WorldWideScience

Sample records for blood vessel prosthesis implantation

  1. 3-D trajectory model for MDT using micro-spheres implanted within large blood vessels

    Science.gov (United States)

    Choomphon-anomakhun, Natthaphon; Natenapit, Mayuree

    2016-09-01

    Implant assisted magnetic drug targeting (IA-MDT) using ferromagnetic spherical targets implanted within large blood vessels and subjected to a uniform externally applied magnetic field (H0) has been investigated and reported for the first time. The capture areas (As) of magnetic drug carrier particles (MDCPs) were determined from the analysis of particle trajectories simulated from equations of motion. Then, the effects of various parameters, such as types of ferromagnetic materials in the targets and MDCPs, blood flow rates, mass fraction of the ferromagnetic material in the MDCPs, average radii of MDCPs (Rp) and the strength of H0 on the As were obtained. Furthermore, the effects of saturation magnetization of the ferromagnetic materials in the MDCPs and within the targets on the As were analyzed. After this, the suitable strengths of H0 and Rp for IA-MDT designs were reported. Dimensionless As, ranging from 2 to 7, was obtained with Rp ranging from 500 to 2500 nm, μ0H0 less than 0.8 T and a blood flow rate of 0.1 m s-1. The target-MDCP materials considered are iron-iron, iron-magnetite and SS409-magnetite, respectively.

  2. Implantable tissue-engineered blood vessels from human induced pluripotent stem cells.

    Science.gov (United States)

    Gui, Liqiong; Dash, Biraja C; Luo, Jiesi; Qin, Lingfeng; Zhao, Liping; Yamamoto, Kota; Hashimoto, Takuya; Wu, Hongwei; Dardik, Alan; Tellides, George; Niklason, Laura E; Qyang, Yibing

    2016-09-01

    Derivation of functional vascular smooth muscle cells (VSMCs) from human induced pluripotent stem cells (hiPSCs) to generate tissue-engineered blood vessels (TEBVs) holds great potential in treating patients with vascular diseases. Herein, hiPSCs were differentiated into alpha-smooth muscle actin (α-SMA) and calponin-positive VSMCs, which were seeded onto polymer scaffolds in bioreactors for vascular tissue growth. A functional TEBV with abundant collagenous matrix and sound mechanics resulted, which contained cells largely positive for α-SMA and smooth muscle myosin heavy chain (SM-MHC). Moreover, when hiPSC-derived TEBV segments were implanted into nude rats as abdominal aorta interposition grafts, they remained unruptured and patent with active vascular remodeling, and showed no evidence of teratoma formation during a 2-week proof-of-principle study. Our studies represent the development of the first implantable TEBVs based on hiPSCs, and pave the way for developing autologous or allogeneic grafts for clinical use in patients with vascular disease. PMID:27336184

  3. Implant-Retained Auricular Prosthesis: A Case Report

    OpenAIRE

    Ozturk, A. Nilgun; Usumez, Aslihan; Tosun, Zekeriya

    2010-01-01

    Extraoral implant retained prosthesis have been proven to be a predictable treatment option for maxillofacial rehabilitation. This case report describes the clinical and laboratory procedures for fabricating an auricular prosthesis. In this case report, an auricular prosthesis was fabricated for a patient who lost the left and right external ear in an electrical burn. Extraoral implants and bar-and-clip retention for the proper connection of the auricular prosthesis to implant were used. This...

  4. 21 CFR 874.3695 - Mandibular implant facial prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mandibular implant facial prosthesis. 874.3695... facial prosthesis. (a) Identification. A mandibular implant facial prosthesis is a device that is... made of materials such as stainless steel, tantalum, titanium, cobalt-chromium based...

  5. Investigation of source-detector separation optimization for an implantable perfusion and oxygenation sensor for liver blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Justin S [ORNL; Akl, Tony [Texas A& M University; Cote, Gerard L. [Texas A& M University; Wilson, Mark A. [University of Pittsburgh School of Medicine, Pittsburgh PA; Ericson, Milton Nance [ORNL

    2011-01-01

    An implanted system is being developed to monitor transplanted liver health during the critical 7-10 day period posttransplantation. The unit will monitor organ perfusion and oxygen consumption using optically-based probes placed on both the inflow and outflow blood vessels, and on the liver parenchymal surface. Sensing probes are based on a 3- wavelength LED source and a photodiode detector. Sample diffuse reflectance is measured at 735, 805, and 940 nm. To ascertain optimal source-to-photodetector spacing for perfusion measurement in blood vessels, an ex vivo study was conducted. In this work, a dye mixture simulating 80% blood oxygen saturation was developed and perfused through excised porcine arteries while collecting data for various preset probe source-to-photodetector spacings. The results from this study demonstrate a decrease in the optical signal with decreasing LED drive current and a reduction in perfusion index signal with increasing probe spacing. They also reveal a 2- to 4-mm optimal range for blood vessel perfusion probe source-to-photodetector spacing that allows for sufficient perfusion signal modulation depth with maximized signal to noise ratio (SNR). These findings are currently being applied to guide electronic configuration and probe placement for in vivo liver perfusion porcine model studies.

  6. 21 CFR 872.3970 - Interarticular disc prosthesis (interpositional implant).

    Science.gov (United States)

    2010-04-01

    ... implant). 872.3970 Section 872.3970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... disc prosthesis (interpositional implant). (a) Identification. An interarticular disc prosthesis (interpositional implant) is a device that is intended to be an interface between the natural articulating...

  7. Computational blood flow and vessel wall modeling in a CT-based thoracic aorta after stent-graft implantation

    Science.gov (United States)

    Hazer, Dilana; Stoll, Markus; Schmidt, Eduard; Richter, Goetz-M.; Dillmann, Rüdiger

    2010-03-01

    Abnormal blood flow conditions and structural fatigue within stented vessels may lead to undesired failure causing death to the patient. Image-based computational modeling provides a physical and realistic insight into the patientspecific biomechanics and enables accurate predictive simulations of development, growth and failure of cardiovascular diseases as well as associated risks. Controlling the efficiency of an endovascular treatment is necessary for the evaluation of potential complications and predictions on the assessment of the pathological state. In this paper we investigate the effects of stent-graft implantation on the biomechanics in a patient-specific thoracic aortic model. The patient geometry and the implanted stent-graft are obtained from morphological data based on a CT scan performed during a controlling routine. Computational fluid dynamics (CFD) and computational structure mechanics (CSM) simulations are conducted based on the finite volume method (FVM) and on the finite element method (FEM) to compute the hemodynamics and the elastomechanics within the aortic model, respectively. Physiological data based on transient pressure and velocity profiles are used to set the necessary boundary conditions. Further, the effects of various boundary conditions and definition of contact interactions on the numerical stability of the blood flow and the vessel wall simulation results are also investigated. The quantification of the hemodynamics and the elastomechanics post endovascular intervention provides a realistic controlling of the state of the stented vessel and of the efficiency of the therapy. Consequently, computational modeling would help in evaluating individual therapies and optimal treatment strategies in the field of minimally invasive endovascular surgery.

  8. Examining blood vessels

    International Nuclear Information System (INIS)

    This patent specification relates to an invention concerned with improvements in or relating to the examination of blood vessels of interest. Particles of dimensions not greater than 8 microns capable of providing detectable signals, are introduced into the blood for examination of a blood vessel. The particles may be sources of radiation, e.g. Ga68. (author)

  9. Cochlear implantation: a biomechanical prosthesis for hearing loss

    OpenAIRE

    Yawn, Robert; Hunter, Jacob B.; Sweeney, Alex D.; Bennett, Marc L.

    2015-01-01

    Cochlear implants are a medical prosthesis used to treat sensorineural deafness, and one of the greatest advances in modern medicine. The following article is an overview of cochlear implant technology. The history of cochlear implantation and the development of modern implant technology will be discussed, as well as current surgical techniques. Research regarding expansion of candidacy, hearing preservation cochlear implantation, and implantation for unilateral deafness are described. Lastly...

  10. Prosthesis

    Science.gov (United States)

    ... by prosthetic devices. False teeth are known as dental prostheses. An artificial replacement of the jaw bone is called a maxillofacial prosthesis. Penis implants are also known as penile prostheses.

  11. Mastication Improvement After Partial Implant-supported Prosthesis Use

    OpenAIRE

    Gonçalves, T.M.S.V.; Campos, C.H.; Gonçalves, G.M.; Moraes, M; Rodrigues Garcia, R.C.M.

    2013-01-01

    Partially edentulous patients may be rehabilitated by the placement of removable dental prostheses, implant-supported removable dental prostheses, or partial implant fixed dental prostheses. However, it is unclear the impact of each prosthesis type over the masticatory aspects, which represents the objective of this paired clinical trial. Twelve patients sequentially received and used each of these 3 prosthesis types for 2 months, after which maximum bite force was assessed by a strain sensor...

  12. Mandrels For Microtextured Small-Vessel Implants

    Science.gov (United States)

    Deininger, William D.; Gabriel, Stephen B.

    1989-01-01

    Research shows artificial blood-vessel and heart-valve implants made more compatible with their biological environments by use of regularly microtextured surfaces. In new manufacturing process, ion beam etches patterned array of small pillars on mandrel used to mold tubular plastic implant. Pillars create tiny regularly spaced holes in inner surface of tube. Holes expected to provide sites for attachment of healthy lining. Polytetrafluoroethylene (PTFE) used as mandrel material because it can be etched by ion beam.

  13. Split-Framework in Mandibular Implant-Supported Prosthesis

    Directory of Open Access Journals (Sweden)

    Danny Omar Mendoza Marin

    2015-01-01

    Full Text Available During oral rehabilitation of an edentulous patient with an implant-supported prosthesis, mandibular flexure must be considered an important biomechanical factor when planning the metal framework design, especially if implants are installed posterior to the interforaminal region. When an edentulous mandible is restored with a fixed implant-supported prosthesis connected by a fixed full-arch framework, mandibular flexure may cause needless stress in the overall restorative system and lead to screw loosening, poor fit of prosthesis, loss of the posterior implant, and patient’s discomfort due to deformation properties of the mandible during functional movements. The use of a split-framework could decrease the stress with a precise and passive fit on the implants and restore a more natural functional condition of the mandible, helping in the longevity of the prosthesis. Therefore, the present clinical report describes the oral rehabilitation of an edentulous patient by a mandibular fixed implant-supported prosthesis with a split-framework to compensate for mandibular flexure. Clinical Significance. The present clinical report shows that the use of a split-framework reduced the risk of loss of the posterior implants or screws loosening with acceptable patient comfort over the period of a year. The split-framework might have compensated for the mandibular flexure during functional activities.

  14. Tumor Blood Vessel Dynamics

    Science.gov (United States)

    Munn, Lance

    2009-11-01

    ``Normalization'' of tumor blood vessels has shown promise to improve the efficacy of chemotherapeutics. In theory, anti-angiogenic drugs targeting endothelial VEGF signaling can improve vessel network structure and function, enhancing the transport of subsequent cytotoxic drugs to cancer cells. In practice, the effects are unpredictable, with varying levels of success. The predominant effects of anti-VEGF therapies are decreased vessel leakiness (hydraulic conductivity), decreased vessel diameters and pruning of the immature vessel network. It is thought that each of these can influence perfusion of the vessel network, inducing flow in regions that were previously sluggish or stagnant. Unfortunately, when anti-VEGF therapies affect vessel structure and function, the changes are dynamic and overlapping in time, and it has been difficult to identify a consistent and predictable normalization ``window'' during which perfusion and subsequent drug delivery is optimal. This is largely due to the non-linearity in the system, and the inability to distinguish the effects of decreased vessel leakiness from those due to network structural changes in clinical trials or animal studies. We have developed a mathematical model to calculate blood flow in complex tumor networks imaged by two-photon microscopy. The model incorporates the necessary and sufficient components for addressing the problem of normalization of tumor vasculature: i) lattice-Boltzmann calculations of the full flow field within the vasculature and within the tissue, ii) diffusion and convection of soluble species such as oxygen or drugs within vessels and the tissue domain, iii) distinct and spatially-resolved vessel hydraulic conductivities and permeabilities for each species, iv) erythrocyte particles advecting in the flow and delivering oxygen with real oxygen release kinetics, v) shear stress-mediated vascular remodeling. This model, guided by multi-parameter intravital imaging of tumor vessel structure

  15. An organized start to implant-supported prosthesis

    OpenAIRE

    Suma Karthigeyan; Seyed Ashraff Ali; Kalarani Mohan; Mangala Deivanai

    2013-01-01

    Various treatment options are available for rehabilitating the complete edentulous patients with implants. However, due consideration for the prosthesis is not given prior to implant surgery. This can result in implant being placed in locations that do not provide the best esthetic and functional result. Incorrect implant localization and angle are the primary cause of non-axial loading and may contribute to loss of Osseo-integration. For predictable outcome, the treatment should begin with v...

  16. Transcatheter aortic valve prosthesis surgically replaced 4 months after implantation

    DEFF Research Database (Denmark)

    Thyregod, Hans Gustav; Lund, Jens Teglgaard; Engstrøm, Thomas;

    2010-01-01

    Transcatheter aortic valve implantation is a new and rapidly evolving treatment option for high-risk surgical patients with degenerative aortic valve stenosis. Long-term results with these new valve prostheses are lacking, and potential valve dysfunction and failure would require valve replacemen....... We report the first case of surgical valve replacement in a patient with a dysfunctional transcatheter-implanted aortic valve prosthesis 4 months after implantation....

  17. Penile prosthesis implantation in a transsexual neophallus

    Institute of Scientific and Technical Information of China (English)

    Hui-MengTAN

    2000-01-01

    Reconstruction surgery for a female to male transsexual usually involves mastectomy, hysterectomy and creating an aesthetically appealing neophallus. We have successfully inserted an inflatable prosthesis using the AMS CX prosthesis in a 45 year old transsexual, who had a large bulky neophallus constructed from the anterior abdominal subcutaneous fat, about 9 years ago. The single cylinder CX prosthesis was well anchored to the symphysis pubis using a dacron windsock tubing, the activation pump was placed in the dependent pouch of the right labium and the reservior in the usual perivesical space. The patient subsequently had debulking procedure using liposuction to create a more aesthetic and functional phallus. To date, the inflatable neophallus prosthesis is functioning well. (Asian J Androl 2000 Dec;2:304-306)

  18. Immediate placement and loading of implants in anterior maxilla using an altered screw-retained implant fixed prosthesis

    Directory of Open Access Journals (Sweden)

    Baig Mirza

    2010-01-01

    Full Text Available This article describes the immediate placement and loading of implants in the aesthetic zone using an implant-retained, fixed prosthesis with a modified design. One section of the implant prosthesis has cemented crowns and the other section is the conventional screw-retained. This combined approach significantly offsets the unsuitable implant position, alignment or angulation, while ensuring the easy retrievability, repair and maintenance of the prosthesis at the same time.

  19. Stress Distribution in Implant Retained Finger Prosthesis: A Finite Element Study

    OpenAIRE

    Amornvit, Pokpong; Rokaya, Dinesh; Keawcharoen, Konrawee; Thongpulsawasdi, Nimit

    2013-01-01

    Background: Finger amputation may result from congenital cause, trauma, infection and tumours. The finger amputation may be rehabilitated with dental implant-retained finger prosthesis. The success of implant-retained finger prosthesis is determined by the implant loading. The type of the force is a determining factor in implant loading.

  20. Intraoral framework pick-up technique to improve fit of a metal-resin implant prosthesis

    Directory of Open Access Journals (Sweden)

    Mirza Rustum Baig

    2012-01-01

    Full Text Available The achievement of passive fit is an important prerequisite for the prevention of complications in full-arch screw-retained implant prosthesis. With cemented prosthesis, the cementation compensates for the discrepancies in the cast framework, but the lack of retrievability seems undesirable. The aim of this paper is to propose a modified screw-retained prosthesis design for complete arch implant fixed rehabilitation. A technique for the fabrication of a full-arch metal-resin implant-supported screw-retained prosthesis is described. Cementation of the framework to the abutments intraorally improves the passivity of fit of the prosthesis on the implants. Maintenance of screw-access channels in the final prosthesis ensures retrievability. The metal-resin design allows for easy repair and maintenance. The prosthesis is cost-effective compared to conventional options and can be employed as a viable treatment alternative when considering metal-acrylic resin complete arch fixed prosthesis.

  1. Maxillary cement retained implant supported monolithic zirconia prosthesis in a full mouth rehabilitation: a clinical report

    OpenAIRE

    Sadid-Zadeh, Ramtin; Liu, Perng-Ru; Aponte-Wesson, Ruth; O'Neal, Sandra J

    2013-01-01

    This clinical report presents the reconstruction of a maxillary arch with a cement retained implant supported fixed prosthesis using a monolithic zirconia generated by CAD/CAM system on eight osseointegrated implants. The prosthesis was copy milled from an interim prosthesis minimizing occlusal adjustments on the definitive prosthesis at the time of delivery. Monolithic zirconia provides high esthetics and reduces the number of metal alloys used in the oral cavity.

  2. Modified cementless total coxofemoral prosthesis: development, implantation and clinical evaluation

    Directory of Open Access Journals (Sweden)

    S.A. Arias

    2013-12-01

    Full Text Available The aim of this study was to modify canine coxofemoral prostheses and the clinical evaluation of the implantation. Fifteen canine hips and femora of cadavers were used in order to study the surface points of modification in prostheses and develop a perforation guide. Femoral stems and acetabular components were perforated and coated with biphasic calcium phosphate layer. Twelve young adult male mongrel dogs were implanted with coxofemoral prostheses. Six were operated upon and implanted with cemented canine modular hip prostheses, establishing the control group. The remaining six were implanted with a novel design of cementless porous tricalcic phosphate-hydroxyapatite coated hip prostheses. Clinical and orthopedic performance, complications, and thigh muscular hypotrophy were assessed up to the 120th post-operatory day. After 120 days, animals with cementless prostheses had similar clinical and orthopedic performance compared to the cemented group despite the increased pain thigh hypotrophy. Animals that underwent cementless hip prosthesis evidenced more pain, compared to animals with cemented hip prosthesis that required longer recuperation time. No luxations, two fractures and two isquiatic neurapraxies were identified in the course of the study. Using both the cemented and the bioactive coated cementless model were suitable to dogs, showing clinical satisfactory results. Osseointegration and biological fixation were observed in the animals with the modified cementless hip prosthesis.

  3. Replacement of a Dislocated Aortic Prosthesis After Transcatheter Valve Implantation.

    Science.gov (United States)

    Mandegar, Mohammad Hossein; Moradi, Bahieh; Roshanali, Farideh

    2016-06-01

    A 77-year-old woman who had severe symptomatic aortic stenosis and was a high risk for conventional surgery underwent transcatheter aortic valve implantation by means of the transfemoral approach. The prosthesis migrated and became embolized in the left ventricle after inflation, causing interference with the mitral valve and also partial outflow tract obstruction. The patient was emergently transferred to the operating room. Vertical aortotomy was performed under cardiopulmonary bypass, and the calcified native leaflets were removed. The migrated Edwards SAPIEN XT valve was extracted and subsequently successfully sewn into the annulus after examination for leaflet and stent competence. The hemodynamic performance of the implanted valve was surprisingly more favorable than that of the conventional tissue prosthesis. PMID:27211978

  4. Stress analysis of different prosthesis materials in implant-supported fixed dental prosthesis using 3D finite element method

    OpenAIRE

    Pedram Iranmanesh; Alireza Abedian; Naeimeh Nasri; Ehsan Ghasemi; Saber Khazaei

    2014-01-01

    Introduction: In the present study, the finite element method (FEM) was used to investigate the effects of prosthesis material types on stress distribution of the bone surrounding implants and to evaluate stress distribution in three-unit implant-supported fixed dental prosthesis (FDP). Materials and Methods: A three-dimensional (3D) finite element FDP model of the maxillary second premolar to the second molar was designed. Three load conditions were statically applied on the functional cusps...

  5. Rehabilitation of orbital defect with silicone orbital prosthesis retained by dental implants

    Science.gov (United States)

    Guttal, Satyabodh Shesharaj; Desai, Jhanvi; Kudva, Adarsh; Patil, Basavaraj R

    2016-01-01

    Orbital defects can result from cancer, birth anomalies, or trauma leading to an onslaught of problems in the function and psyche of the patient. These defects are restored by surgical reconstruction and followed by placement of orbital prosthesis for cosmetic makeup. The use of dental implants in retaining orbital prosthesis improves patient acceptance of the prosthesis owing to better retention and stability than conventional adhesive retained prosthesis. This case report describes a custom-made magnetic retentive assembly anchored by a dental implant which offers the orbital prosthesis the simplicity of self-alignment and ease of use. PMID:26953033

  6. Rehabilitation of orbital defect with silicone orbital prosthesis retained by dental implants

    OpenAIRE

    Satyabodh Shesharaj Guttal; Jhanvi Desai; Adarsh Kudva; Patil, Basavaraj R.

    2016-01-01

    Orbital defects can result from cancer, birth anomalies, or trauma leading to an onslaught of problems in the function and psyche of the patient. These defects are restored by surgical reconstruction and followed by placement of orbital prosthesis for cosmetic makeup. The use of dental implants in retaining orbital prosthesis improves patient acceptance of the prosthesis owing to better retention and stability than conventional adhesive retained prosthesis. This case report describes a custom...

  7. Axial penile rigidity influences patient and partner satisfaction after penile prosthesis implantation

    OpenAIRE

    Abdulla Al Ansari; Raidh A. Talib; Onder Canguven; Ahmad Shamsodini

    2013-01-01

    Introduction: Penile prosthesis implantation is one of the treatment choices that is kept for patients who were not satisfied with other treatments. Although penile prosthesis satisfaction rates are higher, there are some dissatisfied patients. The patients’ reasons are mostly shortness and softness of implanted prosthesis. It was previously demonstrated that penile axial rigidity of more than 500 grams is enough for successful vaginal intromission. To our knowledge, there is no study c...

  8. Blood vessel rupture by cavitation

    OpenAIRE

    Chen, Hong; Brayman, Andrew A.; Bailey, Michael R.; Matula, Thomas J.

    2010-01-01

    Cavitation is thought to be one mechanism for vessel rupture during shock wave lithotripsy treatment. However, just how cavitation induces vessel rupture remains unknown. In this work, a high-speed photomicrography system was set up to directly observe the dynamics of bubbles inside blood vessels in ex vivo rat mesenteries. Vascular rupture correlating to observed bubble dynamics were examined by imaging bubble extravasation and dye leakage. The high-speed images show that bubble expansion ca...

  9. Amputation and prosthesis implantation shape body and peripersonal space representations

    OpenAIRE

    Elisa Canzoneri; Marilena Marzolla; Amedeo Amoresano; Gennaro Verni; Andrea Serino

    2013-01-01

    Little is known about whether and how multimodal representations of the body (BRs) and of the space around the body (Peripersonal Space, PPS) adapt to amputation and prosthesis implantation. In order to investigate this issue, we tested BR in a group of upper limb amputees by means of a tactile distance perception task and PPS by means of an audio-tactile interaction task. Subjects performed the tasks with stimulation either on the healthy limb or the stump of the amputated limb, while wearin...

  10. Effects of Vestibular Prosthesis Electrode Implantation and Stimulation on Hearing in Rhesus Monkeys

    OpenAIRE

    Dai, Chenkai; Fridman, Gene Y.; Della Santina, Charles C.

    2010-01-01

    To investigate the effects of vestibular prosthesis electrode implantation and activation on hearing in rhesus monkeys, we measured auditory brainstem responses (ABR) and distortion product otoacoustic emissions (DPOAE) in four rhesus monkeys before and after unilateral implantation of vestibular prosthesis electrodes in each of 3 left semicircular canals (SCC). Each of the 3 left SCCs were implanted with electrodes via a transmastoid approach. Right ears, which served as controls, were not s...

  11. Axial penile rigidity influences patient and partner satisfaction after penile prosthesis implantation

    Directory of Open Access Journals (Sweden)

    Abdulla Al Ansari

    2013-09-01

    Full Text Available Introduction: Penile prosthesis implantation is one of the treatment choices that is kept for patients who were not satisfied with other treatments. Although penile prosthesis satisfaction rates are higher, there are some dissatisfied patients. The patients’ reasons are mostly shortness and softness of implanted prosthesis. It was previously demonstrated that penile axial rigidity of more than 500 grams is enough for successful vaginal intromission. To our knowledge, there is no study comparing axial rigidity of penile prosthesis and satisfaction. Objectives: The aim of this study was to examine whether axial rigidity of penile prosthesis had impact on patient and partner satisfaction. Materials and Methods: We enrolled one hundred patients who were implanted penile prosthesis before to evaluate their penile axial rigidity. We used Rigidometry (by using the digital inflection rigidometer to assess the minimal axial pressure to bend the implanted penis. Results: We demonstrated that mean axial pressure to bend the implanted penis was 984.8 ± 268.7 grams. Overall satisfaction score with the penile prosthesis implant was 4.55 and 4.49 (out of 5 in patients and partners, respectively. In total, seven men were unsatisfied with their implant and reported a mean satisfaction score of 0.6 ± 0.48 (out of 5. All prostheses types showed good and more than 500 grams axial rigidity. The patients with Ambicor type, which were buckled at about 710.5 grams, showed worse satisfaction rates in comparison to other prostheses in two patients. Digital inflection rigidometer results of other penile prosthesis types in unsatisfied patient were 842.0, 872.0, 887.0 and 920 g. in CX700, Titan, Genesis and Titan OTR, respectively. Conclusion: We demonstrated that dissatisfaction rate was highest in Ambicor prosthesis implanted patients. Additionally, patients with 3-piece penile prosthesis were more satisfied than 2-piece or malleable ones, interestingly, although

  12. [Pulmonary blood vessels in goats].

    Science.gov (United States)

    Roos, H; Hegner, K; Vollmerhaus, B

    1999-05-01

    The blood vessels in the lung of the goat, which until now have received little attention, are described in detail for the first time. With regard to the segments of the lung, blood vessels are bronchovascular units in the lobi craniales, lobus medius and lobus accessorius, but bronchoartery units in the lobi caudales. We investigated the types of branches of the Aa. pulmonales dextra et sinistra, the inter- and intraspecific principles of the outlet of the pulmonary veins and the importance of bronchopulmonary segmentation of the lungs. PMID:10386009

  13. Ion implanted pyrolitic carbon for the hip prosthesis

    International Nuclear Information System (INIS)

    Full text: Hip joint arthroplasty is a successful surgical procedure, but loosening induced by polyethylene wear debris continues to be a problem. Fine grained isotropic graphite (POCO ZXF-5Q) coated with Pyrolite (trademark of Carbomedics Inc.) combines biocompatibility, strength and tribological properties which could be utilised in a hip prosthesis. Some preliminary work has been conducted on this material, and the effect nitrogen ion implantation has on its wear resistance. Finite element analysis was conducted on a femoral head of a canine hip prosthesis with diameter 19mm made from POCO ZXF-5Q . An optimum design was obtained after design variables such as taper angle and width, internal recess radius, crown thickness were varied so that internal stresses were minimised. This was then translated into an human sized femoral head with diameter 28mm, which was subjected to mechanical testing. Loading was at 20 deg C to the taper, with loading rate 10kN/s used in static loading, whilst fatigue testing was carried out between 300 - 3000N at 30Hz for 107 cycles. Pin-on-disc wear testing was carried out using a CSEM Tribometer. A 1N load was applied to 6mm diameter pins. Wear track radii were 11 and 13mm, with linear velocity 5cm/s and sliding distance 2.5km. Test temperature was 37±1degC with Ringer solution and bovine serum being used as lubricant. Nitrogen implanted samples were irradiated to a dose of 5x1016 ions.cm-2 at 50keV. Static testing was carried out to loads of 8000N and all five POCO ZXF-5Q femoral heads tested survived. Then three of these pre-tested femoral heads were subjected to fatigue testing and no failures occured before 107 cycles. Wear was reduced by nitrogen ion implantation only when an irradiated pin was tested against as polished Pyrolite. Nitrogen ion implanted Pyrolite on a POCO ZXF-5Q substrate may have clinical potential. The substrate has appropriate mechanical properties, and nitrogen ion implantation can improve the already

  14. Implant supported prosthesis in an edentulous boy with Hypohidrotic Ectodermal Dysplasia - "A happy boy"

    DEFF Research Database (Denmark)

    Gjørup, Hans; Nyhuus, Lone; Buhl, Jytte

    2009-01-01

    Implant supported prosthesis in an edentulous boy with Hypohidrotic Ectodermal Dysplasia - "A happy boy". Authors; Gjoerup,H1; Nyhuus,L2; Buhl,J3. 1) Center for Oral Health in Rare Conditions, Aarhus University Hospital 2) Prosthodontic Department, the Dental School, Aarhus University 3) Department...... of his oral health has been registered. The boy and his family experience great improvement in the functioning as well as the comfort of his prosthesis after insertion of implants. Conclusion The prosthesis for edentulous boys with HED demand several adjustments and revisions, partly due to growth of...

  15. Tea May Benefit Blood Vessels

    Institute of Scientific and Technical Information of China (English)

    华剑铭

    2000-01-01

    读到有关饮茶有益健康的消息,我总是充满了自豪感:茶的故乡毕竟在中国。饮茶对人的心脏有益,这已经不是新闻,但是到底如何起到此类保健作用,多年来一直是一个谜。本文揭开了此谜底: Drinking a cup of tea makes blood vessels work better within 2 hours, dilating(扩张)the arteries(动脉)and improving blood flow. 文章令我感动之处在于那些科研人员的敬业精神。比如茶中含有caffeine(咖啡因),饮茶对心脏有利,此“利”是否源于caffeine呢?试验人员为了弄清这 一点,便让另一组受试人员服用等量的caffeine,结果证实:Caffeine had no response on the blood vessel function.】

  16. The use of zygomatic implants for the retention of nasal prosthesis following rhinectomy: the Morriston experience.

    Science.gov (United States)

    Scott, N; Kittur, M A; Evans, P L; Dovgalski, L; Hodder, S C

    2016-08-01

    Reconstruction and rehabilitation following rhinectomy remains controversial and presents a complex problem. Although reconstruction with local and microvascular flaps is a valid option, the aesthetic results may not always be satisfactory. The aesthetic results achieved with a nasal prosthesis are excellent; however patient acceptance relies on a secure method of retention. The technique used and results obtained in a large series of patients undergoing rhinectomy and receiving zygomatic implants for the retention of a nasal prosthesis are described here. A total of 56 zygomatic implants (28 patients) were placed, providing excellent retention and durability with the loss of only one implant in 15 years. PMID:26995288

  17. Photoacoustic determination of blood vessel diameter

    Science.gov (United States)

    Kolkman, Roy G. M.; Klaessens, John H. G. M.; Hondebrink, Erwin; Hopman, Jeroen C. W.; de Mul, Frits F. M.; Steenbergen, Wiendelt; Thijssen, Johan M.; van Leeuwen, Ton G.

    2004-10-01

    A double-ring sensor was applied in photoacoustic tomographic imaging of artificial blood vessels as well as blood vessels in a rabbit ear. The peak-to-peak time (tgrpp) of the laser (1064 nm) induced pressure transient was used to estimate the axial vessel diameter. Comparison with the actual vessel diameter showed that the diameter could be approximated by 2ctgrpp, with c the speed of sound in blood. Using this relation, the lateral diameter could also precisely be determined. In vivo imaging and monitoring of changes in vessel diameters was feasible. Finally, acoustic time traces were recorded while flushing a vessel in the rabbit ear with saline, which proved that the main contribution to the laser-induced pressure transient is caused by blood inside the vessel and that the vessel wall gives only a minor contribution.

  18. Photoacoustic determination of blood vessel diameter

    International Nuclear Information System (INIS)

    A double-ring sensor was applied in photoacoustic tomographic imaging of artificial blood vessels as well as blood vessels in a rabbit ear. The peak-to-peak time (τpp) of the laser (1064 nm) induced pressure transient was used to estimate the axial vessel diameter. Comparison with the actual vessel diameter showed that the diameter could be approximated by 2cτpp, with c the speed of sound in blood. Using this relation, the lateral diameter could also precisely be determined. In vivo imaging and monitoring of changes in vessel diameters was feasible. Finally, acoustic time traces were recorded while flushing a vessel in the rabbit ear with saline, which proved that the main contribution to the laser-induced pressure transient is caused by blood inside the vessel and that the vessel wall gives only a minor contribution

  19. Rehabilitation of Partial Maxillectomy Defect with Implant Retained Hollow Bulb Obturator Prosthesis: A Case Report

    OpenAIRE

    Chhabra, Anuj; Anandakrishna, G. N.; Rao, Girish; Makkar, Sumit

    2011-01-01

    Tissue integrated oral implants have initiated a new perspective in oral rehabilitation of tumor patients who have had undergone surgical resection procedure. The present case demonstrated a simple and predictable approach to rehabilitate a patient who had partial maxillectomy using dental implants. The use of an implant in conjunction with hollow bulb obturator shared remarkable improvement in retention and stability of the existing complete denture prosthesis.

  20. Maintenance of bone mineral density after implantation of a femoral neck hip prosthesis

    OpenAIRE

    Zurstegge Matthias; Rokahr Christoph; Decking Ralf; Simon Ulrich; Decking Jens

    2008-01-01

    Abstract Background Stress shielding of the proximal femur has been observed in a number of conventional cementless implants used in total hip arthroplasty. Short femoral-neck implants are claiming less interference with the biomechanics of the proximal femur. The goal of this study was to investigate the changes of bone-mineral density in the proximal femur and the clinical outcome after implantation of a short femoral-neck prosthesis. Methods We prospectively assessed the clinical outcome a...

  1. Prosthetic Rehabilitation of a Patient with Mandibular Resection Prosthesis Using Mini Dental Implants (MDIs) – Case Report

    OpenAIRE

    Vojvodić, Denis; Čelebić, Asja; Mehulić, Ketij; Žabarović, Domagoj

    2012-01-01

    Physical disfigurement and functional impairments associated with facial trauma are a challenge to a prosthodontist, because even novel sophisticated surgical reconstructive techniques fail to provide adequate support for dental resection prosthesis. Therefore, different endosseous implants are often used as prosthesis-supporting elements. Manufacturers of dental implants have recently presented mini dental implants (MDIs) with diameter of only 1.8–2.4 mm. These implants allow very suitable p...

  2. Fabricating a Soft Liner-Retained Implant-Supported Palatal Lift Prosthesis for an Edentulous Patient: A Case Report

    OpenAIRE

    Omid Savabi; Ebrahim Ataei; Niloufar Khodaeian

    2012-01-01

    This case report describes fabrication of a palatal lift prosthesis for a quadriplegic edentulous 30-year-old male with past head traumatic injury. We constructed an implant supported bar and used a soft-lining material for the maxillary palatal lift prosthesis to minimize the possibility of implant overloading and also provide a less complex and less expensive procedure for this patient.

  3. Stress analysis of different prosthesis materials in implant-supported fixed dental prosthesis using 3D finite element method

    Directory of Open Access Journals (Sweden)

    Pedram Iranmanesh

    2014-01-01

    Full Text Available Introduction: In the present study, the finite element method (FEM was used to investigate the effects of prosthesis material types on stress distribution of the bone surrounding implants and to evaluate stress distribution in three-unit implant-supported fixed dental prosthesis (FDP. Materials and Methods: A three-dimensional (3D finite element FDP model of the maxillary second premolar to the second molar was designed. Three load conditions were statically applied on the functional cusps in horizontal (57.0 N, vertical (200.0 N, and oblique (400.0 N, θ = 120° directions. Four standard framework materials were evaluated: Polymethyl methacrylate (PMMA, base-metal, porcelain fused to metal, andporcelain. Results: The maximum of von Mises stress in the oblique direction was higher than the vertical and horizontal directions in all conditions. In the bone-crestal section, the maximum von Mises stress (53.78 MPa was observed in PMMA within oblique load. In FDPs, the maximum stress was generated at the connector region in all conditions. Conclusion: A noticeable difference was not observed in the bone stress distribution pattern with different prosthetic materials. Although, higher stress value could be seen in polymethyl methacrylate, all types of prosthesis yielded the same stress distribution pattern in FDP. More clinical studies are needed to evaluate the survival rate of these materials.

  4. Design and in-vitro evaluation of a tissue engineered large vessel prosthesis

    Science.gov (United States)

    Mahmood, Ayesha

    Tissue engineering of large diameter blood vessels can offer a promising long-term solution to the large population suffering from congenital vascular defects and other vascular disease. In this report design, assembly, in vitro maturation and evaluation of a large diameter, chitosan-based prosthesis is described. To facilitate cell adhesion and proliferation, collagen was included as a scaffold component to a chitosan scaffold. In vitro studies evaluated the role of collagen content, crosslinker type and crosslinking density on degradation kinetics, mechanical properties and cellular interactions. Finally, the vessel scaffold (ID = 12 mm, OD = 15 mm) was fabricated from a moderately cross-linked, 90%/10% chitosan/collagen material. A tubular scaffold with gradient porosity and interconnected pores was generated by controlled freezing and lyophilization of the polymer. For graft culture laminar and pulsatile flow systems were designed and porous scaffolds were seeded with vascular cells under static conditions. Laminar system grafts were seeded and cultured/analyzed over an 8 week period (15ml/min). For the pulsatile system SMC were seeded and after 2 weeks of pulsatile flow culture (360ml/min, 82 beats/min) microvascular EC were seeded lumenally to initiate a microvascular network followed by aortic EC seeding at 3 weeks. For both systems, cell viability at different culture periods showed the formation of high density of cell within few weeks of graft culture. However, the pulsatile flow system graft showed a significant increase in mechanical properties and ECM protein (collagen and elastin) deposition overtime. This novel chitosan based tissue engineered vascular graft shows promising results for large vessel replacements.

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

    Science.gov (United States)

    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

  6. Digital process for an implant-supported fixed dental prosthesis: A clinical report.

    Science.gov (United States)

    Brandt, Jan; Lauer, Hans-Christoph; Peter, Thorsten; Brandt, Silvia

    2015-10-01

    A digital process is presented for an implant-supported single-tooth and a 3-unit fixed dental prosthesis (FDP) with customized abutments and monolithic prosthetic zirconia restorations. The digital impression on the implant level was made with a TRIOS intraoral scanner (3Shape). This process included the fabrication of an implant cast with the fused deposition modeling technique and a 3-dimensional printing process with integrated implant analogs. The process enabled the FDPs to be designed with CAD/CAM on the cast before patient contact. Designing a printed implant cast expands the use of the digital workflow in the dental field. PMID:26187099

  7. Self and partner satisfaction rates after 3 part inflatable penile prosthesis implantation

    Directory of Open Access Journals (Sweden)

    Abdulmuttalip Simsek

    2014-09-01

    Full Text Available Objective: To evaluate and present satisfaction rates of our patients and their partners after 3 part inflatable penile prosthesis implantation. Materials and methods: We searched our hospital electronic data for patients who underwent inflatable penile prosthesis implantation between January 2008 and July 2013. Computer and archived file data were used to get information and reach the patients. We made telephone calls to patients and asked questionnaires about self and partner satisfaction rates. Results: 36 patients underwent prosthesis implantation during the 5 year period. We were able to reach by telephone call 18 of them. The mean age of 18 patients was 55.7 ± 9.4 years and mean body mass index was 24.6 ± 2.1 kg/m2. The etiology was diabetes mellitus on 14 (77.8% and radical pelvic surgery on 4 (22.2% patients. 14 of 18 patients had penile Doppler ultrasound test. Doppler ultrasound demonstrated venous insufficiency in 8 and arterial insufficiency in 6 patients. Mean time from implantation to study was 20.8 ± 13.9 months. Out of 18 patients 2 had prosthesis removal operation because of infection in one patient and perforation in the other. Satisfaction rate was 88.9%, and recommendation rate was 94.4%. Causes of dissatisfaction were pain in one patient and insufficient rigidity plus shortening of the penis in the other one. Partner satisfaction rate was 94.4%. Conclusion: Penile Prosthesis Implantation (PPI is the gold standard treatment of erectile dysfunction (ED irresponsive to medical treatment. Infection and mechanical failure rates are going to be less according to the improvements in synthetic materials and coverings of the prosthesis, so patient and partner satisfaction rates will be higher.

  8. Complete Blood Count and Retinal Vessel Calibers

    OpenAIRE

    Liew, Gerald; Wang, Jie Jin; Rochtchina, Elena; Wong, Tien Yin; Mitchell, Paul

    2014-01-01

    Objective The influence of hematological indices such as complete blood count on microcirculation is poorly understood. Retinal microvasculature can be directly visualized and vessel calibers are associated with a range of ocular and systemic diseases. We examined the association of complete blood count with retinal vessel calibers. Methods Cross-sectional population-based Blue Mountains Eye Study, n = 3009, aged 49+ years. Complete blood count was measured from fasting blood samples taken at...

  9. Implant Supported Prosthesis After Ridge Augmentation Procedure by Distraction Osteogenesis for Atrophic Mandible

    OpenAIRE

    Khongshei, Arlingstone; Banerjee, Saurav; Gupta, Tapas; Banerjee, Ardhendu

    2013-01-01

    Rehabilitation of deficient alveolar ridges has long been a challenge. The distraction osteogenesis procedure before placement of dental implants has solved the puzzle and its advantages over block grafting includes simultaneous expansion of soft tissue, high degree of dimensional stability, abbreviated overall treatment time, and no graft required. In this case report distraction osteogenesis of deficient anterior mandibular ridge was performed and then an implant supported fixed prosthesis ...

  10. Effect of veneering material on the deformation suffered by implant-supported fixed prosthesis framework

    OpenAIRE

    GRANDO, Antônio Francisco; Carlos Eduardo Edwards REZENDE; SOUSA, Edson Antônio Capello; RUBO, José Henrique

    2014-01-01

    Knowing how stresses are dissipated on the fixed implant-supported complex allows adequate treatment planning and better choice of the materials used for prosthesis fabrication. Objectives: The aim of this study was to evaluate the deformation suffered by cantilevered implant-supported fixed prostheses frameworks cast in silver-palladium alloy and coated with two occlusal veneering materials: acrylic resin or porcelain. Material and Methods: Two strain gauges were bonded to the inferior su...

  11. A novel knee prosthesis model of implant-related osteo- myelitis in rats

    DEFF Research Database (Denmark)

    Søe, Niels H.; Jensen, Nina Vendel; Nürnberg, Birgit Meinecke;

    2012-01-01

    There have been numerous reports of animal models of osteomyelitis. Very few of these have been prosthesis models that imitate human conditions. We have developed a new rat model of implant-related osteomyelitis that mimics human osteomyelitis, to investigate the pathology of infection after...

  12. Morphometric evaluation of endometrial blood vessels

    Directory of Open Access Journals (Sweden)

    Makhija Divya

    2008-07-01

    Full Text Available Five hundred endometrial specimens were studied to document the changes in blood vessels in various phases of menstrual cycle, menstrual disturbances and in unexplained infertility. Sixty-three cases were taken as control and 437 cases as study group which included cases of dysfunctional uterine bleeding (DUB, endometrial polyps, fibroids, adenomyosis, infertility and atrophic endometrium. Using light microscopy, the vascular morphology was studied. The blood vessels were concentrated more in basal layer in the proliferative phase and in functional layer in the secretory phase. Cases of complex hyperplasia and pill endometrium had significantly higher vessel concentration. Congestion and dilatation of blood vessels were significantly higher in cases of DUB. The present study showed a positive correlation between endometrial angiogenesis and menstrual disorders. The alteration in blood vessel morphology has significant role in prognosis and in various anti-angiogenic therapies.

  13. Classification & Structure of Blood Vessels

    Science.gov (United States)

    ... Thyroid & Parathyroid Glands Adrenal Gland Pancreas Gonads Other Endocrine Glands Review Quiz Cardiovascular System Heart Structure of the Heart Physiology of the Heart Blood Classification & Structure of Blood ...

  14. Penile prosthesis implant for erectile dysfunction: A new minimally invasive infrapubic surgical technique

    Directory of Open Access Journals (Sweden)

    Gabriele Antonini

    2016-01-01

    Full Text Available Erectile dysfunction, the most common male sexual disorder after premature ejaculation, with its important impact on man and partner’s sexuality and quality of life is a persistent inability to obtain and maintain an erection sufficient to permit satisfactory sexual performance. Non-surgical treatments with controversial results are usually applyed before surgical treatment that has reached high levels of satisfaction. We describe a new surgical technique to implant three-pieces penile prosthesis in patients suffering from erectile dysfunction (ED not responding to conventional medical therapy or reporting side effects with such a therapy. Implantation of an inflatable prosthesis, for treatment of ED, is a safe and efficacious approach with high satisfaction reported by patients and partners. Surgical technique should be minimally invasive and latest technology equipment should be implanted in order to decrease common complications and to obtain a better aesthetic result.

  15. Penile prosthesis implant for erectile dysfunction: A new minimally invasive infrapubic surgical technique.

    Science.gov (United States)

    Antonini, Gabriele; Busetto, Gian Maria; De Berardinis, Ettore; Giovannone, Riccardo; Vicini, Patrizio; Gentile, Vincenzo; Perito, Paul E

    2015-12-01

    Erectile dysfunction, the most common male sexual disorder after premature ejaculation, with its important impact on man and partner's sexuality and quality of life is a persistent inability to obtain and maintain an erection sufficient to permit satisfactory sexual performance. Non-surgical treatments with controversial results are usually applyed before surgical treatment that has reached high levels of satisfaction. We describe a new surgical technique to implant three-pieces penile prosthesis in patients suffering from erectile dysfunction (ED) not responding to conventional medical therapy or reporting side effects with such a therapy. Implantation of an inflatable prosthesis, for treatment of ED, is a safe and efficacious approach with high satisfaction reported by patients and partners. Surgical technique should be minimally invasive and latest technology equipment should be implanted in order to decrease common complications and to obtain a better aesthetic result. PMID:26766806

  16. BLOOD VESSELS EXTRACTION USING MATHEMATICAL MORPHOLOGY

    Directory of Open Access Journals (Sweden)

    Nidhal Khdhair El Abbadi

    2013-01-01

    Full Text Available The retinal vasculature is composed of the arteries and veins with their tributaries which are visible within the retinal image. The segmentation and measurement of the retinal vasculature is of primary interest in the diagnosis and treatment of a number of systemic and ophthalmologic conditions. The accurate segmentation of the retinal blood vessels is often an essential prerequisite step in the identification of retinal anatomy and pathology. In this study, we present an automated approach for blood vessels extraction using mathematical morphology. Two main steps are involved: enhancement operation is applied to the original retinal image in order to remove the noise and increase contrast of retinal blood vessels and morphology operations are employed to extract retinal blood vessels. This operation of segmentation is applied to binary image of top-hat transformation. The result was compared with other algorithms and give better results.

  17. Silk fibroin microtubes for blood vessel engineering.

    Science.gov (United States)

    Lovett, Michael; Cannizzaro, Christopher; Daheron, Laurence; Messmer, Brady; Vunjak-Novakovic, Gordana; Kaplan, David L

    2007-12-01

    Currently available synthetic grafts demonstrate moderate success at the macrovascular level, but fail at the microvascular scale (inner diameter). We report on the development of silk fibroin microtubes for blood vessel repair with several advantages over existing scaffold materials/designs. These microtubes were prepared by dipping straight lengths of stainless steel wire into aqueous silk fibroin, where the addition of poly(ethylene oxide) (PEO) enabled control of microtube porosity. The microtube properties were characterized in terms of pore size, burst strength, protein permeability, enzymatic degradation, and cell migration. Low porosity microtubes demonstrated superior mechanical properties in terms of higher burst pressures, but displayed poor protein permeability; whereas higher porosity tubes had lower burst strengths but increased permeability and enhanced protein transport. The microtubes also exhibited cellular barrier functions as low porosity tubes prevented outward migration of GFP-transduced HUVECs, while the high porosity microtubes allowed a few cells per tube to migrate outward during perfusion. When combined with the biocompatible and suturability features of silk fibroin, these results suggest that silk microtubes, either implanted directly or preseeded with cells, are an attractive biomaterial for microvascular grafts. PMID:17727944

  18. Effect of veneering material on the deformation suffered by implant-supported fixed prosthesis framework

    Directory of Open Access Journals (Sweden)

    Antônio Francisco GRANDO

    2014-06-01

    Full Text Available Knowing how stresses are dissipated on the fixed implant-supported complex allows adequate treatment planning and better choice of the materials used for prosthesis fabrication. Objectives: The aim of this study was to evaluate the deformation suffered by cantilevered implant-supported fixed prostheses frameworks cast in silver-palladium alloy and coated with two occlusal veneering materials: acrylic resin or porcelain. Material and Methods: Two strain gauges were bonded to the inferior surface of the silver-palladium framework and two other were bonded to the occlusal surface of the prosthesis framework covered with ceramic and acrylic resin on each of its two halves. The framework was fixed to a metallic master model and a 35.2 N compression force was applied to the cantilever at 10, 15 and 20 mm from the most distal implant. The measurements of deformation by compression and tension were obtained. The statistical 2-way ANOVA test was used for individual analysis of the experiment variables and the Tukey test was used for the interrelation between all the variables (material and distance of force application. Results: The results showed that both variables had influence on the studied factors (deformation by compression and tension. Conclusion: The ceramic coating provided greater rigidity to the assembly and therefore less distortion compared with the uncoated framework and with the resin-coated framework. The cantilever arm length also influenced the prosthesis rigidity, causing higher deformation the farther the load was applied from the last implant.

  19. Fabricating a Soft Liner-Retained Implant-Supported Palatal Lift Prosthesis for an Edentulous Patient: A Case Report

    Directory of Open Access Journals (Sweden)

    Omid Savabi

    2012-01-01

    Full Text Available This case report describes fabrication of a palatal lift prosthesis for a quadriplegic edentulous 30-year-old male with past head traumatic injury. We constructed an implant supported bar and used a soft-lining material for the maxillary palatal lift prosthesis to minimize the possibility of implant overloading and also provide a less complex and less expensive procedure for this patient.

  20. Problems encountered during the development and implantation of the Baylor-Rice orthotopic cardiac prosthesis

    International Nuclear Information System (INIS)

    The problems associated with the development of an artificial heart are enumerated. In a series of 24 calf implantations, several of the animals stood unassisted and reacted normally, but all eventually died with deteriorating circulatory and pulmonary systems. The problems caused by pump size and geometry represented the most important deterrents to long-term survival. A new prosthesis, though not yet tested in animals, is believed to minimize these problems. (auth)

  1. Mandibular implant-supported fixed dental prosthesis with a modified design: a clinical report.

    Science.gov (United States)

    Tourah, Anita; Moshaverinia, Alireza; Chee, Winston W

    2014-02-01

    This clinical report describes the rehabilitation of a patient with a mandibular implant-supported fixed dental prosthesis. Because of the limited restorative space available in the posterior mandible and in considering the higher wear rate of acrylic resin in comparison with titanium when it opposes metal ceramic restorations, the treatment used a milled titanium bar with acrylic resin denture teeth, which replaced the anterior teeth with milled titanium for the posterior occluding surfaces. PMID:24262946

  2. Clinical Assessment of “All in One” Framework for Partial Implant - Supported Prosthesis

    OpenAIRE

    Vinuela, A.; de Parga, J.Martinez Vazquez; Del Rio, Highsmith J.

    2002-01-01

    INTRODUCTION: Restoration by implant-supported prosthesis seems to be a current option in the treatment of partially edentulous patients. Its success depends on the passive fit of the framework. Searching for new manufacturing materials and techniques to solve these problems, dental companies, combining clinical and experimental research, offer different solutions, such as Nobel Biocare, the “all in one” system, which is a framework designed by CAD/CAM. AIM OF PRESENTATION: Clinical and ra...

  3. Bone density around the fixture after function of implant molar prosthesis using CBCT

    International Nuclear Information System (INIS)

    The purpose of this study was to examine the significance of increased bone density according to whether bone grafts were applied using demographic data with Cone Beam Computed Tomography (CBCT) and to compare the bone densities between before and after implant prosthesis using the Hounsfield index. Thirty-six randomly selected computed tomography (CT) scans were used for the analysis. The same sites were evaluated digitally using the Hounsfield scale with V-Implant 2.0TM, and the results were compared with maxillary posterior bone graft. Statistical data analysis was carried out to determine the correlation between the recorded Hounsfield unit (HU) of the bone graft and implant prosthesis using a Mann-Whitney U test and Wilcoxon Matched-pairs test. The bone grafted maxillary posterior teeth showed an increase in the mean values from-157 HU to 387 HU, whereas non-grafted maxillary posterior teeth showed an increase from 62 HU to 342 HU. After implantation, the grafted and non-grafted groups showed significantly higher bone density than before implantation. However, the grafted group showed significantly more changes than the non-grafted group. Bone density measurements using CBCT might provide an objective assessment of the bone quality as well as the correlation between bone density (Hounsfield scale) and bone grafts in the maxillary molar area.

  4. Bone density around the fixture after function of implant molar prosthesis using CBCT

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jae Hyun; Hwang, In Taik; Jung, Byung Hyun; Kim, Jae Duk; Kang, Dong Wan [School of Dentistry, Oral Biology Research Institute, Chosun University, Gwangju (Korea, Republic of)

    2010-03-15

    The purpose of this study was to examine the significance of increased bone density according to whether bone grafts were applied using demographic data with Cone Beam Computed Tomography (CBCT) and to compare the bone densities between before and after implant prosthesis using the Hounsfield index. Thirty-six randomly selected computed tomography (CT) scans were used for the analysis. The same sites were evaluated digitally using the Hounsfield scale with V-Implant 2.0TM, and the results were compared with maxillary posterior bone graft. Statistical data analysis was carried out to determine the correlation between the recorded Hounsfield unit (HU) of the bone graft and implant prosthesis using a Mann-Whitney U test and Wilcoxon Matched-pairs test. The bone grafted maxillary posterior teeth showed an increase in the mean values from-157 HU to 387 HU, whereas non-grafted maxillary posterior teeth showed an increase from 62 HU to 342 HU. After implantation, the grafted and non-grafted groups showed significantly higher bone density than before implantation. However, the grafted group showed significantly more changes than the non-grafted group. Bone density measurements using CBCT might provide an objective assessment of the bone quality as well as the correlation between bone density (Hounsfield scale) and bone grafts in the maxillary molar area.

  5. OBSERVATIONS ON VASCULAR PATTERN OF CHORIONIC BLOOD VESSELS OF PLACENTA

    Directory of Open Access Journals (Sweden)

    Yousuf Sarwar

    2013-10-01

    Full Text Available ABSTRACT: BACKGROUND: Placenta is a choriodecidual structure develops during pregnancy implanted on the uterine wall and car ries vital functions. It is connected to the foetus through umbilical cord. The branches of umbilical vessels that traverse along foetal surface of placenta are referred as chorionic vessels. There are two different patterns of chorionic vessels – Dispersa l and Magistral. In the dispersal type, the umbilical vessels undergo successive divisions with gradually diminishing caliber towards periphery while in magistral pattern the vessels traverse to the edge of placenta without appreciable decrease in diameter of vessels. The present study has been done for visualization of the pattern of chorionic vessels in placenta obtained from labour room of a tertiary care hospital in eastern Bihar, India. MATERIALS AND METHODS: A total of one hundred and fifty (150 fres h and intact placenta of full term pregnancies collected from Obstetrics & Gynaecology department were included in the study. After washing with distilled water, removal of blood clots were done with slight digital pressure applied over arteries and vein a nd later on by irrigation with saline. The cut end of the umbilical cord was carefully visualized to identify the umbilical arteries and vein. Dye was injected into umbilical vessels under normal physiological pressure and diameter of chorionic blood vesse ls were taken at the center and periphery. Ultimately each vessel was followed and examined to observe the dispersal and magistral pattern of chorionic blood vessels of placenta. RESULTS AND CONCLUSION: Out of the total of one hundred and fifty (150 full term placenta obtained and examined in the Anatomy department during the study period, 64% Dispersal type & 36 % of Magistral type of arterial pattern of branching of chorionic vessels were observed. Vein and its tributaries presented Dispersal pattern in 60% and Magistral pattern in 40%. There is a significant

  6. Maintenance of bone mineral density after implantation of a femoral neck hip prosthesis

    Directory of Open Access Journals (Sweden)

    Zurstegge Matthias

    2008-01-01

    Full Text Available Abstract Background Stress shielding of the proximal femur has been observed in a number of conventional cementless implants used in total hip arthroplasty. Short femoral-neck implants are claiming less interference with the biomechanics of the proximal femur. The goal of this study was to investigate the changes of bone-mineral density in the proximal femur and the clinical outcome after implantation of a short femoral-neck prosthesis. Methods We prospectively assessed the clinical outcome and the changes of bone mineral density of the proximal femur up to one year after implantation of a short femoral neck prosthesis in 20 patients with a mean age of 47 years (range 17 to 65. Clinical outcome was assessed using the Harris Hip Score. The WOMAC was used as a patient-relevant outcome-measure. The bone mineral density was determined using dual energy x-ray absorptiometry, performed 10 days, three months and 12 months after surgery. Results The Harris Hip Score improved from an average preoperative score of 46 to a postoperative score at 12 months of 89 points, the global WOMAC index from 5,3 preoperatively to 0,8 at 12 months postoperatively. In contrast to conventional implants, the DEXA-scans overall revealed a slight increase of bone mineral density in the proximal femur in the 12 months following the implantation. Conclusion The short femoral neck stem lead to a distinct bone reaction. This was significantly different when compared to the changes in bone mineral density reported after implantation of conventional implants.

  7. Videodensitometry for measuring blood vessel diameter

    International Nuclear Information System (INIS)

    A method employing a special computer for determining the internal diameters of blood vessels from photofluorographic image is described; in vitro and in vivo experiments are performed with the system. The amount of contrast medium injected is restricted to 4x3 ml, and it is possible to determine the diameter (in the range from 2 to 16 mm) at any place where blood vessels can be catheterized. In the in vivo experiments the maximum systematic error is +-5 per cent in the 7 to 8 mm range. (Auth.)

  8. Videodensitometry for measuring blood vessel diameter.

    Science.gov (United States)

    Hoornstra, K; Hanselman, J M; Holland, W P; De Wey Peters, G W; Zwamborn, A W

    1980-01-01

    A method employing a special computer for determining the internal diameters of blood vessels from photofluorographic image is described; in vitro and in vivo experiments are performed with the system. The amount of contrast medium injected is restricted to 4 times 3 ml, and it is possible to determine the diameter (in the range from 2 to 16 mm) at any place where blood vessels can be catheterized. In the in vivo experiments the maximum systematic error is +/-5 percent in the 7 to 8 mm range. PMID:7424549

  9. Comparison of Maxillary Implant-Supported Prosthesis in Irradiated and Non-Irradiated Patients

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Summary: In order to investigate the influence of radiation therapy after the treatment of maxillaryimplant-supported prostheses, 27 patients received a total of 131 implants in maxilla after oral cancertreatment and/or reconstructive surgery. Among them, 25 received maxillary implant-supportedprostheses. The cumulative survival rates of implants and prostheses were evaluated by the product-limit-estimates method according to Kaplan-Meier. The cumulative survival rate of implants andprostheses in irradiated patients was compared with that in non-irradiated patients by statistical Log-rank test. The results showed that 112 implants were observed after implant loading. The implantscumulative survival rate was approximately 65 % for overall patients. The cumulative prosthesis suc-cessful rate was approximately 88 % for all 25 patients. Log-rank test analysis revealed that therewas a significant difference in cumulative implants survival rates between non-irradiated and irradiat-ed maxillary bone (P<0. 01). It was concluded that the implants and prostheses in irradiated pa-tients have significantly lower survival rates than in non-irradiated patients.

  10. Impact of patient-prosthesis mismatch after transcatheter aortic valve-in-valve implantation in degenerated bioprostheses

    DEFF Research Database (Denmark)

    Seiffert, Moritz; Conradi, Lenard; Baldus, Stephan;

    2012-01-01

    Transcatheter valve-in-valve implantation is evolving as an alternative to reoperative valve replacement in high-risk patients with degenerated bioprostheses. Nevertheless, hemodynamic performance is limited by the previously implanted xenograft. We report our experience with patient-prosthesis...

  11. Biofeedback With Implanted Blood-Pressure Device

    Science.gov (United States)

    Rischell, Robert E.

    1988-01-01

    Additional uses found for equipment described in "Implanted Blood-Pressure-Measuring Device" (GSC-13042). Implanted with device electronic circuitry that measures, interprets, and transmits data via inductive link through patient's skin to external receiver. Receiver includes audible alarm generator activated when patient's blood pressure exceeds predetermined threshold. Also included in receiver a blood-pressure display, recorder, or both, for use by patient or physician.

  12. Multidisciplinary approach of ectodermal dysplasia with implant retained fixed prosthesis

    Directory of Open Access Journals (Sweden)

    Vishnu Priya

    2013-01-01

    Full Text Available Ectodermal dysplasia represents a group of rare inherited conditions in which two or more ectodermally derived anatomical structures fail to develop. Early dental intervention can improve patient′s appearance, thereby minimizing associated emotional and psychological problems in these patients. Treatment requires a teamwork by medical personnel along with dental professionals of various specialties. Here, a rare case of a young female patient is presented with prosthetic management with implant supported fixed partial denture.

  13. RETENTIVENESS OF VARIOUS LUTING AGENTS USED WITH IMPLANT SUPPORTED- PROSTHESIS: AN INVITRO STUDY.

    Science.gov (United States)

    Garg, Pooja; Pujari, Malesh L; D R, Prithviraj; Khare, Sumit

    2014-03-01

    Abstract ABSTRACT:Purpose: Desired retrievability of cemented implant-supported fixed prosthesis makes the retentive strength of cementing agents an important consideration. The aim of the study was to evaluate the retentiveness of purposely-designed implant cement and to compare its retentiveness with dental cements that are commonly used with implant systems.Materials and method: Ten implant analogs were embedded in auto-polymerizing acrylic resin blocks and titanium abutments were attached to them. 50 standardized copings were waxed directly on the abutment and casted. The cements used were: 1. resin-bonded zinc oxide eugenol cement (Kalzinol, DPI), 2. purposely-designed implant cement (Premier implant cement), 3. zinc phosphate cement (DeTrey Zinc, Dentsply), 4. zinc polycarboxylate cement (Poly-F, Dentsply) and 5. glass ionomer cement (GC Gold Label, GC corporation, Japan). After cementation, each sample was subjected to a pull-out test using universal testing machine and loads required to remove the crowns were recorded. The mean values and standard deviations of cement failure loads were analyzed using ANOVA and Bonferroni test.Results: The mean values (±SD) of loads at failure (n = 10) for various cements were as follows (N): resin-bonded zinc oxide eugenol cement 394.62 (±9.76), Premier implant cement 333.86 (±18.91), zinc phosphate cement 629.30 (±20.65), zinc polycarboxylate cement 810.08 (±11.52) and glass ionomer cement 750.17 (±13.78).Conclusions: The results do not suggest that one cement type is better than another, but they do provide a ranking order of the cements in their ability to retain the prosthesis and to facilitate its easy retrievability. PMID:24588463

  14. The analysis of cost-effectiveness of implant and conventional fixed dental prosthesis

    Science.gov (United States)

    Chun, June Sang; Har, Alix; Lim, Hyun-Pil

    2016-01-01

    PURPOSE This study conducted an analysis of cost-effectiveness of the implant and conventional fixed dental prosthesis (CFDP) from a single treatment perspective. MATERIALS AND METHODS The Markov model for cost-effectiveness analysis of the implant and CFDP was carried out over maximum 50 years. The probabilistic sensitivity analysis was performed by the 10,000 Monte-Carlo simulations, and cost-effectiveness acceptability curves (CEAC) were also presented. The results from meta-analysis studies were used to determine the survival rates and complication rates of the implant and CFDP. Data regarding the cost of each treatment method were collected from University Dental Hospital and Statistics Korea for 2013. Using the results of the patient satisfaction survey study, quality-adjusted prosthesis year (QAPY) of the implant and CFDP strategy was evaluated with annual discount rate. RESULTS When only the direct cost was considered, implants were more cost-effective when the willingness to pay (WTP) was more than 10,000 won at 10th year after the treatment, and more cost-effective regardless of the WTP from 20th year after the prosthodontic treatment. When the indirect cost was added to the direct cost, implants were more cost-effective only when the WTP was more than 75,000 won at the 10th year after the prosthodontic treatment, more than 35,000 won at the 20th year after prosthodontic treatment. CONCLUSION The CFDP was more cost-effective unless the WTP was more than 75,000 won at the 10th year after prosthodontic treatment. But the cost-effectivenss tendency changed from CFDP to implant as time passed. PMID:26949488

  15. Complete blood count and retinal vessel calibers.

    Directory of Open Access Journals (Sweden)

    Gerald Liew

    Full Text Available OBJECTIVE: The influence of hematological indices such as complete blood count on microcirculation is poorly understood. Retinal microvasculature can be directly visualized and vessel calibers are associated with a range of ocular and systemic diseases. We examined the association of complete blood count with retinal vessel calibers. METHODS: Cross-sectional population-based Blue Mountains Eye Study, n = 3009, aged 49+ years. Complete blood count was measured from fasting blood samples taken at baseline examination, 1992-4. Retinal arteriolar and venular calibers were measured from digitized retinal photographs using a validated semi-automated computer program. RESULTS: All analyses adjusted for age, sex, systolic blood pressure, diabetes, smoking and fellow vessel caliber. Higher hematocrit, white cell count and platelet count were associated with narrower arteriolar caliber (p = 0.02, 0.03 and 0.001 respectively, while higher hemoglobin, hematocrit, red cell count, white cell count and platelet count were associated with wider venular caliber (p<0.0001 for all. Each quintile increase in hematocrit, white cell count and platelet count was associated with approximately 0.5 µm narrower arteriolar caliber; whereas each quintile increase in all of the complete blood count components was associated with approximately 1-2 µm wider venular caliber. CONCLUSIONS: These associations show that elevated levels of hematological indices can have adverse effects on the microcirculation.

  16. New method of fixation of in-bone implanted prosthesis

    Directory of Open Access Journals (Sweden)

    Mark Pitkin, PhD

    2013-08-01

    Full Text Available This article presents results on the effectiveness of a new version of the titanium porous composite skin and bone integrated pylon (SBIP. The SBIP is designed for direct skeletal attachment of limb prostheses and was evaluated in a preclinical study with three rabbits. In accordance with the study protocol, a new version of the pylon (SBIP-3 was implanted into the hind leg residuum of three rabbits. The SBIP-3 has side fins that are designed to improve the bond between the bone and pylon. The fins are positioned inside two slots precut in the bone walls; their length can be adjusted to match the thickness of the bone walls. After 13 (animal 1 or 26 (animals 2 and 3 wk, the animals were sacrificed and samples collected for histopathological analysis. The space between the fins and the bone into which they were fit was filled with fibrovascular tissue and woven bone. No substantial inflammation was found. We suggest that if further studies substantiate the present results, the proposed method can become an alternative to the established technique of implanting prostheses into the medullary canal of the hosting bone.

  17. Retentiveness of various luting agents used with implant-supported prosthesis: an in vitro study.

    Science.gov (United States)

    Garg, Pooja; Pujari, Malesh; Prithviraj, D R; Khare, Sumit

    2014-12-01

    Desired retrievability of cemented implant-supported fixed prosthesis makes the retentive strength of cementing agents an important consideration. The aim of the study was to evaluate the retentiveness of purposely designed implant cement and compare its retentiveness with dental cements that are commonly used with implant systems. Ten implant analogs were embedded in auto-polymerizing acrylic resin blocks and titanium abutments were attached to them. Fifty standardized copings were waxed directly on the abutment and casted. The cements used were: (1) resin-bonded zinc oxide eugenol cement, (2) purposely designed implant cement, (3) zinc phosphate cement, (4) zinc polycarboxylate cement, and (5) glass ionomer cement. After cementation, each sample was subjected to a pull-out test using universal testing machine and loads required to remove the crowns were recorded. The mean values and standard deviations of cement failure loads were analyzed using ANOVA and Bonferroni test. The mean values (± SD) of loads at failure (n = 10) for various cements were as follows (N): resin-bonded zinc oxide eugenol cement 394.62 (± 9.76), Premier implant cement 333.86 (± 18.91), zinc phosphate cement 629.30 (± 20.65), zinc polycarboxylate cement 810.08 (± 11.52), and glass ionomer cement 750.17 (± 13.78). The results do not suggest that one cement type is better than another, but they do provide a ranking order of the cements regarding their ability to retain the prosthesis and facilitate easy retrievability. PMID:25506659

  18. Automated measurement of retinal blood vessel tortuosity

    Science.gov (United States)

    Joshi, Vinayak; Reinhardt, Joseph M.; Abramoff, Michael D.

    2010-03-01

    Abnormalities in the vascular pattern of the retina are associated with retinal diseases and are also risk factors for systemic diseases, especially cardiovascular diseases. The three-dimensional retinal vascular pattern is mostly formed congenitally, but is then modified over life, in response to aging, vessel wall dystrophies and long term changes in blood flow and pressure. A characteristic of the vascular pattern that is appreciated by clinicians is vascular tortuosity, i.e. how curved or kinked a blood vessel, either vein or artery, appears along its course. We developed a new quantitative metric for vascular tortuosity, based on the vessel's angle of curvature, length of the curved vessel over its chord length (arc to chord ratio), number of curvature sign changes, and combined these into a unidimensional metric, Tortuosity Index (TI). In comparison to other published methods this method can estimate appropriate TI for vessels with constant curvature sign and vessels with equal arc to chord ratios, as well. We applied this method to a dataset of 15 digital fundus images of 8 patients with Facioscapulohumeral muscular dystrophy (FSHD), and to the other publically available dataset of 60 fundus images of normal cases and patients with hypertensive retinopathy, of which the arterial and venous tortuosities have also been graded by masked experts (ophthalmologists). The method produced exactly the same rank-ordered list of vessel tortuosity (TI) values as obtained by averaging the tortuosity grading given by 3 ophthalmologists for FSHD dataset and a list of TI values with high ranking correlation with the ophthalmologist's grading for the other dataset. Our results show that TI has potential to detect and evaluate abnormal retinal vascular structure in early diagnosis and prognosis of retinopathies.

  19. Zinc oxide nanoflowers make new blood vessels

    Science.gov (United States)

    Barui, Ayan Kumar; Veeriah, Vimal; Mukherjee, Sudip; Manna, Joydeb; Patel, Ajay Kumar; Patra, Sujata; Pal, Krishnendu; Murali, Shruthi; Rana, Rohit K.; Chatterjee, Suvro; Patra, Chitta Ranjan

    2012-11-01

    It is well established that angiogenesis is the process of formation of new capillaries from pre-existing blood vessels. It is a complex process, involving both pro- and anti-angiogenic factors, and plays a significant role in physiological and pathophysiological processes such as embryonic development, atherosclerosis, post-ischemic vascularization of the myocardium, tumor growth and metastasis, rheumatoid arthritis etc. This is the first report of zinc oxide (ZnO) nanoflowers that show significant pro-angiogenic properties (formation of new capillaries from pre-existing blood vessels), observed by in vitro and in vivo angiogenesis assays. The egg yolk angiogenesis assay using ZnO nanoflowers indicates the presence of matured blood vessels formation. Additionally, it helps to promote endothelial cell (EA.hy926 cells) migration in wound healing assays. Formation of reactive oxygen species (ROS), especially hydrogen peroxide (H2O2)--a redox signaling molecule, might be the plausible mechanism for nanoflower-based angiogenesis. Angiogenesis by nanoflowers may provide the basis for the future development of new alternative therapeutic treatment strategies for cardiovascular and ischemic diseases, where angiogenesis plays a significant role.It is well established that angiogenesis is the process of formation of new capillaries from pre-existing blood vessels. It is a complex process, involving both pro- and anti-angiogenic factors, and plays a significant role in physiological and pathophysiological processes such as embryonic development, atherosclerosis, post-ischemic vascularization of the myocardium, tumor growth and metastasis, rheumatoid arthritis etc. This is the first report of zinc oxide (ZnO) nanoflowers that show significant pro-angiogenic properties (formation of new capillaries from pre-existing blood vessels), observed by in vitro and in vivo angiogenesis assays. The egg yolk angiogenesis assay using ZnO nanoflowers indicates the presence of matured blood

  20. Blood Vessel-Derived Acellular Matrix for Vascular Graft Application

    Directory of Open Access Journals (Sweden)

    Luigi Dall’Olmo

    2014-01-01

    Full Text Available To overcome the issues connected to the use of autologous vascular grafts and artificial materials for reconstruction of small diameter (<6 mm blood vessels, this study aimed to develop acellular matrix- (AM- based vascular grafts. Rat iliac arteries were decellularized by a detergent-enzymatic treatment, whereas endothelial cells (ECs were obtained through enzymatic digestion of rat skin followed by immunomagnetic separation of CD31-positive cells. Sixteen female Lewis rats (8 weeks old received only AM or previously in vitro reendothelialized AM as abdominal aorta interposition grafts (about 1 cm. The detergent-enzymatic treatment completely removed the cellular part of vessels and both MHC class I and class II antigens. One month after surgery, the luminal surface of implanted AMs was partially covered by ECs and several platelets adhered in the areas lacking cell coverage. Intimal hyperplasia, already detected after 1 month, increased at 3 months. On the contrary, all grafts composed by AM and ECs were completely covered at 1 month and their structure was similar to that of native vessels at 3 months. Taken together, our findings show that prostheses composed of AM preseeded with ECs could be a promising approach for the replacement of blood vessels.

  1. Endothelium-dependent relaxation of blood vessels

    International Nuclear Information System (INIS)

    Dilation of blood vessels in response to a large number of agents has been shown to be dependent on an intact vascular endothelium. The present studies examine some aspects of endothelium-dependent vasodilation in blood vessels of the rabbit and rat. Using the rabbit ear artery and the subtype-selective muscarinic antagonist pirenzepine, muscarinic receptors of the endothelium and smooth muscle cells were shown to be of the low affinity M2 subtype. Inhibition of [3H](-)quinuclidinyl benzilate was used to determine affinity for the smooth muscle receptors while antagonism of methacholine induced vasodilation yielded the endothelial cell receptor affinity. The effect of increasing age (1-27 months) on endothelium-dependent relaxation was studied in aortic rings, perfused tail artery and perfused mesenteric bed of the Fisher 344 rat. The influence of endothelium on contractile responses was examined using the perfused caudal artery

  2. Noninvasive blood pressure measurement in large vessels

    International Nuclear Information System (INIS)

    Pulse pressure in the aorta was evaluated by the measurement of pulse wave velocity (PWV) and blood flow velocity (BFV). PWV reflects the elasticity of the vessel and was determined by a time-of-flight method. BFV was measured by analyzing the change of magnetization decay due to flow in multiecho experiments. If one neglects pulse wave reflections at vascular branch points and flow resistance due to blood viscosity, pulse pressure is proportional to PWV and BFV. Noninvasive MR imaging measurements were obtained in 12 patients, all of whom underwent correlative arterial catheterization. Values varied between 35 and 100 mm Hg. The results demonstrated a high correlation between the two methods

  3. Water hammer experiment in artificial blood vessel

    Czech Academy of Sciences Publication Activity Database

    Hromádka, D.; Horný, L.; Žitný, R.; Chlup, Hynek

    Liberec : Technical University of Liberec, 2010 - (Čapek, L.), s. 127-132 ISBN 978-80-7372-648-5. [Human Biomechanics 2010. Sychrov (CZ), 04.10.2010-06.10.2010] R&D Projects: GA ČR(CZ) GA106/08/0557 Institutional research plan: CEZ:AV0Z20760514 Keywords : water hammer * artificial blood vessel * reinforced latex tube Subject RIV: JJ - Other Materials

  4. Designer blood vessels and therapeutic revascularization

    OpenAIRE

    Berglund, Joseph D; Galis, Zorina S.

    2003-01-01

    Inadequate vascular perfusion leads to fatal heart attacks, chronic ulcers, and other serious clinical conditions. The body's capacity to restore vascular perfusion through angiogenesis and arteriogenesis is often impaired by pre-existing disease, and availability of native replacements for nonfunctional arteries is limited in many patients. Thus, recreating blood vessels of various calibres through novel engineering technologies has emerged as a radical option among therapeutic strategies fo...

  5. Description of the condition of the implant-prosthesis system: a transverse study

    International Nuclear Information System (INIS)

    Current condition of the implant-prosthesis system of the patients attended in the Facultad de Odontologia de la Universidad de Costa Rica is described, in the included period from January 2001 to December 2006. Parameters of comparison will be established for future evaluations. An appointment was scheduled with each patient to review. A radiovisiograph was used for digital radiography with parallel technique and radiographic positioners, for anterior and posterior sector. In addition, a questionnaire was applied to all patients. The percentage of survival of the implants placed in the years 2001-2006, is 95.2 % and 92.4 % of the patients are satisfied with the aesthetic aspect of their restoration

  6. [Comparative analysis of different types of "implant-prosthesis" connection. Esthetic effect, prosthetic techniques].

    Science.gov (United States)

    Leclercq, P

    1990-12-01

    Thanks to the combined evolutions of surgery and of the concept of implantology it is now possible in the case of prosthetical rehabilitation to associate function, aesthetics and phonetics. The pre-prothetical analysis makes it possible to determine the various stages of an all-inclusive treatment namely: periodontics, surgery, prosthetics and occlusal equilibration, so as to obtain the appropriate results. The surgical problems caused by bone resorption in the toothless places are worsened by mechanical ones due to a deficiency in the parallelism of implants. Nevertheless the post-implants will be placed in the prosthetical corridor chosen before surgery. The aim of this article is to study the different types of junctions, permitting to link the implants to the prosthesis, whether it will be cemented of screwed. Depending on the clinical case, the choice of a connector, hence of a system of implants is determined by a number of questions such as: will it be easy to place the post-implants in the prosthetical corridor and to parallel them? Will it be possible to use systems permitting ductility or not? Is there any risk of the connector going loose? To what extent will the aesthetic function be respected? (Screw heads in the case of removable prostheses as well as gingival finishing lines of the superstructures). PMID:2268787

  7. Therapy of periprosthetical leakage with tissue augmentation using Bioplastique around the implanted voice prosthesis.

    Science.gov (United States)

    Lorincz, B B; Lichtenberger, G; Bihari, A; Falvai, J

    2005-01-01

    Having a voice prosthesis provides a good possibility for speech rehabilitation after total laryngectomy has been performed, especially if common complications such as leakage around the valve can be reduced effectively. The early applications of a voice prosthesis-which was originally invented and applied by Mozolewski in 1972, was further developed by Blom and Singer and became an internationally available implantable instrument by 1980- already made clear not only the typical benefits, but also the complications, such as possible leakage around the implanted valve. Remacle proposed the injection of collagen into the surrounding tissues in order to stop leakage. Knowing that collagen is usually resorbed as time goes by, new substances that can be tolerated by human tissues must be found. This article reports the experiences of the authors in the search for such an injectable material that cannot be resorbed and does not migrate. In order to solve the above-mentioned problem, Lichtenberger introduced the injection of Bioplastique into the perivalvular tissues. This delivered the best results ever achieved in this field at our department. During the past 2 years, Bioplastique augmentation was performed for seven laryngectomized and speech-rehabilitated patients in order to reduce periprosthetical leakage. All procedures were successful in terms of either eliminating or reducing the leakage, and also the non-resorbable property of Bioplastique has been proven. PMID:14986020

  8. Technique for fabricating a custom gingival mask using a maxillary complete-arch implant-supported fixed interim prosthesis with an integrated verification cast.

    Science.gov (United States)

    Esguerra, Roxanna J

    2016-01-01

    The custom gingival mask technique duplicates the tissue contours created by an implant-supported fixed interim prosthesis, which has been verified for satisfactory esthetics, phonetics, hygiene access, and patient comfort. This allows the dental laboratory technician to accurately duplicate the contours of the interim prosthesis in the definitive prosthesis. The technique described also incorporates a cast verification step to ensure the accurate, passive fit of the definitive prosthesis while eliminating the duplicate impression copings and implant replicas typically required for a verification cast. PMID:26384534

  9. Photoelastic Analysis on Different Retention Methods of Implant-Supported Prosthesis.

    Science.gov (United States)

    Pimentel, Angélica Castro; Manzi, Marcello Roberto; Polo, Cristiane Ibanhês; Sendyk, Claudio Luiz; da Graça Naclério-Homem, Maria; Sendyk, Wilson Roberto

    2015-06-01

    The aim of this study was to evaluate the stress distribution of different retention systems (screwed, cemented, and mixed) in 5-unit implant-supported fixed partial dentures through the photoelasticity method. Twenty standardized titanium suprastructures were manufactured, of which 5 were screw retained, 5 were cement retained, and 10 were mixed (with an alternating sequence of abutments), each supported by 5 external hexagon (4.0 mm × 11.5 mm) implants. A circular polariscope was used, and an axial compressive load of 100 N was applied on a universal testing machine. The results were photographed and qualitatively analyzed. We observed the formation of isochromatic fringes as a result of the stresses generated around the implant after installation of the different suprastructures and after the application of a compressive axial load of 100 N. We conclude that a lack of passive adaptation was observed in all suprastructures with the formation of low-magnitude stress in some implants. When cemented and mixed suprastructures were subjected to a compressive load, they displayed lower levels of stress distribution and lower intensity fringes compared to the screwed prosthesis. PMID:25198152

  10. Comparative Finite Element Analysis of Short Implants and Lateralization of the Inferior Alveolar Nerve With Different Prosthesis Heights.

    Science.gov (United States)

    Jayme, Sérgio J; Ramalho, Paulo R; De Franco, Leonardo; Jugdar, Ricardo Elias; Shibli, Jamil Awad; Vasco, Marco A A

    2015-11-01

    The lateralization of the inferior alveolar nerve (LIAN) and short implants are efficient options for rehabilitation of the posterior atrophic mandible. However, the loss of bone leads to prosthesis with greater height and lever effect that in turn can have different impact on treatments. Through the finite element method, the present study tests the hypothesis that conventional implants placed under LIAN and short implants have similar risk of bone loss regarding variable height of the crown and that crown-to-implant ratio is not a reliable resource to evaluate risk in these treatments. Computed tomography scans of mandibles were processed and implants and prosthetic components were reverse engineered for reconstruction of three-dimensional models to simulate 3 elements fixed partial dentures supported by 2 osseointegrated implants. The models of implants were based on MK III implants (Nobel Biocare, Zurich, Switzerland) with 4 mm in diameter by 7 mm in length representing short implants, and 15 mm in length representing implants used in LIAN. The implant/crown ratio for short implants was 1:1.5, 1:2, and 1:2.5 and LIAN models were modeled with exactly the same prosthesis, resulting in implant/crown ratios of 1:0.67, 1:0.89, and 1:1.12. The results partially rejected the hypothesis that LIAN and short implants have similar risk of bone loss, showing that although LIAN results were better in the models evaluated, the variations in height had proportionally similar impact on both treatments and accepted the hypothesis that crown-to-implant ratio was not a reliable resource to evaluate risk. PMID:26491923

  11. Patient’s satisfaction after 2-piece inflatable penile prosthesis implantation: An Italian multicentric study

    Directory of Open Access Journals (Sweden)

    Giorgio Gentile

    2016-03-01

    Full Text Available Introduction: Penile prosthesis implant represents a valuable solution for pts with severe erectile dysfunction (ED, non-responders to medical management. The aim of our study was to evaluate the satisfaction of patients (pts after 2-pieces inflatable penile prosthesis (IPP. Aim of the study: to evaluate safety, reliability and post-operative patient’s satisfaction after implantation of two-pieces IPP. Materials and Methods: This retrospective multicentric analysis concerns a group of 42 patients undergone 2-pieces IPP implantation from November 2005 to November 2013, in four Centers of proven experience. As a first step, a detailed review of all clinical reports was performed. Secondly, every patient was asked to fill the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS specifically modified, in order to assess their own satisfaction after surgery and, its impact on patient’s quality of sexual life. Results: 42 pts were evaluated (AMS-Ambicor: 28; Coloplast- Excell: 14; mean age, at time of operation: 60,7 years; mean follow up: 27,6 months; etiology of ED: vascular 23,8%, diabetes 19%, La Peyronie D. 7,1%, consequence of radical prostatectomy 31%, consequence of other pelvic surgery 11,9%, spinal trauma 7%. Mean operative time: 117 ± 58 min, mean postoperative hospital stay 3 ± 1,6 days. Post operative short-term complications: 4 pts (9,5%. Post operative long-term complications: 4 pts (9,5%. Long-term functional results (Questionnaire: 71% of pts (30 reported regular use of the prosthesis, at least 1 time/week, the satisfaction was good in 42% of pts (18, quite good in 33,3% (14, quite bad in 2,4% (1, very bad in 7,1% (3, 6 pts (14,4% didn’t answer. Conclusions: 2 pieces IPP appears to be associated with a low complication rate and good satisfaction of pts especially in the elderly. It also assures satisfactory rates of aesthetics and functional results.

  12. Stress analysis of different configurations of 3 implants to support a fixed prosthesis in an edentulous jaw

    Directory of Open Access Journals (Sweden)

    João Paulo da Silva-Neto

    2014-01-01

    Full Text Available This study's aims was to evaluate the stress distribution in a mandibular implant-supported prosthesis and peri-implant bone considering implant quantity, diameter and position using linear 3-D finite element analysis. Models of an anterior jaw comprised 4 groups according to implant quantity, diameter, and position: control group C, 5 regular implants; R, 3 regular implants; W, 3 wide implants; and DTR, 3 regular implants with the distal ones tilted 30º distally. The cantilever was loaded with an axial load of 50 N. Data was evaluated using von Mises stress on implants and maximum principal stress and microstrain on the bone. The W group showed the lowest value of maximum principal stress in peri-implant bone of the loaded side (4.64 MPa when compared to C (5.27 MPa, DTR (5.94 MPa, and R (11.12 MPa. Lower stress values in the loaded implants were observed in the experimental groups when compared to the C group. However, the unloaded implants presented opposite results. All the screws of the W group presented lower stress values when compared to the C group. However, the R and DTR groups presented an increase in stress values with the exception of the loaded screw. A reduction in the number of implants associated with wider implants reduced the stress in the bone and prosthetic components.

  13. Imaging and dosimetric considerations for titanium prosthesis implanted within the irradiated region by high photon beams

    International Nuclear Information System (INIS)

    The aim of this research was to observe dose distributions in the vicinity of titanium prosthetic implants during radiotherapy procedures. Data were obtained using a locally fabricated tissue equivalent phantom CT images, and in blue water phantom with titanium prosthesis which was irradiated with 60Co gamma radiation and Elekta Platform photon beams. Images obtained were loaded into Prowess Panther and Oncentra treatment planning systems (TPSs) for dose simulations. Prowess TPS (1.25 MeV) estimated lesser errors whilst Oncentra (6 and 15 MV) dose simulations yielded large variations. Proximal ends of the metal recorded slight increase in doses as a rcsult of backscatter with dose increment below acceptable tolerance of ±3%. Doses measured decreases on the distal side of the prosthesis at a distance less than dmax from the plate on each beam energy. Beyond certain depth along the axis, depth doses increased slightly mainly due to increase in electron fluence by portions receiving unperturbed dose. An increase in the plate thickness showed a corresponding decrease on percentage depth dose. A reduction in the above trend was also noticed with an increase in beam energy primarily because scattered photons are more forwardly directed. Prowess TPS (convolution superposition algorithm) was found to be better at reducing dose variation than OMP (collapse cone algorithm) when correction for artifact. Manual calculations on blue phantom data agree with results from Prowess. Oncentra is not capable of simulating dose around titanium prosthesis as its range of densities, 0.00121 to 2.83, excludes titanium density (rED for titanium is 3.74). (au)

  14. Microfabrication of an Implantable silicone Microelectrode array for an epiretinal prosthesis

    Energy Technology Data Exchange (ETDEWEB)

    Maghribi, M

    2003-06-10

    Millions of people suffering from diseases such as retinitis pigmentosa and macular degeneration are legally blind due to the loss of photoreceptor function. Fortunately a large percentage of the neural cells connected to the photoreceptors remain viable, and electrical stimulation of these cells has been shown to result in visual perception. These findings have generated worldwide efforts to develop a retinal prosthesis device, with the hope of restoring vision. Advances in microfabrication, integrated circuits, and wireless technologies provide the means to reach this challenging goal. This dissertation describes the development of innovative silicone-based microfabrication techniques for producing an implantable microelectrode array. The microelectrode array is a component of an epiretinal prosthesis being developed by a multi-laboratory consortium. This array will serve as the interface between an electronic imaging system and the human eye, directly stimulating retinal neurons via thin film conducting traces. Because the array is intended as a long-term implant, vital biological and physical design requirements must be met. A retinal implant poses difficult engineering challenges due to the size of the intraocular cavity and the delicate retina. Not only does it have to be biocompatible in terms of cytotoxicity and degradation, but it also has to be structurally biocompatible, with regard to smooth edges and high conformability; basically mimicking the biological tissue. This is vital to minimize stress and prevent physical damage to the retina. Also, the device must be robust to withstand the forces imposed on it during fabrication and implantation. In order to meet these biocompatibility needs, the use of non-conventional microfabrication materials such as silicone is required. This mandates the enhancement of currently available polymer-based fabrication techniques and the development of new microfabrication methods. Through an iterative process, devices

  15. Application of Computational Physics: Blood Vessel Constrictions and Medical Infuses

    CERN Document Server

    Suprijadi,; Subekti, Petrus; Viridi, Sparisoma

    2013-01-01

    Application of computation in many fields are growing fast in last two decades. Increasing on computation performance helps researchers to understand natural phenomena in many fields of science and technology including in life sciences. Computational fluid dynamic is one of numerical methods which is very popular used to describe those phenomena. In this paper we propose moving particle semi-implicit (MPS) and molecular dynamics (MD) to describe different phenomena in blood vessel. The effect of increasing the blood pressure on vessel wall will be calculate using MD methods, while the two fluid blending dynamics will be discussed using MPS. Result from the first phenomenon shows that around 80% of constriction on blood vessel make blood vessel increase and will start to leak on vessel wall, while from the second phenomenon the result shows the visualization of two fluids mixture (drugs and blood) influenced by ratio of drugs debit to blood debit. Keywords: molecular dynamic, blood vessel, fluid dynamic, movin...

  16. Carbon-carbon composites for orthopedic prosthesis and implants. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, T D; Klett, J W; Strizak, J P [Oak Ridge National Lab., TN (United States); Baker, C [FMI, Biddeford, ME (United States)

    1998-01-21

    The prosthetic implant market is extensive. For example, because of arthritic degeneration of hip and knee cartilage and osteoporotic fractures of the hip, over 200,000 total joint replacements (TJRs) are performed in the United States each year. Current TJR devices are typically metallic (stainless steel, cobalt, or titanium alloy) and are fixed in the bone with polymethylacrylate (PMMA) cement. Carbon-carbon composite materials offer several distinct advantages over metals for TJR prosthesis. Their mechanical properties can be tailored to match more closely the mechanical properties of human bone, and the composite may have up to 25% porosity, the size and distribution of which may be controlled through processing. The porous nature of carbon-carbon composites will allow for the ingrowth of bone, achieving biological fixation, and eliminating the need for PMMA cement fixation.

  17. Morphogenetic mechanisms of blood vessel fusion in the Zebrafish embryo

    OpenAIRE

    Herwig, Lukas Walter

    2012-01-01

    The formation of a vascular network requires the connection and formation of a lumen between individual endothelial sprouts, a process called vessel fusion or anastomosis. In the vertebrate trunk of the zebrafish (Danio rerio), the intersegmental vessels (ISVs) develop by angiogenesis, i.e. the formation of new vessels by pre-existing vessels, in a conserved metameric manner, which allows the analysis of morphogenetic mechanisms of blood vessel development. From the dorsal aorta (DA) individu...

  18. Blood Vessel Diameter Estimation System Using Active Contours

    OpenAIRE

    Courtney, Jane; Tizon, Ana

    2011-01-01

    The study and analysis of blood vessel geometry has become the basis of medical applications related to early diagnosis and effective monitoring of therapies in vascular diseases. This paper presents a new method to trace the outline of blood vessels from imperfect images and extract useful information about their dimensions in an automated manner. The system consists of a segmentation procedure that uses two Active Contours to detect blood vessel boundaries and a novel approach to measure bl...

  19. Erectile dysfunction patients are more satisfied with penile prosthesis implantation compared with tadalafil and intracavernosal injection treatments.

    Science.gov (United States)

    Kucuk, E V; Tahra, A; Bindayi, A; Onol, F F

    2016-09-01

    There are various treatment modalities for erectile dysfunction with different success and satisfaction rates. We aim to compare patient satisfaction with tadalafil, intracavernosal injection, and penile prosthesis implantation in patients with erectile dysfunction. The records of 3448 men with erectile dysfunction were evaluated retrospectively. A total of 356 men with organic erectile dysfunction were enrolled into this study. Of these patients, 132 (37%) received tadalafil 20 mg twice a week for 12 weeks, 106 (30%) patients received tadalafil 5 mg once-daily for 12 weeks, 96 (27%) patients used intracavernosal injection therapy (Bi-mix; papaverine and phentolamine). Moreover, 22 patients underwent penile prosthesis implantation. Patient and partner satisfaction were assessed with International Index of Erectile Function (IIEF) and Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) questionnaire. Patients' mean age was 52.4 ± 25.76 (32-71). The etiology of erectile dysfunction was chronic systemic diseases in 133 (44%) and radical prostatectomy in 121 patients (40%). The mean IIEF-5 scores improvement after the treatment was higher in penile prosthesis implantation group (12.4 ± 1.3) compared with tadalafil 5 mg (6.7 ± 1.5) (p prosthesis implantation group (78.2 ± 11.3) compared with intracavernosal injection (60.3 ± 6.3), tadalafil 5 mg (72.5 ± 4.5), and tadalafil 20 mg 70.7 ± 3.4 groups (p prosthesis implantation group, 50.2 ± 1.5 in intracavernosal injection group, 62.9 ± 7.8 in tadalafil 5 mg, and 61.3 ± 5.3 in tadalafil 20 mg group (p prosthesis implantation seem to be more satisfied compared with tadalafil treatment and intracavernosal injection. Future clinical trials are warranted to confirm our results. PMID:27368423

  20. Painting blood vessels and atherosclerotic plaques with an adhesive drug depot

    Science.gov (United States)

    Kastrup, Christian J.; Nahrendorf, Matthias; Figueiredo, Jose Luiz; Lee, Haeshin; Kambhampati, Swetha; Lee, Timothy; Cho, Seung-Woo; Gorbatov, Rostic; Iwamoto, Yoshiko; Dang, Tram T.; Dutta, Partha; Yeon, Ju Hun; Cheng, Hao; Pritchard, Christopher D.; Vegas, Arturo J.; Siegel, Cory D.; MacDougall, Samantha; Okonkwo, Michael; Thai, Anh; Stone, James R.; Coury, Arthur J.; Weissleder, Ralph; Langer, Robert; Anderson, Daniel G.

    2012-01-01

    The treatment of diseased vasculature remains challenging, in part because of the difficulty in implanting drug-eluting devices without subjecting vessels to damaging mechanical forces. Implanting materials using adhesive forces could overcome this challenge, but materials have previously not been shown to durably adhere to intact endothelium under blood flow. Marine mussels secrete strong underwater adhesives that have been mimicked in synthetic systems. Here we develop a drug-eluting bioadhesive gel that can be locally and durably glued onto the inside surface of blood vessels. In a mouse model of atherosclerosis, inflamed plaques treated with steroid-eluting adhesive gels had reduced macrophage content and developed protective fibrous caps covering the plaque core. Treatment also lowered plasma cytokine levels and biomarkers of inflammation in the plaque. The drug-eluting devices developed here provide a general strategy for implanting therapeutics in the vasculature using adhesive forces and could potentially be used to stabilize rupture-prone plaques. PMID:23236189

  1. Computer-designed selective laser sintering surgical guide and immediate loading dental implants with definitive prosthesis in edentulous patient: A preliminary method

    Science.gov (United States)

    Giacomo, Giovanni Di; Silva, Jorge; Martines, Rodrigo; Ajzen, Sergio

    2014-01-01

    Objective: The aim of this study was to analyze a preliminary method of immediately loading dental implants and a definitive prosthesis based on the computer-aided design/computer-aided manufacturing systems, after 2 years of clinical follow-up. Materials and Methods: The study comprised one patient in good general health with edentulous maxilla. Cone beam computer tomography (CBCT) was performed using a radiographic template. The surgical plan was made using the digital imaging and communications in medicine protocol with ImplantViewer (version 1.9, Anne Solutions, Sao Paulo, SP, Brazil), the surgical planning software. These data were used to produce a selective laser sintering surgical template. A maxilla prototype was used to guide the prosthesis technician in producing the prosthesis. Eight dental implants and a definitive prosthesis were installed on the same day. A post-operative CBCT image was fused with the image of the surgical planning to calculate the deviation between the planned and the placed implants positions. Patient was followed for 2 years. Results: On average, the match between the planned and placed angular deviation was within 6.0 ± 3.4° and the difference in coronal deviation was 0.7 ± 0.3 mm. At the end of the follow-up, neither the implant nor the prosthesis was lost. Conclusions: Considering the limited samples number, it was possible to install the dental implants and a definitive prosthesis on the same day with success. PMID:24966755

  2. Autoinflation Leading to Failure of Two-Piece Ambicor Implantable Penile Prosthesis: An Outcome from a Methodical Treatment of Recalcitrant Stuttering Priapism

    Directory of Open Access Journals (Sweden)

    R. Charles Welliver

    2014-01-01

    Full Text Available Introduction. We present the case of a patient who received a two-piece Ambicor penile prosthesis for idiopathic recurrent “stuttering” priapism refractory to other treatment options. The patient returned unable to deflate the device due to an interesting anatomically induced mechanical failure. Aims. To describe the method and findings of this inflatable prosthesis failure. Results. Prosthesis failure occurred due to restrictive corporal diameter and the unique characteristics of fluid reservoir location in the two-piece inflatable prosthesis. The patient was successfully converted to a semirigid prosthesis with resolution of the pain that was due to his prosthesis autoinflation. Conclusion. Stuttering priapism remains a challenging clinical problem. Penile implantation is a reasonable long-term solution in a patient refractory to less invasive options. In patients with fibrotic corpora, a malleable device should be considered (at least temporarily if unable to dilate comfortably to 13 mm.

  3. A digital approach to fabricating an abutment replica to control cement volume in a cement-retained implant prosthesis.

    Science.gov (United States)

    Lee, Ju-Hyoung; Park, In-Sook; Sohn, Dong-Seok

    2016-07-01

    If a cement-retained implant prosthesis is placed on an abutment, excess cement should be minimized or removed to prevent periimplant inflammation. Various methods for fabricating an abutment replica have been introduced to maintain tissue health and reduce clean-up time. The purpose of this article is to present an alternative technique for fabricating an abutment replica with computer-aided design/computer-aided manufacturing (CAD/CAM) technology. PMID:26946917

  4. One lesson from arthroplasty to osseointegration in search for better fixation of in-bone implanted prosthesis

    OpenAIRE

    Pitkin, Mark

    2008-01-01

    Direct transcutaneous prosthetic attachment (osseointegration) consists of implanting directly into the residuum bone a metal pylon whose external fraction connects the residuum to the external prosthesis. Since the introduction of osseointegration about 20 years ago, the obvious challenge associated with this technology has been the skin-pylon interface as a source of infections. In comparison, the bone-device interface was considered less problematic because of the knowledge and experience ...

  5. Bentall procedure 39 years after implantation of a Starr-Edwards Aortic Caged- Ball-Valve Prosthesis

    OpenAIRE

    Sohns Christian; Wiese Christoph H; Friedrich Martin; Schotola Hanna; Coskun Kasim O; Popov Aron F; Ortmann Philipp; Schmitto Jan D; Mokashi Suyog A; Didilis Vassilios N; Schoendube Friedrich A

    2010-01-01

    Abstract We report a case of a male patient who received an implantation of a Starr-Edwards-caged-ball-valve-prosthesis in 1967. The surgery and postoperative course were without complications and the patient recovered well after the operation. For the next four decades, the patient remained asymptomatic - no restrictions on his lifestyle and without any complications. In 2006, 39 years after the initial operation, we performed a Bentall-Procedure to treat an aortic ascendens aneurysm with di...

  6.  Evaluation of the humoral and cellular immune responses after implantation of a PTFE vascular prosthesis

    Directory of Open Access Journals (Sweden)

    Jan Skóra

    2012-07-01

    Full Text Available  Introduction:The experiment was designed in order to determine the immunological processes that occur during the healing in synthetic vascular grafts, especially to establish the differences in the location of the complement system proteins between the proximal and distal anastomosis and the differences in the arrangement of inflammatory cells in those anastomoses. The understanding of those processes will provide a true basis for determining risk factors for complications after arterial repair procedures.Material/Methods:The experiment was carried out on 16 dogs that underwent implantation of unilateral aorto-femoral bypass with expanded polytetrafluoroethylene (ePTFE. After 6 months all animals were euthanized to dissect the vascular grafts. Immunohistochemical assays and electron microscopic examinations were performed.Results:Immunohistochemical findings in the structure of neointima between anastomoses of vascular prostheses demonstrated significant differences between humoral and cellular responses. The area of proximal anastomosis revealed the presence of fibroblasts, but no macrophages were detected. The histological structure of the proximal anastomosis indicates that inflammatory processes were ended during the prosthesis healing. The immunological response obtained in the distal anastomosis corresponded to the chronic inflammatory reaction with the presence of macrophages, myofibroblasts and deposits of complement C3.Discussion:The identification of differences in the presence of macrophages and myofibroblasts and the presence of the C3 component between the anastomoses is the original achievement of the present study. In the available literature, no such significant differences have been shown so far in the humoral and cellular immune response caused by the presence of an artificial vessel in the arterial system.

  7. Comparison and Combination of Dual-Energy- and Iterative-Based Metal Artefact Reduction on Hip Prosthesis and Dental Implants

    OpenAIRE

    Malte N Bongers; Schabel, Christoph; Thomas, Christoph; Raupach, Rainer; Notohamiprodjo, Mike; Nikolaou, Konstantin; Bamberg, Fabian

    2015-01-01

    Purpose To compare and combine dual-energy based and iterative metal artefact reduction on hip prosthesis and dental implants in CT. Material and Methods A total of 46 patients (women:50%,mean age:63±15years) with dental implants or hip prostheses (n = 30/20) were included and examined with a second-generation Dual Source Scanner. 120kV equivalent mixed-images were derived from reconstructions of the 100/Sn140kV source images using no metal artefact reduction (NOMAR) and iterative metal artef...

  8. Avian Blood-Vessel Formation in Space

    Science.gov (United States)

    Lelkes, Peter I.

    1999-01-01

    Based on previous studies, we hypothesized that the developmental anomalies observed in the past might be related to or caused by delayed or improper vascular development. The objective of our research is to test the hypothesis that exposure to microgravity during space flight cause delayed or improper vascular development during embryogenesis. The effects of microgravity on the time course and extent of avian blood-vessel formation are assessed using two models, one for angiogenesis and one for vasculogenesis. The methodological approach is dictated by the constraints of the tissue preservation method used in space. Thus, both in the chorioallantoic membrane (CAM) and in the adrenal, we will evaluate microscopically the vascular architecture and immunostain endothelial cells with specific antibodies (anti- vWF and QH1). The extent of ECM protein deposition will be assessed by immunohistochemistry and correlated with the degree of vascularization, using computer-based image analysis. Also, the cellular source for ECM proteins will be assessed by in situ hybridization.

  9. Tumour angiogenesis-Origin of blood vessels.

    Science.gov (United States)

    Krishna Priya, S; Nagare, R P; Sneha, V S; Sidhanth, C; Bindhya, S; Manasa, P; Ganesan, T S

    2016-08-15

    The conventional view of tumour vascularization is that tumours acquire their blood supply from neighbouring normal stroma. Additional methods of tumour vascularization such as intussusceptive angiogenesis, vasculogenic mimicry, vessel co-option and vasculogenesis have been demonstrated to occur. However, the origin of the endothelial cells and pericytes in the tumour vasculature is not fully understood. Their origin from malignant cells has been shown indirectly in lymphoma and neuroblastoma by immuno-FISH experiments. It is now evident that tumours arise from a small population of cells called cancer stem cells (CSCs) or tumour initiating cells. Recent data suggest that a proportion of tumour endothelial cells arise from cancer stem cells in glioblastoma. This was demonstrated both in vitro and in vivo. The analysis of chromosomal abnormalities in endothelial cells showed identical genetic changes to those identified in tumour cells. However, another report contradicted these results from the earlier studies in glioblastoma and had shown that CSCs give rise to pericytes and not endothelial cells. The main thrust of this review is the critical analysis of the conflicting data from different studies and the remaining questions in this field of research. The mechanism by which this phenomenon occurs is also discussed in detail. The transdifferentiation of CSCs to endothelial cells/pericytes has many implications in the progression and metastasis of the tumours and hence it would be a novel target for antiangiogenic therapy. PMID:26934471

  10. 人工关节假体植入后无菌性松动的发病机制%Pathogenesis of aseptic prosthesis loosening after artificial prosthesis implantation

    Institute of Scientific and Technical Information of China (English)

    马玉超; 田京

    2012-01-01

    BACKGROUND: There are many clinical researches on aseptic loosening of artificial prosthesis, but the exact pathogenesis is still unclear.OBJECTIVE: To review the pathogenesis of prosthesis aseptic loosening after artificial prosthesis implantation.METHODS: A computer-based online search of PubMed and CNKI was performed to search related articles published between 2006 and 2011 with the key words of “artificial prosthesis, aseptic loosening” both in English and Chinese. A total of 77 articles were obtained, and finally 38 articles were included.RESULTS AND CONCLUSION: Aseptic loosening after long-term total hip replacement is one of the main failure reasons. In the recent years, analysis of revision total hip replacement for failed hip arthroplasty showed that aseptic loosening is the chief reason. The mechanism of aseptic loosening mainly includes mechanical mechanisms, biological and other mechanisms. With further research and the improvement of implantation method and prosthetic materials, aseptic loosening will eventually be minimized, so that the service life of prosthesis will be longer.%背景:对于人工关节无菌性松动的基础和临床研究很多,但其确切机制仍不甚明确.目的:综述人工关节假体植入后无菌性松动的发病机制.方法:由第一作者应用计算机检索PubMed和中国期刊全文数据库2006/2011相关文献.在标题、摘要、关键词中以"artificial prosthesis,aseptic loosening"或"人工关节、无菌性松动"为检索词进行检索.共检索到77篇文献,最终纳入符合标准的文献38篇.结果与结论:无菌性松动已成为人工关节置换后远期失败的主要原因之一.近年来对人工全髋关节置换后翻修病例回顾性分析的统计显示,无菌性松动位于翻修原因第1位.关于人工关节无菌性松动的机制主要分为机械机制、生物机制及其他机制,它们的共同结果是造成骨吸收、骨溶解,最终导致假体松动.随着研究

  11. Comparison of Quality of Life Between Iranians Using Two Implant-Retained Overdenture Prosthesis and Conventional Complete Denture

    Directory of Open Access Journals (Sweden)

    Semyari

    2013-12-01

    Full Text Available Background Clinicians and policymakers are recognizing the importance of measuring health-related quality of life (HRQL to inform patient management and policy decisions. Objectives With regard to relation between cultural differences and quality of life (QoL, in this study the QoL of Iranian patients with conventional complete denture and implant-retained overdenture prosthesis according to the increasing penchant of use of implant-retained overdenture prosthesis and lack of studies in this field in our country, has been compared. Patients and Methods In this cross-sectional study, cluster sampling was conducted in two stages and 90 edentulous patients (45 patients with conventional complete dentures for two jaws (CD group and 45 patients with a conventional maxillary complete dentures and implant-retained mandibular denture based on two intercanine implants (IOD group with the age of above 35 years were selected according to our inclusion criteria. After obtaining permission from the patients, who had been treated at the selected healthcare and medical treatment centers of Tehran, basic information was obtained by a checklist, including gender, age, educational status and housing status; and QoL was measured by a questionnaire of oral health impact profile (OHIP-20. Results In the group of IOD, 55.6% of the patients had “good” QoL vs. 46.7% of the patients in CD group. Three patients (6.6% in both groups had “poor” QoL. No significant relationship was observed between demographic factors and different dimensions of QoL, except the average of “psychological disability” in the patients of CD group, which was higher in women. Conclusions According to this study results, implant-retained overdenture prosthesis provided better QoL for Iranian patients.

  12. Synthesis of cobalt alloy through smelting method and its characterization as prosthesis bone implant

    Science.gov (United States)

    Aminatun, Putri, N. S. Efinda; Indriani, Arista; Himawati, Umi; Hikmawati, Dyah; Suhariningsih

    2014-09-01

    Cobalt-based alloys are widely used as total hip and knee replacements because of their excellent properties, such as corrosion resistance, fatigue strength and biocompatibility. In this work, cobalt alloys with variation of Cr (28.5; 30; 31.5; 33, and 34.5% wt) have been synthesized by smelting method began with the process of compaction, followed by smelting process using Tri Arc Melting Furnace at 200A. Continued by homogenization process at recrystallization temperature (1250° C) for 3 hours to allow the atoms diffuses and transform into γ phase. The next process is rolling process which is accompanied by heating at 1200° C for ± 15 minutes and followed by quenching. This process is repeated until the obtained thickness of ± 1 mm. The evaluated material properties included microstructure, surface morphology, and hardness value. It was shown that microstructure of cobalt alloys with variation of Cr is dominant by γ phase, thus making the entire cobalt alloys have high hardness. It was also shown from the surface morphology of entire cobalt alloys sample indicated the whole process of synthesis that had good solubility were at flat surface area. Hardness value test showed all of cobalt alloys sample had high hardness, just variation of 33% Cr be in the range of ASTMF75, it were 345,24 VHN which is potential to be applied as an implant prosthesis.

  13. Synthesis of cobalt alloy through smelting method and its characterization as prosthesis bone implant

    International Nuclear Information System (INIS)

    Cobalt-based alloys are widely used as total hip and knee replacements because of their excellent properties, such as corrosion resistance, fatigue strength and biocompatibility. In this work, cobalt alloys with variation of Cr (28.5; 30; 31.5; 33, and 34.5% wt) have been synthesized by smelting method began with the process of compaction, followed by smelting process using Tri Arc Melting Furnace at 200A. Continued by homogenization process at recrystallization temperature (1250° C) for 3 hours to allow the atoms diffuses and transform into γ phase. The next process is rolling process which is accompanied by heating at 1200° C for ± 15 minutes and followed by quenching. This process is repeated until the obtained thickness of ± 1 mm. The evaluated material properties included microstructure, surface morphology, and hardness value. It was shown that microstructure of cobalt alloys with variation of Cr is dominant by γ phase, thus making the entire cobalt alloys have high hardness. It was also shown from the surface morphology of entire cobalt alloys sample indicated the whole process of synthesis that had good solubility were at flat surface area. Hardness value test showed all of cobalt alloys sample had high hardness, just variation of 33% Cr be in the range of ASTMF75, it were 345,24 VHN which is potential to be applied as an implant prosthesis

  14. Pillar-shaped stimulus electrode array for high-efficiency stimulation of fully implantable epiretinal prosthesis

    International Nuclear Information System (INIS)

    We developed a pillar-shaped microelectrode array (MEA) with varying heights for enhancing the spherical conformity of fully implantable epiretinal prosthesis comprising a 3D stacked retinal chip. The fabricated MEA is composed of 100 pillar electrodes with heights ranging from 60 to 80 µm. The Pt-coated Cu pillar electrode with a surface diameter of 70 µm and a height of 75 µm and the Pt planar electrode with a surface diameter of 70 µm have 24.6 and 125 kΩ impedances, respectively, at 1 kHz in vitro experiment. The pillar electrode shows lower impedance than the planar electrode because of a larger surface area. However, to avoid cross-talking between pillar electrodes, we developed a sidewall passivation process of the pillar electrode by using the surface tension of polyimide. The impedance of the isolated pillar electrode 116 kΩ at 1 kHz is similar to the impedance of the planar electrode, because they have similar electrode surface areas. The pillar-shaped MEA shows a better spherical conformity. (paper)

  15. Synthesis of cobalt alloy through smelting method and its characterization as prosthesis bone implant

    Energy Technology Data Exchange (ETDEWEB)

    Aminatun,, E-mail: ami-sofijan@yahoo.co.id; Putri, N.S Efinda, E-mail: ami-sofijan@yahoo.co.id; Indriani, Arista, E-mail: ami-sofijan@yahoo.co.id; Himawati, Umi, E-mail: ami-sofijan@yahoo.co.id; Hikmawati, Dyah, E-mail: ami-sofijan@yahoo.co.id; Suhariningsih, E-mail: ami-sofijan@yahoo.co.id [Department of physics, Faculty of Science and Technology, Airlangga University (Indonesia)

    2014-09-25

    Cobalt-based alloys are widely used as total hip and knee replacements because of their excellent properties, such as corrosion resistance, fatigue strength and biocompatibility. In this work, cobalt alloys with variation of Cr (28.5; 30; 31.5; 33, and 34.5% wt) have been synthesized by smelting method began with the process of compaction, followed by smelting process using Tri Arc Melting Furnace at 200A. Continued by homogenization process at recrystallization temperature (1250° C) for 3 hours to allow the atoms diffuses and transform into γ phase. The next process is rolling process which is accompanied by heating at 1200° C for ± 15 minutes and followed by quenching. This process is repeated until the obtained thickness of ± 1 mm. The evaluated material properties included microstructure, surface morphology, and hardness value. It was shown that microstructure of cobalt alloys with variation of Cr is dominant by γ phase, thus making the entire cobalt alloys have high hardness. It was also shown from the surface morphology of entire cobalt alloys sample indicated the whole process of synthesis that had good solubility were at flat surface area. Hardness value test showed all of cobalt alloys sample had high hardness, just variation of 33% Cr be in the range of ASTMF75, it were 345,24 VHN which is potential to be applied as an implant prosthesis.

  16. Instability and "Sausage-String" Appearance in Blood Vessels during High Blood Pressure

    CERN Document Server

    Alstrøm, P; Colding-Jorgensen, M; Gustafsson, F; Holstein-Rathlou, N H; Alstrom, Preben; Eguiluz, Victor M.; Colding-Jorgensen, Morten; Gustafsson, Finn; Holstein-Rathlou, Niels-Henrik

    1999-01-01

    A new Rayleigh-type instability is proposed to explain the `sausage-string' pattern of alternating constrictions and dilatations formed in blood vessels under influence of a vasoconstricting agent. Our theory involves the nonlinear elasticity characteristics of the vessel wall, and provides predictions for the conditions under which the cylindrical form of a blood vessel becomes unstable.

  17. Instability and `Sausage-String' Appearance in Blood Vessels during High Blood Pressure

    OpenAIRE

    Alstrøm, P.; Eguíluz, Víctor M.; Holstein-Rathlou, Niels-Henrik

    1998-01-01

    A new Rayleigh-type instability is proposed to explain the `sausage-string' pattern of alternating constrictions and dilatations formed in blood vessels under influence of a vasoconstricting agent. Our theory involves the nonlinear elasticity characteristics of the vessel wall, and provides predictions for the conditions under which the cylindrical form of a blood vessel becomes unstable.

  18. Percutaneous Transcatheter One-Step Mechanical Aortic Disc Valve Prosthesis Implantation: A Preliminary Feasibility Study in Swine

    International Nuclear Information System (INIS)

    Purpose. To evaluate the feasibility of one-step implantation of a new type of stent-based mechanical aortic disc valve prosthesis (MADVP) above and across the native aortic valve and its short-term function in swine with both functional and dysfunctional native valves. Methods. The MADVP consisted of a folding disc valve made of silicone elastomer attached to either a nitinol Z-stent (Z model) or a nitinol cross-braided stent (SX model). Implantation of 10 MADVPs (6 Z and 4 SX models) was attempted in 10 swine: 4 (2 Z and 2 SX models) with a functional native valve and 6 (4 Z and 2 SX models) with aortic regurgitation induced either by intentional valve injury or by MADVP placement across the native valve. MADVP function was observed for up to 3 hr after implantation. Results. MADVP implantation was successful in 9 swine. One animal died of induced massive regurgitation prior to implantation. Four MADVPs implanted above functioning native valves exhibited good function. In 5 swine with regurgitation, MADVP implantation corrected the induced native valve dysfunction and the device's continuous good function was observed in 4 animals. One MADVP (SX model) placed across native valve gradually migrated into the left ventricle. Conclusion. The tested MADVP can be implanted above and across the native valve in a one-step procedure and can replace the function of the regurgitating native valve. Further technical development and testing are warranted, preferably with a manufactured MADVP

  19. Effect of cement washout on loosening of abutment screws and vice versa in screw- and cement- retained implant-supported dental prosthesis

    OpenAIRE

    Kim, Seok-Gyu; Chung, Chae-Heon; Son, Mee-Kyoung

    2015-01-01

    PURPOSE The purpose of this study was to examine the abutment screw stability of screw- and cement-retained implant-supported dental prosthesis (SCP) after simulated cement washout as well as the stability of SCP cements after complete loosening of abutment screws. MATERIALS AND METHODS Thirty-six titanium CAD/CAM-made implant prostheses were fabricated on two implants placed in the resin models. Each prosthesis is a two-unit SCP: one screw-retained and the other cemented. After evaluating th...

  20. Distinct bone marrow blood vessels differentially regulate haematopoiesis.

    Science.gov (United States)

    Itkin, Tomer; Gur-Cohen, Shiri; Spencer, Joel A; Schajnovitz, Amir; Ramasamy, Saravana K; Kusumbe, Anjali P; Ledergor, Guy; Jung, Yookyung; Milo, Idan; Poulos, Michael G; Kalinkovich, Alexander; Ludin, Aya; Kollet, Orit; Shakhar, Guy; Butler, Jason M; Rafii, Shahin; Adams, Ralf H; Scadden, David T; Lin, Charles P; Lapidot, Tsvee

    2016-04-21

    Bone marrow endothelial cells (BMECs) form a network of blood vessels that regulate both leukocyte trafficking and haematopoietic stem and progenitor cell (HSPC) maintenance. However, it is not clear how BMECs balance these dual roles, and whether these events occur at the same vascular site. We found that mammalian bone marrow stem cell maintenance and leukocyte trafficking are regulated by distinct blood vessel types with different permeability properties. Less permeable arterial blood vessels maintain haematopoietic stem cells in a low reactive oxygen species (ROS) state, whereas the more permeable sinusoids promote HSPC activation and are the exclusive site for immature and mature leukocyte trafficking to and from the bone marrow. A functional consequence of high permeability of blood vessels is that exposure to blood plasma increases bone marrow HSPC ROS levels, augmenting their migration and differentiation, while compromising their long-term repopulation and survival. These findings may have relevance for clinical haematopoietic stem cell transplantation and mobilization protocols. PMID:27074509

  1. Lattice BGK Simulations of the Blood Flow in Elastic Vessels

    Institute of Scientific and Technical Information of China (English)

    LU Xiao-Yang; YI Hou-Hui; CHEN Ji-Yao; FANG Hai-Ping

    2006-01-01

    @@ The lattice Boltzmann method is applied to study the flow in elastic blood vessels. The volume-flow rate increases considerably when the compliance constant of the blood vessel is below a critical value. There is a region of the compliance constant in which the average volume-flow rate is dramatically enhanced. A harmonic perturbation of the pressure does not change the behaviour of the average volume-flow rate while the harmonic wave attenuates very quickly along the tube when the resonant period is close to that of the input wave. The model, together with the simulation results, is expected to be helpful to understand the mechanism of the blood volume-flow rate related to the compliance constant of the blood vessel, especially on the dependence of the flux of human blood vessel under weather changes, which has medical significance.

  2. Passive Fit in Screw Retained Multi-unit Implant Prosthesis Understanding and Achieving: A Review of the Literature.

    Science.gov (United States)

    Buzayan, Muaiyed Mahmoud; Yunus, Norsiah Binti

    2014-03-01

    One of the considerable challenges for screw-retained multi-unit implant prosthesis is achieving a passive fit of the prosthesis' superstructure to the implants. This passive fit is supposed to be one of the most vital requirements for the maintenance of the osseointegration. On the other hand, the misfit of the implant supported superstructure may lead to unfavourable complications, which can be mechanical or biological in nature. The manifestations of these complications may range from fracture of various components in the implant system, pain, marginal bone loss, and even loss of osseointegration. Thus, minimizing the misfit and optimizing the passive fit should be a prerequisite for implant survival and success. The purpose of this article is to present and summarize some aspects of the passive fit achieving and improving methods. The literature review was performed through Science Direct, Pubmed, and Google database. They were searched in English using the following combinations of keywords: passive fit, implant misfit and framework misfit. Articles were selected on the basis of whether they had sufficient information related to framework misfit's related factors, passive fit and its achievement techniques, marginal bone changes relation with the misfit, implant impression techniques and splinting concept. The related references were selected in order to emphasize the importance of the passive fit achievement and the misfit minimizing. Despite the fact that the literature presents considerable information regarding the framework's misfit, there was not consistency in literature on a specified number or even a range to be the acceptable level of misfit. On the other hand, a review of the literature revealed that the complete passive fit still remains a tricky goal to be achieved by the prosthodontist. PMID:24604993

  3. Preventing pathological regression of blood vessels

    OpenAIRE

    Keshet, Eli

    2003-01-01

    Oxygen administration to premature infants suppresses retinal VEGF expression and results in the catastrophic vessel loss associated with retinopathy of prematurity. A study investigating the development of the retinal vasculature in mice (see related article on pages 50–57) demonstrates that specific activation of VEGF receptor-1 by placental growth factor-1 protects against oxygen-induced vessel loss without stimulating vascular proliferation and neovascularization.

  4. Implantation of AMS 700 LGX penile prosthesis preserves penile length without the need for penile lengthening procedures

    Directory of Open Access Journals (Sweden)

    Carlo Luigi Augusto Negro

    2016-01-01

    Full Text Available Implantation of an inflatable penile prosthesis (IPP is a well-established definitive solution for erectile dysfunction when conservative treatments fail. Penile implants may shorten the penis. The AMS 700 LGX IPP is in common use but reports on its mechanical reliability, medium-term postsurgical patient satisfaction, and mean penile length preservation are lacking. We investigate the mean penile length, mechanical reliability, and patient satisfaction at 6 and 12 months after implantation of the AMS 700 LGX. This prospective study consecutively enrolled men undergoing first-time IPP implant surgery from February 2009 to April 2012. Stretched flaccid penile length, penile length at 50% and 100% of stiffness (P50 and P100 and International Index of Erectile Function (IIEF and Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS scores, were measured at 6 and 12 months postsurgery. Of 45 patients who underwent AMS 700 LGX implantation (median age 61 years and completed 6 months′ follow-up, 36 (80% completed the study. A significant difference in stretched flaccid penile length was seen between 6 and 12 months (P = 0.033. P100 was also significantly increased at 6 and 12 months, with a mean 10% increase (1.3 ± 0.4 cm from baseline to 12 months. Differences in mean IIEF scores at 6 and 12 months were significant for the desired domain (P = 0.0001 and for overall satisfaction (P = 0.002; however, mean EDITS scores at 6 and 12 months were not significantly improved. AMS 700 LGX is a powerful tool for preserving penile length in men undergoing penile prosthesis implantation.

  5. Development of a blood vessel searching device for HMS

    Science.gov (United States)

    Kuroda, Tatsuro; Uenoya, Toshiyuki; Tsuchiya, Kazuyoshi; Uetsuji, Yasutomo; Nakamachi, Eiji

    2007-12-01

    In this study, an automatic blood vessel searching system (BVSS) is newly developed, which is built in the health monitoring system (HMS) and the drug delivery system (DDS) to extract the blood, evaluates the blood sugar level and injects the insulin for the diabetic patients. Main subjects of our BVSS development are 1) a transmittance photo imaging of the finger by using the LED light as a near-infrared light source with peak wave length of 870 nm, and 2) an image processing to detect the location of the center of the blood vessel cross section. The sharp edge focus method was applied in our BVSS to detect the depth of blood vessel. We carried out experiments by using blood vessel phantoms, which consist of an artificial cylindrical blood vessel and skin tissue, which are made of the teflon tube and the silicone rubber. The teflon tube has the size of 0.6 mm in diameter and is filled with the human blood. The experimental results demonstrated that the estimated depth, which is obtained by image analysis corresponding to given depths, shows a good agreement with the real values, and consequently the availability of our BVSS is confirmed.

  6. Bone mineral density after implantation of a femoral neck hip prosthesis – a prospective 5 year follow-up

    OpenAIRE

    Steens, Wolfram; Boettner, Friedrich; Bader, Rainer; Skripitz, Ralf; Schneeberger, Alberto

    2015-01-01

    Background Bone resorption in the proximal femur due to stress shielding has been observed in a number of conventional cementless implants used in total hip arthroplasty. Short femoral-neck implants are claiming less interference with the biomechanics of the proximal femur. The goal of this study was to prospectively investigate the in vivo changes of bone-mineral density as a parameter of bone remodeling around a short, femoral neck prosthesis over the first 5 years following implantation. T...

  7. Effect of non-Newtonian characteristics of blood on magnetic particle capture in occluded blood vessel

    Energy Technology Data Exchange (ETDEWEB)

    Bose, Sayan; Banerjee, Moloy, E-mail: moloy_kb@yahoo.com

    2015-01-15

    Magnetic nanoparticles drug carriers continue to attract considerable interest for drug targeting in the treatment of cancer and other pathological conditions. Magnetic carrier particles with surface-bound drug molecules are injected into the vascular system upstream from the desired target site, and are captured at the target site via a local applied magnetic field. Herein, a numerical investigation of steady magnetic drug targeting (MDT) using functionalized magnetic micro-spheres in partly occluded blood vessel having a 90° bent is presented considering the effects of non-Newtonian characteristics of blood. An Eulerian–Lagrangian technique is adopted to resolve the hemodynamic flow and the motion of the magnetic particles in the flow using ANSYS FLUENT. An implantable infinitely long cylindrical current carrying conductor is used to create the requisite magnetic field. Targeted transport of the magnetic particles in a partly occluded vessel differs distinctly from the same in a regular unblocked vessel. Parametric investigation is conducted and the influence of the insert configuration and its position from the central plane of the artery (z{sub offset}), particle size (d{sub p}) and its magnetic property (χ) and the magnitude of current (I) on the “capture efficiency” (CE) is reported. Analysis shows that there exists an optimum regime of operating parameters for which deposition of the drug carrying magnetic particles in a target zone on the partly occluded vessel wall can be maximized. The results provide useful design bases for in vitro set up for the investigation of MDT in stenosed blood vessels. - Highlights: • Two counter rotating vortices forces the fluid flow back through the more viscous region. • The existence of strong recirculation zone just downstream side of the occlusion. • Configuration 4 produces the better efficient MDT system. • Modified Casson model predicts the highest value of CE, whereas the generalized power law gives

  8. Effect of non-Newtonian characteristics of blood on magnetic particle capture in occluded blood vessel

    International Nuclear Information System (INIS)

    Magnetic nanoparticles drug carriers continue to attract considerable interest for drug targeting in the treatment of cancer and other pathological conditions. Magnetic carrier particles with surface-bound drug molecules are injected into the vascular system upstream from the desired target site, and are captured at the target site via a local applied magnetic field. Herein, a numerical investigation of steady magnetic drug targeting (MDT) using functionalized magnetic micro-spheres in partly occluded blood vessel having a 90° bent is presented considering the effects of non-Newtonian characteristics of blood. An Eulerian–Lagrangian technique is adopted to resolve the hemodynamic flow and the motion of the magnetic particles in the flow using ANSYS FLUENT. An implantable infinitely long cylindrical current carrying conductor is used to create the requisite magnetic field. Targeted transport of the magnetic particles in a partly occluded vessel differs distinctly from the same in a regular unblocked vessel. Parametric investigation is conducted and the influence of the insert configuration and its position from the central plane of the artery (zoffset), particle size (dp) and its magnetic property (χ) and the magnitude of current (I) on the “capture efficiency” (CE) is reported. Analysis shows that there exists an optimum regime of operating parameters for which deposition of the drug carrying magnetic particles in a target zone on the partly occluded vessel wall can be maximized. The results provide useful design bases for in vitro set up for the investigation of MDT in stenosed blood vessels. - Highlights: • Two counter rotating vortices forces the fluid flow back through the more viscous region. • The existence of strong recirculation zone just downstream side of the occlusion. • Configuration 4 produces the better efficient MDT system. • Modified Casson model predicts the highest value of CE, whereas the generalized power law gives the least

  9. Biomaterials and Implants in Cardiac and Vascular Surgery - Review

    Directory of Open Access Journals (Sweden)

    Stanisławska A.

    2014-10-01

    Full Text Available Currently, on prosthesis in cardiac blood vessels and heart valves are used materials of animal or synthetic origin. For animal materials include, among others pericardial sac in which is the heart. Materials such as this (natural are characterized by a remarkable biocompatibility within the human body, but their main disadvantage is the relatively low durability. In turn, synthetic materials, which include the austenitic chromium-nickel-molybdenum steels, alloys with a shape memory (nickel-titanium, or polymeric materials, such as lactic acid, are characterized by high stability in an environment of bodily fluids, wherein the insufficiently high biocompatibility with the organism human requires from patients using after implantation, anticoagulants which prevent anti-platelet deposition on the surface of the prosthesis. The present work is a review of biomaterials using in implantology and implants using in cardiac and vascular surgery.

  10. Stress Analysis on Single Cobalt/Chrome Prosthesis With a 15-mm Cantilever Placed Over 10/13/15-mm-length Implants: A Simulated Photoelastic Model Study.

    Science.gov (United States)

    Gastaldo, José Fábio Guastelli; Pimentel, Angélica Castro; Gomes, Maria Helena; Sendyk, Wilson Roberto; Laganá, Dalva Cruz

    2015-12-01

    The aim of study was to assess the stress around 10/13/15-mm implants in the mandibular area with a 15-mm cantilevered acrylic-resin-coated prostheses following the application force, using the photoelasticity method. Three photoelastic mandibular models were created containing 10-, 13-, and 15-mm implants in length and 3.75 mm in diameter. The implants had bore internal hex connections and were placed parallel to the intermental region. Abutments with 1-mm high cuffs were placed over the implants, and a single cobalt/chrome metallic prosthesis with a 15-mm cantilever, coated with thermoplastic acrylic resin, was placed on top. Loads of 1.0 and 3.0 bars were applied, and the images were photographed and assessed by photoelasticity method. The greatest stress levels were observed for the 10-mm implants. The stress pattern was the same regardless of implant length; only the magnitude of the stress along the implant body revealed changes. Increased implant length played a role in reducing stress on the investigated area of the model, and the 15-mm implants exhibited the best performance in regard to stress distribution. The highest stress levels were found in the implants closest to the cantilever and the central implant. The longest implants were more favorable in regard to the stress distribution on the peri-implant support structures in the 15-mm cantilevered prosthesis under loads. PMID:24914673

  11. Tracking blood vessels in human forearms using visual servoing

    DEFF Research Database (Denmark)

    Savarimuthu, Thiusius Rajeeth; Ellekilde, Lars-Peter; Hansen, Morten

    compensation. By using images taken with near-infrared light to locate the blood vessels in a human forearm and using the same images to detects movements of the arm, this paper shows that it is possible make a robot arm, potentially equipped with a needle for drawing the blood, compensate for the movements of...

  12. DETECTION OF BLOOD VESSELS AND MEASUREMENT OF VESSEL WIDTH FOR DIABETIC RETINOPATHY

    Directory of Open Access Journals (Sweden)

    S.Sukanya

    2014-09-01

    Full Text Available The proposed method measures the retinal blood vessel diameter to identify arteriolar narrowing, arteriovenous (AV nicking, branching coefficients to detect early diabetic retinopathy. It utilizes the vessel centerline and edge information to measure the width for a vessel segment. From the input retinal image, the vascular network is extracted using the local entropy thresholding method. The vessel boundaries are extracted using sobel edge detection method. The skeletonization operation is applied to the vascular network and mapping the vessel boundaries and the skeleton image. The branching point detection method is then performed to localize all crossing locations. A rotational invariant mask to search the pixel pairs from the edge image, and calculate the shortest distance pair which provides the vessel width (or diameter for that cross-section. Variation in the width measurement identifies the diabetic retinopathy.

  13. Brain blood vessel segmentation using line-shaped profiles

    International Nuclear Information System (INIS)

    Segmentation of cerebral blood vessels is of great importance in diagnostic and clinical applications, especially for embolization of cerebral aneurysms and arteriovenous malformations (AVMs). In order to perform embolization of the AVM, the structural and geometric information of blood vessels from 3D images is of utmost importance. For this reason, the in-depth segmentation of cerebral blood vessels is usually done as a fusion of different segmentation techniques, often requiring extensive user interaction. In this paper we introduce the idea of line-shaped profiling with an application to brain blood vessel and AVM segmentation, efficient both in terms of resolving details and in terms of computation time. Our method takes into account both local proximate and wider neighbourhood of the processed pixel, which makes it efficient for segmenting large blood vessel tree structures, as well as fine structures of the AVMs. Another advantage of our method is that it requires selection of only one parameter to perform segmentation, yielding very little user interaction. (paper)

  14. Penile prosthesis implantation and tunica albuginea incision without grafting in the treatment of Peyronie's disease with erectile dysfunction

    Institute of Scientific and Technical Information of China (English)

    Miroslav L Djordjevic; Vladimir Kojovic

    2013-01-01

    We evaluated penile prosthesis implantation with tunica albuginea-relaxing incisions without grafting in the treatment of Peyronie's disease associated with erectile dysfunction.Between April 2005 and June 2011,62 patients underwent surgery due to severe Peyronie's disease associated with erectile dysfunction.Malleable and inflatable penile prostheses ware inserted in 49 and 13 cases,respectively.Penile prostheses were inserted into the corpora cavemosa using the standard ventral approach.After lifting the neurevascular bundle,the tunica albuginea was incised and opened at the plaque region to correct the deformities and to lengthen the penis.Subsequently,the wide neurovascular bundle was replaced,and all incisions of the tunica albuginea were covered to prevent corporal grafting.In the median follow-up of 35 months (range 14-82 months),the penis was completely straightened in 59 (95%) patients.Numbness of the glans,which the patients found initially upsetting,decreased or disappeared spontaneously 3-6 months later.Penile prosthesis implantation with tunica albuginea incisions is a viable alternative in the treatment of Peyronie's disease because the extensive dissection of the neurovascular bundle allows a good approach to the plaque and provides excellent covering of the incised tunica albuginea witheut additional grafting.

  15. Textile blood vessels coated with DLC

    Czech Academy of Sciences Publication Activity Database

    Jelínek, Miroslav; Podlaha, J.; Kocourek, Tomáš; Žížková, V.

    Berlin: Springer, 2009 - (Vander Sloten, J.; Verdonck, P.; Nyssen, M.; Haueisen, J.), s. 2173-2174. (IFMBE Proceedings. vol. 22). ISBN 978-3-540-89207-6. [ECIFMBE 2008. European Conference of the International Federation for Medical and Biological Engineering /4./. Antwerp (BE), 23.11.2008-27.11.2008] Institutional research plan: CEZ:AV0Z10100522 Keywords : PLD * DLC * vascular prostheses * in vivo * textile vessels Subject RIV: BH - Optics, Masers, Lasers http://dx.doi.org/10.1007/978-3-540-89208-3_519

  16. Photoelastic Analysis of Fixed Partial Prosthesis Crown Height and Implant Length on Distribution of Stress in Two Dental Implant Systems

    OpenAIRE

    Evandro Portela Figueirêdo; Eder Alberto Sigua-Rodriguez; Marcele Jardim Pimentel; Ana Regina Oliveira Moreira; Mauro Antônio de Arruda Nóbilo; José Ricardo de Albergaria-Barbosa

    2014-01-01

    The aim of this study was to evaluate by photoelastic analysis stress distribution on short and long implants of two dental implant systems with 2-unit implant-supported fixed partial prostheses of 8 mm and 13 mm heights. Sixteen photoelastic models were divided into 4 groups: I: long implant (5 × 11 mm) (Neodent), II: long implant (5 × 11 mm) (Bicon), III: short implant (5 × 6 mm) (Neodent), and IV: short implants (5 × 6 mm) (Bicon). The models were positioned in a circular polariscope assoc...

  17. Transdermal drug targeting and functional imaging of tumor blood vessels in the mouse auricle.

    Science.gov (United States)

    Schröder, Hannes; Komljenovic, Dorde; Hecker, Markus; Korff, Thomas

    2016-02-01

    Subcutaneously growing tumors are widely utilized to study tumor angiogenesis and the efficacy of antiangiogenic therapies in mice. To additionally assess functional and morphologic alterations of the vasculature in the periphery of a growing tumor, we exploited the easily accessible and hierarchically organized vasculature of the mouse auricle. By site-specific subcutaneous implantation of a defined preformed mouse B16/F0 melanoma aggregate, a solid tumor nodule developed within 14 d. Growth of the tumor nodule was accompanied by a 4-fold increase in its perfusion as well as a 2- to 4-fold elevated diameter and perfusion of peripheral blood vessels that had connected to the tumor capillary microvasculature. By transdermal application of the anticancer drug bortezomib, tumor growth was significantly diminished by about 50% without provoking side effects. Moreover, perfusion and tumor microvessel diameter as well as growth and perfusion of arterial or venous blood vessels supplying or draining the tumor microvasculature were decreased under these conditions by up to 80%. Collectively, we observed that the progressive tumor growth is accompanied by the enlargement of supplying and draining extratumoral blood vessels. This process was effectively suppressed by bortezomib, thereby restricting the perfusion capacity of both extra and intratumoral blood vessels. PMID:26546130

  18. Heritability of retinal vessel diameters and blood pressure

    DEFF Research Database (Denmark)

    Taarnhøj, Nina C B B; Larsen, Michael; Sander, Birgit;

    2006-01-01

    , aged 20 to 46 years, interpolated diameter estimates for the central retinal artery (CRAE), the central retinal vein (CRVE), and the artery-to-vein diameter ratio (AVR) were assessed by analysis of digital gray-scale fundus photographs of right eyes. RESULTS: The heritability was 70% (95% CI: 54...... for CRVE, and 0.67 +/- 0.05 microm for AVR. No significant influence on artery or vein diameters was found for gender, smoking, body mass index (BMI), total cholesterol, fasting blood glucose, or 2-hour oral glucose tolerance test values. CONCLUSIONS: In healthy young adults with normal blood pressure...... and blood glucose, variations in retinal blood vessel diameters and blood pressure were predominantly attributable to genetic effects. A genetic influence may have a role in individual susceptibility to hypertension and other vascular diseases. The results suggest that retinal vessel diameters and the...

  19. Photoelastic Analysis of Fixed Partial Prosthesis Crown Height and Implant Length on Distribution of Stress in Two Dental Implant Systems

    Directory of Open Access Journals (Sweden)

    Evandro Portela Figueirêdo

    2014-01-01

    Full Text Available The aim of this study was to evaluate by photoelastic analysis stress distribution on short and long implants of two dental implant systems with 2-unit implant-supported fixed partial prostheses of 8 mm and 13 mm heights. Sixteen photoelastic models were divided into 4 groups: I: long implant (5×11 mm (Neodent, II: long implant (5×11 mm (Bicon, III: short implant (5×6 mm (Neodent, and IV: short implants (5×6 mm (Bicon. The models were positioned in a circular polariscope associated with a cell load and static axial (0.5 Kgf and nonaxial load (15°, 0.5 Kgf were applied to each group for both prosthetic crown heights. Three-way ANOVA was used to compare the factors implant length, crown height, and implant system (α=0.05. The results showed that implant length was a statistically significant factor for both axial and nonaxial loading. The 13 mm prosthetic crown did not result in statistically significant differences in stress distribution between the implant systems and implant lengths studied, regardless of load type (P>0.05. It can be concluded that short implants showed higher stress levels than long implants. Implant system and length was not relevant factors when prosthetic crown height were increased.

  20. Customizable engineered blood vessels using 3D printed inserts.

    Science.gov (United States)

    Pinnock, Cameron B; Meier, Elizabeth M; Joshi, Neeraj N; Wu, Bin; Lam, Mai T

    2016-04-15

    Current techniques for tissue engineering blood vessels are not customizable for vascular size variation and vessel wall thickness. These critical parameters vary widely between the different arteries in the human body, and the ability to engineer vessels of varying sizes could increase capabilities for disease modeling and treatment options. We present an innovative method for producing customizable, tissue engineered, self-organizing vascular constructs by replicating a major structural component of blood vessels - the smooth muscle layer, or tunica media. We utilize a unique system combining 3D printed plate inserts to control construct size and shape, and cell sheets supported by a temporary fibrin hydrogel to encourage cellular self-organization into a tubular form resembling a natural artery. To form the vascular construct, 3D printed inserts are adhered to tissue culture plates, fibrin hydrogel is deposited around the inserts, and human aortic smooth muscle cells are then seeded atop the fibrin hydrogel. The gel, aided by the innate contractile properties of the smooth muscle cells, aggregates towards the center post insert, creating a tissue ring of smooth muscle cells. These rings are then stacked into the final tubular construct. Our methodology is robust, easily repeatable and allows for customization of cellular composition, vessel wall thickness, and length of the vessel construct merely by varying the size of the 3D printed inserts. This platform has potential for facilitating more accurate modeling of vascular pathology, serving as a drug discovery tool, or for vessel repair in disease treatment. PMID:26732049

  1. Electromechanical Model of Blood Flow in Vessels

    OpenAIRE

    Ivo Cap; Barbora Czippelova

    2008-01-01

    The present paper deals with some theoretical derivations connected with very efficient method of solution of hydrodynamic problems of blood flow in human cardiovascular system. The electromechanical analogy of liquid flow in a tube and electromagnetic wave propagating along an electric transmission line is discussed. We have derived a detailed circuit-like model of an elementary section of the elastic tube with viscose Newtonian liquid. The analogy harmonic current electrical cir...

  2. Electromechanical Model of Blood Flow in Vessels

    Directory of Open Access Journals (Sweden)

    Ivo Cap

    2008-01-01

    Full Text Available The present paper deals with some theoretical derivations connected with very efficient method of solution of hydrodynamic problems of blood flow in human cardiovascular system. The electromechanical analogy of liquid flow in a tube and electromagnetic wave propagating along an electric transmission line is discussed. We have derived a detailed circuit-like model of an elementary section of the elastic tube with viscose Newtonian liquid. The analogy harmonic current electrical circuit has been designed

  3. Performance Analysis of Retinal Image Blood Vessel Segmentation

    Directory of Open Access Journals (Sweden)

    D.Siva Sundhara Raja

    2014-06-01

    Full Text Available The retinal image diagnosis is an important methodology for diabetic retinopathy detection and analysis. in this paper, the morphological operations and svm classifier are used to detect and segment the blood vessels from the retinal image. the proposed system consists of three stages-first is preprocessing of retinal image to separate the green channel and second stage is retinal image enhancement and third stage is blood vessel segmentation using morphological operations and svm classifier. the performance of the proposed system is analyzed using publicly available dataset.

  4. Replacement of Missing Anterior Tooth Using Screw Retained Implant Prosthesis in the Esthetic Zone: A Case Report with 3 Years of Follow Up

    OpenAIRE

    Ahmad, Manawar; B Dhanasekar; I N Aparna; Naim, Hina

    2012-01-01

    As more and more dental practitioners are focusing on implant-supported fixed restorations, some clinicians favor the use of cement retained restorations while others consider screw-retained prosthesis to be the best choice. As both types of prostheses have certain advantages and disadvantages, clinicians should be aware of the limitations of each type. Screw-retained implant restorations have an advantage of predictable retention, retrievability and lack of potentially retained sub-gingival ...

  5. Penile prosthesis implant with bi-triangular excision and graft for surgical therapy of Peyronie’s disease: A case report

    Directory of Open Access Journals (Sweden)

    Alexandre de Freitas Miranda

    2016-01-01

    Full Text Available We present a case of a 65-year-old man, who presented with moderate erectile dysfunction and a dorsal penile deviation of 60° caused by Peyronie’s disease. The patient underwent bi-triangularshaped plaque excision, followed by grafting and implantation of inflatable penile prosthesis. Complete penile straightening, without mechanical or geometric abnormalities, was achieved using bi-triangular excision and grafting. Postoperatively, the patient reported high satisfaction with the results and could perform sexual intercourse naturally. This novel technique corrects any degree of penile curvature, permits malleable and semi-rigid penile prosthesis implantation, avoids penile length loss, and eliminates additional incisions. To our knowledge, this case is the first in the literature in which the bi-triangular technique was successfully used for penile prosthesis implantation secondary to Peyronie’s disease. This new technique appears to be a good solution to correct penile curvature during penile prosthesis implantation for the treatment of Peyronie’s disease associated with erectile dysfunction.

  6. Blood Vessel Segmentation of Fundus Images by Major Vessel Extraction and Subimage Classification.

    Science.gov (United States)

    Roychowdhury, Sohini; Koozekanani, Dara D; Parhi, Keshab K

    2015-05-01

    This paper presents a novel three-stage blood vessel segmentation algorithm using fundus photographs. In the first stage, the green plane of a fundus image is preprocessed to extract a binary image after high-pass filtering, and another binary image from the morphologically reconstructed enhanced image for the vessel regions. Next, the regions common to both the binary images are extracted as the major vessels. In the second stage, all remaining pixels in the two binary images are classified using a Gaussian mixture model (GMM) classifier using a set of eight features that are extracted based on pixel neighborhood and first and second-order gradient images. In the third postprocessing stage, the major portions of the blood vessels are combined with the classified vessel pixels. The proposed algorithm is less dependent on training data, requires less segmentation time and achieves consistent vessel segmentation accuracy on normal images as well as images with pathology when compared to existing supervised segmentation methods. The proposed algorithm achieves a vessel segmentation accuracy of 95.2%, 95.15%, and 95.3% in an average of 3.1, 6.7, and 11.7 s on three public datasets DRIVE, STARE, and CHASE_DB1, respectively. PMID:25014980

  7. Mechanical and biological complication rates of the modified lateral-screw-retained implant prosthesis in the posterior region: an alternative to the conventional Implant prosthetic system

    Science.gov (United States)

    2016-01-01

    PURPOSE The modified lateral-screw-retained implant prosthesis (LSP) is designed to combine the advantages of screw- and cement-retained implant prostheses. This retrospective study evaluated the mechanical and biological complication rates of implant-supported single crowns (ISSCs) inserted with the modified LSP in the posterior region, and determined how these complication rates are affected by clinical factors. MATERIALS AND METHODS Mechanical complications (i.e., lateral screw loosening [LSL], abutment screw loosening, lateral screw fracture, and ceramic fracture) and biological complications (i.e., peri-implant mucositis [PM] and peri-implantitis) were identified from the patients' treatment records, clinical photographs, periapical radiographs, panoramic radiographs, and clinical indices. The correlations between complication rates and the following clinical factors were determined: gender, age, position in the jaw, placement location, functional duration, clinical crown-to-implant length ratio, crown height space, and the use of a submerged or nonsubmerged placement procedure. RESULTS Mechanical and biological complications were present in 25 of 73 ISSCs with the modified LSP. LSL (n=11) and PM (n=11) were the most common complications. The incidence of mechanical complications was significantly related to gender (P=.018). The other clinical factors were not significantly associated with mechanical and biological complication rates. CONCLUSION Within the limitations of this study, the incidence of mechanical and biological complications in the posterior region was similar for both modified LSP and conventional implant prosthetic systems. In addition, the modified LSP is amenable to maintenance care, which facilitates the prevention and treatment of mechanical and biological complications. PMID:27141260

  8. Acrolein generation stimulates hypercontraction in isolated human blood vessels

    International Nuclear Information System (INIS)

    Increased risk of vasospasm, a spontaneous hyperconstriction, is associated with atherosclerosis, cigarette smoking, and hypertension-all conditions involving oxidative stress, lipid peroxidation, and inflammation. To test the role of the lipid peroxidation- and inflammation-derived aldehyde, acrolein, in human vasospasm, we developed an ex vivo model using human coronary artery bypass graft (CABG) blood vessels and a demonstrated acrolein precursor, allylamine. Allylamine induces hypercontraction in isolated rat coronary artery in a semicarbazide-sensitive amine oxidase activity (SSAO) dependent manner. Isolated human CABG blood vessels (internal mammary artery, radial artery, saphenous vein) were used to determine: (1) vessel responses and sensitivity to acrolein, allylamine, and H2O2 exposure (1 μM-1 mM), (2) SSAO dependence of allylamine-induced effects using SSAO inhibitors (semicarbazide, 1 mM; MDL 72274-E, active isomer; MDL 72274-Z, inactive isomer; 100 μM), (3) the vasoactive effects of two other SSAO amine substrates, benzylamine and methylamine, and (4) the contribution of extracellular Ca2+ to hypercontraction. Acrolein or allylamine but not H2O2, benzylamine, or methylamine stimulated spontaneous and pharmacologically intractable hypercontraction in CABG blood vessels that was similar to clinical vasospasm. Allylamine-induced hypercontraction and blood vessel SSAO activity were abolished by pretreatment with semicarbazide or MDL 72274-E but not by MDL 72274-Z. Allylamine-induced hypercontraction also was significantly attenuated in Ca2+-free buffer. In isolated aorta of spontaneously hypertensive rat, allylamine-induced an SSAO-dependent contraction and enhanced norepinephrine sensitivity but not in Sprague-Dawley rat aorta. We conclude that acrolein generation in the blood vessel wall increases human susceptibility to vasospasm, an event that is enhanced in hypertension

  9. Replacement of missing anterior tooth using screw retained implant prosthesis in the esthetic zone: a case report with 3 years of follow up.

    Science.gov (United States)

    Ahmad, Manawar; Dhanasekar, B; Aparna, I N; Naim, Hina

    2014-09-01

    As more and more dental practitioners are focusing on implant-supported fixed restorations, some clinicians favor the use of cement retained restorations while others consider screw-retained prosthesis to be the best choice. As both types of prostheses have certain advantages and disadvantages, clinicians should be aware of the limitations of each type. Screw-retained implant restorations have an advantage of predictable retention, retrievability and lack of potentially retained sub-gingival cement. However, a few disadvantages exist such as precise placement of the implant for optimal and esthetic location of the screw access hole and obtaining passive fit. On the other hand, cement retained restorations eliminates unaesthetic screw access holes; have passive fit of castings; reduce stress to splinted implants because of minor misfit of the framework; reduced complexity of lab procedures; enhanced esthetics; reduced cost factors and non disrupted morphology of the occlusal table. This case report presents the replacement of missing left central incisor using screw-retained implant prosthesis due to palatal trajectory of the implant placement and inadequate abutment height for retention of cement retained prosthesis. PMID:25183915

  10. Full mouth rehabilitation of a patient with mandibular implant screw retained Fp-3 prosthesis opposing maxillary acrylic removable over-denture

    Science.gov (United States)

    Jain, Ashish R.; Nallaswamy, Deepak; Ariga, Padma; Philip, Jacob Mathew

    2013-01-01

    A hybrid denture is one that is fabricated over a metal framework and retained by screws threaded into the implant abutments. The anterior part of a mandibular hybrid denture is fixed on implants while the posterior part of the denture is extended and cantilevered from implants. This article presents the fabrication of a maxillary over-denture opposing mandibular implant retained hybrid prosthesis. A total of four implants were placed in the mandibular arch. Castable abutments were used to produce the optimal angulations. Framework was waxed, cast recovered, and the fit was refined until the framework seated passively on the master cast. The mandibular denture teeth were waxed to the hybrid framework, and a final wax try-in was performed to verify and correct maxillomandibular relations before processing. The prosthesis was inserted after verification of occlusion, retention, and stability. The rehabilitation of edentulous patients with hybrid dentures has been observed to achieve greater masticatory function and psychological satisfaction than with conventional over-dentures. Producing a passive-fitting substructure for a fixed removable screw retained hybrid prosthesis is arguably one of the most technically complex tasks in implant dentistry. The technique presented may not initially produce a perfectly passive framework, but use of disclosing media and adjusting the internal aspect of the casting can result in non-binding, fully seated prostheses. PMID:24015016

  11. Full mouth rehabilitation of a patient with mandibular implant screw retained Fp-3 prosthesis opposing maxillary acrylic removable over-denture

    Directory of Open Access Journals (Sweden)

    Ashish R Jain

    2013-01-01

    Full Text Available A hybrid denture is one that is fabricated over a metal framework and retained by screws threaded into the implant abutments. The anterior part of a mandibular hybrid denture is fixed on implants while the posterior part of the denture is extended and cantilevered from implants. This article presents the fabrication of a maxillary over-denture opposing mandibular implant retained hybrid prosthesis. A total of four implants were placed in the mandibular arch. Castable abutments were used to produce the optimal angulations. Framework was waxed, cast recovered, and the fit was refined until the framework seated passively on the master cast. The mandibular denture teeth were waxed to the hybrid framework, and a final wax try-in was performed to verify and correct maxillomandibular relations before processing. The prosthesis was inserted after verification of occlusion, retention, and stability. The rehabilitation of edentulous patients with hybrid dentures has been observed to achieve greater masticatory function and psychological satisfaction than with conventional over-dentures. Producing a passive-fitting substructure for a fixed removable screw retained hybrid prosthesis is arguably one of the most technically complex tasks in implant dentistry. The technique presented may not initially produce a perfectly passive framework, but use of disclosing media and adjusting the internal aspect of the casting can result in non-binding, fully seated prostheses.

  12. FCM Based Blood Vessel Segmentation Method for Retinal Images

    Directory of Open Access Journals (Sweden)

    Nilanjan Dey

    2012-06-01

    Full Text Available Segmentation of blood vessels in retinal images providesearly diagnosis of diseases like glaucoma, diabeticretinopathy and macular degeneration. Among thesediseases occurrence of Glaucoma is most frequent and hasserious ocular consequences that can even lead toblindness, if it is not detected early. The clinical criteria forthe diagnosis of glaucoma include intraocular pressuremeasurement, optic nerve head evaluation, retinal nervefiber layer and visual field defects. This form of bloodvessel segmentation helps in early detection for ophthalmicdiseases, and potentially reduces the risk of blindness.The low-contrast images at the retina owing to narrowblood vessels of the retina are difficult to extract. Theselow contrast images are, however useful in revealingcertain systemic diseases. Motivated by the goals ofimproving detection of such vessels, this present workproposes an algorithm for segmentation of blood vessels,and compares the results between expert ophthalmologists’hand-drawn ground-truths and segmented image (i.e. theoutput of the present work. Sensitivity, specificity, positivepredictive value (PPV, positive likelihood ratio (PLR andaccuracy are used to evaluate overall performance. It isfound that this work segments blood vessels successfullywith sensitivity, specificity, PPV, PLR and accuracy of99.62%, 54.66%, 95.08%, 219.72 and 95.03%,respectively.

  13. Retinal Blood Vessel Segmentation with Optic Disc Pixels Exclusion

    Directory of Open Access Journals (Sweden)

    Randy Cahya Wihandika

    2013-06-01

    Full Text Available The morphological changes of retinal blood vessels are important indicators used to diagnose and monitor the progression of various diseases. A number of retinal blood vessel segmentation methods have been introduced, including the line operator based methods, which have shown satisfactory results. However, the basic line operator method cannot discriminate the pixels around the retinal optic disc, resulting in false classification of those pixels. In this paper, we integrate the detection of pixels around the retinal optic disc to the line operator method so that those pixels can be excluded from the vessel pixels. The method is evaluated on the widely used retinal dataset, the DRIVE dataset. The results demonstrate that the proposed method has made improvements over the basic and the multi-scale line detector with accuracy and area under curve of 0.942 and 0.9521, respectively.

  14. Method and arrangement for angiography of blood vessels

    International Nuclear Information System (INIS)

    A method and apparatus for angiography in which information contained within multiple serial images of contrast medium flowing through a blood vessel is combined to form a single image having improved vessel edge delineation. More specifically, a method is disclosed whereby a contrast medium opaque to X-rays is injected into a blood vessel distant from an artery section of interest, preferably injected into a vein, whereby the contrast medium is mixed with blood prior to its passing through the artery section. Multiple X-ray images are obtained as the contrast medium and blood mixture flows through the artery section. These multiple images are registered with respect to each other according to a landmark contained within the patient, the landmark having a predetermined relationship to the vessel of interest. The landmark could be a bone, catheter or any other material opaque to X-rays. Density measurements are made with respect to each corresponding image segment or element of the multiple images and are combined to synthesize a composite image. The synthesized image has an edge uncertainty equal to that of one of the individual images. (Auth.)

  15. Blood vessel segmentation for neck and head computed tomography angiography

    OpenAIRE

    Hedblom, Anders

    2013-01-01

    This thesis presents tests and discussions evaluating different methods for doing automatic or semi automatic blood vessel segmentation on single CT data volumes of the head and neck. The two approaches being closest to accomplish this are a bone subtracting registration process, and a more advanced region growing combined with morphology.

  16. The Conditions of Vibrations and Collapse of Human Blood Vessels

    Czech Academy of Sciences Publication Activity Database

    Hemza, J.; Chlup, Hynek; Maršík, František

    Liberec : Technical University of Liberec, 2010 - (Čapek, L.), s. 98-102 ISBN 978-80-7372-648-5. [Human Biomechanics 2010. Sychrov (CZ), 04.10.2010-06.10.2010] Institutional research plan: CEZ:AV0Z20760514 Keywords : viscoelastic properties of human blood vessels * bridging vein * neo-Hooks materialmodel Subject RIV: JJ - Other Materials

  17. Vessel Elasticity Estimation by Normalized Blood Pressure Dynamics

    Czech Academy of Sciences Publication Activity Database

    Jurák, Pavel; Halámek, Josef; Vondra, Vlastimil; Leinveber, Pavel; Plachý, M.; Fráňa, P.; Souček, M.; Kára, T.

    Tel-Aviv : Israel Heart Society, 2008. s. 115. ISBN N. [IDSS 2008 - International Dead Sea Symposium on Cardiac Arrhythmias and Device Therapy /9./. 22.09.2008-24.09.2008, Tel-Aviv] Institutional research plan: CEZ:AV0Z20650511 Keywords : hypertension * vessel compliance * blood pressure * dynamic parameters Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  18. Gene expression analysis in human breast cancer associated blood vessels.

    Directory of Open Access Journals (Sweden)

    Dylan T Jones

    Full Text Available Angiogenesis is essential for solid tumour growth, whilst the molecular profiles of tumour blood vessels have been reported to be different between cancer types. Although presently available anti-angiogenic strategies are providing some promise for the treatment of some cancers it is perhaps not surprisingly that, none of the anti-angiogenic agents available work on all tumours. Thus, the discovery of novel anti-angiogenic targets, relevant to individual cancer types, is required. Using Affymetrix microarray analysis of laser-captured, CD31-positive blood vessels we have identified 63 genes that are upregulated significantly (5-72 fold in angiogenic blood vessels associated with human invasive ductal carcinoma (IDC of the breast as compared with blood vessels in normal human breast. We tested the angiogenic capacity of a subset of these genes. Genes were selected based on either their known cellular functions, their enriched expression in endothelial cells and/or their sensitivity to anti-VEGF treatment; all features implicating their involvement in angiogenesis. For example, RRM2, a ribonucleotide reductase involved in DNA synthesis, was upregulated 32-fold in IDC-associated blood vessels; ATF1, a nuclear activating transcription factor involved in cellular growth and survival was upregulated 23-fold in IDC-associated blood vessels and HEX-B, a hexosaminidase involved in the breakdown of GM2 gangliosides, was upregulated 8-fold in IDC-associated blood vessels. Furthermore, in silico analysis confirmed that AFT1 and HEX-B also were enriched in endothelial cells when compared with non-endothelial cells. None of these genes have been reported previously to be involved in neovascularisation. However, our data establish that siRNA depletion of Rrm2, Atf1 or Hex-B had significant anti-angiogenic effects in VEGF-stimulated ex vivo mouse aortic ring assays. Overall, our results provide proof-of-principle that our approach can identify a cohort of

  19. Predicting the Outcomes of Transcatheter Aortic Valve Prosthesis Implantation Based on the Finite Element Analysis and Microcomputer Tomography Data

    Directory of Open Access Journals (Sweden)

    E.A. Ovcharenko

    2016-03-01

    Full Text Available The aim of the investigation is to assess the possibility of predicting the outcome of transcatheter aortic valve prosthesis implantation in real clinical practice on the basis of patient-specific modeling. Material and Methods. Modeling of transcatheter bioprosthesis implantation was carried out based on clinical data of a patient aged 72 years. Multispiral computed tomography (CT was performed before and after the operative intervention. Reconstruction of aorta and valvular apparatus geometry was done on the basis of obtained slices using computer-aided design (CAD. With the help of microcomputer tomography and a series of projection images and mathematical algorithms a 3D-model of the frame was reconstructed, on which a 3D-mesh from 17,000 cubic (C3D8-elements was built. Simulation of the system component interaction was conducted using a finite element method involving a number of successive steps: preliminary balloon dilatation — frame compression in the catheter — releasing the frame from the catheter. To evaluate the accuracy of modeling results compared to the CT data of the patient with the implanted bioprosthesis a proprietary algorithm was developed using MATLAB R2014a software (The MathWorks, USA. Arrays of points corresponding to the center of the supporting frame beams, obtained in 11 orthogonal sections, were used as input data. Results. Peculiarities of patient-specific approach to modeling the implantation of transcatheter CoreValve bioprothesis by means of the developed bioinformation algorithm has been analyzed. We managed to achieve a high convergence of simulation and CT data for the frame inflow area (the difference of the simulation results for the first three layers did not exceed 4%. Comparison of the results in terms of the annulus area has also demonstrated a high convergence: the identity amounted to more than 90% for the inflow and middle zones of the supporting frame. Conclusion. The highest level of detail

  20. Maxillary Midline diastema closure after replacement of primary teeth with implant prosthesis.

    Science.gov (United States)

    Al-Saqabi, Farah Y; Fenlon, Michael R; Bavisha, Kalpesh A

    2015-05-01

    This case shows an excellent esthetic treatment outcome using implant-retained crowns replacing maxillary laterals and canines in hypodontia patient with unusual incidence of spontaneous diastema closure after the placement of implants. To our knowledge, this is the first case report showing maxillary midline diastema closure after implant placement. PMID:25984308

  1. Maxillary Midline diastema closure after replacement of primary teeth with implant prosthesis

    OpenAIRE

    Al-Saqabi, Farah Y; Fenlon, Michael R; Bavisha, Kalpesh A

    2015-01-01

    Key Clinical Message This case shows an excellent esthetic treatment outcome using implant-retained crowns replacing maxillary laterals and canines in hypodontia patient with unusual incidence of spontaneous diastema closure after the placement of implants. To our knowledge, this is the first case report showing maxillary midline diastema closure after implant placement.

  2. Fracture of abutment screw supporting a cemented implant-retained prosthesis with external hexagon connection: a case report with sem evaluation

    Directory of Open Access Journals (Sweden)

    Mariana Diniz Bisi Santos

    2007-04-01

    Full Text Available One of the causes of implant failures in cemented implant-retained prostheses is the fracture of abutment screw or UCLA abutment. This article reports a case of simultaneous fracture of two UCLA abutments screws occurring in an implant-supported prosthesis placed in the mandibular molar region. The fractured structures were examined under scanning electron microscopy to investigate the probable causes of the failure, which were not related to failures on materials or fabrication of the screws, but rather were due to shear forces. The misfit in cemented prostheses may be the most likely cause of shear force generation.

  3. FRACTURE OF ABUTMENT SCREW SUPPORTING A CEMENTED IMPLANT-RETAINED PROSTHESIS WITH EXTERNAL HEXAGON CONNECTION: A CASE REPORT WITH SEM EVALUATION

    Science.gov (United States)

    Santos, Mariana Diniz Bisi; Pfeifer, Arthur Braga; Silva, Marcos Rogério Pupo; Sendyk, Claudio Luiz; Sendyk, WIlson Roberto

    2007-01-01

    One of the causes of implant failures in cemented implant-retained prostheses is the fracture of abutment screw or UCLA abutment. This article reports a case of simultaneous fracture of two UCLA abutments screws occurring in an implant-supported prosthesis placed in the mandibular molar region. The fractured structures were examined under scanning electron microscopy to investigate the probable causes of the failure, which were not related to failures on materials or fabrication of the screws, but rather were due to shear forces. The misfit in cemented prostheses may be the most likely cause of shear force generation. PMID:19089120

  4. Acquired thrombotic thrombocytopenic purpura after vascular prosthesis implantation for impending rupture of an abdominal aortic aneurysm.

    Science.gov (United States)

    Naito, Chiaki; Ogawa, Yoshiyuki; Yanagisawa, Kunio; Ishizaki, Takuma; Mihara, Masahiro; Handa, Hiroshi; Isonishi, Ayami; Hayakawa, Masaki; Matsumoto, Masanori; Nojima, Yoshihisa

    2016-01-01

    Acquired thrombotic thrombocytopenic purpura (TTP) is caused by autoantibodies against ADAMTS13. TTP patients run a rapidly fatal course unless immediate plasma exchange (PEX) is initiated upon diagnosis. Herein, we report a 72-year-old man with TTP, which developed after he underwent artificial blood vessel replacement surgery for an abdominal aneurysm with impending rupture. In the perioperative period, the patient received several platelet transfusions for severe thrombocytopenia (minimum platelet count: 0.6×10(4)/μl). Thereafter, he was admitted to our department for rapidly progressing coma with multiple cerebral infarctions, and was transferred to the ICU. Based on the tentative diagnosis of TTP, we immediately began PEX and steroid pulse therapy. The diagnosis was confirmed thereafter by markedly reduced ADAMTS13 activity (<0.5%) and his being positive for the ADAMTS13 inhibitor. We performed PEX for five consecutive days and administered high-dose prednisolone (PSL). On the second hospital day (HD), his platelet count rose along with improvement of his consciousness level. The ADAMTS13 inhibitor was not detected on the 10th HD. TTP did not relapse and his general condition improved despite tapering of PSL. In this case, by closely monitoring ADAMTS13-related parameters and minimizing the number of plasma exchanges, the patient was able to achieve a remission without the use of boosting inhibitors. PMID:27076251

  5. Investigation on artificial blood vessels prepared from bacterial cellulose.

    Science.gov (United States)

    Zang, Shanshan; Zhang, Ran; Chen, Hua; Lu, Yudong; Zhou, Jianhai; Chang, Xiao; Qiu, Guixing; Wu, Zhihong; Yang, Guang

    2015-01-01

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1mm and an outer diameter of 4 or 6mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. PMID:25491966

  6. Investigation on artificial blood vessels prepared from bacterial cellulose

    International Nuclear Information System (INIS)

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1 mm and an outer diameter of 4 or 6 mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. - Highlights: • Bacterial cellulose (BC) can be made into tubular shape through PDMS mold. • BC represents a fine nanofiber network. • The mechanical and thermal properties of BC mimic the situation of real vessel. • BC exhibits attractive biocompatible properties as a substitution of vessel

  7. Investigation on artificial blood vessels prepared from bacterial cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Zang, Shanshan; Zhang, Ran; Chen, Hua; Lu, Yudong; Zhou, Jianhai [Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Chang, Xiao; Qiu, Guixing; Wu, Zhihong [Department of Orthopaedics, Peking Union Medical College Hospital, Beijing 100730 (China); Yang, Guang, E-mail: yang_sunny@yahoo.com [Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2015-01-01

    BC (bacterial cellulose) exhibits quite distinctive properties than plant cellulose. The outstanding properties make BC a promising material for preparation of artificial blood vessel. By taking advantage of the high oxygen permeability of PDMS (polydimethylsiloxane) as a tubular template material, a series of BC tubes with a length of 100 mm, a thickness of 1 mm and an outer diameter of 4 or 6 mm were biosynthesized with the help of Gluconacetobacter xylinum. Through characterization by SEM (scanning electron microscope), tensile testing and thermal analysis, it is demonstrated that BC tubes are good enough for artificial blood vessel with elaborated nano-fiber architecture, qualified mechanical properties and high thermal stability. In addition, measurement of biocompatibility also shows that BC tubes are greatly adaptable to the in vivo environment. The results indicate that BC tubes have great potential for being utilized as tubular scaffold materials in the field of tissue engineering. - Highlights: • Bacterial cellulose (BC) can be made into tubular shape through PDMS mold. • BC represents a fine nanofiber network. • The mechanical and thermal properties of BC mimic the situation of real vessel. • BC exhibits attractive biocompatible properties as a substitution of vessel.

  8. DLC coating of textile blood vessels using PLD

    Czech Academy of Sciences Publication Activity Database

    Kocourek, Tomáš; Jelínek, Miroslav; Vorlíček, Vladimír; Zemek, Josef; Janča, T.; Žížková, V.; Podlaha, J.; Popov, C.

    2008-01-01

    Roč. 93, č. 3 (2008), s. 627-632. ISSN 0947-8396 R&D Projects: GA MPO FI-IM2/068; GA ČR GA202/06/0216 Institutional research plan: CEZ:AV0Z10100522 Keywords : blood vessels * PLD * DLC * sp2 * sp3 Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.884, year: 2008

  9. A Computational Model Predicting Disruption of Blood Vessel Development

    OpenAIRE

    Kleinstreuer, Nicole; Dix, David; Rountree, Michael; Baker, Nancy; Sipes, Nisha; Reif, David; Spencer, Richard; Knudsen, Thomas

    2013-01-01

    Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis) and remodeling (angiogenesis) come from a variety of biological pathways linked to endothelial cell (EC) behavior, extracellular matrix (ECM) remodeling and the local generation of chemokines and growth factors. Simulating these interactions at a systems level req...

  10. Transmitted Ultrasound Pressure Variation in Micro Blood Vessel Phantoms

    OpenAIRE

    Qin, Shengping; Kruse, Dustin E; Ferrara, Katherine W.

    2008-01-01

    Silica, cellulose, and polymethylmethacrylate tubes with inner diameters of ten to a few hundred microns are commonly used as blood vessel phantoms in in vitro studies of microbubble or nanodroplet behavior during insonation. However, a detailed investigation of the ultrasonic fields within these micro-tubes has not yet been performed. This technical note provides a theoretical analysis of the ultrasonic fields within micro-tubes. Numerical results show that for the same tube material, the in...

  11. Followup of a Dog with an Intraocular Silicone Prosthesis Combined with an Extraocular Glass Prosthesis

    OpenAIRE

    Gwendolyna Romkes; Johanna Corinna Eule

    2012-01-01

    Because of unpredictable corneal changes, evisceration and implantation of a silicone prosthesis does not always lead to a satisfying cosmetic result. This paper describes the use of an intraocular silicone prosthesis in combination with an extraocular glass prosthesis and shows a followup of two and a half years in a nonexperimental study. An intraocular silicone prosthesis was implanted after evisceration of the left eye in a five-month-old Bernese mountain dog. A glass prosthesis was fitte...

  12. Stem and progenitor cells in biostructure of blood vessel walls

    Directory of Open Access Journals (Sweden)

    Krzysztof Korta

    2013-09-01

    Full Text Available Development of vascular and hematopoietic systems during organogenesis occurs at the same time. During vasculogenesis, a small part of cells does not undergo complete differentiation but stays on this level, “anchored” in tissue structures described as stem cell niches. The presence of blood vessels within tissue stem cell niches is typical and led to identification of niches and ensures that they are functioning. The three-layer biostructure of vessel walls for artery and vein, tunica: intima, media and adventitia, for a long time was defined as a mechanical barrier between vessel light and the local tissue environment. Recent findings from vascular biology studies indicate that vessel walls are dynamic biostructures, which are equipped with stem and progenitor cells, described as vascular wall-resident stem cells/progenitor cells (VW-SC/PC. Distinct zones for vessel wall harbor heterogeneous subpopulations of VW-SC/PC, which are described as “subendothelial or vasculogenic zones”. Recent evidence from in vitro and in vivo studies show that prenatal activity of stem and progenitor cells is not only limited to organogenesis but also exists in postnatal life, where it is responsible for vessel wall homeostasis, remodeling and regeneration. It is believed that VW-SC/PC could be engaged in progression of vascular disorders and development of neointima. We would like to summarize current knowledge about mesenchymal and progenitor stem cell phenotype with special attention to distribution and biological properties of VW-SC/PC in biostructures of intima, media and adventitia niches. It is postulated that in the near future, niches for VW-SC/PC could be a good source of stem and progenitor cells, especially in the context of vessel tissue bioengineering as a new alternative to traditional revascularization therapies.

  13. FEM evaluation of cemented-retained versus screw-retained dental implant single-tooth crown prosthesis.

    Science.gov (United States)

    Cicciu, Marco; Bramanti, Ennio; Matacena, Giada; Guglielmino, Eugenio; Risitano, Giacomo

    2014-01-01

    Prosthetic rehabilitation of partial or total edentulous patients is today a challenge for clinicians and dental practitioners. The application of dental implants in order to recover areas of missing teeth is going to be a predictable technique, however some important points about the implant angulation, the stress distribution over the bone tissue and prosthetic components should be well investigated for having final long term clinical results. Two different system of the prosthesis fixation are commonly used. The screw retained crown and the cemented retained one. All of the two restoration techniques give to the clinicians several advantages and some disadvantages. Aim of this work is to evaluate all the mechanical features of each system, through engineering systems of investigations like FEM and Von Mises analyses. The FEM is today a useful tool for the prediction of stress effect upon material and biomaterial under load or strengths. Specifically three different area has been evaluated through this study: the dental crown with the bone interface; the passant screw connection area; the occlusal surface of the two different type of crown. The elastic features of the materials used in the study have been taken from recent literature data. Results revealed an adequate response for both type of prostheses, although cemented retained one showed better results over the occlusal area. PMID:24955150

  14. FEM evaluation of cemented-retained versus screw-retained dental implant single-tooth crown prosthesis

    Science.gov (United States)

    Cicciu, Marco; Bramanti, Ennio; Matacena, Giada; Guglielmino, Eugenio; Risitano, Giacomo

    2014-01-01

    Prosthetic rehabilitation of partial or total edentulous patients is today a challenge for clinicians and dental practitioners. The application of dental implants in order to recover areas of missing teeth is going to be a predictable technique, however some important points about the implant angulation, the stress distribution over the bone tissue and prosthetic components should be well investigated for having final long term clinical results. Two different system of the prosthesis fixation are commonly used. The screw retained crown and the cemented retained one. All of the two restoration techniques give to the clinicians several advantages and some disadvantages. Aim of this work is to evaluate all the mechanical features of each system, through engineering systems of investigations like FEM and Von Mises analyses. The FEM is today a useful tool for the prediction of stress effect upon material and biomaterial under load or strengths. Specifically three different area has been evaluated through this study: the dental crown with the bone interface; the passant screw connection area; the occlusal surface of the two different type of crown. The elastic features of the materials used in the study have been taken from recent literature data. Results revealed an adequate response for both type of prostheses, although cemented retained one showed better results over the occlusal area. PMID:24955150

  15. By Different Cellular Mechanisms, Lymphatic Vessels Sprout by Endothelial Cell Recruitment Whereas Blood Vessels Grow by Vascular Expansion

    Science.gov (United States)

    Parsons-Wingerter, Patricia; McKay, Terri L.; Leontiev, Dmitry; Condrich, Terence K.; DiCorleto, Paul E.

    2005-01-01

    The development of effective vascular therapies requires the understanding of all modes of vessel formation contributing to vasculogenesis, angiogenesis (here termed hemangiogenesis) and lymphangiogenesis. We show that lymphangiogenesis proceeds by blind-ended vessel sprouting via recruitment of isolated endothelial progenitor cells to the tips of growing vessels, whereas hemangiogenesis occurs by non-sprouting vessel expansion from the capillary network, during middevelopment in the quail chorioallantoic membrane (CAM). Blood vessels expanded out of capillaries that displayed transient expression of alpha smooth muscle actin (alphaSMA), accompanied by mural recruitment of migratory progenitor cells expressing SMA. Lymphatics and blood vessels were identified by confocal/fluorescence microscopy of vascular endothelial growth factor (VEGF) receptors VEGFR-1 and VEGFR-2, alphaSMA (expressed on CAM blood vessels but not on lymphatics), homeobox transcription factor Prox-1 (specific to CAM lymphatic endothelium), and the quail hematopoetic/vascular marker, QH-1. Expression of VEGFR-1 was highly restricted to blood vessels (primarily capillaries). VEGFR-2 was expressed intensely in isolated hematopoietic cells, lymphatic vessels and moderately in blood vessels. Prox-1 was absent from endothelial progenitor cells prior to lymphatic recruitment. Although vascular endothelial growth factor-165 (VEGF(sub 165)) is a key regulator of numerous cellular processes in hemangiogenesis and vasculogenesis, the role of VEGF(sub 165) in lymphangiogenesis is less clear. Exogenous VEGF(sub 165) increased blood vessel density without changing endogenous modes of vascular/lymphatic vessel formation or marker expression patterns. However, VEGF(sub 165) did increase the frequency of blood vascular anastomoses and strongly induced the antimaturational dissociation of lymphatics from blood vessels, with frequent formation of homogeneous lymphatic networks.

  16. Understanding and exploiting nanoparticles' intimacy with the blood vessel and blood.

    Science.gov (United States)

    Setyawati, Magdiel Inggrid; Tay, Chor Yong; Docter, Dominic; Stauber, Roland H; Leong, David Tai

    2015-11-21

    While the blood vessel is seldom the target tissue, almost all nanomedicine will interact with blood vessels and blood at some point of time along its life cycle in the human body regardless of their intended destination. Despite its importance, many bionanotechnologists do not feature endothelial cells (ECs), the blood vessel cells, or consider blood effects in their studies. Including blood vessel cells in the study can greatly increase our understanding of the behavior of any given nanomedicine at the tissue of interest or to understand side effects that may occur in vivo. In this review, we will first describe the diversity of EC types found in the human body and their unique behaviors and possibly how these important differences can implicate nanomedicine behavior. Subsequently, we will discuss about the protein corona derived from blood with foci on the physiochemical aspects of nanoparticles (NPs) that dictate the protein corona characteristics. We would also discuss about how NPs characteristics can affect uptake by the endothelium. Subsequently, mechanisms of how NPs could cross the endothelium to access the tissue of interest. Throughout the paper, we will share some novel nanomedicine related ideas and insights that were derived from the understanding of the NPs' interaction with the ECs. This review will inspire more exciting nanotechnologies that had accounted for the complexities of the real human body. PMID:26239875

  17. The importance of psychosexual counselling in the re-establishment of organic and erotic functions after penile prosthesis implantation.

    Science.gov (United States)

    Pisano, F; Falcone, M; Abbona, A; Oderda, M; Soria, F; Peraldo, F; Marson, F; Barale, M; Fiorito, C; Gurioli, A; Frea, B; Gontero, P

    2015-01-01

    Although many studies about penile prosthesis implantation (PPI) have been published so far, only a small amount of them take into account patients and partners outcome in terms of satisfaction and erotic function. The aim of this study is to explore the value of psycosexual counselling in and the sexual and erotic function of penile prosthesis recipients. Thirty patients and their partners were randomised into two groups. In arm A (case group) patients and their partners underwent a multistep psychosexual counselling before and after surgery. In arm B (control group) surgery was performed without the specific psychosexual counselling scheme. Specific questionnaires (International Index of Erectile Function (IIEF) and the Sexual Daydreaming Scale (SDS)) were administered before surgery and 12 months afterwards. Twenty-four months postoperatively patients were asked to complete the Global Assessment Questions (GAQ) and the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS), while their partners were asked to answer to the EDITS partner's section. Between January 2009 and October 2011, we enrolled 30 patients undergoing PPI in our institution (15 in each arm). Twenty-four months postoperative follow-up is available for all of them. No significant differences between the two groups in terms of baseline questionnaires scores were observed. Mean IIEF score was significantly higher in case group (arm A 68.3, arm B 53.4, P-valueerotic function according to SDS was significantly higher in the study group for both patients and their partners. Improvement in satisfaction rates were confirmed at 24 months, with statistically significant scores for EDITS in arm A patients and partners as compared with arm B. PPI with a pre- and postoperative psychosexual counselling scheme resulted in better postoperative sexual activity and erotic function for both patients and partners than PPI alone. PMID:26268774

  18. Scanning electron microscopy of irradiated recipient blood vessels in head and neck free flaps

    International Nuclear Information System (INIS)

    Irradiated and control recipient blood vessels in a similar patient population were studied with scanning electron microscopy. The vessels that were biopsied were then anastomosed to a free flap. Irradiated arteries display a significantly greater wall thickness and higher incidence of intimal dehiscence compared with control arteries. Fibrin deposition, microthrombi, and endothelium cell dehiscence are present more frequently in irradiated vessels than in control vessels. Details of the preparation and anastomotic technique for irradiated blood vessels are discussed. Microvascular surgery in irradiated human blood vessels carries with it a higher risk of thrombosis due to preexisting vessel wall damage. This risk can be minimized by experience and attention to detail

  19. Computer-designed selective laser sintering surgical guide and immediate loading dental implants with definitive prosthesis in edentulous patient: A preliminary method

    OpenAIRE

    Giacomo, Giovanni Di; Silva, Jorge; Martines, Rodrigo; Ajzen, Sergio

    2014-01-01

    Objective: The aim of this study was to analyze a preliminary method of immediately loading dental implants and a definitive prosthesis based on the computer-aided design/computer-aided manufacturing systems, after 2 years of clinical follow-up. Materials and Methods: The study comprised one patient in good general health with edentulous maxilla. Cone beam computer tomography (CBCT) was performed using a radiographic template. The surgical plan was made using the digital imaging and communica...

  20. Combined implant-residual tooth supported prosthesis after tooth hemisection: A finite element analysis.

    Science.gov (United States)

    He, Yun; Hasan, Istabrak; Keilig, Ludger; Chen, Junliang; Pan, Qing; Huang, Yue; Bourauel, Christoph

    2016-07-01

    Tooth hemisection preserves partial tooth structure and reduces the resorption of alveolar bone. The aim of this study was to analyze the feasibility of preserving a molar after hemisection and inserting a dental implant with different prosthetic superstructures by means of finite element analysis. First, the distance between the root of the mandibular second premolar and the distal root of the first molar were measured in 80 cone beam computed tomography (CBCT) data sets. Based on these data, the lower right posterior jaw segment was reconstructed and the geometries of the appropriate implant were imported. Four models were created: (1) Hemi-1: An implant (3.7×9mm) replaced the mesial root of the molar, and a single crown was placed on the implant and residual tooth. (2) Hemi-2: Two separate crowns were generated for the implant and the residual tooth. (3) Single: An implant (5.5×9mm) with crown replaced the whole molar. (4) FPD: A 3-unit fixed partial denture combined the distal residual part of the molar and premolar. The results indicated that stresses in the cortical bone and strains in the majority region of the spongious bone were below the physiological upper limits. There were higher stresses in implant with the Hemi-1 and Single models, which had the same maximum values of 45.0MPa. The FPD models represented the higher values of stresses in the teeth and strains in PDL compared to other models. From a biomechanical point of view, it can be concluded that a combination of an implant and residual molar after tooth hemisection is an acceptable treatment option. PMID:26851558

  1. Over-expression of Slit2 induces vessel formation and changes blood vessel permeability in mouse brain

    Institute of Scientific and Technical Information of China (English)

    Hai-xiong HAN; Jian-guo GENG

    2011-01-01

    Aim:To investigate the effect of the axon guidance cue Slit2 on the density of blood vessels and permeability of the blood-brain barrier in mouse brain.Methods:hSlit2 transgenic mouse line was constructed,and the phenotypes of the mice were compared with wild-type mice in respect to the lateral ventricle (LV),ventricle pressure,and the choroids plexus.An in vivo Miles permeability assay and an amyloid-β permeability assay were used to assess the permeability of brain blood vessels.Brain vessel casting and intracerebral hemorrhage models were built to investigate vessel density in the transgenic mice.An in vitro permeability assay was used to test whether Slit2 could change the permeability and tight junctions of blood vessel endothelial cells.Results:Hydrocephalus occurred in some transgenic mice,and a significantly larger lateral ventricle area and significantly higher ventricle pressure were observed in the transgenic mice.The transgenic mice displayed changed construction of the choroids plexus,which had more micro vessels,dilated vessels,gaps between epithelial cells and endothelial cells than wild-type mice.Slit2 significantly increased brain vessel density and the permeability of brain vessels to large molecules.These blood vessels were more sensitive to cues that induce brain hemorrhage.At the cellular level,Slit2 disturbed the integrity of tight junctions in blood vessel endothelial cells and improved the permeability of the endothelial cell layer.Thus,it promoted the entry of amyloid-β peptides from the serum into the central nervous system,where they bound to neurons.Conclusion:Slit2 increases vessel density and permeability in the brains of transgenic mice.Thus,Slit2 induces numerous changes in brain vessels and the barrier system.

  2. Modeling Of Blood Vessel Constriction In 2-D Case Using Molecular Dynamics Method

    CERN Document Server

    Rendi, Mohamad; Viridi, Sparisoma

    2013-01-01

    Blood vessel constriction is simulated with particle-based method using a molecular dynamics authoring software known as Molecular Workbench (WM). Blood flow and vessel wall, the only components considered in constructing a blood vessel, are all represented in particle form with interaction potentials: Lennard-Jones potential, push-pull spring potential, and bending spring potential. Influence of medium or blood plasma is accommodated in plasma viscosity through Stokes drag force. It has been observed that pressure p is increased as constriction c is increased. Leakage of blood vessel starts at 80 % constriction, which shows existence of maximum pressure that can be overcome by vessel wall.

  3. Cortical activation following chronic passive implantation of a wide-field suprachoroidal retinal prosthesis

    Science.gov (United States)

    Villalobos, Joel; Fallon, James B.; Nayagam, David A. X.; Shivdasani, Mohit N.; Luu, Chi D.; Allen, Penelope J.; Shepherd, Robert K.; Williams, Chris E.

    2014-08-01

    Objective. The research goal is to develop a wide-field retinal stimulating array for prosthetic vision. This study aimed at evaluating the efficacy of a suprachoroidal electrode array in evoking visual cortex activity after long term implantation. Approach. A planar silicone based electrode array (8 mm × 19 mm) was implanted into the suprachoroidal space in cats (ntotal = 10). It consisted of 20 platinum stimulating electrodes (600 μm diameter) and a trans-scleral cable terminated in a subcutaneous connector. Three months after implantation (nchronic = 6), or immediately after implantation (nacute = 4), an electrophysiological study was performed. Electrode total impedance was measured from voltage transients using 500 μs, 1 mA pulses. Electrically evoked potentials (EEPs) and multi-unit activity were recorded from the visual cortex in response to monopolar retinal stimulation. Dynamic range and cortical activation spread were calculated from the multi-unit recordings. Main results. The mean electrode total impedance in vivo following 3 months was 12.5 ± 0.3 kΩ. EEPs were recorded for 98% of the electrodes. The median evoked potential threshold was 150 nC (charge density 53 μC cm-2). The lowest stimulation thresholds were found proximal to the area centralis. Mean thresholds from multiunit activity were lower for chronic (181 ± 14 nC) compared to acute (322 ± 20 nC) electrodes (P < 0.001), but there was no difference in dynamic range or cortical activation spread. Significance. Suprachoroidal stimulation threshold was lower in chronic than acute implantation and was within safe charge limits for platinum. Electrode-tissue impedance following chronic implantation was higher, indicating the need for sufficient compliance voltage (e.g. 12.8 V for mean impedance, threshold and dynamic range). The wide-field suprachoroidal array reliably activated the retina after chronic implantation.

  4. Combination of natural teeth and osseointegrated implants as prosthesis abutments in a posterior cantilever bridge

    Directory of Open Access Journals (Sweden)

    Michael Josef Kridanto Kamadjaja

    2008-06-01

    Full Text Available Dental implants have been used for several decades. Patients of all ages have chosen dental implants to replace a single tooth or several teeth or to support partial or full dentures. This paper reports two cases of patients treated with dental implant as alternative to replace the missing teeth and connected with natural tooth as abutments in a fixed restoration with distal cantilever bridge. The underlining reasons that we decided to make such kind fixed prostheses are because of clinically imposible to put the implant on certain area and the patients asked for prostheses as optimum as possible, so the mastication function could return to the homeostasis condition. The benefit of these treatments are that prostheses could be made as optimum as possible with a more economic price, so the patients feel quite satisfied. The result shows that a few years after the treatments finished there is no any disadvantageous effect of connecting teeth to implants as abutments in fixed partial dentures and there is no sign of a harmful effect to the opposing teeth either.

  5. Five-year practice of roentgenoendovascularly replacing a nitinol prosthesis

    International Nuclear Information System (INIS)

    Roentgenoendovascular prosthesis hat been made in 103 patients, 121 endoprosthesis implantations, into the ileac, femoral, and popliteal arteries over 5 years, 76.8 % pf the patients had a severe concurrent disease. The age of the patients ranged from 21 to 72 years. Positive results were obtained in 93.7 % of all the implantations. Poor results were obtained with endoprosthesis of the superficial femoral and popliteal arteries, which were associated with impaired distal limb blood flow. Indications for endoprosthesis were defined

  6. Angiogenesis and blood vessel stability in inflammatory arthritis.

    LENUS (Irish Health Repository)

    Kennedy, Aisling

    2012-02-01

    OBJECTIVE: To assess blood vessel stability in inflammatory synovial tissue (ST) and to examine neural cell adhesion molecule (NCAM), oxidative DNA damage, and hypoxia in vivo. METHODS: Macroscopic vascularity and ST oxygen levels were determined in vivo in patients with inflammatory arthritis who were undergoing arthroscopy. Vessel maturity\\/stability was quantified in matched ST samples by dual immunofluorescence staining for factor VIII (FVIII)\\/alpha-smooth muscle actin (alpha-SMA). NCAM and 8-oxo-7,8-dihydro-2\\'-deoxyguanosine (8-oxodG) were examined by immunohistochemistry. Angiogenesis was assessed in vitro, using human dermal endothelial cells (HDECs) in a Matrigel tube formation assay. RESULTS: A significant number of immature vessels (showing no pericyte recruitment) was observed in tissue from patients with inflammatory arthritis (P < 0.001), in contrast to osteoarthritic and normal tissue, which showed complete recruitment of pericytes. Low in vivo PO(2) levels in the inflamed joint (median [range] 22.8 [3.2-54.1] mm Hg) were inversely related to increased macroscopic vascularity (P < 0.04) and increased microscopic expression of FVIII and alpha-SMA (P < 0.04 and P < 0.03, respectively). A significant proportion of vessels showed focal expression of NCAM and strong nuclear 8-oxodG expression, implicating a loss of EC-pericyte contact and increased DNA damage, levels of which were inversely associated with low in vivo PO(2) (P = 0.04 for each comparison). Circulating cells were completely negative for 8-oxodG. Exposure of HDEC to 3% O(2) (reflecting mean ST in vivo measurements) significantly increased EC tube formation (P < 0.05). CONCLUSION: Our findings indicate the presence of unstable vessels in inflamed joints associated with hypoxia, incomplete EC-pericyte interactions, and increased DNA damage. These changes may further contribute to persistent hypoxia in the inflamed joint to further drive this unstable microenvironment.

  7. An Alternative Technique for Fabrication of Frameworks in an Immediate Loading Implant Fixed Mandibular Prosthesis

    Directory of Open Access Journals (Sweden)

    André Gustavo Paleari

    2015-01-01

    Full Text Available The oral rehabilitation of edentulous patients with immediate loading has become a safe procedure with high predictability. The success is related to immediate fabrication of a passive fit framework to attach the implants. Based on these considerations, this case report shows an alternative technique for mandibular rehabilitation using implants immediately loaded, where the framework was fabricated using cylinders with internal reinforcement and precast pieces, electrowelding, and conventional welding providing esthetics and function to the patient in a short period of time.

  8. Plasma membrane electron transport in frog blood vessels

    Indian Academy of Sciences (India)

    Rashmi P Rao; K Nalini; J Prakasa Rao

    2009-12-01

    In an attempt to see if frog blood vessels possess a plasma membrane electron transport system, the postcaval vein and aorta isolated from Rana tigrina were tested for their ability to reduce ferricyanide, methylene blue, and 2,6-dichloroindophenol. While the dyes remained unchanged, ferricyanide was reduced to ferrocyanide. This reduction was resistant to inhibition by cyanide and azide. Heptane extraction or formalin fixation of the tissues markedly reduced the capability to reduce ferricyanide. Denuded aortas retained only 30% of the activity of intact tissue. Our results indicate that the amphibian postcaval vein and aorta exhibit plasma membrane electron transport

  9. Ectodermal Dysplasia: Management of Knife-Edged Irregular Ridge and Its Rehabilitation with Hybrid Implant Prosthesis.

    Science.gov (United States)

    Revanappa, Prithviraj Doddamane; Gaur, Satyam; Srivastava, Rachana; Patil, Abhishekha; Prithviraj, Shruthi Doddamane

    2016-05-01

    Ectodermal Dysplasia Syndrome (EDS) is mainly X-linked inherited disorder with male predominance. According to Lyon hypothesis, female patients may show partial expression of EDS. Oral findings include hypodontia, rarely anodontia, protuberant lips, hyposalivation, conical teeth and loss of vertical dimension. The alveolar process fails to develop in the three dimensions. Such patients present a challenge to dental treatment due to an irregular residual ridge. This case report presents oral, functional and aesthetic rehabilitation of a 21-year-old female diagnosed with EDS using implants in the anterior maxilla at the sites of the canines bilaterally. Following, implant placement, it was noted that implant in the region of right canine was labially inclined compared to implant in the region of left canine, but both were centered in the ridge. To manage non-parallelism, one-piece titanium framework was fabricated using computer numeric controlled (CNC) machine. Subsequently, tooth and gingival shade ceramics were fired to simulate natural teeth and compensate for gingival deficiency respectively. The treatment described here restored patient's aesthetics, function, self-confidence and status in society. PMID:27437373

  10. Implantation of customized 3-D printed titanium prosthesis in limb salvage surgery: a case series and review of the literature

    OpenAIRE

    Fan, Hongbin; Fu, Jun; Li, Xiangdong; Pei, Yanjun; Li, Xiaokang; Pei, Guoxian; Guo, Zheng

    2015-01-01

    Background Although modular prosthesis is commercially available to meet requirements in most limb salvage surgeries, customized prosthesis is still needed. In contrast to traditional complicated procedures, rapid prototyping (RP) technique can directly manufacture customized titanium prosthesis. The objectives of this study were to describe the workflow of this technique and show the follow-up results of patients. Methods Three patients with clavicle Ewing’s sarcoma (ES), scapular ES, and pe...

  11. PET/CT imaging of atherosclerotic blood vessel alterations

    International Nuclear Information System (INIS)

    Atherosclerosis is a chronic inflammatory disease of middle sized and large vessels with sequelae comprising the most frequent causes of death in the Western world. Modern imaging modalities are being introduced for the study of atherosclerosis with emphasis on the detection of vulnerable plaques. The hybrid imaging method PET/CT presents advantages for the localization of vulnerable plaques based on the uptake of various molecular imaging agents indicative of inflammatory processes. Using semiquantitative image analysis fluorodeoxyglucose (FDG) uptake in large peripheral vessels has been identified in a series of 21 patients, who were scanned first with the previous generation of PET/CT scanner and subsequently with a new generation apparatus, after a mean interval of 6.5 months. The mean ratio of FDG uptake in the walls of eight large vessels to the blood-pool activity (TBR) was nearly identical in the two PET/CT sessions (TBR1 1.26 versus TBR2 1.28; p=n.s.), indicating independence of the TBR endpoint from the particular instrumentation. (orig.)

  12. War injuries of the blood vessels of the extremities

    Directory of Open Access Journals (Sweden)

    Radulović Svetozar

    2002-01-01

    Full Text Available Treatment results of 200 injured with the lesions of 282 magisterial blood vessels were analyzed. All were combat injuries, and the majority was caused by the fragments of explosive device. The mechanism of such the injuries produced large defects of soft tissues as well as the high level of the wound contamination, which aggravated reconstructive procedures and increased the risk of infection. In the majority of cases anatomic reconstruction of the artery was performed, and the ligature was used only in the case of graft infection and in the injuries of one artery of the lower leg or the forearm. The majority of injuries was solved by lateral suture or patch plastic, since postoperative constriction caused by those methods did not cause greater hemodynamic disorders due to the size of venous lumen. The duration of ischemic interval was of the utmost importance for the favorable final result of the treatment, as well as the adequate debridement of the wound, good soft-tissue cover of the reconstructed blood vessel and precise a traumatic technique. Total percentage of amputations was 14.5%, and all were involving the lower extremities, and were mostly caused by popliteal artery lesion.

  13. Mathematical Model of Blood Flow in Small Blood Vessel in the Presence of Magnetic Field

    Directory of Open Access Journals (Sweden)

    Rekha Bali

    2011-02-01

    Full Text Available A mathematical model for blood flow in the small blood vessel in the presence of magnetic field is presented in this paper. We have modeled the two phase model for the blood flow consists of a central core of suspended erythrocytes and cell-free layer surrounding the core. The system of differential equations has been solved analytically. We have obtained the result for velocity, flow rate and effective viscosity in presence of peripheral layer and magnetic field .All the result has been obtained and discussed through graphs.

  14. Functional and aesthetic rehabilitation with maxillary prosthesis supported by two zygomatic implants for maxillary defect resulting from cancer ablative surgery: a case report/technique article.

    Science.gov (United States)

    Ozaki, Hisashi; Ishikawa, Shigeo; Kitabatake, Kenichirou; Yusa, Kazuyuki; Sakurai, Hiromasa; Iino, Mitsuyoshi

    2016-05-01

    We report herein a case of functional and aesthetic rehabilitation with maxillary prosthesis supported by only two zygomatic implants for a patient with severe maxillary defect resulting from subtotal maxillectomy for malignant melanoma of the upper gingiva. A 76-year-old woman was referred to our facility with non-painful discoloration of the upper gingiva. After several examinations, a clinical diagnosis of malignant melanoma of the upper gingiva (cT3N1M0 stage IVA, American Joint Committee on Cancer) was made. Subtotal maxillectomy utilizing Le Fort I osteotomy and functional neck dissection were performed. A conventional resection denture was made and employed postoperatively, but was unable to be suitably retained due to insufficient residual maxillary structures. Six months after tumor resection, two zygomatic implants were inserted into bilateral zygomatic bones. Magnetic attachments were applied as a mechanism for attaching the implants and resection denture. After application of these implants, retention and stability of the prosthesis was considerably improved. The patient became able to eat a normal diet. From an aesthetic perspective, the depressed upper lip was also properly restored, leading to an acceptable facial appearance. PMID:26497725

  15. Penile prosthesis implant for erectile dysfunction: A new minimally invasive infrapubic surgical technique

    OpenAIRE

    Gabriele Antonini; Gian Maria Busetto; Ettore De Berardinis; Riccardo Giovannone; Patrizio Vicini; Vincenzo Gentile; Paul E. Perito

    2016-01-01

    Erectile dysfunction, the most common male sexual disorder after premature ejaculation, with its important impact on man and partner’s sexuality and quality of life is a persistent inability to obtain and maintain an erection sufficient to permit satisfactory sexual performance. Non-surgical treatments with controversial results are usually applyed before surgical treatment that has reached high levels of satisfaction. We describe a new surgical technique to implant three-pieces penile prosth...

  16. A survivor of late prosthesis migration and rotation following percutaneous transcatheter aortic valve implantation.

    Science.gov (United States)

    Pang, Philip Y K; Chiam, Paul T L; Chua, Yeow Leng; Sin, Yoong Kong

    2012-05-01

    Transcatheter aortic valve implantation (TAVI) has emerged as a viable alternative endovascular technique in selected patients with severe aortic stenosis, who are either inoperable or at high risk for surgical aortic valve replacement. We report a case of delayed displacement and rotation of an aortic bioprosthesis, 43 days after successful TAVI via the transfemoral approach, with the patient surviving the subsequent open heart surgery required for device retrieval. PMID:22228843

  17. A review of surgical strategies for penile prosthesis implantation in patients with Peyronie’s disease

    Science.gov (United States)

    Anaissie, James

    2016-01-01

    The introduction of the inflatable penile prosthesis (IPP) has revolutionized the treatment of patients with both Peyronie’s disease (PD) and erectile dysfunction (ED). A thorough literature review was performed in order to review the surgical strategies used to treat PD, using the PubMed online database with the keywords “penile prosthesis”, “surgical management” and “Peyronie’s disease”. Patient satisfaction rates of 72–100% and partner satisfaction rates of 89% have been reported in the literature, although strong preoperative education may be needed to prepare patients for risks such as penile shortening, seen in up to 54% of patients. Three-piece IPPs are most commonly used, and when comparing the two most popular models (AMS 700 CX vs. Coloplast Titan), no significant differences were seen in functional outcomes or patient satisfaction. Simple insertion of an IPP has been shown to resolve curvature in 33–90% of patients, but surgeons may often need to also utilize ancillary straightening procedures for residual curvatures. Manual modeling can correct residual curvature with an 86–100% success rate, but with a 4% risk of urethral injury. When the post-modeling residual curvature exceeds 30 degrees, a plaque-releasing incision or plication is recommended to further reduce curvature. Grafting is recommended if the resulting incisional defect is larger than two centimeters. Alternative straightening techniques such as plication prior to IPP insertion, endoscopic plaque resection, the “scratch technique” and bone saw plaque incision have also been described. PMID:27298781

  18. Roentgenologic aspects of acute respiratory in sufficiency after heart valve prosthesis implantation

    International Nuclear Information System (INIS)

    Analysis of the X-ray findings in 156 patients with acute respiratory insufficiency (ART) in the immediate periods after implantation of heart valve prostheses has shown that various pulmonary complications, such as pulmonary edema (in 84% of cases), atelectasis, hypoventilation (5.1%), hemothorax (6.4%), pneumothorax (0.6%) were the prerequisites for the development of respiratory disorders. Pneumonias were not the primary cause of ART but an additional factor for the respiratory disorder progress, for they develop in the presence of previous pulmonary changes. The necessity and possibility of establishing the pathogenetic mechanism of pulmonary edema is shown

  19. CT-Angiography–Based Evaluation of the Aortic Annulus for Prosthesis Sizing in Transcatheter Aortic Valve Implantation (TAVI)–Predictive Value and Optimal Thresholds for Major Anatomic Parameters

    OpenAIRE

    Schwarz, Florian; Lange, Philipp; Zinsser, Dominik; Greif, Martin; Boekstegers, Peter; Schmitz, Christoph; Reiser, Maximilian F.; Kupatt, Christian; Becker, Hans C.

    2014-01-01

    Background/Objectives To evaluate the predictive value of CT-derived measurements of the aortic annulus for prosthesis sizing in transcatheter aortic valve implantation (TAVI) and to calculate optimal cutoff values for the selection of various prosthesis sizes. Methods The local IRB waived approval for this single-center retrospective analysis. Of 441 consecutive TAVI-patients, 90 were excluded (death within 30 days: 13; more than mild aortic regurgitation: 10; other reasons: 67). In the rema...

  20. Two and Three Dimensional Blood Flow Simulations in Different Types of Blood Vessels

    Directory of Open Access Journals (Sweden)

    Balazs ALBERT

    2015-12-01

    Full Text Available In this paper we present a synthesis of our results obtained on blood flow simulation in different types of blood vessels. We present first some remarks on the wall shear stress (WSS in the case of a human abdominal aortic aneurysm (AAA, and then we concentrate on the mechanical conditions which would lead to the “rupture” of the vascular vessel with aneurysm and implicitly to a possible stroke. We also make some investigations on the Fahraeus-Lindqvist effect in arterioles. Considering an axial-symmetric reservoir full of blood and which is linked to an arteriole (with the same particular geometry, we have pointed out the concentration of the red blood cells in this arteriole towards the core of the vessel. To improve our work we have considered a real three-dimensional geometry, which is a serious jump versus our previous results, where only the axial-symmetric geometries were considered. In this respect we have reconsidered the case of a carotid artery stenosis with and without a stent.

  1. A Functional Requirement for Astroglia in Promoting Blood Vessel Development in the Early Postnatal Brain

    OpenAIRE

    Shang Ma; Hyo Jun Kwon; Zhen Huang

    2012-01-01

    Astroglia are a major cell type in the brain and play a key role in many aspects of brain development and function. In the adult brain, astrocytes are known to intimately ensheath blood vessels and actively coordinate local neural activity and blood flow. During development of the neural retina, blood vessel growth follows a meshwork of astrocytic processes. Several genes have also been implicated in retinal astrocytes for regulating vessel development. This suggests a role of astrocytes in p...

  2. Pattern of blood vessels in eyes with coloboma

    Directory of Open Access Journals (Sweden)

    Gopal Lingam

    2013-01-01

    Full Text Available Background: Choroidal coloboma, especially with optic disc involvement affects the blood vessel (BV pattern in the fundus. Aim: The aim of this study was to report the observations on the pattern of retinal BVs in eyes with fundus coloboma. Design: Retrospective observational study. Materials and Methods: Twenty four eyes of 19 patients with fundus coloboma and the disc involvement in the coloboma was classified according to a previous publication. Results: Four varieties of BVs were identified in the area of coloboma - BVs that were continuous with those arising from the optic disc; vessels emanating from the floor of coloboma whose continuity with central retinal artery or its branches could be indirectly established; and those emanating from the floor of coloboma whose continuity with central retinal artery could not be established. In addition, extraocular BVs were visible through the thinned sclera. The retinal BVs often traversed the coloboma to reach the normal retina. The disc itself was found to be small and had no physiological cup (if not colobomatous. Conclusions: One should be aware of the major BVs transgressing the coloboma while performing relaxing cuts in the intercalary membrane, during the surgery for retinal detachments in eyes with coloboma. Physiological cup is usually absent (when the disc is not colobomatous. Hence, any cupping in such eyes should be viewed with suspicion.

  3. Techniques for Evaluating the Fit of Removable and Fixed Prosthesis

    OpenAIRE

    K Kamalakanth Shenoy; Shetty, Mallika S.

    2011-01-01

    The importance of an accurately fitting fixed prosthesis or a removable prosthesis is essential for the success of the restoration. Ill-fitting prosthesis may cause mechanical failures of the prosthesis, implant systems, or biologic complications of the surrounding tissue. There are several causes related to improper seating of the prosthesis. Some of which can be corrected and the others need to be repeated. Hence the clinician must carefully evaluate the adaptation of the prosthesis using t...

  4. Implante transapical de valva aórtica: resultados de uma nova prótese brasileira Transapical aortic valve implantation: results of a brazilian prosthesis

    Directory of Open Access Journals (Sweden)

    Diego Felipe Gaia

    2010-09-01

    procedimento alternativo.OBJECTIVE: The aortic valve replacement is a routine procedure with acceptable risk, but in some cases, such a risk can justify contraindication. The minimally invasive transcatheter aortic valve implantation has been viable, with lower morbidity and mortality. The aim of this study was to develop a national catheter-mounted aortic bioprosthesis for the aortic position implant. METHODS: After animal studies, 14 patients with high EuroSCORE underwent transcatheter aortic valve implantation. Median Logistic EuroSCORE was 43.7%. Four patients presented with dysfunctional bioprosthesis, remaining ones presented calcified aortic stenosis. All patients presented symptoms. Procedures were performed in a hybrid OR under fluoroscopic and echocardiography guidance. Using a left minithoracotomy the prosthesis was implanted through the ventricular apex under ventricular pacing or hemorrhagic shock, after aortic valvoplasty. Echocardiograph and angiograph controls were performed, and the patients were referred to ICU. RESULTS: Implant was feasible in 13 cases. There were no intra-operative deaths. Median peak transvalvular aortic gradient reduced to 25.0 mmHg, and left ventricular function improved in the first seven post-operative days. Paravalvular aortic regurgitation was mild and present in 71%. No definitive pacemaker was needed. There was no peripheral vascular complication. Overall mortality was 42%. CONCLUSION: The transapical implantation of cathetermounted bioprosthesis was a feasible procedure. Long term follow-up is mandatory in order to access efficacy and indications.

  5. 21 CFR 878.3550 - Chin prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Chin prosthesis. 878.3550 Section 878.3550 Food... DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3550 Chin prosthesis. (a) Identification. A chin prosthesis is a silicone rubber solid device intended to be implanted to augment...

  6. 21 CFR 878.3680 - Nose prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nose prosthesis. 878.3680 Section 878.3680 Food... DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3680 Nose prosthesis. (a) Identification. A nose prosthesis is a silicone rubber solid device intended to be implanted to augment...

  7. 21 CFR 876.3750 - Testicular prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Testicular prosthesis. 876.3750 Section 876.3750...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Prosthetic Devices § 876.3750 Testicular prosthesis. (a) Identification. A testicular prosthesis is an implanted device that consists of a solid or gel-filled...

  8. 21 CFR 878.3590 - Ear prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ear prosthesis. 878.3590 Section 878.3590 Food and... GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3590 Ear prosthesis. (a) Identification. An ear prosthesis is a silicone rubber solid device intended to be implanted to reconstruct the...

  9. Ultrastructural characterization of soft tissues surrounding implanted hip prosthesis by complementary PIXE and TEM methods

    Energy Technology Data Exchange (ETDEWEB)

    Jallot, E. E-mail: edouard.jallot@uni-reims.fr; Benhayoune, H.; Kilian, L.; Balossier, G.; Bonhomme, P.; Oudadesse, H.; Irigaray, J.L

    1999-08-01

    We study soft tissues surrounding hip prostheses from three different patients. We evaluate the elemental composition of different fragments. The tissues are examined by means of two complementary methods in such analysis: Particle Induced X-ray Emission (PIXE) and Scanning Transmission Electron Microscopy (STEM) coupled with X-ray microanalysis (Energy Dispersive X-ray, EDX). These methods allow to determine locally at 'macro' and 'micro' level the chemistry of soft tissues. The findings confirmed the presence of metal in soft tissue near the three different hips. The tissues' composition undergoes important modifications with a systematic elevation of trace metal in patients with failed implants. We observe a corrosion which causes the continual release of particles into the tissues. Corrosion alters the shape size and chemical composition of wear particles embedded in soft tissue around the failed hip. EDX analysis showed that the wear particles contained varying quantities of titanium and aluminium. This phenomenon may be related with the variation of time of contact with soft tissues for each particle and Ti solubility.

  10. Ultrastructural characterization of soft tissues surrounding implanted hip prosthesis by complementary PIXE and TEM methods

    Science.gov (United States)

    Jallot, E.; Benhayoune, H.; Kilian, L.; Balossier, G.; Bonhomme, P.; Oudadesse, H.; Irigaray, J. L.

    We study soft tissues surrounding hip prostheses from three different patients. We evaluate the elemental composition of different fragments. The tissues are examined by means of two complementary methods in such analysis: Particle Induced X-ray Emission (PIXE) and Scanning Transmission Electron Microscopy (STEM) coupled with X-ray microanalysis (Energy Dispersive X-ray, EDX). These methods allow to determine locally at `macro' and `micro' level the chemistry of soft tissues. The findings confirmed the presence of metal in soft tissue near the three different hips. The tissues' composition undergoes important modifications with a systematic elevation of trace metal in patients with failed implants. We observe a corrosion which causes the continual release of particles into the tissues. Corrosion alters the shape size and chemical composition of wear particles embedded in soft tissue around the failed hip. EDX analysis showed that the wear particles contained varying quantities of titanium and aluminium. This phenomenon may be related with the variation of time of contact with soft tissues for each particle and Ti solubility.

  11. Blood Vessel Normalization in the Hamster Oral Cancer Model for Experimental Cancer Therapy Studies

    Energy Technology Data Exchange (ETDEWEB)

    Ana J. Molinari; Romina F. Aromando; Maria E. Itoiz; Marcela A. Garabalino; Andrea Monti Hughes; Elisa M. Heber; Emiliano C. C. Pozzi; David W. Nigg; Veronica A. Trivillin; Amanda E. Schwint

    2012-07-01

    Normalization of tumor blood vessels improves drug and oxygen delivery to cancer cells. The aim of this study was to develop a technique to normalize blood vessels in the hamster cheek pouch model of oral cancer. Materials and Methods: Tumor-bearing hamsters were treated with thalidomide and were compared with controls. Results: Twenty eight hours after treatment with thalidomide, the blood vessels of premalignant tissue observable in vivo became narrower and less tortuous than those of controls; Evans Blue Dye extravasation in tumor was significantly reduced (indicating a reduction in aberrant tumor vascular hyperpermeability that compromises blood flow), and tumor blood vessel morphology in histological sections, labeled for Factor VIII, revealed a significant reduction in compressive forces. These findings indicated blood vessel normalization with a window of 48 h. Conclusion: The technique developed herein has rendered the hamster oral cancer model amenable to research, with the potential benefit of vascular normalization in head and neck cancer therapy.

  12. Preservation of Cavernosal Erectile Function after Soft Penile Prosthesis Implant in Peyronie's Disease: Long-Term Followup

    Science.gov (United States)

    Grasso, Marco; Lania, Caterina; Fortuna, Flavio; Blanco, Salvatore; Piacentini, Igor

    2008-01-01

    The aim of this retrospective study is to evaluate the long-term followup of soft penile SSDA prosthesis, without plaque surgery in the treatment of Peyronie's disease. This study included 12 men with Peyronie's disease who underwent placement of a penile prosthesis. All patients were followed for at least 6 years. Prosthesis straightened the penile shaft in all cases, restoring patient sexual satisfaction. No operative or postoperative complications occurred, and no reoperations were needed. All patients have undergone further examination with basal and dynamic eco color Doppler. The findings are encouraging as the penis preserves the ability to enhance the tumescence and penile girth. We can conclude that SSDA penile prosthesis is safe and effective in Peyronie's disease. PMID:19081839

  13. Ionic implantation by plasma in titanium and stainless steels used in prosthesis and medical instruments

    International Nuclear Information System (INIS)

    A study of a process known as plasma immersion ion implantation (PIII) of nitrogen at low voltages (< 4 kV) into three kind of samples: 1) austenitic stainless AISI 316-L steel plates, 2) ferritic stainless AISI 434 steel-based dentistry drills and 3) commercially pure titanium (CPTi) disks. On the case of CPTi the study was conducted in nitrogen- oxygen calibrated mixtures: 90% N-10% O, 80% N-20% O, 70% N-30% O and in 99.5% pure oxygen and 99.9% pure nitrogen. The PIII process was carried out by using a direct current plasma source controlled both in voltage and current, a negative voltage pulse modulator, a stainless AISI 304 steel vacuum chamber and a rod of the same material, horizontally located in the upper region of the chamber, which plays the role of anode in the plasma discharge. The purpose of the nitriding is forming a relatively thick layer on the surface of the steel specimens in order to enhance their both microhardness and general corrosion performances, desirable in medical applications. This layer contains interstitial nitrogen atoms (∼24% at.) which gives place to a deformed lattice (expanded phase) of the steel. Vickers microhardness and potentiodynamic tests (the latter in agreement to the norm ASTM G-61-89) confirm an increase of microhardness up to three times and a decrease of general corrosion rate in one order of magnitude. The nitriding of de dentistry drills is aimed at inhibiting the pitting corrosion produced by the asepsis process which results in pit nucleations, their propagation and consequent fractures when being under cyclic stress (fatigue). Scanning electron microscope micrographs reveal the risks involved in surpassing the critical treatment simple temperature of 450 C as the PIII process itself induces pitting. On its part, cyclic (ASTM G-61) potentiodynamic tests indicate an excellent pitting corrosion resistance of the samples treated under 450 C. In turn, the treatment of CPTi was meant to develop oxidized and

  14. Pericyte coverage of abnormal blood vessels in myelofibrotic bone marrows

    DEFF Research Database (Denmark)

    Zetterberg, Eva; Vannucchi, Alessandro M; Migliaccio, Anna Rita;

    2007-01-01

    BACKGROUND AND OBJECTIVES: Myelofibrotic bone marrow displays abnormal angiogenesis but the pathogenic mechanisms of this are poorly understood. Since pericyte abnormalities are described on solid tumor vessels we studied whether vessel morphology and pericyte coverage in bone marrow samples from...

  15. Blood Vessel Deformations on Microsecond Time Scales by Ultrasonic Cavitation

    OpenAIRE

    Chen, Hong; Kreider, Wayne; Brayman, Andrew A.; Bailey, Michael R.; Matula, Thomas J.

    2011-01-01

    Transient interactions among ultrasound, microbubbles, and microvessels were studied using high-speed photomicrography. We observed liquid jets, vessel distention (motion outward against the surrounding tissue), and vessel invagination (motion inward toward the lumen). Contrary to current paradigms, liquid jets were directed away from the nearest vessel wall and invagination exceeded distention. These observations provide insight into the mechanics of bubble-vessel interactions, which appear ...

  16. 21 CFR 878.3800 - External aesthetic restoration prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External aesthetic restoration prosthesis. 878... External aesthetic restoration prosthesis. (a) Identification. An external aesthetic restoration prosthesis... external prosthesis adhesive. The device is not intended to be implanted. (b) Classification. Class...

  17. Biological and engineering design considerations for vascular tissue engineered blood vessels (TEBVs)

    OpenAIRE

    Fernandez, Cristina E.; Achneck, Hardean E.; Reichert, William M.; Truskey, George A.

    2014-01-01

    Considerable advances have occurred in the development of tissue-engineered blood vessels (TEBVs) to repair or replace injured blood vessels, or as in vitro systems for drug toxicity testing. Here we summarize approaches to produce TEBVs and review current efforts to (1) identify suitable cell sources for the endothelium and vascular smooth muscle cells, (2) design the scaffold to mimic the arterial mechanical properties and (3) regulate the functional state of the cells of the vessel wall. I...

  18. Update on Treated Tooth-Implant Supported Fixed Prosthesis%天然牙与种植体联合固定修复的研究进展

    Institute of Scientific and Technical Information of China (English)

    唐天弘(综述); 宋萌(审校)

    2015-01-01

    The aging of the population in Kennedy Ⅰ class and Ⅱ dentition defect rate is higher than before, with the increasing trend of pulp disease in the remaining teeth. New model that treated tooth-implatnt supported fixed prosthesis not only has a fixed partial denture comfort, but also more economical than implant denture. Aiming at the root canal treatment of tooth-implant supported fixed prosthesis, the article combine fixed restoration mechanism, the effect of treat-ment and common problems.%老龄人口肯氏I类和II类牙列缺损比率较高,且余留牙的牙体牙髓疾病多发。新型的根充后天然牙种植体联合固定修复不仅拥有固定义齿的舒适度,同时也比纯种植体支持式义齿更加经济。本文针对经根管治疗的天然牙-种植体联合固定修复这一方式的作用机制、治疗效果、常见问题等作一综述。

  19. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    OpenAIRE

    Song, Fenglin; Zhou, Wenwu; Tang, Tao; Li, Xiaobing; Wu, Xiaoming; Yang, Jinfu

    2014-01-01

    To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV) was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs...

  20. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    OpenAIRE

    2014-01-01

    To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV) was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex,...

  1. Mathematical modeling of patient-specific ventricular assist device implantation to reduce particulate embolization rate to cerebral vessels.

    Science.gov (United States)

    Ricardo Argueta-Morales, I; Tran, Reginald; Ceballos, Andres; Clark, William; Osorio, Ruben; Divo, Eduardo A; Kassab, Alain J; DeCampli, William M

    2014-07-01

    Stroke is the most devastating complication after ventricular assist device (VAD) implantation, with an incidence of 14%-47% despite improvements in device design and anticoagulation. This complication continues to limit the widespread implementation of VAD therapy. Patient-specific computational fluid dynamics (CFD) analysis may elucidate ways to reduce this risk. A patient-specific three-dimensional model of the aortic arch was generated from computed tomography. A 12 mm VAD outflow-graft (VAD-OG) "anastomosed" to the aorta was rendered. CFD was applied to study blood flow patterns. Particle tracks, originating from the VAD, were computed with a Lagrangian phase model and percentage of particles entering the cerebral vessels was calculated. Twelve implantation configurations of the VAD-OG and three particle sizes (2, 4, and 5 mm) were considered. Percentage of particles entering the cerebral vessels ranged from 6% for the descending aorta VAD-OG anastomosis, to 14% for the ascending aorta at 90 deg VAD-OG anastomosis. Values were significantly different among all configurations (X(2) = 3925, p < 0.0001). Shallower and more cephalad anastomoses prevented formation of zones of recirculation in the ascending aorta. In this computational model and within the range of anatomic parameters considered, the percentage of particles entering the cerebral vessels from a VAD-OG is reduced by nearly 60% by optimizing outflow-graft configuration. Ascending aorta recirculation zones, which may be thrombogenic, can also be eliminated. CFD methods coupled with patient-specific anatomy may aid in identifying the optimal location and angle for VAD-OG anastomosis to minimize stroke risk. PMID:24441718

  2. Tumor blood vessels formation in osteosarcoma:vasculogenesis mimicry

    Institute of Scientific and Technical Information of China (English)

    蔡宣松; 贾永伟; 梅炯; 汤如勇

    2004-01-01

    Background Osteosarcoma is characterized by high neovascularization and a high propensity for metastasis through bloodstream. This study was to examine whether there is evidence for vasculogenic mimicry in osteosarcoma and to illustrate mechanism of tumor blood vessels formation in osteosarcoma.Methods Osteosarcoma cell lines (U-2OS) were tested for their ability to form tubular networks in three-dimensional culture containing type Ⅰ collagen. The structures of the tubular networks were observed with phase contrast microscope and transmission electron microscope (TEM). Morphometric studies using hematoxylin and eosin (HE) stain and CD31 immunohistochemical stain to show tumor-lined channels in human osteosarcoma were also performed.Results Observation with light microscope and TEM showed that highly aggressive osteosarcoma cell lines (U-2OS) formed networks containing channels when grown in three-dimensional culture containing type Ⅰ collagen, in the absence of endothelial cells or fibroblasts. Morphometric observation using HE stain and CD31 immunohistochemical stain showed that tumor cell-lined channels were also detected in vivo in osteosarcoma; by comparison, all vascular areas in the pedicel of osteochondroma or outside osteochondroma were endothelial-lined.Conclusion These observations strongly suggest that aggressive osteosarcoma cells may generate vascular channels that facilitate tumor perfusion independent of tumor angiogenesis and have the ability of vasculogenic mimicry.

  3. Transmitted ultrasound pressure variation in micro blood vessel phantoms.

    Science.gov (United States)

    Qin, Shengping; Kruse, Dustin E; Ferrara, Katherine W

    2008-06-01

    Silica, cellulose and polymethylmethacrylate tubes with inner diameters of ten to a few hundred microns are commonly used as blood vessel phantoms in in vitro studies of microbubble or nanodroplet behavior during insonation. However, a detailed investigation of the ultrasonic fields within these micro-tubes has not yet been performed. This work provides a theoretical analysis of the ultrasonic fields within micro-tubes. Numerical results show that for the same tube material, the interaction between the micro-tube and megaHertz-frequency ultrasound may vary drastically with incident frequency, tube diameter and wall thickness. For 10 MHz ultrasonic insonation of a polymethylmethacrylate (PMMA) tube with an inner diameter of 195 microm and an outer diameter of 260 microm, the peak pressure within the tube can be up to 300% of incident pressure amplitude. However, using 1 MHz ultrasound and a silica tube with an inner diameter of 12 microm and an outer diameter of 50 microm, the peak pressure within the tube is only 12% of the incident pressure amplitude and correspondingly, the spatial-average-time-average intensity within the tube is only 1% of the incident intensity. PMID:18395962

  4. Automated computational framework of blood vessel quantification in chick chorioallantoic membrane angiogenesis

    Science.gov (United States)

    Shi, Peng; Hong, Jinsheng; Huang, Yue; Zhang, Zhenhuan; Zhang, Mei; Zhang, Lurong

    2014-10-01

    Chick chorioallantoic membrane (CAM) angiogenesis assay has been widely used for finding drugs targeting new blood vessel development in cancer research. In addition to the setup materials and protocols, laboratory findings depend on the quantification and analysis of microscopic blood vessel images. However, it is still a challenging problem because of the high complexity of blood vessel branching structures. We applied preprocessing on CAM microscopic images by keeping the integrity of minor branches in the vessel structure. We then proposed an efficient way to automatically extract blood vessel centerlines based on vector tracing starting from detected seed points. Finally, all branches were coded to construct an abstract model of the branching structure, which enabled more accurate modeling for in-depth analysis. The framework was applied in quantifying Icaritin (ICT) inhibition effects on angiogenesis in a CAM model. Experimental results showed the high accuracy in blood vessel quantification and modeling compared with semimanual measurements. Meanwhile, a set of blood vessel growth indicators were extracted to provide fully automated analysis for angiogenesis assays. Further analysis proved that ICT took effect in a dose-dependent manner which could be applied in suppressing tumor blood vessel growth.

  5. Automated computational framework of blood vessel quantification in chick chorioallantoic membrane angiogenesis.

    Science.gov (United States)

    Shi, Peng; Hong, Jinsheng; Huang, Yue; Zhang, Zhenhuan; Zhang, Mei; Zhang, Lurong

    2014-01-01

    Chick chorioallantoic membrane (CAM) angiogenesis assay has been widely used for finding drugs targeting new blood vessel development in cancer research. In addition to the setup materials and protocols, laboratory findings depend on the quantification and analysis of microscopic blood vessel images. However, it is still a challenging problem because of the high complexity of blood vessel branching structures. We applied preprocessing on CAM microscopic images by keeping the integrity of minor branches in the vessel structure. We then proposed an efficient way to automatically extract blood vessel centerlines based on vector tracing starting from detected seed points. Finally, all branches were coded to construct an abstract model of the branching structure, which enabled more accurate modeling for in-depth analysis. The framework was applied in quantifying Icaritin (ICT) inhibition effects on angiogenesis in a CAM model. Experimental results showed the high accuracy in blood vessel quantification and modeling compared with semimanual measurements. Meanwhile, a set of blood vessel growth indicators were extracted to provide fully automated analysis for angiogenesis assays. Further analysis proved that ICT took effect in a dose-dependent manner which could be applied in suppressing tumor blood vessel growth. PMID:25277148

  6. Implante transcateter de valva aórtica: resultados atuais do desenvolvimento e implante de um nova prótese brasileira Transcatheter aortic valve implantation: results of the current development and implantation of a new Brazilian prosthesis

    Directory of Open Access Journals (Sweden)

    Diego Felipe Gaia

    2011-09-01

    . Minimally invasive transcatheter aortic valve implantation has emerged as an alternative, with lower morbidity and mortality. The aim of this study was clinical, safety and efficacy assessment. METHODS: Thirty-three high risk patients underwent transcatheter balloon expandable aortic valve implantation. Mean Logistic EuroScore risk was 39.30% and STS score 30.28%. Eight patients presented with dysfunctional bioprosthesis, remaining ones presented calcified aortic stenosis. Procedures were performed in a hybrid OR under fluoroscopic and echocardiography guidance. Using a left minithoracotomy the prosthesis were implanted trough the ventricular apex under rapid ventricular pacing or hemorrhagic shock. Echocardiographic and angiographic controls were performed. RESULTS: Implant was feasible in 30 cases. Three conversions occured. There was only one case of operative death. Median transvalvular aortic gradient reduced from 43.58 mmHg to 10.54 mmHg. Left ventricular function improved in the first 7 postoperative days. Paravalvular aortic regurgitation was mild and present in 30.30%. One case presented major vascular complication and another one permanent pacemaker implant. One major stroke case occurred. Overall 30-day mortality was 18.18%. CONCLUSION: The transapical implantation of catheter mounted bioprosthesis is a safe procedure with acceptable midterm results. Long term follow-up with increased sample power is mandatory in order to access hemodynamic, life quality and survival

  7. Primo Vascular System Accompanying a Blood Vessel from Tumor Tissue and a Method to Distinguish It from the Blood or the Lymph System

    Directory of Open Access Journals (Sweden)

    Jaekwan Lim

    2013-01-01

    Full Text Available A primo vessel was observed in the abdominal cavity in the lung cancer mouse model, and its function as an extra metastatic path was observed. In this work, we found a primo vessel accompanying a blood vessel emanating from a tumor in the skin. We also presented simple and efficient criteria to distinguish a primo vessel from a blood or a lymph vessel and from a nerve. The criteria for using DAPI and Phalloidin will be useful in clinical situations to find and identify the primo vessels among the blood vessels, lymph vessels, or nerves in the tissue surrounding a tumor such as a melanoma or breast cancer.

  8. Low level arsenic promotes progressive inflammatory angiogenesis and liver blood vessel remodeling in mice

    International Nuclear Information System (INIS)

    The vascular effects of arsenic in drinking water are global health concerns contributing to human disease worldwide. Arsenic targets the endothelial cells lining blood vessels, and endothelial cell activation or dysfunction may underlie the pathogenesis of both arsenic-induced vascular diseases and arsenic-enhanced tumorigenesis. The purpose of the current studies was to demonstrate that exposing mice to drinking water containing environmentally relevant levels of arsenic promoted endothelial cell dysfunction and pathologic vascular remodeling. Increased angiogenesis, neovascularization, and inflammatory cell infiltration were observed in Matrigel plugs implanted in C57BL/6 mice following 5-week exposures to 5-500 ppb arsenic [Soucy, N.V., Mayka, D., Klei, L.R., Nemec, A.A., Bauer, J.A., Barchowsky, A., 2005. Neovascularization and angiogenic gene expression following chronic arsenic exposure in mice. Cardiovasc.Toxicol 5, 29-42]. Therefore, functional in vivo effects of arsenic on endothelial cell function and vessel remodeling in an endogenous vascular bed were investigated in the liver. Liver sinusoidal endothelial cells (LSEC) became progressively defenestrated and underwent capillarization to decrease vessel porosity following exposure to 250 ppb arsenic for 2 weeks. Sinusoidal expression of PECAM-1 and laminin-1 proteins, a hallmark of capillarization, was also increased by 2 weeks of exposure. LSEC caveolin-1 protein and caveolae expression were induced after 2 weeks of exposure indicating a compensatory change. Likewise, CD45/CD68-positive inflammatory cells did not accumulate in the livers until after LSEC porosity was decreased, indicating that inflammation is a consequence and not a cause of the arsenic-induced LSEC phenotype. The data demonstrate that the liver vasculature is an early target of pathogenic arsenic effects and that the mouse liver vasculature is a sensitive model for investigating vascular health effects of arsenic

  9. Development of an accurate 3D blood vessel searching system using NIR light

    Science.gov (United States)

    Mizuno, Yoshifumi; Katayama, Tsutao; Nakamachi, Eiji

    2010-02-01

    Health monitoring system (HMS) and drug delivery system (DDS) require accurate puncture by needle for automatic blood sampling. In this study, we develop a miniature and high accurate automatic 3D blood vessel searching system. The size of detecting system is 40x25x10 mm. Our searching system use Near-Infrared (NIR) LEDs, CMOS camera modules and image processing units. We employ the stereo method for searching system to determine 3D blood vessel location. Blood vessel visualization system adopts hemoglobin's absorption characterization of NIR light. NIR LED is set behind the finger and it irradiates Near Infrared light for the finger. CMOS camera modules are set in front of the finger and it captures clear blood vessel images. Two dimensional location of the blood vessel is detected by luminance distribution of the image and its depth is calculated by the stereo method. 3D blood vessel location is automatically detected by our image processing system. To examine the accuracy of our detecting system, we carried out experiments using finger phantoms with blood vessel diameters, 0.5, 0.75, 1.0mm, at the depths, 0.5 ~ 2.0 mm, under the artificial tissue surface. Experimental results of depth obtained by our detecting system showed good agreements with given depths, and the availability of this system is confirmed.

  10. Estimation of vessel diameter and blood flow dynamics from laser speckle images

    DEFF Research Database (Denmark)

    Postnov, Dmitry D.; Tuchin, Valery V.; Sosnovtseva, Olga

    2016-01-01

    Laser speckle imaging is a rapidly developing method to study changes of blood velocity in the vascular networks. However, to assess blood flow and vascular responses it is crucial to measure vessel diameter in addition to blood velocity dynamics. We suggest an algorithm that allows for dynamical...... masking of a vessel position and measurements of it's diameter from laser speckle images. This approach demonstrates high reliability and stability....

  11. Human Blood-Vessel-Derived Stem Cells for Tissue Repair and Regeneration

    OpenAIRE

    Chien-Wen Chen; Mirko Corselli; Bruno Péault; Johnny Huard

    2012-01-01

    Multipotent stem/progenitor cells with similar developmental potentials have been independently identified from diverse human tissue/organ cultures. The increasing recognition of the vascular/perivascular origin of mesenchymal precursors suggested blood vessels being a systemic source of adult stem/progenitor cells. Our group and other laboratories recently isolated multiple stem/progenitor cell subsets from blood vessels of adult human tissues. Each of the three structural layers of blood ve...

  12. Estimation of vessel diameter and blood flow dynamics from laser speckle images

    Science.gov (United States)

    Postnov, Dmitry D.; Tuchin, Valery V.; Sosnovtseva, Olga

    2016-01-01

    Laser speckle imaging is a rapidly developing method to study changes of blood velocity in the vascular networks. However, to assess blood flow and vascular responses it is crucial to measure vessel diameter in addition to blood velocity dynamics. We suggest an algorithm that allows for dynamical masking of a vessel position and measurements of it’s diameter from laser speckle images. This approach demonstrates high reliability and stability.

  13. Prosthetic rehabilitation with an implant-supported fixed prosthesis using computer-aided design and computer-aided manufacturing dental technology for a patient with a mandibulectomy: A clinical report.

    Science.gov (United States)

    Yoon, Hyung-In; Han, Jung-Suk

    2016-02-01

    The fabrication of dental prostheses with computer-aided design and computer-aided manufacturing shows acceptable marginal fits and favorable treatment outcomes. This clinical report describes the management of a patient who had undergone a mandibulectomy and received an implant-supported fixed prosthesis by using additive manufacturing for the framework and subtractive manufacturing for the monolithic zirconia restorations. PMID:26518985

  14. Development of Automatic 3D Blood Vessel Search and Automatic Blood Sampling System by Using Hybrid Stereo-Autofocus Method

    OpenAIRE

    Eiji Nakamachi; Yusuke Morita; Yoshifumi Mizuno

    2012-01-01

    We developed an accurate three-dimensional blood vessel search (3D BVS) system and an automatic blood sampling system. They were implemented into a point-of-care system designed for medical care, installed in a portable self-monitoring blood glucose (SMBG) device. The system solves problems of human error caused by complicated manual operations of conventional SMBG devices. We evaluated its accuracy of blood-vessel position detection. The 3D BVS system uses near-infrared (NIR) light imaging a...

  15. A computational model predicting disruption of blood vessel development.

    Directory of Open Access Journals (Sweden)

    Nicole Kleinstreuer

    2013-04-01

    Full Text Available Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis and remodeling (angiogenesis come from a variety of biological pathways linked to endothelial cell (EC behavior, extracellular matrix (ECM remodeling and the local generation of chemokines and growth factors. Simulating these interactions at a systems level requires sufficient biological detail about the relevant molecular pathways and associated cellular behaviors, and tractable computational models that offset mathematical and biological complexity. Here, we describe a novel multicellular agent-based model of vasculogenesis using the CompuCell3D (http://www.compucell3d.org/ modeling environment supplemented with semi-automatic knowledgebase creation. The model incorporates vascular endothelial growth factor signals, pro- and anti-angiogenic inflammatory chemokine signals, and the plasminogen activating system of enzymes and proteases linked to ECM interactions, to simulate nascent EC organization, growth and remodeling. The model was shown to recapitulate stereotypical capillary plexus formation and structural emergence of non-coded cellular behaviors, such as a heterologous bridging phenomenon linking endothelial tip cells together during formation of polygonal endothelial cords. Molecular targets in the computational model were mapped to signatures of vascular disruption derived from in vitro chemical profiling using the EPA's ToxCast high-throughput screening (HTS dataset. Simulating the HTS data with the cell-agent based model of vascular development predicted adverse effects of a reference anti-angiogenic thalidomide analog, 5HPP-33, on in vitro angiogenesis with respect to both concentration-response and morphological consequences. These findings support the utility of cell agent-based models for simulating a

  16. Computational Fluid Dynamics Analysis of Pulsatile Blood Flow Behavior in Modelled Stenosed Vessels with Different Severities

    OpenAIRE

    Mohsen Mehrabi; Saeed Setayeshi

    2012-01-01

    This study focuses on the behavior of blood flow in the stenosed vessels. Blood is modelled as an incompressible non-Newtonian fluid which is based on the power law viscosity model. A numerical technique based on the finite difference method is developed to simulate the blood flow taking into account the transient periodic behaviour of the blood flow in cardiac cycles. Also, pulsatile blood flow in the stenosed vessel is based on the Womersley model, and fluid flow in the lumen region is gove...

  17. Do Haematophagous Bugs Assess Skin Surface Temperature to Detect Blood Vessels?

    OpenAIRE

    Raquel A Ferreira; Lazzari, Claudio R.; Marcelo G. Lorenzo; Pereira, Marcos H

    2007-01-01

    Background It is known that some blood-sucking insects have the ability to reach vessels under the host skin with their mouthparts to feed blood from inside them. However, the process by which they locate these vessels remains largely unknown. Less than 5% of the skin is occupied by blood vessels and thus, it is not likely that insects rely on a “random search strategy”, since it would increase the probability of being killed by their hosts. Indeed, heterogeneities along the skin surface migh...

  18. Malfunctioned and Fractured Penile Prosthesis Caused by Cross Placement: Case Report

    Directory of Open Access Journals (Sweden)

    Nihat Karakoyunlu

    2015-05-01

    Full Text Available Penile prosthesis is a functional option for patients who have erectile dysfunction after failed medical and intracavernosal treatments. Malleable penile prosthesis is a good alternative. Penile prosthesis implantation is a surgical process. Seldomly complications occur. In this study we presented a 61 y old man who has malfunctioned and broken penile prosthesis due to cross implantation.

  19. Malfunctioned and Fractured Penile Prosthesis Caused by Cross Placement: Case Report

    OpenAIRE

    Nihat Karakoyunlu; Sercan Sarı; Harun Ozdemir; Hikmet Topaloglu; Ugur Ozok; Levent Sagnak; Hamit Ersoy

    2015-01-01

    Penile prosthesis is a functional option for patients who have erectile dysfunction after failed medical and intracavernosal treatments. Malleable penile prosthesis is a good alternative. Penile prosthesis implantation is a surgical process. Seldomly complications occur. In this study we presented a 61 y old man who has malfunctioned and broken penile prosthesis due to cross implantation.

  20. Blood compatibility of artificial blood vessels probed by infrared spectroscopic imaging

    Science.gov (United States)

    Steiner, Gerald; Maitz, Manfred; Tunc, Sibel; Salzer, Reiner

    2006-02-01

    The determination of protein structure and function plays an important role in biomedical and biochemical research. Common techniques that give full structural information do not permit in-vivo measurements. Infrared spectroscopy has a sufficient sensitivity to examine the structure of proteins solution under in-situ conditions and even on surfaces. However, measurements at few spots on the surface are not suitable to find out the blood compatibility of the protein layer, because the changes in conformation occur often in small domains. Here we report on the investigations of adsorbed fibrinogen with FTIR imaging. FTIR imaging permits an identification of coagulation spots in the micrometer range and the identification of coagulation spots on the implant material.

  1. A functional requirement for astroglia in promoting blood vessel development in the early postnatal brain.

    Directory of Open Access Journals (Sweden)

    Shang Ma

    Full Text Available Astroglia are a major cell type in the brain and play a key role in many aspects of brain development and function. In the adult brain, astrocytes are known to intimately ensheath blood vessels and actively coordinate local neural activity and blood flow. During development of the neural retina, blood vessel growth follows a meshwork of astrocytic processes. Several genes have also been implicated in retinal astrocytes for regulating vessel development. This suggests a role of astrocytes in promoting angiogenesis throughout the central nervous system. To determine the roles that astrocytes may play during brain angiogenesis, we employ genetic approaches to inhibit astrogliogenesis during perinatal corticogenesis and examine its effects on brain vessel development. We find that conditional deletion from glial progenitors of orc3, a gene required for DNA replication, dramatically reduces glial progenitor cell number in the subventricular zone and astrocytes in the early postnatal cerebral cortex. This, in turn, results in severe reductions in both the density and branching frequency of cortical blood vessels. Consistent with a delayed growth but not regression of vessels, we find neither significant net decreases in vessel density between different stages after normalizing for cortical expansion nor obvious apoptosis of endothelial cells in these mutants. Furthermore, concomitant with loss of astroglial interactions, we find increased endothelial cell proliferation, enlarged vessel luminal size as well as enhanced cytoskeletal gene expression in pericytes, which suggests compensatory changes in vascular cells. Lastly, we find that blood vessel morphology in mutant cortices recovers substantially at later stages, following astrogliosis. These results thus implicate a functional requirement for astroglia in promoting blood vessel growth during brain development.

  2. Blood vessel growth blocker may treat AIDS-related Kaposi’s sarcoma

    Science.gov (United States)

    Patients with an AIDS-associated cancer, Kaposi's sarcoma (KS), showed improvement after receiving the combination of bevacizumab, a cancer drug that blocks the growth of new blood vessels, and highly active antiretroviral therapy (HAART).

  3. ENHANCED ABSORPTION OF MILLIMETER WAVE ENERGY IN MURINE SUBCUTANEOUS BLOOD VESSELS

    OpenAIRE

    Alekseev, Stanislav I.; Ziskin, Marvin C.

    2011-01-01

    The aim of the present study was to determine millimeter wave (MMW) absorption by blood vessels traversing the subcutaneous fat layer of murine skin. Most calculations were performed using the finite-difference time-domain (FDTD) technique. We used two types of models: (1) a rectangular block of multilayer tissue with blood vessels traversing the fat layer and (2) cylindrical models with circular and elliptical cross sections simulating the real geometry of murine limbs. We found that the spe...

  4. Assessing the quality of angiographic display of brain blood vessels aneurysms compared to intraoperative state

    OpenAIRE

    Nikolić Igor M.; Tasić Goran M.; Jovanović Vladimir T.; Repac Nikola R.; Janićijević Aleksandar M.; Šćepanović Vuk D.; Nestorović Branislav D.

    2013-01-01

    Background/Aim. Aneurysms in brain blood vessels are expanding bags composed of a neck, body and fundus. Clear visibility of the neck, the position of the aneurysm and surrounding structures are necessary for a proper choice of methods for excluding the aneurysm from the circulation. The aim of this study was to evaluate the reliability of spatial reconstruction of blood vessels of the brain based on the original software for 3D reconstruction of the equipment manufacturer and a persona...

  5. Detection of retinal blood vessel changes in multiple sclerosis with optical coherence tomography

    OpenAIRE

    Bhaduri, Basanta; Nolan, Ryan M.; Shelton, Ryan L.; Pilutti, Lara A.; Motl, Robert W.; Moss, Heather E.; Pula, John H.; Boppart, Stephen A.

    2016-01-01

    Although retinal vasculitis is common in multiple sclerosis (MS), it is not known if MS is associated with quantitative abnormalities in retinal blood vessels (BVs). Optical coherence tomography (OCT) is suitable for examining the integrity of the anterior visual pathways in MS. In this paper we have compared the size and number of retinal blood vessels in patients with MS, with and without a history of optic neuritis (ON), and control subjects from the cross-sectional retinal images from OCT...

  6. Visualisation of blood and lymphatic vessels with increasing exposure time of the detector

    Energy Technology Data Exchange (ETDEWEB)

    Kalchenko, V V; Kuznetsov, Yu L; Meglinski, I V

    2013-07-31

    We describe the laser speckle contrast method for simultaneous noninvasive imaging of blood and lymphatic vessels of living organisms, based on increasing detector exposure time. In contrast to standard methods of fluorescent angiography, this technique of vascular bed imaging and lymphatic and blood vessel demarcation does not employ toxic fluorescent markers. The method is particularly promising with respect to the physiology of the cardiovascular system under in vivo conditions. (laser applications in biology and medicine)

  7. CFD Application in Implantable Rotary Blood Pump Design and Validation

    Institute of Scientific and Technical Information of China (English)

    YI Qian

    2004-01-01

    Implantable rotary blood pump (IRBP) has been promoted to the stage of clinical trial. This paper introduces a unique IRBP without a shaft. Instead of using thrombogenic pivots or power-drawing magnetic suspension, impeller is supported hydrodynamically when rotating, by lubrication flows in the thin spaces between itself and the pump body. To this end, the flow is very difficult to be measured using usual laboratory equipments. Therefore, computational fluid dynamics (CFD) has been applied as an important tool in the IRBP design and its validation procedure. Several CFD results such as pump performance improvement, unsteady hydraulic dynamic analysis, biocapability prediction, validation and verification (V&V), and flow visualization have been performed.

  8. CFD Application in Implantable Rotary Blood Pump Design and Validation

    Institute of Scientific and Technical Information of China (English)

    YIQian

    2004-01-01

    Implantable rotary blood pump (IRBP) has been promoted to the stage of clinical trial. This paper introduces a unique IRBP without a.shaft. Instead of using thrombogenic pivots or power-drawing magnetic suspension, impeller is supported hydrodynamically when rotating, by lubrication flows in the thin spaces between itself and the pump body. To this end, the flow is very difficult to be measured using usual laboratory equipments. Therefore, computational fluid dynamics (CFD) has been applied as an important tool in the IRBP design and its validation procedure. Several CFD results such as pump performance improvement, unsteady hydraulic dynamic analysis, biocapability prediction, validation and verification (V&V), and flow visualization have been performed.

  9. Smooth Muscle Cell Alignment and Phenotype Control by Melt Spun Polycaprolactone Fibers for Seeding of Tissue Engineered Blood Vessels

    Directory of Open Access Journals (Sweden)

    Animesh Agrawal

    2015-01-01

    Full Text Available A method has been developed to induce and retain a contractile phenotype for vascular smooth muscle cells, as the first step towards the development of a biomimetic blood vessel construct with minimal compliance mismatch. Melt spun PCL fibers were deposited on a mandrel to form aligned fibers of 10 μm in diameter. The fibers were bonded into aligned arrangement through dip coating in chitosan solution. This formed a surface of parallel grooves, 10 μm deep by 10 μm across, presenting a surface layer of chitosan to promote cell surface interactions. The aligned fiber surface was used to culture cells present in the vascular wall, in particular fibroblasts and smooth muscle cells. This topography induced “surface guidance” over the orientation of the cells, which adopted an elongated spindle-like morphology, whereas cells on the unpatterned control surface did not show such orientation, assuming more rhomboid shapes. The preservation of VSMC contractile phenotype on the aligned scaffold was demonstrated by the retention of α-SMA expression after several days of culture. The effect was assessed on a prototype vascular graft prosthesis fabricated from polylactide caprolactone; VSMCs aligned longitudinally along a fiberless tube, whereas, for the aligned fiber coated tubes, the VSMCs aligned in the required circumferential orientation.

  10. Growth and Remodeling in Blood Vessels Studied In Vivo With Fractal Analysis

    Science.gov (United States)

    Parsons-Wingerter, Patricia A.

    2003-01-01

    Every cell in the human body must reside in close proximity to a blood vessel (within approximately 200 mm) because blood vessels provide the oxygen, metabolite, and fluid exchanges required for cellular existence. The growth and remodeling of blood vessels are required to support the normal physiology of embryonic development, reproductive biology, wound healing and adaptive remodeling to exercise, as well as abnormal tissue change in diseases such as cancer, diabetes, and coronary heart disease. Cardiovascular and hemodynamic (blood flow dynamics) alterations experienced by astronauts during long-term spaceflight, including orthostatic intolerance, fluid shifts in the body, and reduced numbers of red (erythrocyte) and white (immune) blood cells, are identified as risk factors of very high priority in the NASA task force report on risk reduction for human spaceflight, the "Critical Path Roadmap."

  11. Trigeminal origin or B-preprotachykinin products in feline pial blood vessels

    International Nuclear Information System (INIS)

    A specific and sensitive radioimmunoassay measured the presence of immunoreactive neurokinin A within feline and human pial arteries. Immunoreactivity exhibited a retention time identical to that of synthetic peptide when acid extracts from feline and human blood vessels were subjected to reverse-phase high-performance liquid chromatography. As shown previously for substance P, levels of immunoreactive neurokinin A decreased significantly in the vessels from the ipsilateral rostral circle of Willis l9-24 days following unilateral trigeminal ganglionectomy. Hence, trigeminal projections to cerebral blood vessels contain both products of B-preprotachykinin mRNA. (author)

  12. Application of the Carreau viscosity model to the oscillatory flow in blood vessels

    Science.gov (United States)

    Tabakova, Sonia; Kutev, Nikolay; Radev, Stefan

    2015-11-01

    When studying the oscillatory flow in different types of blood vessels it is very important to know what type of the blood viscosity model has to be used. In general the blood viscosity is defined as a shear-thinning liquid, for which there exist different shear-dependent models, for example the Carreau model, which represents the viscosity as a non-linear function of the shear-rate. In some cases, however, the blood viscosity could be regarded as constant, i.e., the blood is treated as Newtonian fluid. The aim of the present work is to show theoretically and numerically some approximate limits of the Newtonian model application, when the blood vessel is assumed as a 2D straight tube. The obtained results are in agreement with other authors' numerical results based on similar blood viscosity models.

  13. Vascular bursts enhance permeability of tumour blood vessels and improve nanoparticle delivery

    Science.gov (United States)

    Matsumoto, Yu; Nichols, Joseph W.; Toh, Kazuko; Nomoto, Takahiro; Cabral, Horacio; Miura, Yutaka; Christie, R. James; Yamada, Naoki; Ogura, Tadayoshi; Kano, Mitsunobu R.; Matsumura, Yasuhiro; Nishiyama, Nobuhiro; Yamasoba, Tatsuya; Bae, You Han; Kataoka, Kazunori

    2016-06-01

    Enhanced permeability in tumours is thought to result from malformed vascular walls with leaky cell-to-cell junctions. This assertion is backed by studies using electron microscopy and polymer casts that show incomplete pericyte coverage of tumour vessels and the presence of intercellular gaps. However, this gives the impression that tumour permeability is static amid a chaotic tumour environment. Using intravital confocal laser scanning microscopy we show that the permeability of tumour blood vessels includes a dynamic phenomenon characterized by vascular bursts followed by brief vigorous outward flow of fluid (named ‘eruptions’) into the tumour interstitial space. We propose that ‘dynamic vents’ form transient openings and closings at these leaky blood vessels. These stochastic eruptions may explain the enhanced extravasation of nanoparticles from the tumour blood vessels, and offer insights into the underlying distribution patterns of an administered drug.

  14. Evaluation of immunohistochemical markers of lymphatic and blood vessels in canine mammary tumours.

    Science.gov (United States)

    Sleeckx, N; Van Brantegem, L; Fransen, E; Van den Eynden, G; Casteleyn, C; Veldhuis Kroeze, E; Van Ginneken, C

    2013-05-01

    Canine mammary tumours (CMTs) are the most common neoplasms in intact female dogs. Bitches with spontaneously arising CMTs represent a promising animal model for human breast cancer research. The aim of the present study was to develop an immunohistochemical protocol for the identification of blood and lymphatic vessels in CMTs. Antibodies specific for human lymphatic vessels (prox-1, lyve-1, podoplanin and D2-40) and blood vessels (von Willebrand factor [vWf], CD31 and CD34) were utilized. Serial sections of 18 samples (eight samples of normal canine mammary tissue, five benign and five malignant CMTs) were examined. Antibodies specific for podoplanin, D2-40 and CD34 showed no immunoreactivity with canine tissue. Prox-1 and CD31 were determined to be the most suitable markers for lymphatic and blood vessels, respectively. PMID:23123127

  15. Effect of the number of abutments on biomechanics of Branemark prosthesis with straight and tilted distal implants

    OpenAIRE

    Marcos Michelon Naconecy; Tomás Geremia; André Cervieri; Eduardo Rolim Teixeira; Rosemary Sadami Shinkai

    2010-01-01

    OBJECTIVE: This study aimed to evaluate the bending moments, and compressive and tensile forces in implant-supported prostheses with three, four or five abutments. MATERIAL AND METHODS: Ten Pd-Ag frameworks were tested over two master models with: 1) parallel vertical implants, and 2) tilted distal implants. Strain gauges were fixed on the abutments of each master model to measure the deformation when a static load of 50 N was applied on the cantilever (15 mm). The deformation values were mea...

  16. Computational Fluid Dynamics Analysis of Pulsatile Blood Flow Behavior in Modelled Stenosed Vessels with Different Severities

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrabi

    2012-01-01

    Full Text Available This study focuses on the behavior of blood flow in the stenosed vessels. Blood is modelled as an incompressible non-Newtonian fluid which is based on the power law viscosity model. A numerical technique based on the finite difference method is developed to simulate the blood flow taking into account the transient periodic behaviour of the blood flow in cardiac cycles. Also, pulsatile blood flow in the stenosed vessel is based on the Womersley model, and fluid flow in the lumen region is governed by the continuity equation and the Navier-Stokes equations. In this study, the stenosis shape is cosine by using Tu and Devil model. Comparing the results obtained from three stenosed vessels with 30%, 50%, and 75% area severity, we find that higher percent-area severity of stenosis leads to higher extrapressure jumps and higher blood speeds around the stenosis site. Also, we observe that the size of the stenosis in stenosed vessels does influence the blood flow. A little change on the cross-sectional value makes vast change on the blood flow rate. This simulation helps the people working in the field of physiological fluid dynamics as well as the medical practitioners.

  17. Tracing retinal blood vessels by matrix-forest theorem of directed graphs.

    Science.gov (United States)

    Cheng, Li; De, Jaydeep; Zhang, Xiaowei; Lin, Feng; Li, Huiqi

    2014-01-01

    This paper aims to trace retinal blood vessel trees in fundus images. This task is far from being trivial as the crossover of vessels are commonly encountered in image-based vessel networks. Meanwhile it is often crucial to separate the vessel tree structures in applications such as diabetic retinopathy analysis. In this work, a novel directed graph based approach is proposed to cast the task as label propagation over directed graphs, such that the graph is to be partitioned into disjoint sub-graphs, or equivalently, each of the vessel trees is traced and separated from the rest of the vessel network. Then the tracing problem is addressed by making novel usage of the matrix-forest theorem in algebraic graph theory. Empirical experiments on synthetic as well as publicly available fundus image datasets demonstrate the applicability of our approach. PMID:25333171

  18. Tissue-Engineered Blood Vessels in Pediatric Cardiac Surgery

    OpenAIRE

    Shinoka, Toshiharu; Breuer, Christopher

    2008-01-01

    Pediatric cardiovascular surgeons often encounter patients requiring surgical intervention utilizing foreign materials to repair complex lesions. However, the materials that are commonly used lack growth potential, and long-term results have revealed several material-related failures, such as stenosis, thromboembolization, calcium deposition, and risk of infection. To solve these problems, in particular for children who require the implantation of dynamic material with growth potential, we so...

  19. HIFU procedures at moderate intensities-effect of large blood vessels

    International Nuclear Information System (INIS)

    A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams

  20. HIFU procedures at moderate intensities-effect of large blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Hariharan, P [Mechanical, Industrial, and Nuclear Engineering Department, University of Cincinnati, Cincinnati, OH (United States); Myers, M R [Division of Solid and Fluid Mechanics, Center for Devices and Radiological Health, US Food and Drug Administration, 10903 New Hampshire Avenue, Building 62, Silver Spring, MD 20993-0002 (United States); Banerjee, R K [Mechanical, Industrial, and Nuclear Engineering Department, University of Cincinnati, Cincinnati, OH (United States)

    2007-07-21

    A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams.

  1. HIFU procedures at moderate intensities--effect of large blood vessels.

    Science.gov (United States)

    Hariharan, P; Myers, M R; Banerjee, R K

    2007-06-21

    A three-dimensional computational model is presented for studying the efficacy of high-intensity focused ultrasound (HIFU) procedures targeted near large blood vessels. The analysis applies to procedures performed at intensities below the threshold for cavitation, boiling and highly nonlinear propagation, but high enough to increase tissue temperature a few degrees per second. The model is based upon the linearized KZK equation and the bioheat equation in tissue. In the blood vessel the momentum and energy equations are satisfied. The model is first validated in a tissue phantom, to verify the absence of bubble formation and nonlinear effects. Temperature rise and lesion-volume calculations are then shown for different beam locations and orientations relative to a large vessel. Both single and multiple ablations are considered. Results show that when the vessel is located within about a beam width (few mm) of the ultrasound beam, significant reduction in lesion volume is observed due to blood flow. However, for gaps larger than a beam width, blood flow has no major effect on the lesion formation. Under the clinically representative conditions considered, the lesion volume is reduced about 40% (relative to the no-flow case) when the beam is parallel to the blood vessel, compared to about 20% for a perpendicular orientation. Procedures involving multiple ablation sites are affected less by blood flow than single ablations. The model also suggests that optimally focused transducers can generate lesions that are significantly larger (>2 times) than the ones produced by highly focused beams. PMID:17664556

  2. An experimental system for the study of ultrasound exposure of isolated blood vessels

    International Nuclear Information System (INIS)

    An experimental system designed for the study of the effects of diagnostic or therapeutic ultrasound exposure on isolated blood vessels in the presence or absence of intraluminal contrast agent is described. The system comprised several components. A microscope was used to monitor vessel size (and thus vessel functionality), and potential leakage of intraluminal 70 kDa FITC-dextran fluorescence marker. A vessel chamber allowed the mounting of an isolated vessel whilst maintaining its viability, with pressure regulation for the control of intraluminal pressure and induction of flow for the infusion of contrast microbubbles. A fibre-optic hydrophone sensor mounted on the vessel chamber using a micromanipulator allowed pre-exposure targeting of the vessel to within 150 µm, and monitoring of acoustic cavitation emissions during exposures. Acoustic cavitation was also detected using changes in the ultrasound drive voltage and by detection of audible emissions using a submerged microphone. The suitability of this system for studying effects in the isolated vessel model has been demonstrated using a pilot study of 6 sham exposed and 18 high intensity focused ultrasound exposed vessels, with or without intraluminal contrast agent (SonoVue) within the vessels. (paper)

  3. Blood vessel extraction and optic disc removal using curvelet transform and kernel fuzzy c-means.

    Science.gov (United States)

    Kar, Sudeshna Sil; Maity, Santi P

    2016-03-01

    This paper proposes an automatic blood vessel extraction method on retinal images using matched filtering in an integrated system design platform that involves curvelet transform and kernel based fuzzy c-means. Since curvelet transform represents the lines, the edges and the curvatures very well and in compact form (by less number of coefficients) compared to other multi-resolution techniques, this paper uses curvelet transform for enhancement of the retinal vasculature. Matched filtering is then used to intensify the blood vessels' response which is further employed by kernel based fuzzy c-means algorithm that extracts the vessel silhouette from the background through non-linear mapping. For pathological images, in addition to matched filtering, Laplacian of Gaussian filter is also employed to distinguish the step and the ramp like signal from that of vessel structure. To test the efficacy of the proposed method, the algorithm has also been applied to images in presence of additive white Gaussian noise where the curvelet transform has been used for image denoising. Performance is evaluated on publicly available DRIVE, STARE and DIARETDB1 databases and is compared with the large number of existing blood vessel extraction methodologies. Simulation results demonstrate that the proposed method is very much efficient in detecting the long and the thick as well as the short and the thin vessels with an average accuracy of 96.16% for the DRIVE and 97.35% for the STARE database wherein the existing methods fail to extract the tiny and the thin vessels. PMID:26848729

  4. Prevent Diabetes Problems: Keep Your Heart and Blood Vessels Healthy

    Science.gov (United States)

    ... Research Training & Career Development Grant programs for students, postdocs, and faculty Research at NIDDK Labs, faculty, and ... Top ] What can I do to prevent or control PAD? Don't smoke. Keep blood glucose and ...

  5. Prevent Diabetes Problems: Keep Your Heart and Blood Vessels Healthy

    Science.gov (United States)

    ... Association of Diabetes Educators Academy of Nutrition and Dietetics National Heart Lung and Blood Institute American Diabetes ... for Scientists Current Funding Opportunities Funded Grants & Grant History Funding Process Research Programs & Contacts Research Training & Career ...

  6. Aging changes in the heart and blood vessels

    Science.gov (United States)

    ... Some of the things that make your heart work harder are: Certain medicines Emotional stress Physical exertion Illness Infections Injuries COMMON PROBLEMS Angina (chest pain caused by temporarily reduced blood flow to the ...

  7. Stretch due to Penile Prosthesis Reservoir Migration

    OpenAIRE

    Baten, E.; Vandewalle, T.; van Renterghem, K.

    2016-01-01

    A 43-year old patient presented to the emergency department with stretch, due to impossible deflation of the penile prosthesis, 4 years after successful implant. A CT-scan showed migration of the reservoir to the left rectus abdominis muscle. Refilling of the reservoir was inhibited by muscular compression, causing stretch. Removal and replacement of the reservoir was performed, after which the prosthesis was well-functioning again. Migration of the penile prosthesis reservoir is extremely ra...

  8. Development of a Flexible Implantable Sensor for Postoperative Monitoring of Blood Flow

    OpenAIRE

    Cannata, Jonathan M.; Chilipka, Thomas; Yang, Hao-Chung; Han, Sukgu; Ham, Sung W.; Rowe, Vincent L.; Weaver, Fred A; Shung, K. Kirk; Vilkomerson, David

    2012-01-01

    We have developed a blood flow measurement system using Doppler ultrasound flow sensors fabricated of thin and flexible piezoelectric-polymer films. These flow sensors can be wrapped around a blood vessel and accurately measure flow. The innovation that makes this flow sensor possible is the diffraction-grating transducer. A conventional transducer produces a sound beam perpendicular to its face; therefore, when placed on the wall of a blood vessel, the Doppler shift in the backscattered ultr...

  9. Primo Vascular System Accompanying a Blood Vessel from Tumor Tissue and a Method to Distinguish It from the Blood or the Lymph System

    OpenAIRE

    Jaekwan Lim; Sungwoo Lee; Zhendong Su; Hong Bae Kim; Jung Sun Yoo; Kwang-Sup Soh; Sungchul Kim; Yeon Hee Ryu

    2013-01-01

    A primo vessel was observed in the abdominal cavity in the lung cancer mouse model, and its function as an extra metastatic path was observed. In this work, we found a primo vessel accompanying a blood vessel emanating from a tumor in the skin. We also presented simple and efficient criteria to distinguish a primo vessel from a blood or a lymph vessel and from a nerve. The criteria for using DAPI and Phalloidin will be useful in clinical situations to find and identify the primo vessels among...

  10. Collagen-based scaffolds for tissue engineering of small-diameter blood vessels

    OpenAIRE

    Buttafoco, Laura

    2005-01-01

    Atherosclerotic vascular disease, including peripheral and coronary artery disease, is the main cause of morbidity and mortality in the Western society. Although synthetic blood vessel prostheses are successfully being used for large-diameter vascular reconstructions, until now no functional small-diameter (< 6 mm) artificial vascular graft is available. Autologous veins and arteries are currently being used as vessel substitutes, but limitations in arteries supply and compliance mismatch are...

  11. Aging changes in the heart and blood vessels

    Science.gov (United States)

    ... for treating high blood pressure, high cholesterol or diabetes. Reduce or stop smoking. Men between the ages of 65 to 75 who have ever smoked should be screened for aneurysms in their abdominal aorta. Get more exercise: Exercise may help prevent obesity, ...

  12. 21 CFR 872.3950 - Glenoid fossa prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Glenoid fossa prosthesis. 872.3950 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3950 Glenoid fossa prosthesis. (a) Identification. A glenoid fossa prosthesis is a device that is intended to be implanted in the...

  13. 21 CFR 872.3960 - Mandibular condyle prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mandibular condyle prosthesis. 872.3960 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3960 Mandibular condyle prosthesis. (a) Identification. A mandibular condyle prosthesis is a device that is intended to be implanted in the human jaw...

  14. 21 CFR 870.3450 - Vascular graft prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vascular graft prosthesis. 870.3450 Section 870... prosthesis. (a) Identification. A vascular graft prosthesis is an implanted device intended to repair... Prostheses 510(k) Submissions.”...

  15. 21 CFR 888.3025 - Passive tendon prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Passive tendon prosthesis. 888.3025 Section 888...) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3025 Passive tendon prosthesis. (a) Identification. A passive tendon prosthesis is a device intended to be implanted made of silicon elastomer or...

  16. The efficiency of laser radiation absorption by hemoglobin and oxyhemoglobin in the skin blood vessels

    International Nuclear Information System (INIS)

    The results of the investigation of the efficiency of light absorption by oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb) in cutaneous blood vessels in dependence on the radiation wavelength and the optical properties of the tissue is presented. Using the Kubelka - Munk optical model of the tissue the spectral dependence of the efficiency of laser interaction both on HbO2 and Hb of blood vessels at different depths of the tissue layer are calculated. The obtained results show that for blood vessels located in tissue up to a depth of 2500 μm the efficiency of laser radiation absorption follows the shape of the Q -absorption bands of HbO2 and Hb

  17. Mathematical modelling for trajectories of magnetic nanoparticles in a blood vessel under magnetic field

    International Nuclear Information System (INIS)

    A mathematical model is developed to describe the trajectories of a cluster of magnetic nanoparticles in a blood vessel for the application of magnetic drug targeting (MDT). The magnetic nanoparticles are injected into a blood vessel upstream from a malignant tissue and are captured at the tumour site with help of an applied magnetic field. The applied field is produced by a rare earth cylindrical magnet positioned outside the body. All forces expected to significantly affect the transport of nanoparticles were incorporated, including magnetization force, drag force and buoyancy force. The results show that particles are slow down and captured under the influence of magnetic force, which is responsible to attract the magnetic particles towards the magnet. It is optimized that all particles are captured either before or at the centre of the magnet (z≤0) when blood vessel is very close proximity to the magnet (d=2.5 cm). However, as the distance between blood vessel and magnet (d) increases (above 4.5 cm), the magnetic nanoparticles particles become free and they flow away down the blood vessel. Further, the present model results are validated by the simulations performed using the finite element based COMSOL software. - Highlights: • A mathematical model is developed to describe the trajectories of magnetic nanoparticles. • The dominant magnetic, drag and buoyancy forces are considered. • All particles are captured when distance between blood vessel and magnet (d) is up to 4.5 cm. • Further increase in d value (above 4.5 cm) results the free movement of magnetic particles

  18. Do haematophagous bugs assess skin surface temperature to detect blood vessels?

    Directory of Open Access Journals (Sweden)

    Raquel A Ferreira

    Full Text Available BACKGROUND: It is known that some blood-sucking insects have the ability to reach vessels under the host skin with their mouthparts to feed blood from inside them. However, the process by which they locate these vessels remains largely unknown. Less than 5% of the skin is occupied by blood vessels and thus, it is not likely that insects rely on a "random search strategy", since it would increase the probability of being killed by their hosts. Indeed, heterogeneities along the skin surface might offer exploitable information for guiding insect's bites. METHODOLOGY/PRINCIPAL FINDINGS: We tested whether the bug Rhodnius prolixus can evaluate temperature discontinuities along the body surface in order to locate vessels before piercing the host skin. When placed over a rabbit ear, the bug's first bites were mostly directed towards the main vessels. When insects were confronted to artificial linear heat sources presenting a temperature gradient against the background, most bites were directly addressed to the warmer linear source, notwithstanding the temperature of both, the source and the background. Finally, tests performed using uni- and bilaterally antennectomized insects revealed that the bilateral integration of thermal inputs from both antennae is necessary for precisely directing bites. CONCLUSIONS/SIGNIFICANCE: R. prolixus may be able to exploit the temperature differences observed over the skin surface to locate blood vessles. Bugs bite the warmest targets regardless of the target/background temperatures, suggesting that they do not bite choosing a preferred temperature, but select temperature discontinuities along the skin. This strategy seems to be an efficient one for finding blood vessels within a wide temperature range, allowing finding them on different hosts, as well as on different areas of the host body. Our study also adds new insight about the use of antennal thermal inputs by blood sucking bugs.

  19. Mathematical modelling for trajectories of magnetic nanoparticles in a blood vessel under magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Shashi, E-mail: shashisharma1984@gmail.com; Katiyar, V.K.; Singh, Uaday

    2015-04-01

    A mathematical model is developed to describe the trajectories of a cluster of magnetic nanoparticles in a blood vessel for the application of magnetic drug targeting (MDT). The magnetic nanoparticles are injected into a blood vessel upstream from a malignant tissue and are captured at the tumour site with help of an applied magnetic field. The applied field is produced by a rare earth cylindrical magnet positioned outside the body. All forces expected to significantly affect the transport of nanoparticles were incorporated, including magnetization force, drag force and buoyancy force. The results show that particles are slow down and captured under the influence of magnetic force, which is responsible to attract the magnetic particles towards the magnet. It is optimized that all particles are captured either before or at the centre of the magnet (z≤0) when blood vessel is very close proximity to the magnet (d=2.5 cm). However, as the distance between blood vessel and magnet (d) increases (above 4.5 cm), the magnetic nanoparticles particles become free and they flow away down the blood vessel. Further, the present model results are validated by the simulations performed using the finite element based COMSOL software. - Highlights: • A mathematical model is developed to describe the trajectories of magnetic nanoparticles. • The dominant magnetic, drag and buoyancy forces are considered. • All particles are captured when distance between blood vessel and magnet (d) is up to 4.5 cm. • Further increase in d value (above 4.5 cm) results the free movement of magnetic particles.

  20. Transient Non-Newtonian Blood Flow under Magnetic Targeting Drug Delivery in an Aneurysm Blood Vessel with Porous Walls

    Science.gov (United States)

    Alimohamadi, Haleh; Imani, Mohsen

    2014-11-01

    The present investigation deals with numerical solution of blood flow patterns through an aneurysm artery under the applied magnetic field. Transient extended Navier-Stokes, Brinkman, continuity, and heat conduction equations govern this phenomenon and unsteady pulsatile inlet velocity varies by human heart-beating frequency. Our simulation demonstrates applying 105 magnetic field intensity (MnF) to recirculate flow and increase fluid flux and maximum blood temperature by 62.5x and 3.5%, respectively, in the aneurysm region. It is also shown that the vessel's wall porosity plays an important role in magnetic targeting of drug delivery performance, as this parameter can noticeably change maximum blood temperature and pressure.

  1. Inclusion body myositis, muscle blood vessel and cardiac amyloidosis, and transthyretin Val122Ile allele.

    Science.gov (United States)

    Askanas, V; Engel, W K; Alvarez, R B; Frangione, B; Ghiso, J; Vidal, R

    2000-04-01

    Typical of sporadic inclusion body myositis muscle biopsies are vacuolated muscle fibers containing intracellular amyloid deposits and accumulations of "Alzheimer-characteristic" proteins. There is no muscle blood vessel or cardiac amyloidosis. We report on a 70-year-old African-American man homozygous for the transthyretin Val122Ile allele who has both sporadic inclusion body myositis and cardiac amyloidosis. His unique pathological features included transthyretin immunoreactivity in prominent muscle blood vessel amyloid and congophilic amyloid deposits within vacuolated muscle fibers. PMID:10762172

  2. Negative Pressure Wound Therapy - Mechanisms of Action and Protecting Exposed Blood Vessels in the Wound Bed

    OpenAIRE

    Anesäter, Erik

    2015-01-01

    NPWT has recently been associated with severe complications and bleeding when used in wounds with exposed blood vessels. The aims of this work were to investigate the mechanisms of action of NPWT and to explore the possibility of using thin plastic discs to protect exposed blood vessels in the wound bed during NPWT. Three different kinds of wounds were created in pigs: 6 cm and 10 cm diameter circular defect wounds on the back and 6 cm incision wounds in the groin, exposing the...

  3. How to explore the effects of sex hormone on blood vessels

    Institute of Scientific and Technical Information of China (English)

    Sun Mei-li; Nie Min; Liu Bing; Du Zhi-jun; Ge Qin-sheng

    2004-01-01

    The risk of cardiovascular disease increases along with aging. There are increasing interests in researches on the protective effects of hormone replacement therapy (HRT)on cardiovascular system in postmenopausal women. In this article we will review how we have explored the evidence of different sex hormones on blood vessels since 1996. The results showed that low-dose HRT significantly protected cardiovascular system in postmenopausal women.However, the high-dose 17β-estradiol (E2), with or without progesterone (P) or testosterone (T), or any hormone alone, as their concentrations increase, may even inhibit the protective effects of low-dose HRT on blood vessels.

  4. Effect of Rolling Massage on the Vortex Flow in Blood Vessels with Lattice Boltzmann Simulation

    Science.gov (United States)

    Yi, Hou Hui

    The rolling massage manipulation is a classic Chinese Medical Massage, which is a nature therapy in eliminating many diseases. Here, the effect of the rolling massage on the cavity flows in blood vessel under the rolling manipulation is studied by the lattice Boltzmann simulation. The simulation results show that the vortex flows are fully disturbed by the rolling massage. The flow behavior depends on the rolling velocity and the rolling depth. Rolling massage has a better effect on the flows in the cavity than that of the flows in a planar blood vessel. The result is helpful to understand the mechanism of the massage and develop the rolling techniques.

  5. Effect of the number of abutments on biomechanics of Branemark prosthesis with straight and tilted distal implants

    Directory of Open Access Journals (Sweden)

    Marcos Michelon Naconecy

    2010-04-01

    Full Text Available OBJECTIVE: This study aimed to evaluate the bending moments, and compressive and tensile forces in implant-supported prostheses with three, four or five abutments. MATERIAL AND METHODS: Ten Pd-Ag frameworks were tested over two master models with: 1 parallel vertical implants, and 2 tilted distal implants. Strain gauges were fixed on the abutments of each master model to measure the deformation when a static load of 50 N was applied on the cantilever (15 mm. The deformation values were measured when the metallic frameworks were tested over three, four or five abutments, and transformed into force and bending moment values. Data were analyzed by ANOVA and Tukey's test for multiple comparisons at 5% level of significance. RESULTS: Abutment #1 (adjacent to the cantilever had the highest values of force and sagittal bending moment for all tests with three, four or five abutments. Independently from the number of abutments, axial force in abutment #1 was higher in the vertical model than in the tilted model. Total moment was higher with three abutments than with four or five abutments. Independently from the inclination of implants, the mean force with four or five abutments was lower than that with three abutments. CONCLUSION: The results suggest that in the set-ups with four or five abutments tilted distal implants reduced axial force and did not increase bending moments.

  6. Postmortem computed tomography with the use of air for blood vessel enhancement-Early experience.

    Science.gov (United States)

    Borowska-Solonynko, Aleksandra; Solonynko, Bohdan; Fudalej, Marcin; Żyłkowski, Jarosław

    2016-04-01

    Postmortem computed tomography (PMCT) is gaining popularity in forensic medicine. Computed tomography routinely performed in clinical medicine involves intravenous contrast administration. Unfortunately, postmortem examinations are typically limited to uncontrasted CT scans, where blood vessels and their potential injury sites are invisible. One serious problem is the fact that due to the process of decomposition, contrast agents used for vessel visualization in the living cannot be used in cadavers. Therefore, a special contrast agent designed for cadavers has been developed. This contrast agent has a high density and is lipophilic. Its use ensures very good visualization of blood vessels it is, however, associated with high costs and may alter findings of a later histopathological examination. This study presents early experience with the air as negative contrast agent to enhance all blood vessels in the body. The carbon dioxide (CO2) gas has been used as a contrast agent in live individuals with contraindications against the use of iodinated contrast. In corpses with advanced postmortem changes, putrefaction gases also considerably enhance the visibility of blood vessels and organs they fill. There have also been some positive effects with the use of gas in postmortem angiography of coronary vessels. These findings encouraged us to attempt air administration via catheters introduced into the femoral artery or a central venous access site in the superior vena cava. The gas distributed easily throughout the body and surprisingly well contrasted both arteries and veins of various caliber. The presence of the air administered into vessels did not cause any apparent, significant alterations in autopsy findings. Although optimization of the gas administration technique requires further studies, we can already say that this is a promising direction in postmortem angiography. PMID:26921814

  7. Mouse lung contains endothelial progenitors with high capacity to form blood and lymphatic vessels

    Directory of Open Access Journals (Sweden)

    Barleon Bernhard

    2010-07-01

    Full Text Available Abstract Background Postnatal endothelial progenitor cells (EPCs have been successfully isolated from whole bone marrow, blood and the walls of conduit vessels. They can, therefore, be classified into circulating and resident progenitor cells. The differentiation capacity of resident lung endothelial progenitor cells from mouse has not been evaluated. Results In an attempt to isolate differentiated mature endothelial cells from mouse lung we found that the lung contains EPCs with a high vasculogenic capacity and capability of de novo vasculogenesis for blood and lymph vessels. Mouse lung microvascular endothelial cells (MLMVECs were isolated by selection of CD31+ cells. Whereas the majority of the CD31+ cells did not divide, some scattered cells started to proliferate giving rise to large colonies (> 3000 cells/colony. These highly dividing cells possess the capacity to integrate into various types of vessels including blood and lymph vessels unveiling the existence of local microvascular endothelial progenitor cells (LMEPCs in adult mouse lung. EPCs could be amplified > passage 30 and still expressed panendothelial markers as well as the progenitor cell antigens, but not antigens for immune cells and hematopoietic stem cells. A high percentage of these cells are also positive for Lyve1, Prox1, podoplanin and VEGFR-3 indicating that a considerabe fraction of the cells are committed to develop lymphatic endothelium. Clonogenic highly proliferating cells from limiting dilution assays were also bipotent. Combined in vitro and in vivo spheroid and matrigel assays revealed that these EPCs exhibit vasculogenic capacity by forming functional blood and lymph vessels. Conclusion The lung contains large numbers of EPCs that display commitment for both types of vessels, suggesting that lung blood and lymphatic endothelial cells are derived from a single progenitor cell.

  8. Contact-inhibited chemotaxis in de novo and sprouting blood-vessel growth.

    Directory of Open Access Journals (Sweden)

    Roeland M H Merks

    Full Text Available Blood vessels form either when dispersed endothelial cells (the cells lining the inner walls of fully formed blood vessels organize into a vessel network (vasculogenesis, or by sprouting or splitting of existing blood vessels (angiogenesis. Although they are closely related biologically, no current model explains both phenomena with a single biophysical mechanism. Most computational models describe sprouting at the level of the blood vessel, ignoring how cell behavior drives branch splitting during sprouting. We present a cell-based, Glazier-Graner-Hogeweg model (also called Cellular Potts Model simulation of the initial patterning before the vascular cords form lumens, based on plausible behaviors of endothelial cells. The endothelial cells secrete a chemoattractant, which attracts other endothelial cells. As in the classic Keller-Segel model, chemotaxis by itself causes cells to aggregate into isolated clusters. However, including experimentally observed VE-cadherin-mediated contact inhibition of chemotaxis in the simulation causes randomly distributed cells to organize into networks and cell aggregates to sprout, reproducing aspects of both de novo and sprouting blood-vessel growth. We discuss two branching instabilities responsible for our results. Cells at the surfaces of cell clusters attempting to migrate to the centers of the clusters produce a buckling instability. In a model variant that eliminates the surface-normal force, a dissipative mechanism drives sprouting, with the secreted chemical acting both as a chemoattractant and as an inhibitor of pseudopod extension. Both mechanisms would also apply if force transmission through the extracellular matrix rather than chemical signaling mediated cell-cell interactions. The branching instabilities responsible for our results, which result from contact inhibition of chemotaxis, are both generic developmental mechanisms and interesting examples of unusual patterning instabilities.

  9. The role of blood vessels in high-resolution volume conductor head modeling of EEG.

    Science.gov (United States)

    Fiederer, L D J; Vorwerk, J; Lucka, F; Dannhauer, M; Yang, S; Dümpelmann, M; Schulze-Bonhage, A; Aertsen, A; Speck, O; Wolters, C H; Ball, T

    2016-03-01

    Reconstruction of the electrical sources of human EEG activity at high spatio-temporal accuracy is an important aim in neuroscience and neurological diagnostics. Over the last decades, numerous studies have demonstrated that realistic modeling of head anatomy improves the accuracy of source reconstruction of EEG signals. For example, including a cerebro-spinal fluid compartment and the anisotropy of white matter electrical conductivity were both shown to significantly reduce modeling errors. Here, we for the first time quantify the role of detailed reconstructions of the cerebral blood vessels in volume conductor head modeling for EEG. To study the role of the highly arborized cerebral blood vessels, we created a submillimeter head model based on ultra-high-field-strength (7T) structural MRI datasets. Blood vessels (arteries and emissary/intraosseous veins) were segmented using Frangi multi-scale vesselness filtering. The final head model consisted of a geometry-adapted cubic mesh with over 17×10(6) nodes. We solved the forward model using a finite-element-method (FEM) transfer matrix approach, which allowed reducing computation times substantially and quantified the importance of the blood vessel compartment by computing forward and inverse errors resulting from ignoring the blood vessels. Our results show that ignoring emissary veins piercing the skull leads to focal localization errors of approx. 5 to 15mm. Large errors (>2cm) were observed due to the carotid arteries and the dense arterial vasculature in areas such as in the insula or in the medial temporal lobe. Thus, in such predisposed areas, errors caused by neglecting blood vessels can reach similar magnitudes as those previously reported for neglecting white matter anisotropy, the CSF or the dura - structures which are generally considered important components of realistic EEG head models. Our findings thus imply that including a realistic blood vessel compartment in EEG head models will be helpful to

  10. Peristaltic Pumping of Blood Through Small Vessels of Varying Cross-Section

    Science.gov (United States)

    Misra, J. C.; Maiti, S.

    2012-11-01

    The paper is devoted to a study of the peristaltic motion of blood in the micro-circulatory system. The vessel is considered to be of varying cross-section. The progressive peristaltic waves are taken to be of sinusoidal nature. Blood is considered to be a Herschel-Bulkley fluid. Of particular concern here is to investigate the effects of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, streamline pattern and wall shear stress. On the basis of the derived analytical expression, extensive numerical calculations have been made. The study reveals that velocity of blood and wall shear stress are appreciably affected due to the non-uniform geometry of blood vessels. They are also highly sensitive to the magnitude of the amplitude ratio and the value of the fluid index.

  11. Do double gloves protect against contamination during cannulation of blood vessels? A prospective randomized study

    OpenAIRE

    Łukasz Szarpak; Andrzej Kurowski

    2014-01-01

    Background: Undamaged medical gloves protect medical personnel from contact with physiological fluids of the patient. Thus they protect the assistance provider from hand skin contamination with potentially infectious biological material. The aim of the study was to evaluate the occurrence of pierce, perforations or damage of medical gloves during cannulation of blood vessels. Materials and Methods: In the prospective randomized study 303 pairs of gloves, used during cannulation of blood vesse...

  12. Modeling blood flow in vessels with changeable caliber for physiology and biophysics courses.

    Science.gov (United States)

    Kozlova, E K; Badicov, V I; Chemysh, A M; Bogushevich, M S

    1997-06-01

    A model based on elementary principles of hydrodynamics and mathematics is proposed for classroom research on concepts related to blood flow physiology. This is an analog model of the vascular system in which blood flow is represented by electrical current flowing in a resistance circuit. The model permits analysis of the change in hemodynamics with local stenosis of both large and peripheral vessels. PMID:9227648

  13. Development and clinical application of a new testicular prosthesis

    Institute of Scientific and Technical Information of China (English)

    Ye Ning; Zhikang Cai; Huixing Chen; Ping Ping; Peng Li; Zhong Wang; Zheng Li

    2011-01-01

    A new type of testicular prosthesis made of silastic with an elliptical shape to mimic a normal testis was developed by our team and submitted for patenting in China.The prosthesis was produced in different sizes to imitate the normal testis of the patient.To investigate the effects and safety of the testicular prosthesis,20 patients receiving testicular prosthesis implantation were recruited for this study.Follow-up after 6 months revealed no complications in the patients.All the patients answered that they were satisfied with their body image and the position of the implants,19 patients were satisfied with the size and 16 patients were satisfied with the weight.These results show that the testicular prosthesis used in this study can meet patient's expectations.Patients undergoing orchiectomy should be offered the option to receive a testicular prosthesis implantation.The dimensions and weight of the available prosthetic implants should be further addressed to improve patient satisfaction.

  14. Circulating fibrocytes stabilize blood vessels during angiogenesis in a paracrine manner.

    Science.gov (United States)

    Li, Jinqing; Tan, Hong; Wang, Xiaolin; Li, Yuejun; Samuelson, Lisa; Li, Xueyong; Cui, Caibin; Gerber, David A

    2014-02-01

    Accumulating evidence supports that circulating fibrocytes play important roles in angiogenesis. However, the specific role of fibrocytes in angiogenesis and the underlying mechanisms remain unclear. In this study, we found that fibrocytes stabilized newly formed blood vessels in a mouse wound-healing model by inhibiting angiogenesis during the proliferative phase and inhibiting blood vessel regression during the remodeling phase. Fibrocytes also inhibited angiogenesis in a Matrigel mouse model. In vitro study showed that fibrocytes inhibited both the apoptosis and proliferation of vascular endothelial cells (VECs) in a permeable support (Transwell) co-culture system. In a three-dimensional collagen gel, fibrocytes stabilized the VEC tubes by decreasing VEC tube density on stimulation with growth factors and preventing VEC tube regression on withdrawal of growth factors. Further mechanistic investigation revealed that fibrocytes expressed many prosurvival factors that are responsible for the prosurvival effect of fibrocytes on VECs and blood vessels. Fibrocytes also expressed angiogenesis inhibitors, including thrombospondin-1 (THBS1). THBS1 knockdown partially blocked the fibrocyte-induced inhibition of VEC proliferation in the Transwell co-culture system and recovered the fibrocyte-induced decrease of VEC tube density in collagen gel. Purified fibrocytes transfected with THBS1 siRNA partially recovered the fibrocyte-induced inhibition of angiogenesis in both the wound-healing and Matrigel models. In conclusion, our findings reveal that fibrocytes stabilize blood vessels via prosurvival factors and anti-angiogenic factors, including THBS1. PMID:24300950

  15. Mass Spectrometry and Antibody-Based Characterization of Blood Vessels from Brachylophosaurus canadensis.

    Science.gov (United States)

    Cleland, Timothy P; Schroeter, Elena R; Zamdborg, Leonid; Zheng, Wenxia; Lee, Ji Eun; Tran, John C; Bern, Marshall; Duncan, Michael B; Lebleu, Valerie S; Ahlf, Dorothy R; Thomas, Paul M; Kalluri, Raghu; Kelleher, Neil L; Schweitzer, Mary H

    2015-12-01

    Structures similar to blood vessels in location, morphology, flexibility, and transparency have been recovered after demineralization of multiple dinosaur cortical bone fragments from multiple specimens, some of which are as old as 80 Ma. These structures were hypothesized to be either endogenous to the bone (i.e., of vascular origin) or the result of biofilm colonizing the empty osteonal network after degradation of original organic components. Here, we test the hypothesis that these structures are endogenous and thus retain proteins in common with extant archosaur blood vessels that can be detected with high-resolution mass spectrometry and confirmed by immunofluorescence. Two lines of evidence support this hypothesis. First, peptide sequencing of Brachylophosaurus canadensis blood vessel extracts is consistent with peptides comprising extant archosaurian blood vessels and is not consistent with a bacterial, cellular slime mold, or fungal origin. Second, proteins identified by mass spectrometry can be localized to the tissues using antibodies specific to these proteins, validating their identity. Data are available via ProteomeXchange with identifier PXD001738. PMID:26595531

  16. Making Ends Meet: Myeloid Cells Catalyze Blood Vessel Repair in the Brain.

    Science.gov (United States)

    Deczkowska, Aleksandra; Schwartz, Michal

    2016-05-17

    Hemorrhagic stroke, primarily caused by rupture of blood vessels in the brain, is a leading cause of death and disability in adults. In this issue of Immunity, Liu et al. (2016) demonstrate that repair of cerebrovascular ruptures can be directly mediated by myeloid cells. PMID:27192572

  17. Blood Vessel Segmentation Using Moving-Window Robust Automatic Threshold Selection

    NARCIS (Netherlands)

    Wilkinson, Michael H.F.; Wijbenga, Tsjipke; Vries, Gijs de; Westenberg, Michel A.

    2003-01-01

    Two moving-window methods, using either flat or Gaussian weighted windows, for local thresholding with Robust Automatic Threshold Selection are developed. The results show that fast segmentation of blood vessels against a varying background and noise is possible at modest computational cost. Volumes

  18. Prosthesis coupling

    Science.gov (United States)

    Reswick, J. B.; Mooney, V.; Bright, C. W.; Owens, L. J. (Inventor)

    1979-01-01

    A coupling for use in an apparatus for connecting a prosthesis to the bone of a stump of an amputated limb is described which permits a bio-compatible carbon sleeve forming a part of the prosthesis connector to float so as to prevent disturbing the skin seal around the carbon sleeve. The coupling includes a flexible member interposed between a socket that is inserted within an intermedullary cavity of the bone and the sleeve. A lock pin is carried by the prosthesis and has a stem portion which is adapted to be coaxially disposed and slideably within the tubular female socket for securing the prosthesis to the stump. The skin around the percutaneous carbon sleeve is able to move as a result of the flexing coupling so as to reduce stresses caused by changes in the stump shape and/or movement between the bone and the flesh portion of the stump.

  19. Stemless shoulder prosthesis versus conventional anatomic shoulder prosthesis in patients with osteoarthritis

    OpenAIRE

    Berth, Alexander; Pap, Géza

    2012-01-01

    Background The stemless shoulder prosthesis is a new concept in shoulder arthroplasty. To date, only a few studies have investigated the results of this prosthesis. The aim of this study was to investigate the clinical and radiological midterm results of this implant in comparison with a standard anatomic stemmed shoulder prosthesis. Materials and methods The Constant score, the DASH score, the active range of motion (abduction, anteversion, external rotation), and the radiological results we...

  20. Finite-sized gas bubble motion in a blood vessel: non-Newtonian effects.

    Science.gov (United States)

    Mukundakrishnan, Karthik; Ayyaswamy, Portonovo S; Eckmann, David M

    2008-09-01

    We have numerically investigated the axisymmetric motion of a finite-sized nearly occluding air bubble through a shear-thinning Casson fluid flowing in blood vessels of circular cross section. The numerical solution entails solving a two-layer fluid model--a cell-free layer and a non-Newtonian core together with the gas bubble. This problem is of interest to the field of rheology and for gas embolism studies in health sciences. The numerical method is based on a modified front-tracking method. The viscosity expression in the Casson model for blood (bulk fluid) includes the hematocrit [the volume fraction of red blood cells (RBCs)] as an explicit parameter. Three different flow Reynolds numbers, Reapp=rholUmaxdmicroapp , in the neighborhood of 0.2, 2, and 200 are investigated. Here, rhol is the density of blood, Umax is the centerline velocity of the inlet Casson profile, d is the diameter of the vessel, and microapp is the apparent viscosity of whole blood. Three different hematocrits have also been considered: 0.45, 0.4, and 0.335. The vessel sizes considered correspond to small arteries, and small and large arterioles in normal humans. The degree of bubble occlusion is characterized by the ratio of bubble to vessel radius (aspect ratio), lambda , in the range 0.9 - --> +) imparted to the cell surface during bubble motion; (iii) large shear stress gradients together with sign reversals are ascribable to the development of a recirculation vortex at the rear of the bubble; (iv) computed magnitudes of shear stress gradients coupled with their sign reversals may correspond to levels that cause injury to the cell by membrane disruption through impulsive compression and stretching; and (v) for the vessel sizes and flow rates investigated, gravitational effects are negligible. PMID:18851139

  1. Results of a unicentric series of 15 wrist prosthesis implantations at a 5.2 year follow-up.

    Science.gov (United States)

    Chevrollier, Jérémie; Strugarek-Lecoanet, Clotilde; Dap, François; Dautel, Gilles

    2016-03-01

    Our retrospective study aimed to evaluate functional and radiological results of a unicentric series of 17 total wrist prostheses implanted between 2001 and 2011. Nine women and seven men, mean age 59, underwent wrist joint arthroplasty, bilateral in one case. Universal Total Wrist and Remotion prostheses were used and followed-up at a mean of 5.2 years (1.1-10). Fifteen patients were reviewed. Four patients had postoperative complications, three of whom required arthrodesis. The rest obtained satisfactory pain relief. Grip strength nevertheless decreased compared to the contralateral side and mobility was reduced: flexion/extension=33°, ulnar/radial deviation=20°. The Quick DASH score was 29% and PRWE, 26%. Radiological assessment revealed carpal implant loosening in eight patients. Our series confirms the discordance generally observed between patients' subjective satisfaction and mediocre clinical and radiological results over the medium term. PMID:26984652

  2. Segmentation of blood vessels from red-free and fluorescein retinal images.

    Science.gov (United States)

    Martinez-Perez, M Elena; Hughes, Alun D; Thom, Simon A; Bharath, Anil A; Parker, Kim H

    2007-02-01

    The morphology of the retinal blood vessels can be an important indicator for diseases like diabetes, hypertension and retinopathy of prematurity (ROP). Thus, the measurement of changes in morphology of arterioles and venules can be of diagnostic value. Here we present a method to automatically segment retinal blood vessels based upon multiscale feature extraction. This method overcomes the problem of variations in contrast inherent in these images by using the first and second spatial derivatives of the intensity image that gives information about vessel topology. This approach also enables the detection of blood vessels of different widths, lengths and orientations. The local maxima over scales of the magnitude of the gradient and the maximum principal curvature of the Hessian tensor are used in a multiple pass region growing procedure. The growth progressively segments the blood vessels using feature information together with spatial information. The algorithm is tested on red-free and fluorescein retinal images, taken from two local and two public databases. Comparison with first public database yields values of 75.05% true positive rate (TPR) and 4.38% false positive rate (FPR). Second database values are of 72.46% TPR and 3.45% FPR. Our results on both public databases were comparable in performance with other authors. However, we conclude that these values are not sensitive enough so as to evaluate the performance of vessel geometry detection. Therefore we propose a new approach that uses measurements of vessel diameters and branching angles as a validation criterion to compare our segmented images with those hand segmented from public databases. Comparisons made between both hand segmented images from public databases showed a large inter-subject variability on geometric values. A last evaluation was made comparing vessel geometric values obtained from our segmented images between red-free and fluorescein paired images with the latter as the "ground truth

  3. The influence on PGI2-like activity of blood vessel wall following γ ray irradiation

    International Nuclear Information System (INIS)

    In the previous work, it has been shown that the reaction of blood platelet aggregation is risen during the early days following γ ray irradiation of large doses. In this paper, the changes of Rat PGI2-like activity with inhibiting platelet aggregation after γ ray irradiation of 8 Gy are reported. The results indicated that the activity was reduced at the first day after radiation, then recovered at the third day, lowered again at the 5-7 days. The changes have significant concern between the increase of blood platelet aggregation of Rats and the inhibition of PGI2-like activity of blood vessel wall following γ ray irradiation

  4. On ultrasound-induced microbubble oscillation in a capillary blood vessel and its implications for the blood-brain barrier

    Science.gov (United States)

    Wiedemair, W.; Tuković, Ž.; Jasak, H.; Poulikakos, D.; Kurtcuoglu, V.

    2012-02-01

    The complex interaction between an ultrasound-driven microbubble and an enclosing capillary microvessel is investigated by means of a coupled, multi-domain numerical model using the finite volume formulation. This system is of interest in the study of transient blood-brain barrier disruption (BBBD) for drug delivery applications. The compliant vessel structure is incorporated explicitly as a distinct domain described by a dedicated physical model. Red blood cells (RBCs) are taken into account as elastic solids in the blood plasma. We report the temporal and spatial development of transmural pressure (Ptm) and wall shear stress (WSS) at the luminal endothelial interface, both of which are candidates for the yet unknown mediator of BBBD. The explicit introduction of RBCs shapes the Ptm and WSS distributions and their derivatives markedly. While the peak values of these mechanical wall parameters are not affected considerably by the presence of RBCs, a pronounced increase in their spatial gradients is observed compared to a configuration with blood plasma alone. The novelty of our work lies in the explicit treatment of the vessel wall, and in the modelling of blood as a composite fluid, which we show to be relevant for the mechanical processes at the endothelium.

  5. Peristaltic Pumping of Blood in micro-vessels of Non-uniform Cross-section

    CERN Document Server

    Misra, J C

    2010-01-01

    The paper is devoted to a study of the peristaltic motion of blood in the micro-circulatory system. The vessel is considered of non-uniform cross-section. The progressive peristaltic waves are taken to be of sinusoidal nature. The Reynolds number is considered to be small. Blood is considered to be a Herschel-Bulkley fluid. Of particular concern here is to investigate the effects of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, streamline pattern and wall shear stress. Basing upon the study, extensive numerical calculations has been made. The study reveals that peristaltic pumping as well as velocity and wall shear stress are appreciably affected due to the non-uniform geometry of blood vessels. They are also highly sensitive to the magnitude of the amplitude of the amplitude ratio and the value of the fluid index.

  6. Hip painful prosthesis: surgical view

    OpenAIRE

    SPINARELLI, ANTONIO; Patella, Vittorio; Conserva, Vito; Vicenti, Giovanni; Pesce, Vito; Patella, Silvio

    2011-01-01

    Painful hip prosthesis is the most feared immediate and remote complication of a primary implant and usually represents the failure of one or more therapeutic moments. In cases of aseptic implant failure, the causes invoked may be represented by an incorrect indication, the quality of materials, local and general condition of the patient and especially from a bad joint biomechanics. In cases of septic loosening, however, the cause of failure to be found in the location of pathogens within the...

  7. Optics based signal processing methods for intraoperative blood vessel detection and quantification in real time (Conference Presentation)

    Science.gov (United States)

    Chaturvedi, Amal; Shukair, Shetha A.; Le Rolland, Paul; Vijayvergia, Mayank; Subramanian, Hariharan; Gunn, Jonathan W.

    2016-03-01

    Minimally invasive operations require surgeons to make difficult cuts to blood vessels and other tissues with impaired tactile and visual feedback. This leads to inadvertent cuts to blood vessels hidden beneath tissue, causing serious health risks to patients and a non-reimbursable financial burden to hospitals. Intraoperative imaging technologies have been developed, but these expensive systems can be cumbersome and provide only a high-level view of blood vessel networks. In this research, we propose a lean reflectance-based system, comprised of a dual wavelength LED, photodiode, and novel signal processing algorithms for rapid vessel characterization. Since this system takes advantage of the inherent pulsatile light absorption characteristics of blood vessels, no contrast agent is required for its ability to detect the presence of a blood vessel buried deep inside any tissue type (up to a cm) in real time. Once a vessel is detected, the system is able to estimate the distance of the vessel from the probe and the diameter size of the vessel (with a resolution of ~2mm), as well as delineate the type of tissue surrounding the vessel. The system is low-cost, functions in real-time, and could be mounted on already existing surgical tools, such as Kittner dissectors or laparoscopic suction irrigation cannulae. Having been successfully validated ex vivo, this technology will next be tested in a live porcine study and eventually in clinical trials.

  8. A comparison of blood vessel features and local binary patterns for colorectal polyp classification

    Science.gov (United States)

    Gross, Sebastian; Stehle, Thomas; Behrens, Alexander; Auer, Roland; Aach, Til; Winograd, Ron; Trautwein, Christian; Tischendorf, Jens

    2009-02-01

    Colorectal cancer is the third leading cause of cancer deaths in the United States of America for both women and men. By means of early detection, the five year survival rate can be up to 90%. Polyps can to be grouped into three different classes: hyperplastic, adenomatous, and carcinomatous polyps. Hyperplastic polyps are benign and are not likely to develop into cancer. Adenomas, on the other hand, are known to grow into cancer (adenoma-carcinoma sequence). Carcinomas are fully developed cancers and can be easily distinguished from adenomas and hyperplastic polyps. A recent narrow band imaging (NBI) study by Tischendorf et al. has shown that hyperplastic polyps and adenomas can be discriminated by their blood vessel structure. We designed a computer-aided system for the differentiation between hyperplastic and adenomatous polyps. Our development aim is to provide the medical practitioner with an additional objective interpretation of the available image data as well as a confidence measure for the classification. We propose classification features calculated on the basis of the extracted blood vessel structure. We use the combined length of the detected blood vessels, the average perimeter of the vessels and their average gray level value. We achieve a successful classification rate of more than 90% on 102 polyps from our polyp data base. The classification results based on these features are compared to the results of Local Binary Patterns (LBP). The results indicate that the implemented features are superior to LBP.

  9. 硅胶假体植入隆鼻手术并发症的预防措施%Prevention Measures of the Complications of Silica Gel Prosthesis Implantation on Rhinoplasty

    Institute of Scientific and Technical Information of China (English)

    李雄艳; 杨丹; 谢志伟

    2013-01-01

    目的:通过各种预防措施或者手术方法,减少假体植入隆鼻手术并发症。方法:剖析并发症的发生原因,介绍并发症的预防措施。结果:317例假体植入隆鼻手术,除正常的局部术后肿胀外,除顾客对于审美意见不合一例外,无假体外露及感染以及排异等病例。结论:根据患者鼻型,雕刻合适的鼻假体,不能刻意通过假体抬高鼻尖,通过各种措施减少假体被污染的可能性,隆鼻手术并发症明显减少。%Objective To reduce the complications of silica gel prosthesis implantation on rhinoplasty by many prevention countermeasures and operation method. Methods The causes of complications were analyzed,and the prevention countermeasures of complications were introduced. Results In 317 cases of nose augmentation operation,except for local swelling and different customers’ aesthetic opinions,there were no prosthesis exposure and infection and rejection cases. Conclusion According to the patients’ nose,right nasal prosthesis is curved. Apex nasi should not be deliberately elevated through the nose prosthesis,and the possibility of prosthesis contamination be reduced through various measures. Nasal operation significantly reduce the complications of nose augmentation.

  10. ADAMTS1 alters blood vessel morphology and TSP1 levels in LNCaP and LNCaP-19 prostate tumors

    International Nuclear Information System (INIS)

    Decreased expression of the angiogenesis inhibitor ADAMTS1 (ADAM metallopeptidase with thrombospondin type 1 motif, 1) has previously been reported during prostate cancer progression. The aim of this study was to investigate the function of ADAMTS1 in prostate tumors. ADAMTS1 was downregulated by shRNA technology in the human prostate cancer cell line LNCaP (androgen-dependent), originally expressing ADAMTS1, and was upregulated by transfection in its subline LNCaP-19 (androgen-independent), expressing low levels of ADAMTS1. Cells were implanted subcutaneously in nude mice and tumor growth, microvessel density (MVD), blood vessel morphology, pericyte coverage and thrombospondin 1 (TSP1) were studied in the tumor xenografts. Modified expression of ADAMTS1 resulted in altered blood vessel morphology in the tumors. Low expression levels of ADAMTS1 were associated with small diameter blood vessels both in LNCaP and LNCaP-19 tumors, while high levels of ADAMTS1 were associated with larger vessels. In addition, TSP1 levels in the tumor xenografts were inversely related to ADAMTS1 expression. MVD and pericyte coverage were not affected. Moreover, upregulation of ADAMTS1 inhibited tumor growth of LNCaP-19, as evidenced by delayed tumor establishment. In contrast, downregulation of ADAMTS1 in LNCaP resulted in reduced tumor growth rate. The present study demonstrates that ADAMTS1 is an important regulatory factor of angiogenesis and tumor growth in prostate tumors, where modified ADAMTS1 expression resulted in markedly changed blood vessel morphology, possibly related to altered TSP1 levels

  11. Adaptive ultrasonic measurement of blood vessel diameter and wall thickness: theory and experimental results.

    Science.gov (United States)

    Rafii, K; Jaffe, J S

    1998-01-01

    An adaptive ultrasonic technique for measuring blood vessel diameter and wall thickness is presented. This technique allows one to use a target-specific transmitted waveform/receiver filter to obtain a larger signal-to-noise ratio (SNR) in the received signal than conventional techniques. Generally, SNR of a received wave increases as the intensity of the transmit wave increases; however, because of the FDA limitations placed on the amount of transmit energy, it is important to be able to make the most efficient use of the energy that is available to obtain the best possible SNR in the received signal. Adaptive ultrasonic measurement makes the most efficient use of the energy that is available by placing the maximum amount of energy in the largest target scattering mode. This results in more energy backscatter from a given target, which leads to a higher SNR in the received waveform. Computer simulations of adaptive ultrasonic measurement of blood vessel diameter show that for a SNR of 0 dB in the transmitted waveform, the standard deviation of the diameter measurements for a custom-designed transmitted waveform is about two orders of magnitude less than the standard deviation of the diameter measurements using more conventional waveforms. Diameter and wall thickness measurement experiments were performed on a latex tube and a bovine blood vessel using both custom-made and conventionally used transmitted waveforms. Results show that the adaptively designed waveform gives a smaller uncertainty in the measurements. The adaptive ultrasonic blood vessel diameter and wall thickness measuring technique has potential applications in examining vessels which are either too deep inside the body or too small for conventional techniques to be used, because of the low SNR in the received signal. PMID:18244211

  12. The use of a masticatory robot to analyze the shock absorption capacity of different restorative materials for implant prosthesis

    Directory of Open Access Journals (Sweden)

    M. Menini

    2011-01-01

    Full Text Available The aim of the present research was to measure in vitro the chewing load forces transmitted through crowns made of different prosthetic restorative materials onto the dental implant. A masticatory robot that is able to reproduce the mandibular movements and the forces exerted during mastication was used. The forces transmitted to the simulated periimplant bone during the robot mastication were analysis of variance (ANOVA was used. The zirconia and the ceramic crowns transmitted significantly greater forces (p-value < 0.0001 than the other crowns tested. Dental materials with lower elastic modulus were better able to ansorb shock from acclusal forces than more rigid materials.

  13. Screening of specific binding peptide targeting blood vessel of human esophageal cancer in vivo in mice

    Institute of Scientific and Technical Information of China (English)

    ZHI Min; WU Kai-chun; HAO Zhi-ming; GUO Chang-cun; YAO Jia-yin

    2011-01-01

    Background Cancer of the esophagus and gastroesophageal junction remains a virulent malignancy with poor prognosis. Rapid progresses were made in chemotherapeutic agents and the development of molecular markers allowed better identification of candidates for targeted therapy. This study aimed to identify the candidate peptides used for anti-angiogenic therapy of esophageal cancer by in vivo screening C7C peptide library for peptides binding specifically to blood vessels of human esophageal cancer.Methods The phage displayed C7C peptide library was injected intravenously into mice bearing human esophageal tumor xenografts under renal capsule. After 5 rounds of screening, 13 clones were picked up individually and sequenced.During each round of screening, titers of phage recovery were calculated from tumor xenograft and control tissues.Homing of these 9 peptides to tumor vessel was detected by calculating phage titers in the tumor xenograft and control tissues (lung and spleen) after each phage was injected into mice model, and compared with the distribution of phage M13 and Ⅷ-related antigen in tumor xenograft by immunohistochemical staining. Comparisons among groups of data were made using one-way analysis of variance (ANOVA), followed by the Bonferroni multiple comparisons test.Results The number of phage recovered from tumor tissue of each round increased gradually in tumor group while decreased in control groups (P <0.01 in tumor and spleen, P <0.05 in lung). Immunohistochemical staining showed similar staining pattern with M13 antibody or Ⅷ-related antigen antibody, suggesting that phages displaying the selected peptides could home to blood vessel of human esophageal cancer. According to their DNA, 9 corresponding peptide sequences were deduced. And the homing ability to blood vessel of phages displaying the selected peptides was confirmed by comparing with their recovery in tumor and control tissues. Two motifs, YSXNXW and PXNXXN, were also obtained by

  14. Prevalence of blood type A and risk of vascular complications following transcatheter aortic valve implantation

    OpenAIRE

    Rofe, M.-T.; Shacham, Y; Steinvi, A.; Barak, L.; Hareuveni, M; Banai, S.; Keren, G; Finkelstein, A.; Shmilovich, H.

    2016-01-01

    Objectives To assess the prevalence of blood type A among patients referred for transcatheter aortic valve implantation (TAVI) and whether it is related to vascular complications. Backgrounds Vascular complications following TAVI are associated with adverse outcomes. Various blood types, particularly type A, have been shown to be more prevalent in cardiovascular diseases and to be related to prognosis. Methods The prevalence of various blood types in a cohort of 491 consecutive patients who u...

  15. Calcification in Chronically-Implanted Blood Pumps: Experimental Results and Review of the Literature

    OpenAIRE

    Turner, Stephen A.; Bossart, Mattie I.; Milam, John D.; Fuqua, John M.; Igo, Stephen R.; McGee, Michael G.; Frazier, O. Howard

    1982-01-01

    Blood compatibility is a major objective in the development of long-term, implantable circulatory assist (left ventricular assist devices) and replacement (total artificial heart) devices. An important problem in experimental studies in animals has been the propensity for calcification to occur at the blood/material interface. Presented is a summary of our experience (27 studies) with blood pump calcification and a review of the current literature regarding this complication.

  16. Active Path Selection of Fluid Microcapsules in Artificial Blood Vessel by Acoustic Radiation Force

    Science.gov (United States)

    Masuda, Kohji; Muramatsu, Yusuke; Ueda, Sawami; Nakamoto, Ryusuke; Nakayashiki, Yusuke; Ishihara, Ken

    2009-07-01

    Micrometer-sized microcapsules collapse upon exposure to ultrasound. Use of this phenomenon for a drug delivery system (DDS), not only for local delivery of medication but also for gene therapy, should be possible. However, enhancing the efficiency of medication is limited because capsules in suspension diffuse in the human body after injection, since the motion of capsules in blood flow cannot be controlled. To control the behavior of microcapsules, acoustic radiation force was introduced. We detected local changes in microcapsule density by producing acoustic radiation force in an artificial blood vessel. Furthermore, we theoretically estimated the conditions required for active path selection of capsules at a bifurcation point in the artificial blood vessel. We observed the difference in capsule density at both in the bifurcation point and in alternative paths downstream of the bifurcation point for different acoustic radiation forces. Comparing the experimental results with those obtained theoretically, the conditions for active path selection were calculated from the acoustic radiation force and fluid resistance of the capsules. The possibility of controlling capsule flow towards a specific point in a blood vessel was demonstrated.

  17. Threadlike bundle of tubules running inside blood vessels New anatomical structure

    CERN Document Server

    Jiang, X; Shin, H; Lee, B; Choi, C; Soh, K; Cheun, B; Baik, K; Soh, K; Jiang, Xiaowen; Kim, Hee-kyeong; Shin, Hak-soo; Lee, Byong-chon; Choi, Chunho; Soh, Kyung-soon; Cheun, Byeung-soo; Baik, Ku-youn; Soh, Kwang-sup

    2002-01-01

    According to current anatomy, the arteries and veins do not have threadlike structures running inside the vessels. Despite such prevailing knowledge here we report on observation of a novel structure inside the blood vessels of rats and rabbits, which is a semi-transparent elastic bundle of tubules whose diameters are of 10$\\mu$m order. This is a rediscovery of the Bong Han ducts1,2 which have not been confirmed because the observing method was not known. We found a new procedure of observing the intra blood vessel ducts (IBVD) which are too thin, fragile, and semi-transparent to be detected in ordinary surgical operation. The method we contrived is to let blood be coagulated around the IBVD so that they become thick and strong by intravenous injection of 10 per cent dextrose solution at the vena femoralis. A piece of thickened IBVD sample is treated with urokinase to remove blood clots and the thin thread of IBVD is embedded inside of a string of fibrin

  18. Cell-free cryopreserved arterial allografts from multiorgan donors: a new strategy to fabricate artificial blood vessels suited for peripheral vascular surgery

    OpenAIRE

    Papadopulos, Francesca Marzia

    2012-01-01

    Critical lower limb ischemia is a severe disease. A common approach is infrainguinal bypass. Synthetic vascular prosthesis, are good conduits in high-flow low-resistance conditions but have difficulty in their performance as small diameter vessel grafts. A new approach is the use of native decellularized vascular tissues. Cell-free vessels are expected to have improved biocompatibility when compared to synthetic and are optimal natural 3D matrix templates for driving stem cell growth and tiss...

  19. "Sausage-string" appearance of arteries and arterioles can be caused by an instability of the blood vessel wall

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; Beierholm, Ulrik; Mikkelsen, Rene;

    2002-01-01

    observed experimentally. Most importantly, it suggests that the "sausaging" phenomenon is neither caused by a mechanical failure of the vessel wall due to a high blood pressure nor is it due to standing pressure waves caused by the beating of the heart. Rather, it is the expression of a general instability......Vascular damage induced by acute hypertension is preceded by a peculiar pattern where blood vessels show alternating regions of constrictions and dilations ("sausages on a string"). The pattern occurs in the smaller blood vessels, and it plays a central role in causing the vascular damage. A...... related vascular pattern has been observed in larger vessels from several organs during angiography. In the larger vessels the occurrence of the pattern does not appear to be related to acute hypertension. A unifying feature between the phenomenon in large and small vessels seems to be an increase in...

  20. The Emergence of Blood and Blood Vessels in the Embryo and Its Relevance to Postnatal Biology and Disease

    Science.gov (United States)

    Sills, Tiffany M.; Hirschi, Karen K.

    Blood and blood vessels develop in parallel within mammalian systems, and this temporal and spatial association has led to the confirmation of an endothelial origin of hematopoiesis. The extraembryonic yolk sac and aorto-gonado-mesonephros (AGM) region both contain a specialized population of endothelial cells ("hemogenic endothelium") that function to produce hematopoietic stem and progenitor cells, which then differentiate to provide the full complement of blood cells within the developing embryo and furthermore in the adult system. Therefore, this population has great therapeutic potential in the fields of regenerative medicine and tissue engineering. This chapter reviews the development of the vascular and hematopoietic systems, characterization and function of the hemogenic endothelium within embryonic and embryonic stem cell (ES cell) models, and speculate on the presence of such a population within the adult system. In order to harness this endothelial subtype for clinical application, we must understand both the normal functions of these cells and the potential for misregulation in disease states.

  1. Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange.

    Directory of Open Access Journals (Sweden)

    William Ruger Porter

    Full Text Available Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange. Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana was investigated using a differential-contrast, dual-vascular injection (DCDVI technique and high-resolution X-ray microcomputed tomography (μCT. Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory

  2. Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange.

    Science.gov (United States)

    Porter, William Ruger; Witmer, Lawrence M

    2015-01-01

    Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body) as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange). Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana) was investigated using a differential-contrast, dual-vascular injection (DCDVI) technique and high-resolution X-ray microcomputed tomography (μCT). Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory tissue temperature

  3. Vascular Patterns in Iguanas and Other Squamates: Blood Vessels and Sites of Thermal Exchange

    Science.gov (United States)

    Porter, William Ruger; Witmer, Lawrence M.

    2015-01-01

    Squamates use the circulatory system to regulate body and head temperatures during both heating and cooling. The flexibility of this system, which possibly exceeds that of endotherms, offers a number of physiological mechanisms to gain or retain heat (e.g., increase peripheral blood flow and heart rate, cooling the head to prolong basking time for the body) as well as to shed heat (modulate peripheral blood flow, expose sites of thermal exchange). Squamates also have the ability to establish and maintain the same head-to-body temperature differential that birds, crocodilians, and mammals demonstrate, but without a discrete rete or other vascular physiological device. Squamates offer important anatomical and phylogenetic evidence for the inference of the blood vessels of dinosaurs and other extinct archosaurs in that they shed light on the basal diapsid condition. Given this basal positioning, squamates likewise inform and constrain the range of physiological thermoregulatory mechanisms that may have been found in Dinosauria. Unfortunately, the literature on squamate vascular anatomy is limited. Cephalic vascular anatomy of green iguanas (Iguana iguana) was investigated using a differential-contrast, dual-vascular injection (DCDVI) technique and high-resolution X-ray microcomputed tomography (μCT). Blood vessels were digitally segmented to create a surface representation of vascular pathways. Known sites of thermal exchange, consisting of the oral, nasal, and orbital regions, were given special attention due to their role in brain and cephalic thermoregulation. Blood vessels to and from sites of thermal exchange were investigated to detect conserved vascular patterns and to assess their ability to deliver cooled blood to the dural venous sinuses. Arteries within sites of thermal exchange were found to deliver blood directly and through collateral pathways. The venous drainage was found to have multiple pathways that could influence neurosensory tissue temperature

  4. Effects of X-irradiation on artificial blood vessel wall degradation by invasive tumor cells

    International Nuclear Information System (INIS)

    Artificial vessel wall cultures, constructed by growing arterial endothelial cells on preformed layers of rat smooth muscle cells, were used to evaluate the effects of X-irradiation on tumor cell-induced tissue degradation. Bovine endothelial cells had radiation sensitivities similar to those of rat smooth muscle cells. Preirradiation of smooth muscle cells, before the addition of human fibrosarcoma (HT 1080) cells, did not increase the rate of degradation and destruction by the invasive cells. However, the degradation rate was decreased if the cultures were irradiated after the addition of HT 1080 cells. The presence of bovine endothelial cells markedly inhibited the destructive abilities of fibrosarcoma cells, but preirradiation of artificial vessel walls substantially decreased their capabilities to resist HT 1080-induced lysis. These findings suggest that the abilities of blood vessels to limit extravasation may be compromised by ionizing radiation

  5. Shah's Indian penile prosthesis placement after phallic reconstruction with radial forearm flap

    OpenAIRE

    Patwardhan, Sujata K; Shah, Rupin; Kulkarni, Vijay; Varma, Radheshyam R.

    2008-01-01

    We report a successful implantation of Indian penile prosthesis after total phallic reconstruction. The differential stiffness of the Shah penile prosthesis is felt to have less potential for erosion, the most common complication of rigid prosthetic stiffening devices when used in a neo-phallus. This prosthesis is an alternative to the inflatable prosthesis in patients who choose a rigid prosthesis due to economical constraints.

  6. Comparison of two algorithms in the automatic segmentation of blood vessels in fundus images

    Science.gov (United States)

    LeAnder, Robert; Chowdary, Myneni Sushma; Mokkapati, Swapnasri; Umbaugh, Scott E.

    2008-03-01

    Effective timing and treatment are critical to saving the sight of patients with diabetes. Lack of screening, as well as a shortage of ophthalmologists, help contribute to approximately 8,000 cases per year of people who lose their sight to diabetic retinopathy, the leading cause of new cases of blindness [1] [2]. Timely treatment for diabetic retinopathy prevents severe vision loss in over 50% of eyes tested [1]. Fundus images can provide information for detecting and monitoring eye-related diseases, like diabetic retinopathy, which if detected early, may help prevent vision loss. Damaged blood vessels can indicate the presence of diabetic retinopathy [9]. So, early detection of damaged vessels in retinal images can provide valuable information about the presence of disease, thereby helping to prevent vision loss. Purpose: The purpose of this study was to compare the effectiveness of two blood vessel segmentation algorithms. Methods: Fifteen fundus images from the STARE database were used to develop two algorithms using the CVIPtools software environment. Another set of fifteen images were derived from the first fifteen and contained ophthalmologists' hand-drawn tracings over the retinal vessels. The ophthalmologists' tracings were used as the "gold standard" for perfect segmentation and compared with the segmented images that were output by the two algorithms. Comparisons between the segmented and the hand-drawn images were made using Pratt's Figure of Merit (FOM), Signal-to-Noise Ratio (SNR) and Root Mean Square (RMS) Error. Results: Algorithm 2 has an FOM that is 10% higher than Algorithm 1. Algorithm 2 has a 6%-higher SNR than Algorithm 1. Algorithm 2 has only 1.3% more RMS error than Algorithm 1. Conclusions: Algorithm 1 extracted most of the blood vessels with some missing intersections and bifurcations. Algorithm 2 extracted all the major blood vessels, but eradicated some vessels as well. Algorithm 2 outperformed Algorithm 1 in terms of visual clarity, FOM

  7. Fast Photoacoustic Imaging of Blood Vessels Based on an Annular Transducer Array

    International Nuclear Information System (INIS)

    We present a photoacoustic imaging system for rapid high-resolution photoacoustic imaging of blood vessels based on an annular transducer array. The annular transducer array consists of 256 elements arranged along a 300° arc with a 50-mm radius of curvature, using piezocomposite technology for high sensitivity and high signal-to-noise ratio. An eight-channel data acquisition system is applied to capture the photoacoustic signals using multiplexing and a limited-view filtered back projection algorithm is used to reconstruct the photoacoustic images. The experiments with phantom and blood vessels of a chicken are performed and clear photoacoustic images are obtained. The results demonstrate that the photoacoustic imaging system using the annular transducer array holds the potential application in monitoring neovascularization in tumor angiogenesis

  8. Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels.

    Science.gov (United States)

    Zhang, Yue; Yang, Wan-Xi

    2016-01-01

    Since nanoparticles are now widely applied as food additives, in cosmetics and other industries, especially in medical therapy and diagnosis, we ask here whether nanoparticles can cause several adverse effects to human health. In this review, based on research on nanotoxicity, we mainly discuss the negative influence of nanoparticles on blood vessels in several aspects and the potential mechanism for nanoparticles to penetrate endothelial layers of blood vessels, which are the sites of phosphorylation of tight junction proteins (claudins, occludins, and ZO (Zonula occludens)) proteins, oxidative stress and shear stress. We propose a connection between the presence of nanoparticles and the regulation of the tight junction, which might be the key approach for nanoparticles to penetrate endothelial layers and then have an impact on other tissues and organs. PMID:27335757

  9. In Vivo μPIV Measurements of Blood Flow in Small Vessels of a Rat Model.

    Science.gov (United States)

    Wei, Timothy; Conner, Nadine; Russell, John; Legac, Paul

    2007-11-01

    Ongoing research at the University of Wisconsin Medical School is addressing the effects of perfusion of glottal tissue on voice production. Building on the approach developed by Gharib's group at CalTech for embryonic zebra fish, we have modified μPIV to measure flow in capillaries and small blood vessels in a live rat model. In lieu of seeding particles, the DPIV correlation algorithm tracks the motion of red blood cells moving through these vessels. The methodology will be presented along with a video sequence showing measurements made from muscle tissue laid nominally flat on a microscope stage. Challenges of measurements in three-dimensional geometries, i.e. the throat, will be discussed.

  10. Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels

    Science.gov (United States)

    Zhang, Yue

    2016-01-01

    Summary Since nanoparticles are now widely applied as food additives, in cosmetics and other industries, especially in medical therapy and diagnosis, we ask here whether nanoparticles can cause several adverse effects to human health. In this review, based on research on nanotoxicity, we mainly discuss the negative influence of nanoparticles on blood vessels in several aspects and the potential mechanism for nanoparticles to penetrate endothelial layers of blood vessels, which are the sites of phosphorylation of tight junction proteins (claudins, occludins, and ZO (Zonula occludens)) proteins, oxidative stress and shear stress. We propose a connection between the presence of nanoparticles and the regulation of the tight junction, which might be the key approach for nanoparticles to penetrate endothelial layers and then have an impact on other tissues and organs. PMID:27335757

  11. Blood vessel crosstalk during organogenesis-focus on pancreas and endothelial cells.

    Science.gov (United States)

    Azizoglu, D Berfin; Cleaver, Ondine

    2016-09-01

    Blood vessels form a highly branched, interconnected, and largely stereotyped network of tubes that sustains every organ and tissue in vertebrates. How vessels come to take on their particular architecture, or how they are 'patterned,' and in turn, how they influence surrounding tissues are fundamental questions of organogenesis. Decades of work have begun to elucidate how endothelial progenitors arise and home to precise locations within tissues, integrating attractive and repulsive cues to build vessels where they are needed. Conversely, more recent findings have revealed an exciting facet of blood vessel interaction with tissues, where vascular cells provide signals to developing organs and progenitors therein. Here, we discuss the exchange of reciprocal signals between endothelial cells and neighboring tissues during embryogenesis, with a special focus on the developing pancreas. Understanding the mechanisms driving both sides of these interactions will be crucial to the development of therapies, from improving organ regeneration to efficient production of cell based therapies. Specifically, elucidating the interface of the vasculature with pancreatic lineages, including endocrine cells, will instruct approaches such as generation of replacement beta cells for Type I diabetes. WIREs Dev Biol 2016, 5:598-617. doi: 10.1002/wdev.240 For further resources related to this article, please visit the WIREs website. PMID:27328421

  12. Angiopoietin-4 increases permeability of blood vessels and promotes lymphatic dilation.

    Science.gov (United States)

    Kesler, Cristina T; Pereira, Ethel R; Cui, Cheryl H; Nelson, Gregory M; Masuck, David J; Baish, James W; Padera, Timothy P

    2015-09-01

    The angiopoietin (Ang) ligands are potential therapeutic targets for lymphatic related diseases, which include lymphedema and cancer. Ang-1 and Ang-2 functions are established, but those of Ang-4 are poorly understood. We used intravital fluorescence microscopy to characterize Ang-4 actions on T241 murine fibrosarcoma-associated vessels in mice. The diameters of lymphatic vessels draining Ang-4- or VEGF-C (positive control)-expressing tumors increased to 123 and 135 μm, respectively, and parental, mock-transduced (negative controls) and tumors expressing Ang-1 or Ang-2 remained at baseline (∼60 μm). Ang-4 decreased human dermal lymphatic endothelial cell (LEC) monolayer permeability by 27% while increasing human dermal blood endothelial cell (BEC) monolayer permeability by 200%. In vivo, Ang-4 stimulated a 4.5-fold increase in tumor-associated blood vessel permeability compared with control when measured using intravital quantitative multiphoton microscopy. Ang-4 activated receptor signaling in both LECs and BECs, evidenced by tyrosine kinase with Ig and endothelial growth factor homology domains-2 (TIE2) receptor, protein kinase B, and Erk1,2 phosphorylation detectable by immunoblotting. These data suggest that Ang-4 actions are mediated through cell-type-specific networks and that lymphatic vessel dilation occurs secondarily to increased vascular leakage. Ang-4 also promoted survival of LECs. Thus, blocking Ang-4 may prune the draining lymphatic vasculature and decrease interstitial fluid pressure (IFP) by reducing vascular permeability. PMID:25977256

  13. Retinal hemodynamic oxygen reactivity assessed by perfusion velocity, blood oximetry and vessel diameter measurements

    DEFF Research Database (Denmark)

    Klefter, Oliver Niels; Lauritsen, Anne Øberg; Larsen, Michael

    2015-01-01

    PURPOSE: To test the oxygen reactivity of a fundus photographic method of measuring macular perfusion velocity and to integrate macular perfusion velocities with measurements of retinal vessel diameters and blood oxygen saturation. METHODS: Sixteen eyes in 16 healthy volunteers were studied at two...... perfusion velocities, short-term ICCs were 0.79-0.82 and long-term ICCs were 0.06-0.11. Intersession increases in blood glucose were associated with reductions in perfusion velocities (arterial p = 0.0067; venous p = 0.018). CONCLUSION: Oxygen reactivity testing supported that motion-contrast velocimetry is...... a valid method for assessing macular perfusion. Results were consistent with previous observations of hyperoxic blood flow reduction using blue field entoptic and laser Doppler velocimetry. Retinal perfusion seemed to be regulated around individual set points according to blood glucose levels...

  14. Surface modification of cellulose materials : from wood pulps to artificial blood vessels

    OpenAIRE

    Ahrenstedt, Lage

    2007-01-01

    This thesis describes the improvement of two radically different cellulose materials, paper and artificial blood vessels, constructed from two diverse cellulose sources, wood pulp and Acetobacter xylinum. The improvement of both materials was possible due to the natural affinity of the hemicellulose xyloglucan for cellulose. Chemical and mechanical pulps were treated with xyloglucan in the wet-end prior to hand sheet formation or by spray application of dry hand sheets, loading a comparable a...

  15. 3D MRI-based predictive control of a ferromagnetic microrobot navigating in blood vessels

    OpenAIRE

    Belharet, Karim; Folio, David; Ferreira, Antoine

    2010-01-01

    This paper presents an endovascular navigation of a ferromagneticmicrodevice using a MRI-based predictive control. The concept wasstudied for future development of microrobot designed to performminimally invasive interventions in remote sites accessible throughthe human cardiovascular system. A system software architecture ispresented illustrating the different software modules to allow 3Dnavigation of a microdevice in blood vessels, namely: (i) vesselpath extraction, (ii) magnetic gradient s...

  16. Simulation of Molecular Signaling in Blood Vessels: Software Design and Application to Atherogenesis

    OpenAIRE

    Felicetti, Luca; Femminella, Mauro; Reali, Gianluca

    2013-01-01

    This paper presents a software platform, named BiNS2, able to simulate diffusion-based molecular communications with drift inside blood vessels. The contribution of the paper is twofold. First a detailed description of the simulator is given, under the software engineering point of view, by highlighting the innovations and optimizations introduced. Their introduction into the previous version of the BiNS simulator was needed to provide to functions for simulating molecular signaling and commu...

  17. Sensory Nerves Determine the Pattern of Arterial Differentiation and Blood Vessel Branching in the Skin

    OpenAIRE

    Mukouyama, Yoh-suke; Shin, Donghun; Britsch, Stefan; Taniguchi, Masahiko; Anderson, David J.

    2002-01-01

    Nerves and blood vessels are branched structures, but whether their branching patterns are established independently or coordinately is not clear. Here we show that arteries, but not veins, are specifically aligned with peripheral nerves in embryonic mouse limb skin. Mutations that eliminate peripheral sensory nerves or Schwann cells prevent proper arteriogenesis, while those that disorganize the nerves maintain the alignment of arteries with misrouted axons. In vitro, sensory neurons or Schw...

  18. Ectopic fat storage in heart, blood vessels and kidneys in the pathogenesis of cardiovascular diseases

    OpenAIRE

    Montani, Jean-Pierre; Carroll, Joan F; Dwyer, Terry M.; Antic, Vladan; Yang, Zhihong; Abdul G Dulloo

    2005-01-01

    In humans and most animal models, the development of obesity leads not only to increased fat depots in classical adipose tissue locations but also to significant lipid deposits within and around other tissues and organs, a phenomenon known as ectopic fat storage. The purpose of this review is to explore the possible locations of ectopic fat in key target-organs of cardiovascular control (heart, blood vessels and kidneys) and to propose how ectopic fat storage can play a role in the pathogenes...

  19. Segmentation of retinal blood vessels using normalized Gabor filters and automatic thresholding

    OpenAIRE

    Mandlenkosi Victor Gwetu; Jules Raymond Tapamo; Serestina Viriri

    2014-01-01

    Although computerized retinal image blood vessel segmentation has been extensively researched, there is still room for improvement in the quality of the segmented images. Since retinal image analysis is still widely used in the diagnosis of diabetic retinopathy, efficient and accurate image characterization techniques are required. Previous work has mainly focused on improving segmentation accuracy rates with little regard to the false positives that are produced by illumination variation. T...

  20. Blood vessel staining in the myocardium for 3D visualization down to the smallest capillaries

    International Nuclear Information System (INIS)

    Blood vessels formed after medical interventions such as radiofrequency treatment have to be visualized down to the capillary level with diameters of about 5 μm to validate neo-vascularization. Synchrotron radiation-based micro-computed tomography (SRμCT) provides the necessary spatial resolution. Since both the vessels and the surrounding tissue mainly consist of water the difference in absorption is extremely weak. Therefore, it is necessary to search for appropriate contrast agents and to develop suitable staining protocols, which finally allow segmenting the vessel tree. Among the contrast agents used in medicine lyophilic salts with a mean particle diameter of 1.5 μm such as CaSO4, SrSO4 and BaSO4 are most appropriate to stain the vessels. The combination of these salts with a commercially available embedding kit (JB-4, Polysciences Inc.) allows tissue fixation and long-term storage in solid state. Intensity-based segmentation algorithms enable the vessel tree extraction in selected parts of the stained myocardium using the SRμCT data

  1. An Automatic Cognitive Graph-Based Segmentation for Detection of Blood Vessels in Retinal Images

    Directory of Open Access Journals (Sweden)

    Rasha Al Shehhi

    2016-01-01

    Full Text Available This paper presents a hierarchical graph-based segmentation for blood vessel detection in digital retinal images. This segmentation employs some of perceptual Gestalt principles: similarity, closure, continuity, and proximity to merge segments into coherent connected vessel-like patterns. The integration of Gestalt principles is based on object-based features (e.g., color and black top-hat (BTH morphology and context and graph-analysis algorithms (e.g., Dijkstra path. The segmentation framework consists of two main steps: preprocessing and multiscale graph-based segmentation. Preprocessing is to enhance lighting condition, due to low illumination contrast, and to construct necessary features to enhance vessel structure due to sensitivity of vessel patterns to multiscale/multiorientation structure. Graph-based segmentation is to decrease computational processing required for region of interest into most semantic objects. The segmentation was evaluated on three publicly available datasets. Experimental results show that preprocessing stage achieves better results compared to state-of-the-art enhancement methods. The performance of the proposed graph-based segmentation is found to be consistent and comparable to other existing methods, with improved capability of detecting small/thin vessels.

  2. Do double gloves protect against contamination during cannulation of blood vessels? A prospective randomized study

    Directory of Open Access Journals (Sweden)

    Łukasz Szarpak

    2014-04-01

    Full Text Available Background: Undamaged medical gloves protect medical personnel from contact with physiological fluids of the patient. Thus they protect the assistance provider from hand skin contamination with potentially infectious biological material. The aim of the study was to evaluate the occurrence of pierce, perforations or damage of medical gloves during cannulation of blood vessels. Materials and Methods: In the prospective randomized study 303 pairs of gloves, used during cannulation of blood vessels under simulated resuscitation, were analyzed. Gloves were tested by the water leak test. Results: The water test revealed 44 cases of damage to the gloves used during cannulation of blood vessels. Significant differences were noted in the frequency of damage to both the outer and single pairs of gloves and the inner pair of gloves. Conclusions: The study showed that the use of double gloves provides a higher level of security for a paramedic than the use of a single pair of gloves, however, double gloves reduce the manual dexterity of a paramedic. A large number of damages to gloves are not noticed by medical personnel during surgery. Med Pr 2014;65(2:271–278

  3. High-resolution in-situ LDV monitoring system for measuring velocity distribution in blood vessel

    Science.gov (United States)

    Kyoden, Tomoaki; Abe, Shotaro; Ishida, Hiroki; Akiguchi, Shunsuke; Andoh, Tsugunobu; Takada, Yogo; Teranishi, Tsunenobu; Hachiga, Tadashi

    2015-10-01

    We herein describe a cross-sectional multiple-point laser Doppler velocimetry (CS-MLDV) system for monitoring blood vessels that are sutured and connected during an operation. In order to observe the condition of a blood vessel during an operation, the previously developed linear MLDV (L-MLDV) system can realize velocity distribution imaging of the carotid artery in a living mouse by means of traverse laser light. We subsequently developed a CS-MLDV system, which can measure the instantaneous two-dimensional (2D) flow velocity, by upgrading the optical components and signal processing used in L-MLDV. The validity of the CS-MLDV results was verified through comparison with the results of a computational fluid dynamics (CFD) analysis. The results of the CFD analysis were similar to the experimental results obtained under the same flow field condition. Moreover, an instantaneous 2D velocity distribution can be obtained even for the case of flowing blood. Finally, we carried out in-vivo measurement in a mesenteric vessel of a mouse in order to demonstrate the potential of the CS-MLDV for use in surgery.

  4. Sensitivity analysis aimed at blood vessels detection using interstitial optical tomography during brain needle biopsy procedures.

    Science.gov (United States)

    Pichette, Julien; Goyette, Andréanne; Picot, Fabien; Tremblay, Marie-Andrée; Soulez, Gilles; Wilson, Brian C; Leblond, Frédéric

    2015-11-01

    A brain needle biopsy procedure is performed for suspected brain lesions in order to sample tissue that is subsequently analysed using standard histopathology techniques. A common complication resulting from this procedure is brain hemorrhaging from blood vessels clipped off during tissue extraction. Interstitial optical tomography (iOT) has recently been introduced by our group as a mean to assess the presence of blood vessels in the vicinity of the needle. The clinical need to improve safety requires the detection of blood vessels within 2 mm from the outer surface of the needle, since this distance is representative of the volume of tissue that is aspirated durirng tissue extraction. Here, a sensitivity analysis is presented to establish the intrinsic detection limits of iOT based on simulations and experiments using brain tissue phantoms. It is demonstrated that absorbers can be detected with diameters >300 μm located up to >2 mm from the biopsy needle core for bulk optical properties consistent with brain tissue. PMID:26600990

  5. Modeling the Role of the Glymphatic Pathway and Cerebral Blood Vessel Properties in Alzheimer's Disease Pathogenesis.

    Directory of Open Access Journals (Sweden)

    Christina Rose Kyrtsos

    Full Text Available Alzheimer's disease (AD is the most common cause of dementia in the elderly, affecting over 10% population over the age of 65 years. Clinically, AD is described by the symptom set of short term memory loss and cognitive decline, changes in mentation and behavior, and eventually long-term memory deficit as the disease progresses. On imaging studies, significant atrophy with subsequent increase in ventricular volume have been observed. Pathology on post-mortem brain specimens demonstrates the classic findings of increased beta amyloid (Aβ deposition and the presence of neurofibrillary tangles (NFTs within affected neurons. Neuroinflammation, dysregulation of blood-brain barrier transport and clearance, deposition of Aβ in cerebral blood vessels, vascular risk factors such as atherosclerosis and diabetes, and the presence of the apolipoprotein E4 allele have all been identified as playing possible roles in AD pathogenesis. Recent research has demonstrated the importance of the glymphatic system in the clearance of Aβ from the brain via the perivascular space surrounding cerebral blood vessels. Given the variety of hypotheses that have been proposed for AD pathogenesis, an interconnected, multilayer model offers a unique opportunity to combine these ideas into a single unifying model. Results of this model demonstrate the importance of vessel stiffness and heart rate in maintaining adequate clearance of Aβ from the brain.

  6. Measuring properties of nanoparticles in embryonic blood vessels: Towards a physicochemical basis for nanotoxicity

    Science.gov (United States)

    Clancy, Aisling A.; Gregoriou, Yiota; Yaehne, Kristin; Cramb, David T.

    2010-03-01

    The developing field of nanotoxicology aims to relate the physical properties of nanomaterials to potential risk when organisms are exposed to those materials. Regulators are interested in whether a nanoformulation would alter the risk of the native material. It may be that due to the physical nature of embryonic blood vessels (i.e. they are angiogenic and therefore leaky), embryos are at greater risk for bioaccumulation of nanoparticles (NPs) than mature organisms. To study the physicochemical nature of nanoparticle accumulation from embryonic blood vessels, one needs to measure the NP properties in situ, because these properties could be significantly dependent on environment. We have undertaken a study of the dynamics of CdSe/ZnS quantum dots and polystyrene nanospheres in the blood vessels of the chicken embryo chorioallantoic membrane (CAM). We show proof of principle that fluorescence correlation spectroscopy can be used in this system to determine the concentrations and hydrodynamic radii of NP solutions micro-injected into the CAM.

  7. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    Directory of Open Access Journals (Sweden)

    Fenglin Song

    2014-01-01

    Full Text Available To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs. The aortic clamp time and the operative blood loss in the experimental group (using SMSBV were less than those in the control group (using Gore-Tex. The whole blood hematocrit, platelet count, plasma soluble P-selectin, plasma free hemoglobin, and interleukins 2, 6 at each time point were not different significantly between the two groups. Light microscopy and transmission electron microscopy examination showed there were layers of vascular smooth muscle cells and endothelial cells adhered in the inner wall of artificial blood vessel without any signs of thrombosis. Based on the result, we have drawn the conclusion that the application of SMSBV can significantly shorten the vascular anastomosis time, reduce operative blood loss, and show good blood and tissue compatibility.

  8. Adsorption of human blood plasma proteins on titanium implants

    Czech Academy of Sciences Publication Activity Database

    Vetterl, Vladimír; Vaněk, Jiří; Hasoň, Stanislav; Strašák, Luděk; Fojt, Lukáš

    Singapore, 2006. s. 81-81. [International Society of Electrochemistry, ISE Spring Meeting 2006. 17.04.2006-20.04.2006, Singapore] R&D Projects: GA AV ČR(CZ) IAA4004404 Grant ostatní: MŠk(CZ) 1M0528 Institutional research plan: CEZ:AV0Z50040507 Keywords : dental implants * electrochemical impedance spectroscopy * fibrinogen adsorption Subject RIV: BO - Biophysics

  9. Adsorption of human blood plasma proteins on titanium implants

    Czech Academy of Sciences Publication Activity Database

    Vetterl, Vladimír; Vaněk, J.; Hasoň, Stanislav; Strašák, Luděk; Ignác, Jan; Fojt, Lukáš

    Brno : Masarykova univerzita v Brně, 2006. s. 22-22. ISBN 80-210-4150-1. [Středoevropské sympozium, VII. brněnské implantologické dny. 23.11.2006-25.11.2006, Brno] Grant ostatní: MŠk(CZ) 1M0528 Institutional research plan: CEZ:AV0Z50040507 Keywords : dental implants * electrochemical impedance spectroscopy * fibrinogen adsorption Subject RIV: BO - Biophysics

  10. 假体隆乳术后严重包膜挛缩处理结合假体置入%Breast Prosthesis Implantation Combining with Correction for Capsular Contracture after Augmentation Mammoplasty

    Institute of Scientific and Technical Information of China (English)

    陈光平; 罗盛康

    2015-01-01

    Objective To explore the correction for serious capsular contracture after augmentation mammoplasty and the indication of breast prosthesis implantation. Methods From June 2006 to March 2014, 45 cases with serious capsular contracture after breast augmentation (Bilateral, level Ⅳ of Baker classification method) were treated and received breast prosthesis implantation at the same period or at stage Ⅱ. Via breast areola approach, the capsular tissue was kept or removed based on the circumstances, retro-mammary space or posterior pectoralis major space was stripped for prosthesis placing. Results Among all the cases, 38 cases received breast prosthesis at stage I, other 7 cases proceeded the second period of breast prosthesis 6 months later. Postoperative incisions were healed by first intension. Thirty-nine cases were followed up for 6-58 months (mean 13.5 months) successfully and the follow-up rate was 87.9%. Level Ⅳ of capsular contracture was still observed in 7 cases 4 months after the surgery, then the breast prosthesis was removed with no implantation again. The breast shape of remaining cases was good with soft handfeel. Conclusion For serious breast capsular contracture after augmentation mammoplasty, effective processing of the envelope with prosthesis imbedding according to the situation could obtain a better postoperative breast appearance and feel.%目的:探讨假体隆乳术后严重包膜挛缩的处理方法及乳房假体置入的适应征。方法2006年6月至2014年3月,对45例假体隆乳术后严重包膜挛缩(双侧乳房均为Baker分类法Ⅳ级)进行治疗,并进行同期或二期乳房假体置入。手术均采用乳晕切口入路,并根据情况保留或去除包膜组织,在乳腺后间隙或胸大肌后间隙置入假体。结果38例患者均一期置入乳房假体,7例于术后6个月行二期乳房假体置入。术后切口均一期愈合,39例获门诊随访,随访率86.7%,随访时间6~58

  11. Automatic segmentation of blood vessels from retinal fundus images through image processing and data mining techniques

    Indian Academy of Sciences (India)

    R Geetharamani; Lakshmi Balasubramanian

    2015-09-01

    Machine Learning techniques have been useful in almost every field of concern. Data Mining, a branch of Machine Learning is one of the most extensively used techniques. The ever-increasing demands in the field of medicine are being addressed by computational approaches in which Big Data analysis, image processing and data mining are on top priority. These techniques have been exploited in the domain of ophthalmology for better retinal fundus image analysis. Blood vessels, one of the most significant retinal anatomical structures are analysed for diagnosis of many diseases like retinopathy, occlusion and many other vision threatening diseases. Vessel segmentation can also be a pre-processing step for segmentation of other retinal structures like optic disc, fovea, microneurysms, etc. In this paper, blood vessel segmentation is attempted through image processing and data mining techniques. The retinal blood vessels were segmented through color space conversion and color channel extraction, image pre-processing, Gabor filtering, image postprocessing, feature construction through application of principal component analysis, k-means clustering and first level classification using Naïve–Bayes classification algorithm and second level classification using C4.5 enhanced with bagging techniques. Association of every pixel against the feature vector necessitates Big Data analysis. The proposed methodology was evaluated on a publicly available database, STARE. The results reported 95.05% accuracy on entire dataset; however the accuracy was 95.20% on normal images and 94.89% on pathological images. A comparison of these results with the existing methodologies is also reported. This methodology can help ophthalmologists in better and faster analysis and hence early treatment to the patients.

  12. Cooperative phenomena in two-pulse, two-color laser photocoagulation of cutaneous blood vessels.

    Science.gov (United States)

    Barton, J K; Frangineas, G; Pummer, H; Black, J F

    2001-06-01

    A novel laser system has been developed to study the effects of multiple laser pulses of differing wavelengths on cutaneous blood vessels in vivo, using the hamster dorsal skin flap preparation and in vitro, using cuvettes of whole or diluted blood. The system permits sequenced irradiation with well-defined intrapulse spacing at 532 nm, using a long-pulse frequency-doubled Nd:YAG laser, and at 1064 nm, using a long-pulse Nd:YAG laser. Using this system, we have identified a parameter space where two pulses of different wavelengths act in a synergistic manner to effect permanent vessel damage at radiant exposures where the two pulses individually have little or no effect. Using a two-color pump-probe technique in vitro, we have identified a phenomenon we call greenlight-induced infrared absorption, where a pulse of green light causes photochemical and photothermal modifications to the chemical constituents of blood and results in enhanced infrared absorption. We identify a new chemical species, met-hemoglobin, not normally present in healthy human blood but formed during laser photocoagulation which we believe is implicated in the enhanced near-infrared absorption. PMID:11421070

  13. In vivo bioimaging as a novel strategy to detect doxorubicin-induced damage to gonadal blood vessels.

    Directory of Open Access Journals (Sweden)

    Hadas Bar-Joseph

    Full Text Available INTRODUCTION: Chemotherapy may induce deleterious effects in normal tissues, leading to organ damage. Direct vascular injury is the least characterized side effect. Our aim was to establish a real-time, in vivo molecular imaging platform for evaluating the potential vascular toxicity of doxorubicin in mice. METHODS: Mice gonads served as reference organs. Mouse ovarian or testicular blood volume and femoral arterial blood flow were measured in real-time during and after doxorubicin (8 mg/kg intravenously or paclitaxel (1.2 mg/kg administration. Ovarian blood volume was imaged by ultrasound biomicroscopy (Vevo2100 with microbubbles as a contrast agent whereas testicular blood volume and blood flow as well as femoral arterial blood flow was imaged by pulse wave Doppler ultrasound. Visualization of ovarian and femoral microvasculature was obtained by fluorescence optical imaging system, equipped with a confocal fiber microscope (Cell-viZio. RESULTS: Using microbubbles as a contrast agent revealed a 33% (P<0.01 decrease in ovarian blood volume already 3 minutes after doxorubicin injection. Doppler ultrasound depicted the same phenomenon in testicular blood volume and blood flow. The femoral arterial blood flow was impaired in the same fashion. Cell-viZio imaging depicted a pattern of vessels' injury at around the same time after doxorubicin injection: the wall of the blood vessels became irregular and the fluorescence signal displayed in the small vessels was gradually diminished. Paclitaxel had no vascular effect. CONCLUSION: We have established a platform of innovative high-resolution molecular imaging, suitable for in vivo imaging of vessels' characteristics, arterial blood flow and organs blood volume that enable prolonged real-time detection of chemotherapy-induced effects in the same individuals. The acute reduction in gonadal and femoral blood flow and the impairment of the blood vessels wall may represent an acute universal doxorubicin

  14. Multiparameter fluorescence mapping of nonprotein sulfhydryl status in relation to blood vessels and hypoxia in cervical carcinoma xenografts

    International Nuclear Information System (INIS)

    Purpose: Aberrant architecture of the tumor vasculature and temporal fluctuations in blood flow can result in tumor hypoxia. The aim of this study was to classify tumor hypoxia based on distance to blood vessels, and to characterize its biologic significance by determining levels of nonprotein sulfhydryls (NPSH) in hypoxic regions located proximally and distally to tumor blood vessels. Methods and Materials: A dual fluorescence method was developed for the spatial colocalization of the vasculature and hypoxia in frozen sections from SiHa cervical carcinoma xenografts. A parallel section was stained with the sulfhydryl stain mercury orange. Composite fluorescence images were generated by imaging and tiling individual fields of view into 2D image arrays. Image arithmetic techniques were combined with feature-based image segmentation to characterize expression of NPSH as a function of the hypoxic tumor microenvironment. Results: NPSH levels were higher in hypoxic areas of the SiHa xenografts (15.1±0.5 vs. 13.5±0.5 integrated optical density [IOD], p<0.03). When tumor hypoxia was classified by distance to the nearest visible blood vessel, significantly higher NPSH levels were found in hypoxic regions close to blood vessels than in regions at a distance from blood vessels. Conclusion: The results of this study indicate differential expression of NPSH levels in regions of hypoxia that are proximal or distal to blood vessels in SiHa tumors

  15. [A fundamental study of the fabrication of a medical prosthesis by slip casting (author's transl)].

    Science.gov (United States)

    Ohkawa, S

    1982-01-01

    Sintered 316 L stainless steel, made by slip casting, was studied in the present work for its potential use as a medical prosthesis. The physical and mechanical properties were scrutinized to determine characteristics of the specimens. Corrosion tests were conducted in boiling 5% H2SO4. Microstructures of the specimens were examined. The samples were implanted for 31 days in the dorsolateral subcutaneous site of living rats. The results were as follows. The shrinkage during heating varied from 10.3 to 33.0%, the relative density from 0.41 to 0.78, and porosity from 20.4 to 58.2%. Tensile strength varied from 2.3 to 24.6 kg/mm2, yield strength from 2.8 to 11.6 kg/mm2, elastic modulus from 1 075 to 7 400 kg/mm2, elongation from 9.1 to 19%, hardness of Brinell scale from 7.5 to 53.1. Mechanical properties as mentioned above decreased with increasing porosity. Pore size distribution varied 4.4 to 44 mu. Both Si and ferrite, or either of the two were observed in the matrix of austenite. Corrosion resistance were effected greatly by the porosity. Blood vessels, fibroblasts, fibrous tissues were found surrounding the sintered specimens and in the interior pores. No degeneration or necrosis were noted. Based on the tentative findings of the present studies, I can say that sintered stainless steel have a potential for medical application. PMID:6951897

  16. Peripheral white blood cells profile of biodegradable metal implant in mice animal model

    International Nuclear Information System (INIS)

    Biocompatibility or safety of the medical device is considered important. It can be determined by blood profile examination. The aim of this study was to assess the biocompatibility of biodegradable metal implant through peripheral white blood cells (WBCs) profile approach. Forty eight male ddy mice were divided into four groups according to the materials implanted: iron wire (Fe), magnesium rod (Mg), stainless steel surgical wire (SS316L) and control with sham (K). Implants were inserted and attached onto the right femoral bone on latero-medial region. In this study, peripheral white blood cells and leukocyte differentiation were the parameters examined. The result showed that the WBCs value of all groups were decreased at the first day after implantation, increased at the 10th day and continued increasing at the 30th day of observation, except Mg group which has decreased. Neutrophil, as an inflammatory cells, was increased at the early weeks and decreased at the day-30 after surgery in all groups. Despite, these values during the observation were still within the normal range. As a conclus ion, biodegradable metal implants lead to an inflammatory reaction, with no adverse effect on WBC value found

  17. Peripheral white blood cells profile of biodegradable metal implant in mice animal model

    Energy Technology Data Exchange (ETDEWEB)

    Paramitha, Devi; Noviana, Deni, E-mail: deni@ipb.ac.id; Estuningsih, Sri [Faculty of Veterinary Medicine, Bogor Agricultural University (IPB), Bogor (Indonesia); Ulum, Mokhamad Fakhrul [Faculty of Veterinary Medicine, Bogor Agricultural University (IPB), Bogor (Indonesia); Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru (Malaysia); Nasution, Ahmad Kafrawi [Faculty of Biosciences and Medical Engineering, Universiti Teknologi Malaysia (UTM), Johor Bahru (Malaysia); Faculty of Engineering, Muhammadiyah University of Riau (UMRI), Pekanbaru (Indonesia); Hermawan, Hendra [Department of Mining, Metallurgical and Materials Engineering & CHU de Québec Research Center, Laval University (ULaval) (Canada)

    2015-09-30

    Biocompatibility or safety of the medical device is considered important. It can be determined by blood profile examination. The aim of this study was to assess the biocompatibility of biodegradable metal implant through peripheral white blood cells (WBCs) profile approach. Forty eight male ddy mice were divided into four groups according to the materials implanted: iron wire (Fe), magnesium rod (Mg), stainless steel surgical wire (SS316L) and control with sham (K). Implants were inserted and attached onto the right femoral bone on latero-medial region. In this study, peripheral white blood cells and leukocyte differentiation were the parameters examined. The result showed that the WBCs value of all groups were decreased at the first day after implantation, increased at the 10th day and continued increasing at the 30th day of observation, except Mg group which has decreased. Neutrophil, as an inflammatory cells, was increased at the early weeks and decreased at the day-30 after surgery in all groups. Despite, these values during the observation were still within the normal range. As a conclus ion, biodegradable metal implants lead to an inflammatory reaction, with no adverse effect on WBC value found.

  18. Accuracy and Precision of MR Blood Oximetry Based On the Long Paramagnetic Cylinder Approximation of Large Vessels

    OpenAIRE

    Langham, Michael C; Magland, Jeremy F; Epstein, Charles L.; Floyd, Thomas F; Wehrli, Felix W.

    2009-01-01

    An accurate non-invasive method to measure hemoglobin oxygen saturation (%HbO2) of deep-lying vessels without catheterization would have many clinical applications. Quantitative MRI may be the only imaging modality that can address this difficult and important problem. MR susceptometry-based oximetry for measuring blood oxygen saturation in large vessels models the vessel as a long paramagnetic cylinder immersed in an external field. The intravascular magnetic susceptibility relative to surro...

  19. Application of the (G'/G)-expansion method to nonlinear blood flow in large vessels

    International Nuclear Information System (INIS)

    As is widely known today, Navier-Stokes equations are used to describe blood flow in large vessels. In the past several decades, and even in very recent works, these equations have been reduced to Korteweg-de Vries (KdV), modified KdV or Boussinesq equations. In this paper, we avoid such simplifications and investigate the analytical traveling wave solutions of the one-dimensional generic Navier-Stokes equations, through the (G ' /G)-expansion method. These traveling wave solutions include hyperbolic functions, trigonometric functions and rational functions. Since some of them are not yet explored in the study of blood flow, we pay attention to hyperbolic function solutions and we show that the (G ' /G)-expansion method presents a wider applicability that allows us to bring out the widely known blood flow behaviors. The biological implications of the found solutions are discussed accordingly.

  20. Apparatus and method for examining a blood vessel of interest using radiation detected outside the body

    International Nuclear Information System (INIS)

    Stenotic atherosclerotic lesions of the coronary arteries are detected by injecting a number of particulate signal sources such as positron-emitting particles (e.g. gallium 68) into the blood of a subject to determine the velocity of blood flow through the coronary vessels. The particles are tracked in three dimensions whenever they appear in the region of the heart by means of high-resolution high-speed gamma detectors that surround the chest. These recordings of particle position as a function of time are analyzed, and the velocity of blood as it flows through the coronary artery is measured by timing the transit of the particle. From the accumulated data of multiple particle transits through the coronary circulation, a three-dimensional representation of the lumen of the coronary arterial system is constructed

  1. Selective irradiation of the blood vessels by using boron neutron capture reaction - development and its utilization

    International Nuclear Information System (INIS)

    Full text: The purposes are development of the method to irradiate blood vessels selectively by using B-10(n, alpha) Li-7 reaction and examination of its effect on tumor and normal tissues. We made BSH-enclosed large size liposome (=300 nm) conjugated with PEG ; BSH-PEG-liposome. This type liposome is thought to escapes from macrophage in the liver, and can stay in the blood at high concentration level for long time. They are also considered not to be able to leak from the vessels into the surrounding tissues. If they receive neutron, B-10 emits extreme short-range (<9 micron) alpha-particle and recoil Li-7 nucleus. C3H/He mice and tumor model SCCVII were used to examine the character and effect of this type liposome. Thermal neutron irradiation was performed by KUR heavy water facility and B-10 concentrations in the blood or tissues were measured by prompt gamma-ray spectrometry. The B-10 concentration ratio between blood and tumor 30 minutes after BSH-PEG-liposome administration was 35- 40, and this ratio was stable for several hours. The effect on the tumors that received neutrons was examined by colony formation assay. The tumor cell survival rate of the BSH-PEG-liposome neutron group was very slightly suppressed in comparison with that of neutron alone group, however, the growth of the tumors was remarkably suppressed in BSH-PEG-liposome neutron group. In the mice that received whole body neutron irradiation after BSH-PEF-liposome injection, the mouse group of 50 Gy to the endothelium of the vessel did exhibit no death, and in the groups of 127 and 183 Gy, all individuals died. But diarrhea and bloody anal discharge that suggested radiation intestinal death were not observed at all. Cause of the death seemed to be bone marrow death

  2. Management of a Fractured Multiunit Maxillary Implant-Supported Fixed Prosthesis with Stripped Abutment Screws Using a Hybrid Cement-Retained and Screw-Retained Design: A 5-Year Follow-Up Clinical Report.

    Science.gov (United States)

    Al Amri, Mohammad D

    2016-06-01

    Fracture and loosening of implant-supported prostheses (ISPs) are complications encountered in routine dental practice. In the present report, management of a fractured maxillary full-arch cement-retained (CR) fixed dental prosthesis supported by six implants is presented. Due to stripped screws, complications were encountered that prevented the retrieval of two of the six abutment screws, which was managed by using a hybrid retention approach, whereby a single full-arch CR and screw-retained (SR) ISP was used. The techniques used to successfully retrieve four of the abutment screws are described. The final retention design involved a combination of three CR and three SR restorations, which offers the advantages of both retention designs. PMID:26713868

  3. An Automated Graphical User Interface based System for the Extraction of Retinal Blood Vessels using Kirsch’s Template

    OpenAIRE

    Joshita Majumdar; Souvik Tewary; Shreyosi Chakraborty; Debasish Kundu; Sudipta Ghosh; Sauvik Das Gupta

    2015-01-01

    The assessment of Blood Vessel networks plays an important role in a variety of medical disorders. The diagnosis of Diabetic Retinopathy (DR) and its repercussions including micro aneurysms, haemorrhages, hard exudates and cotton wool spots is one such field. This study aims to develop an automated system for the extraction of blood vessels from retinal images by employing Kirsch’s Templates in a MATLAB based Graphical User Interface (GUI). Here, a RGB or Grey image of the retina (Fundus Phot...

  4. 78 FR 38867 - Gastroenterology-Urology Devices; Reclassification of Implanted Blood Access Devices

    Science.gov (United States)

    2013-06-28

    ... discussed in the preamble to the proposed rule (46 FR 7616; January 23, 1981), the Gastroenterology-Urology... section 513(e) proposing the reclassification of implanted blood access devices for hemodialysis (77 FR... reclassification for June 27, 2013 (78 FR 25747; May 2, 2013). The three comments submitted in response to...

  5. Fracture embolization of a Duromedics mitral prosthesis.

    OpenAIRE

    Baumgartner, F J; Munro, A I; Jamieson, W R

    1997-01-01

    The Duromedics bileaflet pyrolitic carbon mechanical prosthesis was introduced by Hemex in 1982 and subsequently acquired by Baxter. This communication documents a case of sudden leaflet fracture of a Duromedics mitral valve 48 months after implantation, which was managed successfully by replacement with a St. Jude Medical mechanical prosthesis. The patient presented in acute distress with paroxysmal atrial tachycardia and pulmonary edema. Transesophageal echocardiography was used to diagnose...

  6. An ensemble classification-based approach applied to retinal blood vessel segmentation.

    Science.gov (United States)

    Fraz, Muhammad Moazam; Remagnino, Paolo; Hoppe, Andreas; Uyyanonvara, Bunyarit; Rudnicka, Alicja R; Owen, Christopher G; Barman, Sarah A

    2012-09-01

    This paper presents a new supervised method for segmentation of blood vessels in retinal photographs. This method uses an ensemble system of bagged and boosted decision trees and utilizes a feature vector based on the orientation analysis of gradient vector field, morphological transformation, line strength measures, and Gabor filter responses. The feature vector encodes information to handle the healthy as well as the pathological retinal image. The method is evaluated on the publicly available DRIVE and STARE databases, frequently used for this purpose and also on a new public retinal vessel reference dataset CHASE_DB1 which is a subset of retinal images of multiethnic children from the Child Heart and Health Study in England (CHASE) dataset. The performance of the ensemble system is evaluated in detail and the incurred accuracy, speed, robustness, and simplicity make the algorithm a suitable tool for automated retinal image analysis. PMID:22736688

  7. A numerical analysis on the curved bileaflet Mechanical Heart Valve (MHV) : leaflet motion and blood flow in an elastic blood vessel

    International Nuclear Information System (INIS)

    In blood flow passing through the Mechanical Heart Valve (MHV) and elastic blood vessel, hemolysis and platelet activation causing thrombus formation can be seen owing to the shear stress in the blood. Also, fracture and deformation of leaflets can be observed depending on the shape and material properties of the leaflets which is opened and closed in a cycle. Hence, comprehensive study is needed on the hemodynamics which is associated with the motion of leaflet and elastic blood vessel in terms of fluid-structure interaction. In this paper, a numerical analysis has been performed for a three-dimensional pulsatile blood flow associated with the elastic blood vessel and curved bileaflet for multiple cycles in light of fluid-structure interaction. From this analysis fluttering phenomenon and rebound of the leaflet have been observed and recirculation and regurgitation have been found in the flow fields of the blood. Also, the pressure distribution and the radial displacement of the elastic blood vessel have been obtained. The motion of the leaflet and flow fields of the blood have shown similar tendency compared with the previous experiments carried out in other studies. The present study can contribute to the design methodology for the curved bileaflet mechanical heart valve. Furthermore, the proposed fluid-structure interaction method will be effectively used in various fields where the interaction between fluid flow and structure are involved

  8. Prosthesis Material

    Science.gov (United States)

    2004-01-01

    In this photograph, Amputee Amie Bradly uses a NASA-developed prosthesis to paint her fingernails. Derived from foam insulation technology used to protect the Space Shuttle External Tank from excessive heat, FAB/CAD, a subsidiary of the Harshberger Prosthetic and Orthotic Center, utilized the technology to replace the heavy, fragile plaster they used to produce master molds for prosthetics. The new material was lighter, cheaper and easier to manufacture than plaster, resulting in lower costs to the customer.

  9. In Silico Magnetic Nanocontainers Navigation in Blood Vessels: A Feedback Control Approach.

    Science.gov (United States)

    Do, Ton Duc; Noh, Yeongil; Kim, Myeong Ok; Yoon, Jungwon

    2016-06-01

    Magnetic nanoparticles (MNPs) are recently used in a drug delivery system to pass the blood brain barrier. However, because the magnetic force acting on particles is proportional to their volumes, as the size of particles is small, the large magnetic field is required to produce enough magnetic force for overcoming the hydrodynamic drag force as well as other forces in blood vessels. Other difficulties for controlling MNPs are the complicated behavior of hydrodynamic drag force and uncertain factors in their dynamics. Therefore, open-loop control methods cannot guarantee guiding every MNP to the correct location. Considering these challenges, this paper introduces a feedback control approach for magnetic nanoparticles (MNPs) in blood vessels. To the best of our knowledge, this is the first time feedback controller that is designed for MNPs without aggregation. Simulation studies in MATLAB and real-time verifications on a physical model in COMSOL-MATLAB interface are performed to prove the feasibility of the proposed approach. It is shown that the proposed control scheme can accurately and effectively navigate the MNP to the correct path with feasible hardware supports. PMID:27427720

  10. Cyclic volatile methylsiloxanes in human blood as markers for ruptured silicone gel-filled breast implants.

    Science.gov (United States)

    Rosendahl, Pia; Hippler, Joerg; Schmitz, Oliver J; Hoffmann, Oliver; Rusch, Peter

    2016-05-01

    The replacement of medical-grade silicone with industrial-grade silicone material in some silicone gel-filled breast implants (SBI) manufactured by Poly Implant Prothèse and Rofil Medical Nederland B.V., reported in 2010, which resulted in a higher rupture tendency of these SBI, demonstrates the need for non-invasive, sensitive monitoring and screening methods. Therefore a sensitive method based on large volume injection-gas chromatography coupled to mass spectrometry (LVI-GC/MS) was developed to determine octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclo-hexasiloxane (D6) in blood samples from women with intact (n = 13) and ruptured SBI (n = 11). With dichloromethane extraction, sample cooling during preparation, and analysis extraction efficiencies up to 100 % and limits of detection of 0.03-0.05 ng D4-D6/g blood were achieved. Blood samples from women with SBI were investigated. In contrast to women with intact SBI, in blood from women with ruptured SBI higher D4 and D6 concentrations up to 0.57 ng D4/g blood and 0.16 ng D6/g blood were detected. With concentrations above 0.18 D4 ng/blood and 0.10 ng D6/g blood as significant criteria for ruptured SBI, this developed analytical preoperative diagnostic method shows a significant increase of the recognition rate. Finally a higher precision (error rate 17 %) than the commonly used clinical diagnostic method, mamma sonography (error rate 46 %), was achieved. Graphical Abstract Comparison of the recognition rate of silicone breast implant failures via commonly used clinical diagnostic method (mamma sonography) and developed analytical method (determination of cyclic volatile siloxanes concentration in human blood with LVI-GC-MS). PMID:26968566

  11. Regional heterogeneity in the reactivity of equine small pulmonary blood vessels.

    Science.gov (United States)

    Stack, Alice; Derksen, Frederik J; Williams, Kurt J; Robinson, N Edward; Jackson, William F

    2016-03-15

    Regional differences in large equine pulmonary artery reactivity exist. It is not known if this heterogeneity extends into small vessels. The hypothesis that there is regional heterogeneity in small pulmonary artery and vein reactivity to sympathomimetics (phenylephrine and isoproterenol) and a parasympathomimetic (methacholine) was tested using wire myography on small vessels from caudodorsal (CD) and cranioventral (CV) lung of 12 horses [9 mares, 3 geldings, 8.67 ± 0.81 (age ± SE) yr, of various breeds that had never raced]. To study relaxation, vessels were precontracted with U46619 (10(-6) M). Methacholine mechanism of action was investigated using l-nitroarginine methylester (l-NAME, 100 μM) and indomethacin (10 μM). Phenylephrine did not contract any vessels. Isoproterenol relaxed CD arteries more than CV arteries (maximum relaxation 28.18% and 48.67%; Log IC50 ± SE -7.975 ± 0.1327 and -8.033 ± 0.1635 for CD and CV, respectively, P < 0.0001), but not veins. Methacholine caused contraction of CD arteries (maximum contraction 245.4%, Log EC50 ± SE -6.475 ± 0.3341), and relaxation of CV arteries (maximum relaxation 40.14%, Log IC50 ± SE -6.791 ± 0.1954) and all veins (maximum relaxation 50.62%, Log IC50 ± SE -6.932 ± 0.1986) in a nonregion-dependent manner. l-NAME (n = 8, P < 0.0001) and indomethacin (n = 7, P < 0.0001) inhibited methacholine-induced relaxation of CV arteries, whereas indomethacin augmented CD artery contraction (n = 8, P < 0.0001). Our data demonstrate significant regional heterogeneity in small blood vessel reactivity when comparing the CD to the CV region of the equine lung. PMID:26769957

  12. Launch Conditions Might Affect the Formation of Blood Vessel in the Quail Chorioallantoic Membrane

    Science.gov (United States)

    Henry, M. K.; Unsworth, B. R.; Sychev, B. R.; Guryeva, T. S.; Dadasheva, O. A.; Piert, S. J.; Lagel, K. E.; Dubrovin, L. C.; Jahns, G. C.; Boda, K.; Sabo, V.; Samet, M. M.; Lelkes, P. I.

    1998-01-01

    AS 2 part of the first joint USA-Russian MIR/Shuttle program, fertilized quail eggs were flown on the MIR 18 mission. Post-flight examination indicated impaired survival of both the embryos in space and also of control embryos exposed to vibrational and g-forces simulating the conditions experienced during the launch of Progress 227. We hypothesized that excess mechanical forces and/or other conditions during the launch might cause abnormal development of the blood supply in the chorioallantoic membrane (CAM) leading to the impaired survival of the embryos. The CAM, a highly vascularized extraembryonic organ, provides for the oxygen exchange across the egg shell and is thus pivotal for proper embryonic development. To test our hypothesis, we compared angiogenesis In CAMS of eggs which were either exposed to the vibration and g-force profile simulating the conditions at launch of Progress 227 (synchronous controls), or kept under routine conditions in a laboratory Incubator (laboratory controls). At various time points during Incubation, the eggs were fixed in paraformaldehyde for subsequent dissection. At the time of dissection, the CAM was carefully lifted from the egg shell and examined as whole mounts by bright-field and fluorescent microscopy. The development or the vasculature (angiogenesis) was assessed from the density of blood vessels per viewing field and evaluated by computer aided image analysis. We observed a significant decrease In blood-vessel density in the synchronous controls versus "normal" laboratory controls beginning from day 10 of Incubation. The decrease in vascular density was restricted to the smallest vessels only, suggesting that conditions during the launch and/or during the subsequent Incubation of the eggs may affect the normal progress of angiogenesis in the CAM. Abnormal angiogenesis In the CAM might contribute to the impaired survival of the embryos observed in synchronous controls as well as in space.

  13. Implantable reflectance pulse transit time blood pressure sensor with oximetry capability

    Science.gov (United States)

    Fiala, J.; Gehrke, R.; Theodor, M.; Bingger, P.; Förster, K.; Heilmann, C.; Beyersdorf, F.; Zappe, H.; Seifert, A.

    2010-04-01

    We present a novel implantable multi-wavelength reflectance sensor for the measurement of blood pressure with pulse transit time (PTT). Continuous long-term monitoring of blood pressure and arterial oxygen saturation is vital for medical diagnostics and the ensuing therapy of cardiovascular diseases. Conventional cuff-based blood pressure monitors do not provide continuous data and put severe constraints on the patients' daily lives. An implantable sensor would eliminate such problems. The new biocompatible sensor is placed subcutaneously on blood perfused tissue. The PTT is calculated by photoplethysmograms and the ECG-signal, that is recorded with intracorporal electrodes. In addition, the sensor detects the arterial oxygen saturation. An ensuing spectralphotometric analysis of the light intensity changes delivers data on the concentration of dysfunctional hemoglobin derivatives. Experimental measurements showed a clear correlation between the estimated PTT and the systolic blood pressure reference. These initial results demonstrate the potential of the sensor as part of an fully implantable sensor system for the longterm-monitoring of cardiovascular parameters.

  14. Effects of Three Types of Long-acting Contraceptive Implants on Menstrual Blood Loss in 89 Women

    Institute of Scientific and Technical Information of China (English)

    韩丽晖; 范慧民; 龚泉; 谢争; 孟凡; 洪玉凤; 王文娟

    1999-01-01

    Objective: To study the effects of three types of contraceptive implants: the domestic No I , No I implants and Norplant on menstrual blood loss (MBL). Method: Eighty-nine healthy subjects were randomly allocated to three groups.Menstrual blood loss was measured before implanting and 3, 6, and 12 months after implantation. Results: MBL of the three groups prior to the use of implant were 43. 3±6. 9ml,48.9±4. 3 ml, and 43.7±5. 5ml respectively, and decreased significantly at all post-implantation periods. MBLs were 32. 8±13. 2ml, 24. 8±5. 5ml, and 19. 7±9.3ml at the 3rd month after implantation and 23. 9±5. 9 ml, 40. 8±10. 4 ml, 25. 9±6. 0 ml at the 12th month after implantation respectively, sigmficantly less than before implantation(P<0. 05~0. 01). A tendency was seen in increase of hemoglobin concentraition. Conclusion: Long-acting contraceptive implants decreased menstrual blood loss and elevates hemoglobin concentration. They are applicable to women as a contraceptive method without blood loss effects.

  15. Corrosion resistance and blood compatibility of lanthanum ion implanted pure iron by MEVVA

    International Nuclear Information System (INIS)

    Pure iron is a potential material applying for coronary artery stents based on its biocorrodible and nontoxic properties. However, the degradation characteristics of pure iron in vivo could reduce the mechanical stability of iron stents prematurely. The purpose of this work was to implant the lanthanum ion into pure iron specimens by metal vapor vacuum arc (MEVVA) source at an extracted voltage of 40 kV to improve its corrosion resistance and biocompatibility. The implanted fluence was up to 5 x 1017 ions/cm2. The X-ray photoelectron spectroscopy (XPS) was used to characterize the chemical state and depth profiles of La, Fe and O elements. The results showed lanthanum existed in the +3 oxidation state in the surface layer, most of the oxygen combined with lanthanum and form a layer of oxides. The lanthanum ion implantation layer could effectively hold back iron ions into the immersed solution and obviously improved the corrosion resistance of pure iron in simulated body fluids (SBF) solution by the electrochemical measurements and static immersion tests. The systematic evaluation of blood compatibility, including in vitro platelets adhesion, prothrombin time (PT), thrombin time (TT), indicated that the number of platelets adhesion, activation, aggregation and pseudopodium on the surface of the La-implanted samples were remarkably decreased compared with pure iron and 316L stainless steel, the PT and TT were almost the same as the original plasma. It was obviously showed that lanthanum ion implantation could effectively improve the corrosion resistance and blood compatibility of pure iron.

  16. A Pulsatile Flow Phantom for Image-Guided HIFU Hemostasis of Blood Vessels

    International Nuclear Information System (INIS)

    A pulsatile flow phantom for studying ultrasound image-guided acoustic hemostasis in a controlled environment has been developed. An ex vivo porcine carotid artery was attached to the phantom and embedded in a visually and ultrasonically transparent gel. Heparinized porcine blood was pumped through the phantom. Power-Doppler and B-mode ultrasound were used to remotely target the HIFU focus to the site of a needle puncture. In nine trials, complete hemostasis was achieved after an average HIFU application of 55 +/- 34 seconds. The vessels remained patent after treatment. With this phantom, it will be possible to do controlled studies of ultrasound image-guided acoustic hemostasis

  17. Effect of Rolling Massage on Particle Moving Behaviour in Blood Vessels

    International Nuclear Information System (INIS)

    The rolling massage manipulation is a classic Chinese massage, which is expected to eliminate many diseases. Here the effect of the rolling massage on the particle moving property in the blood vessels under the rolling massage manipulation is studied by the lattice Boltzmann simulation. The simulation results show that the particle moving behaviour depends on the rolling velocity, the distance between particle position and rolling position. The average values, including particle translational velocity and angular velocity, increase as the rolling velocity increases almost linearly. The result is helpful to understand the mechanism of the massage and develop the rolling techniques. (cross-disciplinary physics and related areas of science and technology)

  18. Effects of a protein glycocalyx in the hemodynamics of small blood vessels

    Science.gov (United States)

    Dimakopoulos, Yiannis; Delidakis, George; Tsamopoulos, John

    2015-11-01

    Glycocalyx is a protein layer of approximate thickness 0.5 μm that lines vessel walls. We study the effects this layer has on the blood flow inside arterioles and venules, where the relative size of the glycocalyx is significant. To properly describe phenomena that naturally occur in blood flow, such as the inhomogeneous distribution of red blood cells and their aggregation, we use an improved viscoelastic constitutive model. The glycocalyx layer is modeled as fixed porous media. Cells cannot penetrate inside it, since its hydraulic permeability is very low, and the flow inside this layer is described by the equations for a viscous fluid with an extra Brinkman term to account for the effects the porous medium has on the flow. The closed set of equations is solved using the Finite Element method, assuming steady-state with dependence only in the r-direction. Our results are favorably compared with the in vivo velocity profiles in venules of mice produced by Damiano et al. (2004) and the formation of cell-free layer near glycocalyx. Flow inside the glycocalyx layer is found to be severely attenuated due to the low hydraulic permeability, which can have interesting implications in the transport of various substances form the blood to the tissues or in the use of shear stresses as signals for the endothelial surface cells. Finally, we simulate the transient blood flow under pulsatile conditions.

  19. A kinematic study of pulsation in the dorsal blood vessel of the blackworm, Lumbriculus variegatus

    Directory of Open Access Journals (Sweden)

    Kameko Halfmann

    2011-01-01

    Full Text Available The aquatic oligochaete Lumbriculus variegatus has a segmented, dorsal blood vessel (DBV that acts as a peristaltic pump to move blood through the animal's closed circulatory system. We conducted a kinematic study using videography and computational modeling as a first step toward understanding the control of DBV pulsation. Results suggested that pulse rates were highest in the posterior segments, while interpulse intervals and intersegmental delays were longest in the midbody segments. Differences in the interpulse interval distributions across regions suggest that some peristaltic waves initiated in the posterior segments do not propagate all the way to the anterior segments. A simple model consisting of a chain of excitable neuromuscular units replicated these kinetics. This model may be useful in future research aimed at understanding the modulatory effect of biogenic amines on peristalsis of the DBV. Moreover, research into the mechanisms of peristalsis of the DBV may lead to insights into disorders of peristalsis in human and veterinary medicine

  20. Apparatus and method for examining a blood vessel of interest using radiation detected outside the body

    International Nuclear Information System (INIS)

    A gamma camera is described in detail for use in examining the blood circulation in vessels adjacent to the heart. The radiation source (e.g. 68Ga) emits positrons whose annihilation is localised and produces two 0.115 MeV gamma rays in exactly opposite directions. By detecting both gamma rays in coincidence in position sensitive multi-wire proportional chambers, lines may be drawn between detected pairs and the intersection of of all such pairs will define the position of the positron emitting source. The radiation source may be tracked in three dimensions by suitably arranging the detectors around the patient's chest. The position of the radiation source can be recorded as a function of time and hence provide information about the velocity of blood flow through each coronary artery. This information may help determine the extent, severity and location of stenotic lesions of the coronary arteries. (U.K.)

  1. An Ultrasound Simulation Model for the Pulsatile Blood Flow Modulated by the Motion of Stenosed Vessel Wall.

    Science.gov (United States)

    Zhang, Qinghui; Zhang, Yufeng; Zhou, Yi; Zhang, Kun; Zhang, Kexin; Gao, Lian

    2016-01-01

    This paper presents an ultrasound simulation model for pulsatile blood flow, modulated by the motion of a stenosed vessel wall. It aims at generating more realistic ultrasonic signals to provide an environment for evaluating ultrasound signal processing and imaging and a framework for investigating the behaviors of blood flow field modulated by wall motion. This model takes into account fluid-structure interaction, blood pulsatility, stenosis of the vessel, and arterial wall movement caused by surrounding tissue's motion. The axial and radial velocity distributions of blood and the displacement of vessel wall are calculated by solving coupled Navier-Stokes and wall equations. With these obtained values, we made several different phantoms by treating blood and the vessel wall as a group of point scatterers. Then, ultrasound echoed signals from oscillating wall and blood in the axisymmetric stenotic-carotid arteries were computed by ultrasound simulation software, Field II. The results show better consistency with corresponding theoretical values and clinical data and reflect the influence of wall movement on the flow field. It can serve as an effective tool not only for investigating the behavior of blood flow field modulated by wall motion but also for quantitative or qualitative evaluation of new ultrasound imaging technology and estimation method of blood velocity. PMID:27478840

  2. 3D Computer Simulations of Pulsatile Human Blood Flows in Vessels and in the Aortic Arch: Investigation of Non-Newtonian Characteristics of Human Blood

    CERN Document Server

    Sultanov, Renat A; Engelbrekt, Brent; Blankenbecler, Richard

    2008-01-01

    Methods of Computational Fluid Dynamics are applied to simulate pulsatile blood flow in human vessels and in the aortic arch. The non-Newtonian behaviour of the human blood is investigated in simple vessels of actual size. A detailed time-dependent mathematical convergence test has been carried out. The realistic pulsatile flow is used in all simulations. Results of computer simulations of the blood flow in vessels of two different geometries are presented. For pressure, strain rate and velocity component distributions we found significant disagreements between our results obtained with realistic non-Newtonian treatment of human blood and widely used method in literature: a simple Newtonian approximation. A significant increase of the strain rate and, as a result, wall sear stress distribution, is found in the region of the aortic arch. We consider this result as theoretical evidence that supports existing clinical observations and those models not using non-Newtonian treatment underestimate the risk of disru...

  3. Fixed Dental Prosthesis on 4.2 mm Length Rough Implants: A Case Series Report after an Average Loading Time of 33 Months

    OpenAIRE

    Reingewirtz, Yves; Tenenbaum, Henri

    2015-01-01

    Aim. Several limiting factors encourage the clinician to use short implants. Among those, the presence of limiting anatomical elements and the simplification of surgical procedures are particularly significant. The goal of this study is to analyse the opportunity to extend the use of short implants to extrashort implants with a length less than 5 mm (ESI). Materials and Methods. Seven patients (3 women, 4 men; mean age 60.4 years) received extrashort implants (Straumann Implant, Palatal Ortho...

  4. Direct blood pressure monitoring in laboratory rodents via implantable radio telemetry.

    Science.gov (United States)

    Huetteman, Daniel A; Bogie, Heather

    2009-01-01

    The ability to monitor and record precise blood pressure fluctuations in research animals is vital to research for human hypertension. Direct measurement of blood pressure via implantable radio telemetry devices is the preferred method for automatic collection of chronic, continuous blood pressure data. Two surgical techniques are described for instrumenting the two most commonly used laboratory rodent species with radiotelemetry devices. The basic rat procedure involves advancing a blood pressure catheter into the abdominal aorta and placing a radio transmitting device in the peritoneal cavity. The mouse technique involves advancing a thin, flexible catheter from the left carotid artery into the aortic arch and placing the telemetry device under the skin along the animal's flank. Both procedures yield a chronically instrumented model to provide accurate blood pressure data from an unrestrained animal in its home cage. PMID:19763922

  5. Protective role of a novel human erythrocyte-derived depressing factor on blood vessels in rats

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The protective role of a human erythrocyte-derived depressing factor (EDDF) on blood vessels was evaluated. The experiments were carried out on 25male Wistar rats aged 6-8 weeks, which were divided into control (n = 8), calcium overload (n = 8) and NG-L-nitro-arginine hypertensive model groups (L-NNA,n = 9), respectively. The isolated vascular ring perfusion assay, two-photon laser scanning fluorescence microscopy (TPM) and transmitted electron microscope were used to examine the effect of EDDF on vascular function and ultrastructure. Results showed that the contractile response of calcium overload rats and L-NNA rats to phenylephrine (PE) was significantly enhanced compared with that of the control (P < 0.05), and EDDF (10-3 g @mL-1) remarkably decreased the vascular contractile response of control's and calcium overload rats (P < 0.05),while EDDF had no effect on that of L-NNA rats. EDDF also alleviated the ultrastructural lesion of aorta VSMC in calcium overload rats by easing the abnormal in the nucleus, mitochondrion and other organell. It is concluded that EDDF could efficiently protect blood vessels against injury by influencing Ca2+ transport and ameliorating the lesion of VSMC, and further supported the hypothesis that the NO-cGMP pathway might contribute to the vasodilation and partially antihypertensive mechanism of EDDF.``

  6. DSA Image Blood Vessel Skeleton Extraction Based on Anti-concentration Diffusion and Level Set Method

    Science.gov (United States)

    Xu, Jing; Wu, Jian; Feng, Daming; Cui, Zhiming

    Serious types of vascular diseases such as carotid stenosis, aneurysm and vascular malformation may lead to brain stroke, which are the third leading cause of death and the number one cause of disability. In the clinical practice of diagnosis and treatment of cerebral vascular diseases, how to do effective detection and description of the vascular structure of two-dimensional angiography sequence image that is blood vessel skeleton extraction has been a difficult study for a long time. This paper mainly discussed two-dimensional image of blood vessel skeleton extraction based on the level set method, first do the preprocessing to the DSA image, namely uses anti-concentration diffusion model for the effective enhancement and uses improved Otsu local threshold segmentation technology based on regional division for the image binarization, then vascular skeleton extraction based on GMM (Group marching method) with fast sweeping theory was actualized. Experiments show that our approach not only improved the time complexity, but also make a good extraction results.

  7. Imaging transient blood vessel fusion events in zebrafish by correlative volume electron microscopy.

    Directory of Open Access Journals (Sweden)

    Hannah E J Armer

    Full Text Available The study of biological processes has become increasingly reliant on obtaining high-resolution spatial and temporal data through imaging techniques. As researchers demand molecular resolution of cellular events in the context of whole organisms, correlation of non-invasive live-organism imaging with electron microscopy in complex three-dimensional samples becomes critical. The developing blood vessels of vertebrates form a highly complex network which cannot be imaged at high resolution using traditional methods. Here we show that the point of fusion between growing blood vessels of transgenic zebrafish, identified in live confocal microscopy, can subsequently be traced through the structure of the organism using Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM and Serial Block Face/Scanning Electron Microscopy (SBF/SEM. The resulting data give unprecedented microanatomical detail of the zebrafish and, for the first time, allow visualization of the ultrastructure of a time-limited biological event within the context of a whole organism.

  8. Segmentation of retinal blood vessels using normalized Gabor filters and automatic thresholding

    Directory of Open Access Journals (Sweden)

    Mandlenkosi Victor Gwetu

    2014-12-01

    Full Text Available Although computerized retinal image blood vessel segmentation has been extensively researched, there is still room for improvement in the quality of the segmented images. Since retinal image analysis is still widely used in the diagnosis of diabetic retinopathy, efficient and accurate image characterization techniques are required. Previous work has mainly focused on improving segmentation accuracy rates with little regard to the false positives that are produced by illumination variation. This research work presents a hybrid approach towards the segmentation of retinal blood vessels. New approaches towards the reduction of background illumination variation are proposed using normalized Gabor filtering. These are the base-offset encoding and a modified version of an existing zero-integral kernel technique. The valley emphasis automatic thresholding scheme is used to segment the Gabor response images. Experiments are conducted on the DRIVE and STARE retinal image data sets. Accuracy rates of up to 94% are achieved through the zero-integral and base offset methods. This is comparable with results from literature, where the same data sets are segmented using other classification techniques. The median-offset method is found to most effectively reduce background illumination variation.

  9. Differentiation of smooth muscle progenitor cells in peripheral blood and its application in tissue engineered blood vessels

    Institute of Scientific and Technical Information of China (English)

    Shang-zhe XIE; Ning-tao FANG; Shui LIU; Ping ZHOU; Yi ZHANG; Song-mei WANG; Hong-yang GAO; Luan-feng PAN

    2008-01-01

    Background: A major shortcoming in tissue engineered blood vessels (TEBVs) is the lack of healthy and easily attainable smooth muscle cells (SMCs). Smooth muscle progenitor cells (SPCs), especially from peripheral blood, may offer an alternative cell source for tissue engineering involving a less invasive harvesting technique. Methods: SPCs were isolated from 5-ml fresh rat peripheral blood by density-gradient centrifugation and cultured for 3 weeks in endothelial growth medium-2-MV (EGM-2-MV) medium containing platelet-derived growth factor-BB (PDGF BB). Before seeded on the synthesized scaffold, SPC-derived smooth muscle outgrowth cell (SOC) phenotypes were assessed by immuno-fluorescent staining, Western blot analysis, and reverse transcription polymerase chain reaction (RT-PCR). The cells were seeded onto the silk fibroin-modified poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (SF-PHBHHx) scaffolds by 6×104 cells/cm'2 and cultured under the static con-dition for 3 weeks. The growth and proliferation of the seeded cells on the scaffold were analyzed by 3-(4,5-dimethylthiazol-2-yl)-diphenyltetrazolium bromide (MTT) assay, scanning electron microscope (SEM), and 4,6-diamidino-2-phenylindole (DAPI) staining. Results: SOCs displayed specific "hill and valley" morphology, expressed the specific markers of the SMC lineage: protein, and extracellular matrix components elastin and matrix Gla protein (MGP), as well as vascular endothelial growth factor (VEGF). After seeded on the SF-PHBHHx scaffold, the cells showed excellent metabolic activity and proliferation. Conclusion: SPCs isolated from peripheral blood can be differentiated into the SMCs in vitro and have an impressive growth potential in the biodegradable synthesized scaffold. Thus, SPCs may be a promising cell source for constructing TEBVs.

  10. 21 CFR 888.3300 - Hip joint metal constrained cemented or uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3300 Section 888.3300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal constrained cemented or uncemented prosthesis. (a) Identification. A hip joint metal constrained cemented or uncemented prosthesis is a device intended to be implanted to replace a hip joint. The...

  11. 21 CFR 888.3100 - Ankle joint metal/composite semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3100 Section 888.3100 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Ankle joint metal/composite semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/composite semi-constrained cemented prosthesis is a device intended to be implanted to replace...

  12. 21 CFR 888.3200 - Finger joint metal/metal constrained uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3200 Section 888.3200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal/metal constrained uncemented prosthesis. (a) Identification. A finger joint metal/metal constrained uncemented prosthesis is a device intended to be implanted to replace a metacarpophalangeal...

  13. 21 CFR 888.3660 - Shoulder joint metal/polymer semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3660 Section 888.3660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Shoulder joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace...

  14. 21 CFR 888.3370 - Hip joint (hemi-hip) acetabular metal cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3370 Section 888.3370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... (hemi-hip) acetabular metal cemented prosthesis. (a) Identification. A hip joint (hemi-hip) acetabular metal cemented prosthesis is a device intended to be implanted to replace a portion of the hip...

  15. 21 CFR 888.3170 - Elbow joint radial (hemi-elbow) polymer prosthesis.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Elbow joint radial (hemi-elbow) polymer prosthesis... (hemi-elbow) polymer prosthesis. (a) Identification. An elbow joint radial (hemi-elbow) polymer prosthesis is a device intended to be implanted made of medical grade silicone elastomer used to replace...

  16. 21 CFR 888.3400 - Hip joint femoral (hemi-hip) metallic resurfacing prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3400 Section 888.3400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... femoral (hemi-hip) metallic resurfacing prosthesis. (a) Identification. A hip joint femoral (hemi-hip) metallic resurfacing prosthesis is a device intended to be implanted to replace a portion of the hip...

  17. 21 CFR 888.3220 - Finger joint metal/polymer constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3220 Section 888.3220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal/polymer constrained cemented prosthesis. (a) Identification. A finger joint metal/polymer constrained cemented prosthesis is a device intended to be implanted to replace a metacarpophalangeal...

  18. 21 CFR 888.3800 - Wrist joint metal/polymer semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3800 Section 888.3800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Wrist joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A wrist joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a wrist...

  19. 21 CFR 888.3210 - Finger joint metal/metal constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3210 Section 888.3210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal/metal constrained cemented prosthesis. (a) Identification. A finger joint metal/metal constrained cemented prosthesis is a device intended to be implanted to replace a metacarpophalangeal (finger)...

  20. 21 CFR 888.3160 - Elbow joint metal/polymer semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3160 Section 888.3160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Elbow joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An elbow joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

  1. 21 CFR 888.3650 - Shoulder joint metal/polymer non-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3650 Section 888.3650 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Shoulder joint metal/polymer non-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace...

  2. 21 CFR 888.3180 - Elbow joint humeral (hemi-elbow) metallic uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... uncemented prosthesis. 888.3180 Section 888.3180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Elbow joint humeral (hemi-elbow) metallic uncemented prosthesis. (a) Identification. An elbow joint humeral (hemi-elbow) metallic uncemented prosthesis is a device intended to be implanted made of...

  3. 21 CFR 888.3480 - Knee joint femorotibial metallic constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3480 Section 888.3480 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Knee joint femorotibial metallic constrained cemented prosthesis. (a) Identification. A knee joint femorotibial metallic constrained cemented prosthesis is a device intended to be implanted to replace part of...

  4. 21 CFR 888.3110 - Ankle joint metal/polymer semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3110 Section 888.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Ankle joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace an...

  5. 21 CFR 888.3150 - Elbow joint metal/polymer constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3150 Section 888.3150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal/polymer constrained cemented prosthesis. (a) Identification. An elbow joint metal/polymer constrained cemented prosthesis is a device intended to be implanted to replace an elbow joint. It is made...

  6. 21 CFR 888.3340 - Hip joint metal/composite semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3340 Section 888.3340 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Hip joint metal/composite semi-constrained cemented prosthesis. (a) Identification. A hip joint metal/composite semi-constrained cemented prosthesis is a two-part device intended to be implanted to replace...

  7. 21 CFR 888.3120 - Ankle joint metal/polymer non-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3120 Section 888.3120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal/polymer non-constrained cemented prosthesis. (a) Identification. An ankle joint metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace an ankle joint. The...

  8. 21 CFR 888.3510 - Knee joint femorotibial metal/polymer constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented prosthesis. 888.3510 Section 888.3510 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Knee joint femorotibial metal/polymer constrained cemented prosthesis. (a) Identification. A knee joint femorotibial metal/polymer constrained cemented prosthesis is a device intended to be implanted to replace...

  9. 21 CFR 888.3310 - Hip joint metal/polymer constrained cemented or uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... uncemented prosthesis. 888.3310 Section 888.3310 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Hip joint metal/polymer constrained cemented or uncemented prosthesis. (a) Identification. A hip joint metal/polymer constrained cemented or uncemented prosthesis is a device intended to be implanted...

  10. 21 CFR 888.3350 - Hip joint metal/polymer semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... prosthesis. 888.3350 Section 888.3350 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... metal/polymer semi-constrained cemented prosthesis. (a) Identification. A hip joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a hip joint. The device...

  11. Differential lectin binding on walls of thoraco-cervical blood vessels and lymphatics in rats.

    Science.gov (United States)

    Kagami, H; Uryu, K; Okamoto, K; Sakai, H; Kaneda, T; Sakanaka, M

    1991-08-01

    Lectin binding in the walls of large to medium-sized blood vessels and lymphatics in the rat thoraco-cervical region was examined histochemically. The tunica intima of the aorta and superficial cervical artery showed positive reactions with wheat germ agglutinin (WGA) and Concanavalin A (ConA) but not with Dolichus biflorus agglutinin (DBA). The tunica media of the aorta exhibited intense WGA binding, especially on the smooth muscle cells, but the tunica media of the superficial cervical artery did not react with the lectin. Neither ConA nor DBA bound to the tunica media of the aorta and superficial cervical artery. The tunica adventitia of both arteries contained sites binding the three lectins, although DBA reactivity declined as the vascular diameter decreased. The tunica intima of the superior vena cava and azygos vein exhibited positive WGA and ConA binding, whereas DBA binding was noted on only part of the tunica intima of the superior vena cava and not on that of the azygos vein. The tunica media and tunica adventitia were reactive for all three lectins. The WGA and ConA binding sites in the tunica adventitia showed loose networks, suggesting lectin binding on connective tissue elements interlacing among smooth muscle bundles. Lectin binding sites in the walls of lymphatics exhibited an arrangement similar to those in the walls of the veins. Moreover valves protruding into the lumen showed intense WGA and ConA binding and scattered DBA binding. Three other lectins (Ulex europaeus agglutinin, peanut agglutinin, Maclura pomifera) were examined, but they showed no reactions with the vessels. Thus, the differential binding of lectins on the walls of blood vessels and lymphatics of various sizes suggests the functional complexity of monosaccharide residues in the vascular walls. PMID:1758681

  12. Implant-supported auricular prosthesis

    OpenAIRE

    Aditi Nanda; Veena Jain; Rakesh Kumar; Krishna Kabra

    2011-01-01

    Differences in the balance of shape, size, and position of body organs are immediately perceived as "looking wrong" and this perception can subject the individual to significant peer ridicule and social ostracism, often expressing as intense shame and anguish in the attitude of the afflicted. Rehabilitation of such patients can be remarkably beneficial on the individual′s self-esteem and body image. The onus of the deed lies in the hands of a team that combines artistic excellence with surgic...

  13. Implant-supported auricular prosthesis

    Directory of Open Access Journals (Sweden)

    Aditi Nanda

    2011-01-01

    Full Text Available Differences in the balance of shape, size, and position of body organs are immediately perceived as "looking wrong" and this perception can subject the individual to significant peer ridicule and social ostracism, often expressing as intense shame and anguish in the attitude of the afflicted. Rehabilitation of such patients can be remarkably beneficial on the individual′s self-esteem and body image. The onus of the deed lies in the hands of a team that combines artistic excellence with surgical expertise, by combining the skills of anaplastologists, surgeons, and prosthodontists. This is a review of a few surgical and prosthetic considerations in the management of auricular defect and a case description of management of a patient of microtia following similar guidelines in fabrication of the epithesis.

  14. Application of LMA-flexible and total intravenous anesthesia in tympanoplusty with prosthesis implant%可弯曲喉罩联合静脉麻醉在听力重建术中的应用

    Institute of Scientific and Technical Information of China (English)

    宋晓红; 李天佐; 杨静; 李小葵

    2011-01-01

    目的 观察可弯曲喉罩联合静脉麻醉用于人工听骨听力重建术的效果.方法 择期人工听骨听力重建术患者40例,随机均分为可弯曲喉罩组(F组)和气管内插管组(I组),均采用瑞芬太尼一丙泊酚静脉麻醉.记录两组SBP、DBP和HR,术野清晰度评分及自主呼吸恢复时间、拔管时间及BIS.结果 术中F组SBP、DBP低于I组,术野清晰度优于I组;拔管时,F组SBP、DBP及HR波动小于I组(P<0.05)、呛咳反应更轻(P<0.01);F组呼吸恢复及拔管时间长于I组(P<0.05);F组BIS值高于I组(P<0.05).结论 与气管内插管相比,可弯曲喉罩联合静脉麻醉应用于人工听骨听力重建术更具优势,但需注意麻醉深度监测.%Objective To observe the characteristics and resuscitation quality of total intravenous anesthesia in combination with LMA flexible in tympanoplasty with prosthesis implant.Methods Forty patients undertaking tympanoplasty with prosthesis implant were randomly divided into two groups: group F (n=20, with LMA flexible) and group Ⅰ (n=20, with endotreacheal intubation).In both groups anesthesia were maintained with remifentanil and propofol.Hemodynamic index, surgical field score, cough reflex during extubation period and recovery time were recorded.Results In the operation period, the SBP and DBP was lower in group F than that in group Ⅰ, and the surgical field score was higher in group Ⅰ.While in the extubation period, cough reflex was significantly suppressed in group F (P<0.01) and the increase of SBP, DBP and HR was prominent in group Ⅰ (P<0.05), but the time of extubation was delayed in group F(P<0.05).At the moment of extubation, the BIS value in group F was higher than that of group Ⅰ (P<0.05).Conclusion The resuscitation quality and the safety of extuhation in tympanoplasty with prosthesis implant were enhanced by use of LMA-flexible.

  15. Fractals and fractal dimension of systems of blood vessels: An analogy between artery trees, river networks, and urban hierarchies

    CERN Document Server

    Chen, Yanguang

    2015-01-01

    An analogy between the fractal nature of networks of arteries and that of systems of rivers has been drawn in the previous works. However, the deep structure of the hierarchy of blood vessels has not yet been revealed. This paper is devoted to researching the fractals, allometric scaling, and hierarchy of blood vessels. By analogy with Horton-Strahler's laws of river composition, three exponential laws have been put forward. These exponential laws can be reconstructed and transformed into three linear scaling laws, which can be named composition laws of blood vessels network. From these linear scaling laws it follows a set of power laws, including the three-parameter Zipf's law on the rank-size distribution of blood vessel length and the allometric scaling law on the length-diameter relationship of blood vessels in different orders. The models are applied to the observed data on human beings and animals early given by other researchers, and an interesting finding is that human bodies more conform to natural r...

  16. Assessment of MRI issues at 3-Tesla for metallic surgical implants: findings applied to 61 additional skin closure staples and vessel ligation clips

    OpenAIRE

    Gill Amreeta; Shellock Frank G

    2012-01-01

    Abstract Purpose Metallic skin closure staples and vessel ligation clips should be tested at 3-Tesla to characterize MRI issues in order to ensure patient safety. Therefore, metallic surgical implants were assessed at 3-Tesla for magnetic field interactions, MRI-related heating, and artifacts. Methods A skin closure staple (Visistat Skin Stapler, staple, Polytetrafluoroethylene, PTFE, coated 316L/316LVM stainless steel; Teleflex Medical, Durham, NC) and a vessel ligation clip (Hemoclip Tradit...

  17. Triamcinolone Acetonide Selectively Inhibits Angiogenesis in Small Blood Vessels and Decreases Vessel Diameter within the Vascular Tree

    Science.gov (United States)

    McKay, Terri L.; Gredeon, Dan J.; Vickerman, Mary B.; Hylton, alan G.; Ribita, Daniela; Olar, Harry H.; Kaiser, Peter K.; Parsons-Wingerter, Patricia

    2007-01-01

    The steroid triamcinolone acetonide (TA) is a potent anti-angiogenesis drug used to treat retinal vascular diseases that include diabetic retinopathy, vascular occlusions and choroidal neovascularization. To quantify the effects of TA on branching morphology within the angiogenic microvascular tree of the chorioallantoic membrane (CAM) of quail embryos. Increasing concentrations of TA (0-16 ng/ml) were applied topically on embryonic day 7 (E7) to the chorioallantoic membrane (CAM) of quail embryos cultured in Petri dishes, and incubated for an additional 24 or 48 hours until fixation. Binary (black/white) microscopic images of arterial end points were quantified by VESGEN software (for Generational Analysis of Vessel Branching) to obtain major vascular parameters that include vessel diameter (Dv), fractal dimension (Df), tortuosity (Tv) and densities of vessel area, length, number and branch point (Av, Lv, Nv and Brv). For assessment of specific changes in vascular morphology induced by TA, the VESGEN software automatically segmented the vascular tree into branching generations (G1...G10) according to changes in vessel diameter and branching. Vessel density decreased significantly up to 34% as the function of increasing concentration of TA according to Av, Lv, Brv, Nv and Df. TA selectively inhibited the growth of new, small vessels, because Lv decreased from 13.14plus or minus 0.61 cm/cm2 for controls to 8.012 plus or minus 0.82 cm/cm2 at 16 ng TA/ml in smaller branching generations (G7-G10), and for Nv from 473.83 plus or minus 29.85 cm(-)2 to 302.32 plus or minus 33.09 cm-()2. In contrast, vessel diameter (Dv) decreased throughout the vascular tree (G1-G10).

  18. Distinct mechanisms of relaxation to bioactive components from chamomile species in porcine isolated blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, R.E., E-mail: Richard.roberts@nottingham.ac.uk; Allen, S.; Chang, A.P.Y.; Henderson, H.; Hobson, G.C.; Karania, B.; Morgan, K.N.; Pek, A.S.Y.; Raghvani, K.; Shee, C.Y.; Shikotra, J.; Street, E.; Abbas, Z.; Ellis, K.; Heer, J.K.; Alexander, S.P.H., E-mail: steve.alexander@nottingham.ac.uk

    2013-11-01

    German chamomile (Matricaria recutita L.), a widely-used herbal medicine, has been reported to have a wide range of biological effects, including smooth muscle relaxation. The aim of this study was to compare the effects of representative compounds from chamomile (apigenin, luteolin, (−)-α-bisabolol, farnesene, umbelliferone; 3–30 μM) on vascular tone using porcine coronary and splenic arteries mounted for isometric tension recording in isolated tissue baths and precontracted with the thromboxane-mimetic U46619. Apigenin, luteolin, and (−)-α-bisabolol produced slow, concentration-dependent relaxations in both the coronary and splenic arteries that were not blocked by inhibition of nitric oxide synthase or potassium channels. Removal of extracellular calcium inhibited the relaxations to all three compounds, and these compounds also inhibited calcium re-addition-evoked contractions, indicating that the relaxation response may be mediated through inhibition of calcium influx. Apigenin and luteolin, but not (−)-α-bisabolol, enhanced the relaxation to the nitric oxide donor sodium nitroprusside, indicating that apigenin and luteolin may act to regulate cyclic GMP levels. Umbelliferone produced a rapid, transient relaxation in the splenic artery, but not the coronary artery, that was inhibited by L-NAME and removal of the endothelium, suggesting an influence on nitric oxide production. Farnesene, at concentrations up to 30 μM, was without effect in either blood vessel. In conclusion, hydroxylated compounds (apigenin, luteolin and (−)-α-bisabolol) found in chamomile all caused a slow relaxation of isolated blood vessels through an effect on calcium influx. Umbelliferone, on the other hand, produced a rapid, transient relaxation dependent upon release of nitric oxide from the endothelium. - Highlights: • Apigenin, luteolin, and (-)-α-bisabolol are present in chamomile. • They produced slow, concentration-dependent relaxations in arteries. • These

  19. Blood-Vessel Mimicking Structures by Stereolithographic Fabrication of Small Porous Tubes Using Cytocompatible Polyacrylate Elastomers, Biofunctionalization and Endothelialization

    OpenAIRE

    Birgit Huber; Sascha Engelhardt; Wolfdietrich Meyer; Hartmut Krüger; Annika Wenz; Veronika Schönhaar; Tovar, Günter E. M.; Kluger, Petra J.; Kirsten Borchers

    2016-01-01

    Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA) for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of appr...

  20. Label-free 3D imaging of microstructure, blood and lymphatic vessels within tissue beds in vivo

    OpenAIRE

    Zhi, Zhongwei; Jung, Yeongri; Wang, Ruikang K.

    2012-01-01

    This letter reports the use of an ultrahigh resolution optical microangiography (OMAG) system for simultaneous 3D imaging of microstructure, lymphatic and blood vessels without the use of exogenous contrast agent. An automatic algorithm is developed to segment the lymphatic vessels from the microstructural images, based on the fact that the lymph fluid is optically transparent. The OMAG system is developed that utilizes a broadband supercontinuum light source, providing an axial resolution of...

  1. The Effect of Silver Nanofibers on the Deformation Properties of Blood Vessels: Towards the Development of New Nanotechnologies to Prevent Rupture of Aneurysms

    Directory of Open Access Journals (Sweden)

    Miguel Gonzalez

    2014-01-01

    Full Text Available An aneurysm is the result of a widening or ballooning of a portion of a blood vessel. The rupture of an aneurysm occurs when the mechanical stress acting on the inner wall exceeds the failure strength of the blood vessel. We propose an innovative approach to prevent the rupture of an aneurysm based on the use of nanotechnology to improve the strength of the blood vessel. We present results on the effect of silver nanofibers on the resistance toward deformation of blood vessels. The silver nanofibers are grown on the surface of the blood vessels. The nanofibers are 120±30 nm in diameter and 2.7±0.8 μm in length. The deformation per applied force of blood vessels was found to decrease from 0.15 m/N in control blood vessels to 0.003 m/N in blood vessels treated with the nanofibers. This represents an increase in the resistance towards deformation of a factor of 50. The increase in the resistance towards deformation is clinically significant since blood pressure increases by factors slightly larger than one in the human body. Treatment of blood vessels with silver nanofibers is a potential translational clinical tool for preventing rupture of aneurysms in a clinical setting.

  2. An Alternative Approach to Combine Orbital Prosthesis and Obturator: A Case Report

    OpenAIRE

    Soganci, Gokce; Yalug, Suat; Kocacikli, Mustafa

    2011-01-01

    This report describes a different approach for diminishing the movements of orbital prosthesis during mimic movements and chewing function. Mechanical devices such as magnets are used to enhance the retention in case lack of the implants. However rigid fixation of obturator and orbital prosthesis can result in movements of the orbital prosthesis during mastication. In this case obturator and orbital prosthesis are combined by magnets. However this combination is not rigid because of an active...

  3. Isolated pump erosion of an inflatable penile prosthesis through the scrotum in a diabetic patient

    OpenAIRE

    Raidh A. Talib; Ahmad Shamsodini; Salem, Emad A.; Onder Canguven; Abdulla Al Ansari

    2013-01-01

    Isolated pump erosion is a rare complication in patients with inflatable penile prosthesis. We describe a case of a diabetic patient who underwent inflatable penile prosthesis implantation with subsequent isolated pump erosion. Repeated attempts of conservative repair of the erosion failed. Finally, the inflatable penile prosthesis was replaced with a malleable one to avoid new pump erosion. In case of isolated pump erosion, replacement of the inflatable penile prosthesis with a malleable one...

  4. [Central auditory prosthesis].

    Science.gov (United States)

    Lenarz, T; Lim, H; Joseph, G; Reuter, G; Lenarz, M

    2009-06-01

    Deaf patients with severe sensory hearing loss can benefit from a cochlear implant (CI), which stimulates the auditory nerve fibers. However, patients who do not have an intact auditory nerve cannot benefit from a CI. The majority of these patients are neurofibromatosis type 2 (NF2) patients who developed neural deafness due to growth or surgical removal of a bilateral acoustic neuroma. The only current solution is the auditory brainstem implant (ABI), which stimulates the surface of the cochlear nucleus in the brainstem. Although the ABI provides improvement in environmental awareness and lip-reading capabilities, only a few NF2 patients have achieved some limited open set speech perception. In the search for alternative procedures our research group in collaboration with Cochlear Ltd. (Australia) developed a human prototype auditory midbrain implant (AMI), which is designed to electrically stimulate the inferior colliculus (IC). The IC has the potential as a new target for an auditory prosthesis as it provides access to neural projections necessary for speech perception as well as a systematic map of spectral information. In this paper the present status of research and development in the field of central auditory prostheses is presented with respect to technology, surgical technique and hearing results as well as the background concepts of ABI and AMI. PMID:19517084

  5. Clinical and functional outcomes of the saddle prosthesis

    OpenAIRE

    Donati, D.; D’Apote, G.; M. Boschi; Cevolani, L.; M.G. Benedetti

    2012-01-01

    Background The implantation of a saddle prosthesis after resection of a pelvic tumor has been proposed as a simple method of reconstruction that provides good stability and reduces the surgical time, thus limits the onset of intraoperative complications. There are no studies in the literature of patients evaluated using gait analysis after being implanted with a saddle prosthesis. The present study is a retrospective case review aimed at illustrating long-term clinical and functional findings...

  6. Conventional X-ray after shoulder prosthesis

    International Nuclear Information System (INIS)

    Three types of shoulder prostheses are commonly used to cover the different indications of shoulder joint replacements: classical modular, inverse and cup. The modular prosthesis can replace the glenoid as well as the humeral head components. Exact visualization of the interface between the glenoid component and bone (or cement-bone interface) is necessary to detect osteolysis, which is relatively common. Therefore, it is mandatory to make true AP and axial projections. When describing the humeral component, the interface between bone and implant must again be considered. Additionally, the position of the humeral head in relation to the glenoid has to be noted. The glenoid component is usually fixed by screws to the bone and an osteolysis is often present at the inferior pole of the glenoid component due to prosthesis bone notching. If the implants are modular devices (classic modular prosthesis, inverse shoulder prosthesis) there is the possibility of dissociation of components and any suspicion of this should be reported. In case of reporting the conventional x-ray of cup prosthesis, the bone implant interface should be mentioned. Again the position of the humeral head to the glenoid requires attention. In all types of prostheses, dislocation of the glenohumeral joint is obvious and has to be addressed in the medical report. (orig.)

  7. Multi-detector spiral CT study of the relationships between pulmonary ground-glass nodules and blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Feng; Li, Ming; Ge, Xiaojun; Ren, Qingguo; Hua, Yanqing [Huadong Hospital Fudan University, Department of Radiology, Shanghai (China); Zheng, Xiangpeng [Huadong Hospital Fudan University, Department of Radiation Oncology, Shanghai (China); Chen, Yan [Huadong Hospital Fudan University, Department of Pathology, Shanghai (China); Lv, Fangzhen [Huadong Hospital Fudan University, Department of Thoracic Surgery, Shanghai (China)

    2013-12-15

    To investigate the relationships between pulmonary ground-glass nodules (GGN) and blood vessels and their diagnostic values in differentiating GGNs. Multi-detector spiral CT imaging of 108 GGNs was retrospectively reviewed. The spatial relationships between GGNs and supplying blood vessels were categorized into four types: I, vessels passing by GGNs; II, intact vessels passing through GGNs; III, distorted, dilated or tortuous vessels seen within GGNs; IV, more complicated vasculature other than described above. Relationship types were correlated to pathologic and/or clinical findings of GGNs. Of 108 GGNs, 10 were benign, 24 preinvasive nodules and 74 adenocarcinomas that were pathologically proven. Types I, II, III and IV vascular relationships were observed in 9, 58, 21 and 20 GGNs, respectively. Type II relationship was the dominating relationship for each GGN group, but significant differences were shown among them. Correlation analysis showed strong correlation between invasive adenocarcinoma and type III and IV relationships. Subgroup analysis indicated that type III was more commonly seen in IAC with comparison to type IV more likely seen in MIA. Different GGNs have different relationships with vessels. Understanding and recognising characteristic GGN-vessel relationships may help identify which GGNs are more likely to be malignant. (orig.)

  8. Accuracy and precision of MR blood oximetry based on the long paramagnetic cylinder approximation of large vessels.

    Science.gov (United States)

    Langham, Michael C; Magland, Jeremy F; Epstein, Charles L; Floyd, Thomas F; Wehrli, Felix W

    2009-08-01

    An accurate noninvasive method to measure the hemoglobin oxygen saturation (%HbO(2)) of deep-lying vessels without catheterization would have many clinical applications. Quantitative MRI may be the only imaging modality that can address this difficult and important problem. MR susceptometry-based oximetry for measuring blood oxygen saturation in large vessels models the vessel as a long paramagnetic cylinder immersed in an external field. The intravascular magnetic susceptibility relative to surrounding muscle tissue is a function of oxygenated hemoglobin (HbO(2)) and can be quantified with a field-mapping pulse sequence. In this work, the method's accuracy and precision was investigated theoretically on the basis of an analytical expression for the arbitrarily oriented cylinder, as well as experimentally in phantoms and in vivo in the femoral artery and vein at 3T field strength. Errors resulting from vessel tilt, noncircularity of vessel cross-section, and induced magnetic field gradients were evaluated and methods for correction were designed and implemented. Hemoglobin saturation was measured at successive vessel segments, differing in geometry, such as eccentricity and vessel tilt, but constant blood oxygen saturation levels, as a means to evaluate measurement consistency. The average standard error and coefficient of variation of measurements in phantoms were cylinder approximation of the incremental field. PMID:19526517

  9. Large blood vessel stretch in lumbar spine through anterior surgical approach: An experimental study in adult goat

    Directory of Open Access Journals (Sweden)

    Liehua Liu

    2014-01-01

    Full Text Available Background: Various anterior lumbar surgical approaches, including the minimally invasive approach, have greatly improved in recent years. Vascular complications resulting from ALIF are frequently reported. Little information is available about the safety of large blood vessel stretch. We evaluated the right side stretch limit (RSSL of the abdominal aorta (AAA and the inferior vena cava (IVC without blood flow occlusion and investigated stretch-induced histological injury and thrombosis in the iliac and femoral arteries and veins and the stretched vessels. Materials and Methods: The RSSL of blood vessels in five adult goats was measured by counting the number of 0.5-cm-thick wood slabs that were inserted between the right lumbar edge and the stretch hook. Twenty seven adult goats were divided into three groups to investigate histological injury and thrombosis under a stretch to 0.5 cm (group I 1.5 cm (group II for 2 h, or no stretch (group III. Blood vessel samples from groups I and II were analyzed on postsurgical days 1, 3, and 7. Thrombogenesis was examined in the iliac and femoral arteries and veins. Results: The RSSL of large blood vessels in front of L4/5 was 1.5 cm from the right lumbar edge. All goats survived surgery without complications. No injury or thrombosis in the large blood vessels in front of the lumbar vertebrae and in the iliac or femoral arteries and veins was observed. Under light microscopy, group I showed slight swelling of endothelial cells in the AAA and no histological injury of the IVC. The AAA of group II showed endothelial cell damage, unclear organelles, and incomplete cell connections by electron microscopy. Conclusions: The AAA and IVC in a goat model can be stretched by ≤0.5 cm, with no thrombosis in the AAA, IVC, iliac or femoral arteries and veins.

  10. Comparison of the number of gingival blood vessels between type 2 diabetes mellitus and chronic periodontitis patients: An immunohistological study

    Directory of Open Access Journals (Sweden)

    Gautami Subhadra Penmetsa

    2015-01-01

    Full Text Available Background: The relationship between diabetes and periodontitis has been studied for more than 50 years and is generally agreed that the periodontal disease is more prevalent in diabetic patients compared to nondiabetics. Vascular changes like increased thickness of basement membrane in small vessels has been reported in diabetic patients, but the quantity of blood vessels in gingiva of diabetic patients has not been discussed much. The aim of this study was to compare the number of blood vessels in gingiva between chronic periodontitis (CP patients, CP with diabetes (type 2, and normal healthy gingiva. Materials and Methods: The study included 75 patients, divided into three groups of 25 patients each-Group I with healthy periodontium (HP, Group II with CP, and Group III with CP with diabetes mellitus (CPDM.Gingival biopsies were obtained from the subjects undergoing crown lengthening procedure for Group I, and in patients with CP and in CPDM biopsies were collected from teeth undergoing extraction. Sections were prepared for immune histochemical staining with CD34. Results: Difference was observed in the average number of blood vessels when compared between HP, CP, and CPDM groups. Statistical significant difference was observed when the HP and CP groups and HP and CPDM groups were compared. Conclusion: The results of the study indicated that the number of blood vessels in gingival connective tissue is significantly higher in CP and CPDM patients.

  11. Wrong theories on the origin of blood vessels: Polybus and De Natura Hominis.

    Science.gov (United States)

    Shoja, Mohammadali M; Tubbs, R Shane; Loukas, Marios; Ardalan, Mohammad R

    2008-06-01

    Polybus of Cos (approximately 400 B.C.) was the son-in-law and the successor of Hippocrates. He is credited with founding the school of Dogmatism, and writing "The Nature of Man" which was important in advancing the theory of the four body humors (humoralism). Some earlier scholars negated Polybus' role as an independent medical figure. However, Corpus Aristotelicum quoted him as having a unique theory regarding the body vasculature which stated that this system was composed of four pairs of blood vessels originating from the head and that these supplied the whole body. In an interpretation of this theory, we opined that numerological mysticism might have been the common motive for both Hippocrates' humoralism and Polybus' theory of the vasculature. A discussion on this issue is presented. PMID:18164081

  12. Ultrastructural analysis of small blood vessels in skin biopsies in CADASIL

    Directory of Open Access Journals (Sweden)

    Lačković Vesna

    2008-01-01

    Full Text Available Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL is an inherited small- and medium-artery disease of the brain caused by mutation of the Notch3 gene. Very often, this disease is misdiagnosed. We examined skin biopsies in two members of the first discovered Serbian family affected by CADASIL. Electron microscopy showed that skin blood vessels of both patients contain numerous deposits of granular osmiophilic material (GOM around vascular smooth muscle cells (VSMCs. We observed degeneration of VSMCs, reorganization of their cytoskeleton and dense bodies, disruption of myoendothelial contacts, and apoptosis. Our results suggest that the presence of GOM in small skin arteries represents a specific marker in diagnosis of CADASIL.

  13. Lattice Boltzmann simulation of behaviour of particles moving in blood vessels under the rolling massage

    International Nuclear Information System (INIS)

    The rolling massage is one of the most important manipulations in Chinese massage, which is expected to eliminate many diseases. Here, the effect of the rolling massage on a pair of particles moving in blood vessels under rolling massage manipulation is studied by the lattice Boltzmann simulation. The simulated results show that the motion of each particle is considerably modified by the rolling massage, and it depends on the relative rolling velocity, the rolling depth, and the distance between particle position and rolling position. Both particles' translational average velocities increase almost linearly as the rolling velocity increases, and obey the same law. The increment of the average relative angular velocity for the leading particle is smaller than that of the trailing one. The result is helpful for understanding the mechanism of the massage and to further develop the rolling techniques. (classical areas of phenomenology)

  14. Streaming flow from ultrasound contrast agents by acoustic waves in a blood vessel model.

    Science.gov (United States)

    Cho, Eunjin; Chung, Sang Kug; Rhee, Kyehan

    2015-09-01

    To elucidate the effects of streaming flow on ultrasound contrast agent (UCA)-assisted drug delivery, streaming velocity fields from sonicated UCA microbubbles were measured using particle image velocimetry (PIV) in a blood vessel model. At the beginning of ultrasound sonication, the UCA bubbles formed clusters and translated in the direction of the ultrasound field. Bubble cluster formation and translation were faster with 2.25MHz sonication, a frequency close to the resonance frequency of the UCA. Translation of bubble clusters induced streaming jet flow that impinged on the vessel wall, forming symmetric vortices. The maximum streaming velocity was about 60mm/s at 2.25MHz and decreased to 15mm/s at 1.0MHz for the same acoustic pressure amplitude. The effect of the ultrasound frequency on wall shear stress was more noticeable. Maximum wall shear stress decreased from 0.84 to 0.1Pa as the ultrasound frequency decreased from 2.25 to 1.0MHz. The maximum spatial gradient of the wall shear stress also decreased from 1.0 to 0.1Pa/mm. This study showed that streaming flow was induced by bubble cluster formation and translation and was stronger upon sonication by an acoustic wave with a frequency near the UCA resonance frequency. Therefore, the secondary radiant force, which is much stronger at the resonance frequency, should play an important role in UCA-assisted drug delivery. PMID:26025507

  15. Distinct cellular mechanisms of blood vessel fusion in the zebrafish embryo.

    Science.gov (United States)

    Herwig, Lukas; Blum, Yannick; Krudewig, Alice; Ellertsdottir, Elin; Lenard, Anna; Belting, Heinz-Georg; Affolter, Markus

    2011-11-22

    Although many of the cellular and molecular mechanisms of angiogenesis have been intensely studied [1], little is known about the processes that underlie vascular anastomosis. We have generated transgenic fish lines expressing an EGFP-tagged version of the junctional protein zona occludens 1 (ZO1) to visualize individual cell behaviors that occur during vessel fusion and lumen formation in vivo. These life observations show that endothelial cells (ECs) use two distinct morphogenetic mechanisms, cell membrane invagination and cord hollowing to generate different types of vascular tubes. During initial steps of anastomosis, cell junctions that have formed at the initial site of cell contacts expand into rings, generating a cellular interface of apical membrane compartments, as defined by the localization of the apical marker podocalyxin-2 (Pdxl2). During the cord hollowing process, these apical membrane compartments are brought together via cell rearrangements and extensive junctional remodeling, resulting in lumen coalescence and formation of a multicellular tube. Vessel fusion by membrane invagination occurs adjacent to a preexisting lumen in a proximal to distal direction and is blood-flow dependent. Here, the invaginating inner cell membrane undergoes concomitant apicobasal polarization and the vascular lumen is formed by the extension of a transcellular lumen through the EC, which forms a unicellular or seamless tube. PMID:22079115

  16. Assessment of MRI issues at 3-Tesla for metallic surgical implants: findings applied to 61 additional skin closure staples and vessel ligation clips

    Directory of Open Access Journals (Sweden)

    Gill Amreeta

    2012-01-01

    Full Text Available Abstract Purpose Metallic skin closure staples and vessel ligation clips should be tested at 3-Tesla to characterize MRI issues in order to ensure patient safety. Therefore, metallic surgical implants were assessed at 3-Tesla for magnetic field interactions, MRI-related heating, and artifacts. Methods A skin closure staple (Visistat Skin Stapler, staple, Polytetrafluoroethylene, PTFE, coated 316L/316LVM stainless steel; Teleflex Medical, Durham, NC and a vessel ligation clip (Hemoclip Traditional, stainless steel; Teleflex Medical, Durham, NC that represented the largest metallic sizes made from materials with the highest magnetic susceptibilities (i.e., based on material information among 61 other surgical implants (52 metallic implants, 9 nonmetallic implants underwent evaluation for magnetic field interactions, MRI-related heating, and artifacts using standardized techniques. MRI-related heating was assessed by placing each implant in a gelled-saline-filled phantom with MRI performed using a transmit/receive RF body coil at an MR system reported, whole body averaged SAR of 2.9-W/kg for 15-min. Artifacts were characterized using T1-weighted, SE and GRE pulse sequences. Results Each surgical implant showed minor magnetic field interactions (20- and 27-degrees, which is acceptable from a safety consideration. Heating was not substantial (highest temperature change, ≤ 1.6°C. Artifacts may create issues if the area of interest is in the same area or close to the respective surgical implant. Conclusions The results demonstrated that it would be acceptable for patients with these metallic surgical implants to undergo MRI at 3-Tesla or less. Because of the materials and dimensions of the surgical implants that underwent testing, these findings pertain to 61 additional similar implants.

  17. Degradation profile and preliminary clinical testing of a resorbable device for ligation of blood vessels.

    Science.gov (United States)

    Aminlashgari, Nina; Höglund, Odd V; Borg, Niklas; Hakkarainen, Minna

    2013-06-01

    A resorbable device for ligation of blood vessels was developed and tested in vitro to reveal the degradation profile of the device and to predict the clinical performance in terms of adequate mechanical support during a healing period of 1week. In addition, preliminary clinical testing was performed that showed complete hemostasis and good tissue grip of renal arteries in five pigs. The device was made by injection molding of poly(glycolide-co-trimethylene carbonate) triblock copolymer, and it consisted of a case with a locking mechanism connected to a partly perforated flexible band. A hydrolytic degradation study was carried out for 7, 30 and 60days in water and buffer medium, following the changes in mass, water absorption, pH and mechanical properties. A new rapid matrix-free laser desorption ionization-mass spectrometry (LDI-MS) method was developed for direct screening of degradation products released into the degradation medium. The combination of LDI-MS and electrospray ionization-mass spectrometry analyses enabled the comparison of the degradation product patterns in water and buffer medium. The identified degradation products were rich in trimethylene carbonate units, indicating preferential hydrolysis of amorphous regions where trimethylene units are located. The crystallinity of the material was doubled after 60days of hydrolysis, additionally confirming the preferential hydrolysis of trimethylene carbonate units and the enrichment of glycolide units in the remaining solid matrix. The mechanical performance of the perforated band was followed for the first week of hydrolysis and the results suggest that sufficient strength is retained during the healing time of the blood vessels. PMID:23438863

  18. Distinct mechanisms of relaxation to bioactive components from chamomile species in porcine isolated blood vessels.

    Science.gov (United States)

    Roberts, R E; Allen, S; Chang, A P Y; Henderson, H; Hobson, G C; Karania, B; Morgan, K N; Pek, A S Y; Raghvani, K; Shee, C Y; Shikotra, J; Street, E; Abbas, Z; Ellis, K; Heer, J K; Alexander, S P H

    2013-11-01

    German chamomile (Matricaria recutita L.), a widely-used herbal medicine, has been reported to have a wide range of biological effects, including smooth muscle relaxation. The aim of this study was to compare the effects of representative compounds from chamomile (apigenin, luteolin, (-)-α-bisabolol, farnesene, umbelliferone; 3-30 μM) on vascular tone using porcine coronary and splenic arteries mounted for isometric tension recording in isolated tissue baths and precontracted with the thromboxane-mimetic U46619. Apigenin, luteolin, and (-)-α-bisabolol produced slow, concentration-dependent relaxations in both the coronary and splenic arteries that were not blocked by inhibition of nitric oxide synthase or potassium channels. Removal of extracellular calcium inhibited the relaxations to all three compounds, and these compounds also inhibited calcium re-addition-evoked contractions, indicating that the relaxation response may be mediated through inhibition of calcium influx. Apigenin and luteolin, but not (-)-α-bisabolol, enhanced the relaxation to the nitric oxide donor sodium nitroprusside, indicating that apigenin and luteolin may act to regulate cyclic GMP levels. Umbelliferone produced a rapid, transient relaxation in the splenic artery, but not the coronary artery, that was inhibited by L-NAME and removal of the endothelium, suggesting an influence on nitric oxide production. Farnesene, at concentrations up to 30 μM, was without effect in either blood vessel. In conclusion, hydroxylated compounds (apigenin, luteolin and (-)-α-bisabolol) found in chamomile all caused a slow relaxation of isolated blood vessels through an effect on calcium influx. Umbelliferone, on the other hand, produced a rapid, transient relaxation dependent upon release of nitric oxide from the endothelium. PMID:23845591

  19. First two cases of living related liver transplantation with complicated anatomy of blood vessels in Beijing

    Institute of Scientific and Technical Information of China (English)

    Wen-Han Wu; Yuan-Lian Wan; Long Lee; Yin-Mo Yang; Yan-Ting Huang; Chao-Long Chen; Sheung-Tat Fan

    2004-01-01

    AIM: Living related liver transplantation (LRLT) has been developed in response to the paediatric organ donor shortage.Though it has been succeeded in many centers worldwide,the safety of the donor is still a major concern, especially in donors with anatomy variation. We succeeded in performing the first two cases of living related liver transplantation with complicated anatomy of blood vessels as a way to overcome cadaveric organ shortage in Beijing.METHODS: Two patients, with congenital liver fibrosis and congenital biliary atresia were performed with living donor liver transplantation in our hospital and then followed up from November 12 to December 13, 2001. The two living donors, mother and father, were healthy aged 34 and 35years. One right lobe (segment Ⅴ, Ⅵ, Ⅶ, Ⅷ) and one left lateral lobe (segment Ⅱ and Ⅲ) were used. The grafts weighed 394 g and 300 g. The ratio of graft weight to the standard liver volume (SLV) of donors was 68% and 27%.The graft weight to recipient body weight ratio was 3.2%and 4.4%. The graft weight to recipient estimated standard liver mass (ESLM) ratio was 63% and 85%. The two donors had complicated blood vessel variation.RESULTS: Two patients undergone living donor liver transplantation had good results. Abnormal liver function with high bilirubin level appeared in a few days after operation, but liver function returned to normal one month after operation with bilirubin level almost decreased to near normal. No bleeding, thrombosis, infection and bile leakage occurred. One had an acute rejection and recovered.The two donors recovered in two weeks. One had slight fever because of a little collection in abdomen and recovered after paracentesis and drainage.CONCLUSION: Living donor liver transplantation has been proved to be a good way that offers a unique opportunity of getting a timely liver graft as a response to shortage of pediatric donors, though it could be a technically difficult operation if there is anatomical

  20. Use of the Structure of Blood Vessel for Detection of Brain Aneurysm and Route Search to Brain Aneurysm

    Directory of Open Access Journals (Sweden)

    Toshihide Miyagi

    2013-08-01

    Full Text Available In this research, we constructed functions that are necessary for the operation simulation system which assists medical students to inhibit brain aneurysm from exploding. The system reported in this paper is "detection of blood vessels", "detection of brain aneurysm" and "route planning to brain aneurysm". Not only the detection method but also the method to reduce the miss detection is realized for the detection of blood vessel. Finally, the future work will be shown including construction of head model consisting of artery, vein, brain and cranium.

  1. Tumor blood vessel "normalization" improves the therapeutic efficacy of boron neutron capture therapy (BNCT) in experimental oral cancer

    Energy Technology Data Exchange (ETDEWEB)

    D. W. Nigg

    2012-01-01

    We previously demonstrated the efficacy of BNCT mediated by boronophenylalanine (BPA) to treat tumors in a hamster cheek pouch model of oral cancer with no normal tissue radiotoxicity and moderate, albeit reversible, mucositis in precancerous tissue around treated tumors. It is known that boron targeting of the largest possible proportion of tumor cells contributes to the success of BNCT and that tumor blood vessel normalization improves drug delivery to the tumor. Within this context, the aim of the present study was to evaluate the effect of blood vessel normalization on the therapeutic efficacy and potential radiotoxicity of BNCT in the hamster cheek pouch model of oral cancer.

  2. In vivo nanomechanical imaging of blood-vessel tissues directly in living mammals using atomic force microscopy

    Science.gov (United States)

    Mao, Youdong; Sun, Quanmei; Wang, Xiufeng; Ouyang, Qi; Han, Li; Jiang, Lei; Han, Dong

    2009-07-01

    Atomic force microscopy (AFM) is difficult to achieve in living mammals but is necessary for understanding mechanical properties of tissues in their native form in organisms. Here we report in vivo nanomechanical imaging of blood-vessel tissues directly in living mammalians by AFM combined with surgical operations. Nanomechanical heterogeneity of blood vessels is observed across the diverse microenvironments of the same tissues in vivo. This method is further used to measure the counteractive nanomechanical changes in real time during drug-induced vasodilation and vasoconstriction in vivo, demonstrating appealing potential in characterization of in vivo nanomechanical dynamics of native tissues.

  3. Predicting effects of blood flow rate and size of vessels in a vasculature on hyperthermia treatments using computer simulation

    Directory of Open Access Journals (Sweden)

    Shih Tzu-Ching

    2010-03-01

    Full Text Available Abstract Background Pennes Bio Heat Transfer Equation (PBHTE has been widely used to approximate the overall temperature distribution in tissue using a perfusion parameter term in the equation during hyperthermia treatment. In the similar modeling, effective thermal conductivity (Keff model uses thermal conductivity as a parameter to predict temperatures. However the equations do not describe the thermal contribution of blood vessels. A countercurrent vascular network model which represents a more fundamental approach to modeling temperatures in tissue than do the generally used approximate equations such as the Pennes BHTE or effective thermal conductivity equations was presented in 1996. This type of model is capable of calculating the blood temperature in vessels and describing a vasculature in the tissue regions. Methods In this paper, a countercurrent blood vessel network (CBVN model for calculating tissue temperatures has been developed for studying hyperthermia cancer treatment. We use a systematic approach to reveal the impact of a vasculature of blood vessels against a single vessel which most studies have presented. A vasculature illustrates branching vessels at the periphery of the tumor volume. The general trends present in this vascular model are similar to those shown for physiological systems in Green and Whitmore. The 3-D temperature distributions are obtained by solving the conduction equation in the tissue and the convective energy equation with specified Nusselt number in the vessels. Results This paper investigates effects of size of blood vessels in the CBVN model on total absorbed power in the treated region and blood flow rates (or perfusion rate in the CBVN on temperature distributions during hyperthermia cancer treatment. Also, the same optimized power distribution during hyperthermia treatment is used to illustrate the differences between PBHTE and CBVN models. Keff (effective thermal conductivity model delivers the

  4. Numerical analysis of an osseointegrated prosthesis fixation with reduced bone failure risk and periprosthetic bone loss

    NARCIS (Netherlands)

    Tomaszewski, P. M.; van Diest, M.; Bulstra, S. K.; Verdonschot, N.; Verkerke, G. J.

    2012-01-01

    Currently available implants for direct attachment of prosthesis to the skeletal system after transfemoral amputation (OPRA system. Integrum AB, Sweden and ISP Endo/Exo prosthesis, ESKA Implants AG, Germany) show many advantages over the conventional socket fixation. However, restraining biomechanic

  5. Numerical analysis of an osseointegrated prosthesis fixation with reduced bone failure risk and periprosthetic bone loss.

    NARCIS (Netherlands)

    Tomaszewski, P.K.; Diest, M. van; Bulstra, S.K.; Verdonschot, N.J.; Verkerke, G.J.

    2012-01-01

    Currently available implants for direct attachment of prosthesis to the skeletal system after transfemoral amputation (OPRA system, Integrum AB, Sweden and ISP Endo/Exo prosthesis, ESKA Implants AG, Germany) show many advantages over the conventional socket fixation. However, restraining biomechanic

  6. Perpendicular Blood Vessel Seals Are Stronger Than Those Made at an Angle

    OpenAIRE

    Voegele, Aaron C.; Korvick, Donna L.; Gutierrez, Mario; Clymer, Jeffrey W.; Amaral, Joseph F.

    2013-01-01

    Vessel sealing devices effectively produce hemostatic seals with minimal thermal damage, but the strength of seals decreases as vessel diameter increases. Because vessels sealed at an angle to the vessel require a greater functional seal diameter than those sealed perpendicularly to the vessel, it was hypothesized that perpendicular seals would have comparably higher burst pressures. Ex vivo, porcine carotid arteries of nominal diameters of 5, 6, and 7 mm were sealed perpendicularly to and at...

  7. Angioblast Derived from ES Cells Construct Blood Vessels and Ameliorate Diabetic Polyneuropathy in Mice

    Directory of Open Access Journals (Sweden)

    Tatsuhito Himeno

    2015-01-01

    Full Text Available Background. Although numerous reports addressing pathological involvements of diabetic polyneuropathy have been conducted, a universally effective treatment of diabetic polyneuropathy has not yet been established. Recently, regenerative medicine studies in diabetic polyneuropathy using somatic stem/progenitor cell have been reported. However, the effectiveness of these cell transplantations was restricted because of their functional and numerical impairment in diabetic objects. Here, we investigated the efficacy of treatment for diabetic polyneuropathy using angioblast-like cells derived from mouse embryonic stem cells. Methods and Results. Angioblast-like cells were obtained from mouse embryonic stem cells and transplantation of these cells improved several physiological impairments in diabetic polyneuropathy: hypoalgesia, delayed nerve conduction velocities, and reduced blood flow in sciatic nerve and plantar skin. Furthermore, pathologically, the capillary number to muscle fiber ratios were increased in skeletal muscles of transplanted hindlimbs, and intraepidermal nerve fiber densities were ameliorated in transplanted plantar skin. Transplanted cells maintained their viabilities and differentiated to endothelial cells and smooth muscle cells around the injection sites. Moreover, several transplanted cells constructed chimeric blood vessels with recipient cells. Conclusions. These results suggest that transplantation of angioblast like cells induced from embryonic stem cells appears to be a novel therapeutic strategy for diabetic polyneuropathy.

  8. Ultrasound sonication with microbubbles disrupts blood vessels and enhances tumor treatments of anticancer nanodrug

    Directory of Open Access Journals (Sweden)

    Lin CY

    2012-04-01

    Full Text Available Chung-Yin Lin1*, Hsiao-Ching Tseng1*, Heng-Ruei Shiu1, Ming-Fang Wu2, Cheng-Ying Chou3, Win-Li Lin1,41Institute of Biomedical Engineering, 2Laboratory Animal Center, 3Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei, Taiwan; 4Division of Medical Engineering Research, National Health Research Institutes, Miaoli, Taiwan*These authors contributed equally to this workAbstract: Ultrasound (US sonication with microbubbles (MBs has the potential to disrupt blood vessels and enhance the delivery of drugs into the sonicated tissues. In this study, mouse ear tumors were employed to investigate the therapeutic effects of US, MBs, and pegylated liposomal doxorubicin (PLD on tumors. Tumors started to receive treatments when they grew up to about 15 mm3 (early stage with injection of PLD 10 mg/kg, or up to 50 mm3 (medium stage with PLD 6 (or 4 mg/kg. Experiments included the control, PLD alone, PLD + MBs + US, US alone, and MBs + US groups. The procedure for the PLD + MBs + US group was that PLD was injected first, MB (SonoVue injection followed, and then US was immediately sonicated on the tumor. The results showed that: (1 US sonication with MBs was always able to produce a further hindrance to tumor growth for both early and medium-stage tumors; (2 for the medium-stage tumors, 6 mg/kg PLD alone was able to inhibit their growth, while it did not work for 4 mg/kg PLD alone; (3 with the application of MBs + US, 4 mg/kg PLD was able to inhibit the growth of medium-stage tumors; (4 for early stage tumors after the first treatment with a high dose of PLD alone (10 mg/kg, the tumor size still increased for several days and then decreased (a biphasic pattern; (5 MBs + US alone was able to hinder the growth of early stage tumors, but unable to hinder that of medium stage tumors. The results of histological examinations and blood perfusion measurements indicated that the application of MBs + US disrupts the tumor blood

  9. About a mechanism of the influence of shear stress for viscosity of the blood in vessels of small diameter

    OpenAIRE

    Катюхин, Лев Николаевич

    2014-01-01

    It is proposed a physiological and experimentally confirmed explanation of Fåhraeus-Lindqvist-effect in capillaries using the profile analyses of osmotic deformability of red blood cells. It was shown the dose-dependent change of the erythrocytes deformability in the stage of isotropic spheres after forming artificial water pores (nystatin) and occlusion (PbCl2) of available pores. The Sigma-effect reducing of hematocrit and viscosity in a shear flow of blood through the vessels of a small di...

  10. Argus II retinal prosthesis system: An update.

    Science.gov (United States)

    Rachitskaya, Aleksandra V; Yuan, Alex

    2016-09-01

    This review focuses on a description of the Argus II retinal prosthesis system (Argus II; Second Sight Medical Products, Sylmar, CA) that was approved for humanitarian use by the FDA in 2013 in patients with retinitis pigmentosa with bare or no light perception vision. The article describes the components of Argus II, the studies on the implant, and future directions. PMID:26855177

  11. Three-dimensional multi-scale model of deformable platelets adhesion to vessel wall in blood flow.

    Science.gov (United States)

    Wu, Ziheng; Xu, Zhiliang; Kim, Oleg; Alber, Mark

    2014-08-01

    When a blood vessel ruptures or gets inflamed, the human body responds by rapidly forming a clot to restrict the loss of blood. Platelets aggregation at the injury site of the blood vessel occurring via platelet-platelet adhesion, tethering and rolling on the injured endothelium is a critical initial step in blood clot formation. A novel three-dimensional multi-scale model is introduced and used in this paper to simulate receptor-mediated adhesion of deformable platelets at the site of vascular injury under different shear rates of blood flow. The novelty of the model is based on a new approach of coupling submodels at three biological scales crucial for the early clot formation: novel hybrid cell membrane submodel to represent physiological elastic properties of a platelet, stochastic receptor-ligand binding submodel to describe cell adhesion kinetics and lattice Boltzmann submodel for simulating blood flow. The model implementation on the GPU cluster significantly improved simulation performance. Predictive model simulations revealed that platelet deformation, interactions between platelets in the vicinity of the vessel wall as well as the number of functional GPIbα platelet receptors played significant roles in platelet adhesion to the injury site. Variation of the number of functional GPIbα platelet receptors as well as changes of platelet stiffness can represent effects of specific drugs reducing or enhancing platelet activity. Therefore, predictive simulations can improve the search for new drug targets and help to make treatment of thrombosis patient-specific. PMID:24982253

  12. Single image correlation for blood flow mapping in complex vessel networks

    Science.gov (United States)

    Chirico, Giuseppe; Sironi, Laura; Bouzin, Margaux; D'Alfonso, Laura; Collini, Maddalena; Ceffa, Nicolo'G.; Marquezin, Cassia

    2015-05-01

    Microcirculation plays a key role in the maintenance and hemodynamics of tissues and organs also due to its extensive interaction with the immune system. A critical limitation of state-of-the-art clinical techniques to characterize the blood flow is their lack of the spatial resolution required to scale down to individual capillaries. On the other hand the study of the blood flow through auto- or cross-correlation methods fail to correlate the flow speed values with the morphological details required to describe an intricate network of capillaries. Here we propose to use a newly developed technique (FLICS, FLow Image Correlation Spectroscopy) that, by employing a single raster-scanned xy-image acquired in vivo by confocal or multi-photon excitation fluorescence microscopy, allows the quantitative measurement of the blood flow velocity in the whole vessel pattern within the field of view, while simultaneously maintaining the morphological information on the immobile structures of the explored circulatory system. Fluorescent flowing objects produce diagonal lines in the raster-scanned image superimposed to static morphological details. The flow velocity is obtained by computing the Cross Correlation Function (CCF) of the intensity fluctuations detected in pairs of columns of the image. The whole analytical dependence of the CCFs on the flow speed amplitude and the flow direction has been reported recently. We report here the derivation of approximated analytical relations that allows to use the CCF peak lag time and the corresponding CCF value, to directly estimate the flow speed amplitude and the flow direction. The validation has been performed on Zebrafish embryos for which the flow direction was changed systematically by rotating the embryos on the microscope stage. The results indicate that also from the CCF peak lag time it is possible to recover the flow speed amplitude within 13% of uncertainty (overestimation) in a wide range of angles between the flow and

  13. NOK/STYK1 promotes the genesis and remodeling of blood and lymphatic vessels during tumor progression.

    Science.gov (United States)

    Liu, Yue; Li, Tianqi; Hu, Dan; Zhang, Shuping

    2016-09-01

    Previous studies have indicated that the overexpression of NOK, also named STYK1, led to tumorigenesis and metastasis. Here, we provide evidence that increased expression of NOK/STYK1 caused marked alterations in the overall and inner structures of tumors and substantially facilitates the genesis and remodeling of the blood and lymphatic vessels during tumor progression. In particular, NOK-expressed HeLa stable cells (HeLa-K) significantly enhanced tumor growth and metastasis in xenografted nude mice. Hematoxylin and eosin (HE) staining demonstrated that the tumor tissues generated by HeLa-K cells were much more ichorous and had more interspaces than those generated by control HeLa cells (HeLa-C). The fluorescent areas stained with cluster of differentiation 31 (CD31), a marker protein for blood vessels, appeared to be in different patterns. The total blood vessels, especially the ring patterns, within the tumors of the HeLa-K group were highly enriched compared with those in the HeLa-C group. NOK-HA was demonstrated to be well colocalized with CD31 in the wall of the tubular structures within tumor tissues. Interestingly, antibody staining of the lymphatic vessel endothelial hyaluronan receptor (LYVE-1) further revealed the increase in ring (oratretic strip-like) lymphatic vessels in either the peritumoral or intratumoral areas in the HeLa-K group compared with the HeLa-C group. Consistently, the analysis of human cancerous tissue also showed that NOK was highly expressed in the walls of tubular structures. Thus, our results reveal a novel tumorigenic function of NOK to mediate the genesis and remodeling of blood and lymphatic vessels during tumor progression. PMID:27444381

  14. Magnetic resonance imaging evaluation after implantation of a titanium cervical disc prosthesis: a comparison of 1.5 and 3 Tesla magnet strength

    OpenAIRE

    Sundseth, Jarle; Jacobsen, Eva A.; Kolstad, Frode; Nygaard, Oystein P.; Zwart, John A.; Hol, Per K.

    2013-01-01

    Purpose Cervical disc prostheses induce significant amount of artifact in magnetic resonance imaging which may complicate radiologic follow-up after surgery. The purpose of this study was to investigate as to what extent the artifact, induced by the frequently used Discover® cervical disc prosthesis, impedes interpretation of the MR images at operated and adjacent levels in 1.5 and 3 Tesla MR. Methods Ten subsequent patients were investigated in both 1.5 and 3 Tesla MR with standard image seq...

  15. An Automated Graphical User Interface based System for the Extraction of Retinal Blood Vessels using Kirsch’s Template

    Directory of Open Access Journals (Sweden)

    Joshita Majumdar

    2015-06-01

    Full Text Available The assessment of Blood Vessel networks plays an important role in a variety of medical disorders. The diagnosis of Diabetic Retinopathy (DR and its repercussions including micro aneurysms, haemorrhages, hard exudates and cotton wool spots is one such field. This study aims to develop an automated system for the extraction of blood vessels from retinal images by employing Kirsch’s Templates in a MATLAB based Graphical User Interface (GUI. Here, a RGB or Grey image of the retina (Fundus Photography is used to obtain the traces of blood vessels. We have incorporated a range of Threshold values for the blood vessel extraction which would provide the user with greater flexibility and ease. This paper also deals with the more generalized implementation of various MATLAB functions present in the image processing toolbox of MATLAB to create a basic image processing editor with different features like noise addition and removal, image cropping, resizing & rotation, histogram adjust, separately viewing the red, green and blue components of a colour image along with brightness control, that are used in a basic image editor. We have combined both Kirsch’s Template and various MATLAB Algorithms to obtain enhanced images which would allow the ophthalmologist to edit and intensify the images as per his/her requirement for diagnosis. Even a non technical person can manage to identify severe discrepancies because of its user friendly appearance. The GUI contains very commonly used English Language viz. Load, Colour Contrast Panel, Image Clarity etc that can be very easily understood. It is an attempt to incorporate maximum number of image processing techniques under one GUI to obtain higher performance. Also it would provide a cost effective solution towards obtaining high definition and resolution images of blood vessel extracted Retina in economically backward regions where costly machine like OCT (Optical Coherence Tomography, MRI (Magnetic Resonance

  16. Taper Hip Prosthesis

    Medline Plus

    Full Text Available Zimmer M/L Taper Hip Prosthesis with Modular Neck Kinectiv® Technology March 12, 2009 7:00 PM EDT Welcome to this "OR Live" Webcast presentation brought to ... approximately one centimeter to the shoulder of my prosthesis. And then I will simply use the prosthesis ...

  17. Molecular Dynamics Simulation of Soft Grains: Malaria-Infected Red Blood Cells Motion within Obstructed 2-D Capillary Vessel

    CERN Document Server

    Haris, Luman; Haryanto, Freddy; Viridi, Sparisoma

    2013-01-01

    Molecular dynamics has been widely used to numerically solve equation of motion of classical many-particle system. It can be used to simulate many systems including biophysics, whose complexity level is determined by the involved elements. Based on this method, a numerical model had been constructed to mimic the behaviour of malaria-infected red blood cells within capillary vessel. The model was governed by three forces namely Coulomb force, normal force, and Stokes force. By utilizing two dimensional four-cells scheme, theoretical observation was carried out to test its capability. Although the parameters were chosen deliberately, all of the quantities were given arbitrary value. Despite this fact, the results were quite satisfactory. Combined with the previous results, it can be said that the proposed model were sufficient enough to mimic the malaria-infected red blood cells motion within obstructed capillary vessel. Keywords: molecular dynamics, two-dimensional model, red-blood cell motion, malaria

  18. A study of the influence scan timing and depiction of blood vessel diameter in CE-3DMRA. Simulation by pulsatile flow

    International Nuclear Information System (INIS)

    In imaging using contrast-enhanced three-dimensional magnetic resonance angiography (CE-3DMRA), optimizing the delay time from the start of intravenous injection of contrast medium to the start of scanning has generally been an important concern when obtaining blood vessel images of good contrast. Recent methods of mechanically assessing the attainment of contrast medium injection include Smart-Prep and others. Another method is the Test Bolus, in which a small amount of contrast medium determines the timing of scan start, in quest of the time intensity curve. Because these methods are not necessarily satisfactory, the corrected method is used in clinical cases. In terms of how scan timing affects blood vessel depiction, no study has examined pulsatile flow, which is carried out by simulation. On the other hand, there are reports on data filling of k-space using imitation blood vessels on a computer and simple experimental equipment. This research examined experimentally blood vessel depiction according to scan timing and the diameter of blood vessels by using a systemic circulation simulator that incorporated hemodynamic circulation in which pulsatile flow is the same as that of a human body, using an artificial heart developed especially for MRI. It is thought that scan timing in CE-3DMRA affects the depiction of blood vessels for which the diameter of the blood vessel differs from the experimental result. Phase-encoding k-space data filling is the contrast-to-noise ratio (CNR) of each blood vessel irrespective of sequential and centric k-space ordering. The timing shift phenomenon, in which a blood vessel is so thin that the scan timing is overdue and shows a relatively high value, can occur. Moreover, that scan timing affects not only the diameter of a blood vessel but also depiction of the narrowing of a stenotic blood vessel or a branch blood vessel was demonstrated clinically and experimentally. Therefore, blood vessel depiction changes with scan timing, and

  19. 21 CFR 888.3320 - Hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis.

    Science.gov (United States)

    2010-04-01

    ... cemented acetabular component, prosthesis. 888.3320 Section 888.3320 Food and Drugs FOOD AND DRUG..., prosthesis. (a) Identification. A hip joint metal/metal semi-constrained, with a cemented acetabular component, prosthesis is a two-part device intended to be implanted to replace a hip joint. The...

  20. 21 CFR 888.3330 - Hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis.

    Science.gov (United States)

    2010-04-01

    ... uncemented acetabular component, prosthesis. 888.3330 Section 888.3330 Food and Drugs FOOD AND DRUG..., prosthesis. (a) Identification. A hip joint metal/metal semi-constrained, with an uncemented acetabular component, prosthesis is a two-part device intended to be implanted to replace a hip joint. The...

  1. 21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.

    Science.gov (United States)

    2010-04-01

    .../polymer porous-coated uncemented prosthesis. 888.3535 Section 888.3535 Food and Drugs FOOD AND DRUG... prosthesis. (a) Identification. A knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis is a device intended to be implanted to replace part of a knee joint. The device...

  2. 21 CFR 888.3410 - Hip joint metal/polymer or ceramic/polymer semiconstrained resurfacing cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    ... semiconstrained resurfacing cemented prosthesis. 888.3410 Section 888.3410 Food and Drugs FOOD AND DRUG... prosthesis. (a) Identification. A hip joint metal/polymer or ceramic/polymer semi-constrained resurfacing cemented prosthesis is a two-part device intended to be implanted to replace the articulating surfaces...

  3. 21 CFR 888.3560 - Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis.

    Science.gov (United States)

    2010-04-01

    .../polymer semi-constrained cemented prosthesis. 888.3560 Section 888.3560 Food and Drugs FOOD AND DRUG... prosthesis. (a) Identification. A knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a knee joint. The device...

  4. Infrared tomography for diagnostic imaging of port wine stain blood vessels

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, D. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    The objective of this work is the development of Infrared Tomography (IRT) for detecting and characterizing subsurface chromophores in human skin. Characterization of cutaneous chromophores is crucial for advances in the laser treatment of pigmented lesions (e.g., port wine stain birthmarks and tatoos). Infrared tomography (IRT) uses a fast infrared focal plane array (IR-FPA) to detect temperature rises in a substrate induced by pulsed radiation. A pulsed laser is used to produce transient heating of an object. The temperature rise, due to the optical absorption of the pulsed laser light, creates an increase in infrared emission which is measured by the IR-FPA. Although the application of IRT to image subsurface cracks due to metal fatigue is a topic of great interest in the aircraft industry, the application to image subsurface chromophores in biological materials is novel. We present an image recovery method based on a constrained conjugate gradient algorithm that has obtained the first ever high quality images of port wine blood vessels.

  5. Formation of an artificial blood vessel: adhesion force measurements with optical tweezers

    Science.gov (United States)

    Knoener, Gregor; Campbell, Julie H.; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina

    2004-10-01

    We are investigating the formation of a tissue capsule around a foreign body. This tissue capsule can be used as an autologous graft for the replacement of diseased blood vessels or for bypass surgery. The graft is grown in the peritoneal cavity of the recipient and the formation starts with the adhesion of cells to the foreign body. We identify the cell type and measure the adhesion of these cells to foreign materials using optical tweezers. Cell adhesion to macroscopic samples and microspheres is investigated. No difference in the adhesion force was measurable for polyethylene, silicon and Tygon on a scale accessible to optical tweezers. The density of adherent cells was found to vary strongly, being highest on polyethylene. The mean rupture forces for cell-microsphere adhesion ranged from 24 to 39 pN and changed upon preadsorption of bovine serum albumin. For plain microspheres, the highest mean rupture force was found for PMMA, which also showed the highest adhesion probability for the cell-microsphere interaction.

  6. Evaluation of local density enhancement of microcapsules in artificial blood vessel during exposure to focused ultrasound

    International Nuclear Information System (INIS)

    We have proposed a physical DDS (Drug Delivery System) which makes use of microcapsules of μm size, which may contain a specified drug and also are easily affected by ultrasound exposure near their resonant frequency, to release various kinds of medications. These capsules are easily detected and actuated by ultrasound. However, because of the diffusion of capsules after injection into human body, it was difficult to enhance the efficiency of drug delivery. Thus we have considered a method for controlling the density of capsules in flow which uses acoustic radiation force, which moves the capsules to balance flow resistance. We have experimented with trapping microcapsules or microbubbles in flow of an artificial blood vessel. We have evaluated the effect of radiation force by measuring the trapped area of capsules or bubbles for various frequencies, sound pressures, and exposure times of sinusoidal ultrasound. The trapped area of capsules or bubbles increased with sound pressure and exposure time, and decreased with frequency. From those results, we have derived optimal conditions for trapping the capsules or bubbles.

  7. Evaluation of local density enhancement of microcapsules in artificial blood vessel during exposure to focused ultrasound

    Science.gov (United States)

    Nakamoto, Ryusuke; Masuda, Kohji; Watarai, Nobuyuki; Taguchi, Yuto; Kato, Toshikazu; Yoshinaga, Takashi; Miyamoto, Yoshitaka; Chiba, Toshio

    2011-09-01

    We have proposed a physical DDS (Drug Delivery System) which makes use of microcapsules of μm size, which may contain a specified drug and also are easily affected by ultrasound exposure near their resonant frequency, to release various kinds of medications. These capsules are easily detected and actuated by ultrasound. However, because of the diffusion of capsules after injection into human body, it was difficult to enhance the efficiency of drug delivery. Thus we have considered a method for controlling the density of capsules in flow which uses acoustic radiation force, which moves the capsules to balance flow resistance. We have experimented with trapping microcapsules or microbubbles in flow of an artificial blood vessel. We have evaluated the effect of radiation force by measuring the trapped area of capsules or bubbles for various frequencies, sound pressures, and exposure times of sinusoidal ultrasound. The trapped area of capsules or bubbles increased with sound pressure and exposure time, and decreased with frequency. From those results, we have derived optimal conditions for trapping the capsules or bubbles.

  8. Knockdown of Zebrafish Blood Vessel Epicardial Substance Results in Incomplete Retinal Lamination

    Directory of Open Access Journals (Sweden)

    Yu-Ching Wu

    2014-01-01

    Full Text Available Cell polarity during eye development determines the normal retinal lamination and differentiation of photoreceptor cells in the retina. In vertebrates, blood vessel epicardial substance (Bves is known to play an important role in the formation and maintenance of the tight junctions essential for epithelial cell polarity. In the current study, we generated a transgenic zebrafish Bves (zbves promoter-EGFP zebrafish line to investigate the expression pattern of Bves in the retina and to study the role of zbves in retinal lamination. Immunostaining with different specific antibodies from retinal cells and transmission electron microscopy were used to identify the morphological defects in normal and Bves knockdown zebrafish. In normal zebrafish, Bves is located at the apical junctions of embryonic retinal neuroepithelia during retinogenesis; later, it is strongly expressed around inner plexiform layer (IPL and retinal pigment epithelium (RPE. In contrast, a loss of normal retinal lamination and cellular polarity was found with undifferentiated photoreceptor cells in Bves knockdown zebrafish. Herein, our results indicated that disruption of Bves will result in a loss of normal retinal lamination.

  9. CCL11-induced eosinophils inhibit the formation of blood vessels and cause tumor necrosis.

    Science.gov (United States)

    Xing, Yanjiang; Tian, Yijun; Kurosawa, Takamasa; Matsui, Sayaka; Touma, Maki; Yanai, Takanori; Wu, Qiong; Sugimoto, Kenkichi

    2016-06-01

    We previously demonstrated that IL-18 and CCL11 were highly expressed in an NFSA tumor cell line that showed limited angiogenesis and severe necrosis. However, IL-18 was not responsible for the immune cell accumulation and necrosis. Here, we attempted to clarify the relevance of CCL11 in angiogenesis and tumor formation. We established CCL11-overexpressing MS-K cell clones (MS-K-CCL11) to assess the role of CCL11 in immune cell accumulation and angiogenesis. The MS-K-CCL11 cells did not form tumors in mice. MS-K-CCL11-conditioned medium (CM) and recombinant CCL11 induced macrophage and eosinophil differentiation from bone marrow cells. The MS-K-CCL11-CM effectively recruited the differentiated eosinophils. Furthermore, the eosinophils damaged the MS-K, NFSA and endothelial cells in a dose-dependent manner. Administration of an antagonist of CCR3, a CCL11 receptor, to NFSA tumor-bearing mice restored the blood vessel formation and blocked the eosinophil infiltration into the NFSA tumors. Furthermore, other CCL11-overexpressing LM8 clones were established, and their tumor formation ability was reduced compared to the parental LM8 cells, accompanied by increased eosinophil infiltration, blockade of angiogenesis and necrosis. These results indicate that CCL11 was responsible for the limited angiogenesis and necrosis by inducing and attracting eosinophils in the tumors. PMID:27169545

  10. The effect of maternal smoke exposure on the ultrastructure of fetal peripheral blood vessels in the mouse.

    Science.gov (United States)

    Kaufmann, R C; Amankwah, K S; Weberg, A D

    1986-01-01

    Ultrastructural changes have been found in umbilical blood vessels, placental blood vessels, and peripheral blood vessels of human fetuses whose mothers smoked during pregnancy. This study was undertaken to determine if similar changes could be found in peripheral blood vessels of mice fetuses whose mothers were exposed to cigarette smoke during pregnancy. Breeding mice of the C57BL/KsJ strain were placed in a smoking box similar to that described by Younoszai and exposed to cigarette smoke intermittently. This produces carbon monoxide levels in the adult mice similar to that found in human adults smoking one pack of cigarettes per day. Similarly caged mice of the same strain were used as controls. The female mice were not removed from their cage from pre-conception time until after delivery. Upon delivery each pup was sacrificed via neck fracture and the entire pup was immersed in a solution of 2.5% glutaraldehyde in 0.1 M cacodylate buffer at pH 7.3. While still under solution, the rear leg muscles were dissected free, sliced, and immersed in the same preservative for four to five hours. They were then placed in fresh 2.5% glutaraldehyde mixture overnight. The tissues were post-fixed in osmium ferrocyanide and en-block stained with uranyl acetate in a graded series of alcohol. The tissues were infiltrated with and embedded in Spurr. Sections were taken via an ultramicrotome and post-stained with uranyl acetate and lead citrate. The sections were examined in a Philips 201 electron microscope at 60 KV. In the peripheral vessels of the fetuses from smoke-exposed mothers, endothelial blebbing (both surface-type and vacuole-type) was seen.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3783394

  11. Production of porous coating on a prosthesis

    Science.gov (United States)

    Sump, Kenneth R.

    1987-01-01

    Preselected surface areas of a prosthesis are covered by a blend of matching primary metallic particles and expendable particles. The particles are compressed and heated to assure that deformation and metallurgical bonding occurs between them and between the primary particles and the surface boundaries of the prosthesis. Porosity is achieved by removal of the expendable material. The result is a coating including discrete bonded particles separated by a network of interconnected voids presenting a homogeneous porous coating about the substrate. It has strength suitable for bone implant usage without intermediate adhesives, and adequate porosity to promote subsequent bone ingrowth.

  12. Oxygen-implanted induced formation of oxide layer enhances blood compatibility on titanium for biomedical applications.

    Science.gov (United States)

    Hung, Wei-Chiang; Chang, Fang-Mo; Yang, Tzu-Sen; Ou, Keng-Liang; Lin, Che-Tong; Peng, Pei-Wen

    2016-11-01

    Titanium dioxide (TiO2) layers were prepared on a Ti substrate by using oxygen plasma immersion ion implantation (oxygen PIII). The surface chemical states, structure, and morphology of the layers were studied using X-ray photoelectron spectroscopy, X-ray diffraction, Raman microscopy, atomic force microscopy and scanning electron microscope. The mechanical properties, such as the Young's modulus and hardness, of the layers were investigated using nanoindentation testing. The Ti(4+) chemical state was determined to be present on oxygen-PIII-treated surfaces, which consisted of nanocrystalline TiO2 with a rutile structure. Compared with Ti substrates, the oxygen-PIII-treated surfaces exhibited decreased Young's moduli and hardness. Parameters indicating the blood compatibility of the oxygen-PIII-treated surfaces, including the clotting time and platelet adhesion and activation, were studied in vitro. Clotting time assays indicated that the clotting time of oxygen-PIII-treated surfaces was longer than that of the Ti substrate, which was associated with decreased fibrinogen adsorption. In conclusion, the surface characteristics and the blood compatibility of Ti implants can be modified and improved using oxygen PIII. PMID:27524050

  13. Percutaneous Revision of a Testicular Prosthesis is Safe, Cost-effective, and Provides Good Patient Satisfaction

    Directory of Open Access Journals (Sweden)

    Eugene B. Cone

    2015-09-01

    Full Text Available Office-based percutaneous revision of a testicular prosthesis has never been reported. A patient received a testicular prosthesis but was dissatisfied with the firmness of the implant. In an office setting, the prosthesis was inflated with additional fluid via a percutaneous approach. Evaluated outcomes included patient satisfaction, prosthesis size, recovery time, and cost savings. The patient was satisfied, with no infection, leak, or complication after more than 1 year of follow-up, at significantly less cost than revision surgery. Percutaneous adjustment of testicular prosthesis fill-volume can be safe, inexpensive, and result in good patient satisfaction.

  14. Malformation of certain brain blood vessels caused by TCDD activation of Ahr2/Arnt1 signaling in developing zebrafish

    International Nuclear Information System (INIS)

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes various signs of toxicity in early life stages of vertebrates through activation of the aryl hydrocarbon receptor (AHR). The AHR also plays important roles in normal development in mice, and AHR-/- mice show abnormal development of vascular structures in various blood vessels. Our previous studies revealed that Ahr type 2 (Ahr2) activation by TCDD and β-naphthoflavone (BNF) caused a significant decrease in blood flow in the dorsal midbrain of zebrafish embryos. Here we report effects of TCDD exposure on the morphology of some blood vessels in the head of developing zebrafish. TCDD caused concentration-dependent anatomical rearrangements in the shape of the prosencephalic artery in zebrafish larvae. In contrast, no major vascular defects were recognized in the trunk and tail regions following exposure to TCDD at least at the concentrations used. Essentially, the same observations were also confirmed in BNF-exposed larvae. Knock-down of either Ahr2 or Ahr nuclear translocator type 1 (Arnt1) by morpholino oligonucleotides (MOs) protected larvae against abnormal shape of the prosencephalic artery caused by TCDD and BNF. On the other hand, knock-down of Ahr2 or Arnt1 in vehicle-exposed zebrafish larvae had no clear effect on morphology of the prosencephalic artery or trunk vessels. Ascorbic acid, an antioxidant, protected against the TCDD-induced decrease in blood flow through the prosencephalic artery, but not the abnormal morphological changes in the shape of this artery. These results indicate that activation of Ahr2/Arnt1 pathway by TCDD and BNF affects the shape of certain blood vessels in the brain of developing zebrafish.

  15. Malformation of certain brain blood vessels caused by TCDD activation of Ahr2/Arnt1 signaling in developing zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Teraoka, Hiroki, E-mail: hteraoka@rakuno.ac.jp [School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501 (Japan); Ogawa, Akira [School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501 (Japan); Kubota, Akira [School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501 (Japan); Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA (United States); Stegeman, John J. [Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA (United States); Peterson, Richard E. [School of Pharmacy, University of Wisconsin, Madison, WI (United States); Hiraga, Takeo [School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501 (Japan)

    2010-08-15

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes various signs of toxicity in early life stages of vertebrates through activation of the aryl hydrocarbon receptor (AHR). The AHR also plays important roles in normal development in mice, and AHR{sup -/-} mice show abnormal development of vascular structures in various blood vessels. Our previous studies revealed that Ahr type 2 (Ahr2) activation by TCDD and {beta}-naphthoflavone (BNF) caused a significant decrease in blood flow in the dorsal midbrain of zebrafish embryos. Here we report effects of TCDD exposure on the morphology of some blood vessels in the head of developing zebrafish. TCDD caused concentration-dependent anatomical rearrangements in the shape of the prosencephalic artery in zebrafish larvae. In contrast, no major vascular defects were recognized in the trunk and tail regions following exposure to TCDD at least at the concentrations used. Essentially, the same observations were also confirmed in BNF-exposed larvae. Knock-down of either Ahr2 or Ahr nuclear translocator type 1 (Arnt1) by morpholino oligonucleotides (MOs) protected larvae against abnormal shape of the prosencephalic artery caused by TCDD and BNF. On the other hand, knock-down of Ahr2 or Arnt1 in vehicle-exposed zebrafish larvae had no clear effect on morphology of the prosencephalic artery or trunk vessels. Ascorbic acid, an antioxidant, protected against the TCDD-induced decrease in blood flow through the prosencephalic artery, but not the abnormal morphological changes in the shape of this artery. These results indicate that activation of Ahr2/Arnt1 pathway by TCDD and BNF affects the shape of certain blood vessels in the brain of developing zebrafish.

  16. Fatores de risco para mortalidade hospitalar no implante de prótese valvar mecânica Risk factors for hospital mortality in valve replacement with mechanical prosthesis

    Directory of Open Access Journals (Sweden)

    Mateus W De Bacco

    2009-09-01

    Full Text Available INTRODUÇÃO: A identificação dos fatores de risco pré-operatórios na cirurgia valvar visa à melhoria do resultado cirúrgico por meio da neutralização de fatores relacionados à mortalidade aumentada. Este estudo tem por objetivo identificar fatores de risco para mortalidade hospitalar em pacientes submetidos a implante de prótese valvar mecânica. MÉTODOS: Estudo prospectivo com aquisição retrospectiva de dados com 335 pacientes consecutivamente submetidos ao implante de prótese mecânica St Jude Medical, entre dezembro de 1994 e setembro de 2005, no Instituto de Cardiologia do RS, sendo 158 aórticos, 146 mitrais e 31 mitro-aórticos. Foi analisada a relação da mortalidade hospitalar com características demográficas e operatórias dos pacientes: sexo, idade, índice de massa corporal, classe funcional (NYHA, fração de ejeção, lesão valvar, hipertensão arterial sistêmica, diabete melito, creatinina, arritmia cardíaca, cirurgia cardíaca prévia, revascularização miocárdica, plastia tricúspide concomitante e caráter da cirurgia (eletivo, de urgência ou de emergência. Utilizada regressão logística para identificar os fatores de risco e quantificada sua influência pelo cálculo de odds-ratio. RESULTADOS: Ocorreram 13 (3,88% óbitos hospitalares. Características relacionadas à mortalidade aumentada foram creatinina sérica (POBJECTIVE: Identification of risk factors for cardiac surgery can improve surgical results. Our aim is to identify factors related to increased hospital mortality for patients who underwent mechanical cardiac prosthesis implant. METHODS: Prospective study with retrospective data acquirement study including 335 consecutive patients who underwent at least one implant of St. Jude Medical mechanical prosthesis between December 1994 and September 2005 at the Cardiology Institute of RS. Valve implants were 158 (47.1% in aortic position, 146 (43.6% in mitral and 31 (9.3% in aortic and mitral. The

  17. Histologic analysis of a retrieved hydroxyapatite-coated femoral prosthesis

    DEFF Research Database (Denmark)

    Søballe, K; Gotfredsen, K; Brockstedt-Rasmussen, H;

    1991-01-01

    A hydroxyapatite-coated hip hemi-prosthesis was retrieved from a 98-year-old osteoporotic woman 12 weeks after implantation. Histologic analysis revealed bone and fibrous tissue almost evenly distributed around the surface of the implant circumference. Quantitative histologic analysis showed that...

  18. Ultrafine Fibrous Membranes by Coaxial Electrospinning for Artificial Blood Vessel%同轴电纺超细纤维膜构建人工血管材料

    Institute of Scientific and Technical Information of China (English)

    曹文轩; 张红; 袁晓燕

    2011-01-01

    以右旋糖酐(DEX)为芯、聚乙二醇-b-聚(L-丙交酯-co-ε-己内酯)(PELCL)为壳,采用同轴电纺技术制备DEX/PELCL超细纤维膜.在该电纺纤维内芯分别负载血管内皮生长因子(VEGF)和血小板衍生生长因子(PDGF-bb),并以此构建双层超细纤维膜人工血管支架.28 d的释放结果表明,VEGF和PDGF-bb 均表现出突释现象,含有肝素的VEGF样品释放量有所下降.大鼠腹主动脉移植实验结果表明,载有VEGF和PDGFbb的超细纤维膜可以用于构建双层人工血管.%Core/shell ultrafine fibers, with dextran(DEX) and poly(ethylene glycol)-b-poly(L-lactide-co-εcaprolactone) (PELCL) as the core and shell, respectively, were prepared by coaxial electrospinning.Double-layered ultraline fibrous tubes of the coaxial-electrospun DEX/PELCL fiberswere constructed for application as artificial blood vessel by loading vascular endothelial growth factor (VEGF) and platelet derived growth factor-bb( PDGF-bb), respectively in the fiber core. The in vitro releasing results of 28 d indicated that initial burst release occurred for both VEGF and PDGF-bb. The in vivo implantation in abdomen aorta of a rat model showed that the double-layered fibrous tubes loading VEGF and PDGF-bb could be potential used as artificial blood vessels.

  19. Analysis by NASA's VESGEN Software of Retinal Blood Vessels Before and After 70-Day Bed Rest: A Retrospective Study

    Science.gov (United States)

    Raghunandan, Sneha; Vyas, Ruchi J.; Vizzeri, Gianmarco; Taibbi, Giovanni; Zanello, Susana B.; Ploutz-Snyder, Robert; Parsons-Wingerter, Patricia A.

    2016-01-01

    Significant risks for visual impairment associated with increased intracranial pressure (VIIP) are incurred by microgravity spaceflight, especially long-duration missions. Impairments include decreased near visual acuity, posterior globe flattening, choroidal folds, optic disc edema and cotton wool spots. We hypothesize that microgravity-induced fluid shifts result in pathological changes within the retinal blood vessels that precede development of visual and other ocular impairments. Potential contributions of retinal vascular remodeling to VIIP etiology are therefore being investigated by NASAs innovative VESsel GENeration Analysis (VESGEN) software for two studies: (1) head-down tilt in human subjects before and after 70 days of bed rest, and (2) U.S. crew members before and after ISS missions. VESGEN analysis in previous research supported by the US National Institutes of Health identified surprising new opportunities to regenerate retinal vessels during early-stage, potentially reversible progression of the visually impairing and blinding disease, diabetic retinopathy.

  20. Noninvasive radioisotopic technique for detection of platelet deposition in mitral valve prosthesis and renal microembolism in dogs

    International Nuclear Information System (INIS)

    At 24 hrs after implantation of Bjoerk-Shiley mitral prosthesis in 5 dogs, in vivo images were obtained with a gamma camera after intravenous administration (0.5-0.6 mCi) one hour postoperatively of autologous Indium-111-labeled platelets. The site of platelet deposition in the teflon ring and perivascular damaged cardiac tissue is clearly delineated in the scintiphoto. In vitro biodistribution (mean % +/- SD of injected dose) at 24 hrs after injection of the 5 implanted and 7 normal dogs performed with a gamma counter demonstrated that (45.1 +/- 10.6)% and (0.7 +/- 0.4)% were in blood and kidneys in normal dogs and (28.5 +/- 6.8)%, (1.6 +/- 0.6)%, (0.3 +/- 0.1)%, and (0.2 +/- 0.1)% were in blood, kidneys, teflon rings, and perivascular damaged cardiac tissue, respectively. The strut and pyrolytic carbon-coated disc retained only (0.0033 +/- 0.0004)% and (0.0031 +/- 0.0003)%, respectively. There was a 2.3-fold increase of labeled platelets in kidneys of implanted dogs due to renal trapping of microembolism. Also, three- to fivefold increase in ratios of lung, brain, cardiac, and skeletal muscle to blood indicates that internal organs and whole body work as filter for microembolism generated by cardiovascular surgery and mitral prosthesis. Twenty percent of the administered platelets are consumed in surgical repair of damaged tissue. Indium-111-labeled platelets thus provide a sensitive marker for noninvasive imaging of Bjoerk-Shiley mitral prosthesis, thromboembolism after implantation of prosthetic device, and in vitro quantitation of surgical consumption

  1. 国产ePTFE人工血管的动物实验研究%Experimental study on Chinese ePTFE vascular prosthesis in animals

    Institute of Scientific and Technical Information of China (English)

    程青; 陈忠庆; 王国斌

    2004-01-01

    Objective: To study the feasibility of Chinese ePTFE vascular prosthesis. Methods: Dogs' femoral arteries were interpositioned with Chinese ePTFE vascular prosthesis in comparision with foreign Dacron vascular prosthesis. After operation we studied the patency of Chinese ePTFE vascular prosthesis by physica/examination,color Doppler. Then we observed intima and adventitia of ePTFE vascular prosthesis by naked eye, mirror lens,scanning electron microscope; and observed endothelial cells growth of vascular prosthesis by immunohistochemistry.Results: The patency of ePTFE and Dacron vascular prosthesis was 83%, 100% respectively. The flow-rate of ePTFE vascular prosthesis was (0.464±0.041) m/s, and the pressure of blood vessel was (0.83±0.12) mmHg. The flow-rate of Dacron vascular prosthesis was (0.461 ±0.044) m/s, and the pressure of blood vessel was (0.78±0.12)mmHg. Both of them were not significantly different (P >0.05). A new intima and adventitia of ePTFE vascular prosthesis and Dacron vascular prosthesis were completely formed when observed by naked eye, mirror lens, scanning electron microscope. Endothelial cells existed on the surface of intima of ePTFE vascular prosthesis and Dacron vascular prosthesis by immunohistochemistry and Ⅷ gene dyeing was weak and positive. Conclusions: Chinese ePTFE vascular prosthesis is a relatively good vascular prosthesis and worth being recommended widely for clinical application.%目的研究国产的ePTEE人工血管动物应用可行性.方法以国产ePTEE人工血管移植于狗的股动脉并与进口Dacron人工血管对照,术后通过体检、彩色多普勒、大标标本、光镜、扫描电镜、免疫组化观察ePTEE人工血管通畅程度、内膜与外膜、内皮细胞生长状况.结果体检ePTEE、Dacron人工血管通畅率分别为83%、100%;彩色多普勒示ePTEE人工血管血流速度(0.464±0.041)m/s、管壁压力为(0.83±0.12)mmHg,Dacron人工血管血流速度为(0.461±0.044)m

  2. Nonparenchymal cells cultivated from explants of fibrotic liver resemble endothelial and smooth muscle cells from blood vessel walls

    International Nuclear Information System (INIS)

    Tissue specimens from human fibrotic liver obtained by needle biopsy were cultured. Two cell types emerged from the tissue explants. From their morphology and biosynthetic products they resembled smooth muscle cells and endothelial cells from blood vessel walls. In the endothelial cells, factor VIII-associated protein was demonstrated by indirect immunofluorescence. Synthesis of collagen types I and III, basement membrane collagen types IV and V, and fibronectin by both cell types was observed by immunofluorescence microscopy. Homogeneous cultures of smooth muscle cells were observed in subcultures. After incubation with [14C]glycine, collagen was isolated and characterized by CM cellulose chromatography, and consisted mainly of types I and III. These data suggest involvement of mesenchymal cells in hepatic fibrosis; they presumably originate from blood vessel or sinusoidal walls

  3. NUMERICAL SIMULATION OF HEMODYNAMICS IN THE HOST BLOOD VESSEL AND MICROVASCULAR NETWORK GENERATED FROM TUMOR-INDUCED ANGIOGENESIS

    Institute of Scientific and Technical Information of China (English)

    ZHAO Gai-ping; WU Jie; XU Shi-xiong; COLLINS M.W.; JIANG Yu-ping; WANG Jian

    2006-01-01

    Numerical simulation of hemodynamics under the combined effects of both the host blood vessel and the microvascular network,which is based on a 2-D tumor inside and outside vascular network generated from a discrete mathematical model of tumor-induced angiogenesis, is performed systemically. And a "microvascular network-transport across microvascular network-flow in interstitium" model is developed to study the flow in solid tumor. Simulations are carried out to examine the effects of the variations of the inlet Reynolds number in the host blood vessel, the hydraulic conductivity of the microvascular wall, and interstitial hydraulic conductivity coefficient on the fluid flow in tumor microcirculation. The results are consistent with data obtained in terms of physiology. These results may provide some theoretical references and the bases for further clinical experimental research.

  4. Imaging functional blood vessels by the laser speckle imaging (LSI) technique using Q-statistics of the generalized differences algorithm.

    Science.gov (United States)

    Ansari, Mohammad Zaheer; Cabrera, Humberto; Ramírez-Miquet, Evelio E

    2016-09-01

    In this work, we report about q statistics concept to improve the performance of generalized differences algorithm based on intensity histogram for imaging functional blood vessel structures in a rodent window chamber of a mice. The method uses the dynamic speckle signals obtained by transilluminating the rodent window chamber to create activity maps of vasculatures. The proposed method of generalized differences with q statistics (GDq) is very sensitive to the values of defined parameters such as: camera exposure time, the q value and the camera frame number. Appropriate choice of q values enhances the visibility (contrast) of functional blood vessels but at the same time without sacrificing the spatial resolution, which is of utmost importance for in-vivo vascular imaging. PMID:27154269

  5. Sinusoïdal flow of blood in a cylindrical deformable vessel exposed to an external magnetic field

    Science.gov (United States)

    Drochon, Agnès

    2016-03-01

    The present work provides an analytical solution for the Sinusoïdal flow of blood in a cylindrical elastic vessel exposed to an external magnetic field. The vessel is supposed to have non-conducting walls and the induced electric and magnetic fields are neglected. In other words, the well-known calculation of Womersley is revisited through the inclusion of the Lorentz force in the Navier-Stokes equations. A dispersion equation is obtained. This equation admits two types of solutions: the Young waves (mainly associated with radial deformation of the vessel) and the Lamb waves (mainly associated with longitudinal displacements in the vessel wall). It is demonstrated that the external magnetic field has an influence on the wave celerities, on the fluid velocity profiles, and on the wall displacements. It tends to reduce the blood flow and flatten the velocity profile, in the case of Young waves. The pulsatile character of the flow is also dampened. However, these effects become detectable for high values of the Hartmann number (M > 4, corresponding to B0 > 36 T with numerical data pertaining to large human arteries) and remain negligible in the context of magnetic resonance imaging (B0 ≤ 3 T, or even 7 T).

  6. Relation of Blood Pressure to Retinal Vessel Diameter in Type 1 Diabetes Mellitus

    Science.gov (United States)

    Klein, Ronald; Myers, Chelsea E.; Klein, Barbara E. K.; Zinman, Bernard; Gardiner, Robert; Suissa, Samy; Sinaiko, Alan R.; Donnelly, Sandra M.; Goodyer, Paul; Strand, Trudy; Mauer, Michael

    2009-01-01

    Objective To examine the relationship of blood pressure (BP) and use of angiotensin receptor blocker (ARB) or angiotensin converting enzyme inhibitor (ACEI) to retinal vessel diameter in normotensive, normoalbuminuric persons with type 1 diabetes mellitus (T1DM). Design Randomized controlled clinical trial. Participants Persons with T1DM and gradable fundus photographs both at baseline (n=147) and 5-year follow-up (n=124). Methods Clinic and 24-hour ambulatory BPs (ABP) were measured. Retinal arteriolar and venular diameters were measured using a computer-assisted technique. Individual arteriolar and venular measurements were combined into summary indices that reflect the average retinal arteriolar (central retinal arteriolar equivalent [CRAE]) and venular (central retinal venular equivalent [CRVE]) diameter of an eye, respectively. Main Outcome Measures CRAE and CRVE. Results While controlling for age, study site, glycosylated hemoglobin and ambulatory pulse rate, daytime ambulatory systolic (-0.29 μm effect per 1mmHg, P=.02) and daytime ambulatory diastolic (-0.44 μm effect per 1mmHg, P=.04), nighttime ambulatory systolic (-0.27 μm effect per 1mmHg, P=.03), and 24-hour ambulatory systolic BP (-0.31 μm effect per 1mmHg, P=.03) were cross-sectionally associated with a smaller CRAE. While controlling for age, study site, glycosylated hemoglobin, ambulatory pulse rate and baseline CRAE, no BP measure was associated with a change in CRAE or CRVE over 5 years of follow-up. Treatment with losartan or enalapril was not associated with a statistically significant change in CRAE or CRVE. Conclusions ACEI or ARB therapy does not affect retinal arteriolar or venular diameter in normotensive persons with T1DM. PMID:20142543

  7. Failed total carpometacarpal joint prosthesis of the thumb

    DEFF Research Database (Denmark)

    Hansen, Torben Bæk; Homilius, Morten

    2010-01-01

    Total joint prosthesis in carpometacarpal joint arthritis of the thumb often fails. Loosening of the implant is often treated by resection arthroplasty, and we reviewed 10 patients, mean age 54 years (range 47-63) who were treated by resection arthroplasty after a failed total joint prosthesis. The...... male:female ratio was 1:4 and the mean duration of observation 32 months (range 6-52). In three patients the revised implant was a MOJE uncemented carpometacarpal joint prosthesis and in seven patients an Elektra uncemented one. At follow-up grip strength was reduced to less than 90% of the other hand...... in eight of 10 patients, but the mean Disabilities of the arm, shoulder, and hand (DASH) scores, self-reported pinch-grip-related function, and pain were comparable with our earlier published results with the Elektra carpometacarpal total joint prosthesis....

  8. BLOOD VESSELS IN GANGLIA IN HUMAN ESOPHAGUS MIGHT EXPLAIN THE HIGHER FREQUENCY OF MEGAESOPHAGUS COMPARED WITH MEGACOLON

    Directory of Open Access Journals (Sweden)

    Sheila Jorge Adad

    2014-12-01

    Full Text Available This study aimed to determine the existence of blood vessels within ganglia of the myenteric plexus of the human esophagus and colon. At necropsy, 15 stillborns, newborns and children up to two years of age, with no gastrointestinal disorders, were examined. Rings of the esophagus and colon were analyzed and then fixed in formalin and processed for paraffin. Histological sections were stained by hematoxylin-eosin, Giemsa and immunohistochemistry for the characterization of endothelial cells, using antibodies for anti-factor VIII and CD31. Blood vessels were identified within the ganglia of the myenteric plexus of the esophagus, and no blood vessels were found in any ganglia of the colon. It was concluded that the ganglia of the myenteric plexus of the esophagus are vascularized, while the ganglia of the colon are avascular. Vascularization within the esophageal ganglia could facilitate the entrance of infectious agents, as well as the development of inflammatory responses (ganglionitis and denervation, as found in Chagas disease and idiopathic achalasia. This could explain the higher frequency of megaesophagus compared with megacolon.

  9. 3D MR sequence capable of simultaneous image acquisitions with and without blood vessel suppression: Utility in diagnosing brain metastases

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Kazufumi; Hiwatashi, Akio; Togao, Osamu; Yamashita, Koji; Yoshiura, Takashi; Honda, Hiroshi [Kyushu University, Department of Clinical Radiology, Graduate School of Medical Sciences, Fukuoka (Japan); Yoneyama, Masami [Yaesu Clinic, Chuo-ku, Tokyo (Japan); Obara, Makoto [Philips Electronics Japan, Minato-ku, Tokyo (Japan); Kishimoto, Junji [Kyushu University, Department of Research and Development of Next Generation Medicine, Faculty of Medical Sciences, Higashi-ku, Fukuoka (Japan)

    2015-04-01

    Volume isotropic simultaneous interleaved bright- and black-blood examination (VISIBLE) is a recently developed 3D MR sequence that provides simultaneous acquisitions of images with blood vessel suppression (Black) and images without it (Bright). Our purpose was to evaluate the usefulness of VISIBLE in detecting brain metastases. This prospective study included patients with suspected brain metastasis imaged with both VISIBLE and MPRAGE. From a data set, we compared the number of visualized blood vessels and the lesion-to-normal contrast-to-noise ratio (CNR) in 60 patients. We also performed an observer test to compare their diagnostic performance with VISIBLE, MPRAGE and only Black in 34 patients. Diagnostic performance was evaluated using a figure of merit (FOM), sensitivity, false-positive results per case (FPs/case) and reading time. The number of vessels was significantly fewer in Black compared to MPRAGE and Bright (P < 0.0001). CNR was significantly higher with both Black and Bright than with MPRAGE (P < 0.005). In the observer test, significantly higher sensitivity (P < 0.0001) and FOM (P < 0.0001), significantly shorter reading time (P = 0.0001) and similar FPs/case were achieved with VISIBLE compared to MPRAGE. Compared to only Black, VISIBLE resulted in comparable sensitivity, but significantly fewer FPs/case (P = 0.0008). VISIBLE can improve radiologists' diagnostic performance for brain metastasis. (orig.)

  10. When to Replace a Prosthesis

    Science.gov (United States)

    ... to Replace a Prosthesis When to Replace a Prosthesis Web Development April 21, 2015 Fact Sheet Last ... workplace, they must be accurately fit with a prosthesis that matches their own anatomy; one that is ...

  11. Hydroxyapatite-coated uncemented implants and peri-implant infection

    NARCIS (Netherlands)

    Oosterbos, Cornelis Johannes Maria

    2004-01-01

    One of the major complications of joint replacement surgery is a peri-implant infection. A hip prosthesis coated with hydroxyapatite, a calcium phosphate (found in human bone), may offer protection in this respect. In a series of patients who were treated with a hydroxyapatite-coated hip prosthesis

  12. Treatment Using Functionally Fixed Prosthesis: A Case Report

    OpenAIRE

    Chandra, Sumi; Singh, Ajay; Gupta, Himanshu; Chandra, Chetan

    2013-01-01

    Most dental practitioners as well as their patients prefer to have fixed rather than removable prosthesis. However, there are many clinical situations that prohibit the use of the fixed treatment modality. These clinical cases can vary from, simply not having the proper number of healthy teeth and/or implants to, the esthetically challenging cases of high smile lines and severe loss of alveolar support. The approach of using a traditional removable prosthesis in these situations has always be...

  13. Design and Evaluation of a Fully Implantable Control Unit for Blood Pumps

    Directory of Open Access Journals (Sweden)

    Kristin Unthan

    2015-01-01

    Full Text Available As the number of donor hearts is limited while more and more patients suffer from end stage biventricular heart failure, Total Artificial Hearts become a promising alternative to conventional treatment. While pneumatic devices sufficiently supply the patients with blood flow, the patient’s quality of life is limited by the percutaneous pressure lines and the size of the external control unit. This paper describes the development of the control unit of the ReinHeart, a fully implantable Total Artificial Heart. General requirements for any implantable control unit are defined from a technical and medical point of view: necessity of a Transcutaneous Energy Transmission, autonomous operation, safety, geometry, and efficiency. Based on the requirements, a prototype is designed; it incorporates a LiFePo4 battery pack with charger, a rectifier for transcutaneous energy transmission, the motor’s driver electronics, and a microcontroller which monitors and controls all functions. In validation tests, the control unit demonstrated a stable operation on TET and battery supply and a safe switching from one supply to the other. The overall mean efficiency is 14% on TET and 22% on battery supply. The control unit is suitable for chronic animal trials of the ReinHeart.

  14. Dosimetric influence of hip prosthesis during radiotherapeutic treatment

    International Nuclear Information System (INIS)

    As the population become aged, many patients with hip prosthesis are treated for a pelvic cancer. The recommended ballistic must avoid to pass in the prosthesis, but sometimes it is inevitable. So it is essential to quantify with accuracy the dose modifications linked to the presence of metallic implant. The aim of this study is to analyze by Monte Carlo method these modifications in simple and complex models (anthropomorphic phantom) which take into account the geometry and the composition of the prosthesis and its coatings. Then, this methodology was used to study the behaviour of a treatment planning system in theses extreme conditions. (authors)

  15. Implantable CMOS Biomedical Devices

    Directory of Open Access Journals (Sweden)

    Toshihiko Noda

    2009-11-01

    Full Text Available 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.

  16. Passividade da estrutura metálica para próteses fixas implanto-suportadas = Passivity of metallic framework for implant-supported fixed prosthesis

    Directory of Open Access Journals (Sweden)

    Stüker, Rafael Augusto

    2005-01-01

    Full Text Available Em virtude da freqüência cada vez maior de reabilitações implanto-suportadas, e de que esta modalidade de tratamento vem se mostrando extremamente eficaz na resolução de várias situações clínicas, foi realizada esta revisão literária com o objetivo de ressaltar questões relacionadas à passividade da estrutura metálica em próteses fixas sobre implantes. São descritos aspectos e alternativas relacionadas a alterações ósseas, assim como procedimentos clínicos e laboratoriais que podem influenciar na passividade de estruturas metálicas, esta que talvez seja o fator mais importante na determinação da longevidade tanto da restauração protética quanto dos implantes

  17. In-vivo imaging of blood flow in human retinal vessels using color Doppler optical coherence tomography

    Science.gov (United States)

    Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

    1999-04-01

    Quantification of retinal blood flow may lead to a better understanding of the progression and treatment of several ocular disorders, including diabetic retinopathy, age- related macular degeneration, and glaucoma. Current techniques, such as fluorescein angiography and laser Doppler velocimetry are limited, failing to provide sufficient information to the clinician. Color Doppler optical coherence tomography (CDOCT) is a novel technique using coherent heterodyne detection for simultaneous cross- sectional imaging of tissue microstructure and blood flow. This technique is capable of high spatial and velocity resolution imaging in highly scattering media. We implemented CDOCT for retinal blood flow mapping in human subjects. No dilation of the pupil was necessary. CDOCT is demonstrated for determining bidirectional flow in sub- 100micrometers diameter vessels in the retina. Additionally, we calculated Doppler broadening using the variance of depth- resolved spectra to identify regions with large velocity gradients within the Xenopus heart. This technique may be useful in quantifying local tissue perfusion in highly vascular retinal tissue.

  18. The blood-tendon barrier: identification and characterisation of a novel tissue barrier in tendon blood vessels.

    Science.gov (United States)

    Lehner, C; Gehwolf, R; Ek, J C; Korntner, S; Bauer, H; Bauer, H C; Traweger, A; Tempfer, H

    2016-01-01

    Tissue barriers function as "gate keepers" between different compartments (usually blood and tissue) and are formed by specialised membrane-associated proteins, localising to the apicolateral plasma membrane domain of epithelial and endothelial cells. By sealing the paracellular space, the free diffusion of solutes and molecules across epithelia and endothelia is impeded. Thereby, tissue barriers contribute to the establishment and maintenance of a distinct internal and external environment, which is crucial during organ development and allows maintenance of an organ-specific homeostatic milieu. So far, various epithelial and endothelial tissue barriers have been described, including the blood-brain barrier, the blood-retina barrier, the blood-testis barrier, the blood-placenta barrier, and the cerebrospinal fluid (CSF)-brain barrier, which are vital for physiological function and any disturbance of these barriers can result in severe organ damage or even death. Here, we describe the identification of a novel barrier, located in the vascular bed of tendons, which we term the blood-tendon barrier (BTB). By using immunohistochemistry, transmission electron microscopy, and tracer studies we demonstrate the presence of a functional endothelial barrier within tendons restricting the passage of large blood-borne molecules into the surrounding tendon tissue. We further provide in vitro evidence that the BTB potentially contributes to the creation of a distinct internal tissue environment impacting upon the proliferation and differentiation of tendon-resident cells, effects which might be fundamental for the onset of tendon pathologies. PMID:27227787

  19. Immediate bleeding complications in dental implants: A systematic review

    OpenAIRE

    Balaguer Martí, José Carlos; Peñarrocha Oltra, David; Balaguer Martínez, José; Peñarrocha Diago, Miguel

    2014-01-01

    Objective: A review is made of the immediate or immediate postoperative bleeding complications in dental implants, with a view to identifying the areas of greatest bleeding risk, the causes of bleeding, the length of the implants associated with bleeding, the most frequently implicated blood vessels, and the treatments used to resolve these complications. Material and Methods: A Medline (PubMed) and Embase search was made of articles on immediate bleeding complications in dental implants publ...

  20. Nestin(+ tissue-resident multipotent stem cells contribute to tumor progression by differentiating into pericytes and smooth muscle cells resulting in blood vessel remodeling

    Directory of Open Access Journals (Sweden)

    DianaKlein

    2014-06-01

    Full Text Available Tumor vessels with resistance to anti-angiogenic therapy are characterized by the normalization of the vascular structures through integration of mature pericytes and smooth muscle cells (SMC into the vessel wall, a process termed vessel stabilization. Unfortunately, stabilization-associated vascular remodeling can result in reduced sensitivity to subsequent anti-angiogenic therapy. We show here that blockade of VEGF by bevacizumab induces stabilization of angiogenic tumor blood vessels in human tumor specimen by recruiting Nestin-positive cells, whereas mature vessels down-regulated Nestin-expression. Using xenograft tumors growing on bone-marrow (BM chimera of C57Bl/6 wildtype and Nestin-GFP transgenic mice we show for first time that Nestin(+ cells inducing the maturation of tumor vessels do not originate from the BM but presumably reside within the adventitia of adult blood vessels. Complementary ex vivo experiments using explants of murine aortas revealed that Nestin(+ multipotent stem cells (MPSCs are mobilized from their niche and differentiated into pericytes and SMC through the influence of tumor-cell secreted factors. We conclude that tissue-resident Nestin(+ cells are more relevant than BM-derived cells for vessel stabilization and therefore have to be considered in future strategies for anti-angiogenic therapy. The identification of proteins mediating recruitment or differentiation of local Nestin(+ cells with potential stem cell character to angiogenic blood vessels may allow the definition of new therapeutic targets to reduce tumor resistance against anti-angiogenic drugs.