Luo, Yi

    2016-01-01

    Purpose. To compare the surgical outcomes of limbal versus pars plana vitrectomy using the 23-gauge microincision system for removal of congenital cataracts with primary intraocular lens implantation. Methods. We retrospectively reviewed all eyes that underwent cataract removal through limbal or pars plana incision. Main outcome measures included visual outcomes and complications. Results. We included 40 eyes (26 patients) in the limbal group and 41 eyes (30 patients) in the pars plana group. The mean age was 46 months. There was no significant difference in best-corrected visual acuity between the two groups (P = 0.64). Significantly, more eyes had at least one intraoperative complication in the limbal group than in the pars plana group (P = 0.03) that were mainly distributed at 1.5–3 years of age (P = 0.01). The most common intraoperative complications were iris aspiration, iris prolapse, and iris injury. More eyes in the limbal group had postoperative complications and required additional intraocular surgery, but the difference was not significant (P = 0.19). Conclusions. The visual results were encouraging in both approaches. We recommend the pars plana approach for lower incidence of complications. The limbal approach should be reserved for children older than 3 years of age and caution should be exercised to minimize iris disturbance. PMID:27313872

  16. Comparison between Limbal and Pars Plana Approaches Using Microincision Vitrectomy for Removal of Congenital Cataracts with Primary Intraocular Lens Implantation.

    PubMed

    Liu, Xin; Zheng, Tianyu; Zhou, Xingtao; Lu, Yi; Zhou, Peng; Fan, Fan; Luo, Yi

    2016-01-01

    Purpose. To compare the surgical outcomes of limbal versus pars plana vitrectomy using the 23-gauge microincision system for removal of congenital cataracts with primary intraocular lens implantation. Methods. We retrospectively reviewed all eyes that underwent cataract removal through limbal or pars plana incision. Main outcome measures included visual outcomes and complications. Results. We included 40 eyes (26 patients) in the limbal group and 41 eyes (30 patients) in the pars plana group. The mean age was 46 months. There was no significant difference in best-corrected visual acuity between the two groups (P = 0.64). Significantly, more eyes had at least one intraoperative complication in the limbal group than in the pars plana group (P = 0.03) that were mainly distributed at 1.5-3 years of age (P = 0.01). The most common intraoperative complications were iris aspiration, iris prolapse, and iris injury. More eyes in the limbal group had postoperative complications and required additional intraocular surgery, but the difference was not significant (P = 0.19). Conclusions. The visual results were encouraging in both approaches. We recommend the pars plana approach for lower incidence of complications. The limbal approach should be reserved for children older than 3 years of age and caution should be exercised to minimize iris disturbance. PMID:27313872

  17. Impact of interseed attenuation and tissue composition for permanent prostate implants

    SciTech Connect

    Carrier, Jean-Francois; Beaulieu, Luc; Therriault-Proulx, Francois; Roy, Rene

    2006-03-15

    The purpose is to evaluate the impact of interseed attenuation and prostate composition for prostate treatment plans with {sup 125}I permanent seed implants using the Monte Carlo (MC) method. The effect of seed density (number of seeds per prostate unit volume) is specifically investigated. The study focuses on treatment plans that were generated for clinical cases. For each plan, four different dose calculation techniques are compared: TG-43 based calculation, superposition MC, full MC with water prostate, and full MC with realistic prostate tissue. The prostate tissue description is from the ICRP report 23 (W. S. Snyer, M. J. Cook, E. S. Nasset, L. R. Karkhausen, G. P. Howells, and I. H. Tipton, ''Report of the task group on reference man,'' Technical Report 23, International Commission on Radiological Protection, 1974). According to the comparisons, the seed density has an influence on interseed attenuation. A plan with a typical low seed density (42 0.6 mCi seeds in a 26 cm{sup 3} prostate) suffers a 1.2% drop in the CTV D{sub 90} value due to interseed attenuation. A drop of 3.0% is calculated for a higher seed density (75 0.3 mCi seeds, same prostate). The influence of the prostate composition is similar for all seed densities and prostate sizes. The difference between MC simulations in water and MC simulations in prostate tissue is between 4.4% and 4.8% for the D{sub 90} parameter. Overall, the effect on D{sub 90} is ranging from 5.8% to 12.8% when comparing clinically approved TG-43 and MC simulations in prostate tissue. The impact varies from one patient to the other and depends on the prostate size and the number of seeds. This effect can reach a significant level when reporting correlations between clinical effect and deposited dose.

  18. An algorithm for efficient metal artifact reductions in permanent seed implants

    SciTech Connect

    Xu Chen; Verhaegen, Frank; Laurendeau, Denis; Enger, Shirin A.; Beaulieu, Luc

    2011-01-15

    Purpose: In permanent seed implants, 60 to more than 100 small metal capsules are inserted in the prostate, creating artifacts in x-ray computed tomography (CT) imaging. The goal of this work is to develop an automatic method for metal artifact reduction (MAR) from small objects such as brachytherapy seeds for clinical applications. Methods: The approach for MAR is based on the interpolation of missing projections by directly using raw helical CT data (sinogram). First, an initial image is reconstructed from the raw CT data. Then, the metal objects segmented from the reconstructed image are reprojected back into the sinogram space to produce a metal-only sinogram. The Steger method is used to determine precisely the position and edges of the seed traces in the raw CT data. By combining the use of Steger detection and reprojections, the missing projections are detected and replaced by interpolation of non-missing neighboring projections. Results: In both phantom experiments and patient studies, the missing projections have been detected successfully and the artifacts caused by metallic objects have been substantially reduced. The performance of the algorithm has been quantified by comparing the uniformity between the uncorrected and the corrected phantom images. The results of the artifact reduction algorithm are indistinguishable from the true background value. Conclusions: An efficient algorithm for MAR in seed brachytherapy was developed. The test results obtained using raw helical CT data for both phantom and clinical cases have demonstrated that the proposed MAR method is capable of accurately detecting and correcting artifacts caused by a large number of very small metal objects (seeds) in sinogram space. This should enable a more accurate use of advanced brachytherapy dose calculations, such as Monte Carlo simulations.

  19. Influence of Prostatic Edema on {sup 131}CS Permanent Prostate Seed Implants: A Dosimetric and Radiobiological Study

    SciTech Connect

    Kehwar, Than S.; Jones, Heather A.; Huq, M. Saiful; Smith, Ryan P.

    2011-06-01

    Purpose: To study the influence of prostatic edema on postimplant physical and radiobiological parameters using {sup 131}Cs permanent prostate seed implants. Methods and Materials: Thirty-one patients with early prostate cancer who underwent {sup 131}Cs permanent seed implantation were evaluated. Dose-volume histograms were generated for each set of prostate volumes obtained at preimplantation and postimplantion days 0, 14, and 28 to compute quality indices (QIs) and fractional doses at level x (FD{sub x}). A set of equations for QI, FD{sub x}, and biologically effective doses at dose level D{sub x} (BED{sub x}) were defined to account for edema changes with time after implant. Results: There were statistically significant differences found between QIs of pre- and postimplant plans at day 0, except for the overdose index (ODI). QIs correlated with postimplant time, and FD{sub x} was found to increase with increasing postimplant time. With the effect of edema, BED at different dose levels showed less improvement due to the short half-life of {sup 131}Cs, which delivers about 85% of the prescribed dose before the prostate reaches its original volume due to dissipation of edema. Conclusions: Results of the study show that QIs, FD{sub x}, and BEDs at the level of D{sub x} changed from preneedle plans to postimplant plans and have statistically significant differences (p < 0.05), except for the ODI (p = 0.106), which suggests that at the time of {sup 131}C seed implantation, the effect of edema must be accounted for when defining the seed positions, to avoid the possibility of poor dosimetric and radiobiologic results for {sup 131}Cs seed implants.

  20. Analysis of postoperative PSA changes after ultrasound-guided permanent [125I] seed implantation for the treatment of prostate cancer.

    PubMed

    Bian, X L; Wang, C Z; Wang, Y; Li, Y N; Zhang, L Z; Liu, L

    2015-01-01

    The aim of this study was to explore postoperative changes in prostate-specific antigen (PSA) levels and risk factors that influence the clinical effects of ultrasound-guided permanent [(125)I] seed implantation in the treatment of prostate cancer. From July 2009 to December 2012, 41 prostate cancer patients who underwent transrectal ultrasound-guided [(125)I] seed implantation were followed up for 3-56 months. The patients were divided into 2 groups according to their results: group A, benign rebound group, 31 cases; and group B, biochemical relapse group, 10 cases. A blood analysis of group A showed that the initial PSA rise after a nadir occurred postoperatively at 16.8 ± 1.2 months, and in 65.8% (27/41) patients the rise occurred during 15-27 weeks. For group B, the initial PSA rise after a nadir occurred postoperatively at 30.2 ± 2.1 months, and the difference in the time parameter of the initial PSA rise after the nadir was statistically significant between the 2 groups (P < 0.01). During treatment, age was shown to be a risk factor for group A (P = 0.0027, P < 0.01). Postoperative changes in PSA levels after ultrasound-guided permanent [(125)I] seed implantation contributed to the assessment of the clinical treatment effects. PMID:26125925

  1. [Evaluation of patients' satisfaction after breast reconstruction with latissimus dorsi myocutaneous flap and immediate permanent breast implant].

    PubMed

    Bognár, Gábor; Gőgh, Bettina; Novák, András; István, Gábor

    2014-04-01

    Current surgical treatment modalities for breast reconstruction include latissimus dorsi mycotaneous flap with immediate permanent breast implant (LDI). The aim of the present study was to analyze reconstruction with LDI in terms of quality of life, cosmesis and patient satisfaction. A chart analysis was carried out with the first ten patients who underwent breast reconstruction with LDI. The patients were interviewed and self-assessment quality of life was administered. They also underwent assessment of satisfaction and cosmesis. The high satisfaction and cosmesis scores in the breast reconstruction group indicate the superior results that can be achieved with breast reconstruction. PMID:24747404

  2. Minimally invasive implantation of an extracorporeal membrane oxygenation circuit used as a temporary left ventricular assist device: a new concept for bridging to permanent cardiac support.

    PubMed

    Saito, Shunsuke; Fleischer, Bernhard; Maeß, Christoph; Baraki, Hassina; Kutschka, Ingo

    2015-03-01

    The implantation of cardiac assist devices is associated with poor outcome in patients with multiple organ failure and unknown neurologic status. Therefore, temporary left ventricular assist devices (LVAD) using, for example, extracorporeal centrifugal pumps may provide the chance to further evaluate the patient's clinical course and a potential qualification for implantable LVAD therapy. On the other hand, a main disadvantage of the temporary LVAD implantation is the need for redo surgery, increasing the risk of the final LVAD Implantation. To minimize this drawback of the temporary LVAD implantation, we implanted the temporary LVAD using a minimally invasive technique. The operation was done without cardiopulmonary bypass support, and the temporary LVAD was implanted through upper hemisternotomy and left anterior mini-thoracotomy. The patient recovered from multiple organ failure and was successfully bridged to a permanent LVAD therapy. PMID:25370719

  3. A Monte Carlo study on the effect of seed design on the interseed attenuation in permanent prostate implants.

    PubMed

    Afsharpour, Hossein; D'Amours, Michel; Coté, Benoit; Carrier, Jean-François; Verhaegen, Frank; Beaulieu, Luc

    2008-08-01

    Standard algorithms for postimplant analysis of transperineal interstitial permanent prostate brachytherapy (TIPPB) are based on AAPM Task Group 43 formalism (TG-43), which makes use of a world entirely made of water. This entails an assignment of the prostate, surrounding organs at risk, as well as all brachytherapy seeds present in a permanent prostate implant to water. Brachytherapy seeds are generally made from high atomic number materials. Because of the simultaneous presence of many brachytherapy seeds in a TIPPB, there is a shielding effect causing an attenuation of energy of the emitted photons generally called the "interseed attenuation" (ISA). This study investigates the impact of seed designs and compositions on the interseed attenuation. For this purpose, six brachytherapy seeds covering a wide variety of seed design and composition were modeled with the GEANT4 Monte Carlo (MC) toolkit. MC has allowed calculation of the contribution of each major component (encapsulation and internal components) of a given seed model to ISA separately. The impact of ISA on real clinical implant configurations was also explored. Two clinical postimplant geometries with different brachytherapy seeds were studied with MC simulations. The change in the clinical parameter D90 was observed. This study shows that Nucletron SelectSeed (similar to the Oncura model 6711), ProstaSeed, and Best Medical model 2335 are the most attenuating designs with 4.8%, 3.9%, and 4.6% of D90 reduction, respectively. The least attenuating seed is a 103Pd seed encapsulated in a polymer shell, the IBt OptiSeed with 1.5%. Finally, based on this systematic study, a new seed design is proposed that is predicted to be the most waterlike brachytherapy seed and thus TG-43 compatible. PMID:18777927

  4. Tolerance and Acceptance Results of a Palladium-103 Permanent Breast Seed Implant Phase I/II Study

    SciTech Connect

    Pignol, Jean-Philippe Rakovitch, Eileen; Keller, Brian M.; Sankreacha, Raxa; Chartier, Carole

    2009-04-01

    Purpose: To test, in a prospective Phase I/II trial, a partial breast irradiation technique using a {sup 103}Pd permanent breast seed implant (PBSI) realized in a single 1-h procedure under sedation and local freezing. Methods and Materials: Eligible patients had infiltrating ductal carcinoma {<=}3 cm in diameter, surgical margin {>=}2 mm, no extensive intraductal component, no lymphovascular invasion, and negative lymph nodes. Patients received a permanent seed implant, and a minimal peripheral dose of 90 Gy was prescribed to the clinical target volume, with a margin of 1.5 cm. Results: From May 2004 to April 2007, 67 patients received the PBSI treatment. The procedure was well tolerated, with 17% of patients having significant pain after the procedure. Only 1 patient (1.5%) had an acute skin reaction (Grade 3 according to the National Cancer Institute Common Toxicity Criteria). The rates of acute moist desquamation, erythema, and indurations were 10.4%, 42%, and 27%, respectively. At 1 year the rate of Grade 1 telangiectasia was 14%. The rate of skin reaction decreased from 65% to 28% when skin received less than the 85% isodose. According to a Radiation Therapy Oncology Group questionnaire, 80-90% of patients were very satisfied with their treatment, and the remainder were satisfied. One patient (1.5%) developed an abscess, which resolved after the use of antibiotics. There was no recurrence after a median follow-up of 32 months (range, 11-49 months). Conclusions: The feasibility, safety, and tolerability of PBSI compares favorably with that of external beam and other partial breast irradiation techniques.

  5. Five-year outcome of intraoperative conformal permanent I-125 interstitial implantation for patients with clinically localized prostate cancer

    SciTech Connect

    Zelefsky, Michael J. . E-mail: zelefskm@mskcc.org; Yamada, Yoshiya; Cohen, Gil'ad N.; Shippy, Alison; Chan, Heather; Fridman, David; Zaider, Marco

    2007-01-01

    Purpose: To report the 5-year tumor control and toxicity outcomes for patients with localized prostate treated with I-125 permanent implantation using an intraoperative real-time conformal planning technique. Methods and Materials: Between January 1998 and June 2002, 367 patients with prostate cancer were treated with I-125 permanent interstitial implantation using a transrectal ultrasound-guided approach. Real-time intraoperative treatment planning which incorporated inverse planning optimization was used. The median follow-up time was 63 months. Results: The median V100 and D90 were 96% and 173 Gy, respectively. In 96% of cases a D90 of >140 Gy was achieved. The median urethral and rectal doses were 100% and 33% of the prescription doses, respectively. The 5-year PSA relapse-free survival outcomes for favorable and intermediate risk patients according to the ASTRO definition were 96% and 89%, respectively. In these patients no dosimetric parameter was identified which influenced the biochemical outcome. Of 38% who developed acute Grade 2 urinary symptoms, 63% had resolution of their symptoms within a median time of 6 months. The incidence of late rectal and urinary Grade 3 or higher toxicities were 1% and 4%, respectively. Seven percent (n = 27) developed late rectal bleeding (Grade 2) and 19% experienced late Grade 2 urinary symptoms. Conclusion: Real-time intraoperative planning consistently achieved optimal coverage of the prostate with the prescription dose with concomitant low doses delivered to the urethra and rectum. Biochemical control outcomes were excellent at 5 years and late toxicity was unusual. These data demonstrate that real-time planning methods can consistently and reliably deliver the intended dose distribution to achieve an optimal therapeutic ratio between the target and normal tissue structures.

  6. Predictors of severe tricuspid regurgitation in patients with permanent pacemaker or automatic implantable cardioverter-defibrillator leads.

    PubMed

    Najib, Mohammad Q; Vittala, Satya S; Challa, Suresh; Raizada, Amol; Tondato, Fernando J; Lee, Howard R; Chaliki, Hari P

    2013-01-01

    Patients with permanent pacemaker or automatic implantable cardioverter-defibrillator (AICD) leads have an increased prevalence of tricuspid regurgitation. However, the roles of cardiac rhythm and lead-placement duration in the development of severe tricuspid regurgitation are unclear. We reviewed echocardiographic data on 26 consecutive patients who had severe tricuspid regurgitation after permanent pacemaker or AICD placement; before treatment, they had no organic tricuspid valve disease, pulmonary hypertension, left ventricular dysfunction, or severe tricuspid regurgitation. We compared the results to those of 26 control subjects who had these same devices but no more than mild tricuspid regurgitation. The patients and control subjects were similar in age (mean, 81 ±6 vs 81 ±8 yr; P = 0.83), sex (male, 42% vs 46%; P = 0.78), and left ventricular ejection fraction (0.60 ±0.06 vs 0.58 ± 0.05; P = 0.4). The patients had a higher prevalence of atrial fibrillation (92% vs 65%; P=0.01) and longer median duration of pacemaker or AICD lead placement (49.5 vs 5 mo; P < 0.001). After adjusting for age, sex, and right ventricular systolic pressure by multivariate logistic regression analysis, we found that atrial fibrillation (odds ratio=6.4; P = 0.03) and duration of lead placement (odds ratio=1.5/yr; P = 0.001) were independently associated with severe tricuspid regurgitation. Out study shows that atrial fibrillation and longer durations of lead placement might increase the risk of severe tricuspid regurgitation in patients with permanent pacemakers or AICDs. PMID:24391312

  7. Predictors of Severe Tricuspid Regurgitation in Patients with Permanent Pacemaker or Automatic Implantable Cardioverter-Defibrillator Leads

    PubMed Central

    Najib, Mohammad Q.; Vittala, Satya S.; Challa, Suresh; Raizada, Amol; Tondato, Fernando J.; Lee, Howard R.; Chaliki, Hari P.

    2013-01-01

    Patients with permanent pacemaker or automatic implantable cardioverter-defibrillator (AICD) leads have an increased prevalence of tricuspid regurgitation. However, the roles of cardiac rhythm and lead-placement duration in the development of severe tricuspid regurgitation are unclear. We reviewed echocardiographic data on 26 consecutive patients who had severe tricuspid regurgitation after permanent pacemaker or AICD placement; before treatment, they had no organic tricuspid valve disease, pulmonary hypertension, left ventricular dysfunction, or severe tricuspid regurgitation. We compared the results to those of 26 control subjects who had these same devices but no more than mild tricuspid regurgitation. The patients and control subjects were similar in age (mean, 81 ±6 vs 81 ±8 yr; P = 0.83), sex (male, 42% vs 46%; P = 0.78), and left ventricular ejection fraction (0.60 ±0.06 vs 0.58 ± 0.05; P = 0.4). The patients had a higher prevalence of atrial fibrillation (92% vs 65%; P=0.01) and longer median duration of pacemaker or AICD lead placement (49.5 vs 5 mo; P < 0.001). After adjusting for age, sex, and right ventricular systolic pressure by multivariate logistic regression analysis, we found that atrial fibrillation (odds ratio=6.4; P = 0.03) and duration of lead placement (odds ratio=1.5/yr; P = 0.001) were independently associated with severe tricuspid regurgitation. Out study shows that atrial fibrillation and longer durations of lead placement might increase the risk of severe tricuspid regurgitation in patients with permanent pacemakers or AICDs. PMID:24391312

  8. Permanent prostate implant using high activity seeds and inverse planning with fast simulated annealing algorithm: A 12-year Canadian experience

    SciTech Connect

    Martin, Andre-Guy; Roy, Jean; Beaulieu, Luc; Pouliot, Jean; Harel, Francois; Vigneault, Eric . E-mail: Eric.Vigneault@chuq.qc.ca

    2007-02-01

    Purpose: To report outcomes and toxicity of the first Canadian permanent prostate implant program. Methods and Materials: 396 consecutive patients (Gleason {<=}6, initial prostate specific antigen (PSA) {<=}10 and stage T1-T2a disease) were implanted between June 1994 and December 2001. The median follow-up is of 60 months (maximum, 136 months). All patients were planned with fast-simulated annealing inverse planning algorithm with high activity seeds ([gt] 0.76 U). Acute and late toxicity is reported for the first 213 patients using a modified RTOG toxicity scale. The Kaplan-Meier biochemical failure-free survival (bFFS) is reported according to the ASTRO and Houston definitions. Results: The bFFS at 60 months was of 88.5% (90.5%) according to the ASTRO (Houston) definition and, of 91.4% (94.6%) in the low risk group (initial PSA {<=}10 and Gleason {<=}6 and Stage {<=}T2a). Risk factors statistically associated with bFFS were: initial PSA >10, a Gleason score of 7-8, and stage T2b-T3. The mean D90 was of 151 {+-} 36.1 Gy. The mean V100 was of 85.4 {+-} 8.5% with a mean V150 of 60.1 {+-} 12.3%. Overall, the implants were well tolerated. In the first 6 months, 31.5% of the patients were free of genitourinary symptoms (GUs), 12.7% had Grade 3 GUs; 91.6% were free of gastrointestinal symptoms (GIs). After 6 months, 54.0% were GUs free, 1.4% had Grade 3 GUs; 95.8% were GIs free. Conclusion: The inverse planning with fast simulated annealing and high activity seeds gives a 5-year bFFS, which is comparable with the best published series with a low toxicity profile.

  9. [Polyethylene in total endoprosthetics--a dead end for permanent implants?].

    PubMed

    Bädorf, D; Willmann, G

    1998-05-01

    Faced with a growing number of younger patients in need of total joint arthroplasty, orthopaedic surgeons are demanding long-term implants for total joint replacement. An assessment of the long-term mechanical behaviour is vivo of all biomaterials in common use in prostheses is in progress. In the present paper, we discuss the long-term reliability of polyethylene (UHMWPE) in joint replacement in terms of tribology and the different biomechanical situation in various human joints. Long-term failure mechanisms for polyethylene in total hip arthoplasty (THA) differ from those seen in total knee arthroplasty (TKA) although the same materials are used. It is thus questionable whether improvements in wear rates of polyethylene in THA would be helpful in TKA. PMID:9616995

  10. SU-E-J-166: Sensitivity of Clinically Relevant Dosimetric Parameters to Contouring Uncertainty During Post Implant Dosimetry of Prostate Permanent Seed Implants

    SciTech Connect

    Mashouf, S; Ravi, A; Morton, G; Song, W

    2015-06-15

    Purpose: There is a strong evidence relating post-implant dosimetry for permanent seed prostate brachytherpy to local control rates. The delineation of the prostate on CT images, however, represents a challenge as it is difficult to confidently identify the prostate borders from soft tissue surrounding it. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to prostate contouring uncertainty. Methods: The post-implant CT images and plans for a cohort of 43 patients, who have received I–125 permanent prostate seed implant in our centre, were exported to MIM Symphony LDR brachytherapy treatment planning system (MIM Software Inc., Cleveland, OH). The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00mm, ±2.00mm, ±3.00mm, ±4.00mm and ±5.00mm (±0.01mm). The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: The mean value of V100 and D90 was obtained as 92.3±8.4% and 108.4±12.3% respectively (Rx=145Gy). V100 was reduced by −3.2±1.5%, −7.2±3.0%, −12.8±4.0%, −19.0±4.8%, − 25.5±5.4% for expanded contours of prostate with margins of +1mm, +2mm, +3mm, +4mm, and +5mm, respectively, while it was increased by 1.6±1.2%, 2.4±2.4%, 2.7±3.2%, 2.9±4.2%, 2.9±5.1% for the contracted contours. D90 was reduced by −6.9±3.5%, −14.5±6.1%, −23.8±7.1%, − 33.6±8.5%, −40.6±8.7% and increased by 4.1±2.6%, 6.1±5.0%, 7.2±5.7%, 8.1±7.3% and 8.1±7.3% for the same set of contours. Conclusion: Systematic expansion errors of more than 1mm may likely render a plan sub-optimal. Conversely contraction errors may Result in labeling a plan likely as optimal. The use of MRI images to contour the prostate should results in better delineation of prostate organ which increases the predictive value of post-op plans. Since observers tend to overestimate the prostate volume on CT, compared with MRI, the impact of the

  11. In vivo evaluation of a permanently implantable thermal ventricular assist system.

    PubMed

    Sugita, Y; Navarro, R R; White, M; Whalen, R; Kiraly, R J; Harasaki, H; Nosé, Y

    1986-01-01

    The System 7 pump/actuator/engine combination has demonstrated biologic compatibility and physiologic effectiveness and responsiveness in five TVAS in vivo studies. The recent 75-day implant supports the feasibility of extended reliability of the system components. Postoperative system maintenance was necessary only because of the nonhermetic design of System 7. However, the ability to pump 11 l/min at 120 beats/min, synchronize at beat rates of 144 beats/min, and pump against mean arterial pressures of more than 150 mmHg while maintaining hematologic and biochemical values within physiologic range sets a very optimistic stage for System 8 hardware. A System 8 concept is shown in Figure 14. The System 8 hardware will include a thermal salt package capable of providing completely untethered circulatory support for a nominal 8-h period. Recharge will be accomplished with a transcutaneous transformer in 1 h. Thermal management problems become minimal, with an average energy input of 15.8 W (peak of 24.9 W). The human preclinical testing of System 8 will start in 1988. PMID:3778718

  12. Long-term outcome in patients receiving permanent pacemaker implantation for atrioventricular block: Comparison of VDD and DDD pacing.

    PubMed

    Liao, Jo-Nan; Chao, Tze-Fan; Tuan, Ta-Chuan; Kong, Chi-Woon; Chen, Shih-Ann

    2016-08-01

    A permanent pacemaker (PPM) with dual chamber pacing (DDD) offers atrioventricular synchronization for patients with atrioventricular block (AVB). Single lead atrial synchronous ventricular pacing mode (VDD) is an alternative, but there are concerns about its efficacy and risk of atrial undersensing. Whether VDD can be a good alternative in patients with AVB remains unknown. The aim of the present study was to compare the long-term risk of mortality of VDD with DDD pacing.A total of 207 patients undergoing PPM implantations for AVB with VDD mode were enrolled from 2000 to 2013. Another 828 age- and sex-matched patients undergoing DDD implantations during the same period of time were selected as the control group in a 1 to 4 ratio. The study endpoint was mortality.A total of 1035 patients (64.3% male) were followed up for 46.5 ± 43.2 months. The mean ages were 75.0 years for VDD, and 74.9 years for DDD. The Kaplan-Meier survival analysis showed no significant difference in long-term survival between the VDD and DDD groups (log-rank P = 0.313). After adjustment for baseline characteristics, the VDD and DDD groups had a similar long-term prognosis with an adjusted hazard ratio of 0.875 (P = 0.445). Further analyses for the risk of cardiovascular and noncardiovascular deaths also showed no significant differences between the 2 groups.The long-term prognosis of VDD mode is comparable to that of DDD mode. Single lead VDD can be considered as an alternative choice in patients with AVB without sinus nodal dysfunction. PMID:27583889

  13. Metallic artifact mitigation and organ-constrained tissue assignment for Monte Carlo calculations of permanent implant lung brachytherapy

    SciTech Connect

    Sutherland, J. G. H.; Miksys, N.; Thomson, R. M.; Furutani, K. M.

    2014-01-15

    assignment within lung contours are employed in generated phantoms, this erroneous assignment is reduced, generally resulting in higher doses. Lung-constrained tissue assignment also results in increased doses in regions of interest due to a reduction in the erroneous assignment of adipose to voxels within lung contours. Differences in dose metrics calculated for different computational phantoms are sensitive to radionuclide photon spectra with the largest differences for{sup 103}Pd seeds and smallest but still considerable differences for {sup 131}Cs seeds. Conclusions: Despite producing differences in CT images, dose metrics calculated using the STR, fan beam + STR, and 3D median filter techniques produce similar dose metrics. Results suggest that the accuracy of dose distributions for permanent implant lung brachytherapy is improved by applying lung-constrained tissue assignment schemes to metallic artifact corrected images.

  14. [Radiological trap and oncological precautions in a patient who has undergone a permanent withdrawal of PIP breast implants].

    PubMed

    Koutsomanis, A; Bruant-Rodier, C; Roedlich, M-N; Bretz-Grenier, M-F; Perrot, P; Bodin, F

    2015-12-01

    We report the case of a 57-year-old patient who presented radiological images similar to ruptured breast implants one year after the supposed withdrawal of the latter. This woman had benefited for the first time from cosmetic PIP breast implants in 2000. Early in 2014, she requested the removal of the implants without renewal because she was feeling pain and functional discomfort. A few months after the operation, she consulted for breast swelling in the upper pole of the breast. Radiological assessment showed liquid formations compatible with the presence of implants. At our request, the rereading of the MRI by the radiologist definitively concluded on a bilateral seroma within the persistent fibrous capsule. In the absence of symptoms, clinical monitoring had been decided. But at the recrudescence of anaplastic large cell lymphoma cases associated with breast implants, a cytological sampling was intended. In case of cytological abnormality or recurrence of the seroma, a surgical procedure should be performed. In conclusion, the removal of a breast implant without capsulectomy may result in the formation of a seroma whose images resemble those of an implant. It is always worthwhile to provide precise clinical data to the radiologist in order to help him to make informed interpretations. Every serous effusion in a breast lodge having contained a silicone implant must evoke the diagnosis of anaplastic large cell lymphoma. PMID:26232069

  15. First report of a permanent breast {sup 103}Pd seed implant as adjuvant radiation treatment for early-stage breast cancer

    SciTech Connect

    Pignol, Jean-Philippe . E-mail: Jean-Philippe.Pignol@sw.ca; Keller, Brian; Rakovitch, Eileen; Sankreacha, Raxa; Easton, Harry; Que, William

    2006-01-01

    Purpose: A new technique of adjuvant partial breast irradiation using {sup 103}Pd permanent breast seed implants (PBSI) is presented. The procedure is performed in a single 1-hour session under local anesthesia. Methods and Materials: Patients referred to a single institution for adjuvant radiotherapy after lumpectomy for an infiltrating ductal carcinoma {<=}3 cm in diameter, surgical margin {>=}2 mm, no extensive in situ carcinoma, no lymphovascular invasion, and minimal or negative lymph node involvement were offered a PBSI. Results: Between May and December 2004, 31 eligible patients underwent CT scan and ultrasound simulations assessing PBSI feasibility. Fifteen were excluded because of feasibility issues, and 16 received PBSI. A minimal peripheral dose of 90 Gy was prescribed to the planning target volume corresponding to the clinical target volume identified on the CT scan plus a margin of 1 cm. The procedure was well tolerated; 56% of the patients reported no pain during the procedure, and 46% of the patients developed National Cancer Institute Common Toxicity Criteria Grade 1 acute reaction. None experienced toxicity Grade 2 or 3. Conclusions: Permanent breast seed implantation seems feasible and well tolerated on these preliminary clinical data and represents an ultimate step in the reduction of treatment fraction for partial breast irradiation.

  16. Selecting Patients for Exclusive Permanent Implant Prostate Brachytherapy: The Experience of the Paris Institut Curie/Cochin Hospital/Necker Hospital Group on 809 Patients

    SciTech Connect

    Cosset, Jean-Marc Flam, Thierry; Thiounn, Nicolas; Gomme, Stephanie; Rosenwald, Jean-Claude; Asselain, Bernard; Pontvert, Dominique; Henni, Mehdi; Debre, Bernard; Chauveinc, Laurent

    2008-07-15

    Purpose: The aim of this study was to analyze overall and relapse-free survival in a cohort of 809 patients, 34% of whom corresponded to a higher-risk group than American Brachytherapy Society (ABS) criteria. Methods and Materials: Between January 1999 and September 2004, 809 patients were treated with permanent loose 125 iodine seed implantation (IsoSeed Bebig, Eckert and Ziegler) by the Paris Institut Curie, Cochin Hospital, and Necker Hospital group. Of these 809 patients, 533 (65.9%) corresponded exactly to ABS criteria. Two hundred and seventy-six patients (34.1%) had a prostate-specific antigen (PSA) level between 10 and 15, or a Gleason score of 7, or both (non-ABS group). Results: Overall 5-year survival was 98%, with no difference between the ABS group and the non-ABS patient subgroups (p 0.62).Five-year relapse-free survival was 97% in the ABS group; it was significantly lower (p = 0.001) in the non-ABS group but remained satisfactory at 94%. On subgroup analysis, the results appeared to be better for the subgroup of patients with PSA 10-15 than for the subgroup with a Gleason score of 7. Conclusions: Our results suggest that selected patients in the intermediate-risk group of localized prostate cancers can be safely proposed as recipients of permanent implant brachytherapy as monotherapy.

  17. Mechanisms of Heart Block after Transcatheter Aortic Valve Replacement – Cardiac Anatomy, Clinical Predictors and Mechanical Factors that Contribute to Permanent Pacemaker Implantation

    PubMed Central

    Young Lee, Mark; Chilakamarri Yeshwant, Srinath; Chava, Sreedivya; Lawrence Lustgarten, Daniel

    2015-01-01

    Transcatheter aortic valve replacement (TAVR) has emerged as a valuable, minimally invasive treatment option in patients with symptomatic severe aortic stenosis at prohibitive or increased risk for conventional surgical replacement. Consequently, patients undergoing TAVR are prone to peri-procedural complications including cardiac conduction disturbances, which is the focus of this review. Atrioventricular conduction disturbances and arrhythmias before, during or after TAVR remain a matter of concern for this high-risk group of patients, as they have important consequences on hospital duration, short- and long-term medical management and finally on decisions of device-based treatment strategies (pacemaker or defibrillator implantation). We discuss the mechanisms of atrioventricular disturbances and characterise predisposing factors. Using validated clinical predictors, we discuss strategies to minimise the likelihood of creating permanent high-grade heart block, and identify factors to expedite the decision to implant a permanent pacemaker when the latter is unavoidable. We also discuss optimal pacing strategies to mitigate the possibility of pacing-induced cardiomyopathy. PMID:26835105

  18. Comparison of implant quality between intraoperatively built custom-linked seeds and loose seeds in permanent prostate brachytherapy using sector analysis

    PubMed Central

    Katayama, Norihisa; Takemoto, Mitsuhiro; Takamoto, Atsushi; Ihara, Hiroki; Katsui, Kuniaki; Ebara, Shin; Nasu, Yasutomo; Kanazawa, Susumu

    2016-01-01

    We compared the implant quality of intraoperatively built custom-linked (IBCL) seeds with loose seeds in permanent prostate brachytherapy. Between June 2012 and January 2015, 64 consecutive prostate cancer patients underwent brachytherapy with IBCL seeds (n = 32) or loose seeds (n = 32). All the patients were treated with 144 Gy of brachytherapy alone. Brachytherapy was performed using a dynamic dose calculation technique. Computed tomography/magnetic resonance imaging fusion-based dosimetry was performed 1 month after brachytherapy. Post-implant dose–volume histogram (DVH) parameters, prostate sector dosimetry, operation time, seed migration, and toxicities were compared between the IBCL seed group and the loose seed group. A sector analysis tool was used to divide the prostate into six sectors (anterior and posterior sectors at the base, mid-gland, and apex). V100 (95.3% vs 89.7%; P = 0.014) and D90 (169.7 Gy vs 152.6 Gy; P = 0.013) in the anterior base sector were significantly higher in the IBCL seed group than in the loose seed group. The seed migration rate was significantly lower in the IBCL seed group than in the loose seed group (6% vs 66%; P < 0.001). Operation time per seed was significantly longer in the IBCL seed group than in the loose seed group (1.31 min vs 1.13 min; P = 0.003). Other post-implant DVH parameters and toxicities did not differ significantly between the two groups. Our study showed more dose coverage post-operatively in the anterior base prostate sector and less seed migration in IBCL seed implantation compared with loose seed implantation. PMID:26976125

  19. Development of virtual patient models for permanent implant brachytherapy Monte Carlo dose calculations: interdependence of CT image artifact mitigation and tissue assignment

    NASA Astrophysics Data System (ADS)

    Miksys, N.; Xu, C.; Beaulieu, L.; Thomson, R. M.

    2015-08-01

    This work investigates and compares CT image metallic artifact reduction (MAR) methods and tissue assignment schemes (TAS) for the development of virtual patient models for permanent implant brachytherapy Monte Carlo (MC) dose calculations. Four MAR techniques are investigated to mitigate seed artifacts from post-implant CT images of a homogeneous phantom and eight prostate patients: a raw sinogram approach using the original CT scanner data and three methods (simple threshold replacement (STR), 3D median filter, and virtual sinogram) requiring only the reconstructed CT image. Virtual patient models are developed using six TAS ranging from the AAPM-ESTRO-ABG TG-186 basic approach of assigning uniform density tissues (resulting in a model not dependent on MAR) to more complex models assigning prostate, calcification, and mixtures of prostate and calcification using CT-derived densities. The EGSnrc user-code BrachyDose is employed to calculate dose distributions. All four MAR methods eliminate bright seed spot artifacts, and the image-based methods provide comparable mitigation of artifacts compared with the raw sinogram approach. However, each MAR technique has limitations: STR is unable to mitigate low CT number artifacts, the median filter blurs the image which challenges the preservation of tissue heterogeneities, and both sinogram approaches introduce new streaks. Large local dose differences are generally due to differences in voxel tissue-type rather than mass density. The largest differences in target dose metrics (D90, V100, V150), over 50% lower compared to the other models, are when uncorrected CT images are used with TAS that consider calcifications. Metrics found using models which include calcifications are generally a few percent lower than prostate-only models. Generally, metrics from any MAR method and any TAS which considers calcifications agree within 6%. Overall, the studied MAR methods and TAS show promise for further retrospective MC dose

  20. Comparison of Combined X-Ray Radiography and Magnetic Resonance (XMR) Imaging-Versus Computed Tomography-Based Dosimetry for the Evaluation of Permanent Prostate Brachytherapy Implants

    SciTech Connect

    Acher, Peter Rhode, Kawal; Morris, Stephen; Gaya, Andrew; Miquel, Marc; Popert, Rick; Tham, Ivan; Nichol, Janette; McLeish, Kate; Deehan, Charles; Dasgupta, Prokar; Beaney, Ronald; Keevil, Stephen F.

    2008-08-01

    Purpose: To present a method for the dosimetric analysis of permanent prostate brachytherapy implants using a combination of stereoscopic X-ray radiography and magnetic resonance (MR) imaging (XMR) in an XMR facility, and to compare the clinical results between XMR- and computed tomography (CT)-based dosimetry. Methods and Materials: Patients who had received nonstranded iodine-125 permanent prostate brachytherapy implants underwent XMR and CT imaging 4 weeks later. Four observers outlined the prostate gland on both sets of images. Dose-volume histograms (DVHs) were derived, and agreement was compared among the observers and between the modalities. Results: A total of 30 patients were evaluated. Inherent XMR registration based on prior calibration and optical tracking required a further automatic seed registration step that revealed a median root mean square registration error of 4.2 mm (range, 1.6-11.4). The observers agreed significantly more closely on prostate base and apex positions as well as outlining contours on the MR images than on those from CT. Coefficients of variation were significantly higher for observed prostate volumes, D90, and V100 parameters on CT-based dosimetry as opposed to XMR. The XMR-based dosimetry showed little agreement with that from CT for all observers, with D90 95% limits of agreement ranges of 65, 118, 79, and 73 Gy for Observers 1, 2, 3, and 4, respectively. Conclusions: The study results showed that XMR-based dosimetry offers an alternative to other imaging modalities and registration methods with the advantages of MR-based prostate delineation and confident three-dimensional reconstruction of the implant. The XMR-derived dose-volume histograms differ from the CT-derived values and demonstrate less interobserver variability.

  1. Development of virtual patient models for permanent implant brachytherapy Monte Carlo dose calculations: interdependence of CT image artifact mitigation and tissue assignment.

    PubMed

    Miksys, N; Xu, C; Beaulieu, L; Thomson, R M

    2015-08-01

    This work investigates and compares CT image metallic artifact reduction (MAR) methods and tissue assignment schemes (TAS) for the development of virtual patient models for permanent implant brachytherapy Monte Carlo (MC) dose calculations. Four MAR techniques are investigated to mitigate seed artifacts from post-implant CT images of a homogeneous phantom and eight prostate patients: a raw sinogram approach using the original CT scanner data and three methods (simple threshold replacement (STR), 3D median filter, and virtual sinogram) requiring only the reconstructed CT image. Virtual patient models are developed using six TAS ranging from the AAPM-ESTRO-ABG TG-186 basic approach of assigning uniform density tissues (resulting in a model not dependent on MAR) to more complex models assigning prostate, calcification, and mixtures of prostate and calcification using CT-derived densities. The EGSnrc user-code BrachyDose is employed to calculate dose distributions. All four MAR methods eliminate bright seed spot artifacts, and the image-based methods provide comparable mitigation of artifacts compared with the raw sinogram approach. However, each MAR technique has limitations: STR is unable to mitigate low CT number artifacts, the median filter blurs the image which challenges the preservation of tissue heterogeneities, and both sinogram approaches introduce new streaks. Large local dose differences are generally due to differences in voxel tissue-type rather than mass density. The largest differences in target dose metrics (D90, V100, V150), over 50% lower compared to the other models, are when uncorrected CT images are used with TAS that consider calcifications. Metrics found using models which include calcifications are generally a few percent lower than prostate-only models. Generally, metrics from any MAR method and any TAS which considers calcifications agree within 6%. Overall, the studied MAR methods and TAS show promise for further retrospective MC dose

  2. In Vivo Dosimetry Using a Linear Mosfet-Array Dosimeter to Determine the Urethra Dose In {sup 125}I Permanent Prostate Implants

    SciTech Connect

    Bloemen-van Gurp, Esther J. Murrer, Lars H.P.; Haanstra, Bjoerk K.C.; Gils, Francis C.J.M. van; Dekker, Andre L.A.J.; Mijnheer, Ben J.; Lambin, Philippe

    2009-01-01

    Purpose: In vivo dosimetry during brachytherapy of the prostate with {sup 125}I seeds is challenging because of the high dose gradients and low photon energies involved. We present the results of a study using metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters to evaluate the dose in the urethra after a permanent prostate implantation procedure. Methods and Materials: Phantom measurements were made to validate the measurement technique, determine the measurement accuracy, and define action levels for clinical measurements. Patient measurements were performed with a MOSFET array in the urinary catheter immediately after the implantation procedure. A CT scan was performed, and dose values, calculated by the treatment planning system, were compared to in vivo dose values measured with MOSFET dosimeters. Results: Corrections for temperature dependence of the MOSFET array response and photon attenuation in the catheter on the in vivo dose values are necessary. The overall uncertainty in the measurement procedure, determined in a simulation experiment, is 8.0% (1 SD). In vivo dose values were obtained for 17 patients. In the high-dose region (> 100 Gy), calculated and measured dose values agreed within 1.7% {+-} 10.7% (1 SD). In the low-dose region outside the prostate (< 100 Gy), larger deviations occurred. Conclusions: MOSFET detectors are suitable for in vivo dosimetry during {sup 125}I brachytherapy of prostate cancer. An action level of {+-} 16% (2 SD) for detection of errors in the implantation procedure is achievable after validation of the detector system and measurement conditions.

  3. 50th Anniversary of the first successful permanent pacemaker implantation in the United States: historical review and future directions.

    PubMed

    Beck, Hiroko; Boden, William E; Patibandla, Sushmitha; Kireyev, Dmitriy; Gutpa, Vipul; Campagna, Franklin; Cain, Michael E; Marine, Joseph E

    2010-09-15

    June 2010 marks the 50th anniversary of the first successful human cardiac pacemaker implantation in the United States. On June 6, 1960, in Buffalo, New York, Dr. William Chardack implanted a pacemaker, designed and built by Wilson Greatbatch, an electrical engineer and inventor, in a 77-year old man with complete atrioventricular block, extending the patient's life by 18 months. This landmark event ushered in a new era of implantable cardiac pacemakers with batteries and leads of high reliability and increasing durability. Over the past half century, the field of electrophysiology and implantable devices for the management of cardiac conduction disturbances has evolved dramatically. Today's pacemakers include increasingly complex features such as telemetry monitoring, auto programmability, and hemodynamic sensors. New-generation leads present a sophisticated design with improved geometry and steroid-eluting tips to reduce chronic inflammation, maintaining a low pacing threshold and high sensing capability. The lithium iodide battery remains the mainstay of implantable pacemaker systems, exhibiting a multiple-year lifespan, slow terminal decay, and a reduced size and cost of production. Although Greatbatch's first successful pacemaker implantation remains a seminal scientific contribution to modern cardiovascular disease management, emerging developments in this field may challenge its preeminence. Important challenges such as imaging compatibility, lead durability, and infection prevention are being addressed. Novel concepts such as leadless and biologic pacing are under active investigation. In conclusion, Greatbatch's historic achievement 50 years ago reminds us that technologic progress is timeless, as efforts to enhance clinical outcomes and the quality of life continue unimpeded into the 21st century. PMID:21391322

  4. Moving Toward Focal Therapy in Prostate Cancer: Dual-Isotope Permanent Seed Implants as a Possible Solution

    SciTech Connect

    Todor, Dorin A.; Barani, Igor J.; Lin, Peck-Sun; Anscher, Mitchell S.

    2011-09-01

    Purpose: To compare the ability of single- and dual-isotope prostate seed implants to escalate biologically effective dose (BED) to foci of disease while reducing prescription dose to the prostate. Methods and Materials: Nine plans, using {sup 125}I, {sup 103}Pd, and {sup 131}Cs alone and in combination were created retrospectively for 2 patients. Ultrasound and MRI/MRS datasets were used for treatment planning. Voxel-by-voxel BED was calculated for single- and dual-isotope plans. Equivalent uniform BED (EUBED) was used to compare plans. The MRS-positive planning target volumes (PTV{sub i}) were delineated along with PTV (prostate + 5 mm), rectum, and urethra. Single-isotope implants, prescribed to conventional doses, were generated to achieve good PTV coverage. The PTV{sub i} were prospectively used to generate implants using mixtures of isotopes. For mixed-radioisotope implants, we also explored the impact on EUBED of lowering prescription doses by 15%. Results: The EUBED of PTV{sub i} in the setting of primary {sup 125}I implant increased 20-66% when {sup 103}Pd and {sup 131}Cs were used compared with {sup 125}I boost. Decreasing prescription dose by 15% in mixed-isotope implants results in a potential 10% reduction in urethral EUBED with preservation of PTV coverage while still boosting PTV{sub i} (up to 80%). When radiobiologic parameters corresponding to more-aggressive disease are assigned to foci, faster-decaying isotopes used in mixed implants have the potential to preserve the equivalent biological effect of mono-isotope implants considering less-aggressive disease distributed in the entire prostate. Conclusions: This is a hypothesis-generating study proposing a treatment paradigm that could be the middle ground between whole-gland irradiation and focal-only treatment. The use of two isotopes concurrent with decreasing the minimal peripheral dose is shown to increase EUBED of selected subvolumes while preserving the therapeutic effect at the level of the

  5. First permanent human implant of the Stimulus Router System, a novel neuroprosthesis: preliminary testing of a polarity reversing stimulation technique.

    PubMed

    Gan, Liu Shi; Ravid, Einat N; Kowalczewski, Jan; Gauthier, Michel; Olson, Jaret; Morhart, Michael; Prochazka, Arthur

    2011-01-01

    Neuroprostheses (NPs) are electrical stimulators that help to restore sensory or motor functions lost as a result of neural damage. The Stimulus Router System (SRS) is a new type of NP developed in our laboratory. The system uses fully implanted, passive leads to "capture" and "route" some of the current flowing between pairs of surface electrodes to the vicinity of the target nerves, hence eliminating the need for an implanted stimulator. In June 2008, 3 SRS leads were implanted in a tetraplegic man for restoration of grasp and release. To reduce the size of the external wristlet and thereby optimize usability, we recently implemented a polarity reversing stimulation technique that allowed us to eliminate a reference electrode. Selective activation of three target muscles was achieved by switching the polarities of the stimulus current delivered between pairs of surface electrodes located over the pick-up terminals of the implanted leads and reducing the amplitude of the secondary phases of the stimulus pulses. PMID:22254983

  6. Dosimetric and radiobiological comparison of volumetric modulated arc therapy, high-dose rate brachytherapy, and low-dose rate permanent seeds implant for localized prostate cancer.

    PubMed

    Yang, Ruijie; Zhao, Nan; Liao, Anyan; Wang, Hao; Qu, Ang

    2016-01-01

    To investigate the dosimetric and radiobiological differences among volumetric modulated arc therapy (VMAT), high-dose rate (HDR) brachytherapy, and low-dose rate (LDR) permanent seeds implant for localized prostate cancer. A total of 10 patients with localized prostate cancer were selected for this study. VMAT, HDR brachytherapy, and LDR permanent seeds implant plans were created for each patient. For VMAT, planning target volume (PTV) was defined as the clinical target volume plus a margin of 5mm. Rectum, bladder, urethra, and femoral heads were considered as organs at risk. A 78Gy in 39 fractions were prescribed for PTV. For HDR and LDR plans, the dose prescription was D90 of 34Gy in 8.5Gy per fraction, and 145Gy to clinical target volume, respectively. The dose and dose volume parameters were evaluated for target, organs at risk, and normal tissue. Physical dose was converted to dose based on 2-Gy fractions (equivalent dose in 2Gy per fraction, EQD2) for comparison of 3 techniques. HDR and LDR significantly reduced the dose to rectum and bladder compared with VMAT. The Dmean (EQD2) of rectum decreased 22.36Gy in HDR and 17.01Gy in LDR from 30.24Gy in VMAT, respectively. The Dmean (EQD2) of bladder decreased 6.91Gy in HDR and 2.53Gy in LDR from 13.46Gy in VMAT. For the femoral heads and normal tissue, the mean doses were also significantly reduced in both HDR and LDR compared with VMAT. For the urethra, the mean dose (EQD2) was 80.26, 70.23, and 104.91Gy in VMAT, HDR, and LDR brachytherapy, respectively. For localized prostate cancer, both HDR and LDR brachytherapy were clearly superior in the sparing of rectum, bladder, femoral heads, and normal tissue compared with VMAT. HDR provided the advantage in sparing of urethra compared with VMAT and LDR. PMID:27400663

  7. Use of SIG device to accurately place permanent miniature dental implants to retain mandibular overdenture. A case report.

    PubMed

    Sussman, Harold I; Goodridge, Opal F

    2006-01-01

    A case of mini-dental implant insertion for retention of a mandibular overdenture in a hospitalized patient has been documented. The additional use of the SIG (drill guide) directional device in the implant placement protocol gave the practitioner more confidence and resulted in the proper alignment of the three ball-top, one-piece fixtures. The three implants were inserted exactly 1 cm apart and parallel to each other. The distal fixtures were approximately 1 cm away from the mental foramina, thereby eliminating the risk of lip paresthesia. Keeper caps were placed in the denture's intaglio after one month. The keeper caps allowed for proper retention of the overdenture. The caps also enabled the patient to easily insert and withdraw his denture, even though he displayed limited manual dexterity. The tissue response was excellent, and oral hygiene was made easier with adequate spacing of the exposed ball-tops. The overall experience for both the operator and the patient was very positive. General dentists should be able to readily master this technique and add it to their armamentarium for the benefit of all their patients. PMID:17036584

  8. Comparison of permanent 125I seeds implants with two different techniques in 500 cases of prostate cancer

    PubMed Central

    Ricós, Jose Vicente; Tortajada, Maria Isabel; Santos, Miguel Angel; Casanova, Juan; Clemente, Jose; Samper, Josefa; Santamaría, Paula; Arribas, Leoncio

    2015-01-01

    Purpose To perform a comparative study of 500 consecutive 125I seeds implants for intracapsular prostate carcinoma with two techniques differing in terms of both strand implantation and planning. Material and methods From 2002 to 2007 we performed 250 implants with fixed stranded seeds (RapidStrand™) and a preplanning system and from 2007 to 2010, 250 with real-time and ProLink™ system. Mean age was 68 and 66, respectively, median PSA (prostate-specific antigen) 7.3 and 7.2, stage T1-T2a in 98% and 94%, and Gleason ≤ 6 in 96% and 86%. Low risk cases were 81% and 71%. The prescribed dose was 145 Gy to the prostate volume, or 108 Gy plus EBRT 46 Gy in some intermediate risk cases. Hormonal treatment was given to 42% and 28%. Results Median follow-up was 48 and 47 months, respectively, 14 patients in the first group and 7 patients in the second developed biochemical failure (BF). Actuarial biochemical relapse-free survival (bRFS) at 5 years increased from 90.2% to 97.2% (low risk from 91.3% to 97.2%, intermediate risk from 84.2% to 97.1%). Biochemical failure was independent of hormone treatment. Rectal complications were G1-2 in 1.2% and 5.2%, respectively. A urinary catheter was necessary in 6.9% and 9.6%, and urethral resection in 1.9% and 4.4%. Genitourinary toxicity was G1-2 in 4.6% and 12%, G3-4 in 1.9% and 4.8%. An assessment of mean D90 in a sample of patients showed that the dosimetry in postoperative planning based on CT improved from a mean D90 of 143 Gy to 157 Gy. Conclusions The outcome of patients with low risk prostate carcinoma treated with 125I seed is very good with low complications rate. The real-time approach in our hands achieved a more precise seed implantation, better dosimetry, and a statistically non-significant better biochemical control. We have made this our standard technique. PMID:26622228

  9. Low elastic modulus Ti-Ta alloys for load-bearing permanent implants: enhancing the biodegradation resistance by electrochemical surface engineering.

    PubMed

    Kesteven, Jazmin; Kannan, M Bobby; Walter, Rhys; Khakbaz, Hadis; Choe, Han-Choel

    2015-01-01

    In this study, the in vitro degradation behaviour of titanium-tantalum (Ti-Ta) alloys (10-30 wt.% Ta) was investigated and compared with conventional implant materials, i.e., commercially pure titanium (Cp-Ti) and titanium-aluminium-vanadium (Ti6Al4V) alloy. Among the three Ti-Ta alloys studied, the Ti20Ta (6.3×10(-4) mm/y) exhibited the lowest degradation rate, followed by Ti30Ta (1.2×10(-3) mm/y) and Ti10Ta (1.4×10(-3) mm/y). All the Ti-Ta alloys exhibited lower degradation rate than that of Cp-Ti (1.8×10(-3) mm/y), which suggests that Ta addition to Ti is beneficial. As compared to Ti6Al4V alloy (8.1×10(-4) mm/y), the degradation rate of Ti20Ta alloy was lower by ~22%. However, the Ti30Ta alloy, which has closer elastic modulus to that of natural bone, showed ~48% higher degradation rate than that of Ti6Al4V alloy. Hence, to improve the degradation performance of Ti30Ta alloy, an intermediate thin porous layer was formed electrochemically on the alloy followed by calcium phosphate (CaP) electrodeposition. The coated Ti30Ta alloy (3.8×10(-3) mm/y) showed ~53% lower degradation rate than that of Ti6Al4V alloy. Thus, the study suggests that CaP coated Ti30Ta alloy can be a viable material for load-bearing permanent implants. PMID:25491981

  10. Multi-institutional analysis of long-term outcome for stages T1-T2 prostate cancer treated with permanent seed implantation

    SciTech Connect

    Zelefsky, Michael J. . E-mail: zelefskm@mskcc.org; Kuban, Deborah A.; Levy, Larry B.; Potters, Louis; Beyer, David C.; Blasko, John C.; Moran, Brian J.; Ciezki, Jay P.; Zietman, Anthony L.; Pisansky, Thomas M.; Elshaikh, Mohamed; Horwitz, Eric M.

    2007-02-01

    Purpose: To assess long-term prostate-specific antigen (PSA) outcome after permanent prostate brachytherapy (BT) and identify predictors of improved disease-free survival. Methods and Materials: Eleven institutions combined data on 2,693 patients treated with permanent interstitial BT monotherapy for T1-T2 prostate cancer. Of these patients, 1,831 (68%) were treated with I-125 (median dose, 144 Gy) and 862 (32%) were treated with Pd-103 (median dose, 130 Gy). Criteria for inclusion were: available pre-BT PSA, BT {>=}5 years before data submission, BT between 1988-1998, and no androgen deprivation before failure. The median follow-up was 63 months. Results: Among patients where the I-125 dose to 90% of the prostate (D90) was {>=}130 Gy, the 8-year PSA relapse-free survival (PRFS) was 93% compared with 76% for those with lower D90 dose levels (p < 0.001). A multivariable analysis identified tumor stage (p = 0.002), Gleason score (p < 0.001), pretreatment PSA level (p < 0.001), treatment year (p = 0.001), and the isotope used (p = 0.004) as pretreatment and treatment variables associated with PRFS. When restricted to patients with available postimplantation dosimetric information, D90 emerged as a significant predictor of biochemical outcome (p = 0.01), and isotope was not significant. The 8-year PRFS was 92%, 86%, 79%, and 67%, respectively, for patients with PSA nadir values of 0-0.49, 0.5-0.99, 1.0-1.99, and >2.0 ng/mL (p < 0.001). Among patients free of biochemical relapse at 8 years, the median nadir level was 0.1 ng/mL, and 90% of these patients achieved a nadir PSA level <0.6 ng/mL. Conclusions: Outcome after permanent BT for prostatic cancer relates to tumor stage, Gleason score, pretreatment PSA, BT year, and post-BT dosimetric quality. PSA nadir {<=}0.5 ng/mL was particularly associated with durable long-term PSA disease-free survival. The only controllable factor to impact on long-term outcome was the D90 which is a reflection of implant quality.

  11. Less restrictive patient-specific radiation-safety precautions can be safely prescribed after permanent seed implantation

    PubMed Central

    Dauer, Lawrence T.; Kollmeier, Marisa A.; Williamson, Matthew J.; St. Germain, Jean; Altamirano, Joaquin; Yamada, Yoshiya; Zelefsky, Michael J.

    2013-01-01

    PURPOSE To utilize radiation exposure-rate measurements to determine patient-specific radiation-safety instructions with the aim of reducing unnecessary precaution times and to evaluate potential doses to members of the public. Materials and Methods Radiation exposure-rate measurements were obtained from 1279 patients with stage T1-2 prostate cancer who underwent transperineal I-125 or Pd-103 seed implantation from January 1995 through July 2008. An algorithm was developed from these measurements to determine required precaution times needed to maintain public effective doses below 50% of the limits for specific exposure situations. Results The median air kerma rates at 30 cm from the anterior skin surface were 4.9 μGy/h (range: 0.1-31.5) for I-125 and 1.5 μGy/h (range: 0.02-14.9) for Pd-103. Derived algorithms depended primarily upon the half-life, Tp, the measured exposure rate at 30 cm, and specific exposure situation factors. For the typical Pd-103 patient, no radiation-safety precautions are required. For the typical I-125 patient, no precautions are required for co-workers, nonpregnant adults that do not sleep with the family member, or nonpregnant adults that sleep with the patient. Typical I-125 patients should only need to avoid sleeping in the “spoon” position (i.e., in contact) with pregnant adults and avoid holding a child for long periods of time in the lap for about 2 months. Conclusions The large number of cases available for this study permitted the development of an algorithm to simply determine patient-specific radiation-safety instructions. Resulting precaution times are significantly less restrictive than precaution times generally prescribed currently. PMID:19853532

  12. Postmastectomy Chest Wall Radiation to a Temporary Tissue Expander or Permanent Breast Implant-Is There a Difference in Complication Rates?

    SciTech Connect

    Anderson, Penny R. Freedman, Gary; Nicolaou, Nicos; Sharma, Navesh; Li Tianyu; Topham, Neal; Morrow, Monica

    2009-05-01

    Purpose: The purpose of this study was to evaluate the likelihood of complications and cosmetic results among breast cancer patients who underwent modified radical mastectomy (MRM) and breast reconstruction followed by radiation therapy (RT) to either a temporary tissue expander (TTE) or permanent breast implant (PI). Methods and Materials: Records were reviewed of 74 patients with breast cancer who underwent MRM followed by breast reconstruction and RT. Reconstruction consisted of a TTE usually followed by exchange to a PI. RT was delivered to the TTE in 62 patients and to the PI in 12 patients. Dose to the reconstructed chest wall was 50 Gy. Median follow-up was 48 months. The primary end point was the incidence of complications involving the reconstruction. Results: There was no significant difference in the rate of major complications in the PI group (0%) vs. 4.8% in the TTE group. No patients lost the reconstruction in the PI group. Three patients lost the reconstruction in the TTE group. There were excellent/good cosmetic scores in 90% of the TTE group and 80% of the PI group (p = 0.22). On multivariate regression models, the type of reconstruction irradiated had no statistically significant impact on complication rates. Conclusions: Patients treated with breast reconstruction and RT can experience low rates of major complications. We demonstrate no significant difference in the overall rate of major or minor complications between the TTE and PI groups. Postmastectomy RT to either the TTE or the PI should be considered as acceptable treatment options in all eligible patients.

  13. A Comparison of Acute and Chronic Toxicity for Men With Low-Risk Prostate Cancer Treated With Intensity-Modulated Radiation Therapy or {sup 125}I Permanent Implant

    SciTech Connect

    Eade, Thomas N.; Horwitz, Eric M. Ruth, Karen; Buyyounouski, Mark K.; D'Ambrosio, David J.; Feigenberg, Steven J.; Chen, David Y.T.; Pollack, Alan

    2008-06-01

    Purpose: To compare the toxicity and biochemical outcomes of intensity-modulated radiation therapy (IMRT) and {sup 125}I transperineal permanent prostate seed implant ({sup 125}I) for patients with low-risk prostate cancer. Methods and Materials: Between 1998 and 2004, a total of 374 low-risk patients (prostate-specific antigen < 10 ng/ml, T1c-T2b, Gleason score of 6 or less, and no neoadjuvant hormones) were treated at Fox Chase Cancer Center (216 IMRT and 158 {sup 125}I patients). Median follow-up was 43 months for IMRT and 48 months for {sup 125}I. The IMRT prescription dose ranged from 74-78 Gy, and {sup 125}I prescription was 145 Gy. Acute and late gastrointestinal (GI) and genitourinary (GU) toxicity was recorded by using a modified Radiation Therapy Oncology Group scale. Freedom from biochemical failure was defined by using the Phoenix definition (prostate-specific antigen nadir + 2.0 ng/ml). Results: Patients treated by using IMRT were more likely to be older and have a higher baseline American Urological Association symptom index score, history of previous transurethral resection of the prostate, and larger prostate volumes. On multivariate analysis, IMRT was an independent predictor of lower acute and late Grade 2 or higher GU toxicity and late Grade 2 or higher GI toxicity. Three-year actuarial estimates of late Grade 2 or higher toxicity were 2.4% for GI and 3.5% for GU by using IMRT compared with 7.7% for GI and 19.2% for GU for {sup 125}I, respectively. Four-year actuarial estimates of freedom from biochemical failure were 99.5% for IMRT and 93.5% for {sup 125}I (p = 0.09). Conclusions: The IMRT and {sup 125}I produce similar outcomes, although IMRT appears to have less acute and late toxicity.

  14. Dose Escalation to the Dominant Intraprostatic Lesion Defined by Sextant Biopsy in a Permanent Prostate I-125 Implant: A Prospective Comparative Toxicity Analysis

    SciTech Connect

    Gaudet, Marc; Vigneault, Eric; Aubin, Sylviane; Varfalvy, Nicolas; Harel, Francois; Beaulieu, L.; Martin, Andre-Guy

    2010-05-01

    Purpose: Using real-time intraoperative inverse-planned permanent seed prostate implant (RTIOP/PSI), multiple core biopsy maps, and three-dimensional ultrasound guidance, we planned a boost volume (BV) within the prostate to which hyperdosage was delivered selectively. The aim of this study was to investigate the potential negative effects of such a procedure. Methods and Materials: Patients treated with RTIOP/PSI for localized prostate cancer with topographic biopsy results received an intraprostatic boost (boost group [BG]). They were compared with patients treated with a standard plan (reference group [RG]). Plans were generated using a simulated annealing inverse planning algorithm. Prospectively recorded urinary, rectal, and sexual toxicities and dosimetric parameters were compared between groups. Results: The study included 120 patients treated with boost technique who were compared with 70 patients treated with a standard plan. Boost technique did not significantly change the number of seeds (55.1/RG vs. 53.6/BG). The intraoperative prostate V150 was slightly higher in BG (75.2/RG vs. 77.2/BG, p = 0.039). Urethra V100, urethra D90, and rectal D50 were significantly lower in the BG. No significant differences were seen in acute or late urinary, rectal, or sexual toxicities. Conclusions: Because there were no differences between the groups in acute and late toxicities, we believe that BV can be planned and delivered to the dominant intraprostatic lesion without increasing toxicity. It is too soon to say whether a boost technique will ultimately increase local control.

  15. Feasibility of MR Imaging/MR Spectroscopy-Planned Focal Partial Salvage Permanent Prostate Implant (PPI) for Localized Recurrence After Initial PPI for Prostate Cancer

    SciTech Connect

    Hsu, Charles C.; Hsu, Howard; Pickett, Barby; Crehange, Gilles; Hsu, I-Chow Joe; Dea, Ryan; Weinberg, Vivian; Gottschalk, Alexander R.; Kurhanewicz, John; Shinohara, Katsuto; Roach, Mack

    2013-02-01

    Purpose: To assess the feasibility of magnetic resonance imaging (MRI)-planned partial salvage permanent prostate implant (psPPI) among patients with biopsy-proven local recurrence after initial PPI without evidence of distant disease. Methods and Materials: From 2003-2009, 15 patients underwent MRI/magnetic resonance spectroscopy (MRS) planning for salvage brachytherapy (psPPI, I-125 [n=14; 144 Gy]; Pd-103 [n=1; 125 Gy]) without hormone therapy. Full dose was prescribed to areas of recurrence and underdosage, without entire prostate implantation. Limiting urethral and rectal toxicity was prioritized. Follow-up was from salvage date to prostate-specific antigen (PSA) concentration failure (Phoenix criteria = nadir + 2.0; ASTRO = 3 consecutive rises), recurrence, distant metastases, or last follow-up PSA level. Progression-free survival (PFS) was defined as no PSA failure or biopsy-proven recurrence without all-cause mortality. Toxicity was scored using Common Terminology Criteria for Adverse Events version 4.0. Results: At salvage, median age was 68 years, and PSA concentration was 3.5 ng/mL (range, 0.9-5.6 ng/mL). Abnormal MRI/MRS findings were evident in 40% of patients. Biopsy-proven recurrences consisted of a single focus (80%) or 2 foci (20%). At recurrence, Gleason score was 6 (67%) or {>=}7 (27%). Median interval between initial and salvage implantation was 69 months (range, 28-132 months). psPPI planning characteristics limited doses to the rectum (mean V100 = 0.5% [0.07 cc]) and urethra (V100 = 12% [0.3 cc]). At median follow-up (23.3 months; range, 8-88 months), treatment failure (n=2) resulted only in localized recurrence; both patients underwent second psPPI with follow-up PSA tests at 12 and 26 months, resulting in 0.6 and 0.7 ng/mL, respectively. American Society for Radiation Oncology PFS rates at 1, 2, and 3 years were 86.7%, 78.4%, and 62.7%, respectively, with 5 patients for whom treatment failed (n=3 with negative transrectal ultrasound

  16. Simulation du comportement thermique en régime permanent d'un moteur asynchrone à refroidissement extérieur. Etude par éléments finis

    NASA Astrophysics Data System (ADS)

    Glises, R.; Hostache, G.; Kauffmann, J. M.

    1994-09-01

    The steady state thermal modelling of an 4kW asynchronous motor is realized. A design has been made thanks to the Flux2D finite element magnetic calculus software converted into a resolution tool of the heat equation. This last is used to simulate the heat flux in fluid and solid areas. A 3D study is effected thanks to two 2D studies. The first concerns a radial view (perpendicular to the mechanical axis) whereas the second is effected for an axial view (parallel to the mechanical axis). Thermal conductivities of the materials and thermal contact resistances of the motor are determined through two different tests creating different overheatings. The first is made with a sinewave supply and pre-determine the thermophysical parameters. The second effected with direct current supplies at the rotor and the stator is used to validate these last parameters. On réalise l'étude du comportement thermique en régime permanent d'un moteur asynchrone de 4kW. Le logiciel de calculs magnétiques par éléments finis flux2D est converti en un outil de résolution de l'équation de la chaleur. Cette dernière équation sert à simuler les transferts thermiques tant dans les domaines fluides que solides. Une pseudo-étude tridimensionnelle est réalisée par le biais de deux études bidimensionnelles : la première effectuée suivant un plan radial (plan perpendiculaire à l'axe du moteur) et la seconde suivant un plan axial (plan parallèle à l'axe). Les conductivités des matériaux et des résistances thermiques de contact composant le moteur sont déterminées à l'aide de deux types d'essais qui induisent des échauffements différents. Le premier est réalisé avec une alimentation sinusoïdale et sert à prédéterminer les paramètres thermophysiques. Le second est effectué avec des alimentations à courant continu tant au stator qu'au rotor et a pour rôle la validation de ces paramètres.

  17. Potential impact of prostate edema on the dosimetry of permanent seed implants using the new {sup 131}Cs (model CS-1) seeds

    SciTech Connect

    Chen Zhe; Deng Jun; Roberts, Kenneth; Nath, Ravinder

    2006-04-15

    Our aim in this work was to study the potential dosimetric effect of prostate edema on the accuracy of conventional pre- and post-implant dosimetry for prostate seed implants using the newly introduced {sup 131}Cs seed, whose radioactive decay half-life ({approx}9.7 days) is directly comparable to the average edema resolution half-life ({approx}10 days) observed previously by Waterman et al. for {sup 125}I implants [Int. J. Radiat. Oncol. Biol. Phys. 41, 1069-1077 (1998)]. A systematic calculation of the relative dosimetry effect of prostate edema on the {sup 131}Cs implant was performed by using an analytic solution obtained previously [Int. J. Radiat. Oncol. Biol. Phys. 47, 1405-1419 (2000)]. It was found that conventional preimplant dosimetry always overestimates the true delivered dose as it ignores the temporary increase of the interseed distance caused by edema. The overestimation for {sup 131}Cs implants ranged from 1.2% (for a small edema with a magnitude of 10% and a half-life of 2 days) to approximately 45% (for larger degree edema with a magnitude of 100% and a half-life of 25 days). The magnitude of pre- and post-implant dosimetry error for {sup 131}Cs implants was found to be similar to that of {sup 103}Pd implants for typical edema characteristics (magnitude <100%, and half-life <25 days); both of which are worse compared to {sup 125}I implants. The preimplant dosimetry error for {sup 131}Cs implants cannot be compensated effectively without knowing the edema characteristics before the seed implantation. On the other hand, the error resulted from a conventional post-implant dosimetry can be minimized (to within {+-}6%) for {sup 131}Cs implants if the post-implant dosimetry is performed at 10{+-}2 days post seed implantation. This 'optimum' post-implant dosimetry time is shorter than those determined previously for the {sup 103}Pd and {sup 125}I implants at 16{+-}4 days and 6{+-}1 weeks, respectively.

  18. Urinary and Rectal Toxicity Profiles After Permanent Iodine-125 Implant Brachytherapy in Japanese Men: Nationwide J-POPS Multi-institutional Prospective Cohort Study

    SciTech Connect

    Ohashi, Toshio; Yorozu, Atsunori; Saito, Shiro; Tanaka, Nobumichi; Katayama, Norihisa; Kojima, Shinsuke; Maruo, Shinichiro; Kikuchi, Takashi; Dokiya, Takushi; Fukushima, Masanori; Yamanaka, Hidetoshi

    2015-09-01

    Purpose: To assess, in a nationwide multi-institutional cohort study begun in 2005 and in which 6927 subjects were enrolled by 2010, the urinary and rectal toxicity profiles of subjects who enrolled during the first 2 years, and evaluate the toxicity profiles for permanent seed implantation (PI) and a combination therapy with PI and external beam radiation therapy (EBRT). Methods and Materials: Baseline data for 2339 subjects out of 2354 patients were available for the analyses. Toxicities were evaluated using the National Cancer Institute's Common Terminology Criteria for Adverse Events, and the International Prostate Symptom Scores were recorded prospectively until 36 months after radiation therapy. Results: Grade 2+ acute urinary toxicities developed in 7.36% (172 of 2337) and grade 2+ acute rectal toxicities developed in 1.03% (24 of 2336) of the patients. Grade 2+ late urinary and rectal toxicities developed in 5.75% (133 of 2312) and 1.86% (43 of 2312) of the patients, respectively. A higher incidence of grade 2+ acute urinary toxicity occurred in the PI group than in the EBRT group (8.49% vs 3.66%; P<.01). Acute rectal toxicity outcomes were similar between the treatment groups. The 3-year cumulative incidence rates for grade 2+ late urinary toxicities were 6.04% versus 4.82% for the PI and the EBRT groups, respectively, with no significant differences between the treatment groups. The 3-year cumulative incidence rates for grade 2+ late rectal toxicities were 0.90% versus 5.01% (P<.01) for the PI and the EBRT groups, respectively. The mean of the postimplant International Prostate Symptom Score peaked at 3 months, but it decreased to a range that was within 2 points of the baseline score, which was observed in 1625 subjects (69.47%) at the 1-year follow-up assessment. Conclusions: The acute urinary toxicities observed were acceptable given the frequency and retention, and the late rectal toxicities were more favorable than those of other studies.

  19. Dosimetric characterization of the GammaClip™ 169Yb low dose rate permanent implant brachytherapy source for the treatment of nonsmall cell lung cancer postwedge resection

    PubMed Central

    Currier, Blake; Munro, John J.; Medich, David C.

    2013-01-01

    Purpose: A novel 169Yb low dose rate permanent implant brachytherapy source, the GammaClip™, was developed by Source Production & Equipment Co. (New Orleans, LA) which is designed similar to a surgical staple while delivering therapeutic radiation. In this report, the brachytherapy source was characterized in terms of “Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO” by Perez-Calatayud [Med. Phys. 39, 2904–2929 (2012)]10.1118/1.3703892 using the updated AAPM Task Group Report No. 43 formalism. Methods: Monte Carlo calculations were performed using Monte Carlo N-Particle 5, version 1.6 in water and air, the in-air photon spectrum filtered to remove photon energies below 10 keV in accordance with TG-43U1 recommendations and previously reviewed 169Yb energy cutoff levels [D. C. Medich, M. A. Tries, and J. M. Munro, “Monte Carlo characterization of an Ytterbium-169 high dose rate brachytherapy source with analysis of statistical uncertainty,” Med. Phys. 33, 163–172 (2006)]10.1118/1.2147767. TG-43U1 dosimetric data, including SK, \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\dot D(r,\\theta)\\end{document}D˙(r,θ), Λ, gL(r), F(r, θ), ϕan(r), and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\bar \\phi _{an}\\end{document}ϕ¯an were calculated along with their statistical uncertainties. Since the source is not axially symmetric, an additional set of calculations were performed to assess the resulting axial anisotropy. Results: The brachytherapy source's dose rate constant was calculated to

  20. Dosimetric characterization of the GammaClip™{sup 169}Yb low dose rate permanent implant brachytherapy source for the treatment of nonsmall cell lung cancer postwedge resection

    SciTech Connect

    Currier, Blake; Munro, John J. III; Medich, David C.

    2013-08-15

    Purpose: A novel {sup 169}Yb low dose rate permanent implant brachytherapy source, the GammaClip™, was developed by Source Production and Equipment Co. (New Orleans, LA) which is designed similar to a surgical staple while delivering therapeutic radiation. In this report, the brachytherapy source was characterized in terms of “Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO” by Perez-Calatayud et al. [Med. Phys. 39, 2904–2929 (2012)] using the updated AAPM Task Group Report No. 43 formalism.Methods: Monte Carlo calculations were performed using Monte Carlo N-Particle 5, version 1.6 in water and air, the in-air photon spectrum filtered to remove photon energies below 10 keV in accordance with TG-43U1 recommendations and previously reviewed {sup 169}Yb energy cutoff levels [D. C. Medich, M. A. Tries, and J. M. Munro, “Monte Carlo characterization of an Ytterbium-169 high dose rate brachytherapy source with analysis of statistical uncertainty,” Med. Phys. 33, 163–172 (2006)]. TG-43U1 dosimetric data, including S{sub K}, D-dot (r,θ), Λ, g{sub L}(r), F(r, θ), φ{sub an}(r), and φ{sub an} were calculated along with their statistical uncertainties. Since the source is not axially symmetric, an additional set of calculations were performed to assess the resulting axial anisotropy.Results: The brachytherapy source's dose rate constant was calculated to be (1.22 ± 0.03) cGy h{sup −1} U{sup −1}. The uncertainty in the dose to water calculations, D-dot (r,θ), was determined to be 2.5%, dominated by the uncertainties in the cross sections. The anisotropy constant, φ{sub an}, was calculated to be 0.960 ± 0.011 and was obtained by integrating the anisotropy factor between 1 and 10 cm using a weighting factor proportional to r{sup −2}. The radial dose function was calculated at distances between 0.5 and 12 cm, with a maximum value of 1.20 at 5.15 ± 0.03 cm. Radial dose

  1. Visual outcome of pars plana vitrectomy with intraocular foreign body removal through sclerocorneal tunnel and sulcus-fixated intraocular lens implantation as a single procedure, in cases of metallic intraocular foreign body with traumatic cataract

    PubMed Central

    Mahapatra, Santosh K; Rao, Nageswar G

    2010-01-01

    Aim: To evaluate visual outcome following pars plana vitrectomy (PPV) and intraocular foreign body (IOFB) removal through the sclerocorneal tunnel combined with simultaneous cataract extraction and sulcus-fixated intraocular lens (IOL) implantation as a single procedure in penetrating ocular trauma with IOFB and traumatic cataract. Materials and Methods: Eighteen cases of penetrating ocular trauma with retained IOFB and traumatic cataract who underwent PPV, IOFB body removal and cataract extraction with posterior chamber IOL (PCIOL) implantation in the same sitting, between June '04 and December '05 were retrospectively analyzed. All the foreign bodies were removed through the sclerocorneal tunnel. Result: All the 18 patients were young males, with an average follow-up period of 12 months. In 12 cases the foreign body was intravitreal and in six cases it was intraretinal but extramacular. Thirteen cases had a best corrected visual acuity ranging from 20/20 to 20/60 at their last follow-up. Five cases developed retinal detachment due to proliferative vitreoretinopathy (PVR) changes postoperatively and were subsequently managed by surgery. Conclusion: Primary IOL implantation with combined cataract and vitreo-retinal surgery is a safe option reducing the need for two separate surgeries in selected patients with retained IOFB and traumatic cataract. This combined procedure provides good visual outcome with early rehabilitation in young working patients. PMID:20195033

  2. Edema-induced increase in tumour cell survival for 125I and 103Pd prostate permanent seed implants - a bio-mathematical model

    NASA Astrophysics Data System (ADS)

    Yue, Ning; Chen, Zhe; Nath, Ravinder

    2002-04-01

    Edema caused by the surgical procedure of prostate seed implantation expands the source-to-point distances within the prostate and hence decreases the dose coverage. The decrease of dose coverage results in an increase in tumour cell survival. To investigate the effects of edema on tumour cell survival, a bio-mathematical model of edema and the corresponding cell killing by continuous low dose rate irradiation (CLDRI) was developed so that tumour cell surviving fractions can be estimated in an edematous prostate for both 125I and 103Pd seed implants. The dynamic nature of edema and its resolution were modelled with an exponential function V(T) = Vp (1 + M exp(-0.693T/Te)) where Vp is the prostate volume before implantation, M is the edema magnitude and Te is edema half-life (EHL). The dose rate of a radioactive seed was calculated according to AAPM TG43, i.e. Λg(r) αBED), where α is the linear coefficient of the survival curve. The tumour cell survival was calculated for both 125I and 103Pd seed implants and for different tumour potential doubling time (TPDT) (from 5 days to 30 days) and for edemas of different magnitudes (from 0% to 95%) and edema half-lives (from 4 days to 30 days). Tumour cell survival increased with the increase of edema magnitude and EHL. For a typical edema of a half-life of 10 days and a magnitude of 50%, the edema increased tumour cell survival by about 1 and 2 orders of magnitude for 125I and 103Pd seed implants respectively. At the extreme (95% edema magnitude and an edema half-life of 30 days), the increase was more than 3 and 5 orders of magnitude for 125I and 103Pd seed implants respectively. The absolute increases were almost independent of TPDT and the prostate edema did not significantly change the effective treatment time. Tumour cell survival for prostate undergoing CLDRI using 125I or 103Pd seeds may be increased substantially due to the presence of edema caused by surgical trauma. This effect appears to be more pronounced for

  3. Report of the NASPE Policy Conference training requirements for permanent pacemaker selection, implantation, and follow-up. North American Society of Pacing and Electrophysiology.

    PubMed

    Hayes, D L; Naccarelli, G V; Furman, S; Parsonnet, V

    1994-01-01

    NASPE proposes and supports the concept of a two-tracked training system in cardiac pacing. Track I training will properly train physicians for the prescription of pacemakers and the monitoring of pacemaker patients, and track II training will properly prepare physicians for the implantation of pacemakers. Regardless of specialty (cardiologist or surgeon) or training venue (cardiac pacing fellowship, cardiac electrophysiology and pacing fellowship, sabbatical or mentor sponsored training), it is recommended that these minimum standards be required for hospital credentialing. NASPE also supports the voluntary institution by training program directors of core pacing training in cardiovascular disease and cardiac electrophysiology fellowships. This core training does not in itself constitute proper track I or II training for physicians interested in adequately prescribing, monitoring, or implanting cardiac pacemakers. PMID:7511233

  4. Résultats fonctionnels de la chirurgie de la cataracte par phacoalternative avec implantation en chambre postérieure: à propos de 300 cas à Bobo Dioulasso (Burkina Faso)

    PubMed Central

    Diallo, Jean Wenceslas; Meda, Nonfounikoun; Ahnoux-Zabsonre, Ahgbatouhabéba; Yameogo, Claudette; Dolo, Mariam; Sanou, Jérôme; Daboue, Arsène

    2015-01-01

    La cataracte est la première cause de cécité curable dans le monde. Son traitement est chirurgical. Le but de notre travail a été d’évaluer les résultats de la phacoalternative ou la chirurgie de la cataracte à petite incision. Il s'est agi d'une étude transversale descriptive à collecte prospective allant du 1er janvier au 31 septembre 2014, chez des patients âgés d'au moins 40 ans. Les données socio-démographiques, l'acuité visuelle, l'astigmatisme et les complications ont été évalués. Nous avons inclus 300 yeux de 286 patients. L’âge moyen était de 66 ans (écart type 9,93) avec une prédominance masculine de 57,7%. Les co-morbidités étaient dominées par l'hypertension artérielle 30,33% des cas. L'acuité visuelle pré-opératoire était de moins de 1/20è dans 70, 7% des cas. En biométrie, la puissance moyenne était de 21,50 dioptries. L'implant posé a été adéquat dans 60%. Les principales complications per-opératoires étaient le chémosis post-anesthésie 4,67% et l'issue de vitrée moins de 2% des cas. Les complications post opératoires précoces ont été dominées par l’œdème de cornée 26,33%, et les complications tardives par la cataracte secondaire. L'astigmatisme induit était de 1, 12 dioptrie en moyenne (écart type 1,26). Sans correction, les résultats visuels étaient mauvais dans moins de 1%, limites dans 31%, et bons 68% suivants les normes de l'Organisation Mondiale de la Santé. La phacoalternative donne des résultats satisfaisants, avec peu de complications. L'amélioration du plateau technique et la disponibilité d'implants adéquats pourraient les améliorer. PMID:26140073

  5. Results of a phase II trial of transrectal ultrasound-guided permanent radioactive implantation of the prostate for definitive management of localized adenocarcinoma of the prostate (Radiation Therapy Oncology Group 98-05)

    SciTech Connect

    Lawton, Colleen A. . E-mail: clawton@radonc.mcw.edu; DeSilvio, Michelle; Lee, W. Robert; Gomella, Leonard; Grignon, David; Gillin, Michael; Morton, Gerard; Pisansky, Thomas; Sandler, Howard

    2007-01-01

    Purpose: To evaluate the effectiveness of transrectal ultrasound-guided permanent radioactive {sup 125}I implantation of the prostate for organ-confined adenocarcinoma of the prostate compared with historical data of prostatectomy and external beam radiotherapy within a cooperative group setting. Methods and Materials: Patients accrued to this study had histologically confirmed, locally confined, adenocarcinoma of the prostate with clinical Stage T1b, T1c, or T2a, no nodal or metastatic disease, prostate-specific antigen level of {<=}10 ng/mL, and Gleason score of {<=}6. All patients underwent transrectal ultrasound-guided radioactive {sup 125}I permanent seed implantation into the prostate. The prescribed dose was 145 Gy to the prostate planning target volume. Results: A total of 27 institutions accrued a total of 101 patients to this protocol, with no institution accruing >8 patients. Six patients were ineligible, leaving 95 properly entered as eligible in the study. The median follow-up was 5.3 years (range, 0.4-6.5 years). At 5 years, 5 patients had local failure, 1 had evidence of distant failure, and 6 (6%) had biochemical failure. The overall survival rate at 5 years was 96.7%. At last follow-up, no patient had died of prostate cancer or related toxicities. Eight patients had a maximal acute toxicity level of 3, and no patient had Grade 4 or 5 acute toxicity. During follow-up, 2 patients had maximal Grade 3 toxicity, both related to bladder issues, and no patient experienced Grade 4 or 5 toxicity. Conclusion: The results of this clinical protocol (a multi-institutional trial of brachytherapy for localized adenocarcinoma of the prostate) have demonstrated that this type of trial can be successfully completed through Radiation Therapy Oncology Group. Biochemical disease-free survival was comparable with other brachytherapy published series and with the results after surgery and external beam radiotherapy.

  6. A permanent breast seed implant as partial breast radiation therapy for early-stage patients: A comparison of palladium-103 and iodine-125 isotopes based on radiation safety considerations

    SciTech Connect

    Keller, Brian; Sankreacha, Raxa; Rakovitch, Eileen; O'Brien, Peter; Pignol, Jean-Philippe . E-mail: Jean-Philippe.Pignol@sw.ca

    2005-06-01

    Purpose: A permanent breast seed implant (PBSI) technique has been developed as a new form of partial adjuvant radiation therapy for early-stage breast cancer. This study compares iodine-125 ({sup 125}I) and palladium-103 ({sup 103}Pd) isotopes by examining the exposure and effective dose (ED) to a patient's partner.Methods and Materials: A low-energy survey meter was used to measure exposure rates as a function of bolus thickness placed over {sup 103}Pd or {sup 125}I seeds. A general mathematical expression for the initial exposure rate at 1 m (x{sub o,1m}) from the skin surface as a function of the implant size, R, and the distance between the skin surface and the implant, d, was derived. Also, a second general equation is proposed to calculate the ED to the patient's partner.Results: The initial exposure rate at 1 meter and the ED are calculated as follows: x{sub o,1m} = (3{alpha})/2R{sup 3}{center_dot}{beta}{sup 3} [e{sup -{beta}}{sup (2R+d)}({beta}R + 1) + e{sup -{beta}}{sup {center_dot}}{sup d}({beta}R - 1)], and ED = aR{sup b} {center_dot} [e{sup -c(2R+d)} {center_dot} (cR + 1) + e{sup -cd} -bar (cR - 1)]. For {sup 125}I, the parameters are: {alpha} = 0.154409, {beta} = 0.388460, a = 197, b = -0.95, and c = 0.38846. For {sup 103}Pd, they are: {alpha} = 0.06877, {beta} = 0.421098, a = 18.6, b -0.78, and c = 0.421098. For implant diameters varying from 2 to 6 cm and skin-to-implant distances varying from 0.7 to 4 cm, the ED is consistently below 2.6 mSv using the {sup 103}Pd isotope, but more than 5 mSv in many instances and possibly up to 20 mSv using {sup 125}I.Conclusions: PBSI using {sup 103}Pd seeds appears safe because the patient's partner ED is consistently below 5 mSv. The{sup 125}I isotope is not recommended for PBSI.

  7. Restoration of ankle movements with the ActiGait implantable drop foot stimulator: a safe and reliable treatment option for permanent central leg palsy.

    PubMed

    Martin, Klaus Daniel; Polanski, Witold Henryk; Schulz, Anne-Kathrin; Jöbges, Michael; Hoff, Hansjoerg; Schackert, Gabriele; Pinzer, Thomas; Sobottka, Stephan B

    2016-01-01

    OBJECT The ActiGait drop foot stimulator is a promising technique for restoration of lost ankle function by an implantable hybrid stimulation system. It allows ankle dorsiflexion by active peroneal nerve stimulation during the swing phase of gait. In this paper the authors report the outcome of the first prospective study on a large number of patients with stroke-related drop foot. METHODS Twenty-seven patients who experienced a stroke and with persisting spastic leg paresis received an implantable ActiGait drop foot stimulator for restoration of ankle movement after successful surface test stimulation. After 3 to 5 weeks, the stimulator was activated, and gait speed, gait endurance, and activation time of the system were evaluated and compared with preoperative gait tests. In addition, patient satisfaction was assessed using a questionnaire. RESULTS Postoperative gait speed significantly improved from 33.9 seconds per 20 meters to 17.9 seconds per 20 meters (p < 0.0001), gait endurance from 196 meters in 6 minutes to 401 meters in 6 minutes (p < 0.0001), and activation time from 20.5 seconds to 10.6 seconds on average (p < 0.0001). In 2 patients with nerve injury, surgical repositioning of the electrode cuff became necessary. One patient showed a delayed wound healing, and in another patient the system had to be removed because of a wound infection. Marked improvement in mobility, social participation, and quality of life was confirmed by 89% to 96% of patients. CONCLUSIONS The ActiGait implantable drop foot stimulator improves gait speed, endurance, and quality of life in patients with stroke-related drop foot. Regarding gait speed, the ActiGait system appears to be advantageous compared with foot orthosis or surface stimulation devices. Randomized trials with more patients and longer observation periods are needed to prove the long-term benefit of this device. PMID:26207599

  8. Small-Gauge Pars Plana Vitrectomy for the Management of Symptomatic Posterior Vitreous Detachment after Phacoemulsification and Multifocal Intraocular Lens Implantation: A Pilot Study from the Pan-American Collaborative Retina Study Group

    PubMed Central

    Navarro, Rodrigo M.; Machado, Leonardo M.; Maia, Ossires; Wu, Lihteh; Farah, Michel E.; Magalhaes, Octaviano; Arevalo, J. Fernando; Maia, Mauricio

    2015-01-01

    Purpose. To determine the efficacy of 23-gauge pars plana vitrectomy (PPV) for symptomatic posterior vitreous detachment (PVD) on visual acuity (VA) and quality after multifocal intraocular lenses (IOLs). Methods. In this prospective case series, patients who developed symptomatic PVD and were not satisfied with visual quality due to floaters and halos after multifocal IOL implantation underwent PPV. Examinations included LogMAR uncorrected visual acuity (UCVA), intraocular pressure, biomicroscopy, and indirect ophthalmoscopy at baseline and 1, 7, 30, and 180 days postoperatively. Ultrasonography and aberrometry were performed. The Visual Functioning Questionnaire 25 (VFQ-25) was administered preoperatively and at 30 days postoperatively. Both the postoperative UCVA and questionnaire results were compared to preoperative findings using the Wilcoxon test. Results. Sixteen eyes of 8 patients were included. VA significantly improved from 0.17 to 0.09 postoperatively (P = 0.017). All patients reported improvement of halos, glare, and floaters. VFQ-25 scores significantly improved in general vision (P = 0.023), near activities (P = 0.043), distance activities (P = 0.041), mental health (P = 0.011), role difficulties (P = 0.042), and driving (P = 0.016). Conclusion. PPV may increase UCVA and quality of vision in patients with bilateral multifocal IOLs and symptomatic PVD. Larger studies are advised. PMID:26504590

  9. Small-Gauge Pars Plana Vitrectomy for the Management of Symptomatic Posterior Vitreous Detachment after Phacoemulsification and Multifocal Intraocular Lens Implantation: A Pilot Study from the Pan-American Collaborative Retina Study Group.

    PubMed

    Navarro, Rodrigo M; Machado, Leonardo M; Maia, Ossires; Wu, Lihteh; Farah, Michel E; Magalhaes, Octaviano; Arevalo, J Fernando; Maia, Mauricio

    2015-01-01

    Purpose. To determine the efficacy of 23-gauge pars plana vitrectomy (PPV) for symptomatic posterior vitreous detachment (PVD) on visual acuity (VA) and quality after multifocal intraocular lenses (IOLs). Methods. In this prospective case series, patients who developed symptomatic PVD and were not satisfied with visual quality due to floaters and halos after multifocal IOL implantation underwent PPV. Examinations included LogMAR uncorrected visual acuity (UCVA), intraocular pressure, biomicroscopy, and indirect ophthalmoscopy at baseline and 1, 7, 30, and 180 days postoperatively. Ultrasonography and aberrometry were performed. The Visual Functioning Questionnaire 25 (VFQ-25) was administered preoperatively and at 30 days postoperatively. Both the postoperative UCVA and questionnaire results were compared to preoperative findings using the Wilcoxon test. Results. Sixteen eyes of 8 patients were included. VA significantly improved from 0.17 to 0.09 postoperatively (P = 0.017). All patients reported improvement of halos, glare, and floaters. VFQ-25 scores significantly improved in general vision (P = 0.023), near activities (P = 0.043), distance activities (P = 0.041), mental health (P = 0.011), role difficulties (P = 0.042), and driving (P = 0.016). Conclusion. PPV may increase UCVA and quality of vision in patients with bilateral multifocal IOLs and symptomatic PVD. Larger studies are advised. PMID:26504590

  10. Three-dimensional conformal external beam radiotherapy compared with permanent prostate implantation in low-risk prostate cancer based on endorectal magnetic resonance spectroscopy imaging and prostate-specific antigen level

    SciTech Connect

    Pickett, Barby . E-mail: pickett@radonc17.ucsf.edu; Kurhanewicz, John; Pouliot, Jean; Weinberg, Vivian; Shinohara, Katsuto; Coakley, Fergus; Roach, Mack

    2006-05-01

    Purpose: To evaluate the metabolic response by comparing the time to resolution of spectroscopic abnormalities (TRSA) and the time to prostate-specific antigen level in low-risk prostate cancer patients after treatment with three-dimensional conformal external beam radiotherapy (3D-CRT) compared with permanent prostate implantation (PPI). Recent studies have suggested that the treatment of low-risk prostate cancer yields similar results for patients treated with 3D-CRT or PPI. Methods and Materials: A total of 50 patients, 25 in each group, who had been treated with 3D-CRT or PPI, had undergone endorectal magnetic resonance spectroscopy imaging before and/or at varying times after therapy. The 3D-CRT patients had received radiation doses of {>=}72 Gy compared with 144 Gy for the PPI patients. The spectra from all usable voxels were examined for detectable levels of metabolic signal, and the percentages of atrophic and cancerous voxels were tabulated. Results: The median time to resolution of the spectroscopic abnormalities was 32.2 and 24.8 months and the time to the nadir prostate-specific antigen level was 52.4 and 38.0 months for the 3D-CRT and PPI patients, respectively. Of the 3D-CRT patients, 92% achieved negative endorectal magnetic resonance spectroscopy imaging findings, with 40% having complete metabolic atrophy. All 25 PPI patients had negative endorectal magnetic resonance spectroscopy imaging findings, with 60% achieving complete metabolic atrophy. Conclusion: The results of this study suggest that metabolic and biochemical responses of the prostate are more pronounced after PPI. Our results have not proved PPI is more effective at curing prostate cancer, but they have demonstrated that it may be more effective at destroying prostate metabolism.

  11. Equivalent Biochemical Control and Improved Prostate-Specific Antigen Nadir After Permanent Prostate Seed Implant Brachytherapy Versus High-Dose Three-Dimensional Conformal Radiotherapy and High-Dose Conformal Proton Beam Radiotherapy Boost

    SciTech Connect

    Jabbari, Siavash; Weinberg, Vivian K.; Shinohara, Katsuto; Speight, Joycelyn L.; Gottschalk, Alexander R.; Hsu, I.-C.; Pickett, Barby; McLaughlin, Patrick W.; Sandler, Howard M.; Roach, Mack

    2010-01-15

    Purpose: Permanent prostate implant brachytherapy (PPI), three-dimensional conformal radiotherapy (3D-CRT), and conformal proton beam radiotherapy (CPBRT) are used in the treatment of localized prostate cancer, although no head-to-head trials have compared these modalities. We studied the biochemical control (biochemical no evidence of disease [bNED]) and prostate-specific antigen (PSA) nadir achieved with contemporary PPI, and evaluated it against 3D-CRT and CPBRT. Patients and Methods: A total of 249 patients were treated with PPI at the University of California, San Francisco, and the outcomes were compared with those from a 3D-CRT cohort and the published results of a high-dose CPBRT boost (CPBRTB) trial. For each comparison, subsets of the PPI cohort were selected with patient and disease criteria similar to those of the reference group. Results: With a median follow-up of 5.3 years, the bNED rate at 5 and 7 years achieved with PPI was 92% and 86%, respectively, using the American Society for Therapeutic Radiology and Oncology (ASTRO) definition, and 93% using the PSA nadir plus 2 ng/mL definition. Using the ASTRO definition, a 5-year bNED rate of 78% was achieved for the 3D-CRT patients compared with 94% for a comparable PPI subset and 93% vs. 92%, respectively, using the PSA nadir plus 2 ng/mL definition. The median PSA nadir for patients treated with PPI and 3D-CRT was 0.10 and 0.40 ng/mL, respectively (p < .0001). For the CPBRT comparison, the 5-year bNED rate after a CPBRTB was 91% using the ASTRO definition vs. 93% for a similar group of PPI patients. A greater proportion of PPI patients achieved a lower PSA nadir compared with those achieved in the CPBRTB trial (PSA nadir <=0.5 ng/mL, 91% vs. 59%, respectively). Conclusion: We have demonstrated excellent outcomes in low- to intermediate-risk patients treated with PPI, suggesting at least equivalent 5-year bNED rates and a greater proportion of men achieving lower PSA nadirs compared with 3D-CRT or

  12. [Permanent percutaneous electric connection. General principles].

    PubMed

    Sabin, P; Labbé, D; Levillain, D; Cazin, L; Caston, J

    1997-01-01

    The Swedes for more than twenty years, and the Germans for over five years have been able to maintain inert or active prostheses with permanent percutaneous connections, thanks to the dependable and proven material and techniques of extraoral implants. The significant improvement extra-oral implants have brought about is not only in a new therapeutic approach to the treatment of important facial defects or transmission deafness; it is also because for some twenty old years now, the few millimeter wide cylinders of Titanium, the affixed on the implants, have crossed the cutaneous barrier for extended periods without complications. The percutaneous abutment thus creates a permanent communication between the interior and the exterior of the organism. If the abutment, instead of simply carrying a Maxillo-Facial Prosthesis or an auditive prosthesis, is modified by placing an electric conductor inside it, the simple "percutaneous peg" will turn out to be, in a way, a "percutaneous electric plug". By adapting classic "mechanical" abutments and implants, authors have created a Permanent Percutaneous Electric Connection (PPEC) which has been successfully experimented on rabbits to record EEG. Clinical applications on humans would make it possible either to receive "bio-electrical information" coming from within the organism, or to send electrical energy into the organism. This last application opens vast perspectives of improvement both in diagnosis and therapy in many fields. PMID:9687654

  13. Pediatric Cochlear Implantation: Why Do Children Receive Implants Late?

    PubMed Central

    Ham, Julia; Whittingham, JoAnne

    2015-01-01

    Objectives: Early cochlear implantation has been widely promoted for children who derive inadequate benefit from conventional acoustic amplification. Universal newborn hearing screening has led to earlier identification and intervention, including cochlear implantation in much of the world. The purpose of this study was to examine age and time to cochlear implantation and to understand the factors that affected late cochlear implantation in children who received cochlear implants. Design: In this population-based study, data were examined for all children who underwent cochlear implant surgery in one region of Canada from 2002 to 2013. Clinical characteristics were collected prospectively as part of a larger project examining outcomes from newborn hearing screening. For this study, audiologic details including age and severity of hearing loss at diagnosis, age at cochlear implant candidacy, and age at cochlear implantation were documented. Additional detailed medical chart information was extracted to identify the factors associated with late implantation for children who received cochlear implants more than 12 months after confirmation of hearing loss. Results: The median age of diagnosis of permanent hearing loss for 187 children was 12.6 (interquartile range: 5.5, 21.7) months, and the age of cochlear implantation over the 12-year period was highly variable with a median age of 36.2 (interquartile range: 21.4, 71.3) months. A total of 118 (63.1%) received their first implant more than 12 months after confirmation of hearing loss. Detailed analysis of clinical profiles for these 118 children revealed that late implantation could be accounted for primarily by progressive hearing loss (52.5%), complex medical conditions (16.9%), family indecision (9.3%), geographical location (5.9%), and other miscellaneous known (6.8%) and unknown factors (8.5%). Conclusions: This study confirms that despite the trend toward earlier implantation, a substantial number of children

  14. Rare earth permanent magnets

    SciTech Connect

    Major-Sosias, M.A.

    1993-10-01

    Permanent magnets were discovered centuries ago from what was known as {open_quotes}lodestone{close_quotes}, a rock containing large quantities of the iron-bearing mineral magnetite (Fe{sub 3}O{sub 4}). The compass was the first technological use for permanent magnetic materials; it was used extensively for navigational purposes by the fifteenth century. During the twentieth century, as new applications for permanent magnets were developed, interest and research in permanent magnetic materials soared. Four major types of permanent magnets have been developed since the turn of the century.

  15. Benefits and Risks of Cochlear Implants

    MedlinePlus

    ... in aircraft interact in unpredictable ways with other computer systems Will have to be careful of static electricity. Static electricity may temporarily or permanently damage a cochlear implant. It ... computer monitors, or synthetic fabric. For more details regarding ...

  16. Implantable Heart Aid

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Medrad utilized NASA's Apollo technology to develop a new device called the AID implantable automatic pulse generator which monitors the heart continuously, recognizes the onset of ventricular fibrillation and delivers a corrective electrical shock. AID pulse generator is, in effect, a miniaturized version of the defibrillator used by emergency squads and hospitals to restore rhythmic heartbeat after fibrillation, but has the unique advantage of being permanently available to the patient at risk. Once implanted, it needs no specially trained personnel or additional equipment. AID system consists of a microcomputer, a power source and two electrodes which sense heart activity.

  17. Pars Injuries in Athletes.

    PubMed

    Oren, Jonathan H; Gallina, Jason M

    2016-03-01

    Pars injuries are common causes of low back pain in adolescent athletes. Workup traditionally has included lumbar radiographs with oblique views and single-photon emission computed tomography (SPECT). However, recent literature has demonstrated the accuracy of MRI as a diagnostic modality. Acute injuries may be amenable to bracing with the goal of a healed lesion. Most cases of spondylolysis will result in asymptomatic non-union, though pars repair is an option for symptomatic pars defects without spondylolisthesis. PMID:26977552

  18. Cochlear Implants.

    ERIC Educational Resources Information Center

    Clark, Catherine; Scott, Larry

    This brochure explains what a cochlear implant is, lists the types of individuals with deafness who may be helped by a cochlear implant, describes the process of evaluating people for cochlear implants, discusses the surgical process for implanting the aid, traces the path of sound through the cochlear implant to the brain, notes the costs of…

  19. Fiber implantation for pattern baldness.

    PubMed

    Hanke, C W; Bergfeld, W F

    1979-01-12

    Examination of 20 patients who had fiber implantation for the treatment of pattern baldness showed that nearly all the fibers had fallen out by ten weeks. Complications observed were facial swelling, infection, foreign-body granulomas, scarring, and permanent hair loss. Scanning electron microscopy identified the fibers as modacrylic fibers. The complications, high monetary cost, and ultimate futility of fiber implantation make it an unacceptable procedure. PMID:364078

  20. [Permanent vascular access for haemodialysis].

    PubMed

    Manafov, E N; Batrashov, V A; Sergeev, O G; Yudaev, S S

    2015-01-01

    The presence of a permanent vascular access (PVA) is the pledge of successful treatment of patients being on chronic haemodialysis (CD). Creation and maintenance of a functioning PVA is the priority task of vascular and endovascular surgeons, nephrologists and specialists of haemodialysis departments. According to the KDOQI guidelines, the most preferable type of PVA is a native arteriovenous fistula (AVF). As an alternative it is possible to use a synthetic prosthesis for creating an arteriovenous shunt (AVS) or implantation of a central venous catheter (CVC). Various complications of vascular accesses leading to their loss create the necessity of forming just another PVA, thus negatively influencing the life span and quality of life of this cohort of patients. Improving surgical technique and approaches to treatment, as well as carrying out dynamic monitoring of the condition of the created PVA make it possible to considerably decrease the incidence rate of such complications and to improve the quality of medical care rendered. PMID:26451410

  1. Permanent contraception for women.

    PubMed

    Micks, Elizabeth A; Jensen, Jeffrey T

    2015-11-01

    Permanent methods of contraception are used by an estimated 220 million couples worldwide, and are often selected due to convenience, ease of use and lack of side effects. A variety of tubal occlusion techniques are available for female permanent contraception, and procedures can be performed using a transcervical or transabdominal approach. This article reviews currently available techniques for female permanent contraception and discusses considerations when helping patients choose a contraceptive method and tubal occlusion technique. PMID:26626698

  2. Nonconsecutive Pars Interarticularis Defects.

    PubMed

    Elgafy, Hossein; Hart, Ryan C; Tanios, Mina

    2015-12-01

    Lumbar spondylolysis is a well-recognized condition occurring in adolescents because of repetitive overuse in sports. Nonconsecutive spondylolysis involving the lumbar spine is rare. In contrast to single-level pars defects that respond well to conservative treatment, there is no consensus about the management of multiple-level pars fractures; a few reports indicated that conservative management is successful, and the majority acknowledged that surgery is often required. The current study presents a rare case of pars fracture involving nonconsecutive segments and discusses the management options. In this case report, we review the patient's history, clinical examination, radiologic findings, and management, as well as the relevant literature. An 18-year-old man presented to the clinic with worsening lower back pain related to nonconsecutive pars fractures at L2 and L5. After 6 months of conservative management, diagnostic computed tomography-guided pars block was used to localize the symptomatic level at L2, which was treated surgically; the L5 asymptomatic pars fracture did not require surgery. At the last follow-up 2 years after surgery, the patient was playing baseball and basketball, and denied any back pain. This article reports a case of rare nonconsecutive pars fractures. Conservative management for at least 6 months is recommended. Successful management depends on the choice of appropriate treatment for each level. Single-photon emission computed tomography scan, and computed tomography-guided pars block are valuable preoperative tools to identify the symptomatic level in such a case. PMID:26665257

  3. Oscillating Permanent Magnets.

    ERIC Educational Resources Information Center

    Michaelis, M. M.; Haines, C. M.

    1989-01-01

    Describes several ways to partially levitate permanent magnets. Computes field line geometries and oscillation frequencies. Provides several diagrams illustrating the mechanism of the oscillation. (YP)

  4. Abdominal wall reconstruction with implantable meshes.

    PubMed

    Masden, Derek; Felder, John M; Iorio, Matthew L; Bhanot, Parag; Attinger, Christopher E

    2011-01-01

    Abdominal wall defects present a difficult problem for the reconstructive surgeon. Over the years, numerous implantable materials have becomes available to aid the surgeon in recreating the abdominal wall. This spectrum of implants includes permanent synthetic meshes, absorbable meshes, composite meshes and biomaterials. This review includes the pros and cons for the commercially available abdominal wall implants as well as a review of the literature regarding outcomes for each material. This review will provide the surgeon with current evidence-based information on implantable abdominal materials to be able to make a more informed decision about which implant to use. PMID:21663579

  5. Permanent magnet assembly

    DOEpatents

    Chell, Jeremy; Zimm, Carl B.

    2006-12-12

    A permanent magnet assembly is disclosed that is adapted to provide a magnetic field across an arc-shaped gap. Such a permanent magnet assembly can be used, for example, to provide a time-varying magnetic field to an annular region for use in a magnetic refrigerator.

  6. Par Pond water balance

    SciTech Connect

    Hiergesell, R.A.; Dixon, K.L.

    1996-06-01

    A water budget for the Par Pond hydrologic system was established in order to estimate the rate of groundwater influx to Par Pond. This estimate will be used in modeling exercises to predict Par Pond reservoir elevation and spillway discharge in the scenario where Savannah River water is no longer pumped and discharged into Par Pond. The principal of conservation of mass was used to develop the water budget, where water inflow was set equal to water outflow. Components of the water budget were identified, and the flux associated with each was determined. The water budget was considered balanced when inflow and outflow summed to zero. The results of this study suggest that Par Pond gains water from the groundwater system in the upper reaches of the reservoir, but looses water to the groundwater system near the dam. The rate of flux of groundwater from the water table aquifer into Par Pond was determined to be 13 cfs. The rate of flux from Par Pond to the water table aquifer near the dam was determined to be 7 cfs.

  7. Serving Deaf Students Who Have Cochlear Implants. PEPNet Tipsheet

    ERIC Educational Resources Information Center

    Searls, J. Matt, Comp.

    2010-01-01

    Cochlear implants (CIs) are complex electronic devices surgically implanted under the skin behind the ear. These devices utilize electrodes placed in the inner ear (the cochlea) to stimulate the auditory nerve of individuals with significant permanent hearing loss. Cochlear implants may not be suitable for everyone. They are designed to provide…

  8. uPAR

    PubMed Central

    Uhrin, Pavel; Breuss, Johannes M.

    2013-01-01

    Vascular endothelial growth factor (VEGF)-initiated angiogenesis requires both coordinated proteolytic degradation of extracellular matrix provided by the urokinase plasminogen activator/urokinase receptor (uPA/uPAR) system and regulation of cell-migration provided by integrin–matrix interaction. Previously we have shown that stimulation of pericellular proteolysis induced by VEGF occurs via the VEGF receptor-2 leading to redistribution of uPAR to focal adhesions at the leading edge of endothelial cells. In our recent work published in Cardiovascular Research, we investigated the mechanisms underlying the uPAR-dependent modulation of VEGF-induced endothelial migration. By applying a micropatterning technique we described that VEGF stimulation results in complex formation between uPAR and α5β1-integrin on the cell surface. The subsequent internalization of this complex, important for receptor redistribution, was demonstrated by flow-cytometry and immunohistochemistry. Targeting of the interaction site between uPAR and α5β1 impairs receptor internalization and leads to the inhibition of endothelial cell migration in vitro and in an angiogenesis model in vivo. This proof-of-principle that the interface of uPAR and α5β1-integrin may represent a promising site to therapeutically target tumor angiogenesis raises hope for the development of an anti-angiogenic approach that is limited to only the mobilizing effect of VEGF to endothelial cells, and does not interfere with the inarguably positive effect of VEGF as survival factor. PMID:23076213

  9. Cochlear Implants

    MedlinePlus

    ... electrodes are inserted. The electronic device at the base of the electrode array is then placed under ... FDA approval for implants The Food and Drug Administration (FDA) regulates cochlear implant devices for both adults ...

  10. Goserelin Implant

    MedlinePlus

    Goserelin implant is used in combination with radiation therapy and other medications to treat localized prostate cancer and is ... treatment of abnormal bleeding of the uterus. Goserelin implant is in a class of medications called gonadotropin- ...

  11. Cochlear Implants

    MedlinePlus

    A cochlear implant is a small, complex electronic device that can help to provide a sense of sound. People who are ... of-hearing can get help from them. The implant consists of two parts. One part sits on ...

  12. Carmustine Implant

    MedlinePlus

    Carmustine implant is used along with surgery and sometimes radiation therapy to treat malignant glioma (a certain type of ... Carmustine implant comes as a small wafer that is placed in the brain by a doctor during surgery to ...

  13. Breast Implants

    MedlinePlus

    ... Updated Safety Information (Consumer Article) FDA Provides Updated Safety Data on Silicone Gel-Filled Breast Implants (Press Announcement) [ARCHIVED] Breast Implant Guidance for Industry (2006) Post Approval Studies Webpage Freedom of Information ...

  14. Cochlear implant

    MedlinePlus

    ... antenna. This part of the implant receives the sound, converts the sound into an electrical signal, and sends it to ... implants allow deaf people to receive and process sounds and speech. However, these devices do not restore ...

  15. Permanent cardiac pacing in pediatric patients.

    PubMed

    Lotfy, Wael; Hegazy, Ranya; AbdElAziz, Osama; Sobhy, Rodina; Hasanein, Hossam; Shaltout, Fawzan

    2013-02-01

    Pediatric pacemaker (PM) implants comprise less than 1 % of all PM implants. This study aimed to investigate permanent cardiac pacing among the pediatric population, identifying different indications and complications of pediatric cardiac pacing, especially focusing on the effect of the pacing sites, the PM lead type, and the indications for pacing. The current work is a cross-sectional study of 103 procedures for permanent PM insertion in pediatric patients between January 2001 and December 2010. The patients were followed up 1, 3, and 6 months after implantation, then every 6 months or as needed. Evaluation included routine clinical examination, electrocardiography, chest X-ray, echocardiography, and a full analysis of the pacing system measurements. The ages of the patients ranged from 0.09 to 12 years (median, 2.3 years). The most common indication for pacing was postoperative complete heart bock, noted in 54 patients (52.4 %). Transvenous endocardial PM insertion was performed in 92 procedures (89.3 %), whereas transthoracic epicardial insertion was performed in 11 procedures (10.7 %). The most common site of pacing was the right ventricular apex (n = 64, 62 %), followed by the right ventricular outflow tract (n = 25, 24.3 %). Transthoracic epicardial PM insertion was associated with a significantly higher percentage and greater severity of complications. In this study, 65 % of the patients with left ventricle (LV) dilation before pacing showed a significant improvement in LV dimensions and function after pacing. This was noted only in those with endocardially inserted PM leads in both the congenital and the postoperative groups regardless of the pacing site. Endocardial PM insertion in children is a safe procedure with fewer complications and a lower ventricular threshold than the epicardial route. Permanent single-chamber right ventricle pacing is safe and can lead to significant improvement in LV function and dimensions. However, long-term follow

  16. THE MEASURES PAR PROJECT

    NASA Astrophysics Data System (ADS)

    Frouin, R. J.; Franz, B.

    2009-12-01

    The solar energy available for photosynthesis, known as PAR, controls the growth of phytoplankton and, therefore, regulates the composition and evolution of marine ecosystems. Knowing the spatial and temporal distribution of PAR over the oceans is critical to understanding biogeochemical cycles of carbon, nutrients, and oxygen, and to address important climate and global change issues such as the fate of anthropogenic atmospheric carbon dioxide. In view of this, a 12-year time series of PAR at the ocean surface, starting in September 1997, is being produced by the NASA Ocean Biology Processing Group from SeaWiFS, MODIS-Terra, and MODIS-Aqua data. The product covers the global oceans, with a spatial resolution of about 9.3x9.3 km (equal area grid) and a temporal resolution of one day. PAR is computed as the difference between the 400-700 nm solar flux incident on the top of the atmosphere (known) and reflected back to space by the atmosphere and surface (derived from satellite radiance), taking into account atmospheric absorption (modeled). Knowledge of pixel composition is not required, eliminating the need for cloud screening and arbitrary assumptions about sub-pixel cloudiness. Combining data from satellite sensors with different equatorial crossing times accounts for the diurnal variability of clouds and, therefore, increases accuracy on a daily time scale. The processing system, including routine check of accuracy and control of quality, is designed to operate during the entire lifetime of SeaWiFS and MODIS, and to accommodate future sensors with ocean-color capabilities. Maps of daily, weekly, and monthly PAR obtained from individual sensors are presented, as well as merged products. Accuracy is quantified in comparisons with other satellite estimates, the National Centers for Environmental Prediction reanalysis product, and in-situ measurements from fixed buoys and platforms. The good statistical performance makes the satellite PAR product suitable for large

  17. Short-Term and Long-Term Effects of Orthopedic Biodegradable Implants

    PubMed Central

    Amini, Ami R.; Wallace, James S.; Nukavarapu, Syam P.

    2012-01-01

    Presently, orthopedic and oral/maxillofacial implants represent a combined $2.8 billion market, a figure expected to experience significant and continued growth. Although traditional permanent implants have been proved clinically efficacious, they are also associated with several drawbacks, including secondary revision and removal surgeries. Non-permanent, biodegradable implants offer a promising alternative for patients, as they provide temporary support and degrade at a rate matching tissue formation, and thus, eliminate the need for secondary surgeries. These implants have been in clinical use for nearly 25 years, competing directly with, or maybe even exceeding, the performance of permanent implants. The initial implantation of biodegradable materials, as with permanent materials, mounts an acute host inflammatory response. Over time, the implant degradation profile and possible degradation product toxicity mediate long-term biodegradable implant-induced inflammation. However, unlike permanent implants, this inflammation is likely to cease once the material disappears. Implant-mediated inflammation is a critical determinant for implant success. Thus, for the development of a proactive biodegradable implant that has the ability to promote optimal bone regeneration and minimal detrimental inflammation, a thorough understanding of short- and long-term inflammatory events is required. Here, we discuss an array of biodegradable orthopedic implants, their associated short- and long- term inflammatory effects, and methods to mediate these inflammatory events. PMID:22043969

  18. Permanent versus disconnectable FPSOs

    NASA Astrophysics Data System (ADS)

    Luo, Yong; Wang, Hong-Wei

    2009-06-01

    Floating production storage and offloading (FPSO) vessels offer a cost-effective field development solution, especially in deepwater areas lacking an adequate pipeline network. Most FPSOs are permanently moored, i.e. the complete system is designed to withstand any kind of extreme environment at the field location. FPSOs that can be quickly disconnected from their moorings and risers have also been designed and deployed. The key feature of this type of disconnectable FPSO is that it can be disconnect and so avoid dangerous environmental conditions such as icebergs, hurricanes in the Gulf of Mexico and typhoons in the South China Sea. In this paper, the concept of disconnectable FPSOs for deepwater field development is presented. Key technologies and their engineering analyses are highlighted. The merits and demerits of disconnectable vs permanent FPSOs are then evaluated. The paper concludes that both permanent and disconnectable FPSOs are versatile floating systems and their selection depends on safety, technological, cost and operational considerations.

  19. Alkaline "Permanent" Paper.

    ERIC Educational Resources Information Center

    Pacey, Antony

    1991-01-01

    Discussion of paper manufacturing processes and their effects on library materials focuses on the promotion of alkaline "permanent" paper, with less acid, by Canadian library preservation specialists. Standards for paper acidity are explained; advantages of alkaline paper are described, including decreased manufacturing costs; and recyclability is…

  20. La pelade par plaques

    PubMed Central

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre l’épidémiologie, la pathogenèse, l’histologie et l’approche clinique au diagnostic de la pelade par plaques. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant la pathogenèse, le diagnostic et le pronostic de la pelade par plaques. Message principal La pelade par plaques est une forme de perte pileuse auto-immune dont la prévalence durant une vie est d’environ 2 %. Des antécédents personnels ou familiaux de troubles auto-immuns concomitants, comme le vitiligo ou une maladie de la thyroïde, peuvent être observés dans un petit sous-groupe de patients. Le diagnostic peut souvent être posé de manière clinique en se fondant sur la perte de cheveux non cicatricielle et circulaire caractéristique, accompagnée de cheveux en « point d’exclamation » en périphérie chez ceux dont le problème en est aux premiers stades. Le diagnostic des cas plus complexes ou des présentations inhabituelles peut être facilité par une biopsie et un examen histologique. Le pronostic varie largement et de mauvais résultats sont associés à une apparition à un âge précoce, une perte importante, la variante ophiasis, des changements aux ongles, des antécédents familiaux ou des troubles auto-immuns concomitants. Conclusion La pelade par plaques est une forme auto-immune de perte de cheveux périodiquement observée en soins primaires. Les médecins de famille sont bien placés pour identifier la pelade par plaques, déterminer la gravité de la maladie et poser le diagnostic différentiel approprié. De plus, ils sont en mesure de renseigner leurs patients à propos de l’évolution clinique de la maladie ainsi que du pronostic général selon le sous-type de patients.

  1. Implantable Microimagers

    PubMed Central

    Ng, David C.; Tokuda, Takashi; Shiosaka, Sadao; Tano, Yasuo; Ohta, Jun

    2008-01-01

    Implantable devices such as cardiac pacemakers, drug-delivery systems, and defibrillators have had a tremendous impact on the quality of live for many disabled people. To date, many devices have been developed for implantation into various parts of the human body. In this paper, we focus on devices implanted in the head. In particular, we describe the technologies necessary to create implantable microimagers. Design, fabrication, and implementation issues are discussed vis-à-vis two examples of implantable microimagers; the retinal prosthesis and in vivo neuro-microimager. Testing of these devices in animals verify the use of the microimagers in the implanted state. We believe that further advancement of these devices will lead to the development of a new method for medical and scientific applications.

  2. High Productivity Implantation ''PARTIAL IMPLANT''

    SciTech Connect

    Hino, Masayoshi; Miyamoto, Naoki; Sakai, Shigeki; Matsumoto, Takao

    2008-11-03

    The patterned ion implantation 'PARTIAL IMPLANT' has been developed as a productivity improvement tool. The Partial Implant can form several different ion dose areas on the wafer surface by controlling the speed of wafer moving and the stepwise rotation of twist axis. The Partial Implant system contains two implant methods. One method is 'DIVIDE PARTIAL IMPLANT', that is aimed at reducing the consumption of the wafer. The Divide Partial Implant evenly divides dose area on one wafer surface into two or three different dose part. Any dose can be selected in each area. So the consumption of the wafer for experimental implantation can be reduced. The second method is 'RING PARTIAL IMPLANT' that is aimed at improving yield by correcting electrical characteristic of devices. The Ring Partial Implant can form concentric ion dose areas. The dose of wafer external area can be selected to be within plus or minus 30% of dose of wafer central area. So the electrical characteristic of devices can be corrected by controlling dose at edge side on the wafer.

  3. Variable Permanent Magnet Quadrupole

    SciTech Connect

    Mihara, T.; Iwashita, Y.; Kumada, M.; Spencer, C.M.; /SLAC

    2007-05-23

    A permanent magnet quadrupole (PMQ) is one of the candidates for the final focus lens in a linear collider. An over 120 T/m strong variable permanent magnet quadrupole is achieved by the introduction of saturated iron and a 'double ring structure'. A fabricated PMQ achieved 24 T integrated gradient with 20 mm bore diameter, 100 mm magnet diameter and 20 cm pole length. The strength of the PMQ is adjustable in 1.4 T steps, due to its 'double ring structure': the PMQ is split into two nested rings; the outer ring is sliced along the beam line into four parts and is rotated to change the strength. This paper describes the variable PMQ from fabrication to recent adjustments.

  4. Permanent Peripheral Neuropathy

    PubMed Central

    Higgins, Elizabeth

    2014-01-01

    The health risks and side effects of fluoroquinolone use include the risk of tendon rupture and myasthenia gravis exacerbation, and on August 15, 2013, the Food and Drug Administration updated its warning to include the risk of permanent peripheral neuropathy. We present a case of fluoroquinolone-induced peripheral neuropathy in a patient treated for clinically diagnosed urinary tract infection with ciprofloxacin antibiotic. PMID:26425618

  5. Permanent magnet design methodology

    NASA Technical Reports Server (NTRS)

    Leupold, Herbert A.

    1991-01-01

    Design techniques developed for the exploitation of high energy magnetically rigid materials such as Sm-Co and Nd-Fe-B have resulted in a revolution in kind rather than in degree in the design of a variety of electron guidance structures for ballistic and aerospace applications. Salient examples are listed. Several prototype models were developed. These structures are discussed in some detail: permanent magnet solenoids, transverse field sources, periodic structures, and very high field structures.

  6. La pelade par plaques

    PubMed Central

    Spano, Frank; Donovan, Jeff C.

    2015-01-01

    Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre les schémas thérapeutiques et les résultats des traitements pour la pelade par plaques, de même que les aider à identifier les patients pour qui une demande de consultation en dermatologie pourrait s’imposer. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant le traitement de la pelade par plaques. Message principal La pelade par plaques est une forme auto-immune de perte pileuse qui touche à la fois les enfants et les adultes. Même s’il n’y a pas de mortalité associée à la maladie, la morbidité découlant des effets psychologiques de la perte des cheveux peut être dévastatrice. Lorsque la pelade par plaques et le sous-type de la maladie sont identifiés, un schéma thérapeutique approprié peut être amorcé pour aider à arrêter la chute des cheveux et possiblement faire commencer la repousse. Les traitements de première intention sont la triamcinolone intralésionnelle avec des corticostéroïdes topiques ou du minoxidil ou les 2. Les médecins de famille peuvent prescrire ces traitements en toute sécurité et amorcer ces thérapies. Les cas plus avancés ou réfractaires pourraient avoir besoin de diphénylcyclopropénone topique ou d’anthraline topique. On peut traiter la perte de cils avec des analogues de la prostaglandine. Les personnes ayant subi une perte de cheveux abondante peuvent recourir à des options de camouflage ou à des prothèses capillaires. Il est important de surveiller les troubles psychiatriques en raison des effets psychologiques profonds de la perte de cheveux. Conclusion Les médecins de famille verront de nombreux patients qui perdent leurs cheveux. La reconnaissance de la pelade par plaques et la compréhension du processus pathologique sous-jacent permettent d’amorcer un schéma thérapeutique approprié. Les cas plus graves ou r

  7. [Implant allergies].

    PubMed

    Thomas, P; Thomsen, M

    2010-03-01

    An increasing number of patients receive and benefit from osteosynthesis materials or artificial joint replacement. The most common complications are mechanical problems or infection. Metals like nickel, chromium and cobalt as well as bone cement components like acrylates and gentamicin are potential contact allergens which can cause intolerance reactions to implants. Eczema, delayed wound/bone healing, recurrent effusions, pain and implant loosening all have been described as manifestation of implant allergy. In contrast to the high incidence of cutaneous metal allergy, allergies associated with implants are rare. Diagnosis of metal implant allergy is still difficult. Thus differential diagnoses--in particular infection--have to be excluded and a combined approach of allergologic diagnostics by patch test and histopathology of peri-implant tissue is recommended. It is still unknown which conditions induce allergic sensitization to implants or trigger peri-implant allergic reactions in the case of preexisting cutaneous metal allergy. Despite the risk of developing complications being unclear, titanium based osteosynthesis materials are recommended for metal allergic patients and the use of metal-metal couplings in arthroplasty is not recommended for such patients. If the regular CoCr-polyethylene articulation is employed, the patient should give informed written consent. PMID:20204719

  8. Lensectomy using a bimanual microincision cataract surgery technique during pars plana vitrectomy.

    PubMed

    Byeon, Suk Ho; Kwon, Oh W

    2009-01-01

    Lens extraction during vitrectomy is sometimes necessary to obtain an adequate view of the retina. Currently, phacoemulsification through a clear corneal incision with implantation of a foldable intraocular lens has become the preferred technique for cataract extraction during pars plana vitrectomy. The authors described the technique of lensectomy using a bimanual microincisional cataract surgery technique during pars plana vitrectomy and insertion of the intraocular lens at the end of surgery, which has several advantages over conventional coaxial phacoemulsification procedures. PMID:19205506

  9. Liquids with permanent porosity.

    PubMed

    Giri, Nicola; Del Pópolo, Mario G; Melaugh, Gavin; Greenaway, Rebecca L; Rätzke, Klaus; Koschine, Tönjes; Pison, Laure; Gomes, Margarida F Costa; Cooper, Andrew I; James, Stuart L

    2015-11-12

    Porous solids such as zeolites and metal-organic frameworks are useful in molecular separation and in catalysis, but their solid nature can impose limitations. For example, liquid solvents, rather than porous solids, are the most mature technology for post-combustion capture of carbon dioxide because liquid circulation systems are more easily retrofitted to existing plants. Solid porous adsorbents offer major benefits, such as lower energy penalties in adsorption-desorption cycles, but they are difficult to implement in conventional flow processes. Materials that combine the properties of fluidity and permanent porosity could therefore offer technological advantages, but permanent porosity is not associated with conventional liquids. Here we report free-flowing liquids whose bulk properties are determined by their permanent porosity. To achieve this, we designed cage molecules that provide a well-defined pore space and that are highly soluble in solvents whose molecules are too large to enter the pores. The concentration of unoccupied cages can thus be around 500 times greater than in other molecular solutions that contain cavities, resulting in a marked change in bulk properties, such as an eightfold increase in the solubility of methane gas. Our results provide the basis for development of a new class of functional porous materials for chemical processes, and we present a one-step, multigram scale-up route for highly soluble 'scrambled' porous cages prepared from a mixture of commercially available reagents. The unifying design principle for these materials is the avoidance of functional groups that can penetrate into the molecular cage cavities. PMID:26560299

  10. Liquids with permanent porosity

    NASA Astrophysics Data System (ADS)

    Giri, Nicola; Del Pópolo, Mario G.; Melaugh, Gavin; Greenaway, Rebecca L.; Rätzke, Klaus; Koschine, Tönjes; Pison, Laure; Gomes, Margarida F. Costa; Cooper, Andrew I.; James, Stuart L.

    2015-11-01

    Porous solids such as zeolites and metal-organic frameworks are useful in molecular separation and in catalysis, but their solid nature can impose limitations. For example, liquid solvents, rather than porous solids, are the most mature technology for post-combustion capture of carbon dioxide because liquid circulation systems are more easily retrofitted to existing plants. Solid porous adsorbents offer major benefits, such as lower energy penalties in adsorption-desorption cycles, but they are difficult to implement in conventional flow processes. Materials that combine the properties of fluidity and permanent porosity could therefore offer technological advantages, but permanent porosity is not associated with conventional liquids. Here we report free-flowing liquids whose bulk properties are determined by their permanent porosity. To achieve this, we designed cage molecules that provide a well-defined pore space and that are highly soluble in solvents whose molecules are too large to enter the pores. The concentration of unoccupied cages can thus be around 500 times greater than in other molecular solutions that contain cavities, resulting in a marked change in bulk properties, such as an eightfold increase in the solubility of methane gas. Our results provide the basis for development of a new class of functional porous materials for chemical processes, and we present a one-step, multigram scale-up route for highly soluble ‘scrambled’ porous cages prepared from a mixture of commercially available reagents. The unifying design principle for these materials is the avoidance of functional groups that can penetrate into the molecular cage cavities.

  11. Permanent Turbidity-Standards

    PubMed Central

    Roessler, William G.; Brewer, Carl R.

    1967-01-01

    Permanent turbidity reference standards suitable for measurement of microbial suspensions were prepared by suspending finely divided titanium dioxide in aryl sulfonamide-formaldehyde or methylstyrene resins. Turbidities of these standards, adjusted to a useful range for microbiological and immunological studies, were compared with other reference standards in use today. Tube holders for a Coleman Photonephelometer and a Nepho-Colorimeter were modified to eliminate the water well and to allow use of optically standardized 10-, 16-, or 18-mm test tubes. The standards and the tube holders have been used satisfactorily for more than 12 years. Images Fig. 5 Fig. 6 PMID:6077410

  12. Long-term management of atrial myopathy in two dogs with single chamber permanent transvenous pacemakers.

    PubMed

    Schmitt, K E; Lefbom, B K

    2016-06-01

    Two young Labrador retriever dogs with bradycardia-induced syncope resulting from atrial myopathy underwent permanent transvenous pacemaker implantation. Both dogs developed heart failure 3-5 years after pacemaker implantation. Both were managed medically for approximately 7 years after pacemaker implantation and, ultimately, were humanely euthanized due to refractory heart failure signs and quality of life concerns. Long-term management of dogs with atrial myopathy and secondary atrial standstill with pacemaker implantation and medical therapy for heart failure is feasible and prognosis may be better than previously reported or speculated. PMID:26923757

  13. Cryogenic Permanent Magnet Undulators

    SciTech Connect

    Chavanne, J.; Lebec, G.; Penel, C.; Revol, F.; Kitegi, C.

    2010-06-23

    For an in-vacuum undulator operated at small gaps the permanent magnet material needs to be highly resistant to possible electron beam exposure. At room temperature, one generally uses Sm{sub 2}Co{sub 17} or high coercivity NdFeB magnets at the expense of a limited field performance. In a cryogenic permanent magnet undulator (CPMU), at a temperature of around 150 K, any NdFeB grade reveals a coercivity large enough to be radiation resistant. In particular, very high remanence NdFeB material can be used to build undulators with enhanced field and X-ray brilliance at high photon energy provided that the pre-baking of the undulator above 100 deg. C can be eliminated. The ESRF has developed a full scale 2 m long CPMU with a period of 18 mm. This prototype has been in operation on the ID6 test beamline since January 2008. A significant effort was put into the characterization of NdFeB material at low temperature, the development of dedicated magnetic measurement systems and cooling methods. The measured heat budget with beam is found to be larger than expected without compromising the smooth operation of the device. Leading on from this first experience, new CPMUs are currently being considered for the upgrade of the ESRF.

  14. Diagnostic Imaging for Dental Implant Therapy

    PubMed Central

    Nagarajan, Aishwarya; Perumalsamy, Rajapriya; Thyagarajan, Ramakrishnan; Namasivayam, Ambalavanan

    2014-01-01

    Dental implant is a device made of alloplastic (foreign) material implanted into the jaw bone beneath the mucosal layer to support a fixed or removable dental prosthesis. Dental implants are gaining immense popularity and wide acceptance because they not only replace lost teeth but also provide permanent restorations that do not interfere with oral function or speech or compromise the self-esteem of a patient. Appropriate treatment planning for replacement of lost teeth is required and imaging plays a pivotal role to ensure a satisfactory outcome. The development of pre-surgical imaging techniques and surgical templates helps the dentist place the implants with relative ease. This article focuses on various types of imaging modalities that have a pivotal role in implant therapy. PMID:25379354

  15. Diagnostic imaging for dental implant therapy.

    PubMed

    Nagarajan, Aishwarya; Perumalsamy, Rajapriya; Thyagarajan, Ramakrishnan; Namasivayam, Ambalavanan

    2014-01-01

    Dental implant is a device made of alloplastic (foreign) material implanted into the jaw bone beneath the mucosal layer to support a fixed or removable dental prosthesis. Dental implants are gaining immense popularity and wide acceptance because they not only replace lost teeth but also provide permanent restorations that do not interfere with oral function or speech or compromise the self-esteem of a patient. Appropriate treatment planning for replacement of lost teeth is required and imaging plays a pivotal role to ensure a satisfactory outcome. The development of pre-surgical imaging techniques and surgical templates helps the dentist place the implants with relative ease. This article focuses on various types of imaging modalities that have a pivotal role in implant therapy. PMID:25379354

  16. Goserelin Implant

    MedlinePlus

    ... which the type of tissue that lines the uterus [womb] grows in other areas of the body ... with the treatment of abnormal bleeding of the uterus. Goserelin implant is in a class of medications ...

  17. Ion Implantation

    NASA Astrophysics Data System (ADS)

    Langouche, G.; Yoshida, Y.

    In this tutorial we describe the basic principles of the ion implantation technique and we demonstrate that emission Mössbauer spectroscopy is an extremely powerful technique to investigate the atomic and electronic configuration around implanted atoms. The physics of dilute atoms in materials, the final lattice sites and their chemical state as well as diffusion phenomena can be studied. We focus on the latest developments of implantation Mössbauer spectroscopy, where three accelerator facilities, i.e., Hahn-Meitner Institute Berlin, ISOLDE-CERN and RIKEN, have intensively been used for materials research in in-beam and on-line Mössbauer experiments immediately after implantation of the nuclear probes.

  18. Dental Implants

    MedlinePlus Videos and Cool Tools

    ... facts so you can make an informed decision as to whether dental implants are right for your ... the jaw bone. It’s obviously not the same as the original connection , but functions just the same. ...

  19. Cochlear Implants

    MedlinePlus

    ... additional visits are needed for activating, adjusting, and programming the various electrodes that have been implanted. Also, ... to the center for checkups once the final programming is made to the speech processor. Both children ...

  20. Histrelin Implant

    MedlinePlus

    ... bone growth and development of sexual characteristics) in girls usually between 2 and 8 years of age ... MRI scans (radiology techniques designed to show the images of body structures) to find the implant when ...

  1. [Permanent cardiac pacing in women--light and shadow].

    PubMed

    Małecka, Barbara; Wysokińsk, Andrzej

    2015-01-01

    Permanent cardiac pacing has survived a sharp increase in quality improvement and frequency of usage. Nowadays particular aspects of this method of treatment are being considered. In this paper distinctiveness of women population treated by permanent pacing is discussed. Indications for heart pacing in women appear at a later age than in men. Moreover, women remain longer in follow-up, therefore their prognosis is better. The most serious late pacing complications, i.e., infections are less frequent in women. However, implantations procedures seem to be more difficult in female gender, most probably due to a smaller body size, especially of afferent veins. This leads to a higher periprocedural complication rate and refers especially to endocardial lead implantation, which in women is connected with double risk of pneumothorax. Late complications of permanent pacing are effectively treated by transvenous lead extraction. Female gender has been demonstrated as an independent risk factor of extraction failure. It seems that reasonable qualification for pacemaker implantations and leaving the procedures in the hands of experienced operators will strengthen the "light side" and limit the "dark side" of this therapy in women. PMID:26455022

  2. Optimization of permanent breast seed implant dosimetry incorporating tissue heterogeneity

    NASA Astrophysics Data System (ADS)

    Mashouf, Shahram

    Seed brachytherapy is currently used for adjuvant radiotherapy of early stage prostate and breast cancer patients. The current standard for calculation of dose around brachytherapy sources is based on the AAPM TG43 formalism, which generates the dose in homogeneous water medium. Recently, AAPM task group no. 186 (TG186) emphasized the importance of accounting for heterogeneities. In this work we introduce an analytical dose calculation algorithm in heterogeneous media using CT images. The advantages over other methods are computational efficiency and the ease of integration into clinical use. An Inhomogeneity Correction Factor (ICF) is introduced as the ratio of absorbed dose in tissue to that in water medium. ICF is a function of tissue properties and independent of the source structure. The ICF is extracted using CT images and the absorbed dose in tissue can then be calculated by multiplying the dose as calculated by the TG43 formalism times ICF. To evaluate the methodology, we compared our results with Monte Carlo simulations as well as experiments in phantoms with known density and atomic compositions. The dose distributions obtained through applying ICF to TG43 protocol agreed very well with those of Monte Carlo simulations and experiments in all phantoms. In all cases, the mean relative error was reduced by at least a factor of two when ICF correction factor was applied to the TG43 protocol. In conclusion we have developed a new analytical dose calculation method, which enables personalized dose calculations in heterogeneous media using CT images. The methodology offers several advantages including the use of standard TG43 formalism, fast calculation time and extraction of the ICF parameters directly from Hounsfield Units. The methodology was implemented into our clinical treatment planning system where a cohort of 140 patients were processed to study the clinical benefits of a heterogeneity corrected dose.

  3. Graded permanent magnets

    NASA Astrophysics Data System (ADS)

    Skomski, R.; Hadjipanayis, G. C.; Sellmyer, D. J.

    2009-04-01

    The effect of semihard magnetic phases and interfaces on the performance of nanostructured two-phase permanent magnets is investigated by model calculations. In addition to the trivial coercivity increase due to the replacement of soft regions by semihard regions, there is a coercivity enhancement even if the volume-averaged anisotropy is kept constant during the introduction of the semihard phase. A variational approach is used to derive analytical results for representative anisotropy profiles. The improvement is operative on length scales slightly larger than that of the soft phase in hard-soft composites, but the main challenge is to find semihard light or heavy transition metal phases with a high magnetization. There are several Fe- and Co-based phases, but most are thin-film systems and difficult to use in bulk magnets. Very hard nanostructured magnets may also be created from soft phases with negative but large anisotropy constants (hard-magnetic soft-soft magnets).

  4. Achieving permanency for LGBTQ youth.

    PubMed

    Jacobs, Jill; Freundlich, Madelyn

    2006-01-01

    This article brings together two significant efforts in the child welfare field: achieving permanence for youth in out-of-home care and meeting the needs of lesbian, gay, bisexual, transgender and questioning (LGBTQ) youth. During the past several years, a national movement has taken place to assure all children and youth have a permanent family connection before leaving the child welfare system; however, LGBTQ youth are not routinely included in the permanency discussions. At the same time, efforts in addressing the needs of LGBTQ youth have increased, but permanency is rarely mentioned as a need. This article offers models of permanence and practices to facilitate permanence with LGBTQ youth and their families. It also offers a youth-driven, individualized process, using youth development principles to achieve relational, physical, and legal permanence. Reunification efforts are discussed, including services, supports, and education required for youth to return to their family of origin. For those who cannot return home, other family resources are explored. The article also discusses cultural issues as they affect permanence for LGBTQ youth, and, finally, addresses the need for ongoing support services to sustain and support permanency. PMID:16846117

  5. Permanent dots in radiation therapy.

    PubMed

    Uyeda, L M

    1987-01-01

    Currently the word tattoo is used to describe the permanent marks used on patients in radiation therapy. This article offers alternative wording and the reasons why a new term is suggested. Guidelines for the standardization and administration of permanent marks concludes the article. PMID:3588884

  6. Permanent-Magnet Meissner Bearing

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    1994-01-01

    Permanent-magnet meissner bearing features inherently stable, self-centering conical configuration. Bearing made stiffer or less stiff by selection of magnets, springs, and spring adjustments. Cylindrical permanent magnets with axial magnetization stacked coaxially on rotor with alternating polarity. Typically, rare-earth magnets used. Magnets machined and fitted together to form conical outer surface.

  7. Protease-activated receptor (PAR)1, PAR2 and PAR4 expressions in esophageal squamous cell carcinoma

    PubMed Central

    LI, Si-Man; JIANG, Ping; XIANG, Yang; WANG, Wei-Wei; ZHU, Yue-Chun; FENG, Wei-Yang; LI, Shu-De; YU, Guo-Yu

    2014-01-01

    Here, we used reverse transcription-PCR (RT-PCR) and western blot to detect protease-activated receptor (PAR) 1, PAR 2 and PAR 4 expression in cancer tissues and cell lines of esophageal squamous cell carcinoma, and investigated the co-relationship between PAR expression and clinic-pathological data for esophageal cancer. The methylation of PAR4 gene promoter involved in esophageal carcinoma was also analyzed. By comparing the mRNA expressions of normal esophageal tissue and human esophageal epithelial cells (HEEpiC), we found that among the 28 cases of esophageal squamous cell carcinoma, PAR1 (60%) and PAR2 (71%) were elevated in 17 and 20 cases, respectively, and PAR4 (68%) expression was lowered in 19 cases. Whereas, in human esophageal squamous cells (TE-1 and TE-10), PAR1 and PAR2 expression was increased but PAR4 was decreased. Combined with clinical data, the expression of PAR1 in poorly differentiated (P=0.016) and middle and lower parts of the esophagus (P=0.016) was higher; expression of PAR4 in poorly differentiated carcinoma was lower (P=0.049). Regarding TE-1 and TE-10 protein expression, we found that in randomized esophageal carcinoma, PAR1 (P=0.027) and PAR2 (P=0.039) expressions were increased, but lowered for PAR4 (P=0.0001). In HEEpiC, TE-1, TE-10, esophageal and normal esophagus tissue samples (case No. 7), the frequency of methylation at the 19 CpG loci of PAR4 was 35.4%, 95.2%, 83.8%, 62.6% and 48.2%, respectively. Our results indicate that the expression of PAR1 and PAR2 in esophageal squamous cell carcinoma is increased but PAR4 is decreased. Hypermethylation of the promoter of the PAR4 gene may contribute to reduced expression of PAR4 in esophageal squamous cell carcinoma. PMID:25297082

  8. Cochlear Implants

    MedlinePlus

    ... outside of the body, behind the ear. A second part is surgically placed under the skin. An implant does not restore normal hearing. It can help a person understand speech. Children and adults can benefit from them. National Institute on Deafness and Other Communication Disorders

  9. Cochlear implant

    MedlinePlus

    ... are sent along the auditory nerve to the brain. A deaf person does not have a functioning inner ear. A cochlear implant tries to replace the function of the inner ear by ... signals to the brain. Sound is picked up by a microphone worn ...

  10. Aqueous misdirection following pars plana vitrectomy and silicone oil injection

    PubMed Central

    Ghoraba, Hammouda H; Ghali, Ali Ahmed; Mansour, Hosam Othman

    2015-01-01

    Purpose To report a retrospective series of seven phakic eyes of seven patients suffering from a malignant glaucoma-like syndrome following pars plana vitrectomy and silicone oil (SO) injection. Materials and methods Seven eyes with retinal detachment treated with pars plana vitrectomy with or without scleral buckling with SO tamponade. This was followed by cataract extraction to manage the elevated intraocular pressure (IOP). Results This was a retrospective review of seven cases that received pars plana vitrectomy and SO with or without scleral buckling for different causes of retinal detachment (three were rhegmatogenous and four were tractional). After a period ranging from 1 week to 1 month, they presented with malignant glaucoma-like manifestations; high IOP, shallow axial anterior chamber, and remarkable decrease of visual acuity. Atropine eye drops and anti-glaucoma medical treatment (topical and systemic) had been tried but failed to improve the condition. Dramatic decrease of IOP and deepening of the axial anterior chamber was observed in all cases in the first postoperative day after phacoemulsification and posterior chamber foldable intraocular lens implantation with posterior capsulotomy. Conclusion Aqueous misdirection syndrome may be observed following pars plana vitrectomy and SO tamponade. This must be differentiated from other causes of post vitrectomy glaucoma. Cataract extraction with posterior capsulotomy controls the condition. PMID:26056429

  11. Par Pond vegetation status 1996

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1996-12-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995, and into the early spring and late summer of 1996. Communities similar to the pre-drawdown, Par Pond aquatic plant communities continue to become re-established. Emergent beds of maidencane, lotus, waterlily, watershield, and Pontederia are extensive and well developed. Measures of percent cover, width of beds, and estimates of area of coverage with satellite data indicate regrowth within two years of from 40 to 60% of levels prior to the draw down. Cattail occurrence continued to increase during the summer of 1996, especially in the former warm arm of Par Pond, but large beds common to Par Pond prior to the draw down still have not formed. Lotus has invaded and occupies many of the areas formerly dominated by cattail beds. To track the continued development of macrophytes in Par Pond, future surveys through the summer and early fall of 1997, along with the evaluation of satellite data to map the extent of the macrophyte beds of Par Pond, are planned.

  12. Immunopathogenic Background of Pars Planitis.

    PubMed

    Przeździecka-Dołyk, Joanna; Węgrzyn, Agnieszka; Turno-Kręcicka, Anna; Misiuk-Hojło, Marta

    2016-04-01

    Pars planitis is defined as an intermediate uveitis of unknown background of systemic disease with characteristic formations such as vitreous snowballs, snowbanks and changes in peripheral retina. The incidence of pars planitis varies 2.4-15.4 % of the uveitis patients. The pathogenesis of the disease is to be determined in future. Clinical and histopathological findings suggest an autoimmune etiology, most likely as a reaction to endogenous antigen of unknown source, with T cells predominant in both vitreous and pars plana infiltrations. T cells subsets play an important role as a memory-effector peripheral cell. Snowbanks are formed as an effect of post inflammatory glial proliferation of fibrous astrocytes. There is also a genetic predisposition for pars planitis by human leukocyte antigen and several other genes. A coexistence of multiple sclerosis and optic neuritis has been described in numerous studies. Epiretinal membrane, cataract, cystoid macular edema, retinal detachment, retinal vasculitis, neovascularization, vitreous peripheral traction, peripheral hole formation, vitreous hemorrhage, disc edema are common complications observed in pars planitis. There is a need to expand the knowledge of the pathogenic and immunologic background of the pars planitis to create an accurate pharmacological treatment. PMID:26438050

  13. Periodic permanent magnet focused klystron

    SciTech Connect

    Ferguson, Patrick; Read, Michael; Ives, R Lawrence

    2015-04-21

    A periodic permanent magnet (PPM) klystron has beam transport structures and RF cavity structures, each of which has permanent magnets placed substantially equidistant from a beam tunnel formed about the central axis, and which are also outside the extent of a cooling chamber. The RF cavity sections also have permanent magnets which are placed substantially equidistant from the beam tunnel, but which include an RF cavity coupling to the beam tunnel for enhancement of RF carried by an electron beam in the beam tunnel.

  14. Experimental implantation of epiretinal retina implants (EPI-RET) with an IOL-type receiver unit

    NASA Astrophysics Data System (ADS)

    Gerding, H.; Benner, F. P.; Taneri, S.

    2007-03-01

    The purpose of this paper is to investigate the surgical feasibility of implantation and long-term structural outcome of retina implant devices with an anterior IOL receiver, a connecting microcable and posterior segment epiretinal microcontacts. Implantation of epiretinal retina (EPI-RET) implants was performed as a one-step surgical procedure including phacoemulsification and pars plana vitrectomy in two adult rabbits. Implants were mechanically stabilized in an anterior position by the lens capsule and in the posterior segment by microtacks with a soft contact collar. Follow-up (6 and 9 months) included regular clinical examination, anterior and posterior segment photography and finally pathohistological evaluation. Implantation was uneventful in case 1 and complicated by vitreous space haemorrhage in case 2. At the end of follow-up, the retina was partially detached in animal 1 and subtotally detached in animal 2. Common features of tissue reaction in both cases were the formation of cyclitic membranes extending around and posterior to the anterior IOL receiver. In addition to that severe proliferations developed around microcables, microcontacts and microtacks forming a tissue capsule around posterior segment foreign materials. Retinal areas in contact to implant devices presented a severe structural damage and disorganization. Results of this preliminary trial suggest that the application of epiretinal prostheses with large diameter IOL receivers may be a critical issue and can give rise to an unfavourable outcome. Further systematic investigation ought to be performed involving a larger number of animals, modified implants and perhaps other species.

  15. Recent progress in developing durable and permanent impeller pump.

    PubMed

    Qian, K X; Zeng, P; Ru, W M; Yuan, H Y

    2002-04-01

    Since 1980s, the author's impeller pump has successively achieved the device implantability, blood compatibility and flow pulsatility. In order to realize a performance durability, the author has concentrated in past years on solving the bearing problems of the impeller pump. Recent progress has been obtained in developing durable and permanent impeller blood pumps. At first, a durable impeller pump with rolling bearing and purge system has been developed, in which the wear-less rollers made of super-high-molecular weight polythene make the pump to work for years without mechanical wear; and the purge system enables the bearing to work in saline and heparin, and no thrombus therefore could be formed. Secondly, a durable centrifugal pump with rolling bearing and axially reciprocating impeller has been developed, the axial reciprocation of rotating impeller makes the fresh blood in and out of the bearing and to wash the rollers once a circle; in such way, no thrombus could be formed and no fluid infusion is necessary, which may bring inconvenience and discomfort to the receptors. Finally, a permanent maglev impeller pump has been developed, its rotor is suspended and floating in the blood under the action of permanent magnetic force and nonmagnetic forces, without need for position measurement and feed-back control. In conclusion, an implantable, pulsatile, and blood compatible impeller pump with durability may have more extensive applications than ever before and could replace the donor heart for transplantation in the future. PMID:12099505

  16. Pupillary block after intraocular lens implantation.

    PubMed

    Van Buskirk, E M

    1983-01-01

    Seventeen patients, ranging in age from 40 to 86 years, developed pupillary block detected one week to three years after intraocular lens implantation. Sixteen of the implants were anterior chamber intraocular lenses and one was a posterior chamber intraocular lens. Despite iris bombé that closed the anterior chamber angle, many cases were asymptomatic and were discovered fortuitously during routine postoperative examinations. Laser iridotomy or iridectomy eliminated the pupillary block in all 17 cases, but permanent synechial closure of a portion of the anterior chamber angle persisted in most cases and sometimes required medication or further surgery. One eye eventually lost all light perception. PMID:6849369

  17. [Radiological picture in the diagnosis of various complications of permanent endocardial electrostimulation].

    PubMed

    Vanaria, D; Mangiameli, S; Circo, A; Fiscella, A; Bulla, V

    1977-09-30

    The close links between the implantation of permanent pacemakers and radiological examination are described with particular reference to position of the the right ventricle. Here radiological examination offers the best chance of diagnosis. The need for close cooperation between specialists is emphasised. PMID:917335

  18. Exploration of locomotion in the ParA/ParB system

    NASA Astrophysics Data System (ADS)

    Jindal, Lavisha; Emberly, Eldon

    2015-03-01

    In many bacteria the ParA/ParB system is responsible for actively segregating DNA during replication. ParB precessively moves by hydrolyzing DNA bound ParA-ATP forming a depleted ParA region in its wake. Recent in-vitro experiments have shown that a ParB covered bead can traverse a ParA bound DNA substrate. It has been suggested that the formation of a gradient in ParA leads to diffusion-ratchet like motion of the ParB bead but its origin and potential consequences requires investigation. We have developed a deterministic model for the in-vitro ParA/ParB system and show that any amount of spatial noise in ParA can lead to the spontaneous formation of its gradient. The velocity of the bead is independent of this noise but depends on the scale over which ParA exerts a force on the bead and the scale over which ParB hydrolyzes ParA from the substrate. There is a particular ratio of these scales at which the velocity is a maximum. We also explore the effects of cooperative vs independent rebinding of ParA to the substrate. Our model shows how the driving force for ParB originates and highlights necessary conditions for directed motion in the in-vitro system that may provide insight into the in-vivo behaviour of the ParA/ParB system.

  19. Implantable Myoelectric Sensors (IMESs) for Intramuscular Electromyogram Recording

    PubMed Central

    Weir, Richard F. ff.; Troyk, Phil R.; DeMichele, Glen A.; Kerns, Douglas A.; Schorsch, Jack F.; Maas, Huub

    2011-01-01

    We have developed a multichannel electrogmyography sensor system capable of receiving and processing signals from up to 32 implanted myoelectric sensors (IMES). The appeal of implanted sensors for myoelectric control is that electromyography (EMG) signals can be measured at their source providing relatively cross-talk-free signals that can be treated as independent control sites. An external telemetry controller receives telemetry sent over a transcutaneous magnetic link by the implanted electrodes. The same link provides power and commands to the implanted electrodes. Wireless telemetry of EMG signals from sensors implanted in the residual musculature eliminates the problems associated with percutaneous wires, such as infection, breakage, and marsupialization. Each implantable sensor consists of a custom-designed application-specified integrated circuit that is packaged into a bio-compatible RF BION capsule from the Alfred E. Mann Foundation. Implants are designed for permanent long-term implantation with no servicing requirements. We have a fully operational system. The system has been tested in animals. Implants have been chronically implanted in the legs of three cats and are still completely operational four months after implantation. PMID:19224729

  20. [Physiology of protease-activated receptors (PARs): involvement of PARs in digestive functions].

    PubMed

    Kawabata, A; Kuroda, R; Hollenberg, M D

    1999-10-01

    The protease-activated receptor (PAR), a G protein-coupled receptor present on cell surface, mediates cellular actions of extracellular proteases. Proteases cleave the extracellular N-terminal of PAR molecules at a specific site, unmasking and exposing a novel N-terminal, a tethered ligand, that binds to the body of receptor molecules resulting in receptor activation. Amongst four distinct PARs that have been cloned, PARs 1, 3 and 4 are activated by thrombin, but PAR-2 is activated by trypsin or mast cell tryptase. Human platelets express two distinct thrombin receptors, PAR-1 and PAR-4, while murine platelets express PAR-3 and PAR-4. Apart from roles of PARs in platelet activation, PARs are distributed to a number of organs in various species, predicting their physiological importance. We have been evaluating agonists specific for each PAR, using multiple procedures including a HEK cell calcium signal receptor desensitization assay. Using specific agonists that we developed, we found the following: 1) the salivary glands express PAR-2 mRNA and secret saliva in response to PAR-2 activation; 2) pancreatic juice secretion occurs following in vivo PAR-2 activation; 3) PAR-1 and PAR-2 modulate duodenal motility. Collectively, PAR plays various physiological and/or pathophysiological roles, especially in the digestive systems, and could be a novel target for drug development. PMID:10629876

  1. Lodestone: Nature's own permanent magnet

    NASA Technical Reports Server (NTRS)

    Wasilewski, P.

    1976-01-01

    Magnetic hysteresis and microstructural details are presented which explain why the class of magnetic iron ores defined as proto-lodestones, can behave as permanent magnets, i.e. lodestones. Certain of these proto-lodestones which are not permanent magnets can be made into permanent magnets by charging in a field greater than 1000 oersted. This fact, other experimental observations, and field evidence from antiquity and the middle ages, which seems to indicate that lodestones are found as localized patches within massive ore bodies, suggests that lightning might be responsible for the charging of lodestones. The large remanent magnetization, high values of coercive force, and good time stability for the remanent magnetization are all characteristics of proto-lodestone iron ores which behave magnetically as fine scale ( 10 micrometer) intergrowths when subjected to magnetic hysteresis analysis. The magnetic results are easily understood by analysis of the complex proto lodestone microstructural patterns observable at the micrometer scale and less.

  2. How Permanent Is Permanent Placement for Substance-Exposed Infants?

    ERIC Educational Resources Information Center

    Twomey, Jean E.; Lester, Barry M.

    2007-01-01

    The authors describe a study of families in the Family Drug Treatment Court (FTDC), an effort to promote permanent placement for substance-exposed infants within time requirements mandated by the 1997 Adoption and Safe Families Act (ASFA). The purpose of the study was to evaluate parent functioning after FTDC involvement, infant developmental…

  3. Semipermanent and permanent injectable fillers.

    PubMed

    Jones, Derek H

    2009-10-01

    Today, an impressive array of injectable dermal fillers for facial soft-tissue augmentation is available in the United States. These agents, most of which were introduced in the last half decade, represent a variety of semipermanent and permanent fillers across several categories. Physicians can choose between semipermanent fillers, such as hyaluronic acid derivatives (HA), calcium hydroxylapatite (CaHA), and poly-L-lactic acid (PLA), and longer-lasting, so-called "permanent fillers," such as polymethyl methacrylate microspheres (PMMA), highly purified forms of liquid silicone, and hydrogel polymers. PMID:19850193

  4. Management of a malpositioned implant using custom abutment and screw-retained fixed dental prosthesis.

    PubMed

    Turkyilmaz, Ilser

    2014-01-01

    A 32-year-old woman with missing permanent mandibular right molars and left first molar presented for treatment. One of the implants were misaligned during the placement due to sudden mouth closure of the patient. All implants success fully osseointegrated. However, the misaligned implant resulted in substantial mechanical and esthetic restorative challenges. The prosthodontic treatment included a custom abutment and a screw-retained fixed dental prosthesis on the right side. The patient did not report any problems with the implants and restorations during the first year of service. The treatment presented in this clinical report may be an alternative option to restore malpositioned implants. PMID:25307826

  5. Update of intraocular lens implantation in children

    PubMed Central

    Al Shamrani, Mohammed; Al Turkmani, Shahira

    2012-01-01

    Cataract is a common problem that affects the vision in children and a major cause of amblyopia in children. However, the management of childhood cataract is tenuous and requires special considerations especially with regard to intraocular lens (IOL) implantation. Age at which an IOL can be implanted is a controversial issue. Implanting an IOL in very young children carries the risk of severe postoperative inflammation and posterior capsule opacification that may need other surgeries and may affect the vision permanently. Accuracy of the calculated IOL power is affected by the short eyes and the steep keratometric values at this age. Furthermore, choosing an appropriate IOL power is not a straight forward decision as future growth of the eye affects the axial length and keratometry readings which may result in an unexpected refractive error as children age. The aim of this review is to cover these issues regarding IOL implantation in children; indications, timing of implantation, types of IOLs, site of implantation and the power calculations. PMID:23961005

  6. Magnetic Fields: Visible and Permanent.

    ERIC Educational Resources Information Center

    Winkeljohn, Dorothy R.; Earl, Robert D.

    1983-01-01

    Children will be able to see the concept of a magnetic field translated into a visible reality using the simple method outlined. Standard shelf paper, magnets, iron filings, and paint in a spray can are used to prepare a permanent and well-detailed picture of the magnetic field. (Author/JN)

  7. Microfilm Permanence and Archival Quality

    ERIC Educational Resources Information Center

    Avedon, Don M.

    1972-01-01

    The facts about microfilm permanence and archival quality are presented in simple terms. The major factors, including the film base material, the film emulsion, processing, and storage conditions are reviewed. The designations on the edge of the film are explained and a list of refernces provided. (14 references) (Author)

  8. Frictionless Bearing Uses Permanent Magnets

    NASA Technical Reports Server (NTRS)

    1965-01-01

    The purpose of this innovation was to develop a frictionless bearing for high speed, light load applications. The device involves the incorporation of permanent magnets in the bearing design. The repulsion of like magnetic poles provides concentric support of the inner member so that no metallic contact occurs between the bearing surfaces.

  9. Par Pond Fish, Water, and Sediment Chemistry

    SciTech Connect

    Paller, M.H.; Wike, L.D.

    1996-06-01

    The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond.

  10. Directed and persistent movement arises from mechanochemistry of the ParA/ParB system

    NASA Astrophysics Data System (ADS)

    Hu, Longhua; Vecchiarelli, Anthony G.; Mizuuchi, Kiyoshi; Neuman, Keir C.; Liu, Jian

    The segregation of DNA prior to cell division is essential for faithful genetic inheritance. In many bacteria, segregation of the low-copy-number plasmids involves an active partition system composed of ParA ATPase and its stimulator protein ParB. Recent experiments suggest that ParA/ParB system motility is driven by a diffusion-ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. We develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA-nucleoid affinity to the motion of the ParB bound cargo. Paradoxically, the resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work sheds light on a new emergent phenomenon in which non-motor proteins work collectively via mechanochemical coupling to propel cargos -- an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria.

  11. The ParB-parS Chromosome Segregation System Modulates Competence Development in Streptococcus pneumoniae

    PubMed Central

    Attaiech, Laetitia; Minnen, Anita; Kjos, Morten; Gruber, Stephan

    2015-01-01

    ABSTRACT ParB proteins bind centromere-like DNA sequences called parS sites and are involved in plasmid and chromosome segregation in bacteria. We previously showed that the opportunistic human pathogen Streptococcus pneumoniae contains four parS sequences located close to the origin of replication which are bound by ParB. Using chromatin immunoprecipitation (ChIP), we found here that ParB spreads out from one of these parS sites, parS(−1.6°), for more than 5 kb and occupies the nearby comCDE operon, which drives competence development. Competence allows S. pneumoniae to take up DNA from its environment, thereby mediating horizontal gene transfer, and is also employed as a general stress response. Mutating parS(−1.6°) or deleting parB resulted in transcriptional up-regulation of comCDE and ssbB (a gene belonging to the competence regulon), demonstrating that ParB acts as a repressor of competence. However, genome-wide transcription analysis showed that ParB is not a global transcriptional regulator. Different factors, such as the composition of the growth medium and antibiotic-induced stress, can trigger the sensitive switch driving competence. This work shows that the ParB-parS chromosome segregation machinery also influences this developmental process. PMID:26126852

  12. A mini axial and a permanent maglev radial heart pump.

    PubMed

    Qian, Kun-Xi; Ru, Wei-Min; Wang, Hao; Jing, Teng

    2007-01-01

    The implantability and durability have been for decades the focus of artificial heart R&D. A mini axial and a maglev radial pump have been developed to meet with such requirements.The mini axial pump weighing 27g (incl.5g rotor) has an outer diameter of 21mm and a length of 10mm in its largest point, but can produce a maximal blood flow of 6l/min with 50mmHg pressure increase. Therefore, it is suitable for the patients of 40-60kg body weight. For other patients of 60-80kg or 80-100kg body weight, the mini axial pumps of 23mm and 25mm outer diameter had been developed before, these devices were acknowledged to be the world smallest LVADs by Guinness World Record Center in 2004.The permanent maglev radial pump weighing 150g is a shaft-less centrifugal pump with permanent magnetic bearings developed by the author. It needs no second coil for suspension of the rotor except the motor coil, different from all other maglev pumps developed in USA, Japan, European, etc. Thus no detecting and controlling systems as well as no additional power supply for maglev are necessary. The pump can produce a blood flow up to as large as 10l/min against 100mmHg pressure.An implantable and durable blood pump will be a viable alternative to natural donor heart for transplantation. PMID:19662120

  13. Retrograde peri-implantitis.

    PubMed

    Mohamed, Jumshad B; Shivakumar, B; Sudarsan, Sabitha; Arun, K V; Kumar, T S S

    2010-01-01

    Retrograde peri-implantitis constitutes an important cause for implant failure. Retrograde peri-implantitis may sometimes prove difficult to identify and hence institution of early treatment may not be possible. This paper presents a report of four cases of (the implant placed developing to) retrograde peri-implantitis. Three of these implants were successfully restored to their fully functional state while one was lost due to extensive damage. The paper highlights the importance of recognizing the etiopathogenic mechanisms, preoperative assessment, and a strong postoperative maintenance protocol to avoid retrograde peri-implant inflammation. PMID:20922082

  14. Parallel Climate Analysis Toolkit (ParCAT)

    Energy Science and Technology Software Center (ESTSC)

    2013-06-30

    The parallel analysis toolkit (ParCAT) provides parallel statistical processing of large climate model simulation datasets. ParCAT provides parallel point-wise average calculations, frequency distributions, sum/differences of two datasets, and difference-of-average and average-of-difference for two datasets for arbitrary subsets of simulation time. ParCAT is a command-line utility that can be easily integrated in scripts or embedded in other application. ParCAT supports CMIP5 post-processed datasets as well as non-CMIP5 post-processed datasets. ParCAT reads and writes standard netCDF files.

  15. Directed and persistent movement arises from mechanochemistry of the ParA/ParB system.

    PubMed

    Hu, Longhua; Vecchiarelli, Anthony G; Mizuuchi, Kiyoshi; Neuman, Keir C; Liu, Jian

    2015-12-22

    The segregation of DNA before cell division is essential for faithful genetic inheritance. In many bacteria, segregation of low-copy number plasmids involves an active partition system composed of a nonspecific DNA-binding ATPase, ParA, and its stimulator protein ParB. The ParA/ParB system drives directed and persistent movement of DNA cargo both in vivo and in vitro. Filament-based models akin to actin/microtubule-driven motility were proposed for plasmid segregation mediated by ParA. Recent experiments challenge this view and suggest that ParA/ParB system motility is driven by a diffusion ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. Here, we develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA-nucleoid affinity to the motion of the ParB-bound cargo. Paradoxically, this resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work thus sheds light on an emergent phenomenon in which nonmotor proteins work collectively via mechanochemical coupling to propel cargos-an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria. PMID:26647183

  16. Directed and persistent movement arises from mechanochemistry of the ParA/ParB system

    PubMed Central

    Hu, Longhua; Vecchiarelli, Anthony G.; Mizuuchi, Kiyoshi; Neuman, Keir C.; Liu, Jian

    2015-01-01

    The segregation of DNA before cell division is essential for faithful genetic inheritance. In many bacteria, segregation of low-copy number plasmids involves an active partition system composed of a nonspecific DNA-binding ATPase, ParA, and its stimulator protein ParB. The ParA/ParB system drives directed and persistent movement of DNA cargo both in vivo and in vitro. Filament-based models akin to actin/microtubule-driven motility were proposed for plasmid segregation mediated by ParA. Recent experiments challenge this view and suggest that ParA/ParB system motility is driven by a diffusion ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. Here, we develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA–nucleoid affinity to the motion of the ParB-bound cargo. Paradoxically, this resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work thus sheds light on an emergent phenomenon in which nonmotor proteins work collectively via mechanochemical coupling to propel cargos—an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria. PMID:26647183

  17. Reuse of permanent cardiac pacemakers.

    PubMed Central

    Rosengarten, M D; Portnoy, D; Chiu, R C; Paterson, A K

    1985-01-01

    Cardiac pacemakers are part of a growing group of expensive implantable electronic devices; hospitals in which 100 pacemakers are implanted per year must budget over $300 000 for these devices. This cost represents a considerable burden to health care resources. Since the "life-span" of modern pacemakers often exceeds that of the patients who receive them, the recovery and reuse of these devices seems logical. Pacemakers can be resterilized and tested with current hospital procedures. Reuse should be acceptable under Canadian law, but the manner in which the pacemakers are recovered and the patients selected should follow careful guidelines. Every patient should provide written informed consent before receiving a recovered pacemaker. Properly executed, reuse of pacemakers should provide a high level of health care while maintaining or reducing the cost of these devices. PMID:4016637

  18. 21 CFR 886.4445 - Permanent magnet.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Permanent magnet. 886.4445 Section 886.4445 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4445 Permanent magnet. (a) Identification. A permanent magnet is a nonelectric device that generates a magnetic field intended to find and remove...

  19. 21 CFR 886.4445 - Permanent magnet.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Permanent magnet. 886.4445 Section 886.4445 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4445 Permanent magnet. (a) Identification. A permanent magnet is a nonelectric device that generates a magnetic field intended to find and remove...

  20. 21 CFR 886.4445 - Permanent magnet.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Permanent magnet. 886.4445 Section 886.4445 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4445 Permanent magnet. (a) Identification. A permanent magnet is a nonelectric device that generates a magnetic field intended to find and remove...

  1. 21 CFR 886.4445 - Permanent magnet.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Permanent magnet. 886.4445 Section 886.4445 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4445 Permanent magnet. (a) Identification. A permanent magnet is a nonelectric device that generates a magnetic field intended to find and remove...

  2. 21 CFR 886.4445 - Permanent magnet.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Permanent magnet. 886.4445 Section 886.4445 Food... DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4445 Permanent magnet. (a) Identification. A permanent magnet is a nonelectric device that generates a magnetic field intended to find and remove...

  3. 22 CFR 401.3 - Permanent offices.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Permanent offices. 401.3 Section 401.3 Foreign Relations INTERNATIONAL JOINT COMMISSION, UNITED STATES AND CANADA RULES OF PROCEDURE General § 401.3 Permanent offices. The permanent offices of the Commission shall be at Washington, in the District...

  4. 22 CFR 401.3 - Permanent offices.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Permanent offices. 401.3 Section 401.3 Foreign Relations INTERNATIONAL JOINT COMMISSION, UNITED STATES AND CANADA RULES OF PROCEDURE General § 401.3 Permanent offices. The permanent offices of the Commission shall be at Washington, in the District...

  5. Teaching Object Permanence: An Action Research Study

    ERIC Educational Resources Information Center

    Bruce, Susan M.; Vargas, Claudia

    2013-01-01

    "Object permanence," also known as "object concept" in the field of visual impairment, is one of the most important early developmental milestones. The achievement of object permanence is associated with the onset of representational thought and language. Object permanence is important to orientation, including the recognition of landmarks.…

  6. Role of PAR-4 in ovarian cancer.

    PubMed

    Meynier, Sonia; Kramer, Marianne; Ribaux, Pascale; Tille, Jean-Christophe; Delie, Florence; Petignat, Patrick; Cohen, Marie

    2015-09-01

    Prostate apoptosis response-4 (PAR-4) is considered as a tumour suppressor due to its ability to selectively induce cell apoptosis in most cancer cells. However little is known about the role of PAR-4 in ovarian cancer. In this study, we investigated for the first time the role of PAR-4 in ovarian carcinogenesis. We showed that PAR-4 mRNA level is not significantly different between healthy and cancer ovarian cells. Immunohistochemistry on ovarian tissue showed that ovarian cancer cells are positive for PAR-4 nuclear and cytoplasmic staining whereas ovarian healthy cells are negative for PAR-4 nuclear staining. We then studied the role of PAR-4 in cell apoptosis. We determined that PAR-4 induces cell apoptosis in response to stimuli, in vitro, but is also involved in the relocation of GRP78 from endoplasmic reticulum to the cell surface of ovarian cancer cell line (SKOV-3 cells). In ovo, PAR-4 decreases ovarian tumour development and increases the response to taxol treatment. These observations suggest that PAR-4 is a very interesting therapeutic target against ovarian carcinogenesis. PMID:26246468

  7. Role of PAR-4 in ovarian cancer

    PubMed Central

    Meynier, Sonia; Kramer, Marianne; Ribaux, Pascale; Tille, Jean-Christophe; Delie, Florence; Petignat, Patrick; Cohen, Marie

    2015-01-01

    Prostate apoptosis response-4 (PAR-4) is considered as a tumour suppressor due to its ability to selectively induce cell apoptosis in most cancer cells. However little is known about the role of PAR-4 in ovarian cancer. In this study, we investigated for the first time the role of PAR-4 in ovarian carcinogenesis. We showed that PAR-4 mRNA level is not significantly different between healthy and cancer ovarian cells. Immunohistochemistry on ovarian tissue showed that ovarian cancer cells are positive for PAR-4 nuclear and cytoplasmic staining whereas ovarian healthy cells are negative for PAR-4 nuclear staining. We then studied the role of PAR-4 in cell apoptosis. We determined that PAR-4 induces cell apoptosis in response to stimuli, in vitro, but is also involved in the relocation of GRP78 from endoplasmic reticulum to the cell surface of ovarian cancer cell line (SKOV-3 cells). In ovo, PAR-4 decreases ovarian tumour development and increases the response to taxol treatment. These observations suggest that PAR-4 is a very interesting therapeutic target against ovarian carcinogenesis. PMID:26246468

  8. Permanent-File-Validation Utility Computer Program

    NASA Technical Reports Server (NTRS)

    Derry, Stephen D.

    1988-01-01

    Errors in files detected and corrected during operation. Permanent File Validation (PFVAL) utility computer program provides CDC CYBER NOS sites with mechanism to verify integrity of permanent file base. Locates and identifies permanent file errors in Mass Storage Table (MST) and Track Reservation Table (TRT), in permanent file catalog entries (PFC's) in permit sectors, and in disk sector linkage. All detected errors written to listing file and system and job day files. Program operates by reading system tables , catalog track, permit sectors, and disk linkage bytes to vaidate expected and actual file linkages. Used extensively to identify and locate errors in permanent files and enable online correction, reducing computer-system downtime.

  9. Psychiatric morbidity and depressive symptomatology in patients with permanent pacemakers.

    PubMed

    Aydemir, O; Ozmen, E; Küey, L; Kültür, S; Yeşil, M; Postaci, N; Bayata, S

    1997-06-01

    Implantation of a permanent pacemaker requires a psychological effort on the patient's part for adaptation in the acute term, and chronically, it restricts activities of the patient and may cause some psychiatric disturbances. To investigate psychiatric morbidity and depressive symptomatology of the patients with permanent pacemakers, 84 pacemaker patients were diagnosed using the DSM-III-R criteria and depressive symptoms were determined by modified Hamilton Depression Rating Scale (mHDRS). Sixteen (19.1%) patients had been given a psychiatric diagnosis. The most frequent diagnoses were adjustment disorder (5.9%) and major depressive episode (4.7%). Nine patients (10.7%) were diagnosed as having clinical depression (mHDRS > or = 17). The mean score of mHDRS was 7.57 +/- 7.46, and the severity of depression was significantly higher in females. The most frequent symptoms are difficulties in work and activities (53.6%), psychic anxiety (48.8%), loss of energy (42.9%), and hypochondriasis and insomnia (39.3%). Depressed mood, psychic anxiety, loss of energy, loss of interest, insomnia, and hypochondriasis were significantly more frequent in females. Uneducated patients had a more significant loss of energy than educated patients. Depressed mood, psychic anxiety, and somatic concerns and symptoms were more frequent in patients with permanent pacemakers than in the general population. These symptoms, resembling mixed anxiety-depression disorder, were related to fears of having a permanent pacemaker, since our series were composed of uneducated patients who did not have enough knowledge about the device. PMID:9227759

  10. Pars triangularis asymmetry and language dominance.

    PubMed Central

    Foundas, A L; Leonard, C M; Gilmore, R L; Fennell, E B; Heilman, K M

    1996-01-01

    The pars triangular is a portion of Broca's area. The convolutions that form the inferior and caudal extent of the pars triangularis include the anterior horizontal and anterior ascending rami of the sylvian fissure, respectively. To learn if there are anatomic asymmetries of the pars triangularis, these convolutions were measured on volumetric magnetic resonance imaging scans of 11 patients who had undergone selective hemispheric anesthesia (Wada testing) to determine hemispheric speech and language lateralization. Of the 10 patients with language lateralized to the left hemisphere, 9 had a leftward asymmetry of the pars triangularis. The 1 patient with language lateralized to the right hemisphere had a significant rightward asymmetry of the pars triangularis. Our data suggest that asymmetries of the pars triangularis may be related to speech-language lateralization. Images Fig. 1 PMID:8570622

  11. Method of making permanent magnets

    DOEpatents

    McCallum, R.W.; Dennis, K.W.; Lograsso, B.K.; Anderson, I.E.

    1993-09-07

    A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles. Wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties. 13 figures.

  12. Method of making permanent magnets

    DOEpatents

    McCallum, R. William; Dennis, Kevin W.; Lograsso, Barbara K.; Anderson, Iver E.

    1993-09-07

    A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties.

  13. Comparison of Marginal Bone Changes with Internal Conus and External Hexagon Design Implant Systems: A Prospective, Randomized Study.

    PubMed

    Cooper, Lyndon F; Tarnow, Dennis; Froum, Stuart; Moriarty, John; De Kok, Ingeborg J

    2016-01-01

    A central dental implant success criterion is the marginal bone response as measured longitudinally. Factors that influence marginal bone changes include osseous and soft tissue architecture, occlusal loading factors, implant position, implant design, and inflammatory processes. The evolution of implant design is multifactorial and includes the implant-abutment interface geometries. The primary objective of this study was to compare the proximal marginal bone changes following placement and loading of internal conus design implants (ICI) and external hex design implants (EXI) used in the treatment of posterior partial edentulism. Among 45 enrolled participants, 39 were treated with 47 ICI or 46 EXI implants using a one-stage implant protocol. Prosthetic restoration was completed after 12 weeks using stock titanium abutments and all-ceramic crowns. Follow-up visits including clinical and radiographic examinations were performed 6 months after permanent restoration and then annually for 3 years. Marginal bone level changes, papilla index scores, condition of the peri-implant mucosa, presence of complications, and participant satisfaction were evaluated. The mean marginal bone level change from implant placement to 3 years was -0.25 ± 0.60 mm and -0.5 ± 0.93 mm for ICI and EXI implants, respectively. The change recorded from permanent restoration to 3 years was a gain of 0.31 ± 0.41 mm versus 0.04 ± 0.51 mm for ICI and EXI implants, respectively (P < .05). In the evaluation of interproximal soft tissue 3 years after permanent restoration, 80% of mandibular and 66% of maxillary interproximal ICI sites received papilla scores of 2 and 3, compared with 50% of mandibular and 60% of maxillary interproximal EXI sites. No significant differences in plaque or bleeding scores were recorded. Abutment/healing abutment complications were recorded for 11 EXI versus 1 ICI participant. The vast majority (> 90%) of participants stated they were satisfied or very satisfied with

  14. Implant survivorship analysis after minimally invasive sacroiliac joint fusion using the iFuse Implant System®

    PubMed Central

    Cher, Daniel J; Reckling, W Carlton; Capobianco, Robyn A

    2015-01-01

    Introduction Surgical revision rate is a key outcome with all permanent implants. The iFuse Implant System® is a permanent implant used to perform minimally invasive sacroiliac joint fusion. The purpose of this study is to determine the surgical revision rate after sacroiliac joint fusion surgery with this system. Methods Using two internal sources of information, revision surgeries were identified and linked to index surgeries. The likelihood of revision surgery was calculated using the Kaplan–Meier life table approach. Predictors of revision were explored. Results Four-year survivorship free from implant revision was 96.46%. Revision rate did not differ by sex and was lower for age >65. In all, 24% of revisions occurred within the first 30 days after surgery; 63.5% occurred within year 1. Implant survivorship has improved annually since the device was introduced in 2009. Conclusion The survivorship rate with this implant is high and improving; the rate is somewhat higher than total hip replacement but lower than that of lumbar spine procedures. PMID:26648762

  15. Urinary incontinence - injectable implant

    MedlinePlus

    Injectable implants are injections of material into the urethra to help control urine leakage ( urinary incontinence ) caused by a ... into the tissue next to the sphincter. The implant procedure is usually done in the hospital. Or ...

  16. Preferred tools and techniques for implantation of cardiac electronic devices in Europe: results of the European Heart Rhythm Association survey.

    PubMed

    Bongiorni, Maria Grazia; Proclemer, Alessandro; Dobreanu, Dan; Marinskis, Germanas; Pison, Laurent; Blomstrom-Lundqvist, Carina

    2013-11-01

    The aim of this European Heart Rhythm Association (EHRA) survey was to assess clinical practice in relation to the tools and techniques used for cardiac implantable electronic devices procedures in the European countries. Responses to the questionnaire were received from 62 members of the EHRA research network. The survey involved high-, medium-, and low-volume implanting centres, performing, respectively, more than 200, 100-199 and under 100 implants per year. The following topics were explored: the side approach for implantation, surgical techniques for pocket incision, first venous access for lead implantation, preference of lead fixation, preferred coil number for implantable cardioverter-defibrillator (ICD) leads, right ventricular pacing site, generator placement site, subcutaneous ICD implantation, specific tools and techniques for cardiac resynchronization therapy (CRT), lead implantation sequence in CRT, coronary sinus cannulation technique, target site for left ventricular lead placement, strategy in left ventricular lead implant failure, mean CRT implantation time, optimization of the atrioventricular (AV) and ventriculo-ventricular intervals, CRT implants in patients with permanent atrial fibrillation, AV node ablation in patients with permanent AF. This panoramic view allows us to find out the operator preferences regarding the techniques and tools for device implantation in Europe. The results showed different practices in all the fields we investigated, nevertheless the survey also outlines a good adherence to the common standards and recommendations. PMID:24170423

  17. Recurrent Pyogenic Granuloma Around Dental Implants: A Rare Case Report.

    PubMed

    Gefrerer, Lidia; Popowski, Wojciech; Perek, Jan Nikodem; Wojtowicz, Andrzej

    2016-01-01

    The aim of this article is to present a rare case of a bilateral recurring pyogenic granuloma around dental implants supported by autogenic bone graft. A 55-year-old woman was treated with vertical bone augmentation and dental implants on both sides in the mandible. The patient was followed up for 2 years. Growing granuloma was observed 3 weeks after implants were loaded with splinted porcelain-fused-to-metal crowns. The granulomatous tissue was removed and samples were evaluated histologically and microbiologically with real-time polymerase chain reaction. The pathologic lesion recurred four times on one side and three times on the other side and was removed after each recurrence. Finally, the patient decided to have the implants removed due to the aggressive, permanent, and relapsing nature of the proliferative lesions associated with exposed implant threads. After implant removal, no hyperplasia was seen. Microbiologic contamination was excluded as a cause of this recurring granuloma, and it was presumed that the lesion could have been associated with an insufficient zone of attached gingiva around the implants and exposure of implant threads. However, the etiology of this pyogenic granuloma remains unknown. Due to the high recurrence rate of reactive hyperplastic lesions, a long-term follow-up is necessary. PMID:27333016

  18. Nerve damage related to implant dentistry: incidence, diagnosis, and management.

    PubMed

    Greenstein, Gary; Carpentieri, Joseph R; Cavallaro, John

    2015-10-01

    Proper patient selection and treatment planning with respect to dental implant placement can preclude nerve injuries. Nevertheless, procedures associated with implant insertion can inadvertently result in damage to branches of the trigeminal nerve. Nerve damage may be transient or permanent; this finding will depend on the cause and extent of the injury. Nerve wounding may result in anesthesia, paresthesia, or dysesthesia. The type of therapy to ameliorate the condition will be dictated by clinical and radiographic assessments. Treatment may include monitoring altered sensations to see if they subside, pharmacotherapy, implant removal, reverse-torquing an implant to decompress a nerve, combinations of the previous therapies, and/or referral to a microsurgeon for nerve repair. Patients manifesting altered sensations due to various injuries require different therapies. Transection of a nerve dictates immediate referral to a microsurgeon for evaluation. If a nerve is compressed by an implant or adjacent bone, the implant should be reverse-torqued away from the nerve or removed. When an implant is not close to a nerve, but the patient is symptomatic, the patient can be monitored and treated pharmacologically as long as symptoms improve or the implant can be removed. There are diverse opinions in the literature concerning how long an injured patient should be monitored before being referred to a microsurgeon. PMID:26448148

  19. Hair implant complications.

    PubMed

    Hanke, C W; Norins, A L; Pantzer, J G; Bennett, J E

    1981-04-01

    Four men who underwent hair implantation for pattern baldness were treated for complications such as infection, foreign-body reaction, pruritus, and scarring. The complications were similar to those reported with synthetic modacrylic fiber implants that have been used for the same purpose. Although we believe this is the first article to report complications from hair implants, the illogical basis of the procedure suggests that complications will occur in many unsuspecting patients who undergo hair implantation. PMID:7009899

  20. Long-Term Retrievability of IVC Filters: Should We Abandon Permanent Devices?

    SciTech Connect

    Berczi, V. Bottomley, J. R.; Thomas, S. M.; Taneja, S.; Gaines, P. A.; Cleveland, T. J.

    2007-09-15

    Thromboembolic disease produces a considerable disease burden, with death from pulmonary embolism in the UK alone estimated at 30,000-40,000 per year. Whilst it is unproven whether filters actually improve longevity, the morbidity and mortality associated with thromboembolic disease in the presence of contraindications to anticoagulation is high. Thus complications associated with filter insertion, and whilst they remain in situ, must be balanced against the alternatives. Permanent filters remain in situ for the remainder of the patient's life and any complications from the filters are of significant concern. Filters that are not permanent are therefore attractive in these circumstances. Retrievable filters, to avoid or decrease long-term filter complications, appear to be a significant advance in the prevention of pulmonary embolism. In this review, we discuss the safety and effectiveness of both permanent and retrievable filters as well as the retrievability of retrievable inferior vena cava (IVC) filters, to explore whether the use of permanent IVC filters can be abandoned in favor of retrievable filters. Currently four types of retrievable filters are available: the Recovery filter (Bard Peripheral Vascular, Tempe, AZ, USA), the Guenther Tulip filter (Cook, Bloomington, IN, USA), the OptEase Filter (Cordis, Roden, The Netherlands), and the ALN filter (ALN Implants Chirurgicaux, Ghisonaccia, France). Efficacy and safety data for retrievable filters are as yet based on small series, with a total number of fewer than 1,000 insertions, and follow-up is mostly short term. Current long-term data are poor and insufficient to warrant the long-term implantation of these devices into humans. The case of fractured wire from a Recovery filter that migrated to the heart causing pericardial tamponade requiring open heart surgery is a reminder that any new endovascular device remaining in situ in the long term may produce unexpected problems. We should also bear in mind that

  1. Implantable Heart Aid

    NASA Technical Reports Server (NTRS)

    1984-01-01

    CPI's human-implantable automatic implantable defibrillator (AID) is a heart assist system, derived from NASA's space circuitry technology, that can prevent erratic heart action known as arrhythmias. Implanted AID, consisting of microcomputer power source and two electrodes for sensing heart activity, recognizes onset of ventricular fibrillation (VF) and delivers corrective electrical countershock to restore rhythmic heartbeat.

  2. PAR for the Course: A Congruent Pedagogical Approach for a PAR Methods Class

    ERIC Educational Resources Information Center

    Hammond, Joyce D.; Hicks, Maria; Kalman, Rowenn; Miller, Jason

    2005-01-01

    In the past two years, three graduate students and a senior faculty member have co-taught a participatory action research (PAR) course to undergraduate and graduate students. In this article the co-teachers advocate a set of pedagogical principles and practices in a PAR-oriented classroom that establishes congruency with community PAR projects in…

  3. Transhepatic venous approach to permanent pacemaker placement in a patient with limited central venous access

    PubMed Central

    Siddiqui, Adeel M; Harris, Gregory S; Movahed, Assad; Chiang, Karl S; Chelu, Mihail G; Nekkanti, Rajasekhar

    2015-01-01

    The end-stage renal disease population poses a challenge for obtaining venous access required for life-saving invasive cardiac procedures. In this case report, we describe an adult patient with end-stage renal disease in whom the hepatic vein was the only available access to implant a single-lead permanent cardiac pacemaker. A 63-year-old male with end-stage renal disease on maintenance hemodialysis and permanent atrial fibrillation/atrial flutter presented with symptomatic bradycardia. Imaging studies revealed all traditional central venous access sites to be occluded/non-accessible. With the assistance of vascular interventional radiology, a trans-hepatic venous catheter was placed. This was then used to place a right ventricular pacing lead with close attention to numerous technical aspects. The procedure was completed successfully with placement of a single-lead permanent cardiac pacemaker. PMID:26380831

  4. Par Pond vegetation status Summer 1995 -- Summary

    SciTech Connect

    Mackey, H.E. Jr.; Riley, R.S.

    1996-01-01

    The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995. Communities similar to the pre-drawdown, Par Pond aquatic plant communities are becoming re-established. Emergent beds of maidencane, lotus, waterlily, and watershield are extensive and well developed. Cattail occurrence continued to increase during the summer, but large beds common to Par Pond prior to the drawdown have not formed. Estimates from SPOT HRV, remote sensing satellite data indicated that as much as 120 hectares of emergent wetlands vegetation may have been present along the Par Pond shoreline by early October, 1995. To track the continued development of macrophytes in Par Pond, future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.

  5. [Anesthesia management in implantation of baroreceptor stimulators].

    PubMed

    Werner, T; Lebar, L; Wittmann, S; Keyser, A; Fischer, M; Schmidli, J; Graf, B M; Zausig, Y A

    2015-09-01

    Baroreceptor stimulators are novel implantable devices that activate the carotid baroreceptor reflex. This results in a decrease in activity of the sympathetic nervous system and inhibition of the renin-angiotensin-aldosterone system. In patients with drug-resistant hypertension, permanent electrical activation of the baroreceptor reflex results in blood pressure reduction and cardiac remodeling. For correct intraoperative electrode placement at the carotid bifurcation, the baroreceptor reflex needs to be activated several times. Many common anesthetic agents, such as inhalation anesthetics and propofol dampen or inhibit the baroreceptor reflex and complicate or even prevent successful placement. Therefore, a specific anesthesia and pharmacological management is necessary to ensure successful implantation of baroreceptor reflex stimulators. PMID:26275386

  6. Torque Performance and Permanent Magnet Arrangement for Interior Permanent Magnet Synchronous Motor

    NASA Astrophysics Data System (ADS)

    Matsumoto, Naohisa; Sanada, Masayuki; Morimoto, Shigeo; Takeda, Yoji

    The use of the interior permanent magnet synchronous motor (IPMSM) has increased in the industrial field because of its excellent characteristics, such as high efficiency, wide range of speed operation and flexibility of the rotor structure. Therefore, the IPMSM, especially one using the rare earth permanent magnet, is being actively studied. In the IPMSM using the rare earth permanent magnet, typically the permanent magnet is deeply embedded in the rotor. However, torque performances are significantly influenced by the rotor structures. This paper describes the torque performances for a single-layer IPMSM using the rare earth permanent magnet when the permanent magnet arrangements are changed.

  7. Trends in Cochlear Implants

    PubMed Central

    Zeng, Fan-Gang

    2004-01-01

    More than 60,000 people worldwide use cochlear implants as a means to restore functional hearing. Although individual performance variability is still high, an average implant user can talk on the phone in a quiet environment. Cochlear-implant research has also matured as a field, as evidenced by the exponential growth in both the patient population and scientific publication. The present report examines current issues related to audiologic, clinical, engineering, anatomic, and physiologic aspects of cochlear implants, focusing on their psychophysical, speech, music, and cognitive performance. This report also forecasts clinical and research trends related to presurgical evaluation, fitting protocols, signal processing, and postsurgical rehabilitation in cochlear implants. Finally, a future landscape in amplification is presented that requires a unique, yet complementary, contribution from hearing aids, middle ear implants, and cochlear implants to achieve a total solution to the entire spectrum of hearing loss treatment and management. PMID:15247993

  8. Comparison of biochemical failure definitions for permanent prostate brachytherapy

    SciTech Connect

    Kuban, Deborah A. . E-mail: dakuban@mdanderson.org; Levy, Larry B.; Potters, Louis; Beyer, David C.; Blasko, John C.; Moran, Brian J.; Ciezki, Jay P.; Zietman, Anthony L.; Zelefsky, Michael J.; Pisansky, Thomas M.; Elshaikh, Mohamed; Horwitz, Eric M.

    2006-08-01

    Purpose: To assess prostate-specific antigen (PSA) failure definitions for patients with Stage T1-T2 prostate cancer treated by permanent prostate brachytherapy. Methods and Materials: A total of 2,693 patients treated with radioisotopic implant as solitary treatment for T1-T2 prostatic adenocarcinoma were studied. All patients had a pretreatment PSA, were treated at least 5 years before analysis, 1988 to 1998, and did not receive hormonal therapy before recurrence. Multiple PSA failure definitions were tested for their ability to predict clinical failure. Results: Definitions which determined failure by a certain increment of PSA rise above the lowest PSA level to date (nadir + x ng/mL) were more sensitive and specific than failure definitions based on PSA doubling time or a certain number of PSA rises. The sensitivity and specificity for the nadir + 2 definition were 72% and 83%, vs. 51% and 81% for 3 PSA rises. The surgical type definitions (PSA exceeding an absolute value) could match this sensitivity and specificity but only when failure was defined as exceeding a PSA level in the 1-3 ng/mL range and only when patients were allowed adequate time to nadir. When failure definitions were compared by time varying covariate regression analysis, nadir + 2 ng/mL retained the best fit. Conclusions: For patients treated by permanent radioisotopic implant for prostate cancer, the definition nadir + 2 ng/mL provides the best surrogate for failure throughout the entire follow-up period, similar to patients treated by external beam radiotherapy. Therefore, the same PSA failure definition could be used for both modalities. For brachytherapy patients with long-term follow-up, at least 6 years, defining failure as exceeding an absolute PSA level in the 0.5 ng/mL range may be reasonable.

  9. Augmented railgun using a permanent magnet

    SciTech Connect

    Katsuki, S.; Akiyama, H.; Eguchi, N.; Sueda, T.; Soejima, M.; Maeda, S.; Sato, K.N.

    1995-08-01

    The use of a permanent magnet instead of an electromagnet has been proposed for the augmentation of the magnetic field of a railgun driven by a current of approximately 20 kA. A permanent magnet has the following advantages in comparison with conventional augmentations using additional turns: (1) simple configuration of the system, (2) temporally and spatially constant magnetic fields, and (3) high efficiency. Here, the operation of a conventional railgun and that of an augmented railgun using a permanent magnet are compared experimentally, and the usefulness of the permanent magnet is described. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  10. ParAB Partition Dynamics in Firmicutes: Nucleoid Bound ParA Captures and Tethers ParB-Plasmid Complexes

    PubMed Central

    Lioy, Virginia S.; Volante, Andrea; Soberón, Nora E.; Lurz, Rudi; Ayora, Silvia; Alonso, Juan C.

    2015-01-01

    In Firmicutes, small homodimeric ParA-like (δ2) and ParB-like (ω2) proteins, in concert with cis-acting plasmid-borne parS and the host chromosome, secure stable plasmid inheritance in a growing bacterial population. This study shows that (ω:YFP)2 binding to parS facilitates plasmid clustering in the cytosol. (δ:GFP)2 requires ATP binding but not hydrolysis to localize onto the cell’s nucleoid as a fluorescent cloud. The interaction of (δ:CFP)2 or δ2 bound to the nucleoid with (ω:YFP)2 foci facilitates plasmid capture, from a very broad distribution, towards the nucleoid and plasmid pairing. parS-bound ω2 promotes redistribution of (δ:GFP)2, leading to the dynamic release of (δ:GFP)2 from the nucleoid, in a process favored by ATP hydrolysis and protein-protein interaction. (δD60A:GFP)2, which binds but cannot hydrolyze ATP, also forms unstable complexes on the nucleoid. In the presence of ω2, (δD60A:GFP)2 accumulates foci or patched structures on the nucleoid. We propose that (δ:GFP)2 binding to different nucleoid regions and to ω2-parS might generate (δ:GFP)2 gradients that could direct plasmid movement. The iterative pairing and unpairing cycles may tether plasmids equidistantly on the nucleoid to ensure faithful plasmid segregation by a mechanism compatible with the diffusion-ratchet mechanism as proposed from in vitro reconstituted systems. PMID:26161642

  11. Silicone breast implant materials.

    PubMed

    Daniels, A U

    2012-01-01

    This opinion article has been written on request because of the recent public controversy over silicone breast implants produced by a now-defunct company, Poly Implant Prosthese (PIP) in France. More than 300,000 PIP devices have been implanted. The purposes of my article are to (1.) provide a general overview of silicone breast implant materials, (2.) to describe the general safety of these materials as reported to date, and (3.) to summarise current publicly available information about these aspects of the PIP prostheses. The materials covered are the silicone rubber from which the implant shells are made and the silicone gel used to fill the shell. The materials safety issues are biocompatibility (especially of the gel) and biodurability of the shell. The literature reviewed indicates that biocompatibility is not an issue with other current generation implants. However, biodurability is. A rough estimate of implant shell rupture rate is ~10+% at 10 years. Information is still emerging about the PIP implants. Initial regulatory disclosures suggest the PIP implants may have both biocompatibility and biodurability problems. They also suggest that PIP implants may have been produced using silicone materials not certified as medical grade. Governmental health and regulatory agencies are just now in the process of deciding what actions should be taken to protect patients. PMID:22826101

  12. A Fully-Implanted Intramuscular Bipolar Myoelectric Signal Recording Electrode

    PubMed Central

    Memberg, William D.; Stage, Thomas G.; Kirsch, Robert F.

    2014-01-01

    Objectives To develop a fully-implanted, intramuscular, bipolar, myoelectric signal recording electrode (IM-MES) for functional electrical stimulation (FES), prosthetic myoelectric control, and other permanently implantable systems. Materials and Methods An existing fully-implanted intramuscular stimulating electrode was modified at each end to allow bipolar recording. The design change also required a modification of the implantation method. Mechanical and in vivo testing was performed on the novel components of the electrode. The first clinical application is also described. Results The electrode design modifications did not create any areas of excess mechanical strain on the wires at the distal end where the leads were wound into electrode surfaces. In vivo testing showed that the IM-MES electrode recorded myoelectric signals that were equivalent to an existing epimysial MES electrode. The modified implantation method was simple to implement. The IM-MES electrode was used in an upper extremity FES system in an individual with a spinal cord injury, and provided signals that were suitable for a command signal. Conclusions A fully-implanted, bipolar intramuscular recording electrode (IM-MES) was developed. Implantation of the IM-MES is straightforward and almost any muscle can be targeted. Testing has been performed to demonstrate the suitability of the IM-MES electrode for clinical use. Initial clinical applications were successful. PMID:24612356

  13. The double capsules in macro-textured breast implants.

    PubMed

    Giot, Jean-Philippe; Paek, Laurence S; Nizard, Nathanael; El-Diwany, Mostafa; Gaboury, Louis A; Nelea, Monica; Bou-Merhi, Joseph S; Harris, Patrick G; Danino, Michel A

    2015-10-01

    Breast implants are amongst the most widely used types of permanent implants in modern medicine and have both aesthetic and reconstructive applications with excellent biocompatibility. The double capsule is a complication associated with textured prostheses that leads to implant displacement; however, its etiology has yet to be elucidated. In this study, 10 double capsules were sampled from breast expander implants for in-depth analysis; histologically, the inner capsular layer demonstrated highly organized collagen in sheets with delamination of fibers. At the prosthesis interface (PI) where the implant shell contacts the inner capsular layer, scanning electron microscopy (SEM) revealed a thin layer which mirrored the three-dimensional characteristics of the implant texture; the external surface of the inner capsular layer facing the intercapsular space (ICS) was flat. SEM examination of the inner capsule layer revealed both a large bacterial presence as well as biofilm deposition at the PI; a significantly lower quantity of bacteria and biofilm were found at the ICS interface. These findings suggest that the double capsule phenomenon's etiopathogenesis is of mechanical origin. Delamination of the periprosthetic capsule leads to the creation of the ICS; the maintained separation of the 2 layers subsequently alters the biostability of the macro-textured breast implant. PMID:26210173

  14. Ion implantation induced nanotopography on titanium and bone cell adhesion

    NASA Astrophysics Data System (ADS)

    Braceras, Iñigo; Vera, Carolina; Ayerdi-Izquierdo, Ana; Muñoz, Roberto; Lorenzo, Jaione; Alvarez, Noelia; de Maeztu, Miguel Ángel

    2014-08-01

    Permanent endo-osseous implants require a fast, reliable and consistent osseointegration, i.e. intimate bonding between bone and implant, so biomechanical loads can be safely transferred. Among the parameters that affect this process, it is widely admitted that implant surface topography, surface energy and composition play an important role. Most surface treatments to improve osseointegration focus on micro-scale features, as few can effectively control the effects of the treatment at nanoscale. On the other hand, ion implantation allows controlling such nanofeatures. This study has investigated the nanotopography of titanium, as induced by different ion implantation surface treatments, its similarity with human bone tissue structure and its effect on human bone cell adhesion, as a first step in the process of osseointegration. The effect of ion implantation treatment parameters such as energy (40-80 keV), fluence (1-2 e17 ion/cm2) and ion species (Kr, Ar, Ne and Xe) on the nanotopography of medical grade titanium has been measured and assessed by AFM and contact angle. Then, in vitro tests have been performed to assess the effect of these nanotopographies on osteoblast adhesion. The results have shown that the nanostructure of bone and the studied ion implanted surfaces, without surface chemistry modification, are in the same range and that such modifications, in certain conditions, do have a statistically significant effect on bone tissue forming cell adhesion.

  15. Clinicopathologic correlate of a fresh eyelid pigment implantation

    SciTech Connect

    Tse, D.T.; Folberg, R.; Moore, K.

    1985-10-01

    An eyelid with freshly applied black eyeliner pigment was examined histologically. X-ray microanalysis of the pigment suspension from the manufacturer's vial indicated that its composition was 98% iron and 2% titanium. Transmission electron microscopic examination disclosed that particles were in the extracellular matrix; intracellular particles were not seen. By light microscopy, implant material was detected in various levels of the dermis and was found in dermal lymphatics as well as within and surrounding a hair follicle. This study suggests that systemic exposure to the implant material is possible and offers explanations for permanent eyelash loss, which the authors have seen following this procedure.

  16. Axillary vein technique for pacemaker and implantable defibrillator leads implantation: a safe and alternative approach?

    PubMed

    Migliore, Federico; Curnis, Antonio; Bertaglia, Emanuele

    2016-04-01

    Different methods for venous access are used for permanent pacemaker or implantable cardioverter defibrillator (ICD), of which subclavian vein puncture technique is the most widely practised. Although this approach is relatively easy to learn, quick and offers high success rates, it may be associated with potential serious acute complications including pneumothorax, emopneumothorax, brachial plexus injury and longer-term complications such as lead fracture, loss of lead insulation and subclavian crush syndrome especially in young patients with ICD leads. Axillary vein approach seems to be a favourable technique not only for the prevention of acute complications but also to reduce lead failure including lead insulation and lead fracture prevention with a consequently better long-term lead survival compared with the classical subclavian approach. Although randomized studies are lacking, recent reports not only evaluated the safety and effectiveness of new fluoroscopic axillary venous puncture technique, but also compared it with the conventional intrathoracic subclavian venous puncture technique for the implantation of leads in permanent pacing. Various techniques of axillary vein puncture have been proposed ranging from a blind percutaneous puncture to the use of different tools such as contrast venography and ultrasound. In this article, we report a case of subclavian crush syndrome, the use of a modified Bellot's technique of axillary vein puncture that we currently use and the potential benefits of axillary vein puncture for pacemaker and ICD leads implantation compared with subclavian approach to avoid acute and long-term lead complications. PMID:25252042

  17. Permanent versus Retrievable Inferior Vena Cava Filters: Rethinking the "One-Filter-for-All" Approach to Mechanical Thromboembolic Prophylaxis.

    PubMed

    Ghatan, Christine E; Ryu, Robert K

    2016-06-01

    Inferior vena cava (IVC) filtration for thromboembolic protection is not without risks, and there are important differences among commercially available IVC filters. While retrievable filters are approved for permanent implantation, they may be associated with higher device-related complications in the long term when compared with permanent filters. Prospective patient selection in determining which patients might be better served by permanent or retrievable filter devices is central to resource optimization, in addition to improved clinical follow-up and a concerted effort to retrieve filters when no longer needed. This article highlights the differences between permanent and retrievable devices, describes the interplay between these differences and the clinical indications for IVC filtration, advises against a "one-filter-for-all" approach to mechanical thromboembolic prophylaxis, and discusses strategies for optimizing personalized device selection. PMID:27247474

  18. Leadership in a (permanent) crisis.

    PubMed

    Heifetz, Ronald; Grashow, Alexander; Linsky, Marty

    2009-01-01

    The current economic crisis is not just another rough spell. Today's mix of urgency, high stakes, and uncertainty will continue even after the recession ends. The immediate crisis--which we will get through with policy makers' expert technical adjustments--sets the stage for a sustained, or even permanent, crisis, a relentless series of challenges no one has encountered before. Instead of hunkering down and relying on their familiar expertise to deal with the sustained crisis, people in positions of authority--whether they are CEOs or managers heading up a company initiative--must practice what the authors call adaptive leadership. They must, of course, tackle the underlying causes of the crisis, but they must also simultaneously make the changes that will allow their organizations to thrive in turbulent environments. Adaptive leadership is an improvisational and experimental art, requiring some new practices. Like Julie Gilbert, who overcame internal resistance to reorient Best Buy toward female purchasers, adaptive leaders get things done to meet today's challenges and then modify those things to thrive in tomorrow's world. They also embrace disequilibrium, using turbulence as an opportunity to build crucial new capacities, as Paul Levy did to rescue Beth Israel Deaconess Medical Center from a profound financial crisis. Finally, adaptive leaders, such as Egon Zehnder, the founder of an executive search firm, draw out the leadership skills that reside deep in the organization, recognizing the interdependence of all employees and mobilizing everyone to generate solutions. PMID:19630256

  19. Implant-connected versus tooth-connected implant-supported partial dentures: 2-year clinical and radiographic comparative evaluation.

    PubMed

    Mostafa, Tamer Mohamed; El-Sheikh, Mohamed M; Abd El-Fattah, Fadel

    2015-01-01

    The purpose of this study was to clinically and radiographically compare implant-connected and tooth-connected implant-supported fixed-detachable mandibular partial dentures. Twenty partially edentulous patients (age range: 25 to 50 years) with mandibular Kennedy Class II configurations were equally divided into two groups receiving a three-unit, fixed-detachable, screw-retained partial denture. Group 1 comprised patients with unilateral missing mandibular molars and premolars. Two implants were placed at the mandibular first premolar and first molar areas. Group 2 comprised patients with missing mandibular molars and second premolars. An implant was placed at the mandibular first molar area, the first premolar was prepared, and a coping was cemented to the tooth with permanent cement. Each case was evaluated clinically and radiographically at baseline (partial denture insertion) and after 6, 12, and 24 months. Data were collected and statistically analyzed using repeated-measures one-way and two-way analysis of variance tests. There was no statistically significant difference between the two groups (P > .05). The implant-tooth-supported prosthesis provided an equally predictable treatment option compared to the totally implant-supported prosthesis in terms of implant survival and loss of marginal bone. PMID:25909533

  20. Gating of Permanent Molds for ALuminum Casting

    SciTech Connect

    David Schwam; John F. Wallace; Tom Engle; Qingming Chang

    2004-03-30

    This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.

  1. Permanent-magnet multipole with adjustable strength

    DOEpatents

    Halbach, K.

    1982-09-20

    Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to each other to vary the coupling there between. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.

  2. Permanent magnet multipole with adjustable strength

    DOEpatents

    Halbach, Klaus

    1985-01-01

    Two or more magnetically soft pole pieces are symmetrically positioned along a longitudinal axis to provide a magnetic field within a space defined by the pole pieces. Two or more permanent magnets are mounted to an external magnetically-soft cylindrical sleeve which rotates to bring the permanent magnets into closer coupling with the pole pieces and thereby adjustably control the field strength of the magnetic field produced in the space defined by the pole pieces. The permanent magnets are preferably formed of rare earth cobalt (REC) material which has a high remanent magnetic field and a strong coercive force. The pole pieces and the permanent magnets have corresponding cylindrical surfaces which are positionable with respect to each other to vary the coupling therebetween. Auxiliary permanent magnets are provided between the pole pieces to provide additional magnetic flux to the magnetic field without saturating the pole pieces.

  3. Larynx: implants and stents

    PubMed Central

    Sittel, Christian

    2011-01-01

    In the human larynx, implants a primarily used for the correction of glottis insufficiency. In a broader sense laryngeal stents may be considered as implants as well. Laryngeal implants can be differentiated into injectable and solid. The most important representatives of both groups are discussed in detail along with the respective technique of application. Laryngeal stents are primarily used perioperatively. Different types and their use are presented. PMID:22073097

  4. Implants in adolescents

    PubMed Central

    Shah, Rohit A.; Mitra, Dipika K.; Rodrigues, Silvia V.; Pathare, Pragalbha N.; Podar, Rajesh S.; Vijayakar, Harshad N.

    2013-01-01

    Implants have gained tremendous popularity as a treatment modality for replacement of missing teeth in adults. There is extensive research present on the use of implants in adults, but there is a dearth of data available on the same in adolescents. The treatment planning and execution of implant placement in adolescents is still in its infancy. This review article is an attempt to bring together available literature. PMID:24174743

  5. Theoretical analysis of a transdermal ferromagnetic implant for retention of magnetic drug carrier particles

    NASA Astrophysics Data System (ADS)

    Avilés, Misael O.; Ebner, Armin D.; Chen, Haitao; Rosengart, Axel J.; Kaminski, Michael D.; Ritter, James A.

    2005-05-01

    The use of a ferromagnetic wire implant placed near an artery to assist the collection of magnetic drug carrier particles (MDCPs) using an external magnet is theoretically studied. Three magnetic drug targeting (MDT) systems are evaluated in terms of their MDCP collection efficiency (CE): a permanent magnet and wire is better than a permanent magnet alone, which is better than a homogeneous magnetic field and wire.

  6. Bioplastique: a new biphasic polymer for minimally invasive injection implantation.

    PubMed

    Ersek, R A; Beisang, A A

    1992-01-01

    The search for prosthetic materials that are biocompatible, nontoxic, and permanent led the authors to develop a micronized, inert, biphasic polymer particle for permanent soft tissue augmentation which neither migrates nor is absorbed by the body. Placed in a bioexcretable gel carrier, these textured microparticles are easily implanted using a specially designed blunt-tipped cannula with local anesthesia on an outpatient basis. Research using this implant material, Bioplastique (Bioplasty, St. Paul, MN), in rabbits has shown that when the textured particle size is maintained within a critical range, neither particle migration nor storage disease occurs. The gel carrier is rapidly phagocytized and replaced by fibrin matrix within a few days. Host collagen then gradually forms a fibrotic capsule around each textured particle, making use of the naturally occurring foreign body reaction to create a stable inplant. After being followed for over two years, Bioplastique has proven to be useful in many clinical applications with few complications. PMID:1734632

  7. Comparative cactus architecture and par interception

    SciTech Connect

    Geller, G.N.; Nobel, P.S. )

    1987-07-01

    Because CO{sup 2} uptake by cacti can be limited by low levels of photosynthetically active radiation (PAR) and because plant form affects PAR interception, various cactus forms were studied using a computer model, field measurements, and laboratory phototropic studies. Model predictions indicated that CO{sub 2} uptake by individual stems at an equinox was greatest when the stem were vertical, but at the summer and the winter solstice CO{sub 2} uptake was greatest for stems titled 30{degree} away from the equator. Stem tilting depended on form and taxonomic group. Not only can the shape of cacti be affected by PAR, but also shape influences PAR interception and hence CO{sub 2} uptake.

  8. Bulk Metallic Glasses for Implantable Medical Devices and Surgical Tools.

    PubMed

    Meagher, Philip; O'Cearbhaill, Eoin D; Byrne, James H; Browne, David J

    2016-07-01

    With increasing knowledge of the materials science of bulk metallic glasses (BMGs) and improvements in their properties and processing, they have started to become candidate materials for biomedical devices. A dichotomy in the types of medical applications has also emerged, in which some families of BMGs are being developed for permanent devices whilst another family - of Mg-based alloys - is showing promise in bioabsorbable implants. The current status of these metallurgical and technological developments is summarized. PMID:27031058

  9. Radioecological implications of the Par Pond drawdown

    SciTech Connect

    Hickey, H.; Whicker, F.W.

    1991-12-05

    The drawdown of the Par Pond reservoir created dramatic alterations in this formerly stable lentic ecosystem. In addition, the radiation environment at Par Pond has changed significantly because of the exposure of Cesium 137-contaminated sediments and the appearance of new transport pathways to the terrestrial environment. In response to this situation, SREL was asked to study the radioecological implications of the reservoir drawdown. This report contains the objectives, methods, and results of the SREL study.

  10. Permanency and the Foster Care System.

    PubMed

    Lockwood, Katie K; Friedman, Susan; Christian, Cindy W

    2015-10-01

    Each year over 20,000 youth age out of the child welfare system without reaching a permanent placement in a family. Certain children, such as those spending extended time in foster care, with a diagnosed disability, or adolescents, are at the highest risk for aging out. As young adults, this population is at and increased risk of incarceration; food, housing, and income insecurity; unemployment; educational deficits; receipt of public assistance; and mental health disorders. We reviewed the literature on foster care legislation, permanency, outcomes, and interventions. The outcomes of children who age out of the child welfare system are poor. Interventions to increase permanency include training programs for youth and foster parents, age extension for foster care and insurance coverage, an adoption tax credit, and specialized services and programs that support youth preparing for their transition to adulthood. Future ideas include expanding mentoring, educational support, mental health services, and post-permanency services to foster stability in foster care placements and encourage permanency planning. Children in the child welfare system are at a high risk for physical, mental, and emotional health problems that can lead to placement instability and create barriers to achieving permanency. Failure to reach the permanency of a family leads to poor outcomes, which have negative effects on the individual and society. Supporting youth in foster care throughout transitions may mediate the negative outcomes that have historically followed placement in out-of-home care. PMID:26403649

  11. Structural analysis of the ParR/parC plasmid partition complex.

    PubMed

    Møller-Jensen, Jakob; Ringgaard, Simon; Mercogliano, Christopher P; Gerdes, Kenn; Löwe, Jan

    2007-10-17

    Accurate DNA partition at cell division is vital to all living organisms. In bacteria, this process can involve partition loci, which are found on both chromosomes and plasmids. The initial step in Escherichia coli plasmid R1 partition involves the formation of a partition complex between the DNA-binding protein ParR and its cognate centromere site parC on the DNA. The partition complex is recognized by a second partition protein, the actin-like ATPase ParM, which forms filaments required for the active bidirectional movement of DNA replicates. Here, we present the 2.8 A crystal structure of ParR from E. coli plasmid pB171. ParR forms a tight dimer resembling a large family of dimeric ribbon-helix-helix (RHH)2 site-specific DNA-binding proteins. Crystallographic and electron microscopic data further indicate that ParR dimers assemble into a helix structure with DNA-binding sites facing outward. Genetic and biochemical experiments support a structural arrangement in which the centromere-like parC DNA is wrapped around a ParR protein scaffold. This structure holds implications for how ParM polymerization drives active DNA transport during plasmid partition. PMID:17898804

  12. Permanent Iodine-125 Interstitial Planar Seed Brachytherapy for Close or Positive Margins for Thoracic Malignancies

    SciTech Connect

    Mutyala, Subhakar; Stewart, Alexandra; Khan, Atif J.; Cormack, Robert A.; O'Farrell, Desmond; Sugarbaker, David; Devlin, Phillip M.

    2010-03-15

    Purpose: To assess toxicity and outcome following permanent iodine-125 seed implant as an adjunct to surgical resection in cases of advanced thoracic malignancy. Methods and Materials: An institutional review board-approved retrospective review was performed. Fifty-nine patients were identified as having undergone thoracic brachytherapy seed implantation between September 1999 and December 2006. Data for patient demographics, tumor details, and morbidity and mortality were recorded. Results: Fifty-nine patients received 64 implants. At a median follow-up of 17 months, 1-year and 2-year Kaplan-Meier rates of estimated overall survival were 94.1% and 82.0%, respectively. The 1-year and 2-year local control rates were 80.1% and 67.4%, respectively. The median time to develop local recurrence was 11 months. Grades 3 and 4 toxicity rates were 12% at 1 year. Conclusions: This review shows relatively low toxicity for interstitial planar seed implantation after thoracic surgical resection. The high local control results suggest that an incomplete oncologic surgery plus a brachytherapy implant for treating advanced thoracic malignancy merit further investigation.

  13. Permanent Magnetic Bearing for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    Morales, Winfredo; Fusaro, Robert; Kascak, Albert

    2008-01-01

    A permanent, totally passive magnetic bearing rig was designed, constructed, and tested. The suspension of the rotor was provided by two sets of radial permanent magnetic bearings operating in the repulsive mode. The axial support was provided by jewel bearings on both ends of the rotor. The rig was successfully operated to speeds of 5500 rpm using an air impeller. Radial and axial stiffnesses of the permanent magnetic bearings were experimentally measured and then compared to finite element results. The natural damping of the rotor was measured and a damping coefficient was calculated.

  14. Macroscopic simulation of isotropic permanent magnets

    NASA Astrophysics Data System (ADS)

    Bruckner, Florian; Abert, Claas; Vogler, Christoph; Heinrichs, Frank; Satz, Armin; Ausserlechner, Udo; Binder, Gernot; Koeck, Helmut; Suess, Dieter

    2016-03-01

    Accurate simulations of isotropic permanent magnets require to take the magnetization process into account and consider the anisotropic, nonlinear, and hysteretic material behaviour near the saturation configuration. An efficient method for the solution of the magnetostatic Maxwell equations including the description of isotropic permanent magnets is presented. The algorithm can easily be implemented on top of existing finite element methods and does not require a full characterization of the hysteresis of the magnetic material. Strayfield measurements of an isotropic permanent magnet and simulation results are in good agreement and highlight the importance of a proper description of the isotropic material.

  15. Permanent multipole magnets with adjustable strength

    SciTech Connect

    Halbach, K.

    1983-03-01

    Preceded by a short discussion of the motives for using permanent magnets in accelerators, a new type of permanent magnet for use in accelerators is presented. The basic design and most important properties of a quadrupole will be described that uses both steel and permanent magnet material. The field gradient produced by this magnet can be adjusted without changing any other aspect of the field produced by this quadrupole. The generalization of this concept to produce other multipole fields, or combination of multipole fields, will also be presented.

  16. Gold bead implants.

    PubMed

    Durkes, T E

    1992-03-01

    Gold bead implantation is an experimental area of study in the acupuncture field dealing with chronic diseases. Special acupuncture techniques are required to implant the gold beads successfully in the proper location. Gold beads are used to treat degenerative joint disease, osteochondritis, osteochondritis dessicans, ventral spondylosis, and seizures. PMID:1581658

  17. Implantable, Ingestible Electronic Thermometer

    NASA Technical Reports Server (NTRS)

    Kleinberg, Leonard

    1987-01-01

    Small quartz-crystal-controlled oscillator swallowed or surgically implanted provides continuous monitoring of patient's internal temperature. Receiver placed near patient measures oscillator frequency, and temperature inferred from previously determined variation of frequency with temperature. Frequency of crystal-controlled oscillator varies with temperature. Circuit made very small and implanted or ingested to measure internal body temperature.

  18. Synthetic facial implants.

    PubMed

    Quatela, Vito C; Chow, Jen

    2008-02-01

    This article presents a range of synthetic implant materials for use in facial plastic surgery. The authors discuss alternatives to autogenous tissue transfer in terms of biocompatibility, technique, complications, controversies, and cautions. The reader is presented information about a range of synthetic implant materials such as silicone, polyester fiber, polyamide mesh, metal, polyethylene, polyacrylamide gel, hydroxyapatite, polylactic acid, collagen, and others. PMID:18063244

  19. Smoking and dental implants

    PubMed Central

    Kasat, V.; Ladda, R.

    2012-01-01

    Smoking is a prevalent behaviour in the population. The aim of this review is to bring to light the effects of smoking on dental implants. These facts will assist dental professionals when implants are planned in tobacco users. A search of “PubMed” was made with the key words “dental implant,” “nicotine,” “smoking,” “tobacco,” and “osseointegration.” Also, publications on tobacco control by the Government of India were considered. For review, only those articles published from 1988 onward in English language were selected. Smoking has its influence on general as well as oral health of an individual. Tobacco negatively affects the outcome of almost all therapeutic procedures performed in the oral cavity. The failure rate of implant osseointegration is considerably higher among smokers, and maintenance of oral hygiene around the implants and the risk of peri-implantitis are adversely affected by smoking. To increase implant survival in smokers, various protocols have been recommended. Although osseointegrated dental implants have become the state of the art for tooth replacement, they are not without limitations or complications. In this litigious era, it is extremely important that the practitioner clearly understands and is able and willing to convey the spectrum of possible complications and their frequency to the patients. PMID:24478965

  20. Batteryless implanted echosonometer

    NASA Technical Reports Server (NTRS)

    Kojima, G. K.

    1977-01-01

    Miniature ultrasonic echosonometer implanted within laboratory animals obtains energy from RF power oscillator that is electronically transduced via induction loop to power receiving loop located just under animal's skin. Method of powering device offers significant advantages over those in which battery is part of implanted package.

  1. Implantable CMOS Biomedical Devices

    PubMed Central

    Ohta, Jun; Tokuda, Takashi; Sasagawa, Kiyotaka; Noda, Toshihiko

    2009-01-01

    The results of recent research on our implantable CMOS biomedical devices are reviewed. Topics include retinal prosthesis devices and deep-brain implantation devices for small animals. Fundamental device structures and characteristics as well as in vivo experiments are presented. PMID:22291554

  2. Clinical efficacy of modified partial pars plana vitrectomy combined with phacoemulsification for malignant glaucoma.

    PubMed

    He, F; Qian, Z; Lu, L; Jiang, J; Fan, X; Wang, Z; Xu, X

    2016-08-01

    ObjectiveThe objective of this study was to evaluate the clinical effects of modified partial pars plana vitrectomy together with phacoemulsification, intraocular lens (IOL) implantation, posterior capsulectomy, and zonulohyaloidectomy for patients with malignant glaucoma after trabeculectomy or cataract surgery.DesignRetrospective, cohort study.ParticipantsThirty consecutive patients (30 eyes) with malignant glaucoma after trabeculectomy surgery or ultrasonic phacoemulsification of cataract between January 2008 and September 2014 were enrolled.MethodsA retrospective analysis of 30 eyes with malignant glaucoma after trabeculectomy surgery for angle-closure glaucoma or ultrasonic phacoemulsification of cataract was performed. All patients underwent modified partial pars plana vitrectomy with zonulohyaloidectomy. Phacoemulsification and IOL implantation was performed in 25 patients with no previous cataract surgery. Pre-operative and post-operative ocular parameters were recorded in detail.Main outcome measuresClinical features, anterior chamber depth, best-corrected visual acuity, and intraocular pressure (IOP).ResultsIn these 30 patients, 25 had undergone trabeculectomy surgery and 5 had undergone cataract surgery. The mean axial length was 21.3±0.8 mm. After surgery, mean IOP decreased from 34±8.3 mm Hg to 10.5±4.1 mm Hg (P<0.001), and mean anterior chamber depth increased from 0.8±0.4 mm to 2.7±0.3 mm (P<0.001). No severe complications occurred.ConclusionsModified partial pars plana vitrectomy combined with phacoemulsification, IOL implantation, posterior capsulectomy, and zonulohyaloidectomy not only simplifies the process of traditional vitrectomy, but effectively resolves the ciliary block and corrects the misdirection of aqueous humor in malignant glaucoma. PMID:27229700

  3. Percutaneous and skeletal biocarbon implants

    NASA Technical Reports Server (NTRS)

    Mooney, V.

    1977-01-01

    Review of carbon implants developed by NASA discussed four different types of implants and subsequent improvements. Improvements could be of specific interest to rehabilitation centers and similar organizations.

  4. Risk Factors Associated With Complication Rates of Becker-Type Expander Implants in Relation to Implant Survival: Review of 314 Implants in 237 Patients.

    PubMed

    Taboada-Suarez, Antonio; Brea-García, Beatriz; Magán-Muñoz, Fernando; Couto-González, Iván; González-Álvarez, Eduardo

    2015-12-01

    Although autologous tissue reconstruction is the best option for breast reconstruction, using implants is still a reliable and simple method, offering acceptable aesthetic results. Becker-type implants are permanent implants that offer a 1-stage reconstructive option. A retrospective study was carried out in our center reviewing the clinical reports of 237 patients, in whom a total of 314 Becker-type prostheses were implanted. Overall survival was calculated using a Kaplan-Meier estimate. Cox proportional hazard models were used to calculate adjusted hazard ratios. At the end of the study, 214 expanders (68.15%) presented no complications, 40 (12.47%) developed significant capsular contracture, in 27 (8.60%) infection occurred, 24 (7.64%) suffered minor complications, and 9 (2.87%) ruptured. The mean survival time of the expanders was 120.41 months (95% CI: 109.62, 131.19). Radiotherapy, chemotherapy, high Molecular Immunology Borstel, age, mastectomy performed previously to the implant, ductal carcinoma, advanced tumoral stage, experience of the surgeon, and Becker 35-type implants were significantly related to a high number of complications in relation to the survival of the implants. Cox regression analysis revealed that the main risk factors for the survival of expander implants included radiotherapy and surgeon experience. The complication hazard ratio or relative risk caused by these 2 factors was 1.976 and 1.680, respectively. One-stage reconstruction using Becker-type expanders is an appropriate, simple, and reliable option in delayed breast reconstruction in patients who have not received radiotherapy and as long as the procedure is carried out by surgeons skilled in the technique. PMID:25003425

  5. Number of implants for mandibular implant overdentures: a systematic review

    PubMed Central

    Lee, Jeong-Yol; Kim, Ha-Young; Bryant, S. Ross

    2012-01-01

    PURPOSE The aim of this systematic review is to address treatment outcomes of Mandibular implant overdentures relative to implant survival rate, maintenance and complications, and patient satisfaction. MATERIALS AND METHODS A systematic literature search was conducted by a PubMed search strategy and hand-searching of relevant journals from included studies. Randomized Clinical Trials (RCT) and comparative clinical trial studies on mandibular implant overdentures until August, 2010 were selected. Eleven studies from 1098 studies were finally selected and data were analyzed relative to number of implants. RESULTS Six studies presented the data of the implant survival rate which ranged from 95% to 100% for 2 and 4 implant group and from 81.8% to 96.1% for 1 and 2 implant group. One study, which statistically compared implant survival rate showed no significant differences relative to the number of implants. The most common type of prosthetic maintenance and complications were replacement or reattaching of loose clips for 2 and 4 implant group, and denture repair due to the fracture around an implant for 1 and 2 implant groups. Most studies showed no significant differences in the rate of prosthetic maintenance and complication, and patient satisfaction regardless the number of implants. CONCLUSION The implant survival rate of mandibular overdentures is high regardless of the number of implants. Denture maintenance is likely not inflenced substantially by the number of implants and patient satisfaction is typically high again regardless os the number of implants. PMID:23236572

  6. Graphene for Biomedical Implants

    NASA Astrophysics Data System (ADS)

    Moore, Thomas; Podila, Ramakrishna; Alexis, Frank; Rao, Apparao; Clemson Bioengineering Team; Clemson Physics Team

    2013-03-01

    In this study, we used graphene, a one-atom thick sheet of carbon atoms, to modify the surfaces of existing implant materials to enhance both bio- and hemo-compatibility. This novel effort meets all functional criteria for a biomedical implant coating as it is chemically inert, atomically smooth and highly durable, with the potential for greatly enhancing the effectiveness of such implants. Specifically, graphene coatings on nitinol, a widely used implant and stent material, showed that graphene coated nitinol (Gr-NiTi) supports excellent smooth muscle and endothelial cell growth leading to better cell proliferation. We further determined that the serum albumin adsorption on Gr-NiTi is greater than that of fibrinogen, an important and well understood criterion for promoting a lower thrombosis rate. These hemo-and biocompatible properties and associated charge transfer mechanisms, along with high strength, chemical inertness and durability give graphene an edge over most antithrombogenic coatings for biomedical implants and devices.

  7. [Implantable medical devices].

    PubMed

    Crickx, B; Arrault, X

    2008-01-01

    Medical devices have been individualized to include a category of implantable medical devices, "designed to be totally implanted in the human body or to replace an epithelial surface or a surface of the eye, through surgery, and remain in place after the intervention" (directive 93/42/CEE and decree of 20 April 206). Each implantable medical device has a common name and a commercial name for precise identification of the model (type/references). The users' service and the implanting physician should be clearly identified. There are a number of rules concerning health traceability to rapidly identify patients exposed to risks in which the implantable medical devices of a particular batch or series were used and to monitor the consequences. The traceability data should be preserved 10 years and the patient's medical file for 20 years. PMID:18442666

  8. Cochlear implants in children.

    PubMed

    Young, N M

    1994-04-01

    Children with such profound deafness that they are not helped by hearing aids are now candidates for cochlear implantation. This technology permits us to provide these children with a significant degree of useful hearing. The degree of improvement in speech perception and spoken language in pediatric cochlear implant recipients varies. However, the younger the children and the less time they have been completely deprived of auditory stimuli, the more likely they are to make significant progress. The evaluation of the deaf child for implantation is best done by a multidisciplinary team who understands the needs of hearing-impaired children and who can work with the family, the child, and classroom teachers, as well as other school professionals. The decision to proceed with cochlear implantation in a child is one that requires long-term commitment on the part of the family and the cochlear implant team. PMID:8039409

  9. Combined Left Atrial Appendage Closure and Pacemaker Implant through a Single Right Femoral Vein Access.

    PubMed

    Regoli, François; Moccetti, Tiziano; Pasotti, Elena; Auricchio, Angelo; Moccetti, Marco

    2016-08-01

    Left atrial appendage (LAA) closure is indicated in patients with atrial fibrillation (AF) and high bleeding as well as thromboembolic risks. A subgroup of these patients may also present an indication for a single-chamber permanent pacemaker due to symptomatic low-rate AF or when "ablate and pace" strategy is indicated for rate control. A miniaturized wireless transcatheter pacing system (TPS) is now available as a single-chamber permanent pacemaker. This case presents how combined LAA closure and permanent pacemaker implant, by means of TPS, is feasible through a single femoral venous access. PMID:26970532

  10. Techniques for measuring intercepted and absorbed PAR in corn canopies

    NASA Technical Reports Server (NTRS)

    Gallo, K. P.; Daughtry, C. S. T.

    1984-01-01

    The quantity of radiation potentially available for photosynthesis that is captured by the crop is best described as absorbed photosynthetically active radiation (PAR). Absorbed PAR (APAR) is the difference between descending and ascending fluxes. The four components of APAR were measured above and within two planting densities of corn (Zea mays L.) and several methods of measuring and estimating APAR were examined. A line quantum sensor that spatially averages the photosynthetic photon flux density provided a rapid and portable method of measuring APAR. PAR reflectance from the soil (Typic Argiaquoll) surface decreased from 10% to less than 1% of the incoming PAR as the canopy cover increased. PAR reflectance from the canopy decreased to less than 3% at maximum vegetative cover. Intercepted PAR (1 - transmitted PAR) generally overestimated absorbed PAR by less than 4% throughout most of the growing season. Thus intercepted PAR appears to be a reasonable estimate of absorbed PAR.