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Sample records for alar batten grafts

  1. Simple Correction of Alar Retraction by Conchal Cartilage Extension Grafts

    PubMed Central

    Jang, Yong Jun; Kim, Sung Min; Lew, Dae Hyun

    2016-01-01

    Background Alar retraction is a challenging condition in rhinoplasty marked by exaggerated nostril exposure and awkwardness. Although various methods for correcting alar retraction have been introduced, none is without drawbacks. Herein, we report a simple procedure that is both effective and safe for correcting alar retraction using only conchal cartilage grafting. Methods Between August 2007 and August 2009, 18 patients underwent conchal cartilage extension grafting to correct alar retraction. Conchal cartilage extension grafts were fixed to the caudal margins of the lateral crura and covered with vestibular skin advancement flaps. Preoperative and postoperative photographs were reviewed and analyzed. Patient satisfaction was surveyed and categorized into 4 groups (very satisfied, satisfied, moderate, or unsatisfied). Results According to the survey, 8 patients were very satisfied, 9 were satisfied, and 1 considered the outcome moderate, resulting in satisfaction for most patients. The average distance from the alar rim to the long axis of the nostril was reduced by 1.4 mm (3.6 to 2.2 mm). There were no complications, except in 2 cases with palpable cartilage step-off that resolved without any aesthetic problems. Conclusions Conchal cartilage alar extension graft is a simple, effective method of correcting alar retraction that can be combined with aesthetic rhinoplasty conveniently, utilizing conchal cartilage, which is the most similar cartilage to alar cartilage, and requiring a lesser volume of cartilage harvest compared to previously devised methods. However, the current procedure lacks efficacy for severe alar retraction and a longer follow-up period may be required to substantiate the enduring efficacy of the current procedure. PMID:27896189

  2. Alar

    Integrated Risk Information System (IRIS)

    Alar ; CASRN 1596 - 84 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects ) a

  3. Batten augmented triangular beam

    NASA Technical Reports Server (NTRS)

    Adams, Louis R.; Hedgepeth, John M.

    1986-01-01

    The BAT (Batten-Augmented Triangular) BEAM is characterized by battens which are buckled in the deployed state, thus preloading the truss. The preload distribution is determined, and the effects of various external loading conditions are investigated. The conceptual design of a deployer is described and loads are predicted. The influence of joint imperfections on effective member stiffness is investigated. The beam is assessed structurally.

  4. Batten's Disease: Determining Educational Interventions.

    ERIC Educational Resources Information Center

    Johnson, Barbara; Jochum, Julie

    1996-01-01

    This article presents basic information on the causes, physical and emotional characteristics, diagnosis and treatment, and educational implications of Batten's Disease, a degenerative neurological disorder which strikes children and adults, causes progressive loss of neurological function, and leads to eventual premature death. Discussion also…

  5. Batten Disease Support and Research Association

    MedlinePlus

    ... Resource Corner Meet Batten Families Centers of Excellence Research Our Role In Research BDSRA Annual Funding Cycle Past Grant Awards Clinical Research and News Learn About Clinical Trials BDSRA 2017 ...

  6. Reconstruction of the alar groove.

    PubMed

    Chait, L A; Fayman, M S

    1989-05-01

    The obliteration of a well-defined alar groove is common after nasal alar reconstruction. A method is described that can be used at the time of reconstruction to ensure the continued definition of the groove or to restore it in cases where it has been obliterated. The technique is based on the natural tendency of the skin to tube itself. Cheek skin is advanced beneath the posterior free edge of the reconstructed ala so that this edge now comes into contact with an epidermal surface. As this edge now tends to tube itself, a natural alar groove is produced. This method has been used successfully in six cases.

  7. Batten disease: past, present, and future.

    PubMed

    Rider, J A; Rider, D L

    1988-01-01

    The name Batten disease (or neuronal ceroid lipofuscinosis) is used to unify the spectrum of clinical and pathological conditions covered by the names infantile, late infantile, juvenile, and adult variants with their respective eponyms. The past was largely devoted to clinical diagnosis. The present is devoted to specific diagnostic tests. The future will be devoted to prevention and treatment. Treatment may consist of specific drug treatment, enzyme replacement, or gene replacement. Early diagnosis is important in order to provide genetic counseling and to establish family support for those patients who have a protracted, progressive disabling and ultimate fatal course.

  8. Modeling of Triangular Lattice Space Structures with Curved Battens

    NASA Technical Reports Server (NTRS)

    Chen, Tzikang; Wang, John T.

    2005-01-01

    Techniques for simulating an assembly process of lattice structures with curved battens were developed. The shape of the curved battens, the tension in the diagonals, and the compression in the battens were predicted for the assembled model. To be able to perform the assembly simulation, a cable-pulley element was implemented, and geometrically nonlinear finite element analyses were performed. Three types of finite element models were created from assembled lattice structures for studying the effects of design and modeling variations on the load carrying capability. Discrepancies in the predictions from these models were discussed. The effects of diagonal constraint failure were also studied.

  9. PERSPECTIVE FROM SOUTH SHOWING WEATHERED BOARD AND BATTEN SIDING. NOTE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PERSPECTIVE FROM SOUTH SHOWING WEATHERED BOARD AND BATTEN SIDING. NOTE BRIDGE SITS ON ONE CONCRETEFACED ABUTMENT AND ONE STONE PIER. - Beaverkill Bridge, Spanning Beaver Kill, TR 30 (Craigie Claire Road), Roscoe, Sullivan County, NY

  10. Glutamic acid decarboxylase autoimmunity in Batten disease and other disorders.

    PubMed

    Pearce, David A; Atkinson, Mark; Tagle, Danilo A

    2004-12-14

    Degenerative diseases of the CNS, such as stiff-person syndrome (SPS), progressive cerebellar ataxia, and Rasmussen encephalitis, have been characterized by the presence of autoantibodies. Recent findings in individuals with Batten disease and in animal models for the disorder indicate that this condition may be associated with autoantibodies against glutamic acid decarboxylase (GAD), an enzyme that converts the excitatory neurotransmitter glutamate to the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). Anti-GAD autoantibodies could result in excess excitatory neurotransmitters, leading to the seizures and other symptoms observed in patients with Batten disease. The pathogenic potential of GAD autoantibodies is examined in light of what is known for other autoimmune disorders, such as multiple sclerosis, SPS, Rasmussen encephalitis, and type 1 diabetes, and may have radical implications for diagnosis and management of Batten disease.

  11. A Novel Approach for Full-Thickness Defect of the Nasal Alar Rim: Primary Closure of the Defect and Reduction of the Contralateral Normal Ala for Symmetry

    PubMed Central

    Choe, Yun Seon; Kim, Min-Woo

    2015-01-01

    In full-thickness defects of the nasal alar rim, to achieve projection and maintain airway patency, cartilage graft is frequently needed. However, cartilage graft presents a challenge in considerations such as appropriate donor site, skeletal shape and size, and healing of the donor area. To avoid these demerits, we tried primary closure of alar rim defects by also making the contralateral normal ala smaller. We treated two patients who had a full-thickness nasal alar defect after tumor excision. Cartilage graft was considered for the reconstruction. However, their alar rims were overly curved and their nostril openings were large. To utilize their nasal shape, we did primary closure of the defect rather than cartilage graft, and then downsized the contralateral nasal ala by means of wedge resection to make the alae symmetric. Both patients were satisfied with their aesthetic results, which showed a smaller nostril and nearly straight alar rims. Moreover, functionally, there was no discomfort during breathing in both patients. We propose our idea as one of the reconstruction options for nasal alar defects. It is a simple and easy-to-perform procedure, in addition to enhancing the nasal contour. This method would be useful for patients with a large nostril and an overly curved alar rim. PMID:26719646

  12. INTERIOR VIEW OF BEDROOM 1. SHOWING THE BOARD AND BATTEN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF BEDROOM 1. SHOWING THE BOARD AND BATTEN WALLS WITH PICTURE RAIL. NOTE THE MIRROR-PANEL CLOSET DOOR AND FIVE-PANEL DOOR TO THE HALL. VIEW FACING EAST. - Hickam Field, Fort Kamehameha Officers' Housing Type Y, 27 Worchester Avenue, Honolulu, Honolulu County, HI

  13. Teach and Be Taught: A Guide to Teaching Students with Batten Disease.

    ERIC Educational Resources Information Center

    Bills, Wendy; Johnston, Lance W.; Wilhelm, Robert; Graham, Leslie

    This guide provides information on Batten Disease to assist in planning a quality educational program for the student with the disease. Because Batten Disease, or neuronal ceroid lipofuscinosis, causes the death of brain cells, students with the disease are described as suffering from mental impairment, worsening seizures, and progressive loss of…

  14. Cyclic performance of concrete-filled steel batten built-up columns

    NASA Astrophysics Data System (ADS)

    Razzaghi, M. S.; Khalkhaliha, M.; Aziminejad, A.

    2016-03-01

    Steel built-up batten columns are common types of columns in Iran and some other parts of the world. They are economic and have acceptable performance due to gravity loads. Although several researches have been conducted on the behavior of the batten columns under axial loads, there are few available articles about their seismic performance. Experience of the past earthquakes, particularly the 2003 Bam earthquake in Iran, revealed that these structural members are seismically vulnerable. Thus, investigation on seismic performance of steel batten columns due to seismic loads and providing a method for retrofitting them are important task in seismic-prone areas. This study aims to investigate the behavior of concrete-filled batten columns due to combined axial and lateral loads. To this end, nonlinear static analyses were performed using ANSYS software. Herein, the behaviors of the steel batten columns with and without concrete core were compared. The results of this study showed that concrete-filled steel batten columns, particularly those filled with high-strength concrete, may cause significant increases in energy absorption and capacity of the columns. Furthermore, concrete core may improve post-buckling behavior of steel batten columns.

  15. Aroma potential of oak battens prepared from decommissioned oak barrels.

    PubMed

    Li, Sijing; Crump, Anna M; Grbin, Paul R; Cozzolino, Daniel; Warren, Peter; Hayasaka, Yoji; Wilkinson, Kerry L

    2015-04-08

    During barrel maturation, volatile compounds are extracted from oak wood and impart aroma and flavor to wine, enhancing its character and complexity. However, barrels contain a finite pool of extractable material, which diminishes with time. As a consequence, most barrels are decommissioned after 5 or 6 years. This study investigated whether or not decommissioned barrels can be "reclaimed" and utilized as a previously untapped source of quality oak for wine maturation. Oak battens were prepared from staves of decommissioned French and American oak barrels, and their composition analyzed before and after toasting. The oak lactone glycoconjugate content of untoasted reclaimed oak was determined by liquid chromatography-tandem mass spectrometry, while the concentrations of cis- and trans-oak lactone, guaiacol, 4-methlyguaiacol, vanillin, eugenol, furfural, and 5-methylfurfural present in toasted reclaimed oak were determined by gas chromatography-mass spectrometry. Aroma potential was then evaluated by comparing the composition of reclaimed oak with that of new oak. Comparable levels of oak lactone glycoconjugates and oak volatiles were observed, demonstrating the aroma potential of reclaimed oak and therefore its suitability as a raw material for alternative oak products, i.e., chips or battens, for the maturation of wine. The temperature profiles achieved during toasting were also measured to evaluate the viability of any yeast or bacteria present in reclaimed oak.

  16. Alar base reduction: the boomerang-shaped excision.

    PubMed

    Foda, Hossam M T

    2011-04-01

    A boomerang-shaped alar base excision is described to narrow the nasal base and correct the excessive alar flare. The boomerang excision combined the external alar wedge resection with an internal vestibular floor excision. The internal excision was inclined 30 to 45 degrees laterally to form the inner limb of the boomerang. The study included 46 patients presenting with wide nasal base and excessive alar flaring. All cases were followed for a mean period of 18 months (range, 8 to 36 months). The laterally oriented vestibular floor excision allowed for maximum preservation of the natural curvature of the alar rim where it meets the nostril floor and upon its closure resulted in a considerable medialization of alar lobule, which significantly reduced the amount of alar flare and the amount of external alar excision needed. This external alar excision measured, on average, 3.8 mm (range, 2 to 8 mm), which is significantly less than that needed when a standard vertical internal excision was used ( P < 0.0001). Such conservative external excisions eliminated the risk of obliterating the natural alar-facial crease, which did not occur in any of our cases. No cases of postoperative bleeding, infection, or vestibular stenosis were encountered. Keloid or hypertrophic scar formation was not encountered; however, dermabrasion of the scars was needed in three (6.5%) cases to eliminate apparent suture track marks. The boomerang alar base excision proved to be a safe and effective technique for narrowing the nasal base and elimination of the excessive flaring and resulted in a natural, well-proportioned nasal base with no obvious scarring.

  17. Alar and Apples: Newspaper Coverage of a Major Risk Issue.

    ERIC Educational Resources Information Center

    Friedman, Sharon M.; And Others

    A study reviewed coverage in 13 newspapers during 1989 of the issue of spraying the pesticide Alar on apples. Using VU/TEXT, a newspaper database, 297 articles in 13 newspapers that included the specified code words "Alar" with or without "apple" or "apples" were retrieved and analyzed using a 33-question coding…

  18. Atomic oxygen durability evaluation of the flexible batten for the photovoltaic array mast on Space Station

    NASA Technical Reports Server (NTRS)

    Stidham, Curtis R.; Rutledge, Sharon K.; Sechkar, Edward A.; Flaherty, David S.; Roig, David M.; Edwards, Jonathan L.

    1994-01-01

    A test program was conducted at the National Aeronautics and Space Administration's Lewis Research Center (LeRC) to evaluate the long term low Earth orbital (LEO) atomic oxygen (AO) durability of a flexible (fiberglass-epoxy composite) batten. The flexible batten is a component used to provide structural rigidity in the photovoltaic array mast on Space Station. The mast is used to support and articulate the photovoltaic array, therefore, the flexible batten must be preloaded for the 15 year lifetime of an array blanket. Development hardware and composite materials were evaluated in ground testing facilities for AO durability and dynamic retraction-deployment cyclic loading representative of expected full life in-space application. The CV1144 silicone (AO protective) coating was determined to provide adequate protection against AO degradation of the composite material and provided fiber containment, thus the structural integrity of the flexible batten was maintained. Both silicone coated and uncoated flexible battens maintained load carrying capabilities. Results of the testing did indicate that the CV1144 silicone protective coating was oxidized by AO reactions to form a brittle glassy (SiO2) skin that formed cracking patterns on all sides of the coated samples. The cracking was observed in samples that were mechanically stressed as well as samples in non-stressed conditions. The oxidized silicon was observed to randomly spall in small localized areas, on the flexible battens that underwent retraction-deployment cycling. Some darkening of the silicon, attributed to vacuum ultraviolet (VUV) radiation, was observed.

  19. Forensic psychiatry and the forensic sciences: in memory of Peter J. Batten, MD.

    PubMed

    Bloom, Joseph D

    2009-01-01

    This commentary is dedicated to the memory of Peter J. Batten, MD. He was a public health physician, a psychiatrist, and a medical examiner who spent his entire career in Salem, the capital of the State of Oregon. Salem was a unique place to work because, early in the history of Oregon, the state elected to build all of its original public institutions in the environs of the city. As the county medical examiner, Dr. Batten reviewed all questionable deaths that occurred within the county and in particular within the public institutions. Many of his findings were subsequently published, and these reports influenced the direction of mental health policy in these same institutions. He also used his position as county medical examiner to examine deaths in road rage incidents and those occurring at railroad crossings in Salem. The commentary also emphasizes the benefits of collaboration within the forensic sciences.

  20. Experience, Knowledge, and Opinions about Childhood Genetic Testing in Batten Disease

    PubMed Central

    Rose, Katherine; Augustine, Erika F.; Kwon, Jennifer M.; deBlieck, Elisabeth A.; Marshall, Frederick J.; Vierhile, Amy; Mink, Jonathan W.; Nance, Martha A.

    2013-01-01

    Background and Objectives Policies for genetic testing in children (GTIC) focus on medical or psychosocial benefit to the child, discouraging or prohibiting carrier testing, and advising caution regarding pre-symptomatic diagnosis if no treatment exists. This study sought to understand parents’ perspectives on these issues and determine their experiences and knowledge related to genetic testing for Batten disease – a set of inherited neurodegenerative diseases of childhood onset for which no disease modifying therapies yet exist. Methods Parents of children with Batten disease completed a survey of their knowledge of genetics, experience with genetic testing, and opinions regarding GTIC. Results 54% had sought genetic testing for non-affected family members, including predictive diagnosis of healthy, at-risk children. Participation in any genetic counseling was associated with greater knowledge on questions about genetics. The majority of parents felt it was better to know ahead of time that a child would develop Batten disease, believed that this knowledge would not alter how they related to their child, and that parents should have the final say in deciding whether to obtain GTIC. Conclusions Parents of children with an inherited disease are knowledgeable about genetics and wish to establish predictive or carrier status of at-risk children. PMID:24246680

  1. Translational neurophysiology in sheep: measuring sleep and neurological dysfunction in CLN5 Batten disease affected sheep

    PubMed Central

    Perentos, Nicholas; Martins, Amadeu Q.; Watson, Thomas C.; Bartsch, Ullrich; Mitchell, Nadia L.; Palmer, David N.; Jones, Matthew W.

    2015-01-01

    Creating valid mouse models of slowly progressing human neurological diseases is challenging, not least because the short lifespan of rodents confounds realistic modelling of disease time course. With their large brains and long lives, sheep offer significant advantages for translational studies of human disease. Here we used normal and CLN5 Batten disease affected sheep to demonstrate the use of the species for studying neurological function in a model of human disease. We show that electroencephalography can be used in sheep, and that longitudinal recordings spanning many months are possible. This is the first time such an electroencephalography study has been performed in sheep. We characterized sleep in sheep, quantifying characteristic vigilance states and neurophysiological hallmarks such as sleep spindles. Mild sleep abnormalities and abnormal epileptiform waveforms were found in the electroencephalographies of Batten disease affected sheep. These abnormalities resemble the epileptiform activity seen in children with Batten disease and demonstrate the translational relevance of both the technique and the model. Given that both spontaneous and engineered sheep models of human neurodegenerative diseases already exist, sheep constitute a powerful species in which longitudinal in vivo studies can be conducted. This will advance our understanding of normal brain function and improve our capacity for translational research into neurological disorders. PMID:25724202

  2. Alar and apples: newspapers, risk and media responsibility.

    PubMed

    Friedman, S M; Villamil, K; Suriano, R A; Egolf, B P

    1996-01-01

    During 1989, a major environmental and health risk issue, the spraying of Alar on apples, created a furor among the American people. After hearing charges from the Natural Resources Defense Council (NRDC) that eating Alar-laden apples significantly increased a child's risk of developing cancer, numbers of school districts dropped apples from their menus and parents poured apple juice down the drains. Apple sales plummeted. The NRDC's charges, which were disseminated by a well-planned and effective public relations campaign, brought counter-charges from the US environmental Protection Agency, which accused the NRDC of basing its study on poor data, among other things. The core of the dispute was in the risk figures and risk interpretations being used by each organization.

  3. Rapid and Progressive Regional Brain Atrophy in CLN6 Batten Disease Affected Sheep Measured with Longitudinal Magnetic Resonance Imaging

    PubMed Central

    Sawiak, Stephen J.; Perumal, Sunthara Rajan; Rudiger, Skye R.; Matthews, Loren; Mitchell, Nadia L.; McLaughlan, Clive J.; Bawden, C. Simon; Palmer, David N.; Kuchel, Timothy; Morton, A. Jennifer

    2015-01-01

    Variant late-infantile Batten disease is a neuronal ceroid lipofuscinosis caused by mutations in CLN6. It is a recessive genetic lysosomal storage disease characterised by progressive neurodegeneration. It starts insidiously and leads to blindness, epilepsy and dementia in affected children. Sheep that are homozygous for a natural mutation in CLN6 have an ovine form of Batten disease Here, we used in vivo magnetic resonance imaging to track brain changes in 4 unaffected carriers and 6 affected Batten disease sheep. We scanned each sheep 4 times, between 17 and 22 months of age. Cortical atrophy in all sheep was pronounced at the baseline scan in all affected Batten disease sheep. Significant atrophy was also present in other brain regions (caudate, putamen and amygdala). Atrophy continued measurably in all of these regions during the study. Longitudinal MRI in sheep was sensitive enough to measure significant volume changes over the relatively short study period, even in the cortex, where nearly 40% of volume was already lost at the start of the study. Thus longitudinal MRI could be used to study the dynamics of progression of neurodegenerative changes in sheep models of Batten disease, as well as to assess therapeutic efficacy. PMID:26161747

  4. Relationship between Hyperactivity of Depressor Septi Nasi Muscle and Changes of Alar Base and Flaring during Smile

    PubMed Central

    Beiraghi-Toosi, Arash; Rezaei, Ezatollah; Zanjani, Elham

    2016-01-01

    BACKGROUND Hyperactivity of depressor septi nasi muscle leads to smiling deformity and nasal tip depression. Lateral fascicles of this muscle help in widening the nostrils. The purpose of this study was to evaluate the relationship between the nasal length changes and the alar base and the alar flaring changes during smile. METHODS Standard photographs are performed in the face and lateral views with forward gaze in the repose and maximum smile. Nasal length, alar base, and alar flaring were measured on the prints of the photographs. To decrease possible errors in the size of the printed photographs, middle face height from glabella to ANS was measured in the lateral view and the interpupil distance in the face view to standardize the measurements. RESULTS Fifty cases were enrolled in this study. In 39 cases (78%), the nasal length was increased during smile. Forty-six cases (92%) had an increase in alar base diameter during smile. Alar flaring during smile increased in 48 cases (96%). Nasal length and alar base changes during smiling were not significantly correlated. Nasal length and alar flaring changes during smiling were not significantly related too. On the other hand, alar base and alar flaring changes during smile showed correlation. Alar base and alar flaring changes during smile were not significantly different in hyperactive and non-hyperactive cases. CONCLUSION Nasal length change during smiling and hypertrophy of the medial fascicles of depressor septi nasi were not related to alar base or alar flaring change during smile. PMID:27308240

  5. The yeast Batten disease orthologue Btn1 controls endosome–Golgi retrograde transport via SNARE assembly

    PubMed Central

    Kama, Rachel; Kanneganti, Vydehi; Ungermann, Christian

    2011-01-01

    The human Batten disease gene CLN3 and yeast orthologue BTN1 encode proteins of unclear function. We show that the loss of BTN1 phenocopies that of BTN2, which encodes a retromer accessory protein involved in the retrieval of specific cargo from late endosomes (LEs) to the Golgi. However, Btn1 localizes to Golgi and regulates soluble N-ethyl-maleimide sensitive fusion protein attachment protein receptor (SNARE) function to control retrograde transport. Specifically, BTN1 overexpression and deletion have opposing effects on phosphorylation of the Sed5 target membrane SNARE, on Golgi SNARE assembly, and on Golgi integrity. Although Btn1 does not interact physically with SNAREs, it regulates Sed5 phosphorylation by modulating Yck3, a palmitoylated endosomal kinase. This may involve modification of the Yck3 lipid anchor, as substitution with a transmembrane domain suppresses the deletion of BTN1 and restores trafficking. Correspondingly, deletion of YCK3 mimics that of BTN1 or BTN2 with respect to LE–Golgi retrieval. Thus, Btn1 controls retrograde sorting by regulating SNARE phosphorylation and assembly, a process that may be adversely affected in Batten Disease patients. PMID:21987636

  6. Batten Disease: Clinical Aspects, Molecular Mechanisms, Translational Science, and Future Directions

    PubMed Central

    Dolisca, Sarah-Bianca; Mehta, Mitali; Pearce, David A.; Mink, Jonathan W.; Maria, Bernard L.

    2014-01-01

    The neuronal ceroid lipofuscinoses, collectively the most common neurodegenerative disorders of childhood, are primarily caused by an autosomal recessive genetic mutation leading to a lysosomal storage disease. Clinically these diseases manifest at varying ages of onset, and associated symptoms include cognitive decline, movement disorders, seizures, and retinopathy. The underlying cell biology and biochemistry that cause the clinical phenotypes of neuronal ceroid lipofuscinoses are still being elaborated. The 2012 Neurobiology of Disease in Children Symposium, held in conjunction with the 41st Annual Meeting of the Child Neurology Society, aimed to (1) provide a survey of the currently accepted forms of neuronal ceroid lipofuscinoses and their associated genetic mutations and clinical phenotypes; (2) highlight the specific pathology of Batten disease; (3) discuss the contemporary understanding of the molecular mechanisms that lead to pathology; and (4) introduce strategies that are being translated from bench to bedside as potential therapeutics. PMID:23838031

  7. Batten Disease

    MedlinePlus

    ... CLN3), but the protein for which this gene codes has not been identified. In addition, research scientists ... CLN3), but the protein for which this gene codes has not been identified. In addition, research scientists ...

  8. Batten Disease

    MedlinePlus

    ... Strategy Current Research Research Funded by NINDS Basic Neuroscience Clinical Research Translational Research Research at NINDS Focus ... Information Current Research Research Funded by NINDS Basic Neuroscience Clinical Research Translational Research Research at NINDS Focus ...

  9. Remote Assessment of Cognitive Function in Juvenile Neuronal Ceroid Lipofuscinosis (Batten disease) – a Pilot Study of Feasibility and Reliability

    PubMed Central

    Ragbeer, Shayne N.; Augustine, Erika F.; Mink, Jonathan W.; Thatcher, Alyssa R.; Vierhile, Amy E.; Adams, Heather R.

    2015-01-01

    Remote technology provides an opportunity to extend the reach of clinical care and research for pediatric rare disease. This pilot study evaluated the feasibility and reliability of neuropsychological evaluation, using remote audiovisual technology, in the assessment of children with juvenile Batten disease. Three children with Batten disease and one healthy sibling completed a standardized cognitive assessment. Results indicated high agreement between an in-person and a remote evaluator, when comparing the subjects’ cognitive test scores. This initial test of remote cognitive assessment suggests it is feasible and reliable in children with pediatric neurodegenerative disease, for whom disease burden may limit travel and access to expert care and/or clinical trials. PMID:26336202

  10. Neurodegeneration and Epilepsy in a Zebrafish Model of CLN3 Disease (Batten Disease)

    PubMed Central

    Fu, Sonia; Cooper, Jonathan D.; Harvey, Robert J.

    2016-01-01

    The neuronal ceroid lipofuscinoses are a group of lysosomal storage disorders that comprise the most common, genetically heterogeneous, fatal neurodegenerative disorders of children. They are characterised by childhood onset, visual failure, epileptic seizures, psychomotor retardation and dementia. CLN3 disease, also known as Batten disease, is caused by autosomal recessive mutations in the CLN3 gene, 80–85% of which are a ~1 kb deletion. Currently no treatments exist, and after much suffering, the disease inevitably results in premature death. The aim of this study was to generate a zebrafish model of CLN3 disease using antisense morpholino injection, and characterise the pathological and functional consequences of Cln3 deficiency, thereby providing a tool for future drug discovery. The model was shown to faithfully recapitulate the pathological signs of CLN3 disease, including reduced survival, neuronal loss, retinopathy, axonopathy, loss of motor function, lysosomal storage of subunit c of mitochondrial ATP synthase, and epileptic seizures, albeit with an earlier onset and faster progression than the human disease. Our study provides proof of principle that the advantages of the zebrafish over other model systems can be utilised to further our understanding of the pathogenesis of CLN3 disease and accelerate drug discovery. PMID:27327661

  11. Comprehensive functional characterization of murine infantile Batten disease including Parkinson-like behavior and dopaminergic markers

    PubMed Central

    Dearborn, Joshua T.; Harmon, Steven K.; Fowler, Stephen C.; O’Malley, Karen L.; Taylor, George T.; Sands, Mark S.; Wozniak, David F.

    2015-01-01

    Infantile neuronal ceroid lipofuscinosis (INCL, Infantile Batten disease) is a neurodegenerative lysosomal storage disease caused by a deficiency in palmitoyl protein thioesterase-1 (PPT1). The PPT1-deficient mouse (Cln1−/−) is a useful phenocopy of human INCL. Cln1−/− mice display retinal dysfunction, seizures, motor deficits, and die at ~8 months of age. However, little is known about the cognitive and behavioral functions of Cln1−/− mice during disease progression. In the present study, younger (~1–2 months of age) Cln1−/− mice showed minor deficits in motor/sensorimotor functions while older (~5–6 months of age) Cln1−/− mice exhibited more severe impairments, including decreased locomotor activity, inferior cued water maze performance, decreased running wheel ability, and altered auditory cue conditioning. Unexpectedly, certain cognitive functions such as some learning and memory capabilities seemed intact in older Cln1−/− mice. Younger and older Cln1−/− mice presented with walking initiation defects, gait abnormalities, and slowed movements, which are analogous to some symptoms reported in INCL and parkinsonism. However, there was no evidence of alterations in dopaminergic markers in Cln1−/− mice. Results from this study demonstrate quantifiable changes in behavioral functions during progression of murine INCL and suggest that Parkinson-like motor/sensorimotor deficits in Cln1−/− mice are not mediated by dopamine deficiency. PMID:26238334

  12. Forensic Facial Reconstruction: Relationship Between the Alar Cartilage and Piriform Aperture.

    PubMed

    Strapasson, Raíssa Ananda Paim; Herrera, Lara Maria; Melani, Rodolfo Francisco Haltenhoff

    2017-03-29

    During forensic facial reconstruction, facial features may be predicted based on the parameters of the skull. This study evaluated the relationships between alar cartilage and piriform aperture and nose morphology and facial typology. Ninety-six cone beam computed tomography images of Brazilian subjects (49 males and 47 females) were used in this study. OsiriX software was used to perform the following measurements: nasal width, distance between alar base insertion points, lower width of the piriform aperture, and upper width of the piriform aperture. Nasal width was associated with the lower width of the piriform aperture, sex, skeletal vertical pattern of the face, and age. The current study contributes to the improvement of forensic facial guides by identifying the relationships between the alar cartilages and characteristics of the biological profile of members of a population that has been little studied thus far.

  13. Bone graft

    MedlinePlus

    Autograft - bone; Allograft - bone; Fracture - bone graft; Surgery - bone graft; Autologous bone graft ... Fuse joints to prevent movement Repair broken bones (fractures) that have bone loss Repair injured bone that ...

  14. The Dissociation Energies of AlH2 and AlAr

    NASA Technical Reports Server (NTRS)

    Ricca, Alessandra; Partridge, Harry; Bauschlicher, Charles W., Jr.; Visscher, Luuk; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    The D(sub 0) values for AlH2 and AlAr are computed using the coupled cluster approach in conjunction with large basis sets. Basis set superposition and spin-orbit effects are accounted for as they are sizeable due to the small binding energy. The computed dissociation energy for AlAr is 101 /cm , which is 83% of the experimental value (122.4/ cm). Our best estimate for the H2 binding energy in AlH2 is 40 +/- 28 /cm.

  15. The transmembrane topology of Batten disease protein CLN3 determined by consensus computational prediction constrained by experimental data.

    PubMed

    Nugent, Timothy; Mole, Sara E; Jones, David T

    2008-04-02

    The CLN3 gene encodes an integral membrane protein of unknown function. Mutations in CLN3 can cause juvenile neuronal ceroid lipofuscinosis, or Batten disease, an inherited neurodegenerative lysosomal storage disease affecting children. Here, we report a topological study of the CLN3 protein using bioinformatic approaches constrained by experimental data. Our results suggest that CLN3 has a six transmembrane helix topology with cytoplasmic N and C-termini, three large lumenal loops, one of which may contain an amphipathic helix, and one large cytoplasmic loop. Surprisingly, varied topological predictions were made using different subsets of orthologous sequences, highlighting the challenges still remaining for bioinformatics.

  16. Efficacy of phosphodiesterase‐4 inhibitors in juvenile Batten disease (CLN3)

    PubMed Central

    Aldrich, Amy; Bosch, Megan E.; Fallet, Rachel; Odvody, Jessica; Burkovetskaya, Maria; Rama Rao, Kakulavarapu V.; Cooper, Jonathan D.; Drack, Arlene V.

    2016-01-01

    Objective Juvenile neuronal ceroid lipofuscinosis (JNCL), or juvenile Batten disease, is a pediatric lysosomal storage disease caused by autosomal recessive mutations in CLN3, typified by blindness, seizures, progressive cognitive and motor decline, and premature death. Currently, there is no treatment for JNCL that slows disease progression, which highlights the need to explore novel strategies to extend the survival and quality of life of afflicted children. Cyclic adenosine monophosphate (cAMP) is a second messenger with pleiotropic effects, including regulating neuroinflammation and neuronal survival. Here we investigated whether 3 phosphodiesterase‐4 (PDE4) inhibitors (rolipram, roflumilast, and PF‐06266047) could mitigate behavioral deficits and cell‐specific pathology in the Cln3Δex7/8 mouse model of JNCL. Methods In a randomized, blinded study, wild‐type (WT) and Cln3Δex7/8 mice received PDE4 inhibitors daily beginning at 1 or 3 months of age and continuing for 6 to 9 months, with motor deficits assessed by accelerating rotarod testing. The effect of PDE4 inhibitors on cAMP levels, astrocyte and microglial activation (glial fibrillary acidic protein and CD68, respectively), lysosomal pathology (lysosomal‐associated membrane protein 1), and astrocyte glutamate transporter expression (glutamate/aspartate transporter) were also examined in WT and Cln3Δex7/8 animals. Results cAMP levels were significantly reduced in the Cln3Δex7/8 brain, and were restored by PF‐06266047. PDE4 inhibitors significantly improved motor function in Cln3Δex7/8 mice, attenuated glial activation and lysosomal pathology, and restored glutamate transporter expression to levels observed in WT animals, with no evidence of toxicity as revealed by blood chemistry analysis. Interpretation These studies reveal neuroprotective effects for PDE4 inhibitors in Cln3Δex7/8 mice and support their therapeutic potential in JNCL patients. Ann Neurol 2016;80:909–923 PMID:27804148

  17. The Batten disease gene CLN3 confers resistance to endoplasmic reticulum stress induced by tunicamycin

    SciTech Connect

    Wu, Dan; Liu, Jing; Wu, Baiyan; Tu, Bo; Zhu, Weiguo; Luo, Jianyuan

    2014-04-25

    Highlights: • The work reveals a protective properties of CLN3 towards TM-induced apoptosis. • CLN3 regulates expression of the GRP78 and the CHOP in response to the ER stress. • CLN3 plays a specific role in the ERS response. - Abstract: Mutations in CLN3 gene cause juvenile neuronal ceroid lipofuscinosis (JNCL or Batten disease), an early-onset neurodegenerative disorder that is characterized by the accumulation of ceroid lipofuscin within lysosomes. The function of the CLN3 protein remains unclear and is presumed to be related to Endoplasmic reticulum (ER) stress. To investigate the function of CLN3 in the ER stress signaling pathway, we measured proliferation and apoptosis in cells transfected with normal and mutant CLN3 after treatment with the ER stress inducer tunicamycin (TM). We found that overexpression of CLN3 was sufficient in conferring increased resistance to ER stress. Wild-type CLN3 protected cells from TM-induced apoptosis and increased cell proliferation. Overexpression of wild-type CLN3 enhanced expression of the ER chaperone protein, glucose-regulated protein 78 (GRP78), and reduced expression of the proapoptotic protein CCAAT/-enhancer-binding protein homologous protein (CHOP). In contrast, overexpression of mutant CLN3 or siRNA knockdown of CLN3 produced the opposite effect. Together, our data suggest that the lack of CLN3 function in cells leads to a failure of management in the response to ER stress and this may be the key deficit in JNCL that causes neuronal degeneration.

  18. Refinement of Nasal Reconstruction with a V/Y-alar-perforator Flap

    PubMed Central

    Langer, Martin F.; Roldán, J. Camilo

    2017-01-01

    Background: The ala of the nose is vascularized by a dense net of perforators originating from the lateral nasal artery or the angular artery. These vessels reach the ala in a cascade fashion from the alar groove/lateral nasal wall. Based on these vessels, a V/Y flap can be dissected with a wide range of mobility. Materials and Methods: Nineteen patients underwent reconstruction of the nose by means of a V/Y-alar-perforator flap alone or in combination with a myocutaneous rotation flap from the lateral nasal wall and/or from the nasal dorsum for reconstruction of defects at the nasal tip, ala of the nose, and/or lateral nasal wall. All patients were followed up 8 months after surgery in average. Results: There was no prolonged congestion or any tissue loss. All patients presented postoperatively with excellent aesthetic results, and no nasal distortion was observed. Conclusion: The V/Y-alar-perforator flap alone or in combination with a myocutaneous rotation flap proved to be a reliable tool in the armamentarium for reconstruction of nasal tip and alar defects providing good aesthetic results. PMID:28203497

  19. The Shark Alar Hypothalamus: Molecular Characterization of Prosomeric Subdivisions and Evolutionary Trends.

    PubMed

    Santos-Durán, Gabriel N; Ferreiro-Galve, Susana; Menuet, Arnaud; Quintana-Urzainqui, Idoia; Mazan, Sylvie; Rodríguez-Moldes, Isabel; Candal, Eva

    2016-01-01

    The hypothalamus is an important physiologic center of the vertebrate brain involved in the elaboration of individual and species survival responses. To better understand the ancestral organization of the alar hypothalamus we revisit previous data on ScOtp, ScDlx2/5, ScTbr1, ScNkx2.1 expression and Pax6 immunoreactivity jointly with new data on ScNeurog2, ScLhx9, ScLhx5, and ScNkx2.8 expression, in addition to immunoreactivity to serotonin (5-HT) and doublecortin (DCX) in the catshark Scyliorhinus canicula, a key species for this purpose since cartilaginous fishes are basal representatives of gnathostomes (jawed vertebrates). Our study revealed a complex genoarchitecture for the chondrichthyan alar hypothalamus. We identified terminal (rostral) and peduncular (caudal) subdivisions in the prosomeric paraventricular and subparaventricular areas (TPa/PPa and TSPa/PSPa, respectively) evidenced by the expression pattern of developmental genes like ScLhx5 (TPa) and immunoreactivity against Pax6 (PSPa) and 5-HT (PPa and PSPa). Dorso-ventral subdivisions were only evidenced in the SPa (SPaD, SPaV; respectively) by means of Pax6 and ScNkx2.8 (respectively). Interestingly, ScNkx2.8 expression overlaps over the alar-basal boundary, as Nkx2.2 does in other vertebrates. Our results reveal evidences for the existence of different groups of tangentially migrated cells expressing ScOtp, Pax6, and ScDlx2. The genoarchitectonic comparative analysis suggests alternative interpretations of the rostral-most alar plate in prosomeric terms and reveals a conserved molecular background for the vertebrate alar hypothalamus likely acquired before/during the agnathan-gnathostome transition, on which Otp, Pax6, Lhx5, and Neurog2 are expressed in the Pa while Dlx and Nkx2.2/Nkx2.8 are expressed in the SPa.

  20. The Shark Alar Hypothalamus: Molecular Characterization of Prosomeric Subdivisions and Evolutionary Trends

    PubMed Central

    Santos-Durán, Gabriel N.; Ferreiro-Galve, Susana; Menuet, Arnaud; Quintana-Urzainqui, Idoia; Mazan, Sylvie; Rodríguez-Moldes, Isabel; Candal, Eva

    2016-01-01

    The hypothalamus is an important physiologic center of the vertebrate brain involved in the elaboration of individual and species survival responses. To better understand the ancestral organization of the alar hypothalamus we revisit previous data on ScOtp, ScDlx2/5, ScTbr1, ScNkx2.1 expression and Pax6 immunoreactivity jointly with new data on ScNeurog2, ScLhx9, ScLhx5, and ScNkx2.8 expression, in addition to immunoreactivity to serotonin (5-HT) and doublecortin (DCX) in the catshark Scyliorhinus canicula, a key species for this purpose since cartilaginous fishes are basal representatives of gnathostomes (jawed vertebrates). Our study revealed a complex genoarchitecture for the chondrichthyan alar hypothalamus. We identified terminal (rostral) and peduncular (caudal) subdivisions in the prosomeric paraventricular and subparaventricular areas (TPa/PPa and TSPa/PSPa, respectively) evidenced by the expression pattern of developmental genes like ScLhx5 (TPa) and immunoreactivity against Pax6 (PSPa) and 5-HT (PPa and PSPa). Dorso-ventral subdivisions were only evidenced in the SPa (SPaD, SPaV; respectively) by means of Pax6 and ScNkx2.8 (respectively). Interestingly, ScNkx2.8 expression overlaps over the alar-basal boundary, as Nkx2.2 does in other vertebrates. Our results reveal evidences for the existence of different groups of tangentially migrated cells expressing ScOtp, Pax6, and ScDlx2. The genoarchitectonic comparative analysis suggests alternative interpretations of the rostral-most alar plate in prosomeric terms and reveals a conserved molecular background for the vertebrate alar hypothalamus likely acquired before/during the agnathan-gnathostome transition, on which Otp, Pax6, Lhx5, and Neurog2 are expressed in the Pa while Dlx and Nkx2.2/Nkx2.8 are expressed in the SPa. PMID:27932958

  1. Management of the droopy tip: a comparison of three alar cartilage-modifying techniques.

    PubMed

    Foda, Hossam M T

    2003-10-01

    The droopy tip is a common nasal deformity in which the tip is inferiorly rotated. Five hundred consecutive rhinoplasty cases were studied to assess the incidence and causes of the droopy tip deformity and to evaluate the role of three alar cartilage-modifying techniques--lateral crural steal, lateral crural overlay, and tongue in groove--in correcting such a deformity. The external rhinoplasty approach was used in all cases. Only one of the three alar cartilage-modifying techniques was used in each case, and the degree of tip rotation and projection was measured both preoperatively and postoperatively. The incidence of droopy tip was 72 percent, and the use of an alar cartilage-modifying technique was required in 85 percent of these cases to achieve the desired degree of rotation. The main causes of droopy tip included inferiorly oriented alar cartilages (85 percent), overdeveloped scrolls of upper lateral cartilages (73 percent), high anterior septal angle (65 percent), and thick skin of the nasal lobule (56 percent). The lateral crural steal technique increased nasal tip rotation and projection, the lateral crural overlay technique increased tip rotation and decreased tip projection, and the tongue-in-groove technique increased tip rotation without significantly changing the amount of projection. The lateral crural overlay technique resulted in the highest degrees of rotation, followed by the lateral crural steal and finally the tongue-in-groove technique. According to these results, the lateral crural steal technique is best indicated in cases with droopy underprojected nasal tip, the lateral crural overlay technique in cases of droopy overprojected nasal tip, and the tongue-in-groove technique in cases where the droopy nasal tip is associated with an adequate amount of projection.

  2. Primary rhinocheiloplasty: Comparison of open and closed methods of alar cartilage reposition

    PubMed Central

    Yasonov, S. A.; Lopatin, A. V.; Kugushev, A. Yu.

    2016-01-01

    Aims: To establish which rhinoplasty method for primary repairing of unilateral cleft lip (UCL) is better. Settings and Design: Two patient groups with cleft lip were compared. Each group was operated on either by McComb's technique as closed rhinoplasty method or by Vissarionov–Kosin technique as an open method. Subjects and Methods: First group included 29 patients and the second consisted of 31. All patients were operated on by single surgeon over 10 years. Randomization was based on wishes and intention of surgeon to use one of two methods. Evaluation of results was based on impartial data, and subjective information collected from respondents with different levels of knowledge about UCL. The objective scale was based on the evaluation of five noticeable residual deformations of nose that usually appear after primary lip-nose surgery: Alar flattening, low position of alar, widening or narrowing of nostril, and deformation of the upper part of nostril rim. Subjective evaluation was based on the opinion of respondents who were ranged every case depending on own judgment. Statistical Analysis: Was performed using Fisher method and Chi-square by Statistica 10.0, StatSoft Inc. Results: Approach with general analysis indicated no difference between two methods. Despite of absence of clear differences between two groups we consider the closed rhinoplasty more favorable due to less damage to alar cartilages and no scars inside nostrils. Conclusions: We think that mentioned scarring may complicate secondary rhinoplasty, which is often needed to correct nose deformation. PMID:27563601

  3. Paradox of mistranslation of serine for alanine caused by AlaRS recognition dilemma.

    PubMed

    Guo, Min; Chong, Yeeting E; Shapiro, Ryan; Beebe, Kirk; Yang, Xiang-Lei; Schimmel, Paul

    2009-12-10

    Mistranslation arising from confusion of serine for alanine by alanyl-tRNA synthetases (AlaRSs) has profound functional consequences. Throughout evolution, two editing checkpoints prevent disease-causing mistranslation from confusing glycine or serine for alanine at the active site of AlaRS. In both bacteria and mice, Ser poses a bigger challenge than Gly. One checkpoint is the AlaRS editing centre, and the other is from widely distributed AlaXps-free-standing, genome-encoded editing proteins that clear Ser-tRNA(Ala). The paradox of misincorporating both a smaller (glycine) and a larger (serine) amino acid suggests a deep conflict for nature-designed AlaRS. Here we show the chemical basis for this conflict. Nine crystal structures, together with kinetic and mutational analysis, provided snapshots of adenylate formation for each amino acid. An inherent dilemma is posed by constraints of a structural design that pins down the alpha-amino group of the bound amino acid by using an acidic residue. This design, dating back more than 3 billion years, creates a serendipitous interaction with the serine OH that is difficult to avoid. Apparently because no better architecture for the recognition of alanine could be found, the serine misactivation problem was solved through free-standing AlaXps, which appeared contemporaneously with early AlaRSs. The results reveal unconventional problems and solutions arising from the historical design of the protein synthesis machinery.

  4. Bone grafts.

    PubMed

    Hubble, Matthew J W

    2002-09-01

    Bone grafts are used in musculoskeletal surgery to restore structural integrity and enhance osteogenic potential. The demand for bone graft for skeletal reconstruction in bone tumor, revision arthroplasty, and trauma surgery, couple with recent advances in understanding and application of the biology of bone transplantation, has resulted in an exponential increase in the number of bone-grafting procedures performed over the last decade. It is estimated that 1.5 million bone-grafting procedures are currently performed worldwide each year, compared to a fraction of that number 20 years ago. Major developments also have resulted in the harvesting, storage, and use of bone grafts and production of graft derivatives, substitutes, and bone-inducing agents.

  5. Unilateral cleft nasal deformity correction using conchal cartilage lily flower graft.

    PubMed

    Hwang, Kun; Kim, Han Joon; Paik, Moo Hyun

    2012-11-01

    We present a conchal cartilage lily flower graft for correcting depressed and laterally displaced alar cartilage for correction of unilateral cleft nasal deformity.After making a V incision at the base of the columellar and then marginal incisions, the alar cartilages were exposed. A fusiform-shaped cartilage larger than 2.5 cm in length and 1 cm in width was obtained. The midline long axis was scored with a No. 15 knife, and the lateral one third was split. Two-thirds length portions were folded in half, and they became straightened in the shape of a stalk of a lily flower. Two symmetrical one-third length portions were fanned out bilaterally in the shape of the leaf of a lily flower. The stalk portion was positioned in a pocket between the medial crura, and the 2 leaf portions were placed on the dome of the alar cartilages. The marked points of the cleft side and contralateral side were secured with sutures. The V incision at the base of the columellar and the marginal incisions were closed with a V-Y shape. In this technique, the 2 leaf portions were placed on the dome of the alar cartilages and sutured; therefore, the suture holds the dome of the cleft side to the contralateral side without peaking.Thirteen patients (6 male and 7 female subjects; age range, 13-30 years) were operated. Among them, 6 patients were very satisfied, and 5 patients were satisfied with the results. Two patients felt they were improved.We think the conchal cartilage lily flower graft might be a good method for correction of depressed and laterally displaced alar cartilage in unilateral cleft nasal deformity.

  6. Rhinoplasty. The difficult nasal tip: total resection of the alar cartilages.

    PubMed

    Rodriguez-Camps, Salvador

    2009-01-01

    There are many ways to reconstruct and make nasal tips more attractive. Sometimes we cannot find the best way unless we at least remove all surplus from the tip. This may occur in primary or secondary rhinoplasty. In principle, anything is possible when relocating and reconstructing. However, sometimes we face reality when we uncover the tip: broken or bulging cartilages that are difficult to put right. For this reason, in 1987 we thought of totally resectioning the alar cartilages in a case of secondary rhinoplasty with an unsightly appearance. After a year the result was seen to be correct from an aesthetic and a functional perspective and is still so today. Aesthetically, it kept its shape and did not collapse with nasal respiratory failure. We covered the end of the crus medialis with a small, temporary, one- to two-layered fascia patch. Except in exceptional cases, we now use this procedure: Total sectioning of the alar cartilages including the domes, or maintenance of them by preserving the fibroadipose tip tissue with a suture in the middle of the end of the crus medialis and by covering this with temporary fascia, which usually has two layers depending on the thickness of the skin of the tip. This procedure is indicated mainly in secondary rhinoplasty when the cartilages of the tip are completely destroyed, and in primary rhinoplasty when the tip is excessively wide and bulbous. Our philosophy is, therefore, elegance and beauty of the nasal tip with a solid and equilateral base without prejudices.

  7. Skin graft

    MedlinePlus

    ... that need skin grafts to heal Venous ulcers, pressure ulcers , or diabetic ulcers that do not heal Very ... chap 17. Read More Burns Patient Instructions Preventing pressure ulcers Surgical wound care - open Review Date 3/13/ ...

  8. Toward less misleading comparisons of uncertain risks: the example of aflatoxin and alar.

    PubMed Central

    Finkel, A M

    1995-01-01

    Critics of comparative risk assessment (CRA), the increasingly common practice of juxtaposing disparate risks for the purpose of declaring which one is the "larger" or the "more important," have long focused their concern on the difficulties in accommodating the qualitative differences among risks. To be sure, people may disagree vehemently about whether "larger" necessarily implies "more serious," but the attention to this aspect of CRA presupposes that science can in fact discern which of two risks has the larger statistical magnitude. This assumption, encouraged by the indiscriminate calculation of risk ratios using arbitrary point estimates, is often incorrect: the fact that environmental and health risks differ in unknown quantitative respects is at least as important a caution to CRA as the fact that risks differ in known qualitative ways. To show how misleading CRA can be when uncertainty is ignored, this article revisits the claim that aflatoxin contamination of peanut butter was "18 times worse" than Alar contamination of apple juice. Using Monte Carlo simulation, the number 18 is shown to lie within a distribution of plausible risk ratios that ranges from nearly 400:1 in favor of aflatoxin to nearly 40:1 in the opposite direction. The analysis also shows that the "best estimates" of the relative risk of aflatoxin to Alar are much closer to 1:1 than to 18:1. The implications of these findings for risk communication and individual and societal decision-making are discussed, with an eye toward improving the general practice of CRA while acknowledging that its outputs are uncertain, rather than abandoning it for the wrong reasons. Images Figure 1. Figure 2. PMID:7607139

  9. Feasibility, repeatability, and safety of ultrasound-guided stimulation of the first cervical nerve at the alar foramen in horses.

    PubMed

    Mespoulhès-Rivière, Céline; Brandenberger, Olivier; Rossignol, Fabrice; Robert, Céline; Perkins, Justin D; Marie, Jean-Paul; Ducharme, Norm

    2016-11-01

    OBJECTIVE To develop and assess the feasibility, repeatability, and safety of an ultrasound-guided technique to stimulate the first cervical nerve (FCN) at the level of the alar foramen of the atlas of horses. ANIMALS 4 equine cadavers and 6 clinically normal Standardbreds. PROCEDURES In each cadaver, the FCN pathway was determined by dissection, and any anastomosis between the first and second cervical nerves was identified. Subsequently, each of 6 live horses underwent a bilateral ultrasound-guided stimulation of the FCN at the alar foramen 3 times at 3-week intervals. After each procedure, horses were examined daily for 5 days. RESULTS In each cadaver, the FCN passed through the alar foramen; a communicating branch between the FCN and the accessory nerve and anastomoses between the ventral branches of the FCN and second cervical nerve were identified. The anastomoses were located in the upper third of the FCN pathway between the wing of the atlas and the nerve's entry in the omohyoideus muscle. Successful ultrasound-guided electrical stimulation was confirmed by twitching of the ipsilateral omohyoideus muscle in all 6 live horses; this finding was observed bilaterally during each of the 3 experimental sessions. No complications developed at the site of stimulation. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that ultrasound-guided stimulation of the FCN at the alar foramen appears to be a safe and straightforward procedure in horses. The procedure may have potential for use in horses with naturally occurring recurrent laryngeal neuropathy to assess reinnervation after FCN transplantation or nerve-muscle pedicle implantation in the cricoarytenoideus dorsalis muscle.

  10. Proximal Tibial Bone Graft

    MedlinePlus

    ... All Site Content AOFAS / FootCareMD / Treatments Proximal Tibial Bone Graft Page Content What is a bone graft? Bone grafts may be needed for various ... the proximal tibia. What is a proximal tibial bone graft? Proximal tibial bone graft (PTBG) is a ...

  11. Coronary Artery Bypass Grafting

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Coronary Artery Bypass Grafting? Coronary artery bypass grafting (CABG) is ... bypass multiple coronary arteries during one surgery. Coronary Artery Bypass Grafting Figure A shows the location of ...

  12. What Is Batten Disease

    MedlinePlus

    ... children retain some awareness of color and light/dark until later. By the end of primary school, ... 2017 By tkirby Leave a Comment Your Membership Matters April 7, 2017 By tkirby Leave a Comment ...

  13. Are MRI high-signal changes of alar and transverse ligaments in acute whiplash injury related to outcome?

    PubMed Central

    2010-01-01

    Background Upper neck ligament high-signal changes on magnetic resonance imaging (MRI) have been found in patients with whiplash-associated disorders (WAD) but also in non-injured controls. The clinical relevance of such changes is controversial. Their prognostic role has never been evaluated. The purpose of this study was to examine if alar and transverse ligament high-signal changes on MRI immediately following the car accident are related to outcome after 12 months for patients with acute WAD grades 1-2. Methods Within 13 days after a car accident, 114 consecutive acute WAD1-2 patients without prior neck injury or prior neck problems underwent upper neck high-resolution proton-weighted MRI. High-signal changes of the alar and transverse ligaments were graded 0-3. A questionnaire including the impact of event scale for measuring posttraumatic stress response and questions on patients' expectations of recovery provided clinical data at injury. At 12 months follow-up, 111 (97.4%) patients completed the Neck Disability Index (NDI) and an 11-point numeric rating scale (NRS-11) on last week neck pain intensity. Factors potentially related to these outcomes were assessed using multiple logistic regression analyses. Results Among the 111 responders (median age 29.8 years; 63 women), 38 (34.2%) had grades 2-3 alar ligament changes and 25 (22.5%) had grades 2-3 transverse ligament changes at injury. At 12 months follow-up, 49 (44.1%) reported disability (NDI > 8) and 23 (20.7%) neck pain (NRS-11 > 4). Grades 2-3 ligament changes in the acute phase were not related to disability or neck pain at 12 months. More severe posttraumatic stress response increased the odds for disability (odds ratio 1.46 per 10 points on the impact of event scale, p = 0.007) and so did low expectations of recovery (odds ratio 4.66, p = 0.005). Conclusions High-signal changes of the alar and transverse ligaments close after injury did not affect outcome for acute WAD1-2 patients without previous

  14. Morphology of the transverse ligament of the atlas and the alar ligaments in the silver fox (Vulpes vulpes var)

    PubMed Central

    2013-01-01

    Background Recent new anatomical and histological features of craniocervical junction in dogs and cats were described providing evidence of differences between the carnivore species. No information on these structures in foxes exists. Results Two parts of the alar ligaments were found. A longer one aroused from dens of axis to the internal (medial) surface of the occipital condyles and was called apical part. A shorter part originated from the entire length of the lateral edge of the dens of axis and terminated on the internal wall of the vertebral foramen of atlas and thus was called the lateral part. The transverse ligament of the atlas was widened in the mid region, above the dens of axis, and thickened at enthesis. Periosteal fibrocartilage was detected in the transverse ligament of the atlas at the enthesis, and sesamoid fibrocartilage was present on periphery in the middle of the ligament. Conclusions The craniocervical junction in foxes differs in part from other carnivores such as dogs and cats but resembles that of mesaticephalic dogs. The sesamoid and periosteal fibrocartilage supports the transverse ligament of the atlas whereas the alar ligaments have no cartilage. PMID:23557095

  15. Wnt signal specifies the intrathalamic limit and its organizer properties by regulating Shh induction in the alar plate.

    PubMed

    Martinez-Ferre, Almudena; Navarro-Garberi, Maria; Bueno, Carlos; Martinez, Salvador

    2013-02-27

    The structural complexity of the brain depends on precise molecular and cellular regulatory mechanisms orchestrated by regional morphogenetic organizers. The thalamic organizer is the zona limitans intrathalamica (ZLI), a transverse linear neuroepithelial domain in the alar plate of the diencephalon. Because of its production of Sonic hedgehog, ZLI acts as a morphogenetic signaling center. Shh is expressed early on in the prosencephalic basal plate and is then gradually activated dorsally within the ZLI. The anteroposterior positioning and the mechanism inducing Shh expression in ZLI cells are still partly unknown, being a subject of controversial interpretations. For instance, separate experimental results have suggested that juxtaposition of prechordal (rostral) and epichordal (caudal) neuroepithelium, anteroposterior encroachment of alar lunatic fringe (L-fng) expression, and/or basal Shh signaling is required for ZLI specification. Here we investigated a key role of Wnt signaling in the molecular regulation of ZLI positioning and Shh expression, using experimental embryology in ovo in the chick. Early Wnt expression in the ZLI regulates Gli3 and L-fng to generate a permissive territory in which Shh is progressively induced by planar signals of the basal plate.

  16. A Refined Technique for Management of Nasal Flaring: The Quest for the Holy Grail of Alar Base Modification

    PubMed Central

    Agrawal, Kapil S; Pabari, Mansi

    2016-01-01

    “A smile is happiness you'll find right under your nose”– Tom Wilson. This quote holds true just for patients, not for surgeons. The correction of the nose always poses a challenge to the cosmetic surgeon. Deformities of the external and internal nose may be congenital or acquired and may be secondary to soft tissue and/or osseo-cartilaginous abnormalities, leading to aesthetic and/or functional consequences. Alar flare poses a common problem, sometimes alone and sometimes in conjunction with other external deformities. Alar base reduction is generally considered when the interalar distance exceeds the intercanthal distance. It has been well documented that this simple additional procedure brings about a substantial enhancement in the nose. Various techniques have been described and used in the past, each having their benefits and drawbacks, with the modified Weir wedge excision, Aufricht nasal sill excision, and Bernstein V-Y advancement being the common ones. We hereby describe a technique that is simple yet effective in achieving the desired results and at the same time aims at preventing relapse to obtain satisfactory long term results. PMID:27896197

  17. Signal changes of the alar ligament in a healthy population: a dispositional or degenerative consequence?

    PubMed

    Wenz, Holger; Kerl, Hans Ulrich; Maros, Mate Elod; Wenz, Ralf; Kalvin, Kira; Groden, Christoph; Nölte, Ingo

    2015-07-17

    OBJECT The alar ligaments (ALs) are vital for stabilizing the craniocervical junction. In terms of morphology, their appearance varies and is visible on MRI. Dark signal of the AL on proton-density (PD)-weighted images is generally considered the norm, but the etiology of frequently observed signal hyperintensities is poorly understood. Using spectral fat suppression, signal hyperintensities can be differentiated into fat- and nonfat-related hyperintensities (NFH). Although signal hyperintensities have no evident association with whiplash-associated disorder, age-related degeneration has often been theorized. Therefore, this study investigates the signal intensities of the ALs on 3.0-T MRI with special reference to age. Expanding thereon, the authors investigated the relationship between signal hyperintensities and patient characteristics, such as height, weight, and sex. METHODS Sixty-six healthy volunteers were scanned using 3.0-T PD-weighted MRI, including spectral fat suppression of the craniocervical junction. The study population was separated into 2 groups (old vs young) using 2 approaches: dichotomization at the median age (40.0 years) and the calculated threshold (28.5 years) using receiver operating characteristics (ROC). The AL was independently characterized with respect to continuity, course, shape, signal intensity, and graduation of homogeneity by 2 experienced neuroradiologists. Signal intensity was differentiated into fat-related hyperintensity and NFH. Univariate and multivariate logistic regression models were employed to investigate the relationship between patient characteristics and signal intensities. RESULTS Two different AL patterns were observed: inhomogeneous (33.3%) and homogeneous (66.7%). The latter pattern was mostly surrounded by a small dark rim (56.8%). Fat could be identified in 15.9% of all ALs (21 of 132 patients), and NFH was identified in 17.4% of all ALs (23 of 132 patients). Here, 28.5 years was the preferred threshold

  18. Electrostrictive Graft Elastomers

    NASA Technical Reports Server (NTRS)

    Su, Ji (Inventor); Harrison, Joycelyn S. (Inventor); St.Clair, Terry L. (Inventor)

    2003-01-01

    An electrostrictive graft elastomer has a backbone molecule which is a non-crystallizable, flexible macromolecular chain and a grafted polymer forming polar graft moieties with backbone molecules. The polar graft moieties have been rotated by an applied electric field, e.g., into substantial polar alignment. The rotation is sustained until the electric field is removed. In another embodiment, a process for producing strain in an elastomer includes: (a) providing a graft elastomer having a backbone molecule which is a non-crystallizable, flexible macromolecular chain and a grafted polymer forming polar graft moieties with backbone molecules; and (b) applying an electric field to the graft elastomer to rotate the polar graft moieties, e.g., into substantial polar alignment.

  19. Deletion of btn1, an orthologue of CLN3, increases glycolysis and perturbs amino acid metabolism in the fission yeast model of Batten disease.

    PubMed

    Pears, Michael R; Codlin, Sandra; Haines, Rebecca L; White, Ian J; Mortishire-Smith, Russell J; Mole, Sara E; Griffin, Julian L

    2010-06-01

    The neuronal ceroid lipofuscinoses (NCLs) constitute a group of autosomal recessive neurodegenerative diseases affecting children. To date, the disease pathogenesis remains unknown, although the role of lysosomal impairment is widely recognized across the different diseases. Recently, the creation of simple models of juvenile NCL (Batten disease) has provided additional insights into the disease mechanism at the molecular level. We report defects in metabolism identified in the Schizosacchromyces pombe yeast model, where btn1, the orthologue of CLN3, has been deleted, using a metabolomics approach based on high resolution 1H and 13C NMR spectroscopy. Such changes represent the first documented metabolic changes associated with deletion of btn1. A decrease in extracellular glucose and increases in the concentration of extracellular ethanol and alanine labelling demonstrate increased glycolytic flux that may arise from vacuolar impairment, whilst amino acid changes were detected which were also in accordance with defective vacuolar functionality. That these changes were detected using a metabolomic based approach advocates its use to further analyse other yeast models of human disease to better understand the function of orthologue genes.

  20. Unbiased Cell-based Screening in a Neuronal Cell Model of Batten Disease Highlights an Interaction between Ca2+ Homeostasis, Autophagy, and CLN3 Protein Function*

    PubMed Central

    Chandrachud, Uma; Walker, Mathew W.; Simas, Alexandra M.; Heetveld, Sasja; Petcherski, Anton; Klein, Madeleine; Oh, Hyejin; Wolf, Pavlina; Zhao, Wen-Ning; Norton, Stephanie; Haggarty, Stephen J.; Lloyd-Evans, Emyr; Cotman, Susan L.

    2015-01-01

    Abnormal accumulation of undigested macromolecules, often disease-specific, is a major feature of lysosomal and neurodegenerative disease and is frequently attributed to defective autophagy. The mechanistic underpinnings of the autophagy defects are the subject of intense research, which is aided by genetic disease models. To gain an improved understanding of the pathways regulating defective autophagy specifically in juvenile neuronal ceroid lipofuscinosis (JNCL or Batten disease), a neurodegenerative disease of childhood, we developed and piloted a GFP-microtubule-associated protein 1 light chain 3 (GFP-LC3) screening assay to identify, in an unbiased fashion, genotype-sensitive small molecule autophagy modifiers, employing a JNCL neuronal cell model bearing the most common disease mutation in CLN3. Thapsigargin, a sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) Ca2+ pump inhibitor, reproducibly displayed significantly more activity in the mouse JNCL cells, an effect that was also observed in human-induced pluripotent stem cell-derived JNCL neural progenitor cells. The mechanism of thapsigargin sensitivity was Ca2+-mediated, and autophagosome accumulation in JNCL cells could be reversed by Ca2+ chelation. Interrogation of intracellular Ca2+ handling highlighted alterations in endoplasmic reticulum, mitochondrial, and lysosomal Ca2+ pools and in store-operated Ca2+ uptake in JNCL cells. These results further support an important role for the CLN3 protein in intracellular Ca2+ handling and in autophagic pathway flux and establish a powerful new platform for therapeutic screening. PMID:25878248

  1. AAV gene transfer delays disease onset in a TPP1-deficient canine model of the late infantile form of Batten disease

    PubMed Central

    Katz, Martin L.; Tecedor, Luis; Chen, Yonghong; Williamson, Baye G.; Lysenko, Elena; Wininger, Fred A.; Young, Whitney M.; Johnson, Gayle C.; Whiting, Rebecca E. H.; Coates, Joan R.; Davidson, Beverly L.

    2016-01-01

    The most common form of the childhood neurodegenerative disease late infantile neuronal ceroid lipofuscinosis (also called Batten disease) is caused by deficiency of the soluble lysosomal enzyme tripeptidyl peptidase 1 (TPP1) resulting from mutations in the TPP1 gene. We tested whether TPP1 gene transfer to the ependyma, the epithelial lining of the brain ventricular system, in TPP1-deficient dogs would be therapeutically beneficial. A one-time administration of recombinant adeno-associated virus (rAAV) expressing canine TPP1 (rAAV.caTPP1) resulted in high expression of TPP1 predominantly in ependymal cells and secretion of the enzyme into the cerebrospinal fluid leading to clinical benefit. Diseased dogs treated with rAAV.caTPP1 showed delays in onset of clinical signs and disease progression, protection from cognitive decline, and extension of life span. By immunostaining and enzyme assay, recombinant protein was evident throughout the brain and spinal cord, with correction of the neuropathology characteristic of the disease. This study in a naturally occurring canine model of TPP1 deficiency highlights the utility of AAV transduction of ventricular lining cells to accomplish stable secretion of recombinant protein for broad distribution in the central nervous system and therapeutic benefit. PMID:26560358

  2. Assessment of the 18-month permanence of onlay tip cartilage grafts following rhinoplasty.

    PubMed

    Persichetti, Paolo; Simone, Pierfranco; Carusi, Carlo

    2013-09-01

    Augmentation rhinoplasty requires addition of materials of various natures to reshape the nasal pyramid. Onlay tip grafts are single or multilayered grafts placed horizontally over the alar domes. The aim of the present study was to assess the 18-month permanence of onlay septal cartilage grafts. Twenty-eight patients underwent rhinoplasty with onlay tip cartilage graft, between June 2008 and November 2008 at the Campus Bio-Medico University in Rome, Italy. They were reviewed and photographed 6 months and 18 months postoperatively. Comparison of 6-month and 18-month postoperative pictures was performed with Adobe Photoshop CS. Measurements on pictures were taken with AutoCAD. Comparison of photographs showed no visible difference in nasal tip projection. Comparison of the measurements of tip projection showed a mean reduction of 0.06 mm (0.19%). Considerable stability of nasal tip projection after rhinoplasty with onlay tip grafts was observed postoperatively. Comparison of standardised digital photographs is a valid procedure to assess contour alterations of various anatomical structures after plastic surgery.

  3. Ablative fractionated erbium:YAG laser for the treatment of ice pick alar scars due to neodymium:YAG laser burns.

    PubMed

    Cohen, Joel L; Babcock, Michael J

    2009-01-01

    The authors present a case of ice pick scars forming in the nasal alar grooves of a patient who was treated with a 1064-nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser for facial telangiectasias. Treatment options for these types of scars are reviewed and specifically we report the success of an ablative fractionated 2940-nm erbium:yttrium-aluminum-garnet (Er:YAG) laser.

  4. Calcar bone graft

    SciTech Connect

    Bargar, W.L.; Paul, H.A.; Merritt, K.; Sharkey, N.

    1986-01-01

    A canine model was developed to investigate the use of an autogeneic iliac bone graft to treat the calcar deficiency commonly found at the time of revision surgery for femoral component loosening. Five large male mixed-breed dogs had bilateral total hip arthroplasty staged at three-month intervals, and were sacrificed at six months. Prior to cementing the femoral component, an experimental calcar defect was made, and a bicortical iliac bone graft was fashioned to fill the defect. Serial roentgenograms showed the grafts had united with no resorption. Technetium-99 bone scans showed more uptake at three months than at six months in the graft region. Disulfine blue injection indicated all grafts were perfused at both three and six months. Thin section histology, fluorochromes, and microradiographs confirmed graft viability in all dogs. Semiquantitative grading of the fluorochromes indicated new bone deposition in 20%-50% of each graft at three months and 50%-80% at six months. Although the calcar bone graft was uniformly successful in this canine study, the clinical application of this technique should be evaluated by long-term results in humans.

  5. Grafts in "closed" rhinoplasty.

    PubMed

    Scattolin, A; D'Ascanio, L

    2013-06-01

    Rhinoplasty is a fascinating and complex surgical procedure aiming at attaining a well-functioning and aesthetically pleasant nose. The use of grafts is of the utmost importance for the nasal surgeon to achieve such results. However, the philosophy and technical use of nasal grafts are different in "closed" and "open" rhinoplasty. The aim of this paper is not detailed description of the numerous grafts reported in the literature; we will describe the main principles of grafts use in "closed" rhinoplasty derived from our experience, with special reference to the philosophical and technical differences in their employment between "closed" and "open" rhinoplasty. Some cases are reported as an example of graft use in "endonasal" approach rhinoplasty.

  6. Bone graft substitutes.

    PubMed

    Bhatt, Reena A; Rozental, Tamara D

    2012-11-01

    Replacement of missing bone stock is a reconstructive challenge to upper extremity surgeons and decision-making with regards to available choices remains difficult. Preference is often given to autograft in the form of cancellous, cortical, or corticocancellous grafts from donor sites. However, the available volume from such donor sites is limited and fraught with potential complications. Advances in surgical management and medical research have produced a wide array of potential substances that can be used for bone graft substitute. Considerations in selecting bone grafts and substitutes include characteristic capabilities, availability, patient morbidity, immunogenicity, potential disease transmission, and cost variability.

  7. Nostril and alar reshaping.

    PubMed

    Planas, J; Planas, J

    1993-01-01

    The authors recommend, when necessary, the use of external excisions for correcting variations in the shape of the nostrils and alae in the cleft lip-nose deformity, in primary rhinoplasties, and in secondary rhinoplasties. Their experience in the use of external incisions was originally stimulated by Millard's paper of 1960 which recommended different types of remodeling external excisions in his analysis of how to handle variations in the shape of the nostrils and alae.

  8. AlAr3(THF): highly efficient reagents for cross-couplings with aryl bromides and chlorides catalyzed by the economic palladium complex of PCy3.

    PubMed

    Ku, Shih-Lun; Hui, Xin-Ping; Chen, Chien-An; Kuo, Yi-Ying; Gau, Han-Mou

    2007-10-07

    Novel and highly efficient cross couplings of aryl bromides and chlorides with AlAr3(THF) (Ar = Ph, 2,4,6-Me3C6H2, 2-naphthyl or 4-Me3SiC6H4) catalyzed by the economic palladium catalyst of PCy3 are reported without the use of a base and under mild reaction conditions at room temperature or temperatures < or = 60 degrees C even for couplings of bulky aryl halides and the Al(2,4,6-Me3C6H2)3(THF) reagent.

  9. Grafting in revision rhinoplasty.

    PubMed

    Bussi, M; Palonta, F; Toma, S

    2013-06-01

    Rhinoplasty is one of the most difficult aesthetic surgery procedures with a high rate of revision. In revision rhinoplasty the surgeon should explore the patient's concerns and then verify the possibility to satisfy expectations after complete internal and external examination of the nose. For the vast majority of complex secondaries, an open approach is the only reasonable method. In fact, in secondary nasal surgery, because of the scarring process following the primary operation, dissection is tedious, and landmarks are lost. One of the main objectives for the surgeon who approaches secondary rhinoplasty is to restore the structural support of the nose and to replace the lost volume of soft tissues. To achieve this purpose, the surgeon must often rely on grafts. An ideal grafting material must be easy to sculpt, resistant to trauma, infection and extrusion, mechanically stable, inert and readily available. For all these reasons, autogenous cartilage grafts harvested from septum, auricular concha and rib represent the first choice in rhinoplasty. In order to obtain a camouflage graft that provides natural contouring to the nose, temporalis fascia can be used. All these carefully trimmed grafts are useful in tip revision surgery, in secondary surgery of the dorsum and to resolve or reduce functional problems.

  10. Comparison of effects of spreader grafts and flaring sutures on nasal airway resistance in rhinoplasty.

    PubMed

    Jalali, Mir Mohammad

    2015-09-01

    Cephalic resection of the lateral crura of the alar cartilages, lateral osteotomies, and removal of the nasal hump during rhinoplasty may cause collapse of the internal nasal valve angle. This study was performed to compare preventive effects of two techniques (spreader grafts and flaring sutures) on rhinoplasty by rhinomanometry. Two hundred and forty-eight patients participated in this semi-experimental study. The patients were assigned into two groups. 28 of them were not available for follow-up. All patients had a straight nose in the midline and no severe septal deviations. 87 of 220 patients underwent the spreader grafts technique and the flaring sutures technique was performed in 133 patients. The nasal airway resistance was calculated by active anterior rhinomanometry on admission to hospital and again between 3 and 6 months following surgery. The mean of follow-up was 20.9 ± 2.9 weeks. After rhinoplasty, nasal airway resistance decreased in 46 patients (52.9 percent) of spreader grafts group and in 84 patients (63.2 percent) of flaring sutures group. The median nasal airway resistance difference (before-after surgery) of spreader grafts and flaring sutures groups was 0.027 Pa/ml/s (range -110 to 130) and 0.017 Pa/ml/s (range -0.690 to 0.790), respectively. The difference of nasal airway resistance between before and after rhinoplasty in two groups was insignificance (Mann-Whitney U test, P = 0.5). The spreader grafts and flaring sutures move the dorsal border of the upper lateral cartilage in a lateral direction and had similar preventive effect on nasal airway resistance after rhinoplasty.

  11. Grafts for Ridge Preservation

    PubMed Central

    Jamjoom, Amal; Cohen, Robert E.

    2015-01-01

    Alveolar ridge bone resorption is a biologic phenomenon that occurs following tooth extraction and cannot be prevented. This paper reviews the vertical and horizontal ridge dimensional changes that are associated with tooth extraction. It also provides an overview of the advantages of ridge preservation as well as grafting materials. A Medline search among English language papers was performed in March 2015 using alveolar ridge preservation, ridge augmentation, and various graft types as search terms. Additional papers were considered following the preliminary review of the initial search that were relevant to alveolar ridge preservation. The literature suggests that ridge preservation methods and augmentation techniques are available to minimize and restore available bone. Numerous grafting materials, such as autografts, allografts, xenografts, and alloplasts, currently are used for ridge preservation. Other materials, such as growth factors, also can be used to enhance biologic outcome. PMID:26262646

  12. Modified alar base cinch suture fixation at the bilateral lower border of the piriform rim after a maxillary Le Fort I osteotomy.

    PubMed

    Yen, C Y; Kuo, C L; Liu, I H; Su, W C; Jiang, H R; Huang, I G; Liu, S Y; Lee, S Y

    2016-11-01

    Classic cinch suture narrowing of the nasal alar base by medially suturing the bilateral nasolabial soft tissue with one long suture has a limited effect. The modified cinch method described in the present study anchors non-absorbable sutures to the bilateral lower border of the piriform rim and provides optimal direction, position, and stability. The sutures can be shortened and the strength kept stable while the surgical wounds heal. Separate bilateral sutures can also reduce interference and distortion from nasotracheal intubation and make the nasolabial profile more symmetrical. Seventeen consecutive cases of maxillary Le Fort I osteotomy were analyzed. The nasal and alar base width changes were 0.4±1.2mm and 0.1±1.1mm, respectively, and the widening rate was only 1.1%. Compared with the results of other studies, postoperative nasal flaring was well controlled using the modified cinch suture anchored to the bilateral lower border of the piriform rim described in this study.

  13. Graft-versus-host disease

    MedlinePlus

    GVHD; Bone marrow transplant - graft-versus-host disease; Stem cell transplant - graft-versus-host disease; Allogeneic transplant - ... GVHD may occur after a bone marrow, or stem cell, transplant in which someone receives bone marrow ...

  14. Bone Grafts in Craniofacial Surgery

    PubMed Central

    Elsalanty, Mohammed E.; Genecov, David G.

    2009-01-01

    Reconstruction of cranial and maxillofacial defects is a challenging task. The standard reconstruction method has been bone grafting. In this review, we shall describe the biological principles of bone graft healing, as pertinent to craniofacial reconstruction. Different types and sources of bone grafts will be discussed, as well as new methods of bone defect reconstruction. PMID:22110806

  15. Grafting effects on vegetable quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the United States, vegetable grafting is rare and few experiments have been done to determine optimal grafting procedures and production practices for different geographical and climatic regions in America. Grafting vegetables to control soilborne disease is a common practice in Asia, parts of E...

  16. Skin graft - slideshow

    MedlinePlus

    ... anatomy URL of this page: //medlineplus.gov/ency/presentations/100100.htm Skin graft - series—Normal anatomy To use the sharing features on this page, please enable JavaScript. Go to slide 1 out of 4 Go to slide 2 ...

  17. Acrylonitrile grafted to PVDF

    SciTech Connect

    Yang, Jin; Eitouni, Hany Basam

    2015-03-31

    PVDF-g-PAN has been synthesized by grafting polyacrylonitrile onto polyvinylidene fluoride using an ATRP/AGET method. The novel polymer is ionically conducive and has much more flexibility than PVDF alone, making it especially useful either as a binder in battery cell electrodes or as a polymer electrolyte in a battery cell.

  18. Grafting for disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary purpose of grafting vegetables worldwide has been to provide resistance to soilborne diseases. The potential loss of methyl bromide as a soil fumigant combined with pathogen resistance to commonly used pesticides will make resistance to soil born pathogens even more important in the futu...

  19. Grafting for disease resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary purpose of grafting vegetables worldwide has been to provide resistance to soil-borne diseases. The potential loss of methyl bromide as a soil fumigant combined with pathogen resistance to commonly used pesticides will make resistance to soil-borne pathogens even more important in the fu...

  20. The versatile autogenous rib graft in septorhinoplasty.

    PubMed

    Sherris, D A; Kern, E B

    1998-01-01

    In the graft depleted revision rhinoplasty patient and the patient with major tissue needs, alternatives to septal and conchal cartilage grafts are needed. The costal cartilage graft and rib bone/costal cartilage combination graft are excellent alternatives. In this study 14 patients received 40 grafts from 20 autogenous ribs harvested during septorhinoplasty. Materials were harvested for use as septal replacement grafts, cantilevered grafts, dorsal onlay grafts, columellar struts, and tip grafts. Patient followup was 6 to 31 months, and no evidence of graft resorption or warpage was evident during that period. Complications of harvest were minimal, and harvest techniques are detailed.

  1. Bone Graft Substitution and Augmentation.

    PubMed

    Nauth, Aaron; Lane, Joseph; Watson, J Tracy; Giannoudis, Peter

    2015-12-01

    Selection of appropriate bone graft or bone graft substitute requires careful recognition of the bone healing needs of the patient's specific clinical problem and a thorough understanding of the different properties possessed by the available bone grafts and substitutes. Although autogenous iliac crest bone graft remains the gold standard of treatment for delayed unions, nonunions, and bone defects, there are a number of promising alternatives available, and emerging evidence suggests that they can be very effective when used in the proper setting. Among these, reamer-irrigator-aspirator bone graft, bone marrow concentrate, bone morphogenetic proteins, and calcium phosphate cements have received a great deal of attention in the literature. This review describes these grafts in detail along with the evidence for their use. In addition, a framework is provided for selecting the appropriate graft or substitute based on their provided properties.

  2. Corneal grafting and banking.

    PubMed

    Ehlers, Niels; Hjortdal, Jesper; Nielsen, Kim

    2009-01-01

    Corneal transplantation was conceptualized at the end of the 18th century, but it took more than 100 years before human corneal grafting was introduced. The greatest step forward was the demonstration by Filatov that corneal tissue can be collected and used post mortem. The history of eye banking includes the development of preservation techniques. Storage in cold to minimize microbial growth and tissue disintegration was first choice but during the last 30 years this has been taken over by warm storage (organ culture) where the donor cornea proves its sterility and vitality before being transferred to the recipient. The long-term organ culture storage makes exchange between centres possible and allows for histocompatibility matching. The internationalization led to the establishing of the European Eye Bank Association but also to an increasing number of governmental regulations. Developments in years to come may lead to control of graft biomechanics and optics. This technical development tends to favour a centralization.

  3. [Grafting of carotid arteries].

    PubMed

    Belov, Iu V; Stepanenko, A B; Gens, A P; Bazylev, V V; Seleznev, M N; Savichev, D D

    2005-01-01

    Over 5-years, 167 reconstructive surgeries for stenosis of internal carotid arteries (ICA) were performed in 124 patients. Mean age of the patients was 63.5 years. One hundred and twenty-nine carotid endarterectomies (CEAE) in 86 patients and 38 reconstructive operations of ICA in 38 patients were performed. There were no lethal outcomes in short- and long-term postoperative period. In short-term period after prosthesis of ICA restenosis was revealed in 3% patients, after eversion CEAE in 3% patients the embolism was seen, after standard CEAE restenosis were diagnosed in 8% patients and thrombosis -- in 3%. In long-term period after grafting of ICA the strokes were seen in 3%, stenosis -- in 6% patients, after eversion endarterectomy -- in 0 and 3% patients, and after standard CEAE -- in 3 and 24% patients, respectively. It is concluded that grafting of ICA is adequate surgical method of reconstruction and stroke prevention in specific variants of carotid atherosclerosis.

  4. Calcification of the Alar Ligament Mimics Fracture of the Craniovertebral Junction (CVJ): An Incidental Finding from Computerised Tomography of the Cervical Spine Following Trauma.

    PubMed

    Che Mohamed, Siti Kamariah; Abd Aziz, Azian

    2009-10-01

    When performing a radiological assessment for a trauma case with associated head injury, a fragment of dense tissue detected near the craniovertebral junction would rapidly be assessed as a fractured bone fragment. However, if further imaging and evaluation of the cervical spine with computerised tomography (CT) did not demonstrate an obvious fracture, then the possibility of ligament calcification would be considered. We present a case involving a previously healthy 44-yearold man who was admitted following a severe head injury from a road traffic accident. CT scans of the head showed multiple intracranial haemorrhages, while scans of the cervical spine revealed a small, well-defined, ovoid calcification in the right alar ligament. This was initially thought to be a fracture fragment. Although such calcification is uncommon, accident and emergency physicians and radiologists may find this useful as a differential diagnosis in patients presenting with neck pain or traumatic head injury.

  5. Dacron Graft Aneurysm Treated by Endovascular Stent-Graft

    SciTech Connect

    Ofer, Amos; Nitecki, Samy; Hoffman, Aaron; Engel, Ahuva

    2001-01-15

    A 72-year old man who underwent aorto-bifemoral bypass with insertion of a Dacron graft 18 years previously presented with an aneurysm in the left limb of his graft. Angiography also demonstrated a bilateral occlusion of the popliteal arteries. Computed tomography (CT) angiography was performed and showed a localized dilation of 3 cm in the left limb of the graft, which had a diameter of 14 mm throughout. In view of the technical difficulties of a surgical procedure, an endovascular stent was considered. Through a left femoral arteriotomy, a stent graft was inserted and deployed in the left limb of the graft. This resulted in total exclusion of the Dacron graft aneurysm. To the best of our knowledge, this is the first report of such a procedure.

  6. Siloxane-grafted membranes

    DOEpatents

    Friesen, D.T.; Obligin, A.S.

    1989-10-31

    Composite cellulosic semipermeable membranes are disclosed which are the covalently bonded reaction product of an asymmetric cellulosic semipermeable membrane and a polysiloxane containing reactive functional group. The two reactants chemically bond by ether, ester, amide or acrylate linkages to form a siloxane-grafted cellulosic membrane having superior selectivity and flux stability. Selectivity may be enhanced by wetting the surface with a swelling agent such as water.

  7. Siloxane-grafted membranes

    DOEpatents

    Friesen, Dwayne T.; Obligin, Alan S.

    1989-01-01

    Composite cellulosic semipermeable membranes are disclosed which are the covalently bonded reaction product of an asymmetric cellulosic semipermeable membrane and a polysiloxane containing reactive functional groups. The two reactants chemically bond by ether, ester, amide or acrylate linkages to form a siloxane-grafted cellulosic membrane having superior selectivity and flux stability. Selectivity may be enhanced by wetting the surface with a swelling agent such as water.

  8. Femoral impaction grafting

    PubMed Central

    Scanelli, John A; Brown, Thomas E

    2013-01-01

    Femoral impaction grafting is a reconstruction option applicable to both simple and complex femoral component revisions. It is one of the preferred techniques for reconstructing large femoral defects when the isthmus is non-supportive. The available level of evidence is primarily derived from case series, which shows a mean survivorship of 90.5%, with revision or re-operation as the end-point, with an average follow-up of 11 years. The rate of femoral fracture requiring re-operation or revision of the component varies between several large case series, ranging from 2.5% to 9%, with an average of 5.4%. PMID:23362469

  9. Spasm in Arterial Grafts in Coronary Artery Bypass Grafting Surgery.

    PubMed

    He, Guo-Wei; Taggart, David P

    2016-03-01

    Spasm of arterial grafts in coronary artery bypass grafting surgery is still a clinical problem, and refractory spasm can occasionally be lethal. Perioperative spasm in bypass grafts and coronary arteries has been reported in 0.43% of all coronary artery bypass grafting surgery, but this may be an underestimate. Spasm can develop not only in the internal mammary artery but more frequently in the right gastroepiploic and radial artery. The mechanism of spasm can involve many pathways, particularly those involving regulation of the intracellular calcium concentration. Endothelial dysfunction also plays a role in spasm. Depending on the clinical scenario, the possibility of spasm during and after coronary artery bypass grafting should be confirmed by angiography. If present, immediate intraluminal injection of vasodilators is often effective, although other procedures such as an intraaortic balloon pump or extracorporeal membrane oxygenation may also become necessary to salvage the patient. Prevention of spasm involves many considerations, and the principles are discussed in this review article.

  10. Polyether/Polyester Graft Copolymers

    NASA Technical Reports Server (NTRS)

    Bell, Vernon L., Jr.; Wakelyn, N.; Stoakley, D. M.; Proctor, K. M.

    1986-01-01

    Higher solvent resistance achieved along with lower melting temperature. New technique provides method of preparing copolymers with polypivalolactone segments grafted onto poly (2,6-dimethyl-phenylene oxide) backbone. Process makes strong materials with improved solvent resistance and crystalline, thermally-reversible crosslinks. Resulting graft copolymers easier to fabricate into useful articles, including thin films, sheets, fibers, foams, laminates, and moldings.

  11. Graft selection in cerebral revascularization.

    PubMed

    Baaj, Ali A; Agazzi, Siviero; van Loveren, Harry

    2009-05-01

    Cerebral revascularization constitutes an important treatment modality in the management of complex aneurysms, carotid occlusion, tumor, and moyamoya disease. Graft selection is a critical step in the planning of revascularization surgery, and depends on an understanding of graft and regional hemodynamics, accessibility, and patency rates. The goal of this review is to highlight some of these properties.

  12. Grafting effects on vegetable quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetable grafting began in the 1920s to control soil-borne disease. It is now a common practice in Asia, parts of Europe, and the Middle East. In Japan and Korea most of the cucurbits and tomatoes (Lycopersicon esculentum Mill.) grown are grafted. This practice is rare in the U.S. and there have...

  13. Continuous ACL graft, results

    PubMed Central

    Díaz, Jorge Luis; Vega, Marcelo; Matesevach, Ivan

    2017-01-01

    Objectives: describe our technique using hamstring graft that respects the proximal continuity of Semitendinosus and uses the superior biological potential of the distal periosteum., preserving and stressing the ST reinforce the retropulsión and dynamic control of external rotation of the knee. Here the technique, results, difficulties and foundations. Methods: The sample of this research was composed of 229 cases operated between 01/03/97 and 01/03/13 in Arthroscopy Private Center., 166 male and 63 female, the postop follow-up was 86 months. Evaluated with IKDC, Lysholm, Hamstring EMG. Comparative histology study in rabbits. Results: IKDC and Lysholm score showed 93% of very good results. Conclusion: Dynamic ACL reconstruction achieves a static-dynamic stabilization of the knee. Grafts have a plus in their biological potential (proximal continuity - osteo-periosteal insertion of the tendons in the femoral tunnel). The hamstring maintains its functionality (EMG). 93% satisfactory results (IKDC, Lysholm). It is a valid surgical option in ACL injuries.

  14. [Stent Grafting for Aortic Dissection].

    PubMed

    Uchida, Naomichi

    2016-07-01

    The purpose of stent graft for aortic dissection is to terminate antegrade blood flow into the false lumen through primary entry. Early intervention for primary entry makes excellent aortic remodeling and emergent stent grafting for complicated acute type B aortic dissection is supported as a class I. On the other hand stent grafting for chronic aortic dissection is controversial. Early stent grafting is considered with in 6 months after on-set if the diameter of the descending aorta is more than 40 mm. Additional interventions for residual false lumen on the downstream aorta are still required. Stent graft for re-entry, candy-plug technique, and double stenting, other effective re-interventions were reported. Best treatment on the basis of each anatomical and physical characteristics should be selected in each institution. Frozen elephant trunk is alternative procedure for aortic dissection without the need to take account of proximal anatomical limitation and effective for acute type A aortic dissection.

  15. Radiation grafting on natural films

    NASA Astrophysics Data System (ADS)

    Lacroix, M.; Khan, R.; Senna, M.; Sharmin, N.; Salmieri, S.; Safrany, A.

    2014-01-01

    Different methods of polymer grafting using gamma irradiation are reported in the present study for the preparation of newly functionalized biodegradable films, and some important properties related to their mechanical and barrier properties are described. Biodegradable films composed of zein and poly(vinyl alcohol) (PVA) were gamma-irradiated in presence of different ratios of acrylic acid (AAc) monomer for compatibilization purpose. Resulting grafted films (zein/PVA-g-AAc) had their puncture strength (PS=37-40 N mm-1) and puncture deformation (PD=6.5-9.8 mm) improved for 30% and 50% PVA in blend, with 5% AAc under 20 kGy. Methylcellulose (MC)-based films were irradiated in the presence of 2-hydroxyethyl methacrylate (HEMA) or silane, in order to determine the effect of monomer grafting on the mechanical properties of films. It was found that grafted films (MC-g-HEMA and MC-g-silane) using 35% monomer performed higher mechanical properties with PS values of 282-296 N mm-1 and PD of 5.0-5.5 mm under 10 kGy. Compatibilized polycaprolactone (PCL)/chitosan composites were developed via grafting silane in chitosan films. Resulting trilayer grafted composite film (PCL/chitosan-g-silane/PCL) presented superior tensile strength (TS=22 MPa) via possible improvement of interfacial adhesion (PCL/chitosan) when using 25% silane under 10 kGy. Finally, MC-based films containing crystalline nanocellulose (CNC) as a filling agent were prepared and irradiated in presence of trimethylolpropane trimethacrylate (TMPTMA) as a grafted plasticizer. Grafted films (MC-g-TMPTMA) presented superior mechanical properties with a TS of 47.9 MPa and a tensile modulus (TM) of 1792 MPa, possibly due to high yield formation of radicals to promote TMPTMA grafting during irradiation. The addition of CNC led to an additional improvement of the barrier properties, with a significant 25% reduction of water vapor permeability (WVP) of grafted films.

  16. Are Aortic Stent Grafts Safe in Pregnancy?

    PubMed Central

    Khandanpour, Nader; Mehta, Tapan A.; Adiseshiah, M.; Meyer, Felicity J.

    2015-01-01

    Aortic stent grafts are increasingly used to treat aortic aneurysms and also other aortic pathologies. The safety of aortic stent grafts in pregnancy has never been studied or reported. We report on two cases of aortic stent grafts in pregnant women and discuss the effect of pregnancy on these aortic stent grafts. PMID:26229702

  17. Histoplasma infection of aortofemoral bypass graft.

    PubMed

    Patel, Nishit; Bronze, Michael S

    2014-05-01

    Histoplasma infection of vascular grafts is extremely rare. To our knowledge, there are only 4 cases reported with Histoplasma capsulatum infection of the aortic graft. All had previous disseminated histoplasmosis and atherosclerotic peripheral vascular disease. They were treated surgically with explantation of the infected graft and reimplantation of new graft in extra-anatomic uninfected site. The authors present a new case of H capsulatum infection of aortofemoral bypass graft, but unlike the other cases, this case was managed without surgical intervention.

  18. [Kidney grafts from elderly donors].

    PubMed

    Hiesse, Christian; Pessione, Fabienne; Cohen, Sophie

    2003-06-07

    FROM AN EPIDEMIOLOGICAL POINT OF VIEW: The epidemiology of renal transplantation had greatly changed over the past 10 years. The increasing number of patients with renal failure and candidates for transplantation increases the demand for grafts, whereas the sampling rate of organs remains stable. The mean age of the donors is rising, hence underlining the question of the use of organs of so-called "borderline" quality. THE WEAK POINTS OF ELDERLY GRAFTS: Aging of the kidneys affects the structure of the parenchyma and renal function, which decreases, notably in hypertensive persons. The elderly graft exhibits a critical mass of nephrons that is insufficient to fulfil the functional requirements of a poorly equipped recipient. The recipient is more sensitive to the added agressions: prolonged ischemia and immunological and medicinal agressions. THE RESULTS OF RENAL GRAFT FROM ELDERLY DONORS: They are quantitatively and qualitatively inferior to those of renal transplants from "ideal" donors. The donor's age is a significant factor influencing negatively influences the survival of the transplanted kidney, but dependent on past vascular history. Good results regarding the maintenance of dialysis are obtained by selecting the donors and by avoiding added risk factors. THE ASSESSMENT OF A GRAFT FROM AN ELDERLY DONOR: This, basically, relies on clinical criteria: donor's history, cause of death and accurate measurement of the renal function. A biopsy of the graft, at the time of sampling, provides useful information. TRANSPLANTATION STRATEGY OF A GRAFT FROM AN ELDERLY DONOR: Donor-recipient matching by age is a common approach. Grafting of both kidneys in the same recipient is a method presently under assessment. The episode of ischemia must be reduced and the immunosuppressive therapy adapted.

  19. Bone Grafting: Sourcing, Timing, Strategies, and Alternatives.

    PubMed

    Egol, Kenneth A; Nauth, Aaron; Lee, Mark; Pape, Hans-Christoph; Watson, J Tracy; Borrelli, Joseph

    2015-12-01

    Acute fractures, nonunions, and nonunions with bone defects or osteomyelitis often need bone graft to facilitate union. There are several factors to consider when it is determined that a bone graft is needed. These factors include the source of the bone graft (autograft vs. allograft), proper timing for placement of the bone graft, strategies to avoid further complications (particularly in the setting of osteomyelitis), and with the development of a variety of bone graft substitutes, whether alternatives to autograft are available and appropriate for the task at hand. Autograft bone has commonly been referred to as the "gold standard" of bone grafts, against which the efficacy of other grafts has been measured. The best timing for when to place a bone graft or substitute is also somewhat controversial, particularly after an open fracture or a potentially contaminated bed. The treatment of infected nonunions, particularly those that require a graft to facilitate healing, can be quite challenging. Typically, the infection is completely eradicated before placement of a bone graft, but achieving a sterile bed and the timing of a bone graft require strategic thinking and planning. This review outlines the benefits of autografts, the most suitable sites for harvesting bone grafts, the timing of bone graft procedures, the potential risks and benefits of grafting in the face of infection, and the currently available bone graft extenders.

  20. Costal Grafting in Mandibular Reconstruction

    PubMed Central

    Bourlet, Jerôme; Château, Joseph; Jacquemart, Mathieu; Dufour, Clémence; Mojallal, Ali; Gleizal, Arnaud

    2015-01-01

    Background: Reconstruction of mandibular bone defect is a common indication in craniomaxillofacial surgery, and free fibular flap is the gold standard for this indication. However, there are alternatives; nonvascular bone grafting is one of them, and we present the costal grafting for mandibular reconstruction, a classic technique that is reliable, efficient, and produced less morbidity than the technique of using composite free flaps. Method: A 9-year retrospective review of 54 patients treated surgically for mandibular reconstruction was performed. The criterion mainly analyzed was graft survival. The surgical technique was described in detail. Results: A total of 54 patients with mandibular bone defect were identified. Five symphysis, 46 corpus, and 20 ramus defects were considered. These patients underwent reconstruction by costal grafting, and the engrafting was successful in 92.6% of cases. Dental rehabilitation with dental implants was realized in 70% of cases. Conclusions: The approach described in this article allowed the authors to obtain good results with costal grafting for mandibular reconstruction and dental rehabilitation. Costal grafting is a good alternative for fibula free flap in specific indications. Reconstruction of mandibular bone defect is a common indication in craniomaxillofacial surgery. Since the 1980s, the gold standard for these defects is the use of free fibular flap.1 In some cases, this technique is contradicted; the surgeon then has several possibilities for the use of free osteomyocutaneous flaps (iliac crest, scapula, and serrato-costal flaps).2–8 PMID:26893990

  1. Interventions in Infrainguinal Bypass Grafts

    SciTech Connect

    Mueller-Huelsbeck, S. Order, B.-M.; Jahnke, T.

    2006-02-15

    The interventional radiologist plays an important role in the detection and prevention of infrainguinal bypass failure. Early detection and evaluation of flow-limiting lesions effectively preserve graft (venous bypass and polyester or expanded polytetrafluoroethylene bypass) patency by identifying stenoses before occlusion occurs. Delay in treatment of the at-risk graft may result in graft failure and a reduced chance of successful revascularization. For this reason, surveillance protocols form an important part of follow-up after infrainguinal bypass surgery. As well as having an understanding of the application of imaging techniques including ultrasound, MR angiography, CT angiography and digital subtraction angiography, the interventional radiologist should have detailed knowledge of the minimally invasive therapeutic options. Percutaneous transluminal angioplasty (PTA), or alternatively cutting balloon angioplasty, is the interventional treatment of choice in prevention of graft failure and occlusion. Further alternatives include metallic stent placement, fibrinolysis, and mechanical thrombectomy. Primary assisted patency rates following PTA can be up to 65% at 5 years. When the endovascular approach is unsuccessful, these therapeutic options are complemented by surgical procedures including vein patch revision, jump grafting, or placement of a new graft.

  2. Bilateral internal thoracic artery grafting

    PubMed Central

    2013-01-01

    The effectiveness of the left internal mammary artery graft to the anterior descending coronary artery as a surgical strategy has been shown to improve the survival rate and decrease the risk of adverse cardiac events in patients undergoing coronary bypass surgery. These clinical benefits appear to be related to the superior short and long-term patency rates of the internal thoracic artery graft. Although the advantages of using of both internal thoracic arteries (ITA) for bypass grafting have taken longer to prove, recent results from multiple data sets now support these findings. The major advantage of bilateral ITA grafting appears to be improved survival rate, while the disadvantages of complex ITA grafting include the increased complexity of operation, and an increased risk of wound complications. While these short-term disadvantages have been mitigated in contemporary surgical practice, they have not eliminated. Bilateral ITA grafting should be considered the procedure of choice for patients undergoing coronary bypass surgery that have a predicted survival rate of longer than ten years. PMID:23977627

  3. [Graft or CVC? A prosthetic graft is the better choice].

    PubMed

    Cifarelli, M

    2009-01-01

    For more than 30 years, research and industry have attempted to introduce into clinical practice solutions and products that could remedy the impossibility to use native veins. Vascular grafts of various types have been created that would approach the ideal characteristics as closely as possible with low antigenic power, high resistance to infections, low risk of thrombosis, and easy pierceability but high resistance to puncturing. For this purpose various materials, either totally synthetic such as PTFE, biological homologous or heterologous, or biosynthetic with mixed components have been created. In addition, different configurations to improve the hemodynamic outline of synthetic grafts have been studied: grafts of varying caliber, conical or equipped with cuffs, and various systems of wall reinforcement to increase the resistance to punctures. But each of these types favors one aspect over another: biological grafts show better compliance with the native vein but offer less resistance to punctures and ectatic processes; synthetic grafts, instead, tend to be more vulnerable to intimal hyperplasia at the venous anastomosis, which is the Achilles' heel of grafts. In recent years, the use of tunneled central venous catheters (CVCs) has grown exponentially. This has offered a new, important solution to the vascular access problem, but the extensive use of CVCs is not always justified. In comparison with grafts, CVCs have various disadvantages including insertion-related complications, possible malfunctioning, risk of infections and thrombosis, but above all a high risk of steno-occlusion of central veins. Also in this field, research and industry are offering more and more reliable and secure products. More resistant, flexible, tolerable and less thrombogenic materials are being used and various configurations which would offer the best performance with the least insertion-related risks have been introduced: double-lumen CVCs with input and output staggered in oval

  4. Patency of femoropopliteal and femorotibial grafts after outflow revascularization (jump grafts) to bypass distal disease.

    PubMed

    Andros, G; Harris, R W; Dulawa, L B; Oblath, R W; Salles-Cunha, S X

    1984-11-01

    Repair of failing femorodistal bypass grafts with secondary distal "jump" grafts was performed 34 times in 33 patients. Indication for operation was limb salvage for all distal jump grafts and for 85% of the initial femorodistal bypass grafts. Autogenous vein bypass grafts were used in 28 of 33 initial femorodistal grafts (85%) and in 29 of 34 secondary jump grafts (85%). Sixteen of the 33 initial grafts in jeopardy extended to the infrapopliteal level (48%) and 19 of the jump grafts terminated in foot or ankle arteries (56%). The 12 jump grafts performed in the first 2 months of the initial graft were associated with high rates (9%) of graft thrombosis and amputation. Early loss of viability of initial grafts probably resulted from technical and judgment errors or underestimation of distal disease. Progression of distal disease produced late failure after 1 year of implantation of the initial grafts. The 1-year patency rate of the initial femorodistal grafts was 63% but only 32% of these grafted limbs were viable and were not at risk of amputation. Distal jump grafts produced a 49% improvement in limb viability (to an 81% limb salvage rate) and an 11% increase in the initial graft patency rate (to 74%) at 1 year.

  5. Craniofacial Bone Grafting: Wolff's Law Revisited

    PubMed Central

    Oppenheimer, Adam J.; Tong, Lawrence; Buchman, Steven R.

    2008-01-01

    Bone grafts are used for the reconstruction of congenital and acquired deformities of the facial skeleton and, as such, comprise a vital component of the craniofacial surgeon's armamentarium. A thorough understanding of bone graft physiology and the factors that affect graft behavior is therefore essential in developing a more intelligent use of bone grafts in clinical practice. This article presents a review of the basic physiology of bone grafting along with a survey of pertinent concepts and current research. The factors responsible for bone graft survival are emphasized. PMID:22110789

  6. Anterior Cruciate Ligament Graft Choices

    PubMed Central

    Macaulay, Alec A.; Perfetti, Dean C.; Levine, William N.

    2012-01-01

    Context: Reconstruction of the anterior cruciate ligament (ACL) is a common surgical procedure; however, there is no consensus to what the best graft option is to replace the injured ACL. The main options available consist of allografts and autografts, which include patellar tendon, hamstring tendon, and quadriceps tendon autografts. Evidence Acquisition: The PubMed database was searched in August 2010 for English-language articles pertaining to ACL grafts. Results: Postoperative outcome variables were analyzed to determine similarities and differences among the different graft options. These variables include stability, strength, function, return to sports, patient satisfaction, complications, and cost. Conclusions: Both allografts and the 3 main options for autografts can provide excellent results in ACL reconstruction and lead to a high percentage of satisfied patients. However, differences exist among the graft choices. Both the similarities and the differences are important to discuss with a patient who will be undergoing ACL reconstruction so that he or she has the best information available when making a choice of graft. PMID:23016071

  7. Nasal reconstruction using porous polyethylene implants.

    PubMed

    Romo, T; Sclafani, A P; Jacono, A A

    2000-01-01

    Nasal reconstruction presents a significant challenge to the facial plastic surgeon. The dual goals of reconstruction are restoration of the desired aesthetic nasal contour and an improved nasal airway. Autologous cartilage and bone are considered optimal grafting material, but their supply is often limited and harvesting entails additional morbidity. Many synthetic materials have been introduced in nasal reconstruction, but high infection and extrusion rates limited their use. Porous high density polyethylene implants present an alternative to autologous material as they allow for fibrovascular ingrowth, leading to stability of the implant and decreased rates of infection. Herein we describe the use of porous high density polyethylene implants for reconstruction of the platyrrhine nose and in revision rhinoplasty. The use of preformed nasal-dorsal tip and alar batten implants are described, as well as the use of columellar strut and premaxillary plumper implants. We believe that porous high density polyethylene implants provide a safe, desirable alternative in functional and aesthetic nasal reconstruction.

  8. Plant grafting: new mechanisms, evolutionary implications

    PubMed Central

    Goldschmidt, Eliezer E.

    2014-01-01

    Grafting, an old plant propagation practice, is still widely used with fruit trees and in recent decades also with vegetables. Taxonomic proximity is a general prerequisite for successful graft-take and long-term survival of the grafted, composite plant. However, the mechanisms underlying interspecific graft incompatibility are as yet insufficiently understood. Hormonal signals, auxin in particular, are believed to play an important role in the wound healing and vascular regeneration within the graft union zone. Incomplete and convoluted vascular connections impede the vital upward and downward whole plant transfer routes. Long-distance protein, mRNA and small RNA graft-transmissible signals currently emerge as novel mechanisms which regulate nutritional and developmental root/top relations and may play a pivotal role in grafting physiology. Grafting also has significant pathogenic projections. On one hand, stock to scion mechanical contact enables the spread of diseases, even without a complete graft union. But, on the other hand, grafting onto resistant rootstocks serves as a principal tool in the management of fruit tree plagues and vegetable soil-borne diseases. The ‘graft hybrid’ historic controversy has not yet been resolved. Recent evidence suggests that epigenetic modification of DNA-methylation patterns may account for certain graft-transformation phenomena. Root grafting is a wide spread natural phenomenon; both intraspecific and interspecific root grafts have been recorded. Root grafts have an evolutionary role in the survival of storm-hit forest stands as well as in the spread of devastating diseases. A more fundamental evolutionary role is hinted by recent findings that demonstrate plastid and nuclear genome transfer between distinct Nicotiana species in the graft union zone, within a tissue culture system. This has led to the formation of alloploid cells that, under laboratory conditions, gave rise to a novel, alloploid Nicotiana species

  9. Types of Coronary Artery Bypass Grafting

    MedlinePlus

    ... from the NHLBI on Twitter. Types of Coronary Artery Bypass Grafting There are several types of coronary ... for you based on your needs. Traditional Coronary Artery Bypass Grafting Traditional CABG is used when at ...

  10. Who Needs Coronary Artery Bypass Grafting?

    MedlinePlus

    ... from the NHLBI on Twitter. Who Needs Coronary Artery Bypass Grafting? Coronary artery bypass grafting (CABG) is used to treat people ... or after a heart attack to treat blocked arteries. Your doctor may recommend CABG if other treatments, ...

  11. Costal Cartilage Grafts in Rhinoplasty.

    PubMed

    Fedok, Fred G

    2016-01-01

    Cartilage grafts are regularly used in rhinoplasty. Septal and auricular donor sites are commonly used. Many situations compel the surgeon to use other alternative donor sites, including revision rhinoplasty and trauma. Many patients have a small amount of native septal cartilage and are unable to provide adequate septal cartilage to be used for frequently performed rhinoplasty maneuvers. The rib cage provides an enormous reserve of costal cartilage that can be carved into a variety of necessary grafts. A description of the technique of harvesting costal cartilage, a review of complications and management, and illustrative cases examples are included.

  12. Organosiloxane-grafted natural polymer coatings

    DOEpatents

    Sugama, Toshifumi

    1998-01-01

    A new family of polysaccharide graft polymers are provided as corrosion resistant coatings having antimicrobial properties which are useful on light metals such as aluminum, magnesium, zinc, steel and their alloys. Methods of making the polysaccharide graft polymers are also included. The methods of making the polysaccharide graft polymers involve reacting a polysaccharide source with an antimicrobial agent under conditions of hydrolysis-condensation.

  13. Grafting efficiency of synthetic polymers onto biomaterials: a comparative study of grafting-from versus grafting-to.

    PubMed

    Hansson, Susanne; Trouillet, Vanessa; Tischer, Thomas; Goldmann, Anja S; Carlmark, Anna; Barner-Kowollik, Christopher; Malmström, Eva

    2013-01-14

    In the present study, the two grafting techniques grafting-from - by activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) - and grafting-to - by copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) - were systematically compared, employing cellulose as a substrate. In order to obtain a meaningful comparison, it is crucial that the graft lengths of the polymers that are grafted from and to the substrates are essentially identical. Herein, this was achieved by utilizing the free polymer formed in parallel to the grafting-from reaction as the polymer for the grafting-to reaction. Four graft lengths were investigated, and the molar masses of the four free polymers (21 ≤ M(n) ≤ 100 kDa; 1.07 ≤ Đ(M) ≤ 1.26), i.e. the polymers subsequently employed in the grafting-to reaction, were shown to be in the same range as the molar masses of the polymers grafted from the surface (23 ≤ M(n) ≤ 87 kDa; 1.08 ≤ Đ(M) ≤ 1.31). The molecular weights of the chains grafted from the surface were established after cleavage from the cellulose substrates via size exclusion chromatography (SEC). High-resolution Fourier transform infrared microscopy (FT-IRM) was employed as an efficient tool to study the spatial distribution of the polymer content on the grafted substrates. In addition, the functionalized substrates were analyzed by X-ray photoelectron spectroscopy (XPS), contact angle (CA) measurements, and field-emission scanning electron microscopy (FE-SEM). For cellulose substrates modified via the grafting-from approach, the content of polymer on the surfaces increased with increasing graft length, confirming the possibility to tailor not only the length of the polymer grafts but also the polymeric content on the surface. In comparison, for the grafting-to reaction, the grafted content could not be controlled by varying the length of the preformed polymer: the polymer content was essentially the same for the four graft lengths

  14. Polyether-polyester graft copolymer

    NASA Technical Reports Server (NTRS)

    Bell, Vernon L. (Inventor)

    1987-01-01

    Described is a polyether graft polymer having improved solvent resistance and crystalline thermally reversible crosslinks. The copolymer is prepared by a novel process of anionic copolymerization. These polymers exhibit good solvent resistance and are well suited for aircraft parts. Previous aromatic polyethers, also known as polyphenylene oxides, have certain deficiencies which detract from their usefulness. These commercial polymers are often soluble in common solvents including the halocarbon and aromatic hydrocarbon types of paint thinners and removers. This limitation prevents the use of these polyethers in structural articles requiring frequent painting. In addition, the most popular commercially available polyether is a very high melting plastic. This makes it considerably more difficult to fabricate finished parts from this material. These problems are solved by providing an aromatic polyether graft copolymer with improved solvent resistance and crystalline thermally reversible crosslinks. The graft copolymer is formed by converting the carboxyl groups of a carboxylated polyphenylene oxide polymer to ionic carbonyl groups in a suitable solvent, reacting pivalolactone with the dissolved polymer, and adding acid to the solution to produce the graft copolymer.

  15. Radiation-induced grafting of diallyldimethylammonium chloride onto acrylic acid grafted polyethylene

    NASA Astrophysics Data System (ADS)

    Francis, Sanju; Dhanawade, B. R.; Mitra, D.; Varshney, Lalit; Sabharwal, Sunil

    2009-01-01

    Diallyldimethylammonium chloride (DADMAC) was grafted onto polyethylene (PE) films by a double grafting procedure. The PE film was initially modified by grafting acrylic acid (AA), through a mutual irradiation method. AA-g-PE film, thus obtained was subjected to subsequent radiation grafting reaction of DADMAC, to give a DADMAC-g-AA-g-PE film having a comb-type structure. The influence of different conditions, such as the extent of AA grafting, DADMAC concentration, absorbed dose and dose rate, on the grafting yield of DADMAC was investigated. A maximum DADMAC grafting of 30% was achieved. The equilibrium degree of swelling (EDS) of the grafted films were gravimetrically determined. TGA and FT-IR techniques were employed to characterize the grafted PE films.

  16. Surgical Outcomes of Porcine Acellular Dermis Graft in Anophthalmic Socket: Comparison with Oral Mucosa Graft

    PubMed Central

    Teo, Livia; Woo, Young Jun; Kim, Dong Kyu; Kim, Chang Yeom

    2017-01-01

    Purpose We describe our experience with the Permacol graft in anophthalmic socket reconstruction, and compare it to the autologous buccal mucosal graft, emphasizing the postoperative vascularization and contraction of each graft. Methods This was a retrospective comparative study. We measured the time necessary for the graft surface to be completely vascularized, as well as the fornix depth of the conjunctival sac in anophthalmic patients. Results Ten patients underwent Permacol graft reconstruction, with 44 undergoing buccal mucosal graft reconstruction. Seven eyelids (70%) in the Permacol group had a good outcome, with improvement in lower eyelid position and prosthesis retention. Nine out of 10 eyelids (90%) in this group showed complete vascularization of the graft at 2.6 ± 1.9 months postoperatively, while the grafted buccal mucosa was fully vascularized at 1.1 ± 0.3 months postoperatively (p < 0.01). Postoperative fornix depth in the Permacol group was 9.1 ± 2.2 mm, compared to 14.9 ± 4.5 mm in the buccal mucosal graft group (p < 0.01). Mean increases in fornix depth were 33.1% and 67.9% of the mean vertical length of the implanted graft. Conclusions The Permacol graft can be useful as spacer graft material in anophthalmic socket patients. It takes longer to vascularize, and undergoes greater graft shrinkage with time, compared to the buccal mucosal graft. PMID:28243018

  17. Grafting of water turbines runner

    SciTech Connect

    Yang, I.T.

    1983-12-01

    It is possible to graft upon or hybridize two different types of water turbines' runner in order to attain more perfect performance to meeting engineering needs. The answer is positive and very interesting, as shown in the research experiment in the Hydromachines Laboratory of Gansu University of Technology. Grafting a group of propeller blades (Ns=440 N.KW) on a Francis turbine runner (Ns=200) with certain boundary conditions in the flow areas, a new hybrid multiplex runner performance has been achieved. Its efficiency curve has been improved at high speed and large flow rate operating conditions that could be able to meet the engineering requirements when the head of the hydropower station is lower than normal. Its unit rotation speed is increased about 25% over that of the Francis. The general performance curve of this hybrid runner will be provided in this paper.

  18. [Bone grafts using tissue engineering].

    PubMed

    Delloye, C

    2001-01-01

    An overview of bone grafts and, in particular, the allografts is presented. The availability of bone allografts, has promoted their use at the expense of the autograft. However, the loss of the cellular activity in an allograft, makes them less performant than an autograft. The use of an allograft in a small size defect can be advocated provided that the implantation technique is stringent. In case of a large segmental bone defect, an allograft can be considered whereas an autograft is not anymore possible. A massive bone allograft allows an anatomical reconstruction and the preservation of strong tendon insertions. In tumor surgery, a bone allograft has become one of the best options to reshape the skeleton. To offset the poor remodeling of the massive bone allografts, and to improve the take of small size bone allografts, researches are presently carried on, using tissue engineering in order to recover a cellular population. The aim is to combine an acellular bone graft with the cells of the recipient. Cells are procured from the bone marrow. Stromal cells are isolated, cultured, so that they will grow with an osteoblastic phenotype. They can be used alone or in association with a bone graft. It is believed that tomorrow such cellular therapy will become a routine procedure.

  19. Conservative Pancreas Graft Preservation at the Extreme

    PubMed Central

    Laurence, Jerome Martin; Sapisochin, Gonzalo; Selzner, Markus; Norgate, Andrea; Kumar, Deepali; McGilvary, Ian D.; Preig, Paul D.; Schiff, Jeffrey; Cattral, Mark S.

    2016-01-01

    Because of the value some patients place in remaining insulin-independent after pancreas transplantation, they may be reluctant to undergo graft pancreatectomy, even in the face of extreme complications, such as graft thrombosis and duodenal segment leak. Partly, for this reason, a variety of complex salvage techniques have been described to save the graft in such circumstances. We report a case of a series of extreme complications related to a leak from the duodenal segment after a simultaneous pancreas and kidney transplant. These included infected thrombosis of the inferior vena cava associated with a graft venous thrombosis and a retroperitoneal fistula. The patient retained graft function with insulin independence and repeatedly declined graft pancreatectomy against the advice of the transplant team. Conservative treatment with percutaneous drainage, antibiotics, and anticoagulation was eventually successful. This outcome is unique in our experience and may be instructive to teams caring for pancreas transplant recipients. PMID:27500244

  20. Grafting chitosan and polyHEMA on carbon nanotubes surfaces: "grafting to" and "grafting from" methods.

    PubMed

    Mahmoodian, Hossein; Moradi, Omid; Shariatzadeh, Behnam

    2014-02-01

    We report a simple method for engineering chitosan (CS) functionalized multi-walled carbon nanotube (MWCNT) composites with a biomedically important polymer, poly-2-hydroxyethyl methacrylate (polyHEMA), by chemical grafting HEMA monomers via free radical polymerization. Functionalization of CS and polyHEMA occurred in three steps. First, using microwave irradiation, CS was grafted onto the surface and sidewall of the carbon nanotubes. Second, HEMA monomers were grafted onto the polymeric matrix surface. The final step involved free radical polymerization of HEMA monomers. Composite synthesis was confirmed by Fourier transform infrared (FTIR) spectroscopy. Moreover, the presence of polyHEMA on the surface of the CS functionalized carbon nanotubes was confirmed by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and thermo gravimetric analysis (TGA) analyses. Furthermore, in the aqueous phase, our novel composites exhibited higher dispersibility compared with pristine MWCNTs. Considering the biomedical importance of polyHEMA and CS polymers, we expect these materials to be useful in the pharmaceutical industry as novel biomaterial composites with potential applications in drug delivery.

  1. Novel expansion techniques for skin grafts

    PubMed Central

    Kadam, Dinesh

    2016-01-01

    The quest for skin expansion is not restricted to cover a large area alone, but to produce acceptable uniform surfaces, robust engraftment to withstand mechanical shear and infection, with a minimal donor morbidity. Ease of the technique, shorter healing period and reproducible results are essential parameters to adopt novel techniques. Significant advances seen in four fronts of autologous grafting are: (1) Dermal–epidermal graft expansion techniques, (2) epidermal graft harvests technique, (3) melanocyte-rich basal cell therapy for vitiligo and (4) robust and faster autologous cell cultures. Meek's original concept that the sum of perimeter of smaller grafts is larger than the harvested graft, and smaller the graft size, the greater is the potential for regeneration is witnessed in newer modification. Further, as graft size becomes smaller or minced, these micrografts can survive on the wound bed exudate irrespective of their dermal orientation. Expansion produced by 4 mm × 4 mm sized Meek micrografts is 10-folds, similarly 0.8 mm × 0.8 mm size micrografts produce 100-fold expansion, which becomes 700-fold with pixel grafts of 0.3 mm × 0.3 mm size. Fractional skin harvest is another new technique with 700 μ size full thickness graft. These provide instant autologous non-cultured graft to cover extensive areas with similar quality of engraftment surface as split skin grafts. Newer tools for epidermal blister graft harvest quickly, with uniform size to produce 7-fold expansions with reproducible results. In addition, donor area heals faster with minimal scar. Melanocyte-rich cell suspension is utilised in vitiligo surgery tapping the potential of hair root melanocytes. Further advances in the cell culture to reduce the cultivation time and provide stronger epidermal sheets with dermal carrier are seen in trials. PMID:27274117

  2. Preoperative graft assessment in aortocoronary bypass surgery

    PubMed Central

    Tinica, Grigore; Vartic, Cristina Luca; Mocanu, Veronica; Baran, Dana; Butcovan, Doina

    2016-01-01

    Coronary artery bypass graft (CABG) is a surgical procedure able to improve the blood supply to the myocardium. In the present study, the distal segments of grafts taken from the internal thoracic artery (ITA), radial artery (RA) and saphenous vein (SV) for use in aortocoronary bypass surgery were examined. The morphologies of the grafts were investigated in order to draw conclusions concerning their patency and viability. In addition, clinical and laboratory risk factors considered to be significant predictors of lesion severity in graft vessels used in CABGs were investigated. In total, 54 distal graft segments of ITAs, RAs and SVs from 20 men and 6 women aged between 42 and 78 years, were evaluated. Histological analyses were used to visualize graft lesions. Morphometrically, the intimal thickness index (ITI) and luminal narrowing were assessed as an indication of graft patency. The histological changes observed in the graft vessel walls included the presence of distinct atheromatous plaques (fatty streaks in 2 cases) or thickening of the intima (20 cases) and media (17 cases). Morphometric analysis showed that the mean ITI of the vessel conduits was 0.37 in the SVs, 0.95 in the RAs, and 1.66 in the ITAs. No patient had >50% conduit stenosis. By assessing the association between risk factors and graft lesions, it was found that all the patients showed risk factors for atherosclerosis, such as age (61.54%), arterial hypertension (65.38%), hyperlipidemia (65.38%), smoking (34.61%), diabetes mellitus (38.46%) and obesity (15.38%). The presence of pre-existing lesions in bypass grafts may contribute to a reduction in their viability, particularly in the case of venous grafts. Further long-term follow-ups are mandatory to evaluate the consequences of such lesions upon the patency of the grafts. PMID:27446279

  3. Organosiloxane-grafted natural polymer coatings

    DOEpatents

    Sugama, Toshifumi

    1998-12-01

    A new family of polysaccharide graft polymers are provided as corrosion resistant coatings having antimicrobial properties which are useful on light metals such as aluminum, magnesium, zinc, steel and their alloys. Methods of making the polysaccharide graft polymers are also included. The methods of making the polysaccharide graft polymers involve reacting a polysaccharide source with an antimicrobial agent under conditions of hydrolysis-condensation. 17 figs.

  4. Interdigitating reticulum cells in human renal grafts.

    PubMed

    Wakabayashi, T; Onoda, H

    1991-01-01

    Seventeen human renal graft biopsies taken 1 h to 50 days after transplantation and 3 human renal non-graft biopsies (2 minimal change and 1 non-tumour portion of angiomyolipoma) were investigated with immunoelectron microscopy in order to identify interdigitating reticulum cells (IDC) or dendritic cells (DC) in renal tissues. The antibodies used consisted of a rabbit polyclonal antibody of antihuman S100 beta protein, mouse monoclonal antibodies of antihuman HLA-DR, anti-CD3, and anti-CD1a. IDC or DC were identified in 11 renal grafts. They were found both in the glomerular and interstitial (peritubular) capillary lumens but not in the interstitium of 1 case: both were present in the interstitial capillary lumens and interstitium of another case, and in the interstitium only of 9 cases. In the remaining 6 grafts and 3 non-grafts they were not detected. These 6 grafts and 3 non-grafts did not show any pathological change except for foot process fusion of the glomerular epithelia in 2 cases of minimal change. These findings suggest that IDC or DC are not normally present in human renal tissues. The presence of the cell in the glomerular and peritubular capillary lumens of a biopsy taken after 1 h and their presence in the interstitial capillary lumens of another graft biopsy, suggest that the IDC or DC in human renal grafts are derived from recipients, not donors, and that they migrate from the circulating blood toward the interstitium.

  5. Plant grafting: insights into tissue regeneration

    PubMed Central

    2016-01-01

    Abstract For millennia, people have cut and joined different plants together through a process known as grafting. The severed tissues adhere, the cells divide and the vasculature differentiates through a remarkable process of regeneration between two genetically distinct organisms as they become one. Grafting is becoming increasingly important in horticulture where it provides an efficient means for asexual propagation. Grafting also combines desirable roots and shoots to generate chimeras that are more vigorous, more pathogen resistant and more abiotic stress resistant. Thus, it presents an elegant and efficient way to improve plant productivity in vegetables and trees using traditional techniques. Despite this horticultural importance, we are only beginning to understand how plants regenerate tissues at the graft junction. By understanding grafting better, we can shed light on fundamental regeneration pathways and the basis for self/non‐self recognition. We can also better understand why many plants efficiently graft whereas others cannot, with the goal of improving grafting so as to broaden the range of grafted plants to create even more desirable chimeras. Here, I review the latest findings describing how plants graft and provide insight into future directions in this emerging field. PMID:28316790

  6. Late infection in Dacron arterial grafts.

    PubMed

    Harvey, D R; Bliss, B P

    1975-06-01

    We report a series of cases of late infection in Dacron arterial grafts. Late infection is defined as that presenting de novo 6 months or more after the patient's discharge from hospital with a clean healed wound. One hundred and ten patients were followed up and 6 cases of this type of infection occurred. The diagnosis was made on clinical grounds and usually pain, suppuration in the line of graft, or graft exposure were the presenting features. Secondary haemorrhage, common in early infection, did not occur. Conservative management failed in most cases and removal of the infected graft was necessary. The difficult problems associated with revascularization are discussed.

  7. What to Expect during Coronary Artery Bypass Grafting

    MedlinePlus

    ... NHLBI on Twitter. What To Expect During Coronary Artery Bypass Grafting Coronary artery bypass grafting (CABG) requires ... surgery to newer, less-invasive methods. Traditional Coronary Artery Bypass Grafting This type of surgery usually lasts ...

  8. Initiator Effects in Reactive Extrusion of Starch Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of starch with water-soluble polymers such as polyacrylamide have potential applications including hydrogels, superabsorbents, and thickening agents. Reactive extrusion is a rapid, continuous method for production of starch graft copolymers with high reaction and grafting efficienc...

  9. Mouse models for graft arteriosclerosis.

    PubMed

    Qin, Lingfeng; Yu, Luyang; Min, Wang

    2013-05-14

    Graft arteriosclerois (GA), also called allograft vasculopathy, is a pathologic lesion that develops over months to years in transplanted organs characterized by diffuse, circumferential stenosis of the entire graft vascular tree. The most critical component of GA pathogenesis is the proliferation of smooth muscle-like cells within the intima. When a human coronary artery segment is interposed into the infra-renal aortae of immunodeficient mice, the intimas could be expand in response to adoptively transferred human T cells allogeneic to the artery donor or exogenous human IFN-γ in the absence of human T cells. Interposition of a mouse aorta from one strain into another mouse strain recipient is limited as a model for chronic rejection in humans because the acute cell-mediated rejection response in this mouse model completely eliminates all donor-derived vascular cells from the graft within two-three weeks. We have recently developed two new mouse models to circumvent these problems. The first model involves interposition of a vessel segment from a male mouse into a female recipient of the same inbred strain (C57BL/6J). Graft rejection in this case is directed only against minor histocompatibility antigens encoded by the Y chromosome (present in the male but not the female) and the rejection response that ensues is sufficiently indolent to preserve donor-derived smooth muscle cells for several weeks. The second model involves interposing an artery segment from a wild type C57BL/6J mouse donor into a host mouse of the same strain and gender that lacks the receptor for IFN-γ followed by administration of mouse IFN-γ (delivered via infection of the mouse liver with an adenoviral vector. There is no rejection in this case as both donor and recipient mice are of the same strain and gender but donor smooth muscle cells proliferate in response to the cytokine while host-derived cells, lacking receptor for this cytokine, are unresponsive. By backcrossing additional

  10. Fat grafting in facial rejuvenation.

    PubMed

    Marten, Timothy J; Elyassnia, Dino

    2015-04-01

    Patients with significant facial atrophy and age-related loss of facial fat generally achieve suboptimal improvement from both surface treatments of facial skin and surgical lifts. Restoring lost facial volume by fat grafting is a powerful technique that is now acknowledged by most plastic surgeons and other physicians engaged in treating the aging face as one of the most important advances in aesthetic surgery. Properly performed, the addition of fat to areas of the face that have atrophied because of age or disease can produce a significant and sustained improvement in appearance that is unobtainable by other means.

  11. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

    Trochimcznk, A.W.; Gatrone, R.C.; Alexandratos, S.; Horwitz, E.P.

    1997-04-08

    An ion exchange resin is disclosed that is comprised of an insoluble copolymer onto which are grafted pendent groups that provide 1.0 to about 10 mmol/g dry weight phosphorus. The pendent groups have the formula as shown in the patent wherein R is hydrogen, a cation or mixtures thereof; and R{sup 1} is hydrogen or an C{sub 1}-C{sub 2} alkyl group. The resin also contains zero to about 5 mmol/g dry weight of pendent aromatic sulfonate groups. Processes for making and using an ion exchange resin are also disclosed.

  12. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

    Trochimcznk, Andrzej W.; Gatrone, Ralph C.; Alexandratos, Spiro; Horwitz, E. Philip

    1998-01-27

    An ion exchange resin is disclosed that is comprised of an insoluble copolymer onto which are grafted pendent groups that provide 1.0 to about 10 mmol/g dry weight phosphorous. The pendent groups have the formula ##STR1## wherein R is hydrogen, a cation or mixtures thereof; and R.sup.1 is hydrogen or an C.sub.1 -C.sub.2 alkyl group. The resin also contains zero to about 5 mmol/g dry weight of pendent aromatic sulfonate groups. Processes for making and using an ion exchange-resin are also disclosed.

  13. Grafted methylenediphosphonate ion exchange resins

    DOEpatents

    Trochimcznk, Andrzej W.; Gatrone, Ralph C.; Alexandratos, Spiro; Horwitz, E. Philip

    1997-01-01

    An ion exchange resin is disclosed that is comprised of an insoluble copolymer onto which are grafted pendent groups that provide 1.0 to about 10 mmol/g dry weight phosphorous. The pendent groups have the formula ##STR1## wherein R is hydrogen, a cation or mixtures thereof; and R.sup.1 is hydrogen or an C.sub.1 -C.sub.2 alkyl group. The resin also contains zero to about 5 mmol/g dry weight of pendent aromatic sulfonate groups. Processes for making and using an ion exchange resin are also disclosed.

  14. Design and development of multilayer vascular graft

    NASA Astrophysics Data System (ADS)

    Madhavan, Krishna

    2011-07-01

    Vascular graft is a widely-used medical device for the treatment of vascular diseases such as atherosclerosis and aneurysm as well as for the use of vascular access and pediatric shunt, which are major causes of mortality and morbidity in this world. Dysfunction of vascular grafts often occurs, particularly for grafts with diameter less than 6mm, and is associated with the design of graft materials. Mechanical strength, compliance, permeability, endothelialization and availability are issues of most concern for vascular graft materials. To address these issues, we have designed a biodegradable, compliant graft made of hybrid multilayer by combining an intimal equivalent, electrospun heparin-impregnated poly-epsilon-caprolactone nanofibers, with a medial equivalent, a crosslinked collagen-chitosan-based gel scaffold. The intimal equivalent is designed to build mechanical strength and stability suitable for in vivo grafting and to prevent thrombosis. The medial equivalent is designed to serve as a scaffold for the activity of the smooth muscle cells important for vascular healing and regeneration. Our results have shown that genipin is a biocompatible crosslinker to enhance the mechanical properties of collagen-chitosan based scaffolds, and the degradation time and the activity of smooth muscle cells in the scaffold can be modulated by the crosslinking degree. For vascular grafting and regeneration in vivo, an important design parameter of the hybrid multilayer is the interface adhesion between the intimal and medial equivalents. With diametrically opposite affinities to water, delamination of the two layers occurs. Physical or chemical modification techniques were thus used to enhance the adhesion. Microscopic examination and graft-relevant functional characterizations have been performed to evaluate these techniques. Results from characterization of microstructure and functional properties, including burst strength, compliance, water permeability and suture

  15. Radiation resistivity of polyacenaphthylene-grafted polyethylene

    NASA Astrophysics Data System (ADS)

    Hayakawa, Kiyoshi; Kawase, Kaoru; Yamakita, Hiromi

    Thin poly (ethylene-g-acenaphthylene) films prepared by the vapor-phase grafting method were subjected to the γ-irradiation in air, and various changes in tensile and structural properties of the film were investigated by comparing with those of the untreated or crosslinked polyethylene film. Polyethylene got to lose its inherent necking property by oxidative degradation and to be brittle-fractured by the irradiation dose less than 100 Mrad in air. The polyacenaphthylene-grafted polyethylenes (extent of grafting, ˜ 54 by {100( P-P°) }/{P°}), however, kept their ductility up to 200 Mrad or more, and the rate of increase in elastic modulus as well as yield strength with the increasing irradiation dose was considerably lower than that of untreated or crosslinked polyethylene. The effect of the grafting extent, and that of the irradiation dose-rate on the fracture energy were also examined. The weight increase of polyethylene due to the oxygen consumption and the resulting formation of carbonyl group which proceeded proportionally with the irradiation dose were remarkably suppressed by the grafting, whereas the double bond formation seemed to be unaffected by it. The grafted film held the original content of gel fraction unchanged during the irradiation in air, but the average molecular weight of the sol fraction decreased gradually. Meanwhile, the gel fraction of the crosslinked polyethylene was degenerated by a small dose of irradiation. The analysis of gaseous products revealed the formation of water, methanol, acetaldehyde and so forth from the irradiated grafted film. The grafting procedure and the subsequent irradiation of the grafted film did not affect the degree of crystallinity of the backbone polyethylene. The role played by the grafted polyacenaphthylene for endowing the radiation resistivity to polyethylene and its inherent limitation in effect were discussed from the structural point of view of the grafted film.

  16. Recipient Wound Bed Characteristics Affect Scarring and Skin Graft Contraction

    DTIC Science & Technology

    2015-02-13

    skin grafting onto hypodermis vs. onto fascia. Compared to autografts grafted onto fascia, identical thickness autografts grafted onto fat demonstrated...reduced contraction, enhanced mobility and vascularity, and reduced topographical variability. Grafts onto fat also showed reduced levels of...skin grafts onto fat report better range of motion compared with patients who receive skin grafts directly onto fascia.3 The same study also found that

  17. Biodegradability of poly(3-hydroxybutyrate) film grafted with vinyl acetate: Effect of grafting and saponification

    NASA Astrophysics Data System (ADS)

    Wada, Yuki; Seko, Noriaki; Nagasawa, Naotsugu; Tamada, Masao; Kasuya, Ken-ichi; Mitomo, Hiroshi

    2007-06-01

    Radiation-induced graft polymerization of vinyl acetate (VAc) onto poly(3-hydroxybutyrate) (PHB) film was carried out. At a degree of grafting higher than 5%, the grafted films (PHB-g-VAc) completely lost the enzymatic degradability that is characteristic of PHB due to the grafted VAc covering the surface of the PHB film. However, the biodegradability of the PHB-g-VAc films was recovered when the films were saponified in alkali solution under optimum conditions. Graft chains of the PHB-g-VAc film reacted selectively to become biodegradable polyvinyl alcohol (PVA). The biodegradability of the saponified PHB-g-VAc film increased rapidly with time.

  18. Ethylene vinyl acetate based radiation grafted hydrophilic matrices: Process parameter standardization, grafting kinetics and characterization

    NASA Astrophysics Data System (ADS)

    Chaudhari, C. V.; Mondal, R. K.; Dubey, K. A.; Grover, V.; Panicker, L.; Bhardwaj, Y. K.; Varshney, L.

    2016-08-01

    A transparent, elastomeric, grafted matrix for several potential applications was synthesized by single-step simultaneous radiation grafting of methacrylic acid onto ethylene vinyl acetate (EVA). CuSO4 was found to be the most suitable homo-polymerization inhibitor among different inhibitors tried. The grafting kinetics was found to be a strong function of dose rate (D) and monomer content (M) and an equation relating grafting rate Rg=Kg [M]1.13D0.23 was deduced. Crystallinity of the grafted matrices as assessed from XRD and DSC measurements indicated decrease in crystalline content with increase in grafting yield, suggesting crystalline domain of EVA get disrupted on grafting. Elastic modulus increased linearly with the increase in grafting yield, though elongation at break decreased precipitously from 900% to 30% at even ~9% grafting. Thermo-gravimetric analysis showed three step weight loss of the grafted EVA matrix. The grafting of MAA resulted in increase in surface energy mainly due to enhanced polar component.

  19. Xenon treatment protects against cold ischemia associated delayed graft function and prolongs graft survival in rats.

    PubMed

    Zhao, H; Watts, H R; Chong, M; Huang, H; Tralau-Stewart, C; Maxwell, P H; Maze, M; George, A J T; Ma, D

    2013-08-01

    Prolonged hypothermic storage causes ischemia-reperfusion injury (IRI) in the renal graft, which is considered to contribute to the occurrence of the delayed graft function (DGF) and chronic graft failure. Strategies are required to protect the graft and to prolong renal graft survival. We demonstrated that xenon exposure to human proximal tubular cells (HK-2) led to activation of range of protective proteins. Xenon treatment prior to or after hypothermia-hypoxia challenge stabilized the HK-2 cellular structure, diminished cytoplasmic translocation of high-mobility group box (HMGB) 1 and suppressed NF-κB activation. In the syngeneic Lewis-to-Lewis rat model of kidney transplantation, xenon exposure to donors before graft retrieval or to recipients after engraftment decreased caspase-3 expression, localized HMGB-1 within nuclei and prevented TLR-4/NF-κB activation in tubular cells; serum pro-inflammatory cytokines IL-1β, IL-6 and TNF-α were reduced and renal function was preserved. Xenon treatment of graft donors or of recipients prolonged renal graft survival following IRI in both Lewis-to-Lewis isografts and Fischer-to-Lewis allografts. Xenon induced cell survival or graft functional recovery was abolished by HIF-1α siRNA. Our data suggest that xenon treatment attenuates DGF and enhances graft survival. This approach could be translated into clinical practice leading to a considerable improvement in long-term graft survival.

  20. Thermal stability of grafted fibers. [Gamma radiation

    SciTech Connect

    Sundardi, F.; Kadariah; Marlianti, I.

    1983-10-01

    Presented the experimental results on the study of thermal stability of grafted fibers, i.e., polypropylene-, polyester-, and rayon-grafted fibers. These fibers were obtained by radiation grafting processes using hydrophylic monomers such as 1-vinyl 2-pyrolidone, acrylic acid, N-methylol acrylamide, and acrylonitrile. The thermal stability of the fibers was studied using a Shimadzu Thermal Analyzer DT-30. The thermal stability of the fibers, which can be indicated by the value of the activation energy for thermal degradation, was not improved by radiation grafting. The degree of improvement depends on the thermal stability of the monomers used for grafting. The thermal stability of a polypropylene fiber, either a grafted or an ungrafted one, was found to be inferior compared to the polyester of a rayon fiber, which may be due to the lack of C=O and C=C bonds in the polypropylene molecules. The thermal stability of a fiber grafted with acrylonitrile monomer was found to be better than that of an ungrafted one. However, no improvement was detected in the fibers grafted with 1-vinyl 2-pyrrolidone monomer, which may be due to the lower thermal stability of poly(1-vinyl-2-pyrrolidone), compared to the polypropylene or polyester fibers. 17 figures, 3 tables.

  1. Intraoperative anterior cruciate ligament graft contamination.

    PubMed

    Pasque, Charles B; Geib, Timothy M

    2007-03-01

    Intraoperative anterior cruciate ligament graft contamination is a rare but potentially devastating occurrence for any surgeon to encounter. Most instances in our experience have happened when a surgeon first enters practice or is operating in a new environment with new staff. Based on the currently available literature and the senior author's personal experience with 3 cases, intraoperative cleansing of the graft followed by implantation is a reasonable option. The protocol used successfully in these 3 cases includes getting the graft off of the floor immediately, removing any suture material in the graft, cleansing the graft for 15 to 30 minutes each in chlorohexidine and triple antibiotic solution, followed by a normal saline rinse. All graft sutures should then be replaced. The graft should then be resized and the tibial and femoral tunnels adjusted if needed. After implantation of the graft, additional intraoperative and postoperative intravenous antibiotic and/or oral antibiotic administration is also recommended for the first 1 to 2 weeks. Close clinical follow-up is also very important the first 6 weeks postoperatively and should include candid communication with the patient and family.

  2. Mycobacterium chelonei infection of a corneal graft.

    PubMed Central

    Aylward, G. W.; Stacey, A. R.; Marsh, R. J.

    1987-01-01

    We present a case of Mycobacterium chelonei infection in a corneal graft. The chronic ulceration and stromal infiltration followed a well defined course and eventually responded to topical amikacin, though a further graft was required. Previous cases of keratitis due to the M. fortuitum complex are reviewed. Images PMID:3311141

  3. Spreader Grafts in Functional Rhinoplasty.

    PubMed

    Kim, Leslie; Papel, Ira D

    2016-02-01

    Management of the middle vault is paramount to achieving optimal aesthetic and functional outcomes in rhinoplasty. The ideal treatment for middle vault complications, such as internal nasal valve collapse, inverted-V deformity, and middle vault dorsal asymmetry, is prevention. Risk factors for middle vault problems in rhinoplasty that may be identified in preoperative consultation include short nasal bones, long and weak upper lateral cartilages, thin skin, previous trauma or surgery, preoperative positive Cottle maneuver, tension nose deformity, and anteriorly positioned inferior turbinates. When any of these risk factors are identified, preventive measures should be pursued. These include preservation of middle vault support structures, judicious resection in dorsal hump reduction, use of conservative osteotomies, and reconstruction of the cartilaginous middle vault with structural grafting. Spreader grafts have become the workhorse in middle vault reconstruction. They are invaluable in restoring nasal dorsal aesthetic lines, repairing or maintaining the internal nasal valve, and buttressing a corrected crooked nose. Functional and aesthetic problems related to the middle nasal vault are among the most common reasons for patients seeking revision rhinoplasty. Although complications in rhinoplasty are inevitable, underlying their etiology and instituting prophylactic treatment can significantly help reduce their occurrence.

  4. Electrostrictive Graft Elastomers and Applications

    NASA Technical Reports Server (NTRS)

    Su, J.; Harrison, J. S.; St.Clair, T. L.; Bar-Cohen, Y.; Leary, S.

    1999-01-01

    Efficient actuators that are lightweight, high performance and compact are needed to support telerobotic requirements for future NASA missions. In this work, we present a new class of electromechanically active polymers that can potentially be used as actuators to meet many NASA needs. The materials are graft elastomers that offer high strain under an applied electric field. Due to its higher mechanical modulus, this elastomer also has a higher strain energy density as compared to previously reported electrostrictive polyurethane elastomers. The dielectric, mechanical and electromechanical properties of this new electrostrictive elastomer have been studied as a function of temperature and frequency. Combined with structural analysis using x-ray diffraction and differential scanning calorimetry on the new elastomer, structure-property interrelationship and mechanisms of the electric field induced strain in the graft elastomer have also been investigated. This electroactive polymer (EAP) has demonstrated high actuation strain and high mechanical energy density. The combination of these properties with its tailorable molecular composition and excellent processability makes it attractive for a variety of actuation tasks. The experimental results and applications will be presented.

  5. [Autologous fat grafting and rhinoplasty].

    PubMed

    Nguyen, P S; Baptista, C; Casanova, D; Bardot, J; Magalon, G

    2014-12-01

    Revision rhinoplasty can be very challenging especially in cases of thin skin. Autologous fat graft is utilized in numerous applications in plastic surgery; however, its use relative to the nasal region remains uncommon. Adipose tissue, by virtue of its volumetric qualities and its action on skin trophicity, can be considered to be a gold standard implant. From 2006 until 2012, we have treated patients by lipofilling in order to correct sequelae of rhinoplasty. The mean quantity of adipose tissue injected was 2.1cm(3) depending on the importance of the deformity and the area of injection: irregularity of the nasal dorsum, visible lateral osteotomies, saddle nose. Following the course of our practice, we conceived micro-cannulas that allow a much greater accuracy in the placement of the graft and enable to perform interventions under local anesthesia. These non-traumatic micro-cannulas do not cause post-operative ecchymosis and swelling which shorten the recovery time for the patient. On patients who have undergone multiple operations, lipofilling can be a simple and reliable alternative to correct imperfections that may take place after a rhinoplasty.

  6. Coaxial electrospinning multicomponent functional controlled-release vascular graft: Optimization of graft properties.

    PubMed

    Yin, Anlin; Luo, Rifang; Li, Jiukai; Mo, Xiumei; Wang, Yunbing; Zhang, Xingdong

    2017-04-01

    Small diameter vascular grafts possessing desirable biocompatibility and suitable mechanical properties have become an urgent clinic demand. Herein, heparin loaded fibrous grafts of collagen/chitosan/poly(l-lactic acid-co-ε-caprolactone) (PLCL) were successfully fabricated via coaxial electrospinning. By controlling the concentration of heparin and the ratio of collagen/chitosan/PLCL, most grafts had the heparin encapsulation efficiency higher than 70%, and the heparin presented sustained release for more than 45 days. Particularly, such multicomponent grafts had relative low initial burst release, and after heparin releasing for 3 weeks, the grafts still showed good anti-platelet adhesion ability. In addition, along with the excellent cell biocompatibility, the fabricated grafts possessed suitable mechanical properties including good tensile strength, suture retention strength, burst pressure and compliance which could well match the native blood vessels. Thus, the optimized graft properties could be properly addressed for vascular tissue application via coaxial electrospinning.

  7. Polyethylene oxide hydration in grafted layers

    NASA Astrophysics Data System (ADS)

    Dormidontova, Elena; Wang, Zilu

    Hydration of water soluble polymers is one of the key-factors defining their conformation and properties, similar to biopolymers. Polyethylene oxide (PEO) is one of the most important biomedical-applications polymers and is known for its reverse temperature solubility due to hydrogen bonding with water. As in many practical applications PEO chains are grafted to surfaces, e.g. of nanoparticles or planar surfaces, it is important to understand PEO hydration in such grafted layers. Using atomistic molecular dynamic simulations we investigate the details of molecular conformation and hydration of PEO end-grafted to gold surfaces. We analyze polymer and water density distribution as a function of distance from the surface for different grafting densities. Based on a detailed analysis of hydrogen bonding between polymer and water in grafted PEO layers, we will discuss the extent of PEO hydration and its implication for polymer conformation, mobility and layer properties. This research is supported by NSF (DMR-1410928).

  8. Human acellular dermal matrix grafts for rhinoplasty.

    PubMed

    Sherris, David A; Oriel, Brad S

    2011-09-01

    Rhinoplasty often relies on graft material for structural support in the form of cartilage, bone grafts, or fascia. In addition, pliable grafts are often helpful for contouring and can function as a barrier. Unfortunately, grafts carry the disadvantage of requiring an additional donor site, with associated complications. Human acellular dermal matrix (ADM) biological implants offer an exciting alternative for structural support and nonstructural implantation in rhinoplasty procedures. To examine the efficacy of ADM placement in rhinoplasty and septoplasty, the authors report the results from a series of 51 patients. In this series, there were no cases of infection, skin discoloration, seroma formation, septal perforation, significant resorption, extrusion, or other complications related to ADM placement. Therefore, the authors believe that ADM offers a safe and effective alternative to traditional grafting methods for functional and aesthetic rhinoplasty.

  9. Operative strategies in aortic graft infections: is complete graft excision always necessary?

    PubMed

    Hart, Joseph P; Eginton, Mark T; Brown, Kellie R; Seabrook, Gary R; Lewis, Brian D; Edmiston, Charles E; Towne, Jonathan B; Cambria, Robert A

    2005-03-01

    The classic approach to aortic graft infections involves complete excision of the graft material with remote reconstruction of the distal circulation. Certain patients may not be well suited for this approach for physiologic or anatomic reasons. This study was undertaken to determine the outcome of partial graft excision in selected patients with aortic graft infection who were not felt to be candidates for complete graft excision. Retrospective analysis of 30 consecutive patients treated with infected grafts arising from the aorta over the past 10 years was performed. Mean interval between graft placement and infection was 5.5 years. Complete graft excision with bypass via clean tissue planes was achieved in 15 patients (group A), and partial or complete graft salvage or in situ graft replacement was performed at the discretion of the surgeon in 15 patients (group B). Perioperative mortality occurred in eight subjects (27%), including six in group A (40%) and two in group B (13%; p = NS). Six patients (20%) developed recurrent infection following graft excision, two (13%) in group A and four (27%) in group B (p = NS). Microorganisms were recovered from 24 of 30 (80%) graft cultures: 13 (43%) were gram positive, 4 (13%) were gram negative, and both gram-positive and gram-negative organisms were recovered from 7 (23%). Identification of culture isolates did not influence either perioperative mortality or the development of recurrent infection. Long-term survival was no different between the groups. We conclude that in certain high-risk patients who may not tolerate complete graft excision, local resection of infected graft segments may be preferable and leads to similar short- and long-term outcome.

  10. Prognostic factors for corneal graft recovery after severe corneal graft rejection following penetrating keratoplasty

    PubMed Central

    2013-01-01

    Background To investigate the outcome and prognostic factors for corneal graft recovery after severe corneal graft rejection following penetrating keratoplasty (PKP) treated with topical and systemic steroids. Methods Fifty-eight eyes in 58 patients with severe corneal graft rejection following PKP were treated with topical and systemic steroids. Factors affecting the reversibility and maintenance of graft transparency were analyzed. Results Graft transparency was restored in 37 of 58 eyes (63.8%). Clarity of the graft was maintained in 25 of 37 eyes after transparency was restored, while corneal decompensation developed at a mean of 6.0 ± 4.3 months in the remainder. The interval between rejection and treatment with systemic steroids was shorter in cases that recovered graft transparency (OR, 0.88, 95% CI. 0.80–0.97, P = 0.0093). Corneal decompensation after the recovery of corneal transparency tend to occur in cases of regraft (OR, 0.09, 95% CI. 0.01–0.54, P = 0.0091). Conclusions Severe corneal graft rejection after PKP was reversible in approximately two-thirds of the cases, with graft transparency being maintained in two-thirds of them when treated with both topical and systemic steroids. Early treatment confers a benefit in terms of the recovery of graft transparency. PMID:23432898

  11. Evaluation of synthetic vascular grafts in a mouse carotid grafting model

    PubMed Central

    Tan, Richard P.; Michael, Praveesuda L.; Lee, Bob S. L.; Vanags, Laura Z.; Ng, Martin K. C.; Bursill, Christina A.; Wise, Steven G.

    2017-01-01

    Current animal models for the evaluation of synthetic grafts are lacking many of the molecular tools and transgenic studies available to other branches of biology. A mouse model of vascular grafting would allow for the study of molecular mechanisms of graft failure, including in the context of clinically relevant disease states. In this study, we comprehensively characterise a sutureless grafting model which facilitates the evaluation of synthetic grafts in the mouse carotid artery. Using conduits electrospun from polycaprolactone (PCL) we show the gradual development of a significant neointima within 28 days, found to be greatest at the anastomoses. Histological analysis showed temporal increases in smooth muscle cell and collagen content within the neointima, demonstrating its maturation. Endothelialisation of the PCL grafts, assessed by scanning electron microscopy (SEM) analysis and CD31 staining, was near complete within 28 days, together replicating two critical aspects of graft performance. To further demonstrate the potential of this mouse model, we used longitudinal non-invasive tracking of bone-marrow mononuclear cells from a transgenic mouse strain with a dual reporter construct encoding both luciferase and green fluorescent protein (GFP). This enabled characterisation of mononuclear cell homing and engraftment to PCL using bioluminescence imaging and histological staining over time (7, 14 and 28 days). We observed peak luminescence at 7 days post-graft implantation that persisted until sacrifice at 28 days. Collectively, we have established and characterised a high-throughput model of grafting that allows for the evaluation of key clinical drivers of graft performance. PMID:28355300

  12. Graft irradiation abrogates graft-versus-host disease in combined pancreas-spleen transplantation

    SciTech Connect

    Schulak, J.A.; Sharp, W.J.

    1986-04-01

    A model of combined pancreas-spleen transplantation (PST) was studied in LBN F1 recipients of Lewis grafts in order to evaluate the efficacy of pretransplant graft irradiation in preventing lethal graft-versus-host disease (GVHD). Recipients of unmodified PST uniformly developed severe GVHD and died (MST = 16.7 +/- 3.8 days). Whole body donor irradiation with either 500 or 250 rad prevented lethal GVHD. Similarly, ex vivo graft irradiation with either 1000 or 500 rad also resulted in normal weight gain, graft function, and host survival for the 6-week study period. Conversely, delay of graft irradiation until 3 days after transplantation failed to prevent this complication (MST = 15.8 +/- 3.7 days). Recipients of irradiated grafts displayed glucose tolerance tests that were identical to those in the control group indicating that the doses of radiation employed in these experiments were not deleterious to islet function. Irradiated spleen grafts appeared histologically normal at 6 weeks after transplantation. Cells derived from these grafts failed to stimulate lymph node enlargement in a popliteal lymph node assay for GVHD, suggesting that these spleens may have become repopulated with host cells. These experiments confirm that PST has the potential to cause lethal GVHD and suggest that pretransplant graft irradiation may be used to prevent its occurrence.

  13. Adaptive significance of root grafting in trees

    SciTech Connect

    Loehle, C.; Jones, R.

    1988-12-31

    Root grafting has long been observed in forest trees but the adaptive significance of this trait has not been fully explained. Various authors have proposed that root grafting between trees contributes to mechanical support by linking adjacent root systems. Keeley proposes that this trait would be of greatest advantage in swamps where soils provide poor mechanical support. He provides as evidence a greenhouse study of Nyssa sylvatica Marsh in which seedlings of swamp provenance formed between-individual root grafts more frequently than upland provenance seedlings. In agreement with this within-species study, Keeley observed that arid zone species rarely exhibit grafts. Keeley also demonstrated that vines graft less commonly than trees, and herbs never do. Since the need for mechanical support coincides with this trend, these data seem to support his model. In this paper, the authors explore the mechanisms and ecological significance of root grafting, leading to predictions of root grafting incidence. Some observations support and some contradict the mechanical support hypothesis.

  14. Grafted dopamine neurons: Morphology, neurochemistry, and electrophysiology.

    PubMed

    Strömberg, Ingrid; Bickford, Paula; Gerhardt, Greg A

    2010-02-09

    Grafting of dopamine-rich tissue to counteract the symptoms in Parkinson's disease became a promising tool for future treatment. This article discusses how to improve the functional outcome with respect to graft outgrowth and functions of dopamine release and electrophysiological responses to graft implantation in the host brain striatal target. It has been documented that a subpopulation of the dopamine neurons innervates the host brain in a target-specific manner, while some of the grafted dopamine neurons never project to the host striatum. Neurochemical studies have demonstrated that the graft-induced outgrowth synthesize, store, metabolize and release dopamine and possibly other neurotransmitters such as 5-HT. Furthermore, the released dopamine affects the dopamine-depleted brain in areas that are larger than the graft-derived nerve fibers reach. While stem cells will most likely be the future source of cells to be used in grafting, it is important to find the guiding cues for how to reinnervate the dopamine-depleted striatum in a proper way with respect to the dopamine subpopulations of A9 and A10 to efficiently treat the motor abnormalities seen in Parkinson's disease.

  15. Polypeptide Grafted Hyaluronan: Synthesis and Characterization

    PubMed Central

    Wang, Xiaojun; Messman, Jamie; Mays, Jimmy W.; Baskaran, Durairaj

    2010-01-01

    Poly(L-leucine) grafted hyaluronan (HA-g-PLeu) has been synthesized via a Michael addition reaction between primary amine terminated poly(L-leucine) and acrylate functionalized HA (TBAHA-acrylate). The precursor hyaluronan was first functionalized with acrylate groups by reaction with acryloyl chloride in the presence of triethylamine in N,N-dimethylformamide. 1H NMR analysis of the resulting product indicated that an increase in the concentration of acryloylchoride with respect to hydroxyl groups on HA has only a moderate effect on functionalization efficiency, f. A precise control of stoichiometry was not achieved, which could be attributed to partial solubility of intermolecular aggregates and the hygroscopic nature of HA. Michael addition at high [PLeu-NH2]/[acrylate]TBAHA ratios gave a molar grafting ratio of only 0.20 with respect to the repeat unit of HA, indicating grafting limitation due to insolubility of the grafted HA-g-PLeu. Soluble HA-g-PLeu graft copolymers were obtained for low grafting ratios (< 0.039) with < 8.6 % by mass of PLeu and were characterized thoroughly using light scattering, 1H NMR, FT-IR and AFM techniques. Light scattering experiments showed a strong hydrophobic interaction between PLeu chains, resulting in aggregates with segregated non-grafted HA segments. This yields local networks of aggregates as demonstrated by atomic force microscopy. Circular dichroism spectroscopy showed a β-sheet conformation for aggregates of poly(L-leucine). PMID:20690642

  16. A Reappraisal of Saphenous Vein Grafting

    PubMed Central

    Yuan, Shi-Min; Jing, Hua

    2011-01-01

    Autologous saphenous vein grafting has been broadly used as a bypass conduit, interposition graft, and patch graft in a variety of operations in cardiac, thoracic, neurovascular, general vascular, vascular access, and urology surgeries, since they are superior to prosthetic veins. Modified saphenous vein grafts (SVG), including spiral and cylindrical grafts, and vein cuffs or patches, are employed in vascular revascularization to satisfy the large size of the receipt vessels or to obtain a better patency. A loop SVG helps flap survival in a muscle flap transfer in plastic and reconstructive surgery. For dialysis or transfusion purposes, a straight or loop arteriovenous fistula created in the forearm or the thigh with an SVG has acceptable patency. The saphenous vein has even been used as a stent cover to minimize the potential complications of standard angioplasty technique. However, the use of saphenous vein grafting is now largely diminished in treating cerebrovascular disorders, superior vena cava syndrome, and visceral revascularization due to the introduction of angioplasty and stenting techniques. The SVG remains the preferable biomaterial in coronary artery bypass, coronary ostioplasty, free flap transfer, and surgical treatment of Peyronie disease. Implications associated with saphenous vein grafting in vascular access surgery for the purpose of dialysis and chemotherapy are considerable. Vascular cuffs and patches have been developed as an important and effective means of enhancing the patency rates of the grafts by linking the synthetic material to the receipt vessel. In addition, saphenous veins can be a cell source for tissue engineering. We review the versatile roles that saphenous vein grafting has played as well as its current status in therapy. PMID:21245602

  17. Flow characteristics in narrowed coronary bypass graft

    NASA Astrophysics Data System (ADS)

    Bernad, S. I.; Bosioc, A.; Bernad, E. S.; Petre, I.; Totorean, A. F.

    2016-06-01

    Tortuous saphenous vein graft (SVG) hemodynamics was investigated using computational fluid dynamics (CFD) techniques. Computed tomography (CT) technology is used for non-invasive bypass graft assessment 7 days after surgery. CT investigation shown two regions with severe shape remodelling first is an elbow type contortion and second is a severe curvature with tortuous area reduction. In conclusion, the helical flow induced by vessel torsion may stabilize the blood flow in the distal part of the SVG, reducing the flow disturbance and suppressing the flow separation, but in the distal end of the graft, promote the inflammatory processes in the vessels.

  18. Feasibility of the Use of RapiGraft and Skin Grafting in Reconstructive Surgery

    PubMed Central

    Cho, In Gook; Kwon, Joon Hyun; Lee, Jeong Woo; Choi, Kang Young; Chung, Ho Yun; Cho, Byung Chae

    2016-01-01

    Background Skin grafting is a relatively simple and thus widely used procedure. However, the elastic and structural quality of grafted skin is poor. Recently, various dermal substitutes have been developed to overcome this disadvantage of split-thickness skin grafts. The present study aims to determine the feasibility of RapiGraft as a new dermal substitute. Methods This prospective study included 20 patients with partial- or full-thickness skin defects; the patients were enrolled between January 2013 and March 2014. After skin defect debridement, the wound was divided into two parts by an imaginary line. Split-thickness skin grafting alone was performed on one side (group A), and RapiGraft and split-thickness skin grafting were used on the other side (group B). All patients were evaluated using photographs and self-questionnaires. The Manchester scar scale (MSS), a chromameter, and a durometer were used for the scar evaluation. The average follow-up period was 6 months. Results The skin graft take rates were 93% in group A and 89% in group B, a non-significant difference (P=0.082). Statistically, group B had significantly lower MSS, vascularity, and pigmentation results than group A (P<0.05 for all). However, the groups did not differ significantly in pliability (P=0.155). Conclusions The present study indicates that a simultaneous application of RapiGraft and a split-thickness skin graft is safe and yields improved results. Therefore, we conclude that the use of RapiGraft along with skin grafting will be beneficial for patients requiring reconstructive surgery. PMID:27689048

  19. Self-monitoring bypass grafts enable early intervention

    NASA Astrophysics Data System (ADS)

    Neville, Richard F.; Gupta, Samit K.; Kuraguntla, David J.

    2016-09-01

    Prosthetic grafts used for lower extremity revascularization and dialysis access fail due to hyperplastic stenosis and thrombosis. Graft surveillance is advocated to monitor function, however, graft failure can occur between episodic examinations. An innovative self-monitoring graft system allows automated surveillance with assessment of graft function using a cloud-based algorithm. We performed proof of concept experiments with in vitro and in vivo models to assess the feasibility such a real-time graft surveillance system. Initial in-vitro and in-vivo experiments demonstrate the ability for a self-monitoring graft system to remotely monitor hemodynamic parameters reflecting graft function using wireless data transmission. This automated system shows promise to deliver real-time data that can be analyzed by cloud-based algorithms alerting the clinician of a change in graft function or development of stenosis for further diagnostic study or intervention prior to graft failure.

  20. The tripod graft: nasal tip cartilage reconstruction during revision rhinoplasty.

    PubMed

    Pedroza, Fernando; Pedroza, Luis Fernando; Achiques, Maria Teresa; Felipe, Edgar; Becerra, Felix

    2014-01-01

    IMPORTANCE Nasal tip revision remains one of the most challenging surgical procedures for facial plastic surgeons to perform. OBJECTIVE To describe preoperative and postoperative findings related to nasal tip functional and aesthetic aspects following revision rhinoplasty using the "tripod" technique. DESIGN, SETTING, AND PARTICIPANTS A retrospective descriptive study was performed in patients who underwent revision rhinoplasty between 2007 and 2012 at a clinic in Bogota, Colombia. A preoperative diagnosis of nasal tip deformity was made on the basis of photographic records and compared with postoperative nasal tip findings in patients who required the tripod technique. Photographs were evaluated before and after surgery every month for the first 3 months, and after 6, 9, and 12 months postoperatively. MAIN OUTCOMES AND MEASURES Nasal projection, tip rotation, columellar and alar retraction, alar pinch, lack of tip definition, and nasal tip asymmetry. RESULTS Sixty-four of the 69 patients who received revision rhinoplasty using the tripod technique during the study period were enrolled in the study. The tripod technique improved all of the following aesthetic and functional parameters (all P < .001). Nasal tip definition improved in 43 of 49 patients (88%). After surgery, projection was normal in 28 of 40 patients (70%) who had underprojection and overprojection preoperatively, and rotation improved in 29 of 38 patients (76%) who had overrotation or underrotation preoperatively. Columellar retraction improved after surgery in 18 of 24 patients (75%). The alar region improved in 41 of 52 patients (79%) who had alar retraction and/or pinch preoperatively, and inspiratory collapse improved in 49 of 50 patients (98%). CONCLUSIONS AND RELEVANCE The tripod technique is an efficient surgical alternative for nasal tip reconstruction during revision rhinoplasty. This technique allows the destroyed cartilaginous framework to be recreated and returns original nasal tip

  1. Prosthetic Arteriovenous Graft Contact Dermatitis Masquerading as an Arteriovenous Graft Infection in a Hemodialysis Patient

    PubMed Central

    Ramagiri-Vinod, Nagadarshini; Tahir, Hassan; Narukonda, Sandhya; Joshi, Medha

    2016-01-01

    Prosthetic arteriovenous (AV) graft is the second most common vascular access of choice in hemodialysis patients. Rare complications of such grafts are increasingly seen due to rising population of patients on hemodialysis. Infections and thrombosis are the most common complications. Though metallic implants are known to cause hypersensitivity skin reactions, prosthetic AV grafts are rarely known to cause such kind of reactions due to inert nature of materials used in their preparation. We present a case of 54-year-old male who developed contact dermatitis after AV graft creation which was mistreated initially as infection. PMID:27493977

  2. Anterior cervical discectomy: to graft or not to graft?

    PubMed

    Konduru, S; Findlay, G

    2009-02-01

    The debate regarding whether to perform an interbody fusion after anterior cervical discectomy (ACD) has been going on for the last 50 years. Several prospective randomized clinical trials have been performed to evaluate the clinical outcome following anterior cervical discectomy with and without interbody fusion. None of these studies show a significant difference between the two techniques in terms of relief of arm pain or neck pain. The operative time, in-hospital stay and time for return to work seem to be slightly longer following anterior cervical discectomy with interbody grafting (ACDF) compared to ACD alone. However a temporary increase in postoperative axial pain seems to be a common complication following ACD. There is also no difference in the clinical outcomes between ACD and ACDF with plating and ACDF with interbody spacers. However, if a fusion procedure is undertaken, the use of interbody spacers does have the advantage of avoiding donor site complications. There is also some evidence to suggest that plate fixation can lead to increased fusion rates. There is a significant risk of a degree of segmental kyphosis following ACD. These radiological features, however, do not correlate with the clinical outcome. Radiological and clinical studies fail to show a significant difference in recurrence of foraminal narrowing or the rates of reoperation following ACD or ACDF. The available body of evidence suggests that the addition of a fusion procedure following anterior cervical decompression may give improved radiological results but does not necessarily result in improved clinical outcomes.

  3. Infected aortoiliofemoral grafts: magnetic resonance imaging.

    PubMed

    Justich, E; Amparo, E G; Hricak, H; Higgins, C B

    1985-01-01

    Three patients with proved infected aortoiliofemoral grafts were examined by magnetic resonance (MR) imaging using a spin echo technique. MR clearly identified the perigraft abscess, the involvement of adjacent structures, and the longitudinal extent of the process in all patients. The MR findings were: Abscesses create a high signal intensity, somewhat less than fat. The perigraft abscess has a great contrast with the signal void of flowing blood in the graft. Inflammatory changes cause an inhomogeneous intermediate signal, slightly more intense than muscle. Both abscesses and edematous areas increase their signal intensity with long repetition rates and long echo delays. Areas of gas appear black. They cannot be distinguished from calcified plaques. Additional information is gained about the graft patency. Although the specificity has to be proved, MR imaging is sensitive in the detection of infected grafts and for defining the longitudinal extent of the perigraft abscess.

  4. Polyethylene glycol-grafted polystyrene particles.

    PubMed

    Meng, Fenghua; Engbers, Gerard H M; Feijen, Jan

    2004-07-01

    Densely pegylated particles that can serve as a model system for artificial cells were prepared by covalently grafting amino polyethylene glycol (PEG, molecular weight 3400 or 5000) onto carboxyl polystyrene particles (PS-COOH) using carbodiimide chemistry. PEG-modified particles (PS-PEG) were characterized by determination of the PEG surface concentration, zeta-potential, size, and morphology. Under optimized grafting conditions, a dense "brush-like" PEG layer was formed. A PEG surface concentration of approximately 60 pmol/cm2, corresponding with an average distance between grafted PEG chains of approximately 17 A can be realized. It was shown that grafting of PEG onto PS-COOH reduced the adsorption of proteins from human plasma (85 vol %) in phosphate-buffered saline up to 90%.

  5. Fluorescent Bioactive Corrole Grafted-Chitosan Films.

    PubMed

    Barata, Joana F B; Pinto, Ricardo J B; Vaz Serra, Vanda I R C; Silvestre, Armando J D; Trindade, Tito; Neves, Maria Graça P M S; Cavaleiro, José A S; Daina, Sara; Sadocco, Patrizia; Freire, Carmen S R

    2016-04-11

    Transparent corrole grafted-chitosan films were prepared by chemical modification of chitosan with a corrole macrocycle, namely, 5,10,15-tris(pentafluorophenyl)corrole (TPFC), followed by solvent casting. The obtained films were characterized in terms of absorption spectra (UV-vis), FLIM (fluorescence lifetime imaging microscopy), structure (FTIR, XPS), thermal stability (TGA), thermomechanical properties (DMA), and antibacterial activity. The results showed that the chemical grafting of chitosan with corrole units did not affect its film-forming ability and that the grafting yield increased with the reaction time. The obtained transparent films presented fluorescence which increases with the amount of grafted corrole units. Additionally, all films showed bacteriostatic effect against S. aureus, as well as good thermomechanical properties and thermal stability. Considering these features, promising applications may be envisaged for these corrole-chitosan films, such as biosensors, bioimaging agents, and bioactive optical devices.

  6. Free Fat Graft for Congenital Hand Differences

    PubMed Central

    Ishigaki, Daisuke; Satake, Hiroshi; Iba, Kousuke

    2012-01-01

    Background Free fat graft has been used for the treatment of congenital hand differences. However, there have been a few reports about the outcome of that treatment. In this study, the outcome of free fat grafts for congenital hand and foot differences was investigated. Methods Fourteen bones with longitudinal epiphyseal bracket, 3 wrists with Madelung deformity, and 5 cases of osseous syndactyly were treated with free fat graft with osteotomy, physiolysis, or separation of osseous syndactyly. Of the fourteen bones with longitudinal epiphyseal bracket, 9 were treated with open wedge osteotomy with free fat graft and 5 with physiolysis and free fat graft. The Madelung deformity was treated with physiolysis with free fat graft. For osseous syndactyly, syndactyly release with free fat graft was performed five times on four hands. Results In the fourteen cases with longitudinal epiphyseal bracket, lateral deviation improved in all except two cases after surgery. The average lateral deviation angle changed from 32.5 degrees before surgery to 15.2 degrees after surgery. The average improvement of the lateral deviation angle was 12.2 degrees in the osteotomy group and 20.6 degrees in the physiolysis group. The mean ratio of improvement of the lateral deviation angle to the lateral deviation angle before surgery was 39.4% in the osteotomy group and 51.2% in the physiolysis group. The Madelung deformity improved after surgery in two cases but there was no improvement in one case. For these conditions, the results were not good enough when surgery was done after age 13 or at age four for severely hypoplastic brachymesophalangy. Of the 5 cases of osseous syndactyly, reunion of the separated bones occurred in one case. The grafted free fat should be deep enough to cover the osteotomy site of the bones to prevent reunion of the separated bones. Conclusions Physiolysis and free fat graft performed during the growth period can correct the deviation due to longitudinal epiphyseal

  7. Non-Anastomotic Rupture of a Woven Dacron Graft in the Descending Thoracic Aorta Treated with Endovascular Stent Grafting.

    PubMed

    Lee, Youngok; Kim, Gun-Jik; Kim, Young Eun; Hong, Seong Wook; Lee, Jong Tae

    2016-12-01

    The intrinsic structural failure of a Dacron graft resulting from the loss of structural integrity of the graft fabric can cause late graft complications. Late non-anastomotic rupture has traditionally been treated surgically via open thoracotomy. We report a case of the successful use of thoracic endovascular repair to treat a Dacron graft rupture in the descending aorta. The rupture occurred 20 years after the graft had been placed. Two stent grafts were placed at the proximal portion of the surgical graft, covering almost its entire length.

  8. DNA nanosensor surface grafting and salt dependence

    NASA Astrophysics Data System (ADS)

    Carvalho, B. G.; Fagundes, J.; Martin, A. A.; Raniero, L.; Favero, P. P.

    2013-02-01

    In this paper we investigated the Paracoccidoides brasiliensis fungus nanosensor by simulations of simple strand DNA grafting on gold nanoparticle. In order to improve the knowledge of nanoparticle environment, the addiction of salt solution was studied at the models proposed by us. Nanoparticle and DNA are represented by economic models validated by us in this paper. In addition, the DNA grafting and salt influences are evaluated by adsorption and bond energies calculations. This theoretical evaluation gives support to experimental diagnostics techniques of diseases.

  9. Biomaterials in Maxillofacial Surgery: Membranes and Grafts

    PubMed Central

    Rodella, Luigi F.; Favero, Gaia; Labanca, Mauro

    2011-01-01

    Today, significant differences in the use of biomaterials (membranes and grafts) of animal or synthetic origin have yet to be reported. Nevertheless, some evidences suggest that synthetic materials have a lower risk of disease transmission. This review aims to assess the available informations on regenerative bone technique using reasorbable membranes and bone grafts. In particular, biocompatibility, immunological response, tissue reaction, reabsorption time and histological features of materials daily use in dentistry and in maxillofacial surgery were emphasized. PMID:23675225

  10. Biomaterials in maxillofacial surgery: membranes and grafts.

    PubMed

    Rodella, Luigi F; Favero, Gaia; Labanca, Mauro

    2011-06-01

    Today, significant differences in the use of biomaterials (membranes and grafts) of animal or synthetic origin have yet to be reported. Nevertheless, some evidences suggest that synthetic materials have a lower risk of disease transmission. This review aims to assess the available informations on regenerative bone technique using reasorbable membranes and bone grafts. In particular, biocompatibility, immunological response, tissue reaction, reabsorption time and histological features of materials daily use in dentistry and in maxillofacial surgery were emphasized.

  11. Oversized vein grafts develop advanced atherosclerosis in hypercholesterolemic minipigs

    PubMed Central

    2012-01-01

    Background Accelerated atherosclerosis is the main cause of late aortocoronary vein graft failure. We aimed to develop a large animal model for the study of pathogenesis and treatment of vein graft atherosclerosis. Methods An autologous reversed jugular vein graft was inserted end-to-end into the transected common carotid artery of ten hypercholesteroemic minipigs. The vein grafts were investigated 12-14 weeks later with ultrasound and angiograpy in vivo and microscopy post mortem. Results One minipig died during follow up (patent vein graft at autopsy), and one vein graft thrombosed early. In the remaining eight patent vein grafts, the mean (standard deviation) intima-media thickness was 712 μm (276 μm) versus 204 μm (74 μm) in the contralateral control internal jugular veins (P < .01). Advanced atherosclerotic plaques were found in three of four oversized vein grafts (diameter of graft > diameter of artery). No plaques were found in four non-oversized vein grafts (P < .05). Conclusions Our model of jugular vein graft in the common carotid artery of hypercholesterolemic minipigs displayed the components of human vein graft disease, i.e. thrombosis, intimal hyperplasia, and atherosclerosis. Advanced atherosclerosis, the main cause of late failure of human aortocoronary vein grafts was only seen in oversized grafts. This finding suggests that oversized vein grafts may have detrimental effects on patient outcome. PMID:22463679

  12. Polypeptide Grafted Hyaluronan: Synthesis and Characterization

    SciTech Connect

    Wang, Xiaojun; Messman, Jamie M; Mays, Jimmy; Baskaran, Durairaj

    2010-01-01

    Poly(L-leucine) grafted hyaluronan (HA-g-PLeu) has been synthesized via a Michael addition reaction between primary amine terminated poly(L-leucine) and acrylate-functionalized HA (TBAHA-acrylate). The precursor hyaluronan was first functionalized with acrylate groups by reaction with acryloyl chloride in the presence of triethylamine in N,N-dimethylformamide. 1H NMR analysis of the resulting product indicated that an increase in the concentration of acryloylchoride with respect to hydroxyl groups on HA has only a moderate effect on functionalization efficiency, f. A precise control of stoichiometry was not achieved, which could be attributed to partial solubility of intermolecular aggregates and the hygroscopic nature of HA. Michael addition at high [PLeu- NH2]/[acrylate]TBAHA ratios gave a molar grafting ratio of only 0.20 with respect to the repeat unit of HA, indicating grafting limitation due to insolubility of the grafted HA-g-PLeu. Soluble HA-g-PLeu graft copolymers were obtained for low grafting ratios (<0.039) with <8.6% by mass of PLeu and were characterized thoroughly using light scattering, 1H NMR, FT-IR, and AFM techniques. Light scattering experiments showed a strong hydrophobic interaction between PLeu chains, resulting in aggregates with segregated nongrafted HA segments. This yields local networks of aggregates, as demonstrated by atomic force microscopy. Circular dichroism spectroscopy showed a -sheet conformation for aggregates of poly(L-leucine).

  13. Photoacoustic detection of neovascularities in skin graft

    NASA Astrophysics Data System (ADS)

    Yamazaki, Mutsuo; Sato, Shunichi; Saitoh, Daizo; Ishihara, Miya; Okada, Yoshiaki; Ashida, Hiroshi; Obara, Minoru

    2005-04-01

    We previously proposed a new method for monitoring adhesion of skin graft by measuring photoacoustic (PA) signal originated from the neovascularities. In this study, immunohistochemical staining (IHC) with CD31 antibody was performed for grafted skin tissue to observe neovascularity, and the results were compared with PA signals. We also used a laser Doppler imaging (LDI) to observe blood flow in the grafted skin, and sensitivity of PA measurement and that of LDI were compared. In rat autograft models, PA signals were measured for the grafted skin at postgrafting times of 0-48 h. At 6 h postgrafting, PA signal was observed in the skin depth region of 500-600 mm, while the results of IHC showed that angiogenesis occurred at the depth of about 600 mm. Depths at which PA signal and angiogenesis were observed decreased with postgrafting time. These indicate that the PA signal observed at 6 h postgrafting originated from the neovascularities in the skin graft. Results of LDI showed no blood-originated signal before 48 h postgrafting. These findings suggest that PA measurement is effective in monitoring the adhesion of skin graft in early stage after transplantation.

  14. Neointimal hyperplasia associated with synthetic hemodialysis grafts

    PubMed Central

    Li, Li; Terry, Christi M.; Shiu, Yan-Ting E.; Cheung, Alfred K.

    2008-01-01

    Stenosis is a major cause of failure of hemodialysis vascular grafts and is primarily caused by neointimal hyperplasia (NH) at the anastomoses. The objective of this article is to provide a scientific review of the biology underlying this disorder and a critical review of the state-of-the-art investigational preventive strategies in order to stimulate further research in this exciting area. The histology of the NH shows myofibroblasts (that are probably derived from adventitial fibroblasts), extracellular matrices, pro-inflammatory cells including foreign-body giant cells, a variety of growth factors and cytokines, and neovasculature. The contributing factors of the pathogenesis of NH include surgical trauma, bioincompatibility of the synthetic graft, and the various mechanical stresses that result from luminal hypertension and compliance mismatch between the vessel wall and graft. These mechanical stimuli are focal in nature and may have a significant influence on the preferential localization of the NH. Novel mechanical graft designs and local drug delivery strategies show promise in animal models in preventing graft NH development. Successful prevention of graft stenosis would provide a superior alternative to the native fistula as hemodialysis vascular access. PMID:18668026

  15. Bone-Grafting in Polyostotic Fibrous Dysplasia

    PubMed Central

    Leet, Arabella I.; Boyce, Alison M.; Ibrahim, Khalda A.; Wientroub, Shlomo; Kushner, Harvey; Collins, Michael T.

    2016-01-01

    Background: Polyostotic fibrous dysplasia is a skeletal disease that results from somatic activating mutations in the gene GNAS in skeletal stem cells, leading to proliferation of immature osteogenic cells with replacement of normal marrow and bone with fibro-osseous tissue. Lesions may cause bone deformity or fracture. In the surgical care of polyostotic fibrous dysplasia, the role of grafting and the optimal grafting material are not clear. The purpose of this study was to evaluate the long-term survival of bone-grafting procedures in subjects with polyostotic fibrous dysplasia over time. Methods: The operative reports and radiographs of a cohort of subjects with polyostotic fibrous dysplasia followed in a natural history study were reviewed. Twenty-three subjects (mean age at the time of enrollment, thirteen years [range, two to forty years]) with fifty-two bone-grafting procedures had a mean follow-up time of 19.6 years (range, twenty-nine months to forty-seven years). Kaplan-Meier life table estimates, Cox proportional hazard models, and t tests comparing means were performed to assess various aspects of graft survival. Results: Kaplan-Meier curves showed a 50% estimate of survival of 14.5 years. Cox proportional hazards models showed no advantage comparing allograft with autograft or structural with nonstructural graft materials. The mean age of the patients was significantly greater (p < 0.001) in the subgroup of subjects in whom grafts were maintained over time (20.9 years) compared with the subgroup of patients whose grafts were resorbed over time (9.8 years). Conclusions: Bone-grafting, including both allograft and autograft, is of limited value in ablating the lesions of fibrous dysplasia. The expectations of patients and surgeons should include the high probability of graft resorption over time with return of bone characteristics of fibrous dysplasia, particularly in younger patients. This suggests the maintenance of normal bone mechanics with implant

  16. ACL Revision in Synthetic ACL graft failure

    PubMed Central

    Etcheto, H. Rivarola; Zordán, J.; Escobar, G.; Collazo, C.; Palanconi, M.; Autorino, C.; Salinas, E. Alvarez

    2017-01-01

    The development of synthetic grafts as an alternative to biological grafts for reconstruction of the anterior cruciate ligament dates from 1980. The interest is awakened due to the potential advantages of: The absence of morbidity associated with donor site, and early return to sport. However, this surgical technique has had multiple complications associated with graft: mechanical failures (synthetic graft failure, loss of fixation), synovial foreign body reaction, recurrent stroke, recurrent instability and ultimately, early osteoarthritis. Objectives: We describe the synthetic graft failure LCA, intraoperative findings and details of surgical technique. Methods: Patient 35 years old, with a history of ACL reconstruction four years of evolution in another health center, consultation with the Service knee arthroscopy for acute knee pain left knee during secondary sporting event to a rotation mechanism with fixed foot. On physical examination, presents and positive Lachman maneuver Pivot. Radiografia in a widening of the tibial tunnel is observed. NMR shows a discontinuity of fibers of synthetic graft. Results: First time arthroscopic revision where synthetic plastic LCA identifies with Disruption fiber pattern. Intraoperatively, hypertrophic chronic synovitis localized predominantly in intercóndilo is observed. debridement thereof is performed, and proceeds to the extraction of the synthetic ligament. Then he was made prior cruentado and revival of the edges of the tunnel, filling them with non-irradiated structural bone allograft. At four months as planned and after confirmation by studies incorporating bone graft was performed the second time with the new plastic ACL. It was planned like a primary graft surgery with autologous hamstring prepared in fourfold form, and fixation with modified transtibial technique Biotransfix system proximal and distal screw Biocomposite (arthrex®). A quadruple graft 9 mm was obtained, making good positioning of tunnels and stable

  17. Analysis of Fibular Single Graft and Fibular Double-barrel Graft for Mandibular Reconstruction

    PubMed Central

    Shimizu, Yusuke; Ihara, Jyun; Kishi, Kazuo

    2016-01-01

    Background: High-quality mandibular reconstruction using vascularized free fibular graft is necessary to provide an osseointegrated dental implant and fixed denture. An appropriate crown–implant ratio is needed, and a good match between bones is extremely important. There are no articles describing the analysis and evaluation of both the fibula and mandible in the same patients. Methods: Computed tomography images of both mandible and fibula of 80 patients were selected in a random manner. We measured bone height of the fibula and mandible at specified points and evaluated the difference of bone height between the fibula and mandible using fibular single or double-barrel grafts. Results: The percentage of patients who had a “good” result for a fibular single graft was only 13.8%. There was no significant difference in bone heights when analyzed by gender. Whether patients were dentulous or not had a large influence on the difference between fibular and mandibular bone heights. Most young patients, but only half of older patients, needed fibular double-barrel grafts. Overweight patients with a high body mass index more often needed fibular double-barrel grafts. Conclusions: For mandibular reconstruction using a fibular graft, preoperative analysis of the patient’s profile and proper use of a fibular single or double-barrel graft contribute to minimizing the difference between the height of the grafted fibula and native mandible and are keys to an ideal reconstruction with good cosmetics and function. PMID:27622091

  18. Treatment of Venous Aortorenal Bypass Graft Aneurysm Using a Stent-Graft

    SciTech Connect

    Novotny, Jiri Peregrin, Jan H.; Stribrna, Jarmila; Janousek, Radim

    2010-02-15

    We present the case of a 77-year-old male patient who had undergone a bilateral venous aortorenal bypass graft 30 years previously. Thirteen years previously, the patient was shown to have a decrease in renal function, with mild shrinking of both kidneys; additionally, a stenosis was found in the left proximal anastomosis. At the most recent follow-up visit (1 year previously), ultrasound revealed an aneurysm (42 mm in diameter) of the left renal bypass graft; the finding was confirmed by CT angiography. A significant ostial stenosis of the left renal bypass graft was also confirmed. It was decided to place a self-expandable stent-graft into the aneurysm while also attempting to dilate the stenosis. Proximal endoleak after stent-graft placement necessitated the implantation of another, balloon-expandable stent-graft into the bypass graft ostium. Postprocedural angiography and follow-up by CT angiography at 3 months confirmed good patency of the stent-grafts and complete thrombosis of the aneurysmal sac, with preserved kidney perfusion. Renal function remained unaltered, while the hypertension is better controlled.

  19. Grafting Seedless Watermelons, How and Why? Will Grafting Help With Disease Control?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, the practice of grafting seedless watermelons (triploids) onto rootstocks belonging to other Cucurbitaceae genera has gained importance in the United States. Grafting vegetable crops, especially cucurbit’s, is very common in Europe and Asia. In these regions, the practice of crop ...

  20. Physical properties of agave cellulose graft polymethyl methacrylate

    SciTech Connect

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan

    2013-11-27

    The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm{sup −1} which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

  1. Postoperative irradiation of fresh autogenic cancellous bone grafts

    SciTech Connect

    Schwartz, H.C.; Leake, D.L.; Kagan, A.R.; Snow, H.; Pizzoferrato, A.

    1986-01-01

    Discontinuity defects were created in the mandibles of dogs and then reconstructed immediately with fresh autogenic cancellous bone grafts and Dacron-urethane prostheses. The grafts were irradiated to a total dose of 5000 rads after waiting intervals of between 3 and 12 weeks. Nonirradiated grafts served as controls. The grafts were evaluated clinically, radiographically, and histologically. There was complete incorporation of all grafts, regardless of the interval between surgery and radiotherapy. There were no soft-tissue complications. The controls were distinguishable from the irradiated grafts only by the presence of hematopoietic bone marrow. Fibrofatty marrow was observed in the irradiated grafts. Theoretical support for this technique is found in the biology of cancellous bone grafting and the pathology of radiation injury. In view of the difficulties associated with mandibular bone grafting in preoperatively irradiated patients, a new method of reconstructing selected cancer patients who require both mandibular resection and radiotherapy is suggested.

  2. Physical properties of agave cellulose graft polymethyl methacrylate

    NASA Astrophysics Data System (ADS)

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan

    2013-11-01

    The grafting polymerization of methyl methacrylate and Agave cellulose was prepared and their structural analysis and morphology were investigated. The grafting reaction was carried out in an aqueous medium using ceric ammonium nitrate as an initiator. The structural analysis of the graft copolymers was carried out by Fourier transform infrared and X-ray diffraction. The graft copolymers were also characterized by field emission scanning electron microscopy (FESEM). An additional peak at 1732 cm-1 which was attributed to the C=O of ester stretching vibration of poly(methyl methacrylate), appeared in the spectrum of grafted Agave cellulose. A slight decrease of crystallinity index upon grafting was found from 0.74 to 0.68 for cellulose and grafted Agave cellulose, respectively. Another evidence of grafting showed in the FESEM observation, where the surface of the grafted cellulose was found to be roughed than the raw one.

  3. Reconstruction of Alar Nasal Cartilage Defects Using a Tissue Engineering Technique Based on a Combined Use of Autologous Chondrocyte Micrografts and Platelet-rich Plasma: Preliminary Clinical and Instrumental Evaluation

    PubMed Central

    Scioli, Maria G.; Bielli, Alessandra; Orlandi, Augusto; Cervelli, Valerio

    2016-01-01

    Background: Developing cartilage constructs with injectability, appropriate matrix composition, and persistent cartilaginous phenotype remains an enduring challenge in cartilage repair. The combined use of autologous chondrocyte micrografts and platelet-rich plasma (PRP) is an alternative that opens a new era in this field. Methods: At the Department of Plastic and Reconstructive Surgery, University of Rome Tor Vergata, Italy, 11 patients underwent nasal alar reconstruction with chondrocyte micrografts gently poured onto PRP in solid form. A computed tomographic scan control was performed after 12 months. Pearson’s Chi-square test was used to investigate difference in cartilage density between native and newly formed cartilages. Results: The constructs of chondrocyte micrografts–PRP that were subcutaneously injected resulted in a persistent cartilage tissue with appropriate morphology, adequate central nutritional perfusion without central necrosis or ossification, and further augmented nasal dorsum without obvious contraction and deformation. Conclusion: This report demonstrated that chondrocyte micrografts derived from nasal septum poured onto PRP in solid form are useful for cartilage regeneration in patients with external nasal valve collapse. PMID:27826462

  4. Repeat corneal graft failure due to graft-to-host herpetic infection

    PubMed Central

    2013-01-01

    Background Herein, we present the case of a young female patient with keratoconus, who was subjected twice to repeat keratoplasty, and each time, she experienced a corneal graft failure. Findings Under the suspicion of herpetic eye disease, we administered topical and systemic anti-herpetic treatment after the second repeat keratoplasty. The postoperative course was uneventful, and the corneal graft is clear, until recently. Immunohistochemistry and DNA-polymerase chain reaction were negative for herpes simplex virus-1 (HSV-1) in the host cornea, but they detected HSV-1 in both transplanted corneal grafts, thereby supporting our clinical hypothesis that graft-to-host HSV-1 infection elicited this chain reaction of complications in our patient. Conclusion This clinical report illustrates in a unique way the dramatic impact an unsuspected herpetic infection in the corneal graft in cases of keratoplasty may have and underscores the necessity of suspecting and adequately treating these distinct cases. PMID:23514192

  5. Adolescent External Iliac Artery Trauma: Recurrent Aneurysmal Dilatation of an Iliofemoral Saphenous Vein Graft Treated by Stent-Grafting

    SciTech Connect

    Lenton, James; Davies, John; Homer-Vanniasinkam, S.; McPherson, Simon

    2008-09-15

    An adolescent male sustained a severe penetrating injury to the external iliac artery. Emergency surgical revascularization was with a reversed long saphenous vein interposition graft. The primary graft and the subsequent revision graft both became aneurysmal. The second graft aneurysm was successfully excluded by endovascular stent-grafts with medium-term primary patency. A venous graft was used initially rather than a synthetic graft to reduce the risk of infection and the potential problems from future growth. Aneurysmal dilatation of venous grafts in children and adolescents is a rare but recognized complication. To the best of our knowledge, exclusion of these aneurysms with stent-grafts has not been previously reported in the adolescent population.

  6. Onlay Bone Grafts in Head and Neck Reconstruction

    PubMed Central

    Yazar, Sukru

    2010-01-01

    Bone grafts are used in a variety of clinical situations and can be divided into two categories: treatment of bone gaps (inlay bone grafting) and bone projection (onlay bone grafting). Cortical grafts are useful in situations requiring immediate mechanical strength. These grafts can survive with or without complete revascularization or resorption and are primarily used by plastic surgeons in the treatment of bone volume deficiency. Cancellous grafts, in contrast, have no mechanical strength and therefore require additional support to bridge bone defects. Thus, they are used primarily for the treatment of bone gaps and in general revascularize quickly, resorb completely, and stimulate significant new bone formation. PMID:22550447

  7. Aorto-coronary vein graft 'Y' anastomosis made easy.

    PubMed

    Jarvis, Martin Amadee

    2011-10-01

    Vein graft-to-vein graft anastomosis, creating a 'Y' graft, is a useful technique when there is a lack of good-quality autologous vein to perform individual aorto-coronary bypass grafts or when the ascending aorta is short or atheromatous, limiting the space for proximal graft anastomosis. Unlike artery-to-artery composite grafts, which are resistant to flow-limiting technique-based distortions, the accurate construction of vein-to-vein anastomoses is critical. A technique is described that facilitates accurate placement of the anastomosis that prevents kinking, twisting or displacement.

  8. Shear-induced metastable states of end-grafted polystyrene

    SciTech Connect

    Sasa, Leslie A.; Yearley, Eric J.; Jablin, Michael S.; Majewski, Jaroslaw; Hjelm, Rex P.; Gilbertson, Robert D.; Lavine, Adrienne S.

    2011-08-15

    The in situ molecular scale response of end-grafted polystyrene to shear against a deuterated polystyrene melt was investigated with neutron reflectometry. The derived grafted polystyrene density profiles showed that the grafted polystyrene was retained on the quartz wafer during the measurements. The profiles suggested that the end-grafted polystyrene response to shear results in a series of metastable states, rather than equilibrium states assumed in the current theory. Except for some possible extension and/or contraction of the grafted polystyrene with shear, there was no obvious correlation between the grafted polymer structure and the shear thinning behavior observed in these samples.

  9. Engineering anatomically shaped human bone grafts.

    PubMed

    Grayson, Warren L; Fröhlich, Mirjam; Yeager, Keith; Bhumiratana, Sarindr; Chan, M Ete; Cannizzaro, Christopher; Wan, Leo Q; Liu, X Sherry; Guo, X Edward; Vunjak-Novakovic, Gordana

    2010-02-23

    The ability to engineer anatomically correct pieces of viable and functional human bone would have tremendous potential for bone reconstructions after congenital defects, cancer resections, and trauma. We report that clinically sized, anatomically shaped, viable human bone grafts can be engineered by using human mesenchymal stem cells (hMSCs) and a "biomimetic" scaffold-bioreactor system. We selected the temporomandibular joint (TMJ) condylar bone as our tissue model, because of its clinical importance and the challenges associated with its complex shape. Anatomically shaped scaffolds were generated from fully decellularized trabecular bone by using digitized clinical images, seeded with hMSCs, and cultured with interstitial flow of culture medium. A bioreactor with a chamber in the exact shape of a human TMJ was designed for controllable perfusion throughout the engineered construct. By 5 weeks of cultivation, tissue growth was evidenced by the formation of confluent layers of lamellar bone (by scanning electron microscopy), markedly increased volume of mineralized matrix (by quantitative microcomputer tomography), and the formation of osteoids (histologically). Within bone grafts of this size and complexity cells were fully viable at a physiologic density, likely an important factor of graft function. Moreover, the density and architecture of bone matrix correlated with the intensity and pattern of the interstitial flow, as determined in experimental and modeling studies. This approach has potential to overcome a critical hurdle-in vitro cultivation of viable bone grafts of complex geometries-to provide patient-specific bone grafts for craniofacial and orthopedic reconstructions.

  10. LVAD Outflow Graft Angle and Thrombosis Risk.

    PubMed

    Aliseda, Alberto; Chivukula, Venkat Keshav; Mcgah, Patrick; Prisco, Anthony R; Beckman, Jennifer A; Garcia, Guilherme J M; Mokadam, Nahush A; Mahr, Claudius

    This study quantifies thrombogenic potential (TP) of a wide range of left ventricular assist device (LVAD) outflow graft anastomosis angles through state-of-the-art techniques: 3D imaged-based patient-specific models created via virtual surgery and unsteady computational fluid dynamics with Lagrangian particle tracking. This study aims at clarifying the influence of a single parameter (outflow graft angle) on the thrombogenesis associated with flow patterns in the aortic root after LVAD implantation. This is an important and poorly-understood aspect of LVAD therapy, because several studies have shown strong inter and intrapatient thrombogenic variability and current LVAD implantation strategies do not incorporate outflow graft angle optimization. Accurate platelet-level investigation, enabled by statistical treatment of outliers in Lagrangian particle tracking, demonstrates a strong influence of outflow graft anastomoses angle on thrombogenicity (platelet residence times and activation state characterized by shear stress accumulation) with significantly reduced TP for acutely-angled anastomosed outflow grafts. The methodology presented in this study provides a device-neutral platform for conducting comprehensive thrombogenicity evaluation of LVAD surgical configurations, empowering optimal patient-focused surgical strategies for long-term treatment and care for advanced heart failure patients.

  11. Polymer Grafted Nanoparticle-based Oil Dispersants

    NASA Astrophysics Data System (ADS)

    Kim, Daehak; Krishnamoorti, Ramanan

    2015-03-01

    Particle-based oil dispersants mainly composed of inorganic nanoparticles such as silica nanoparticles are considered as environmentally friendly oil dispersants due to their biocompatibility and relatively low toxicity. The oil-water interfacial tension is reduced when nanoparticles segregate to the oil-water interface and this segregation is improved by grafting interfacially active polymer brushes. In this study, surfactant-like amphiphilic block copolymers were grafted from silica nanoparticles using an atom transfer radical polymerization (ATRP) method in order to increase their interfacial activity. We have studied the interfacial activity of such hybrid nanoparticles using pendant drop interfacial tension measurements, and their structure using small angle X-ray scattering. Amphiphilic copolymer grafted nanoparticles significantly reduced oil-water interfacial tension compared to the interfacial tension reduction induced by homopolymer grafted nanoparticles or the corresponding free ungrafted copolymer. Moreover, hard and stable oil-water emulsions were formed by applying the block copolymer grafted nanoparticles due to the formation of interparticle network structures, which were observed by cryo-scanning electron microscopy (SEM) and small angle neutron scattering (SANS)

  12. Why Do Grafts Clot Despite Access Blood Flow Surveillance?

    SciTech Connect

    Arbabzadeh, Massoud; Mepani, Bhupendra; Murray, Brian M.

    2002-12-15

    Purpose: To look in more detail at those grafts that clot despite access blood flow (ABF) surveillance and the outcome of radiological thrombectomy in those grafts. Methods: Retrospective review was carried out of all polytetrafluoroethylene grafts that clotted from September 1, 1998 to October 30, 2000. During this period, each graft had ABF measured monthly and was referred for prophylactic angioplasty if flow fell below 600 ml/min or by 25%. Results: Thirty-one of 62 monitored grafts clotted (0.44 episodes per patient per month). Five were surgically thrombectomized and 19 were radiologically thrombectomized. The last available ABF prior to graft thrombosis averaged 804 {+-} 108 ml/min and ranged from 215 to 2497 ml/min.Nine of the 23 grafts failed to trigger either of the ABF criteria prior to initial thrombosis. All but one of the 17 grafts throbolysedradiologically showed evidence of significant (>50%) venous stenoses,though additional lesions were found in nine. Thrombolysis was successful in 14 grafts, with ABF rising from 693 {+-} 96 to 941 {+-} 135 ml/min (p <0.05). Six additional grafts reclotted and were lost (6-month graft survival 37%). Conclusion: (1) A significant proportion (40%)of graft thromboses that occur despite ABF surveillance occur in grafts with preserved ABF (>600 ml/min); (2) over 70% can be successfully thrombectomized /angioplastied with about 35% long-term (6 months)survival.

  13. Cold-Plasma Assisted Grafting of Paper

    NASA Astrophysics Data System (ADS)

    Gaiolas, C.; Costa, A. P.; Nunes, M.; Silva, M. J. Santos; Belgacem, M. N.

    2008-08-01

    The treatment of cellulose with cold-plasma in the presence of two silanes (vinyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane) was found to be efficient in grafting of cellulose macromolecules. The occurrence of the grafting was proved by contact angle measurement, ESCA and SEM. Thus, after solvent extraction of the modified substrates, in order to remove unbounded grafts, the polar component of the surface energy of treated samples decreased from 23 mJ/m2 to practically zero. The ESCA spectra showed the appearance of two new peaks at 102 and 150 eV, relative to the presence of Si atoms and a substantial increase in C1 signal, attributed to the enrichment of the surface by C-H moieties borne by the silanes.

  14. COLD-PLASMA ASSISTED GRAFTING OF PAPER

    SciTech Connect

    Gaiolas, C.; Costa, A. P.; Nunes, M.; Silva, M. J. Santos; Belgacem, M. N.

    2008-08-28

    The treatment of cellulose with cold-plasma in the presence of two silanes (vinyltrimethoxysilane and {gamma}-methacryloxypropyltrimethoxysilane) was found to be efficient in grafting of cellulose macromolecules. The occurrence of the grafting was proved by contact angle measurement, ESCA and SEM. Thus, after solvent extraction of the modified substrates, in order to remove unbounded grafts, the polar component of the surface energy of treated samples decreased from 23 mJ/m{sup 2} to practically zero. The ESCA spectra showed the appearance of two new peaks at 102 and 150 eV, relative to the presence of Si atoms and a substantial increase in C1 signal, attributed to the enrichment of the surface by C-H moieties borne by the silanes.

  15. [Fundamentals and principles of grafts and flaps].

    PubMed

    Cruz-Navarro, Natalio; León-Dueñas, Eduardo

    2014-01-01

    Reconstructive surgery of large urethral stenosis and the management of congenital anomalies such as hypospadias and epispadias require covering large cutaneous and mucosal defects with different techniques. The objective of this work is to define the main differences between tissues to be transferred and to study the principles that must govern the management of the various flaps and grafts used for these techniques. We analyze the anatomical and physiological features that may be key to understand the success and possible failures of these procedures, and we review technical details that must accompany in every case, not only during the operation, but also during the preoperative and postoperative period. We conclude stating that grafts (mainly oral and preputial mucosa) and flaps are increasingly used for the repair of urethral stenosis. Grafts must be prepared adequately in the back table and thinned to the maximum, and also be fixed properly, to guarantee their immobility until neovascularization is assured.

  16. Grafting Polymer Loops onto Functionalized Nanotubes: Monitoring Grafting and Loop Formation

    SciTech Connect

    Ashcraft, Earl C; Ji, Haining; Mays, Jimmy; Dadmun, Mark D

    2011-01-01

    Polystyrene functionalized at both ends (telechelic polymer) with epoxide groups (epoxy PS epoxy) was reacted with carboxylated multiwall carbon nanotubes (COOH MWNT) in solution in order to graft polymer chains at both ends onto the MWNT surface, forming loops. FT-IR spectroscopy was employed to monitor the formation of aromatic esters and to quantify the amount of telechelic grafted to the nanotube surface as a function of reaction time. When the samples were further annealed in the melt, an increase in the aromatic ester peak was observed, indicating that the unreacted chain ends further grafted to MWNT surfaces to form loops. By reacting the grafted nanotube samples further with monocarboxy terminated poly(4-methylstyrene) (COOH P4MS), the amount of epoxy PS epoxy that had only reacted at one end was determined. Reaction rate analysis indicates that that the grafting of epoxy PS epoxy to the nanotube surface is reaction controlled, as the FT-IR spectroscopy signal grows as a function of approximately t0.3. These studies exemplify how FT-IR spectroscopy can be used as a novel technique to quantify the amount of grafted polymer, grafting rate, and percent of difunctional polymers that form loops, and provide a method to create loop covered nanoparticles.

  17. Cartilage grafting in facial reconstruction with special consideration of irradiated grafts

    SciTech Connect

    Donald, P.J.

    1986-07-01

    The search for the perfect facial implant for reconstruction of the face continues. Cartilage, once thought to be an undesirable graft material because of its propensity for absorption, has regained popularity in the past decade. Various preparation techniques have been employed to ensure graft sterility and diminished absorption. An improved understanding of cartilage structure and physiology has shed considerable light on the host-graft relationship. Gamma irradiation is a time-honored method of preservation. An experiment was undertaken to investigate the physiology of irradiated cartilage grafts following prolonged implantation on the facial skeleton of sheep and dog. Merthiolate preserved grafts were used as controls. Direct observation, histochemical techniques, autoradiography, and transmission electron micrography were used to determine chondrocyte viability and matrix composition. It was surprising to note that following implantation of 16 to 72 months, complete resorption was seen in 87.7% of the irradiated grafts and in 43.8% of the Merthiolate stored controls. Many of the grafts acquired chondrocytes from the host and produced new proteoglycan matrix as well as undergoing some degree of ossification. A comparison to the clinical situation in humans is made. 98 references.

  18. Graft preservation solutions in cardiovascular surgery.

    PubMed

    Winkler, Bernhard; Reineke, David; Heinisch, Paul Philip; Schönhoff, Florian; Huber, Christoph; Kadner, Alexander; Englberger, Lars; Carrel, Thierry

    2016-08-01

    Vein grafts are still the most commonly used graft material in cardiovascular surgery and much effort has been spent in recent years on investigating the optimal harvesting technique. One other related topic of similar importance remained more or less an incidental one. The storage solutions of vein grafts following procurement and prior to implantation are, despite their assumed impact, a relatively neglected theme. There is no doubt that the endothelium plays a key role in long-term patency of vein grafts, but the effects of the different storage solutions on the endothelium remain unclear : In a review of the literature, we could find 20 specific papers that addressed the question, of which the currently available preservation solutions are superior, harmless, damaging or ineffective. The focus lies on saline and autologous whole blood. Besides these two storage media, novel or alternative solutions have been investigated with surprising findings. In addition, a few words will be spent on potential alternatives and novel solutions on the market. As there is currently no randomized clinical trial regarding saline versus autologous whole blood available, this review compares all previous studies and methods of analysis to provide a certain level of evidence on this topic. In summary, saline has negative effects on the endothelial layers and therefore may compromise graft patency. Related factors, such as distension pressure, may outbalance the initial benefit of autologous whole blood or storage solutions and intensify the harmful effects of warm saline. In addition, there is no uniform consent on the superiority of autologous whole blood for vein graft storage. This may open the door to alternatives such as the University of Wisconsin solution or one of the specific designed storage solutions like TiProtec™ or Somaluthion™. Whether these preservation solutions are superior or advantageous remains the subject of further studies.

  19. Platelet--arterial synthetic graft interaction and its modification

    SciTech Connect

    Callow, A.D.; Connolly, R.; O'Donnell, T.F. Jr.; Gembarowicz, R.; Keough, E.; Ramberg-Laskaris, K.; Valeri, C.R.

    1982-11-01

    We compared the in vivo platelet reactivity of two commonly used clinical grafts, Dacron and expanded polytetrafluoroethylene (PTFE), with that of a control autogenous artery graft and assessed whether platelet reactivity was modified by the platelet-antiaggregating agent prostacyclin (PGI2) (epoprostenol). Grafts were randomly placed into the carotid arteries of 21 baboons. Platelets labeled with /sup 111/In were infused within one hour after implantation graft for gamma camera scanning of platelet uptake. The accumulation of platelets on Dacron grafts began almost immediately after injection and reached a peak after one to two hours. The PTFE and control autogenous artery grafts accumulated comparable small amounts of platelets. Prostacyclin was then infused in a second series of baboons with Dacron grafts, at a rate of 150 to 200 ng/kg/min. It prevented the usual platelet uptake when administered concomitant with graft implantation and reduced previously established platelet activity.

  20. Vascularized bone graft from the supracondylar region of the femur.

    PubMed

    Doi, Kazuteru; Hattori, Yasunori

    2009-01-01

    Free vascularized thin corticoperiosteal grafts and small periosteal bone grafts harvested from the supracondylar region of the femur are described. These grafts are nourished from the articular branch of the descending genicular artery and vein. Unlike currently used vascularized bone grafts, this graft can be successfully harvested with disturbing the vascularity. Thin corticoperiosteal grafts consist of periosteum with a thin layer of outer cortical bone and include the cambium layer, which has a better osteogenic capacity. This graft is elastic and readily conforms to the recipient bed configuration. Thin corticoperiosteal grafts were used for fracture nonunion of the long bone with smaller bone defect and to treat forty-six patients with avascular necrosis of the body of the talus, scaphoid, and lunate bone.

  1. Modification of microcrystalline cellulose by gamma radiation-induced grafting

    NASA Astrophysics Data System (ADS)

    Madrid, Jordan F.; Abad, Lucille V.

    2015-10-01

    Modified microcrystalline cellulose (MCC) was prepared through gamma radiation-induced graft polymerization of glycidyl methacrylate (GMA). Simultaneous grafting was employed wherein MCC with GMA in methanol was irradiated with gamma radiation in nitrogen atmosphere. The effects of different experimental factors such as monomer concentration, type of solvent and absorbed dose on the degree of grafting, Dg, were studied. The amount of grafted GMA, expressed as Dg, was determined gravimetrically. Information from grafted samples subjected to Fourier transformed infrared spectroscopy (FTIR) in attenuated total reflectance (ATR) mode showed peaks corresponding to GMA which indicates successful grafting. The X-ray diffraction (XRD) analysis revealed that the crystalline region of MCC was not adversely affected after grafting with GMA. The thermogravimetric analysis (TGA) data showed that the decomposition of grafted MCC occurred at higher temperature compared to the base MCC polymer.

  2. Conduits for Coronary Bypass: Vein Grafts

    PubMed Central

    Farkas, Emily A

    2012-01-01

    The saphenous vein has been the principal conduit for coronary bypass grafting from the beginning, circa 1970. This report briefly traces this history and concomitantly presents one surgeons experience and personal views on use of the vein graft. As such it is not exhaustive but meant to be practical with a modest number of references. The focus is that of providing guidance and perspective which may be at variance with that of others and recognizing that there may be many ways to accomplish the task at hand. Hopefully the surgeon in training/early career may find this instructive on the journey to surgical maturity. PMID:23130300

  3. Autologous Bone Graft in Foot and Ankle Surgery.

    PubMed

    Miller, Christopher P; Chiodo, Christopher P

    2016-12-01

    Bone graft is a common adjunct procedure in orthopedic surgery used for fusions, fracture repair, and the reconstruction of skeletal defects in the foot and ankle. Autologous graft, or autograft, involves the transport of bone from a donor site to another location in the same patient. It is considered by many to be the gold standard of bone grafting, as it is provides all biologic factors required for functional graft. Further, autograft is 100% histocompatible with no risk of disease transmission.

  4. Superhydrophobic bio-fibre surfaces via tailored grafting architecture.

    PubMed

    Nyström, Daniel; Lindqvist, Josefina; Ostmark, Emma; Hult, Anders; Malmström, Eva

    2006-09-14

    Superhydrophobic bio-fibre surfaces with a micro-nano-binary surface structure have been achieved via the surface-confined grafting of glycidyl methacrylate, using a branched "graft-on-graft" architecture, followed by post-functionalisation to obtain fluorinated brushes.

  5. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Bone grafting material. 872.3930 Section 872.3930...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3930 Bone grafting material. (a) Identification. Bone grafting material is a material such as hydroxyapatite, tricalcium phosphate, polylactic...

  6. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Bone grafting material. 872.3930 Section 872.3930...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3930 Bone grafting material. (a) Identification. Bone grafting material is a material such as hydroxyapatite, tricalcium phosphate, polylactic...

  7. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone grafting material. 872.3930 Section 872.3930...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3930 Bone grafting material. (a) Identification. Bone grafting material is a material such as hydroxyapatite, tricalcium phosphate, polylactic...

  8. Defense mechanisms involved in disease resistance of grafted vegetables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetable grafting with resistant rootstocks is an effective strategy to control a variety of soil-borne diseases and root-knot nematodes in the Cucurbitaceae and Solanaceae. In addition, improved resistance to some foliar diseases and viruses has also been reported in grafted plants. Hence, graft...

  9. Immobilization of peroxidase on SPEU film via radiation grafting

    NASA Astrophysics Data System (ADS)

    Hongfei, Ha; Guanghui, Wang; Jilan, Wu

    The acrylic acid or acrylamide were grafted via radiation onto segmented polyetherurethane (SPEU) film which is a kind of biocompatible material. Then the Horse radish peroxidase was immobilized on the grafted SPEU film through chemical binding. Some quantitative relationships between the percent graft and the activity, amount of immobilized enzyme were given. The properties and application of obtained biomaterial was studied as well.

  10. Adding value to grafted watermelon: Novel benefits and potential pitfalls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grafted watermelons are commonly used in Asia and areas of Europe but are not widely used in the United States. The traditional reason for grafting watermelons has been for resistance to soil borne diseases such as Fusarium. We began to explore novel benefits which might make grafted watermelons m...

  11. Treatment of Secondary Stent-Graft Collapse After Endovascular Stent-Grafting for Iliac Artery Pseudoaneurysms

    SciTech Connect

    Clevert, D.-A. Stickel, M.; Steitz, H.-O.; Kopp, R.; Strautz, T.; Flach, P.; Johnson, T.; Jung, E.M.; Jauch, K.W.; Reiser, M.

    2007-02-15

    We report the case of a patient who developed an asymptomatic pseudoaneurysm in the left external iliac artery after transplant nephrectomy. The pseudoaneurysm most probably arose as a suture aneurysm from the external iliac artery after removal of the graft renal artery. Obviously we can not exclude the possibility it was a true aneurysm, although this seems much less likely. The pseudoaneurysm was detected during a routine CT scan and was treated interventionally with a stent-graft. One month later the asymptomatic patient underwent a vascular ultrasound examination including color Doppler, power Doppler, and B-flow as a routine control. An endoleak with collapse of the stent-graft was diagnosed. There was no evidence of stent infection. At a reintervention, the pseudoaneurysm was successfully treated using two uncovered Palmaz stents at the proximal and distal edge of the stent graft. Peri- and post-interventional ultrasound and CT angiography confirmed the exclusion of the aneurysm without an endoleak.

  12. Grafted silane monolayers: reconsideration of growth mechanisms

    NASA Astrophysics Data System (ADS)

    Ivanov, D. A.; Nysten, B.; Jonas, A. M.; Legras, R.

    1998-03-01

    Chemical force microscopy is a new technique devised to image chemical heterogeneities on surfaces. It requires the chemical modification of Atomic Force Microscopy (AFM) tips in order to create chemical probes. In this respect, self-assembled monolayers (SAM) of alkylchlorosilanes are particularly interesting as modifying agents for AFM tips. We report here our results on the kinetics of silanization and on the structure of such SAM's grafted on model surfaces (hydroxylated Si(100) wafers). AFM, contact angle measurements, X-ray reflectivity and X-ray photoelectron spectroscopy were used to characterize SAM's of octadecyltrichlorosilane (OTS) and octadecyldimethylchlorosilane (ODMS) grown from hexadecane and toluene solutions. The mechanism of grafting of OTS follows two stages. The first rapid stage corresponds to the nucleation and growth of island-like monolayer domains. The second slower stage is related to the densification of the monolayer. SAM's of ODMS were found to form thinner layers as compared to OTS, due to their lower grafting density probably resulting in a more disordered state of grafted alkyl chains. We also address the problems concerning the relationships between the quality of final SAM structures and the water content as well as the nature of the solvent used for silanization.

  13. Skin flaps and grafts -- self-care

    MedlinePlus

    ... drainage from the wound Drainage becoming thick, tan, green, or yellow, or smells bad (pus) Your temperature is above 100°F (37.8°C) for more than 4 hours Red streaks appear that lead away from the wound Alternative Names Autograft - self-care; Skin transplant - self-care; Split-skin graft - self- ...

  14. [Pseudoaneurysm of saphenous vein graft after CABG].

    PubMed

    Nakamura, T; Shimamoto, M; Yamazaki, F; Fujita, S; Yoshimura, T; Ueno, T; Shinozaki, T

    1995-04-01

    A 69-year-old man was admitted because of angina pectoris and thoracic descending aorta aneurysm. Staged operations were planned. First, he underwent CABG (coronary artery bypass grafting) with SVGs (saphenous vein grafts) to #4 PD, #7 and #12. Aprotinin was administrated to reduce blood loss. The routine postoperative graft angiography and enhanced CT showed a pseudoaneurysm in the SVG to #4 PD. We planned an elective operation of pseudoaneurysm repair and graft replacement of thoracic descending aorta. Also in this second operation, continuous infusion of aprotinin was started after the induction of anesthesia. About 30 minutes later, he suddenly fell in shock and cardiac arrest. Partial cardiopulmonary bypass was established and median sternotomy was performed. In the mediastinum, no bleeding was found. We found out a bleeding point of the SVG to #4 PD and a hemostatic clip on the right ventricule, and closed the bleeding point with suture. The cause of the pseudoaneurysm seemed to be defluxion of the hemostatic clip for a side brunch of the SVG. The cause of the preoperative shock may be an anaphylaxis to readministrated aprotinin.

  15. Endothelialized ePTFE Graft by Nanobiotechnology

    ClinicalTrials.gov

    2013-11-29

    The Apparatus for Processing the Tubular Graft Modification Will be Designed and Evaluated.; The On-site Capturing of the Endothelial (Progenitor) Cells by Peptide-mediated Selective Adhesion in Vitro and in Vivo Will Also be Elucidated.; The Patency Rate of ITRI-made Artificial Blood Vessels Will be Evaluated by the Porcine Animal Model.

  16. Dynamics of solvent-free grafted nanoparticles

    NASA Astrophysics Data System (ADS)

    Chremos, Alexandros; Panagiotopoulos, Athanassios Z.; Koch, Donald L.

    2012-01-01

    The diffusivity and structural relaxation characteristics of oligomer-grafted nanoparticles have been investigated with simulations of a previously proposed coarse-grained model at atmospheric pressure. Solvent-free, polymer-grafted nanoparticles as well as grafted nanoparticles in a melt were compared to a reference system of bare (ungrafted) particles in a melt. Whereas longer chains lead to a larger hydrodynamic radius and lower relative diffusivity for grafted particles in a melt, bulk solvent-free nanoparticles with longer chains have higher relative diffusivities than their short chain counterparts. Solvent-free nanoparticles with short chains undergo a glass transition as indicated by a vanishing diffusivity, diverging structural relaxation time and the formation of body-centered-cubic-like order. Nanoparticles with longer chains exhibit a more gradual increase in the structural relaxation time with decreasing temperature and concomitantly increasing particle volume fraction. The diffusivity of the long chain nanoparticles exhibits a minimum at an intermediate temperature and volume fraction where the polymer brushes of neighboring particles overlap, but must stretch to fill the interparticle space.

  17. Enhancement of surface nonwettability by grafting loops.

    PubMed

    Pei, Han-Wen; Liu, Xiao-Li; Liu, Hong; Zhu, You-Liang; Lu, Zhong-Yuan

    2017-02-08

    We present a computer simulation study on the nonwettability of a flat surface tethered with deformable looped polymer chains. Two kinds of loops are studied: monodispersed loops (loops with the same length) and polydispersed loops (loops with different lengths). Both kinds of loops include two arrangements: with regularly tethered sites and with randomly tethered sites. Regularly grafted loops form typical grooves on the surface, while randomly grafted loops form a more rugged surface. For monodispersed loops, we analyze the factors that influence the nonwettability when varying the rigidity of the loops. The loops are divided into two categories based on their rigidity according to our previous analysis procedure (Phys. Chem. Chem. Phys., 2016, 18, 18767-18775): rigid loops and flexible loops. It is found that the loop can partially form a re-entrant-like structure, which is helpful to increase the nonwettability of the surface. The surfaces with grafted loops have increased nonwettability, especially those grafted with flexible chains. However, the contact angle on the loop structure cannot further increase for the rigid chains due to a large top layer density (Phys. Chem. Chem. Phys., 2016, 18, 18767-18775). For polydispersed loops, the contact angle is highly related to the rigidity of the long loops that contact the droplet. Different from monodispersed loops, the mechanism of the nonwettability of polydispersed loops is attributed to the supporting ability (rigidity) of long loops.

  18. Grafting functional antioxidants on highly crosslinked polyethylene

    NASA Astrophysics Data System (ADS)

    Al-Malaika, S.; Riasat, S.; Lewucha, C.

    2016-05-01

    The problem of interference of antioxidants, such as hindered phenols, with peroxide-initiated crosslinking of polyethylene was addressed through the use of functional (reactive) graftable antioxidants (g-AO). Reactive derivatives of hindered phenol and hindered amine antioxidants were synthesised, characterised and used to investigate their grafting reactions in high density polyethylene; both non-crosslinked (PE) and highly peroxide-crosslinked (PEXa). Assessment of the extent of in-situ grafting of the antioxidants, their retention after exhaustive solvent extraction in PE and PEXa, and the stabilising performance of the grafted antioxidants (g-AO) in the polymer were examined and benchmarked against conventionally stabilised crosslinked & non-crosslinked polyethylene. It was shown that the functional antioxidants graft to a high extent in PEXa, and that the level of interference of the g-AOs with the polymer crosslinking process was minimal compared to that of conventional antioxidants which bear the same antioxidant function. The much higher level of retention of the g-AOs in PEXa after exhaustive solvent extraction, compared to that of the corresponding conventional antioxidants, accounts for their superior long-term thermal stabilising performance under severe extractive conditions.

  19. Fatal Saccharomyces Cerevisiae Aortic Graft Infection

    NASA Technical Reports Server (NTRS)

    Meyer, Michael (Technical Monitor); Smith, Davey; Metzgar, David; Wills, Christopher; Fierer, Joshua

    2002-01-01

    Saccharomyces cerevisiae is a yeast commonly used in baking and a frequent colonizer of human mucosal surfaces. It is considered relatively nonpathogenic in immunocompetent adults. We present a case of S. cerevisiae fungemia and aortic graft infection in an immunocompetent adult. This is the first reported case of S. cerevisiue fungemia where the identity of the pathogen was confirmed by rRNA sequencing.

  20. Modulation of graft architectures for enhancing hydrophobic interaction of biomolecules with thermoresponsive polymer-grafted surfaces.

    PubMed

    Idota, Naokazu; Kikuchi, Akihiko; Kobayashi, Jun; Sakai, Kiyotaka; Okano, Teruo

    2012-11-01

    This paper describes the effects of graft architecture of poly(N-isopropylacrylamide) (PIPAAm) brush surfaces on thermoresponsive aqueous wettability changes and the temperature-dependent hydrophobic interaction of steroids in silica capillaries (I.D.: 50 μm). PIPAAm brushes were grafted onto glass substrates by surface-initiated atom transfer radical polymerization (ATRP) that is one of the living radical polymerization techniques. Increases in the graft density and chain length of PIPAAm brushes increased the hydration of polymer brushes, resulting in the increased hydrophilic properties of the surface below the transition temperature of PIPAAm at 32 °C. More hydrophobic surface properties were also observed on surfaces modified with the block copolymers of IPAAm and n-butyl methacrylate (BMA) than that with IPAAm homopolymer-grafted surfaces over the transition temperature. Using PBMA-b-PIPAAm-grafted silica capillaries, the baseline separation of steroids was successfully achieved by only changing temperature. The incorporation of hydrophobic PBMA chains in grafted PIPAAm enhanced the hydrophobic interaction with testosterone above the transition temperature. The surface modification of hydrophobicity-enhanced thermoresponsive polymers is a promising method for the preparation of thermoresponsive biointerfaces that can effectively modulated their biomolecule and cell adsorption with the wide dynamic range of hydrophilic/hydrophobic property change across the transition temperature.

  1. Delayed Graft Function 5 Months After Living Donor Kidney Transplantation

    PubMed Central

    Schulz, Tim; Pries, Alexandra; Kapischke, Matthias

    2016-01-01

    Patient: Female, 59 Final Diagnosis: Delayed kidney graft function Symptoms: — Medication: — Clinical Procedure: Living donor kidney transplantation Specialty: Transplantology Objective: Unusual clinical course Background: Delayed graft function is a clinical term to describe the failure of the transplanted kidney to function immediately after transplantation. Case Report: A 59-year-old woman suffered from a rare case of delayed graft function lasting 148 days after unrelated living donor kidney transplantation. Until now, 15 years after transplantation, organ function is still good, with serum creatinine levels about 1.4 to 2.0 mg/dl. Conclusions: Even after prolonged graft dysfunction, good graft function can be achieved. PMID:26915643

  2. Novel treatment of an 11-cm saphenous vein graft aneurysm.

    PubMed

    Harrison, Joshua W; Swartz, Michael F; Fink, Gregory W

    2009-04-01

    Saphenous vein graft pseudoaneurysms are rare and potentially fatal complications after coronary artery bypass graft surgery. Here we present an 11-cm saphenous vein graft pseudoaneurysm from a 20-year-old vein graft to the obtuse marginal artery. The pseudoaneurysm was directly located beneath the sternum and adjacent to two patent grafts. Therefore, we used a novel approach to access the aorta through a right thoracotomy, and using a pericardial patch, we closed the ostia to the pseudoaneurysm. Postoperatively there was no longer flow into the aneurysm, and at 1-year follow-up the patient is doing well.

  3. Graft copolymers of natural fibers for green composites.

    PubMed

    Thakur, Vijay Kumar; Thakur, Manju Kumari; Gupta, Raju Kumar

    2014-04-15

    In the present study, free radical induced graft-copolymerization of natural cellulosic polymers (Grewia optiva) has been carried out to develop the novel materials meant for green composites and many other applications. During the graft copolymer synthesis diverse reaction parameters that significantly affect the percentage of grafting were optimized. The structural, thermal and physico-chemical changes in the natural cellulosic polymers based graft copolymers have been ascertained with scanning electron micrography, Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA) and swelling studies. The swelling studies of the grafted cellulosic polymers have been carried out in different solvents to assess the possible applicability of these natural polymers. Green composites were also prepared using raw/grafted cellulosic polymers. It has been found that grafted polymers (Grewia optiva) based green composites gives better tensile properties than the parent natural cellulosic polymers based composites.

  4. Duplex ultrasound assessment of femorodistal grafts: correlation with angiography.

    PubMed

    McShane, M D; Gazzard, V M; Clifford, P C; Hacking, C N; Fairhurst, J J; Humphries, K N; Birch, S J; Webster, J H; Chant, A D

    1987-12-01

    Fifty-eight grafts have been assessed using duplex scanning and ankle brachial pressure indices. This assessment is compared with the findings by angiography. Eighteen grafts were occluded and 40 patent. Duplex scanning defined graft status with a greater accuracy than pressure indices. Pressure indices alone would not differentiate "satisfactory" grafts from those with localised, haemodynamically significant disease. Only 55% of those grafts with localised stenoses demonstrated a fall of greater than 0.2 in ankle brachial pressure index after exercise. When the information obtained using pressure indices and duplex scanning was combined non-invasive assessment had a sensitivity of 86% and specificity of 94% for detection of localised, haemodynamically significant disease in patent grafts. Haemodynamically significant disease, as defined by angiography, can be detected and localised with duplex scanning complementing the use of pressure indices in graft assessment.

  5. Small caliber vascular grafts. Part I: state of the art.

    PubMed

    Zdrahala, R J

    1996-04-01

    Vascular grafts, devices designed to augment inefficiently functioning vascular systems, represent a significant part of implantable medical devices, with major participation in over a million vascular surgeries performed worldwide. By definition accepted in the art, a small caliber graft is a conduit with internal diameter (ID) of 6 mm or less; large caliber grafts start at ID of 7 mm. While the autologous grafts utilizing saphenous veins (SVG) and internal iliac, or mammary arteries are used exclusively in cardiac artery bypass grafts (CABG) procedures and preferentially in many peripheral indications, and while the use of grafts with biological origin did not proliferate, polymer-based artificial grafts of controlled patterns and porosity are prostheses of choice for the large caliber. The polyester (PET) yarn is knitted or woven into various porous patterns. The PTFE tubes are expanded into porous conduits (ePTFE). Although these technologies are used to produce the grafts with ID larger than 6 mm, the dominant principles are being applied to the development of small caliber graft. Polyurethanes are also evaluated for small caliber application. The grafts (regardless of the ID) produced by the above technologies are porous. This porosity, considered to be critical for proper healing and overall graft patency, causes the blood to leak through the graft wall or at anastomosis through the suture holes. Both the wall leakage and suture hole bleeding remain rather serious drawbacks. Currently, collagen, gelatin, albumin and their derivatives are used as sealants. Various modes of application and degrees of crosslinking are utilized to control in vivo degradation and graft healing. Other hydrogels, both natural and synthetic, could play significant roles as sealants and modifiers of the graft performance. Enhancement of graft patency via improvement of initial hemocompatibility could be achieved by application of bioactive coatings. Heparinized systems seem to

  6. Osteofibrous Dysplasia managed with Extraperiosteal excision, Autologous free fibular graft and bone graft substitute

    PubMed Central

    Abraham, Vineet T; Marimuthu, Chandrasekaran; Subbaraj, Ravichandran; Rengarajan, Nandakumar

    2015-01-01

    Introduction: Osteofibrous Dysplasia is a rare benign self-limiting fibro-osseous lesion most commonly seen in the diaphysis of the tibia. Its incidence is reported to be 0.2% of all primary bone tumors. It occurs in the first two decades of life with a slight male preponderance. Surgical options include extra periosteal resection, autologous graft, limb lengthening procedures etc. There are no case reports mentioning the use of synthetic bone graft to fill the defect following extraperiosteal excision. Case Report: A 13 year old girl presented with pain and swelling of the (R) leg since 2 months following a trivial injury at school. Examination revealed a 5×3cm tender swelling on the anteromedial aspect of the middle third tibia. Radiographs and MRI, revealed an eccentric expansile lytic lesion, which was multilocular and was present at the junction of the metaphysis and diaphysis on the antero -medial aspect of tibia. The cortex had ballooned out and there was a possibility of an impending fracture. Biopsy was done which revealed osteofibrous dysplasia. We did an extraperiosteal excision of the lesion. To fill the cavity we harvested 10 cm of the contralateral fibula and since there was still space in the cavity, we packed bone graft substitute (hydroxyapatite crystals) into the defect. The surgical management of osteofibrous dysplasia is controversial. Various methods of treatment of such cases have been described in literature. The use of synthetic graft is an option in these patients as it reduces morbidity; and in our case we had good graft incorporation with this method. Conclusion: Extraperiosteal Excision of Osteofibrous dysplasia combined with autologous free fibular graft and bone graft substitute is a good surgical option to prevent recurrence and mange bone defects in this rare lesion. PMID:27299018

  7. Adipose-derived regenerative cell (ADRC)-enriched fat grafting: optimal cell concentration and effects on grafted fat characteristics

    PubMed Central

    2013-01-01

    Background To overcome the absorption of traditional fat grafting, techniques for adipose-derived regenerative cell (ADRC)-enriched fat grafting are currently being adapted for practical application. The Celution®800/CRS (Cytori Therapeutics, San Diego, CA) has enabled rapid grafting of the patient’s own freshly harvested ADRCs without requiring a culturing step. However, the optimal cell concentration and the effects of ADRCs on the characteristics of grafted fat after free fat grafting remain unclear. Methods ADRCs were isolated and purified from human fat tissue using the Celution®800/CRS. Animals that received fat grafting without the addition of ADRCs were designated the control group (group A). The number of ADRCs per grafted fat volume (mL) was adjusted to 3 × 105, 1.5 × 106, and 3 × 106 cells/mL (groups B, C, and D, respectively), mixed with free fat, and transplanted as ADRC-enriched fat grafting. These mixtures were transplanted subcutaneously into BALB/C Jcl-nu/nu mice. The volume of grafted fat was determined 5 months after transplantation, and histological assessments were performed. Results ADRC-enriched fat grafting resulted in decreased fat absorption and the formation of greater numbers of new blood vessels in the grafted fat. The optimal ADRC concentration in this study was found to be 3 × 105 cells/mL (group B), with higher concentrations resulting in increased cyst and fibril formation in the grafted fat. Conclusions This study used the Celution®800/CRS for free fat grafting and demonstrated that the concentration of transplanted ADRCs affected the engraftment and quality of the grafted fat. PMID:24107489

  8. Grafting Sulfated Zirconia on Mesoporous Silica

    SciTech Connect

    Wang, Yong; Lee, Kwan Young; Choi, Saemin; Liu, Jun; Wang, Li Q.; Peden, Charles HF

    2007-06-01

    Sulfated zirconia has received considerable attention as a potential solid acid catalyst in recent years. In this paper, the preparation and properties of acid catalysts obtained by grafting ziconia with atomic precision on MCM-41 mesoporous silica were studied. TEM and potential titration characterizations revealed that ZrO2/MCM-41 with monolayer coverage can be obtained using this grafting technique. Sulfated ZrO2/MCM-41 exhibits improved thermal stability than that of bulk sulfated zirconia, as evidenced by temperature programmed characterizations and XRD analysis. Temperature programmed reaction of isopropanol was used to evaluate the acidity of sulfated ZrO2/MCM-41. It was found that the acid strength of sulfated ZrO2/MCM-41 with monolayer coverage is weaker than bulk sulfated zirconia but stronger than SiO2-Al2O3, a common strong acid catalyst.

  9. Tooth-derived bone graft material

    PubMed Central

    Kim, Young-Kyun; Lee, Junho; Kim, Kyung-Wook; Murata, Masaru; Akazawa, Toshiyuki; Mitsugi, Masaharu

    2013-01-01

    With successful extraction of growth factors and bone morphogenic proteins (BMPs) from mammalian teeth, many researchers have supported development of a bone substitute using tooth-derived substances. Some studies have also expanded the potential use of teeth as a carrier for growth factors and stem cells. A broad overview of the published findings with regard to tooth-derived regenerative tissue engineering technique is outlined. Considering more than 100 published papers, our team has developed the protocols and techniques for processing of bone graft material using extracted teeth. Based on current studies and studies that will be needed in the future, we can anticipate development of scaffolds, homogenous and xenogenous tooth bone grafts, and dental restorative materials using extracted teeth. PMID:24471027

  10. Modification of polyetherurethane for biomedical application by radiation-induced grafting. I. Grafting procedure, determination of mechanical properties, and chemical modification of grafted films

    SciTech Connect

    Jansen, B.; Ellinghorst, G.

    1985-11-01

    Radiation grafting of monomers onto suitable trunk polymers is a useful tool for tailoring new polymers for special purposes. This technique has been used in the past for the development of biocompatible materials, e.g., by grafting hydrogels onto mechanically stable polymers. In this first part of our work, the radiation grafting of hydrophilic or reactive monomers onto a polyetherurethane film using the pre-swelling technique is described. Following this technique the trunk polymer was swollen in the monomer before irradiation. As monomers 2-hydroxyethyl methacrylate (HEMA), 2,3-epoxypropyl methacrylate (GMA), 2,3-dihydroxypropyl methacrylate (GOMA), and acrylamide (AAm) were used. The kinetics of the grafting reactions were examined, and the distribution of the graft component inside the trunk polymer was investigated by means of infrared (IR) spectroscopy. Surface-grafted as well as bulk- and surface-grafted products could be obtained. The mechanical behavior of the grafted films--especially in the water-swollen state--was examined and compared with that of the pure trunk polymer. In nearly all cases it was found that the tensile strength sigma B and the elongation at break epsilon R decreases as the grafting yield increases. Modification of GMA- and AAm-grafted films via chemical reactions was performed to create new functional groups of biomedical interest. In this manner a diol structure, a carboxylic acid structure, and a sulfonic acid group could be introduced in the grafted polymer. The water uptake of such modified films is increased markedly when compared with that of the unmodified samples.

  11. Bilateral Mooren’s ulcer – Customised corneal graft with additional amniotic membrane graft

    PubMed Central

    Bhandari, Vipul; Siddharthan, K.S.

    2015-01-01

    Mooren’s ulcer (MU) is a rare and painful peripheral corneal ulceration which occurs in the absence of any associated scleritis, and any detectable systemic disease. A 60-year-old male patient was referred to us with bilateral peripheral corneal ulceration. Best corrected visual acuity (BCVA) in both eyes was counting finger at one metre. The right eye showed a 180° thinning with perforation at 8 o’clock position. The left eye showed a 360° thinning with central contact lens type cornea. After complete blood analysis we started the patient on cyclophosphamide orally along with high doses of oral steroids. A crescentic excision of the thinned cornea and crescentic customised corneal graft with additional amniotic membrane graft (AMG) was done first for the right eye and a 360° peripheral lamellar corneal graft with additional AMG for the left eye. The BCVA of RE was 1/60 improving to 6/36 with plus ten aphakic glasses and LE was 3/60. Hand fashioned full thickness crescentic customised corneal graft with additional AMG and a peripheral 360° lamellar corneal graft with additional AMG in these cases are a novel approach to Mooren’s ulcer with gratifying results. PMID:26155087

  12. Hydrogen, a potential safeguard for graft-versus-host disease and graft ischemia-reperfusion injury?

    PubMed Central

    Yuan, Lijuan; Shen, Jianliang

    2016-01-01

    Post-transplant complications such as graft-versus-host disease and graft ischemia-reperfusion injury are crucial challenges in transplantation. Hydrogen can act as a potential antioxidant, playing a preventive role against post-transplant complications in animal models of multiple organ transplantation. Herein, the authors review the current literature regarding the effects of hydrogen on graft ischemia-reperfusion injury and graft-versus-host disease. Existing data on the effects of hydrogen on ischemia-reperfusion injury related to organ transplantation are specifically reviewed and coupled with further suggestions for future work. The reviewed studies showed that hydrogen (inhaled or dissolved in saline) improved the outcomes of organ transplantation by decreasing oxidative stress and inflammation at both the transplanted organ and the systemic levels. In conclusion, a substantial body of experimental evidence suggests that hydrogen can significantly alleviate transplantation-related ischemia-reperfusion injury and have a therapeutic effect on graft-versus-host disease, mainly via inhibition of inflammatory cytokine secretion and reduction of oxidative stress through several underlying mechanisms. Further animal experiments and preliminary human clinical trials will lay the foundation for hydrogen use as a drug in the clinic. PMID:27652837

  13. Bilateral Mooren's ulcer - Customised corneal graft with additional amniotic membrane graft.

    PubMed

    Bhandari, Vipul; Siddharthan, K S

    2015-01-01

    Mooren's ulcer (MU) is a rare and painful peripheral corneal ulceration which occurs in the absence of any associated scleritis, and any detectable systemic disease. A 60-year-old male patient was referred to us with bilateral peripheral corneal ulceration. Best corrected visual acuity (BCVA) in both eyes was counting finger at one metre. The right eye showed a 180° thinning with perforation at 8 o'clock position. The left eye showed a 360° thinning with central contact lens type cornea. After complete blood analysis we started the patient on cyclophosphamide orally along with high doses of oral steroids. A crescentic excision of the thinned cornea and crescentic customised corneal graft with additional amniotic membrane graft (AMG) was done first for the right eye and a 360° peripheral lamellar corneal graft with additional AMG for the left eye. The BCVA of RE was 1/60 improving to 6/36 with plus ten aphakic glasses and LE was 3/60. Hand fashioned full thickness crescentic customised corneal graft with additional AMG and a peripheral 360° lamellar corneal graft with additional AMG in these cases are a novel approach to Mooren's ulcer with gratifying results.

  14. Probable graft-vs-graft reaction in an infant after exchange transfusion and marrow transplantation.

    PubMed

    Lauer, B A; Githens, J H; Hayward, A R; Conrad, P D; Yanagihara, R T; Tubergen, D G

    1982-07-01

    A newborn with graft-vs-host (GVH) disease following an exchange transfusion was treated by attempting to eradicate the incompatible graft and to reconstitute the child hematologically and immunologically with a bone marrow transplant. The patient was a female term infant (blood group B, Rh+ Coombs test positive) who received a one-unit group O, Rh- exchange transfusion from an unrelated female donor for hyperbilirubinemia due to ABO incompatibility on day 2. Signs of acute GVH disease began on day 8 and the clinical diagnosis was supported by skin biopsy. With antithymocyte globulin and high dose dexamethasone, the GVH reaction improved somewhat. Cyclophosphamide, 200 mg/kg total dose, was given over four days followed by a marrow graft from a brother who was HLA-A, B identical, and probably also D locus compatible in mixed lymphocyte culture. All signs of GVH resolved with cyclophosphamide treatment and hematologic reconstitution was evident by 14 days after transplant. Two weeks later the GVH reaction and aplastic anemia recurred and Y chromatin was detected in only 6% of marrow cells. The infant died on day 80. Autopsy showed disseminated candidiasis, disseminated cytomegalovirus infection, thymic dysplasia, hypoplastic marrow, and other histopathologic changes consistent with GVH disease. The persistence of female cells in blood and bone marrow and the destruction of the reconstituted marrow suggest that the original incompatible transfusion-derived graft was not eliminated and that it ultimately rejected the histocompatible marrow graft.

  15. A new mechanism associated with compositae graft success.

    PubMed

    Son, Daegu; Jeong, Hoijoon; Choi, Taehyun; Kim, Junhyung; Han, Kihwan

    2010-11-01

    It is believed that the subcutaneous fat of the skin compositae grafts acts as a mechanical barrier limiting vascularisation. This study aims to determine a new mechanism associated with compositae graft take. Ten 3×3 cm rectangular full-thickness skin compositae grafts on the back of a pig were taken and then randomly changed to another place. Silicone sheets were then inserted between the graft and the recipient to block the direct contact of the dermis at the lateral surface of the graft and control the number of surface contacts. The take rate was measured using the digital VISITRAK(®). The microcirculation of the graft was evaluated by microangiograms using a latex-lead oxide solution. There was a 20.5% graft take in all four surface-blocked groups. The microangiograms showed vessel connections not only between the vessels of the dermis, but also between the subcutaneous fat of the graft and perforators from the basal surface of the wound. The subcutaneous layer does not produce a barrier but works as a significant source of vessel communication. Direct vessel-to-vessel anastomosis between the vessels of the subcutaneous fat at the graft and the basal surface of the recipient wound are another important mechanism for the success of compositae grafts.

  16. Factors influencing acute thrombus formation on carotid artery vascular grafts

    SciTech Connect

    Torem, S.; Schneider, P.A.; Paxton, L.D.; Yasuda, H.; Hanson, S.R.

    1988-10-01

    Scintillation camera imaging of 111Indium-labeled platelets has been used to measure acute thrombus formation on modified expanded Teflon (ePTFE) vascular grafts placed in the carotid arteries of normal baboons. Platelet deposition plateaued over 2 hr postoperatively and occurred primarily at the graft-vessel anastomoses. A positive correlation was found between the circulating platelet count in individual animals and the extent of early platelet thrombus deposition. Unmodified ePTFE grafts accumulated 4.6 +/- 1.2 x 10(9) platelets per graft, or 2.3 +/- 0.71 x 10(9) platelets per anastomosis. Acutely, platelet accumulation was reduced versus control graft results by coating the graft lumenal surfaces with a smooth layer of silicone rubber polymer (0.60 +/- 0.19 x 10(9) platelets per anastomosis; P less than 0.02) but not by coating the grafts using a plasma polymer based on methane, which did not modify graft texture (8.2 +/- 1.7 x 10(9) platelets per graft; P greater than 0.10). The benefit of the silicone rubber coating persisted for at least 48 hr. However, longer term patency was not preserved because 10 of 12 grafts placed had failed within 1 to 2 months.

  17. The effects of early postoperative radiation on vascularized bone grafts

    SciTech Connect

    Evans, H.B.; Brown, S.; Hurst, L.N. )

    1991-06-01

    The effects of early postoperative radiation were assessed in free nonvascularized and free vascularized rib grafts in the canine model. The mandibles of one-half of the dogs were exposed to a cobalt 60 radiation dose of 4080 cGy over a 4-week period, starting 2 weeks postoperatively. The patency of vascularized grafts was confirmed with bone scintigraphy. Histological studies, including ultraviolet microscopy with trifluorochrome labeling, and histomorphometric analyses were performed. Osteocytes persist within the cortex of the vascularized nonradiated grafts to a much greater extent than in nonvascularized, nonradiated grafts. Cortical osteocytes do not persist in either vascularized or nonvascularized grafts subjected to radiation. New bone formation is significantly retarded in radiated grafts compared with nonradiated grafts. Periosteum and endosteum remained viable in the radiated vascularized grafts, producing both bone union and increased bone turnover, neither of which were evident to any significant extent in nonvascularized grafts. Bone union was achieved in vascularized and non-vascularized nonradiated bone. In the radiated group of dogs, union was only seen in the vascularized bone grafts.

  18. PRFM enhance wound healing process in skin graft.

    PubMed

    Reksodiputro, Mirta; Widodo, Dini; Bashiruddin, Jenny; Siregar, Nurjati; Malik, Safarina

    2014-12-01

    Facial plastic and reconstructive surgery often used skin graft on defects that cannot be covered primarily by a local flap. However, wound healing using skin graft is slow, most of the time the graft is contractured and the take of graft is not optimal. Platelet rich fibrin matrix (PRFM) is a new generation of concentrated platelets that produce natural fibrin and reported to speed up the healing process. Application of PRFM in the skin graft implants is expected to increase the survival of the graft. We used porcine as animal models to elucidate the effect of autologous PRFM on wound healing in full-thickness (FTSG) and split-thickness (STSG) skin grafts. Survival level of the skin graft was determined by using ImageJ software based on the formation of collagen type 1 and graft take. We observed that the use of PRFM in FTSG and STSG increased type 1 collagen formation. We also found that PRFM addition in STSG gave the best skin graft take.

  19. Helical type coronary bypass graft performance: Experimental investigations.

    PubMed

    Bernad, Sandor I; Bosioc, Alin I; Bernad, Elena S; Craina, Marius L

    2015-01-01

    Optimal graft design has been an objective of many researchers to find correlations between hemodynamics and graft failure. Compared to planar grafts, the helical graft configurations improve hemodynamic performance including the promotion of flow mixing and reduction of flow stagnation regions. In order to evaluate the advantages and disadvantages of the suggested helical type bypass graft model in comparison to a conventional bypass graft configuration, three experimental models were designed and evaluated. The character of complex vortex structures created in the area between the heel and the occluded section depends on the flow parameters (in the case of the straight graft). We have identified two vortices in the symmetrical plane (proximal and distal to the anastomosis). In the new design of the two-turn helical graft, the stagnation point is eliminated from the anastomoses at different time intervals compared to the conventional straight bypass model The present study indicated that the magnitude of the pressure drop along a helical graft was considerably increased compared to a traditional graft which, while still physiologically advantageous, can be surpassed by an optimal geometry model.

  20. Pancreas transplantation. An immunohistologic and histopathologic examination of 100 grafts.

    PubMed Central

    Sibley, R. K.; Sutherland, D. E.

    1987-01-01

    The authors examined tissues obtained by biopsy, pancreatectomy, and autopsy from 100 pancreas grafts to determine the cause of dysfunction or failure of the graft. Immunohistologic examination of 42 tissues to determine the mononuclear cell phenotypes and Class I and II antigen expression was performed as well. Technical factors--infections, thrombosis, obstruction--accounted for a large number of graft losses, but immunologic-mediated mechanisms resulted in graft dysfunction and failure as well. Pleomorphic inflammatory infiltrates were present in grafts with acute rejection, as well as Silastic and Prolamine duct-obstructed grafts. Criteria useful in the identification of acute rejection from pancreatitis included a more intense, predominantly mononuclear cell infiltration of transformed lymphocytes in the exocrine pancreas and evidence of vascular rejection--endovasculitis or fibrinoid necrosis. Increased expression and/or induction of Class I and II antigens on pancreatic constituents occurred in grafts with evidence of acute rejection, but also with Silastic and prolamine duct-obstructed pancreatitis. An isletitis occurred in 25% of the grafts. Nine of the 25 grafts (36%) with isletitis also had selective loss of beta cells from the islets. Recurrent diabetes mellitus appeared to have developed in these cases, which accounted for loss of graft function. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 PMID:3037911

  1. Peripheral Stent Placement in Hemodialysis Grafts

    SciTech Connect

    Kariya, Shuji Tanigawa, Noboru; Kojima, Hiroyuki; Komemushi, Atsushi; Shomura, Yuzo; Shiraishi, Tomokuni; Kawanaka, Toshiaki; Sawada, Satoshi

    2009-09-15

    The purpose of the present study was to evaluate the clinical outcome of peripheral stent placement after failed balloon angioplasty in patients with grafts who are on hemodialysis. We examined 30 Wallstents that were placed in 26 patients because balloon angioplasty failed or early restenosis (<3 months) occurred within 3 months. We retrospectively reviewed 267 consecutive balloon angioplasties performed in 71 patients with graft access between August 2000 and March 2007. Stent placements accounted for 30 (11.2%) of the 267 balloon angioplasties. The clinical success rate of stent placement was 93.3% (28 of 30 stent placements). The 3-, 6-, and 12-month primary patency rates were 73.3%, 39.3%, and 17.7%, respectively. The 1-, 2-, and 3-year secondary patency rates were 90.2%, 83.8%, and 83.8%, respectively. Primary patency was significantly prolonged by stent placement after early restenosis compared with previous balloon angioplasty alone (P = 0.0059). Primary patency after stent placement was significantly lower than after successful balloon angioplasty without indications for stent placement (P = 0.0279). Secondary patency rates did not significantly differ between stent placement and balloon angioplasty alone. The mean number of reinterventions required to maintain secondary patency after stent placement was significantly larger than that after balloon angioplasty alone (Mann-Whitney U test, P = 0.0419). We concluded that peripheral stent placement for graft access is effective for salvaging vascular access after failed balloon angioplasty and for prolonging patency in early restenosis after balloon angioplasty. However, reinterventions are required to maintain secondary patency after stent placement. Furthermore, peripheral stent placement for graft access cannot achieve the same primary patency as balloon angioplasty alone.

  2. Improvement of tomato local varieties by grafting in organic farming

    NASA Astrophysics Data System (ADS)

    Moreno, Marta M.; Villena, Jaime; Moreno, Carmen; García, Arántzazu M.; Mancebo, Ignacio; Meco, Ramón

    2015-04-01

    Grafting is the union of two or more pieces of living plant tissue that grow as a single plant. The early use of grafted vegetables was associated with protected cultivation which involves successive cropping (Lee et al., 2010). For this reason, in the past, grafting was used with vegetable crops to limit the effects of soil-borne diseases. However, the reasons for grafting as well as the kinds of vegetable grafted have increased considerably over the years. In tomato (Solanum lycopersicum L.), one of the most important horticultural crops in the world, the effect of grafting has also been widely studied. These effects on commercial tomato varieties can be summarized in increasing plant vigor and crop yield or inducing tolerance to abiotic stresses, although the effects on tomato fruit quality or on the sensory properties are not so patent (David et al., 2008). However, a few studies about the effect of grafting on local tomato varieties, which are especially recommended for organic production in spite of their lower yields in many cases, have been developed. In this work we evaluated the effect of grafting on tomato local varieties under organic management using vigorous commercial rootstocks, and aspects related to vigor, yield and tomato fruit composition were analyzed. In general terms, grafting increased the plant vigor, the crop yield and the fruit antioxidant content, although no modification of morphological fruit attributes was observed. Keywords: grafting, Solanum lycopersicum L., local varieties, organic farming. References: Davis A.R., Perkins-Veazie P., Hassell R., Levi A., King S.R., Zhang X. 2008. Grafting effects on vegetable quality. HortScience 43(6): 1670-1671. Lee J.M., Kubota C., Tsao S.J., Bie Z., Hoyos-Echevarría P., Morra L., Oda M. 2010. Current status of vegetable grafting: Diffusion, grafting techniques, automation. Scientia Horticulturae 127: 93-105.

  3. Dynamic, Nondestructive Imaging of a Bioengineered Vascular Graft Endothelium

    PubMed Central

    Lu, Peng; Xu, Yong; Rylander, Christopher G.; Wang, Ge; Sapoznik, Etai; Criswell, Tracy; Lee, Sang Jin; Soker, Shay; Rylander, Marissa Nichole

    2013-01-01

    Bioengineering of vascular grafts holds great potential to address the shortcomings associated with autologous and conventional synthetic vascular grafts used for small diameter grafting procedures. Lumen endothelialization of bioengineered vascular grafts is essential to provide an antithrombogenic graft surface to ensure long-term patency after implantation. Conventional methods used to assess endothelialization in vitro typically involve periodic harvesting of the graft for histological sectioning and staining of the lumen. Endpoint testing methods such as these are effective but do not provide real-time information of endothelial cells in their intact microenvironment, rather only a single time point measurement of endothelium development. Therefore, nondestructive methods are needed to provide dynamic information of graft endothelialization and endothelium maturation in vitro. To address this need, we have developed a nondestructive fiber optic based (FOB) imaging method that is capable of dynamic assessment of graft endothelialization without disturbing the graft housed in a bioreactor. In this study we demonstrate the capability of the FOB imaging method to quantify electrospun vascular graft endothelialization, EC detachment, and apoptosis in a nondestructive manner. The electrospun scaffold fiber diameter of the graft lumen was systematically varied and the FOB imaging system was used to noninvasively quantify the affect of topography on graft endothelialization over a 7-day period. Additionally, results demonstrated that the FOB imaging method had a greater imaging penetration depth than that of two-photon microscopy. This imaging method is a powerful tool to optimize vascular grafts and bioreactor conditions in vitro, and can be further adapted to monitor endothelium maturation and response to fluid flow bioreactor preconditioning. PMID:23585885

  4. A Patient with Recurrent Arteriovenous Graft Thrombosis

    PubMed Central

    2015-01-01

    Arteriovenous grafts (AVGs) are prone to frequent thrombosis that is superimposed on underlying hemodynamically significant stenosis, most commonly at the graft-vein anastomosis. There has been great interest in detecting AVG stenosis in a timely fashion and performing preemptive angioplasty, in the belief that this will prevent AVG thrombosis. Three surveillance methods (static dialysis venous pressure, flow monitoring, and duplex ultrasound) can detect AVG stenosis. Whereas observational studies have reported that surveillance with preemptive angioplasty substantially reduces AVG thrombosis, randomized clinical trials have failed to confirm such a benefit. There is a high frequency of early AVG restenosis after angioplasty caused by aggressive neointimal hyperplasia resulting from vascular injury. Stent grafts prevent AVG restenosis better than balloon angioplasty, but they do not prevent AVG thrombosis. Several pharmacologic interventions to prevent AVG failure have been evaluated in randomized clinical trials. Anticoagulation or aspirin plus clopidogrel do not prevent AVG thrombosis, but increase hemorrhagic events. Treatment of hyperhomocysteinemia does not prevent AVG thrombosis. Dipyridamole plus aspirin modestly decreases AVG stenosis or thrombosis. Fish oil substantially decreases the frequency of AVG stenosis and thrombosis. In patients who have exhausted all options for vascular access in the upper extremities, thigh AVGs are a superior option to tunneled internal jugular vein central vein catheters (CVCs). An immediate-use AVG is a reasonable option in patients with recurrent CVC dysfunction or infection. Tunneled femoral CVCs have much worse survival than internal jugular CVCs. PMID:25883073

  5. Research of Customized Aortic Stent Graft Manufacture

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Chen, Xin; Liu, Muhan

    2017-03-01

    Thoracic descending aorta diseases include aortic dissection and aortic aneurysm, of which the natural mortality rate is extremely high. At present, endovascular aneurysm repair (EVAR) has been widely used as an effective means for the treatment of descending aortic disease. Most of the existing coating stents are standard design, which are unable to meet the size or structure of different patients. As a result, failure of treatment would be caused by dimensional discrepancy between stent and vessels, which could lead to internal leakage or rupture of blood vessels. Therefore, based on rapid prototyping sacrificial core – coating forming (RPSC-CF), a customized aortic stent graft manufactured technique has been proposed in this study. The aortic stent graft consists of film and metallic stent, so polyether polyurethane (PU) and nickel-titanium (NiTi) shape memory alloy with good biocompatibility were chosen. To minimum film thickness without degrading performance, effect of different dip coating conditions on the thickness of film were studied. To make the NiTi alloy exhibit super-elasticity at body temperature (37°C), influence of different heat treatment conditions on austenite transformation temperature (Af) and mechanical properties were studied. The results show that the customized stent grafts could meet the demand of personalized therapy, and have good performance in blasting pressure and radial support force, laying the foundation for further animal experiment and clinical experiment.

  6. PHYSICOCHEMICAL CHARACTERIZATION OF LYOPHILIZED BOVINE BONE GRAFTS

    PubMed Central

    Galia, Carlos Roberto; Lourenço, André Luis; Rosito, Ricardo; Souza Macedo, Carlos Alberto; Camargo, Lourdes Maria Araujo Quaresma

    2015-01-01

    To evaluate the physicochemical characteristics of lyophilized bovine grafts manufactured on a semi-industrial scale (Orthogen; Baumer S/A*) in accordance with a protocol previously developed by the authors. Methods: The lyophilized bovine bone grafts were characterized by means of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffractometry (XRD), thermogravimetric (TG) analysis, differential exploratory scanning calorimetry (DSC) and Fourier-transform infrared (FT-IR) spectroscopy. Results: Ca was the main component (60%) found in the samples, followed by P (28%) and O (5%). The mean (sd) pore size was 316 μm (146.7), ranging from 91.2 to 497.8 μm, and 333.5 μm (304.8), ranging from 87.2 to 963.9 μm, at 50x and 150x magnification, respectively. The hydroxyapatite peaks were at 26°C and 32°C, and mass losses were observed between 250°C and 640°C, corresponding to organic material and water. Two temperature transitions (45.67°C and 91.89°C) showed denaturation of type 1 collagen and dehydration of hydroxyapatite. Conclusion: The physicochemical assessment of lyophilized bovine bone grafts in accordance with the protocol developed at semi-industrial scale confirmed that this product presents excellent biocompatibility, with characteristics similar to natural bone. PMID:27027036

  7. Block and Graft Copolymers of Polyhydroxyalkanoates

    NASA Astrophysics Data System (ADS)

    Marchessault, Robert H.; Ravenelle, François; Kawada, Jumpei

    2004-03-01

    Polyhydroxyalkanoates (PHAs) were modified for diblock copolymer and graft polymer by catalyzed transesterification in the melt and by chemical synthesis to extend the side chains of the PHAs, and the polymers were studied by transmission electron microscopy (TEM) X-ray diffraction, thermal analysis and nuclear magnetic resonance (NMR). Catalyzed transesterification in the melt is used to produce diblock copolymers of poly[3-hydroxybutyrate] (PHB) and monomethoxy poly[ethylene glycol] (mPEG) in a one-step process. The resulting diblock copolymers are amphiphilic and self-assemble into sterically stabilized colloidal suspensions of PHB crystalline lamellae. Graft polymer was synthesized in a two-step chemical synthesis from biosynthesized poly[3-hydroxyoctanoate-co-3-hydroxyundecenoate] (PHOU) containing ca. 25 mol chains. 11-mercaptoundecanoic acid reacts with the side chain alkenes of PHOU by the radical addition creating thioether linkage with terminal carboxyl functionalities. The latter groups were subsequently transformed into the amide or ester linkage by tridecylamine or octadecanol, respectively, producing new graft polymers. The polymers have different physical properties than poly[3-hydroxyoctanoate] (PHO) which is the main component of the PHOU, such as non-stickiness and higher thermal stability. The combination of biosynthesis and chemical synthesis produces a hybrid thermoplastic elastomer with partial biodegradability.

  8. Fluorescence spectroscopy for assessment of liver transplantation grafts concerning graft viability and patient survival

    NASA Astrophysics Data System (ADS)

    Vollet Filho, José D.; da Silveira, Marina R.; Castro-e-Silva, Orlando; Bagnato, Vanderlei S.; Kurachi, Cristina

    2015-06-01

    Evaluating transplantation grafts at harvest is essential for its success. Laser-induced fluorescence spectroscopy (LIFS) can help monitoring changes in metabolic/structural conditions of tissue during transplantation. The aim of the present study is to correlate LIFSobtained spectra of human hepatic grafts during liver transplantation with post-operative patients' mortality rate and biochemical parameters, establishing a method to exclude nonviable grafts before implantation. Orthotopic liver transplantation, piggyback technique was performed in 15 patients. LIFS was performed under 408nm excitation. Collection was performed immediately after opening donor's abdominal cavity, after cold perfusion, end of back-table period, and 5 min and 1 h after warm perfusion at recipient. Fluorescence information was compared to lactate, creatinine, bilirubin and INR levels and to survival status. LIFS was sensitive to liver changes during transplantation stages. Study-in-progress; initial results indicate correlation between fluorescence and life/death status of patients.

  9. Protective constriction of coronary vein grafts with knitted nitinol

    PubMed Central

    Moodley, Loven; Franz, Thomas; Human, Paul; Wolf, Michael F.; Bezuidenhout, Deon; Scherman, Jacques; Zilla, Peter

    2013-01-01

    OBJECTIVES Different flow patterns and shear forces were shown to cause significantly more luminal narrowing and neointimal tissue proliferation in coronary than in infrainguinal vein grafts. As constrictive external mesh support of vein grafts led to the complete suppression of intimal hyperplasia (IH) in infrainguinal grafts, we investigated whether mesh constriction is equally effective in the coronary position. METHODS Eighteen senescent Chacma baboons (28.8 ± 3.6 kg) received aorto-coronary bypass grafts to the left anterior descending artery (LAD). Three groups of saphenous vein grafts were compared: untreated controls (CO); fibrin sealant-sprayed controls (CO + FS) and nitinol mesh-constricted grafts (ME + FS). Meshes consisted of pulse-compliant, knitted nitinol (eight needles; 50 μm wire thickness; 3.4 mm resting inner diameter, ID) spray attached to the vein grafts with FS. After 180 days of implantation, luminal dimensions and IH were analysed using post-explant angiography and macroscopic and histological image analysis. RESULTS At implantation, the calibre mismatch between control grafts and the LAD expressed as cross-sectional quotient (Qc) was pronounced [Qc = 0.21 ± 0.07 (CO) and 0.18 ± 0.05 (CO + FS)]. Mesh constriction resulted in a 29 ± 7% reduction of the outer diameter of the vein grafts from 5.23 ± 0.51 to 3.68 ± 0 mm, significantly reducing the calibre discrepancy to a Qc of 0.41 ± 0.17 (P < 0.02). After 6 months of implantation, explant angiography showed distinct luminal irregularities in control grafts (ID difference between widest and narrowest segment 74 ± 45%), while diameter variations were mild in mesh-constricted grafts. In all control grafts, thick neointimal tissue was present [600 ± 63 μm (CO); 627 ± 204 μm (CO + FS)] as opposed to thin, eccentric layers of 249 ± 83 μm in mesh-constricted grafts (ME + FS; P < 0.002). The total wall thickness had increased by 363 ± 39% (P < 0.00001) in CO and 312 ± 61% (P < 0

  10. Radiation grafting of various water-soluble monomers on ultra-high molecular weight polyethylene powder:. Part I. Grafting conditions and grafting yield

    NASA Astrophysics Data System (ADS)

    Aydinli, Bahattin; Tinçer, Teoman

    2001-02-01

    Monomers of some water-soluble polymers; acrylic acid, methacrylic acid, acrylamide, N, N -dimethyl acrylamide and 1-vinyl-2 pyrrolidone, were grafted on ultra-high molecular weight polyethylene (UHMWPE) powders by a direct grafting method in an aqueous medium in air. Inhibition of homopolymerisation was achieved by adding various concentrations of Fe 2+ or Cu 2+ ions. It was found that the degree of grafting increases linearly with dose till a gelation state is reached, and varies between 40 and 12% depending on the monomer. Four million molecular weight UHMWPE gave a higher per cent grafting than a 6 million counterpart for the monomers used, with the exception of acrylic acid monomer grafting.

  11. Sodium and chloride exclusion and retention by non-grafted and grafted melon and Cucurbita plants.

    PubMed

    Edelstein, M; Plaut, Z; Ben-Hur, M

    2011-01-01

    The effects of grafting on Na and Cl(-) uptake and distribution in plant tissues were quantified in a greenhouse experiment using six combinations of melon (Cucumis melo L. cv. Arava) and pumpkin (Cucurbita maxima Duchesne×Cucurbita moschata Duchesne cv. TZ-148): non-grafted, self-grafted, melons grafted on pumpkins, and pumpkins grafted on melons. Total Na concentration in shoots of plants with pumpkin or melon rootstocks was <60 mmol kg(-1) and >400 mmol kg(-1), respectively, regardless of the scion. In contrast, shoot Cl(-) concentrations were quite similar among the different scion-rootstock combinations. Na concentrations in exudates from cut stems of plants with a pumpkin rootstock were very low (<0.18 mM), whereas those in the exudates of plants with melon rootstocks ranged from 4.7 mM to 6.2 mM, and were quite similar to the Na concentration in the irrigation water. Root Na concentrations averaged 11.7 times those in the shoots of plants with pumpkin rootstocks, while in plants with melon rootstocks, values were similar. Two mechanisms could explain the decrease in shoot Na concentrations in plants with pumpkin rootstocks: (i) Na exclusion by the pumpkin roots; and (ii) Na retention and accumulation within the pumpkin rootstock. Quantitative analysis indicated that the pumpkin roots excluded ∼74% of available Na, while there was nearly no Na exclusion by melon roots. Na retention by the pumpkin rootstocks decreased its amount in the shoot by an average 46.9% compared with uniform Na distribution throughout the plant. In contrast, no retention of Na could be found in plants grafted on melons.

  12. Preirradiation grafting of ethylene vinyl acetate copolymer resins

    NASA Astrophysics Data System (ADS)

    Ringrose, B. J.; Kronfli, E.

    1999-07-01

    Acrylic acid was graft copolymerised on to EVA powdered resins containing 9%, 18% and 28% vinyl acetate. A preirradiation grafting method was used and the effect on graft level of varying the parameters of gamma irradiation dose (2-50 kGy), dose rate (0.5-5 kGy h -1), monomer concentration (2.5-25%) and grafting time (1-4 h) and temperature (35-98°C) was investigated. The graft copolymer resins were converted into film and characterised in terms of their hydrophilicity and electrolytic resistance in alkaline solutions. Depending on the vinyl acetate content and rheological properties of the base EVA copolymer, high graft weight resins can be converted into semipermeable films suitable for a range of applications including battery separator membranes and topical medical dressings.

  13. Buccal mucosal graft in reconstructive urology: uses beyond urethral stricture.

    PubMed

    Pandey, Abhishek; Dican, Razvan; Beier, Jörn; Keller, Hansjörg

    2014-07-01

    The use of buccal mucosal grafts for the reconstruction of urethral strictures is an established procedure. Because of its robustness, the buccal mucosal graft could also potentially provide an alternative for other indications in reconstructive urology. We report here six consecutive patients who received a buccal mucosal graft for ureteral strictures, glans reconstruction and stoma stenosis. The follow up for all patients ranged from 26 to 50 months. The buccal mucosal graft showed excellent functional results for the ureteral strictures and stenosis from ureterocutaneostomy. For glans reconstructions, the buccal mucosal grafts delivered excellent cosmetic and functional results without causing meatal stenosis. We conclude the buccal mucosal graft can be used in reconstructive surgery beyond the reconstruction of urethral strictures.

  14. Role of Bone Graft in Reconstruction of Skull Base Defect

    PubMed Central

    Yamamoto, Yuhei; Minakawa, Hidehiko; Yoshida, Tetsunori; Igawa, Hiroharu; Sugihara, Tsuneki; Ohura, Takehiko; Nohira, Kunihiko

    1993-01-01

    Ten patients underwent reconstruction of skull base defects between 1989 and 1992. In this series, the maximum size of the skull base defect was 6 × 5 cm. Three patients underwent bone grafts to reinforce the skull base. The postoperative course of seven patients without bone grafts was uneventful. There was no cerebrospinal fluid leakage, meningitis, extradural abscess, on brain herniation. On the other hand, two of the three patients with bone grafts developed extradural abseesses requiring the bone grafts to be removed. Although the number of patients in this series is not large, this study demonstrates that the use of bone grafts in reconstruction of skull base detects could be one of the factors in increasing the chances of infectious complications. We think that a bone graft is not necessary to reconstruct moderate-sized skull base defects. ImagesFigure 1Figure 2Figure 2Figure 3Figure 3Figure 4p228-aFigure 4Figure 4 PMID:17170915

  15. Synthesis of graft copolymers onto starch and its semiconducting properties

    NASA Astrophysics Data System (ADS)

    Çankaya, Nevin

    Literature review has revealed that, although there are studies about grafting on natural polymers, especially on starch, few of them are about electrical properties of graft polymers. Starch methacrylate (St.met) was obtained by esterification of OH groups on natural starch polymer for this purpose. Grafting of synthesized N-cyclohexyl acrylamide (NCA) and commercial methyl methacrylate (MMA) monomers with St.met was done by free radical polymerization method. The graft copolymers were characterized with FT-IR spectra, thermal and elemental analysis. Thermal stabilities of the graft copolymers were determined by TGA (thermo gravimetric analysis) method and thermal stability of the copolymers is decreased via grafting. The electrical conductivity of the polymers was measured as a function of temperature and it has been observed that electrical conductivity increases with increasing temperature. The absorbance and transmittance versus wavelength of the polymers have been measured.

  16. Occurrence of occlusive intimal changes in an expanded polytetrafluoroethylene graft.

    PubMed

    Carson, S N; Hunter, G; French, S; Lord, P; Wong, H N

    1980-01-01

    A case report is presented demonstrating pathologic changes in the neointima that formed when a polytetrafluoroethylene (PTFE) graft was placed in a 35 year old white male with severe arteriosclerosis. Representative sections of the patient's artery and graft were taken which demonstrated considerable smooth muscle proliferation in both along with full wall healing in the latter. Partial oclusion of the total length of the PTFE graft by a process similar to that occurring in the patient's own arteriosclerotic arteries was found. The consistency and extent of the involvement (> 10 cm in length) would appear to preclude entities such as neointimal fibrous hyperplasia and may point to another consequence of intimal injury and full wall graft healing which may be an undesirable effect of arteriosclerotic metabolism in the human. It is conceivable that full wall graft healing in an arteriosclerotic individual may have untoward events that need to be further investigated as new graft materials are developed.

  17. Impact of solvent selection on graft polymerization of acrylamide onto starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact on polymer properties [molecular weight, monomer conversion, graft content, graft efficiency and anhydroglucose units between grafts (AGU/graft)] that result from changing the solvent for the graft co-polymerization of acrylamide onto starch from water to dimethylsulfoxide (DMSO) was eval...

  18. Stent graft repair of anastomotic pseudoaneurysm of femoral–popliteal bypass graft following patch angioplasty

    PubMed Central

    Carollo, Andrea; Gagliardo, Giovanni; DeVito, Peter M.; Cicchillo, Michael

    2016-01-01

    Pseudoaneurysm (PA) following vascular reconstruction is a complication of bypass surgery. Historically, the mainstay of treatment was an open repair; the surgical management consisted of resection of the initial graft with reimplantation of a new bypass either into the original arteriotomy or to a more distal target. Placement of a stent graft to exclude the PA is a viable option. We present a case of an 85-year-old man with prior history of polytetrafluoroethylene femoral–popliteal bypass now with an 8 × 5.6 cm PA of the distal anastomosis site treated with endovascular placement of a Viabahn stent. PMID:27994009

  19. Facile grafting of bioactive cellulose derivatives onto PVC surfaces

    NASA Astrophysics Data System (ADS)

    Bigot, Sandra; Louarn, Guy; Kébir, Nasreddine; Burel, Fabrice

    2013-10-01

    Bioactive methyl cellulose and hydroxyethyl cellulose were successfully grafted onto PVC films using a two-step pathway. PVC surface was first modified with isothiocyanate in DMSO/water medium. Then, unmodified polysaccharides were directly grafted onto the thiocyanated surface in acetonitrile/DMSO mixture, in presence of DBTL as catalyst. The polysaccharide grafting onto the PVC surface was evidenced by contact angle measurements, AFM and XPS.

  20. ROMP from ROMP: A New Approach to Graft Copolymer Synthesis

    PubMed Central

    Allen, Matthew J.; Wangkanont, Kittikhun; Raines, Ronald T.; Kiessling, Laura L.

    2009-01-01

    A new strategy is presented for the synthesis of graft copolymers using only the ring-opening metathesis polymerization (ROMP). From a ROMP-derived main chain, pendant maleimide functional groups are converted into norbornene moieties via a Diels–Alder reaction with cyclopentadiene. The norbornene groups serve as sites of initiation, and subsequent ROMP from the main chain yields graft copolymers with both main and side chains derived from ROMP. This strategy offers ready access to defined graft copolymers. PMID:20161406

  1. [Coronary artery bypass grafting using side-to-side anastomosis].

    PubMed

    Niinami, H; Takeuchi, Y

    2000-08-01

    Recently, to obtain better long-term patency after coronary artery bypass grafting (CABG) arterial conduits such as internal mammary arteries (IMAs) and the right gastroepiploic artery have been frequently used. For coronary site anastomosis, end-to-side anastomosis is common. These conduits have a smaller diameter than the saphenous vein graft, so that, usually, longitudinal slits are made on the distal end of these grafts to obtain a more effective anastomotic orifice area. However, there is a potential for anastomotic leakage due to mismatch between the incision of the coronary artery and the arterial graft. We report here the efficacy of side-to-side anastomosis using small arterial conduits. This method has several advantages. Firstly, there is no chance of anastomotic leakage, since the coronary incision and graft incision can be perfectly matched. Secondly, if there is at least a 5-mm distance between the distal end of the graft incision and the surgical clip, the graft incision can be extended during anastomosis for adjustment. Thirdly, the distal end of the graft can be held beyond the surgical clip by forceps without damaging the arterial graft, which makes it easier for the anastomosis to be performed. Finally, the anastomosis can be checked by passing a probe through the distal end of the graft after removing the surgical clip. Also dye can be injected from the distal end of the graft at "Off Pump CABG", intraoperatively. This technique can be applied not only for distal end anastomosis, but also for proximal end, using free IMA to the ascending aorta and to make a Y-graft.

  2. Biofabrication and testing of a fully cellular nerve graft.

    PubMed

    Owens, Christopher M; Marga, Francoise; Forgacs, Gabor; Heesch, Cheryl M

    2013-12-01

    Rupture of a nerve is a debilitating injury with devastating consequences for the individual's quality of life. The gold standard of repair is the use of an autologous graft to bridge the severed nerve ends. Such repair however involves risks due to secondary surgery at the donor site and may result in morbidity and infection. Thus the clinical approach to repair often involves non-cellular solutions, grafts composed of synthetic or natural materials. Here we report on a novel approach to biofabricate fully biological grafts composed exclusively of cells and cell secreted material. To reproducibly and reliably build such grafts of composite geometry we use bioprinting. We test our grafts in a rat sciatic nerve injury model for both motor and sensory function. In particular we compare the regenerative capacity of the biofabricated grafts with that of autologous grafts and grafts made of hollow collagen tubes by measuring the compound action potential (for motor function) and the change in mean arterial blood pressure as consequence of electrically eliciting the somatic pressor reflex. Our results provide evidence that bioprinting is a promising approach to nerve graft fabrication and as a consequence to nerve regeneration.

  3. Corrective osteotomies of the radius: Grafting or not?

    PubMed Central

    Mugnai, Raffaele; Tarallo, Luigi; Lancellotti, Enrico; Zambianchi, Francesco; Di Giovine, Ettore; Catani, Fabio; Adani, Roberto

    2016-01-01

    AIM: To review the current literature regarding corrective osteotomies to provide the best evidence of the rule of bone grafting. METHODS: Our MEDLINE literature search included 280 studies using the following key words “Malunited distal radius fracture” and 150 studies using key words “Corrective osteotomy of the distal radius”. Inclusion criteria were: Malunited distal radial, extra articular fracture, volar locking plate, use of iliac bone graft (cancellous or corticocancellous), non-use of bone graft. Twelve studies met the inclusion criteria. RESULTS: Seven of the 12 studies considered, described the use of a graft; the remaining five studies didn’t use any graft. Type of malunion was dorsal in most of the studies. The healing time was comparable using the graft or not (mean 12.5 wk), ranging from 7.5 to 16 wk. The mean disabilities of the arm, shoulder and hand score improvement was 23 points both in the studies that used the graft and in those not using the graft. CONCLUSION: This review demonstrated that corrective osteotomy of extra-articular malunited fractures of the distal radius treated by volar locking plate does not necessarily require bone graft. PMID:26925385

  4. pH responsive graft copolymers of chitosan.

    PubMed

    Yilmaz, Elvan; Yalinca, Zulal; Yahya, Kovan; Sirotina, Uliana

    2016-09-01

    Grafting suitable polymers onto chitosan can produce cationic or polyampholyte polymers or hydrogels that are potential smart biomedical materials. Chitosan-graft-[poly(diethylamino)ethyl methacrylate] has been prepared in three different physical forms as linear free chains in solution, chemical gels crosslinked with glutaraldehyde, and poly(diethylamino)ethyl methacrylate] grafted onto chitosan tripolyphosphate gel beads. In addition to chemical structure, the graft copolymers were characterized with respect to their dissolution and swelling behavior in aqueous solution. It has been established that solubility of the products is controlled by the grafting yield. While pH sensitive polymers, which collapse at a given pH value are obtained at lower grafting yields, hydrogels form at higher grafting yields with pH responsive swelling behavior. Glutaraldehyde crosslinked chitosan-graft-[poly(diethylamino)ethyl methacrylate] gels and chitosan tripolyphosphate gel beads grafted with poly[(diethylamino)ethyl methacrylate] exhibit pH sensitive swelling with highest equilibrium swelling capacity at pH=1.2.

  5. R&D for graft adsorbents by radiation processing

    NASA Astrophysics Data System (ADS)

    Seko, Noriaki; Tamada, Masao

    Fibrous adsorbent for removal and recovery of metal ions have been synthesized by graft polymerization. In the grafting, the functional groups which have high selectivity against for target metal ions such as Fe, Sc, As, and U are introduced onto nonwoven fabric. When the monomer has a chelate group which makes selective coordination bond to specific these ions, it was directly grafted on the trunk polymer. In the case of precursor monomer having functional groups such as epoxy ring, the grafted trunk fabric is chemically modified. The resultant fibrous adsorbent leads the swift adsorption of metal ions. This property by using fibrous material can reduce the column size of adsorbent in the purification of waste water. The size of purification equipment becomes quite compact and that implies total volume of equipment can reduce. Instead of organic solvent, emulsion system which disperses monomer micelles in water with assistance of surfactant was found to accelerate the graft polymerization. This means the air pollution from organic solvent can be avoided by water system grafting. Furthermore, since the emulsion grafting was highly efficient, the required irradiation dose was considerably lower compared to general organic solvent system. As a result, the emulsion grafting has enormous potential for natural polymer to use as a trunk material for grafting. If a natural polymer such as cellulose can be used, the dependence on petroleum resources, the amount of industrial waste and the generation of carbon dioxide will be reduced to some extent.

  6. Grafting onto wool. XX. Graft copolymerization of vinyl monomers by use of redox initiators. Comparison of monomer reactivities

    SciTech Connect

    Misra, B.N.; Singha, A.S.; Sharma, R.K.

    1982-04-01

    Methyl methacrylate (MMA) and ethylacrylate (EA) have been graft copolymerized onto Himachali wool in aqueous medium by using a ferrous ammonium sulfate-hydrogen peroxide (FAS-H/sub 2/O/sub 2/) system as redox initiator. Percentage of grafting has been determined as functions of concentration of monomer, molar ratio of (FAS)/(H/sub 2/O/sub 2/), time, and temperature. Percentage of grafting is found to depend upon the molar ratio of (FAS)/(H/sub 2/O/sub 2/). An attempt has been made to compare the reactivities of the acceptor monomer (MMA and EA) with that of the donor monomer (VAc) toward grafting onto wool.

  7. Anti-fouling ultrafiltration membrane prepared from polysulfone-graft-methyl acrylate copolymers by UV-induced grafting method.

    PubMed

    Hua, Helin; Li, Na; Wu, Linlin; Zhong, Hui; Wu, Guangxial; Yuan, Zonghuan; Lin, Xiangwei; Tang, Lianyi

    2008-01-01

    Membrane fouling is one of the most important challenges faced in membrane ultrafiltration operations. The copolymers of polysulfone-graft-methyl acrylate were synthesized by homogeneous photo-initiated graft copolymerization. The variables affecting the degree of grafting, such as the time of UV (Ultraviolet-visible) irradiation and the concentrations of the methyl acrylate and photoinitiator, were investigated. The graft copolymer membranes were prepared by the phase inversion method. The chemical and morphological changes were characterized by attenuated total reflection-Fourier transform infrared spectroscopy (ATR/FT-IR), scanning electron microscopy, and water contact angles measurements. Results revealed that methyl acrylate groups were present on the membranes and the graft degree of methyl acrylate had remarkable effect on the performance of membranes. Pure water contact angle on the membrane surface decreases with the increase of methyl acrylate graft degree, which indicated that the hydrophilicity of graft copolymer membranes was improved. The permeation fluxes of pure water and bovine serum albumin solution were measured to evaluate the antifouling property of graft copolymer membranes, the results of which have shown an enhancement of antifouling property for graft copolymer membranes.

  8. Angiographic Evaluation of Carotid Artery Grafting with Prefabricated Small-Diameter, Small-Intestinal Submucosa Grafts in Sheep

    SciTech Connect

    Pavcnik, Dusan; Obermiller, Josef; Uchida, Barry T.; Van Alstine, William; Edwards, James M.; Landry, Gregory J.; Kaufman, John A.; Keller, Frederick S.; Roesch, Josef

    2009-01-15

    The purpose of this study was to report the longitudinal angiographic evaluation of prefabricated lyophilized small-intestinal submucosa (SIS) grafts placed in ovine carotid arteries and to demonstrate a variety of complications that developed. A total of 24 grafts, 10 cm long and 6 mm in diameter, were placed surgically as interposition grafts. Graft patency at 1 week was evaluated by Doppler ultrasound, and angiography was used for follow-up at 1 month and at 3 to 4 months. A 90% patency rate was found at 1 week, 65% at 1 month, and 30% at 3 to 4 months. On the patent grafts, angiography demonstrated a variety of changes, such as anastomotic stenoses, graft diffuse dilations and dissections, and aneurysm formation. These findings have not been previously demonstrated angiographically by other investigators reporting results with small-diameter vessel grafts made from fresh small-intestinal submucosa (SIS). The complications found were partially related to the graft construction from four SIS layers. Detailed longitudinal angiographic study should become an essential part of any future evaluation of small-vessel SIS grafting.

  9. Insitu grafting silica nanoparticles reinforced nanocomposite hydrogels

    NASA Astrophysics Data System (ADS)

    Yang, Jun; Han, Chun-Rui; Duan, Jiu-Fang; Xu, Feng; Sun, Run-Cang

    2013-10-01

    Highly flexible nanocomposite hydrogels were prepared by using silica nanoparticles (SNPs) as fillers and multi-functional cross-links to graft hydrophilic poly(acrylic acid) (PAA) by free radical polymerization from an aqueous solution. The SNPs were collected by neighboring polymer chains and dispersed uniformly within a PAA matrix. The mechanical properties of the nanocomposite hydrogels were tailored by the concentration of SNPs according to the percolation model. It was proposed that covalent bonds of adsorbed chains on the filler surface resulted in the formation of a shell of an immobilized glassy layer and trapped entanglements, where the glassy polymer layer greatly enhanced the elastic modulus and the release of trapped entanglements at deformation contributed to the viscoelastic properties.Highly flexible nanocomposite hydrogels were prepared by using silica nanoparticles (SNPs) as fillers and multi-functional cross-links to graft hydrophilic poly(acrylic acid) (PAA) by free radical polymerization from an aqueous solution. The SNPs were collected by neighboring polymer chains and dispersed uniformly within a PAA matrix. The mechanical properties of the nanocomposite hydrogels were tailored by the concentration of SNPs according to the percolation model. It was proposed that covalent bonds of adsorbed chains on the filler surface resulted in the formation of a shell of an immobilized glassy layer and trapped entanglements, where the glassy polymer layer greatly enhanced the elastic modulus and the release of trapped entanglements at deformation contributed to the viscoelastic properties. Electronic supplementary information (ESI) available: FTIR spectra of SNP after silane treatment, dynamic oscillatory shear measurements as a function of frequency, constrained polymer chain analysis by a change in the peak height in loss factor spectra, molecular weight of grafted chains at different stages of gelation, prediction of the SNP reinforcing mechanism in the

  10. Synthesis and characterization of polyvinylimidazole-grafted superparamagnetic iron oxide nanoparticles (Si-PVIm-grafted SPION)

    NASA Astrophysics Data System (ADS)

    Erdemi, H.; Sözeri, H.; Şenel, M.; Baykal, A.

    2012-08-01

    Polyvinylimidazole (PVIm)-grafted superparamagnetic iron oxide nanoparticles (SPION) (Si-PVIm-grafted Fe3O4 NPs) were prepared by grafting of telomere of PVIm on the SPION. The product identified as magnetite, which has an average crystallite size of 9 ± 2 nm as estimated from X-ray line profile fitting. Particle size was estimated as 10.0 ± 0.5 nm from TEM micrographs. Mean particle size is found as 8.4 ± 1.0 nm which agrees well with the values calculated from XRD patterns (9 ± 2 nm). Vibrating Sample Magnetometer (VSM) analysis explained the superparamagnetic nature of the nanocomposite. Thermogravimetric analysis showed that the Si-Imi is 25 % of the Si-PVIm-grafted SPION, which means an inorganic content is about 75 %. Detailed electrical and dielectric properties of the properties of the product are also presented. The conductivity of the sample increases significantly with temperature and has the value in the range of 1.14 × 10-7-1.78 × 10-4 S cm-1. Analysis of the real and imaginary parts of the permittivities indicated temperature and frequency dependency representing interfacial polarization and temperature-assisted reorganization effects.

  11. Mass transport disturbances in the distal graft/artery junction of a peripheral bypass graft.

    PubMed

    Devereux, P D; O'Callaghan, S M; Walsh, M T; McGloughlin, T

    2005-11-01

    Intimal hyperplasia (IH) development is a primary cause of failure of reconstructive bypass surgery. While the exact mechanism by which IH initiates and proliferates has yet to be fully elucidated, it is clear that the abnormal haemodynamics present in the downstream graft/artery junction are intrinsic in its development. Mass transport disturbances owing to abnormal haemodynamics have been associated with atherogenesis and it is for this reason that an investigation into transport of platelet-derived growth factor (PDGF), a known promoter of the intimal hyperplastic response, at the downstream graft/artery junction was carried out. A steady flow analysis in a three-dimensional, idealized, downstream graft/artery junction was carried out using commercial computational fluid dynamics software. It was found that there is a two-and-half fold increase in the transport of PDGF to the artery wall at the bed of the junction when compared with an idealized, healthy artery. The presence of secondary flows in the downstream arterial section also leads to large disturbances in mass transport. It was concluded that PDGF transport in the downstream graft/artery junction tends to be highly disturbed and that there may be a role of this disturbance in the initiation and subsequent development of distal anastomotic intimal hyperplasia.

  12. Vascularized fibular graft to replace resected cervical vertebral bodies. Case report.

    PubMed

    Freidberg, S R; Gumley, G J; Pfeifer, B A; Hybels, R L

    1989-08-01

    Use of a vascularized free fibular graft is described as a method of replacing excised cervical vertebrae when severe instability is present. The vascularized bone graft heals more rapidly and with greater strength than a nonvascularized autogenous graft.

  13. Reshaping Human Antibodies: Grafting an Antilysozyme Activity

    NASA Astrophysics Data System (ADS)

    Verhoeyen, Martine; Milstein, Cesar; Winter, Greg

    1988-03-01

    The production of therapeutic human monoclonal antibodies by hybridoma technology has proved difficult, and this has prompted the ``humanizing'' of mouse monoclonal antibodies by recombinant DNA techniques. It was shown previously that the binding site for a small hapten could be grafted from the heavy-chain variable domain of a mouse antibody to that of a human myeloma protein by transplanting the hypervariable loops. It is now shown that a large binding site for a protein antigen (lysozyme) can also be transplanted from mouse to human heavy chain. The success of such constructions may be facilitated by an induced-fit mechanism.

  14. Surface-grafted polymers from electrodeposited macroprecursors

    NASA Astrophysics Data System (ADS)

    Rellamas Tria, Maria Celeste

    The use of electrochemically deposited macroprecursors for tethering polymers onto conducting surfaces is presented. Specifically, anodic electropolymerization was used as a tool to electrodeposit the precursors on electrodes that mediated the grafting of polymers onto surfaces. With this approach, patterning of surface-grafted polymers was also made possible through selective electrodeposition of the conjugated polymer network of the macroprecursors. This approach was used to fabricate protein and cell-resistant poly(poly(ethylene glycol) methyl ether methacrylate) (PPEGMEMA) brushes on Au surfaces. A chain transfer agent (CTA) was electrodeposited on the Au surface that served as the macroprecursor for the subsequent surface-initiated reversible addition-fragmentation chain transfer (SI-RAFT) polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMEMA). X-ray photoelectron spectroscopy (XPS) results showed the stability of the electrogenerated CTA under anodic conditions while successful brush growth was confirmed by surface techniques including XPS, ellipsometry, atomic force microscopy (AFM), and contact angle measurements. The PPEGMEMA-coated substrate exhibited protein and cell-repellant properties comparable to other reported PEG-functionalized surfaces. The proposed approach also yielded polymer-patterned surfaces as discussed in Chapters 3 and 4. An electroactive photocrosslinker was employed to facilitate the dual mode patterning of polystyrene (PS) on the surface by either electropatterning or photopatteming route. An electrodeposited CTA was also utilized to selectively grow surface-grafted PS on conducting regions of the substrate. Subsequent backfilling of nonconducting areas with a silane atom transfer radical polymerization (ATRP) initiator directed the growth of poly-N-isopropylacrylamide (PNIPAM) that produced a patterned binary polymer system. The patterns were successfully characterized by AFM and IR-imaging. Surface-grafted poly

  15. Autologus parietal grafts in preprosthethic surgery

    PubMed Central

    GHERLONE, E.F.; VINCI, R.; D’AVERSA, L.

    2010-01-01

    SUMMARY Edentulous patients usually request implant supported/fixed rehabilitation. Ridge resorption after teeth loss usually affect three-dimensional implant position. Vertical and/or horizontal bone augmentation procedures are often the only choice the clinician has to deliver prosthetic guided restoration. Gold standard for augmentation procedures such as sinus lift, onlay or inlay grafts, is still autologous bone. The patient in this report underwent a pre-prosthetic reconstruction of the jaws with parietal bone, followed by fixtures insertion and fixed prosthetic rehabilitation. This clinical report aims to underline the importance of multidisciplinary treatment to optimize the results of the rehabilitation. PMID:23285358

  16. [Frenectomy associated with a triangular gingival graft].

    PubMed

    Borghetti, A; Guy, J P; Cesano, B

    1991-11-01

    In periodontal therapy, frenectomy is indicated when the frenum exerts tension on the gingival margin and interferes with proper oral hygiene. The procedure is also employed when the frenum prevents closure of a diastema during orthodontic therapy. Frenectomy should be done after the canines have erupted and before retention is started to prevent separation of the teeth. For an improved surgical and cosmetic result, the authors propose a triangular-shaped gingival graft after the frenum has been excised. The advantage of the procedure is to create an area of attached gingiva and enhance healing.

  17. Radiation-induced grafting of acrylamide onto guar gum in aqueous medium: Synthesis and characterization of grafted polymer guar-g-acrylamide

    NASA Astrophysics Data System (ADS)

    Biswal, Jayashree; Kumar, Virendra; Bhardwaj, Y. K.; Goel, N. K.; Dubey, K. A.; Chaudhari, C. V.; Sabharwal, S.

    2007-10-01

    Mutual radiation grafting technique has been applied to carry out grafting of acrylamide (AAm) onto guar gum (GG) using high-energy Co 60γ radiation to enhance its flocculating properties for industrial effluents. The grafted product was characterized using analytical probes like elemental analysis, thermal analysis, Fourier transformed infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The grafting extent was observed to decrease with the dose rate and increase with the concentration of AAm. Thermo gravimetric analysis (TGA) of grafted and ungrafted samples indicated better stability of grafted product. γ and microwave radiation effect on grafted and virgin GG has also been reported.

  18. Epoxy and Silicone Optical Nanocomposites Filled with Grafted Nanoparticles

    NASA Astrophysics Data System (ADS)

    Tao, Peng

    Polymer nanocomposites, as a technologically important class of materials, exhibit diverse functional properties, and are used for applications ranging from structural and biomedical to electronic and optical. The properties of polymer nanocomposites are determined, in part, by the chemical composition of the polymer matrix and the nanofillers. Their properties are also sensitive to the geometry and size of the nanofillers, and to spatial distribution of the fillers. Control of the nanoparticle size and dispersion within a given polymer provides opportunities to tailor and optimize the properties of nanocomposites for specific application. For optical applications such as encapsulation of light emitting diodes (LEDs), polymer nanocomposites filled with homogeneously dispersed nanoparticles would endow the polymer encapsulant with new functionality without sacrificing optical transparency. To this end, this thesis focuses on developing a simple and versatile approach towards the fabrication of epoxy and silicone transparent nanocomposites using matrix compatible chain-grafted nanoparticles as fillers, and studying the optical properties of the nanocomposites. The surface chemistry and grafted polymer chain design have been shown to play an important role in determining the dispersion state of the grafted nanoparticles and hence the final optical properties of the nanocomposites. To prepare transparent epoxy nanocomposites, poly (glycidyl methacrylate) (PGMA) chains were grafted onto the optical nanoparticle surfaces via a combined phosphate ligand exchange process and azide-alkyne "click" chemistry. The dispersion behavior of PGMA-grafted nanoparticles within the epoxy matrix was investigated by systematically varying the grafting density and grafted chain length. It was found that within the small molecular weight epoxy resins, the dispersion states are more sensitive to the grafting density than the molecular weight of grafted chains. With high grafting densities

  19. Self-Assembled Amphiphilic Macromolecule Coatings: Comparison of Grafting-From and Grafting-To Approaches for Bioactive Delivery.

    PubMed

    Chan, Jennifer W; Huang, Amy; Uhrich, Kathryn E

    2016-05-24

    Although drug-eluting stent technologies have significantly improved clinical outcomes over the past decade, substantial issues with postimplantation vessel reocclusion still remain. To combat these issues, bioactive amphiphilic macromolecules (AMs), comprised of a functional end group, a branched hydrophobic domain, and a hydrophilic poly(ethylene glycol) tail, were investigated as a therapeutic coating to reduce smooth muscle cell (SMC) proliferation and platelet adhesion. In this study, grafting-from and grafting-to approaches for AM surface functionalization were compared to determine the effects of fabrication method on bioactive delivery characteristics, including the AM loading, release, and biological activity. Grafted-from coatings were formed by stepwise synthesis of phosphonate AMs, 1pM, on the substrate, first by alkyl phosphonate coordination to stainless steel and subsequent carbodiimide coupling to conjugate the hydrophobic and hydrophilic domains. In contrast, grafted-to monolayers were assembled utilizing presynthesized 1pM in a tethering by aggregation and growth technique. Coatings formed using the grafting-from approach yielded high AM grafting density and a highly ordered layer, which corresponded to a slower release rate and sustained bioactivity over 28 days. In contrast, the grafted-to coatings yielded less dense, heterogeneous layers, which released faster and were therefore less efficacious in suppressing prolonged SMC proliferation. Both coatings significantly reduced platelet adhesion compared to an uncoated control, but similar platelet adhesion results between grafted-from and grafted-to coatings suggest that both surfaces maintained a molecular density favorable for antiplatelet activity. Overall, the grafting-from method produced uniform coatings with improved loading, release, and bioactive properties compared to the grafting-to approach, highlighting the potential of AM controlled release coatings for therapeutic delivery.

  20. A prospective study on the effectiveness of newly developed autogenous tooth bone graft material for sinus bone graft procedure

    PubMed Central

    Jun, Sang-Ho; Ahn, Jin-Soo; Lee, Jae-Il; Ahn, Kyo-Jin; Yun, Pil-Young

    2014-01-01

    PURPOSE The purpose of this prospective study was to evaluate the effectiveness of newly developed autogenous tooth bone graft material (AutoBT)application for sinus bone graft procedure. MATERIALS AND METHODS The patients with less than 5.0 mm of residual bone height in maxillary posterior area were enrolled. For the sinus bone graft procedure, Bio-Oss was grafted in control group and AutoBT powder was grafted in experimental group. Clinical and radiographic examination were done for the comparison of grafted materials in sinus cavity between groups. At 4 months after sinus bone graft procedure, biopsy specimens were analyzed by microcomputed tomography and histomorphometric examination for the evaluation of healing state of bone graft site. RESULTS In CT evaluation, there was no difference in bone density, bone height and sinus membrane thickness between groups. In microCT analysis, there was no difference in total bone volume, new bone volume, bone mineral density of new bone between groups. There was significant difference trabecular thickness (0.07 µm in Bio-Oss group Vs. 0.08 µm in AutoBT group) (P=.006). In histomorphometric analysis, there was no difference in new bone formation, residual graft material, bone marrow space between groups. There was significant difference osteoid thickness (8.35 µm in Bio-Oss group Vs. 13.12 µm in AutoBT group) (P=.025). CONCLUSION AutoBT could be considered a viable alternative to the autogenous bone or other bone graft materials in sinus bone graft procedure. PMID:25551014

  1. The effect of platelet concentrates on graft maturation and graft-bone interface healing in ACL reconstruction in human patients

    PubMed Central

    Vavken, Patrick; Sadoghi, Patrick; Murray, Martha M

    2011-01-01

    Purpose To systematically review the current evidence for effects of platelet concentrates on (1) graft maturation and (2) graft-bone interface healing in ACL reconstruction in human, controlled trials, and for ensuing differences in clinical outcomes. Methods A systematic search of PubMed, CINAHL, EMBASE, CCTR and CDSR was performed for controlled trials of human ACL reconstruction with and without platelet concentrates. Data validity was assessed and data were collected on graft maturation, graft-bone interface healing and clinical outcome. Results Eight studies met the inclusion criteria. Seven studies reported on graft maturation with significantly better outcomes in the platelet groups in four, and large differences in means in two (underpowered) studies. Five studies report on tunnel healing, but four found no difference between groups. Three studies assessed clinical outcome but found no differences, regardless whether they had shown a benefical (1/3) or no effect (2/3) of platelets on graft and tunnel healing. Conclusion The current best evidence suggests that the addition of platelet concentrates to ACL reconstruction may have a beneficial effect on graft maturation and could improve it by 20–30% on average, but with substantial variability. The most likely mode of action is that treatment with platelets accelerates graft repopulation and remodeling, and this interpretation is supported by the existing data and biologically plausible. However, the current evidence also shows only a very limited influence of platelet concentrates on graft-bone interface healing and no significant difference in clinical outcomes. Clinical Relevance This systematic review collected evidence that the use of platelet concentrates may be a safe and inexpensive way to optimize graft maturation after ACL reconstruction, but there is no evidence for improved graft-bone interface healing or a significant difference in clinical outcomes. Level of Evidence Level IV, systematic

  2. Biological Indexing of Graft Transmissible Diseases of Citrus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological indexing for the detection of graft transmissible diseases of citrus is essential for maintaining a citrus certification program. Many of the graft transmissible diseases of citrus are harbored as latent infections in the scions, but when propagated on a susceptible rootstock that allow...

  3. Immobilization of urease on grafted starch by radiation method

    NASA Astrophysics Data System (ADS)

    Dung, Nguyen anh; Huyen, Nguyen dinh; Hang, Nguyen duy; Canh, Tran tich

    1995-09-01

    The acrylamide was grafted by radiation onto starch which is a kind polymeric biomaterial. The urease was immobilized on the grafted starch. Some experiments to observe the quantitative relationships between the percent grafl and the activity of immobilized enzyme were determined. The enzyme activity was maintained by more than seven batch enzyme reactions.

  4. Structural grafts and suture techniques in functional and aesthetic rhinoplasty

    PubMed Central

    Gassner, Holger G.

    2011-01-01

    Rhinoplasty has undergone important changes. With the advent of the open structure approach, requirements for structural grafting and direct manipulation of the cartilaginous skeleton through suture techniques have increased substantially. The present review analyzes the current literature on frequently referenced structural grafts and suture techniques. Individual techniques are described and their utility is discussed in light of available studies and data. PMID:22073105

  5. HRP-Mediated Synthesis of Starch-Polyacrylamide Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modified starch-based polymers can be engineered for specific properties by combining starch with synthetic polymers through graft copolymerization. Polyacrylamide grafted starch have received a great deal of applications in areas such as superabsorbent paper-making additives, drag reduction and te...

  6. HRP-Mediated Synthesis of Starch-Polyacrylamide Graft Copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modified starch-based polymers can be engineered for specific properties by combining starch with synthetic polymers through graft copolymerization. Polyacrylamide grafted starches have received a great deal of applications in areas such as superabsorbent paper-making additives, drag reduction and ...

  7. Stent Graft in Managing Juxta-Renal Aortoiliac Occlusion

    SciTech Connect

    Prabhudesai, V. Mitra, K.; West, D. J.; Dean, M. R. E.

    2003-09-15

    Endovascular procedures are frequently used as an alternative to surgical bypass in aortic and iliac occlusion. Stents have revolutionized the scope of such endovascular procedures, but there are few reports of stents or stent grafts in occlusive juxta-renal aortic occlusion. We present a case where such occlusion was managed by use of a stent graft with successful outcome.

  8. Which mesh or graft? Prosthetic devices for abdominal wall reconstruction.

    PubMed

    Abid, Shazia; El-Hayek, Kevin

    2016-03-01

    This article reviews the ever-increasing number of prosthetic devices--both synthetic mesh and biologic grafts--now in use for abdominal wall reconstruction. It also introduces a novel hybrid synthetic/biologic graft (Zenapro) and suture passer device (Novapass).

  9. Bone Graft Harvest Using a New Intramedullary System

    PubMed Central

    Belthur, Mohan V.; Jindal, Gaurav; Ranade, Ashish; Herzenberg, John E.

    2008-01-01

    Obtaining autogenous bone graft from the iliac crest can entail substantial morbidity. Alternatively, bone graft can be harvested from long bones using an intramedullary (IM) harvesting system. We measured bone graft volume obtained from the IM canals of the femur and tibia and documented the complications of the harvesting technique. Donor site pain and the union rate were compared between the IM and the traditional iliac crest bone graft (ICBG) harvest. Forty-one patients (23 male, 18 female) with an average age of 44.9 years (range, 15–78 years) had graft harvested from long bones using an IM harvest system (femoral donor site, 37 patients; tibial donor site, four patients). Forty patients (23 male, 17 female; average age, 46.4 years; range, 15–77 years) underwent anterior ICBG harvest. We administered patient surveys to both groups to determine pain intensity and frequency. IM group reported lower pain scores than the ICBG group during all postoperative periods. Mean graft volume for the IM harvest group was 40.3 mL (range, 25–75 mL) (graft volume was not obtained for the ICBG group). Using an intramedullary system to harvest autogenous bone graft from the long bones is safe provided a meticulous technique is used. Level of Evidence: Level III, retrospective comparative study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18841433

  10. Impact of reaction conditions on grafting acrylamide onto starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have explored the radical initiated graft polymerization reaction of acrylamide onto starch where the solvent, concentration, temperature and reaction times were varied. We have found that the morphology of the resulting grafted polymer is dramatically different and is dependent on the reaction c...

  11. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bone grafting material. 872.3930 Section 872.3930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... grafting materials that do not contain a drug that is a therapeutic biologic. The special control is...

  12. 21 CFR 872.3930 - Bone grafting material.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Bone grafting material. 872.3930 Section 872.3930 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... grafting materials that do not contain a drug that is a therapeutic biologic. The special control is...

  13. Mandibular Tori: A source of autogenous bone graft

    PubMed Central

    Santhanakrishnan, Muthukumar; Rangarao, Suresh

    2014-01-01

    Restoration of lost alveolar bone support remains as one of the main objectives of periodontal surgery. Amongst the various types of bone grafts available for grafting procedures, autogenous bone grafts are considered to be the gold standard in alveolar defect reconstruction. Although there are various sources for autogenous grafts including the mandibular symphysis and ramus, they are almost invariably not contiguous with the area to be augmented. An alternative mandibular donor site that is continuous with the recipient area and would eliminate the need for an extra surgical site is the tori/exostoses. Bone grafting was planned for this patient as there were angular bone loss present between 35-36 and 36-37. As the volume of bone required was less and bilateral tori were present on the lingual side above the mylohyoid line, the tori was removed and used as a source of autogenous bone graft, which were unnecessary bony extensions present on the mandible and continuous with the recipient area. Post-operative radiographs taken at 6 and 12 month intervals showed good bone fill and also areas of previous pockets, which did not probe after treatment indicates the success of the treatment. The use of mandibular tori as a source of autogenous bone graft should be considered whenever a patient requires bone grafting procedure to be done and presents with a tori. PMID:25624635

  14. [Skin graft, smoking and diabetes mellitus type 2].

    PubMed

    Pérez-Guisado, Joaquín; Fidalgo-Rodríguez, Félix T; Gaston, Kate L; Rioja, Luis F; Thomas, Steven J

    2012-01-01

    Smoking and hyperglycemia decrease the success of skin graft survival in specific circumstances. It is well known that smoking and diabetes mellitus (DM) type 2 increase the oxidative and impair the endothelial function. The objective of this retrospective study was to determine if smoking and DM type 2 are factors associated with lower skin graft survival, in different etiologies of the injury associated to the skin loss. It was a bicentric, retrospective, cross sectional case control study, carried out on 2457 medical patients who met the inclusion criteria. It was carried out over a 10 years period between January 2000-December 2009, at Reina Sofía University Hospital (Córdoba, Spain) and UAB Hospital at Birmingham (Alabama, USA). The percentage of successful graft for each group and its control were analyzed by Chi-square test. The confidence interval chosen for statistical differences was 95%. Smoking and DM type 2 decreased the percentage of skin graft survival when compared with their control groups. DM type 2 was associated with greater negative success on skin graft survival than smoking when compared with their control groups. There was a statistically significant drop in skin graft of 18% in smoking group (range: 68-86%) and 25% in DM type 2 group (53-78%). The OR showed a clear association between the risk factors studied and the lower skin graft success, being stronger for DM type 2. In conclusion, DM type 2 and smoking are factors associated to lower skin graft take.

  15. 21 CFR 870.3450 - Vascular graft prosthesis.

    Code of Federal Regulations, 2010 CFR

    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..., and to provide vascular access. It is commonly constructed of materials such as...

  16. Messenger RNA exchange between scions and rootstocks in grafted grapevines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We demonstrated the existence of genome-scale mRNA exchange in grafted grapevines, a woody fruit species with significant economic importance. By using diagnostic SNPs derived from high throughput genome sequencing, we identified more than three thousand genes transporting mRNAs across graft junctio...

  17. Adult Patent Ductus Arteriosus: Treatment with a Stent-Graft

    SciTech Connect

    Munoz, J.J. Urbaneja, A.; Gonzalez, N.; Martinez, J.L.

    2008-03-15

    We present the case of a 63-year-old woman with a short patent ductus arteriosus and aneurysmal pulmonary arteries who was treated by placement of a stent-graft. The technique proved simple and safe. Further research is required to improve the design of stent-grafts and their release system for use of this technique in adult patients with this disorder.

  18. Serial Transmission of Plant Viruses by Cutting During Grafting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reciprocal grafts of two tomato (Solanum lycopersicum L.) cultivars were made by hand using commercial grafting techniques. The razor blade used to cut rootstock or scion was first contaminated by making a single cut on tomato plants infected with either tomato spotted wilt virus (TSWV) or tomato m...

  19. Gas Transport in Polymer-Grafted Nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhang, Kai; Kumar, Sanat

    The efficient separation of gases is crucial for clean energy technologies. With their intrinsic multiscale features and excellent self-assembly properties, polymer-grafted nanoparticles (PGNP) material makes a good candidate for effective gas separation, but the basic understanding of gas transport in PGNPs is still missing. While the nanoparticles cores are spherical, the corona of the PGNPs can be deformed into anisotropic space-filling polygons at high density that are commensurate with the crystal structures (Wigner-Seitz cells). Such deformation indicates that the polymer chains are extended or compressed along different directions and create cavities within the crystals that can help to improve the gas selectivity. We use coarse-grained computer simulations to study the solubility and diffusion of gas molecules inside the crystalline packing of the NP cores. By tuning the degree of polymerization, the surface density of grafting chains and the size of gas molecules, we systematically investigate the dependence of gas transport on these parameters. We find that the void formed by three contacting monomers imposes a critical lengthscale beyond which the transport becomes highly size selective.

  20. Pediatric burn wound impetigo after grafting.

    PubMed

    Aikins, Kimberly; Prasad, Narayan; Menon, Seema; Harvey, John G; Holland, Andrew J A

    2015-01-01

    Modern burn care techniques have reduced the risk of infection of the acute burn wound, resulting in more rapid healing and a lower incidence of graft loss. Secondary breakdown may still occur. The loss of epithelium in association with multifocal superficial abscesses and ulceration has been termed burns impetigo. This may result in considerable morbidity and require prolonged treatment. The events preceding development, the impact on the patient, and the ideal treatment appear unclear and poorly reported. In 5 years, between 2006 and 2011, 406 pediatric burns were treated with skin grafts, with 7% developing burns impetigo. Time to resolution ranged from 5 to 241 days: the mean time to complete healing was greatest with conservative management (96 days), followed by antibacterial dressings (37 days), oral antibiotics (36 days), topical steroids (16 days), and oral antibiotics in combination with topical steroids (13.5 days). Burns impetigo resulted in significant morbidity, requiring multiple visits to the treatment center and prolonged symptoms. Delay in diagnosis and treatment resulted in worse outcomes. Prompt consideration of burns impetigo should occur when postgraft patients present with suggestive clinical signs and treatment with oral antibiotics plus topical steroids should be considered.

  1. Responsive interfaces grafted with polyelectrolyte or polyampholyte

    NASA Astrophysics Data System (ADS)

    Tran, Yvette; Sanjuan, Sarah; Pantoustier, Nadège; Perrin, Patrick

    2007-01-01

    We synthesize and investigate the swelling behavior of polyelectrolyte and polyampholyte grafted layers on planar substrates. The polymer brushes are prepared using the "grafting from" method with surface-initiated atom transfer radical polymerization (ATRP), which allows a good control of the chain length and a weak polydispersity of chains. Ellipsometry and neutron reflectivity are used to determine the swollen thickness and the monomer volume fraction profile. The scaling behavior of the neutral polymer brush and the strong polyelectrolyte brush is in good agreement with scaling laws predicted by mean-field theories. The swelling behavior of the pH-responsive polybase brush is between the situation of the neutral polymer brush in good solvent and the quenched polyelectrolyte. Polyampholyte brushes are contracted in the pH range of zero net charge. A barrier zone likely due to the attraction between positively and negatively charged monomer units is observed in the density profile. This barrier could prevent from a collective ionization of the chains and reduce the expected collapse of the brush.

  2. Acellular dermal graft reinforcement at the hiatus.

    PubMed

    Freedman, Bruce

    2012-11-01

    The ideal technique to repair large hiatal and diaphragmatic defects remains controversial. Due to high recurrence rates with primary repair alone, attempts at crural reinforcement with various products has been investigated. Initial evaluation of synthetic mesh at the hiatus in retrospective studies led to the conclusion that there were too many serious complications with these products. The next step was to see how biologic grafts fared in this location. Beginning with porcine intestine submucosa in a laminated array and progressing through human and porcine acellular dermal matrices, multiple, retrospective studies looked at the efficacy and safety of these products. Unfortunately, most of these studies evaluated a small sample size with a relatively short follow-up period. The one study followed out to 5 years failed to show any benefit using the biologic (porcine intestinal submucosa) compared with the primary repair alone. Additional, prospective, randomized studies with ample numbers carried out for years will be necessary to see which biologic graft is not only safe but also successful in preventing recurrent herniations.

  3. Studies of host graft interactions in vitro

    NASA Astrophysics Data System (ADS)

    Liljekvist-Larsson, Ingela; Johansson, Kjell

    2007-09-01

    Progenitor and stem cell transplantation represent therapeutic strategies for retinal disorders that are accompanied by photoreceptor degeneration. The transplanted cells may either replace degenerating photoreceptors or secrete beneficial factors that halt the processes of photoreceptor degeneration. The present study analyzes whether rat retinal progenitor cells differentiated into photoreceptor phenotypic cells in neurospheres have a potential to interact with rat retinal explants. Immunocytochemistry for rhodopsin and synaptophysin indicated photoreceptor cell-like differentiation in neurospheres that were stimulated by basic fibroblast growth factor and epidermal growth factor. Differentiation into neural phenotypes including photoreceptor cells was effectively blocked by an addition of leukemia inhibitory factor. Grafting of neurospheres onto retinal explants demonstrated a consistent penetration of glial cell processes into the explanted tissue. On the other hand, the incorporation of donor cells into explants was very low. A general finding was that neurospheres grafting was associated with local decrease in Müller cell activation in the explants. Further characterization of these effect(s) could provide further insight into progenitor cell-based therapies of retinal degenerative disorders.

  4. Graft-versus-host disease management.

    PubMed

    Mistrik, M; Bojtarova, E; Sopko, L; Masakova, L; Roziakova, L; Martinka, J; Batorova, A

    Graft-versus-host disease (GVHD) remains a major problem of allogeneic hematopoietic-stem cell transplantation (HSCT) and an obstacle for successful outcome. Clinically significant acute GVHD (grade II or higher) developed in 20 to 65 percent of the patients. Death due to this complication accounts for approximately 50 percent of the deaths that are not due to a relapse of the neoplasm. Up to 70 % of patients who survive beyond day 100 develop chronic GVHD and it is the leading cause of nonrelapse mortality more than 2 years after allogeneic HSCT. In addition, chronic GVHD is associated with decreased quality of life, impaired functional status, and ongoing need for immunosuppressive medications. The incidence of chronic GVHD is increasing because of expansion of the donor population beyond HLA-identical siblings, older recipient age, use of peripheral blood cells as the graft source, and infusion of donor lymphocytes for treatment of recurrent malignancy after HSCT. With the current rush in new findings related to GVHD, we see a significant advancement in its management. Given these various new options and challenges, it is important to identify the minimal requirements for diagnosis and treatment of GVHD, as access to the most sophisticated advances may vary depending on local circumstances (Tab. 4, Fig. 1, Ref. 51).

  5. Involvement of adrenal medulla grafts in the open field behavior.

    PubMed

    Jousselin-Hosaja, M; Venault, P; Tobin, C; Joubert, C; Delacour, J; Chapouthier, G

    2001-06-01

    Immunohistochemical and behavioral techniques were used to study the effects of adrenal medulla grafts, implanted in striatum after bilateral kainic acid (KA) lesions of this structure, on the open field behavior of mice. KA-induced behavioral changes in leaning, grooming and locomotor activity of the open field test were significantly improved after grafting of the adrenal medulla, and in some respects, fully restored. Immunohistochemical identification showed that grafts contained neuron-like cells with a tyrosine hydroxylase (TH), phenylethanolamine N-methyltransferase, gamma-aminobutyric acid (GABA), choline acetyltransferase (ChAT), and enkephalin-like immunostainings. A likely interpretation of this complex pattern of results is that adrenal medullary grafts may restore the deficits of GABAergic neurons which in turn reverse the abnormalities in emotionality and locomotion. Neurobiologically, these behavioral improvements probably involve GABAergic and catecholaminergic factors of adrenal medulla grafts, although other neuroactive substances, such as acetylcholine and enkephalins, cannot be excluded.

  6. Composite vascular repair grafts via micro-imprinting and electrospinning

    SciTech Connect

    Liu, Yuanyuan Hu, Qingxi; Xiang, Ke Chen, Haiping Li, Yu

    2015-04-15

    Composite vascular grafts formed by micro-imprinting and electrospinning exhibited improved mechanical properties relative to those formed by electrospinning alone. The three-layered composite grafts mimic the three-layered structure of natural blood vessels. The middle layer is made by micro-imprinting poly-p-dioxanone (PPDO), while the inner and outer layers are electrospun mixtures of chitosan and polyvinyl alcohol. The graft morphology is characterized with scanning electron microscopy. For constant graft thicknesses, the PPDO increases the mechanical strength. Cells cultivated on the vascular grafts adhere and proliferate better because of the natural, biological chitosan in the inner and outer layers. Overall, the composite scaffolds could be good candidates for blood vessel repair.

  7. Temporal fossa bone grafts: a new technique in craniofacial surgery.

    PubMed

    Spear, S L; Wiegering, C E

    1987-04-01

    The calvarium has become an increasingly popular bone-graft donor site. Previously described harvesting techniques are often difficult to perform and may produce unsatisfactory bone fragments. However, full-thickness bone grafts taken from the region of the temporal fossa, beneath the temporaiis muscle, have proven to be of high quality and technically easy to obtain. In our experience with eight patients, temporal fossa bone grafts were used primarily around the orbit, including reconstruction of the orbital floor, frontal bone, and zygoma. The procedure begins with a hemicoronal or bicoronal incision; the temporalis muscle is reflected, and an underlying bone plate up to 4 X 6 cm is removed. The resulting bone graft is consistently 3 to 4 mm in thickness. The cranial defect is packed with bone debris, and the muscle is replaced. This technique has proven to be safe, technically simple, consistently productive of high-quality bone grafts, and within discernible donor-site deformity.

  8. Cross-facial nerve grafting for facial reanimation.

    PubMed

    Peng, Grace Lee; Azizzadeh, Babak

    2015-04-01

    Dynamic facial reanimation is the gold standard treatment for a paralyzed face. Over the last century, multiple nerves have been utilized for grafting to the facial nerve in an attempt to produce improved movement. However, in recent years, the use of cross facial nerve grafting with a second stage gracilis free flap has gained popularity due to the ability to generate a spontaneous smile and facial movement. Preoperative history taking and careful examination, as well as pre-surgical planning, are imperative to whether cross facial nerve grafting with a second stage gracilis free flap is appropriate for the patient. A sural nerve graft is ideal given the accessibility of the nerve, the length, as well as the reliability and ease of the nerve harvest. The nerve can be harvested using a small incision, which leaves the patient with minimal post operative morbidity. In this chapter, we highlight the pearls and pitfalls of cross facial nerve grafting.

  9. Giant venous aneurysm jeopardising internal mammary arterial graft patency.

    PubMed

    Van Caenegem, Olivier; le Polain de Waroux, Jean-Benoit; de Kerchove, Laurent; Coche, Emmanuel

    2012-09-01

    The authors report a 79-year old man with a history of coronary bypass surgery, presenting with acute heart failure and elevated troponin. Coronarography revealed a giant saphenous vein graft aneurysm, which was compressing the left internal mammary artery bypass graft. This was confirmed by a multislice enhanced-ECG gated cardiac CT, showing the venous aneurysm responsible for external compression of the arterial graft and its functional occlusion. Myocardial ischaemia, the mechanism leading to cardiac failure, was confirmed by hypoperfusion of the sub-endocardial area shown by the CT. The aneurysm was surgically removed without complications. The patient recovered and his cardiac function improved. This is the first recorded case of compression of the left internal mammary artery by an giant saphenous vein graft aneurysm having triggered severe myocardial ischaemia and heart failure. The authors review the incidence and complications of giant venous bypass graft aneurysms reported in the literature.

  10. Giant venous aneurysm jeopardising internal mammary arterial graft patency

    PubMed Central

    Van Caenegem, Olivier; le Polain de Waroux, Jean-Benoit; de Kerchove, Laurent; Coche, Emmanuel

    2012-01-01

    The authors report a 79-year old man with a history of coronary bypass surgery, presenting with acute heart failure and elevated troponin. Coronarography revealed a giant saphenous vein graft aneurysm, which was compressing the left internal mammary artery bypass graft. This was confirmed by a multislice enhanced-ECG gated cardiac CT, showing the venous aneurysm responsible for external compression of the arterial graft and its functional occlusion. Myocardial ischaemia, the mechanism leading to cardiac failure, was confirmed by hypoperfusion of the sub-endocardial area shown by the CT. The aneurysm was surgically removed without complications. The patient recovered and his cardiac function improved. This is the first recorded case of compression of the left internal mammary artery by an giant saphenous vein graft aneurysm having triggered severe myocardial ischaemia and heart failure. The authors review the incidence and complications of giant venous bypass graft aneurysms reported in the literature. PMID:22723090

  11. Dupuytren Disease Infiltrating a Full-Thickness Skin Graft.

    PubMed

    Wade, Ryckie George; Igali, Laszlo; Figus, Andrea

    2016-08-01

    Although the role of the skin in the development and propagation of Dupuytren disease remains unclear, dermofasciectomy and full-thickness skin grafting (FTSG) appears to delay recurrence. In 2011, a 71-year-old, left-handed man presented with recurrent Dupuytren disease in the dominant hand. In 1991, he originally underwent a primary dermofasciectomy and FTSG for Dupuytren disease involving the palmar skin. Twenty years later, the left middle finger was drawn into flexion by a recurrent cord, and the old graft and adjacent palmar skin were clinically involved by fibromatosis. We performed a revision dermofasciectomy and FTSG. Microscopic analysis of the excised graft demonstrated dense infiltration of the entire skin graft by Dupuytren disease, with areas of active and burnt-out fibromatosis distinct from hypertrophic scarring. This report of Dupuytren fibromatosis infiltrating a skin graft raises questions about the pathophysiology of Dupuytren disease.

  12. Creeping attachment: autogenous graft vs dermal matrix allograft.

    PubMed

    Haeri, A; Parsell, D

    2000-09-01

    For many years, free autogenous grafts have been used as a method of gaining keratinized tissue around teeth with mucogingival problems. Creeping attachment using autogenous graft material has been actively studied. In addition, biocompatible, acellular connective-tissue material has recently been used as an alternative to free gingival grafts to increase the zone of keratinization. This report presents a patient with bilateral mucogingival defects in the canine and premolar areas. The patient received an autogenous graft on one side and a dermal matrix allograft on the contralateral side. Creeping attachments were measured and compared at 3 months and 12 months after surgery. After 12 months of healing, an average of 1.23 mm of creeping attachment was measured on the free gingival graft side and 0.96 mm of creeping attachment was measured with the dermal matrix allograft.

  13. Thromboembolic potential of synthetic vascular grafts in baboons

    SciTech Connect

    Schneider, P.A.; Kotze, H.F.; Heyns, A.D.; Hanson, S.R.

    1989-07-01

    We have compared in baboons the capacity of two types of synthetic vascular grafts to accumulate thrombus, activate circulating platelets, and generate occlusive platelet microemboli. Grafts were incorporated into femoral arterial-arterial shunts placed unilaterally in 10 baboons; the unoperated contralateral limbs served as controls. The accumulation of indium 111 (111In)-labeled platelets onto the grafts (expanded polytetrafluoroethylene (ePTFE) or knitted Dacron, 4 mm inner diameter) and the appearance of 111In radioactivity in distal microcirculatory beds (calf and foot) were quantified by dynamic scintillation camera imaging. After 1 hour total platelet deposition per graft was higher with Dacron (49.0 +/- 8.0 x 10(9) platelets) than with ePTFE (3.7 +/- 0.6 x 10(9) platelets, p less than 0.01). Platelet counts decreased and beta-thromboglobulin levels increased with Dacron graft placement but were unaffected by ePTFE graft placement (p less than 0.05 and p less than 0.01, respectively). Emboli shed from Dacron grafts were detected as multifocal, irregular, and changing deposits in the calves and feet. Indium 111 platelet activity in the feet distal to the Dacron grafts increased 81.1% +/- 21.4% from baseline values over 1 hour, whereas the activities in the feet distal to the ePTFE grafts were unchanged (p less than 0.05). The increase 111In-platelet radioactivity above the control limb values (excess radioactivity) was higher for the Dacron graft group than for the ePTFE group in both the feet (139.6% +/- 46.9% vs 6.2%, p less than 0.05) and the calves (86.7% +/- 21.7% vs 7.3% +/- 3.6%, p less than 0.05).

  14. Grafting: A Technique to Modify Ion Accumulation in Horticultural Crops

    PubMed Central

    Nawaz, Muhammad A.; Imtiaz, Muhammad; Kong, Qiusheng; Cheng, Fei; Ahmed, Waqar; Huang, Yuan; Bie, Zhilong

    2016-01-01

    Grafting is a centuries-old technique used in plants to obtain economic benefits. Grafting increases nutrient uptake and utilization efficiency in a number of plant species, including fruits, vegetables, and ornamentals. Selected rootstocks of the same species or close relatives are utilized in grafting. Rootstocks absorb more water and ions than self-rooted plants and transport these water and ions to the aboveground scion. Ion uptake is regulated by a complex communication mechanism between the scion and rootstock. Sugars, hormones, and miRNAs function as long-distance signaling molecules and regulate ion uptake and ion homeostasis by affecting the activity of ion transporters. This review summarizes available information on the effect of rootstock on nutrient uptake and utilization and the mechanisms involved. Information on specific nutrient-efficient rootstocks for different crops of commercial importance is also provided. Several other important approaches, such as interstocking (during double grafting), inarching, use of plant-growth-promoting rhizobacteria, use of arbuscular mycorrhizal fungi, use of plant growth substances (e.g., auxin and melatonin), and use of genetically engineered rootstocks and scions (transgrafting), are highlighted; these approaches can be combined with grafting to enhance nutrient uptake and utilization in commercially important plant species. Whether the rootstock and scion affect each other's soil microbiota and their effect on the nutrient absorption of rootstocks remain largely unknown. Similarly, the physiological and molecular bases of grafting, crease formation, and incompatibility are not fully identified and require investigation. Grafting in horticultural crops can help reveal the basic biology of grafting, the reasons for incompatibility, sensing, and signaling of nutrients, ion uptake and transport, and the mechanism of heavy metal accumulation and restriction in rootstocks. Ion transporter and miRNA-regulated nutrient

  15. Biodegradable, thermoplastic polyurethane grafts for small diameter vascular replacements.

    PubMed

    Bergmeister, Helga; Seyidova, Nargiz; Schreiber, Catharina; Strobl, Magdalena; Grasl, Christian; Walter, Ingrid; Messner, Barbara; Baudis, Stefan; Fröhlich, Sophie; Marchetti-Deschmann, Martina; Griesser, Markus; di Franco, Matt; Krssak, Martin; Liska, Robert; Schima, Heinrich

    2015-01-01

    Biodegradable vascular grafts with sufficient in vivo performance would be more advantageous than permanent non-degradable prostheses. These constructs would be continuously replaced by host tissue, leading to an endogenous functional implant which would adapt to the need of the patient and exhibit only limited risk of microbiological graft contamination. Adequate biomechanical strength and a wall structure which promotes rapid host remodeling are prerequisites for biodegradable approaches. Current approaches often reveal limited tensile strength and therefore require thicker or reinforced graft walls. In this study we investigated the in vitro and in vivo biocompatibility of thin host-vessel-matched grafts (n=34) formed from hard-block biodegradable thermoplastic polyurethane (TPU). Expanded polytetrafluoroethylene (ePTFE) conduits (n=34) served as control grafts. Grafts were analyzed by various techniques after retrieval at different time points (1 week; 1, 6, 12 months). TPU grafts showed significantly increased endothelial cell proliferation in vitro (P<0.001). Population by host cells increased significantly in the TPU conduits within 1 month of implantation (P=0.01). After long-term implantation, TPU implants showed 100% patency (ePTFE: 93%) with no signs of aneurysmal dilatation. Substantial remodeling of the degradable grafts was observed but varied between subjects. Intimal hyperplasia was limited to ePTFE conduits (29%). Thin-walled TPU grafts offer a new and desirable form of biodegradable vascular implant. Degradable grafts showed equivalent long-term performance characteristics compared to the clinically used, non-degradable material with improvements in intimal hyperplasia and ingrowth of host cells.

  16. Bacterial adherence to vascular grafts after in vitro bacteremia

    SciTech Connect

    Rosenman, J.E.; Pearce, W.H.; Kempczinski, R.F.

    1985-06-01

    All currently used arterial prosthetics have a greater susceptibility to infection following bacteremia than does autogenous tissue. This experiment compares quantitative bacterial adherence to various prosthetic materials after bacteremia carried out in a tightly controlled and quantitative fashion. Ten centimeters long, 4 mm i.d. Dacron, umbilical vein (HUV), and polytetrafluoroethylene (PTFE) grafts, as well as PTFE grafts with a running suture line at the midportion were tested. Each graft was interposed into a pulsatile perfusion system modified from a Waters MOX 100 TM renal transplant pump. Indium-111-labeled Staphylococcus aureus were added to heparinized canine blood to give a mean concentration of 4.7 X 10(6) bacteria/cc. This infected blood was recirculated through each graft for 30 min at a rate of 125 cc/m, 100 Torr (sys), 60 beats/min. The gamma counts/graft were used to calculate the number of bacteria/cm2 of graft surface. After nine experiments, a mean of 9.63 X 10(5) bacteria/cm2 were adherent to the Dacron, 1.04 X 10(5) bacteria/cm2 to the HUV, and 2.15 X 10(4) bacteria/cm2 to the PTFE. These differences were all significant at the 0.05 level. The addition of a suture line increased bacterial adherence to the PTFE graft by 50%. These results suggest that PTFE is the vascular graft material of choice when a prosthetic graft must be implanted despite a high risk of subsequent clinical bacteremia. An in vitro, pulsatile perfusion model gave accurate and reproducible results, and appears well suited for further studies of bacterial, or platelet adherence to grafts, as well as the biomechanics of vascular conduits.

  17. Graft and Patient Survival Outcomes of a Third Kidney Transplant

    PubMed Central

    Redfield, Robert R.; Gupta, Meera; Rodriguez, Eduardo; Wood, Alexander; Abt, Peter L.; Levine, Matthew H.

    2014-01-01

    Background The waiting time for deceased donor renal transplantation in the United States continues to grow. Retransplant candidates make up a small but growing percentage of the overall transplant waiting list and raise questions about the stewardship of scarce resources. The utility of renal transplantation among individuals with two prior renal transplants is not described in the literature and we thus sought to determine the survival benefit associated with a third kidney transplant (3KT). Methods Multivariable Cox regression models were created to determine characteristics associated with 3KT outcomes and the survival benefit of 3KT among recipients wait listed and transplanted within the United States between 1995 and 2009. Results 4,334 patients were waitlisted for a 3KT and 2,492 patients received a 3KT. In a multivariate analysis, 3KT demonstrated an overall patient survival benefit compared to the wait list (HR-0.379, CI=0.302-0.475 p<0.001) for those awaiting their first, second or third kidney transplants, although an inferior graft outcome compared to first kidney transplants. The time to survival benefit did not accrue until 8-months after transplant. Additionally we found that the duration of second graft survival was predictive of third graft survival, such that second graft survival beyond 5 years is associated with superior 3KT graft survival. Second graft loss in 30 days or less was not associated with inferior 3KT graft survival. Conclusion 3KT achieves a survival benefit over remaining on the wait list, although is associated with inferior graft outcomes compared to first kidney transplants. Graft survival of the second transplant beyond 5 years is associated with superior 3KT graft survival. PMID:25121473

  18. Grafting: A Technique to Modify Ion Accumulation in Horticultural Crops.

    PubMed

    Nawaz, Muhammad A; Imtiaz, Muhammad; Kong, Qiusheng; Cheng, Fei; Ahmed, Waqar; Huang, Yuan; Bie, Zhilong

    2016-01-01

    Grafting is a centuries-old technique used in plants to obtain economic benefits. Grafting increases nutrient uptake and utilization efficiency in a number of plant species, including fruits, vegetables, and ornamentals. Selected rootstocks of the same species or close relatives are utilized in grafting. Rootstocks absorb more water and ions than self-rooted plants and transport these water and ions to the aboveground scion. Ion uptake is regulated by a complex communication mechanism between the scion and rootstock. Sugars, hormones, and miRNAs function as long-distance signaling molecules and regulate ion uptake and ion homeostasis by affecting the activity of ion transporters. This review summarizes available information on the effect of rootstock on nutrient uptake and utilization and the mechanisms involved. Information on specific nutrient-efficient rootstocks for different crops of commercial importance is also provided. Several other important approaches, such as interstocking (during double grafting), inarching, use of plant-growth-promoting rhizobacteria, use of arbuscular mycorrhizal fungi, use of plant growth substances (e.g., auxin and melatonin), and use of genetically engineered rootstocks and scions (transgrafting), are highlighted; these approaches can be combined with grafting to enhance nutrient uptake and utilization in commercially important plant species. Whether the rootstock and scion affect each other's soil microbiota and their effect on the nutrient absorption of rootstocks remain largely unknown. Similarly, the physiological and molecular bases of grafting, crease formation, and incompatibility are not fully identified and require investigation. Grafting in horticultural crops can help reveal the basic biology of grafting, the reasons for incompatibility, sensing, and signaling of nutrients, ion uptake and transport, and the mechanism of heavy metal accumulation and restriction in rootstocks. Ion transporter and miRNA-regulated nutrient

  19. Magnesium inference screw supports early graft incorporation with inhibition of graft degradation in anterior cruciate ligament reconstruction

    PubMed Central

    Cheng, Pengfei; Han, Pei; Zhao, Changli; Zhang, Shaoxiang; Zhang, Xiaonong; Chai, Yimin

    2016-01-01

    Patients after anterior cruciate ligament (ACL) reconstruction surgery commonly encounters graft failure in the initial phase of rehabilitation. The inhibition of graft degradation is crucial for the successful reconstruction of the ACL. Here, we used biodegradable high-purity magnesium (HP Mg) screws in the rabbit model of ACL reconstruction with titanium (Ti) screws as a control and analyzed the graft degradation and screw corrosion using direct pull-out tests, microCT scanning, and histological and immunohistochemical staining. The most noteworthy finding was that tendon graft fixed by HP Mg screws exhibited biomechanical properties substantially superior to that by Ti screws and the relative area of collagen fiber at the tendon-bone interface was much larger in the Mg group, when severe graft degradation was identified in the histological analysis at 3 weeks. Semi-quantitative immunohistochemical results further elucidated that the MMP-13 expression significantly decreased surrounding HP Mg screws with relatively higher Collagen II expression. And HP Mg screws exhibited uniform corrosion behavior without displacement or loosening in the femoral tunnel. Therefore, our results demonstrated that Mg screw inhibited graft degradation and improved biomechanical properties of tendon graft during the early phase of graft healing and highlighted its potential in ACL reconstruction. PMID:27210585

  20. Enhancement of the grafting performance and of the water absorption of cassava starch graft copolymer by gamma radiation

    NASA Astrophysics Data System (ADS)

    Kiatkamjornwong, Suda; Meechai, Nispa

    1997-06-01

    Enhancement of the gamma radiation grafting of acrylonitrile onto gelatinized cassava starch was investigated. Infrared spectrometry was used to follow the chemical changes in the grafting reaction and from saponification. The saponified starch- g-PAN (HSPAN) was then characterized in terms of grafting parameters to provide a guide for the optimum total dose (kGy) and the appropriate ratio of starch/acrylonitrile for a fixed dose rate of 2.5 × 10 -1 kGy/min. Other dose rates were also carried out to obtain the appropriate result of grafting copolymerization and of water absorption. A thin aluminium foil, covering the inner wall of the reaction vessel, was found to be far more effective than any other metal films in the enhancement of the grafting reaction and the water absorption as well. Nitric acid in the medium increases the grafting yield and the water absorption. Methyl ether hydroquinone inhibitor was evaluated for its ability to increase homopolymerization and decrease graft reaction. When styrene was used as a comonomer, it hampered the grafting of acrylonitrile onto starch backbone. The water absorption capacity was improved by freeze-drying the HSPAN. The treatment of the HSPAN with aluminium trichloride hexahydrate was found to enhance the degree of wicking, but to decrease the water absorbency.

  1. Magnesium inference screw supports early graft incorporation with inhibition of graft degradation in anterior cruciate ligament reconstruction

    NASA Astrophysics Data System (ADS)

    Cheng, Pengfei; Han, Pei; Zhao, Changli; Zhang, Shaoxiang; Zhang, Xiaonong; Chai, Yimin

    2016-05-01

    Patients after anterior cruciate ligament (ACL) reconstruction surgery commonly encounters graft failure in the initial phase of rehabilitation. The inhibition of graft degradation is crucial for the successful reconstruction of the ACL. Here, we used biodegradable high-purity magnesium (HP Mg) screws in the rabbit model of ACL reconstruction with titanium (Ti) screws as a control and analyzed the graft degradation and screw corrosion using direct pull-out tests, microCT scanning, and histological and immunohistochemical staining. The most noteworthy finding was that tendon graft fixed by HP Mg screws exhibited biomechanical properties substantially superior to that by Ti screws and the relative area of collagen fiber at the tendon-bone interface was much larger in the Mg group, when severe graft degradation was identified in the histological analysis at 3 weeks. Semi-quantitative immunohistochemical results further elucidated that the MMP-13 expression significantly decreased surrounding HP Mg screws with relatively higher Collagen II expression. And HP Mg screws exhibited uniform corrosion behavior without displacement or loosening in the femoral tunnel. Therefore, our results demonstrated that Mg screw inhibited graft degradation and improved biomechanical properties of tendon graft during the early phase of graft healing and highlighted its potential in ACL reconstruction.

  2. Periosteal BMP2 activity drives bone graft healing.

    PubMed

    Chappuis, Vivianne; Gamer, Laura; Cox, Karen; Lowery, Jonathan W; Bosshardt, Dieter D; Rosen, Vicki

    2012-10-01

    Bone graft incorporation depends on the orchestrated activation of numerous growth factors and cytokines in both the host and the graft. Prominent in this signaling cascade is BMP2. Although BMP2 is dispensable for bone formation, it is required for the initiation of bone repair; thus understanding the cellular mechanisms underlying bone regeneration driven by BMP2 is essential for improving bone graft therapies. In the present study, we assessed the role of Bmp2 in bone graft incorporation using mice in which Bmp2 has been removed from the limb prior to skeletal formation (Bmp2(cKO)). When autograft transplantations were performed in Bmp2cKO mice, callus formation and bone healing were absent. Transplantation of either a vital wild type (WT) bone graft into a Bmp2(cKO) host or a vital Bmp2(cKO) graft into a WT host also resulted in the inhibition of bone graft incorporation. Histological analyses of these transplants show that in the absence of BMP2, periosteal progenitors remain quiescent and healing is not initiated. When we analyzed the expression of Sox9, a marker of chondrogenesis, on the graft surface, we found it significantly reduced when BMP2 was absent in either the graft itself or the host, suggesting that local BMP2 levels drive periosteal cell condensation and subsequent callus cell differentiation. The lack of integrated healing in the absence of BMP2 was not due to the inability of periosteal cells to respond to BMP2. Healing was achieved when grafts were pre-soaked in rhBMP2 protein, indicating that periosteal progenitors remain responsive in the absence of BMP2. In contrast to the requirement for BMP2 in periosteal progenitor activation in vital bone grafts, we found that bone matrix-derived BMP2 does not significantly enhance bone graft incorporation. Taken together, our data show that BMP2 signaling is not essential for the maintenance of periosteal progenitors, but is required for the activation of these progenitors and their subsequent

  3. Bioactive Polymer Grafting onto Titanium Alloy Surfaces for Improved Osteointegration

    PubMed Central

    Michiardi, Alexandra; Hélary, Gérard; Nguyen, Phuong-Cac Thi; Gamble, Lara J.; Anagnostou, Fani; Castner, David G.; Migonney, Véronique

    2013-01-01

    Bioactive polymers bearing sulfonate (styrene sodium sulfonate, NaSS) and carboxylate (methylacrylic acid, MA) groups were grafted onto Ti6Al4V alloy surfaces by a two-step procedure. The Ti alloy surfaces were first chemically oxidized in a piranha solution and then directly subjected to radical polymerization at 70°C in absence of oxygen. The grafted surfaces were characterized by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and the Toluidin blue colorimetric method. Toluidin blue results showed 1 to 5 μg/cm2 of polymer was grafted onto the oxidized Ti surfaces. Grafting resulted in a decrease in the XPS Ti and O signals from the underlying Ti substrate and a corresponding increase in the XPS C and S signals from the polymer layer. The ToF-SIMS intensities of the S− and SO− ions correlated linearly with the XPS atomic percent S concentrations and the ToF-SIMS intensity of the TiO3H2− ion correlated linearly with the XPS atomic percent Ti concentration. Thus, the ToF-SIMS S−, SO− and TiO3H2− intensities can be used to quantify composition and amount of grafted polymer. ToF-SIMS also detected ions that were more characteristic of the polymer molecular structure (C6H4SO3− and C8H7SO3− from NaSS, C4H5O2− from MA), but the intensity of these peaks depended on the polymer thickness and composition. An in vitro cell culture test was carried out with human osteoblast-like cells to assess the influence of the grafted polymers on cell response. Cell adhesion after 30 min of incubation showed significant differences between the grafted and un-grafted surfaces. The NaSS grafted surfaces showed the highest degree of cell adhesion while the MA-NaSS grafted surfaces showed the lowest degree of cell adhesion. After 4 weeks in vivo in rabbit femoral bones bone was observed to be in direct contact with all implants. The percent of mineralized tissue around the implants was similar for NaSS grafted and non-grafted

  4. Deficiency of Endothelial Progenitor Cells Associates with Graft Thrombosis in Patients Undergoing Endovascular Therapy of Dysfunctional Dialysis Grafts

    PubMed Central

    Chen, Tsung-Yan; Lin, Lin; Hsieh, Mu-Yang; Kuo, Jui-Cheng; Wang, Chia-Ling; Wang, Ren-Huei; Lai, Chao-Lun; Huang, Po-Hsun; Wu, Chih-Cheng

    2017-01-01

    Background The deficiency of endothelial progenitor cells has been demonstrated to be associated with cardiovascular events in patients undergoing dialysis. However, their correlation with dialysis graft outcomes remains unknown. The objective of this study was to investigate the relationship between circulating endothelial progenitor cells and dialysis graft outcomes. Methods After excluding 14 patients with acute coronary syndrome, decompensated heart failure or graft thrombosis in the prior three months, a total of 120 patients undergoing dialysis who underwent endovascular therapy of dysfunctional dialysis grafts were prospectively enrolled. Blood was sampled from study subjects in the morning of a mid-week non-dialysis day. Surface makers of CD34, KDR, and CD133 were used in combination to determine the number of circulating endothelial progenitor cells. All participants were prospectively followed until June 2013. Results The median follow-up duration was 13 months, within which 62 patients experienced at least one episode of graft thrombosis. Patients with graft thrombosis had lower CD34+KDR+ cell counts compared with patients without graft thrombosis (median 4.5 vs. 8 per 105 mononuclear cells, p = 0.02). Kaplan-Meier analysis demonstrated thrombosis-free survival was lower in the low CD34+KDR+ cell count group (30%) than in the high CD34+KDR+ cell count group (61%; p = 0.007). Univariate analysis showed diabetes, high sensitive C-reactive protein, lesion length and CD34+KDR+ cell counts associated with graft thrombosis. Multivariate analyses confirmed an independent association between low CD34+KDR+ cell counts and graft thrombosis (hazard ratio, 2.52; confidence interval, 1.43-4.44; p = 0.001). Conclusions Our study demonstrated an independent association between low circulating endothelial progenitor cell counts and dialysis graft thrombosis. PMID:28115811

  5. The use of contrast media in deceased kidney donors does not affect initial graft function or graft survival.

    PubMed

    Vigneau, C; Fulgencio, J-P; Godier, A; Chalem, Y; El Metaoua, S; Rondeau, E; Tuppin, P; Bonnet, F

    2006-09-01

    Patients receiving cadaveric kidney transplants often experience delayed graft function. As iodinated contrast media injection (ICMI), necessary for cerebral angiography, which is often used to diagnose brain death, can be nephrotoxic, we compared renal function recovery (RFR) and 1-year and long-term graft survival according to the method used to diagnose brain death. Data from 9921 cadaveric kidneys, transplanted between 1 January 1998 and 31 December 2003, were retrieved from the French National Registry for organ donation. We defined RFR as the number of days for the recipient to reach a plasma creatinine less than 250 mumol/l, and/or a 24-h urine output greater than 1000 ml. RFR and 1-year and long-term graft survival were compared between four different donor groups (according to ICMI and diabetes mellitus). A total of 41.5% of deceased donors received ICMI before organ procurement and 1.95% of them were diabetic. History of ICMI or diabetes in the donor did not influence RFR or 1-year graft survival. Long-term graft survival was decreased in the group of patients transplanted with a diabetic graft as compared to patients transplanted with a non-diabetic graft (P=0.001). History of ICMI in the donor did not affect long-term graft survival in the non-diabetic donor group (P=0.2); however, in the diabetic group, ICMI tended to decrease long-term graft survival (P=0.056). ICMI did not affect RFR or graft survival in non-diabetic deceased donors. However, its use in diabetic deceased donors requires further study.

  6. Successful Antibiotic Treatment of Severe Staphylococcal Infection of a Long Stent Graft in the Superficial Femoral Artery with Graft Preservation in the Long Term

    SciTech Connect

    Treitl, Marcus; Rademacher, Antje; Becker-Lienau, Johanna; Reiser, Maximilian F.; Hoffmann, Ulrich; Czihal, Michael

    2011-06-15

    Introduction: Bacterial infection of endovascular stent grafts is a serious condition, regularly leading to graft replacement by open bypass surgery.Case ReportWe describe the case of a staphylococcal infection of a 150-mm covered stent graft (Gore Viabahn), placed in the superficial femoral artery. Stent graft infection was successfully treated by oral administration of penicillinase-resistant flucloxacillin and the lipopeptide daptomycin with complete graft preservation, not requiring surgical treatment. During 1-year follow-up, the graft infection did not reappear. However, the patient developed restenosis at the proximal margin of the stent with recurrence of mild claudication, so far treated conservatively. Conclusion: With the increased use of covered stent grafts in the peripheral vasculature, the frequency of graft infection will increase. We demonstrate that with newly developed antibiotics, it is possible to treat this severe complication conservatively, with complete graft preservation and without the need for bypass surgery in selected cases.

  7. Antibacterial activity of triclosan chitosan coated graft on hernia graft infection model.

    PubMed

    Cakmak, Attila; Cirpanli, Yasemin; Bilensoy, Erem; Yorganci, Kaya; Caliş, Sema; Saribaş, Zeynep; Kaynaroğlu, Volkan

    2009-11-03

    The use of mesh in hernia repair has become common, because of lower recurrence rate and simple application. Data from the meta-analysis and the multi-central studies support the use of meshes in hernia repair. One of the complications due to the hernia repair with mesh is the infection. The incidence range is between 1 and 10%. Triclosan embedded commercial absorbable suture materials are used to reduce surgical site infection rate. This study was planned on mesh infection model, because of the low incidence rate. The agent isolated from mesh infections was mostly Staphylococcus aureus and thus it was used as the infecting agent in this research. To achieve a better therapeutic efficacy, triclosan was formulated in chitosan gels. Chitosan is an attractive biopolymer because of its biocompatible, biodegradable, bioadhesive properties. Gel formulations using chitosans (low, medium and high molecular weight) were prepared in 1% (v/v) acetic acid solution and in vitro release profiles were evaluated. Gel formulations showed release profile extended up to 7 days and high molecular weight chitosan gel formulation was released higher quantity drug than other formulations. Meshes coated with triclosan loaded chitosan gel were used to reduce bacterial count and to prevent mesh infection in the study. 24h and simultaneous bacteria inoculation was used to model mesh infection. The rats were observed for 8 days by means of surgical site infection. On the eighth day, the animals were sacrificed and the grafts were removed. Tissue squeezers were used to liberate bacterias from removed grafts. The isolated suspensions were cultured on blood agar plates and colony-forming units were counted overnight. Grafts coated with triclosan loaded chitosan gel presented satisfactory preventive effect against graft infection.

  8. Development in intracerebral stem cell grafts

    PubMed Central

    Reyes, Stephanny; Tajiri, Naoki; Borlongan, Cesar V.

    2015-01-01

    The field of stem cell therapy has emerged as a promising research area for brain repair. Optimizing the safety and efficacy of the therapy for clinical trials will require revisiting transplantation protocols. The cell delivery route stands as a key translational item that warrants careful consideration in facilitating the success of stem cell therapy in the clinic. Intracerebral administration, compared to peripheral route, requires an invasive procedure to directly implant stem cells into injured brain. Although invasive, intracerebral transplantation circumvents the prohibitive blood brain barrier in allowing grafted cells when delivered peripherally to penetrate the brain and reach the discreet damaged brain tissues. This review will highlight milestone discoveries in cell therapy for neurological disorders, with emphasis on intracerebral transplantation in relevant animal models and provide insights necessary to optimize the safety and efficacy of cell therapy for the treatment of Parkinson’s disease, Huntington’s disease, stroke, and traumatic brain injury. PMID:25739415

  9. PEM Anchorage on Titanium Using Catechol Grafting

    PubMed Central

    Marie, Hélène; Barrere, Amélie; Schoentstein, Frédérique; Chavanne, Marie-Hélène; Grosgogeat, Brigitte; Mora, Laurence

    2012-01-01

    Background This study deals with the anchorage of polyelectrolyte films onto titanium surfaces via a cathecol-based linker for biomedical applications. Methodology The following study uses a molecule functionalized with a catechol and a carboxylic acid: 3-(3,4-dihydroxyphenyl)propanoic acid. This molecule is anchored to the TiO2 substrate via the catechol while the carboxylic acid reacts with polymers bearing amine groups. By providing a film anchorage of chemisorption type, it makes possible to deposit polyelectrolytes on the surface of titanium. Principal Findings Infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), contact angle and atomic force microscopy (AFM) measurements show that the different steps of grafting have been successfully performed. Conclusions This method based on catechol anchorage of polyelectrolytes open a window towards large possibilities of clinical applications. PMID:23226262

  10. Redesigning Aldolase Stereoselectivity by Homologous Grafting

    PubMed Central

    Henßen, Birgit; Metz, Alexander; Gohlke, Holger; Pietruszka, Jörg

    2016-01-01

    The 2-deoxy-d-ribose-5-phosphate aldolase (DERA) offers access to highly desirable building blocks for organic synthesis by catalyzing a stereoselective C-C bond formation between acetaldehyde and certain electrophilic aldehydes. DERA´s potential is particularly highlighted by the ability to catalyze sequential, highly enantioselective aldol reactions. However, its synthetic use is limited by the absence of an enantiocomplementary enzyme. Here, we introduce the concept of homologous grafting to identify stereoselectivity-determining amino acid positions in DERA. We identified such positions by structural analysis of the homologous aldolases 2-keto-3-deoxy-6-phosphogluconate aldolase (KDPG) and the enantiocomplementary enzyme 2-keto-3-deoxy-6-phosphogalactonate aldolase (KDPGal). Mutation of these positions led to a slightly inversed enantiopreference of both aldolases to the same extent. By transferring these sequence motifs onto DERA we achieved the intended change in enantioselectivity. PMID:27327271

  11. Outcomes of coronary artery bypass graft surgery

    PubMed Central

    Hawkes, Anna Louise; Nowak, Madeleine; Bidstrup, Benjamin; Speare, Richard

    2006-01-01

    This review article summarizes the major studies that have investigated the outcomes of coronary artery bypass graft surgery (CABG). The article includes a review of the literature in the areas of: history of CABG; indications for CABG; and measurement of quality of life following CABG, including prolongation of life, physical functioning (ie, relief from angina and dyspnea, physical activity, as well as complications of surgery and re-hospitalization), psychological functioning, and social functioning. Overall, the literature demonstrates that the outcomes of CABG have historically been measured in terms of mortality and morbidity; however, it has now been well recognized that adjustment to CABG is a multidimensional phenomenon that is not fully explained by medical factors. Therefore, in addition to studying mortality and morbidity outcomes following CABG, many recent studies have identified that it is important to investigate various physical, psychological, and social variables that have a significant impact on post-operative adjustment to CABG. PMID:17323602

  12. Microphase segregation in molten randomly grafted copolymers

    NASA Astrophysics Data System (ADS)

    Qi, Shuyan; Chakraborty, Arup K.; Balsara, Nitash P.

    2001-08-01

    We study microphase ordering of molten randomly grafted copolymers (RGCs) by using a mean field theory and the replica method to calculate the quenched average. Our results illustrate that in the weak segregation limit (WSI), the optimal wave vector q* of the lamellar phase formed by molten RGCs, has a temperature dependence different from either linear random copolymers (LRCs) or diblock copolymers (DCPs): when close, but below the microphase separation transition (MST) temperature, q* increases sharply with decreasing temperature; then q* gradually acquires an asymptotic value determined by the length of the branch and the average distance between branch points on the backbone. Our results are compared with recent experiments, and the effects of chain architecture on the microphase separation characteristics of RGCs are delineated. Our results suggest a new method for controlling the microphase spacing by exploiting quenched disorder.

  13. Primary Graft Dysfunction after Lung Transplantation

    PubMed Central

    Altun, Gülbin Töre; Arslantaş, Mustafa Kemal; Cinel, İsmail

    2015-01-01

    Primary graft dysfunction (PGD) is a severe form of acute lung injury that is a major cause of early morbidity and mortality encountered after lung transplantation. PGD is diagnosed by pulmonary oedema with diffuse alveolar damage that manifests clinically as progressive hypoxemia with radiographic pulmonary infiltrates. Inflammatory and immunological response caused by ischaemia and reperfusion is important with regard to pathophysiology. PGD affects short- and long-term outcomes, the donor organ is the leading factor affecting these adverse ramifications. To minimize the risk of PGD, reduction of lung ischaemia time, reperfusion optimisation, prostaglandin level regulation, haemodynamic control, hormone replacement therapy, ventilator management are carried out; for research regarding donor lung preparation strategies, certain procedures are recommended. In this review, recent updates in epidemiology, pathophysiology, molecular and genetic biomarkers and technical developments affecting PGD are described. PMID:27366539

  14. Grafting of genetically manipulated cells into adult brain: toward graft-gene therapy.

    PubMed

    Uchida, K; Toya, S

    1996-06-01

    Accumulating evidence has shown that functional recoveries in various kinds of animal models of neurodegenerative diseases can be achieved by grafting fetal neurons into the brain. On the basis of these successful results, clinical trials are under way to determine whether human fetal mesencephalic tissue can ameliorate motor functions in patients with Parkinson's disease. Recent autopsy findings of parkinsonian patient implanted with human fetal mesencephalic tissue clearly revealed that the fetal neuronal graft can survive for extended period of time in the human brain and densely reinnervate the surrounding host striatal tissue. It is, however, still important to obtain more practical, effective and ethically justifiable donor material for the future clinical application of the procedures. Desirable properties for the donor cells include long-term survival in the host brain, neuronal cell type for the reconstruction of damaged neural circuits, and susceptibility to genetic manipulation for the practical use. With the development of molecular biology techniques, genetic modification and transplantation of the donor neuronal cells might be a feasible way to cure many kinds of central nervous system diseases toward a "graft-gene therapy".

  15. Numerical Assessment of Novel Helical/Spiral Grafts with Improved Hemodynamics for Distal Graft Anastomoses

    PubMed Central

    Kabinejadian, Foad; McElroy, Michael; Ruiz-Soler, Andres; Leo, Hwa Liang; Slevin, Mark A.; Badimon, Lina

    2016-01-01

    In the present work, numerical simulations were conducted for a typical end-to-side distal graft anastomosis to assess the effects of inducing secondary flow, which is believed to remove unfavourable flow environment. Simulations were carried out for four models, generated based on two main features of 'out-of-plane helicity' and 'spiral ridge' in the grafts as well as their combination. Following a qualitative comparison against in vitro data, various mean flow and hemodynamic parameters were compared and the results showed that helicity is significantly more effective in inducing swirling flow in comparison to a spiral ridge, while their combination could be even more effective. In addition, the induced swirling flow was generally found to be increasing the wall shear stress and reducing the flow stagnation and particle residence time within the anastomotic region and the host artery, which may be beneficial to the graft longevity and patency rates. Finally, a parametric study on the spiral ridge geometrical features was conducted, which showed that the ridge height and the number of spiral ridges have significant effects on inducing swirling flow, and revealed the potential of improving the efficiency of such designs. PMID:27861485

  16. Biomechanical Evaluation of Flexor Tendon Graft With Different Repair Techniques and Graft Surface Modification

    PubMed Central

    Wu, Jingheng; Thoreson, Andrew R.; Reisdorf, Ramona L.; An, Kai-Nan; Moran, Steven L.; Amadio, Peter C.; Zhao, Chunfeng

    2016-01-01

    The purpose of this study was to investigate the biomechanical properties of modified repair techniques for flexor tendon reconstruction and the effects of surface modification using carbodiimide-derivatized synovial fluid plus gelatin (cd-SF-G), compared to the traditional repair techniques. The second and fifth digits from 16 canine forepaws were randomly divided into 4 groups: (1) traditional graft repairs (TGR group) including distal Bunnell repair and proximal Pulvertaft weave repair; (2) modified graft repairs (MGR group) including distal graft bony attachment repair and proximal step-cut repair; (3) group TGR coated with cd-SF-G (TGR-C group); and (4) group MGR coated with cd-SF-G (MGR-C group). Digit normalized work of flexion (nWOF), ultimate failure strength, and stiffness were measured. The nWOF in MGR group was significantly less than TGR group (p < 0.05). The nWOF in groups treated with cd-SF-G was significantly less than their untreated counterparts (p < 0.05). Ultimate load to failure of the MGR-C group was significantly greater than the TGR-C group (p < 0.05), but no significant difference in stiffness was found between these two groups. The modified techniques cannot only improve tendon gliding abilities but can also improve breaking strength. Additionally, surface modification with cd-SF-G significantly decreased the work of flexion. PMID:25665071

  17. Albumin grafting on biomaterial surfaces using gamma-irradiation

    SciTech Connect

    Kamath, K.R.

    1993-01-01

    Surface modification has been used extensively in various fields to introduce desirable surface properties without affecting the bulk properties of the material. In the area of biomaterials, the approach of surface modification offers an effective alternative to the synthesis of new biomaterials. The specific objective of this study was to modify different biomaterial surfaces by albumin grafting to improve their blood compatibility. The modified surfaces were characterized for surface-induced platelet activation and thrombus formation. This behavior was correlated with the conditions used for grafting. In particular, albumin was functionalized to introduce pendant double bonds into the molecule. The functionalized albumin was covalently attached to various surfaces, such as dimethyldichlorosilane-coated glass, polypropylene, polycarbonate, poly(vinyl chloride), and polyethylene by gamma-irradiation. Platelet adhesion and activation on these surfaces was examined using video microscopy and scanning electron microscopy. The extent of grafting was found to be dependent on the albumin concentration used for adsorption and the gamma-irradiation time. Release of the grafted albumin during exposure to blood was minimal. The albumin-grafted fibers maintained their thromboresistant properties even after storage at elevated temperatures for prolonged time periods. Finally, the approach was used to graft albumin on the PLEXUS Adult Hollow Fiber Oxygenators (Shiley). The blood compatibility of the grafted oxygenators improved significantly when compared to controls.

  18. Response of canine bone to a synthetic bone graft material.

    PubMed

    St John, K R; Zardiackas, L D; Black, R J; Armstrong, R

    1993-01-01

    A model simulating a spiral diaphyseal fracture with butterfly fragments and bone loss was utilized to evaluate an hydroxyapatite/tricalcium phosphate, and collagen composite bone graft substitute in twelve dogs. The resultant grafted and contralateral control femora were tested in torsion at one year. This study examines the histological response to the graft material as well as crack propagation and fracture surface morphology using light microscopy and SEM. SEM and gross evaluation of the grafted bones revealed that 8/12 had fractured through bone outside the osteotomy site and all fractures included bone outside the graft site. No graft material was demonstrated at the points of initiation or termination of fracture for any of the bones. It was apparent that recorticalization had begun to occur at the graft site but the canal had not yet fully formed. The HA/TCP was seen to be tightly bound in tissue which had the appearance of new bone. Bone was found to be in direct apposition to the surface of the ceramic and within pores with no intervening soft tissue. Much of the new bone had remodeled into well organized Haversian systems with some patchy areas of woven bone and osteoid seen with polarized light illumination.

  19. Analysis of cartilage-polydioxanone foil composite grafts.

    PubMed

    Kim, James H; Wong, Brian

    2013-12-01

    This study presents an analytical investigation into the mechanical behavior of a cartilage-polydioxanone (PDS) plate composite grafts. Numerical methods are used to provide a first-order, numerical model of the flexural stiffness of a cartilage-PDS graft. Flexural stiffness is a measure of resistance to bending and is inversely related to the amount of deformation a structure may experience when subjected to bending forces. The cartilage-PDS graft was modeled as a single composite beam. Using Bernoulli-Euler beam theory, a closed form equation for the theoretical flexural stiffness of the composite graft was developed. A parametric analysis was performed to see how the flexural properties of the composite model changed with varying thicknesses of PDS foil. The stiffness of the cartilage-PDS composite using 0.15-mm-thick PDS was four times higher than cartilage alone. The composite with a 0.5-mm-thick PDS graft was only 1.7 times stiffer than the composite with the 0.15-mm-thick PDS graft. Although a thicker graft material will yield higher flexural stiffness for the composite, the relationship between composite stiffness and PDS thickness is nonlinear. After a critical point, increments in graft thickness produce gradually smaller improvements in flexural stiffness. The small increase in stiffness when using the thicker PDS foils versus the 0.15 mm PDS foil may not be worth the potential complications (prolonged foreign body reaction, reduction in nutrient diffusion to cartilage) of using thicker artificial grafts.

  20. Implant biomechanics in grafted sinus: a finite element analysis.

    PubMed

    Fanuscu, Mete I; Vu, Hung V; Poncelet, Bernard

    2004-01-01

    This in vitro study investigated the stress distribution in the bone surrounding an implant that is placed in a posterior edentulous maxilla with a sinus graft. The standard threaded implant and anatomy of the crestal cortical bone, cancellous bone, sinus floor cortical bone, and grafted bone were represented in the 3-dimensional finite element models. The thickness of the crestal cortical bone and stiffness of the graft were varied in the models to simulate different clinical scenarios, representing variation in the anatomy and graft quality. Axial and lateral loads were considered and the stresses developed in the supporting structures were analyzed. The finite element models showed different stress patterns associated with helical threads. The von Mises stress distribution indicated that stress was maximal around the top of the implant with varying intensities in both loading cases. The stress was highest in the cortical bone, lower in the grafted bone, and lowest in the cancellous bone. When the stiffness of the grafted bone approximated the cortical bone, axial loading resulted in stress reduction in all the native bone layers; however, lateral loading produced stress reduction in only the cancellous bone. When the stiffness of the graft was less than that of the cancellous bone, the graft assumed a lesser proportion of axial loads. Thus, it caused a concomitant stress increase in all the native bones, whereas this phenomenon was observed in only the cancellous bone with lateral loading. The crestal cortical bone, though receiving the highest intensity stresses, affected the overall stress distribution less than the grafted bone. The stress from the lateral load was up to 11 times higher than that of the axial load around the implant. These findings suggest that the type of loading affects the load distribution more than the variations in bone, and native bone is the primary supporting structure.

  1. Cartilage repair with autogenic perichondrium cell and polylactic acid grafts.

    PubMed

    Dounchis, J S; Bae, W C; Chen, A C; Sah, R L; Coutts, R D; Amiel, D

    2000-08-01

    The repair of articular cartilage injuries remains a challenge, with many of the current therapeutic strategies based on the grafting or recruitment of chondrogenic tissues or cells. This 1-year study compared the repair of a 3.7-mm diameter by 3-mm deep osteochondral defect in the medial femoral condyle of 24 New Zealand White rabbits; the defect was obtained using an autogenic perichondrium cell polylactic acid composite graft with a contralateral control in which the osteochondral defect remained empty. To elucidate the effect of host immune responses on the repair process after perichondrium cell transplantation, the results of the autogenic perichondrium cell polylactic acid graft group were compared with those obtained in the authors' previous 1-year study of allogenic perichondrium cell polylactic acid composite grafts implanted in a similar model. One year after surgery, the repair site underwent gross inspection and histologic, histomorphometric, biochemical, and biomechanical analyses. The autogenic perichondrium cell polylactic acid graft group (92%) and the control group in which the osteochondral defect remained empty (88%) resulted in a high percentage of grossly acceptable repairs. The autogenic grafts appeared to augment the intrinsic healing capacity of the animals (as compared with the animals in the No Implant Group). The autogenic perichondrium cell polylactic and grafts improved the histologic appearance and percentage of Type II collagen of the cartilaginous repair tissue. Compared with allogenic grafts, the autogenic grafts had better reconstitution of the subchondral bone. However, the results of this experimental model suggest a suboptimal concentration of glycosaminoglycans in the neocartilage matrix, a depressed surface of the repair tissue, a histologic appearance that was not equivalent to that of normal articular cartilage, and reduced biomechanical properties for the repair tissue. The future application of growth factors to this

  2. [Graft hybridization and the specificity of heredity in fruit trees].

    PubMed

    Liu, Yong-Sheng; Li, Bao-Yin; Li, Gui-Rong; Zhou, Xiu-Mei

    2004-09-01

    Emphatically discusses the relationship between graft hybridization and the specificity of heredity in fruit trees on the basis of introducing the recent achievements in plant graft hybridization. We propose that genetic materials in rootstock being translocated and integrated into the genome of the germ cells and embryonic cells in scion are the main reasons why the majority of the hybrid seedlings have wild properties and the heredity of fruit trees violate Mendel's laws of heredity. The potential of graft hybridization in fruit breeding are also discussed.

  3. A graduated method of tip graft fixation in rhinoplasty.

    PubMed

    Papel, I D

    1995-06-01

    Projection of the nasal tip has gained increased recognition as a measurable and visual characteristic that has an impact on the results of aesthetic rhinoplasty. Autologous cartilage tip grafts have been used in many techniques to increase tip projection and contour the tip during rhinoplasty. This article introduces a graduated method of tip graft fixation correlated with specific clinical measurements related to tip projection. After careful analysis of tip projection and contour, a predictable graft fixation technique can be selected to obtain the desired degree of nasal tip projection and sculpting.

  4. Biomechanical factors as regulators of biological responses to vascular grafts.

    PubMed

    Fortunato, J E; Glagov, S; Bassiouny, H S

    1999-03-01

    Biomechanical forces have been implicated in the induction and progression of intimal hyperplastic thickening in vein, prosthetic, and endovascular bypass grafts. Graft implantation imposes significant alterations is shear and tensile forces. Such physical forces play an important role in modulating those cellular and molecular events that underlie regulation of vascular healing and adaptation. Characterization of such hemodynamic variables that induce perpetual medial vascular smooth muscle cell proliferation and migration will help in identification of those grafts at risk for occlusion and limited long-term patency and in design of therapeutic strategies that attenuate progressive intimal hyperplasia.

  5. Caudal and dorsal septal reconstruction: an algorithm for graft choices.

    PubMed

    Sherris, D A

    1997-01-01

    The objective of this study is to present an algorithm for choosing graft materials for the reconstruction of severe caudal and/or dorsal septal cartilage abnormalities and to examine the long-term results obtained with these techniques. Retrospective review of 21 consecutive cases of caudal and/or dorsal septal reconstruction via the external approach using the algorithms is presented. The techniques used are carefully described. Patient survey at least 1 year after the initial procedure, rhinologic examination before and after the procedure, and photographic analysis of preoperative and postoperative views are presented. The graft choice algorithm presented helps the surgeon to consider appropriate graft choice alternatives before surgery.

  6. Role of vascularized bone grafts in lower extremity osteomyelitis.

    PubMed

    Tu, Yuan-Kun; Yen, Cheng-Yo

    2007-01-01

    Vascularized bone grafting seems to be a valuable reconstructive technique for the treatment of osteomyelitis with skeletal defects greater than 6 cm in length. Fibular osteocutaneous, composite rib, and iliac osteocutaneous flaps are the most commonly used vascularized bone grafts clinically. Vascularized bone can obliterate dead space, bridge large bone defects, enhance bone healing, resist infection by ensuring blood supply, allow early rehabilitation, and ensure better clinical outcomes in the treatment of lower extremity osteomyelitis. Success rates range from 80% to 95%. Complications of surgery include anastomosis failure, donor site problems, and fracture of the grafted bone.

  7. Process for radiation grafting hydrogels onto organic polymeric substrates

    DOEpatents

    Ratner, Buddy D.; Hoffman, Allan S.

    1976-01-01

    An improved process for radiation grafting of hydrogels onto organic polymeric substrates is provided comprising the steps of incorporating an effective amount of cupric or ferric ions in an aqueous graft solution consisting of N-vinyl-2 - pyrrolidone or mixture of N-vinyl-2 - pyrrolidone and other monomers, e.g., 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, propylene glycol acrylate, acrylamide, methacrylic acid and methacrylamide, immersing an organic polymeric substrate in the aqueous graft solution and thereafter subjecting the contacted substrate with ionizing radiation.

  8. Fibrin Adhesive: Clinical Application in Coronary Artery Bypass Graft Surgery

    PubMed Central

    Fundaró, Pino; Velardi, Antonio R.; Santoli, Carmine

    1985-01-01

    Fibrin adhesive was used 72 times in a group of 67 patients undergoing elective coronary artery bypass graft surgery. The indications were prophylactic sealing of potential sources of bleeding, topical hemostasis (control of bleeding sites dangerous or difficult to suture), and fixation of the graft in the optimal position. The method of glue application under varying circumstances is described and the results are reported. This experience suggests that in some cases the glue expedites the operation and makes it safer. We conclude that the fibrin sealing represents a valid aid in coronary artery bypass graft surgery. PMID:15227018

  9. Nickel adsorption by sodium polyacrylate-grafted activated carbon.

    PubMed

    Ewecharoen, A; Thiravetyan, P; Wendel, E; Bertagnolli, H

    2009-11-15

    A novel sodium polyacrylate grafted activated carbon was produced by using gamma radiation to increase the number of functional groups on the surface. After irradiation the capacity for nickel adsorption was studied and found to have increased from 44.1 to 55.7 mg g(-1). X-ray absorption spectroscopy showed that the adsorbed nickel on activated carbon and irradiation-grafted activated carbon was coordinated with 6 oxygen atoms at 2.04-2.06 A. It is proposed that this grafting technique could be applied to other adsorbents to increase the efficiency of metal adsorption.

  10. Acromioclavicular joint reconstruction using a tendon graft: a biomechanical study comparing a novel “sutured throughout” tendon graft to a standard tendon graft

    PubMed Central

    Naziri, Qais; Williams, Nadine; Hayes, Westley; Kapadia, Bhaveen H.; Chatterjee, Dipal; Urban, William P.

    2016-01-01

    Background: With a recurrence rate of over 30%, techniques that offer stronger acromioclavicular (AC) joint reconstruction through increased graft strength may provide longevity. The purpose of our study was to determine the biomechanical strength of a novel tendon graft sutured throughout compared to a native tendon graft in Grade 3 anatomical AC joint reconstruction. Methods: For this in vitro experiment, nine paired (n = 18) embalmed cadaveric AC joints of three males and six females (age 86 years, range 51–94 years) were harvested. Anatomic repair with fresh bovine Achilles tendon grafts without bone block was simulated. Specimens were divided into two groups; with group 1 using grafts with ultra-high molecular-weight polyethylene (UHMWPE) suture ran throughout the entire length. In group 2, reconstruction with only native allografts was performed. The distal scapula and humerus were casted in epoxy compound and mounted on the mechanical testing machine. Tensile tests were performed using a mechanical testing machine at the rate of 50 mm/min. Maximum load and displacement to failure were collected. Results: The average load to failure was significantly higher for group 1 compared to group 2, with mean values of 437.5 N ± 160.7 N and 94.4 N ± 43.6 N, (p = 0.001). The average displacement to failure was not significantly different, with 29.7 mm ± 10.6 mm in group 1 and 25 mm ± 9.1 mm in group 2 (p = 0.25). Conclusion: We conclude that a UHMWPE suture reinforced graft can provide a 3.6 times stronger AC joint reconstruction compared to a native graft. PMID:27163106

  11. Possible roles of 5-HT in vein graft failure due to intimal hyperplasia 5-HT, nitric oxide and vein graft.

    PubMed

    Kodama, Akio; Itoh, Takeo; Komori, Kimihiro

    2014-02-01

    For vascular occlusive disease, an autologous vein graft is the most suitable conduit for arterial reconstruction. Intimal hyperplasia, resulting from the migration and proliferation of vascular smooth muscle cells, is a major obstacle to patency after vein grafting. The degree to which the function of nitric oxide (NO) in the vein graft is preserved has been reported to be associated with the magnitude of intimal hyperplasia. Serotonin (5-HT) is released from platelets in the vascular system and plays physiological roles in controlling the vascular tone. The subtype receptors contributing to the 5-HT-induced mechanical responses vary by vessel type (artery and vein) and among species (dogs, rabbits, rats, and so on). Recent studies have demonstrated that 5-HT induces vasoconstriction through the activation of 5-HT2A receptors in smooth muscle cells or vasodilatation through the activation of endothelial 5-HT1B receptors in arteries from various animals. However, the effects of 5-HT have not been clarified in grafted veins. We herein demonstrate the responses to 5-HT in un-operated veins and then autogenous vein grafts. Next, we describe the effects of chronic in vivo administration of Rho-kinase inhibitors and 5-HT2A receptor antagonists, both of which reduce the 5-HT-induced contraction and intimal hyperplasia in vein grafts. Further studies targeting 5-HT are required to evaluate its possible benefits for autologous vein grafts with respect to vasospasm, function, and patency.

  12. Radiation-grafted polymers for biomaterial applications. I. 2-hydroxyethyl methacrylate: ethyl methacrylate grafting onto low density polyethylene films

    SciTech Connect

    Cohn, D.; Hoffman, A.S.; Ratner, B.D.

    1984-08-01

    Studies were conducted on the radiation grafting of 2-hydroxyethyl methacrylate (HEMA) and ethyl methacrylate (EMA) by the mutual irradation technique onto low density polyethylene. Four different solution concentrations were used, and radiation doses ranged from 0.03 to 0.50 Mrad. Four copolymer compositions having different HEMA:EMA ratios were also studied using two total monomer concentrations. The kinetics of the grafting process demonstrated by the two monomers were basically different. While EMA showed a typical diffusion-controlled kinetic pattern, HEMA exhibited a more complex behavior, the main features of which were an induction period, a slight autoacceleration and a significant drop in graft level after a maximum is reached. The difference in behavior was interpreted in terms of partitioning of monomers into the polyethlene substrate. The surface topography of the grafted films was studied by means of scanning electron microscopy. A mechanism based on osmotic cell formation was suggested for the HEMA graft system. The copolymer systems investigated showed that the graft reaction is faster in the initial stages for higher percentages of EMA in the monomer mixtures; as grafting proceeds the trend is reversed. 24 references, 16 figures, 2 tables.

  13. The relevance of arterial wall microbiology to the treatment of prosthetic graft infections: graft infection vs. arterial infection.

    PubMed

    Macbeth, G A; Rubin, J R; McIntyre, K E; Goldstone, J; Malone, J M

    1984-11-01

    One potential, but poorly studied source for intraoperative contamination of vascular grafts is the native artery to which the prosthetic graft is attached. The purpose of this study was to analyze the relationship between arterial wall microbiology and graft infection. Between July 1, 1981, and March 31, 1982, arterial specimens were cultured from 88 (30%) of 298 patients undergoing clean, elective arterial reconstructive procedures. Control cultures were obtained from adjacent adipose or lymph node tissue. Positive cultures were obtained from 38 of 88 (43%) of the arterial walls cultured but from none of the control cultures (0 of 20) (p less than 0.001). The most common organism cultured was Staphylococcus epidermidis (27 of 38; 71%). Our overall graft infection rate since January 1, 1981, is 0.9% (3 of 335). All three graft infections occurred in patients with positive arterial cultures. Arterial and graft cultures were also obtained from 20 patients treated for 22 graft infections over the past 13 years. Organisms recovered included staphylococcal species (36%), enteric organisms (46%), and mixtures of the two (18%). These patients with culture-positive graft infections were divided retrospectively into two groups: those with positive and those with negative arterial cultures. Positive arterial cultures were associated with suture line disruption in 8 of 14 cases (57%), but there were no arterial disruptions in patients with negative cultures (0 of 8) (p less than 0.01). These data document a significant correlation between positive arterial wall cultures and subsequent prosthetic infection and also suggest that infection involving the arterial wall is a major determinant of the morbidity and mortality associated with the treatment of prosthetic graft sepsis.

  14. Modification of polyetherurethane for biomedical application by radiation induced grafting. II. Water sorption, surface properties, and protein adsorption of grafted films

    SciTech Connect

    Jansen, B.; Ellinghorst, G.

    1984-07-01

    A series of polyetherurethane films grafted by means of gamma radiation with hydrophilic or reactive monomers (2-hydroxyethyl methacrylate, 2,3-epoxypropyl methacrylate, 2,3-dihydroxypropyl methacrylate, and acrylamide) and partially chemically modified were subjected to various physico-chemical investigation methods involving water sorption, contact angle, and protein adsorption measurements. From contact angle data the interfacial free energy gamma sw between grafted films and water was calculated. It was found that the water uptake of grafted films increases with grafting yield or, in the case of grafted and afterwards chemically modified films, with reaction yield; the diffusion coefficient of water in the modified films also increases with grafting yield. Contact angle studies revealed all grafted films to have surfaces more hydrophilic than the ungrafted trunk polymer. The degree of hydrophilicity--especially of HEMA-grafted films--strongly depends on grafting conditions. For some grafted samples with high surface hydrophilicity very low interfacial free energies approaching zero were measured. The study of the competitive adsorption of bovine serum albumin, gamma-globulin, and fibrinogen from a synthetic protein solution onto modified films showed that the adsorption of albumin increases markedly with increasing grafting yields, whereas the fibrinogen and gamma-globulin adsorption only slightly increases. A correlation between interfacial free energy and protein adsorption in the sense of the minimum interfacial free energy hypothesis was found only for samples with grafting yields below 5%. At higher grafting yields the increased surface area complicates the analysis.

  15. What to Expect After Coronary Artery Bypass Grafting

    MedlinePlus

    ... What To Expect After Coronary Artery Bypass Grafting Recovery in the Hospital After surgery, you'll typically ... for 3 to 5 days before going home. Recovery at Home Your doctor will give you specific ...

  16. Vascular grafts in microvascular surgery. An experimental study

    SciTech Connect

    Marrangoni, A.G.; Marcelli, G.; Culig, M.; Simone, S.T.

    1988-02-01

    The patency of microvascular grafts depends on the luminal diameter, which is determined by the amount of fibrin and platelets deposited on the intraluminal surface and the anastomotic site, and the extent of pseudointimal formation. An experimental microvascular model in rats has been developed in our laboratory using Indium-111-labeled platelets to measure the amount of deposition on grafts inserted into the infrarenal aorta. This study was designed to assess the patency rates in these grafts and the pathologic maturation as determined by light and electron microscopy. Our study suggests that substantial patency rates can be achieved in aspirin-treated rats, although there was little influence on the pathologic maturation. Indium-111 oxine-labeled platelets can be used to document platelet aggregation, and the technique can be a valuable adjunct in the study of microvascular grafts.

  17. Invertase immobilization onto radiation-induced graft copolymerized polyethylene pellets

    NASA Astrophysics Data System (ADS)

    de Queiroz, Alvaro Antonio Alencar; Vitolo, Michele; de Oliveira, Rômulo Cesar; Higa, Olga Zazuco

    1996-06-01

    The graft copolymer poly(ethylene-g-acrylic acid) (LDPE-g-AA) was prepared by radiation-induced graft copolymerization of acrylic acid onto low density polyethylene (LDPE) pellets, and characterized by infrared photoacoustic spectroscopy and scanning electron microscopy (SEM). The presence of the grafted poly(acrylic acid) (PAA) was established. Invertase was immobilized onto the graft polymer and the thermodynamic parameters of the soluble and immobilized enzyme were determined. The Michaelis constant, Km, and the maximum reaction velocity, Vmax, were determined for the free and the immobilized invertase. The Michaelis constant, Km was larger for the immobilized invertase than for the free enzyme, whereas Vmax was smaller for the immobilized invertase. The thermal stability of the immobilized invertase was higher than that of the free enzyme.

  18. Pantaloon femoral vein graft as "neoaorta" in infected aortic disease.

    PubMed

    Verma, Himanshu; Mohan, Satish; Tripathi, Ramesh K

    2015-10-01

    Infected abdominal aortic disease and graft infections pose a significant challenge for the vascular surgeon. Thorough radical débridement, either preceded by extra-anatomic bypass or followed by in situ aortic replacement, is the mainstay of treatment. The role of endovascular repair by stent grafts is being increasingly described but is limited to relatively less virulent mycotic aneurysms or as a "bridging" option in sick patients with florid sepsis that necessitates eventual delayed definitive surgical management. Autologous femoral vein has been an excellent conduit for aortic bifurcation reconstruction in this setting. Although various configurations of femoral vein conduit have been described for aortobi-iliac reconstruction, an in-depth knowledge of the venous anatomy, physiology, mechanisms of "profundization," and techniques of harvest and graft preparation is essential for efficient conduct of the operation and its optimal outcomes. We review in detail these aspects of "pantaloon" femoral vein graft creation as a "neoaorta".

  19. Deformation mechanism in swollen radiation-grafted polyethylene

    NASA Astrophysics Data System (ADS)

    Ungar, G.; Dlugosz, J.; Ranogajec, F.

    Stress-strain behaviour of anisotropic polyethylene (PE) film radiation-grafted with styrene was studied with the samples immersed in xylene. The glassy polystyrene (PS) phase (1) is softened by swelling. Whereas the tensile modulus of dry graft increases somewhat with increasing PS content, for the swollen graft it decreases sharply. However the yield stress and the elongation at break remain fairly large. For highly grafted films (PS/PE > 1) deformation is almost fully reversible and proceeds without necking up to draw ratios as high as 5:1. With the aid of additional X-ray diffraction and transmission electron microscopy results the deformation mechanism is interpreted in terms of the known morphology of the copolymer.

  20. Ibrutinib Effective against Graft-Versus-Host Disease

    Cancer.gov

    A Cancer Currents blog post on results from a small clinical trial showing that ibrutinib can effectively treat graft-versus-host-disease, a common and serious complication of allogeneic stem cell transplants.

  1. [Psychoprophylaxis in patients after coronary artery bypass graft operations].

    PubMed

    Rymaszewska, Joanna; Chładzińska-Kiejna, Sylwia; Górna, Renata; Kustrzycki, Wojciech

    2004-05-01

    The paper presented problems of quality of life and psychosocial functioning of patients following coronary artery bypass grafting operations. Possibilities of psychoprophylactic effects towards these patients and its efficacy were described.

  2. New frontiers in urethral reconstruction: injectables and alternative grafts

    PubMed Central

    2015-01-01

    Contemporary management of anterior urethral strictures requires both endoscopic as well as complex substitution urethroplasty, depending on the nature of the urethral stricture. Recent clinical and experimental studies have explored the possibility of augmenting traditional endoscopic urethral stricture management with anti-fibrotic injectable medications. Additionally, although buccal mucosa remains the gold standard graft for substitution urethroplasty, alternative grafts are necessary for reconstructing particularly complex urethral strictures in which there is insufficient buccal mucosa or in cases where it may be contraindicated. This review summarizes the data of the most promising injectable adjuncts to endoscopic stricture management and explores the alternative grafts available for reconstructing the most challenging urethral strictures. Further research is needed to define which injectable medications and alternative grafts may be best suited for urethral reconstruction in the future. PMID:26813260

  3. [Subcapsular hematoma and rupture of the liver graft].

    PubMed

    Görög, Dénes; Fehérvári, Imre; Doros, Attila; Nemes, Balázs; Máthé, Zoltán; Kóbori, László; Járay, Jeno

    2008-08-01

    Subcapsular hematoma and/or rupture of the graft is uncommon but serious complication of liver transplantation. It may develop spontaneously or following parenchymal injuries or percutaneous transhepatic invasive procedures. This report describes three cases of subcapsular hematoma and/or rupture of the graft with different courses among 350 liver transplantations. In the first case, the patient died due to graft rupture caused by a pseudoaneurysm after biopsy. In the second case, a small injury of the donor liver resulted in a deep rupture, which required partial resection of the graft. The patient died in sepsis later. The third patient presented with a large subcapsular haematoma during transplantation, which was successfully treated. The authors' strategies developed intraoperatively for the management of hematomas. These involve opening and removing of the haematoma, haemostasis with Argon coagulation, which resulted in an adherent Glisson's capsule to the parenchyma and covering with collagen fleece coated with fibrinogen and thrombin.

  4. Clinical Study of Graft Selection in Malaysian Rhinoplasty Patients

    PubMed Central

    2013-01-01

    Graft selection remains the greatest challenge for surgeons performing rhinoplasty. The preferred choice thus far for nasal reconstruction would be autograft compared to allograft due to its lower rate of infection and extrusion as it does not induce an immune response. We have evaluated 26 patients who underwent open structured rhinoplasty at our center and compared our experience regarding the operative technique, graft availability, indications, and limitations. The racial distribution was 18 Indians, 5 Chinese, and 3 Malays with a mean age, hospitalization, and followup of 30.5 years, 16.9 months, and 4.4 days, respectively. Majority of the patients (57.6%) presented with twisted nose and 30.7% of the patients presented with history of nasal trauma. All the patients had deviated septum of varying severity. The most common graft used was quadrangular cartilage graft and the common complications noted were ala deformity and tip anaesthesia in 7.6% patients respectively. PMID:24078883

  5. Enhancement of lignocellulose-carbon nanotubes composites by lignocellulose grafting.

    PubMed

    Huang, Jintian; Zhang, Shaobo; Zhang, Feiran; Guo, Zhiqing; Jin, Liping; Pan, Yefei; Wang, Yu; Guo, Tongcheng

    2017-03-15

    Lignocellulose (LNC) multi-walled carbon nanotubes (MWCNTs) composites were synthesized by covalently grafting a natural polymer, lignocellulose, onto MWCNTs in an ionic liquid, 1-allyl-3-methylimidazolium chloride (AmimCl). Furthermore, the grafting of LNC facilitated the dispersion of the MWCNTs in AmimCl and MWCNTs/LNC films. The elongation at break and tensile strength of grafted-MWCNTs/LNC films with 3wt% of MWCNTs content were 12.2% and 106.7MPa respectively, which was almost 93.7% and 10.7% higher than those of the pristine MWCNTs/LNC films. This finding clearly revealed that the mechanical properties of grafted-MWCNTs/LNC films were dramatically superior to those of the MWCNTs/LNC films.

  6. Bone grafting simultaneous to implant placement. Presentation of a case.

    PubMed

    Peñarrocha-Diago, Miguel; Gómez-Adrián, Maria Dolores; García-Mira, Berta; Ivorra-Sais, Mariola

    2005-01-01

    Bone defects at mandibular alveolar crest level complicate the placement of dental implants in the ideal location. Surgical reconstruction using autologous bone grafts allows implant fixation in an esthetic and functional manner. We describe a patient with large mandibular bone loss secondary to periodontal inflammatory processes. Reconstruction of the mandibular alveolar process was carried out using onlay block bone grafts harvested from the mandible. The grafts were stabilized by positioning the dental implants through them--a procedure that moreover afforded good primary implant fixation. After two years of follow-up the clinical and radiological outcome is good. In the lower jaw, where bone regeneration is complicated, we were able to achieve good results in this patient--minimizing the corresponding waiting time by grafting and placing the implants in the same surgical step.

  7. Hydration of polyethylene glycol-grafted liposomes.

    PubMed

    Tirosh, O; Barenholz, Y; Katzhendler, J; Priev, A

    1998-03-01

    This study aimed to characterize the effect of polyethylene glycol of 2000 molecular weight (PEG2000) attached to a dialkylphosphatidic acid (dihexadecylphosphatidyl (DHP)-PEG2000) on the hydration and thermodynamic stability of lipid assemblies. Differential scanning calorimetry, densitometry, and ultrasound velocity and absorption measurements were used for thermodynamic and hydrational characterization. Using a differential scanning calorimetry technique we showed that each molecule of PEG2000 binds 136 +/- 4 molecules of water. For PEG2000 covalently attached to the lipid molecules organized in micelles, the water binding increases to 210 +/- 6 water molecules. This demonstrates that the two different structural configurations of the PEG2000, a random coil in the case of the free PEG and a brush in the case of DHP-PEG2000 micelles, differ in their hydration level. Ultrasound absorption changes in liposomes reflect mainly the heterophase fluctuations and packing defects in the lipid bilayer. The PEG-induced excess ultrasound absorption of the lipid bilayer at 7.7 MHz for PEG-lipid concentrations over 5 mol % indicates the increase in the relaxation time of the headgroup rotation due to PEG-PEG interactions. The adiabatic compressibility (calculated from ultrasound velocity and density) of the lipid bilayer of the liposome increases monotonically with PEG-lipid concentration up to approximately 7 mol %, reflecting release of water from the lipid headgroup region. Elimination of this water, induced by grafted PEG, leads to a decrease in bilayer defects and enhanced lateral packing of the phospholipid acyl chains. We assume that the dehydration of the lipid headgroup region in conjunction with the increase of the hydration of the outer layer by grafting PEG in brush configuration are responsible for increasing thermodynamic stability of the liposomes at 5-7 mol % of PEG-lipid. At higher PEG-lipid concentrations, compressibility and partial volume of the lipid phase

  8. Hydration of polyethylene glycol-grafted liposomes.

    PubMed Central

    Tirosh, O; Barenholz, Y; Katzhendler, J; Priev, A

    1998-01-01

    This study aimed to characterize the effect of polyethylene glycol of 2000 molecular weight (PEG2000) attached to a dialkylphosphatidic acid (dihexadecylphosphatidyl (DHP)-PEG2000) on the hydration and thermodynamic stability of lipid assemblies. Differential scanning calorimetry, densitometry, and ultrasound velocity and absorption measurements were used for thermodynamic and hydrational characterization. Using a differential scanning calorimetry technique we showed that each molecule of PEG2000 binds 136 +/- 4 molecules of water. For PEG2000 covalently attached to the lipid molecules organized in micelles, the water binding increases to 210 +/- 6 water molecules. This demonstrates that the two different structural configurations of the PEG2000, a random coil in the case of the free PEG and a brush in the case of DHP-PEG2000 micelles, differ in their hydration level. Ultrasound absorption changes in liposomes reflect mainly the heterophase fluctuations and packing defects in the lipid bilayer. The PEG-induced excess ultrasound absorption of the lipid bilayer at 7.7 MHz for PEG-lipid concentrations over 5 mol % indicates the increase in the relaxation time of the headgroup rotation due to PEG-PEG interactions. The adiabatic compressibility (calculated from ultrasound velocity and density) of the lipid bilayer of the liposome increases monotonically with PEG-lipid concentration up to approximately 7 mol %, reflecting release of water from the lipid headgroup region. Elimination of this water, induced by grafted PEG, leads to a decrease in bilayer defects and enhanced lateral packing of the phospholipid acyl chains. We assume that the dehydration of the lipid headgroup region in conjunction with the increase of the hydration of the outer layer by grafting PEG in brush configuration are responsible for increasing thermodynamic stability of the liposomes at 5-7 mol % of PEG-lipid. At higher PEG-lipid concentrations, compressibility and partial volume of the lipid phase

  9. Photoinduced graft-copolymer synthesis and characterization of methacrylic acid onto natural biodegradable lignocellulose fiber.

    PubMed

    Khan, Ferdous

    2004-01-01

    UV radiation induced graft copolymerization of methacrylic acid onto natural lignocellulose (jute) fiber was carried out both by "simultaneous irradiation and grafting" and by preirradiation methods using 1-hydroxycyclohexyl-phenyl ketone as a photoinitiator. In the "simultaneous irradiation and grafting" method, the variation of graft weight with UV-radiation time, monomer concentration, and the concentration of photoinitiator was investigated. In the case of the preirradiation method, the incorporation of 2-methyl-2-propene 1-sulfonic acid, sodium salt, into the grafting reaction solution played a most important role in suppressing the homopolymer/gel formation and facilitating graft copolymerization. The optimum value of the reaction parameters on the percentage of grafting was evaluated. In comparison, results showed that the method of graft-copolymer synthesis has significant influence on graft weight. The study on the mechanical and thermal properties of grafted samples was conducted. The results showed that the percentage of grafting has a significant effect on the mechanical and thermal properties in the case of grafted samples. Considering the water absorption property, the jute-poly(methacrylic acid)-grafted sample showed a maximum up to 42% increase in hydrophilicity with respect to that of the "as received" sample. Attenuated total reflection infrared studies indicate that the estimation of the degree of grafting could be achieved by correlating band intensities with the percent graft weight.

  10. A Dynamical System that Describes Vein Graft Adaptation and Failure

    PubMed Central

    Garbey, Marc; Berceli, Scott A.

    2013-01-01

    Adaptation of vein bypass grafts to the mechanical stresses imposed by the arterial circulation is thought to be the primary determinant for lesion development, yet an understanding of how the various forces dictate local wall remodeling is lacking. We develop a dynamical system that summarizes the complex interplay between the mechanical environment and cell/matrix kinetics, ultimately dictating changes in the vein graft architecture. Based on a systematic mapping of the parameter space, three general remodeling response patterns are observed: 1) shear stabilized intimal thickening, 2) tension induced wall thinning and lumen expansion, and 3) tension stabilized wall thickening. Notable is our observation that the integration of multiple feedback mechanisms leads to a variety of non-linear responses that would be unanticipated by an analysis of each system component independently. This dynamic analysis supports the clinical observation that the majority of vein grafts proceed along an adaptive trajectory, where grafts dilate and mildly thicken in response to the increased tension and shear, but a small portion of the grafts demonstrate a maladaptive phenotype, where progressive inward remodeling and accentuated wall thickening lead to graft failure. PMID:23871714

  11. Cytocompatibility of amine functionalized carbon nanoparticles grafted on polyethylene.

    PubMed

    Žáková, Pavlína; Slepičková Kasálková, Nikola; Kolská, Zdeňka; Leitner, Jindřich; Karpíšková, Jana; Stibor, Ivan; Slepička, Petr; Švorčík, Václav

    2016-03-01

    Five types of amide-amine Carbon Nano-Particles (CNPs) were prepared by functionalization of CNPs and characterized by several analytical methods. The successful grafting of amines on CNPs was verified by X-ray photoelectron spectroscopy (XPS), organic elemental analysis and electrokinetic analysis. The size and morphology of CNPs were determined from transmission electron microscopy. The surface area and porosity of CNPs were examined by adsorption and desorption isotherms. Differential scanning calorimetry was used to investigate thermal stability of CNPs. The amount of bonded amine depends on its dimensionality arrangement. Surface area and pore volumes of CNPs decrease several times after individual amino-compound grafting. Selected types of functionalized CNPs were grafted onto a plasma activated surface of HDPE. The successful grafting of CNPs on the polymer surface was verified by XPS. Wettability was determined by contact angle measurements. Surface morphology and roughness were studied by atomic force microscopy. A dramatic decrease of contact angle and surface morphology was observed on CNP grafted polymer surface. Cytocompatibility of modified surfaces was studied in vitro, by determination of adhesion, proliferation and viability of vascular smooth muscle cells (VSMCs). Grafting of CNPs onto the polymer surface has a positive effect on the adhesion, proliferation and viability of VSMCs.

  12. Tissue-engineered lymphatic graft for the treatment of lymphedema

    PubMed Central

    Kanapathy, Muholan; Patel, Nikhil M.; Kalaskar, Deepak M.; Mosahebi, Afshin; Mehrara, Babak J.; Seifalian, Alexander M.

    2015-01-01

    Background Lymphedema is a chronic debilitating condition and curative treatment is yet to be found. Tissue engineering approach, which combines cellular components, scaffold, and molecular signals hold great potential in the treatment of secondary lymphedema with the advent of lymphatic graft to reconstruct damaged collecting lymphatic vessel. This review highlights the ideal characteristics of lymphatic graft, the limitation and challenges faced, and the approaches in developing tissue-engineered lymphatic graft. Methods Literature on tissue engineering of lymphatic system and lymphatic tissue biology was reviewed. Results The prime challenge in the design and manufacturing of this graft is producing endothelialized conduit with intraluminal valves. Suitable scaffold material is needed to ensure stability and functionality of the construct. Endothelialization of the construct can be enhanced via biofunctionalization and nanotopography, which mimics extracellular matrix. Nanocomposite polymers with improved performance over existing biomaterials are likely to benefit the development of lymphatic graft. Conclusions With the in-depth understanding of tissue engineering, nanotechnology, and improved knowledge on the biology of lymphatic regeneration, the aspiration to develop successful lymphatic graft is well achievable. PMID:25248852

  13. Late occlusion of microvascular vein grafts in replantation.

    PubMed

    Morrison, W A; Mitchell, G M; Hickey, M J

    1998-11-01

    Two cases are described in which patients presented 16 and 17 years, respectively, after complete or incomplete amputation/replantation of the arm. In case 1, the patient complained of coldness, pain, and tingling in the replanted arm in the previous 24 hours and noticed that his fingers had gone white. Arteriography and subsequent surgery revealed obliteration of the vein graft (inserted in the distal brachial artery) by neointimal thickening and atherosclerotic plaque, which was confirmed in a subsequent morphologic examination. In case 2, the patient presented with discomfort and a pulsatile swelling on the inner aspect of his upper arm. Arteriography and surgery revealed an aneurysm in the previously inserted vein graft in the brachial artery, with some atherosclerotic degeneration. Both vein grafts were successfully replaced with a fresh autologous vein graft and the patients remain well several years later. The 2 cases suggest that as part of replantation surgery of a limb, it is essential to maintain postoperative clinical monitoring for signs of graft degeneration in all patients with long-term vein graft insertion.

  14. Superhydrophocity via gas-phase monomers grafting onto carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Zha, Jinlong; Batisse, Nicolas; Claves, Daniel; Dubois, Marc; Frezet, Lawrence; Kharitonov, Alexander P.; Alekseiko, Leonid N.

    2016-05-01

    Superhydrophobic films were prepared using dispersions of fluorinated multi-walled carbon nanotubes (MWCNTs) or nanofibers (CNFs) in toluene. The grafting of polystyrene allowed stable dispersions to be obtained. The grafting of polystyrene (PS), polyacrylic acid (PAA) and polyaniline (PANI) onto nanofibers and MWCNTs was first evidenced by solid state NMR and Infrared Spectroscopy. The graft polymerization of styrene, acrylic acid and aniline monomers was initiated by radicals (dangling bonds) formed due to the initial fluorination. The process appeared as highly versatile and efficient for different polymers. The consumption of those radicals in the course of grafting was evidenced by EPR, through decrease of the spin density. The hydrophobic/hydrophilic character was tuned according to the grafted polymer nature, i.e. hydrophobic with PS or hydrophilic with PAA. Finally, in order to reach superhydrophobicity, films were prepared from CNFs or MWCNTs, irrespective of their average diameter, that allowed adequate structuring of the surface. The presence of fluorine atoms on their surface also favors superhydrophobicity. Water contact angles of 155 ± 2° and 159 ± 2° were measured for the films casted from fluorinated CNFs or MWCNTs with grafted polystyrene, respectively.

  15. Patient experiences living with split thickness skin grafts.

    PubMed

    Burnett, L N; Carr, E; Tapp, D; Raffin Bouchal, S; Horch, J D; Biernaskie, J; Gabriel, V

    2014-09-01

    The standard of care for deep burns is autologous split thickness skin grafting. Although adequate to resurface a deep wound, the resulting skin is chronically abnormal. The purpose of this study was to describe the experience of patients with split thickness skin grafts to help guide future investigations related to skin regeneration. In this study, an interpretive description qualitative methodology was employed. Subjects participated in a two-part single patient interview that was recorded and transcribed. A nurse with experience in clinical burn care coded and interpreted the data. Participants were recruited through presentation to a university based outpatient burn clinic for follow up from autologous split thickness skin grafting. Eight male patients and four female patients 20-62 years old ranging 2-29 months post-skin grafting were enrolled in the study. The most significant concerns voiced by patients were identified and organized into five themes: (1) a new normal, (2) split thickness skin graft symptoms, (3) appearance of new skin, (4) coping, and (5) participation in future clinical trials. Participants reported that the abnormalities related to their split thickness skin grafts were significant enough that they would be willing to participate in a future clinical trial investigating new cell-based therapies.

  16. Reconstruction of isolated caudate portal vein in left liver graft.

    PubMed

    Kokudo, Norihiro; Sugawara, Yasuhiko; Kaneko, Junichi; Imamura, Hiroshi; Sano, Keiji; Makuuchi, Masatoshi

    2004-09-01

    The addition of the caudate lobe to a left liver graft is known to increase graft volume by 9% and has been shown to be useful for overcoming borderline graft-recipient size mismatch in adult living donor liver transplantation. To assure full graft viability and regeneration, all of the feeding vessels for the caudate lobe should be preserved or reconstructed. However, more knowledge is needed about portal vein reconstruction for the caudate lobe. From January 1996 to August 2003, 238 living donor liver transplantations were performed at our institution. Of these, 67 donors underwent left hepatectomy with the caudate lobe and the middle hepatic vein. An isolated caudate portal vein originating from the left sidewall of the portal branches for the Spiegelian lobe (P1) was encountered in 9 donors (13.4%). The isolated P1 was reconstructed in 3 of the 9 cases using the pantaloon technique or interposition of an autovein graft. There were no complications related to P1 reconstruction and patency was confirmed by computerized tomography (CT) 1 month after transplantation. In the remaining 6 cases, the isolated P1 was very small (less than .5 mm) and did not require reconstruction. Isolated P1s are relatively rare, but when they are both present and large, it is advisable to undertake reconstruction that assures full graft function of the caudate lobe.

  17. High compliance vascular grafts based on semi-interpenetrating networks

    PubMed Central

    Dempsey, David K.; Nezarati, Roya M.; Mackey, Calvin E.

    2014-01-01

    Current synthetic vascular grafts have poor patency rates in small diameter applications (<6 mm) due to intimal hyperplasia arising from a compliance mismatch between the graft and native vasculature. Enormous efforts have focused on improving biomechanical properties; however, polymeric grafts are often constrained by an inverse relationship between burst pressure and compliance. We have developed a new, semi-interpenetrating network (semi-IPN) approach to improve compliance without sacrificing burst pressure. The effects of heat treatment on graft morphology, fiber architecture, and resultant biomechanical properties are presented. In addition, biomechanical properties after equilibration at physiological temperature were investigated in relation to polyurethane microstructure to better predict in vivo performance. Compliance values as high as 9.2 ± 2.7 %/mmHg x 10−4 were observed for the semi-IPN graft while also maintaining high burst pressure, 1780 ± 230 mm Hg. The high compliance of these heat-treated poly(carbonate urethane) (PCU) and semi-IPN grafts is expected to improve long-term patency rates beyond even saphenous vein autografts by preventing intimal hyperplasia. The fundamental structure-property relationships gained from this work may also be utilized to advance biomedical device designs based on thermoplastic polyurethanes. PMID:25601822

  18. Control of Surface Wound Infection: Skin Versus Synthetic Grafts

    PubMed Central

    Saymen, Dennis G.; Nathan, Paul; Holder, Ian Alan; Hill, Edward O.; Macmillan, Bruce G.

    1973-01-01

    Auto-, iso-, or xenografts of skin and synthetics placed on surface wounds freshly contaminated with Pseudomonas aeruginosa stabilizes the wound bacterial population in rats over a 24-h period. When these wounds contained a bacterial contamination established for 24 h prior to grafting, only skin and the synthetic polyhydroxyethylmethacrylate were effective in lowering the initial bacterial concentration. Polyurethane foam and nylon velour were not effective in the established infection model. Skin placed on a contaminated wound for 2 h or longer appeared to equilibrate with the underlying muscle so that the bacterial count per milligram of skin was similar to that of the muscle. It was suggested that this preparation would be useful to obtain an estimate of surface contamination without biopsy of the infected muscle. Skin grafts in place for 2 h significantly lowered the bacterial count in a wound with an established infection. A second decrease occurred between 4 and 24 h after grafting. Histological studies of contaminated and exposed panniculus muscle showed that leukocytes tend to migrate from the muscle surface to its base. Skin grafts and polyhydroxyethylmethacrylate appear to reverse the white cell migration so that the cells move toward the surface of the muscle with preservation of normal staining characteristics in the muscle. It is suggested that this alteration in cell movement after graft application might modify the white cell function and result in a greater bactericidal activity. Apparently, grafts lower bacterial levels in an established infection by modifying the host response to the surface contamination. Images PMID:4197768

  19. Autologous fat grafting: use of closed syringe microcannula system for enhanced autologous structural grafting

    PubMed Central

    Alexander, Robert W; Harrell, David B

    2013-01-01

    Objectives Provide background for use of acquiring autologous adipose tissue as a tissue graft and source of adult progenitor cells for use in cosmetic plastic surgery. Discuss the background and mechanisms of action of closed syringe vacuum lipoaspiration, with emphasis on accessing adipose-derived mesenchymal/stromal cells and the stromal vascular fraction (SVF) for use in aesthetic, structural reconstruction and regenerative applications. Explain a proven protocol for acquiring high-quality autologous fat grafts (AFG) with use of disposable, microcannula systems. Design Explain the components and advantage of use of the patented super luer-lock and microcannulas system for use with the closed-syringe system. A sequential explanation of equipment selection for minimally traumatic lipoaspiration in small volumes is presented, including use of blunt injection cannulas to reduce risk of embolism. Results Thousands of AFG have proven safe and efficacious for lipoaspiration techniques for large and small structural fat grafting procedures. The importance and advantages of gentle harvesting of the adipose tissue complex has become very clear in the past 5 years. The closed-syringe system offers a minimally invasive, gentle system with which to mobilize subdermal fat tissues in a suspension form. Resulting total nuclear counting of undifferentiated cells of the adipose-derived -SVF suggests that the yield achieved is better than use of always-on, constant mechanical pump applied vacuum systems. Conclusion Use of a closed-syringe lipoaspiration system featuring disposable microcannulas offers a safe and effective means of harvesting small volumes of nonmanipulated adipose tissues and its accompanying progenitor cells within the SVF. Closed syringes and microcannulas are available as safe, sterile, disposable, compact systems for acquiring high-quality AFG. Presented is a detailed, step-by-step, proven protocol for performing quality autologous structural adipose

  20. [Clinical outcome of the coronary arterial bypass graft with inferior epigastric artery as a composite graft].

    PubMed

    Ayabe, T; Fukushima, Y; Yoshioka, M; Onizuka, T

    2003-08-01

    Based on a good long-patency of the internal thoracic arteries (ITA) in coronary arterial bypass graft (CABG), the postoperative early patency of the inferior epigastric artery (IEA) was evaluated by means of the proximal anastomosed types as a composite graft. Among patients performed with CABG during October in 1998 to June, 2000, 39 cases with the IEA composite graft were studied for this clinical outcome (31 males and 8 females, the averaged age was 66.4 +/- 8.0 year old). The preoperative diagnosis were done as acute myocardial infarction (4), old myocardial infarction with angina pectoris (8), effort angina (12), and unstable angina (15). The coronary disease was left main trunk disease (8), 3 vessels (22), and 2 vessels (9). The operation was performed with cold blood-cardioplegia (20 degrees C, blood-GIK liquor used) on cardiopulmonary bypass with a single atrial and aortic cannulation. The averaged extracorporeal circulation time and the aortic clamping one were done for 169 and 131 min, respectively. The bypass number was double (n = 5), triple (n = 10), quadruple (n = 16), and quintuple (n = 8). Total bypass number was 150 (the averaged bypass number was 3.7 +/- 0.9), and total anastomosal number was 145. The postoperative early-patency of IEA was 94.9% (37/39). The proximal sites of IEA were anastomozed to ITA with I-shaped end-to-end (n = 15), to ITA with Y-shaped end-to-side (n = 5), and to SVG with Y-shaped end-to-side (n = 19). Compared with the postoperative early-patency of I-shaped anastomosis to ITA and that of Y-shaped one to ITA or SVG, there was no significance among these cases (100%, 15/15 versus 91.7%, 22/24, p = 0.6738), however, that of Y-shaped one to ITA was significantly better than that of Y-shaped one to SVG (60%, 3/5 versus 100%, 19/19, p = 0.0488). It should be available for spreading of the anastomotic objective vessels that the IEA as a composite graft was used with the proximal site anastomozed to ITA by I-shaped end-to-end and

  1. Oral graft-versus-host disease

    PubMed Central

    Imanguli, MM; Alevizos, I; Brown, R; Pavletic, SZ; Atkinson, JC

    2008-01-01

    OBJECTIVE: Graft-versus-host disease (GVHD) is a leading cause of morbidity and mortality in patients receiving hematopoietic cell transplant. It is estimated that 40–70% of engrafted patients surviving the initial transplant eventually develop chronic GVHD (cGVHD), which can persist for months to years and require long-term management from multiple disciplines. This review describes the oral component of this transplant complication. DESIGN: The search related to GVHD patho-biology, salivary gland disease after hematopoietic cell transplant and treatments for oral GVHD encompassed literature from 1966 through 2008. Searches were limited to the MEDLINE/PubMed database and English language literature in peer-reviewed journals. RESULTS: Our understanding of the patho-biology of oral cGVHD is based on studies of other affected tissues. It is difficult to determine the prevalence and incidence of salivary gland disease after transplant because there is no universally accepted case definition. In general, clinical trials for treatment of oral cGVHD have been too small to make strong recommendations for use in clinical practice. CONCLUSIONS: Larger well-designed clinical studies are needed to understand the patho-biology of oral cGVHD and determine best treatments for this disease. PMID:18593456

  2. Decellularized bone matrix grafts for calvaria regeneration

    PubMed Central

    Lee, Dong Joon; Diachina, Shannon; Lee, Yan Ting; Zhao, Lixing; Zou, Rui; Tang, Na; Han, Han; Chen, Xin; Ko, Ching-Chang

    2016-01-01

    Decellularization is a promising new method to prepare natural matrices for tissue regeneration. Successful decellularization has been reported using various tissues including skin, tendon, and cartilage, though studies using hard tissue such as bone are lacking. In this study, we aimed to define the optimal experimental parameters to decellularize natural bone matrix using 0.5% sodium dodecyl sulfate and 0.1% NH4OH. Then, the effects of decellularized bone matrix on rat mesenchymal stem cell proliferation, osteogenic gene expression, and osteogenic differentiations in a two-dimensional culture system were investigated. Decellularized bone was also evaluated with regard to cytotoxicity, biochemical, and mechanical characteristics in vitro. Evidence of complete decellularization was shown through hematoxylin and eosin staining and DNA measurements. Decellularized bone matrix displayed a cytocompatible property, conserved structure, mechanical strength, and mineral content comparable to natural bone. To study new bone formation, implantation of decellularized bone matrix particles seeded with rat mesenchymal stem cells was conducted using an orthotopic in vivo model. After 3 months post-implantation into a critical-sized defect in rat calvaria, new bone was formed around decellularized bone matrix particles and also merged with new bone between decellularized bone matrix particles. New bone formation was analyzed with micro computed tomography, mineral apposition rate, and histomorphometry. Decellularized bone matrix stimulated mesenchymal stem cell proliferation and osteogenic differentiation in vitro and in vivo, achieving effective bone regeneration and thereby serving as a promising biological bone graft. PMID:28228929

  3. Steric interactions between two grafted polymer brushes

    NASA Astrophysics Data System (ADS)

    Ruckenstein, Eli; Li, Buqiang

    1997-07-01

    A lattice model and a generator-matrix method are employed to calculate the interaction force profile between two grafted polymer brushes. The correlation between neighboring bonds and the interdigitation between the two brushes are taken into account. The calculations show that the effect of incorporating the bond correlations is equivalent to an increase in the value of the polymer-solvent interaction parameter when the bond correlations are ignored. The interdigitation between the two brushes decreases the free energy of the system and consequently results in a smaller steric repulsion. A complete interdigitation occurs at a separation close to half the separation between the two plates for which the interaction force is zero. The model is compared with the experimental interaction force profiles for ten systems which involve poly(2-vinylpyridine)-polyisoprene (PVP-PI), poly(2-vinylpyridine)-polystyrene (PVP-PS) block copolymers as well as end-functionalized polystyrenes (PS-X). For most of the systems, the theoretical predictions are in good agreement with experiment. In addition, the present results are compared with the equations proposed by de Gennes, based on the assumption of a step distribution function for the segment density, and by Milner et al., based on the parabolic distribution of the segment density. Both equations neglected interdigitation. It is shown in this paper that the interdigitation is not negligible and that it can decrease by an order of magnitude the repulsive force.

  4. Graft vasculopathy in clinical hand transplantation.

    PubMed

    Kaufman, C L; Ouseph, R; Blair, B; Kutz, J E; Tsai, T M; Scheker, L R; Tien, H Y; Moreno, R; Ozyurekoglu, T; Banegas, R; Murphy, E; Burns, C B; Zaring, R; Cook, D F; Marvin, M R

    2012-04-01

    Allogeneic hand transplantation is now a clinical reality. While results have been encouraging, acute rejection rates are higher than in their solid-organ counterparts. In contrast, chronic rejections, as defined by vasculopathy and/or fibrosis and atrophy of skin and other tissues, as well as antibody mediated rejection, have not been reported in a compliant hand transplant recipient. Monitoring vascularized composite allograft (VCA) hand recipients for rejection has routinely involved punch skin biopsies, vascular imaging and graft appearance. Our program, which has transplanted a total of 6 hand recipients, has experience which challenges these precepts. We present evidence that the vessels, both arteries and veins may also be a primary target of rejection in the hand. Two of our recipients developed severe intimal hyperplasia and vasculopathy early post-transplant. An analysis of events and our four other patients has shown that the standard techniques used for surveillance of rejection (i.e. punch skin biopsies, DSA and conventional vascular imaging studies) are inadequate for detecting the early stages of vasculopathy. In response, we have initiated studies using ultrasound biomicroscopy (UBM) to evaluate the vessel wall thickness. These findings suggest that vasculopathy should be a focus of frequent monitoring in VCA of the hand.

  5. Grafting single molecule magnets on gold nanoparticles.

    PubMed

    Perfetti, Mauro; Pineider, Francesco; Poggini, Lorenzo; Otero, Edwige; Mannini, Matteo; Sorace, Lorenzo; Sangregorio, Claudio; Cornia, Andrea; Sessoli, Roberta

    2014-01-29

    The chemical synthesis and characterization of the first hybrid material composed by gold nanoparticles and single molecule magnets (SMMs) are described. Gold nanoparticles are functionalized via ligand exchange using a tetrairon(III) SMM containing two 1,2-dithiolane end groups. The grafting is evidenced by the shift of the plasmon resonance peak recorded with a UV-vis spectrometer, by the suppression of nuclear magnetic resonance signals, by X-ray photoemission spectroscopy peaks, and by transmission electron microscopy images. The latter evidence the formation of aggregates of nanoparticles as a consequence of the cross-linking ability of Fe4 through the two 1,2-dithiolane rings located on opposite sides of the metal core. The presence of intact Fe4 molecules is directly proven by synchrotron-based X-ray absorption spectroscopy and X-ray magnetic circular dichroism spectroscopy, while a detailed magnetic characterization, obtained using electron paramagnetic resonance and alternating-current susceptibility, confirms the persistence of SMM behavior in this new hybrid nanostructure.

  6. Alveolar graft in the cleft lip and palate patient: Review of 104 cases

    PubMed Central

    Tobella-Camps, María L.; Rivera-Baró, Alejandro

    2014-01-01

    Introduction: Alveolar bone grafting is a vital part of the rehabilitation of cleft patients. The factors that have been most frequently associated with the success of the graft are the age at grafting and the pre-grafting orthodontic treatment. Objectives: 1) Describe the cases of alveolar bone grafts performed at the Maxilofacial Unit of Hospital Sant Joan de Déu, Barcelona (HSJD); and 2) Analyze the success/failure of alveolar grafts and related variables. Material and Methods: Descriptive retrospective study using a sample of 104 patients who underwent a secondary alveolar graft at the Craniofacial Unit of HSJD between 1998 and 2012. The graft was done by the same surgeon in all patients using bone from the iliac crest. Results: 70% of the patients underwent the procedure before the age of 15 (median 14.45 years); 70% of the graft patients underwent pre-graft maxillary expansion. A total of 100 cases were recorded as successful (median age of 14.58 years, 68 underwent pre-graft expansion) and only 4 were recorded as failures (median age of 17.62 years, 3 underwent pre-graft expansion). We did not find statistically significant differences in age at the time of grafting or pre-surgical expansion when comparing the success and failure groups. We found the success rate of the graft to be 96.2%. Conclusions: The number of failures was too small to establish a statistically significant conclusion in our sample regarding the age at grafting and pre-grafting expansion. The use of alveolar bone grafting from the iliac crest has a very high success rate with a very low incidence of complications. Existing controversies regarding secondary bone grafting and the wide range of success rates found in the literature suggest that it is necessary to establish a specific treatment protocol that ensures the success of this procedure. Key words:Alveolar graft, cleft lip and palate, alveolar cleft, alveolar defect. PMID:24880440

  7. Anti-Donor HLA Antibody Response After Pancreatic Islet Grafting: Characteristics, Risk Factors, and Impact on Graft Function.

    PubMed

    Pouliquen, E; Baltzinger, P; Lemle, A; Chen, C-C; Parissiadis, A; Borot, S; Frimat, L; Girerd, S; Berney, T; Lablanche, S; Benhamou, P Y; Morelon, E; Badet, L; Dubois, V; Kessler, L; Thaunat, O

    2017-02-01

    Pancreatic islet grafting restores endogenous insulin production in type 1 diabetic patients, but long-term outcomes remain disappointing as a result of immunological destruction of allogeneic islets. In solid organ transplantation, donor-specific anti-HLA antibodies (DSA) are the first cause of organ failure. This retrospective multicentric study aimed at providing in-depth characterization of DSA response after pancreatic islet grafting, identifying the risk factor for DSA generation and determining the impact of DSA on graft function. Forty-two pancreatic islet graft recipients from the Groupe Rhin-Rhône-Alpes-Genève pour la Greffe d'Ilots de Langerhans consortium were enrolled. Pre- and postgrafting sera were screened for the presence of DSA and their ability to activate complement. Prevalence of DSA was 25% at 3 years postgrafting. The risk of sensitization increased steeply after immunosuppressive drug withdrawal. DSA repertoire diversity correlated with the number of HLA and eplet mismatches. DSA titer was significantly lower from that observed in solid organ transplantation. No detected DSA bound the complement fraction C3d. Finally, in contrast with solid organ transplantation, DSA did not seem to negatively affect pancreatic islet graft survival. This might be due to the low DSA titers, specific features of IgG limiting their ability to activate the complement and/or the lack of allogenic endothelial targets in pancreatic islet grafts.

  8. Radiation-induced grafting of sweet sorghum stalk for copper(II) removal from aqueous solution.

    PubMed

    Dong, Jing; Hu, Jun; Wang, Jianlong

    2013-11-15

    The influence of main components (cellulose, hemicellulose and lignin) of the sweet sorghum stalk on radiation-induced grafting reaction and adsorption of copper from aqueous solution was investigated. Sweet sorghum stalk was grafted with acrylic acid induced by γ-irradiation. The results showed that the grafted stalk contained 1.6 mmol/g carboxyl groups, and its maximal adsorption capacity was 13.32 mg/g. The cellulose, hemicellulose and lignin of the raw materials were confirmed to involve in grafting reaction through comparing the grafting yield and the structure of the grafted materials. Both the structure and the composition of the sweet sorghum stalk had influence on the grafting reaction and adsorption capacity. The adsorption capacity of the grafted sweet sorghum stalk increased about five times, and the adsorption isotherm of the grafted materials conformed to the Langmuir model. The main mechanism for copper adsorption involved in ion exchange.

  9. COMPOUNDING PHARMACIES' POTENTIAL TO CREATE Graft Storage Solutions for Bypass Surgeries.

    PubMed

    Guth, Michael A S

    2015-01-01

    Several studies have addressed the optimal storage conditions for vascular grafts during bypass surgery. These studies have repeatedly shown that placing vascular graft conduits in isotonic saline solutions, and to a lesser extent in heparinized autologous blood, leads to a profound decline in endothelial cell viability. Endothelial damage to vein grafts can occur at multiple points during a coronary artery bypass graft surgery procedure: graft harvesting, handling, flushing, storage, anastomosis, and arterialization (e.g., damage caused by exposure to arterial blood pressure). This damage to endothelial cells causes the release of pro-inflammatory chemical signals that trigger thrombosis, intimal hyperplasia, and accelerated graft atherosclerosis, all of which ultimately contribute to graft failure. Cardiothoracic surgeons performing coronary artery bypass graft surgery and vascular surgeons performing peripheral artery bypass graft surgery have attempted to overcome the damage to the vascular grafts by using buffers to maintain the physiological pH of the storage solution. However, the endothelial layers in the grafts would benefit from having proper oxygenation and antioxidants added to the storage solution. Compounding pharmacies can perform a vital role in ensuring the patency of the vascular grafts by creating compounded flushing and storage solutions that have an optimal mix of nitric oxide substrates, antioxidants, and other nutrients for the endothelium. Maintaining structural and functional viability of the endothelia in grafts by using an appropriate vessel storage medium would lead to improved long-term graft patency.

  10. Radiation-induced grafting of acrylic acid onto polypropylene film and its biodegradability

    NASA Astrophysics Data System (ADS)

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Chaudhari, C. V.; Dubey, K. A.; Varshney, L.

    2016-06-01

    Polypropylene based commodity polyolefins are widely used in packaging, manufacturing, electrical, pharmaceutical and other applications. The aim of the present work is to study the effect of grafting of acrylic acid on the biodegradability of acrylic acid grafted polypropylene. The effect of different conditions showed that grafting percentage increased with increase in monomer concentration, radiation dose and inhibitor concentration but decreased with increase in radiation dose rate. The maximum grafting of 159.4% could be achieved at optimum conditions. The structure of grafted polypropylene films at different degree of grafting was characterized by EDS, FTIR, TGA, DSC, SEM and XRD. EDS studies showed that the increase in acrylic acid grafting percentage increased the hydrophilicity of the grafted films. FTIR studies indicated the presence of acrylic acid on the surface of polypropylene film. TGA studies revealed that thermal stability decreased with increase in grafting percentage. DSC studies showed that melting temperature and crystallinity of the grafted polypropylene films lower than polypropylene film. SEM studies indicated that increase in acrylic acid grafting percentage increased the wrinkles in the grafted films. The maximum biodegradability could be achieved to 6.85% for 90.5% grafting. This suggested that microorganisms present in the compost could biodegrade acrylic acid grafted polypropylene.

  11. Surgical time for graft preparation using different suture techniques

    PubMed Central

    Camarda, Lawrence; Giambartino, Sebastian; Lauria, Michele; Saporito, Michele; Triolo, Vito; D’Arienzo, Michele

    2016-01-01

    Summary Background The purpose of the present study was to compare the operative time for graft preparation using different techniques for graft suturing. Material and methods Flexor profundus tendons were harvested from fresh pig hind-leg trotters. Three different suture techniques were investigated: the Krackow stitch (K), the Whipstitch (W), and the Modified Finger-Trap suture (MFT). Tendons were sutured starting at 10 mm from the distal free end of the tendon. The suture configurations of the Krackow stitch and Whipstitch were completed with five suture throws. According to the MFT technique, the suture was wrapped five times around the tendon over a distance of 30 mm. The time required to perform a complete suture on each tendon was measured. Five independent examiners of different levels of training measured the time required for graft preparation during 3 separate occasions to determine intraobserver repeatability and interobserver reproducibility. Results The mean time required for graft preparation following the Krackow technique was 69.1 seconds ± 18.3 SD (range 31.8–120). The Whipstitch technique took an average of 59.9 seconds ± 21.2 SD (range 27–93). The MFT suture required a mean of 29.3 seconds ± 11.4 SD for completing the suture (range 21.6–33). In all examiners the time required to complete the MFT suture was significantly less than the other suture techniques (p < 0.05). Intraobserver intraclass correlation coefficients for each examiner ranged from 0.72 to 0.83. Conclusion Low graft preparation time is required to complete a MFT suture in a porcine tendon model. Further, time required for graft preparation using the MFT was shorter than other suturing techniques such as the Krackow and Whipstitch techniques. Clinical relevance The MFT suture could be used for graft set-up with the main advantage of reducing the time required in comparison with other suture techniques. PMID:27900298

  12. Degeneration and regeneration of perivascular innervation in arterial grafts.

    PubMed

    Heikki, Penttilä; Timo, Waris; Nureddin, Ashammakhi; Sampsa, Vanhatalo

    2004-07-01

    Because the understanding of postoperative changes in arterial graft innervation is limited, this study was performed to characterize neuronal degeneration and regeneration events immunohistochemically in femoral arterial grafts transplanted to carotid arteries in rats. Specimens taken 1 day, 3 days, 7 days, 1 month, 3 months, and 5 months after surgery were assessed for vasoactive intestinal peptide, neurofilaments, growth-associated protein 43, tyrosine hydroxylase, and nitric oxide synthase isoenzymes. During neuronal degeneration, vasoactive intestinal peptide disappeared within 1 day, transmitter-synthesizing enzymes (nitric oxide synthase and tyrosine hydroxylase) had vanished by day 7, and neurofilaments (cytoskeletal markers) had essentially disappeared after 1 week. In the regeneration phase, the most robust axonal growth, as visualized by growth-associated protein 43, was observed at 1 month, followed by a gradual increase in neurotransmitter markers at 1 and 3 months, whereas the neurofilaments increased gradually up to the end of the 5-month observation period. Reinnervation proceeded from the proximal carotid (host) trunk distally to the graft. Axonal re-growth occurred mainly in arterial adventitia. Innervation density, as visually assessed, was denser in the graft than in the host. These findings suggest that 1) the main sequence of degeneration and regeneration follows that reported in other models of neuronal degeneration; 2) reinnervation of the arterial grafts comes mainly from the host arteries; and 3) the innervation density in the graft may differ from that in the host, which may suggest target-derived regulation of innervation. The latter finding may have clinical implications. It suggests that for a good outcome it would be beneficial to choose a sparsely innervated graft rather than a densely innervated one.

  13. Modification of an endovascular stent graft for abdominal aortic aneurysm

    NASA Astrophysics Data System (ADS)

    Moloye, Olajompo Busola

    Endovascular surgery is currently used to treat abdominal aortic aneurysms (AAA). A stent graft is deployed to exclude blood flow from the aneurysm sac. It is an effective procedure used in preventing aneurysm rupture, with reduced patient morbidity and mortality compared to open surgical repair. Migration and leakage around the device ("endoleak") due to poor sealing of the stent graft to the aorta have raised concerns about the long-term durability of endovascular repair. A preliminary study of cell migration and proliferation is presented as a prelude to a more extensive in vivo testing. A method to enhance the biological seal between the stent graft and the aorta is proposed to eliminate this problem. This can be achieved by impregnating the stent graft with 50/50 poly (DL-lactide co glycolic acid) (PLGA) and growth factors such as basic fibroblast growth factor (bFGF) or connective tissue growth factor (CTGF), at the proximal and distal ends. It is hypothesized that as PLGA degrades it will release the growth factors that will promote proliferation and migration of aortic smooth muscle cells to the coated site, leading to a natural seal between the aorta and the stent graft. In addition, growth factor release should promote smooth muscle cell (SMC) contraction that will help keep the stent graft in place at the proximal and distal ends. It is shown that a statistically significant effect of increased cell proliferation and migration is observed for CTGF release. Less of an effect is noted for bFGF or just the PLGA. The effect is estimated to be large enough to be clinically significant in a future animal study. The long term goal of this study is to reduce migration encounter after graft deployment and to reduce secondary interventions of EVAR especially for older patients who are unfit for open surgical treatment.

  14. Synthesis and properties of silane-fluoroacrylate grafted starch.

    PubMed

    Qu, Jia; He, Ling

    2013-10-15

    The latex of silane-fluoroacrylate grafted starch for coating materials, VTMS-starch/P(MMA/BA/3FMA), is obtained by two step grafting reactions. Vinyltrimethoxysilane (VTMS) is primarily grafted onto starch by condensation between Si-OH and C-OH at 120 °C, and then the copolymer of methyl methacrylate (MMA), butyl acrylate (BA) and 2,2,2-trifluoroethyl methacrylate (3FMA) is grafted onto the VTMS-starch by emulsion polymerization. Fourier transform infrared spectrometry (FTIR) and X-ray photoelectron spectroscopy (XPS) have been used to confirm the chemically grafting reactions in every step. The conversion percent, grafting percent and grafting efficiency for VTMS-starch/p(MMA/BA/3FMA) latex indicate that the optimum conditions should be controlled at 75 °C for 1h as VTMS-starch/P(MMA/BA/3FMA) in 1/3 weight ratio. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis have revealed that the latexes exhibit the uniform spherical particles of 40-60 nm in a narrow size distribution. The latex films perform the obvious hydrophobic (107°) property, lower surface free energy (25-35 mN/m) and the higher thermostability (330-440 °C) than starch (51°, 51.32 mN/m, 100-330 °C). Dynamic thermomechanical analysis (DMA) shows that the latex film could gain considerable toughness and strength with an elongation at break of 39.45% and a tensile strength of 11.97 MPa.

  15. Tunable Pickering emulsions with polymer-grafted lignin nanoparticles (PGLNs).

    PubMed

    Silmore, Kevin S; Gupta, Chetali; Washburn, Newell R

    2016-03-15

    Lignin is an abundant biopolymer that has native interfacial functions but aggregates strongly in aqueous media. Polyacrylamide was grafted onto kraft lignin nanoparticles using reversible addition-fragmentation chain transfer (RAFT) chemistry to form polymer-grafted lignin nanoparticles (PGLNs) that tune aggregation strength while retaining interfacial activities in forming Pickering emulsions. Polymer graft density on the particle surface, ionic strength, and initial water and cyclohexane volume fractions were varied and found to have profound effects on emulsion characteristics, including emulsion volume fraction, droplet size, and particle interfacial concentration that were attributed to changes in lignin aggregation and hydrophobic interactions. In particular, salt concentration was found to have a significant effect on aggregation, zeta potential, and interfacial tension, which was attributed to changes in solubility of both the kraft lignin and the polyacrylamide grafts. Dynamic light scattering, UV-vis spectroscopy, optical microscopy, and tensiometry were used to quantify emulsion properties and nanoparticle behavior. Under all conditions, the emulsions exhibited relatively fast creaming but were stable against coalescence and Ostwald ripening for a period of months. All emulsions were also oil-in-water (o/w) emulsions, as predicted by the Bancroft rule, and no catastrophic phase inversions were observed for any nanoparticle compositions. We conclude that lower grafting density of polyacrylamide on a lignin core resulted in high levels of interfacial activity, as characterized by higher concentration at the water-cyclohexane interface with a corresponding decrease in interfacial tension. These results indicate that the interfacial properties of polymer-grafted lignin nanoparticles are primarily due to the native hydrophobic interactions of the lignin core. These results suggest that the forces that drive aggregation are also correlated with interfacial

  16. Comparative Analysis of Early Excision and Grafting vs Delayed Grafting in Burn Patients in a Developing Country.

    PubMed

    Puri, Vinita; Khare, Nishant A; Chandramouli, M V; Shende, Nilesh; Bharadwaj, Sumit

    2016-01-01

    The present study attempts to compare how the patients who undergo early excision and grafting behave as compared with patients who are treated along usual conservative lines of management in centers where the resources are less than optimal. The data of 20 female patients were analyzed. Age of the patients ranged between 20 and 30 years, percentage area burn ranged between 20 and 40%, and percentage area resurfaced by skin grafting 5 to 10%. The patients were divided into two groups of 10 patients each. Group I included those patients who underwent early excision and grafting within 5 days of burn injury. Group II included those patients who were treated conservatively and the residual raw area was grafted 3 weeks or more after sustaining the burn. The two groups were compared for the amount of blood loss, transfusion requirement, graft take, and the total hospital stay. Statistical significance was tested by the application of Mann-Whitney U test. The mean percentage area burn was 29.1 ± 5.6% in group I and 24.7 ± 4.9% in group II. Mean percentage area resurfaced by skin grafting in group I was 9.4 ± 2.3% and 8.1 ± 1.6% in group II. Graft take in group I was 90 ± 7.8%, whereas that in group II was 95 ± 6.7%. Mean blood loss in group I and group II was 346 ± 17.6 ml and 241 ± 14.7 ml respectively. (P = .001). Mean transfusion requirement in the perioperative period was 1.6 pints in group I and 1.1 pints in group II. The mean hospital stay in the patients who underwent early excision and grafting was 15.1 ± 4.1 days, whereas that in the patients who underwent delayed grafting was 36.2 ± 6.3 days (P = .001). Early excision and grafting decreases the hospital stay of burn patients. The present study suggests that it has a definite applicability even in places where the resources might be less than optimal.

  17. Local mobility of polymer chain grafted onto polyethylene monitored by fluorescence depolarization

    NASA Astrophysics Data System (ADS)

    Tsuneda, Satoshi; Endo, Toshihiro; Saito, Kyoichi; Sugita, Kazuyuki; Horie, Kazuyuki; Yamashita, Takashi; Sugo, Takanobu

    1997-08-01

    The fluorescence depolarization method was used for investigating the local mobility of polymer chains grafted onto a porous polyethylene membrane. The real value of the rotational diffusion coefficient of a dansyl probe attached to the grafted polymer chain was obtained by using a correction method which eliminated the effect of multiple scattering on fluorescence anisotropy. The rotational mobility of the dansyl probe attached to the grafted polymer chain was sensitive to both degree of grafting and solvent polarity, which indicated that the conformation of the grafted polymer chain and the pore size of the base membrane strongly governed the dynamic parameters of the grafted polymer chain.

  18. Pre-irradiation induced emulsion graft polymerization of acrylonitrile onto polyethylene nonwoven fabric

    NASA Astrophysics Data System (ADS)

    Liu, Hanzhou; Yu, Ming; Deng, Bo; Li, Linfan; Jiang, Haiqing; Li, Jingye

    2012-01-01

    Acrylonitrile has been widely used in the modification of polymers by graft polymerization. In the present work, pre-irradiation induced emulsion graft polymerization method is used to introduce acrylonitrile onto PE nonwoven fabric instead of the traditional reaction in organic solvents system. The degree of grafting (DG) is measured by gravimetric method and the kinetics of the graft polymerization is studied. The existence of the graft chains is proven by Fourier transform infrared spectroscopy (FT-IR) analysis. Thermal stability of the grafted polymer is measured by Thermogravimetric analysis (TGA).

  19. Gamma radiation grafted polymers for immobilization of Brucella antigen in diagnostic test studies

    NASA Astrophysics Data System (ADS)

    Docters, E. H.; Smolko, E. E.; Suarez, C. E.

    The radiation grafting process has a wide field of industrial applications, and in the recent years the immobilization of biocomponents in grafted polymeric materials obtained by means of ionizing radiations is a new and important contribution to biotechnology. In the present work, gamma preirradiation grafting method was employed to produce acrylics hydrogels onto polyethylene (PE), polyvinyl chloride (PVC) and polystyrene (PS). Two monomers were used to graft the previously mentioned polymers: methacrylic acid (MAAc) and acrylamide (AAm), and several working conditions were considered as influencing the degree of grafting. All this grafted polymers were used to study the possibility of a subsequent immobilization of Brucella antigen (BAg) in diagnostic test studies (ELISA).

  20. Fetal allogeneic dopaminergic cell suspension grafts in the ventricular system of the rat: characterization of transplant morphology and graft-host interactions.

    PubMed

    Oertel, J; Samii, M; Walter, G F

    2004-05-01

    Experimental transplantation trials of fetal cells in Parkinson's and Huntington's disease or multiple sclerosis still require allogeneic graft material and raise questions of graft rejection and immunosuppression. Alternatively to the striatum, the lateral ventricles have been discussed as grafting site in Parkinson's and Huntington's disease although little is known of the specific immunology of the ventricular system. To address this question, 28 adult female LEW1.W rats received intraventricular allogeneic dopaminergic cell suspension grafts from E14 DA rat fetuses. Twelve animals with syngeneic grafts served as control. Immunohistochemical examination was performed with staining for MHC expression, microglia-macrophages, various lymphocyte subsets, dopaminergic neurons and astrocytes at 4 days, and 1, 3, 6, and 12 weeks after transplantation. In all animals, intraventricular transplants were found, which showed maturation and integration in the host parenchyma at the later time points. Animals with allogeneic grafts developed a vivid immune response with strong MHC class I expression and dense lymphocyte infiltrates. Surprisingly, this immune response subsided at 12 weeks and healthy grafts remained. These results indicate (1) that, in contrast to intraparenchymal grafts, a strong immune response to allogeneic fetal cell suspension grafts can be elicited by intraventricular grafting, (2) that a peculiar immunological role of the ventricular system has to be considered in further studies, and (3) that a vivid immune response to allografts in the brain may subside without graft destruction.

  1. Genome-wide identification and comparative analysis of grafting-responsive mRNA in watermelon grafted onto bottle gourd and squash rootstocks by high-throughput sequencing.

    PubMed

    Liu, Na; Yang, Jinghua; Fu, Xinxing; Zhang, Li; Tang, Kai; Guy, Kateta Malangisha; Hu, Zhongyuan; Guo, Shaogui; Xu, Yong; Zhang, Mingfang

    2016-04-01

    Grafting is an important agricultural technique widely used to improve plant growth, yield, and adaptation to either biotic or abiotic stresses. However, the molecular mechanisms underlying grafting-induced physiological processes remain unclear. Watermelon (Citrullus lanatus L.) is an important horticultural crop worldwide. Grafting technique is commonly used in watermelon production for improving its tolerance to stresses, especially to the soil-borne fusarium wilt disease. In the present study, we used high-throughput sequencing to perform a genome-wide transcript analysis of scions from watermelon grafted onto bottle gourd and squash rootstocks. Our transcriptome and digital gene expression (DGE) profiling data provided insights into the molecular aspects of gene regulation in grafted watermelon. Compared with self-grafted watermelon, there were 787 and 3485 genes differentially expressed in watermelon grafted onto bottle gourd and squash rootstocks, respectively. These genes were associated with primary and secondary metabolism, hormone signaling, transcription factors, transporters, and response to stimuli. Grafting led to changes in expression of these genes, suggesting that they may play important roles in mediating the physiological processes of grafted seedlings. The potential roles of the grafting-responsive mRNAs in diverse biological and metabolic processes were discussed. Obviously, the data obtained in this study provide an excellent resource for unraveling the mechanisms of candidate genes function in diverse biological processes and in environmental adaptation in a graft system.

  2. Vascularized bone grafts for the treatment of carpal bone pathology.

    PubMed

    Derby, Brian M; Murray, Peter M; Shin, Alexander Y; Bueno, Reuben A; Mathoulin, Christophe L; Ade, Tim; Neumeister, Michael W

    2013-03-01

    Primary bone healing fails to occur in 5-15 % of scaphoid bones that undergo fracture fixation. Untreated, occult fractures result in nonunion up to 12 % of the time. Conventional bone grafting is the accepted management in the treatment algorithm of scaphoid nonunion if the proximal pole is vascularized. Osteonecrosis of the proximal scaphoid pole intuitively suggests a need for transfer of the vascularized bone to the nonunion site. Scaphoid nonunion treatment aims to prevent biological and mechanical subsidence of the involved bone, destabilization of the carpus, and early degenerative changes associated with scaphoid nonunion advanced collapse. Pedicled distal radius and free vascularized bone grafts (VBGs) offer hand surgeons an alternative treatment option in the management of carpal bone nonunion. VBGs are also indicated in the treatment of avascular necrosis of the scaphoid (Preiser's disease), lunate (Kienböck's disease), and capitate. Relative contraindications to pedicled dorsal radius vascularized bone grafting include humpback deformity, carpal instability, or collapse. The free medial femoral condyle bone graft has offered a novel treatment option for the humpback deformity to restore geometry of the carpus, otherwise not provided by pedicled grafts. In general, VBGs are contraindicated in the setting of a carpal bone without an intact cartilaginous shell, in advanced carpal collapse with degenerative changes, and in attempts to salvage small or collapsed bone fragments. Wrist salvage procedures are generally accepted as the more definitive treatment option under such circumstances. This manuscript offers a current review of the techniques and outcomes of VBGs to the carpal bones.

  3. Postcatheterization Femoral Arteriovenous Fistulas: Endovascular Treatment with Stent-Grafts

    SciTech Connect

    Onal, Baran Kosar, Sule; Gumus, Terman; Ilgit, Erhan T.; Akpek, Sergin

    2004-09-15

    Purpose: To report our results of stent-graft implantation for the endovascular treatment of postcatheterization femoral arteriovenous fistulas (AVFs) occurring between the deep femoral artery and the femoral vein.Methods: Endovascular treatment of iatrogenic femoral AVFs as a result of arterial puncture for coronary angiography and/or angioplasty was attempted in 10 cases. Balloon-expandable stent-grafts, one for each lesion, were used to repair the fistulas, which were between the deep femoral artery and the femoral vein in all cases. Stent-graft implantation to the deep femoral artery was performed by a contralateral retrograde approach.Results: All stent-grafts were deployed successfully. Complete closure of the fistulas was accomplished immediately in nine of 10 cases. In one case, complete closure could not be obtained but the fact that the complaint subsided was taken to indicate clinical success. In three cases, side branch occlusion of the deep femoral artery occurred. No complications were observed after implantation. Follow-up for 8-31 months (mean 18.5 months) with color Doppler ultrasonography revealed patency of the stented arterial segments without recurrent arteriovenous shunting in those nine patients who had successful immediate closure of their AVFs.Conclusion: Our results with a mean follow-up 18.5 months suggest that stent-graft implantation for the closure of postcatheterization femoral AVFs originating from the deep femoral artery is an effective, minimally invasive alternative procedure.

  4. Preparation of cassava starch grafted with polystyrene by suspension polymerization.

    PubMed

    Kaewtatip, Kaewta; Tanrattanakul, Varaporn

    2008-09-05

    Cassava starch grafted with polystyrene (PS-g-starch) copolymer was synthesized via free-radical polymerization of styrene by using suspension polymerization technique. Potassium persulfate (PPS) was used as an initiator and water was used as a medium. The graft copolymer was characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, X-ray diffraction and scanning electron microscopy. The sub-micron spherical beads of PS were observed on the surface of starch granules. SEM micrographs showed porous patches of PS adhering on the starch granules after Soxhlet extraction. FTIR spectra also indicated the presence of PS-g-starch copolymer. XRD analysis exhibited insignificant changes in crystalline structure and degree of crystallinity. The effects of starch:styrene weight ratio, amount of PPS, reaction time and reaction temperature on the percentage of grafting - G (%), were investigated. G (%) increased with increasing starch content. Other variables showed their own individual optimal values. The optimum condition yielding 31.47% of G (%) was derived when the component ratio was 1:3 and reaction temperature and time were 50°C and 2h, respectively. Graft copolymerization did not change granular shape and crystallinity of starch. This study demonstrated the capability of polymerization of styrene monomer on the granular starch without emulsifier and the synthesis of graft copolymer without gelatinization of starch.

  5. Bone graft complications: what can we do to prevent them?

    NASA Astrophysics Data System (ADS)

    Tandon, Rahul; Herford, Alan S.

    2014-03-01

    Introduction: Bone grafts are commonly used in oral and maxillofacial surgery, helping to restore missing bone structure and provide osseous support. In spite of their reported success, complications can and do arise. Examples include loosening and resorption of the graft, infection, and complete loss of the graft. These complications can potentially lead to larger defects, necessitating additional procedures to correct the problem. This not only causes great discomfort to the patient, but also drains considerable time and resources away from the clinician. Thus, improvements on identifying ways to identify and prevent these complications are constantly being sought. We have performed a literature review and identified several areas in the field of optics that could potentially help solve our problem. Optical Techniques: Raman spectroscopy has been shown to provide a transcutaneous measurement of bone mineral and matrix Raman bands. This could potentially provide surgeons with the ability to more accurately assess bone graft osseointegration. In-vivo near-infrared optical imaging could potentially provide accurate diagnosis of pathologic lesions such as osteosarcoma. Contrast-enhanced ultrasound could be used to detect vascular disturbances and other information related to the transplantation of osseous components. Conclusion: Bone graft complications can be one of the most devastating consequences of osseous surgery. As surgeons, we are constantly searching for ways to identify them earlier and prevent them. We hope that by presenting areas that could be used, we can gain a better insight to ways in which both fields can benefit.

  6. [Revascularization with the branched graft in middle aortic syndrome].

    PubMed

    Urayama, H; Fujioka, S; Katada, S; Kawabe, K; Watanabe, Y; Iwa, T; Horimoto, T

    1989-01-01

    A case of middle aortic syndrome which was thought to be the thoracoabdominal type of Takayasu's disease was successfully treated with the branched graft bypass. Patient was a 23 year-old woman with hypertension and abdominal pain. The preoperative angiography revealed aortic stenosis from the celiac axis to the left renal artery. The operative procedures were as follows; patient was positioned in supine with her left shoulder and arm raised. Eighth intercostal thoracotomy and midline laparotomy was performed with the thoracoabdominal incision. The branched graft was made previously with woven Dacron (phi 18 mm) and three EPTFEs (phi 8mm). The woven Dacron of the graft was used for the bypass from the descending thoracic aorta to the infrarenal abdominal aorta, and the branched EPTFEs of the graft were used for the bypasses to the common hepatic artery, the superior mesenteric artery and the right renal artery in this order. The bypasses were placed along the anatomical courses in the retroperitoneal space. Postoperatively, the blood pressure dropped and the abdominal pain disappeared. The plasma renin activity decreased and the renal function improved. Two months after operation the bypasses were patent by the angiography and now six months after operation she has returned to her social life healthily. The approach to the aorta and its abdominal branches by thoracotomy and laparotomy and bypass with the three branched graft was useful for middle aortic syndrome.

  7. Simulation of flow through a Miller cuff bypass graft.

    PubMed

    Henry, F S; Küpper, C; Lewington, N P

    2002-06-01

    Unnatural temporal and spatial distributions of wall shear stress in the anastomosis of distal bypass grafts have been identified as possible factors in the development of anastomotic intimal hyperplasia in these grafts. Distal bypass graft anastomoses with an autologus vein cuff (a Miller cuff) interposed between the graft and artery have been shown to alleviate the effects of intimal hyperplasia. In this study, pulsatile flow through models of a standard end-to-side anastomosis and a Miller cuff anastomosis are computed and the resulting wall shear stress and pressure distributions analysed. The results are inconclusive, and could be taken to suggest that the unnatural distributions of shear stress that do occur along the anastomosis floor may not be particularly important in the development of intimal hyperplasia. However, it seems more likely that the positive effects of the biological and material properties of the vein cuff, which are not considered in this study, somehow outweigh the negative effects of the shear stress distributions predicted to occur on the floor of the Miller-cuff graft.

  8. Genetic therapy for vein bypass graft disease: current perspectives.

    PubMed

    Simosa, Hector F; Conte, Michael S

    2004-01-01

    Although continued progress in endovascular technology holds promise for less invasive approaches to arterial diseases, surgical bypass grafting remains the mainstay of therapy for patients with advanced coronary and peripheral ischemia. In the United States, nearly 400,000 coronary and 100,000 lower extremity bypass procedures are performed annually. The autogenous vein, particularly the greater saphenous vein, has proven to be a durable and versatile arterial substitute, with secondary patency rates at 5 years of 70 to 80% in the extremity. However, vein graft failure is a common occurrence that incurs significant morbidity and mortality, and, to date, pharmacologic approaches to prolong vein graft patency have produced limited results. Dramatic advances in genetics, coupled with a rapidly expanding knowledge of the molecular basis of vascular diseases, have set the stage for genetic interventions. The attraction of a genetic approach to vein graft failure is based on the notion that the tissue at risk is readily accessible to the clinician prior to the onset of the pathologic process and the premise that genetic reprogramming of cells in the wall of the vein can lead to an improved healing response. Although the pathophysiology of vein graft failure is incompletely understood, numerous relevant molecular targets have been elucidated. Interventions designed to influence cell proliferation, thrombosis, inflammation, and matrix remodeling at the genetic level have been described, and many have been tested in animal models. Both gene delivery and gene blockade strategies have been investigated, with the latter reaching the stage of advanced clinical trials.

  9. Accelerating in Situ Endothelialisation of Cardiovascular Bypass Grafts

    PubMed Central

    Goh, Ee Teng; Wong, Eleanor; Farhatnia, Yasmin; Tan, Aaron; Seifalian, Alexander M.

    2014-01-01

    The patency of synthetic cardiovascular grafts in the long run is synonymous with their ability to inhibit the processes of intimal hyperplasia, thrombosis and calcification. In the human body, the endothelium of blood vessels exhibits characteristics that inhibit such processes. As such it is not surprising that research in tissue engineering is directed towards replicating the functionality of the natural endothelium in cardiovascular grafts. This can be done either by seeding the endothelium within the lumen of the grafts prior to implantation or by designing the graft such that in situ endothelialisation takes place after implantation. Due to certain difficulties identified with in vitro endothelialisation, in situ endothelialisation, which will be the focus of this article, has garnered interest in the last years. To promote in situ endothelialisation, the following aspects can be taken into account: (1) Endothelial progenital cell mobilization, adhesion and proliferation; (2) Regulating differentiation of progenitor cells to mature endothelium; (3) Preventing thrombogenesis and inflammation during endothelialisation. This article aims to review and compile recent developments to promote the in situ endothelialisation of cardiovascular grafts and subsequently improve their patency, which can also have widespread implications in the field of tissue engineering. PMID:25551605

  10. Therapeutic strategies to combat neointimal hyperplasia in vascular grafts

    PubMed Central

    Collins, Michael J; Li, Xin; Lv, Wei; Yang, Chenzi; Protack, Clinton D; Muto, Akihito; Jadlowiec, Caroline C; Shu, Chang; Dardik, Alan

    2012-01-01

    Neointimal hyperplasia (NIH) in bypass conduits such as veins and prosthetic grafts is an important clinical entity that limits the long-term success of vascular interventions. Although the development of NIH in the conduits shares many of the same features of NIH that develops in native arteries after injury, vascular grafts are exposed to unique circumstances that predispose them to NIH, including surgical trauma related to vein handling, hemodynamic changes creating areas of low flow, and differences in biocompatibility between the conduit and the host environment. Multiple different approaches, including novel surgical techniques and targeted gene therapies, have been developed to target and prevent the causes of NIH. Recently, the PREVENT trials, the first molecular biology trials in vascular surgery aimed at preventing NIH, have failed to produce improved clinical outcomes, highlighting the incomplete knowledge of the pathways leading to NIH in vascular grafts. In this review, we aim to summarize the pathophysiologic pathways that underlie the formation of NIH in both vein and synthetic grafts and discuss current and potential mechanical and molecular approaches under investigation that may limit NIH in vascular grafts. PMID:22651839

  11. Novel technologies to engineer graft for tolerance induction

    PubMed Central

    Woodward, Kyle B.; Wang, Feng; Zhao, Hong; Yolcu, Esma S.; Shirwan, Haval

    2015-01-01

    Purpose of review Conquering allograft rejection remains an elusive goal in spite of recent breakthroughs in the field of immunosuppression. Much of the problem lies in the toxicity and side effects of long-term use of systemic immunosuppressant drugs, which are sometimes ineffective in controlling rejection, but also hinder establishment of transplant tolerance. In this review, we discuss novel technologies that use grafts engineered with immunomodulatory molecules as a means of inducing tolerance. Recent findings Several recent studies have demonstrated the feasibility of engineering cells, tissues, or solid organ grafts with immunoregulatory biologics to achieve long termgraft survival without the use of chronic immunosuppression. This approach was shown to primarily change the ratio of T effector versus CD4+CD25+FoxP3+ T regulatory cells within the graft microenvironment in favor of attaining localized tolerance induction and maintenance. Summary Localized immunomodulation using biologic-engineered allografts represent a new paradigm for achieving long term graft survival in the absence of chronic use of immunosuppression. The manipulation of the graft, rather than the recipient, not only ensures short and long-term safety by minimizing the adverse effects of immunosuppression, but also allows retention of immune competency critical for the ability of the recipient to fight infections and cancer. PMID:26626421

  12. Pediatric penile reconstruction using autologous split-thickness skin graft.

    PubMed

    Diaz, E C; Corcoran, J F; Johnson, E K

    2016-06-01

    This video provides a case report of penis entrapment secondary to excessive skin removal during circumcision. It highlights the technical aspects of pediatric penile reconstruction using autologous split-thickness skin graft (STSG). Key points include: 1. Infection prevention is paramount and antibiotic prophylaxis is routine. 2. The usual harvest site for the STSG is the lateral thigh because of its source of glabrous skin and convenient proximity to the penis. The lateral thigh is also outside of the diapered area, which helps lessen postoperative pain and infectious risks. 3. A dermatome is used to harvest the STSG. Skin thickness for penis coverage at this age is usually 10-12/1000 of an inch. 4. Direct contact of the graft and wound bed is essential for graft uptake. Hemostasis of the wound bed is critical to prevent hematoma formation. Elimination of redundant tissue is also important to ensure maximal contact between the graft and underlying wound bed. 5. A pressure dressing or bolster is used to prevent shear, and provide contact between the graft and wound bed for at least the first 5 days. 6. A semi-occlusive dressing, Tegaderm, was used on the donor site and it is believed that it provides a moist environment conducive for epithelial and dermal healing. 7. Lymphedema can result if excess distal penile skin is not excised. It is prudent to limit the amount of mucosal collar or consider direct anastomosis to the glans.

  13. Graft copolymerization of acrylic acid onto polyamide fibers

    NASA Astrophysics Data System (ADS)

    Makhlouf, Chahira; Marais, Stéphane; Roudesli, Sadok

    2007-04-01

    The grafting of acrylic acid (AA) monomer (CH 2dbnd CH sbnd COOH) on polyamide 6.6 monofilaments (PA 6.6) using benzoyl peroxide (BPO) as initiator was carried out in order to enhance the hydrophilic nature of fibers. The grafting rate depends on the AA concentration, the BPO concentration, the time and the temperature of reaction. The best conditions for optimum rate of grafting were obtained with a AA concentration of 0.5 M, a BPO concentration of 0.03 M, a reaction temperature of T = 85 °C and a reaction time of 120 mn. The fiber surface has been investigated by many experimental techniques of characterization such as Fourier transform infrared spectroscopy (FTIR), calorimetric analysis (DSC), scanning electron microscopy (SEM), and contact angle measurements. The effect of grafting of acrylic acid onto PA 6.6 fibers on their moisture and mechanical resistances was analyzed from water sorption and elongation at break measurements. The analysis of the experimental data shows clearly the efficiency of the grafting reaction used, leading to a significant increase of the hydrophilic character of the PA 6.6 surface.

  14. Study on biotribological properties of UHMWPE grafted with MPDSAH.

    PubMed

    Deng, Yaling; Xiong, Dangsheng; Shao, Silong

    2013-04-01

    In order to prolong the service life of artificial joints, a zwitterion monomer of MPDSAH ((3-(methacryloylamino)propyl)dimethyl (3-sulfopropyl)ammonium hydroxide) was grafted onto ultra-high molecular weight polyethylene (UHMWPE) powders to construct a brush-like structure by UV irradiation, and then the grafted UHMWPE powders were hot pressed as the bulk materials. The wettability of bulk materials surface with different monomer concentrations was analyzed. The tribological properties of modified UHMWPE bulk materials were investigated under distilled water and saline by sliding against stainless steel ball. The measurement of Fourier-transform infrared (FT-IR) spectroscopy indicates that MPDSAH is successfully grafted onto the surface of UHMWPE powders by UV irradiation. The contact angles of modified UHMWPE are decreased and the surface wettability is effectively improved. The friction coefficient of the modified sample is lower than that of untreated UHMWPE in aqueous lubricants during a long-term friction. With the increase of monomer concentration, the wear rate of grafted UHMWPE decreases gradually in distilled water. The grafting hydrophilic macromolecule polymer is helpful to form a lubricating film of water, which leads to the improvement of the lubricity of UHMWPE.

  15. Dental Hetero-Graft Materials with Nano Hydroxyapatite Surface Treatment.

    PubMed

    Kim, Dai-Hwan; Kim, Kyung-Il; Yoon, Seokyoung; Kim, Hyung-Jo; Ahn, Jin-Soo; Jun, Sang Ho; Kang, Ho Chang; Pang, Changhyun; Kim, Jaeyun; Cha, Hyung Joon; Han, Kwon-Hoon; Kim, Dong-Myong; Lee, Jung Heon

    2015-10-01

    We report the development of hydroxyapatite nanoparticle (HAp NP)-functionalized hetero-graft materials (HGMs) for dental applications. These HGMs were prepared by attaching platelet-, needle-, and sphere-shaped HAp NPs to the surface of xenograft materials through chemical conjugation. Although all three HAp NPs contributed to increase the surface area of bone graft material (BGM), the shape of the HAp NPs was a determining factor. Platelet HAp NPs were most effective, because they caused a 48.9% increase in BGM surface area whereas the influence of the spherical NP was only a 6.7% increase. This suggests that geometric factors regarding both the attached HAp NPs and graft material surface are essential in controlling the surface roughness of graft materials. Among the three HAp NPs, it was the platelet HAp NPs that helped to increase the efficacy of the BGM most significantly. Compared with BGM with no HAp NP attachment, HGM with platelet HAp NP ('platelet-HGM) treatment had ~46.1% higher cell attachment and proliferation rate. The MTT assay also showed that the HAp NP-treated hetero-graft materials had negligible cytotoxicity.

  16. Optimization of acrylic acid grafting onto polypropylene using response surface methodology and its biodegradability

    NASA Astrophysics Data System (ADS)

    Mandal, Dev K.; Bhunia, Haripada; Bajpai, Pramod K.; Kushwaha, Jai P.; Chaudhari, Chandrasekhar V.; Dubey, Kumar A.; Varshney, Lalit

    2017-03-01

    Simultaneous radiation grafting was optimized to graft acrylic acid monomer on the polypropylene (PP) films to make them hydrophilic and enhance their biodegradability. Experiments were designed based on full factorial central composite design (response surface methodology) and influence of monomer concentration, radiation dose, inhibitor concentration, solvent concentration on degree of grafting was investigated. The extent of grafting was found to increase with increasing monomer concentration, inhibitor concentration and radiation dose. The targeted 35% grafting could be achieved at optimum condition viz. monomer concentration 12.09 wt%, radiation dose 12.40 kGy, inhibitor concentration 0.07 M and solvent concentration 0.12 M. The grafted PP films at different degrees of grafting were tested for tensile properties and characterized by swelling studies, fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Successful grafting of acrylic acid onto polypropylene films was indicated by FTIR and confirmed quantitatively by determination of carboxylic groups on the film surface. Tensile strength of grafted PP films decreased with increase in degree of grafting. The crystallinity of the grafted PP films was lower than that of PP film as indicated by DSC studies. Grafting of acrylic acid increased the roughness on the surface of PP films indicated by SEM studies. The maximum biodegradability of the 34.55% grafted film was 5.5%.

  17. Open stent grafting for complex diseases of the thoracic aorta: clinical utility.

    PubMed

    Uchida, Naomichi

    2013-03-01

    Open stent grafting is an alternative treatment for extensive thoracic aortic replacement. However, this procedure is associated with a high incidence of spinal cord injury, which has limited its application. Multiple factors have been suggested to explain the risk of spinal cord injury, including deep delivery of the stent graft, history of operation of the downstream aorta, and postoperative low blood pressure. Cerebrospinal fluid drainage or a hybrid operation in combination with trans-femoral thoracic stent grafting is useful for preventing spinal cord injury. Open stent grafting remains an alternative treatment for atherosclerotic aneurysms with dilatation of the ascending aorta. Open stent grafting for acute aortic dissection is effective for remodeling of the false lumen. The graft diameter for aortic dissection should be 90 % of the total diameter of the aorta, and the distal landing zone should be limited to the T7 vertebral level to prevent new intimal tears or spinal cord injury. Open stent grafting seems a feasible bailout strategy for the treatment of retrograde aortic dissection after TEVAR for type B aortic dissection. Newly designed devices for open stent grafts include the Matsui-Kitamura stent graft or branched open stent graft, which is produced in Japan. The effectiveness of open stent grafting in the treatment of Marfan syndrome remains unclear. A commercially available device for open stent grafting would be desired in Japan. In conclusion, an open stent graft remains an alternative treatment for complex thoracic aortic pathologies.

  18. In vivo bone tunnel evaluation of nanoparticle-grafts using an ACL reconstruction rabbit model.

    PubMed

    Grant, Sheila A; Smith, Sarah E; Schmidt, Hilary; Pfeiffer, Ferris; Kuroki, Kei; Sherman, Seth; White, Richard; Grant, David A

    2017-04-01

    Acellular human gracilis tendons conjugated with gold nanoparticles (AuNP) and hydroxyapatite nanoparticles (nano-HAp) were used as a graft in an anterior cruciate ligament (ACL) reconstruction rabbit model. The ACLs of 11 New Zealand rabbits were reconstructed using grafts conjugated without nanoparticles, with AuNP only, and with both AuNP and nano-HAp. Semi-quantitative histological scoring of bone tunnel portion of grafts was performed after 14 weeks. Bone tunnels were scored for graft degeneration, graft remodeling, percentage of new host fibrous connective, collateral connection, head-to-head connection, graft collagen fiber organization, new host fibrous connective tissue organization, and graft and interface vascularity. All grafts were intact at 14 weeks. Results of bone tunnel scoring indicate remodeling in all graft types with new organized host fibrous connective tissue, head-to-head connection to bone and mild inflammation associated with remodeling. Components of the 20 nm AuNP grafts have significantly more graft degeneration, more new host fibrous connective tissue, and more vascularity compared to crosslinked grafts. Comparison between femoral and tibial tunnel scores indicate more degeneration in femoral tunnels compared to tibial tunnels. Overall results indicated potentially enhanced remodeling from the use of 20 nm AuNP grafts. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1071-1082, 2017.

  19. Autologous great saphenous vein tailored graft to replace an infected prosthetic graft in the groin.

    PubMed

    Barbon, Bruno; Militello, Carmelo; De Rossi, Aldo; Martella, Bruno; Ballotta, Enzo

    2007-01-01

    The authors propose a technique using the autologous great saphenous vein to replace an infected prosthetic limb graft at the groin. The whole great saphenous vein is incised longitudinally and divided into 2 approximately equal segments, which are sewn side to side. The longitudinal edges of the resulting great saphenous vein are then joined and anastomosed side to side to form a conduit, whose caliber is twice the original vein's diameter. The authors have used this technique to replace 1 limb of a prosthetic aortofemoral bypass infected at the groin. After 5 years, the new venous conduit is patent, with no recurrent infection, dilation, or aneurysmal degeneration. If validated by further experiences, this might be an attractive alternative to restoring flow through clean tissue planes using extra-anatomic bypass or the femoral vein in the infected fields.

  20. A comparative study of lingual mucosal graft urethroplasty with buccal mucosal graft urethroplasty in urethral stricture disease: An institutional experience

    PubMed Central

    Pal, Dilip Kumar; Gupta, Depak Kumar; Ghosh, Bastab; Bera, Malay Kumar

    2016-01-01

    Aims: A prospective study to compare the outcomes of lingual versus buccal mucosal graft urethroplasty in patients with long segment anterior urethral strictures disease. Materials and Methods: The study included 30 patients for buccal mucosal graft urethroplasty (group I) and 30 patients for lingual mucosal graft urethroplasty (group II) for treatment of long segment (>3 cm) incomplete anterior urethral stricture disease using single-stage dorsal onlay free oral mucosal graft urethroplasty by Barbagli's technique between February 2013 to September 2014. All patients underwent complete evaluation of the stricture including inspection of the oral cavity. Results: The results of urethroplasty in between two group were not significant (P > 0.05) in terms of Qmax (P = 0.63), mean postoperative AUA symptom score (P = 0.83), operative time (P = 0.302) intra operative blood loss (P = 0.708), duration of postoperative hospitalization (P = 0.83), but slurring of speech complications was seen in group II, but not in group I. Long-term complications of salivary disturbance, tightness of the mouth, persistent pain at graft site, perioral numbness, seen only in group I (BMGU). Conclusion: LMG urethroplasty is an excellent alternative to BMG urethroplasty with comparable results of urethroplasty and minimal donor site complications. PMID:27141184

  1. Stearyl methacrylate-grafted-chitosan nanoparticle as a nanofiller for PLA: Radiation-induced grafting and characterization

    NASA Astrophysics Data System (ADS)

    Rattanawongwiboon, Thitirat; Haema, Kamonwon; Pasanphan, Wanvimol

    2014-01-01

    This paper reports a one-pot synthesis using radiation-induced grafting technique to modify biopolymer-based chitosan nanoparticles as a nanofiller for blending with poly(lactic acid) (PLA). Hydrophobic stearyl methacrylate (SMA) was grafted onto non-irradiated chitosan (CS0) and pre-irradiated chitosan with a γ-ray dose of 40 kGy (CS40) to obtain stearyl methacrylate-grafted-chitosan nanoparticles (SMA-g-CSNPs).The effects of the pre-irradiated CS, grafting doses and SMA concentrations on degree of grafting (DG) and particle formation were studied. FT-IR and XRD were used to characterize the chemical and packing structure of SMA-g-CSNPs. The particle formulation and size of SMA-g-CSNPs were observed by TEM and AFM. The spherical core-shell SMA-g-CSNPs with the size ranging from 50 to 140 nm were successfully prepared. The SMA-g-CSNPs from CS40 has higher DG and smaller particle size when compared with CS0. The SMA-g-CSNPs are able to improve the compatibility between CS and PLA.

  2. Periosteal pedicle graft: A novel root coverage approach.

    PubMed

    Shah, Mishal Piyush; Patel, Akash Prahlad; Shah, Kinnari Mishal

    2015-01-01

    Gingival recession along with reduced width of attached gingiva and inadequate vestibular depth is a very common finding. Many techniques have been adopted in order to treat such defects and obtain predictable root coverage. Several graft procedures are used to obtain the coverage, but they have not been able to deliver predictable and satisfactory results (except connective tissue graft). Some of them also resulted in the secondary surgical site that was very uncomfortable for the patients. There was an intense need for a technique that provides not only good and predictable root coverage, but also reduces the need for secondary surgical site. Hence, this paper describes a single stage technique for increasing the width of attached gingiva and root coverage by using the periosteal pedicle graft.

  3. Electrochemical water oxidation with carbon-grafted iridium complexes.

    PubMed

    deKrafft, Kathryn E; Wang, Cheng; Xie, Zhigang; Su, Xin; Hinds, Bruce J; Lin, Wenbin

    2012-02-01

    Hydrogen production from water splitting provides a potential solution to storing harvested solar energy in chemical fuels, but this process requires active and robust catalysts that can oxidize water to provide a source of electrons for proton reduction. Here we report the direct, covalent grafting of molecular Ir complexes onto carbon electrodes, with up to a monolayer coverage. Carbon-grafted Ir complexes electrochemically oxidize water with a turnover frequency of up to 3.3 s(-1) and a turnover number of 644 during the first hour. Electrochemical water oxidation with grafted catalysts gave enhanced rates and stability compared to chemically driven water oxidation with the corresponding molecular catalysts. This strategy provides a way to systematically evaluate catalysts under tunable conditions, potentially providing new insights into electrochemical water oxidation processes and water oxidation catalyst design.

  4. Connexin43 Inhibition Prevents Human Vein Grafts Intimal Hyperplasia

    PubMed Central

    Longchamp, Alban; Allagnat, Florent; Alonso, Florian; Kuppler, Christopher; Dubuis, Céline; Ozaki, Charles-Keith; Mitchell, James R.; Berceli, Scott; Corpataux, Jean-Marc

    2015-01-01

    Venous bypass grafts often fail following arterial implantation due to excessive smooth muscle cells (VSMC) proliferation and consequent intimal hyperplasia (IH). Intercellular communication mediated by Connexins (Cx) regulates differentiation, growth and proliferation in various cell types. Microarray analysis of vein grafts in a model of bilateral rabbit jugular vein graft revealed Cx43 as an early upregulated gene. Additional experiments conducted using an ex-vivo human saphenous veins perfusion system (EVPS) confirmed that Cx43 was rapidly increased in human veins subjected ex-vivo to arterial hemodynamics. Cx43 knock-down by RNA interference, or adenoviral-mediated overexpression, respectively inhibited or stimulated the proliferation of primary human VSMC in vitro. Furthermore, Cx blockade with carbenoxolone or the specific Cx43 inhibitory peptide 43gap26 prevented the burst in myointimal proliferation and IH formation in human saphenous veins. Our data demonstrated that Cx43 controls proliferation and the formation of IH after arterial engraftment. PMID:26398895

  5. Aspirin decreases platelet uptake on Dacron vascular grafts in baboons

    SciTech Connect

    Mackey, W.C.; Connolly, R.J.; Callow, A.D.; Keough, E.M.; Ramberg-Laskaris, K.; McCullough, J.L.; O'Donnell, T.F. Jr.; Melaragno, A.; Valeri, C.R.; Weiblen, B.

    1984-07-01

    The influence of a single dose of aspirin (5.4-7.4 mg/kg) on platelet uptake on 4-mm Dacron interposition grafts was studied in a baboon model using gamma camera scanning for 111-Indium labeled platelets. In vitro assessment of platelet function after aspirin administration revealed that in the baboon, as in the human, aspirin abolished arachidonic acid-induced platelet aggregation, prolonged the lag time between exposure to collagen and aggregation, and decreased plasma thromboxane B2 levels. Aspirin also prolonged the template bleeding time. Scans for 111-Indium labeled platelets revealed that pretreatment with a single dose of aspirin decreased platelet uptake on 4-mm Dacron carotid interposition grafts. This decrease in platelet uptake was associated with a significant improvement in 2-hour graft patency and with a trend toward improved 2-week patency.

  6. Bioreactor cultivation of anatomically shaped human bone grafts.

    PubMed

    Temple, Joshua P; Yeager, Keith; Bhumiratana, Sarindr; Vunjak-Novakovic, Gordana; Grayson, Warren L

    2014-01-01

    In this chapter, we describe a method for engineering bone grafts in vitro with the specific geometry of the temporomandibular joint (TMJ) condyle. The anatomical geometry of the bone grafts was segmented from computed tomography (CT) scans, converted to G-code, and used to machine decellularized trabecular bone scaffolds into the identical shape of the condyle. These scaffolds were seeded with human bone marrow-derived mesenchymal stem cells (MSCs) using spinner flasks and cultivated for up to 5 weeks in vitro using a custom-designed perfusion bioreactor system. The flow patterns through the complex geometry were modeled using the FloWorks module of SolidWorks to optimize bioreactor design. The perfused scaffolds exhibited significantly higher cellular content, better matrix production, and increased bone mineral deposition relative to non-perfused (static) controls after 5 weeks of in vitro cultivation. This technology is broadly applicable for creating patient-specific bone grafts of varying shapes and sizes.

  7. Immobilization of bacteria in microgel grafted onto macroporous polyethylene

    NASA Astrophysics Data System (ADS)

    Trelles, J. A.; Quiroga, F.; Britos, C.; Smolko, Eduardo E.; Grasselli, Mariano

    2010-03-01

    The development of " Green Chemistry" requires new materials to replace the conventional organic chemistry by biological catalysts, to produce fine chemicals in an environmentally friendly manner. Microbial whole cells can be directly used as biocatalysts, providing a simple and cheap methodology since enzyme isolation and purification are avoided. High-density polyethylene (HDPE) is a very stable polymer though it can be activated by gamma radiation to induce grafting. Glycidyl methacrylate was grafted onto macroporous HDPE and PP in the range of 1-6%, proportional to the initial monomer concentration. Grafted polymers were further chemically modified with ethylenediamine to generate a cationic hydrogel of micron-size thickness onto the internal polymer surfaces. Modified polymers were able to immobilize Gram-positive and Gram-negative bacteria that can catalyze a chemical reaction as efficient as free cells do.

  8. Hemodynamically Driven Vein Graft Remodeling: A Systems Biology Approach

    PubMed Central

    Berceli, Scott A.; Tran-Son-Tay, Roger; Garbey, Marc; Jiang, Zhihua

    2011-01-01

    Despite intense investigation over several decades to understand the mechanisms of vein graft failure, few therapeutic modalities have emerged. Emphasis using standard reductionist approaches has been focused on cataloging the components involved in the early events following vein graft implantation, but limited insight has been gained in understanding the dynamic interaction of these components. We propose that the application of systems theory offers the opportunity for significant advances in this area. Focused on modeling the dynamic relationships that define living organisms, systems biology provides the necessary tools to further our understanding of the complex series of overlapping biologic events on surgical implantation of the vein graft. Through the use of ordinary differential equation and agent-based modeling techniques, we present our ongoing efforts to define the nonlinear interactions between hemodynamics and vascular adaptation. PMID:19426605

  9. Modeling Interfacial Adsorption of Polymer-Grafted Nanoparticles

    NASA Astrophysics Data System (ADS)

    Yong, Xin

    2014-11-01

    Numerous natural and industrial processes demand advances in our fundamental understanding of colloidal adsorption at liquid interfaces. Using dissipative particle dynamics (DPD), we model the interfacial adsorption of core-shell nanoparticles at the water-oil interface. The solid core of the nanoparticle encompasses beads arranged in an fcc lattice structure and its surface is uniformly grafted with polymer chains. The nanoparticles bind to the interface from either phase to minimize total surface energy. With a single nanoparticle, we demonstrate detailed kinetics of different stages in the adsorption process. Prominent effect of grafted polymer chains is characterized by varying molecular weight and polydispersity of the chains. We also preload nanoparticles straddling the interface to reveal the influence of nanoparticle surface density on further adsorption. Importantly, these studies show how surface-grafted polymer chains can alter the interfacial behavior of colloidal particles and provide guidelines for designing on-demand Pickering emulsion.

  10. Connexin43 Inhibition Prevents Human Vein Grafts Intimal Hyperplasia.

    PubMed

    Longchamp, Alban; Allagnat, Florent; Alonso, Florian; Kuppler, Christopher; Dubuis, Céline; Ozaki, Charles-Keith; Mitchell, James R; Berceli, Scott; Corpataux, Jean-Marc; Déglise, Sébastien; Haefliger, Jacques-Antoine

    2015-01-01

    Venous bypass grafts often fail following arterial implantation due to excessive smooth muscle cells (VSMC) proliferation and consequent intimal hyperplasia (IH). Intercellular communication mediated by Connexins (Cx) regulates differentiation, growth and proliferation in various cell types. Microarray analysis of vein grafts in a model of bilateral rabbit jugular vein graft revealed Cx43 as an early upregulated gene. Additional experiments conducted using an ex-vivo human saphenous veins perfusion system (EVPS) confirmed that Cx43 was rapidly increased in human veins subjected ex-vivo to arterial hemodynamics. Cx43 knock-down by RNA interference, or adenoviral-mediated overexpression, respectively inhibited or stimulated the proliferation of primary human VSMC in vitro. Furthermore, Cx blockade with carbenoxolone or the specific Cx43 inhibitory peptide 43gap26 prevented the burst in myointimal proliferation and IH formation in human saphenous veins. Our data demonstrated that Cx43 controls proliferation and the formation of IH after arterial engraftment.

  11. Robot-Assisted Antegrade In-Situ Fenestrated Stent Grafting

    SciTech Connect

    Riga, Celia V. Bicknell, Colin D.; Wallace, Daniel; Hamady, Mohamad; Cheshire, Nicholas

    2009-05-15

    To determine the technical feasibility of a novel approach of in-situ fenestration of aortic stent grafts by using a remotely controlled robotic steerable catheter system in the porcine model. A 65-kg pig underwent robot-assisted bilateral antegrade in-situ renal fenestration of an abdominal aortic stent graft with subsequent successful deployment of a bare metal stent into the right renal artery. A 16-mm iliac extension covered stent served as the porcine aortic endograft. Under fluoroscopic guidance, the graft was punctured with a 20-G customized diathermy needle that was introduced and kept in place by the robotic arm. The needle was exchanged for a 4 x 20 mm cutting balloon before successful deployment of the renal stent. Robot-assisted antegrade in-situ fenestration is technically feasible in a large mammalian model. The robotic system enables precise manipulation, stable positioning, and minimum instrumentation of the aorta and its branches while minimizing radiation exposure.

  12. Crosslink-induced shrinkage of grafted Gaussian chains

    NASA Astrophysics Data System (ADS)

    Benetatos, Panayotis

    2014-04-01

    The statistical mechanics of polymers grafted on surfaces has been the subject of intense research activity because of many potential applications. In this paper, we analytically investigate the conformational changes caused by a single crosslink on two ideal (Gaussian) chains grafted onto a rigid planar surface. Both the crosslink and the surface reduce the number of allowed configurations. In the absence of the hard substrate, the sole effect of the crosslink is a reduction in the effective Kuhn length of a tethered chain. The crosslink-induced shrinkage (collapse) of the grafted chains (mushrooms) turns out to be a reduction in the variance of the distribution of the height of the chain rather than a reduction of the height itself.

  13. Fatal pyoderma gangrenosum with pathergy after coronary artery bypass grafting.

    PubMed

    Bryan, Charles S

    2012-01-01

    Surgeons and others who perform invasive procedures should be aware of the possibility of pyoderma gangrenosum and the risk of pathergy in patients who have a history of unexplained skin ulcers or poor wound-healing. We report the case of a 70-year-old man in whom diffuse erythema over the anterior chest wall and marked leukocytosis developed after coronary artery bypass grafting. This prompted débridement and opening of the sternotomy wound. The cause of the erythema was pyoderma gangrenosum that expressed the pathergy phenomenon. The pyoderma gangrenosum subsequently involved the saphenous vein harvest site, a chest-tube site, and a previously healed abdominal scar. The patient died when an exposed saphenous vein graft was perforated. To our knowledge, this is the 9th reported case of pathergy due to pyoderma gangrenosum after coronary artery bypass grafting and the first with a fatal outcome.

  14. Confirmation of a purple-leaved plum graft hybrid.

    PubMed

    Zhou, X M; Liu, Y S; Li, X J

    2013-03-11

    Fifty-seven scions from an adult purple-leaved plum tree were grafted onto the crown of a 6-year-old Yuhuang plum tree and compared to the control of a non-grafted tree. The floral buds of the purple-leaved plum were fully removed before blossoming to avoid sexual hybridization between the two species. The seeds of the Yuhuang plum were picked in July and sown in the spring after stratification. Three, eleven and eight variants with purplish red leaves were found among the seedlings that grew from the seeds picked in 1999, 2000, and 2001, respectively. The ratio of variant occurrence ranged from 2.3 to 15.8%. Our results confirmed the observation of a graft hybrid by Luther Burbank.

  15. Immobilized enzymes in blood plasma exchangers via radiation grafting

    NASA Astrophysics Data System (ADS)

    Gombotz, Wayne; Hoffman, Allan; Schmer, Gottfried; Uenoyama, Satoshi

    The enzyme asparaginase was immobilized onto a porous hollow polypropylene (PP) fiber blood plasma exchange device for the treatment of acute lymphocytic leukemia. The devices were first radiation grafted with polymethacrylic acid (poly(MAAc)). This introduces carboxyl groups onto the surface of the fibers. Several variables were studied in the grafting reaction including the effects of solvent type and monomer concentration. The carboxyl groups were activated with N-hydroxy succinimide (NHS) using carbodiimide chemistry. Asparaginase was then covalently immobilized on the activated surfaces. Quantitative relationships were found relating the percent graft to the amount of immobilized enzyme which was active. The enzyme reactor was tested both in vitro and in vivo using a sheep as an animal model.

  16. [Surface grafting modification and stabilization of Kevlar fiber].

    PubMed

    Zheng, Yu-ying; Fu, Ming-lian; Wang, Can-yao; Wang, Liang-en

    2005-11-01

    Chemical disposal was used to bring the activity group onto the surface of Kevlar fiber for the purpose of surface grafting modification. The interfacial constitution of the grafting of toluene-2,4-diisocyanate (TDI) onto Kevlar fiber was determined by Fourier transform infrared spectroscopy. In the mean time, hexyl-lactam stabilization and poly-glycol (400, PEG) stabilization on the grafted product were also studied. The effects of different nTDI:nPEG ratios on the production's interfacial constitution was analysed. It is concluded that the stabilization took place on the surface. The intensity of the bands relented at about 3300 cm(-1) and was reinforced at about 1700-1720 cm(-1) when the ratio of nTDI:nPEG = 1:3, but when the ratio is 1:1 and 1:2, the bands at about 3 300 and 1700-1720 cm(-1) are almost the same.

  17. Vanishing Venous Coronary Artery Bypass Grafts after Sepsis

    PubMed Central

    Park, Soo Jin; Park, Ji Ye; Jung, Joonho; Hong, You Sun; Lee, Cheol Joo; Lim, Sang Hyun

    2016-01-01

    The dehiscence of saphenous vein grafts (SVGs) is a rare, often fatal, complication of coronary artery bypass grafting (CABG). We present the case of a 57-year-old man who underwent hemiarch graft interposition and CABG for a Stanford type A aortic dissection. Five months after discharge, the patient developed streptococcal sepsis caused by a hemodialysis catheter. Complete rupture of the proximal anastomoses of the saphenous veins and containment by the obliterated pericardial cavity was observed 25 months after the initial operation. The patient was successfully treated surgically. This report describes a patient who developed potentially fatal dehiscence of SVGs secondary to infection and outlines preventive and management strategies for this complication. PMID:27734001

  18. Mechanical characterisation of Dacron graft: Experiments and numerical simulation.

    PubMed

    Bustos, Claudio A; García-Herrera, Claudio M; Celentano, Diego J

    2016-01-04

    Experimental and numerical analyses focused on the mechanical characterisation of a woven Dacron vascular graft are presented. To that end, uniaxial tensile tests under different orientations have been performed to study the anisotropic behaviour of the material. These tests have been used to adjust the parameters of a hyperelastic anisotropic constitutive model which is applied to predict through numerical simulation the mechanical response of this material in the ring tensile test. The obtained results show that the model used is capable of representing adequately the nonlinear elastic region and, in particular, it captures the progressive increase of the rigidity and the anisotropy due to the stretching of the Dacron. The importance of this research lies in the possibility of predicting the graft׳s mechanical response under generalized loading such as those that occur under physiological conditions after surgical procedures.

  19. Grafting of activated carbon cloths for selective adsorption

    NASA Astrophysics Data System (ADS)

    Gineys, M.; Benoit, R.; Cohaut, N.; Béguin, F.; Delpeux-Ouldriane, S.

    2016-05-01

    Chemical functionalization of an activated carbon cloth with 3-aminophthalic acid and 4-aminobenzoic acid groups by the in situ formation of the corresponding diazonium salt in aqueous acidic solution is reported. The nature and amount of selected functions on an activated carbon surface, in particular the grafted density, were determined by potentiometric titration, elemental analysis and X-ray photoelectron spectroscopy (XPS). The nanotextural properties of the modified carbon were explored by gas adsorption. Functionalized activated carbon cloth was obtained at a discrete grafting level while preserving interesting textural properties and a large porous volume. Finally, the grafting homogeneity of the carbon surface and the nature of the chemical bonding were investigated using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) technique.

  20. Intraoperative Analysis of Flow Dynamics in Arteriovenous Composite Y Grafts

    PubMed Central

    Lobo Filho, Heraldo Guedis; Lobo Filho, José Glauco; Pimentel, Matheus Duarte; Silva, Bruno Gadelha Bezerra; de Souza, Camylla Santos; Montenegro, Marília Leitão; Leitão, Maria Cláudia de Azevedo; Jamacuru, Francisco Vagnaldo Fechine

    2016-01-01

    Objective Composite graft of left internal thoracic artery and great saphenous vein in revascularization of the left coronary system is a technique well described in literature. The aim of this study is to analyze blood flow dynamics in this configuration of composite graft especially in what concerns left internal thoracic artery's adaptability and influence of great saphenous vein segment on left internal thoracic artery's flow. Methods Revascularization of left coronary system with composite graft, with left internal thoracic artery revascularizing the anterior interventricular artery and a great saphenous vein segment, anastomosed to the left internal thoracic artery, revascularizing another branch of the left coronary system, was performed in 23 patients. Blood flow was evaluated by transit time flowmetry in all segments of the composite graft (left internal thoracic artery proximal segment, left internal thoracic artery distal segment and great saphenous vein segment). Measures were performed in baseline condition and after dobutamine-induced stress, without and with non-traumatic temporary clamping of the distal segments of the composite graft. Results Pharmacological stress resulted in increase of blood flow values in the analyzed segments (P<0.05). Non-traumatic temporary clamping of great saphenous vein segment did not result in statistically significant changes in the flow of left internal thoracic artery distal segment, both in baseline condition and under pharmacological stress. Similarly, non-traumatic temporary clamping of left internal thoracic artery distal segment did not result in statistically significant changes in great saphenous vein segment flow. Conclusion Composite grafts with left internal thoracic artery and great saphenous vein for revascularization of left coronary system, resulted in blood flow dynamics with physiological adaptability, both at rest and after pharmacological stress, according to demand. Presence of great saphenous vein

  1. HDL Cholesterol Efflux Predicts Graft Failure in Renal Transplant Recipients

    PubMed Central

    Annema, Wijtske; Dikkers, Arne; Freark de Boer, Jan; Dullaart, Robin P. F.; Sanders, Jan-Stephan F.; Bakker, Stephan J. L.

    2016-01-01

    High-density lipoprotein (HDL) particles are involved in the protection against cardiovascular disease by promoting cholesterol efflux, in which accumulated cholesterol is removed from macrophage foam cells. We investigated whether HDL cholesterol efflux capacity is associated with cardiovascular mortality, all-cause mortality, and graft failure in a cohort of renal transplant recipients (n=495, median follow-up 7.0 years). Cholesterol efflux capacity at baseline was quantified using incubation of human macrophage foam cells with apolipoprotein B–depleted plasma. Baseline efflux capacity was not different in deceased patients and survivors (P=0.60 or P=0.50 for cardiovascular or all-cause mortality, respectively), whereas recipients developing graft failure had lower efflux capacity than those with functioning grafts (P<0.001). Kaplan–Meier analysis demonstrated a lower risk for graft failure (P=0.004) but not cardiovascular (P=0.30) or all-cause mortality (P=0.31) with increasing gender-stratified tertiles of efflux capacity. Cox regression analyses adjusted for age and gender showed that efflux capacity was not associated with cardiovascular mortality (hazard ratio [HR], 0.89; 95% confidence interval [95% CI], 0.67 to 1.19; P=0.43). Furthermore, the association between efflux capacity and all-cause mortality (HR, .79; 95% CI, 0.63 to 0.98; P=0.031) disappeared after further adjustment for potential confounders. However, efflux capacity at baseline significantly predicted graft failure (HR, 0.43; 95% CI, 0.29 to 0.64; P<0.001) independent of apolipoprotein A-I, HDL cholesterol, or creatinine clearance. In conclusion, this prospective study shows that cholesterol efflux capacity from macrophage foam cells is not associated with cardiovascular or all-cause mortality but is a strong predictor of graft failure independent of plasma HDL cholesterol levels in renal transplant recipients. PMID:26319244

  2. ARGET ATRP for versatile grafting of cellulose using various monomers.

    PubMed

    Hansson, Susanne; Ostmark, Emma; Carlmark, Anna; Malmström, Eva

    2009-11-01

    In recent years, cellulose-based materials have attracted significant attention. To broaden the application areas for cellulose, polymers are often grafted to/from the surface to modify its properties. This study applies ARGET (activators regenerated by electron transfer) ATRP (atom transfer radical polymerization) when straightforwardly grafting methyl methacrylate (MMA), styrene (St), and glycidyl methacrylate (GMA) from cellulose in the form of conventional filter paper in the presence of a sacrificial initiator. The free polymer, formed from the free initiator in parallel to the grafting, was characterized by (1)H NMR and SEC, showing that sufficient control is achieved. However, the analyses also indicated that the propagation from the surface cannot be neglected compared to the propagation of the free polymer at higher targeted molecular weights, which is an assumption often made. The grafted filter papers were evaluated with FT-IR, suggesting that the amount of polymer on the surface increased with increasing monomer conversion, which the FE-SEM micrographs of the substrates also demonstrated. Water contact angle (CA) measurements implied that covering layers of PMMA and PS were formed on the cellulose substrate, making the surface hydrophobic, in spite of low DPs. The CA of the PGMA-grafted filter papers revealed that, by utilizing either aprotic or protic solvents when washing the substrates, it was possible to either preserve or hydrolyze the epoxy groups. Independent of the solvent used, all grafted filter papers were essentially colorless after the washing procedure because of the low amount of copper required when performing ARGET ATRP. Nevertheless, surface modification of cellulose via ARGET ATRP truly facilitates the manufacturing since no thorough freeze-thaw degassing procedures are required.

  3. Magnetizable stent-grafts enable endothelial cell capture

    NASA Astrophysics Data System (ADS)

    Tefft, Brandon J.; Uthamaraj, Susheil; Harburn, J. Jonathan; Hlinomaz, Ota; Lerman, Amir; Dragomir-Daescu, Dan; Sandhu, Gurpreet S.

    2017-04-01

    Emerging nanotechnologies have enabled the use of magnetic forces to guide the movement of magnetically-labeled cells, drugs, and other therapeutic agents. Endothelial cells labeled with superparamagnetic iron oxide nanoparticles (SPION) have previously been captured on the surface of magnetizable 2205 duplex stainless steel stents in a porcine coronary implantation model. Recently, we have coated these stents with electrospun polyurethane nanofibers to fabricate prototype stent-grafts. Facilitated endothelialization may help improve the healing of arteries treated with stent-grafts, reduce the risk of thrombosis and restenosis, and enable small-caliber applications. When placed in a SPION-labeled endothelial cell suspension in the presence of an external magnetic field, magnetized stent-grafts successfully captured cells to the surface regions adjacent to the stent struts. Implantation within the coronary circulation of pigs (n=13) followed immediately by SPION-labeled autologous endothelial cell delivery resulted in widely patent devices with a thin, uniform neointima and no signs of thrombosis or inflammation at 7 days. Furthermore, the magnetized stent-grafts successfully captured and retained SPION-labeled endothelial cells to select regions adjacent to stent struts and between stent struts, whereas the non-magnetized control stent-grafts did not. Early results with these prototype devices are encouraging and further refinements will be necessary in order to achieve more uniform cell capture and complete endothelialization. Once optimized, this approach may lead to more rapid and complete healing of vascular stent-grafts with a concomitant improvement in long-term device performance.

  4. Noninvasive imaging of islet grafts using positron-emission tomography

    NASA Astrophysics Data System (ADS)

    Lu, Yuxin; Dang, Hoa; Middleton, Blake; Zhang, Zesong; Washburn, Lorraine; Stout, David B.; Campbell-Thompson, Martha; Atkinson, Mark A.; Phelps, Michael; Gambhir, Sanjiv Sam; Tian, Jide; Kaufman, Daniel L.

    2006-07-01

    Islet transplantation offers a potential therapy to restore glucose homeostasis in type 1 diabetes patients. However, islet transplantation is not routinely successful because most islet recipients gradually lose graft function. Furthermore, serological markers of islet function are insensitive to islet loss until the latter stages of islet graft rejection. A noninvasive method of monitoring islet grafts would aid in the assessment of islet graft survival and the evaluation of interventions designed to prolong graft survival. Here, we show that recombinant adenovirus can engineer isolated islets to express a positron-emission tomography (PET) reporter gene and that these islets can be repeatedly imaged by using microPET after transplantation into mice. The magnitude of signal from engineered islets implanted into the axillary cavity was directly related to the implanted islet mass. PET signals attenuated over the following weeks because of the transient nature of adenovirus-mediated gene expression. Because the liver is the preferred site for islet implantation in humans, we also tested whether islets could be imaged after transfusion into the mouse liver. Control studies revealed that both intrahepatic islet transplantation and hyperglycemia altered the biodistribution kinetics of the PET probe systemically. Although transplanted islets were dispersed throughout the liver, clear signals from the liver region of mice receiving PET reporter-expressing islets were detectable for several weeks. Viral transduction, PET reporter expression, and repeated microPET imaging had no apparent deleterious effects on islet function after implantation. These studies lay a foundation for noninvasive quantitative assessments of islet graft survival using PET. diabetes | transplantation

  5. Hyperbaric Oxygen Therapy for the Compromised Graft or Flap

    PubMed Central

    Francis, Ashish; Baynosa, Richard C.

    2017-01-01

    Significance: Tissue grafts and flaps are used to reconstruct wounds from trauma, chronic disease, tumor extirpation, burns, and infection. Despite careful surgical planning and execution, reconstructive failure can occur due to poor wound beds, radiation, random flap necrosis, vascular insufficiency, or ischemia–reperfusion (IR). Traumatic avulsions and amputated composite tissues—compromised tissue—may fail from crush injury and excessively large sizes. While never intended, these complications result in tissue loss, additional surgery, accrued costs, and negative psychosocial patient effects. Recent Advances: Hyperbaric oxygen (HBO) has demonstrated utility in the salvage of compromised grafts/flaps. It can increase the likelihood and effective size of composite graft survival, improve skin graft outcomes, and enhance flap survival. Mechanisms underlying these beneficial effects include increased oxygenation, improved fibroblast function, neovascularization, and amelioration of IR injury. Critical Issues: Common strategies for the compromised graft or flap include local wound care, surgical debridement, and repeated reconstruction. These modalities are associated with added costs, time, need for reoperation, morbidity, and psychosocial effects. Preservation of the amputated/avulsed tissues minimizes morbidity and maximizes the reconstructive outcome by salvaging the compromised tissue and obviating additional surgery. HBO is often overlooked as a potential tool that can limit these issues. Future Directions: Animal studies demonstrate a benefit of HBO in the treatment of compromised tissues. Clinical studies support these findings, but are limited to case reports and series. Further research is needed to provide multicenter prospective clinical studies and cost analyses comparing HBO to other adjunctive therapies in the treatment of compromised grafts/flaps. PMID:28116225

  6. Outcomes utilizing imported liver grafts for recipients with hepatocellular carcinoma.

    PubMed

    Battula, Narendra; Reichman, Trevor W; Amiri, Yamah; Carmody, Ian C; Galliano, Gretchen; Seal, John; Bugeaud, Emily; Bohorquez, Humberto; Bruce, David; Cohen, Ari; Loss, George E

    2017-03-01

    Liver transplantation (LT) offers the best chance of survival in selected patients with hepatocellular carcinoma (HCC). Wait-list mortality or dropout due to tumor progression can be significant, and therefore, timely transplantation is critical. Liver grafts discarded by outside organ procurement organizations are a potential source of grafts for low Model for End-Stage Liver Disease tumor patients. The primary aim of this study was to assess the disease-free and overall survival of patients with HCC transplanted with imported liver grafts (ILGs). Review of all patients transplanted for HCC between June 2005 and December 2014 was performed. Data on demographics, survival, and HCC recurrence were analyzed. During this time period, 59 out of 190 (31%) recipients with HCC received ILG. Of these 59 grafts, 54 were imported from within the region and 5 were from national offers (outside the region). The mean cold ischemia time for local liver grafts (LLGs) was 4.1 ± 1.5 hours versus 5.1 ± 1.4 hours for ILG (P < 0.001). The 1-, 3-, and 5-year patient survival was 90%, 85%, and 83% and 85%, 80%, and 79% for LLG and ILG (P = 0.08), respectively. The observed disease recurrence rate for both LLG and ILG recipients was equivalent. The median wait-list time for HCC recipients was 43 days (range, 2-1167 days). In conclusion, with careful graft assessment, the use of ILGs results in comparable outcomes following LT and no increased risk of HCC recurrence. Use of ILGs maximizes the donor pool and results in a higher rate of transplantation for HCC recipients. Liver Transplantation 23 299-304 2017 AASLD.

  7. Spontaneous grafting of diazonium salts: chemical mechanism on metallic surfaces.

    PubMed

    Mesnage, Alice; Lefèvre, Xavier; Jégou, Pascale; Deniau, Guy; Palacin, Serge

    2012-08-14

    The spontaneous reaction of diazonium salts on various substrates has been widely employed since it consists of a simple immersion of the substrate in the diazonium salt solution. As electrochemical processes involving the same diazonium salts, the spontaneous grafting is assumed to give covalently poly(phenylene)-like bonded films. Resistance to solvents and to ultrasonication is commonly accepted as indirect proof of the existence of a covalent bond. However, the most relevant attempts to demonstrate a metal-C interface bond have been obtained by an XPS investigation of spontaneously grafted films on copper. Similarly, our experiments give evidence of such a bond in spontaneously grafted films on nickel substrates in acetonitrile. In the case of gold substrates, the formation of a spontaneous film was unexpected but reported in the literature in parallel to our observations. Even if no interfacial bond was observed, formation of the films was explained by grafting of aryl cations or radicals on the surface arising from dediazoniation, the film growing later by azo coupling, radical addition, or cationic addition on the grafted phenyl layer. Nevertheless, none of these mechanisms fits our experimental results showing the presence of an Au-N bond. In this work, we present a fine spectroscopic analysis of the coatings obtained on gold and nickel substrates that allow us to propose a chemical structure of such films, in particular, their interface with the substrates. After testing the most probable mechanisms, we have concluded in favor of the involvement of two complementary mechanisms which are the direct reaction of diazonium salts with the gold surface that accounts for the observed Au-N interfacial bonds as well as the formation of aryl cations able to graft on the substrate through Au-C linkages.

  8. The "stegosaurus" dressing: a simple and effective method of securing skin grafts in the burn patient.

    PubMed

    Fullerton, J K; Smith, C E; Milner, S M

    2000-10-01

    Skin grafts are vulnerable to shear stress, infection, and hematoma formation during the postoperative period, all of which reduce graft survival. Various methods of dressing application and materials have been described in the literature to try and prevent graft loss. The authors report the use of the "stegosaurus dressing" (Eggcrate Pad) in 6 patients to secure skin grafts. Patients chosen were those who were either noncompliant or who sustained burns in unfavorable anatomic sites. All grafts demonstrated complete take without infection and hematoma formation. This foam dressing provides an even pressure to the recipient bed, absorbs drainage, and protects the graft from shearing. It also demonstrates the versatility to be used in difficult nonburn skin graft areas. The stegosaurus dressing is easy to apply, inexpensive, and provides a very secure dressing over the skin graft.

  9. Tissue engineering of acellular vascular grafts capable of somatic growth in young lambs

    PubMed Central

    Syedain, Zeeshan; Reimer, Jay; Lahti, Matthew; Berry, James; Johnson, Sandra; Bianco, Richard; Tranquillo, Robert T.

    2016-01-01

    Treatment of congenital heart defects in children requiring right ventricular outflow tract reconstruction typically involves multiple open-heart surgeries because all existing graft materials have no growth potential. Here we present an ‘off-the-shelf' vascular graft grown from donor fibroblasts in a fibrin gel to address this critical unmet need. In a proof-of-concept study, the decellularized grafts are implanted as a pulmonary artery replacement in three young lambs and evaluated to adulthood. Longitudinal ultrasounds document dimensional growth of the grafts. The lambs show normal growth, increasing body weight by 366% and graft diameter and volume by 56% and 216%, respectively. Explanted grafts display physiological strength and stiffness, complete lumen endothelialization and extensive population by mature smooth muscle cells. The grafts also show substantial elastin deposition and a 465% increase in collagen content, without signs of calcification, aneurysm or stenosis. Collectively, our data support somatic growth of this completely biological graft. PMID:27676438

  10. Late pseudocoarctation syndrome after stent-graft implantation for traumatic aortic rupture.

    PubMed

    Letocart, Vincent; Fau, Georges; Tirouvanziam, Ashok; Toquet, Claire; Al Habash, Oussama; Guerin, Patrice; Rousseau, Hervé; Crochet, Dominique

    2013-06-01

    The present observation illustrates an unusual complication occurring after stent-grafting (S-graft) for aortic isthmus rupture. A 22-year-old patient, treated by S-graft in the emergency department for traumatic aortic rupture, was readmitted 10 months later with pseudocoarctation syndrome. A membrane was found inside the stent-graft that had induced a pseudo-dissection, which caused the pseudocoarctation syndrome. Surgical treatment consisted of removing the stent-graft and membrane and replacing it with a vascular implant. The patient's clinical course was fair. The suggested mechanism was circumferential neoendothelialization of the stent-graft. Dehiscence caused the superior part of the membrane to drop into the lumen of the stent-graft creating a "false channel" that compressed the "true lumen" and induced "pseudocoarctation" syndrome. The cause of the extensive neointimalization remains unexplained. Thoracic aortic stent-grafts require regular follow-up monitoring by angioscan or angio-magnetic resonance imaging.

  11. Cellulose functionalization via high-energy irradiation-initiated grafting of glycidyl methacrylate and cyclodextrin immobilization

    NASA Astrophysics Data System (ADS)

    Desmet, Gilles; Takács, Erzsébet; Wojnárovits, László; Borsa, Judit

    2011-12-01

    Cotton-cellulose was functionalized using gamma-irradiation-induced grafting of glycidyl methacrylate (GMA) to obtain a hydrophobic cellulose derivative with epoxy groups suitable for further chemical modification. Two grafting techniques were applied. In pre-irradiation grafting (PIG) cellulose was irradiated in air and then immersed in a GMA monomer solution, whereas in simultaneous grafting (SG) cellulose was irradiated in an inert atmosphere in the presence of the monomer. PIG led to a more homogeneous fiber surface, while SG resulted in higher grafting yield but showed clear indications of some GMA-homopolymerization. Effects of the reaction parameters (grafting method, absorbed dose, monomer concentration, solvent composition) were evaluated by SEM, gravimetry (grafting yield) and FTIR spectroscopy. Water uptake of the cellulose decreased while adsorption of a pesticide molecule increased upon grafting. The adsorption was further enhanced by β-cyclodextrin immobilization during SG. This method can be applied to produce adsorbents from cellulose based agricultural wastes.

  12. Correlation between Density and Resorption of Fresh-Frozen and Autogenous Bone Grafts

    PubMed Central

    Manfredi, Edoardo; Consolo, Ugo; Marchetti, Claudio; Bonanini, Mauro; Salgarelli, Attilio; Macaluso, Guido M.

    2014-01-01

    Trial Design. This analysis compared the outcome of fresh-frozen versus autologous bone block grafts for horizontal ridge augmentation in patients with Cawood and Howell class IV atrophies. Methods. Seventeen patients received autologous grafts and 21 patients received fresh-frozen bone grafts. Patients underwent CT scans 1 week and 6 months after surgery for graft volume and density analysis. Results. Two autologous and 3 fresh-frozen grafts failed. Autologous and fresh-frozen grafts lost, respectively, 28% and 46% of their initial volume (P = 0.028). It is noteworthy that less dense fresh-frozen blocks lost more volume than denser grafts (61% versus 16%). Conclusions. According to these 6-month results, only denser fresh-frozen bone graft may be an acceptable alternative to autologous bone for horizontal ridge augmentation. Further studies are needed to investigate its behaviour at longer time points. PMID:25050354

  13. Late Pseudocoarctation Syndrome After Stent-Graft Implantation For Traumatic Aortic Rupture

    SciTech Connect

    Letocart, Vincent Fau, Georges Tirouvanziam, Ashok; Toquet, Claire; Al Habash, Oussama Guerin, Patrice; Rousseau, Herve; Crochet, Dominique

    2013-06-15

    The present observation illustrates an unusual complication occurring after stent-grafting (S-graft) for aortic isthmus rupture. A 22-year-old patient, treated by S-graft in the emergency department for traumatic aortic rupture, was readmitted 10 months later with pseudocoarctation syndrome. A membrane was found inside the stent-graft that had induced a pseudo-dissection, which caused the pseudocoarctation syndrome. Surgical treatment consisted of removing the stent-graft and membrane and replacing it with a vascular implant. The patient's clinical course was fair. The suggested mechanism was circumferential neoendothelialization of the stent-graft. Dehiscence caused the superior part of the membrane to drop into the lumen of the stent-graft creating a 'false channel' that compressed the 'true lumen' and induced 'pseudocoarctation' syndrome. The cause of the extensive neointimalization remains unexplained. Thoracic aortic stent-grafts require regular follow-up monitoring by angioscan or angio-magnetic resonance imaging.

  14. The influence of stenosis degrees and graft suture position on local hemodynamics of coronary bypass

    NASA Astrophysics Data System (ADS)

    Totorean, A. F.; Bernad, S. I.; Susan-Resiga, R. F.

    2016-06-01

    Bypass graft failure is mainly caused by intimal hyperplasia (IH) that occurs at the graft anastomosis after coronary artery bypass grafting (CABG) surgery. It has been shown that local hemodynamics influences the process of IH initiation and progression. A main concern at this type of surgery is to increase the graft patency, respectively to improve the local hemodynamics. This paper analyzes the influence of different degree of stenosis severity and graft suture position on graft patency, taking into consideration the local hemodynamics. Bypass configurations with anastomosis angle of 45° were numerically investigated, with respect to wall shear stress and pressure variation. We can assume that in the conditions of our study, different stenosis degrees and position of the graft suture influence the local blood flow conditions, and, nevertheless, the graft patency.

  15. Hydrophobic modification of cellulose isolated from Agave angustifolia fibre by graft copolymerisation using methyl methacrylate.

    PubMed

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan; Mohamed, Faizal

    2015-07-10

    Graft copolymerisation of methyl methacrylate (MMA) onto Agave angustifolia was conducted with ceric ammonium nitrate (CAN) as the redox initiator. The maximum grafting efficiency was observed at CAN and MMA concentrations of 0.91 × 10(-3) and 5.63 × 10(-2)M, respectively, at 45°C for 3h reaction time. Four characteristic peaks at 2995, 1738, 1440, and 845 cm(-1), attributed to PMMA, were found in the IR spectrum of grafted cellulose. The crystallinity index dropped from 0.74 to 0.46, while the thermal stability improved upon grafting. The water contact angle increased with grafting yield, indicating increased hydrophobicity of cellulose. SEM images showed the grafted cellulose to be enlarged and rougher. The changes in the physical nature of PMMA-grafted cellulose can be attributed to the PMMA grafting in the amorphous regions of cellulose, causing it to expand at the expense of the crystalline component.

  16. Wolfe's part in the Italian Risorgimento and his skin graft.

    PubMed

    Sykes, Philip J

    2012-09-01

    A little known episode in the history of plastic surgery occurred during the Italian Risorgimento 150 years ago. Dr. J. R. Wolfe, who described the full-thickness graft which bears his name, was involved with Garibaldi in the war to unite Italy. He crossed swords with an English nurse, Jessie White Mario, and was thrown into prison. The events were recorded in the Lancet as "A Neapolitan Outrage." This article gives the details of the sad story and goes on to describe the first attempts at full-thickness grafting to correct ectropion. Wolfe was not the first to carry out this procedure and the name of Lawson is rarely remembered.

  17. VUV modification promotes endothelial cell proliferation on PTFE vascular grafts

    NASA Astrophysics Data System (ADS)

    Cezeaux, J. L.; Romoser, C. E.; Benson, R. S.; Buck, C. K.; Sackman, J. E.

    1998-05-01

    Small diameter (⩽6 mm ID ) synthetic vascular grafts, used as lower-limb vessel replacements in patients without suitable autologous saphenous veins, have a failure rate of 53% after 4 yr. Graft failure is due to thrombosis and intimal hyperplasia, an increase in smooth muscle cells in the lumen of the vessel which leads to progressive closing and ultimate occlusion of the vessel. In an effort to increase patency rates of synthetic grafts, investigators have seeded vascular grafts with endothelial cells prior to implantation in an attempt to control both thrombosis and smooth muscle proliferation. This technique has been successful for the development of an endothelial monolayer in animal trials, but has met with limited success in humans. The hydrophobicity, low surface energy, and weak electrical charge of expanded polytetrafluoroethylene (ePTFE) provides conditions which are not optimal for endothelial cell attachment. The purpose of this study is to evaluate the effect of vacuum ultraviolet (VUV) modification of ePTFE on endothelial cell adhesion and proliferation. Pieces of ePTFE graft material were exposed to 10, 20 or 40 W VUV radiation for 10, 20 or 40 min using a UV excimer lamp. Prior to cell adhesion and proliferation experiments, the grafts pieces were autoclaved and cut into pledgets. Half of the pledgets were precoated with fibronectin ( 20 μg/ml). Cell adhesion was measured by seeding 3H-thymidine labeled human umbilical vein endothelial cells (HUVEC) onto the pledgets for 60 min. The pledgets were then washed and the remaining radioactivity assayed using scintillation counting. For the cell proliferation experiments, pledgets were seeded with unlabeled HUVEC which were allowed to adhere to the graft material for 18 h. The cells were then exposed to 3H-thymidine ( 1 μCi/ml) for approximately 48 h and then washed to remove any unincorporated 3H-thymidine. Incorporation of 3H-thymidine was measured using scintillation counting. Four replicate

  18. Fractional CO2 laser treatment for a skin graft.

    PubMed

    Stephan, Farid E; Habre, Maya B; Helou, Josiane F; Tohme, Roland G; Tomb, Roland R

    2016-01-01

    Skin grafts are widely used in reconstructive and plastic surgery, leaving an inevitable scar appearance on the body, affecting the quality of life of the patients. Fractional ablative lasers have become a leading procedure for the treatment of acne and burn scars. We report a case of a skin graft showing excellent improvement in overall appearance after three sessions of fractional CO2 laser. The undamaged tissue left between the microthermal treatment zones is responsible of collagen formation and reepithelialization. Remodeling and collagen formation are observed even 6 months after a fractional CO2 laser session.

  19. Spreader graft in closed rhinoplasty: the "rail spreader".

    PubMed

    Scattolin, Alberto; Orlando, Niana; D'Ascanio, Luca

    2013-12-01

    Spreader grafts (SGs) have been widely used for both aesthetic and functional reasons to prevent middle vault collapse and treat internal nasal valve insufficiency. Although SG precise fixation can be easily achieved in open rhinoplasty, the difficulties of SG placement in closed rhinoplasties can be discouraging. In the present report, we describe a new custom-made SG (called "rail spreader") and the personal easy method of application of such graft in "endonasal" rhinoplasty. The technical details and results are reported along with the advantages of our technique over previously described approaches.

  20. Anatomic changes due to interspecific grafting in cassava (Manihot esculenta).

    PubMed

    Bomfim, N; Ribeiro, D G; Nassar, N M A

    2011-05-31

    Cassava rootstocks of varieties UnB 201 and UnB 122 grafted with scions of Manihot fortalezensis were prepared for anatomic study. The roots were cut, stained with safranin and alcian blue, and examined microscopically, comparing them with sections taken from ungrafted roots. There was a significant decrease in number of pericyclic fibers, vascular vessels and tyloses in rootstocks. They exhibited significant larger vessels. These changes in anatomic structure are a consequence of genetic effects caused by transference of genetic material from scion to rootstock. The same ungrafted species was compared. This is the first report on anatomic changes due to grafting in cassava.

  1. EVOLUTION AND EVALUATION OF AUTOLOGOUS MINI PUNCH GRAFTING IN VITILIGO

    PubMed Central

    Lahiri, Koushik

    2009-01-01

    Vitiligo is a result of disrupted epidermal melanization with an undecided etiology and incompletely understood pathogenesis. Various treatment options have resulted in various degrees of success. Various surgical modalities and transplantation techniques have evolved during the last few decades. Of them, miniature punch grafting (PG) has established its place as the easiest, fastest, and least expensive method. Various aspects of this particular procedure have been discussed here. The historical perspective, the instruments, evolution of mini grafting down the ages, and the methodology, advantages, and disadvantages have been discussed. A detailed discussion on the topic along with a review of relevant literature has been provided in this article. PMID:20101312

  2. Techniques and standards in intraoperative graft verification by transit time flow measurement after coronary artery bypass graft surgery: a critical review.

    PubMed

    Niclauss, Lars

    2017-01-01

    Transit time flow measurement (TTFM) is a quality control tool for intraoperative graft evaluation in coronary artery bypass graft (CABG) surgery. A critical review of the literature available using TTFM in CABG surgery is the focus of this article. The main objectives will be to detail precise parameters for flow evaluation, to show limitations of TTFM and to prove its predictive impact on postoperative graft failure rate. Publications listed in the PubMed database were reviewed, searching for intraoperative graft verification in coronary surgery by TTFM, with postoperative imaging follow-up (FU) modality and with a special focus on publications released after European guidelines from 2010. Nine included publications revealed an overall graft failure rate of ∼12%. Mean graft flow had a positive predictive value in the largest study, and cut-offs, of at least 20 ml/min for internal mammary artery (IMA) grafts, therein partially confirming guidelines, and 30-40 ml/min for saphenous venous grafts (SVGs) were proposed. An explicit correlation between graft flow, patency rate and severity of coronary stenosis, by indicating the fractional flow reserve, was found for IMA grafts. Increased pulsatility index and increased systolic reverse flow probably predict worse outcome and may help identifying competitive flow. Diastolic filling, rarely indicated, could not be confirmed as the predictive marker. No significant correlation of TTFM and graft failure rate for radial and other arterial grafts could be found, partially due to the small number of these types of grafts analysed. Larger target vessels and lower postoperative CK-MB levels may predict better graft patency rates. Low sensitivity for TTFM to reliably detect graft failure is certainly a major issue, as found in randomized analyses. However, methodical limitations and varying threshold values for TTFM render a general consensus difficult. Influence of quantity (vessel territory distribution) and quality

  3. Platelet adhesion, contact phase coagulation activation, and C5a generation of polyethylene glycol acid-grafted high flux cellulosic membrane with varieties of grafting amounts.

    PubMed

    Fushimi, F; Nakayama, M; Nishimura, K; Hiyoshi, T

    1998-10-01

    Grafting of polyethylene glycol chains onto cellulosic membrane can be expected to reduce the interaction between blood (plasma protein and cells) and the membrane surface. Alkylether carboxylic acid (PEG acid) grafted high flux cellulosic membranes for hemodialysis, in which the polyethylene glycol chain bears an alkyl group at one side and a carboxyl group at the other side, have been developed and evaluated. PEG acid-grafted high flux cellulosic membranes with various grafting amounts have been compared with respect to platelet adhesion, the contact phase of blood coagulation, and complement activation in vitro. A new method of quantitating platelet adhesion on hollow-fiber membrane surfaces has been developed, which is based on the determination of lactate dehydrogenase (LDH) activity after lysis of the adhered platelets. PEG acid-grafted high flux cellulosic membranes showed reduced platelet adhesion and complement activation effects in grafting amounts of 200 ppm or higher without detecting adverse effects up to grafting amounts of 850 ppm. The platelet adhesion of a PEG acid-grafted cellulosic membrane depends on both the flux and grafting amounts of the membrane. It is concluded that the grafting of PEG acid onto a cellulosic membrane improves its biocompatibility as evaluated in terms of platelet adhesion, complement activation, and thrombogenicity.

  4. Study on chemical, UV and gamma radiation-induced grafting of 2-hydroxyethyl methacrylate onto chitosan

    NASA Astrophysics Data System (ADS)

    Casimiro, M. H.; Botelho, M. L.; Leal, J. P.; Gil, M. H.

    2005-04-01

    In the present study, 2-hydroxyethyl methacrylate has been grafted onto chitosan by using either chemical initiation, or photo-induction or gamma radiation-induced polymerisation, all under heterogeneous conditions. The evidence of grafting was provided by Fourier transform infrared spectroscopy and thermal analysis. The results concerning the effect of initiator concentration, initial monomer concentration and dose rate influencing on the yield of grafting reactions are presented. These suggest that gamma irradiation is the method that leads to higher yields of grafting.

  5. Cutaneous graft-versus-host disease after hematopoietic stem cell transplant - a review*

    PubMed Central

    Villarreal, Cesar Daniel Villarreal; Alanis, Julio Cesar Salas; Pérez, Jose Carlos Jaime; Candiani, Jorge Ocampo

    2016-01-01

    Graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic stem cell transplants (allo-HSCT) associated with significant morbidity and mortality. The earliest and most common manifestation is cutaneous graft-versus-host disease. This review focuses on the pathophysiology, clinical features, prevention and treatment of cutaneous graft-versus-host disease. We discuss various insights into the disease's mechanisms and the different treatments for acute and chronic skin graft-versus-host disease. PMID:27438202

  6. Distal end side-to-side anastomoses of sequential vein graft to small target coronary arteries improve intraoperative graft flow

    PubMed Central

    2014-01-01

    Background End-to-side anastomoses to connect the distal end of the great saphenous vein (GSV) to small target coronary arteries are commonly performed in sequential coronary artery bypass grafting (CABG). However, the oversize diameter ratio between the GSV and small target vessels at end-to-side anastomoses might induce adverse hemodynamic condition. The purpose of this study was to describe a distal end side-to-side anastomosis technique and retrospectively compare the effect of distal end side-to-side versus end-to-side anastomosis on graft flow characteristics. Methods We performed side-to-side anastomoses to connect the distal end of the GSV to small target vessels on 30 patients undergoing off-pump sequential CABG in our hospital between October 2012 and July 2013. Among the 30 patients, end-to-side anastomoses at the distal end of the GSV were initially performed on 14 patients; however, due to poor graft flow, those anastomoses were revised into side-to-side anastomoses. We retrospectively compared the intraoperative graft flow characteristics of the end-to-side versus side-to-side anastomoses in the 14 patients. The patient outcomes were also evaluated. Results We found that the side-to-side anastomosis reconstruction improved intraoperative flow and reduced pulsatility index in all the 14 patients significantly. The 16 patients who had the distal end side-to-side anastomoses performed directly also exhibited satisfactory intraoperative graft flow. Three-month postoperative outcomes for all the patients were satisfactory. Conclusions Side-to-side anastomosis at the distal end of sequential vein grafts might be a promising strategy to connect small target coronary arteries to the GSV. PMID:24884776

  7. Autologous Fat Grafting for Treating Blepharoplasty-induced Lower Eyelid Retraction

    PubMed Central

    Bernardini, Francesco P.; Fezza, John; Hartstein, Morris E.

    2016-01-01

    Summary: Autologous fat grafting for blepharoplasty-induced lower eyelid retraction offers potential for a long-term solution while avoiding the morbidity associated with posterior lamellar spacer grafts. By combining traditional methods of lifting the retracted lower eyelid with autologous fat grafting, both functional and aesthetic concerns can be successfully addressed in these patients. PMID:28293531

  8. Structure-function properties of starch spherulites grafted with poly(methyl acrylate)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spherulites, produced by steam jet-cooking high-amylose starch and oleic acid, were grafted with methyl acrylate, both before and after removal of un-complexed amylopectin. For comparison, granular high-amylose corn starch was graft polymerized in a similar manner. The amount of grafted and ungrafte...

  9. Structure-function properties of starch graft poly(methyl acrylate)copolymers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spherulites, produced by steam jet-cooking high-amylose starch and oleic acid, were grafted with methyl acrylate, both before and after removal of un-complexed amylopectin. For comparison, granular high-amylose corn starch was graft polymerized in a similar manner. The amount of grafted and ungrafte...

  10. Effect of Graft Material on Red Blood Cell Loss Following Aortic Surgery

    DTIC Science & Technology

    2007-11-02

    PTFE (Gore-Tex) grafts. A total of 25 patients (13 Dacron, 12 PTFE) were studied including 21 with abdominal aortic aneurysms , and 4 with aorto-iliac...It has been suggested that red blood cell loss after abdominal aortic grafting is influenced by the type of synthetic graft used. A prospective

  11. Traumatic pseudoaneurysm of left internal mammary artery graft.

    PubMed

    Agathos, E A; Hussein, A; Trehan, H; Trenholme, S E; Floten, H S

    1993-10-01

    Traumatic pseudoaneurysm of the left internal mammary artery was recognized as a possible causal factor in the early recurrence of angina in a 51-year-old man. This patient underwent reoperation for revascularization with the left internal mammary artery graft in situ.

  12. Bifunctional mesoporous silicas with clearly distinguished localization of grafted groups

    NASA Astrophysics Data System (ADS)

    Roik, N. V.; Belyakova, L. A.

    2013-12-01

    Bifunctional mesoporous silicas with clearly distinguished localization of grafted groups on the surface of particles and inside their pores were obtained by means of sol-gel synthesis with postsynthetic vapor-phase treatment in vacuum. It was found that the synthesized materials have the hexagonally ordered porous structure typical of MCM-41 type silica.

  13. Grafting of Conductive Polymers onto the Functionalized Carbon Nanotubes

    DTIC Science & Technology

    2010-08-23

    2,5- benzimidazole )/carbon nanotube composite film” Journal of Polymer Science, Part A: Polymer Chemistry 2010, 48, 1067. 3. Han, S.-W.; Oh, S.-J...34Synthesis and Characterization of poly(2,5- benzimidazole ) (ABPBI) Grafted CArbon Nanotubes." MRS. 2009 fall meeting, Prepr. Boston, MA, November 30

  14. Sinusfloor elevation and grafting with autogenous iliac crest bone.

    PubMed

    van den Bergh, J P; ten Bruggenkate, C M; Krekeler, G; Tuinzing, D B

    1998-12-01

    Insufficient bone height in the posterior area of the maxilla, due to expansion of the maxillary sinus and atrophic reduction of the alveolar process of the maxilla, represents a contra-indication for insertion of dental implants. This anatomic problem can, in many cases, be solved by augmentation of the floor of the maxillary sinus. This surgical technique was introduced by Tatum. The so-called top hinge door method creates a new floor of the maxillary sinus at a more cranial level. Underneath this new floor the existing space is filled with a bone graft. Implantation in the alveolar process with increased bone height allows insertion of dental implants. This sinus grafting technique was used in the present study. In total, 62 sinusfloor elevations were performed with cancellous iliac bone grafts in 42 patients. In those 62 augmented sinuses, 161 ITI screw type implants were inserted. The follow-up was 1-6 years after implantation. In 2 cases infections occurred. One implant needed an extended integration time. No implants were lost. The ITI solid screw implant appears to be a suitable implant following sinusfloor elevation operations, due to its rough surface, its shape and the size of the thread. The sinusfloor elevation procedure with autogenous cancellous bone graft appears to be a valuable and reliable pre-implantological procedure, provided a proper pre-operative investigation and careful surgery are performed. This procedure allows dental implant placement with a high success rate.

  15. A Perspective: Engineering Periosteum for Structural Bone Graft Healing

    PubMed Central

    Awad, Hani A.; O’Keefe, Regis J.; Guldberg, Robert E.; Schwarz, Edward M.

    2008-01-01

    Autograft is superior to both allograft and synthetic bone graft in repair of large structural bone defect largely due to the presence of multipotent mesenchymal stem cells in periosteum. Recent studies have provided further evidence that activation, expansion and differentiation of the donor periosteal progenitor cells are essential for the initiation of osteogenesis and angiogenesis of donor bone graft healing. The formation of donor cell-derived periosteal callus enables efficient host-dependent graft repair and remodeling at the later stage of healing. Removal of periosteum from bone autograft markedly impairs healing whereas engraftment of multipotent mesenchymal stem cells on bone allograft improves healing and graft incorporation. These studies provide rationale for fabrication of a biomimetic periosteum substitute that could fit bone of any size and shape for enhanced allograft healing and repair. The success of such an approach will depend on further understanding of the molecular signals that control inflammation, cellular recruitment as well as mesenchymal stem cell differentiation and expansion during the early phase of the repair process. It will also depend on multidisciplinary collaborations between biologists, material scientists and bioengineers to address issues of material selection and modification, biological and biomechanical parameters for functional evaluation of bone allograft healing. PMID:18509709

  16. Polyhedral oligomeric silsesquioxane grafted polymer in polymeric foam

    DOEpatents

    King, Bruce A.; Patankar, Kshitish A.; Costeux, Stephane; Jeon, Hyun K.

    2017-01-17

    A polymeric foam article with a polymer matrix defining multiple cells therein has a polymer component with a first polymer that is a polyhedral oligomeric silsesquioxane grafted polymer that has a weight-average molecular weight of two kilograms per mole or higher and 200 kilograms per mole or lower.

  17. Implantation of Inferior Vena Cava Interposition Graft in Mouse Model

    PubMed Central

    Lee, Yong-Ung; Yi, Tai; Tara, Shuhei; Lee, Avione Y.; Hibino, Narutoshi; Shinoka, Toshiharu; Breuer, Christopher K.

    2014-01-01

    Biodegradable scaffolds seeded with bone marrow mononuclear cells (BMCs) are often used for reconstructive surgery to treat congenital cardiac anomalies. The long-term clinical results showed excellent patency rates, however, with significant incidence of stenosis. To investigate the cellular and molecular mechanisms of vascular neotissue formation and prevent stenosis development in tissue engineered vascular grafts (TEVGs), we developed a mouse model of the graft with approximately 1 mm internal diameter. First, the TEVGs were assembled from biodegradable tubular scaffolds fabricated from a polyglycolic acid nonwoven felt mesh coated with ε-caprolactone and L-lactide copolymer. The scaffolds were then placed in a lyophilizer, vacuumed for 24 hr, and stored in a desiccator until cell seeding. Second, bone marrow was collected from donor mice and mononuclear cells were isolated by density gradient centrifugation. Third, approximately one million cells were seeded on a scaffold and incubated O/N. Finally, the seeded scaffolds were then implanted as infrarenal vena cava interposition grafts in C57BL/6 mice. The implanted grafts demonstrated excellent patency (>90%) without evidence of thromboembolic complications or aneurysmal formation. This murine model will aid us in understanding and quantifying the cellular and molecular mechanisms of neotissue formation in the TEVG. PMID:24961688

  18. Maxillary antral bone grafts for repair of orbital fractures.

    PubMed

    Copeland, M; Meisner, J

    1991-04-01

    Use of bone from the maxillary antrum to repair defects in the orbital floor was described more than 20 years ago but has not been reported for correction of orbital rim fractures. The method is appealing because the source is contiguous with the recipient site; enhanced exposure might allow better fracture reduction and evacuation of debris and hematoma from the maxillary sinus. The intraoral approach also avoids an external incision and scar, prevents such complications as pneumothorax or dural perforation, and reduces postoperative pain. In 60 cases of orbital and zygomatic complex fractures seen between 1985 and 1990, less than 8% required more extensive graft material than the maxillary antra could provide. To assess the potential advantages of local over extraanatomical bone grafts, we evaluated maxillary antral bone grafts obtained through buccal sulcus incisions in 14 patients for restoration following fractures of the orbit. Several of these patients are described. Bone union was complete in all patients and there was no morbidity related to infection, oroantral fistula formation, dehiscence, or disfigurement. Sufficient bone was available from the uninvolved contralateral side to repair even severely comminuted fractures. In zygomatic complex fractures, maxillary antral grafts appeared to provide additional strength in the region of the fractured maxillary buttress. The success of the procedure in our experience, coupled with the safety of bone harvesting from this source, and the avoidance of an external scar make maxillary antral bone well suited to reconstruction of all areas of the orbit.

  19. 3D Stereoscopic Visualization of Fenestrated Stent Grafts

    SciTech Connect

    Sun Zhonghua; Squelch, Andrew; Bartlett, Andrew; Cunningham, Kylie; Lawrence-Brown, Michael

    2009-09-15

    The purpose of this study was to present a technique of stereoscopic visualization in the evaluation of patients with abdominal aortic aneurysm treated with fenestrated stent grafts compared with conventional 2D visualizations. Two patients with abdominal aortic aneurysm undergoing fenestrated stent grafting were selected for inclusion in the study. Conventional 2D views including axial, multiplanar reformation, maximum-intensity projection, and volume rendering and 3D stereoscopic visualizations were assessed by two experienced reviewers independently with regard to the treatment outcomes of fenestrated repair. Interobserver agreement was assessed with Kendall's W statistic. Multiplanar reformation and maximum-intensity projection visualizations were scored the highest in the evaluation of parameters related to the fenestrated stent grafting, while 3D stereoscopic visualization was scored as valuable in the evaluation of appearance (any distortions) of the fenestrated stent. Volume rendering was found to play a limited role in the follow-up of fenestrated stent grafting. 3D stereoscopic visualization adds additional information that assists endovascular specialists to identify any distortions of the fenestrated stents when compared with 2D visualizations.

  20. Optical methods for diagnostic of cell-tissue grafts

    NASA Astrophysics Data System (ADS)

    Timchenko, P. E.; Timchenko, E. V.; Volova, L. T.; Boltovskaya, V. V.; Zherdeva, L. A.; Belousov, N. V.; Pershutkina, S. V.

    2015-08-01

    In this work the results of cell-tissue grafts research with a complex of optical methods - confocal fluorescent microscopy and Raman spectroscopy are presented. It was established that coefficient M scatter is related to irregularity of demineralization process. It was microscopically shown that the quantity of integrated cells into these types of transplants amounts to 20% of its surface.

  1. 21 CFR 870.3450 - Vascular graft prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Vascular graft prosthesis. 870.3450 Section 870.3450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3450 Vascular...

  2. 21 CFR 870.3450 - Vascular graft prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Vascular graft prosthesis. 870.3450 Section 870.3450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3450 Vascular...

  3. 21 CFR 870.3450 - Vascular graft prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Vascular graft prosthesis. 870.3450 Section 870.3450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3450 Vascular...

  4. 21 CFR 870.3450 - Vascular graft prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Vascular graft prosthesis. 870.3450 Section 870.3450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3450 Vascular...

  5. Off-pump coronary artery bypass grafting in octogenarians

    PubMed Central

    2016-01-01

    Enhanced life expectancy has confronted cardiac surgery with a rapidly growing population of octogenarians needing coronary artery bypass grafting (CABG). Octogenarians are deemed a high-risk patient population with increased postoperative morbidity and mortality following conventional CABG using cardiopulmonary bypass (CPB). In such patients reducing the invasiveness of the surgical procedure by avoiding CPB may be tried in an attempt to improve outcomes. The increasing performance of off-pump coronary artery bypass (OPCAB) grafting within certain centers reflects surgeon preference to avoid the inherent risks of CPB and cardioplegic arrest including hemodilution, nonpulsatile arterial flow, global myocardial ischemia, atherosclerotic embolization from aortic manipulation, and systemic inflammatory response. Although OPCAB grafting is a well-established surgical myocardial revascularization strategy, its actual benefits in terms of morbidity and mortality remain questionable in the general population. In the higher risk octogenarian patients, however, there is a potential for more tangible clinical benefits when CPB is avoided. This review article provides an overview of the impact of OPCAB grafting on postoperative mortality and morbidity in octogenarians. PMID:27942398

  6. Scattering properties and transparency characterization of human corneal grafts

    NASA Astrophysics Data System (ADS)

    Casadessus, Olivier; Georges, Ga"lle; Siozade-Lamoine, Laure; Deumié, Carole; Conrath, John; Hoffart, Louis

    2011-06-01

    The cornea is the single human tissue being transparent. This unique property may be explained by the particular structure of the cornea, but the precise role of each of its constituents remains unsolved. On other matter, prior to corneal transplant, graft must be evaluated during a sorting procedure where a technician assesses of its transparency quality. Nevertheless, this criterion remains subjective and qualitative. This study proposes to combine 3D imagery using Full-Field Optical Coherence Tomography jointly with angular resolved scattering measurement to achieve a quantitative transparency characterization of the cornea. The OCT provides micrometric resolution structural information about the cornea, and we observe the evolution occurring when oedema develops within the tissue. Scattering properties are evaluated and compared parallely, as the transparency of the graft. A close link between the scattering intensity level of the cornea and its thickness is highlighted through this study. Furthermore, the three-dimensional imagery offers a view over the structural modifications leading to a change in transparency, and the combination with scattering properties measurement provides clues over the characteristic scale of scatterers to consider for a better understanding of corneal transparency evolution. Achieving an objective and quantified parameter for the transparency would be helpful for a more efficient corneal graft sorting, and may be able to detect the presence of localized wounds as the ones related to a previous refractive surgery. However, the study of graft nearly eligible for corneal transplant would be needed to confirm the results this study presents.

  7. Clinical and Economic Benefits of Autologous Epidermal Grafting

    PubMed Central

    Kirsner, Robert S

    2016-01-01

    Chronic wounds are an increasingly prevalent disease with a significant healthcare burden. These wounds often do not respond to standard of care therapy alone, requiring the use of adjuvant therapies. Epidermal grafting, previously utilized primarily for correction of leukoderma, is increasingly being recognized as a beneficial therapy for wounds, both acute and chronic. Epidermal grafting has been shown to be effective in the management of chronic wounds, with successful healing in refractory patients. It has not only been shown to be effective, but it is also associated with lower cost and morbidity than traditional skin grafting techniques as well as improved donor site healing. Through the use of a novel epidermal harvesting system, the CelluTome™ Epidermal Harvesting System (KCI, an Acelity company, San Antonio, TX), this treatment modality has become more standardized, reproducible, and easy to use as well as less time consuming, making its use in the clinical setting more convenient and beneficial. Epidermal grafting, therefore, represents a promising, efficacious, and cost-effective option for treatment of refractory non-healing wounds. PMID:27994993

  8. Polymer Grafted Janus Multi-Walled Carbon Nanotubes

    SciTech Connect

    Priftis, Dimitrios; Sakellariou, Georgios; Baskaran, Durairaj; Mays, Jimmy; Hadjichristidis, Nikos

    2009-01-01

    We describe a novel and facile strategy to modify the surface of carbon nanotubes (CNTs) with two chemically different polymer brushes utilizing the grafting from technique. A [4 + 2] Diels Alder cycloaddition reaction was used to functionalize multi-walled carbon nanotubes (MWNTs) with two different precursor initiators, one for ring opening polymerization (ROP) and one for atom transfer radical polymerization (ATRP). The binary functionalized MWNTs were used for the simultaneous surface initiated polymerizations of different monomers resulting in polymer grafted MWNTs that can form Janus type structures under appropriate conditions. 1H NMR, FTIR and Raman spectra showed that the precursor initiators were successfully synthesized and covalently attached on the CNT surface. Thermogravimetric analysis (TGA) revealed that the grafted polymer content varies when different monomer ratios and polymerization times are used. The presence of an organic layer around the CNTs was observed through transmission electron microscopy (TEM). Differential scanning calorimetry (DSC) proved that the glass transition (Tg) and melting (Tm) temperatures of the grafted polymers are affected by the presence of the CNTs, while circular dichroism (CD) spectra indicated that the PLLA ahelix conformation remains intact.

  9. Subcapsular hematoma of the graft after liver transplantation.

    PubMed

    Massarollo, P C B; Shiroma, M E; Rodrigues, A J; Mies, S

    2004-05-01

    Subcapsular hematoma of the graft is an underreported complication of liver transplantation (LT). Among 408 LT performed from September 1, 1985, to September 1, 2000, eight patients developed a subcapsular hematoma within 30 days after LT (8/408 = 2.0%). Among the six early cases observed, five required further surgical approaches due to hematoma progression, rupture, and hemorrhage. One patient underwent liver retransplantation due to uncontrollable hepatic hemorrhage. The two more recent cases were successfully treated by early opening of the Glisson's capsule with hemostasis of the hepatic raw bleeding surface. The five patients who developed acute renal failure required dialysis. Three patients died during hospitalization. Among the survivors, two were discharged on the postoperative (PO) day 15; the others on PO day 37, 38, and 56. In conclusion, subcapsular hematoma of the graft is a potentially serious complication of LT that may produce severe hemorrhage, shock, and in extreme cases, graft loss or even death. The severity of the complication is related to the extension of the decapsulated area of the graft. An early surgical approach with intentional opening of the hematoma before progression of the lesion seems to facilitate hemostasis and improve results.

  10. Vein graft adaptation and fistula maturation in the arterial environment.

    PubMed

    Lu, Daniel Y; Chen, Elizabeth Y; Wong, Daniel J; Yamamoto, Kota; Protack, Clinton D; Williams, Willis T; Assi, Roland; Hall, Michael R; Sadaghianloo, Nirvana; Dardik, Alan

    2014-05-01

    Veins are exposed to the arterial environment during two common surgical procedures, creation of vein grafts and arteriovenous fistulae (AVF). In both cases, veins adapt to the arterial environment that is characterized by different hemodynamic conditions and increased oxygen tension compared with the venous environment. Successful venous adaptation to the arterial environment is critical for long-term success of the vein graft or AVF and, in both cases, is generally characterized by venous dilation and wall thickening. However, AVF are exposed to a high flow, high shear stress, low-pressure arterial environment and adapt mainly via outward dilation with less intimal thickening. Vein grafts are exposed to a moderate flow, moderate shear stress, high-pressure arterial environment and adapt mainly via increased wall thickening with less outward dilation. We review the data that describe these differences, as well as the underlying molecular mechanisms that mediate these processes. Despite extensive research, there are few differences in the molecular pathways that regulate cell proliferation and migration or matrix synthesis, secretion, or degradation currently identified between vein graft adaptation and AVF maturation that account for the different types of venous adaptation to arterial environments.

  11. Grafting odorant binding proteins on diamond bio-MEMS.

    PubMed

    Manai, R; Scorsone, E; Rousseau, L; Ghassemi, F; Possas Abreu, M; Lissorgues, G; Tremillon, N; Ginisty, H; Arnault, J-C; Tuccori, E; Bernabei, M; Cali, K; Persaud, K C; Bergonzo, P

    2014-10-15

    Odorant binding proteins (OBPs) are small soluble proteins found in olfactory systems that are capable of binding several types of odorant molecules. Cantilevers based on polycrystalline diamond surfaces are very promising as chemical transducers. Here two methods were investigated for chemically grafting porcine OBPs on polycrystalline diamond surfaces for biosensor development. The first approach resulted in random orientation of the immobilized proteins over the surface. The second approach based on complexing a histidine-tag located on the protein with nickel allowed control of the proteins' orientation. Evidence confirming protein grafting was obtained using electrochemical impedance spectroscopy, fluorescence imaging and X-ray photoelectron spectroscopy. The chemical sensing performances of these OBP modified transducers were assessed. The second grafting method led to typically 20% more sensitive sensors, as a result of better access of ligands to the proteins active sites and also perhaps a better yield of protein immobilization. This new grafting method appears to be highly promising for further investigation of the ligand binding properties of OBPs in general and for the development of arrays of non-specific biosensors for artificial olfaction applications.

  12. Nerve regeneration in nerve grafts conditioned by vibration exposure.

    PubMed

    Bergman, S; Widerberg, A; Danielsen, N; Lundborg, G; Dahlin, L B

    1995-01-01

    Regeneration distances were studied in nerves from vibration-exposed limbs. One hind limb of anaesthetized rats was attached to a vibration exciter and exposed to vibration (80 Hz/32 m/s2) for 5 h/day for 2 or 5 days. Seven days after the latest vibration period a 10-mm long nerve graft was taken from the vibrated sciatic nerve and sutured into a corresponding defect in the con-tralateral sciatic nerve and vice versa, thereby creating two different models within the same animal: (i) regeneration from a freshly transected unvibrated nerve into a vibrated graft and (ii) regeneration from a vibrated nerve into a fresh nerve graft (vibrated recipient side). Four, 6 or 8 days postoperatively (p.o.) the distances achieved by the regenerating axons were determined using the pinch reflex test. Two days of vibration did not influence the regeneration, but 5 days of vibration reduced the initial delay period and a slight reduction of regeneration rate was observed. After 5 days of vibration an increased regeneration distance was observed in both models at day 4 p.o. and at day 6 p.o. in vibrated grafts. This study demonstrates that vibration can condition peripheral nerves and this may be caused by local changes in the peripheral nerve trunk and in the neuron itself.

  13. Grafting of Polycaprolactone on Oxidized Nanocelluloses by Click Chemistry

    PubMed Central

    Benkaddour, Abdelhaq; Jradi, Khalil; Robert, Sylvain; Daneault, Claude

    2013-01-01

    The main objective of this work is the grafting of polycaprolactone diol (PCL) on the surface of oxidized nanocelluloses (ONC) in order to enhance the compatibility between the hydrophilic cellulose nanofibres and the hydrophobic polymer matrix. This grafting was successfully realized with a new strategy known as click chemistry. In this context, the oxidized nanocelluloses bearing alkyl groups (ONC-PR) were prepared by reacting amino groups of propargylamine (PR) with carboxyl groups of ONC. In parallel, PCL was converted into azido-polycaprolactone (PCL-N3) in two steps: (i) tosylation of polycaprolactone (PCL-OTs) and (ii) conversion of PCL-OTs into PCL-N3 by nucleophilic displacement using sodium azide. Finally, ONC-PR was reacted with PCL-N3 in heterogeneous conditions through click chemistry in order to prepare polycaprolactone grafted oxidized nanocellulose (ONC-g-PCL), which could be suitable for improving the interfacial adhesion in the composite materials. The grafted samples were characterized by transmission electron microscopy and by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Carbon-13 nuclear magnetic resonance spectroscopy (13C-NMR) spectroscopic techniques.

  14. A Monte Carlo study of fluctuating polymer-grafted membranes.

    PubMed

    Laradji, Mohamed

    2004-07-15

    Using Monte Carlo simulations of an off-lattice model, we study the elastic properties of polymer-grafted membranes. Our results are found to be in good agreement with those predicted by the classical path approximation of the self-consistent field theory and scaling theory based on de Gennes' blob picture. In particular, we found that when the membrane is grafted on both sides by brushes with same molecular weight N and grafting density sigma, the excess bending modulus induced by the polymers scales as N3 sigmaalpha where alpha is consistent with 7/3, as predicted by the self-consistent field theory, and 5/2, as predicted by the scaling theory. When the polymers are grafted to one side of the membrane only, the membrane bends away from the polymers with a spontaneous curvature with a scaling that is consistent with both scaling and self-consistent field theories. When the thickness of the brush exceeds the membrane's spontaneous radius of curvature, the bending modulus approaches a constant which is of the same order as the bending modulus of the bare membrane.

  15. Defluoridation potential of jute fibers grafted with fatty acyl chain

    NASA Astrophysics Data System (ADS)

    Manna, Suvendu; Saha, Prosenjit; Roy, Debasis; Sen, Ramkrishna; Adhikari, Basudam

    2015-11-01

    Waterborne fluoride is usually removed from water by coagulation, adsorption, ion exchange, electro dialysis or reverse osmosis. These processes are often effective over narrow pH ranges, release ions considered hazardous to human health or produce large volumes of toxic sludge that are difficult to handle and dispose. Although plant matters have been shown to remove waterborne fluoride, they suffer from poor removal efficiency. Following from the insight that interaction between microbial carbohydrate biopolymers and anionic surfaces is often facilitated by lipids, an attempt has been made to enhance fluoride adsorption efficiency of jute by grafting the lignocellulosic fiber with fatty acyl chains found in vegetable oils. Fluoride removal efficiency of grafted jute was found to be comparable or higher than those of alternative defluoridation processes. Infrared and X-ray photoelectron spectroscopic evidence indicated that hydrogen bonding, protonation and C-F bonding were responsible for fluoride accumulation on grafted jute. Adsorption based on grafted jute fibers appears to be an economical, sustainable and eco-friendly alternative technique for removing waterborne fluoride.

  16. Left ventricular assist device outflow graft: alternative sites.

    PubMed

    El-Sayed Ahmed, Magdy M; Aftab, Muhammad; Singh, Steve K; Mallidi, Hari R; Frazier, Oscar H

    2014-09-01

    We describe three alternative approaches for the left ventricular assist device (LVAD) outflow graft during implantation of the LVAD. The supraceliac abdominal aorta, innominate artery and left axillary artery were employed as alternative sites for the LVAD outflow graft in the setting of a heavily calcified ascending aorta or a hostile chest wall and mediastinum. The first approach involved the use of the supraceliac abdominal aorta. Given that the patient had a history of multiple previous breast surgeries and chest wall radiation for breast cancer treatment, a left subcostal incision was employed as a sternotomy-sparing approach. The second approach was the use of the innominate artery in a patient with a porcelain ascending aorta. The patient underwent pulmonary valve replacement, right ventricle outflow tract reconstruction and tricuspid valve annuloplasty in addition to the LVAD implantation. The third approach was the use of the left axillary artery. This patient had a history of LVAD implantation and subsequently developed infection with pseudoaneurysm formation at the aortic anastomosis of the outflow graft. We conclude that the supraceliac abdominal aorta, the innominate artery and the left axillary artery are potential alternative routes for the LVAD outflow graft in the settings of heavily calcified ascending aorta or a hostile chest wall and mediastinum. Although the described alternative approaches are safe and viable options, we highly recommend utilizing these approaches only in selected patients with significantly higher risks and hazards to the standard surgical approach.

  17. The Use of Bone Graft Substitute in Hand Surgery

    PubMed Central

    Liodaki, Eirini; Kraemer, Robert; Mailaender, Peter; Stang, Felix

    2016-01-01

    Abstract Bone defects are a very common problem in hand surgery, occurring in bone tumor surgery, in complicated fractures, and in wrist surgery. Bone substitutes may be used instead of autologous bone graft to avoid donor site morbidity. In this article, we will review our experience with the use of Cerament bone void filler (Bonesupport, Lund, Sweden) in elective and trauma hand surgery. A prospective clinical study was conducted with 16 patients treated with this bone graft substitute in our department over a period of 3.5 years. Twelve patients (2 female, 10 male; with an average age of 42.42 years) with monostoic enchondroma of the phalanges were treated and 4 patients (1 female, 3 male; with an average age of 55.25 years) with complicated metacarpal fractures with bone defect. Data such as postoperative course with rating of pain, postoperative complications, functional outcome assessment at 1, 2, 3, 6 months, time to complete remodeling were registered. Postoperative redness and swelling after bone graft substitute use was noticed in 7 patients with enchondroma surgery due to the thin soft-tissue envelope of the fingers. Excellent total active motion of the involved digit was noticed in 10 of 12 enchondroma patients and in all 4 fracture patients at 2-month follow-up. In summary, satisfying results are described, making the use of injectable bone graft substitute in the surgical treatment of enchondromas, as well as in trauma hand surgery a good choice. PMID:27310946

  18. Renal allograft eosinophilia: An unusual presentation of sudden graft dysfunction

    PubMed Central

    Yuvaraj, A.; Ghosh, S.; Abraham, G.; Koshy, P.

    2017-01-01

    We present a case of sudden allograft dysfunction 11 months after renal transplantation which presented as severe peripheral and allograft eosinophilia and was managed as a case of an acute cellular rejection with significant interstitial graft eosinophilic infiltration. Patient had partial response to antirejection therapy and eventually ended up in a chronic allograft dysfunction. PMID:28356665

  19. Antibiotic therapy of aortic graft infection: treatment and prevention recommendations.

    PubMed

    Hodgkiss-Harlow, Kelley D; Bandyk, Dennis F

    2011-12-01

    Surgical site infection (SSI) after aortic intervention, an uncommon but serious vascular condition, requires patient-specific antibiotic therapy. Effective treatment and prevention requires the vascular surgeon to be cognizant of changing SSI microbiology, advances in antibiotic delivery, and patient characteristics. The majority of aortic graft infections are caused by Gram-positive bacteria, with methicillin-resistant Staphylococcus aureus now the prevalent pathogen. Nasal carriage of methicillin-sensitive or methicillin-resistant S aureus strains, diabetes mellitus, recent hospitalization, a failed arterial reconstruction, and the presence of a groin incision are important SSI risk factors. Overall, the aortic SSI rate is higher than predicted by the Centers for Disease Control and Prevention's National Nosocomial Infections Surveillance risk category system; ranging from 5% after open or endovascular aortic interventions to as high as 10% to 15% after aortofemoral bypass or uni-aortoiliac grafting with femorofemoral bypass. Perioperative measures to reduce S aureus nares and skin colonization, administration of antibiotic prophylaxis, meticulous wound closure/care, and therapy directed to optimize patient host defense regulation mechanisms (eg, temperature, oxygenation, blood sugar) can minimize SSI occurrence. Antibiotic therapy for aortic graft infection should utilize bactericidal drugs that penetrate bacteria biofilms and can be delivered to the surgical site both parenterally and locally in the form of antibiotic-impregnated beads or prosthetic grafts.

  20. Developing cryotherapy to eliminate graft-transmissible pathogens in citrus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article summarizes research being conducted as part of a project funded by the California Citrus Research Board to develop cryotherapy (freezing buds in liquid nitrogen, and then recovering them) as a viable method for elimination of graft transmissible pathogens from Citrus. There are current...