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Sample records for noncultured cellular grafting

  1. Cellular grafts in management of leucoderma

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    Mysore Venkataram

    2009-01-01

    Full Text Available Cellular grafting methods constitute important advances in the surgical management of leucoderma. Different methods such as noncultured epidermal suspensions, melanocyte cultures, and melanocyte-keratinocyte cultures have all been shown to be effective. This article reviews these methods.

  2. Blister roof grafting, cultured melanocytes transplantation and non-cultured epidermal cell suspension transplantation in treating stable vitiligo: A mutual self-control study.

    Science.gov (United States)

    Bao, Huaye; Hong, Weisong; Fu, Lifang; Wei, Xiaodong; Qian, Guopei; Xu, Aie

    2015-01-01

    To compare the efficacy of blister roof grafting (BG), cultured melanocytes transplantation (CMT) and non-cultured epidermal cell suspension transplantation (NCES) in the treatment of stable vitiligo. In each person of 83 vitiligo patients one vitiligo macule was selected and divided in three areas for separate treatment with BG, CMT and NCES in the same session. The results were evaluated 12-month post-surgery for the extent of repigmentation and color match. A satisfactory result (>50% repigmentation) was achieved in 92%, 82% and 81% of the 83 patients with the BG, CMT and NCES methods, respectively. Significant differences between the BG and CMT groups (p = 0.038), and between BG and NCES groups (p = 0.017) were observed, but not between the CMT and NCES groups (p = 0.986). The extent of repigmentation on the head neck and trunk was superior to that of the extremities by all the three methods. A difference in the time of onset of repigmentation was observed, with repigmentation first appearing after 10 days, 20-30 days and >30 days in the BG, CMT and NCES groups, respectively. All the three methods are safe and effective to treat vitiligo. Future studies with larger groups are warranted to confirm our results.

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

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    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.

  4. Achievement of Cellular Immunity and Discordant Xenogeneic Tolerance in Mice by Porcine Thymus Grafts

    Institute of Scientific and Technical Information of China (English)

    Yong Zhao; Zuyue Sun; Yimin Sun; Alan N. Langnas

    2004-01-01

    Specific cellular immune tolerance may be essential for successful xenotransplantation in humans. Thymectomized (ATX), T and NK cell-depleted immunocompetent mice grafted with xenogeneic fetal pig thymic and liver tissue (FP THY/LIV) result in efficient mouse thymopoiesis and peripheral repopulation of functional mouse CD4+ T cell. Very importantly, the reconstituted mouse T cells are specifically tolerant to pig donor antigens. Studies demonstrated that porcine MHCs mediated positive and negative selection of mouse thymocytes in FP THY grafts, whereas mouse MHCs were involved in negative selection in grafts. Therefore, T cell tolerance to xenogeneic donor antigens could be induced by grafting donor thymus tissue. Xenogeneic thymic replacement might have a potential role in the reconstitution of cellular immunity in patients with AIDS or other immunodeficiencies caused by thymus dysfunction.

  5. Achievement of Cellular Immunity and Discordant Xenogeneic Tolerance in Mice by Porcine Thymus Grafts

    Institute of Scientific and Technical Information of China (English)

    YongZhao; ZuyueSun; YiminSun; AlanN.Langnas

    2004-01-01

    Specific cellular immune tolerance may be essential for successful xenotransplantation in humans. Thymectomized (ATX), T and NK ceil-depleted immunocompetent mice grafted with xenogeneic fetal pig thymic and liver tissue (FP THY/LIV) result in efficient mouse thymopoiesis and peripheral repopulation of functional mouse CD4+ T cell.Very importantly, the reconstituted mouse T cells are specifically tolerant to pig donor antigens. Studies demonstrated that porcine MHCs mediated positive and negative selection of mouse thymocytes in FP THY grafts, whereas mouse MHCs were involved in negative selection in grafts. Therefore, T cell tolerance to xenogeneic donor antigens could be induced by grafting donor thymus tissue. Xenogeneic thymic replacement might have a potential role in the reconstitution of cellular immunity in patients with AIDS or other immunodeficiencies caused bv thvmus dvsfunction.

  6. FETAL PORCINE VENTRAL MESENCEPHALON GRAFTS - DISSECTION PROCEDURE AND CELLULAR CHARACTERIZATION IN CULTURE

    NARCIS (Netherlands)

    VANROON, WMC; COPRAY, JCVM; HOGENESCH, RI; KEMA, [No Value; MEYER, EM; MOLENAAR, G; LUGARD, C; STAAL, MJ; GO, KG

    1995-01-01

    The objective of this study was to develop an optimal dissection procedure for fetal porcine ventral mesencephalon (VM) grafts and to characterize the cellular composition of such an explant, in particular with respect to the dopaminergic and GABAergic components. We have used a monolayer cell cultu

  7. Arterial grafts exhibiting unprecedented cellular infiltration and remodeling in vivo: the role of cells in the vascular wall.

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    Row, Sindhu; Peng, Haofan; Schlaich, Evan M; Koenigsknecht, Carmon; Andreadis, Stelios T; Swartz, Daniel D

    2015-05-01

    To engineer and implant vascular grafts in the arterial circulation of a pre-clinical animal model and assess the role of donor medial cells in graft remodeling and function. Vascular grafts were engineered using Small Intestinal Submucosa (SIS)-fibrin hybrid scaffold and implanted interpositionally into the arterial circulation of an ovine model. We sought to demonstrate implantability of SIS-Fibrin based grafts; examine the remodeling; and determine whether the presence of vascular cells in the medial wall was necessary for cellular infiltration from the host and successful remodeling of the implants. We observed no occlusions or anastomotic complications in 18 animals that received these grafts. Notably, the grafts exhibited unprecedented levels of host cell infiltration that was not limited to the anastomotic sites but occurred through the lumen as well as the extramural side, leading to uniform cell distribution. Incoming cells remodeled the extracellular matrix and matured into functional smooth muscle cells as evidenced by expression of myogenic markers and development of vascular reactivity. Interestingly, tracking the donor cells revealed that their presence was beneficial but not necessary for successful grafting. Indeed, the proliferation rate and number of donor cells decreased over time as the vascular wall was dominated by host cells leading to significant remodeling and development of contractile function. These results demonstrate that SIS-Fibrin grafts can be successfully implanted into the arterial circulation of a clinically relevant animal model, improve our understanding of vascular graft remodeling and raise the possibility of engineering mural cell-free arterial grafts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Early Inflammatory Responses Following Cell Grafting in the CNS Trigger Activation of the Subventricular Zone: A Proposed Model of Sequential Cellular Events.

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    Praet, Jelle; Santermans, Eva; Daans, Jasmijn; Le Blon, Debbie; Hoornaert, Chloé; Goossens, Herman; Hens, Niel; Van der Linden, Annemie; Berneman, Zwi; Ponsaerts, Peter

    2015-01-01

    While multiple rodent preclinical studies, and to a lesser extent human clinical trials, claim the feasibility, safety, and potential clinical benefit of cell grafting in the central nervous system (CNS), currently only little convincing knowledge exists regarding the actual fate of the grafted cells and their effect on the surrounding environment (or vice versa). Our preceding studies already indicated that only a minor fraction of the initially grafted cell population survives the grafting process, while the surviving cell population becomes invaded by highly activated microglia/macrophages and surrounded by reactive astrogliosis. In the current study, we further elaborate on early cellular and inflammatory events following syngeneic grafting of eGFP(+) mouse embryonic fibroblasts (mEFs) in the CNS of immunocompetent mice. Based on obtained quantitative histological data, we here propose a detailed mathematically derived working model that sequentially comprises hypoxia-induced apoptosis of grafted mEFs, neutrophil invasion, neoangiogenesis, microglia/macrophage recruitment, astrogliosis, and eventually survival of a limited number of grafted mEFs. Simultaneously, we observed that the cellular events following mEF grafting activates the subventricular zone neural stem and progenitor cell compartment. This proposed model therefore further contributes to our understanding of cell graft-induced cellular responses and will eventually allow for successful manipulation of this intervention.

  9. Changes of Ca2+ activated potassium channels and cellular proliferation in autogenous vein grafts

    Institute of Scientific and Technical Information of China (English)

    钱济先; 宋胜云; 马保安; 范清宇

    2003-01-01

    Objective: To investigate changes of Ca2+ activated potassium channels (KCa) in autogenous vein grafts. Methods: Contraction of venous ring was measured by means of perfusion in vitro. The intimal rabbits proliferation of vascular and proliferation of cultured smooth muscle cells(vascular smooth muscle cells, VSMCs)were observed by the means of computerised image analysis and MTT method respectively. Furthermore, whole cell mode of patch clamp was used to record KCa of VSMCs isolated from autogenous vein grafts. Results: One week after transplantation there were no significant differences of contraction and intimal relative thickness between autogenous vein grafts and control. Contraction and intimal relative thickness of autogenous vein graft were significantly increased 2 weeks after transplantation (P<0.05, n=8 vs control), and they was more enhanced 4 weeks after vein transplantation (P<0.01, n=8 vs control).TEA(blocker of Ca2+ activated potassium channels)increased MTT A490 nm value of VSMCs from femoral vein in a dose dependent manner(P<0.05, n=8). KCa current density was significantly attenuated in VSMCs from autogenous vein grafts (1-4) week after transplantation(P<0.05, n=5).Conclusion: KCa is inhibited in autogenous vein graft, which account for vasospasm and intimal proliferation.

  10. Comparison of epoxides on grafting collagen to polyurethane and their effects on cellular growth.

    Science.gov (United States)

    Huang, L L; Lee, P C; Chen, L W; Hsieh, K H

    1998-03-15

    The current study investigated the effects of vary epoxides on linking capacity of collagen to carboxyl-group-enriched polyurethane (PU) and the consequent effects on the growth of endothelial cells. Epoxides of EX-810, 1,4BDE, DER732, DER331, and DER332 were initially reacted with the carboxyl groups of PU substrates at 110 degrees C for 20 h. Free epoxy rings of epoxide-PU substrates, characterized by Fourier transform infrared spectroscopy and quantified by titration with HCl and NaOH, were available for collagen grafting. The amounts of collagen grafted were in accordance with the amounts of free epoxy rings detected and correlated with the growth of endothelial cells on the substrates. Our results indicated that epoxides with shorter aliphatic intermediate chain can graft more collagen to the epoxide-PU substrates than epoxides with longer intermediate chain or with aromatic groups. Epoxides were also demonstrated to be nontoxic linking agents for biomaterials.

  11. Lack of response of INT-407 cells to the presence of non-culturable Campylobacter jejuni

    NARCIS (Netherlands)

    Verhoeff-Bakkenes, L.; Hazeleger, W.C.; Zwietering, M.H.; Jonge, de R.

    2008-01-01

    Many contradictory articles on the infectivity of non-culturable Campylobacter jejuni can be found. We studied the effect of non-culturable C. jejuni in an in vitro assay. To prevent the potential effect of a few culturable bacteria in the non-culturable suspension, INT-407 cells, which mimic the

  12. Membrane damage and active but nonculturable state in liquid cultures of Escherichia coli treated with an atmospheric pressure plasma jet.

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    Dolezalova, Eva; Lukes, Petr

    2015-06-01

    Electrical discharge plasmas can efficiently inactivate various microorganisms. Inactivation mechanisms caused by plasma, however, are not fully understood because of the complexity of both the plasma and biological systems. We investigated plasma-induced inactivation of Escherichia coli in water and mechanisms by which plasma affects bacterial cell membrane integrity. Atmospheric pressure argon plasma jet generated at ambient air in direct contact with bacterial suspension was used as a plasma source. We determined significantly lower counts of E. coli after treatment by plasma when they were assayed using a conventional cultivation technique than using a fluorescence-based LIVE/DEAD staining method, which indicated that bacteria may have entered the viable-but-nonculturable state (VBNC). We did not achieve resuscitation of these non-culturable cells, however, we detected their metabolic activity through the analysis of cellular mRNA, which suggests that cells may have been rather in the active-but-nonculturable state (ABNC). We hypothesize that peroxidation of cell membrane lipids by the reactive species produced by plasma was an important pathway of bacterial inactivation. Amount of malondialdehyde and membrane permeability of E. coli to propidium iodide increased with increasing bacterial inactivation by plasma. Membrane damage was also demonstrated by detection of free DNA in plasma-treated water.

  13. RECOVERY IN VIVO OF NONCULTURABLE SUBPOPULATION OF SALMONELLA ENTERICA

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    Yudin I.P.

    2015-12-01

    Full Text Available Introduction. As one of mesophilic, easily cultivated species of pathogenic bacteria, Salmonella enterica transformed into viable but nonculturable (VNC state in response to environmental stresses, including action of biocides. The cells in this state, preserve the integrity of membranes and metabolism of some, but not detected by conventional methods of cultivation. Some researchers suggest that the evolutionary significance of this phenomenon is part of an adaptive response aimed at long-term survival of bacteria in adverse conditions; others argue that it is the result of stochastic cellular damage, in which nonculturable cells are in a state of gradual death. In any case, the phenomenon of existence VNC pathogens if they retain the ability to restore its growth in vivo is a significant problem in medicine, pharmaceutical, veterinary, food industry. VNC subpopulation of S. enterica was obtained under action of ethanol. In this paper was investigated in vivo resuscitation VNC S. enterica using intraperitoneal injection of mice. Materials and methods. Obtaining of stressful S. enterica populations. Bacteria were grown to exponential phase in broth Luria–Bertani (LB. To 1.0 ml sample suspension diluted to 1.5 × 106 cells/ml was added 1.0 ml of ethanol at a concentration of 40 % (v/v. After exposure of 10 to 600 minutes in the suspension were added 8.0 ml of phosphate buffered saline (FBS, washed by centrifugation (4500 g for 5 minutes and serially diluted at a ratio of 1:10 (v/v samples were stained with LIVE/DEAD BacLight (produced by "Invitrogen", USA, filtrated on membrane filters for fluorescence microscopy and parallel plated on LB agar cup to determine colony-forming units (CFU per ml. In vivo resuscitation VNC S. enterica was made following way. Three groups of animals were inoculated by intraperitoneal injection: 1 103 culturable cells (0.1 ml suspension containing 104 CFU / ml; 2 103 VNC cells (0.1 ml suspension containing 104 cells

  14. Carboxymethyl Cellulose-Grafted Mesoporous Silica Hybrid Nanogels for Enhanced Cellular Uptake and Release of Curcumin

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    Neha Tiwari

    2017-02-01

    Full Text Available Mesoporous silica nanoparticles (MSNs with ordered pore structure have been synthesized and used as carriers for the anticancer drug curcumin. MSNs were functionalized with amine groups and further attached with carboxymethyl cellulose (CMC using 1-ethyl-3-(3-dimethylaminopropyl-carbodiimide (EDC coupling chemistry, which increased the hydrophilicity and biocompatibility of MSNs. The functionalized MSNs (MSN-NH2 and MSN-CMC were characterized using Scanning Electron Microscopy (SEM, Transmission Electron Microscopy (TEM, Dynamic Light Scattering (DLS, N2 adsorption, X-Ray Diffraction (XRD, Thermo Gravimetric Analysis (TGA and Fourier Transform Infrared Spectroscopy (FT-IR. The in vitro release of curcumin from the –NH2 and CMC functionalized MSNs (MSN-cur-NH2 and MSN-cur-CMC was performed in 0.5% aqueous solution of sodium lauryl sulphate (SLS. The effect of CMC functionalization of MSNs towards cellular uptake was studied in the human breast cancer cell line MDA-MB-231 and was compared with that of MSN-NH2 and free curcumin (cur. Both MSN-NH2 and MSN-CMC showed good biocompatibility with the breast cancer cell line. The MTT assay study revealed that curcumin-loaded MSN-cur-CMC showed better uptake as compared to curcumin-loaded MSN-cur-NH2. Free curcumin was used as a control and was shown to have much less internalization as compared to the curcumin-loaded functionalized MSNs due to poor bioavailability. Fluorescence microscopy was used to localize the fluorescent drug curcumin inside the cells. The work demonstrates that CMC-functionalized MSNs can be used as potential carriers for loading and release of hydrophobic drugs that otherwise cannot be used effectively in their free form for cancer therapy.

  15. Entry of Yersinia pestis into the viable but nonculturable state in a low-temperature tap water microcosm.

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    David R Pawlowski

    Full Text Available Yersinia pestis, the causative agent of plague, has caused several pandemics throughout history and remains endemic in the rodent populations of the western United States. More recently, Y. pestis is one of several bacterial pathogens considered to be a potential agent of bioterrorism. Thus, elucidating potential mechanisms of survival and persistence in the environment would be important in the event of an intentional release of the organism. One such mechanism is entry into the viable but non-culturable (VBNC state, as has been demonstrated for several other bacterial pathogens. In this study, we showed that Y. pestis became nonculturable by normal laboratory methods after 21 days in a low-temperature tap water microcosm. We further show evidence that, after the loss of culturability, the cells remained viable by using a variety of criteria, including cellular membrane integrity, uptake and incorporation of radiolabeled amino acids, and protection of genomic DNA from DNase I digestion. Additionally, we identified morphological and ultrastructural characteristics of Y. pestis VBNC cells, such as cell rounding and large periplasmic spaces, by electron microscopy, which are consistent with entry into the VBNC state in other bacteria. Finally, we demonstrated resuscitation of a small number of the non-culturable cells. This study provides compelling evidence that Y. pestis persists in a low-temperature tap water microcosm in a viable state yet is unable to be cultured under normal laboratory conditions, which may prove useful in risk assessment and remediation efforts, particularly in the event of an intentional release of this organism.

  16. Molecular, cellular and pharmaceutical aspects of autologous grafts for peri-implant hard and soft tissue defects.

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    Lu, Jiayu; Hao, Yongming; Zhao, Wei; Lv, Chengqi; Zou, Derong

    2016-12-01

    The lack of supporting hard and soft tissues always prevents the rehabilitation with dental implants. Among various hard and soft tissue augmentation procedures, autologous grafts have been considered to be the gold standard. Autologous mesenchymal stem cells (MSCs) from bone marrow, dental tissue and adipose tissue have been described as promising alternatives for bone regeneration in the field of dental implantation. Mucosal cells, gingival fibroblasts and dental progenitor cells (DPS) can enhance peri-implant soft tissue augmentation and regenerate periodontal tissues around dental implants. Obtained from patients, platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) are enriched in autologous platelets, which contain a great deal of growth factors and cytokines that are conducive to the regeneration of both hand and soft tissues around dental implants. Pharmaceutical treatments for osteoporosis and diabetes should be locally applied with implant procedures to restrict the resorption of autologous bone grafts and reduction of bone volume. Although autografts hold great potentials for dental implants, new approaches should also be explored with minimally invasion donor sites methods such as tissue engineering combined with autologous three factors and bio-3D printing involving self-assembling cell aggregates.

  17. Transplantation of autologous noncultured epidermal cell suspension in treatment of patients with stable vitiligo

    Institute of Scientific and Technical Information of China (English)

    XU Ai-e; WEI Xiao-dong; CHENG Dong-qing; ZHOU He-fen; QIAN Guo-pei

    2005-01-01

    @@ Treatment of vitiligo by transplantation of noncultured melanocytes containing keratino-cytes has been successful since 1992,1 We report the encouraging results of autologous epidermal cell suspension in the treatment of 24 patients with stable vitiligo since 1998.

  18. Wharton’s Jelly-Derived Mesenchymal Stromal Cells as a Promising Cellular Therapeutic Strategy for the Management of Graft-versus-Host Disease

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    Joseph P. McGuirk

    2015-04-01

    Full Text Available Allogeneic hematopoietic cell transplantation (allo-HCT, a treatment option in hematologic malignancies and bone marrow failure syndromes, is frequently complicated by Graft-versus-host disease (GVHD. The primary treatment for GVHD involves immune suppression by glucocorticoids. However, patients are often refractory to the steroid therapy, and this results in a poor prognosis. Therefore alternative therapies are needed to treat GVHD. Here, we review data supporting the clinical investigation of a novel cellular therapy using Wharton’s jelly (WJ-derived mesenchymal stromal cells (MSCs as a potentially safe and effective therapeutic strategy in the management of GVHD. Adult-derived sources of MSCs have demonstrated signals of efficacy in the management of GVHD. However, there are limitations, including: limited proliferation capacity; heterogeneity of cell sources; lengthy expansion time to clinical dose; expansion failure in vitro; and a painful, invasive, isolation procedure for the donor. Therefore, alternative MSC sources for cellular therapy are sought. The reviewed data suggests MSCs derived from WJ may be a safe and effective cellular therapy for GVHD. Laboratories investigated and defined the immune properties of WJ-MSCs for potential use in cellular therapy. These cells represent a more uniform cell population than bone marrow-derived MSCs, displaying robust immunosuppressive properties and lacking significant immunogenicity. They can be collected safely and painlessly from individuals at birth, rapidly expanded and stored cryogenically for later clinical use. Additionally, data we reviewed suggested licensing MSCs (activating MSCs by exposure to cytokines to enhance effectiveness in treating GVHD. Therefore, WJCs should be tested as a second generation, relatively homogeneous allogeneic cell therapy for the treatment of GVHD.

  19. Wharton’s Jelly-Derived Mesenchymal Stromal Cells as a Promising Cellular Therapeutic Strategy for the Management of Graft-versus-Host Disease

    Science.gov (United States)

    McGuirk, Joseph P.; Smith, J. Robert; Divine, Clint L.; Zuniga, Micheal; Weiss, Mark L.

    2015-01-01

    Allogeneic hematopoietic cell transplantation (allo-HCT), a treatment option in hematologic malignancies and bone marrow failure syndromes, is frequently complicated by Graft-versus-host disease (GVHD). The primary treatment for GVHD involves immune suppression by glucocorticoids. However, patients are often refractory to the steroid therapy, and this results in a poor prognosis. Therefore alternative therapies are needed to treat GVHD. Here, we review data supporting the clinical investigation of a novel cellular therapy using Wharton’s jelly (WJ)-derived mesenchymal stromal cells (MSCs) as a potentially safe and effective therapeutic strategy in the management of GVHD. Adult-derived sources of MSCs have demonstrated signals of efficacy in the management of GVHD. However, there are limitations, including: limited proliferation capacity; heterogeneity of cell sources; lengthy expansion time to clinical dose; expansion failure in vitro; and a painful, invasive, isolation procedure for the donor. Therefore, alternative MSC sources for cellular therapy are sought. The reviewed data suggests MSCs derived from WJ may be a safe and effective cellular therapy for GVHD. Laboratories investigated and defined the immune properties of WJ-MSCs for potential use in cellular therapy. These cells represent a more uniform cell population than bone marrow-derived MSCs, displaying robust immunosuppressive properties and lacking significant immunogenicity. They can be collected safely and painlessly from individuals at birth, rapidly expanded and stored cryogenically for later clinical use. Additionally, data we reviewed suggested licensing MSCs (activating MSCs by exposure to cytokines) to enhance effectiveness in treating GVHD. Therefore, WJCs should be tested as a second generation, relatively homogeneous allogeneic cell therapy for the treatment of GVHD. PMID:25894816

  20. Cellular growth under hydrostatic pressure using bovine aortic EC-SMC co-cultured ePTFE vascular graft

    Institute of Scientific and Technical Information of China (English)

    SUN Lei; NIWA Koichi; LIN Jian-zhong; KARINO Takeshi

    2005-01-01

    High blood pressure (hypertension) is implicated in the development of atherosclerosis. Blood vessels are constantly subjected to stretch due to blood pressure and changes in stretch usually instigate adaptive vascular remodeling, including abnormal growth and proliferation of vascular smooth muscle cells (VSMCs) as well as extracellular matrix (ECM). In this experiment, we used bovine aortic endothelial cells and smooth muscle cells (EC-SMC) co-cultured ePTFE vascular grafts subjected to normal atmospheric pressure (as a control), and 100 mmHg hydrostatic pressure for 7 d. The increase of cell layer thickness was observed. When measured, the cell layer thickness increased by 116.2%. The increase of collagen (Type Ⅳ)synthesis was also observed in the immunohistochemistry assay. When stained with toluidine blue, the cells showed metachromatic phenomenon.

  1. Engineered outer membrane vesicle is potent to elicit HPV16E7-specific cellular immunity in a mouse model of TC-1 graft tumor.

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    Wang, Shijie; Huang, Weiwei; Li, Kui; Yao, Yufeng; Yang, Xu; Bai, Hongmei; Sun, Wenjia; Liu, Cunbao; Ma, Yanbing

    2017-01-01

    Currently, therapeutic tumor vaccines under development generally lack significant effects in human clinical trials. Exploring a powerful antigen delivery system is a potential approach to improve vaccine efficacy. We sought to explore engineered bacterial outer membrane vesicles (OMVs) as a new vaccine carrier for efficiently delivering tumor antigens and provoking robust antitumor immune responses. First, the tumoral antigen human papillomavirus type 16 early protein E7 (HPV16E7) was presented on Escherichia coli-derived OMVs by genetic engineering methods, acquiring the recombinant OMV vaccine. Second, the ability of recombinant OMVs delivering their components and the model antigen green fluorescent protein to antigen-presenting cells was investigated in the macrophage Raw264.7 cells and in bone marrow-derived dendritic cells in vitro. Third, it was evaluated in TC-1 graft tumor model in mice that the recombinant OMVs displaying HPV16E7 stimulated specific cellular immune response and intervened the growth of established tumor. E. coli DH5α-derived OMVs could be taken up rapidly by dendritic cells, for which vesicle structure has been proven to be important. OMVs significantly stimulated the expression of dendritic cellmaturation markers CD80, CD86, CD83 and CD40. The HPV16E7 was successfully embedded in engineered OMVs through gene recombinant techniques. Subcutaneous immunization with the engineered OMVs induced E7 antigen-specific cellular immune responses, as shown by the increased numbers of interferon-gamma-expressing splenocytes by enzyme-linked immunospot assay and interferon-gamma-expressing CD4(+) and CD8(+) cells by flow cytometry analyses. Furthermore, the growth of grafted TC-1 tumors in mice was significantly suppressed by therapeutic vaccination. The recombinant E7 proteins presented by OMVs were more potent than those mixed with wild-type OMVs or administered alone for inducing specific cellular immunity and suppressing tumor growth. The

  2. Protecting drinking water: Rapid detection of human fecal contamination, injured and non-culturable pathogenic microbes in water systems

    Energy Technology Data Exchange (ETDEWEB)

    White, D.C.; Nivens, D.E.; Arrage, A.A.; Appelgate, B.M.; Reardon, S.R.; Sayler, G.S.

    1996-05-01

    The rapid, potentially-automatable extraction of filter retentates has allowed quantitative detection of the unique biomarker for human fecal contamination, coprostanol, and the signature lipid biomarkers for total cellular biomass, viable cellular biomass, lipopolysaccharide (endotoxin). This method may be integrated with DNA based gene probe analysis for specific strains and enzyme activities. Not only does the analysis provide for detection of injured and non-culturable microbes but it also provides biomarkers characteristic of microbes exposed to biocides and disinfectants that can be utilized to monitor effectiveness of water mitigation/treatment. The analysis schemes involve filtration of the water or direct extraction of biofilms in sidestream chambers, supercritical fluid and/or liquid extraction, derivatization, and analysis of ``signature`` patterns by gas chromatography/mass spectrometry. Signature lipid biomarkers of interest are diglycerides, steroids including coprostanol and its isomers, poly-{beta}- hydroxyalcanoates (PHA), phospholipid ester-linked fatty acids (PLFA), and the lipopolysaccharide lipid A hydroxy fatty acids. PLFA found in polar lipid fractions estimate total viable cellular biomass, whereas the total cellular biomass can be calculated from diglyceride/phospholipid ester-linked fatty acids ratios. Furthermore, direct evidence of mitigation/treatment effectiveness can be ascertained by detection of diglycerides, respiratory quinones, PHA, and PLFA markers indicative of metabolic stress and toxicity such as trans monoenoic PLFA as well as oxirane and dicarboxylic fatty acids derived from the PLFA.

  3. Formation and resuscitation of viable but nonculturable Salmonella typhi.

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    Zeng, Bin; Zhao, Guozhong; Cao, Xiaohong; Yang, Zhen; Wang, Chunling; Hou, Lihua

    2013-01-01

    Salmonella typhi is a pathogen that causes the human disease of typhoid fever. The aim of this study was to investigate the viable but nonculturable (VBNC) state of S. typhi. Some samples were stimulated at 4°C or -20°C, while others were induced by different concentrations of CuSO4. Total cell counts remained constant throughout several days by acridine orange direct counting; however, plate counts declined to undetectable levels within 48 hours by plate counting at -20°C. The direct viable counts remained fairly constant at this level by direct viable counting. Carbon and nitrogen materials slowly decreased which indicated that a large population of cells existed in the VBNC state and entered the VBNC state in response to exposure to 0.01 or 0.015 mmol/L CuSO4 for more than 14 or 12 days, respectively. Adding 3% Tween 20 or 1% catalase enabled cells to become culturable again, with resuscitation times of 48 h and 24 h, respectively. The atomic force microscope results showed that cells gradually changed in shape from short rods to coccoids, and decreased in size when they entered the VBNC state. Further animal experiments suggested that resuscitated cells might regain pathogenicity.

  4. Stepwise changes in viable but nonculturable Vibrio cholerae cells.

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    Imamura, Daisuke; Mizuno, Tamaki; Miyoshi, Shin-ichi; Shinoda, Sumio

    2015-05-01

    Many bacterial species are known to become viable but nonculturable (VBNC) under conditions that are unsuitable for growth. In this study, the requirements for resuscitation of VBNC-state Vibrio cholerae cells were found to change over time. Although VBNC cells could initially be converted to culturable by treatment with catalase or HT-29 cell extract, they subsequently entered a state that was not convertible to culturable by these factors. However, fluorescence microscopy revealed the presence of live cells in this state, from which VBNC cells were resuscitated by co-cultivation with HT-29 human colon adenocarcinoma cells. Ultimately, all cells entered a state from which they could not be resuscitated, even by co-cultivation with HT-29. These characteristic changes in VBNC-state cells were a common feature of strains in both V. cholerae O1 and O139 serogroups. Thus, the VBNC state of V. cholerae is not a single property but continues to change over time. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

  5. Cellular uptake and degradation behaviour of biodegradable poly(ethylene glycol-graft-methyl methacrylate) nanoparticles crosslinked with dimethacryloyl hydroxylamine.

    Science.gov (United States)

    Scheler, Stefan; Kitzan, Martina; Fahr, Alfred

    2011-01-17

    Crosslinked polymers with hydrolytically cleavable linkages are highly interesting materials for the design of biodegradable drug carriers. The aim of this study was to investigate if nanoparticles made of such polymers have the potential to be used also for intracellular drug delivery. PEGylated nanoparticles were prepared by copolymerization of methacrylic acid esters and N,O-dimethacryloylhydroxylamine (DMHA). The particles were stable at pH 5.0. At pH 7.4 and 9.0 the degradation covered a time span of about 14 days, following first-order kinetics with higher crosslinked particles degrading slower. Cellular particle uptake and cytotoxicity were tested with L929 mouse fibroblasts. The particle uptake rate was found to correlate linearly with the surface charge and to increase as the zeta potential becomes less negative. Coating of the particle surface with polysorbate 80 drops the internalization rate close to zero and the charge dependence disappears. This indicates the existence of a second effect apart from surface charge. A similar pattern of correlation with zeta potential and coating was also found for the degree of membrane damage while there was no effect of polysorbate on the cell metabolism which increased as the negative charge decreased. It is discussed whether exocytotic processes may explain this behaviour.

  6. Socio-Demographic Factors Affecting Levels of Cultural and Non-Cultural Prejudice: Comparing Korean, Chinese, and Japanese College Students

    Science.gov (United States)

    Chung, Hyun Sook; Jung, Sun Young; Lee, Jeeyon

    2017-01-01

    This study examined how socio-demographic factors related to the levels of cultural and non-cultural prejudice among college students from Korea, China, and Japan. We used data collected from the Asian Value Survey. The main findings are as follows. First, Chinese students showed the lowest levels of cultural and non-cultural prejudice. Second,…

  7. A comprehensive two-dimensional gel protein database of noncultured unfractionated normal human epidermal keratinocytes: towards an integrated approach to the study of cell proliferation, differentiation and skin diseases

    DEFF Research Database (Denmark)

    Celis, J E; Madsen, Peder; Rasmussen, H H

    1991-01-01

    proteins in alphabetical order), "basal cell markers", "differentiation markers", "proteins highly up-regulated in psoriatic skin", "microsequenced proteins" and "human autoantigens". For reference, we have also included 2-D gel (isoelectric focusing) patterns of cultured normal and psoriatic keratinocytes......A two-dimensional (2-D) gel database of cellular proteins from noncultured, unfractionated normal human epidermal keratinocytes has been established. A total of 2651 [35S]methionine-labeled cellular proteins (1868 isoelectric focusing, 783 nonequilibrium pH gradient electrophoresis) were resolved...

  8. Simple in vitro generation of human leukocyte antigen-G-expressing T-regulatory cells through pharmacological hypomethylation for adoptive cellular immunotherapy against graft-versus-host disease.

    Science.gov (United States)

    Stamou, Panagiota; Marioli, Dimitra; Patmanidi, Alexandra L; Sgourou, Argyro; Vittoraki, Angeliki; Theofani, Efthymia; Pierides, Chryso; Taraviras, Stavros; Costeas, Paul A; Spyridonidis, Alexandros

    2017-04-01

    Major barriers in using classical FOXP3+ regulatory T cells (Tregs) in clinical practice are their low numbers in the circulation, the lack of specific cell surface markers for efficient purification and the loss of expression of Treg signature molecules and suppressive function after in vitro expansion or in a pro-inflammatory microenviroment. A surface molecule with potent immunosuppressive function is the human leukocyte antigen-G (HLA-G), which is normally expressed in placenta protecting the "semi-allogeneic" fetus from maternal immune attack. Because HLA-G expression is strongly regulated by methylation, we asked whether hypomethylating agents (HA) may be used in vitro to induce HLA-G expression on conventional T cells and convert them to Tregs. Human peripheral blood T cells were exposed to azacytidine/decitabine and analyzed for HLA-G expression and their in vitro suppressor properties. HA treatment induces de novo expression of HLA-G on T cells through hypomethylation of the HLA-G proximal promoter. The HA-induced CD4(+)HLA-G(pos) T cells are FOXP3 negative and have potent in vitro suppression function, which is dependent to a large extent, but not exclusively, on the HLA-G molecule. Converted HLA-G(pos) suppressors retain their suppressor function in the presence of tumor necrosis factor (TNF) and preserve hypomethylated the HLA-G promoter for at least 2 days after azacytidine exposure. Decitabine-treated T cells suppressed ex vivo the proliferation of T cells isolated from patients suffering from graft-versus-host disease (GVHD). We propose, in vitro generation of HLA-G-expressing T cells through pharmacological hypomethylation as a simple, Good Manufacturing Practice (GMP)-compatible and efficient strategy to produce a stable Treg subset of a defined phenotype that can be easily purified for adoptive immunotherapy. Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

  9. Quantitative Approach to Determining the Contribution of Viable-but-Nonculturable Subpopulations to Malolactic Fermentation Processes▿

    OpenAIRE

    2009-01-01

    Different sizes of viable-but-nonculturable cell subpopulations of a lactic acid bacterium strain were induced by adding increasing amounts of SO2. The experimental data obtained here were fitted to a segregated kinetic model developed previously. This procedure allowed us to determine in quantitative terms the contribution of this physiological state to malolactic fermentation.

  10. Non-culturable bioaerosols in indoor settings: Impact on health and molecular approaches for detection

    Science.gov (United States)

    Blais-Lecours, Pascale; Perrott, Phillipa; Duchaine, Caroline

    2015-06-01

    Despite their significant impact on respiratory health, bioaerosols in indoor settings remain understudied and misunderstood. Culture techniques, predominantly used for bioaerosol characterisation in the past, allow for the recovery of only a small fraction of the real airborne microbial burden in indoor settings, given the inability of several microorganisms to grow on agar plates. However, with the development of new tools to detect non-culturable environmental microorganisms, the study of bioaerosols has advanced significantly. Most importantly, these techniques have revealed a more complex bioaerosol burden that also includes non-culturable microorganisms, such as archaea and viruses. Nevertheless, air quality specialists and consultants remain reluctant to adopt these new research-developed techniques, given that there are relatively few studies found in the literature, making it difficult to find a point of comparison. Furthermore, it is unclear as to how this new non-culturable data can be used to assess the impact of bioaerosol exposure on human health. This article reviews the literature that describes the non-culturable fraction of bioaerosols, focussing on bacteria, archaea and viruses, and examines its impact on bioaerosol-related diseases. It also outlines available molecular tools for the detection and quantification of these microorganisms and states various research needs in this field.

  11. Genotypic analysis of meningococcal factor h-binding protein from non-culture clinical specimens.

    Directory of Open Access Journals (Sweden)

    Stephen A Clark

    Full Text Available Factor H-Binding Protein (fHbp is an outer membrane protein antigen included in two novel meningococcal group B vaccines and, as such, is an important typing target. Approximately 50% of meningococcal disease cases in England and Wales are confirmed using real-time PCR on non-culture clinical specimens only. Protocols for typing fHbp from this subset of cases have not yet been established. Here we present a nested PCR-based assay designed to amplify and sequence fHbp from non-culture clinical specimens. From analytical sensitivity experiments carried out using diluted DNA extracts, an estimated analytical sensitivity limit of 6 fg/µL of DNA (<3 genome copies/µL was calculated. The sensitivity of the assay was shown to be comparable to the ctrA-directed real-time PCR assay currently used to confirm invasive disease diagnoses from submitted clinical specimens. A panel of 96 diverse, patient-matched clinical specimen/isolate pairs from invasive disease cases was used to illustrate the breadth of strain coverage for the assay. All fHbp alleles sequenced from the isolates matched those derived from previous whole genome analyses. The first-round PCR primer binding sites are highly conserved, however an exceptional second-round PCR primer site mismatch in one validation isolate prevented amplification. In this case, amplification from the corresponding clinical specimen was achieved, suggesting that the use of a nested PCR procedure may compensate for any minor mismatches in round-two primer sites. The assay was successful at typing 91/96 (94.8% of the non-culture clinical specimens in this study and exhibits sufficient sensitivity to type fHbp from the vast majority of non-culture clinical specimens received by the Meningococcal Reference Unit, Public Health England.

  12. Acanthamoeba polyphaga resuscitates viable non-culturable Legionella pneumophila after disinfection.

    Science.gov (United States)

    García, María Teresa; Jones, Snake; Pelaz, Carmen; Millar, Richard D; Abu Kwaik, Yousef

    2007-05-01

    Amoebae are the natural hosts for Legionella pneumophila and play essential roles in bacterial ecology and infectivity to humans. When L. pneumophila colonizes an aquatic installation, it can persist for years despite repeated treatments with disinfectants. We hypothesized that freshwater amoebae play an important role in bacterial resistance to disinfectants, and in subsequent resuscitation of viable non-culturable (VNC) L. pneumophila that results in re-emergence of the disease-causing strain in the disinfected water source. Our work showed that in the absence of Acanthamoeba polyphaga, seven L. pneumophila strains became non-culturable after treatment by 256 p.p.m. of sodium hypochlorite (NaOCl). In contrast, intracellular L. pneumophila within A. polyphaga was resistant to 1024 p.p.m. of NaOCl. In addition, L. pneumophila-infected A. polyphaga exhibited increased resistance to NaOCl. When chlorine-sterilized water samples were co-cultured with A. polyphaga, the non-culturable L. pneumophila were resuscitated and proliferated robustly within A. polyphaga. Upon treatment by NaOCl, uninfected amoebae differentiated into cysts within 48 h. In contrast, L. pneumophila-infected A. polyphaga failed to differentiate into cysts, and L. pneumophila was never detected in cysts of A. polyphaga. We conclude that amoebic trophozoites protect intracellular L. pneumophila from eradication by NaOCl, and play an essential role in resuscitation of VNC L. pneumophila in NaOCl-disinfected water sources. Intracellular L. pneumophila within trophozoites of A. polyphaga block encystation of the amoebae, and the resistance of both organisms to NaOCl is enhanced. To ensure long-term eradication and complete loss of the VNC state of L. pneumophila, we recommend that Legionella-protozoa co-culture should be an important tool to ensure complete loss of the VNC state of L. pneumophila.

  13. Virulence of viable but nonculturable S. Typhimurium LT2 after peracetic acid treatment.

    Science.gov (United States)

    Jolivet-Gougeon, A; Sauvager, F; Bonnaure-Mallet, M; Colwell, R R; Cormier, M

    2006-11-01

    S. Typhimurium LT2 cells suspended in sterilized sewage effluent water (SEW) and in distilled water microcosms were exposed to 0, 7, 15 and 20 mg/l peracetic acid, and tested for viability and virulence. After treatment for one hour, colony forming units decreased by at least 5 log units at peracetic acid concentration of 7 mg/l. In SEW, at peracetic acid concentration of 15 mg/l, the cells were nonculturable (VNC), but retained virulence as demonstrated by invasion assays of HeLa cells. Higher concentrations (greater than or equal to 20 mg/l) resulted in bacterial death, i.e. substrate non-responsive cells. Despite morphological alterations of the bacteria after peracetic acid treatment, visualized by transmission electronic microscopy, conservation of both adhesive and invasive capacities was confirmed by scanning electron microscopy after exposure to 0-15 mg/l peracetic acid. Public health professionals need to recognize that peracetic acid-treated Salmonella is capable of modifying its physiological characteristics, including entering and recovering from the viable but nonculturable state, and may remain virulent after a stay in SEW followed by peracetic acid treatment.

  14. Cultural and noncultural predictors of health outcomes in Korean daughter and daughter-in-law caregivers.

    Science.gov (United States)

    Kim, Jin-Sun; Lee, Eun-Hyun

    2003-01-01

    In Western cultures, adverse health effects resulting from providing care for impaired elders is well documented for family caregivers, but little is known about the health of Korean caregivers. This study examined the level of depression and physical health of 120 daughter and daughter-in-law caregivers who cared for cognitively or functionally impaired elderly in Korea. It was hypothesized that cultural factors would have a greater effect on caregivers' health outcomes than noncultural factors, but, contrary to this expectation, the effects of noncultural factors were found to outweigh those of cultural factors. Moreover, the caregivers in this study reported a relatively high level of depression, and more caregivers rated their own health as "poor" than did Western caregivers in previous studies. Family caregiving for the impaired elderly is stressful and negatively affects Korean caregivers' health outcomes regardless of societal values such as filial piety and familism regarding parent care in Korea. Culturally acceptable and sensible support programs may be useful in sustaining long-term care at home by Korean daughter and daughter-in-law caregivers. Further family caregiving studies in the Korean sociocultural context are recommended.

  15. Noncultured Autologous Adipose-Derived Stem Cells Therapy for Chronic Radiation Injury

    Directory of Open Access Journals (Sweden)

    Sadanori Akita

    2010-01-01

    Full Text Available Increasing concern on chronic radiation injuries should be treated properly for life-saving improvement of wound management and quality of life. Recently, regenerative surgical modalities should be attempted with the use of noncultured autologous adipose-derived stem cells (ADSCs with temporal artificial dermis impregnated and sprayed with local angiogenic factor such as basic fibroblast growth factor, and secondary reconstruction can be a candidate for demarcation and saving the donor morbidity. Autologous adipose-derived stem cells, together with angiogenic and mitogenic factor of basic fibroblast growth factor and an artificial dermis, were applied over the excised irradiated skin defect and tested for Patients who were uneventfully healed with minimal donor-site morbidity, which lasts more than 1.5 years.

  16. Invasive Candidiasis in Various Patient Populations: Incorporating Non-Culture Diagnostic Tests into Rational Management Strategies

    Directory of Open Access Journals (Sweden)

    Cornelius J. Clancy

    2016-02-01

    Full Text Available Mortality rates due to invasive candidiasis remain unacceptably high, in part because the poor sensitivity and slow turn-around time of cultures delay the initiation of antifungal treatment. β-d-glucan (Fungitell and polymerase chain reaction (PCR-based (T2Candida assays are FDA-approved adjuncts to cultures for diagnosing invasive candidiasis, but their clinical roles are unclear. We propose a Bayesian framework for interpreting non-culture test results and developing rational patient management strategies, which considers test performance and types of invasive candidiasis that are most common in various patient populations. β-d-glucan sensitivity/specificity for candidemia and intra-abdominal candidiasis is ~80%/80% and ~60%/75%, respectively. In settings with 1%–10% likelihood of candidemia, anticipated β-d-glucan positive and negative predictive values are ~4%–31% and ≥97%, respectively. Corresponding values in settings with 3%–30% likelihood of intra-abdominal candidiasis are ~7%–51% and ~78%–98%. β-d-glucan is predicted to be useful in guiding antifungal treatment for wide ranges of populations at-risk for candidemia (incidence ~5%–40% or intra-abdominal candidiasis (~7%–20%. Validated PCR-based assays should broaden windows to include populations at lower-risk for candidemia (incidence ≥~2% and higher-risk for intra-abdominal candidiasis (up to ~40%. In the management of individual patients, non-culture tests may also have value outside of these windows. The proposals we put forth are not definitive treatment guidelines, but rather represent starting points for clinical trial design and debate by the infectious diseases community. The principles presented here will be applicable to other assays as they enter the clinic, and to existing assays as more data become available from different populations.

  17. Dynamics of bone graft healing around implants

    Directory of Open Access Journals (Sweden)

    Narayan Venkataraman

    2015-01-01

    A few questions arise pertaining to the use of bone grafts along with implants are whether these are successful in approximation with implant. Do they accelerate bone regeneration? Are all defects ultimately regenerated with new viable bone? Is the bone graft completely resorbed or integrated in new bone? Does the implant surface characteristic positively affect osseointegration when used with a bone graft? What type of graft and implant surface can be used that will have a positive effect on the healing type and time? Finally, what are the dynamics of bone graft healing around an implant? This review discusses the cellular and molecular mechanisms of bone graft healing in general and in vicinity of another foreign, avascular body, namely the implant surface, and further, the role of bone grafts in osseointegration and/or clinical success of the implants.

  18. Bone graft

    Science.gov (United States)

    ... around the area. The bone graft can be held in place with pins, plates, or screws. Why ... Orthopaedic Surgery, San Francosco, CA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the ...

  19. Entry of Yersinia Pestis into the Viable but Nonculturable State in a Low-Temperature Tap Water Microcosm

    Science.gov (United States)

    2011-03-16

    to enter the VBNC state [17,18,19,20]. In addition, many other bacterial pathogens, including Francisella tularensis, Vibrio cholerae , and Escherichia... Vibrio cholerae , and Escherichia coli enter the VBNC state [12,21]. In addition, the two closest pathogenic relatives of Y. pestis, namely Y...2001) Viability of the Nonculturable Vibrio cholerae O1 and O139. Systematic and Applied Microbiology 24: 331–341. 38. Jang KI, Kim MG, Ha SD, Kim KS

  20. Interspecific quorum sensing mediates the resuscitation of viable but nonculturable vibrios.

    Science.gov (United States)

    Ayrapetyan, Mesrop; Williams, Tiffany C; Oliver, James D

    2014-04-01

    Entry and exit from dormancy are essential survival mechanisms utilized by microorganisms to cope with harsh environments. Many bacteria, including the opportunistic human pathogen Vibrio vulnificus, enter a form of dormancy known as the viable but nonculturable (VBNC) state. VBNC cells can resuscitate when suitable conditions arise, yet the molecular mechanisms facilitating resuscitation in most bacteria are not well understood. We discovered that bacterial cell-free supernatants (CFS) can awaken preexisting dormant vibrio populations within oysters and seawater, while CFS from a quorum sensing mutant was unable to produce the same resuscitative effect. Furthermore, the quorum sensing autoinducer AI-2 could induce resuscitation of VBNC V. vulnificus in vitro, and VBNC cells of a mutant unable to produce AI-2 were unable to resuscitate unless the cultures were supplemented with exogenous AI-2. The quorum sensing inhibitor cinnamaldehyde delayed the resuscitation of wild-type VBNC cells, confirming the importance of quorum sensing in resuscitation. By monitoring AI-2 production by VBNC cultures over time, we found quorum sensing signaling to be critical for the natural resuscitation process. This study provides new insights into the molecular mechanisms stimulating VBNC cell exit from dormancy, which has significant implications for microbial ecology and public health.

  1. Biological changes of Enterococcus faecalis in the viable but nonculturable state.

    Science.gov (United States)

    E, J; Jiang, Y T; Yan, P F; Liang, J P

    2015-11-23

    Enterococcus faecalis may enter a viable but nonculturable (VBNC) state under adverse conditions. E. faecalis, the major bacterial species present in failed root canal treatments, is thought to survive after endodontic treatment by entering a VBNC state. In this study, we characterized the VBNC state of E. faecalis. We designed 3 different protocols to successfully induce the VBNC state. Approximately one-third of bacteria entered a VBNC state after 15-30 days, and all remained viable for at least 2 months. The morphology, glycometabolism, and adhesion capabilities of VBNC cells differed from those of E. faecalis during the exponential growth phase. Specifically, VBNC E. faecalis cells could not decompose lactose, D-mannitol, or D-sorbitol, although they were able to metabolize sucrose. Transmission electron microscopy showed that the morphology of the VBNC E. faecalis cells changed significantly; the cytoplasmic matrix was unevenly condensed and the overall morphology of the cells became irregular, but the cell membranes remained intact. Although the adhesion ability of the bacteria decreased, VBNC E. faecalis could still adhere to collagen fiber type I and tooth dentine. The persistence of this adhesion ability may be important in the virulence of VBNC E. faecalis.

  2. Fate of viable but non-culturable Listeria monocytogenes in pig manure microcosms

    Directory of Open Access Journals (Sweden)

    Jeremy eDesneux

    2016-03-01

    Full Text Available The fate of two strains of L. monocytogenes and their ability to become viable but non-culturable (VBNC was investigated in microcosms containing piggery effluents (two raw manures and two biologically treated manures stored for two months at 8°C and 20°C. Levels of L. monocytogenes were estimated using the culture method, qPCR, and propidium monoazide treatment combined with qPCR (qPCRPMA. The chemical composition and the microbial community structure of the manures were also analysed. The strains showed similar decline rates and persisted up to 63 days. At day zero, the percentage of VBNC cells among viable cells was higher in raw manures (81.5-94.8% than in treated manures (67.8-79.2%. The changes in their proportion over time depended on the temperature and on the type of effluent: the biggest increase was observed in treated manures at 20°C and the smallest increase in raw manures at 8°C. The chemical parameters had no influence on the behaviour of the strains, but decrease of the persistence of viable cells was associated with an increase in the microbial richness of the manures. This study demonstrated that storing manure altered the culturability of L. monocytogenes, which rapidly entered the VBNC state, and underlines the importance of including VBNC cells when estimating the persistence of the pathogens in farm effluents.

  3. Undiagnosed invasive candidiasis: incorporating non-culture diagnostics into rational prophylactic and preemptive antifungal strategies.

    Science.gov (United States)

    Clancy, Cornelius J; Nguyen, Minh Hong

    2014-07-01

    The insensitivity of blood cultures for diagnosing invasive candidiasis fuels prophylactic and preemptive antifungal treatment. Assays like serum β-D-glucan or mannan/anti-mannan detection can identify blood culture-negative invasive candidiasis, but their roles in guiding antifungal therapy are undefined. We propose that non-culture tests can be incorporated into rational management strategies, based on clinical setting. As an example, β-D-glucan sensitivity/specificity for blood culture-negative, deep-seated candidiasis is approximately 60/75%. In intensive care units with candidiasis rates, positive/negative predictive values are 99% and 6/98%, respectively. With pre-test likelihoods of 10 and 33%, positive/negative predictive values are 20/94% and 54/79%, respectively. Based on these data, negative and positive β-D-glucan results likely will be most useful for discontinuing prophylaxis among low-risk to moderate-risk patients (pre-test likelihoods ∼3-10%), and triggering preemptive therapy among moderate-risk to high-risk patients (pre-test likelihoods ∼10-25%), respectively. In extremely high-risk patients, universal prophylaxis is likely to be the best strategy.

  4. Current Perspectives on Viable but Non-Culturable (VBNC Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Thandavarayan eRamamurthy

    2014-07-01

    Full Text Available Under stress conditions, many species of bacteria enter into starvation mode of metabolism or a physiologically viable but non-culturable (VBNC state. Several human pathogenic bacteria have been reported to enter into the VBNC state under these conditions. The pathogenic VBNC bacteria cannot be grown using conventional culture media, although they continue to retain their viability and express their virulence. Though there have been debates on the VBNC concept in the past, several molecular studies have shown that not only VBNC state can be induced under in vitro conditions but also that resuscitation from this state is possible under appropriate conditions. The most notable advance in resuscitating VBNC bacteria is the discovery of resuscitation-promoting factor (Rpf, which is a bacterial cytokines found in both Gram-positive and Gram-negative organisms. VBNC state is a survival strategy adopted by the bacteria, which has important implication in several fields, including environmental monitoring, food technology and infectious disease management and hence it is important to investigate the association of bacterial pathogens under VBNC state and the water/foodborne outbreaks. In this review, we describe various aspects of VBNC bacteria, which include their proteomic and genetic profiles under the VBNC state, conditions of resuscitation, methods of detection, antibiotic resistance and observations on Rpf.

  5. The importance of the viable but non-culturable state in human bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Laam eLi

    2014-06-01

    Full Text Available Many bacterial species have been found to exist in a viable but non-culturable (VBNC state since its discovery in 1982. VBNC cells are characterized by a loss of culturability on routine agar, which impairs their detection by conventional plate count techniques. This leads to an underestimation of total viable cells in environmental or clinical samples, and thus poses a risk to public health. In this review, we present recent findings on the VBNC state of human bacterial pathogens. The characteristics of VBNC cells, including the similarities and differences to viable, culturable cells and dead cells, and different detection methods are discussed. Exposure to various stresses can induce the VBNC state, and VBNC cells may be resuscitated back to culturable cells under suitable stimuli. The conditions that trigger the induction of the VBNC state and resuscitation from it are summarized and the mechanisms underlying these two processes are discussed. Last but not least, the significance of VBNC cells and their potential influence on human health are also reviewed.

  6. The viable but non-culturable state in pathogenic Escherichia coli: A general review.

    Science.gov (United States)

    Pienaar, Jennifer A; Singh, Atheesha; Barnard, Tobias G

    2016-01-01

    The persistence and pathogenicity of pathogenic bacteria are dependent on the ability of the species to survive in adverse conditions. During the infectious process, the organism may need to pass through certain hostile anatomical sites, such as the stomach. Under various environmental stresses, many bacteria enter into the viable but non-culturable (VBNC) state, where they are 'alive' or metabolically active, but will not grow on conventional media. Escherichia coli bacteria encounter several diverse stress factors during their growth, survival and infection and thus may enter into the VBNC state. This review discusses various general aspects of the VBNC state, the mechanisms and possible public health impact of indicator and pathogenic E. coli entering into the VBNC state. A literature review was conducted to ascertain the possible impact of E. coli entering into the VBNC state. Escherichia coli enter into the VBNC state by means of several induction mechanisms. Various authors have found that E. coli can be resuscitated post-VBNC. Certain strains of pathogenic E. coli are still able to produce toxins in the VBNC state, whilst others are avirulent during the VBNC state but are able to regain virulence after resuscitation. Pathogenic and indicator E. coli entering into the VBNC state could have an adverse effect on public health if conventional detection methods are used, where the number of viable cells could be underestimated and the VBNC cells still produce toxins or could, at any time, be resuscitated and become virulent again.

  7. Heat resistance of viable but non-culturable Escherichia coli cells determined by differential scanning calorimetry.

    Science.gov (United States)

    Castro-Rosas, Javier; Gómez-Aldapa, Carlos Alberto; Villagómez Ibarra, José Roberto; Santos-López, Eva María; Rangel-Vargas, Esmeralda

    2017-10-16

    Several reports have suggested that the viable but non-culturable (VBNC) state is a resistant form of bacterial cells that allows them to remain in a dormant form in the environment. Nevertheless, studies on the resistance of VBNC bacterial cells to ecological factors are limited, mainly because techniques that allow this type of evaluation are lacking. Differential scanning calorimetry (DSC) has been used to study the thermal resistance of culturable bacteria but has never been used to study VBNC cells. In this work, the heat resistance of Escherichia coli cells in the VBNC state was studied using the DSC technique. The VBNC state was induced in E. coli ATCC 25922 by suspending bacterial cells in artificial sea water, followed by storage at 3 ± 2°C for 110 days. Periodically, the behaviour of E. coli cells was monitored by plate counts, direct viable counts and DSC. The entire bacterial population entered the VBNC state after 110 days of storage. The results obtained with DSC suggest that the VBNC state does not confer thermal resistance to E. coli cells in the temperature range analysed here. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Stent graft placement for dysfunctional arteriovenous grafts

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Gyeong Sik [Dept. of Radiology, CHA Bundang Medical Center, College of Medicine, CHA University, Seongnam (Korea, Republic of); Shin, Byung Seok; Ohm, Joon Young; Ahn, Moon Sang [Chungnam National University Hospital, Daejeon (Korea, Republic of)

    2015-07-15

    This study aimed to evaluate the usefulness and outcomes of stent graft use in dysfunctional arteriovenous grafts. Eleven patients who underwent stent graft placement for a dysfunctional hemodialysis graft were included in this retrospective study. Expanded polytetrafluoroethylene covered stent grafts were placed at the venous anastomosis site in case of pseudoaneurysm, venous laceration, elastic recoil or residual restenosis despite the repeated angioplasty. The patency of the arteriovenous graft was evaluated using Kaplan-Meier analysis. Primary and secondary mean patency was 363 days and 741 days. Primary patency at 3, 6, and 12 months was 82%, 73%, and 32%, respectively. Secondary patency at the 3, 6, 12, 24, and 36 months was improved to 91%, 82%, 82%, 50%, and 25%, respectively. Fractures of the stent graft were observed in 2 patients, but had no effect on the patency. Stent graft placement in dysfunctional arteriovenous graft is useful and effective in prolonging graft patency.

  9. Change of protein profiles in the induction of the viable but nonculturable state of Vibrio parahaemolyticus.

    Science.gov (United States)

    Lai, Chiou-Jour; Chen, Shau-Yan; Lin, I-Hsuan; Chang, Chuan-Hsiung; Wong, Hin-Chung

    2009-10-31

    This work reports on the metabolic response in the induction of the viable but nonculturable (VBNC) state of the seafood enteropathogen Vibrio parahaemolyticus, as determined by analyzing the corresponding change in protein profiles. V. parahaemolyticus ST550 was incubated at 4 degrees C in the Morita mineral salt-0.5% NaCl medium to induce the VBNC state in six weeks. Starving the cells by incubation at 25 degrees C for 24 h prior to 4 degrees C incubation inhibited the cells from entering VBNC state. Protein profiles were determined by two-dimensional polyacrylamide gel electrophoresis and the proteins which were enhanced in the VBNC induction/VBNC state or strongly down-regulated in the starved cells were identified by mass spectrophotometry. The 13 up-regulated proteins are known to be associated with transcription (two homologues of alpha subunit DNA-directed RNA polymerase, phosphoribosylaminoimidazole carboxamide formyltransferase/IMP cyclohydrolase), translation (ribosomal protein S1, two homologues of elongation factor TU, elongation factor EF-G), ATP synthase (F1 alpha subunit), gluconeogenesis-related metabolism (dihydrolipoamide acetyltransferase, glyceraldehyde 3-phosphate dehydrogenase), antioxidants (2 homologues of peroxiredoxins, AhpC/Tsa family) and a conserved hypothetical protein with unknown function. Expressions of the genes encoding four of these proteins were at high levels in the second week of VBNC induction; declined afterwards, and were down-regulated in the starved cells. These proteins may play important roles in the induction or maintenance of VBNC V. parahaemolyticus. The results of this investigation improve our understanding of the metabolic activities in the VBNC state of bacteria.

  10. Enumeration of viable non-culturable Vibrio cholerae using propidium monoazide combined with quantitative PCR.

    Science.gov (United States)

    Wu, Bin; Liang, Weili; Kan, Biao

    2015-08-01

    The well-known human pathogenic bacterium, Vibrio cholerae, can enter a physiologically viable but non-culturable (VBNC) state under stress conditions. The differentiation of VBNC cells and nonviable cells is essential for both disease prevention and basic research. Among all the methods for detecting viability, propidium monoazide (PMA) combined with real-time PCR is popular because of its specificity, sensitivity, and speed. However, the effect of PMA treatment is not consistent and varies among different species and conditions. In this study, with an initial cell concentration of 1×10(8) CFU/ml, time and dose-effect relationships of different PMA treatments were evaluated via quantitative real-time PCR using live cell suspensions, dead cell suspensions and VBNC cell suspensions of V. cholerae O1 El Tor strain C6706. The results suggested that a PMA treatment of 20 μM PMA for 20 min was optimal under our conditions. This treatment maximized the suppression of the PCR signal from membrane-compromised dead cells but had little effect on the signal from membrane-intact live cells. In addition to the characteristics of PMA treatment itself, the initial concentration of the targeted bacteria showed a significant negative influence on the stability of PMA-PCR assay in this study. We developed a strategy that mimicked a 1×10(8) CFU/ml cell concentration with dead bacteria of a different bacterial species, the DNA of which cannot be amplified using the real time PCR primers. With this strategy, our optimal approach successfully overcame the impact of low cell density and generated stable and reliable results for counting viable cells of V. cholerae in the VBNC state. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. The viable but non-culturable state in pathogenic Escherichia coli: A general review

    Directory of Open Access Journals (Sweden)

    Jennifer A. Pienaar

    2016-02-01

    Full Text Available Background: The persistence and pathogenicity of pathogenic bacteria are dependent on the ability of the species to survive in adverse conditions. During the infectious process, the organism may need to pass through certain hostile anatomical sites, such as the stomach. Under various environmental stresses, many bacteria enter into the viable but non-culturable (VBNC state, where they are ‘alive’ or metabolically active, but will not grow on conventional media. Escherichia coli bacteria encounter several diverse stress factors during their growth, survival and infection and thus may enter into the VBNC state.Objectives: This review discusses various general aspects of the VBNC state, the mechanisms and possible public health impact of indicator and pathogenic E. coli entering into the VBNC state.Method: A literature review was conducted to ascertain the possibleimpact of E. coli entering into the VBNC state.Results: Escherichia coli enter into the VBNC state by means of several induction mechanisms. Various authors have found that E. coli can be resuscitated post-VBNC. Certain strains of pathogenic E. coli are still able to produce toxins in the VBNC state, whilst others are avirulent during the VBNC state but are able to regain virulence after resuscitation.Conclusion: Pathogenic and indicator E. coli entering into the VBNC state could have an adverse effect on public health if conventional detection methods are used, where the number of viable cells could be underestimated and the VBNC cells still produce toxins or could, at anytime, be resuscitated and become virulent again.

  12. Reduced infectivity of waterborne viable but nonculturable Helicobacter pylori strain SS1 in mice.

    Science.gov (United States)

    Boehnke, Kevin F; Eaton, Kathryn A; Fontaine, Clinton; Brewster, Rebecca; Wu, Jianfeng; Eisenberg, Joseph N S; Valdivieso, Manuel; Baker, Laurence H; Xi, Chuanwu

    2017-08-01

    Helicobacter pylori infection has been consistently associated with lack of access to clean water and proper sanitation, but no studies have demonstrated that the transmission of viable but nonculturable (VBNC) H. pylori can occur from drinking contaminated water. In this study, we used a laboratory mouse model to test whether waterborne VBNCH. pylori could cause gastric infection. We performed five mouse experiments to assess the infectivity of VBNCH. pylori in various exposure scenarios. VBNC viability was examined using Live/Dead staining and Biolog phenotype metabolism arrays. High doses of VBNCH. pylori in water were chosen to test the "worst-case" scenario for different periods of time. One experiment also investigated the infectious capabilities of VBNC SS1 using gavage. Further, immunocompromised mice were exposed to examine infectivity among potentially vulnerable groups. After exposure, mice were euthanized and their stomachs were examined for H. pylori infection using culture and PCR methodology. VBNC cells were membrane intact and retained metabolic activity. Mice exposed to VBNCH. pylori via drinking water and gavage were not infected, despite the various exposure scenarios (immunocompromised, high doses) that might have permitted infection with VBNCH. pylori. The positive controls exposed to viable, culturable H. pylori did become infected. While other studies that have used viable, culturable SS1 via gavage or drinking water exposures to successfully infect mice, in our study, waterborne VBNC SS1 failed to colonize mice under all test conditions. Future studies could examine different H. pylori strains in similar exposure scenarios to compare the relative infectivity of the VBNC vs the viable, culturable state, which would help inform future risk assessments of H. pylori in water. © 2017 The Authors. Helicobacter Published by John Wiley & Sons Ltd.

  13. Culture-and nonculture-based antibiotics for complicated soft tissue infections are comparable

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    Ronald Irwanto

    2013-04-01

    Full Text Available BACKGROUND Data collected in 2010 from Cipto Mangunkusumo Hospital indicate that complicated skin and soft tissue infections accounted for more than 10% of cases. Etiological diagnoses are based on the findings on bacterial culture and thus evaluation of the effectiveness of bacterial culture becomes a necessity. The purpose of this study was to evaluate the operational effectiveness of bacterial culture for etiological diagnosis of complicated skin and soft tissue infections. Methods This was a historical cohort study using secondary data of patients with complicated skin and soft tissue infections admitted for hospitalization to Cipto Mangunkusumo Hospital, Jakarta from July 2011 to July 2012. The 90 subjects meeting the inclusion and exclusion criteria were divided into 2 groups of 45 patients each. Group 1 comprised patients who received initial antibiotic therapy according to cultural results, while the patients in group 2 received initial antibiotic therapy without reference to cultural results. Successful diagnostic culture was assessed by the absence of therapeutic failure. Therapeutic failure was determined using 3 parameters that had to be fulfilled, viz. absence of antibiotic escalation, repeat operations, and clinical deterioration. The latter parameter was assessed by clinical judgement of the attending physician. Results After controlling for confounding variables (age, severity of infection, comorbidity, there was no statistical difference in therapeutic success between culture-based and non-culture based initial antibiotic therapies (OR=0.45, p=0.085. Conclusion This study demonstrates the ineffectiveness of bacterial culture as a diagnostic criterion for appropriate antibiotic therapy of complicated skin and soft tissue infections.

  14. Non-cultural methods of human microflora evaluation for the benefit of crew medical control in confined habitat

    Science.gov (United States)

    Viacheslav, Ilyin; Lana, Moukhamedieva; Georgy, Osipov; Aleksey, Batov; Zoya, Soloviova; Robert, Mardanov; Yana, Panina; Anna, Gegenava

    2011-05-01

    Current control of human microflora is a great problem not only for the space medicine but also for practical health care. Due to many reasons its realization by classical bacteriological method is difficult in practical application or cannot be done. To evaluate non-cultural methods of microbial control of crews in a confined habitat we evaluated two different methods. The first method is based on digital treatment of microbial visual images, appearing after gram staining of microbial material from natural sample. This way the rate between gram-positive and gram-negative microbe could be gained as well as differentiation of rods and cocci could be attained, which is necessary for primary evaluation of human microbial cenosis in remote confined habitats. The other non-culture method of human microflora evaluation is gas chromatomass spectrometry (gcms) analysis of swabs gathered from different body sites. Gc-ms testing of swabs allows one to validate quantitative and special microflora based on specific lipid markers analysis.

  15. Modeling the effect of light and salinity on viable but non-culturable (VBNC) Enterococcus.

    Science.gov (United States)

    Gin, Karina Yew-Hoong; Goh, Shin Giek

    2013-06-15

    Enterococci have been recommended as suitable bacteria indicators for assessing the microbial quality of recreational waters. However, recent studies have shown that bacteria, including enterococci, are able to enter a viable but non-culturable (VBNC) state under environmentally stressed conditions, where they may remain undetected if culture-based methods are employed. To appreciate the extent of transformation of these cells in surface waters, a model Enterococcus organism, E. faecalis, was examined in laboratory controlled microcosms under different light and salinity conditions. Cells were detected by both standard culture-based and PMA-qPCR (propidium monoazide quantitative PCR) methods so that the VBNC cells could be enumerated. The decay rates from the culture based method (kc) and PMA-qPCR method (kp) were established for the different conditions. In general, the kC values (ranging from 0.0088 hr(-1) to 0.9755 hr(-1)) were always higher than the kP values (0.0019 hr(-1) to 0.2373 hr(-1)), implying that cells were able to retain their viability for much longer periods than what is shown by the culture-based method. In both cases, the k values generally showed an increasing trend with an increase in light irradiation, implying greater die-off with light. For freshwater microcosms, the kp values were 3-6 times lower than the kc values for different irradiation conditions, whereas for seawater the difference was up to 12 times, showing that E. faecalis adapts well to seawater. The kinetic data were used to develop models to describe the dynamics of VBNC formation in natural waters. At low light intensities (less than about 20 Wm(-2)), the proportion of VBNC cells was found to steadily increase to as high as 50%, even after 4 days. However, at higher light levels, this proportion was achieved more quickly (less than 5 h) but also diminished more rapidly. Hence, at high light levels, the percentage of VBNC cells is expected to be significant only for a few hours

  16. Revascularização miocárdica com circulação extracorpórea: aspectos bioquímicos, hormonais e celulares On-pump coronary artery bypass graft surgery: biochemical, hormonal and cellular features

    Directory of Open Access Journals (Sweden)

    Edmo Atique Gabriel

    2011-12-01

    artery bypass graft (CABG surgery. METHODS: Eighteen patients underwent on-pump CABG surgery. Mean time of CPB was 80.3 minutes. Hormonal, biochemical and cellular measurements were taken in some time points - preoperatively, immediately after coming off CPB, 24 and 48 hours postoperatively. Friedman and Wilcoxon tests were applied based on significance level of 5%. RESULTS: There was activation and significant elevation of total leukocytes and neutrophils count over CPB, remaining this way up to 48 hours postoperatively. Total platelets count, in turn, was marked by relevant reduction immediately after coming off CPB as well as in two postoperative time points. Serum levels of total proteins and albumin, immediately after coming off CPB and also in two postoperative time points, were significantly decreased comparing with preoperative status. There was remarkable reduction of total T3, free T3 and total T4 particularly up to first 24 hours postoperatively. CONCLUSION: In on-pump CABG surgery, inflammatory effects encompass activation of total leukocytes, neutrophils and platelets, reduction of serum level of total proteins and albumin and decreased thyroid hormones levels, especially within first postoperative 24 hours.

  17. Design and development of multilayer vascular graft

    Science.gov (United States)

    Madhavan, Krishna

    2011-07-01

    strength, showed that the multilayer graft possessed properties mimicking those of native vessels. Achieving these FDA-required functional properties is essential because they play critical roles in graft performances in vivo such as thrombus formation, occlusion, healing, and bleeding. In addition, cell studies and animal studies have been performed on the multilayer graft. Our results show that the multilayer graft support mimetic vascular culture of cells and the acellular graft serves as an artery equivalent in vivo to sustain the physiological conditions and promote appropriate cellular activity. In conclusion, the newly-developed hybrid multilayer graft provides a proper balance of biomechanical and biochemical properties and demonstrates the potential for the use of vascular tissue engineering and regeneration.

  18. Bone grafting: An overview

    Directory of Open Access Journals (Sweden)

    D. O. Joshi

    2010-08-01

    Full Text Available Bone grafting is the process by which bone is transferred from a source (donor to site (recipient. Due to trauma from accidents by speedy vehicles, falling down from height or gunshot injury particularly in human being, acquired or developmental diseases like rickets, congenital defects like abnormal bone development, wearing out because of age and overuse; lead to bone loss and to replace the loss we need the bone grafting. Osteogenesis, osteoinduction, osteoconduction, mechanical supports are the four basic mechanisms of bone graft. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. An ideal bone graft material is biologically inert, source of osteogenic, act as a mechanical support, readily available, easily adaptable in terms of size, shape, length and replaced by the host bone. Except blood, bone is grafted with greater frequency. Bone graft indicated for variety of orthopedic abnormalities, comminuted fractures, delayed unions, non-unions, arthrodesis and osteomyelitis. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. By adopting different procedure of graft preservation its antigenicity can be minimized. The concept of bone banking for obtaining bone grafts and implants is very useful for clinical application. Absolute stability require for successful incorporation. Ideal bone graft must possess osteogenic, osteoinductive and osteocon-ductive properties. Cancellous bone graft is superior to cortical bone graft. Usually autologous cancellous bone graft are used as fresh grafts where as allografts are employed as an alloimplant. None of the available type of bone grafts possesses all these properties therefore, a single type of graft cannot be recomm-ended for all types of orthopedic abnormalities. Bone grafts and implants can be selected as per clinical problems, the equipments available and preference of

  19. [Management of graft failure and erythroblastopenia in patients undergoing allogeneic hematopoietic stem cell transplantation: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)].

    Science.gov (United States)

    Cornillon, Jérôme; Sicre de Fontbrune, Flore; Chantepie, Sylvain; Coiteux, Valérie; Gauthier, Jordan; Masouridi-Levrat, Stavroula; Pochon, Cécile; Terriou, Louis; Yakoub-Agha, Ibrahim; Dalle, Jean-Hugues

    2016-11-01

    Success of allogeneic hematopoietic stem cells transplantation requires both the underlying disease eradication and satisfying reconstitution of hematopoiesis from donor cells. However, reconstitution delays, secondary development or persistence of cytopenia are regularly observed and are potential causes of failure after allogeneic transplantation. These graft dysfunctions should be distinguished from non-engraftment/engraftment failure. Although these situations are relatively common, there is no consensus in the literature for their management. During the workshop of the SFGM-TC, the working group proposed recommendations from an analysis of the literature. Copyright © 2016. Published by Elsevier Masson SAS.

  20. First evidence of division and accumulation of viable but nonculturable Pseudomonas fluorescens cells on surfaces subjected to conditions encountered at meat processing premises.

    Science.gov (United States)

    Peneau, Sophie; Chassaing, Danielle; Carpentier, Brigitte

    2007-05-01

    Cleaning and disinfection of open surfaces in food industry premises leave some microorganisms behind; these microorganisms build up a resident flora on the surfaces. Our goal was to explore the phenomena involved in the establishment of this biofilm. Ceramic coupons were contaminated, once only, with Pseudomonas fluorescens suspended in meat exudate incubated at 10 degrees C. The mean adhering population after 1 day was 10(2) CFU x cm(-2) and 10(3) total cells x cm(-2), i.e., the total number of cells stained by DAPI (4',6'-diamidino-2-phenylindole). The coupons were subjected daily to a cleaning product, a disinfectant, and a further soiling with exudate. The result was a striking difference between the numbers of CFU, which reached 10(4) CFU x cm(-2), and the numbers of total cells, which reached 2 x 10(6) cells x cm(-2) in 10 days. By using hypotheses all leading to an overestimation of the number of dead cells, we showed that the quantity of nonculturable cells (DAPI-positive cells minus CFU) observed cannot be accounted for as an accumulation of dead cells. Some nonculturable cells are therefore dividing on the surface, although cell division is unable to continue to the stage of macrocolony formation on agar. The same phenomenon was observed when only a chlorinated alkaline product was used and the number of cells capable of reducing 5-cyano-2,3-ditolyl tetrazolium chloride was close to the number of total cells, confirming that most nonculturable cells are viable but nonculturable. Furthermore, the daily shock applied to the cells does not prompt them to enter a new lag phase. Since a single application of microorganisms is sufficient to produce this accumulation of cells, it appears that the phenomenon is inevitable on open surfaces in food industry premises.

  1. First Evidence of Division and Accumulation of Viable but Nonculturable Pseudomonas fluorescens Cells on Surfaces Subjected to Conditions Encountered at Meat Processing Premises▿

    Science.gov (United States)

    Peneau, Sophie; Chassaing, Danielle; Carpentier, Brigitte

    2007-01-01

    Cleaning and disinfection of open surfaces in food industry premises leave some microorganisms behind; these microorganisms build up a resident flora on the surfaces. Our goal was to explore the phenomena involved in the establishment of this biofilm. Ceramic coupons were contaminated, once only, with Pseudomonas fluorescens suspended in meat exudate incubated at 10°C. The mean adhering population after 1 day was 102 CFU·cm−2 and 103 total cells·cm−2, i.e., the total number of cells stained by DAPI (4′,6′-diamidino-2-phenylindole). The coupons were subjected daily to a cleaning product, a disinfectant, and a further soiling with exudate. The result was a striking difference between the numbers of CFU, which reached 104 CFU·cm−2, and the numbers of total cells, which reached 2 × 106 cells·cm−2 in 10 days. By using hypotheses all leading to an overestimation of the number of dead cells, we showed that the quantity of nonculturable cells (DAPI-positive cells minus CFU) observed cannot be accounted for as an accumulation of dead cells. Some nonculturable cells are therefore dividing on the surface, although cell division is unable to continue to the stage of macrocolony formation on agar. The same phenomenon was observed when only a chlorinated alkaline product was used and the number of cells capable of reducing 5-cyano-2,3-ditolyl tetrazolium chloride was close to the number of total cells, confirming that most nonculturable cells are viable but nonculturable. Furthermore, the daily shock applied to the cells does not prompt them to enter a new lag phase. Since a single application of microorganisms is sufficient to produce this accumulation of cells, it appears that the phenomenon is inevitable on open surfaces in food industry premises. PMID:17337551

  2. Bone grafts in dentistry

    Directory of Open Access Journals (Sweden)

    Prasanna Kumar

    2013-01-01

    Full Text Available Bone grafts are used as a filler and scaffold to facilitate bone formation and promote wound healing. These grafts are bioresorbable and have no antigen-antibody reaction. These bone grafts act as a mineral reservoir which induces new bone formation.

  3. Non-culturable Bacteria and Test Methods%活的不可培养细菌及其检测

    Institute of Scientific and Technical Information of China (English)

    刘红; 张明; 姜明洪; 吴光虹

    2015-01-01

    Viable But Non-culturable State(VBNC)is a special condition of the bacteria in the bad environment,but it is difficult or unable to separate culture,and can not detected in this state. It is harm for food safety and public health. Introduction to inducements and recovery conditions ofSalmonella,Staphylococcusaureus,Escherichiacoli,Vibrio parahaemolyticus,Klebsiella peneumoniae, Enterococcus faecal, Vibrio cholerae,Campylobacter jejuni, Shigella bacteria, and current commonly used detection methods of VBNC state of bacteria commonly used detection methods,and current situation of pathogenic microorganisms VBNC in water environment in pathogenic microorganisms and susceptible VBNC in beer VBNC will provide some reference of bacteria in CBNC State for researchers.%活的不可培养(viable but non-culturable state,VBNC)细菌是细菌抵抗恶劣生存环境的一种自我保护形式。细菌在不良环境中,其细胞缩成球形或表现为细胞伸长,体积增大,用常规方法较难或无法进行分离培养,也不能进行检测,但仍具有代谢活性,在一定条件下仍可诱导复苏,具有潜在致病性,给食品安全、公共卫生带来隐患。介绍食品和环境中常见的沙门氏菌、金黄色葡萄球菌、大肠埃希氏菌、副溶血弧菌、肺炎克雷伯氏菌、粪链球菌、霍乱弧菌、空肠弯曲菌、志贺氏菌等细菌的诱导和复苏条件,和目前对VBNC状态细菌常用的检测方法,以及水环境中致病微生物VBNC和啤酒中易感微生物VBNC研究现状,希望能够对细菌VBNC状态的研究者提供一定的参考。

  4. Growth Phase, Oxygen, Temperature and Starvation Affect the Development of Viable but Non-Culturable State of Vibrio cholerae

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    Bin eWu

    2016-03-01

    Full Text Available AbstractVibrio cholerae can enter into a viable but non-culturable (VBNC state in order to survive in unfavourable environments. In this study, we studied the roles of five physicochemical and microbiological factors or states, namely, different strains, growth phases, oxygen, temperature, and starvation, on the development of VBNC of V. cholerae in artificial sea water (ASW. Different strains of the organism, the growth phase, and oxygen levels affected the progress of VBNC development. It was found that the VBNC state was induced faster in V. cholerae serogroup O1 classical biotype strain O395 than in O1 El Tor biotype strains C6706 and N16961. When cells in different growth phases were used for VBNC induction, stationary-phase cells lost their culturability more quickly than exponential-phase cells, while induction of a totally non-culturable state took longer to achieve for stationary-phase cells in all three strains, suggesting that heterogeneity of cells should be considered. Aeration strongly accelerated the loss of culturability. During the development of the VBNC state, the culturable cell count under aeration conditions was almost 106-fold lower than under oxygen-limited conditions for all three strains. The other two factors, temperature and nutrients-rich environment, may prevent the induction of VBNC cells. At 22°C or 37°C in ASW, most of the cells rapidly died and the culturable cell count reduced from about 108 CFU/mL to 106–105 CFU/mL. The total cell counts showed that cells that lost viability were decomposed, and the viable cell counts were the same as culturable cell counts, indicating that the cells did not reach the VBNC state. VBNC state development was blocked when ASW was supplied with Luria-Bertani broth (LB, but it was not affected in ASW with M9, suggesting that specific nutrients in LB may prevent the development of VBNC state. These results revealed that the five factors evaluated in this study had different

  5. Growth Phase, Oxygen, Temperature, and Starvation Affect the Development of Viable but Non-culturable State of Vibrio cholerae.

    Science.gov (United States)

    Wu, Bin; Liang, Weili; Kan, Biao

    2016-01-01

    Vibrio cholerae can enter into a viable but non-culturable (VBNC) state in order to survive in unfavorable environments. In this study, we studied the roles of five physicochemical and microbiological factors or states, namely, different strains, growth phases, oxygen, temperature, and starvation, on the development of VBNC of V. cholerae in artificial sea water (ASW). Different strains of the organism, the growth phase, and oxygen levels affected the progress of VBNC development. It was found that the VBNC state was induced faster in V. cholerae serogroup O1 classical biotype strain O395 than in O1 El Tor biotype strains C6706 and N16961. When cells in different growth phases were used for VBNC induction, stationary-phase cells lost their culturability more quickly than exponential-phase cells, while induction of a totally non-culturable state took longer to achieve for stationary-phase cells in all three strains, suggesting that heterogeneity of cells should be considered. Aeration strongly accelerated the loss of culturability. During the development of the VBNC state, the culturable cell count under aeration conditions was almost 10(6)-fold lower than under oxygen-limited conditions for all three strains. The other two factors, temperature and nutrients-rich environment, may prevent the induction of VBNC cells. At 22 or 37°C in ASW, most of the cells rapidly died and the culturable cell count reduced from about 10(8) to 10(6)-10(5) CFU/mL. The total cell counts showed that cells that lost viability were decomposed, and the viable cell counts were the same as culturable cell counts, indicating that the cells did not reach the VBNC state. VBNC state development was blocked when ASW was supplied with Luria-Bertani broth (LB), but it was not affected in ASW with M9, suggesting that specific nutrients in LB may prevent the development of VBNC state. These results revealed that the five factors evaluated in this study had different roles during the progress of VBNC

  6. Olecranon bone graft: revisited.

    Science.gov (United States)

    Mersa, Berkan; Ozcelik, Ismail Bulent; Kabakas, Fatih; Sacak, Bulent; Aydin, Atakan

    2010-09-01

    Autogenous bone grafts are frequently in use in the field of reconstructive upper extremity surgery. Cancellous bone grafts are applied to traumatic osseous defects, nonunions, defects after the resection of benign bone tumors, arthrodesis, and osteotomy procedures. Cancellous bone grafts do not only have benefits such as rapid revascularization, but they also have mechanical advantages. Despite the proximity to the primary surgical field, cancellous olecranon grafts have not gained the popularity they deserve in the field of reconstructive hand surgery. In this study, the properties, advantages, and technical details of harvesting cancellous olecranon grafts are discussed.

  7. A Study of Noncultured Extracted Hair Follicle Outer Root Sheath Cell Suspension for Transplantation in Vitiligo

    Science.gov (United States)

    Shah, Aarti N; Marfatia, Ritu K; Saikia, Siddhartha S

    2016-01-01

    Context: Vitiligo surgeries have come a long way from tissue grafts to cultured and non cultured cell transplantation. Extracted hair follicle outer root sheath cell transplantation (EHF ORS) suspension is more enriched with melanocyte. In a hair bulb, there is one melanocyte for every five keratinocytes which is much higher than the epidermal melanin unit. Aims: To analyse the effectiveness of cultured EHF ORS and to perform objective evaluation based on clinical improvement & photographic evidence. To observe any untoward events or side effects. Settings and Design: The study was open and uncontrolled. All the patients were screened at preliminary visit. Reviews were done every two weeks. The endpoint selected was six months post procedure. Materials and Methods: Twenty five patients of stable Vitiligo were included in the study and follicular unit were harvested by Follicular Unit Extraction method. Outer root sheath cells were extracted by trypsinization. The solution was transplanted over dermabraded recipient site. Pressure dressing was given. Patients were followed up regularly. Statistical Analysis Used: Descriptive Statistics, Chi-Square. Results: Mean ± SD repigmentation was 80.15% ± 22.9% with excellent repigmentation (90-100%) in 60% of patients. Conclusions: This method is safe, effective, and simpler than the other methods involving cell culturing and requiring a laboratory set-up but selection of patients is crucial for the success of the outcome. PMID:27601859

  8. Cellular automata

    CERN Document Server

    Codd, E F

    1968-01-01

    Cellular Automata presents the fundamental principles of homogeneous cellular systems. This book discusses the possibility of biochemical computers with self-reproducing capability.Organized into eight chapters, this book begins with an overview of some theorems dealing with conditions under which universal computation and construction can be exhibited in cellular spaces. This text then presents a design for a machine embedded in a cellular space or a machine that can compute all computable functions and construct a replica of itself in any accessible and sufficiently large region of t

  9. PMA-LAMP for rapid detection of Escherichia coli and shiga toxins from viable but non-culturable state.

    Science.gov (United States)

    Yan, Muxia; Xu, Ling; Jiang, Hua; Zhou, Zhenwen; Zhou, Shishui; Zhang, Li

    2017-04-01

    In exposure to outer pressure, microorganisms are capable of entry into the Viable But Non-Culturable (VBNC) state, and thus survive under various elimination processing. The survival microorganisms may yield negative results on culturing, and cause false negative for this golden standard methodology. In this study, a novel PMA-LAMP assay on the detection of Enterohemorrhage E. coli and shiga toxins has been developed and evaluated, with further application on a number of food borne E. coli strains. LAMP primers were designed on the target of rfbe for Enterohemorrhage E. coli and stx1with stx2 for shiga toxins. Via specific penetration through the damaged cell membrane of dead cells and intercalating into DNA, PMA could prevent DNA amplification of dead bacteria from LAMP, which enabled the differentiation of bacteria between VBNC state and dead state. The established PMA-LAMP showed significant advantage in rapidity, sensitivity and specificity, compared with regular PCR assay. The applicability had also been verified, demonstrating the PMA-LAMP was capable of detection on Enterohemorrhage E. coli and shiga toxins.

  10. SURVIVAL, INDUCTION AND RESUSCITATION OF Vibrio cholerae FROM THE VIABLE BUT NON-CULTURABLE STATE IN THE SOUTHERN CARIBBEAN SEA

    Directory of Open Access Journals (Sweden)

    Milagro Fernández-Delgado

    2015-02-01

    Full Text Available The causative agent of cholera, Vibrio cholerae, can enter into a viable but non-culturable (VBNC state in response to unfavorable conditions. The aim of this study was to evaluate the in situ survival of V. cholerae in an aquatic environment of the Southern Caribbean Sea, and its induction and resuscitation from the VBNC state. V. cholerae non-O1, non-O139 was inoculated into diffusion chambers placed at the Cuare Wildlife Refuge, Venezuela, and monitored for plate, total and viable cells counts. At 119 days of exposure to the environment, the colony count was < 10 CFU/mL and a portion of the bacterial population entered the VBNC state. Additionally, the viability decreased two orders of magnitude and morphological changes occurred from rod to coccoid cells. Among the aquatic environmental variables, the salinity had negative correlation with the colony counts in the dry season. Resuscitation studies showed significant recovery of cell cultivability with spent media addition (p < 0.05. These results suggest that V. cholerae can persist in the VBNC state in this Caribbean environment and revert to a cultivable form under favorable conditions. The VBNC state might represent a critical step in cholera transmission in susceptible areas.

  11. SURVIVAL, INDUCTION AND RESUSCITATION OF Vibrio cholerae FROM THE VIABLE BUT NON-CULTURABLE STATE IN THE SOUTHERN CARIBBEAN SEA

    Science.gov (United States)

    Fernández-Delgado, Milagro; García-Amado, María Alexandra; Contreras, Monica; Incani, Renzo Nino; Chirinos, Humberto; Rojas, Héctor; Suárez, Paula

    2015-01-01

    The causative agent of cholera, Vibrio cholerae, can enter into a viable but non-culturable (VBNC) state in response to unfavorable conditions. The aim of this study was to evaluate the in situ survival of V. cholerae in an aquatic environment of the Southern Caribbean Sea, and its induction and resuscitation from the VBNC state. V. cholerae non-O1, non-O139 was inoculated into diffusion chambers placed at the Cuare Wildlife Refuge, Venezuela, and monitored for plate, total and viable cells counts. At 119 days of exposure to the environment, the colony count was < 10 CFU/mL and a portion of the bacterial population entered the VBNC state. Additionally, the viability decreased two orders of magnitude and morphological changes occurred from rod to coccoid cells. Among the aquatic environmental variables, the salinity had negative correlation with the colony counts in the dry season. Resuscitation studies showed significant recovery of cell cultivability with spent media addition (p < 0.05). These results suggest that V. cholerae can persist in the VBNC state in this Caribbean environment and revert to a cultivable form under favorable conditions. The VBNC state might represent a critical step in cholera transmission in susceptible areas. PMID:25651322

  12. Use of Flow Cytometry for Quantitative Analysis of Metabolism of Viable but Non-culturable (VBNC) Salmonella.

    Science.gov (United States)

    Morishige, Yuta; Fujimori, Ko; Amano, Fumio

    2015-01-01

    A simple and rapid assay method for analysis of the metabolic activity of viable but non-culturable (VBNC) Salmonella was established. An environmental isolate of Salmonella Enteritidis (SE), grown to the logarithmic phase, rapidly lost its culturability during incubation with 1-10 mM H2O2 in Luria-Bertani (LB) medium. To assess the viability of the bacteria, we measured 3 different metabolic activities: Respiratory activity by 5-cyano-2,3-ditolyl-tetrazolium chloride (CTC) reduction, glucose uptake assessed with 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxyglucose (2-NBDG), and DNA synthesis activity evaluated by 5-ethynyl-2'-deoxyuridine (EdU) incorporation. These activities were analyzed by both confocal laser-scanning microscopy and flow cytometry, together with colony-formation assays on LB-agar plates. The results showed that some of the H2O2-treated SE cells were in the VBNC state and that the extent of H2O2-induced decrease in each metabolic activity varied according to the activity. That is, glucose-uptake activity was not markedly changed, being kept at the highest level; whereas the respiratory activity was less than that of the glucose-uptake, and DNA synthesis activity was the lowest among them. These results suggest that the VBNC state might be characterized by different metabolic activities that vary and correspond to the kind and strength of the stress, threatening bacterial survival in an adverse environment.

  13. A factor converting viable but nonculturable Vibrio cholerae to a culturable state in eukaryotic cells is a human catalase.

    Science.gov (United States)

    Senoh, Mitsutoshi; Hamabata, Takashi; Takeda, Yoshifumi

    2015-08-01

    In our previous work, we demonstrated that viable but nonculturable (VBNC) Vibrio cholerae O1 and O139 were converted to culturable by coculture with eukaryotic cells. Furthermore, we isolated a factor converting VBNC V. cholerae to culturable (FCVC) from a eukaryotic cell line, HT-29. In this study, we purified FCVC by successive column chromatographies comprising UNO Q-6 anion exchange, Bio-Scale CHT2-1 hydroxyapatite, and Superdex 200 10/300 GL. Homogeneity of the purified FCVC was demonstrated by SDS-PAGE. Nano-LC MS/MS analysis showed that the purified FCVC was a human catalase. An experiment of RNAi knockdown of catalase mRNA from HT-29 cells and treatment of the purified FCVC with a catalase inhibitor, 3-amino-1,2,4-triazole confirmed that the FCVC was a catalase. A possible role of the catalase in converting a VBNC V. cholerae to a culturable state in the human intestine is discussed.

  14. Quantification of viable but nonculturable Salmonella spp. and Shigella spp. during sludge anaerobic digestion and their reactivation during cake storage.

    Science.gov (United States)

    Fu, B; Jiang, Q; Liu, H-B; Liu, H

    2015-10-01

    The presence of viable but nonculturable (VBNC) bacterial pathogens which often fail to be detected by cultivation and can regain the cultivability if the living conditions improve were reported. The objective of this study was to determine the occurrence of VBNC Salmonella spp. and Shigella spp. in the biosolids during anaerobic digestion and its reactivation during the cake storage. The occurrence of VBNC Salmonella spp. and Shigella spp. during mesophilic, temperature-phased, thermophilic anaerobic digestion of sewage sludge and the subsequent storage were studied by RT-qPCR and most probable number (MPN) method. The VBNC incidence of Salmonella spp. and Shigella spp. during thermophilic digestion was four orders of magnitude higher than those of mesophilic digestion. Accordingly, higher resuscitation ratio of VBNC pathogens was also achieved in thermophilic digested sludge. As a result, the culturable Salmonella typhimurium contents in thermophilic digested sludge after cake storage were two orders of magnitude higher than mesophilic digestion. Both quantitative PCR and reverse transcription quantitative PCR assay results showed the two bacterial counting numbers remained stable throughout the cake storage. The results indicate that the increase in the culturable Salmonella spp. and Shigella spp. after centrifugal dewatering was attributed to the resuscitation from the VBNC state to the culturable state. Thermophilic anaerobic digestion mainly induced Salmonella spp. and Shigella spp. into VBNC state rather than killed them, suggesting that the biological safety of sewage sludge by temperature-phased anaerobic digestion should be carefully assessed. © 2015 The Society for Applied Microbiology.

  15. Current and future approaches to treat graft failure after allogeneic hematopoietic stem cell transplantation.

    Science.gov (United States)

    Locatelli, Franco; Lucarelli, Barbarella; Merli, Pietro

    2014-01-01

    One significant obstacle to the success of allogeneic hematopoietic stem cell transplantation (HSCT) is represented by graft failure, defined as either lack of initial engraftment of donor cells (primary graft failure) or loss of donor cells after initial engraftment (secondary graft failure). Graft failure mediated by host immune cells attacking donor stem cells is named graft rejection. Factors associated with graft failure include HLA disparity in the donor/recipient pair, underlying disease, viral infections, type of conditioning regimen and stem cell source employed. In this article, the experts summarize current approaches to treat graft failure/rejection after HSCT, and they discuss new strategies of graft manipulation and immune therapy of particular interest for preventing/treating this complication. A limited array of options is available to treat graft failure. The experts believe that re-transplantation from another donor or the same donor (if there is no evidence of immunologically mediated graft failure) is the treatment of choice for patients with primary graft failure or acute graft rejection. The experts think that strategies based on innovative approaches of graft manipulation, new agents or cellular therapies could render in the future graft failure a much less relevant problem for HSCT recipients.

  16. Tissue grafts in vitiligo surgery - past, present, and future

    Directory of Open Access Journals (Sweden)

    Khunger Niti

    2009-01-01

    Full Text Available Vitiligo, characterized by depigmented macules is a common disorder with a high psychosocial impact, particularly in darker skins. Surgical methods become important in cases where medical therapy fails to cause repigmentation or in cases of segmental vitiligo where the response to surgery is excellent. The basic principle of surgical treatment is autologous grafting of viable melanocytes from pigmented donor skin to recipient vitiliginous areas. Various grafting methods have been described including tissue grafts and cellular grafts. Stability of the disease is the most important criterion to obtain a successful outcome. Counseling of the patient regarding the outcome is vital before surgery. The technique and followup management of the tissue grafts has been described in detail in this review.

  17. Meniscal allograft transplantation. Part 1: systematic review of graft biology, graft shrinkage, graft extrusion, graft sizing, and graft fixation.

    Science.gov (United States)

    Samitier, Gonzalo; Alentorn-Geli, Eduard; Taylor, Dean C; Rill, Brian; Lock, Terrence; Moutzouros, Vasilius; Kolowich, Patricia

    2015-01-01

    To provide a systematic review of the literature regarding five topics in meniscal allograft transplantation: graft biology, shrinkage, extrusion, sizing, and fixation. A systematic literature search was conducted using the PubMed (MEDLINE), ScienceDirect, and EBSCO-CINAHL databases. Articles were classified only in one topic, but information contained could be reported into other topics. Information was classified according to type of study (animal, in vitro human, and in vivo human) and level of evidence (for in vivo human studies). Sixty-two studies were finally included: 30 biology, 3 graft shrinkage, 11 graft extrusion, 17 graft size, and 6 graft fixation (some studies were categorized in more than one topic). These studies corresponded to 22 animal studies, 22 in vitro human studies, and 23 in vivo human studies (7 level II, 10 level III, and 6 level IV). The principal conclusions were as follows: (a) Donor cells decrease after MAT and grafts are repopulated with host cells form synovium; (b) graft preservation alters collagen network (deep freezing) and causes cell apoptosis with loss of viable cells (cryopreservation); (c) graft shrinkage occurs mainly in lyophilized and gamma-irradiated grafts (less with cryopreservation); (d) graft extrusion is common but has no clinical/functional implications; (e) overall, MRI is not superior to plain radiograph for graft sizing; (f) graft width size matching is more important than length size matching; (g) height appears to be the most important factor influencing meniscal size; (h) bone fixation better restores contact mechanics than suture fixation, but there are no differences for pullout strength or functional results; and (i) suture fixation has more risk of graft extrusion compared to bone fixation. Systematic review of level II-IV studies, Level IV.

  18. Case Report: Industrial X-Ray Injury Treated With Non-Cultured Autologous Adipose-Derived Stromal Vascular Fraction (SVF).

    Science.gov (United States)

    Iddins, C J; Cohen, S R; Goans, R E; Wanat, R; Jenkins, M; Christensen, D M; Dainiak, N

    2016-08-01

    Local cutaneous injuries induced by ionizing radiation (IR) are difficult to treat. Many have reported local injection of adipose-derived stromal vascular fraction (SVF), often with additional therapies, as an effective treatment of IR-induced injury even after other local therapies have failed. The authors report a case of a locally recurrent, IR-induced wound that was treated with autologous, non-cultured SVF without other concurrent therapy. A nondestructive testing technician was exposed to 130 kVp x rays to his non-dominant right thumb on 5 October 2011. The wound healed 4 mo after initial conservative therapy with oral/topical α-tocopherol, oral pentoxifylline, naproxen sodium, low-dose oral steroids, topical steroids, hyperbaric oxygen therapy (HBOT), oral antihistamines, and topical aloe vera. Remission lasted approximately 17 mo with one minor relapse in July 2012 after minimal trauma and subsequent healing. Aggressive wound breakdown during June 2013 required additional therapy with HBOT. An erythematous, annular papule developed over the following 12 mo (during which time the patient was not undergoing prescribed treatment). Electron paramagnetic resonance (EPR) done more than 2 mo after exposure to IR revealed dose estimates of 14 ± 3 Gy and 19 ± 6 Gy from two centers using different EPR techniques. The patient underwent debridement of the 0.5 cm papular area, followed by SVF injection into and around the wound bed and throughout the thumb without complication. Eleven months post SVF injection, the patient has been essentially asymptomatic with an intact integument. These results raise the possibility of prolonged benefit from SVF therapy without the use of cytokines. Since there is currently no consensus on the use of isolated SVF therapy in chronic, local IR-induced injury, assessment of this approach in an appropriately powered, controlled trial in experimental animals with local radiation injury appears to be indicated.

  19. Molecular and biochemical characterization of the NS1 protein of non-cultured influenza B virus strains circulating in Singapore

    KAUST Repository

    Jumat, Muhammad Raihan

    2016-08-04

    In this study we compared the NS1 protein of Influenza B/Lee/40 and several non-cultured Influenza B virus clinical strains detected in Singapore. In B/Lee/40 virus-infected cells and in cells expressing the recombinant B/Lee/40 NS1 protein a full-length 35 kDa NS1 protein and a 23 kDa NS1 protein species (p23) were detected. Mutational analysis of the NS1 gene indicated that p23 was generated by a novel cleavage event within the linker domain between an aspartic acid and proline at amino acid residues at positions 92 and 93 respectively (DP92–93), and that p23 contained the first 92 amino acids of the NS1 protein. Sequence analysis of the Singapore strains indicated the presence of either DP92–93 or NP92–93 in the NS1 protein, but protein expression analysis showed that p23 was only detected in NS1 proteins with DP92–93.. An additional adjacent proline residue at position 94 (P94) was present in some strains and correlated with increased p23 levels, suggesting that P94 has a synergistic effect on the cleavage of the NS1 protein. The first 145 amino acids of the NS1 protein are required for inhibition of ISG15-mediated ubiquitination, and our analysis showed that Influenza B viruses circulating in Singapore with DP92–93 expressed truncated NS1 proteins and may differ in their capacity to inhibit ISG15 activity. Thus, DP92–93 in the NS1 protein may confer a disadvantage to Influenza B viruses circulating in the human population and interestingly the low frequency of DP92–93detection in the NS1 protein since 2004 is consistent with this suggestion.

  20. Persistence and Potential Viable but Non-culturable State of Pathogenic Bacteria during Storage of Digestates from Agricultural Biogas Plants

    Science.gov (United States)

    Maynaud, Geraldine; Pourcher, Anne-Marie; Ziebal, Christine; Cuny, Anais; Druilhe, Céline; Steyer, Jean-Philippe; Wéry, Nathalie

    2016-01-01

    Despite the development of on-farm anaerobic digestion as a process for making profitable use of animal by-products, factors leading to the inactivation of pathogenic bacteria during storage of digestates remain poorly described. Here, a microcosm approach was used to evaluate the persistence of three pathogenic bacteria (Salmonella enterica Derby, Campylobacter coli and Listeria monocytogenes) in digestates from farms, stored for later land spreading. Nine samples, including raw digestates, liquid fractions of digestate and composted digestates, were inoculated with each pathogen and maintained for 40 days at 24°C. Concentrations of pathogens were monitored using culture and qPCR methods. The persistence of L. monocytogenes, detected up to 20 days after inoculation, was higher than that of Salmonella Derby, detected for 7–20 days, and of C. coli (not detected after 7 days). In some digestates, the concentration of the pathogens by qPCR assay was several orders of magnitude higher than the concentration of culturable cells, suggesting a potential loss of culturability and induction of Viable but Non-Culturable (VBNC) state. The potential VBNC state which was generally not observed in the same digestate for the three pathogens, occurred more frequently for C. coli and L. monocytogenes than for Salmonella Derby. Composting a digestate reduced the persistence of seeded L. monocytogenes but promoted the maintenance of Salmonella Derby. The effect of NH4+/NH3 on the culturability of C. coli and Salmonella Derby was also shown. The loss of culturability may be the underlying mechanism for the regrowth of pathogens. We have also demonstrated the importance of using molecular tools to monitor pathogens in environmental samples since culture methods may underestimate cell concentration. Our results underline the importance of considering VBNC cells when evaluating the sanitary effect of an anaerobic digestion process and the persistence of pathogens during the storage of

  1. Persistence and potential Viable but Non-culturable state of pathogenic bacteria during storage of digestates from agricultural biogas plants

    Directory of Open Access Journals (Sweden)

    Geraldine Maynaud

    2016-09-01

    Full Text Available Despite the development of on-farm anaerobic digestion as a process for making profitable use of animal by-products, factors leading to the inactivation of pathogenic bacteria during storage of digestates remain poorly described. Here, a microcosm approach was used to evaluate the persistence of three pathogenic bacteria (Salmonella enterica Derby, Campylobacter coli and Listeria monocytogenes in digestates from farms, stored for later land spreading. Nine samples, including raw digestates, liquid fractions of digestate and composted digestates, were inoculated with each pathogen and maintained for 40 days at 24°C. Concentrations of pathogens were monitored using culture and qPCR methods. The persistence of L. monocytogenes, detected up to 20 days after inoculation, was higher than that of Salmonella Derby, detected for 7-20 days, and of C. coli (not detected after 7 days. In some digestates, the concentration of the pathogens by qPCR assay was several orders of magnitude higher than the concentration of culturable cells, suggesting a potential loss of culturability and induction of Viable but Non-Culturable (VBNC state. The potential VBNC state which was generally not observed in the same digestate for the three pathogens, occurred more frequently for C. coli and L. monocytogenes than for Salmonella Derby. Composting a digestate reduced the persistence of seeded L. monocytogenes but promoted the maintenance of Salmonella Derby. The effect of NH4+/NH3 on the culturability of C. coli and Salmonella Derby was also shown.The loss of culturability may be the underlying mechanism for the regrowth of pathogens. We have also demonstrated the importance of using molecular tools to monitor pathogens in environmental samples since culture methods may underestimate cell concentration. Our results underline the importance of considering VBNC cells when evaluating the sanitary effect of an anaerobic digestion process and the persistence of pathogens during

  2. Intense association of non-culturable endophytic bacteria with antibiotic-cleansed in vitro watermelon and their activation in degenerating cultures.

    Science.gov (United States)

    Thomas, Pious

    2011-12-01

    The study was undertaken with a view to unravel the source of bacterial colony growth observed in a section of micropropagated triploid watermelon cultures that were supposedly cleansed of the associated endophytic bacteria through antibiotic treatment, and thereafter maintained under stringent sterility checks to prevent lateral intrusion of contaminants. Five different bacteria were retrieved from colony growth-displaying watermelon cultures that were previously treated with gentamycin and five isolates from cefazolin-treated stocks with the organisms showing tolerance to the respective antibiotic. These watermelon cultures were in degeneration phase (over 6 months after the previous sub-culturing), while the actively maintained counterpart stocks appeared healthy with no colony growth on different bacteriological media during tissue-screenings. The latter cultures, however, revealed abundant motile, tetrazolium-stained bacterial cells in microscopy, suggesting tissue colonization by non-culturable endophytes. PCR screening on healthy cultures endorsed tissue colonization by different bacterial phylogenic groups. A few organisms could be activated to cultivation from healthy watermelon stocks through host tissue extract supplementation, which also enhanced the growth of all the organisms. The study indicated that a fraction of antibiotic-tolerant bacteria survived intra-tissue in non-culturable form during the preceding cleansing activity, multiplied to substantial numbers thereafter, and turned cultivable in degenerating cultures contributed by tissue breakdown products. This study brings out the existence of a deep endophyte association in tissue cultures which is not easily dissociable. It also signifies the utility of in vitro system for investigations into plant-endophyte association and to bring normally non-culturable novel organisms to cultivation facilitating their future exploitation.

  3. Induction of the viable but nonculturable state of Ralstonia solanacearum by low temperature in the soil microcosm and its resuscitation by catalase.

    Directory of Open Access Journals (Sweden)

    Hyun Gi Kong

    Full Text Available Ralstonia solanacearum is the causal agent of bacterial wilt on a wide variety of plants, and enters a viable but nonculturable (VBNC state under stress conditions in soil and water. Here, we adopted an artificial soil microcosm (ASM to investigate the VBNC state of R. solanacearum induced by low temperature. The culturability of R. solanacearum strains SL341 and GMI1000 rapidly decreased at 4°C in modified ASM (mASM, while it was stably maintained at 25°C in mASM. We hypothesized that bacterial cells at 4°C in mASM are viable but nonculturable. Total protein profiles of SL341 cells at 4°C in mASM did not differ from those of SL341 culturable cells at 25°C in mASM. Moreover, the VBNC cells maintained in the mASM retained respiration activity. Catalase treatment effectively restored the culturability of nonculturable cells in mASM, while temperature increase or other treatments used for resuscitation of other bacteria were not effective. The resuscitated R. solanacearum from VBNC state displayed normal level of bacterial virulence on tomato plants compared with its original culturable bacteria. Expression of omp, oxyR, rpoS, dps, and the 16S rRNA gene quantified by RT-qPCR did not differ significantly between the culturable and VBNC states of R. solanacearum. Our results suggested that the VBNC bacterial cells in mASM induced by low temperature exist in a physiologically unique state.

  4. Non-cultured adipose-derived CD45(-) side population cells are enriched for progenitors that give rise to myofibres in vivo

    DEFF Research Database (Denmark)

    Andersen, Ditte C; Schrøder, Henrik D; Jensen, Charlotte H

    2008-01-01

    skeletal muscle repair mainly relies on the satellitecell, several reports have shown that vessel-associated cells may adopt a myogenic phenotype when exposed to a muscle environment. In accordance with these findings, we also observed invitro myogenic specification of SPCD45(-) cells when cocultured...... with myoblasts. Furthermore, immediate intramuscular engraftment of non-cultured SPCD45(-) cells gave rise to myofibres andcells lining blood vessels, whereas the SVF only provided donor derived mononuclear cells. We therefore conclude that the SPCD45(-) fraction of adipose-derived SVF is enriched for cells...

  5. Cellular Telephone

    Institute of Scientific and Technical Information of China (English)

    杨周

    1996-01-01

    Cellular phones, used in automobiles, airliners, and passenger trains, are basically low-power radiotelephones. Calls go through radio transmitters that are located within small geographical units called cells. Because each cell’s signals are too weak to interfere with those of other cells operating on the same fre-

  6. Survival or revival: long-term preservation induces a reversible viable but non-culturable state in methane-oxidizing bacteria.

    Directory of Open Access Journals (Sweden)

    Sven Hoefman

    Full Text Available Knowledge on long-term preservation of micro-organisms is limited and research in the field is scarce despite its importance for microbial biodiversity and biotechnological innovation. Preservation of fastidious organisms such as methane-oxidizing bacteria (MOB has proven difficult. Most MOB do not survive lyophilization and only some can be cryopreserved successfully for short periods. A large-scale study was designed for a diverse set of MOB applying fifteen cryopreservation or lyophilization conditions. After three, six and twelve months of preservation, the viability (via live-dead flow cytometry and culturability (via most-probable number analysis and plating of the cells were assessed. All strains could be cryopreserved without a significant loss in culturability using 1% trehalose in 10-fold diluted TSB (TT as preservation medium and 5% DMSO as cryoprotectant. Several other cryopreservation and lyophilization conditions, all of which involved the use of TT medium, also allowed successful preservation but showed a considerable loss in culturability. We demonstrate here that most of these non-culturables survived preservation according to viability assessment indicating that preservation induces a viable but non-culturable (VBNC state in a significant fraction of cells. Since this state is reversible, these findings have major implications shifting the emphasis from survival to revival of cells in a preservation protocol. We showed that MOB cells could be significantly resuscitated from the VBNC state using the TT preservation medium.

  7. Skin graft - slideshow

    Science.gov (United States)

    ... ency/presentations/100100.htm Skin graft - series—Normal anatomy To use the sharing features on this page, ... 2017 Updated by: Debra G. Wechter, MD, FACS, general surgery practice specializing in breast cancer, Virginia Mason ...

  8. [Chickenpox, burns and grafts].

    Science.gov (United States)

    Rojas Zegers, J; Fidel Avendaño, L

    1979-01-01

    An outbreak of chickenpox that occurred at the Burns Repair Surgery Unit, Department of Children's Surgery, Hospital R. del Río, between June and November, 1975, is reported. 27 cases of burned children were studied, including analysis of correlations of the stages and outcome of the disease (varicela), the trauma (burns) and the graft (repair surgery). As a result, the authors emphasize the following findings: 1. Burns and their repair are not aggravating factors for varicella. In a small number of cases the exanthema looked more confluent in the graft surgical areas and in the first degree burns healing spontaneously. 2. Usually there was an uneventful outcome of graft repair surgery on a varicella patient, either during the incubation period, the acme or the convalescence. 3. The fact that the outmost intensity of secondary viremia of varicella occurs before the onset of exanthemia, that is, during the late incubation period, is confirmed.

  9. Alveolar bone grafting

    Directory of Open Access Journals (Sweden)

    Lilja Jan

    2009-10-01

    Full Text Available In patients with cleft lip and palate, bone grafting in the mixed dentition in the residual alveolar cleft has become a well-established procedure. The main advantages can be summarised as follows: stabilisation of the maxillary arch; facilitation of eruption of the canine and sometimes facilitation of the lateral incisor eruption; providing bony support to the teeth adjacent to the cleft; raising the alar base of the nose; facilitation of closure of an oro-nasal fistula; making it possible to insert a titanium fixture in the grafted site and to obtain favourable periodontal conditions of the teeth within and adjacent to the cleft. The timing of the ABG surgery take into consideration not only eruption of the canine but also that of the lateral incisor, if present. The best time for bone grafting surgery is when a thin shell of bone still covers the soon erupting lateral incisor or canine tooth close to the cleft.

  10. Arteriovenous shunt graft ulceration with sinus and graft epithelialization

    Directory of Open Access Journals (Sweden)

    Pooja Singhal

    2015-03-01

    Full Text Available Arteriovenous fistula and grafts are used as access sites for patients with chronic kidney disease and are prone for complications. Stent grafts are used to treat access site complications. We report a rare and unusual finding of epithelialization of the sinus tract and the lumen of a polytetrafluoroethylene graft, following ulceration of the overlying skin.

  11. Periosteal BMP2 activity drives bone graft healing.

    Science.gov (United States)

    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

  12. Primary renal graft thrombosis

    NARCIS (Netherlands)

    Bakir, N; Sluiter, WJ; Ploeg, RJ; van Son, WJ; Tegzess, Adam

    1996-01-01

    Background. Renal allograft thrombosis is a serious complication of kidney transplantation that ultimately leads to graft loss. Its association with acute and hyperacute rejection is well documented; however, in a large proportion of patients the precise cause remains obscure. The exact incidence an

  13. [Grafting of carotid arteries].

    Science.gov (United States)

    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.

  14. Buccal Mucosal Graft Urethroplasty

    Directory of Open Access Journals (Sweden)

    Angela M. Arlen

    2010-01-01

    Full Text Available At our institution, the majority of buccal mucosal graft urethroplasties are performed using a two-team approach with an otolaryngologic surgeon. We report our two-surgeon experience with buccal mucosal grafting for reconstruction of all anterior urethral strictures. Twenty-four men underwent autologous buccal mucosal graft urethroplasty between October 2001 and September 2008 for recurrent urethral stricture disease. Twenty-two underwent a single-stage repair and two underwent a two-stage repair. Medical charts were retrospectively reviewed for demographics, comorbidities, etiology, location and length of stricture, and prior interventions in order to identify predictors of buccal urethroplasty success, defined as no evidence of stricture recurrence. All patients underwent retrograde urethrogram and cystoscopy. Operative and anesthesia times were evaluated. We determined an overall success rate of 83.3% (20 of 24 cases. Mean anesthesia time for single-stage urethroplasty was 155 min and mean operative time was 123 min. One of the two two-stage urethroplasties experienced stricture recurrence (50%. The single-stage buccal graft success rate was 86.4% (19 of 22 cases. Two of the four who developed recurrent stricture disease that required intervention had undergone a previous mesh urethroplasty. Complications developed in four of 24 patients (16.6%, including superficial wound infection (one, superficial wound dehiscence (two, and abscess/fistula formation requiring reoperation (one. The buccal mucosa is an ideal tissue for both single- and two-stage substitution urethroplasty for patients with recurrent stricture disease. Our two-surgeon technique minimizes anesthesia and operative times, and contributes to the overall high success rate and relatively low complication rate.

  15. Engineering an improved acellular nerve graft via optimized chemical processing.

    Science.gov (United States)

    Hudson, Terry W; Liu, Stephen Y; Schmidt, Christine E

    2004-01-01

    The long-term goal of our research is to engineer an acellular nerve graft for clinical nerve repair and for use as a model system with which to study nerve-extracellular matrix interactions during nerve regeneration. To develop this model acellular nerve graft we (1) examined the effects of detergents on peripheral nerve tissue, and (2) used that knowledge to create a nerve graft devoid of cells with a well-preserved extracellular matrix. Using histochemistry and Western analysis, the impact of each detergent on cellular and extracellular tissue components was determined. An optimized protocol was created with the detergents Triton X-200, sulfobetaine-16, and sulfobetaine-10. This study represents the most comprehensive examination to date of the effects of detergents on peripheral nerve tissue morphology and protein composition. Also presented is an improved chemical decellularization protocol that preserves the internal structure of native nerve more than the predominant current protocol.

  16. Bioreactor cultivation of anatomically shaped human bone grafts.

    Science.gov (United States)

    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.

  17. The gene expression profile of non-cultured, highly purified human adipose tissue pericytes: Transcriptomic evidence that pericytes are stem cells in human adipose tissue.

    Science.gov (United States)

    da Silva Meirelles, Lindolfo; de Deus Wagatsuma, Virgínia Mara; Malta, Tathiane Maistro; Bonini Palma, Patrícia Viana; Araújo, Amélia Goes; Panepucci, Rodrigo Alexandre; Silva, Wilson Araújo; Kashima, Simone; Covas, Dimas Tadeu

    2016-12-10

    Pericytes (PCs) are a subset of perivascular cells that can give rise to mesenchymal stromal cells (MSCs) when culture-expanded, and are postulated to give rise to MSC-like cells during tissue repair in vivo. PCs have been suggested to behave as stem cells (SCs) in situ in animal models, although evidence for this role in humans is lacking. Here, we analyzed the transcriptomes of highly purified, non-cultured adipose tissue (AT)-derived PCs (ATPCs) to detect gene expression changes that occur as they acquire MSC characteristics in vitro, and evaluated the hypothesis that human ATPCs exhibit a gene expression profile compatible with an AT SC phenotype. The results showed ATPCs are non-proliferative and express genes characteristic not only of PCs, but also of AT stem/progenitor cells. Additional analyses defined a gene expression signature for ATPCs, and revealed putative novel ATPC markers. Almost all AT stem/progenitor cell genes differentially expressed by ATPCs were not expressed by ATMSCs or culture-expanded ATPCs. Genes expressed by ATMSCs but not by ATPCs were also identified. These findings strengthen the hypothesis that PCs are SCs in vascularized tissues, highlight gene expression changes they undergo as they assume an MSC phenotype, and provide new insights into PC biology. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Grafting the alar rim: application as anatomical graft.

    Science.gov (United States)

    Gruber, Ronald P; Fox, Paige; Peled, Anne; Belek, Kyle A

    2014-12-01

    Alar rim contour and alar rim grafts have become essential components of rhinoplasty. Ideally, grafts of the nose should be anatomical in shape. So doing might make grafts of the alar rim more robust. The authors considered doing that by applying the graft as a continuous extension of the lateral crus. Twelve patients (two men and 10 women) constituted the study group (seven primary and five secondary cases). Of those, there were five concave rims, two concave rims with rim retraction, two boxy tips, and three cephalically oriented lateral crura. Surgical technique included the following: (1) an open approach was used; (2) a marginal incision that ignored the caudal margin of the lateral crus (the incision went straight posteriorly to a point 5 to 6 mm from the rim margin) was used; (3) a triangular graft was made to cover the exposed vestibular skin; (4) it was secured end to end to the caudal border of the lateral crus; and (5) the poster end was allowed to sit in a small subcutaneous pocket. Follow-up was 11 to 19 months. All 12 patients exhibited good rims as judged by a blinded panel. Rim retraction was not fully corrected in one patient, but no further treatment was required. One patient did require a secondary small rim graft for residual rim concavity. The concept of grafting the alar rim is strongly supported by the authors' results. The modifications the authors applied by designing the graft to be anatomical in shape has been a technical help.

  19. Suction blister grafting - Modifications for easy harvesting and grafting

    Directory of Open Access Journals (Sweden)

    2012-01-01

    Full Text Available Suction blister grafting is a simple modality of treatment of patients with resistant and stable vitiligo. But raising the blisters may be time consuming and transferring to the recipient site may be difficult as the graft is ultrathin. By doing some modifications we can make the technique simpler and easier. We can decrease the blister induction time by intradermal injection of saline, exposure to Wood′s lamp, intrablister injection of saline. By these methods we can decrease the blister induction time from 2-3 hrs to 45-90 minutes. After harvesting the graft, it can be transferred to the recipient area by taking the graft on a sterile glass slide, on the gloved finger, rolling the graft over a sterile syringe and then spreading on the recipient area, or taking on the sterile wrapper of paraffin dressing and then placing over the recipient area.

  20. Polyether/Polyester Graft Copolymers

    Science.gov (United States)

    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.

  1. Graft selection in cerebral revascularization.

    Science.gov (United States)

    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.

  2. Radiation grafting on natural films

    Science.gov (United States)

    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.

  3. Unexplained Graft Dysfunction after Heart Transplantation—Role of Novel Molecular Expression Test Score and QTc-Interval: A Case Report

    Directory of Open Access Journals (Sweden)

    Khurram Shahzad

    2010-01-01

    Full Text Available In the current era of immunosuppressive medications there is increased observed incidence of graft dysfunction in the absence of known histological criteria of rejection after heart transplantation. A noninvasive molecular expression diagnostic test was developed and validated to rule out histological acute cellular rejection. In this paper we present for the first time, longitudinal pattern of changes in this novel diagnostic test score along with QTc-interval in a patient who was admitted with unexplained graft dysfunction. Patient presented with graft failure with negative findings on all known criteria of rejection including acute cellular rejection, antibody mediated rejection and cardiac allograft vasculopathy. The molecular expression test score showed gradual increase and QTc-interval showed gradual prolongation with the gradual decline in graft function. This paper exemplifies that in patients presenting with unexplained graft dysfunction, GEP test score and QTc-interval correlate with the changes in the graft function.

  4. Acute mixed cellular and humoral rejection of renal allograft with leucopenia.

    Science.gov (United States)

    Agarwal, D K; Hota, J K; Malhotra, V

    2011-08-01

    Diagnosis and management of acute renal allograft dysfunction often pose challenge to nephrologists during practice. Acute rejection is a major cause of acute graft dysfunction but is rare in patients with leucopenia. Acute rejection can have either humoral or cellular components or sometimes mixed components. Mixed acute cellular and humoral rejection often present as steroid resistant rejection. Here we report a patient with live related renal transplant recipient with acute graft dysfunction with leucopenia who was found to have mixed acute cellular and humoral rejection.

  5. Delivery of Nucleic Acids and Proteins from Grafted Rootstocks for Pathogen and Pest Control

    Directory of Open Access Journals (Sweden)

    Victor eHaroldsen

    2012-03-01

    Full Text Available Grafting has been used in agriculture for over two thousand years. With modern advances in biotechnology, new options for utilizing this proven horticultural technique are emerging. Specifically, trans-grafting, the combination of a genetically engineered (GE rootstock with a wild-type (WT scion, has the potential to provide biotic and abiotic stress tolerance or to increase plant vigor and productivity. Yet, it is unclear whether nucleic acids and proteins will be transmitted across a graft and, if so, whether this movement may affect the efficacy of the trans-grafting approach and/or regulatory oversight of the WT scion and its products. There are reports of the movement of organellar DNA and cellular mRNAs and proteins across graft unions, but to what extent these molecules affect performance of the scion is not clear. Strategies that can be used to limit or enhance nucleic acid or protein movement in order to maximize trans-grafting benefits have not been defined. This paper reviews, using specific examples, the transport of nucleic acids and proteins between rootstock and scion with the objectives of increasing the benefits grafting, particularly for pathogen resistance and defining how use of GE rootstocks effectively extends the horticultural utility of grafting.

  6. Graft stability after endothelial keratoplasty

    Directory of Open Access Journals (Sweden)

    Jovanović Vesna

    2015-01-01

    Full Text Available Bacground/Aim. Techniques for replacing the corneal endothelium have been improved. The host-graft interface is the key to graft adhesion and visual recovery. The aim of this study was to establish graft stability after Descemet stripping with endothelial keratoplasty (DSEK, compare it to the graft stability after endothelial keratoplasty with the intact posterior corneal layers (nDSEK in the rabbit cornea, and to investigate the nature of wound healing. Methods. Adult white rabbits (n = 20 were divided in two experimental groups: ten rabbits underwent monocular DSEK, and ten rabbits underwent endothelial keratoplasty without Descemet stripping (nDSEK. On the second postoperative day a horizontal dislocation of the graft was tried using the Lindstrom roller in each animal. Corneas were processed for the light microscopy study. Results. Rolling the Lindstrom instrument over the corneal surface did not cause horizontal dislocation in any of the operated eyes. In the DSEK group light microscopy revealed the lack of inflammation and fibrosis at the clearly distinctive donor-recipient interface (DRI. Retrocorneal membrane was found in two eyes. In nDSEK group, the host Descemet` s membrane (DM was intact without endothelial cells, with good graft apposition, without inflammation, fibrosis, or retrocorneal membrane. Conclusion. This study suggests that there is no difference in graft stability in DSEK compared to nDSEK in rabbit corneas. Wounds healed at DRI by hypocellular scarring only in both experimental groups.

  7. Resorbable extracellular matrix grafts in urologic reconstruction

    Directory of Open Access Journals (Sweden)

    Richard A. Santucci

    2005-06-01

    Full Text Available PURPOSE: There is an increasingly large body of literature concerning tissue-engineering products that may be used in urology. Some of these are quite complex (such as multilayer patient-specific cell-seeded implants yet the most simple and successful products to date are also the most uncomplicated: resorbable acellular extra-cellular matrices (ECMs harvested from animals. ECMs have been used in a variety of difficult urologic reconstruction problems, and this review is intended to summarize this complex literature for the practicing urologist. METHODS: Medline search of related terms such as "SIS, small intestinal submucosa, ECM, extracellular matrix, acellular matrix and urologic reconstruction". Manuscripts missed in the initial search were taken from the bibliographies of the primary references. RESULTS: Full review of potential clinical uses of resorbable extra-cellular matrices in urologic reconstruction. CONCLUSIONS: Currently, the "state of the art" in tissue engineering solutions for urologic reconstruction means resorbable acellular xenograft matrices. They show promise when used as a pubovaginal sling or extra bolstering layers in ureteral or urethral repairs, although recent problems with inflammation following 8-ply pubovaginal sling use and failures after 1- and 4-ply SIS repair of Peyronie's disease underscore the need for research before wide adoption. Preliminary data is mixed concerning the potential for ECM urethral patch graft, and more data is needed before extended uses such as bladder augmentation and ureteral replacement are contemplated. The distant future of ECMs in urology likely will include cell-seeded grafts with the eventual hope of producing "off the shelf" replacement materials. Until that day arrives, ECMs only fulfill some of the requirements for the reconstructive urologist.

  8. Graft nephrectomy: The SGPGI experience

    Directory of Open Access Journals (Sweden)

    Nand Kishore Arvind

    2002-01-01

    Full Text Available Background: Graft nephrectomy is often considered a hazardous procedure with high morbidity and occasional mortality, and this may pose a technical challenge. The aim of this study was to evaluate the indications, etiology and complications following graft nephrectomy. Materials and Methods: From 1988 to 2001, among total of 1,019 live related renal transplants carried at our center, 46 underwent graft nephrectomy. Patients were divided into 2 groups depending on timing of graft re-moval. The early group included 27 patients (within 2 months of transplantation while in late group (graft re-moval after 2 months of transplantation there were 19 patients. The 2 groups were compared in terms of indica-tion, etiology and complications. Results: In early group the indications for graft removal were acute rejection, thrombosis/infarction and hyper-acute rejection, while in late group the indications were pain, hematuria, fever, hypertension and infection along with chronic failure. Overall, the external iliac artery in-jury occurred in I and 4 patients in early and late group respectively. Major blood loss occurred in I and 6 pa-tients in early and late graft removal respectively. There were 2 deaths in early group due to ftdminant pneumoni-tis that progressed to sepsis and disseminated intravascu-lar coagulation. There were 9 major wound infections all in early group except in 2 patients of late group. Respira-tory infections occurred in 14 patients in early group and 1 in late group. In early group patients had CNS compli-cations in form of seizures, clinical depression and delusional psychosis in 12 patients. Conclusions: Our experience highlights the risk in-volved in graft nephrectomies. Severe acute rejection and thrombosis lead to early graft nephrectomies. Pain, hematuria, infection and hypertension in setting of chronic rejection are predominant causes for the delayed graft ne- phrectomies. Early graft nephrectomy, though technically easy, is

  9. Rule-based model of vein graft remodeling.

    Directory of Open Access Journals (Sweden)

    Minki Hwang

    Full Text Available When vein segments are implanted into the arterial system for use in arterial bypass grafting, adaptation to the higher pressure and flow of the arterial system is accomplished thorough wall thickening and expansion. These early remodeling events have been found to be closely coupled to the local hemodynamic forces, such as shear stress and wall tension, and are believed to be the foundation for later vein graft failure. To further our mechanistic understanding of the cellular and extracellular interactions that lead to global changes in tissue architecture, a rule-based modeling method is developed through the application of basic rules of behaviors for these molecular and cellular activities. In the current method, smooth muscle cell (SMC, extracellular matrix (ECM, and monocytes are selected as the three components that occupy the elements of a grid system that comprise the developing vein graft intima. The probabilities of the cellular behaviors are developed based on data extracted from in vivo experiments. At each time step, the various probabilities are computed and applied to the SMC and ECM elements to determine their next physical state and behavior. One- and two-dimensional models are developed to test and validate the computational approach. The importance of monocyte infiltration, and the associated effect in augmenting extracellular matrix deposition, was evaluated and found to be an important component in model development. Final model validation is performed using an independent set of experiments, where model predictions of intimal growth are evaluated against experimental data obtained from the complex geometry and shear stress patterns offered by a mid-graft focal stenosis, where simulation results show good agreements with the experimental data.

  10. Design of a Sapling Branch Grafting Robot

    Directory of Open Access Journals (Sweden)

    Qun Sun

    2014-01-01

    Full Text Available The automatic sapling grafting methods and grafting robot technologies are not comprehensively studied despite the fact that they are urgently required in practice. For this reason, a sapling grafting robot is developed to implement automatic grafting for saplings. The developed grafting robot includes clipping mechanism, moving mechanism, cutting mechanism, binding mechanism, and Arduino MCU based control system, which is capable of clipping, moving, positioning, cutting, grafting, and binding saplings. Experiments show that the stock cutting efficiency is 98.4%, the scion cutting efficiency is 98.9%, the grafting efficiency is 87.3%, and the binding efficiency is 68.9%.

  11. Vascular graft infections with Mycoplasma

    DEFF Research Database (Denmark)

    Levi-Mazloum, Niels Donald; Skov Jensen, J; Prag, J;

    1995-01-01

    Vascular graft infection is one of the most serious complications in vascular surgery. It is associated with mortality rates ranging from 25% to 75% and with morbidity in the form of amputation in approximately 30% of patients. Staphylococcus aureus is the leading pathogen. With conventional...... laboratory techniques, the percentage of culture-negative yet grossly infected vascular grafts seems to be increasing and is not adequately explained by the prior use of antibiotics. We have recently reported the first case of aortic graft infection with Mycoplasma. We therefore suggest the hypothesis...... that the large number of culture-negative yet grossly infected vascular grafts may be due to Mycoplasma infection not detected with conventional laboratory technique....

  12. Synthesis and characterization of polypyrrole grafted chitin

    Science.gov (United States)

    Ramaprasad, A. T.; Latha, D.; Rao, Vijayalakshmi

    2017-05-01

    Synthesis and characterization of chitin grafted with polypyrrole (PPy) is reported in this paper. Chitin is soaked in pyrrole solution of various concentrations for different time intervals and polymerized using ammonium peroxy disulphate (APS) as an initiator. Grafting percentage of polypyrrole onto chitin is calculated from weight of chitin before and after grafting. Grafting of polymer is further verified by dissolution studies. The grafted polymer samples are characterized by FTIR, UV-Vis absorption spectrum, XRD, DSC, TGA, AFM, SEM and conductivity studies.

  13. Evaluation of autogenous grafts used in vestibuloplasty.

    Science.gov (United States)

    Metin, M; Dolanmaz, D; Alkan, A

    2003-01-01

    Vestibuloplasty is indicated when prosthesis stability is poor due to mandibular or maxillary atrophy. The use of autogenous grafts to provide sufficient vestibular depth is widely accepted. In this retrospective study, the outcomes of vestibuloplasty performed on 41 patients using various types of autogenous grafts (full-thickness skin, dermal, reversed dermal, meshed skin and palatal mucosal) are presented. The best results were obtained with palatal mucosal grafts, but graft size is limited. Meshed skin grafts were shown to be the best alternative.

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

    Science.gov (United States)

    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.

  15. Flat Cellular (UMTS) Networks

    NARCIS (Netherlands)

    Bosch, H.G.P.; Samuel, L.G.; Mullender, S.J.; Polakos, P.; Rittenhouse, G.

    2007-01-01

    Traditionally, cellular systems have been built in a hierarchical manner: many specialized cellular access network elements that collectively form a hierarchical cellular system. When 2G and later 3G systems were designed there was a good reason to make system hierarchical: from a cost-perspective i

  16. Domino liver graft from a patient with homozygous familial hypercholesterolemia.

    Science.gov (United States)

    Liu, Chinsu; Niu, Dau-Ming; Loong, Che-Chuan; Hsia, Cheng-Yuan; Tsou, Mei-Yung; Tsai, Hsin-Lin; Wei, Choufu

    2010-05-01

    HFH is a metabolic disease caused by a defect in the gene that encodes the synthesis of the cellular receptor for LDL-Rs. A high plasma level of cholesterol is present from birth and leads to severe atherosclerosis in childhood, and death from myocardial infarction usually occurs before the age of 20 yr. The liver contains approximately 50-75% of the total body LDL-Rs; therefore, liver transplantation has been carried out to treat this metabolic disorder effectively. The rationale for using an HFH liver for a domino graft is that the absence of functional LDL-Rs in the liver may be compensated for by the extra-hepatic LDL-Rs. Therefore, an HFH liver can possibly be used as a domino graft for a recipient with a normal plasma cholesterol level before transplantation. We herein report a domino liver transplantation using an HFH liver as a domino graft with successful results. To expand the donor pool, especially in Asian countries, domino grafts from HFH should be encouraged by careful selection of the domino recipient.

  17. Modelling ultrasound-induced mild hyperthermia of hyperplasia in vascular grafts

    Directory of Open Access Journals (Sweden)

    Cheung Alfred K

    2011-11-01

    Full Text Available Abstract Background Expanded polytetrafluoroethylene (ePTFE vascular grafts frequently develop occlusive neointimal hyperplasia as a result of myofibroblast over-growth, leading to graft failure. ePTFE exhibits higher ultrasound attenuation than native soft tissues. We modelled the selective absorption of ultrasound by ePTFE, and explored the feasibility of preventing hyperplasia in ePTFE grafts by ultrasound heating. Specifically, we simulated the temperature profiles of implanted grafts and nearby soft tissues and blood under ultrasound exposure. The goal was to determine whether ultrasound exposure of an ePTFE graft can generate temperatures sufficient to prevent cell growth on the graft without damaging nearby soft tissues and blood. Methods Ultrasound beams from two transducers (1.5 and 3.2 MHz were simulated in two graft/tissue models, with and without an intra-graft cellular layer mimicking hyperplasia, using the finite-difference time-domain (FDTD method. The resulting power deposition patterns were used as a heat source for the Pennes bioheat equation in a COMSOL® Multiphysics heat transfer model. 50°C is known to cause cell death and therefore the transducer powers were adjusted to produce a 13°C temperature rise from 37°C in the ePTFE. Results Simulations showed that both the frequency of the transducers and the presence of hyperplasia significantly affect the power deposition patterns and subsequent temperature profiles on the grafts and nearby tissues. While neither transducer significantly raised the temperature of the blood, the 1.5-MHz transducer was less focused and heated larger volumes of the graft and nearby soft tissues than the 3.2-MHz transducer. The presence of hyperplasia had little effect on the blood's temperature, but further increased the temperature of the graft and nearby soft tissues in response to either transducer. Skin cooling and blood flow play a significant role in preventing overheating of the native

  18. Evolution of skin grafting for treatment of burns: Reverdin pinch grafting to Tanner mesh grafting and beyond.

    Science.gov (United States)

    Singh, Mansher; Nuutila, Kristo; Collins, K C; Huang, Anne

    2017-09-01

    Skin grafting is the current standard care in the treatment of full thickness burns. It was first described around 1500 BC but the vast majority of advancements have been achieved over the past 200 years. An extensive literature review was conducted on Pubmed, Medline and Google Scholar researching the evolution of skin grafting techniques. The authors concentrated on the major landmarks of skin grafting and also provide an overview of ongoing research efforts in this field. The major innovations of skin grafting include Reverdin pinch grafting, Ollier grafting, Thiersch grafting, Wolfe grafting, Padgett dermatome and modifications, Meek-wall microdermatome and Tanner mesh grafting. A brief description of the usage, advantages and limitations of each technique is included in the manuscript. Skin grafting technique have evolved significantly over past 200 years from Reverdin pinch grafting to modern day meshed skin grafts using powered dermatome. Increasing the expansion ratio and improving the cosmetic and functional outcome are the main focus of ongoing skin grafting research and emerging techniques (such as Integra(®), Recell(®), Xpansion(®)) are showing promise. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

  19. Vestibuloplasty: allograft versus mucosal graft.

    Science.gov (United States)

    Hashemi, H M; Parhiz, A; Ghafari, S

    2012-04-01

    The aim of the present study was to compare the application of alloderm and mucosal graft for vestibuloplasty. This randomized controlled trial with split mouth design was carried out on 20 edentulous patients. Patients underwent vestibuloplasty surgery with the Clark technique. Half of the prepared bed in each patient was covered with alloderm and the other half with mucosal graft. Vestibule depth (width of fixed tissue) and relapse in the two sides immediately after surgery, and 1, 3 and 6 months after surgery were measured and compared. Statistical analysis was carried out using the Kolmogorov-Smirnov, Student's paired t and Friedman tests. The width of the fixed tissue in the alloderm graft at 1, 3 and 6 month intervals was significantly lower than that in the autograft (Pvestibuloplasty. Copyright © 2011 International Association of Oral and Maxillofacial Surgeons. All rights reserved.

  20. Prevention of primary vascular graft infection with silver-coated polyester graft in a porcine model

    DEFF Research Database (Denmark)

    Gao, H; Sandermann, J; Prag, J;

    2010-01-01

    To evaluate the efficacy of a silver-coated vascular polyester graft in the prevention of graft infection after inoculation with Staphylococcus aureus in a porcine model.......To evaluate the efficacy of a silver-coated vascular polyester graft in the prevention of graft infection after inoculation with Staphylococcus aureus in a porcine model....

  1. Acute graft versus host disease after orthotopic liver transplantation

    Directory of Open Access Journals (Sweden)

    Rogulj Inga

    2012-08-01

    Full Text Available Abstract Graft versus host disease (GVHD is an uncommon complication after orthotopic liver transplantation (OLT with an incidence of 0.1–2%, but an 80–100% mortality rate. Patients can present with skin rashes, diarrhea, and bone marrow aplasia between two to eight weeks after OLT. Diagnosis of GVHD is made based on clinical and histologic evidence, supported by chimerism studies showing donor HLA alleles in the recipient bone marrow or blood. Several therapeutic approaches have been used for the management of GVHD after OLT including increased immunosuppression, decreased immunosuppression, and cellular therapies. However, success rates have been low, and new approaches are needed.

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

    Science.gov (United States)

    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

  3. Reversible quantum cellular automata

    CERN Document Server

    Schumacher, B

    2004-01-01

    We define quantum cellular automata as infinite quantum lattice systems with discrete time dynamics, such that the time step commutes with lattice translations and has strictly finite propagation speed. In contrast to earlier definitions this allows us to give an explicit characterization of all local rules generating such automata. The same local rules also generate the global time step for automata with periodic boundary conditions. Our main structure theorem asserts that any quantum cellular automaton is structurally reversible, i.e., that it can be obtained by applying two blockwise unitary operations in a generalized Margolus partitioning scheme. This implies that, in contrast to the classical case, the inverse of a nearest neighbor quantum cellular automaton is again a nearest neighbor automaton. We present several construction methods for quantum cellular automata, based on unitaries commuting with their translates, on the quantization of (arbitrary) reversible classical cellular automata, on quantum c...

  4. STUDY OF GRAFT SITES IN EPOXY GRAFT COPOLYMERS BY QUANTUM CHEMISTRY CALCULATIONS

    Institute of Scientific and Technical Information of China (English)

    Song Chen; Xiao-yu Li

    2009-01-01

    Exploration and characterization of grafting productions by experimental methods are often cumbersome or sometimes impossible. Therefore, quantum chemistry calculations were performed to characterize the graft sites of epoxy resin. According to the Gibbs free energy criterion of the second law of thermodynamic, the reported graft sites were confirmed, and more important, some unreported graft sites were found. In addition, method of increasing the number of graft sites was studied in this article.

  5. Polyether-polyester graft copolymer

    Science.gov (United States)

    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.

  6. The caudal septum replacement graft.

    Science.gov (United States)

    Foda, Hossam M T

    2008-01-01

    To describe a technique for reconstructing the lost tip support in cases involving caudal septal and premaxillary deficiencies. The study included 120 patients with aesthetic and functional nasal problems resulting from the loss of caudal septal and premaxillary support. An external rhinoplasty approach was performed to reconstruct the lost support using a cartilaginous caudal septum replacement graft and premaxillary augmentation with Mersilene mesh. The majority of cases (75%) involved revisions in patients who had previously undergone 1 or more nasal surgical procedures. A caudal septum replacement graft was combined with premaxillary augmentation in 93 patients (77.5%). The mean follow-up period was 3 years (range, 1-12 years). The technique succeeded in correcting the external nasal deformities in all patients and resulted in a significant improvement in breathing in 74 patients (86%) with preoperative nasal obstruction. There were no cases of infection, displacement, or extrusion. The caudal septum replacement graft proved to be very effective in restoring the lost tip support in patients with caudal septal deficiency. Combining the graft with premaxillary augmentation using Mersilene mesh helped increase support and stability over long-term follow-up.

  7. Endocytosis of PEGylated nanoparticles accompanied by structural and free energy changes of the grafted polyethylene glycol.

    Science.gov (United States)

    Li, Ying; Kröger, Martin; Liu, Wing Kam

    2014-10-01

    Nanoparticles (NPs) are in use to efficiently deliver drug molecules into diseased cells. The surfaces of NPs are usually grafted with polyethylene glycol (PEG) polymers, during so-called PEGylation, to improve water solubility, avoid aggregation, and prevent opsonization during blood circulation. The interplay between grafting density σp and grafted PEG polymerization degree N makes cellular uptake of PEGylated NPs distinct from that of bare NPs. To understand the role played by grafted PEG polymers, we study the endocytosis of 8 nm sized PEGylated NPs with different σp and N through large scale dissipative particle dynamics (DPD) simulations. The free energy change Fpolymer of grafted PEG polymers, before and after endocytosis, is identified to have an effect which is comparable to, or even larger than, the bending energy of the membrane during endocytosis. Based on self-consistent field theory Fpolymer is found to be dependent on both σp and N. By incorporating Fpolymer, the critical ligand-receptor binding strength for PEGylated NPs to be internalized can be correctly predicted by a simple analytical equation. Without considering Fpolymer, it turns out impossible to predict whether the PEGylated NPs will be delivered into the diseased cells. These simulation results and theoretical analysis not only provide new insights into the endocytosis process of PEGylated NPs, but also shed light on the underlying physical mechanisms, which can be utilized for designing efficient PEGylated NP-based therapeutic carriers with improved cellular targeting and uptake.

  8. Dual grafts in adult-to-adult living donor liver transplantation: a single center experience in Taiwan.

    Science.gov (United States)

    Yang, Chin-Hsiang; Chen, Chao-Long; Wang, Chih-Chi; Concejero, Allan M; Wang, Shih-Ho; Liu, Yueh-Wei; Yong, Chee-Chien; Lin, Tsan-Shiun

    2009-02-01

    Volume mismatch is encountered when a single live donor cannot provide adequate graft volume to the recipient with a remnant liver volume which is safe for donation. Our objective is to present our experience in living donor liver transplantation using dual grafts. Record review of 4 dual graft recipients was done. The results were compared with 122 consecutive patients who received a single right lobe. All dual graft recipients were surviving with satisfactory liver function at a median follow-up of 21 months. Two recipients received 1 right and 1 left lobe graft, while the other 2 recipients received 2 left lobe grafts. One donor developed biloma and was managed by percutaneous drainage. The first recipient required re-laparotomy for postoperative bleeding. The second recipient underwent re-laparotomy for bile leak. The third recipient developed grade II decubitus ulcers due to a prolonged sedentary position. When compared with recipients who received a single right lobe, the operative time was prolonged in the dual graft group. There was no apparent increase in the rate of vascular and biliary complications or the incidence of acute cellular rejection. Actuarial patient survivals were comparable in both groups. Dual graft transplantation provides sufficient volume in the recipient without jeopardizing donor safety.

  9. Functional integration of grafted neural stem cell-derived dopaminergic neurons monitored by optogenetics in an in vitro Parkinson model.

    Directory of Open Access Journals (Sweden)

    Jan Tønnesen

    Full Text Available Intrastriatal grafts of stem cell-derived dopamine (DA neurons induce behavioral recovery in animal models of Parkinson's disease (PD, but how they functionally integrate in host neural circuitries is poorly understood. Here, Wnt5a-overexpressing neural stem cells derived from embryonic ventral mesencephalon of tyrosine hydroxylase-GFP transgenic mice were expanded as neurospheres and transplanted into organotypic cultures of wild type mouse striatum. Differentiated GFP-labeled DA neurons in the grafts exhibited mature neuronal properties, including spontaneous firing of action potentials, presence of post-synaptic currents, and functional expression of DA D₂ autoreceptors. These properties resembled those recorded from identical cells in acute slices of intrastriatal grafts in the 6-hydroxy-DA-induced mouse PD model and from DA neurons in intact substantia nigra. Optogenetic activation or inhibition of grafted cells and host neurons using channelrhodopsin-2 (ChR2 and halorhodopsin (NpHR, respectively, revealed complex, bi-directional synaptic interactions between grafted cells and host neurons and extensive synaptic connectivity within the graft. Our data demonstrate for the first time using optogenetics that ectopically grafted stem cell-derived DA neurons become functionally integrated in the DA-denervated striatum. Further optogenetic dissection of the synaptic wiring between grafted and host neurons will be crucial to clarify the cellular and synaptic mechanisms underlying behavioral recovery as well as adverse effects following stem cell-based DA cell replacement strategies in PD.

  10. Functional integration of grafted neural stem cell-derived dopaminergic neurons monitored by optogenetics in an in vitro Parkinson model.

    Science.gov (United States)

    Tønnesen, Jan; Parish, Clare L; Sørensen, Andreas T; Andersson, Angelica; Lundberg, Cecilia; Deisseroth, Karl; Arenas, Ernest; Lindvall, Olle; Kokaia, Merab

    2011-03-04

    Intrastriatal grafts of stem cell-derived dopamine (DA) neurons induce behavioral recovery in animal models of Parkinson's disease (PD), but how they functionally integrate in host neural circuitries is poorly understood. Here, Wnt5a-overexpressing neural stem cells derived from embryonic ventral mesencephalon of tyrosine hydroxylase-GFP transgenic mice were expanded as neurospheres and transplanted into organotypic cultures of wild type mouse striatum. Differentiated GFP-labeled DA neurons in the grafts exhibited mature neuronal properties, including spontaneous firing of action potentials, presence of post-synaptic currents, and functional expression of DA D₂ autoreceptors. These properties resembled those recorded from identical cells in acute slices of intrastriatal grafts in the 6-hydroxy-DA-induced mouse PD model and from DA neurons in intact substantia nigra. Optogenetic activation or inhibition of grafted cells and host neurons using channelrhodopsin-2 (ChR2) and halorhodopsin (NpHR), respectively, revealed complex, bi-directional synaptic interactions between grafted cells and host neurons and extensive synaptic connectivity within the graft. Our data demonstrate for the first time using optogenetics that ectopically grafted stem cell-derived DA neurons become functionally integrated in the DA-denervated striatum. Further optogenetic dissection of the synaptic wiring between grafted and host neurons will be crucial to clarify the cellular and synaptic mechanisms underlying behavioral recovery as well as adverse effects following stem cell-based DA cell replacement strategies in PD.

  11. Use of Brilliant Blue FCF during vein graft preparation inhibits intimal hyperplasia.

    Science.gov (United States)

    Osgood, Michael J; Sexton, Kevin; Voskresensky, Igor; Hocking, Kyle; Song, Jun; Komalavilas, Padmini; Brophy, Colleen; Cheung-Flynn, Joyce

    2016-08-01

    Intimal hyperplasia remains the primary cause of vein graft failure for the 1 million yearly bypass procedures performed using human saphenous vein (HSV) grafts. This response to injury is caused in part by the harvest and preparation of the conduit. The use of Brilliant Blue FCF (FCF) restores injury-induced loss of function in vascular tissues possibly via inhibition of purinergic receptor signaling. This study investigated whether pretreatment of the vein graft with FCF prevents intimal hyperplasia. Cultured rat aortic smooth muscle cells (A7r5) were used to determine the effect of FCF on platelet-derived growth factor-mediated migration and proliferation, cellular processes that contribute to intimal hyperplasia. The effectiveness of FCF treatment during the time of explantation on preventing intimal hyperplasia was evaluated in a rabbit jugular-carotid interposition model and in an organ culture model using HSV. FCF inhibited platelet-derived growth factor-induced migration and proliferation of A7r5 cells. Treatment with FCF at the time of vein graft explantation inhibited the subsequent development of intimal thickening in the rabbit model. Pretreatment with FCF also prevented intimal thickening of HSV in organ culture. Incorporation of FCF as a component of vein graft preparation at the time of explantation represents a potential therapeutic approach to mitigate intimal hyperplasia, reduce vein graft failure, and improve outcome of the autologous transplantation of HSV. Copyright © 2016. Published by Elsevier Inc.

  12. Posterior repair with perforated porcine dermal graft

    Directory of Open Access Journals (Sweden)

    G. Bernard Taylor

    2008-02-01

    Full Text Available OBJECTIVE: To compare postoperative vaginal incision separation and healing in patients undergoing posterior repair with perforated porcine dermal grafts with those that received grafts without perforations. Secondarily, the tensile properties of the perforated and non-perforated grafts were measured and compared. MATERIALS AND METHODS: This was a non-randomized retrospective cohort analysis of women with stage II or greater rectoceles who underwent posterior repair with perforated and non-perforated porcine dermal grafts (PelvicolTM CR Bard Covington, GA USA. The incidence of postoperative vaginal incision separation (dehiscence was compared. A secondary analysis to assess graft tensile strength, suture pull out strength, and flexibility after perforation was performed using standard test method TM 0133 and ASTM bending and resistance protocols. RESULTS: Seventeen percent of patients (21/127 who received grafts without perforations developed vaginal incision dehiscence compared to 7% (5/71 of patients who received perforated grafts (p = 0.078. Four patients with vaginal incision dehiscence with non-perforated grafts required surgical revision to facilitate healing. Neither tensile strength or suture pull out strength were significantly different between perforated and non-perforated grafts (p = 0.81, p = 0.29, respectively. There was no difference in the flexibility of the two grafts (p = 0.20. CONCLUSION: Perforated porcine dermal grafts retain their tensile properties and are associated with fewer vaginal incision dehiscences.

  13. Additive Manufacturing of Vascular Grafts and Vascularized Tissue Constructs.

    Science.gov (United States)

    Elomaa, Laura; Yang, Yunzhi Peter

    2017-01-10

    There is a great need for engineered vascular grafts among patients with cardiovascular diseases who are in need of bypass therapy and lack autologous healthy blood vessels. In addition, because of the severe worldwide shortage of organ donors, there is an increasing need for engineered vascularized tissue constructs as an alternative to organ transplants. Additive manufacturing (AM) offers great advantages and flexibility of fabrication of cell-laden, multimaterial, and anatomically shaped vascular grafts and vascularized tissue constructs. Various inkjet-, extrusion-, and photocrosslinking-based AM techniques have been applied to the fabrication of both self-standing vascular grafts and porous, vascularized tissue constructs. This review discusses the state-of-the-art research on the use of AM for vascular applications and the key criteria for biomaterials in the AM of both acellular and cellular constructs. We envision that new smart printing materials that can adapt to their environment and encourage rapid endothelialization and remodeling will be the key factor in the future for the successful AM of personalized and dynamic vascular tissue applications.

  14. Renal graft irradiation in acute rejection

    Energy Technology Data Exchange (ETDEWEB)

    Pilepich, M.V.; Sicard, G.A.; Breaux, S.R.; Etheredge, E.E.; Blum, J.; Anderson, C.B.

    1983-03-01

    To evaluate the effect of graft irradiation in the treatment of acute rejection of renal transplants, a randomized study was conducted from 1978 to 1981. Patients with acute rejection were given standard medical management in the form of intravenous methylprednisolone, and were chosen randomly to receive either graft irradiation (175 rads every other day, to a total of 525 rads) or simulated (sham) irradiation. Eighty-three rejections occurring in 64 grafts were randomized to the protocol. Rejection reversal was recorded in 84.5% of control grafts and 75% of the irradiated grafts. Recurrent rejections were more frequent and graft survival was significantly lower in the irradiated group (22%) than in the control group (54%). Graft irradiation does not appear to be beneficial in the treatment of acute rejection of renal transplants when used in conjunction with high-dose steroids.

  15. Starch Modification by Graft Copolymerization of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    刘瑞贤; 李莉; 茹宗玲; 张黎明; 高建平; 田汝川

    2003-01-01

    The graft copolymerization of acrylonitrile (AN) onto starch under the initiation of potassium permanganate was investigated. The effect of various reaction conditions on the graft copolymerization was studied. The relationships between the grafting rate and the initiator concentration of potassium permanganate, monomer acrylonitrile and backbone starch, as well as reaction temperature were established. The oxidation reaction of starch with manganic ions and valence changes of manganic ions during the graft copolymerization were discussed. The results show that manganic ion Mn7+ underwent a series of valence changes during the graft copolymerization: Mn(Ⅶ) → Mn(Ⅳ) → Mn(Ⅲ) → Mn(Ⅱ). The grafting rate of the graft copolymerization of acrylonitrile onto starch is also given.

  16. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Sanju [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)], E-mail: sanju@barc.gov.in; Dhanawade, B.R.; Mitra, D.; Varshney, Lalit; Sabharwal, Sunil [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2009-01-15

    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.

  19. Modeling cellular systems

    CERN Document Server

    Matthäus, Franziska; Pahle, Jürgen

    2017-01-01

    This contributed volume comprises research articles and reviews on topics connected to the mathematical modeling of cellular systems. These contributions cover signaling pathways, stochastic effects, cell motility and mechanics, pattern formation processes, as well as multi-scale approaches. All authors attended the workshop on "Modeling Cellular Systems" which took place in Heidelberg in October 2014. The target audience primarily comprises researchers and experts in the field, but the book may also be beneficial for graduate students.

  20. Epigenetics and Cellular Metabolism

    OpenAIRE

    Wenyi Xu; Fengzhong Wang; Zhongsheng Yu; Fengjiao Xin

    2016-01-01

    Living eukaryotic systems evolve delicate cellular mechanisms for responding to various environmental signals. Among them, epigenetic machinery (DNA methylation, histone modifications, microRNAs, etc.) is the hub in transducing external stimuli into transcriptional response. Emerging evidence reveals the concept that epigenetic signatures are essential for the proper maintenance of cellular metabolism. On the other hand, the metabolite, a main environmental input, can also influence the proce...

  1. Nanostructured cellular networks.

    Science.gov (United States)

    Moriarty, P; Taylor, M D R; Brust, M

    2002-12-01

    Au nanocrystals spin-coated onto silicon from toluene form cellular networks. A quantitative statistical crystallography analysis shows that intercellular correlations drive the networks far from statistical equilibrium. Spin-coating from hexane does not produce cellular structure, yet a strong correlation is retained in the positions of nanocrystal aggregates. Mechanisms based on Marangoni convection alone cannot account for the variety of patterns observed, and we argue that spinodal decomposition plays an important role in foam formation.

  2. Bioceramics for osteogenesis, molecular and cellular advances.

    Science.gov (United States)

    Demirkiran, Hande

    2012-01-01

    The remarkable need for bone tissue replacement in clinical situations, its limited availability and some major drawbacks of autologous (from the patient) and allogeneic (from a donor) bone grafts are driving researchers to search for alternative approaches for bone repair. In order to develop an appropriate bone substitute, one should understand bone structure and properties and its growth, which will guide researchers to select the optimal conditions for tissue culture and implantation. It's well accepted that bioceramics are excellent candidates as bone replacement with osteogenesis, osteoinduction and osteoconduction capacity. Therefore, the molecular and cellular interactions that take place at the surface of bioceramics and their relevance in osteogenesis excites many researchers to delve deeper into this line of research.

  3. [Autologous fat grafting in children].

    Science.gov (United States)

    Baptista, C; Bertrand, B; Philandrianos, C; Degardin, N; Casanova, D

    2016-10-01

    Lipofilling or fat grafting transfer is defined as a technique of filling soft tissue by autologous fat grafting. The basic principle of lipofilling is based on a harvest of adipose tissue, followed by a reinjection after treatment. Lipofilling main objective is a volume defect filling, but also improving cutaneous trophicity. Lipofilling specificities among children is mainly based on these indications. Complications of autologous fat grafting among children are the same as those in adults: we distinguish short-term complications (intraoperative and perioperative) and the medium and long-term complications. The harvesting of fat tissue is the main limiting factor of the technique, due to low percentage of body fat of children. Indications of lipofilling among children may be specific or similar to those in adults. There are two types of indications: cosmetic, in which the aim of lipofilling is correcting a defect density, acquired (iatrogenic, post-traumatic scar) or malformation (otomandibular dysplasia, craniosynostosis, Parry Romberg syndrom, Poland syndrom, pectus excavatum…). The aim of functional indications is correcting a velar insufficiency or lagophthalmos. In the paediatric sector, lipofilling has become an alternative to the conventional techniques, by its reliability, safety, reproducibility, and good results.

  4. Hybrid Graft Anterior Cruciate Ligament Reconstruction: A Predictable Graft for Knee Stabilization.

    Science.gov (United States)

    Alvarez-Pinzon, Andres M; Barksdale, Leticia; Krill, Michael K; Leo, Brian M

    2015-06-01

    Trauma to the anterior cruciate ligament (ACL) is a season-ending injury and involves months of activity modification and rehabilitation. The annual incidence of ACL tears in the United States is approximately 200,000, which allows for a broad range of individualized treatment options. Various surgical techniques, including transtibial and independent tunnel drilling, allograft and autograft tissue, and various implants, have been described in the literature. This article describes the indications and technique for a hybrid soft tissue graft for ACL reconstruction. Autologous grafts eliminate the risk of disease transmission and have recently been shown to have a lower rerupture rate, particularly in younger, active patients; however, the harvesting of autologous hamstring grafts carries a risk of donor-site morbidity, iatrogenic injury of the graft, and inadequate graft size. In contrast to a traditional autologous soft tissue graft, the hybrid graft allows for graft size customization for a desired reconstruction, especially in cases where autograft hamstrings may be iatrogenically damaged or of inadequate size when harvested. The goal of a hybrid graft ACL reconstruction is to provide a favorable-sized graft with clinical outcomes comparable with autologous soft tissue grafts. In contrast to a traditional autologous soft tissue graft, this technique provides another option in the event of unforeseen deficiencies or complications associated with harvesting and preparation of the autologous gracilis and semitendinosis soft tissue graft.

  5. Cellular, physiological, and molecular adaptive responses of Erwinia amylovora to starvation.

    Science.gov (United States)

    Santander, Ricardo D; Oliver, James D; Biosca, Elena G

    2014-05-01

    Erwinia amylovora causes fire blight, a destructive disease of rosaceous plants distributed worldwide. This bacterium is a nonobligate pathogen able to survive outside the host under starvation conditions, allowing its spread by various means such as rainwater. We studied E. amylovora responses to starvation using water microcosms to mimic natural oligotrophy. Initially, survivability under optimal (28 °C) and suboptimal (20 °C) growth temperatures was compared. Starvation induced a loss of culturability much more pronounced at 28 °C than at 20 °C. Natural water microcosms at 20 °C were then used to characterize cellular, physiological, and molecular starvation responses of E. amylovora. Challenged cells developed starvation-survival and viable but nonculturable responses, reduced their size, acquired rounded shapes and developed surface vesicles. Starved cells lost motility in a few days, but a fraction retained flagella. The expression of genes related to starvation, oxidative stress, motility, pathogenicity, and virulence was detected during the entire experimental period with different regulation patterns observed during the first 24 h. Further, starved cells remained as virulent as nonstressed cells. Overall, these results provide new knowledge on the biology of E. amylovora under conditions prevailing in nature, which could contribute to a better understanding of the life cycle of this pathogen.

  6. Evaluation of early coronary graft patency after coronary artery bypass graft surgery using multislice computed tomography angiography

    Directory of Open Access Journals (Sweden)

    Raissi Kamal

    2009-12-01

    Full Text Available Abstract Background Coronary artery bypass graft (CABG surgery is the standard of care in the treatment of advanced coronary artery disease, and its long-term results are affected by the failure of bypass grafts. The aim of the present study was to evaluate the early patency rate in coronary bypass grafts. Methods A total of 107 consecutive patients who underwent CABG were included in this study. Early graft patency was evaluated via computed tomography (CT angiography in the first week after surgery. Results There were a total of 366 grafts, comprised of 250 venous grafts and 116 arterial grafts. Multi-slice CT detected acute graft occlusions in 32 (8.7% of all the grafts, including 26 (10% of the 250 venous grafts and 6 (5% of the 116 arterial grafts. The patency rates obtained were 97.3% for the left internal mammary (IMA grafts, 50% for the radial artery grafts, and 50% for the right IMA grafts. Additionally, 107 (96.4% grafts to the left anterior descending artery (LAD were classified as patent, whereas 1 (30% of the 3 grafts in the left circumflex (LCX region and 1 (50% of the 2 grafts in the right coronary artery (RCA territory were found to be occluded. In the venous category, 8 (13.7% of the 58 grafts to LAD were found to be occluded. In the LCX region, 9 (8.5% of the 106 grafts were classified as occluded, while the remaining 97 (91.5% grafts were patent. The venous grafts to RCA were occluded in 9 (10.4% of the 86 grafts. Amongst the multiple preoperative, intraoperative, and postoperative factors, pump time was significantly longer in the patients with occluded grafts than in those with patent grafts (P = 0.04. Conclusion The IMA grafts had the highest early patency rate amongst the coronary bypass grafts. However, the other arterial grafts were associated with a high rate of acute occlusions.

  7. Twist and its effect on ACL graft forces.

    NARCIS (Netherlands)

    Arnold, M.P.; Blankevoort, L.; Ham, A. ten; Verdonschot, N.J.J.; Kampen, A. van

    2004-01-01

    Graft tension is a controversial topic in anterior cruciate ligament (ACL) surgery. Evidence suggests a narrow range of graft tensions, which allow the graft to remodel to a stable and mature neoligament. In previous cadaver experiments, we showed that twisting the graft could modulate the graft for

  8. Twist and its effect on ACL graft forces

    NARCIS (Netherlands)

    Arnold, MP; Blankevoort, L; ten Ham, A; Verdonschot, N; van Kampen, A

    2004-01-01

    Graft tension is a controversial topic in anterior cruciate ligament (ACL) surgery. Evidence suggests a narrow range of graft tensions, which allow the graft to remodel to a stable and mature neoligament. In previous cadaver experiments, we showed that twisting the graft could modulate the graft for

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

    Science.gov (United States)

    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. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Fixation of tibial plateau fractures with synthetic bone graft versus natural bone graft: a comparison study.

    LENUS (Irish Health Repository)

    Ong, J C Y

    2012-06-01

    The goal of this study was to determine differences in fracture stability and functional outcome between synthetic bone graft and natural bone graft with internal fixation of tibia plateau metaphyseal defects.

  11. CHEMICAL MORPHOLOGY IN GRAFTING ACRYLAMIDE TO POLYETHYLENE

    Institute of Scientific and Technical Information of China (English)

    S. Termnak; K. Sintasanai; T. Amomsakchai; T. Nipithakul; D. Triampo

    2008-01-01

    The scanning force microscopy (SFM)/chemical force microscopy (CFM) were used to study the growth of grafted polyacrylamide (PAM) chains onto polyethylene (PE)-film with varying grafting time. Results from the CFM reveal reduced interaction between the probe and areas with grafted-PAM on the surface. The topography and the friction trace-minus-retrace (TMR) images are complementary to one another resulting from the reduced interaction of the probe that has specificity to chemical domains.

  12. Architected Cellular Materials

    Science.gov (United States)

    Schaedler, Tobias A.; Carter, William B.

    2016-07-01

    Additive manufacturing enables fabrication of materials with intricate cellular architecture, whereby progress in 3D printing techniques is increasing the possible configurations of voids and solids ad infinitum. Examples are microlattices with graded porosity and truss structures optimized for specific loading conditions. The cellular architecture determines the mechanical properties and density of these materials and can influence a wide range of other properties, e.g., acoustic, thermal, and biological properties. By combining optimized cellular architectures with high-performance metals and ceramics, several lightweight materials that exhibit strength and stiffness previously unachievable at low densities were recently demonstrated. This review introduces the field of architected materials; summarizes the most common fabrication methods, with an emphasis on additive manufacturing; and discusses recent progress in the development of architected materials. The review also discusses important applications, including lightweight structures, energy absorption, metamaterials, thermal management, and bioscaffolds.

  13. Epigenetics and Cellular Metabolism

    Science.gov (United States)

    Xu, Wenyi; Wang, Fengzhong; Yu, Zhongsheng; Xin, Fengjiao

    2016-01-01

    Living eukaryotic systems evolve delicate cellular mechanisms for responding to various environmental signals. Among them, epigenetic machinery (DNA methylation, histone modifications, microRNAs, etc.) is the hub in transducing external stimuli into transcriptional response. Emerging evidence reveals the concept that epigenetic signatures are essential for the proper maintenance of cellular metabolism. On the other hand, the metabolite, a main environmental input, can also influence the processing of epigenetic memory. Here, we summarize the recent research progress in the epigenetic regulation of cellular metabolism and discuss how the dysfunction of epigenetic machineries influences the development of metabolic disorders such as diabetes and obesity; then, we focus on discussing the notion that manipulating metabolites, the fuel of cell metabolism, can function as a strategy for interfering epigenetic machinery and its related disease progression as well. PMID:27695375

  14. Outcomes of AV Fistulas and AV Grafts after Interventional Stent-Graft Deployment in Haemodialysis Patients.

    Science.gov (United States)

    Schmelter, Christopher; Raab, Udo; Lazarus, Friedrich; Ruppert, Volker; Vorwerk, Dierk

    2015-08-01

    The study was designed to assess outcomes of arteriovenous (AV) accesses after interventional stent-graft deployment in haemodialysis patients. 63 haemodialysis patients with 66 AV fistulas and AV grafts were treated by interventional stent-graft deployment from 2006 to 2012 at our hospital. Data of these patients were retrospectively analysed for location of deployed stent-grafts, occurrence and location of (re-)stenosis and (re-)thrombosis. Complex stenosis was the most frequent indication for stent-graft deployment (45.5%), followed by complications of angioplasty with vessel rupture or dissection (31.8%). A high rate of procedural success was achieved (98.5%). The most frequent location of the deployed stent-graft was the draining vein (66.7%). Stent-graft deployment was more frequent in AV grafts than in AV fistulas. Primary patency was 45.5% at 6 month, 31.3% at 12 month and 19.2% at 24 month. Primary patency was significantly better for AV fistulas than for AV grafts with deployed stent-grafts. Patency of the deployed stent-graft was much better than overall AV access primary patency with deployed stent-graft. Re-stenosis with thrombosis was the most frequent indication for re-intervention. Most frequent location of re-stenosis was the draining vein (37.1%), followed by stenosis at the AV access (29.5%) and the deployed stent-graft (23.5%). Re-stenosis and re-thrombosis remain frequent in AV fistulas and AV grafts in haemodialysis patients despite stent-graft deployment. Re-stenosis of the deployed stent-graft is, only in the minority of the cases, responsible for AV access dysfunction.

  15. Outcomes of AV Fistulas and AV Grafts after Interventional Stent-Graft Deployment in Haemodialysis Patients

    Energy Technology Data Exchange (ETDEWEB)

    Schmelter, Christopher, E-mail: christopher.schmelter@klinikum-ingolstadt.de; Raab, Udo, E-mail: udo.raab@klinikum-ingolstadt.de [Klinikum Ingolstadt, Department of Diagnostic and Interventional Radiology (Germany); Lazarus, Friedrich, E-mail: friedrich.lazarus@klinikum-ingolstadt.de [Klinikum Ingolstadt, Department of Nephrology (Germany); Ruppert, Volker, E-mail: volker.ruppert@klinikum-ingolstadt.de [Klinikum Ingolstadt, Department of Vascular Surgery (Germany); Vorwerk, Dierk, E-mail: dierk.vorwerk@klinikum-ingolstadt.de [Klinikum Ingolstadt, Department of Diagnostic and Interventional Radiology (Germany)

    2015-08-15

    PurposeThe study was designed to assess outcomes of arteriovenous (AV) accesses after interventional stent-graft deployment in haemodialysis patients.Materials and Methods63 haemodialysis patients with 66 AV fistulas and AV grafts were treated by interventional stent-graft deployment from 2006 to 2012 at our hospital. Data of these patients were retrospectively analysed for location of deployed stent-grafts, occurrence and location of (re-)stenosis and (re-)thrombosis. Complex stenosis was the most frequent indication for stent-graft deployment (45.5 %), followed by complications of angioplasty with vessel rupture or dissection (31.8 %).ResultsA high rate of procedural success was achieved (98.5 %). The most frequent location of the deployed stent-graft was the draining vein (66.7 %). Stent-graft deployment was more frequent in AV grafts than in AV fistulas. Primary patency was 45.5 % at 6 month, 31.3 % at 12 month and 19.2 % at 24 month. Primary patency was significantly better for AV fistulas than for AV grafts with deployed stent-grafts. Patency of the deployed stent-graft was much better than overall AV access primary patency with deployed stent-graft. Re-stenosis with thrombosis was the most frequent indication for re-intervention. Most frequent location of re-stenosis was the draining vein (37.1 %), followed by stenosis at the AV access (29.5 %) and the deployed stent-graft (23.5 %).ConclusionRe-stenosis and re-thrombosis remain frequent in AV fistulas and AV grafts in haemodialysis patients despite stent-graft deployment. Re-stenosis of the deployed stent-graft is, only in the minority of the cases, responsible for AV access dysfunction.

  16. Cellular structural biology.

    Science.gov (United States)

    Ito, Yutaka; Selenko, Philipp

    2010-10-01

    While we appreciate the complexity of the intracellular environment as a general property of every living organism, we collectively lack the appropriate tools to analyze protein structures in a cellular context. In-cell NMR spectroscopy represents a novel biophysical tool to investigate the conformational and functional characteristics of biomolecules at the atomic level inside live cells. Here, we review recent in-cell NMR developments and provide an outlook towards future applications in prokaryotic and eukaryotic cells. We hope to thereby emphasize the usefulness of in-cell NMR techniques for cellular studies of complex biological processes and for structural analyses in native environments. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Cellular blue naevus

    Directory of Open Access Journals (Sweden)

    Mittal R

    2001-01-01

    Full Text Available A 31-year-old man had asymptomatic, stationary, 1.5X2 cm, shiny, smooth, dark blue nodule on dorsum of right hand since 12-14 years. In addition he had developed extensive eruption of yellow to orange papulonodular lesions on extensors of limbs and buttocks since one and half months. Investigations confirmed that yellow papules were xanthomatosis and he had associated diabetes mellitus and hyperlipidaemia. Biopsy of blue nodule confirmed the clinical diagnosis of cellular blue naevus. Cellular blue naevus is rare and its association with xanthomatosis and diabetes mellitus were interesting features of above patients which is being reported for its rarity.

  18. Dynamics of the alar rim graft.

    Science.gov (United States)

    Guyuron, Bahman; Bigdeli, Yaas; Sajjadian, Ali

    2015-04-01

    The purpose of this study was to review the dynamics and frequency of the use of the alar rim graft. The recorded intraoperative information for the purpose of rhinoplasty research was reviewed to investigate the frequency of the use of alar rim grafts. Intraoperative observations were also made while inserting the alar rim graft to identify the changes that occur in the structures that could be influenced by placement of this graft. The data were tabulated in an Excel file and analyzed. Of the 1427 patients who underwent nose reconstruction or rhinoplasty in this study, 565 (39.56 percent) received alar rim grafts. This included 73 primary nose reconstructions, 20 secondary nose reconstructions, two revision nose reconstructions, 304 primary rhinoplasties, 107 secondary rhinoplasties, 43 revision operations following primary rhinoplasties, and seven revision operations following secondary rhinoplasties. However, when 100 more recent consecutive cases were reviewed, 88 percent of primary rhinoplasty patients and 67 percent of secondary rhinoplasty patients received alar rim grafts. The observed dynamic changes after insertion of each graft included (1) correction of the concavity of the ala, (2) caudal advancement of the alar rim, (3) elongation of nostril, and (4) widening of the nostril. The majority of patients who undergo rhinoplasty would benefit from the alar rim graft, and this study demonstrates a steady increase in its use. Placement of an alar rim graft results in elongation of the short nostril, correction of the alar concavity, widening of the nostril, and slight caudal transposition of the alar rim.

  19. The autologus graft of epithelial tissue culture

    Directory of Open Access Journals (Sweden)

    Minaee B

    1999-08-01

    Full Text Available With the intention of research about culture and autologus graft of epithelial tissue we used 4 french Albino Rabbits with an average age of 2 months. After reproduction on the support in EMEM (Eagle's Minimum Essential Medium we used this for graft after 4 weeks. This region which grafted total replaced. After fixation of this sample and passing them through various process, histological sections were prepared. These sections were stained with H & E and masson's trichrome and studied by light microscope. We succeeded in graft. We hope in the near future by using the method of epithelium tissue culture improving to treat burned patients.

  20. Successful repigmentation of vitiligo after allogeneic bone marrow transplantation for Hodgkin′s lymphoma by autologous noncultured melanocyte-keratinocyte transplantation

    Directory of Open Access Journals (Sweden)

    Huijuan Tang

    2015-01-01

    Full Text Available The treatment of vitiligo is derisory since the pathogenesis of vitiligo is not clear at present. Most conservative treatments are difficult to approach satisfactory therapy. So transplantation is the only way left when the disease becomes insensitive to those conservative treatments. Here we describe an 18-year-old patient who developed vitiligo, which was triggered by graft-versus-host disease after a allogeneic bone marrow transplantation for the treatment of Hodgkin′s lymphoma from his sister. In the following treatment to vitiligo, the patient successfully performed the transplantation of autologous uncultured melanocyte on the premise of poor reaction to other conservative methods. We infer that transplantation can be a treatment of the vitiligo after allogeneic bone marrow transplantation.

  1. Zwitterionic phosphorylcholine grafted chitosan nanofiber: Preparation, characterization and in-vitro cell adhesion behavior.

    Science.gov (United States)

    Oktay, Burcu; Kayaman-Apohan, Nilhan; Süleymanoğlu, Mediha; Erdem-Kuruca, Serap

    2017-04-01

    In this study, zwitterionic phosphorylcholine grafted electrospun chitosan fiber was accomplished in three steps: (1) Azide groups on the chitosan were regioselectively replaced with hydroxyl side group and then the product was electrospun. (2) Chitosan based macroinitiator was prepared using an azide-alkyne click reaction from azide-functionalized electrospun chitosan fiber. (3) Poly(2-methacryloyloxyethyl phosphorylcholine) (MPC) was grafted onto the electrospun chitosan fiber by atom transfer radical polymerization (ATRP) in order to enhance cellular viability and proliferation of 3T3, ECV and Saos. The structure of surface modified chitosan was characterized by Fourier transform infrared spectrometer (FT-IR) and (1)H nuclear magnetic resonance ((1)H NMR). The surface morphology of the nanofibers was investigated by scanning electron microscope (SEM). In-vitro cellular attachment and spreading experiments of 3T3, ECV304 and Saos were performed on electrospun chitosan fibers in the presence and the absence of MPC grafting. Poly(MPC) grafted electrospun fiber showed an excellent performance due to phosphorylcholine groups mimicking the natural phospholipid. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Engineering Cellular Metabolism

    DEFF Research Database (Denmark)

    Nielsen, Jens; Keasling, Jay

    2016-01-01

    of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation....

  3. Electromagnetic cellular interactions.

    Science.gov (United States)

    Cifra, Michal; Fields, Jeremy Z; Farhadi, Ashkan

    2011-05-01

    Chemical and electrical interaction within and between cells is well established. Just the opposite is true about cellular interactions via other physical fields. The most probable candidate for an other form of cellular interaction is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular interactions. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular interactions in the modern scientific literature. Although small, it is continuously accumulating. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Cellular rehabilitation of photobiomodulation

    Science.gov (United States)

    Liu, Timon Cheng-Yi; Yuan, Jian-Qin; Wang, Yan-Fang; Xu, Xiao-Yang; Liu, Song-Hao

    2007-05-01

    Homeostasis is a term that refers to constancy in a system. A cell in homeostasis normally functions. There are two kinds of processes in the internal environment and external environment of a cell, the pathogenic processes (PP) which disrupts the old homeostasis (OH), and the sanogenetic processes (SP) which restores OH or establishes a new homeostasis (NH). Photobiomodualtion (PBM), the cell-specific effects of low intensity monochromatic light or low intensity laser irradiation (LIL) on biological systems, is a kind of modulation on PP or SP so that there is no PBM on a cell in homeostasis. There are two kinds of pathways mediating PBM, the membrane endogenetic chromophores mediating pathways which often act through reactive oxygen species, and membrane proteins mediating pathways which often enhance cellular SP so that it might be called cellular rehabilitation. The cellular rehabilitation of PBM will be discussed in this paper. It is concluded that PBM might modulate the disruption of cellular homeostasis induced by pathogenic factors such as toxin until OH has been restored or NH has been established, but can not change homeostatic processes from one to another one.

  5. Cellular Response to Irradiation

    Institute of Scientific and Technical Information of China (English)

    LIU Bo; YAN Shi-Wei

    2011-01-01

    To explore the nonlinear activities of the cellular signaling system composed of one transcriptional arm and one protein-interaction arm, we use an irradiation-response module to study the dynamics of stochastic interactions.It is shown that the oscillatory behavior could be described in a unified way when the radiation-derived signal and noise are incorporated.

  6. Nanotribological study of grafted polymer

    Science.gov (United States)

    Bouhacina, T.; Aimé, J. P.; Attias, A. J.

    1998-06-01

    The frictional forces between grafted layers, organosilanes and polymer, on silica and a nanotip have been investigated as a function of the tip velocity. From the interpretation of these results and one gets a step forward for more quantitative information. Les forces de friction entre des couches greffées sur silice et une nanopointe ont été étudiées en fonction de la vitesse de la pointe. À partir de l'interprétation de ces résultats on s'avance vers plus d'infor mations quantitatives.

  7. Diffusion and Perfusion: The Keys to Fat Grafting

    Directory of Open Access Journals (Sweden)

    Roger K. Khouri, Jr, BS

    2014-09-01

    Conclusions: These models confirm that initial fat grafting survival is limited by oxygen diffusion. Preoperative expansion increases oxygen diffusion capacity allowing for additional graft retention. These models provide a scientific framework for testing the current fat grafting theories.

  8. Radiation resistivity of polyacenaphthylene-grafted polyethylene

    Science.gov (United States)

    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.

  9. Unmanipulated Native Fat Exposed To High-energy Diet, But Not Autologous Grafted Fat By Itself, May Lead To Overexpression Of Ki67 And Pai-1

    OpenAIRE

    Claro, Francisco; Morari, Joseane; Moreira, Luciana R; Sarian, Luís O Z; Pinto, Glauce A; Licio A Velloso; Pinto-Neto, Aarão M

    2016-01-01

    Background: Although its unclear oncological risk, which led to more than 20 years of prohibition of its use, fat grafting to the breast is widely used nowadays even for aesthetic purposes. Thus, we proposed an experimental model in rats to analyze the inflammatory activity, cellular proliferation and levels of Plasminogen Activator Inhibitor (PAI-1) in grafted fat, and in native fat exposed to high-energy diet in order to study the oncological potential of fat tissue. Methods: Samples of gra...

  10. Grafting as a method for studying development in the filamentous fungus Podospora anserina.

    Science.gov (United States)

    Silar, Philippe

    2011-08-01

    While grafting and transplant experiments have extensively been used to study development in animals and plants, they have seldom been employed to study fungal development. Here, grafting is used to study the interplay between mycelium and multicellular fruiting bodies during maturation in the model ascomycete Podospora anserina. Data indicate that grafts need a competent mycelium to continue their ripening. Vegetative incompatibility does not prevent transplanted fructifications to undergo development. Grafting onto mutant mycelia confirmed a previous model stating that the NADPH oxidase PaNox1 is required in the developing fruiting bodies, while the MAP kinase cascade PaMpk1 is required in the mycelium. Data also show that the IDC1 protein is required not only in the developing fruiting bodies but also in the mycelium, likely because of its role in anastomosis. Finally, entry inside the grafted fruiting bodies of a ribosomal protein tagged with GFP could be detected, suggesting that cellular components are imported from the underlying mycelium during maturation.

  11. Subepithelial connective tissue graft for root coverage: clinical case reports and histologic evaluation.

    Science.gov (United States)

    Roman, Alexandra; Câmpian, R; Domşa, I; Soancă, Andrada; Gocan, H

    2010-01-01

    If the clinical goal of the periodontal plastic surgery is the complete root coverage of gingival recessions, then the microscopically goal standard is to obtain a true periodontal regeneration. Only the histological examination can reveal cellular events unrolled into the grafted tissue-root surface interface and the nature of the clinically observed attachment. To our knowledge, there are no studies that obtained the biopsies of grafted tissues from humans, in vivo, and so, the aim of the present study was to develop such a method, using a bone marrow biopsy needle. Two patients with gingival recessions were treated with coronally advanced flap and subepithelial connective tissue graft, and the clinical and histological results were observed. Complete root coverage was obtained for both cases. Clinically, the grafted tissues seemed to be attached to the root surfaces. The histological findings revealed dense grafted tissues, providing long-term stability of the area. No ligament or bone, characteristic for periodontal regeneration were observed. However, no sign of healing characterized by a long junctional epithelium was observed either. This indicated that the healing that occurred in our cases was a long connective tissue attachment, which has been shown to be stable over time. However, even if the method we proposed is not invasive, it is very difficult to convince the patient to accept a biopsy elevation once the exposed root surface was covered.

  12. Fabrication of engineered heart tissue grafts from alginate/collagen barium composite microbeads

    Energy Technology Data Exchange (ETDEWEB)

    Bai, X P; Zheng, H X; Fang, R; Wang, T R; Li, Y; Tian, W M [Department of Life Science and Engineering, Harbin Institute of Technology, Harbin, 150080 (China); Hou, X L [The Fourth Affiliated Hospital of Harbin Medical University, Harbin, 150001 (China); Chen, X B, E-mail: tianweiming@gmail.com [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon (Canada)

    2011-08-15

    Cardiac tissue engineering holds great promise for the treatment of myocardial infarction. However, insufficient cell migration into the scaffolds used and inflammatory reactions due to scaffold biodegradation remain as issues to be addressed. Engineered heart tissue (EHT) grafts fabricated by means of a cell encapsulation technique provide cells with a tissue-like environment, thereby potentially enhancing cellular processes such as migration, proliferation, and differentiation, and tissue regeneration. This paper presents a study on the fabrication and characterization of EHT grafts from novel alginate/collagen composite microbeads by means of cell encapsulation. Specifically, the microbeads were fabricated from alginate and collagen by barium ion cross-linking, with neonatal rat cardiomyocytes encapsulated in the composite microbeads during the fabrication of the EHT grafts. To evaluate the suitablity of these EHT grafts for heart muscle repair, the growth of cardiac cells in the microbeads was examined by means of confocal microscopy and staining with DAPI and F-actin. The EHT grafts were analyzed by scanning electron microscopy and transmission electron microscopy, and the contractile function of the EHT grafts monitored using a digital video camera at different time points. The results show the proliferation of cardiac cells in the microbeads and formation of interconnected multilayer heart-like tissues, the presence of well-organized and dense cell structures, the presence of intercalated discs and spaced Z lines, and the spontaneous synchronized contractility of EHT grafts (at a rate of 20-30 beats min{sup -1} after two weeks in culture). Taken together, these observations demonstrate that the novel alginate/collagen composite microbeads can provide a tissue-like microenvironment for cardiomyocytes that is suitable for fabricating native heart-like tissues.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Yuki [Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan)]. E-mail: wada.yuki@jaea.go.jp; Seko, Noriaki [Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Nagasawa, Naotsugu [Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Tamada, Masao [Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan); Kasuya, Ken-ichi [Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Mitomo, Hiroshi [Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan)

    2007-06-15

    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.

  15. Influence of ischemia before vein grafting on early hyperplasia of the graft and the dynamic changes of the intima after grafting

    Directory of Open Access Journals (Sweden)

    Zou RongJiang

    2012-09-01

    Full Text Available Abstract Background To investigate both the influence of ischemia before grafting on early hyperplasia of the vein grafts, and the dynamic changes of the intima after grafting in a rabbit model of vein graft disease. Methods We performed paired vein graft experiments under different ischemic conditions (15 vs. 60 min; 15 vs. 90 min in the neck of the rabbits and compared the differences between the grafts. Clopidogrel, an anti-platelet agent, was administered before and after surgery. Twenty-eight days after the grafting procedure, the veins were evaluated microscopically. The dynamic changes of the intima after grafting were evaluated by scanning electron microscopy over time. Results The vein grafts subjected to 60- or 90-min ischemia exhibited no differences compared to those subjected to 15-min ischemia in terms of the mean thickness of the intimal, medial, and adventitial layers of the graft. Similarly, there was no difference in the Ki-67 labeling index (proliferation marker between the vein grafts. Vein grafts with 15-min ischemia lost endothelial cells (ECs but healed by 3 days post graft, whereas vein grafts with 90-min ischemia suffered serious EC loss, which was restored with new ECs during days 2 to 14 post graft. Conclusions Ninety-minute ischemia before vein grafting can cause serious EC loss, but does not increase early intimal hyperplasia when clopidogrel is administered. Protecting the vein from ischemia and reperfusion injury preserves ECs.

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

    Science.gov (United States)

    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.

  17. A novel initiating system for wool grafting

    Directory of Open Access Journals (Sweden)

    Magdy Kandil Zahran

    2016-05-01

    Full Text Available This paper describes a new method for the grafting of methacrylic acid (MAA and other acrylic monomers onto wool fabric in aqueous medium. The novelty principally concerns the chemical approach of the redox grafting reaction that was carried out in the presence of sodium perborate (SPB initiator. Before the grafting reaction was started, the wool fabric was treated first with a freshly prepared ferrous ammonium sulfate (FAS solution. The so-treated fabric formed, with SPB, an efficacious redox system capable of initiating grafting of methacrylic acid (MAA and other acrylic monomers onto the wool fabric. The effect of the polymerization conditions on the polymer criteria, namely, graft yield (%GY, homopolymer (%HP, total conversion (%TC, and grafting efficiency (%GE, was studied. These polymer criteria were found to depend spaciously upon concentrations of the Fe2+ ion (activator, SPB (initiator, and MAA, pH of the polymerization medium, duration and temperature of polymerization. The graft copolymerization reaction has also been carried out in the presence of polymerization activators (e.g. reductant transition metal ions and an inhibitor (e.g. hydroquinone. A suitable mechanism for the grafting processes has been suggested, in accordance with the experimental results.

  18. Multimodality imaging of coronary artery bypass grafts

    NARCIS (Netherlands)

    Salm, Liesbeth Pauline

    2006-01-01

    This thesis describes multiple imaging modalities to examine coronary artery bypass grafts, and the research which was performed to further develop noninvasive imaging techniques to detect stenoses in native coronary arteries and bypass grafts in patients who experienced recurrent chest pain after

  19. Multimodality imaging of coronary artery bypass grafts

    NARCIS (Netherlands)

    Salm, Liesbeth Pauline

    2006-01-01

    This thesis describes multiple imaging modalities to examine coronary artery bypass grafts, and the research which was performed to further develop noninvasive imaging techniques to detect stenoses in native coronary arteries and bypass grafts in patients who experienced recurrent chest pain after c

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

    Science.gov (United States)

    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.

  1. Vestibuloplasty with Retroauricular Skin Grafts for Dental Implant Rehabilitation in Vascularized Fibula Grafts: Two Case Reports.

    Science.gov (United States)

    Sencimen, Metin; Gulses, Aydin; Varol, Altan; Ayna, Mustafa; Ozen, Jölide; Dogan, Necdet; Açil, Yahya

    The aim of this study was to present the use of retroauricular full-thickness skin grafts in vestibuloplasty surgeries for dental implant rehabilitation in vascularized fibula grafts. Two patients underwent mandibular reconstruction with vascularized fibula grafts due to mandibular gunshot injuries. Inadequate sulcus gaps secondary to mandibular soft tissue deficiencies were managed by full-thickness autologous skin grafts harvested from the retroauricular region. Dental rehabilitation was achieved by implants placed in free fibula grafts. In both cases, complete graft survival was achieved. Cosmetic and functional outcomes were satisfactory. Owing to its high resiliency and elasticity and its thin and hairless structure, full-thickness retroauricular skin graft is an effective treatment modality in the management of intraoral soft tissue deficiencies. Patients with gunshot injuries present great functional and esthetic demands, and every report presenting new treatment modalities is helpful in the management of the condition.

  2. Polyethylene oxide hydration in grafted layers

    Science.gov (United States)

    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).

  3. Graft Take-Rates After Tympanoplasty

    DEFF Research Database (Denmark)

    Andersen, Steven Arild Wuyts; Aabenhus, Kristine; Glad, Henrik;

    2014-01-01

    , technique, graft material, and revision surgery) for tympanoplasty type I were studied. A comparison with the graft take-rates for tympanoplasty types II to IV and/or cholesteatoma was made. RESULTS: A user-friendly ear surgery database with fast data entry and direct import of audiometric data......OBJECTIVE: To present a prospective ear surgery database and investigate the graft take-rate and prognostic factors for graft take-rate in tympanoplasty using the database. STUDY DESIGN: Prospective database study. SETTING: Tertiary referral center. PATIENTS: A total of 1606 cases undergoing...... tympanoplasty types I to IV were registered in the database in the period from February 2004 to November 2013. INTERVENTION: A total of 837 cases underwent myringoplasty/tympanoplasty type I. MAIN OUTCOME MEASURE: Graft take-rate and prognostic factors (age, discharge at time of surgery, tuba function...

  4. Molecular and Cellular Signaling

    CERN Document Server

    Beckerman, Martin

    2005-01-01

    A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

  5. Environment Aware Cellular Networks

    KAUST Repository

    Ghazzai, Hakim

    2015-02-01

    The unprecedented rise of mobile user demand over the years have led to an enormous growth of the energy consumption of wireless networks as well as the greenhouse gas emissions which are estimated currently to be around 70 million tons per year. This significant growth of energy consumption impels network companies to pay huge bills which represent around half of their operating expenditures. Therefore, many service providers, including mobile operators, are looking for new and modern green solutions to help reduce their expenses as well as the level of their CO2 emissions. Base stations are the most power greedy element in cellular networks: they drain around 80% of the total network energy consumption even during low traffic periods. Thus, there is a growing need to develop more energy-efficient techniques to enhance the green performance of future 4G/5G cellular networks. Due to the problem of traffic load fluctuations in cellular networks during different periods of the day and between different areas (shopping or business districts and residential areas), the base station sleeping strategy has been one of the main popular research topics in green communications. In this presentation, we present several practical green techniques that provide significant gains for mobile operators. Indeed, combined with the base station sleeping strategy, these techniques achieve not only a minimization of the fossil fuel consumption but also an enhancement of mobile operator profits. We start with an optimized cell planning method that considers varying spatial and temporal user densities. We then use the optimal transport theory in order to define the cell boundaries such that the network total transmit power is reduced. Afterwards, we exploit the features of the modern electrical grid, the smart grid, as a new tool of power management for cellular networks and we optimize the energy procurement from multiple energy retailers characterized by different prices and pollutant

  6. [Graft reconstruction of flexor tendons].

    Science.gov (United States)

    Pauchard, N; Pedeutour, B; Dautel, G

    2014-12-01

    The improvement of primary flexor tendon repair has limited the indications of secondary repairs to neglected initial wound care and deficiencies in the surgical technique or rehabilitation. The surgical and rehabilitation care is complex and prolonged, requiring full cooperation of the patient. That is why the surgeon must evaluate patient's ability to integrate instructions and to comply with a long and demanding protocol. The functional needs of the patient are important in treatment decisions and the surgeon should not hesitate to use an appropriate surgical alternative (tenodesis, arthrodesis, tendon transfer, etc.). After a brief historical review, the authors discuss the indications, technical procedures and finally the results of one-stage and two-stage flexor tendon graft, which despite mixed results keep a real place in our current armamentarium.

  7. Increasing the potency of a cytotoxin with an arginine graft.

    Science.gov (United States)

    Fuchs, Stephen M; Rutkoski, Thomas J; Kung, Vanessa M; Groeschl, Ryan T; Raines, Ronald T

    2007-10-01

    Variants and homologs of bovine pancreatic ribonuclease (RNase A) can exhibit cytotoxic activity. This toxicity relies on cellular internalization of the enzyme. Residues Glu49 and Asp53 form an anionic patch on the surface of RNase A. We find that replacing these two residues with arginine does not affect catalytic activity or affinity for the cytosolic ribonuclease inhibitor (RI) protein. This 'arginine graft' does, however, increase toxicity towards human cancer cells. Appending a nonaarginine domain to this cationic variant results in an additional increase in cytotoxicity, providing one of the most cytotoxic known variants of RNase A. These findings correlate the potency of a ribonuclease with its deliverance of ribonucleolytic activity to the cytosol, and indicate a rational means to enhance the efficacy of ribonucleases and other cytotoxic proteins.

  8. 霍乱弧菌活的非可培养状态研究进展%Progress in research of viable but non-culturable state of Vibrio cholerae

    Institute of Scientific and Technical Information of China (English)

    陈保立; 阚飙

    2013-01-01

    霍乱弧菌是霍乱的病原体,广泛存在于海洋及江河入海口环境中.在不良环境中霍乱弧菌会进入活的非可培养状态(viable but non-culturable state,VBNC),常规分离方法检测不到,在条件合适时VBNC状态的霍乱弧菌会复苏为可培养状态.本文对近年霍乱弧菌VBNC相关研究做了回顾,以期能够为霍乱弧菌越冬机制以及霍乱的监测提供参考.%Vibrio cholerae, widely existing in marine and estuarine environments, is the causative agent of cholera. When V. cholerae cells are subjected to stringent conditions they may form viable but not culturable (VBNC) cells. These bacteria can recover from VBNC state and may pose risk to human. This paper summarizes the progress in the research of the VBNC state of V. cholerae for the better surveillance of V. cholerae.

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

    Science.gov (United States)

    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.

  10. Cellular communication through light.

    Directory of Open Access Journals (Sweden)

    Daniel Fels

    Full Text Available Information transfer is a fundamental of life. A few studies have reported that cells use photons (from an endogenous source as information carriers. This study finds that cells can have an influence on other cells even when separated with a glass barrier, thereby disabling molecule diffusion through the cell-containing medium. As there is still very little known about the potential of photons for intercellular communication this study is designed to test for non-molecule-based triggering of two fundamental properties of life: cell division and energy uptake. The study was performed with a cellular organism, the ciliate Paramecium caudatum. Mutual exposure of cell populations occurred under conditions of darkness and separation with cuvettes (vials allowing photon but not molecule transfer. The cell populations were separated either with glass allowing photon transmission from 340 nm to longer waves, or quartz being transmittable from 150 nm, i.e. from UV-light to longer waves. Even through glass, the cells affected cell division and energy uptake in neighboring cell populations. Depending on the cuvette material and the number of cells involved, these effects were positive or negative. Also, while paired populations with lower growth rates grew uncorrelated, growth of the better growing populations was correlated. As there were significant differences when separating the populations with glass or quartz, it is suggested that the cell populations use two (or more frequencies for cellular information transfer, which influences at least energy uptake, cell division rate and growth correlation. Altogether the study strongly supports a cellular communication system, which is different from a molecule-receptor-based system and hints that photon-triggering is a fine tuning principle in cell chemistry.

  11. Failover in cellular automata

    CERN Document Server

    Kumar, Shailesh

    2010-01-01

    A cellular automata (CA) configuration is constructed that exhibits emergent failover. The configuration is based on standard Game of Life rules. Gliders and glider-guns form the core messaging structure in the configuration. The blinker is represented as the basic computational unit, and it is shown how it can be recreated in case of a failure. Stateless failover using primary-backup mechanism is demonstrated. The details of the CA components used in the configuration and its working are described, and a simulation of the complete configuration is also presented.

  12. Review of cellular mechanotransduction

    Science.gov (United States)

    Wang, Ning

    2017-06-01

    Living cells and tissues experience physical forces and chemical stimuli in the human body. The process of converting mechanical forces into biochemical activities and gene expression is mechanochemical transduction or mechanotransduction. Significant advances have been made in understanding mechanotransduction at the cellular and molecular levels over the last two decades. However, major challenges remain in elucidating how a living cell integrates signals from mechanotransduction with chemical signals to regulate gene expression and to generate coherent biological responses in living tissues in physiological conditions and diseases.

  13. Cellular automata: structures

    OpenAIRE

    Ollinger, Nicolas

    2002-01-01

    Jury : François Blanchard (Rapporteur), Marianne Delorme (Directeur), Jarkko Kari (Président), Jacques Mazoyer (Directeur), Dominique Perrin, Géraud Sénizergues (Rapporteur); Cellular automata provide a uniform framework to study an important problem of "complex systems" theory: how and why do system with a easily understandable -- local -- microscopic behavior can generate a more complicated -- global -- macroscopic behavior? Since its introduction in the 40s, a lot of work has been done to ...

  14. Characterization of the inflammatory response to four commercial bone graft substitutes using a murine biocompatibility model

    Directory of Open Access Journals (Sweden)

    Markel DC

    2012-01-01

    Full Text Available David C Markel1, S Trent Guthrie2, Bin Wu3, Zheng Song4, Paul H Wooley41Department of Orthopaedics, Providence Hospital and Medical Centers, Southfield, MI, 2Henry Ford Hospital, Detroit, MI, 3Department of Biomedical Engineering, Wayne State University, Detroit, MI, 4Orthopaedic Research Institute, Wichita, KS, USAAbstract: Bone grafting is utilized in nearly all orthopedic subspecialties and in most anatomic regions. Bone graft substitutes have the potential to offer similar efficacy as autogenous grafts without the morbidity of harvest. Several studies have noted the efficacy of new-generation bone substitute products, but few studies have evaluated their safety. This study characterizes and quantifies the inflammatory reaction to four different commercially available bone graft substitutes, which were examined using the in vivo murine air pouch biocompatibility model. One coralline hydroxyapatite product was chosen as an example of a purely osteoconductive material. Three demineralized bone matrix products were chosen to represent products that are both osteoconductive and osteoinductive. Samples were implanted in a murine air pouch and harvested after 14 days in situ. Pouch fluid was extracted, mRNA isolated, and reverse transcription polymerase chain reactions carried out to detect interleukin-1 gene expression as a marker for inflammation. In addition, multiple histological characteristics were examined to quantify cellular responses to the implanted materials. All bone graft substitutes induced a significant inflammatory response compared with negative controls. Histology and polymerase chain reaction data indicated that the level of inflammatory reaction was elevated in materials with a higher demineralized bone matrix to carrier proportion. The hydroxyapatite product generated a low inflammatory reaction. In conclusion, this study used an in vivo model of biocompatibility to demonstrate that a significant inflammatory reaction occurs

  15. Flow characteristics in narrowed coronary bypass graft

    Energy Technology Data Exchange (ETDEWEB)

    Bernad, S. I. [Romanian Academy – Timisoara Branch, Mihai Viteazul Str. 24, RO-300223, Timisoara (Romania); Bosioc, A.; Totorean, A. F. [University Politehnica of Timisoara, Department of Hydraulic Machinery, Mihai Viteazul Str. 1, RO-300222, Timisoara (Romania); Bernad, E. S.; Petre, I. [University of Medicine and Pharmacy Victor Babes Timisoara, P-ta Eftimie Murgu, 2, Timisoara (Romania)

    2016-06-08

    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.

  16. Hemodynamics Simulation of Stenosed Coronary Bypass Graft

    Institute of Scientific and Technical Information of China (English)

    LIU You-jun; QIAO Aike; DU Jian-jun

    2005-01-01

    By means of FEM, the physiological blood flow in coronary bypass graft is simulated. The stenosis in coronary artery is involved in the graft model,and the deformation of graft end to allow the surgical suture with a smaller diameter coronary is taken into consideration. The flow pattern, secondary flow and wall shear stress in the vicinity of anastomosis are analyzed. It is shown that a zone of low wall stress and high wall stress gradient exists downstream the toe. The floor opposed to the anastomosis is an area of high wall stress and high wall stress gradient. Both the toe downstream and the anastomosis bottom floor are prone to intimal hyperplasia.

  17. Flow characteristics in narrowed coronary bypass graft

    Science.gov (United States)

    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. Bone Graft Substitutes : Developed for Trauma and Orthopaedic Surgery

    NARCIS (Netherlands)

    J. van der Stok (Johan)

    2015-01-01

    markdownabstract__Abstract__ Bone grafting was established in the 19th century and has become a common procedure in which bone defects are filled with bone grafts or bone graft substitutes. Bone defects that require bone grafting are encountered in approximately 10% of trauma and orthopaedic surger

  19. Immunohistochemical localization of IAA in graft union of explanted internode grafting

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The dynamic changes of IAA in graft union of explanted internode autografting of Cucumber (Cucumis sativus Linn.) have been investigated using the immunohistochemical localization technique.It is shown that the efficiency of IAA fixation using lyophilization-gas fixation is higher than that using liquid chemical fixation.In contrast to few silver particles and no significant changes during the development of graft union cultured in hormone-free medium,more silver particles in graft union and significant changes of IAA related to graft union development have been found when graft union was cultured in medium supplemented with appropriate hormones.The fixation procedure of plant hormones and the roles of IAA in graft union are discussed.

  20. Designer interface peptide grafts target estrogen receptor alpha dimerization

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, S. [Laboratory of Computational Biophysics & Bioengineering, Department of Physics, Tougaloo College, Tougaloo, MS 39174 (United States); Asare, B.K. [Department of Pharmacology and Toxicology, University of Buffalo, Buffalo, NY 14214 (United States); Biswas, P.K., E-mail: pbiswas@tougaloo.edu [Laboratory of Computational Biophysics & Bioengineering, Department of Physics, Tougaloo College, Tougaloo, MS 39174 (United States); Rajnarayanan, R.V., E-mail: rajendra@buffalo.edu [Department of Pharmacology and Toxicology, University of Buffalo, Buffalo, NY 14214 (United States)

    2016-09-09

    The nuclear transcription factor estrogen receptor alpha (ERα), triggered by its cognate ligand estrogen, regulates a variety of cellular signaling events. ERα is expressed in 70% of breast cancers and is a widely validated target for anti-breast cancer drug discovery. Administration of anti-estrogen to block estrogen receptor activation is still a viable anti-breast cancer treatment option but anti-estrogen resistance has been a significant bottle-neck. Dimerization of estrogen receptor is required for ER activation. Blocking ERα dimerization is therefore a complementary and alternative strategy to combat anti-estrogen resistance. Dimer interface peptide “I-box” derived from ER residues 503–518 specifically blocks ER dimerization. Recently using a comprehensive molecular simulation we studied the interaction dynamics of ERα LBDs in a homo-dimer. Based on this study, we identified three interface recognition peptide motifs LDKITDT (ERα residues 479–485), LQQQHQRLAQ (residues 497–506), and LSHIRHMSNK (residues 511–520) and reported the suitability of using LQQQHQRLAQ (ER 497–506) as a template to design inhibitors of ERα dimerization. Stability and self-aggregation of peptide based therapeutics poses a significant bottle-neck to proceed further. In this study utilizing peptide grafted to preserve their pharmacophoric recognition motif and assessed their stability and potential to block ERα mediated activity in silico and in vitro. The Grafted peptides blocked ERα mediated cell proliferation and viability of breast cancer cells but did not alter their apoptotic fate. We believe the structural clues identified in this study can be used to identify novel peptidometics and small molecules that specifically target ER dimer interface generating a new breed of anti-cancer agents. - Highlights: • Designer peptide grafts retain core molecular recognition motif during MD simulations. • Designer peptide grafts with Poly-ALA helix form stable

  1. Resolution of severe graft steatosis following dual-graft living donor liver transplantation.

    Science.gov (United States)

    Moon, DeokBog; Lee, SungGyu; Hwang, Shin; Kim, KiHun; Ahn, ChulSoo; Park, KwangMin; Ha, TaeYong; Song, GiWon

    2006-07-01

    Although severely steatotic liver grafts are not suitable for transplantation, they have been used when other, more optimal donors were not available, especially for living donor liver transplantation (LDLT) using two liver grafts. Here we present two cases of dual-graft LDLT in which the recipients showed rapid and complete clearing of fat from livers with previously severe steatosis. In the first case, two left lateral segment grafts were used, one of which was 70% steatotic. Preoperative and posttransplant two-week liver-to-spleen computed tomography-value (L/S) ratios were 0.48 and 1.25, respectively. A liver biopsy taken two weeks after transplantation showed that the fatty changes had almost disappeared. The second case used one left lobe and one left lateral segment graft, the latter of which was 80% steatotic. Preoperative and two-week L/S ratio were 0.58 and 1.34, respectively, and a liver biopsy taken two weeks after transplantation showed less than 3% steatosis. The two donors of the severely steatotic liver grafts recovered uneventfully. These findings show that the fat content of the liver grafts was rapidly removed after transplantation. This observation is helpful in understanding the recovery sequences following transplantation of steatotic liver grafts, as well as expanding the acceptability of steatotic liver grafts.

  2. Smashed skin grafting or smash grafting - a novel method of vitiligo surgery.

    Science.gov (United States)

    Krishnan, Ajay; Kar, Sumit

    2012-10-01

    Vitiligo is an acquired progressive disorder characterized by destruction of melanocytes in the lesion and the lesional hair follicles. A number of new therapeutic options for vitiligo have become available over the last decade or so both on the medical as well as surgical side. One among them is the smashed skin grafting or simply smash grafting, which is a modification of split-thickness grafting. In this method, the graft undergoes "smashing" before being applied to the recipient site. Though a simple and effective procedure, very few people are doing the procedure either due to lack of awareness or due to lack of published data. Smash skin grafting was performed in 26 patients with vitiligo in Mahatma Gandhi Institute of Medical Sciences, Sewagram, Maharashtra, India. Smashed skin grafting helped to achieve more than 90% repigmentation of the vitiligo patches in our patients. Smashed skin grafting is a simple procedure with fewer side effects, better outcome, and high patient satisfaction or, in simple words, it can be considered as an alternative to various conventional surgical modalities like punch grafting and melanocyte cell culture methods. This article deals with the steps of the procedure, results of the surgery in a small group of patients, and the necessity of increasing the awareness of smash grafting. © 2012 The International Society of Dermatology.

  3. Treatment of gingival recession in two surgical stages: Free gingival graft and connective tissue grafting.

    Science.gov (United States)

    Henriques, Paulo Sergio Gomes; Nunes, Marcelo Pereira; Pelegrine, Andre Antonio

    2011-01-01

    This report describes a clinical case of severe Miller Class II gingival recession treated by two stages of surgery that combined a free gingival graft and connective tissue grafting. First, a free gingival graft (FGG) was performed to obtain an adequate keratinized tissue level. Three months later, a connective tissue graft (CTG) was performed to obtain root coverage. The results indicated that the FGG allows for a gain in the keratinized tissue level and the CTG allows for root coverage with decreased recession level after 16 months. Therefore, for this type of specific gingival recession, the combination of FGG and CTG can be used.

  4. Polyomavirus specific cellular immunity: from BK-virus-specific cellular immunity to BK-virus-associated nephropathy ?

    Directory of Open Access Journals (Sweden)

    manon edekeyser

    2015-06-01

    Full Text Available In renal transplantation, BK-virus-associated nephropathy has emerged as a major complication, with a prevalence of 5–10% and graft loss in >50% of cases. BK-virus is a member of the Polyomavirus family and rarely induces apparent clinical disease in the general population. However, replication of polyomaviruses, associated with significant organ disease, is observed in patients with acquired immunosuppression, which suggests a critical role for virus-specific cellular immunity to control virus replication and prevent chronic disease. Monitoring of specific immunity combined with viral load could be used to individually assess the risk of viral reactivation and virus control. We review the current knowledge on BK-virus specific cellular immunity and, more specifically, in immunocompromised patients. In the future, immune-based therapies could allow us to treat and prevent BK-virus-associated nephropathy.

  5. Enrichment of autologous fat grafts with ex-vivo expanded adipose tissue-derived stem cells for graft survival

    DEFF Research Database (Denmark)

    Kølle, Stig-Frederik Trojahn; Fischer-Nielsen, Anne; Mathiasen, Anders Bruun

    2013-01-01

    Autologous fat grafting is increasingly used in reconstructive surgery. However, resorption rates ranging from 25% to 80% have been reported. Therefore, methods to increase graft viability are needed. Here, we report the results of a triple-blind, placebo-controlled trial to compare the survival...... of fat grafts enriched with autologous adipose-derived stem cells (ASCs) versus non-enriched fat grafts....

  6. Compliance Study of Endovascular Stent Grafts Incorporated with Polyester and Polyurethane Graft Materials in both Stented and Unstented Zones

    Directory of Open Access Journals (Sweden)

    Ying Guan

    2016-08-01

    Full Text Available Compliance mismatch between stent graft and host artery may induce complications and blood flow disorders. However, few studies have been reported on stent graft compliance. This study aims to explore the deformation and compliance of stent graft in stented and unstented zones under three pressure ranges. Compliance of two stent grafts incorporated with polyurethane graft (nitinol-PU and polyester graft (nitinol-PET materials respectively were tested; the stents used in the two stent grafts were identical. For the circumferential deformation of the stent grafts under each pressure range, the nitinol-PET stent graft was uniform in both zones. The nitinol-PU stent graft was circumferentially uniform in the stented zone, however, it was nonuniform in the unstented zone. The compliance of the PU graft material was 15 times higher than that of the PET graft. No significant difference in compliance was observed between stented and unstented zones of the nitinol-PET stent graft regardless of the applied pressure range. However, for the nitinol-PU stent graft, compliance of the unstented PU region was approximately twice that of the stented region; thus, compliance along the length of the nitinol-PU stent graft was not constant and different from that of the nitinol-PET stent graft.

  7. Donor age dependent graft development and recovery in a rat model of Huntington's disease: histological and behavioral analysis.

    Science.gov (United States)

    Schackel, Stefanie; Pauly, Marie-Christin; Piroth, Tobias; Nikkhah, Guido; Döbrössy, Máté D

    2013-11-01

    Neural cell replacement therapy using fetal striatal cells has provided evidence of disease modification in clinical trials in Huntington's disease (HD) patients, although the results have been inconsistent. One of the contributing factors to the variable outcome could be the different capacity of transplanted cells derived from the primordial striatum to proliferate and maturate into striatal projection neurons. Based on the rodent lesion model of HD, the current study investigated how intrastriatal-striatal grafts from variable aged donors develop in vivo and how they influence functional recovery. Young adult female Sprague-Dawley rats were lesioned unilaterally in the dorso-striatum with quinolinic acid (0.12 M) and transplanted 14 days later with single cell suspension grafts equivalent of one whole ganglionic eminence (WGE) from donors of embryonic developmental age E13, E14, or E15; animals with or without striatal lesion served as controls. All animals were tested on the Cylinder and the Corridor tests, as well as on apomorphine-induced rotation at baseline, post-lesion/pre-grafting, and at 6 and 10 weeks post-grafting. A week prior to perfusion, a sub-group in each grafted group received fluorogold injections into the ipsilateral globus pallidus to study graft efferent projections. In summary, the data demonstrates that the age of the embryonic donor tissue has an impact on both the graft mediated functional recovery, and on the in vivo cellular composition of the striatal transplant. E13 tissue grafts gave the best overall outcome indicating that WGE from different donor ages have different potential to promote functional recovery. Understanding the stages and process in rodent striatal development could improve tissue selection in clinical trials of cell therapy in HD. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Harvesting split thickness costal cartilage graft

    Directory of Open Access Journals (Sweden)

    Sunil Gaba

    2017-01-01

    Full Text Available Aim: There are few complications associated with harvesting of full thickness coastal cartilage grafts i.e., pneumothorax (0.9%, contour deformities and prolonged post-operative pain. To address these issues, authors devised special scalpel to harvest split-thickness costal cartilage grafts. Materials and Methods: Standard inframammary incision was used for harvesting rib. Incision was made directly over the desired rib. Specially designed scalpel was used to cut through the rib cartilage to the half of the thickness. The study was conducted in two parts – cadaveric and clinical. Results: There was significantly less pain and no pneumothorax in the patients in whom the split thickness graft was harvested. Wounds healed without any complication. Discussion: Thus, newly devised angulated scalpel used in the current study, showed the potential to supply the reconstructive surgeon with split thickness rib graft without risk of complications such as pneumothorax or warping contour deformities and post-operative pain.

  9. Polyethylene glycol-grafted polystyrene particles.

    Science.gov (United States)

    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%.

  10. Fluorescent Bioactive Corrole Grafted-Chitosan Films.

    Science.gov (United States)

    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.

  11. Grafting of a LLDPE using gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Catari, E. [Centro de Quimica, Laboratorio de Polimeros Instituto Venezolano de Investigaciones Cientificas (IVIC) (Venezuela); Albano, C. [Centro de Quimica, Laboratorio de Polimeros Instituto Venezolano de Investigaciones Cientificas (IVIC) (Venezuela) and Universidad Central de Venezuela, Facultad de Ingenieria, Escuela de Ingenieria Quimica (Venezuela)]. E-mail: calbano@ivic.ve; Karam, A. [Centro de Quimica, Laboratorio de Polimeros Instituto Venezolano de Investigaciones Cientificas (IVIC) (Venezuela)]. E-mail: akaram@quimica.ivic.ve; Perera, R. [Departamento de Mecanica, Universidad Simon Bolivar (Venezuela); Silva, P. [Centro de Fisica, Laboratorio de Fisica de la Materia Condensada, Instituto Venezolano de Investigaciones Cientificas (IVIC), Caracas (Venezuela); Gonzalez, J. [Departamento de Mecanica, Universidad Simon Bolivar (Venezuela)

    2005-07-01

    In this investigation, the grafting of a commercial linear low-density polyethylene (LLDPE) with different concentrations of diethyl maleate (DEM, 5 and 15 wt.%) was carried out at different absorbed doses from a cobalt-60 source of gamma rays (0, 15, 30, 50, 100, 200 kGy). This process was performed in a decalin solution at 10% w/v to obtain a homogeneous dispersion of the monomer into the polyethylene matrix. The grafting degree was estimated by means of FTIR using a calibration curve reported in literature. Thermal properties of the functional polymers were studied by thermogravimetric analysis (TGA). Melt flow index (MFI) values were also taken. The results found indicate that the grafting degree increases as the concentration of DEM in the reaction mixture and the absorbed doses are increased upto 100 kGy, as expected. However, the behavior at higher doses is attributed to secondary reactions such as long-chain branching and/or crosslinking, which are faster than radical reactions responsible for the grafting of the DEM onto the polymeric chain. This fact was ascertained by the decrease of the MFI values as the applied irradiation was increased, irrespective of the quantity of DEM used in the grafting reaction. Therefore, in order to obtain a high grafting degree, the absorbed dose should be estimated carefully. Initial degradation temperatures of the grafted PEs decreased when the gamma irradiation dose was higher than 100 kGy. This indicates that the thermal stability decreases as higher doses are applied to the material, which is associated to branching and crosslinking. The grafting degree never exceeded 0.3 mol%, which demonstrates the low efficiency of the functionalization procedure here presented.

  12. Prevention of grafted liver from reperfusive injury

    Institute of Scientific and Technical Information of China (English)

    Kai Ma; Yang yu; Xian-Min Bu; Yan-Jun Li; Xian-Wei Dai; Liang Wang; Yang Dai; Hai-Ying Zhao; Xiang-Hong Yang

    2001-01-01

    @@ INTRODUCTIONThe incidence of primary non-function(PNF)of grafted liver in the early postoperative stage is 2%-23%[1-4],its main cause is the ischemic-rechemic injure[5,6].In this experiment,anisodamine was added into the preserving fluid and the grafted liver was rewarmed at different temperatures to protect the cell membranc and prevent ischemic-reperfusive injury.

  13. DNA nanosensor surface grafting and salt dependence

    Science.gov (United States)

    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.

  14. [Senescence and cellular immortality].

    Science.gov (United States)

    Trentesaux, C; Riou, J-F

    2010-11-01

    Senescence was originally described from the observation of the limited ability of normal cells to grow in culture, and may be generated by telomere erosion, accumulation of DNA damages, oxidative stress and modulation of oncogenes or tumor suppressor genes. Senescence corresponds to a cellular response aiming to control tumor progression by limiting cell proliferation and thus constitutes an anticancer barrier. Senescence is observed in pre-malignant tumor stages and disappears from malignant tumors. Agents used in standard chemotherapy also have the potential to induce senescence, which may partly explain their therapeutic activities. It is possible to restore senescence in tumors using targeted therapies that triggers telomere dysfunction or reactivates suppressor genes functions, which are essential for the onset of senescence.

  15. Engineering Cellular Metabolism.

    Science.gov (United States)

    Nielsen, Jens; Keasling, Jay D

    2016-03-10

    Metabolic engineering is the science of rewiring the metabolism of cells to enhance production of native metabolites or to endow cells with the ability to produce new products. The potential applications of such efforts are wide ranging, including the generation of fuels, chemicals, foods, feeds, and pharmaceuticals. However, making cells into efficient factories is challenging because cells have evolved robust metabolic networks with hard-wired, tightly regulated lines of communication between molecular pathways that resist efforts to divert resources. Here, we will review the current status and challenges of metabolic engineering and will discuss how new technologies can enable metabolic engineering to be scaled up to the industrial level, either by cutting off the lines of control for endogenous metabolism or by infiltrating the system with disruptive, heterologous pathways that overcome cellular regulation.

  16. Cellular image classification

    CERN Document Server

    Xu, Xiang; Lin, Feng

    2017-01-01

    This book introduces new techniques for cellular image feature extraction, pattern recognition and classification. The authors use the antinuclear antibodies (ANAs) in patient serum as the subjects and the Indirect Immunofluorescence (IIF) technique as the imaging protocol to illustrate the applications of the described methods. Throughout the book, the authors provide evaluations for the proposed methods on two publicly available human epithelial (HEp-2) cell datasets: ICPR2012 dataset from the ICPR'12 HEp-2 cell classification contest and ICIP2013 training dataset from the ICIP'13 Competition on cells classification by fluorescent image analysis. First, the reading of imaging results is significantly influenced by one’s qualification and reading systems, causing high intra- and inter-laboratory variance. The authors present a low-order LP21 fiber mode for optical single cell manipulation and imaging staining patterns of HEp-2 cells. A focused four-lobed mode distribution is stable and effective in optical...

  17. Multiuser Cellular Network

    CERN Document Server

    Bao, Yi; Chen, Ming

    2011-01-01

    Modern radio communication is faced with a problem about how to distribute restricted frequency to users in a certain space. Since our task is to minimize the number of repeaters, a natural idea is enlarging coverage area. However, coverage has restrictions. First, service area has to be divided economically as repeater's coverage is limited. In this paper, our fundamental method is to adopt seamless cellular network division. Second, underlying physics content in frequency distribution problem is interference between two close frequencies. Consequently, we choose a proper frequency width of 0.1MHz and a relevantly reliable setting to apply one frequency several times. We make a few general assumptions to simplify real situation. For instance, immobile users yield to homogenous distribution; repeaters can receive and transmit information in any given frequency in duplex operation; coverage is mainly decided by antenna height. Two models are built up to solve 1000 users and 10000 users situations respectively....

  18. Polypeptide Grafted Hyaluronan: Synthesis and Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaojun [ORNL; Messman, Jamie M [ORNL; Mays, Jimmy [ORNL; Baskaran, Durairaj [University of Tennessee, Knoxville (UTK)

    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).

  19. Local graft irradiation in renal transplant rejection

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Masashi; Kataoka, Masaaki; Itoh, Hisao (Ehime Univ., Matsuyama (Japan). School of Medicine)

    1990-04-01

    From 1977 to 1988, of 142 renal transplantations, seven recipients (4.9%) received local graft irradiation following rejective reaction refractory to antirejection medical managements. Concurrent with the administration of pulsed high dose methylprednisolone and other antirejection medical managements, the graft was irradiated with a total dose of 6.0 Gy-150 cGy per fraction every other day at the midplane of the graft using two opposing portals of 4MX Linac. The fields were defined by palpation and echography. All patients had improvements in serum creatinine on the 10th day after beginning the irradiation. Four patients with peripheral lymphocytosis during the irradiation combined with pulsed high dose methylprednisolone improved in renal functions. On the other hand, out of 3 patients with lymphcytopenic changes, in two the transplanted graft was removed due to deteriorations, and the other patient is currently suffering from chronic rejection. Local graft irradiation can be useful in maintaining a rejective graft and reversing its functions in some patients whose rejective reaction failed to respond to the antirejection medical managements. (author).

  20. External inosculation as a feature of revascularization occurs after free transplantation of murine liver grafts.

    Science.gov (United States)

    Kuehl, A-R; Abshagen, K; Eipel, C; Laschke, M W; Menger, M D; Laue, M; Vollmar, B

    2013-02-01

    The induction of angiogenesis is essential for successful engraftment of freely transplanted cells or cellular composites. How to augment angiogenesis to ensure an appropriate viability of the grafts is still under investigation. This study evaluated the proangiogenic capability of different syngeneic free liver transplants and elucidated the origin of the newly formed vascular network via use of an eGFP(+) /eGFP(-) (enhanced green fluorescent protein) cross-over design. Using intravital fluorescence microscopy, we found that neonatal and resected murine liver transplants implanted into dorsal skinfold chambers display a significantly enhanced vascularization compared to regular adult transplants. Immunohistochemically, less tissue hypoxia, apoptosis and macrophage infiltration was observed in the neonatal and resected transplants, which is in line with improved vascularization of those grafts. Additionally, electron microscopy revealed morphological hallmarks of liver cells. eGFP(+) liver transplants implanted on eGFP(-) recipients displayed vascular sprouting from the grafts themselves and connection to the recipients` microvasculature, which also undergoes transient proangiogenic response. This process is described as external inosculation, with microvessels exhibiting a chimeric nature of the endothelial lining. These data collectively show that proliferative stimulation is taking effect on angiogenic properties of free transplants and might provide a novel tool for modulating the revascularization of free grafts.

  1. Development of Decellularized Human Umbilical Arteries as Small-Diameter Vascular Grafts

    Science.gov (United States)

    Gui, Liqiong; Muto, Akihito; Chan, Stephen A.; Breuer, Christopher K.

    2009-01-01

    Objective Developing a tissue-engineered small-diameter (<6 mm) vascular graft for reconstructive surgery has remained a challenge for the past several decades. This study was conducted to develop a decellularized umbilical artery and to evaluate its composition, endothelial cell compatibility, mechanical properties, and in vivo stability for potential use as a small-diameter vascular graft. Methods and Results Human umbilical arteries were isolated and decellularized by incubation in CHAPS and sodium dodecyl sulfate buffers followed by incubation in endothelial growth media-2. Decellularized umbilical arteries were completely devoid of cellular and nuclear material while retaining the integrity of extracellular collagenous matrix. The mechanical strength of the decellularized umbilical artery as assessed by its burst pressure in vitro showed no significant change from its native form. Decellularized umbilical arteries supported endothelial adherence as indicated by the re-endotheliazation with a monolayer of human umbilical vein endothelial cells. Furthermore, decellularized vessels that were implanted into nude rats as abdominal aorta interposition grafts remained mechanically intact and patent for up to 8 weeks. Conclusion Decellularized human umbilical arteries preserved the extracellular matrix, supported endothelialization, and retained function in vivo for up to 8 weeks. These properties suggest the potential use of decellularized umbilical arteries as small-diameter vascular grafts. PMID:19207043

  2. ACL Revision in Synthetic ACL graft failure

    Science.gov (United States)

    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

  3. Quantitative PCR Detection Method about Viable but Nonculturable State Shigella dysenteriae in Water%水中活的非可培养状态痢疾志贺菌荧光定量PCR检测方法研究

    Institute of Scientific and Technical Information of China (English)

    孙宗科; 张伟; 鲁波; 郑萍; 王友斌; 丁培; 陈西平

    2012-01-01

    目的 建立活的非可培养(viable but nonculturable state,VBNC)状态痢疾志贺菌逆转录荧光定量PCR (reverse transcription quantitative PCR,RT-qPCR)检测方法.方法 低温寡营养诱导痢疾志贺菌进入VBNC状态,用平板计数法和荧光显微镜检法确定细菌的可培养数和活菌数,以痢疾志贺菌的志贺毒素基因stx( GenBank:M19437)、侵袭性毒力基因ipaH( GenBank:NC_007607)为目的基因设计引物,提取RNA进行RT-qPCR检测,研究检出限并建立标准曲线,用加标于环境水体中的志贺菌水样进行方法验证.结果 建立处于VBNC状态的痢疾志贺菌RT-qPCR检测技术,检测时间少于6h,复杂环境水体中每500μl水样可培养的痢疾志贺菌检出限为1~5 cfu,VBNC状态的痢疾志贺菌3~25 cfu.结论 该方法检测快速,可实现对VBNC状态志贺菌的检测,可用于复杂水样的直接检测,适用于水体污染调查和应急反应时快速筛查志贺菌.%Objective To establish the reverse transcription quantitative PCR (RT-qPCR) method for the determination of Shigslla dysenteriae in viable but nonculturable state. Methods S. dysenteriae was induced into VBNC state in low temperature and oligotrophic environment, culturable bacteria count was detected by pour plate method and viable count by fluorescence microscopy. The primers were designed according to the target gene of Shigella toxin gene stx (GenBank: M19437) and invasive virulence gene ipaH(GenBank: NC_007607), and RNA were extracted and detected by RT-qPCR. Then the standard curve was established and the detection limit was tested. Results The RT-qPCR detection method of 5. dysenteriae in VBNC state was established, the detection time was less than six hours, the detection limit of culturable bacteria was 1 to 5 cfu, and VBNC state bacteria was 3 to 25 cfu while inoculated into complicated environment water sample (500 (μl). Conclusion The established rapid RT—qPCR method can detect S. dysenteriae in VBNC

  4. Impact of bone graft harvesting techniques on bone formation and graft resorption

    DEFF Research Database (Denmark)

    Saulacic, Nikola; Bosshardt, Dieter D; Jensen, Simon S;

    2015-01-01

    formation and graft resorption in vivo. MATERIAL AND METHODS: Four harvesting techniques were used: (i) corticocancellous blocks particulated by a bone mill; (ii) bone scraper; (iii) piezosurgery; and (iv) bone slurry collected from a filter device upon drilling. The grafts were placed into bone defects...

  5. Physical properties of agave cellulose graft polymethyl methacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Rosli, Noor Afizah; Ahmad, Ishak; Abdullah, Ibrahim; Anuar, Farah Hannan [Polymer Research Centre (PORCE), School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi Selangor (Malaysia)

    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.

  6. Physical properties of agave cellulose graft polymethyl methacrylate

    Science.gov (United States)

    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.

  7. Acute graft versus host disease

    Directory of Open Access Journals (Sweden)

    Vogelsang Georgia B

    2007-09-01

    Full Text Available Abstract Acute graft-versus-host disease (GVHD occurs after allogeneic hematopoietic stem cell transplant and is a reaction of donor immune cells against host tissues. Activated donor T cells damage host epithelial cells after an inflammatory cascade that begins with the preparative regimen. About 35%–50% of hematopoietic stem cell transplant (HSCT recipients will develop acute GVHD. The exact risk is dependent on the stem cell source, age of the patient, conditioning, and GVHD prophylaxis used. Given the number of transplants performed, we can expect about 5500 patients/year to develop acute GVHD. Patients can have involvement of three organs: skin (rash/dermatitis, liver (hepatitis/jaundice, and gastrointestinal tract (abdominal pain/diarrhea. One or more organs may be involved. GVHD is a clinical diagnosis that may be supported with appropriate biopsies. The reason to pursue a tissue biopsy is to help differentiate from other diagnoses which may mimic GVHD, such as viral infection (hepatitis, colitis or drug reaction (causing skin rash. Acute GVHD is staged and graded (grade 0-IV by the number and extent of organ involvement. Patients with grade III/IV acute GVHD tend to have a poor outcome. Generally the patient is treated by optimizing their immunosuppression and adding methylprednisolone. About 50% of patients will have a solid response to methylprednisolone. If patients progress after 3 days or are not improved after 7 days, they will get salvage (second-line immunosuppressive therapy for which there is currently no standard-of-care. Well-organized clinical trials are imperative to better define second-line therapies for this disease. Additional management issues are attention to wound infections in skin GVHD and fluid/nutrition management in gastrointestinal GVHD. About 50% of patients with acute GVHD will eventually have manifestations of chronic GVHD.

  8. Cellular bioluminescence imaging.

    Science.gov (United States)

    Welsh, David K; Noguchi, Takako

    2012-08-01

    Bioluminescence imaging of live cells has recently been recognized as an important alternative to fluorescence imaging. Fluorescent probes are much brighter than bioluminescent probes (luciferase enzymes) and, therefore, provide much better spatial and temporal resolution and much better contrast for delineating cell structure. However, with bioluminescence imaging there is virtually no background or toxicity. As a result, bioluminescence can be superior to fluorescence for detecting and quantifying molecules and their interactions in living cells, particularly in long-term studies. Structurally diverse luciferases from beetle and marine species have been used for a wide variety of applications, including tracking cells in vivo, detecting protein-protein interactions, measuring levels of calcium and other signaling molecules, detecting protease activity, and reporting circadian clock gene expression. Such applications can be optimized by the use of brighter and variously colored luciferases, brighter microscope optics, and ultrasensitive, low-noise cameras. This article presents a review of how bioluminescence differs from fluorescence, its applications to cellular imaging, and available probes, optics, and detectors. It also gives practical suggestions for optimal bioluminescence imaging of single cells.

  9. Cellular neurothekeoma with melanocytosis.

    Science.gov (United States)

    Wu, Ren-Chin; Hsieh, Yi-Yueh; Chang, Yi-Chin; Kuo, Tseng-Tong

    2008-02-01

    Cellular neurothekeoma (CNT) is a benign dermal tumor mainly affecting the head and neck and the upper extremities. It is characterized histologically by interconnecting fascicles of plump spindle or epithelioid cells with ample cytoplasm infiltrating in the reticular dermis. The histogenesis of CNT has been controversial, although it is generally regarded as an immature counterpart of classic/myxoid neurothekeoma, a tumor with nerve sheath differentiation. Two rare cases of CNT containing melanin-laden cells were described. Immunohistochemical study with NKI/C3, vimentin, epithelial membrane antigen, smooth muscle antigen, CD34, factor XIIIa, collagen type IV, S100 protein and HMB-45 was performed. Both cases showed typical growth pattern of CNT with interconnecting fascicles of epithelioid cells infiltrating in collagenous stroma. One of the nodules contained areas exhibiting atypical cytological features. Melanin-laden epithelioid or dendritic cells were diffusely scattered throughout one nodule, and focally present in the peripheral portion of the other nodule. Both nodules were strongly immunoreactive to NKI/C3 and vimentin, but negative to all the other markers employed. CNT harboring melanin-laden cells may pose diagnostic problems because of their close resemblance to nevomelanocytic lesions and other dermal mesenchymal tumors. These peculiar cases may also provide further clues to the histogenesis of CNT.

  10. Red fluorescent chitosan nanoparticles grafted with poly(2-methacryloyloxyethyl phosphorylcholine) for live cell imaging.

    Science.gov (United States)

    Wang, Ke; Fan, Xingliang; Zhang, Xiaoyong; Zhang, Xiqi; Chen, Yi; Wei, Yen

    2016-08-01

    Poly(2-methacryloyloxyethyl phosphorylcholine) conjugated red fluorescent chitosan nanoparticles (GCC-pMPC) were facilely fabricated by "grafting from" method via surface initiated atom transfer radical polymerization (ATRP). Firstly, glutaraldehyde crosslinked red fluorescent chitosan nanoparticles (GCC NPs) with many amino groups and hydroxyl groups on their surface were prepared, which were then reacted with 2-bromoisobutyryl bromide to form GCC-Br; subsequently, poly(MPC) (pMPC) brushes were grafted onto GCC NPs surface using GCC-Br as initiator via ATRP. Compared with PEGylated nanoparticles, zwitterionic polymers modified nanoparticles demonstrated better performance in their cellular uptake. Moreover, the obtained GCC-pMPC demonstrated excellent water-dispersibility, biocompatibility, and photostability, which made them highly potential for long-term tracing applications. Importantly, the successful live cell imaging of GCC-pMPC would remarkably advance the research of their further bioapplications.

  11. Aortic reconstruction with bovine pericardial grafts

    Directory of Open Access Journals (Sweden)

    Silveira Lindemberg Mota

    2003-01-01

    Full Text Available INTRODUCTION: Glutaraldehyde-treated crimped bovine pericardial grafts are currently used in aortic graft surgery. These conduits have become good options for these operations, available in different sizes and shapes and at a low cost. OBJECTIVE:To evaluate the results obtained with bovine pericardial grafts for aortic reconstruction, specially concerning late complications. METHOD: Between January 1995 and January 2002, 57 patients underwent different types of aortic reconstruction operations using bovine pericardial grafts. A total of 29 (50.8% were operated on an urgent basis (mostly acute Stanford A dissection and 28 electively. Thoracotomy was performed in three patients for descending aortic replacement (two patients and aortoplasty with a patch in one. All remaining 54 underwent sternotomy, cardiopulmonary bypass and aortic resection. Deep hypothermia and total circulatory arrest was used in acute dissections and arch operations. RESULTS: Hospital mortality was 17.5%. Follow-up was 24.09 months (18.5 to 29.8 months confidence interval and complication-free actuarial survival curve was 92.3% (standard deviation ± 10.6. Two patients lately developed thoracoabdominal aneurysms following previous DeBakey II dissection and one died from endocarditis. One "patch" aortoplasty patient developed local descending aortic pseudoaneurysm 42 months after surgery. All other patients are asymptomatic and currently clinically evaluated with echocardiography and CT scans, showing no complications. CONCLUSION: Use of bovine pericardial grafts in aortic reconstruction surgery is adequate and safe, with few complications related to the conduits.

  12. Bone graft substitutes: past, present, future.

    Directory of Open Access Journals (Sweden)

    Parikh S

    2002-04-01

    Full Text Available Bone grafts are necessary to provide support, fill voids, and enhance biologic repair of skeletal defects. They are used by orthopaedic surgeons, neurosurgeons, craniofacial surgeons, and periodontists. Bone harvested from donor sites is the gold standard for this procedure. It is well documented that there are limitations and complications from the use of autograft, including the limited quantity and associated chronic donor site pain. Despite the increase in the number of procedures that require bone grafts, there has not been a single ideal bone graft substitute Scientists, surgeons, and medical companies, thus, have a tremendous responsibility to develop biologic alternatives that will enhance the functional capabilities of the bone graft substitute, and potentially reduce or eliminate the need for autograft. This article is an attempt to review the past and existing bone graft substitutes, and future directions of research. The historical data was extracted after thorough review of the literature. The data for the current concepts and future directions was compiled from the Internet, and from direct correspondence with medical companies. Since many products are undergoing clinical trials, and are yet not commercially available, their data cannot be found in literature. The main purpose of this article is to give the reader an idea about the existing market products and products likely to be available in near future.

  13. Vascularized tail bone grafts in rats.

    Science.gov (United States)

    Sempuku, T; Tamai, S; Mizumoto, S; Yajima, H

    1993-03-01

    A new experimental model for vascularized corticocancellous bone grafts was established by investigation of vascular anatomy of the tail in 15 adult Fischer 344 rats and determination of the viability of vascularized tail bone grafts into the abdominal wall in 22 7-week-old rats. The tail bones of 40 rats were then raised on the pedicle of the caudal artery and its venae comitantes, transferred to a resected portion in the femur, and observed for 16 weeks. The vascularized graft showed marked reactive periosteal bone formation during the first and second weeks following transfer, and thereafter, the graft continued to show active bone formation. In transverse section, the sharp processes became rounded. In the cancellous bone, both bone resorption and bone formation were noticeably activated early after transfer, although resorption predominated and the amount of the cancellous bone consequently diminished. The nonvascularized grafts showed "creeping substitution." The results suggest that morphologic adaptation occurs if living (i.e., vascularized) tail bones are transferred to long-bone femurs.

  14. Novel anterior cruciate ligament graft fixation device reduces slippage.

    Science.gov (United States)

    Lopez, Mandi J; Borne, Allen; Monroe, W Todd; Bommala, Prakash; Kelly, Laura; Zhang, Nan

    2013-01-01

    Clinically significant laxity occurs in 10%-30% of knees after anterior cruciate ligament reconstruction. Graft slippage and tension loss at the hamstring graft tibial fixation site during and after reconstruction surgery contribute to postoperative joint laxity and are detrimental to long-term knee stability and graft properties. Limiting graft slippage will reduce associated complications. We sought to compare the in vitro mechanical properties and in vivo joint stabilization, postoperative limb use, and graft incorporation of the novel GraftGrab™ (GG) device designed to reduce hamstring graft tibial fixation slippage with the commercially available bioabsorbable Bio-Post™ and spiked washer (BP). Mechanical testing was performed on canine tibia-hamstring graft constructs to quantify initial fixation properties. In vivo joint stabilization, postoperative limb use and graft incorporation of hamstring graft reconstructions were determined in a canine model. Outcomes included tibial translation and ground reaction forces preoperatively and 4 and 8 weeks postoperatively, three-dimensional graft and bone tunnel dimensions at the latter two time points, and graft-bone microstructure, as well as mechanical properties 8 weeks after implantation. Immediately after fixation, all grafts slipped from the BP constructs versus about 30% of GG constructs. In vivo limb use remained low, and tibial translation increased with time in the BP cohort. These results together confirm that initial graft slippage is lower with GG versus BP extracortical hamstring graft tibial fixation. In addition, postoperative recovery and joint stability are more consistent with the GG. This information supports the GG as an alternative to extracortical tibial hamstring graft fixation that has procedural advantages over current implants and reduces graft failure from slippage.

  15. Free fall and cellular automata

    Directory of Open Access Journals (Sweden)

    Pablo Arrighi

    2016-03-01

    Full Text Available Three reasonable hypotheses lead to the thesis that physical phenomena can be described and simulated with cellular automata. In this work, we attempt to describe the motion of a particle upon which a constant force is applied, with a cellular automaton, in Newtonian physics, in Special Relativity, and in General Relativity. The results are very different for these three theories.

  16. About Strongly Universal Cellular Automata

    Directory of Open Access Journals (Sweden)

    Maurice Margenstern

    2013-09-01

    Full Text Available In this paper, we construct a strongly universal cellular automaton on the line with 11 states and the standard neighbourhood. We embed this construction into several tilings of the hyperbolic plane and of the hyperbolic 3D space giving rise to strongly universal cellular automata with 10 states.

  17. Reactive Programming of Cellular Automata

    OpenAIRE

    Boussinot, Frédéric

    2004-01-01

    Implementation of cellular automata using reactive programming gives a way to code cell behaviors in an abstract and modular way. Multiprocessing also becomes possible. The paper describes the implementation of cellular automata with the reactive programming language LOFT, a thread-based extension of C. Self replicating loops considered in artificial life are coded to show the interest of the approach.

  18. Meshed split skin graft for extensive vitiligo

    Directory of Open Access Journals (Sweden)

    Srinivas C

    2004-05-01

    Full Text Available A 30 year old female presented with generalized stable vitiligo involving large areas of the body. Since large areas were to be treated it was decided to do meshed split skin graft. A phototoxic blister over recipient site was induced by applying 8 MOP solution followed by exposure to UVA. The split skin graft was harvested from donor area by Padgett dermatome which was meshed by an ampligreffe to increase the size of the graft by 4 times. Significant pigmentation of the depigmented skin was seen after 5 months. This procedure helps to cover large recipient areas, when pigmented donor skin is limited with minimal risk of scarring. Phototoxic blister enables easy separation of epidermis thus saving time required for dermabrasion from recipient site.

  19. Dermal graft correction of extraordinary chordee.

    Science.gov (United States)

    Kogan, S J; Reda, E F; Smey, P L; Levitt, S B

    1983-11-01

    Severe degrees of primary chordee and persistent or recurrent chordee following previous surgical attempts at correction present a challenging problem. Inadequate resection of involved tissues, which may involve all layers of the penile investiture, or recurrent scarring of the ventral skin, Buck's fascia and tunica albuginea is usually the cause. Reoperation to achieve penile straightening often is unsuccessful unless all chordee-bearing tissue is resected extensively. Excision of large segments of tunica albuginea or wide separation of the margins creates a defect that tends to heal by dense scarring unless the defect is bridged by a graft. Various autogenous materials have been used, including blood vessel, fascia, free fat graft, dermis and tunica albuginea, as well as prosthestic materials, such as polytetrafluoroethylene, with varying results. A series of patients with extensive chordee is presented in whom tunical resection was necessary to achieve penile straightening. The results of free dermal graft replacement of the tunica are reported.

  20. Novel features of radiation-induced bystander signaling in Arabidopsis thaliana demonstrated using root micro-grafting

    OpenAIRE

    Wang, Ting; Li, Fanghua; Xu, Wei; Bian, Po; Wu, Yuejin; WU, LIJUN

    2012-01-01

    Radiation-induced bystander effects (RIBE) have been well demonstrated in whole organisms, as well as in single-cell culture models in vitro and multi-cellular tissues models in vitro, however, the underlying mechanisms remain unclear, including the temporal and spatial course of bystander signaling. The RIBE in vivo has been shown to exist in the model plant Arabidopsis thaliana (A. thaliana). Importantly, the unique plant grafting provides a delicate approach for studying the temporal and s...

  1. Brazilian situation of blood component irradiation practice for the prevention of transfusion associated Graft-versus-Host disease

    Energy Technology Data Exchange (ETDEWEB)

    Goes, E.G.; Borges, J.C. [EE/COPPE-UFRJ (Brazil); Covas, D.T. [Faculdade deMedicina-USP-RP (Brazil); Motta, I. [Instituto Nacional do Cancer- Rio deJaneiro (Brazil)

    1998-12-31

    Transfusion-associated graft-versus-host disease (TA-GVHD) is a usually complication of transfusion of blood component containing T lymphocytes what recently has also involved immunocompetent patient. Gamma irradiation of cellular blood components has been the mainstay against TA-GVHD, nevertheless there is little information in the literature about current transfusion medicine practices regarding gamma irradiation of blood products. This work presents an overview of the Brazilian reality and suggests policies to optimize TA-GVHD prevention. (Author)

  2. MIMO Communication for Cellular Networks

    CERN Document Server

    Huang, Howard; Venkatesan, Sivarama

    2012-01-01

    As the theoretical foundations of multiple-antenna techniques evolve and as these multiple-input multiple-output (MIMO) techniques become essential for providing high data rates in wireless systems, there is a growing need to understand the performance limits of MIMO in practical networks. To address this need, MIMO Communication for Cellular Networks presents a systematic description of MIMO technology classes and a framework for MIMO system design that takes into account the essential physical-layer features of practical cellular networks. In contrast to works that focus on the theoretical performance of abstract MIMO channels, MIMO Communication for Cellular Networks emphasizes the practical performance of realistic MIMO systems. A unified set of system simulation results highlights relative performance gains of different MIMO techniques and provides insights into how best to use multiple antennas in cellular networks under various conditions. MIMO Communication for Cellular Networks describes single-user,...

  3. Cellular automata analysis and applications

    CERN Document Server

    Hadeler, Karl-Peter

    2017-01-01

    This book focuses on a coherent representation of the main approaches to analyze the dynamics of cellular automata. Cellular automata are an inevitable tool in mathematical modeling. In contrast to classical modeling approaches as partial differential equations, cellular automata are straightforward to simulate but hard to analyze. In this book we present a review of approaches and theories that allow the reader to understand the behavior of cellular automata beyond simulations. The first part consists of an introduction of cellular automata on Cayley graphs, and their characterization via the fundamental Cutis-Hedlund-Lyndon theorems in the context of different topological concepts (Cantor, Besicovitch and Weyl topology). The second part focuses on classification results: What classification follows from topological concepts (Hurley classification), Lyapunov stability (Gilman classification), and the theory of formal languages and grammars (Kůrka classification). These classifications suggest to cluster cel...

  4. Coracoid graft positioning in the Latarjet procedure.

    Science.gov (United States)

    Kraus, Tobias M; Graveleau, Nicolas; Bohu, Yoann; Pansard, Erwan; Klouche, Shahnaz; Hardy, Philippe

    2016-02-01

    The success of shoulder stabilization with the Latarjet procedure depends on the correct positioning of the coracoid graft at the glenoid. The aim of this study was to assess intra-observer reproducibility and inter-observer reproducibility of a new standardized CT scan analysis for coracoid graft positioning in the axial plane after the Latarjet procedure and to assess the positioning in the study group. A consecutive series of 27 patients (22 men, 5 woman, 26.1 ± 6.4 years-13 right, 14 left shoulders) were followed up with CT scans between 2010 and 2012. The analysis of the CT scans (2.4 ± 0.7 months postoperatively) was performed with Osirix™ software. The assessment included two criteria in the axial plane: relation of the graft to the articular surface of the glenoid and impingement of the graft with the maximal humeral head circumference. Grafts were judged to be lateral, congruent, flush or medial. The strength of intra-observer agreement and inter-observer agreement was measured by the Kappa coefficient. The Kappa coefficient for intra-observer agreement was "substantial" (K = 0.64 ± 0.14, z = 4.6) to "almost perfect" (K = 0.81 ± 0.14, z = 5.7). The Kappa coefficient for inter-observer variability was "substantial" (K = 0.59 ± 0.14, z = 4.3) to "almost perfect" (K = 0.89 ± 0.14, z = 6.0). In our study, in the axial plane, 3 (11 %) transplants were lateral; 6 (22 %) transplants were congruent; 16 (60 %) flush and 2 (7 %) medial. This standardized CT scan analysis after Latarjet procedure has shown to accurately describe graft positioning in the axial plane with both good intra-observer reproducibility and inter-observer reproducibility. Case series, treatment study, Level IV.

  5. Autologous Fat Grafting for Whole Breast Reconstruction

    Directory of Open Access Journals (Sweden)

    Benjamin H. L. Howes, MBBS

    2014-03-01

    Full Text Available Summary: This is the first reported case of a patient who had a single-stage large-volume breast reconstruction with autologous fat grafting, following rotation flap approach (RoFA mastectomy. The purpose of this case study was to evaluate the viability of reconstruction of the breast by autologous fat grafting alone, in the context of RoFA mastectomy. The hypothesis was that there would be minimal interval loss of autologous fat on the whole breast reconstruction side. Right RoFA mastectomy was used for resection of an invasive primary breast cancer and resulted in the right breast skin envelope. Eleven months later, the patient underwent grafting of 400 ml of autologous fat into the skin envelope and underlying pectoralis major muscle. Outcome was assessed by using a validated 3D laser scan technique for quantitative breast volume measurement. Other outcome measures included the BREAST-Q questionnaire and 2D clinical photography. At 12-month follow-up, the patient was observed to have maintenance of volume of the reconstructed breast. Her BREAST-Q scores were markedly improved compared with before fat grafting, and there was observable improvement in shape, contour, and symmetry on 2D clinical photography. The 2 new techniques, RoFA mastectomy and large-volume single-stage autologous fat grafting, were used in combination to achieve a satisfactory postmastectomy breast reconstruction. Novel tools for measurement of outcome were the 3D whole-body laser scanner and BREAST-Q questionnaire. This case demonstrates the potential for the use of fat grafting for reconstruction. Outcomes in a larger patient populations are needed to confirm these findings.

  6. A trans-well-based cellular model for the rapid pre-evaluation of tympanic membrane repair materials.

    Science.gov (United States)

    Hung, Shih-Han; Su, Chin-Hui; Tseng, How

    2016-08-01

    It is important to have a standardized tympanic membrane (TM) perforation platform to evaluate the various myringoplasty materials that have been studied and developed extensively during recent years. However, currently there are no cellular models specifically designed for this purpose, and animal models remain unsatisfactory. The purpose of this study is to propose an inexpensive, readily available, well-controlled, and easy-to-create cellular model as a substitute for use in the evaluation of TM repairing materials. A trans-well model was created using a cell culture insert with a round hole created at the center of the polycarbonate membrane. HaCaT cells were cultured on the fenestrated culture insert, and the desired myringoplasty graft was placed at the center of the window for one week and observed by fluorescent microscopy under vital staining. Under this cellular model, there was notable migration of HaCaT cells onto the positive control graft (rabbit fascia), while only a few cell clusters were observed on the negative control graft (paper). Model validation showed that the cell migration ratio for the PLLA + 1% hyaluronic acid (HA) graft is significantly higher than using myringoplasty paper, poly L-lactide (PLLA), or PLLA + 0.5% HA (p model might be a useful pre-evaluation platform for the evaluation of TM repairing materials. The model is inexpensive, readily available, easy to create, and standardized for use.

  7. Sulfonated hydrocarbon graft architectures for cation exchange membranes

    DEFF Research Database (Denmark)

    Nielsen, Mads Møller; Jankova Atanasova, Katja; Hvilsted, Søren

    2013-01-01

    A synthetic strategy to hydrocarbon graft architectures prepared from a commercial polysulfone and aimed as ion exchange membrane material is proposed. Polystyrene is grafted from a polysulfone macroinitiator by atom transfer radical polymerization, and subsequently sulfonated with acetyl sulfate...

  8. Tympanoplasty: does dry or wet temporalis fascia graft matter?

    Science.gov (United States)

    Singh, G B; Kumar, D; Aggarwal, K; Garg, S; Arora, R; Kumar, S

    2016-08-01

    To evaluate the success rate of dry and wet temporalis fascia grafts in type I underlay tympanoplasty. A prospective, randomised study was conducted. One hundred adult patients (males and females) with chronic suppurative otitis media (mucosal type) were divided into 2 groups of 50 each: one group underwent dry graft tympanoplasty and the other underwent wet graft tympanoplasty. Fibroblast count was calculated in dry and wet grafts. The dry graft and wet graft groups had overall surgical success rates of 82 and 90 per cent, respectively; this finding was not statistically significant. A statistically significant high fibroblast count was observed in wet grafts, but it did not correlate with surgical success. A dry or wet temporalis fascia graft does not influence the outcome of tympanoplasty type I.

  9. Graft patency in off-pump and conventional coronary artery bypass grafting for treatment of triple vessel coronary disease

    Institute of Scientific and Technical Information of China (English)

    胡盛寿; 王小启; 宋云虎; 吕锋

    2003-01-01

    Objective To compare graft patency in off-pump and conventional coronary artery bypass grafting by using the transit time flow meter in the treatment of triple vessel coronary artery disease. Methods Between June 2000 and April 2001, 60 patients with triple vessel coronary artery disease underwent coronary artery bypass grafting. They were divided into two groups: off-pump and conventional coronary artery bypass. All completed grafts were tested intraoperatively using Transit Time Flow Measurement (TTFM). Preoperative and postoperative variables of the two groups were also compared. Results There were no significant differences in sex, age, weight, acute or remote myocardial infarction, hypertension, diabetes and type of bypass grafts between the two groups. The number of bypass grafts and the assisted respiratory time of the off-pump coronary artery bypass grafting (OPCAB) group were significantly less than those of the conventional coronary artery bypass grafting (CCABG) group. The flow and pulsatile index (PI) of the left anterior descending artery bypass grafts and the right coronary artery bypass grafts were not significantly different between the OPCAB and CCABG groups. The flow of OM in the CCABG group with the multiple anastomosis site of sequential grafts was higher than that in the OPCAB group. Diffused narrow coronary artery bypass grafts in both groups had less flow.Conclusion No signficant differences in graft patency were observed in patients with triple vessel coronary artery disease who had undergone OPCAB or CCABG.

  10. Patency rates and the role of newer grafts in coronary artery bypass grafting.

    Science.gov (United States)

    Rai, Mridula; Rustagi, Tarun

    2013-10-01

    Coronary artery bypass grafting (CABG) was one of major surgical advances of the 20th century and it has proven to be one of the most effective and long-lasting therapies in the treatment of ischemic heart disease. Despite its success, the long-term outcome of coronary bypass surgery is strongly influenced by the fate of the vascular conduits used. We seek to review the emerging role and patency rates of newer arterial grafts in comparison with the traditional saphenous vein grafts.

  11. The use of bone grafts and bone graft substitutes in pediatric orthopaedics: an overview.

    Science.gov (United States)

    Gross, Richard H

    2012-01-01

    Bone graft substitutes have become progressively more widely used, and are currently heavily marketed. To make intelligent decisions, a complete knowledge of autograaft and allograft bone healing is essential, including the definition of "sterile". Differences in donor selection and tissue processing may confound the user not familiar with the implications of these different approaches. Specific products include demineralized bone matrix (DBM), specific growth factors (recombinant BMP's), ceramic grafts, and platelet-rich plasma (PRP). There are a number of useful applications of bone graft substitues for pediatric orthopaedists, but the data base is evolving. This paper describes the current status of these products.

  12. Plasma Induced Grafting of PMMA onto Titanium Dioxide Powder

    Institute of Scientific and Technical Information of China (English)

    Zhong Shaofeng; Meng Yuedong; Ou Qiongrong; Xu Xu

    2005-01-01

    Grafting of polymer of methyl methacrylate (PMMA) onto titanium dioxide powder is investigated in this paper. The graft polymerization reaction is induced by dielectric-barrierdischarge produced N2 plasma treatment of titanium dioxide surfaces. IR, XPS and TGA results show that PMMA is grafted onto the surfaces of titanium dioxide powder. And crystal structure of the titanium dioxide powder observed with XRD spectra is unchanged after plasma graft polymerization.

  13. Hemocompatibility of Chitosan/poly(acrylic acid) Grafted Polyurethane Tubing

    OpenAIRE

    Lee, Hyun-Su; Tomczyk, Nancy; Kandel, Judith; Composto, Russell J.; Eckmann, David M.

    2013-01-01

    The activation and adhesion of platelets or whole blood exposed to chitosan (CH) grafted surfaces is used to evaluate the hemocompatibility of biomaterials. The biomaterial surfaces are polyurethane (PU) tubes grafted with an inner poly(acrylic acid) (PAA) and an outer CH or quaternary ammonium modified CH (CH-Q) brush. The CH, CH-Q and PAA grafted layers were characterized by ellipsometry and fluorescence microscopy. Material wear tests demonstrate that CH (CH-Q) is stably grafted onto PU tu...

  14. Electrical Properties of n-Butyl Acrylate-Grafted Polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.R.; Oh, W.J.; Suh, K.S. [Korea University (Korea, Republic of)

    1997-04-01

    The electrical properties of n-butyl acrylate-grafted polyethylene (PE-g-nBA) were investigated. In PE-g-nBA, hetero charge founded in LDPE slightly increased due to the nBA grafting. Conduction currents decreased with the increase of nBA graft ratio. AC breakdown strength increased and water treeing length decreased with the increase of graft ratio in PE-g-nBA. (author). 4 refs., 6 figs.

  15. Striatal grafts in a rat model of Huntington's disease

    DEFF Research Database (Denmark)

    Guzman, R; Meyer, M; Lövblad, K O;

    1999-01-01

    Survival and integration into the host brain of grafted tissue are crucial factors in neurotransplantation approaches. The present study explored the feasibility of using a clinical MR scanner to study striatal graft development in a rat model of Huntington's disease. Rat fetal lateral ganglionic...... eminences grown as free-floating roller-tube cultures can be successfully grafted in a rat Huntington model and that a clinical MR scanner offers a useful noninvasive tool for studying striatal graft development....

  16. Interaction of platelet-rich concentrate with bone graft materials: an in vitro study.

    Science.gov (United States)

    Butcher, Andrew; Milner, Richard; Ellis, Keith; Watson, J Tracy; Horner, Alan

    2009-03-01

    alone. The data obtained from these in vitro investigations demonstrate that the cellular responses induced by PRC and bone graft materials in hBMSC can be significantly (positively or negatively) modified by adding the agents in combination. These in vitro data highlight the need to consider the potential interaction between biologic agents when added in combination.

  17. Immuohistochemical study on smooth muscle cell proliferation, phenotypic modulation, and extracellular matrix accumulation in venous arterial grafts in rabbits

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-da; ZHU Hai-long

    2002-01-01

    Objective: To study the kinetics and distribution of smooth muscle cell (SMC) proliferation, phenotypic modulation, and various extracellular matrix (ECM) components accumulation during vein graft remodeling. Methods: Normal vein and vein graft in carotid arteries were examined on d 4, d 7, d 14, d 60 and d180 after bypass grafting with immunohistochemical markers of cellular proliferation (proliferating cell nuclear antigen, PCNA), cytoskeletal protein production (α-actin SMC), myosin heavy chain (MHC) isoforms, ECM proteins, and histochemistry (hematoxylin eosin and Elastica-van Gieson stain). Results: Normal veins demonstrated an extremely low level of cellular proliferation and expressed as adult phenotype SMCs in media. After bypass grafting, medial SMCs in the graft appeared to be damaged and began to proliferate on d 4, and subsequently migrated and formed the neointima on d 7. Thereafter, the neointima thickened throughout the 180-day period of the experiment, although the neointimal SMC proliferation decreased after d 14. Meanwhile SMCs underwent a distinct phenotypic change from normal adult type to embryonic type.On d 60, embryonic phenotype SMCs began to return to the adult phenotype, but remain to be present in the neointima for as long as 180 d. ECM components including type Ⅰ collagen, heparin sulfate proteoglucan (HSPG), and dermatan sulfate proteoglcan (decorin) were detected within the neointima on d 7. Thereafter,the accumulation of ECM increased progressively with time. On d 180, a large amount of ECM components were found in the neointima. HSPG mainly accumulated in the superficial and cellular region of the neointima, decorin, on other hand, located in hypocellular area deep in neointima. Type Ⅰ collagen scatted in both regions. The elastic fibers became rich and arranged continuously in the neointima. Conclusion.. The neointima of vein graft was initially formed by proliferation of the embryonic-type SMCs and then thickened infinitely

  18. Revascularisation of fresh compared with demineralised bone grafts in rats

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Talsnes, O

    2001-01-01

    Revascularisation of bone grafts is influenced by both the anatomical origin and the pre-implantation processing of the graft. We investigated the revascularisation by entrapment of 141Ce (cerium)-labelled microspheres in large, fresh and demineralised syngeneic grafts of predominantly cancellous...

  19. AUTOLOGOUS VEIN SUPPORTED WITH A BIODEGRADABLE PROSTHESIS FOR ARTERIAL GRAFTING

    NARCIS (Netherlands)

    ZWEEP, HP; SATOH, S; VANDERLEI, B; HINRICHS, WLJ; DIJK, F; FEIJEN, J; WILDEVUUR, CRH

    1993-01-01

    To evaluate the potential of a supporting, compliant, biodegradable prosthesis to function as a temporary protective scaffold for autologous vein grafts in the arterial circulation, we implanted vein grafts into the carotid arteries of rabbits, either with (composite grafts) or without (control graf

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

    Science.gov (United States)

    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.

  1. REGENERATION OF FULL-THICKNESS WOUNDS USING COLLAGEN SPLIT GRAFTS

    NARCIS (Netherlands)

    VANLUYN, MJA; VERHEUL, J; VANWACHEM, PB

    1995-01-01

    Collagen-based skin substitutes are among the most promising materials to improve regeneration of full-thickness wounds. However, additional meshed grafts or cultured epidermal grafts are still required to create epidermal regeneration. To avoid this, we substituted collagen-based split grafts, i.e.

  2. 21 CFR 872.3930 - Bone grafting material.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3930 Bone grafting material. (a) Identification... “Class II Special Controls Guidance Document: Dental Bone Grafting Material Devices.” (See § 872.1(e) for... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone grafting material. 872.3930 Section...

  3. Primary Adenocarcinoma in an Oesophageal Gastric Graft – Case Report

    Directory of Open Access Journals (Sweden)

    Dranka-Bojarowska Daria

    2015-02-01

    Full Text Available Primary adenocarcinoma in the esophageal gastric graft is a rare complication diagnosed in patients with long-term survival. Most data concerning the diagnosis and treatment of patients with metachronic cancer in esophageal grafts is derived from Japan and South Korea. The diagnosis of cancer in esophageal gastric grafts in the European countries is rare.

  4. Cellular systems biology profiling applied to cellular models of disease.

    Science.gov (United States)

    Giuliano, Kenneth A; Premkumar, Daniel R; Strock, Christopher J; Johnston, Patricia; Taylor, Lansing

    2009-11-01

    Building cellular models of disease based on the approach of Cellular Systems Biology (CSB) has the potential to improve the process of creating drugs as part of the continuum from early drug discovery through drug development and clinical trials and diagnostics. This paper focuses on the application of CSB to early drug discovery. We discuss the integration of protein-protein interaction biosensors with other multiplexed, functional biomarkers as an example in using CSB to optimize the identification of quality lead series compounds.

  5. Complications in skin grafts when continuing antithrombotic therapy prior to cutaneous surgery requiring skin grafting

    DEFF Research Database (Denmark)

    Jarjis, Reem Dina; Jørgensen, Lone; Finnerup, Kenneth

    2015-01-01

    Abstract The risk of postoperative bleeding and wound healing complications in skin grafts among anticoagulated patients undergoing cutaneous surgery has not been firmly established. The objective was to examine the literature and assess the risk of postoperative bleeding or wound healing...... studies were of prospective and retrospective design. Most of the reviewed studies suggest that the use of antithrombotic therapy can increase the risk of bleeding complications in skin grafts. These complications are only wound threatening and not life threatening. Therefore, this is of concern mostly...... complications in skin grafts among anticoagulated patients, compared with patients who discontinue or patients who are not receiving antithrombotic therapy prior to cutaneous surgery requiring skin grafting. A systematic review examining the effect of antithrombotic therapy on cutaneous surgery was performed...

  6. Preparation and Mechanical Properties of Solid-phase Grafting Nanocomposites of PVC/Graft Copolymers/MMT

    Institute of Scientific and Technical Information of China (English)

    ZHOU Dunbai; CAI Changgen; JIA Demin

    2006-01-01

    In order to improve the mechanical properties of PVC, by solid-phase grafting reaction, grafting on and nano-modifying the PVC process synchronously, acrylic monomers not only graft on PVC, but also are intercalated into the layers of MMT in the heating process. Blending PVC and the MMT-PVC grafting copolymers, we can get nanocomposites of PVC/ grafters/ MMT, and the mechanical performance of the material is improved.

  7. Tissue Engineering: Creating Living Cardiovascular Grafts

    NARCIS (Netherlands)

    Muylaert, D.E.P.

    2016-01-01

    When heart valves or coronary arteries fail, the surgical implantation of a replacement structure can be a life-saving operation. Right now, replacement vessels for bypass grafting are harvested from the leg or chest of the patient, which is an additional and invasive procedure. Similarly, heart val

  8. Dynamics of solvent-free grafted nanoparticles

    KAUST Repository

    Chremos, Alexandros

    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. © 2012 American Institute of Physics.

  9. Polyethylene glycol-grafted polystyrene particles

    NARCIS (Netherlands)

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

    2004-01-01

    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 chara

  10. Naevus depiomentosus treated with suction blister grafting

    Directory of Open Access Journals (Sweden)

    Ravikumar B

    2000-01-01

    Full Text Available Naevus depigmentosus is a congenital hypomelanotic condition in which the off white lesions are permanent and cosmetically embarassing. There has been no effective treatment reported so for for this condition. Here we are reporting a patient of naevus depigmentosus on whom we performed suction blister grafting and the resultant pigmentation was satisfactory

  11. Femoral revision surgery with impaction bone grafting

    NARCIS (Netherlands)

    B.L.E.F. ten Have (Bas); R.W. Brouwer (Reinoud); F.C. van Biezen (Frans); J.A.N. Verhaar (Jan)

    2012-01-01

    textabstractThe purpose of this prospective study was to evaluate the long-term clinical and radiological outcomes of revision of the femoral component of a total hip replacement using impaction bone grafting. Femoral revision with an impacted allograft was performed on 29 patients (31 hips). In all

  12. Experimental vascular graft for liver transplantation

    NARCIS (Netherlands)

    Kobori, L; Nemeth, T; Nemes, B; Dallos, G; Sotonyi, P; Fehervari, [No Value; Patonai, A; Slooff, MJH; Jaray, J; De Jong, KP

    2003-01-01

    Hepatic artery thrombosis is a major cause of graft failure in liver transplantation. Use of donor interponates are common, but results are controversial because of necrosis or thrombosis after rejection. Reperfusion injury, hypoxia and free radical production determinate the survival. The aim of th

  13. Fatal Saccharomyces Cerevisiae Aortic Graft Infection

    Science.gov (United States)

    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.

  14. Grafted silane monolayers: reconsideration of growth mechanisms

    Science.gov (United States)

    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.

  15. Endothelialized ePTFE Graft by Nanobiotechnology

    Science.gov (United States)

    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. Surface Grafting of Thermoresponsive Microgel Nanoparticles (Postprint)

    Science.gov (United States)

    2011-01-01

    particles, made of temperature- responsive polymers, have been widely researched for carrying out separations, as substrates for bioreactors, for enzyme ...Corporation (Model PDC-32G) plasma cleaner /sterilizer was used in the current study to treat PVDF fibers and tungsten wires prior to the grafting. To

  17. A decision tree for soft tissue grafting.

    Science.gov (United States)

    Leong, Daylene Jack-Min; Wang, Hom-Lay

    2011-06-01

    Periodontal plastic surgery is commonly performed for esthetic and physiologic reasons, such as alleviating root sensitivity, root caries, and cervical abrasion and facilitating plaque control at the affected site. Currently, there is a lack of information regarding the most appropriate treatment method for the various clinical situations encountered. The aims of this paper are to review and discuss the various clinical situations that require soft tissue grafting and to attempt to provide recommendations for the most predictable technique. Using MEDLINE and The Cochrane Library, a review of all available literature was performed. Papers published in peer-reviewed journals written in English were chosen and reviewed to validate the decision-making process when planning for soft tissue grafting. A decision tree was subsequently developed to guide clinicians to choose the most appropriate soft tissue grafting procedure by taking into consideration the following clinical parameters: etiology, purpose of the procedure, adjacent interproximal bone level, and overlying tissue thickness. The decision tree proposed serves as a guide for clinicians to select the most appropriate and predictable soft tissue grafting procedure to minimize unnecessary mistakes while providing the ultimate desired treatment outcome.

  18. Skin flaps and grafts - self-care

    Science.gov (United States)

    ... Regional flaps - self-care; Distant flaps - self-care; Free flap - self-care; Skin autografting - self-care; Pressure ulcer ... your wound To care for the graft or flap site: You may need to rest ... around it clean and free from dirt or sweat. DO NOT let the ...

  19. Neoaortic Xenoprosthetic Grafts for Treatment of Mycotic Aneurysms and Infected Aortic Grafts.

    Science.gov (United States)

    Anibueze, Chukwudubem; Sankaran, Visesh; Sadat, Umar; Tan, Kelvin; Wilson, Yvonne G; Brightwell, Robert E; Delbridge, Michael S; Stather, Philip W

    2017-10-01

    There is no international consensus regarding the optimum management of infected aortae (mycotic aneurysms, infected aortic grafts). Neoaortoiliac reconstruction has advantages over extra-anatomical bypass grafting; however, the use of autologous vein is associated with venous hypertension and compartment syndrome, alternatively cadaveric homografts are associated with high rates of perianastomotic hemorrhage, limb occlusion, and pseudoaneurysm. Arterial repair using xenoprosthetic patches is associated with lower infection rates compared to the use of prosthetic material. The aim of this case series and literature review is to report the use of xenoprosthetic bovine biomaterial for neoaortic repair of mycotic aneurysmal disease and infected aortic grafts. Patients with evidence of infected aortic grafts or mycotic aneurysms who were suitable for open aortic surgery were included. Following removal of the graft/excision of the aneurysmal sac, a 10 × 16 cm XenoSure Biologic Surgical Patch (LeMaitre, Germany) was rolled into a tube, or bifurcated tube graft, and secured with prolene sutures. Proximal and distal anastomoses were conducted as per standard aortic anastomoses. Patients were continued on long-term antibiotics and surveyed with computerized tomography at 1, 3, 6, and 12 months. Six patients underwent bovine aortic repair between 2013 and 2015: an infected Dacron aortobi-iliac graft causing iliac pseudoaneurysm, an infected Dacron aortic graft from open repair later relined with endovascular stent graft, a mycotic iliac aneurysm, and 3 mycotic aortic aneurysms. All were treated with bovine reconstructed aortic grafts or patches. Patients had a median age of 69.5 years (range 67-75), with perioperative and 30-day mortality of 0%. Median follow-up was 13 months (range 2-23). Postoperative contrast-enhanced computed tomography revealed no evidence of infection at the operative site in all patients. Freedom from reinfection and reintervention was 100

  20. Induction Conditions and EMA-qPCR Detection of Staphyloccocus aureus in Viable but Non-Culturable State%金黄色葡萄球菌VBNC状态的诱导条件和EMA-qPCR检测

    Institute of Scientific and Technical Information of China (English)

    余以刚; 田聪; 肖性龙; 陶文扬; 黎金霞; 吴晖

    2013-01-01

    In order to establish a model for the determination of induction conditions of Staphyloccocus aureus in viable but non-culturable (VBNC) state and to reveal the effects of temperature, salt concentration and pH value on the culturable cell number of Staphyloccocus aureus, orthogonal experiments were carried out to optimize the induction conditions. Then, the culturable cells were monitored and a method based on the DNA-binding dye EMA ( Ethidium Bromide Monoazide) and the qPCR technology was proposed to detect Staphyloccocus aureus in VBNC state. The results show that pH value greatly influences the culturable cell number, and that the cultivation in a nutrient broth medium with 15% (mass fraction) NaCl and 0. 3% (volume fraction) acetic acid at 4℃ for 12 d is best for the induction of Staphyloccocus aureus in VBNC state. Moreover, it is indicated that EMA-qPCR is an effective method to detect Staphyloccocus aureus in VBNC state under different induction conditions, with a Ct value improvement (cycle threshold) varying from 1. 29 to 8. 56.%为建立金黄色葡萄球菌(Staph yloccocus aureus)活的非可培养(VBNC)状态的诱导条件模型,考察了温度、盐度和酸度3个因素对金黄色葡萄球菌细菌可培养数的影响,通过正交试验优化得到了VBNC状态的诱导条件,同时观察细菌可培养数的变化,建立了DNA结合染料叠氮溴乙锭(EMA)与qPCR技术相结合检测VBNC金黄色葡萄球菌的方法.实验结果表明:细菌可培养数受酸度的影响最大,VBNC状态的最佳诱导条件为菌液在含15% NaCl和0.3%乙酸的营养肉汤培养基中于4℃下培养12d;通过正交试验诱导后的不可培养茵可由EMA-qPCR方法有效检出,其与qPCR法的Ct值(荧光信号达到设定的阈值所经历的循环数)之差在1.29 ~ 8.56之间变化.

  1. Nasal bone grafts from the removed hump used as overlay grafts to camouflage concave lateral crura.

    Science.gov (United States)

    Kubilay, Utku; Erdogdu, Suleyman; Sezen, Ozan Seymen

    2014-01-01

    Alar cartilage consists of a medial crus, middle crus and lateral crus. The lateral crus is an important aesthetic and functional structure of the nose. A 32-year-old male patient with concave lateral crura was operated by the authors. An open rhinoplasty with a dorsal approach to the septum is preferred. The nasal bones harvested from the hump, which is an autogenous graft trimmed and sutured on both concave lateral crura as an overlay camouflage grafts. Satisfactory result was achieved.

  2. Effect of Grafting Method, Graft Cover and Foliar Spray of some Mineral Elements on Persian Walnut Graft-take and Winter Survival Rate

    Directory of Open Access Journals (Sweden)

    Reza Rezaee

    2017-02-01

    Full Text Available Introduction: Persian walnut (Juglans regia L. is an important nut crop in Iran and many parts of the world. One of the major challenges of growing walnut is planting of non-grafted walnut trees in orchards, which leads to the reduction of yield, quality and productivity of walnut orchards. Compared to the other fruit trees, walnut grafting is difficult and even newly grafted walnut seedlings are vulnerable to fall or winter frost chilling, so that most of the seedlings are lost after subjecting to the cold winter. There are a few studies reporting successful grafting in outdoor conditions, however, final grafting take after winter has been usually ignored. Hence, increased walnut grafting success and improved tree growth after grafting through foliar nutrient application may lead to increased tolerance of chilling. Therefore, main goals of this research were to investigate the effect of some graft covers and role of foliar spray of calcium, boron and zinc on the reduction of frost damage in newly grafted seedlings under outdoor conditions. Materials and methods: This research was conducted at agricultural research station, Khoy city, west Azerbaijan province, during 2012-2014. In the first experiment, three methods of grafting including cleft, bark and V-shaped, and two kinds of graft covers including moist sawdust and superabsorbent plus cotton wool were investigated in terms of grafting success and quality of seedlings. In the second experiment, effect of the three above-mentioned grafting methods and two levels of foliar spray including sequential spray of Ca (4 ppm, B and Zn (2% (3 times during growth season and control (no spray were studied in terms of frost damage. The experiments conducted in factorial based on randomized complete block design with 10 trees in each plot. Data were collected 45 days after grafting take, final grafting take after one winter, subsequent scion growth length and diameter and concentration of Ca, B and Zn in

  3. A Course in Cellular Bioengineering.

    Science.gov (United States)

    Lauffenburger, Douglas A.

    1989-01-01

    Gives an overview of a course in chemical engineering entitled "Cellular Bioengineering," dealing with how chemical engineering principles can be applied to molecular cell biology. Topics used are listed and some key references are discussed. Listed are 85 references. (YP)

  4. Novel Materials for Cellular Nanosensors

    DEFF Research Database (Denmark)

    Sasso, Luigi

    The monitoring of cellular behavior is useful for the advancement of biomedical diagnostics, drug development and the understanding of a cell as the main unit of the human body. Micro- and nanotechnology allow for the creation of functional devices that enhance the study of cellular dynamics...... by providing platforms that offer biocompatible surfaces for the cell culturing in lab-on-chip devices integrated with optimized nanosensors with high specificities and sensitivities towards cellular analytes. In this project, novel materials were investigated with a focus on providing suitable surface...... modifications for electrochemical nanosensors for the detection of analytes released from cells. Two type of materials were investigated, each pertaining to the two different aspects of such devices: peptide nanostructures were studied for the creation of cellular sensing substrates that mimic in vivo surfaces...

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

    Science.gov (United States)

    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.

  6. Numerical Simulation of Coronary Artery Bypass Graft with an Assistant Graft

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; WANG Feng

    2014-01-01

    The conventional bypass design is to implant a graft on the stenosed host artery allowing blood to flow bypass the stenotic artery. However, restenosis is a challenging problem which finally results in reoperation. The purpose of this paper is to propose a new bypass graft design of coronary artery with an assistant graft for the treatment of coronary artery stenosis. An additional assistant graft was employed in the new design compared with the conventional ETS anastomosis. Numerical simulations were performed by means of finite volume method using computational fluid dynamics (CFD) solver. Results demonstrated that the new anastomoses model provided a more smooth flow at the distal ETS anastomosis without any stagnation point on anastomotic bed and vortex formation in the heel region. Oscillatory shear index (OSI) and time-averaged wall shear stress gradient (TAWSSG) at the artery bed of the distal ETS anastomosis were reduced. The coronary artery bypass graft with an assistant graft is feasible to improve the local hemodynamics and diminish the probability of restenosis in the treatment of coronary artery stenosis.

  7. Infrarenal abdominal aortic aneurysm. Endovascular repair with stent grafts; Infrarenales Bauchaortenaneurysma. Endovaskulaere Stent-Graft-Therapie

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, M.; Voshage, G.; Landwehr, P. [Klinik fuer Diagnostische und Interventionelle Radiologie, Gefaesszentrum Hannover, Diakoniekrankenhaus Henriettenstiftung gGmbH, Hannover (Germany); Busch, T. [Klinik fuer Gefaesschirurgie, Gefaesszentrum Hannover, Diakoniekrankenhaus Henriettenstiftung gGmbH, Hannover (Germany)

    2008-09-15

    As an alternative to surgery, endovascular therapy with stent grafts has become the second main treatment option for infrarenal abdominal aortic aneurysms. Unlike surgery, endovascular treatment with stent grafts is also applicable in patients unfit for open repair. Despite current improvements in endovascular repair devices, significant anatomic barriers still exclude this technique for a large number of patients. Computed tomography, magnetic resonance imaging, and ultrasound are essential for diagnostics, preintervention planning, and postintervention follow-up of abdominal aneurysms treated with stent grafts. This review covers etiology, pathology, and diagnostic aspects. Materials and methods for endovascular treatment of abdominal aortic aneurysms are presented in detail, and clinical results and complications are discussed. (orig.) [German] Die endovaskulaere Therapie des infrarenalen Bauchaortenaneurysmas hat sich als Alternative zur offenen chirurgischen Versorgung etabliert. Im Gegensatz zu Letzterer ist die Aneurysmatherapie mittels Stent-Grafts auch bei schwerkranken, nicht operationsfaehigen Patienten moeglich, wobei der Nutzen kontrovers diskutiert wird. Im Gegensatz zur klassischen transabdominellen Operation ist die Stent-Graft-Technik anatomischen Einschraenkungen unterworfen, die aber kuenftig aufgrund bereits abzusehender technischer Weiterentwicklungen eine geringere Rolle spielen werden. Die Diagnostik, die Entscheidung fuer eine endovaskulaere Therapie, die praeinterventionelle Planung und die Nachsorge erfordern den Einsatz bildgebender Verfahren, v. a. der Computer- und Magnetresonanztomographie sowie der Sonographie. Die fuer die endovaskulaere Aneurysmabehandlung relevanten Aspekte der Diagnostik werden dargestellt. Auf die Technik, die Materialien, die Ergebnisse und die Komplikationen der Stent-Graft-Behandlung wird ausfuehrlich eingegangen. (orig.)

  8. Poly(amide-graft-acrylate) interfacial compounds

    Science.gov (United States)

    Zamora, Michael Perez

    Graft copolymers with segments of dissimilar chemistries have been shown to be useful in a variety of applications as surfactants, compatibilizers, impact modifiers, and surface modifiers. The most common route to well defined graft copolymers is through the use of macromonomers, polymers containing a reactive functionality and thus capable of further polymerization. However, the majority of the studies thus far have focused on the synthesis of macromonomers capable of reacting with vinyl monomers to form graft copolymers. This study focused on the synthesis of macromonomers capable of participating in condensation polymerizations. A chain transfer functionalization method was utilized. Cysteine was evaluated as a chain transfer agent for the synthesis of amino acid functionalized poly(acrylate) and poly(methacrylate) macromonomers. Low molar mass, functionalized macromonomers were produced. These macromonomers were proven to be capable of reacting with amide precursors to form poly(amide-g-acrylate) graft copolymers. Macromonomers and graft copolymers were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy, elemental analysis (EA), inductively coupled plasma (ICP), and differential scanning calorimetry (DSC). The second part of this research involved poly(dimethacrylate) dental restorative materials. Volumetric shrinkage during the cure of these resins results in a poor interface between the resin and the remaining tooth structure, limiting the lifetime of these materials. Cyclic anhydrides were incorporated into common monomer compositions used in dental applications. Volume expansion from the ring opening hydrolysis of these anhydrides was shown to be feasible. The modified dental resins were characterized by swelling, extraction and ultraviolet spectroscopy (UV), and density measurements. Linear poLymers designed to model the crosslinked dental resins were

  9. Energy Landscape of Cellular Networks

    Science.gov (United States)

    Wang, Jin

    2008-03-01

    Cellular Networks are in general quite robust and perform their biological functions against the environmental perturbations. Progresses have been made from experimental global screenings, topological and engineering studies. However, there are so far few studies of why the network should be robust and perform biological functions from global physical perspectives. In this work, we will explore the global properties of the network from physical perspectives. The aim of this work is to develop a conceptual framework and quantitative physical methods to study the global nature of the cellular network. The main conclusion of this presentation is that we uncovered the underlying energy landscape for several small cellular networks such as MAPK signal transduction network and gene regulatory networks, from the experimentally measured or inferred inherent chemical reaction rates. The underlying dynamics of these networks can show bi-stable as well as oscillatory behavior. The global shapes of the energy landscapes of the underlying cellular networks we have studied are robust against perturbations of the kinetic rates and environmental disturbances through noise. We derived a quantitative criterion for robustness of the network function from the underlying landscape. It provides a natural explanation of the robustness and stability of the network for performing biological functions. We believe the robust landscape is a global universal property for cellular networks. We believe the robust landscape is a quantitative realization of Darwinian principle of natural selection at the cellular network level. It may provide a novel algorithm for optimizing the network connections, which is crucial for the cellular network design and synthetic biology. Our approach is general and can be applied to other cellular networks.

  10. Mathematical Modeling of Cellular Metabolism.

    Science.gov (United States)

    Berndt, Nikolaus; Holzhütter, Hermann-Georg

    2016-01-01

    Cellular metabolism basically consists of the conversion of chemical compounds taken up from the extracellular environment into energy (conserved in energy-rich bonds of organic phosphates) and a wide array of organic molecules serving as catalysts (enzymes), information carriers (nucleic acids), and building blocks for cellular structures such as membranes or ribosomes. Metabolic modeling aims at the construction of mathematical representations of the cellular metabolism that can be used to calculate the concentration of cellular molecules and the rates of their mutual chemical interconversion in response to varying external conditions as, for example, hormonal stimuli or supply of essential nutrients. Based on such calculations, it is possible to quantify complex cellular functions as cellular growth, detoxification of drugs and xenobiotic compounds or synthesis of exported molecules. Depending on the specific questions to metabolism addressed, the methodological expertise of the researcher, and available experimental information, different conceptual frameworks have been established, allowing the usage of computational methods to condense experimental information from various layers of organization into (self-) consistent models. Here, we briefly outline the main conceptual frameworks that are currently exploited in metabolism research.

  11. Humidity Sensing Properties of Pre-irradiation Grafted HDPE Membranes

    Institute of Scientific and Technical Information of China (English)

    Zheng Jiao; Qun Fu; Xiang Geng; Zhen Li; Haijian Zhong

    2006-01-01

    Grafted high density polyethylene (HDPE) films have been prepared by grafting sodium styrene sulfonate (SSS) and acrylic acid (AA) onto HDPE using preirradiation method. The structure and surface morphology of both grafted and ungrafted HDPE films were observed by FTIR spectroscopy and scanning electron microscope (SEM), respectively. The humidity sensing properties of grafted HDPE films were investigated. The results show that the impedance of the film decreases with increasing of relative humidity (RH). The films display high sensitivity with nearly three orders of magnitude change in the resistance during the relative humidity variation from 5% to 98%. Grafted HDPE films exhibit excellent properties as humidity sensors.

  12. Stretch Polytetrafluoroethylene Grafts for Hemodialysis Angioaccess: Three-year Experience

    Directory of Open Access Journals (Sweden)

    Al Dayel Adel

    2001-01-01

    Full Text Available We report the results of 90 stretch polytetrafluoroethylene (PTFE grafts in 78 chronic renal failure patients over a 3-year period from 1995-1998. The grafts were used as primary access in 15% of the patients. The cumulative patency was 63.3% and there were no complications in 48.8% of the cases. Infection was encountered in 15.5% and thrombosis in 31.1% of the grafts. Intimal hyperplasia, venous anastomotic stenosis, improper puncture technique and subclavian vein stenosis were the major causes of failure of grafts. We conclude that stretch PTFE grafts as angioaccesses may provide good patency and durability.

  13. Recent Developments in Cellular Immunotherapy for HSCT-associated Complications

    Directory of Open Access Journals (Sweden)

    Monica Reis

    2016-11-01

    Full Text Available Allogeneic HSCT is associated with serious complications and improvement of the overall clinical outcome of patients with hematological malignancies is necessary. During the last decades, post-transplant donor-derived adoptive cellular immunotherapeutic strategies have been progressively developed for the treatment of graft versus host disease (GvHD, infectious complications, and tumor relapses. To date, the common challenge of all these cell-based approaches is their implementation for clinical application. Establishing an appropriate manufacturing process, to guarantee safe and effective therapeutics with simultaneous consideration of economic requirements is one of the most critical hurdles. In this review we will discuss the recent scientific findings, clinical experiences, and technological advances for cell processing, towards the application of MSC as a therapy for treatment of severe GvHD, virus-specific T cells for targeting life-threating infections, and of CAR-engineered T cells to treat relapsed leukemia.

  14. Cellular metabolism as a basis for immune privilege.

    Science.gov (United States)

    Newell, M Karen; Villalobos-Menuey, Elizabeth; Schweitzer, Susan C; Harper, Mary-Ellen; Camley, Robert E

    2006-03-17

    We hypothesize that the energy strategy of a cell is a key factor for determining how, or if, the immune system interacts with that cell. Cells have a limited number of metabolic states, in part, depending on the type of fuels the cell consumes. Cellular fuels include glucose (carbohydrates), lipids (fats), and proteins. We propose that the cell's ability to switch to, and efficiently use, fat for fuel confers immune privilege. Additionally, because uncoupling proteins are involved in the fat burning process and reportedly in protection from free radicals, we hypothesize that uncoupling proteins play an important role in immune privilege. Thus, changes in metabolism (caused by oxidative stresses, fuel availability, age, hormones, radiation, or drugs) will dictate and initiate changes in immune recognition and in the nature of the immune response. This has profound implications for controlling the symptoms of autoimmune diseases, for preventing graft rejection, and for targeting tumor cells for destruction.

  15. Establishment of a rat and guinea pig aortic interposition graft model reveals model-specific patterns of intimal hyperplasia.

    Science.gov (United States)

    Gregory, Elaine K; Vercammen, Janet M; Flynn, Megan E; Kibbe, Melina R

    2016-12-01

    Although the aortic interposition bypass model has been widely used to evaluate biomaterials for bypass grafting, there is no comprehensive description of the procedure or of the distribution of intimal hyperplasia that results. The objectives of this study were to (1) review and summarize approaches of aortic interposition grafting in animal models, (2) determine the pertinent anatomy for this procedure, (3) validate this model in the rat and guinea pig, and (4) compare the distribution of intimal hyperplasia that develops in each species. A literature search was performed in PubMed from 1980 to the present to analyze the use of anesthesia, anticoagulation, antiplatelet agents, graft material, suture, and anastomotic techniques. Using 10-week-old male Sprague-Dawley rats and Hartley guinea pigs, we established pertinent aortic anatomy, developed comparable models, and assessed complications for each model. At 30 days, the graft and associated aorta were explanted, intimal formation was assessed morphometrically, and cellularity was assessed via nuclear counting. We reviewed 30 articles and summarized the pertinent procedural findings. Upon establishing both animal models, key anatomic differences between the species that affect this model were noted. Guinea pigs have a much larger cecum, increased retroperitoneal fat, and lack the iliolumbar vessels compared with the rat. Surgical outcomes for the rat model included a 53% technical success rate and a 32% technical error rate. Surgical outcomes for the guinea pig model included a 69% technical success rate and a 31% technical error rate. These two species demonstrated unique distribution of intimal hyperplasia at 30 days. Intimal hyperplasia in the rat model was greatest at two areas, the proximal graft (5400 μm(2); P hyperplasia throughout the graft (4500-5100 μm(2); P < .01). In this report, we summarize the literature on the aortic interposition graft model, present a detailed description of the anatomy

  16. A grafting from approach to graft polystyrene chains at the surface of graphene nanolayers by RAFT polymerization: Various graft densities from hydroxyl groups

    Energy Technology Data Exchange (ETDEWEB)

    Roghani-Mamaqani, Hossein, E-mail: r.mamaghani@sut.ac.ir [Department of Polymer Engineering, Sahand University of Technology, PO Box 51335-1996, Tabriz (Iran, Islamic Republic of); Khezri, Khezrollah [School of Chemistry, University College of Science, University of Tehran, PO Box 14155-6455, Tehran (Iran, Islamic Republic of)

    2016-01-01

    Graphical abstract: (3-Aminopropyl) triethoxysilane was grafted at the surface of GO in low and high different graft densities to yield GOHAL and GOHAH, respectively. Subsequently, 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid (RA) was attached at the surface of GOHAL and GOHAH by an amidation reaction to yield GOHRL and GOHRH, respectively. Then, GOHRL and GOHRH were used in grafting from RAFT polymerization of styrene. - Highlights: • A RAFT agent grafted GO was used in grafting from RAFT polymerization of styrene. • The efficiency of RAFT agent attachment at the surface of GO is 41.12% for high density sample. • Polystyrene molecular weight is decreased by the addition of graphene content and also graft density of RAFT agent. - Abstract: (3-Aminopropyl) triethoxysilane was grafted at the surface of GO in low and high different graft densities to yield GOHAL and GOHAH, respectively. Subsequently, 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid (RA) was attached at the surface of GOHAL and GOHAH by an amidation reaction to yield GOHRL and GOHRH, respectively. Then, GOHRL and GOHRH were used in grafting from RAFT polymerization of styrene. Grafting of APTES and RA was approved by Fourier transform infrared spectroscopy, X-ray photo electron spectroscopy, and Raman spectroscopy. Expansion of graphene interlayer by oxidation and functionalization processes was evaluated by X-ray diffraction. Conversion values of styrene were calculated using gas chromatography. Molecular weight and PDI values of attached polystyrene (PS) chains were studied by size exclusion chromatography. Thermogravimetric analysis was also used to investigate the degradation temperatures, char contents, and graft contents of modifiers and PS chains. GOHRH and GOHRL reach to char content of 55.3 and 45.2% at 600 °C, which shows that weight ratio of modifier (APTES and RA moieties) is 15.3 and 5.2%, respectively. Scanning and transmission electron microscopies show that

  17. ESR spectroscopic investigations of the radiation-grafting of fluoropolymers

    Energy Technology Data Exchange (ETDEWEB)

    Huebner, G.; Roduner, E. [University of Stuttgart (Germany); Brack, H.P.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    ESR spectroscopic investigations have clarified the influence of several preparative parameters on the reaction rates and yields obtained in the radiation-grafting method used at PSI to prepare proton-conducting polymer membranes. At a given irradiation dose, a higher concentration of reactive radical sites was detected in ETFE films than in FEP films. This higher concentration explains the higher grafting levels and rates of the ETFE films found in our previous grafting experiments. Taken together, the in-situ ESR experiments and grafting experiments show that the rates of disappearance of radical species and grafting rates and final grafting levels depend strongly on the reaction temperature and the oxygen content of the system. Average grafted chain lengths were calculated to contain about 1,000 monomer units. (author) 2 figs., 4 refs.

  18. Hierarchical Cellular Structures in High-Capacity Cellular Communication Systems

    CERN Document Server

    Jain, R K; Agrawal, N K

    2011-01-01

    In the prevailing cellular environment, it is important to provide the resources for the fluctuating traffic demand exactly in the place and at the time where and when they are needed. In this paper, we explored the ability of hierarchical cellular structures with inter layer reuse to increase the capacity of mobile communication network by applying total frequency hopping (T-FH) and adaptive frequency allocation (AFA) as a strategy to reuse the macro and micro cell resources without frequency planning in indoor pico cells [11]. The practical aspects for designing macro- micro cellular overlays in the existing big urban areas are also explained [4]. Femto cells are inducted in macro / micro / pico cells hierarchical structure to achieve the required QoS cost effectively.

  19. Embryonic Cell Grafts in a Culture Model of Spinal Cord Lesion: Neuronal Relay Formation is Essential for Functional Regeneration

    Directory of Open Access Journals (Sweden)

    Anne Tscherter

    2016-09-01

    Full Text Available Presently there exists no cure for spinal cord injury. However, transplantation of embryonic tissue into spinal cord lesions resulted in axon outgrowth across the lesion site and some functional recovery, fostering hope for future stem cell therapies. Although in vivo evidence for functional recovery is given, the exact cellular mechanism of the graft support remains elusive: either the grafted cells provide a permissive environment for the host tissue to regenerate itself or the grafts actually integrate functionally into the host neuronal network reconnecting the separated spinal cord circuits. We tested the two hypotheses in an in vitro spinal cord lesion model that is based on propagation of activity between two rat organotypic spinal cord slices in culture. Transplantation of dissociated cells from E14 rat spinal cord or forebrain re-established the relay of activity over the lesion site and, thus, provoked functional regeneration. Combining patch-clamp recordings from transplanted cells with network activity measurements from the host tissue on multi-electrode arrays we here show that neurons differentiate from the grafted cells and integrate into the host circuits. Optogenetic silencing of neurons developed from transplanted embryonic mouse forebrain cells provides clear evidence that they replace the lost neuronal connections to relay and synchronize activity between the separated spinal cord circuits. In contrast, transplantation of neurospheres induced neither the differentiation of mature neurons from the grafts nor an improvement of functional regeneration. Together these findings suggest, that the formation of neuronal relays from grafted embryonic cells is essential to re-connect segregated spinal cord circuits.

  20. Electrospun vascular scaffold for cellularized small diameter blood vessels: A preclinical large animal study.

    Science.gov (United States)

    Ju, Young Min; Ahn, Hyunhee; Arenas-Herrera, Juan; Kim, Cheil; Abolbashari, Mehran; Atala, Anthony; Yoo, James J; Lee, Sang Jin

    2017-09-01

    The strategy of vascular tissue engineering is to create a vascular substitute by combining autologous vascular cells with a tubular-shaped biodegradable scaffold. We have previously developed a novel electrospun bilayered vascular scaffold that provides proper biological and biomechanical properties as well as structural configuration. In this study, we investigated the clinical feasibility of a cellularized vascular scaffold in a preclinical large animal model. We fabricated the cellularized vascular construct with autologous endothelial progenitor cell (EPC)-derived endothelial cells (ECs) and smooth muscle cells (SMCs) followed by a pulsatile bioreactor preconditioning. This fully cellularized vascular construct was tested in a sheep carotid arterial interposition model. After preconditioning, confluent and mature EC and SMC layers in the scaffold were achieved. The cellularized constructs sustained the structural integrity with a high degree of graft patency without eliciting an inflammatory response over the course of the 6-month period in sheep. Moreover, the matured EC coverage on the lumen and a thick smooth muscle layer were formed at 6months after transplantation. We demonstrated that electrospun bilayered vascular scaffolds in conjunction with autologous vascular cells may be a clinically applicable alternative to traditional prosthetic vascular graft substitutes. This study demonstrates the utility of tissue engineering to provide platform technologies for rehabilitation of patients recovering from severe, devastating cardiovascular diseases. The long-term goal is to provide alternatives to vascular grafting using bioengineered blood vessels derived from an autologous cell source with a functionalized vascular scaffold. This novel bilayered vascular construct for engineering blood vessels is designed to offer "off-the-shelf" availability for clinical translation. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. Cellular interactions with tissue-engineered microenvironments and nanoparticles

    Science.gov (United States)

    Pan, Zhi

    Tissue-engineered hydrogels composed of intermolecularlly crosslinked hyaluronan (HA-DTPH) and fibronectin functional domains (FNfds) were applied as a physiological relevant ECM mimic with controlled mechanical and biochemical properties. Cellular interactions with this tissue-engineered environment, especially physical interactions (cellular traction forces), were quantitatively measured by using the digital image speckle correlation (DISC) technique and finite element method (FEM). By correlating with other cell functions such as cell morphology and migration, a comprehensive structure-function relationship between cells and their environments was identified. Furthermore, spatiotemporal redistribution of cellular traction stresses was time-lapse measured during cell migration to better understand the dynamics of cell mobility. The results suggest that the reinforcement of the traction stresses around the nucleus, as well as the relaxation of nuclear deformation, are critical steps during cell migration, serving as a speed regulator, which must be considered in any dynamic molecular reconstruction model of tissue cell migration. Besides single cell migration, en masse cell migration was studied by using agarose droplet migration assay. Cell density was demonstrated to be another important parameter to influence cell behaviors besides substrate properties. Findings from these studies will provide fundamental design criteria to develop novel and effective tissue-engineered constructs. Cellular interactions with rutile and anatase TiO2 nanoparticles were also studied. These particles can penetrate easily through the cell membrane and impair cell function, with the latter being more damaging. The exposure to nanoparticles was found to decrease cell area, cell proliferation, motility, and contractility. To prevent this, a dense grafted polymer brush coating was applied onto the nanoparticle surface. These modified nanoparticles failed to adhere to and penetrate

  2. Prognosis of Different Cellular Generations

    Directory of Open Access Journals (Sweden)

    Preetish Ranjan

    2013-04-01

    Full Text Available Technological advancement in mobile telephony from 1G to 3G, 4G and 5G has a very axiomatic fact that made an entire world a global village. The cellular system employs a different design approach and technology that most commercial radio and television system use. In the cellular system, the service area is divided into cells and a transmitter is designed to serve an individual cell. The system seeks to make efficient use of available channels by using low-power transmitters to allow frequency reuse at a smaller distance. Maximizing the number of times each channel can be reused in a given geographical area is the key to an efficient cellular system design. During the past three decades, the world has seen significant changes in telecommunications industry. There have been some remarkable aspects to the rapid growth in wireless communications, as seen by the large expansion in mobile systems. This paper focuses on “Past, Present & Future of Cellular Telephony” and some light has been thrown upon the technologies of the cellular systems, namely 1G, 2G, 2.5G, 3G and future generations like 4G and 5G systems as well.

  3. Continuum representations of cellular solids

    Energy Technology Data Exchange (ETDEWEB)

    Neilsen, M.K.

    1993-09-01

    Cellular materials consist of interconnected struts or plates which form cells. The struts or plates are constructed from a variety of metals, polymers, ceramics and wood products. Cellular materials are often used in impact limiters for shipping containers to protect the contents from accidental impact events. These materials exhibit a variety of complex behavior when subjected to crushing loads. This research focuses on the development of continuum representations of cellular solids that can be used in the finite element analysis of shipping container accidents. A significant portion of this work is the development of a new methodology to relate localized deformations to appropriate constitutive descriptions. This methodology provides the insight needed to select constitutive descriptions for cellular solids that capture the localized deformations that are observed experimentally. Constitutive relations are developed for two different cellular materials, aluminum honeycomb and polyurethane foam. These constitutive relations are based on plasticity and continuum damage theories. Plasticity is used to describe the permanent deformation exhibited by both aluminum honeycomb and polyurethane foam. Continuum damage is needed to capture the change in elastic parameters due to cracking of the polyurethane cell wall materials. The new constitutive description of polyurethane foam is implemented in both static and dynamic finite element codes, and analytical and numerical predictions are compared with available experimental data.

  4. Classifying cellular automata using grossone

    Science.gov (United States)

    D'Alotto, Louis

    2016-10-01

    This paper proposes an application of the Infinite Unit Axiom and grossone, introduced by Yaroslav Sergeyev (see [7] - [12]), to the development and classification of one and two-dimensional cellular automata. By the application of grossone, new and more precise nonarchimedean metrics on the space of definition for one and two-dimensional cellular automata are established. These new metrics allow us to do computations with infinitesimals. Hence configurations in the domain space of cellular automata can be infinitesimally close (but not equal). That is, they can agree at infinitely many places. Using the new metrics, open disks are defined and the number of points in each disk computed. The forward dynamics of a cellular automaton map are also studied by defined sets. It is also shown that using the Infinite Unit Axiom, the number of configurations that follow a given configuration, under the forward iterations of cellular automaton maps, can now be computed and hence a classification scheme developed based on this computation.

  5. Plasma treatment for improving cell biocompatibility of a biodegradable polymer scaffold for vascular graft applications.

    Science.gov (United States)

    Valence, Sarra de; Tille, Jean-Christophe; Chaabane, Chiraz; Gurny, Robert; Bochaton-Piallat, Marie-Luce; Walpoth, Beat H; Möller, Michael

    2013-09-01

    Biodegradable synthetic scaffolds are being evaluated by many groups for the application of vascular tissue engineering. In addition to the choice of the material and the structure of the scaffold, tailoring the surface properties can have an important effect on promoting adequate tissue regeneration. The objective of this study was to evaluate the effect of an increased hydrophilicity of a polycaprolactone vascular graft by treatment with a cold air plasma. To this end, treated and untreated scaffolds were characterized, evaluated in vitro with smooth muscle cells, and implanted in vivo in the rat model for 3 weeks, both in the subcutaneous location and as an aortic replacement. The plasma treatment significantly increased the hydrophilicity of the scaffold, with complete wetting after a treatment of 60 sec, but did not change fiber morphology or mechanical properties. Smooth muscle cells cultured on plasma treated patches adopt a spread out morphology compared to a small, rounded morphology on untreated patches. Subcutaneous implantation revealed a low foreign body reaction for both types of scaffolds and a more extended and dense cellular infiltrate in the plasma treated scaffolds. In the vascular position, the plasma treatment induced a better cellularization of the graft wall, while it did not affect endothelialization rate or intimal hyperplasia. Plasma treatment is therefore an accessible tool to easily increase the biocompatibility of a scaffold and accelerate tissue regeneration without compromising mechanical strength, which are valuable advantages for vascular tissue engineering.

  6. Skin and kidney histological changes in graft-versus-host disease (GVHD) after kidney transplantation.

    Science.gov (United States)

    Pintar, Tadeja; Alessiani, Mario; Pleskovič, Alojz; Pleskovič, Aleš; Zorc-Pleskovič, Ruda; Milutinović, Aleksandra

    2011-05-01

    Kidney transplantation (Ktx) is generally performed during end stage renal disease due to a loss of the kidneys' ability to filter wastes from the circulatory system. Acute graft-versus-host disease (GVHD) after Ktx is a life-threatening complication that progresses to organ failure, systemic complications, and death. The current study evaluated the significance of histologic findings of GVHD as obtained from skin biopsies following Ktx in swine. A swine model of Ktx with tacrolimus-based immunosuppression was used to assess possible correlations between acute-graft-cellular rejection and skin histological findings for prediction of GVHD. Animals were divided into a Ktx treatment group or a control group with no Ktx and skin and kidney biopsies were histologically assessed at postoperative days 0, 15, 30, 45 and 60. Skin samples were analyzed and classified from grade 1 to 4 of skin GVHD and the major histopathological changes of kidney acute cellular rejection were described using Banff's score system. We observed a significant linear correlation between the histological grading values of skin biopsy changes and the histological grading values of kidney biopsies (Kendall's tau_b=0.993) in the Ktx experimental group. No histological changes were observed in controls. Our findings demonstrate the diagnostic value of staging skin GVHD after Ktx and suggest it's future utility for monitoring long term Ktx-induced changes.

  7. [Bovine heterologous bone graft in orbital surgery].

    Science.gov (United States)

    Morax, S; Hurbli, T; Smida, R

    1993-08-01

    Lubboc (T650) is a bovine heterologous bone implant obtained by specific preparation of trabecular of bone. In vitro and in vivo biocompatibility studies have revealed the absence of any cytotoxicity or systemic toxicity. Lubboc has many fields of application, including all bone graft surgical indications. We report our first results concerning the use of this product in orbital surgery either as a filling or contention material or as an apposition material. On all 20 operated patients we did not encounter any intolerance, inflammation or infection. The follow-up is still too short to appreciate the long term integration of this material which has the advantage of being a substitute for autologous bone, avoiding bone graft harvesting.

  8. Vestibuloplasty after secondary alveolar bone grafting.

    Science.gov (United States)

    Iino, M; Fukuda, M; Murakami, K; Horiuchi, T; Niitsu, K; Seto, K

    2001-11-01

    This paper introduces a surgical technique for vestibuloplasty after secondary alveolar bone grafting of patients with cleft lip and palate (CLP). This paper also reports on the patients who underwent this modified vestibuloplasty. The vestibuloplasty technique described in this paper consists of: (1) reduction of submucosal scar tissue of the upper lip, (2) V-Y plasty of the superficial mucosa, (3) placement of horizontal mattress sutures between nostril floor skin and freed marginal mucosa, (4) application of artificial skin to cover the exposed periosteal surface, and (5) use of a removable retention splint. This surgical procedure appears to be very useful for patients with CLP. The technique enables the surgeon to obtain an adequate sulcus depth around the graft area. In addition, this technique releases the mucosal scar contraction and improves the shape and mobility of the upper lip.

  9. Primary Graft Failure after Heart Transplantation

    Directory of Open Access Journals (Sweden)

    Arjun Iyer

    2011-01-01

    Full Text Available Primary graft failure (PGF is a devastating complication that occurs in the immediate postoperative period following heart transplantation. It manifests as severe ventricular dysfunction of the donor graft and carries significant mortality and morbidity. In the last decade, advances in pharmacological treatment and mechanical circulatory support have improved the outlook for heart transplant recipients who develop this complication. Despite these advances in treatment, PGF is still the leading cause of death in the first 30 days after transplantation. In today's climate of significant organ shortages and growing waiting lists, transplant units worldwide have increasingly utilised “marginal donors” to try and bridge the gap between “supply and demand.” One of the costs of this strategy has been an increased incidence of PGF. As the threat of PGF increases, the challenges of predicting and preventing its occurrence, as well as the identification of more effective treatment modalities, are vital areas of active research and development.

  10. Supercritical carbon dioxide-processed resorbable polymer nanocomposites for bone graft substitute applications

    Science.gov (United States)

    Baker, Kevin C.

    Numerous clinical situations necessitate the use of bone graft materials to enhance bone formation. While autologous and allogenic materials are considered the gold standards in the setting of fracture healing and spine fusion, their disadvantages, which include donor site morbidity and finite supply have stimulated research and development of novel bone graft substitute materials. Among the most promising candidate materials are resorbable polymers, composed of lactic and/or glycolic acid. While the characteristics of these materials, such as predictable degradation kinetics and biocompatibility, make them an excellent choice for bone graft substitute applications, they lack mechanical strength when synthesized with the requisite porous morphology. As such, porous resorbable polymers are often reinforced with filler materials. In the presented work, we describe the use of supercritical carbon dioxide (scCO2) processing to create porous resorbable polymeric constructs reinforced by nanostructured, organically modified Montmorillonite clay (nanoclay). scCO2 processing simultaneously disperses the nanoclay throughout the polymeric matrix, while imparting a porous morphology to the construct conducive to facilitating cellular infiltration and neoangiogenesis, which are necessary components of bone growth. With the addition of as little as 2.5wt% of nanoclay, the compressive strength of the constructs nearly doubles putting them on par with human cortico-cancellous bone. Rheological measurements indicate that the dominant mode of reinforcement of the nanocomposite constructs is the restriction of polymer chain mobility. This restriction is a function of the positive interaction between polymer chains and the nanoclay. In vivo inflammation studies indicate biocompatibility of the constructs. Ectopic osteogenesis assays have determined that the scCO2-processed nanocomposites are capable of supporting growth-factor induced bone formation. scCO 2-processed resorbable

  11. Novel anterior cruciate ligament graft fixation device reduces slippage

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    Lopez MJ

    2013-05-01

    Full Text Available Mandi J Lopez,1 Allen Borne,2 W Todd Monroe,3 Prakash Bommala,1 Laura Kelly,1 Nan Zhang11Laboratory for Equine and Comparative Orthopedic Research, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, 2Louisiana State University, New Orleans Health Sciences Center, School of Medicine, New Orleans, 3Department of Biological and Agricultural Engineering, Agricultural Center, Louisiana State University, Baton Rouge, LA, USAAbstract: Clinically significant laxity occurs in 10%–30% of knees after anterior cruciate ligament reconstruction. Graft slippage and tension loss at the hamstring graft tibial fixation site during and after reconstruction surgery contribute to postoperative joint laxity and are detrimental to long-term knee stability and graft properties. Limiting graft slippage will reduce associated complications. We sought to compare the in vitro mechanical properties and in vivo joint stabilization, postoperative limb use, and graft incorporation of the novel GraftGrab™ (GG device designed to reduce hamstring graft tibial fixation slippage with the commercially available bioabsorbable Bio-Post™ and spiked washer (BP. Mechanical testing was performed on canine tibia-hamstring graft constructs to quantify initial fixation properties. In vivo joint stabilization, postoperative limb use and graft incorporation of hamstring graft reconstructions were determined in a canine model. Outcomes included tibial translation and ground reaction forces preoperatively and 4 and 8 weeks postoperatively, three-dimensional graft and bone tunnel dimensions at the latter two time points, and graft-bone microstructure, as well as mechanical properties 8 weeks after implantation. Immediately after fixation, all grafts slipped from the BP constructs versus about 30% of GG constructs. In vivo limb use remained low, and tibial translation increased with time in the BP cohort. These results together

  12. Histologic Assessment of Drug-Eluting Grafts Related to Implantation Site

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    Jean-Christophe Tille

    2016-02-01

    Full Text Available Drug-eluting vascular prostheses represent a new direction in vascular surgery to reduce early thrombosis and late intimal hyperplasia for small calibre grafts. Subcutaneous implantation in rats is a rapid and cost-effective screening model to assess the drug-elution effect and could, to some extent, be useful to forecast results for vascular prostheses. We compared biological and histological responses to scaffolds in different implantation sites. Polycaprolactone (PCL, paclitaxel-loaded PCL (PCL-PTX and dexamethasone-loaded PCL (PCL-DXM electrospun scaffolds were implanted subcutaneously and in an infrarenal abdominal aortic model in rats for up to 12 weeks. At the conclusion of the study, a histological analysis was performed. Cellular graft invasion revealed differences in the progression of cellular infiltration between PCL-PTX and PCL/PCL-DXM groups in both models. Cell infiltration increased over time in the aortic model compared to the subcutaneous model for all groups. Cell counting revealed major differences in fibroblast, macrophage and giant cell graft colonisation in all groups and models over time. Macrophages and giant cells increased in the PCL aortic model; whereas in the subcutaneous model these cell types increased only after three weeks or even decreased in the drug-eluting PCL groups. Other major findings were observed only in the aortic replacement such as extracellular matrix deposition and neo-angiogenesis. The subcutaneous implant model can be used for screening, especially when drug-eluting effects are studied. However, major histological differences were observed in cell type reaction and depth of cell penetration compared to the aortic model. Our results demonstrate that the implantation site is a critical determinant of the biological response.

  13. Cellular islet autoimmunity associates with clinical outcome of islet cell transplantation.

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    Volkert A L Huurman

    Full Text Available BACKGROUND: Islet cell transplantation can cure type 1 diabetes (T1D, but only a minority of recipients remains insulin-independent in the following years. We tested the hypothesis that allograft rejection and recurrent autoimmunity contribute to this progressive loss of islet allograft function. METHODOLOGY/PRINCIPAL FINDINGS: Twenty-one T1D patients received cultured islet cell grafts prepared from multiple donors and transplanted under anti-thymocyte globulin (ATG induction and tacrolimus plus mycophenolate mofetil (MMF maintenance immunosuppression. Immunity against auto- and alloantigens was measured before and during one year after transplantation. Cellular auto- and alloreactivity was assessed by lymphocyte stimulation tests against autoantigens and cytotoxic T lymphocyte precursor assays, respectively. Humoral reactivity was measured by auto- and alloantibodies. Clinical outcome parameters--including time until insulin independence, insulin independence at one year, and C-peptide levels over one year--remained blinded until their correlation with immunological parameters. All patients showed significant improvement of metabolic control and 13 out of 21 became insulin-independent. Multivariate analyses showed that presence of cellular autoimmunity before and after transplantation is associated with delayed insulin-independence (p = 0.001 and p = 0.01, respectively and lower circulating C-peptide levels during the first year after transplantation (p = 0.002 and p = 0.02, respectively. Seven out of eight patients without pre-existent T-cell autoreactivity became insulin-independent, versus none of the four patients reactive to both islet autoantigens GAD and IA-2 before transplantation. Autoantibody levels and cellular alloreactivity had no significant association with outcome. CONCLUSIONS/SIGNIFICANCE: In this cohort study, cellular islet-specific autoimmunity associates with clinical outcome of islet cell transplantation under ATG

  14. Graft selection in anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Miller, Suzanne L; Gladstone, James N

    2002-10-01

    Selecting the appropriate graft for ACL reconstruction depends on numerous factors including surgeon philosophy and experience, tissue availability (affected by anatomical anomalies or prior injury or surgery), and patient activity level and desires. Although the patella tendon autograft has the widest experience in the literature, and is probably the most commonly used graft source, this must be tempered with the higher reported incidences of potential morbidity and pitfalls associated with its use. The hamstring tendons are gaining increasing popularity, mostly due to reduced harvest morbidity and improved soft tissue fixation techniques, and many recent studies in the literature report equal results to BTB ACL reconstruction with respect to functional outcome and patient satisfaction. On the other hand, many of these studies report higher degrees of instrument (KT-100) tested laxity for hamstring reconstruction, and some have reported lower returns to preinjury levels of activity. One question that remains to be addressed is how closely objectively measured laxity tests correlate with subjectively assessed outcomes and ability to return to high levels of competitive sports. Allograft use, which decreased in popularity during the 1990s, appears to be undergoing a resurgence, with better sterilization processes and new graft sources (tibialis tendons), leading to increased availability and improved fixation techniques. The benefits of decreased surgical morbidity and easier rehabilitation must be weighed against the potential for greater failure of biologic incorporation, infection, and possibly slower return to activities. In our practice, for high-demand individuals (those playing cutting, pivoting, or jumping sports and skiing) BTB tends to be the graft of choice. For lower demand or older individuals, hamstring reconstructions will be performed. Allograft tissue will be used in older individuals (generally over 45 years old), those with signs of arthritis (and

  15. Coronary artery bypass grafting for Kawasaki disease

    Institute of Scientific and Technical Information of China (English)

    GUO Hong-wei; CHANG Qian; XU Jian-ping; SONG Yun-hu; SUN Han-song; HU Sheng-shou

    2010-01-01

    Background Kawasaki disease (KD) is the leading cause of pediatric ischemic heart disease. The incidence of serious coronary sequelae is low and about 2%-3% of patients with KD, but once myocardial infarction occurs in children, the mortality is quite high and 22% at the first infarction.This study aimed to evaluate the efficacy of coronary artery bypass grafting (CABG) in patients with KD.Methods Eight patients with a history of KD underwent CABG between October 1997 and July 2005. The number of bypass grafts placed was 2 to 4 per patient (mean 2.5±0.8). Various bypass grafts were used in patients, i.e. the left internal mammary artery (LIMA) in 3 patients, bilateral internal mammary artery (IMA) in 2 patients, LIMA plus gastroepiploic artery (GEA) in 1 patient and total saphenous vein grafts (SVGs) in 2 patients. The combined procedures included ventricular aneurysmectomy in 1 patient, mitral valve plasty in 1 and right coronary aneurysmectomy in 1. One patient was not able to wean from cardiopulmonary bypass (CPB), after being supported with intra-aortic balloon pump (IABP), the patient was weaned from CPB successfully.Results One patient died of low cardiac output syndrome and acute renal failure 19 days after operation. Other patients recovered and were discharged uneventfully. During the follow-up that ranged from 3 to 57 months (mean 27 months),clincal angina disappeared or improved. Cardiac function was in Class Ⅰ-Ⅱ (NYHA).Conclusion CABG is a safe and effective procedure for Kawasaki coronary artery disease. However long-term results need to be followed up.

  16. LATE RENAL GRAFT REJECTION: PATHOLOGY AND PROGNOSIS

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    E.S. Stolyarevich

    2014-01-01

    Full Text Available Rejection has always been one of the most important cause of late renal graft dysfunction. Aim of the study was to analyze the prevalence of different clinico-pathological variants of rejection that cause late graft dysfunction, and evaluate their impact on long-term outcome. Materials and methods. This is a retrospective study that analyzed 294 needle core biopsy specimens from 265 renal transplant recipients with late (48,8 ± 46,1 months after transplantation allograft dysfunction caused by late acute rejection (LAR, n = 193 or chronic rejection (CR, n = 78 or both (n = 23. C4d staining was performed by immunofl uorescence (IF on frozen sections using a standard protocol. Results. Peritubular capillary C4d deposition was identifi ed in 36% samples with acute rejection and in 62% cases of chronic rejection (including 67% cases of transplant glomerulopathy, and 50% – of isolated chronic vasculopathy. 5-year graft survival for LAR vs CR vs their combination was 47, 13 and 25%, respectively. The outcome of C4d– LAR was (p < 0,01 better than of C4d+ acute rejection: at 60 months graft survival for diffuse C4d+ vs C4d− was 33% vs 53%, respectively. In cases of chronic rejection C4d+ vs C4d– it was not statistically signifi cant (34% vs 36%. Conclusion. In long-term allograft biopsy C4d positivity is more haracteristic for chronic rejection than for acute rejection. Only diffuse C4d staining affects the outcome. C4d– positivity is associated with worse allograft survival in cases of late acute rejection, but not in cases of chronic rejection. 

  17. Importance of the third arterial graft in multiple arterial grafting strategies.

    Science.gov (United States)

    Glineur, David

    2013-07-01

    The long-term benefit of multiple arterial grafts for coronary artery bypass (CABG) is not clear. This protocol was elaborated to see if multiple arterial grafts would provide better long-term outcomes when compared with conventional strategies. Prospective data was collected for 588 patients undergoing isolated CABG between 1985 and 1995. We analyzed long term survival and freedom from cardiac death. The analysis compared patients with BITA grafting receiving a right gastro-epiploic artery (RGEA) versus those receiving a saphenous vein graft (SVG) as a third conduit. Cox proportional hazards modelling was used to adjust for relevant confounders. The mean age was 59±9 years and 49% received BITA. Mean follow-up was 16.1±5.4 years. Multivariable analysis revealed in that patients receiving the RGEA as a third conduit had superior overall survival (HR, 0.46; P=0.015) and cardiac survival (HR, 0.20; P=0.005) compared to those receiving an SVG. In our experience, the use of multiple arterial grafting is independently associated with superior outcomes. Furthermore, the use of a third arterial conduit targeted to the RCA should be considered to improve long-term survival.

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

    Science.gov (United States)

    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.

  19. Cellular models for Parkinson's disease.

    Science.gov (United States)

    Falkenburger, Björn H; Saridaki, Theodora; Dinter, Elisabeth

    2016-10-01

    Developing new therapeutic strategies for Parkinson's disease requires cellular models. Current models reproduce the two most salient changes found in the brains of patients with Parkinson's disease: The degeneration of dopaminergic neurons and the existence of protein aggregates consisting mainly of α-synuclein. Cultured cells offer many advantages over studying Parkinson's disease directly in patients or in animal models. At the same time, the choice of a specific cellular model entails the requirement to focus on one aspect of the disease while ignoring others. This article is intended for researchers planning to use cellular models for their studies. It describes for commonly used cell types the aspects of Parkinson's disease they model along with technical advantages and disadvantages. It might also be helpful for researchers from other fields consulting literature on cellular models of Parkinson's disease. Important models for the study of dopaminergic neuron degeneration include Lund human mesencephalic cells and primary neurons, and a case is made for the use of non-dopaminergic cells to model pathogenesis of non-motor symptoms of Parkinson's disease. With regard to α-synuclein aggregates, this article describes strategies to induce and measure aggregates with a focus on fluorescent techniques. Cellular models reproduce the two most salient changes of Parkinson's disease, the degeneration of dopaminergic neurons and the existence of α-synuclein aggregates. This article is intended for researchers planning to use cellular models for their studies. It describes for commonly used cell types and treatments the aspects of Parkinson's disease they model along with technical advantages and disadvantages. Furthermore, this article describes strategies to induce and measure aggregates with a focus on fluorescent techniques. This article is part of a special issue on Parkinson disease.

  20. Evaluation of different graft material in type 1 tympanoplasty

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    Kshitij Patil

    2014-01-01

    Full Text Available Aims and Objective: The present study was undertaken to compare the results of various autogeneous tissues temporalis fascia, tragal perichondrium, and fascia lata as graft materials for the type 1 tympanoplasty. Materials and Methods: A total of 120 cases with large, subtotal and total perforation were considered in the study. Of the 120 cases, temporalis fascia graft was used in 60 cases (Group-I, tragal perichondrium graft in 40 cases (Group-II, and fascia lata graft in 20 cases (Group-III. The results were evaluated in the form of rate of graft success, hearing gain, and mean residual air-bone gap with respect to the graft materials. Results and Observation: A nonsignificant association was observed between the groups, that is, temporalis fascia (Group-I, tragal perichondrium (Group-II, and fascia lata (Group-III and the graft uptake. (P = 0.96 > 0.05 and air bone closure (χ2 = 2.908, P = 0.059 > 0.05. Conclusion: The graft take-up rate and Hearing improvement are similar for the different graft materials used. Size of the perforation doesn′t significantly influence the success rate of tympanoplasty as per our study. Normal translucent appearance of neotympanum in the postoperative period was seen only with temporalis fascia, while in tragal perichondrial and fascia lata grafts the neotympanum was whitish, thicker, and translucent to opaque.

  1. Progression from stenosis to occlusion in the proximal native coronary artery after coronary artery bypass grafting.

    Science.gov (United States)

    Tanaka, Akihito; Ishii, Hideki; Oshima, Hideki; Shibata, Yohei; Tatami, Yosuke; Osugi, Naohiro; Ota, Tomoyuki; Kawamura, Yoshihiro; Suzuki, Susumu; Usui, Akihiko; Murohara, Toyoaki

    2016-07-01

    Coronary artery bypass grafting (CABG) is an established treatment for multivessel coronary artery disease. However, problematic situations are occasionally encountered after CABG, such as disease progression in the native coronary artery with graft occlusion, which causes difficulty in revascularization. The purpose of this study was to evaluate changes in the native coronary artery after CABG. Between 2009 and 2012 in our institution, 351 patients underwent CABG, and 768 bypass grafts were anastomosed to non-occluded coronary arteries. Of these, 489 bypass grafts had available early postoperative angiographic results (≤6 months) suitable for assessment in this study. We defined malignant graft failure after CABG to be bypass graft occlusion and de novo complete occlusion of the target native coronary artery proximal to the graft anastomosis site. In the early angiographic results, 17 grafts were occluded (17/489; 3.5 %). Two of the grafts displayed malignant graft failure (a saphenous vein graft to the right coronary artery and a saphenous vein graft to the diagonal branch) (2 of 17 occluded grafts, and 2 of 489 studied grafts). Of the patent bypass grafts, 24 involved progression to occlusion in the proximal native coronary artery (19 saphenous vein grafts, 4 left internal thoracic artery grafts, and 1 right internal thoracic artery graft). Malignant graft failure was uncommon during short-term follow-up after CABG. At the same time, disease progression in the proximal native coronary artery from stenosis to occlusion following patent bypass grafting was relatively common, especially for vein grafts.

  2. Dynamic, nondestructive imaging of a bioengineered vascular graft endothelium.

    Directory of Open Access Journals (Sweden)

    Bryce M Whited

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  4. Block and Graft Copolymers of Polyhydroxyalkanoates

    Science.gov (United States)

    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.

  5. Patient's Perception About Coronary Artery Bypass Grafting

    Directory of Open Access Journals (Sweden)

    Kelminda Maria Bulhões Mendonça

    2015-10-01

    Full Text Available ABSTRACT OBJECTIVE: The diagnosis of coronary artery disease referred for heart surgery has an important psychological component. The purpose of this study was to access the difficulties experienced by individuals awaiting coronary artery bypass grafting and to determine strategies that facilitate adaptation to a new lifestyle, modified by the disease. METHODS: A qualitative, exploratory study involving patients admitted to a university teaching hospital in the city of Salvador, Bahia, Brazil, awaiting coronary artery bypass grafting. Semi-structured interviews were performed in accordance with a previously defined script based on the study objective. Each transcription was read in its entirety to verify the representativeness, homogeneity and pertinence of the data obtained (pre-analysis, followed by separation of categories of analysis. RESULTS: The descriptions of this study show that patients admitted to the completion of coronary artery bypass grafting experience a wide range of psychological difficulties, considering that surgery acquires interpretations that vary according to individuals' subjectivity. The patients recognized the benefit of being able to discuss their feelings as a means of diminishing their fear and anxiety. CONCLUSION: Helping patients find resources to confront more positively the daily hospitalization is an important aspect for the health care professionals who assist them. This goal can be achieved through modification of the biomedical model of care for a biopsychosocial view. The investment of time and attention is of fundamental importance and aims to overcome existing deficiencies that interfere with the outcome of patients after cardiac surgery.

  6. Grafting of protein-protein binding sites

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A strategy for grafting protein-protein binding sites is described. Firstly, key interaction residues at the interface of ligand protein to be grafted are identified and suitable positions in scaffold protein for grafting these key residues are sought. Secondly, the scaffold proteins are superposed onto the ligand protein based on the corresponding Ca and Cb atoms. The complementarity between the scaffold protein and the receptor protein is evaluated and only matches with high score are accepted. The relative position between scaffold and receptor proteins is adjusted so that the interface has a reasonable packing density. Then the scaffold protein is mutated to corresponding residues in ligand protein at each candidate position. And the residues having bad steric contacts with the receptor proteins, or buried charged residues not involved in the formation of any salt bridge are mutated. Finally, the mutated scaffold protein in complex with receptor protein is co-minimized by Charmm. In addition, we deduce a scoring function to evaluate the affinity between mutated scaffold protein and receptor protein by statistical analysis of rigid binding data sets.

  7. A Patient with Recurrent Arteriovenous Graft Thrombosis.

    Science.gov (United States)

    Allon, Michael

    2015-12-01

    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.

  8. Fat graft myringoplasty in small central perforations

    Directory of Open Access Journals (Sweden)

    Chandni Sharma

    2014-01-01

    Full Text Available Background: Perforations of the tympanic membrane (TM are treated with various surgical techniques and materials. Although autologous temporalis fascia is the most common material used for the closure of TM perforations, however for a dry, small central perforation the fat graft myringoplasty (FM is a good alternative as it is a simple and cost-effective technique. Objectives: The aim of this study was to determine the efficacy of FM for repair of small central perforations. Suggestions for optimizing the outcome of FM are presented. Material and Methods: Twenty patients (10 males and 10 females who had uncomplicated dry small central perforation, which was confined to one quadrant of the pars tensa underwent FM. The outcome was evaluated after 1-week, 1-month, and 3 months. Results: After 3 months of follow-up, a closure rate of 80% was achieved. Mean preoperative air-bone (AB gap was 22.90 ± 6.54 dB and mean postoperative AB gap was 21.80 ± 6.28 dB. Mean improvement in AB gap postoperatively was 1.1 ± 2.63 dB. Conclusion: Fat graft myringoplasty, with its ease of technique and good graft uptake rate justifies its use in the closure of small dry central TM perforations.

  9. Transabdominal sacrocolpopexy with autologous rectus fascia graft.

    Science.gov (United States)

    Abraham, Nitya; Quirouet, Adrienne; Goldman, Howard B

    2016-08-01

    Extrusion and infection are potential postoperative complications when using synthetic mesh for abdominal sacrocolpopexy. Long-term follow-up in the Colpopexy and Urinary Reduction Efforts (CARE) trial revealed an estimated 9.9 % risk of mesh extrusion. There are 26 reports of spondylodiscitis after sacrocolpopexy with synthetic mesh. These surgical risks may be decreased by using autologous fascia. To date, there have been no reports of extrusion or spondylodiscitis after using autologous fascia for sacrocolpopexy. This video demonstrates transabdominal sacrocolpopexy with an autologous rectus fascia graft. A 76-year-old woman with symptomatic stage 3 prolapse also had a history of diverticulitis and sigmoid abscess requiring sigmoid colectomy with end colostomy and incidental left ureteral transection with subsequent left nephrostomy tube placement. She presented for colostomy reversal, ureteral reimplantation, and prolapse repair. Given the need for concomitant colon and ureteral reconstruction, the risk of infection was potentially higher if synthetic mesh were used. The patient therefore underwent transabdominal sacrocolpopexy with autologous rectus fascia graft. At 4 months' follow-up the patient reported resolution of her symptoms and on examination she had no pelvic organ prolapse. Transabdominal sacrocolpopexy using autologous rectus fascia graft is a feasible option, especially in cases in which infection and synthetic mesh extrusion risks are potentially higher.

  10. Cellular uptake of metallated cobalamins

    DEFF Research Database (Denmark)

    Tran, Mai Thanh Quynh; Stürup, Stefan; Lambert, Ian Henry

    2016-01-01

    Cellular uptake of vitamin B12-cisplatin conjugates was estimated via detection of their metal constituents (Co, Pt, and Re) by inductively coupled plasma mass spectrometry (ICP-MS). Vitamin B12 (cyano-cob(iii)alamin) and aquo-cob(iii)alamin [Cbl-OH2](+), which differ in the β-axial ligands (CN......(-) and H2O, respectively), were included as control samples. The results indicated that B12 derivatives delivered cisplatin to both cellular cytosol and nuclei with an efficiency of one third compared to the uptake of free cisplatin cis-[Pt(II)Cl2(NH3)2]. In addition, uptake of charged B12 derivatives...

  11. Cellular basis of Alzheimer's disease.

    Science.gov (United States)

    Bali, Jitin; Halima, Saoussen Ben; Felmy, Boas; Goodger, Zoe; Zurbriggen, Sebastian; Rajendran, Lawrence

    2010-12-01

    Alzheimer's disease (AD) is the most common form of neurodegenerative disease. A characteristic feature of the disease is the presence of amyloid-β (Aβ) which either in its soluble oligomeric form or in the plaque-associated form is causally linked to neurodegeneration. Aβ peptide is liberated from the membrane-spanning -amyloid precursor protein by sequential proteolytic processing employing β- and γ-secretases. All these proteins involved in the production of Aβ peptide are membrane associated and hence, membrane trafficking and cellular compartmentalization play important roles. In this review, we summarize the key cellular events that lead to the progression of AD.

  12. Delivery of antisense oligonucleotides using poly(alkylene oxide)-poly(propylacrylic acid) graft copolymers in conjunction with cationic liposomes.

    Science.gov (United States)

    Peddada, Lavanya Y; Garbuzenko, Olga B; Devore, David I; Minko, Tamara; Roth, Charles M

    2014-11-28

    The clinical application of gene silencing is hindered by poor stability and low delivery efficiency of naked oligonucleotides. Here, we present the in vitro and in vivo behaviors of a rationally designed, ternary, self-assembled nanoparticle complex, consisting of an anionic copolymer, cationic DOTAP liposome, and antisense oligonucleotide (AON). The multifunctional copolymers are based on backbone poly(propylacrylic acid) (PPAA), a pH-sensitive hydrophobic polymer, with grafted poly(alkylene oxides) (PAOs) varying in extent of grafting and PAO chemistry. The nanoparticle complexes with PPAA-g-PAO copolymers enhance antisense gene silencing effects in A2780 human ovarian cancer cells. A greater amount of AON is delivered to ovarian tumor xenografts using the ternary copolymer-stabilized delivery system, compared to a binary DOTAP/AON complex, following intraperitoneal injection in mice. Further, intratumoral injection of the nanoparticle complexes containing 1 mol% grafted PAO reduced tumoral bcl-2 expression by up to 60%. The data for complexes across the set of PAO polymers support a strong role for the hydrophilic-lipophilic balance of the graft copolymer in achieving serum stability and cellular uptake. Based upon these results, we anticipate that this novel nanoparticle delivery system can be extended to the delivery of plasmid DNA, siRNA, or aptamers for preclinical and clinical development. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Construction and biofunctional evaluation of electrospun vascular graft loaded with selenocystamine for in situ catalytic generation of nitric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Siyuan; An, Jun; Weng, Lei [State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials for Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China); Li, Yandong [Institute of Polymer Chemistry, College of Chemistry, Nankai University, Tianjin 300071 (China); Xu, Han; Wang, Yaping; Ding, Dan; Kong, Deling [State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials for Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China); Wang, Shufang, E-mail: wangshufang@nankai.edu.cn [State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials for Ministry of Education, College of Life Sciences, Nankai University, Tianjin 300071 (China)

    2014-12-01

    Construction and biofunctional evaluation of a novel vascular graft with in situ catalytic generation of nitric oxide were described in this paper. Poly α-lysine and poly (γ-glutamic acid) were deposited alternately onto the surface of an electrospun poly ε-caprolactone matrix via electrostatic layer-by-layer self-assembly, and then selenocystamine was loaded as a catalyst. Measurement of in vitro catalytic generation of nitric oxide demonstrated that this catalyst-loaded material could considerably accelerate the release of nitric oxide from S-nitrosoglutathione. A fibroblast proliferation assay showed that the material possessed satisfactory cellular compatibility. The catalyst-loaded material could inhibit the spread of smooth muscle cells in the presence of nitric oxide donors. In arteriovenous-shunt experiment, the catalyst-loaded graft exhibited good anti-thrombotic property where it could prevent acute thrombosis by decreasing the adhesion and activation of platelets and other blood cells. These data suggest a new method of building vascular grafts with improved hemocompatibility and biological functions. - Highlights: • A porous small-diameter vascular graft was prepared by electrospinning. • Selenocystamine was loaded for in situ catalytic and sustained NO generation. • There was a significant catalytic NO generation on the catalyst-loaded sample. • The spread of smooth muscle cells was inhibited on the catalyst-loaded sample. • The catalyst-loaded sample showed anti-thrombotic property in AV-shunt experiment.

  14. Mycophenolate mofetil toxicity mimicking acute cellular rejection in a small intestinal transplant

    Science.gov (United States)

    Apostolov, Ross; Asadi, Khashayar; Lokan, Julie; Kam, Ning; Testro, Adam

    2017-01-01

    Mycophenolate mofetil (MMF) is an important medication used for maintenance immunosuppression in solid organ transplants. A common gastrointestinal (GI) side effect of MMF is enterocolitis, which has been associated with multiple histological features. There is little data in the literature describing the histological effects of MMF in small intestinal transplant (SIT) recipients. We present a case of MMF toxicity in a SIT recipient, with histological changes in the donor ileum mimicking persistent acute cellular rejection (ACR). Concurrent biopsies of the patient’s native colon showed similar changes to those from the donor small bowel, suggesting a non-graft specific process, raising suspicion for MMF toxicity. The MMF was discontinued and complete resolution of these changes occurred over three weeks. MMF toxicity should therefore be considered as a differential diagnosis for ACR and graft-versus-host disease in SITs. PMID:28280702

  15. The Palatal Bone Block Graft for Onlay Grafting Combined with Maxillary Implant Placement: A Case Series.

    Science.gov (United States)

    Gluckman, Howard; Du Toit, Jonathan; Salama, Maurice

    2016-01-01

    The aim of this study was to introduce an intraoral bone block harvesting technique--the palatal bone block graft (PBBG)--as an alternative harvest site for autogenous bone blocks. The PBBG technique was used to onlay graft esthetic zone defects simultaneous to implant placement in five patients. Measurable objectives were used to evaluate outcomes, and treatment was reassessed at up to 6 years. Defects of the maxilla were successfully grafted with PBBG in all five cases, and tissues remained stable at 1- and 6-year follow-ups. Harvesting an autogenous bone block from the palate is an advantageous, predictable, and reproducible method for augmenting buccofacial defects at implant placement, and may be considered as an alternative to conventional intraoral bone block donor sites when treating the maxilla.

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

    Science.gov (United States)

    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.

  17. Tuning the Mechanical Properties of Polymer Nanocomposites Filled with Grafted Nanoparticles by Varying the Grafted Chain Length and Flexibility

    Directory of Open Access Journals (Sweden)

    Zixuan Wang

    2016-08-01

    Full Text Available By employing coarse-grained molecular dynamics simulation, we simulate the spatial organization of the polymer-grafted nanoparticles (NPs in homopolymer matrix and the resulting mechanical performance, by particularly regulating the grafted chain length and flexibility. The morphologies ranging from the agglomerate, cylinder, sheet, and string to full dispersion are observed, by gradually increasing the grafted chain length. The radial distribution function and the total interaction energy between NPs are calculated. Meanwhile, the stress–strain behavior of each morphology and the morphological evolution during the uniaxial tension are simulated. In particular, the sheet structure exhibits the best mechanical reinforcement compared to other morphologies. In addition, the change of the grafted chain flexibility to semi-flexibility leads to the variation of the morphology. We also find that at long grafted chain length, the stress–strain behavior of the system with the semi-flexible grafted chain begins to exceed that of the system with the flexible grafted chain, attributed to the physical inter-locking interaction between the matrix and grafted polymer chains. A similar transition trend is as well found in the presence of the interfacial chemical couplings between grafted and matrix polymer chains. In general, this work is expected to help to design and fabricate high performance polymer nanocomposites filled with grafted NPs with excellent and controllable mechanical properties.

  18. Study of two grafting methods for obtaining a 3-aminopropyltriethoxysilane monolayer on silica surface.

    Science.gov (United States)

    Simon, A; Cohen-Bouhacina, T; Porté, M C; Aimé, J P; Baquey, C

    2002-07-15

    In order to establish a 3-aminopropyltriethoxysilane (APTES) grafting procedure with limited number of APTESs noncovalently linked to the silica surface, two different methods of grafting (in acid-aqueous solution and in anhydrous solution) were compared. The grafted surface state was investigated by atomic force microscopy (AFM). The stability of the grafting was checked at different temperatures by AFM. Continuous and plane APTES grafted surfaces were successfully prepared using both grafting preparations. The grafting in an anhydrous solution behaves homogeneously and stably compared to the grafting in an acid-aqueous solution. Moreover, with anhydrous solution, results showed that a unique monolayer of APTES was grafted.

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

    Science.gov (United States)

    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 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.

  20. Control of Grafting Density and Distribution in Graft Polymers by Living Ring-Opening Metathesis Copolymerization.

    Science.gov (United States)

    Lin, Tzu-Pin; Chang, Alice B; Chen, Hsiang-Yun; Liberman-Martin, Allegra L; Bates, Christopher M; Voegtle, Matthew J; Bauer, Christina A; Grubbs, Robert H

    2017-03-15

    Control over polymer sequence and architecture is crucial to both understanding structure-property relationships and designing functional materials. In pursuit of these goals, we developed a new synthetic approach that enables facile manipulation of the density and distribution of grafts in polymers via living ring-opening metathesis polymerization (ROMP). Discrete endo,exo-norbornenyl dialkylesters (dimethyl DME, diethyl DEE, di-n-butyl DBE) were strategically designed to copolymerize with a norbornene-functionalized polystyrene (PS), polylactide (PLA), or polydimethylsiloxane (PDMS) macromonomer mediated by the third-generation metathesis catalyst (G3). The small-molecule diesters act as diluents that increase the average distance between grafted side chains, generating polymers with variable grafting density. The grafting density (number of side chains/number of norbornene backbone repeats) could be straightforwardly controlled by the macromonomer/diluent feed ratio. To gain insight into the copolymer sequence and architecture, self-propagation and cross-propagation rate constants were determined according to a terminal copolymerization model. These kinetic analyses suggest that copolymerizing a macromonomer/diluent pair with evenly matched self-propagation rate constants favors randomly distributed side chains. As the disparity between macromonomer and diluent homopolymerization rates increases, the reactivity ratios depart from unity, leading to an increase in gradient tendency. To demonstrate the effectiveness of our method, an array of monodisperse polymers (PLA(x)-ran-DME(1-x))n bearing variable grafting densities (x = 1.0, 0.75, 0.5, 0.25) and total backbone degrees of polymerization (n = 167, 133, 100, 67, 33) were synthesized. The approach disclosed in this work therefore constitutes a powerful strategy for the synthesis of polymers spanning the linear-to-bottlebrush regimes with controlled grafting density and side chain distribution, molecular

  1. Passive graft perfusion in off-pump coronary artery bypass grafting

    Institute of Scientific and Technical Information of China (English)

    LU Feng; JI Bing-yang; LIU Jin-ping; LIU Ming-zheng; WANG Gu-yan; HU Sheng-shou

    2007-01-01

    Background Myocardial protection during off-pump coronary artery bypass grafting (OPCABG) is a multifactorial problem in which maintaining stable systemic hemodynamics is very important. In this study passive graft perfusion (PGP) was applied to investigate the effect during and after OPCABG as evaluated by cardiac troponin I (CTnl) and hemodynamic indexes.Methods Thirty first-time patients underwent OPCABG under one surgeon. They were randomly divided into two groups: The passive graft perfusion group (PGP, n=15) received distal coronary perfusion during the anastomosis and immediate graft perfusion after the distal anastomosis. The control group, no graft perfusion group, (NGP, n=15)received no graft perfusion after the distal anastomosis. The results of the two protocols were evaluated by concentration of CTnl and hemodynamic indexes before induction and after operation.Results There were no statistically significant differences between these two groups in their perioperation parameters.The level of CTnl increased postoperatively, reached its peak at 6 hours (P<0.05) and recovered by the 6 days postoperative. Compared with the control group the concentration of CTnl in the PGP group was significantly lower at 6 and 24 hours (P<0.01). Compared with the NGP group, cardiac index (Cl) in the PGP group was higher at 12 and 24 hours after operation (P<0.05). The period of mechanical ventilation was significantly shorter in the PGP group than in the NGP group (P<0.05).Conclusion PGP can increase the flow to the myocardium and shorten the heart ischemia time, thus maintain stable systemic hemodynamics, supply a satisfactory Cl after surgery and improve surgery outcome.

  2. The Articulated Alar Rim Graft: Reengineering the Conventional Alar Rim Graft for Improved Contour and Support.

    Science.gov (United States)

    Ballin, Annelyse C; Kim, Haena; Chance, Elizabeth; Davis, Richard E

    2016-08-01

    Surgical refinement of the wide nasal tip is challenging. Achieving an attractive, slender, and functional tip complex without destabilizing the lower nasal sidewall or deforming the contracture-prone alar rim is a formidable task. Excisional refinement techniques that rely upon incremental weakening of wide lower lateral cartilages (LLC) often destabilize the tip complex and distort tip contour. Initial destabilization of the LLC is usually further exacerbated by "shrink-wrap" contracture, which often leads to progressive cephalic retraction of the alar margin. The result is a misshapen tip complex accentuated by a conspicuous and highly objectionable nostril deformity that is often very difficult to treat. The "articulated" alar rim graft (AARG) is a modification of the conventional rim graft that improves treatment of secondary alar rim deformities, including postsurgical alar retraction (PSAR). Unlike the conventional alar rim graft, the AARG is sutured to the underlying tip complex to provide direct stationary support to the alar margin, thereby enhancing graft efficacy. When used in conjunction with a well-designed septal extension graft (SEG) to stabilize the central tip complex, lateral crural tensioning (LCT) to tighten the lower nasal sidewalls and minimize soft-tissue laxity, and lysis of scar adhesions to unfurl the retracted and scarred nasal lining, the AARG can eliminate PSAR in a majority of patients. The AARG is also highly effective for prophylaxis against alar retraction and in the treatment of most other contour abnormalities involving the alar margin. Moreover, the AARG requires comparatively little graft material, and complications are rare. We present a retrospective series of 47 consecutive patients treated with the triad of AARG, SEG, and LCT for prophylaxis and/or treatment of alar rim deformities. Outcomes were favorable in nearly all patients, and no complications were observed. We conclude the AARG is a simple and effective method for

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Aydinli, Bahattin; Tincer, Teoman E-mail: teotin@metu.edu.tr

    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{sup 2+} or Cu{sup 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. (author)

  5. Redox control of cellular signalling

    NARCIS (Netherlands)

    Putker, M.

    2014-01-01

    Reactive oxygen species (ROS) are natural by-products of cellular energy production. Consequently, mammalian cells encounter them on a daily basis. Increased ROS levels are associated with the onset of cancer and accelerated ageing, and historically, ROS are therefore considered harmful molecules.

  6. On Cellular MIMO Channel Capacity

    Science.gov (United States)

    Adachi, Koichi; Adachi, Fumiyuki; Nakagawa, Masao

    To increase the transmission rate without bandwidth expansion, the multiple-input multiple-output (MIMO) technique has recently been attracting much attention. The MIMO channel capacity in a cellular system is affected by the interference from neighboring co-channel cells. In this paper, we introduce the cellular channel capacity and evaluate its outage capacity, taking into account the frequency-reuse factor, path loss exponent, standard deviation of shadowing loss, and transmission power of a base station (BS). Furthermore, we compare the cellular MIMO downlink channel capacity with those of other multi-antenna transmission techniques such as single-input multiple-output (SIMO) and space-time block coded multiple-input single-output (STBC-MISO). We show that the optimum frequency-reuse factor F that maximizes 10%-outage capacity is 3 and both 50%- and 90%-outage capacities is 1 irrespective of the type of multi-antenna transmission technique, where q%-outage capacity is defined as the channel capacity that gives an outage probability of q%. We also show that the cellular MIMO channel capacity is always higher than those of SIMO and STBC-MISO.

  7. Cellular uptake of metallated cobalamins

    DEFF Research Database (Denmark)

    Tran, MQT; Stürup, Stefan; Lambert, Ian H.;

    2016-01-01

    Cellular uptake of vitamin B12-cisplatin conjugates was estimated via detection of their metal constituents (Co, Pt, and Re) by inductively coupled plasma mass spectrometry (ICP-MS). Vitamin B12 (cyano-cob(iii)alamin) and aquo-cob(iii)alamin [Cbl-OH2](+), which differ in the β-axial ligands (CN(-...

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

    Science.gov (United States)

    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.

  9. [Intraoperative graft assessment using fluorescent imaging system (SPY)].

    Science.gov (United States)

    Kawashima, T; Naraoka, S; Kakizaki, T

    2009-07-01

    We investigated the efficacy of intraoperative fluorescent imaging system for the assessment of coronary artery bypass grafting (CABG). We used SPY imaging system in 100 CABG (57 off-pump and 43 on-pump CABG), totalling 287 distal anastomoses. The total graft patency rate on postoperative angiography in this series was 96.2% (276/287). Graft revision was done in 10 cases (10.0%) and 13 anastomoses (4.5%) by SPY imaging, which all resulted in good patency at postoperative angiography. On the other hand, 7 distal anastomoses and 1 mammary graft (2.8%) appeared to be successful on intraoperative SPY imaging, but were revealed to be occluded by postoperative angiography. SPY imaging system is useful for graft validation, and may contribute to improvement of coronary bypass graft patency.

  10. Full-thickness skin grafting in nasal reconstruction.

    Science.gov (United States)

    Weathers, William M; Bhadkamkar, Mohin; Wolfswinkel, Erik M; Thornton, James F

    2013-05-01

    Skin grafting in nasal reconstruction, long used by dermatologists, can provide superior results and can well be the "go to" procedure for nasal reconstruction. The upper two-thirds of the nose is composed of both flattened, featureless and often thin skin that is well recreated with defect-only full-thickness grafting. Skin grafting for the lower third of the nose has been practiced for years by dermatologists; over the last 4 to 5 years, it has been embraced by plastic surgeons. The patient and donor site selection is critical. Meticulous attention to graft selection, utilization of a no-touch technique during graft harvest and placement of surgical bolsters with through-and-through tacking sutures are essential to ensure 100% graft take and a successful aesthetic result.

  11. Quantifying Long-term Retention of Excised Fat Grafts

    DEFF Research Database (Denmark)

    bxg165, bxg165; Ørholt, Mathias; Glovinski, Peter V.

    2017-01-01

    Background: Predicting the degree of fat graft retention is essential whenplanning reconstruction or augmentation with free fat grafting. Most surgeonsobserve volume loss over time after fat grafting; however, the portion lost toresorption after surgery is still poorly defined, and the time...... to reach steadystate is unknown. Methods: The authors compiled a retrospective, longitudinal cohort of patientswith vestibular schwannoma who had undergone ablative surgery and reconstructionwith excised fat between the years 2006 and 2015. Fat volume retentionwas quantified by computed tomography....... The average baseline graft volumewas 18.1 ± 4.8 ml. The average time to reach steady state was 806 days aftertransplantation. By this time, the average fat graft retention was 50.6 percent(95 percent CI, 46.4 to 54.7 percent). No statistically significant association wasfound between baseline graft volume...

  12. Post-radiation grafting of styrene to polyethylene film and distribution of grafted polystyrene in it

    Energy Technology Data Exchange (ETDEWEB)

    Shevlyakova, N.V.; D' yakova, M.G.; Luzina, N.N.; Semenov, V.I.; Shifrina, R.R.; Tverskoj, V.A.; Pravednikov, A.N.

    1987-02-01

    The post-radiation grafting of styrene to polyethylene (PE) film irradiated in air with WCo source (dose rate 520 R/s) and electron accelerator (dose rate 1.5x10V R/s) has been studied, in the range 1-100 Mrad. The influence of additives of ferrous salts on kinetics of this process is shown. The distribution of grafted polystyrene in PE for various power and dose of irradiation has been analysed basing on IR spectra. The essential role of diffusion of iron ions into the film volume on kinetics of the process and polystyrene distribution is concluded.

  13. Resorption of bone graft after maxillary sinus grafting and simultaneous implant placement

    OpenAIRE

    Kim, Young-Kyun; Kim, Su-Gwan; Kim, Bum-Su; Jeong, Kyung-In

    2014-01-01

    Objectives The purpose of this study was to evaluate the sinus bone graft resorption over 3 years after two-stage implant placement. Materials and Methods The subjects for this study included 30 patients whose maxillary posterior ridges were too atrophic for implants. Bone-added osteotome sinus floor elevation was used in 15 maxillary sinuses, while the bone graft by lateral approach technique was used in 25 maxillary sinuses. The height from the top of the fixture to the sinus floor was esti...

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

    Science.gov (United States)

    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...

  15. Coupled cellular therapy and magnetic targeting for airway regeneration.

    Science.gov (United States)

    Ordidge, Katherine L; Gregori, Maria; Kalber, Tammy L; Lythgoe, Mark F; Janes, Sam M; Giangreco, Adam

    2014-06-01

    Airway diseases including COPD (chronic obstructive pulmonary disease), cystic fibrosis and lung cancer are leading causes of worldwide morbidity and mortality, with annual healthcare costs of billions of pounds. True regeneration of damaged airways offers the possibility of restoring lung function and protecting against airway transformation. Recently, advances in tissue engineering have allowed the development of cadaveric and biosynthetic airway grafts. Although these have produced encouraging results, the ability to achieve long-term functional airway regeneration remains a major challenge. To promote regeneration, exogenously delivered stem and progenitor cells are being trialled as cellular therapies. Unfortunately, current evidence suggests that only small numbers of exogenously delivered stem cells engraft within lungs, thereby limiting their utility for airway repair. In other organ systems, magnetic targeting has shown promise for improving long-term robust cell engraftment. This technique involves in vitro cell expansion, magnetic actuation and magnetically guided cell engraftment to sites of tissue damage. In the present paper, we discuss the utility of coupling stem cell-mediated cellular therapy with magnetic targeting for improving airway regeneration.

  16. Stent-graft repair of carotid endarterectomy-related pseudoaneurysm

    Institute of Scientific and Technical Information of China (English)

    Manuela Carnini; Gabriele Piffaretti; Chiara Lomazzi

    2013-01-01

    Objective: Carotid endarterectomy-related pseudoaneurysms are rare lesions challenging to be treated with conventional open surgery. Endovascular stent-graft has been rarely adopted with encouraging results. We present a case of a huge carotid pseudoaneurysm treated with a stent-graft and managed with a stent-graft and reviewed the available literature on the management and results of this technique for these challenging lesions.

  17. Successful Treatment of Secondary Aortoenteric Fistula with a Special Graft

    OpenAIRE

    Ömer Faruk Çiçek; Mustafa Cüneyt Çiçek; Ersin Kadiroğulları; Alper Uzun; Mahmut Ulaş

    2016-01-01

    Aortoenteric fistula is an uncommon but life-threatening cause of gastrointestinal blood loss. We report a case of a 70-year-old man who presented to the emergency department with an episode of melena and infection in the left inguinal region. Diagnosis of secondary aortoenteric fistula was made between the left limb of the aortobifemoral graft and the descending colon. We performed excision of the infected graft and in situ silver acetate coating of prosthetic vascular graft replacement (aor...

  18. Living donor liver transplantation using dual grafts:Ultrasonographic evaluation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM: To evaluate the dual-graft living donor liver transplantation (LDLT) with ultrasonography, with special emphasis on the postoperative complications. METHODS: From January 2002 to August 2007, 110 adult-to-adult LDLTs were performed in West China Hos- pital of Sichuan University. Among them, dual-graft implantations were performed in six patients. Sonographic findings of the patients were retrospectively reviewed. RESULTS: All the six recipients survived the dual-graft adult-to-adult LDLT surgery. All h...

  19. Preparation of thermo-responsive graft copolymer by using a novel macro-RAFT agent and its application for drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Song, Cunfeng; Yu, Shirong [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Liu, Cheng; Deng, Yuanming; Xu, Yiting [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Fujian Provincial Key Laboratory of Fire Retardant Materials, Xiamen University, Xiamen 361005 (China); Chen, Xiaoling, E-mail: tinachen0628@163.com [Department of Endodontics, Xiamen Stomatology Hospital, Teaching Hospital of Fujian Medical University, Xiamen 361003 (China); Dai, Lizong, E-mail: lzdai@xmu.edu.cn [Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005 (China); Fujian Provincial Key Laboratory of Fire Retardant Materials, Xiamen University, Xiamen 361005 (China)

    2016-05-01

    A methodology to prepare thermo-responsive graft copolymer by using a novel macro-RAFT agent was proposed. The macro-RAFT agent with pendant dithioester (ZC(S)SR) was facilely prepared via the combination of RAFT polymerization and esterification reaction. By means of ZC(S)SR-initiated RAFT polymerization, the thermo-responsive graft copolymer consisting of poly(methyl methacrylate-co-hydroxylethyl methacrylate) (P(MMA-co-HEMA)) backbone and hydrophilic poly(N-isopropylacrylamide) (PNIPAAm) side chains was constructed through the “grafting from” approach. The chemical compositions and molecular weight distributions of the synthesized polymers were respectively characterized by {sup 1}H nuclear magnetic resonance ({sup 1}H NMR) and gel permeation chromatography (GPC). Self-assembly behavior of the amphiphilic graft copolymers (P(MMA-co-HEMA)-g-PNIPAAm) was studied by transmission electron microscopy (TEM), dynamic light scattering (DLS) and spectrofluorimeter. The critical micelle concentration (CMC) value was 0.052 mg mL{sup −1}. These micelles have thermo-responsibility and a low critical solution temperature (LCST) of 33.5 °C. Further investigation indicated that the guest molecule release property of these micelles, which can be well described by a first-order kinetic model, was significantly affected by temperature. Besides, the micelles exhibited excellent biocompatibility and cellular uptake property. Hence, these micelles are considered to have potential application in controlled drug delivery. - Highlights: • A novel macro-RAFT agent with ZC(S)SR was used for preparing graft copolymer. • P(MMA-co-HEMA)-g-PNIPAAm was successful prepared via the “grafting from” approach. • Thermo-responsibility of the P(MMA-co-HEMA)-g-PNIPAAm micelles was investigated. • The drug release behavior of the P(MMA-co-HEMA)-g-PNIPAAm micelles was studied. • These micelles exhibited excellent biocompatibility and cellular uptake property.

  20. Reconstruction of neglected patellar tendon ruptures using the quadriceps graft.

    Science.gov (United States)

    Gomes, João Luiz Ellera; de Oliveira Alves, Jairo André; Zimmermann, José Mauro

    2014-08-01

    Several techniques using different grafts have been described for reconstruction of the patellar tendon after a neglected rupture. Retraction of the quadriceps tendon may compromise repair integrity due to progressive stretching of the graft. The authors present a surgical technique using the central one-third of the quadriceps tendon. This is supported by the fact that the resistance to traction of this segment of the quadriceps tendon equals that of a double-looped semitendinosus graft and that the harvesting of this specific graft promotes muscle inhibition, thus protecting the reconstruction during the recovery period.

  1. FREE GRAFT TWO-STAGE URETHROPLASTY FOR HYPOSPADIAS REPAIR

    Institute of Scientific and Technical Information of China (English)

    Zhong-jin Yue; Ling-jun Zuo; Jia-ji Wang; Gan-ping Zhong; Jian-ming Duan; Zhi-ping Wang; Da-shan Qin

    2005-01-01

    Objective To evaluate the effectiveness of free graft transplantation two-stage urethroplasty for hypospadias repair.Methods Fifty-eight cases with different types of hypospadias including 10 subcoronal, 36 penile shaft, 9 scrotal, and 3 perineal were treated with free full-thickness skin graft or (and) buccal mucosal graft transplantation two-stage urethroplasty. Of 58 cases, 45 were new cases, 13 had history of previous failed surgeries. Operative procedure included two stages: the first stage is to correct penile curvature (chordee), prepare transplanting bed, harvest and prepare full-thickness skin graft, buccal mucosal graft, and perform graft transplantation. The second stage is to complete urethroplasty and glanuloplasty.Results After the first stage operation, 56 of 58 cases (96.6%) were successful with grafts healing well, another 2foreskin grafts got gangrened. After the second stage operation on 56 cases, 5 cases failed with newly formed urethras opened due to infection, 8 cases had fistulas, 43 (76.8%) cases healed well.Conclusions Free graft transplantation two-stage urethroplasty for hypospadias repair is a kind of effective treatment with broad indication, comparatively high success rate, less complicationsand good cosmatic results, indicative of various types of hypospadias repair.

  2. Surface Grafting of Phenolic Resole onto LDPE Films

    Institute of Scientific and Technical Information of China (English)

    Jue CHENG; Yi ZHENG; Wan Tai YANG

    2006-01-01

    Low density polyethylene film surface-grafted phenolic resole was prepared by a sequential processes. Firstly, acrylic acid was grafted to the surface of low density polyethylene by photo-grafting. Secondly, the carboxylic groups in poly(acrylic acid) chains were transferred to sulfonic groups by the reaction of carboxylic groups with sulfanilic acid. Finally, a thin layer of phenolic resole was cured onto the surface of low density polyethylene. The grafting process was characterized by FTIR-ATR and gravimetric analysis. A possible model was proposed to interpret the experimental results.

  3. Structural Changes of Polyethylene Terephthalate Fibers Grafted by Acrylamide

    Institute of Scientific and Technical Information of China (English)

    施琴芬; 戴礼兴

    2003-01-01

    A group of grafted PET fibers with different graft yield are formed by grafiing acrylamide onto the PET main chains. The structure of grafted fibers are studied by scanning electronic microscope ( SEM ), infra-red spectrophotometer (IR), and differential scanning calorimetry( DSC ). At the same time, the moisture regain, dyeability, strength, and elongation at break of the samples are measured and their relations with structural changes are discussed. Compared with ungrafted fiber, shape of the fiber cross-section, IR characteristic absorption peaks, and melting behavior of the grafted fibers have been changed, causing the fiber dyeability and moisture regain to be increased, and mechanical properties to be changed.

  4. Chrysanthemum Cutting Productivity and Rooting Ability Are Improved by Grafting

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    2013-01-01

    Full Text Available Chrysanthemum has been commercially propagated by rooting of cuttings, whereas the quality will decline over multiple collections from a single plant. Therefore, we compared the vigour, rooting ability, and some physiological parameters between cuttings harvested from nongrafted “Jinba” (non-grafted cuttings with those collected from grafted “Jinba” plants onto Artemisia scoparia as a rootstock (grafted cuttings. The yield, length, node number, stem diameter, fresh weight, and dry weight of the grafted cuttings were superior to the non-grafted cuttings. Also grafted cuttings “Jinba” rooted 1 day earlier, but showing enhanced rooting quality including number, length, diameter, and dry weight of roots, where compared to the non-grafted. The physiological parameters that indicated contents of soluble protein, peroxidase activity, soluble sugar, and starch, ratios of soluble sugar/nitrogen ratio, and carbohydrate/nitrogen (C/N, as well as contents of indole-3-acetic acid (IAA and abscisic acid (ABA, and IAA/ABA ratio were significantly increased in the grafted cuttings. This suggested their important parts in mediating rooting ability. Results from this study showed that grafting improved productivity and rooting ability related to an altered physiology, which provide a means to meet the increasing demand.

  5. Nerve repair and cable grafting for facial paralysis.

    Science.gov (United States)

    Humphrey, Clinton D; Kriet, J David

    2008-05-01

    Facial nerve injury and facial paralysis are devastating for patients. Although imperfect, primary repair is currently the best option to restore facial nerve function. Cable, or interposition, nerve grafting is an acceptable alternative when primary repair is not possible. Several donor nerves are at the surgeon's disposal. Great auricular, sural, or medial and lateral antebrachial cutaneous nerves are all easily obtained. Both primary repair and interposition grafting typically result in better facial function than do other dynamic and static rehabilitation strategies. Proficient anastomotic technique and, when necessary, selection of an appropriate interposition graft will optimize patient outcomes. Promising research is under way that will enhance future nerve repair and grafting efforts.

  6. Eyebrow Reconstruction Using a Composite Skin Graft from Sideburns

    Directory of Open Access Journals (Sweden)

    Ken Matsuda, MD, PhD

    2015-01-01

    Full Text Available Summary: Wide resection of malignant skin tumors in the upper orbital region often results in soft-tissue defects involving the eyebrow. We used composite skin grafts from the area around the sideburns for 1-stage reconstruction of skin and eyebrow defects. The results were aesthetically satisfying because the hair and shape of these regions were similar to those of the original eyebrow, and donor-site closure was easy with inconspicuous scar. The survival of full-thickness skin graft area of composite grafts from sideburn facilitates revascularization of thicker hair follicles in the graft and allows safe, natural eyebrow reconstruction.

  7. R&D for graft adsorbents by radiation processing

    Science.gov (United States)

    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.

  8. Target-like pigmentation after minipunch grafting in stable vitiligo

    Directory of Open Access Journals (Sweden)

    Nelee Bisen

    2014-01-01

    Full Text Available Surgical treatment for vitiligo has been ever evolving. Each surgical modality has its own benefits and limitations. Miniature punch grafting is the most extensively performed surgery, which gives good results in stable vitiligo. Herein we report an unusual type of repigmentation observed after minipunch grafting in a patient of stable vitiligo, which resembled target-like lesions with a "perigraft halo" surrounding individual grafts. Such pigment spread occurred despite the use of 0.5 mm larger graft from the donor site.

  9. Cytocompatibility of amine functionalized carbon nanoparticles grafted on polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Žáková, Pavlína, E-mail: pavlina.zakova@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic); Slepičková Kasálková, Nikola [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic); Kolská, Zdeňka [Faculty of Science, J. E. Purkyně University, Ústí nad Labem (Czech Republic); Leitner, Jindřich [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic); Karpíšková, Jana; Stibor, Ivan [Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec (Czech Republic); Slepička, Petr; Švorčík, Václav [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic)

    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. - Highlights: • Amine functionalized CNPs were successfully grafted on HDPE surface. • Significant change to the positive zeta potential for grafted CNPs was induced. • Grafting of CNPs significantly enhanced cell cytocompatibility and viability. • Homogeneous distribution of cells with correct size was achieved.

  10. PVDF multifilament yarns grafted with polystyrene induced by γ-irradition: Influence of the grafting parameters on the mechanical properties

    Science.gov (United States)

    Marmey, P.; Porté, M. C.; Baquey, Ch.

    2003-08-01

    The development of alternative prosthetic materials for cardiovascular applications has found growing interest due to the failure to date to be able to implement functional patent small diameter vascular grafts (∅polystyrene onto the PVDF surface by γ irradiation. The purpose of this study was to evaluate the influence of grafting parameters on the mechanical properties: (i) γ-ray irradiation time and (ii) grafting time of styrene monomers, which polymerize and form polystyrene bound to the PVDF surface.

  11. MRI of double-bundle ACL reconstruction: evaluation of graft findings

    Energy Technology Data Exchange (ETDEWEB)

    Kiekara, Tommi; Paakkala, Antti [Tampere University Hospital, Medical Imaging Centre, Tampere (Finland); Jaervelae, Timo [Sports Clinic and Hospital Mehilaeinen, Tampere (Finland); Huhtala, Heini [University of Tampere, School of Health Sciences, Tampere (Finland)

    2012-07-15

    To demonstrate the magnetic resonance imaging (MRI) findings of double-bundle (DB) anterior cruciate ligament (ACL) reconstruction grafts. Sixty-six patients with DB ACL reconstruction were evaluated with MRI 2 years postoperatively. Graft thickness was measured separately by two musculoskeletal radiologists. The MRI findings of graft disruption, signal intensity (SI) changes, cystic degeneration, arthrofibrosis, and impingement were analyzed. The statistical significance of the association between MRI findings was calculated. The mean anteromedial (AM) graft thickness was reduced 9% and the mean posterolateral (PL) graft thickness was reduced 18% from the original graft thickness. Disruption was seen in 3% of AM grafts and 6% of PL grafts and a partial tear in 8 and 23%, respectively. Both grafts were disrupted in 3% of patients. Increased SI was seen in 14% of intact AM grafts and in 60% of partially torn AM grafts (p = 0.032). In PL grafts the increased SI was seen in 51% of the intact grafts and in 93% of the partially torn grafts (p = 0.005). Cystic degeneration was seen in 8% of AM grafts and in 5% of PL grafts. Diffuse arthrofibrosis was seen in 5% of patients and a localized cyclops lesion in 3% of patients. Impingement of the AM graft was seen in 8% of patients. Both grafts were disrupted in 3% of patients. Also, the frequencies of other complications were low. The use of orthogonal sequences in the evaluation of the PL graft SI seems to cause volume-averaging artefacts. (orig.)

  12. Insitu grafting silica nanoparticles reinforced nanocomposite hydrogels

    Science.gov (United States)

    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

  13. Graftpolyrotaxane: Graft polymer possessing movable graft chains on cyclodextrins as the polyrotaxane wheels

    Energy Technology Data Exchange (ETDEWEB)

    Takashima, T; Hinoue, K; Kihara, N; Hayashi, M; Koyama, Y; Takata, T, E-mail: ttakata@polymer.titech.ac.j [Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8552 (Japan)

    2009-08-01

    Graftpolyrotaxanes having graft chains on the wheel components were prepared from main chain-type polyrotaxane having monofunctional cyclodextrin wheels and terminal end-reactive poly(ethylene glycol) (PEG). The well-defined polyrotaxane having mono(6-hydroxyl) permethyl-{alpha}-CD (monoOH-{alpha}-CD) as the wheel components and a polytetrahydrofuran (PTHF) axle with bulky end-capping groups was synthesized by the two pathways; (i) synthesis by solid-state end-capping of pseudopolyrotaxane consisting of monoOAc-{alpha}-CD and hydroxy-terminated PTHF and (ii) one-pot synthesis using monoOH-{alpha}-CD and amine-terminated PTHF in water. The grafting reaction on the wheel moieties of the resulting polyrotaxane was carried out by acylation reaction with PEG-mono-carboxylic acid derivatives in high conversion yields. To estimate the relative rotary movement of CDs and the axle polymer in the polyrotaxane and graftpolyrotaxane, the rotational correlation time ({tau}{sub c}) of polyrotaxanes was estimated from the longitudinal relaxation time (T{sub 1}) of {sup 13}C NMR. The results clearly indicate that the graftpolyrotaxane described here is a new type of graft polymer in terms of the special circumrotation behavior such as the independent rotary movement of CDs with the graft chain and the axle polymer.

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

    Energy Technology Data Exchange (ETDEWEB)

    Erdemi, H. [Yalova University, Department of Polymer Engineering (Turkey); Soezeri, H. [TUBITAK-UME, National Metrology Institute (Turkey); Senel, M.; Baykal, A., E-mail: hbaykal@fatih.edu.tr [Fatih University, Department of Chemistry, Faculty of Arts and Sciences (Turkey)

    2012-08-15

    Polyvinylimidazole (PVIm)-grafted superparamagnetic iron oxide nanoparticles (SPION) (Si-PVIm-grafted Fe{sub 3}O{sub 4} 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 Multiplication-Sign 10{sup -7}-1.78 Multiplication-Sign 10{sup -4} S cm{sup -1}. Analysis of the real and imaginary parts of the permittivities indicated temperature and frequency dependency representing interfacial polarization and temperature-assisted reorganization effects.

  15. SPY: an innovative intra-operative imaging system to evaluate graft patency during off-pump coronary artery bypass grafting.

    Science.gov (United States)

    Takahashi, Masao; Ishikawa, Toshihiro; Higashidani, Koichi; Katoh, Hiroki

    2004-09-01

    Off-pump coronary artery bypass grafting (CABG) has been rapidly increased, because of its less invasiveness with low complications. However, graft patency rate highly depends on the operators' capability due to technical difficulties. The SPY system, based on the fluorescence of indocyanine green, is an innovative device that permits validation of graft patency intra-operatively. Real time images of grafts are obtained with no need for catheterization, X-rays or iodine contrast medium. High-quality images could be obtained in all 290 grafts of 72 off-pump CABG cases (mean 4.0 grafts per patient). Four anastomoses (1.4%), including two proximal and two distal, were revised because of defects detected by SPY images. In one case, the SPY system revealed no blood flow in a radial sequential graft, although transit-time flow meter measurements showed a diastolic dominant pattern. SPY images provide critical information to surgeons to detect non-patent grafts, allowing them to be revised while the patient is still on the operating table. Using the SPY system, technical failures could be completely resolved during surgery. The use of the SPY system for intra-operative graft validation during off-pump CABG may become the gold standard for surgical management in the near future.

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

    Science.gov (United States)

    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.

  17. Peroxisome Metabolism and Cellular Aging

    Science.gov (United States)

    Titorenko, Vladimir I.; Terlecky, Stanley R.

    2010-01-01

    The essential role of peroxisomes in fatty acid oxidation, anaplerotic metabolism, and hydrogen peroxide turnover is well established. Recent findings suggest these and other related biochemical processes governed by the organelle may also play a critical role in regulating cellular aging. The goal of this review is to summarize and integrate into a model, the evidence that peroxisome metabolism actually helps define the replicative and chronological age of a eukaryotic cell. In this model, peroxisomal reactive oxygen species (ROS) are seen as altering organelle biogenesis and function, and eliciting changes in the dynamic communication networks that exist between peroxisomes and other cellular compartments. At low levels, peroxisomal ROS activate an anti-aging program in the cell; at concentrations beyond a specific threshold, a pro-aging course is triggered. PMID:21083858

  18. Cellular proliferation and hypusine synthesis.

    Science.gov (United States)

    Torrelio, B M; Paz, M A; Gallop, P M

    1984-10-01

    Hypusine (N(-)-(4-amino-2-hydroxybutyl) lysine), a spermidine-dependent post-translational protein modification, is synthesized by various mammalian cells in culture. Experiments described in this paper demonstrated a relationship between rates of cellular growth and the synthesis of hypusine. Cells that divide at fast rates have a high rate of hypusine synthesis. In kinetic experiments, a positive relationship is evident between the rates of protein, DNA and hypusine synthesis. Cells seeded at high density, growing non-exponentially, synthesized less hypusine than logarithmically growing cells seeded at low density. Slowing the growth rate of cells by modification of the external milieu also results in a decreased rate of hypusine synthesis. These results provide additional evidence of the association of hypusine with cell proliferation in cultured cell lines and suggest a possible role for this unusual post-translational modification in the complex macromolecular events leading to cellular growth.

  19. Total Male Breast Reconstruction with Fat Grafting

    Directory of Open Access Journals (Sweden)

    Tarik Al-Kalla, MD

    2014-11-01

    Full Text Available Summary: Cancer of a male breast represents less than 1% of all breast cancer. As with to female patients, mastectomy in men creates a substantial emotional burden. Breast reconstruction may improve the patient’s psychological well-being, compliance with adjuvant treatments, and overall outcome. However, due to the unique anatomy of the male breast, standard reconstructive strategies using anatomic or prosthetic modalities are not entirely applicable. We describe a case of a 68-year-old male patient who underwent successful unilateral breast reconstruction solely with fat grafting technique.

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

    Science.gov (United States)

    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.

  1. Identification of Nonstationary Cellular Automata

    Institute of Scientific and Technical Information of China (English)

    AndrewI.Adamatzky

    1992-01-01

    The principal feature of nonstationary cellular automata(NCA) is that a local transitiol rule of each cell is changed at each time step depending on neighborhood configuration at previous time step.The identification problem for NCA is extraction of local transition rules and the establishment of mechanism for changing these rules using sequence of NCA configurations.We present serial and parallel algorithms for identification of NCA.

  2. CELLULAR INTERACTIONS MEDIATED BY GLYCONECTIDS

    OpenAIRE

    Popescu, O.; Sumanovski, L. T.; I. Checiu; Elisabeta Popescu; G. N. Misevic

    1999-01-01

    Cellular interactions involve many types of cell surface molecules and operate via homophilic and/or heterophilic protein-protein and protein-carbohydrate binding. Our investigations in different model-systems (marine invertebrates and mammals) have provided direct evidence that a novel class of primordial proteoglycans, named by us gliconectins, can mediate cell adhesion via a new alternative molecular mechanism of polyvalent carbohydrate-carbohydrate binding. Biochemical characterization of...

  3. Stochastic Nature in Cellular Processes

    Institute of Scientific and Technical Information of China (English)

    刘波; 刘圣君; 王祺; 晏世伟; 耿轶钊; SAKATA Fumihiko; GAO Xing-Fa

    2011-01-01

    The importance of stochasticity in cellular processes is increasingly recognized in both theoretical and experimental studies. General features of stochasticity in gene regulation and expression are briefly reviewed in this article, which include the main experimental phenomena, classification, quantization and regulation of noises. The correlation and transmission of noise in cascade networks are analyzed further and the stochastic simulation methods that can capture effects of intrinsic and extrinsic noise are described.

  4. Glycosylation regulates prestin cellular activity.

    Science.gov (United States)

    Rajagopalan, Lavanya; Organ-Darling, Louise E; Liu, Haiying; Davidson, Amy L; Raphael, Robert M; Brownell, William E; Pereira, Fred A

    2010-03-01

    Glycosylation is a common post-translational modification of proteins and is implicated in a variety of cellular functions including protein folding, degradation, sorting and trafficking, and membrane protein recycling. The membrane protein prestin is an essential component of the membrane-based motor driving electromotility changes (electromotility) in the outer hair cell (OHC), a central process in auditory transduction. Prestin was earlier identified to possess two N-glycosylation sites (N163, N166) that, when mutated, marginally affect prestin nonlinear capacitance (NLC) function in cultured cells. Here, we show that the double mutant prestin(NN163/166AA) is not glycosylated and shows the expected NLC properties in the untreated and cholesterol-depleted HEK 293 cell model. In addition, unlike WT prestin that readily forms oligomers, prestin(NN163/166AA) is enriched as monomers and more mobile in the plasma membrane, suggesting that oligomerization of prestin is dependent on glycosylation but is not essential for the generation of NLC in HEK 293 cells. However, in the presence of increased membrane cholesterol, unlike the hyperpolarizing shift in NLC seen with WT prestin, cells expressing prestin(NN163/166AA) exhibit a linear capacitance function. In an attempt to explain this finding, we discovered that both WT prestin and prestin(NN163/166AA) participate in cholesterol-dependent cellular trafficking. In contrast to WT prestin, prestin(NN163/166AA) shows a significant cholesterol-dependent decrease in cell-surface expression, which may explain the loss of NLC function. Based on our observations, we conclude that glycosylation regulates self-association and cellular trafficking of prestin(NN163/166AA). These observations are the first to implicate a regulatory role for cellular trafficking and sorting in prestin function. We speculate that the cholesterol regulation of prestin occurs through localization to and internalization from membrane microdomains by

  5. Cellular fiber–reinforced concrete

    OpenAIRE

    Isachenko S.; Kodzoev M.

    2016-01-01

    Methods disperse reinforcement of concrete matrix using polypropylene, glass, basalt and metal fibers allows to make the construction of complex configuration, solve the problem of frost products. Dispersed reinforcement reduces the overall weight of the structures. The fiber replaces the secondary reinforcement, reducing the volume of use of structural steel reinforcement. Cellular Fiber concretes are characterized by high-performance properties, especially increased bending strength and...

  6. Superhydrophobic modification fails to improve the performance of small diameter expanded polytetrafluoroethylene vascular grafts

    NARCIS (Netherlands)

    Toes, GJ; van Muiswinkel, KW; van Oeveren, W; Suurmeijer, AJH; Timens, W; Stokroos, [No Value; van den Dungen, JJAM

    To determine whether superhydrophobic modification of small diameter expanded polytetrafluoroethylene (ePTFE) vascular grafts improves the performance of these grafts, we assessed neointima formation and platelet deposition in standard and superhydrophobic modified ePTFE grafts. Standard and

  7. Osseous scintigraphy and auxiliary graft. Scintigraphie osseuse et greffe d'appoint

    Energy Technology Data Exchange (ETDEWEB)

    Khelifa, F.; Siles, S. (Hopital de la Timone, 13 - Marseille (France)); Puech, B.

    1992-12-01

    The scintigraphy could be a good way to survey the osseous graft: three cases are studied in which were recognized the presence of a graft, surinfection, graft lysis, pseudo-arthrosis, algodystrophy. 8 refs., 5 figs.

  8. Progress of cellular dedifferentiation research

    Institute of Scientific and Technical Information of China (English)

    LIU Hu-xian; HU Da-hai; JIA Chi-yu; FU Xiao-bing

    2006-01-01

    Differentiation, the stepwise specialization of cells, and transdifferentiation, the apparent switching of one cell type into another, capture much of the stem cell spotlight. But dedifferentiation, the developmental reversal of a cell before it reinvents itself, is an important process too. In multicellular organisms, cellular dedifferentiation is the major process underlying totipotency, regeneration and formation of new stem cell lineages. In humans,dedifferentiation is often associated with carcinogenesis.The study of cellular dedifferentiation in animals,particularly early events related to cell fate-switch and determination, is limited by the lack of a suitable,convenient experimental system. The classic example of dedifferentiation is limb and tail regeneration in urodele amphibians, such as salamanders. Recently, several investigators have shown that certain mammalian cell types can be induced to dedifferentiate to progenitor cells when stimulated with the appropriate signals or materials. These discoveries open the possibility that researchers might enhance the endogenous regenerative capacity of mammals by inducing cellular dedifferentiation in vivo.

  9. The insect cellular immune response

    Institute of Scientific and Technical Information of China (English)

    Michael R. Strand

    2008-01-01

    The innate immune system of insects is divided into humoral defenses that include the production of soluble effector molecules and cellular defenses like phagocytosis and encapsulation that are mediated by hemocytes. This review summarizes current understanding of the cellular immune response. Insects produce several terminally differentiated types of hemocytes that are distinguished by morphology, molecular and antigenic markers, and function. The differentiated hemocytes that circulate in larval or nymphal stage insects arise from two sources: progenitor cells produced during embryogenesis and mesodermally derived hematopoietic organs. Regulation of hematopoiesis and hemocyte differentiation also involves several different signaling pathways. Phagocytosis and encapsulation require that hemocytes first recognize a given target as foreign followed by activation of downstream signaling and effector responses. A number of humoral and cellular receptors have been identified that recognize different microbes and multicellular parasites. In turn, activation of these receptors stimulates a number of signaling pathways that regulate different hemocyte functions. Recent studies also identify hemocytes as important sources of a number of humoral effector molecules required for killing different foreign invaders.

  10. [Cellular phones and public health].

    Science.gov (United States)

    Leventhal, Alex; Karsenty, Eric; Sadetzki, Siegal

    2004-08-01

    The increased use of mobile cellular phone by the public is associated with a wave of contradictory reports about the possible health effects, due to the exposure of the users to electromagnetic non-ionizing radiation. This article reviews the state of the art of the present knowledge concerning the biological and medical effects of exposure to cellular phones, with an emphasis on its possible carcinogenic effect. Health conditions, which have been ascribed to the use of mobile phones mainly include some types of cancer and changes of brain activity. However, the balance of evidence from available studies has not yet supported these claims. Following the recommendation of special international expert committees, the IARC (International Association for Research on Cancer) is conducting a multi-center study to determine the possible effect of cellular phone use on brain and salivary gland tumors. Israel is one of the participants of this study. The only established health effect associated with the use of such technology is an increased risk for road accidents, unrelated to the amount of radiation emitted by phone. The challenge posed by this new technology to health authorities all over the world has lead to the definition of a new principle, the so-called "prudent avoidance", used as guidelines for the definition of an adequate public health policy. The public policy in Israel has used the prudent avoidance principles, while awaiting the results of the multi-national epidemiological studies.

  11. Electrospun vascular grafts with anti-kinking properties

    Directory of Open Access Journals (Sweden)

    Bode M.

    2015-09-01

    Full Text Available One of the major challenges in developing appropriate vascular substitutes is to produce a graft that adapts to the biological and mechanical conditions at the application or implantation site. One approach is the use of tissue engineered electrospun grafts pre-seeded with autologous cells. However, bending stresses during in vivo applications could lead to kinking of the graft which may result in life-threatening stenosis. The aim of this study was to develop an electrospun vascular graft consisting of biodegradable polymers which can reduce or prevent kinking, due to their higher flexibility. In order to improve the bendability of the grafts, various electrospinning collectors were designed using six different patterns. Subsequently, the grafts were examined for scaffold morphology, mechanical strength and bendability. Scaffolds spun on a collector structured with a v-shaped thread (flank angle of 120° showed a homogenous and reproducible fiber deposition as compared to the unstructured reference sample. The results of the tensile tests were comparable to the unstructured reference sample, supporting the first observation. Studies on bendability were performed using a custom made flow-bending test setup. It was shown that the flow through the v-shaped grafts was reduced to less than 45 % of the reference value even after bending the graft to an angle of 140°. In contrast, the flow through an unstructured graft was reduced to more than 50 % after bending to an angle of 55°. The presented data demonstrate the need for optimizing the bendability of the commonly used electrospun vascular grafts. Using of macroscopic v-shaped collectors is a promising solution to overcome the issue of graft kinking.

  12. Controlling Bone Graft Substitute Microstructure to Improve Bone Augmentation.

    Science.gov (United States)

    Sheikh, Zeeshan; Drager, Justin; Zhang, Yu Ling; Abdallah, Mohamed-Nur; Tamimi, Faleh; Barralet, Jake

    2016-07-01

    Vertical bone augmentation procedures are frequently carried out to allow successful placement of dental implants in otherwise atrophic ridges and represent one of the most common bone grafting procedures currently performed. Onlay autografting is one of the most prevalent and predictable techniques to achieve this; however, there are several well documented complications and drawbacks associated with it and synthetic alternatives are being sought. Monetite is a bioresorbable dicalcium phosphate with osteoconductive and osteoinductive potential that has been previously investigated for onlay bone grafting and it is routinely made by autoclaving brushite to simultaneously sterilize and phase convert. In this study, monetite disc-shaped grafts are produced by both wet and dry heating methods which alter their physical properties such as porosity, surface area, and mechanical strength. Histological observations after 12 weeks of onlay grafting on rabbit calvaria reveal higher bone volume (38%) in autoclaved monetite grafts in comparison with the dry heated monetite grafts (26%). The vertical bone height gained is similar for both the types of monetite grafts (up to 3.2 mm). However, it is observed that the augmented bone height is greater in the lateral than the medial areas of both types of monetite grafts. It is also noted that the higher porosity of autoclaved monetite grafts increases the bioresorbability, whereas the dry heated monetite grafts having lower porosity but higher surface area resorb to a significantly lesser extent. This study provides information regarding two types of monetite onlay grafts prepared with different physical properties that can be further investigated for clinical vertical bone augmentation applications.

  13. Surgical thrombectomy for thrombosed dialysis grafts: comparison of adjunctive treatments.

    Science.gov (United States)

    Liu, Yun-Hen; Hung, Yen-Ni; Hsieh, Hung-Chang; Ko, Po-Jen

    2008-02-01

    Vascular surgeons often encounter dialysis graft failure in hemodialysis patients during their daily practice. Despite advances in percutaneous treatment, there remains a role for surgical thrombectomy of thrombosed dialysis grafts. This study was designed to investigate the long-term outcome of dialysis graft thrombectomy and to examine the indications for and effectiveness of therapies adjuvant to Fogarty thrombectomy. Surgical outcomes of 590 consecutive dialysis graft thrombectomies performed between 2001 and 2003 were retrospectively reviewed. The 590 cases were classified into four groups based on the procedure performed adjuvant to Fogarty thrombectomy: group A, surgical thrombectomy by Fogarty thrombectomy catheter alone; group B, thrombectomy plus intraoperative angioplasty of graft outlet; group C, thrombectomy plus sequential balloon angioplasty in subsequent intervention; group D, thrombectomy plus graft outlet surgical revision. Age, gender, co-morbidity, and primary patency of grafts were reviewed and analyzed. The four groups exhibited similar demographic features and comorbidities (p>0.05). Mean primary patency in the four groups was 1.99+/-4.02, 7.21+/-7.61, 8.35+/-9.53, and 7.26+/-6.99 (months), respectively. Survival curves for each group were determined by Kaplan-Meier methods. Primary patency in group A was statistically inferior to all of the other three groups, whereas groups B, C, and D did not significantly differ with regard to graft patency. Surgical thrombectomy alone is inadequate for treating a thrombosed dialysis graft. The underlying graft outlet stricture requires direct surgical revision or balloon angioplasty during surgery or intervention in the angiography suite to ensure long-term patency of the graft.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Biswal, Jayashree [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Kumar, Virendra [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Bhardwaj, Y.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)]. E-mail: ykbhard@magnum.barc.ernet.in; Goel, N.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Dubey, K.A. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Chaudhari, C.V. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Sabharwal, S. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)

    2007-10-15

    Mutual radiation grafting technique has been applied to carry out grafting of acrylamide (AAm) onto guar gum (GG) using high-energy Co{sup 60} {gamma} 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. {gamma} and microwave radiation effect on grafted and virgin GG has also been reported.

  16. Tissue-engineered graft constructed by self-derived cells and heterogeneous acellular matrix

    Institute of Scientific and Technical Information of China (English)

    HUANG Hui-min; WU Shao-feng; REN Hong

    2006-01-01

    Background: Endothelial and smooth muscle cells were used as seeding cells and heterogeneous acellularized matrix was used as scaffold to construct the tissue-engineered graft. Methods: A 2 weeks piglet was selected as a donor of seeding cells. Two-centimetre length of common carotid artery was dissected. Endothelial cells and smooth muscle cells were harvested by trypsin and collagenase digestion respectively. The isolated cells were cultured and expanded using routine cell culture technique.An adult sheep was used as a donor of acellularized matrix. The thoracic aorta was harvested and processed by a multi-step decellularizing technique to remove the original cells and preserve the elastic and collagen fibers. The cultured smooth muscle cells and endothelial cells were then seeded to the acellularized matrix and incubated in vitro for another 2 weeks. The cell seeded graft was then transplanted to the cell-donated piglet to substitute part of the native pulmonary artery. Results: The cultured cells from piglet were characterized as endothelial cells by the presence of specific antigens vWF and CD31, and smooth muscle cells by the presence of specific antigen α-actin on the cell surface respectively with immunohistochemical technique. After decellularizing processing for the thoracic aorta from sheep, all the cellular components were extracted and elastic and collagen fibers kept their original morphology and structure. The maximal load of acellular matrix was decreased and 20% lower than that of untreated thoracic aorta, but the maximal tensions between them were not different statistically and they had similar load-tension curves. Three months after transplantation, the animal was sacrificed and the graft was removed for observation. The results showed that the inner surfaces of the graft were smooth, without thrombosis and calcification. Under microscopy, a great number of growing cells could be seen and elastic and collagen fibers were abundant. Conclusion

  17. Alveolar graft in the cleft lip and palate patient: Review of 104 cases

    OpenAIRE

    Luque Martín, Estela; Tobella Camps, Lluïsa M.; 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...

  18. Cellular communications a comprehensive and practical guide

    CERN Document Server

    Tripathi, Nishith

    2014-01-01

    Even as newer cellular technologies and standards emerge, many of the fundamental principles and the components of the cellular network remain the same. Presenting a simple yet comprehensive view of cellular communications technologies, Cellular Communications provides an end-to-end perspective of cellular operations, ranging from physical layer details to call set-up and from the radio network to the core network. This self-contained source forpractitioners and students represents a comprehensive survey of the fundamentals of cellular communications and the landscape of commercially deployed

  19. Functional vascularized lung grafts for lung bioengineering

    Science.gov (United States)

    Dorrello, N. Valerio; Guenthart, Brandon A.; O’Neill, John D.; Kim, Jinho; Cunningham, Katherine; Chen, Ya-Wen; Biscotti, Mauer; Swayne, Theresa; Wobma, Holly M.; Huang, Sarah X. L.; Snoeck, Hans-Willem; Bacchetta, Matthew; Vunjak-Novakovic, Gordana

    2017-01-01

    End-stage lung disease is the third leading cause of death worldwide, accounting for 400,000 deaths per year in the United States alone. To reduce the morbidity and mortality associated with lung disease, new therapeutic strategies aimed at promoting lung repair and increasing the number of donor lungs available for transplantation are being explored. Because of the extreme complexity of this organ, previous attempts at bioengineering functional lungs from fully decellularized or synthetic scaffolds lacking functional vasculature have been largely unsuccessful. An intact vascular network is critical not only for maintaining the blood-gas barrier and allowing for proper graft function but also for supporting the regenerative cells. We therefore developed an airway-specific approach to removing the pulmonary epithelium, while maintaining the viability and function of the vascular endothelium, using a rat model. The resulting vascularized lung grafts supported the attachment and growth of human adult pulmonary cells and stem cell–derived lung-specified epithelial cells. We propose that de-epithelialization of the lung with preservation of intact vasculature could facilitate cell therapy of pulmonary epithelium and enable bioengineering of functional lungs for transplantation. PMID:28875163

  20. Pediatric burn wound impetigo after grafting.

    Science.gov (United States)

    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. An experimental study of nerve bypass graft

    Institute of Scientific and Technical Information of China (English)

    XU Jie; LI Xue-shi

    2008-01-01

    Objective: To study the use of a nerve "bypass" graft as a possible alternative to neurolysis or segmental resection with interposition grafting in the treatment of neuroma-in-continuity. Methods: A sciatic nerve crush injury model was established in the Sprague-Dawley rat by compression with a straight hemostatic forceps. Epineurial windows were created proximal and distal to the injury site. An 8-mm segment of radial nerve was harvested and coaptated to the sciatic nerve at the epineurial window sites proximal and distal to the compressed segment (bypass group). A sciatic nerve crush injury without bypass served as a control. Nerve conduction studies were performed over an 8-week period. Sciatic nerves were then harvested and studied under transmission electron microscopy. Myelinated axon counts were obtained. Results: Nerve conduction velocity was significantly faster in the bypass group than in the control group at 8 weeks (63.57 m/s±5.83 m/s vs. 54.88 m/s±4.79m/s, P<0.01). Myelinated axon counts in distal segments were found more in the experimental sciatic nerve than in the control sciatic nerve. Significant axonal growth was noted in the bypass nerve segment itself. Conclusion: Nerve bypass may serve to augment peripheral axonal growth while avoiding further loss of the native nerve.

  2. Preimplantation biopsy predicts delayed graft function, glomerular filtration rate and long-term graft survival of transplanted kidneys

    Directory of Open Access Journals (Sweden)

    José A. Pedroso

    2016-01-01

    Full Text Available The predictive value of preimplantation biopsies for long-term graft function is often limited by conflicting results. The aim of this study was to evaluate the influence of time-zero graft biopsy histological scores on early and late graft function, graft survival and patient survival, at different time points. We retrospectively analyzed 284 preimplantation biopsies at a single center, in a cohort of recipients with grafts from live and deceased donors (standard and nonstandard, and their impact in posttransplant renal function after a mean follow-up of 7 years (range 1-16. Implantation biopsy score (IBS, a combination score derived from 4 histopathological aspects, was determined from each sample. The correlation with incidence of delayed graft function (DGF, creatinine clearance (1st, 3rd and 5th posttransplant year and graft and patient survival at 1 and 5 years were evaluated. Preimplantation biopsies provided somewhat of a prognostic index of early function and outcome of the transplanted kidney in the short and long term. In the immediate posttransplantation period, the degree of arteriolosclerosis and interstitial fibrosis correlated better with the presence of DGF. IBS values between 4 and 6 were predictive of worst renal function at 1st and 3rd years posttransplant and 5-year graft survival. The most important histological finding, in effectively transplanted grafts, was the grade of interstitial fibrosis. Patient survival was not influenced by IBS. Higher preimplantation biopsy scores predicted an increased risk of early graft losses, especially primary nonfunction. Graft survival (at 1st and 5th years after transplant but not patient survival was predicted by IBS.

  3. Grafted hydroxypropyl guargum: Development, characterization and application as flocculating agent

    Indian Academy of Sciences (India)

    B R Nayak; D R Biswal; N C Karmakar; R P Singh

    2002-11-01

    Synthesis of hydroxypropyl guargum--polyacrylamide was carried out by ceric ion induced redox polymerization technique at 28 ± 1°C. The graft copolymer was characterized by IR and thermal analysis. The flocculation performance of graft copolymer was tested in 1 wt% coal suspension.

  4. Impact of reaction conditions on grafting acrylamide onto starch

    Science.gov (United States)

    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...

  5. History of free skin grafting. Knowledge of empiricism?

    NARCIS (Netherlands)

    Klasen, Hendrik Jan

    1981-01-01

    In the course of more than a hundred years, skin grafting has become a standard procedure in surgery. The indications for the several types of grafting have become rather uniform.The technical aids at the operations only differ in details. Especially the vast experience gained in World War II provid

  6. 21 CFR 870.3450 - Vascular graft prosthesis.

    Science.gov (United States)

    2010-04-01

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

  7. Tunica vaginalis free graft for the correction of chordee.

    Science.gov (United States)

    Perlmutter, A D; Montgomery, B T; Steinhardt, G F

    1985-08-01

    Tunica vaginalis free grafts were used to correct severe chordee not amenable to other surgical maneuvers in 11 boys. Postoperatively, the penis was straight in 10 patients and had some degree of downward angulation in 1 boy. The tunica vaginalis free graft seems to be a useful technique for the correction of severe chordee.

  8. History of free skin grafting. Knowledge of empiricism?

    NARCIS (Netherlands)

    Klasen, Hendrik Jan

    1981-01-01

    In the course of more than a hundred years, skin grafting has become a standard procedure in surgery. The indications for the several types of grafting have become rather uniform.The technical aids at the operations only differ in details. Especially the vast experience gained in World War II provid

  9. Experimental autologous substitute vascular graft for transplantation surgery

    NARCIS (Netherlands)

    Kobori, L; Dallos, G; Gouw, ASH; Nemeth, T; Nemes, B; Fehervari, I; Tegzess, Adam; Slooff, MJH; Perner, F; De Jong, KP

    2000-01-01

    Vascular complications in fiver transplantation are a major cause of graft failure and mortality. The aim of the study was to create autologous vascular graft without risk of rejection. Posterior rectus fascia sheath lined with peritoneum was used for iliac artery replacement in seven mongrel dogs.

  10. Renal cell carcinoma in functional renal graft: Toward ablative treatments.

    Science.gov (United States)

    Tillou, Xavier; Guleryuz, Kerem; Collon, Sylvie; Doerfler, Arnaud

    2016-01-01

    The occurrence of a kidney transplant tumor is a rare but serious issue with a double risk: the return to dialysis and the development of metastatic cancer. Publications on this topic are mainly case reports. The purpose of this review was to report an exhaustive literature review of functional graft renal cell carcinomas to highlight the impact of tumors on the renal graft outcomes. 201 de novo renal carcinomas in functional renal grafts from 69 publications were included. Incidence was estimated at 0.18%. Graft tumors were mostly asymptomatic (85.9%). Whatever the discovery circumstances of graft tumors, they were mostly documented by graft ultrasounds supplemented by CT-scanning or MR imaging. Nephron sparing surgery (95 patients) was the first treatment performed followed by radiofrequency ablation (38 patients) and cryotherapy (10 patients). The most common tumor graft histology was clear cell carcinoma (46.4%), followed by papillary carcinoma (43.7%). Specific mortality was 2.9% with 6 deaths. Renal graft cell carcinoma is a rare pathology with a low specific death. When possible, conservative treatment should be the first choice. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    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 (Pbiodegradable 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.

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

    Science.gov (United States)

    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).

  13. Structures of Silk Fibers Grafted with Hexafluorobutyl Methacrylate

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The relationship between the graft yield and the effect of hexafluorobutyl methacrylate graft treatment on the structural changes of the silk fibers was studied on the basis of the results of scanning electron micrograph photographs (SEM), infrared spectroscopy (IR), Raman spectrum,wide-angle X-ray diffraction patterns (WAXD), nuclear magnetic resonance(NMR) and amion acid analysis. The results showed that the crystalline regions of grafted fibers were hardly affected and the fiber fission occurred on the cross sections of grafted fibers. The surface of fibers was covered with a high polymer film. The Raman spectrum showed there was little change in the conformation of grafted fibers which mainly remained β-sheet conformation. The IR of the grafted silk fibers showed new absorption of bands occurred which belonged to the stretching-vibrationabsorption-peak bands of VC=O and VC-F of aliphatic ester species. The CF3-,-CF2- and -CFH- structures of grafted silk macromdlecule were verified in the NMR spectrum.The amion acid analysis indicated fluoride monomers were inclined to graft with TYR,ARG and GLU of silk fibers.

  14. History of free skin grafting. Knowledge of empiricism?

    NARCIS (Netherlands)

    Klasen, Hendrik Jan

    1981-01-01

    In the course of more than a hundred years, skin grafting has become a standard procedure in surgery. The indications for the several types of grafting have become rather uniform.The technical aids at the operations only differ in details. Especially the vast experience gained in World War II

  15. Biological Indexing of Graft Transmissible Diseases of Citrus

    Science.gov (United States)

    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...

  16. Adsorption of graft copolymers onto silica and titania.

    NARCIS (Netherlands)

    Bijsterbosch, H.D.; Cohen Stuart, M.A.; Fleer, G.J.

    1998-01-01

    The adsorption of graft copolymers of poly(acrylamide) (PAAm, backbone) and poly(ethylene oxide) (PEO, side chains) from aqueous solution onto silica and titania was studied with reflectometry. Two high-molar-mass copolymers were used with different PEO graft densities (10 and 18% w/w PEO in copolym

  17. Brushes and soap : Grafted polymers and their interactions with nanocolloids

    NARCIS (Netherlands)

    Currie, E.P.K.

    2000-01-01

    Layers of polymer chains end-attached to a grafting plane at high densities, so-called brushes, are a curious state of matter. The (average) monomer density within the brush is as high as in a semi-dilute polymer solution, resulting in a high osmotic pressure in the brush. Due to the grafting, howev

  18. Study on biotribological properties of UHMWPE grafted with MPDSAH

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Yaling; Xiong, Dangsheng, E-mail: xiongds@163.com; 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. - Highlights: ► PMPDSAH brushes were grafted onto UHMWPE powders by UV radiation. ► Wettability of PMPDSAH-grafted UHMWPE bulk material is improved. ► UHMWPE grafted with PMPDSAH brushes shows lower friction coefficient and wear rate.

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

    Science.gov (United States)

    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...

  20. Operative considerations in implantation of the Perma-Flow graft.

    Science.gov (United States)

    Emery, R W; Joyce, L D; Arom, K V; King, R M; Nicoloff, D M

    1994-12-01

    The Perma-Flow coronary bypass graft (Possis Medical, Inc, Minneapolis, MN) currently is undergoing expanded clinical trial. From November 1992 through June 1994 we have used this artificial conduit in 8 patients without autologous alternatives. These cases allowed the establishment of a technical basis for successful implantation of this graft. All studied coronary anastomoses are patent.

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

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yuanyuan, E-mail: yuanyuan-liu@shu.edu.cn; Hu, Qingxi, E-mail: huqingxi@shu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China); Shanghai Key Laboratory of Intelligent Manufacturing and Robotics, Shanghai 200072 (China); Xiang, Ke, E-mail: xiangke@shu.edu.cn; Chen, Haiping, E-mail: 519673062@qq.com; Li, Yu, E-mail: liyu@hpu.edu.cn [Rapid Manufacturing Engineering Center, Shanghai University, Shanghai 200444 (China)

    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.

  2. Evaluation the success of osseointegrated implants in maxillary sinus grafts

    Directory of Open Access Journals (Sweden)

    Rubens Eduardo Gigli

    2008-01-01

    Full Text Available Objective: To analyze implants placed in maxillary sinus grafts with biomaterial of bovine origin and platelet-rich plasma, observing bone neoformation and the clinical and histologic success rate presented.Methods: Analysis of the clinical findings was based on 36 maxillary sinus grafts with 101 implants placed in 30 patients with a mean age of 47 years, and the histologic analysis, based on nine samples of the 36 grafts performed, with a mean interval of 7.5 months time of the graft, the majority of patients being men with a mean age of 42 years. Results: Clinically, 91 implants placed were osseointegrated.Conclusion: Based on the results presented, it was concluded that when implants are placed in the maxillary sinus region grafted with biomaterial, they present a high success rate. ISRCTN24003246

  3. Cell-free vascular grafts: Recent developments and clinical potential.

    Science.gov (United States)

    Row, Sindhu; Santandreu, Ana; Swartz, Daniel D; Andreadis, Stelios T

    2017-03-01

    Recent advances in vascular tissue engineering have led to the development of cell-free grafts that are available off-the-shelf for on demand surgery. Challenges associated with cell-based technologies including cell sourcing, cell expansion and long-term bioreactor culture motivated the development of completely cell-free vascular grafts. These are based on decellularized arteries, decellularized cultured cell-based tissue engineered grafts or biomaterials functionalized with biological signals that promote in situ tissue regeneration. Clinical trials undertaken to demonstrate the applicability of these grafts are also discussed. This comprehensive review summarizes recent developments in vascular graft technologies, with potential applications in coronary artery bypass procedures, lower extremity bypass, vascular injury and trauma, congenital heart diseases and dialysis access shunts, to name a few.

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

    Science.gov (United States)

    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.

  5. Reuse of a Pediatric Liver Graft: A Case Report

    Directory of Open Access Journals (Sweden)

    Koray Karabulut

    2012-01-01

    Full Text Available We report the reuse of a liver graft after brain death of the first recipient. The liver donor was an 8-year-old male who died as a result of head injury. The graft was implanted first to a 4-year-old girl for fulminant hepatic failure. Unfortunately she developed progressive coma and brain death on fifth day of transplantation. The graft functions were normal, and reuse of the liver graft was planned. After informed consent, the graft was transplanted to a 31-year-old female recipient who has hepatocellular carcinoma with an underlying cryptogenic liver cirrhosis. The patient was discharged to home on 9th day after an uneventful postoperative period. However, she was readmitted to hospital with an acute abdominal pain 30 days after the operation. Hepatic artery thrombosis was diagnosed, and the attempt to open the artery by interventional radiology was unsuccessful. She died of sepsis and multiorgan failure on 37th posttransplant day.

  6. Salvage of a costochondral graft for microtia after postoperative infection.

    Science.gov (United States)

    Driscoll, Daniel N; Walker, Marc E; D'Achille, Julian

    2014-01-01

    Costochondral grafts have been the gold standard for ear reconstruction in cases of microtia repair for decades. Microtia repair has been traditionally associated with a low complication rate, yet little exists in the literature regarding the management of complications when they do occur. Postoperative infections of costochondral grafts have traditionally resulted in complete graft loss, necessitating additional surgery or leaving the patient with continued physical disfigurement and the accompanying psychological and emotional distress. The authors wish to present a case report demonstrating the treatment of a fulminant postoperative infection of a costochondral graft and its cutaneous pocket in a 16-year-old male patient with microtia. In this report, we discuss the successful treatment of the infection and 5 years of follow-up demonstrating the complete salvage of the costochondral construct. This is the first case report on the successful treatment and salvage of an infected costochondral graft in microtia repair.

  7. ANALYSIS OF 312 CASES OF REPEAT CORONARY ARTERY BYPASS GRAFTING

    Institute of Scientific and Technical Information of China (English)

    陈长志; 陆佩中

    2003-01-01

    Objective To evaluate repeat coronary artery bypass grafting (CABG) in 312 patients.Methods The data of 312 patients (average age 65±9 years) who had CABG operation in Hartford hospital were collected and analyzed. The mean duration follow up after the first CABG was 11.8±4.5 years. A total of 1069 bypass grafts were performed. Among them, 386 were arterial grafts such as internal mammary artery, radial artery and gastroepiploic artery; 682 were venous grafts and 1 Gore-Tex graft. Results The operative mortality was 4. 5%. Fifteen patients (4. 8%) had peri-operative myocardial infarction and 46 patients (15%) had low cardiac output syndrome. Intra-aortic balloon pump (IABP) was used in 131 patients before, during and after operation. One hundred and nineteen patients weaned off IABP and recovered. ConclusionAlthough the difficulties and risk factors were increased, the results of redo CABG were still good.

  8. Polytrimethylsylylpropyne gas separation membranes modified by radiochemical grafting of divinylbenzene

    Energy Technology Data Exchange (ETDEWEB)

    Vigo, F.; Traverso, M.; Uliana, C. [Univ. of Genoa (Italy); Costa, G. [I.M.A.G.-C.N.R., Genoa (Italy)

    1996-02-01

    A radiochemical method was employed to obtain poly(1-trimethylsilyl-1-propyne)(PTMSP)-divinylbenzene (DVB) grafted films. DVB monomer vapors were absorbed by the PTMSP, and the grafting reaction was thereafter accomplished by {sup 60}Co {gamma}-irradiation in a nitrogen atmosphere. The films so obtained were tested for nitrogen-oxygen separation. The performances of the membranes were studied as functions of time and percent of grafting. The DVB-grafted membranes show an increased selectivity factor and stability with time. The experimental data and some SEM observations confirm the presence of large voids in the PTMSP matrix. These voids are responsible for permeability changes during operation and disappear after the grafting procedure. 8 refs., 5 figs.

  9. Mesenchymal Stem Cell Therapy in the Treatment of Acute and Chronic Graft versus Host Disease

    Directory of Open Access Journals (Sweden)

    Partow eKebriaei

    2011-07-01

    Full Text Available Mesenchymal stem cells (MSC are a cellular component of the supportive microenvironment (stroma found in the bone marrow, umbilical cord, placenta and adipose tissues. In addition to providing cellular and extracellular cues to support the proliferation and differentiation of cells that comprise functional tissues, MSC also contribute to tissue repair and have immunomodulatory properties. Their ability to modulate immunologic reactions while themselves not provoking immunologic responses from alloreactive T-lymphocytes and/or other effector cells, make MSC a potentially ideal therapeutic agent with which to treat graft versus host disease (GvHD following hematopoietic transplantation. Despite in vitro experiments confirming that MSC suppress mixed lymphocyte reactions (MLR and in vivo evidence from mouse models that show evidence that MSC can ameliorate GvHD, clinical trials to date using MSC to treat GvHD have shown mixed results. Whether this is a consequence of suboptimal timing and dose of administered MSC remains to be clarified. It is clear that immunomodulatory potential of MSC as a cellular therapy for GvHD remains to be realized in the clinic.

  10. Alveolar bone grafting with simultaneous cleft lip rhinoplasty.

    Science.gov (United States)

    Kim, Young-Eun; Han, Jihyeon; Baek, Rong-Min; Kim, Baek-Kyu

    2016-11-01

    Optimal timing for cleft lip rhinoplasty is controversial. Definitive rhinoplasty is deferred until facial skeletal growth is completed. Intermediate rhinoplasty is performed after stabilization of the grafted alveolar bone, because the grafted bone tends to be absorbed over several months postoperatively, distorting the nasal profile. Here, we report our experience with simultaneous rhinoplasty during alveolar bone grafting for indicated patients, describe our surgical technique that ensures long-term bone graft survival, and report graft take rates and nasal profile changes. This retrospective chart review included a total of 54 patients; 44 underwent alveolar bone grafting only, and 10 underwent simultaneous cleft lip rhinoplasty. All surgeries were conducted with a judicious mucosal incision for tensionless wound closure. Bone graft take was evaluated with dental radiographs by the Bergland classification. Further, nasal aesthetic outcome was evaluated with medical photographs, based on nostril height and width and alar base width. In total, 96.3% of clefts showed graft success with Type I (66.7%) or Type II (27.8%) classifications; only 3.7% of clefts showed unfavorable results classified as Type III, and no clefts showed Type IV failure. The nasal shape was flatter with a decreased nostril height and increased nostril width after alveolar bone grafting, while nostril height was increased and nostril width was decreased in patients who underwent simultaneous rhinoplasty. With surgical techniques ensuring alveolar bone graft survival, simultaneous cleft lip rhinoplasty can result in nasal aesthetic improvement for patients with severe nasal deformities, decreasing the number of operations. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  11. Portal pressure liver transplantation utilizing smaller grafts than before.

    Science.gov (United States)

    Ogura, Yasuhiro; Hori, Tomohide; El Moghazy, Walid M; Yoshizawa, Atsushi; Oike, Fumitaka; Mori, Akira; Kaido, Toshimi; Takada, Yasutsugu; Uemoto, Shinji

    2010-06-01

    To prevent small-for-size syndrome in adult-to-adult living donor liver transplantation (A-LDLT), larger grafts (ie, right lobe grafts) have been selected in many transplant centers. However, some centers are investigating the benefits of portal pressure modulation. Five hundred sixty-six A-LDLT procedures using right or left lobe grafts were performed between 1998 and 2008. In 2006, we introduced intentional portal pressure control, and we changed the graft selection criteria to include a graft/recipient weight ratio >0.7% instead of the original value of >0.8%. All recipients were divided into period I (1998-2006, the era of unintentional portal pressure control; n = 432) and period II (2006-2008, the era of intentional portal pressure control; n = 134). The selection of small-for-size grafts increased from 7.8% to 23.9%, and the selection of left lobe grafts increased from 4.9% to 32.1%. Despite the increase in the number of smaller grafts in period II, 1-year patient survival was significantly improved (87.9% versus 76.2%). In 129 recipients in period II, portal pressure was monitored. Patients with a portal pressure or=15 mm Hg (n = 43, 66.3%). The recovery from hyperbilirubinemia and coagulopathy after transplantation was significantly better in patients with a portal pressure graft-based A-LDLT to controlled portal pressure-based A-LDLT with smaller grafts. A portal pressure <15 mm Hg seems to be a key for successful A-LDLT.

  12. Grafting: a technique to modify ion accumulation in horticultural crops

    Directory of Open Access Journals (Sweden)

    Muhammad Azher Nawaz

    2016-10-01

    Full Text Available 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 mi

  13. Bacterial adherence to vascular grafts after in vitro bacteremia

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    HUA Helin; LI Na; WU Linlin; ZHONG Hui; WU Guangxia; 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 allgle on the membrane surface decreases with the increase of methyl acrylate graftdegree. 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 copoly mermembranes.

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

    Science.gov (United States)

    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.

  16. Full-thickness skin grafts from eyelids to penis, plus split-thickness grafts in chronic balanitis xerotica obliterans.

    Science.gov (United States)

    Rudolph, R; Walther, P

    1997-02-01

    Balanitis xerotica obliterans is a progressive, sclerotic, constrictive scar-forming disease process of the penile prepuce that can involve the frenulum and urethral meatus. Full-thickness skin grafting from the upper eyelids supplemented with split-thickness skin grafting was successfully used in a patient to end a 57-year symptomatic course.

  17. Game of Life Cellular Automata

    CERN Document Server

    Adamatzky, Andrew

    2010-01-01

    In the late 1960s, British mathematician John Conway invented a virtual mathematical machine that operates on a two-dimensional array of square cell. Each cell takes two states, live and dead. The cells' states are updated simultaneously and in discrete time. A dead cell comes to life if it has exactly three live neighbours. A live cell remains alive if two or three of its neighbours are alive, otherwise the cell dies. Conway's Game of Life became the most programmed solitary game and the most known cellular automaton. The book brings together results of forty years of study into computational

  18. Repaglinide at a cellular level

    DEFF Research Database (Denmark)

    Krogsgaard Thomsen, M; Bokvist, K; Høy, M

    2002-01-01

    To investigate the hormonal and cellular selectivity of the prandial glucose regulators, we have undertaken a series of experiments, in which we characterised the effects of repaglinide and nateglinide on ATP-sensitive potassium ion (KATP) channel activity, membrane potential and exocytosis in rat...... pancreatic alpha-cells and somatotrophs. We found a pharmacological dissociation between the actions on KATP channels and exocytosis and suggest that compounds that, unlike repaglinide, have direct stimulatory effects on exocytosis in somatotrophs and alpha- and beta-cells, such as sulphonylureas...... and nateglinide, may have a clinically undesirable general stimulatory effect on cells within the endocrine system....

  19. ING proteins in cellular senescence.

    Science.gov (United States)

    Menéndez, Camino; Abad, María; Gómez-Cabello, Daniel; Moreno, Alberto; Palmero, Ignacio

    2009-05-01

    Cellular senescence is an effective anti-tumor barrier that acts by restraining the uncontrolled proliferation of cells carrying potentially oncogenic alterations. ING proteins are putative tumor suppressor proteins functionally linked to the p53 pathway and to chromatin regulation. ING proteins exert their tumor-protective action through different types of responses. Here, we review the evidence on the participation of ING proteins, mainly ING1 and ING2, in the implementation of the senescent response. The currently available data support an important role of ING proteins as regulators of senescence, in connection with the p53 pathway and chromatin organization.

  20. Cellular automata a parallel model

    CERN Document Server

    Mazoyer, J

    1999-01-01

    Cellular automata can be viewed both as computational models and modelling systems of real processes. This volume emphasises the first aspect. In articles written by leading researchers, sophisticated massive parallel algorithms (firing squad, life, Fischer's primes recognition) are treated. Their computational power and the specific complexity classes they determine are surveyed, while some recent results in relation to chaos from a new dynamic systems point of view are also presented. Audience: This book will be of interest to specialists of theoretical computer science and the parallelism challenge.

  1. Cellular immune responses to HIV

    Science.gov (United States)

    McMichael, Andrew J.; Rowland-Jones, Sarah L.

    2001-04-01

    The cellular immune response to the human immunodeficiency virus, mediated by T lymphocytes, seems strong but fails to control the infection completely. In most virus infections, T cells either eliminate the virus or suppress it indefinitely as a harmless, persisting infection. But the human immunodeficiency virus undermines this control by infecting key immune cells, thereby impairing the response of both the infected CD4+ T cells and the uninfected CD8+ T cells. The failure of the latter to function efficiently facilitates the escape of virus from immune control and the collapse of the whole immune system.

  2. CELLULAR AUTOMATA AND COMPUTER GRAPHICS

    Directory of Open Access Journals (Sweden)

    Şen ÇAKIR

    1999-01-01

    Full Text Available Cellular Automata (CA are simple mathematical systems which provide models for a variety of physical processes. They show how minute changes and simple rules lead to enormous changes in the behaviour of a system. They can also be used as computer graphics tools to produce a rich reservoir of interesting figures. In recent years, CA have attracked the attention of many scientists. Today, CA are used in many fields from ecology to image processing. In this paper, it is shown that a large number of complex and interesting patterns can be created with relatively simple CA rules.

  3. 5G Ultra-Dense Cellular Networks

    OpenAIRE

    Ge, Xiaohu; Tu, Song; Mao, Guoqiang; Wang, Cheng-xiang; Han, Tao

    2015-01-01

    Traditional ultra-dense wireless networks are recommended as a complement for cellular networks and are deployed in partial areas, such as hotspot and indoor scenarios. Based on the massive multiple-input multi-output (MIMO) antennas and the millimeter wavecommunication technologies, the 5G ultra-dense cellular network is proposed to deploy in overall cellular scenarios. Moreover, a distribution network architecture is presented for 5G ultra-dense cellular networks. Furthermore, the backhaul ...

  4. A new grafting technique for tympanoplasty: tympanoplasty with a boomerang-shaped chondroperichondrial graft (TwBSCPG).

    Science.gov (United States)

    Dündar, Rıza; Soy, Fatih Kemal; Kulduk, Erkan; Muluk, Nuray Bayar; Cingi, Cemal

    2014-10-01

    The aim of this study was to introduce a new grafting technique in tympanoplasty that involves use of a boomerang-shaped chondroperichondrial graft (BSCPG). The anatomical and functional results were evaluated. A new tympanoplasty with boomerang-shaped chondroperichondrial graft (TwBSCPG) technique was used in 99 chronic otitis media patients with central or marginal perforation of the tympanic membrane and a normal middle ear mucosa. All 99 patients received chondroperichondrial cartilage grafts with a boomerang-shaped cartilage island left at the anterior and inferior parts. Postoperative follow-ups were conducted at months 1, 6, and 12. Preoperative and postoperative audiological examinations were performed and air-bone gaps were calculated according to the pure-tone averages (PTAs) of the patients. In the preoperative period, most (83.8%) air-bone gaps were ≥ 16 dB; after operating using the TwBSCPG technique, the air-bone gaps decreased to 0-10 dB in most patients (77.8%). In the TwBSCPG patients, the mean preoperative air-bone gap was 22.02 ± 6.74 dB SPL. Postoperatively, the mean postoperative air-bone gap was 8.70 ± 5.74 dB SPL. The TwBSCPG technique therefore decreased the postoperative air-bone gap compared to that preoperatively (p = 0.000, z = -8.645). At the 1-month follow-up, there were six graft perforations and one graft retraction. At the 6-month follow-up, there were nine graft perforations and three graft retractions. At 12 months, there were seven graft perforations and four graft retractions. During the first year after the boomerang tympanoplasty surgery, graft lateralization was not detected in any patient. Retractions were grade 1 according to the Sade classification and were localized to the postero-superior quadrant of the tympanic membrane. The TwBSCPG technique has benefits with respect to postoperative anatomical and audiological results. It prevents perforation of the tympanic membrane at the anterior quadrant and avoids graft

  5. Comparison of mesencephalic free-floating tissue culture grafts and cell suspension grafts in the 6-hydroxydopamine-lesioned rat

    DEFF Research Database (Denmark)

    Meyer, Morten; Widmer, H R; Wagner, B

    1998-01-01

    improvements in terms of significant reductions in amphetamine-induced rotations were observed in rats grafted with FFRT cultures (127%) and rats grafted with cell suspensions (122%), while control animals showed no normalization of rotational behavior. At 84 days after transplantation, there were similar...... days in culture or directly as dissociated cell suspensions, and compared with regard to neuronal survival and ability to normalize rotational behavior in adult rats with unilateral 6-hydroxydopamine (6-OHDA) lesions. Other lesioned rats received injections of cell-free medium and served as controls...... numbers of TH-immunoreactive (TH-ir) neurons in grafts of cultured tissue (775 +/- 98, mean +/- SEM) and grafts of fresh, dissociated cell suspension (806 +/- 105, mean +/- SEM). Cell counts in fresh explants, 7-day-old cultures, and grafted cultures revealed a 68.2% loss of TH-ir cells 7 days after...

  6. Engineering vascularized bone grafts by integrating a biomimetic periosteum and β-TCP scaffold.

    Science.gov (United States)

    Kang, Yunqing; Ren, Liling; Yang, Yunzhi

    2014-06-25

    Treatment of large bone defects using synthetic scaffolds remain a challenge mainly due to insufficient vascularization. This study is to engineer a vascularized bone graft by integrating a vascularized biomimetic cell-sheet-engineered periosteum (CSEP) and a biodegradable macroporous beta-tricalcium phosphate (β-TCP) scaffold. We first cultured human mesenchymal stem cells (hMSCs) to form cell sheet and human umbilical vascular endothelial cells (HUVECs) were then seeded on the undifferentiated hMSCs sheet to form vascularized cell sheet for mimicking the fibrous layer of native periosteum. A mineralized hMSCs sheet was cultured to mimic the cambium layer of native periosteum. This mineralized hMSCs sheet was first wrapped onto a cylindrical β-TCP scaffold followed by wrapping the vascularized HUVEC/hMSC sheet, thus generating a biomimetic CSEP on the β-TCP scaffold. A nonperiosteum structural cell sheets-covered β-TCP and plain β-TCP were used as controls. In vitro studies indicate that the undifferentiated hMSCs sheet facilitated HUVECs to form rich capillary-like networks. In vivo studies indicate that the biomimetic CSEP enhanced angiogenesis and functional anastomosis between the in vitro preformed human capillary networks and the mouse host vasculature. MicroCT analysis and osteocalcin staining show that the biomimetic CSEP/β-TCP graft formed more bone matrix compared to the other groups. These results suggest that the CSEP that mimics the cellular components and spatial configuration of periosteum plays a critical role in vascularization and osteogenesis. Our studies suggest that a biomimetic periosteum-covered β-TCP graft is a promising approach for bone regeneration.

  7. Fluorescent graphene oxide via polymer grafting: an efficient nanocarrier for both hydrophilic and hydrophobic drugs.

    Science.gov (United States)

    Kundu, Aniruddha; Nandi, Sudipta; Das, Pradip; Nandi, Arun K

    2015-02-18

    Functionalized graphene-based drug delivery vehicles have conquered a significant position because functionalization improves its biocompatibility and stability in cell medium, leaving sufficient graphitic basal plane for drug loading through π-π stacking. In this study, poly(N-isopropylacrylamide) (PNIPAM) is covalently grafted from the surface of graphene oxide (GO) via a facile, eco-friendly and an easy procedure of free radical polymerization (FRP) using ammonium persulfate initiator. Various spectroscopic and microscopic studies confirm the successful grafting of PNIPAM from GO surface. PNIPAM-grafted GO (GPNM) exhibits enhanced thermal stability, improved dispersibility both in aqueous and cell medium, and better biocompatibility and cell viability compared to GO. Interestingly, GPNM displays an exciting fluorescence property in aqueous medium, which is a hike of intensity at 36 °C due to the lower critical solution temperature (LCST) of PNIPAM chains (32 °C). Moreover both hydrophilic (doxorubicin (DOX)) and hydrophobic (indomethacin (IMC)) drugs loaded on the surface of GPNM hybrid exhibits its efficacy as an efficient carrier for both types of drugs. Cellular uptakes of free DOX and DOX-loaded GPNM (GPNM-DOX) are evidenced both from optical and fluorescence imaging of live cells, and the efficiency of drug is significantly improved in the loaded system. The release of DOX from GPNM-DOX was achieved at pH 4, relevant to the environment of cancer cells. The pH-triggered release of hydrophobic drug was also studied using UV-vis spectroscopy via alginate encapsulation, showing a great enhancement at pH = 7.4. The IMC is also found to be released by human serum albumin using dialysis technique. The GPNM nanomaterial shows the property of simultaneous loading of DOX and IMC as well as pH-triggered simultaneous release of both of the drugs.

  8. A phage-targeting strategy for the design of spatiotemporal drug delivery from grafted matrices

    Directory of Open Access Journals (Sweden)

    Sawada Ritsuko

    2011-02-01

    Full Text Available Abstract Background The natural response to injury is dynamic and normally consists of complex temporal and spatial cellular changes in gene expression, which, when acting in synchrony, result in patent tissue repair and, in some instances, regeneration. However, current therapeutic regiments are static and most rely on matrices, gels and engineered skin tissue. Accordingly, there is a need to design next-generation grafting materials to enable biotherapeutic spatiotemporal targeting from clinically approved matrices. To this end, rather then focus on developing completely new grafting materials, we investigated whether phage display could be deployed onto clinically approved synthetic grafts to identify peptide motifs capable of linking pharmaceutical drugs with differential affinities and eventually, control drug delivery from matrices over both space and time. Methods To test this hypothesis, we biopanned combinatorial peptide libraries onto different formulations of a wound-healing matrix (Integra® and eluted the bound peptides with 1 high salt, 2 collagen and glycosaminoglycan or 3 low pH. After three to six rounds of biopanning, phage recovery and phage amplification of the bound particles, any phage that had acquired a capacity to bind the matrix was sequenced. Results In this first report, we identify distinct classes of matrix-binding peptides which elute differently from the screened matrix and demonstrate that they can be applied in a spatially relevant manner. Conclusions We suggest that further applications of these combinatorial techniques to wound-healing matrices may offer a new way to improve the performance of clinically approved matrices so as to introduce temporal and spatial control over drug delivery.

  9. Ligand peptide-grafted PEGylated liposomes using HER2 targeted peptide-lipid derivatives for targeted delivery in breast cancer cells: The effect of serine-glycine repeated peptides as a spacer.

    Science.gov (United States)

    Suga, Tadaharu; Fuchigami, Yuki; Hagimori, Masayori; Kawakami, Shigeru

    2017-02-22

    Ligand peptide-grafted PEGylated liposomes have been widely studied for targeted drug delivery systems. Because ligand peptides are commonly grafted using PEG as a spacer on the surface of PEGylated liposomes, the interaction between ligand peptides and their corresponding receptors can be interrupted by steric hindrance of the PEG layer. Therefore, we aimed to develop ligand peptide-lipid derivatives to enhance the targeting efficiency of ligand peptide-grafted PEGylated liposomes, and designed a new ligand peptide-lipid derivatives having serine-glycine repeats (SG)n as a spacer based on the peptide length calculated by PyMol (v0.99). We selected KCCYSL (KCC) as the ligand peptide for binding to human epidermal growth factor receptor-2 (HER2). We synthesized new KCC-(SG)n-lipid derivatives (n=3, 5, 7) and evaluated their cellular association in breast cancer cells. KCC-(SG)n/PEGylated liposomes dramatically increased cellular association on HER2-positive breast cancer cells. The results suggest that KCC can be grafted on the surface of KCC-(SG)n/PEGylated liposomes prepared from KCC-(SG)n-lipid derivatives (n=3, 5, 7). In summary, we succeeded in developing KCC-(SG)n-lipid derivatives for the preparation of ligand peptide-grafted PEGylated liposomes.

  10. Scaphoid nonunions treated with vascularised bone grafts: MRI assessment

    Energy Technology Data Exchange (ETDEWEB)

    Dailiana, Z.H.; Zachos, V.; Varitimidis, S.; Papanagiotou, P.; Karantanas, A.; Malizos, K.N. E-mail: kmalizos@otenet.gr

    2004-06-01

    Purpose: To assess the value of MR imaging (MRI) with regard to union, graft viability and proximal pole bone marrow status, after use of vascularized bone grafts for treating scaphoid nonunions. Materials and methods: Vascularized bone grafts from the distal radius were used to treat 47 scaphoid nonunions resulting from fractures or enchondromas. Clinical and imaging evaluation was used for the pre- and postoperative assessment of all patients. Apart of conventional radiographs obtained in all cases, 15 patients were also assessed postoperatively with MRI at 3 months. From these 15 patients, eight were assessed preoperatively with MRI whereas nine had serial MRI evaluations at 6 and 12 months. The clinical follow-up time of this subgroup of 15 patients ranged from 6 to 27 months. Results: All patients showed clinical signs of union within 12 weeks form the procedure and at the latest follow-up they experienced complete (10 cases) or almost complete (five cases) relief from pain. Both plain and contrast-enhanced MRI obtained at 3 months showed viability of the bone graft in all cases. At 3 months union was established with plain radiographs in 12 patients at both sides of the graft and in three patients between the graft and proximal pole. At 3 months plain MRI showed nonunion in four patients (two between graft and proximal pole, two between graft and distal pole and one at both sides of the graft) whereas contrast-enhanced MRI revealed only one case of nonunion between graft and proximal pole. Four patients were considered to have osteonecrosis of the proximal pole intraoperatively. Two of them showed necrosis of the proximal pole with preoperative and postoperative plain radiographs and three of them with plain postoperative MRI. Contrast-enhanced MRI at 3 months showed postoperative reversal of necrotic changes in all four scaphoids. MRI also revealed bone marrow oedema of the carpal bones surrounding the scaphoid in 14 cases. Serial MRI at 6 and 12 months

  11. Cellular functions of the microprocessor.

    Science.gov (United States)

    Macias, Sara; Cordiner, Ross A; Cáceres, Javier F

    2013-08-01

    The microprocessor is a complex comprising the RNase III enzyme Drosha and the double-stranded RNA-binding protein DGCR8 (DiGeorge syndrome critical region 8 gene) that catalyses the nuclear step of miRNA (microRNA) biogenesis. DGCR8 recognizes the RNA substrate, whereas Drosha functions as an endonuclease. Recent global analyses of microprocessor and Dicer proteins have suggested novel functions for these components independent of their role in miRNA biogenesis. A HITS-CLIP (high-throughput sequencing of RNA isolated by cross-linking immunoprecipitation) experiment designed to identify novel substrates of the microprocessor revealed that this complex binds and regulates a large variety of cellular RNAs. The microprocessor-mediated cleavage of several classes of RNAs not only regulates transcript levels, but also modulates alternative splicing events, independently of miRNA function. Importantly, DGCR8 can also associate with other nucleases, suggesting the existence of alternative DGCR8 complexes that may regulate the fate of a subset of cellular RNAs. The aim of the present review is to provide an overview of the diverse functional roles of the microprocessor.

  12. Melanoma screening with cellular phones.

    Directory of Open Access Journals (Sweden)

    Cesare Massone

    Full Text Available BACKGROUND: Mobile teledermatology has recently been shown to be suitable for teledermatology despite limitations in image definition in preliminary studies. The unique aspect of mobile teledermatology is that this system represents a filtering or triage system, allowing a sensitive approach for the management of patients with emergent skin diseases. METHODOLOGY/PRINCIPAL FINDINGS: In this study we investigated the feasibility of teleconsultation using a new generation of cellular phones in pigmented skin lesions. 18 patients were selected consecutively in the Pigmented Skin Lesions Clinic of the Department of Dermatology, Medical University of Graz, Graz (Austria. Clinical and dermoscopic images were acquired using a Sony Ericsson with a built-in two-megapixel camera. Two teleconsultants reviewed the images on a specific web application (http://www.dermahandy.net/default.asp where images had been uploaded in JPEG format. Compared to the face-to-face diagnoses, the two teleconsultants obtained a score of correct telediagnoses of 89% and of 91.5% reporting the clinical and dermoscopic images, respectively. CONCLUSIONS/SIGNIFICANCE: The present work is the first study performing mobile teledermoscopy using cellular phones. Mobile teledermatology has the potential to become an easy applicable tool for everyone and a new approach for enhanced self-monitoring for skin cancer screening in the spirit of the eHealth program of the European Commission Information for Society and Media.

  13. Melanoma screening with cellular phones.

    Science.gov (United States)

    Massone, Cesare; Hofmann-Wellenhof, Rainer; Ahlgrimm-Siess, Verena; Gabler, Gerald; Ebner, Christoph; Soyer, H Peter

    2007-05-30

    Mobile teledermatology has recently been shown to be suitable for teledermatology despite limitations in image definition in preliminary studies. The unique aspect of mobile teledermatology is that this system represents a filtering or triage system, allowing a sensitive approach for the management of patients with emergent skin diseases. In this study we investigated the feasibility of teleconsultation using a new generation of cellular phones in pigmented skin lesions. 18 patients were selected consecutively in the Pigmented Skin Lesions Clinic of the Department of Dermatology, Medical University of Graz, Graz (Austria). Clinical and dermoscopic images were acquired using a Sony Ericsson with a built-in two-megapixel camera. Two teleconsultants reviewed the images on a specific web application (http://www.dermahandy.net/default.asp) where images had been uploaded in JPEG format. Compared to the face-to-face diagnoses, the two teleconsultants obtained a score of correct telediagnoses of 89% and of 91.5% reporting the clinical and dermoscopic images, respectively. The present work is the first study performing mobile teledermoscopy using cellular phones. Mobile teledermatology has the potential to become an easy applicable tool for everyone and a new approach for enhanced self-monitoring for skin cancer screening in the spirit of the eHealth program of the European Commission Information for Society and Media.

  14. Cellular automata modelling of SEIRS

    Institute of Scientific and Technical Information of China (English)

    Liu Quan-Xing; Jin Zhen

    2005-01-01

    In this paper the SEIRS epidemic spread is analysed, and a two-dimensional probability cellular automata model for SEIRS is presented. Each cellular automation cell represents a part of the population that may be found in one of five states of individuals: susceptible, exposed (or latency), infected, immunized (or recovered) and death. Here studied are the effects of two cases on the epidemic spread. i.e. the effects of non-segregation and segregation on the latency and the infected of population. The conclusion is reached that the epidemic will persist in the case of non-segregation but it will decrease in the case of segregation. The proposed model can serve as a basis for the development of algorithms to simulate real epidemics based on real data. Last we find the density series of the exposed and the infected will fluctuate near a positive equilibrium point, when the constant for the immunized is less than its corresponding constant τ0. Our theoretical results are verified by numerical simulations.

  15. Minimal change disease in graft versus host disease: a podocyte response to the graft?

    Science.gov (United States)

    Huskey, Janna; Rivard, Chris; Myint, Han; Lucia, Scott; Smith, Maxwell; Shimada, Michiko; Ishimoto, Takuji; Araya, Carlos; Garin, Eduardo H; Johnson, Richard J

    2013-12-01

    Nephrotic syndrome is a rare complication of hematopoietic cell transplantation. It has been suggested that nephrotic syndrome may represent a limited form of graft-versus-host disease although the pathological link between these two entities remains unclear. In this paper, we report a case of a 61-year-old female who underwent nonmyeloablative allogenic stem cell transplantation for T-cell prolymphocytic leukemia and subsequently developed biopsy proven minimal change disease shortly after cessation of her immunosuppression therapy. Urinary CD80 was markedly elevated during active disease and disappeared following corticosteroid-induced remission. We hypothesize that alloreactive donor T cells target the kidney and induce podocyte expression of CD80 that results in proteinuria from limited 'graft versus host' disease.

  16. The effect of graft strength on knee laxity and graft in-situ forces after posterior cruciate ligament reconstruction.

    Directory of Open Access Journals (Sweden)

    Yu-Shu Lai

    Full Text Available Surgical reconstruction is generally recommended for posterior cruciate ligament (PCL injuries; however, the use of grafts is still a controversial problem. In this study, a three-dimensional finite element model of the human tibiofemoral joint with articular cartilage layers, menisci, and four main ligaments was constructed to investigate the effects of graft strengths on knee kinematics and in-situ forces of PCL grafts. Nine different graft strengths with stiffness ranging from 0% (PCL rupture to 200%, in increments of 25%, of an intact PCL's strength were used to simulate the PCL reconstruction. A 100 N posterior tibial drawer load was applied to the knee joint at full extension. Results revealed that the maximum posterior translation of the PCL rupture model (0% stiffness was 6.77 mm in the medial compartment, which resulted in tibial internal rotation of about 3.01°. After PCL reconstruction with any graft strength, the laxity of the medial tibial compartment was noticeably improved. Tibial translation and rotation were similar to the intact knee after PCL reconstruction with graft strengths ranging from 75% to 125% of an intact PCL. When the graft's strength surpassed 150%, the medial tibia moved forward and external tibial rotation greatly increased. The in-situ forces generated in the PCL grafts ranged from 13.15 N to 75.82 N, depending on the stiffness. In conclusion, the strength of PCL grafts have has a noticeable effect on anterior-posterior translation of the medial tibial compartment and its in-situ force. Similar kinematic response may happen in the models when the PCL graft's strength lies between 75% and 125% of an intact PCL.

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

    Science.gov (United States)

    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.

  18. Impact Insertion of Osteochondral Grafts: Interference Fit and Central Graft Reduction Affect Biomechanics and Cartilage Damage.

    Science.gov (United States)

    Su, Alvin W; Chen, Yunchan; Wailes, Dustin H; Wong, Van W; Cai, Shengqiang; Chen, Albert C; Bugbee, William D; Sah, Robert L

    2017-07-06

    An osteochondral graft (OCG) is an effective treatment for articular cartilage and osteochondral defects. Impact of an OCG during insertion into the osteochondral recipient site (OCR) can cause chondrocyte death and matrix damage. The aim of the present study was to analyze the effects of graft-host interference fit and a modified OCG geometry on OCG insertion biomechanics and cartilage damage. The effects of interference fit (radius of OCG - radius of OCR), loose (0.00mm), moderate (0.05mm), tight (0.10mm), and of a tight fit with OCG geometry modification (central region of decreased radius) were analyzed for OCG cylinders and OCR blocks from adult bovine knee joints with an instrumented drop tower apparatus. An increasingly tight OCG-OCR interference fit led to increased taps for insertion, peak axial force, graft cartilage axial compression, cumulative and total energy delivery to cartilage, lower time of peak axial force, lesser graft advancement during each tap, higher total crack length in the cartilage surface, and lower chondrocyte viability. The modified OCG, with reduction of diameter in the central area, altered the biomechanical insertion variables and biological consequences to be similar to those of the moderate interference fit scenario. Micro-computed tomography confirmed structural interference between the OCR bone and both the proximal and distal bone segments of the OCGs, with the central regions being slightly separated for the modified OCGs. These results clarify OCG insertion biomechanics and mechanobiology, and introduce a simple modification of OCGs that facilitates insertion with reduced energy while maintaining a structural interference fit. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  19. Biosynthetic bacterial cellulose graft as arteriovenous fistula and ndash; a complement to existing synthetic grafts?

    Directory of Open Access Journals (Sweden)

    Johan Magnusson

    2016-06-01

    Materials and Methods: As graftmaterial bacterial cellulose was used, produced around a preformed scaffold. Bacterial cellulose (BC is a material produced by the bacteria acetobacter xylinum. A pilotstudy was conducted on 6 pigs to validate the animalmodel and the new graftmaterial. In the following survival study a BC-graft AV-fistula was constructed in 15 pigs. Results: In the pilot study, 5 out of 6 animals had a patent AV-fistula 4 hours after implantation. In the survival study, after 4 (n3 and 8 (n10 weeks an angiography was performed prior to explantation of the BC-graft. All grafts were occluded with a presumed platelet plug. We conducted an additional acute patch-test comparing the BC and expanded PolyTetraFluoro- Ethylene. A patch of BC and ePTFE was applied to the right and left common femoral artery respectively. At explantation three hours later, all BC-patches showed a thin gel like layer, most likely consisting of platelets, throughout the whole sur- face while the ePTFE-patch showed no, or minimal, signs of platelet adhesions. Conclusion: Theoretically the cellulose might be similar to autologous veins considering risk of infections and thrombo- genicity. The animal model and the graft material showed good potential in the pilot study. The survival study was discour- aging with the reason for occlusion still to be explained. Bacterial cellulose has a good potential but further development and studies need to be performed. [Arch Clin Exp Surg 2016; 5(2.000: 70-77

  20. PCP copolymers grafted with RGD enhance the rates of RGD-PCP micelles internalized into cells.

    Science.gov (United States)

    Chung, Tze-Wen; Tyan, Yu-Chang; Yang, Jean-Dean

    2010-01-01

    RGD-PCP copolymers were fabricated by grafting Arg-Gly-Asp (RGD) peptide to poly(epsilon-caprolactone)-b-chitooligosaccharide-b-poly(ethylene glycol) (PCP) copolymers and the rate of internalization of RGD-PCP micelles by PC 12 cells were examined. Increasing intensity of the absorbance of amine groups in FT-IR spectra of RGD-PCP copolymers compared with those of PCP copolymers indicated the presence of RGD in new copolymers. Moreover, the grafting efficiency and molar ratio of RGD peptides to PCP copolymers were 88.2% and 0.45, respectively, analysed with HPLC. The RGD-PCP copolymers self-assemble to micelles at the critical micelle concentration (CMC) of 0.018 wt% (178 mg L(-1)) and with a mean diameter of 90 nm using a dynamic light-scattering (DLS) analyser. Interestingly, the internalization of DPH-loaded RGD-PCP micelles into PC 12 cells is much faster (e.g. within 5 min) than that of PCP micelles. The new RGD-PCP micelles may potentially be used in cellular drug delivery.

  1. A stimuli-responsive nanoparticulate system using poly(ethylenimine)-graft-polysorbate for controlled protein release

    Science.gov (United States)

    Lai, Wing-Fu; Shum, Ho Cheung

    2015-12-01

    Proteins have emerged as an important class of therapeutic agents due to their high specificity in their physiological actions. Over the years, diverse protein carriers have been developed; however, some concerns, such as the relatively low loading efficiency and release sustainability, have limited the efficiency of protein delivery. This study reports the use of hydrogel nanoparticles based on a novel copolymer, poly(ethylenimine)-graft-polysorbate (PEIP), as effective protein carriers. The copolymer is fabricated by grafting poly(ethylenimine) (PEI) with polysorbate 20 using carbonyldiimidazole chemistry. Its cytotoxicity is much lower than that of unmodified PEI in RGC5 and HEK293 cells. In comparison with nanoparticles formed by unmodified PEI, our nanoparticles are not only more efficient in cellular internalization, as indicated by the 5- to 6-fold reduction in the time they take to cause 90% of cells to exhibit intracellular fluorescence, but also give a protein loading efficiency as high as 70-90%. These, together with the salt-responsiveness of the nanoparticles in protein release and the retention of the activity of the loaded protein, suggest that PEIP and its hydrogel nanoparticles warrant further development as protein carriers for therapeutic applications.

  2. [Regional graft vs host reaction to H-Y antigen (immunological mechanisms)].

    Science.gov (United States)

    Volkova, L V; Verbitskiĭ, M Sh; Sapin, M R; Aminova, G G; Rusina, A K

    1987-08-01

    Structural changes in the regional popliteal lymph nodes have been studied in C57Bl/6 male mice at the peak of the reaction "graft-versus-host" to H-Y antigen. Morphological and morphometrical investigations have been carried out in three groups of males (10 animals in each group). The first group includes intact animals (the first control group). To the males of the second group (the second control group) lymphoid cells are inoculated from intact C57Bl/6 females. To the males of the third group (experimental group) lymphoid cells are inoculated from H-Y antigen immunized C57Bl/6 females (anti-H-Y effector lymphocytes). The popliteal lymph nodes of the male mice from the third group twice increase in their size comparing to those in the control (the first and the second groups). Miotic activity increases in them 4.5 times, amount of cellular blast forms in medullary cords--4 times and 10 times--in the light zone of the cortical substance. Ratio of macrophages and eosinophils in structural components of the lymph nodes studied changes; this is, evidently, connected with massive destructive progresses, that take place in the lymph nodes of the animals from the third group. The results of the morphological investigations are in agreement with the hypothesis suggested, explaining the mechanism of development of the regional reaction "graft-versus-host" to H-Y antigen, basing on idiotype-antiidiotype interaction (the idiotypic network in the immune system).

  3. Hybrid Matrix Grafts to Favor Tissue Regeneration in Rabbit Femur Bone Lesions

    Science.gov (United States)

    Goy, Dante Pascual; Gorosito, Emmanuel; Costa, Hermes S; Mortarino, Pablo; Pedemonte, Noelia Acosta; Toledo, Javier; Mansur, Herman S; Pereira, Marivalda M; Battaglino, Ricardo; Feldman, Sara

    2012-01-01

    At present, typical approaches employed to repair fractures and other bone lesions tend to use matrix grafts to promote tissue regeneration. These grafts act as templates, which promote cellular adhesion, growth and proliferation, osteoconduction, and even osteoinduction, which commonly results in de novo osteogenesis. The present work aimed to study the bone-repairing ability of hybrid matrixes (HM) prepared with polyvinyl alcohol (PVA) and bioactive glass in an experimental rabbit model. The HM were prepared by combining 30% bioactive glass (nominal composition of 58% SiO2 -33 % CaO - 9% P2O5) and 70% PVA. New Zealand rabbits were randomly divided into the control group (C group) and two groups with bone lesions, in which one received a matrix implant HM (Implant group), while the other did not (no Implant group). Clinical monitoring showed no altered parameters from either the Implant or the no Implant groups as compared to the control group, for the variables of diet grades, day and night temperatures and hemograms. In the Implant group, radiologic and tomographic studies showed implanted areas with clean edges in femoral non-articular direction, and radio-dense images that suggest incipient integration. Minimum signs of phlogosis could be observed, whereas no signs of rejection at this imaging level could be identified. Histological analysis showed evidence of osteo-integration, with the formation of a trabecular bone within the implant. Together, these results show that implants of hybrid matrixes of bioactive glass are capable of promoting bone regeneration. PMID:22848334

  4. Percutaneous mechanical declotting of thrombosed dialysis graft

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seung Boo; Goo, Dong Erk; Kim, Dae Ho; Lee, Hae Kyung; Choi, Deuk Lin; Kwon, Kee Hyang; Hong, Hyun Sook; Moon, Chul [College of Medicine, Soonchunhyang University, Seoul (Korea, Republic of)

    2000-10-01

    To evaluate the effectiveness of percutaneous mechanical declotting. Using a 7-F Desilets-Hoffman sheath and the crossed-catheter technique, we aspirated the intragraft clot and pushed the residual clot into the central circulation with balloon catheters. The success rate, procedure time, complications and patency rates were evaluated. Technical success was achieved in 24 of 32 cases, with a procedure time of 30-240 (average, 111) minutes. In five of eight cases in which technical failure occurred, the guide wire failed to reach the stenotic site and in the other three, there was insufficient luminal dilatation. Complications included vein ruptures (n=2), arterial emboli (n=1) and arterial dissection (1), but there was no evidence of clinical symptoms of pulmonary embolism. The six-month patency rate was 67.8%. Mechanical declotting of thrombosed dialysis graft using a balloon catheter is relatively inexpensive, safe and fast, and is well tolerated. (author)

  5. Lycopene and flesh colour differences in grafted and non-grafted watermelon

    Directory of Open Access Journals (Sweden)

    Fekete D.

    2015-01-01

    Full Text Available The experiment was carried out in three regions in Hungary (Jászszentandrás, Cece, Újkígyós in 2013 to determine the fruit quality of grafted watermelon (Citrullus lanatus Thunb.. The “RX 467” seedless watermelon variety was grafted on two commercial rootstocks “FR STRONG” [Lagenaria siceraria (Mol. Standl.] and “RS 841” (Cucurbita maxima Duchesne × Cucurbita moschata Duchesne. The lycopene and flesh colours are important quality characteristics even of the selfrooted and grafted watermelon. Some differences can be attributed to different environments, technological methods and to the type of rootstockscion combination. Lycopene is a strong antioxidant; therefore, we considered to examine the content change. Regardless of growing location, the lycopene concentration and the chroma (C* showed the best result in the case of interspecific rootstock. The result also showed that in two regions (Jászszentandrás, Cece we can find negative correlation between the lycopene concentration and the L* value of the flesh colour.

  6. Covalent grafting of the RGD-peptide onto polyetheretherketone surfaces via Schiff base formation.

    Science.gov (United States)

    Becker, Marc; Lorenz, Steffen; Strand, Dennis; Vahl, Christian-Friedrich; Gabriel, Matthias

    2013-01-01

    In recent years, the synthetic polymer polyetheretherketone (PEEK) has increasingly been used in a number of orthopedic implementations, due to its excellent mechanical properties, bioinertness, and chemical resistance. For in vivo applications, the surface of PEEK, which does not naturally support cell adhesion, has to be modified to improve tissue integration. In the present work we demonstrate a novel wet-chemical modification of PEEK to modify the surface, enabling the covalent grafting of the cell-adhesive RGD-peptide. Modification of the polymer surface was achieved via Schiff base formation using an aliphatic diamine and subsequent crosslinker-mediated immobilization of the peptide. In cell culture experiments with primary osteoblasts it was shown that the RGD-modified PEEK not only significantly promoted cellular adhesion but also strongly enhanced the proliferation of osteoblasts on the modified polymer surface.

  7. Size dependent transitions in grafted polymer brushes

    Science.gov (United States)

    Bosse, Courtney E.

    Finding probabilities in order to solve for the most likely configuration of a grafted polymer chain is easily calculated by solving a random walk problem, starting form a given point (the surface). A property of the random walk is used to describe the partition function of a polymer in terms of a sum over possible loops configurations, which simplifies tremendously the problem of calculating the partition function of the grafted polymer. Instead of solving the non-interacting random walk that has been well studied in the theory of the probability, the focus is on the problem of self-interacting random walks, which cannot be solved exactly and has had various approximations suggested. The idea was to take the easily solved equations that give the solutions for the non-interacting random walks and add a new term with a specific given energy. This finds the probabilities of loop formation, and from there, the most likely configuration of interacting random walks. The most likely configuration has also been calculated by Monte Carlo but in order to be accurate, it needs many sampling points, which means much computer time. Practically, they are limited to chains with less than 1000 segments, which are not close to the phase transitions. It is well known that the most accurate treatment planning procedures are based on Monte-Carlo calculations; however, their accuracy is limited by the computer time available. This method could be a better analytical approximation than Monte-Carlo calculations, and could drastically decrease the computing time requirement, and hence, more accurate TPS (Treatment Planning Systems) would be available to the Medical Physics community.

  8. Vascularized fibular graft in infected tibial bone loss

    Directory of Open Access Journals (Sweden)

    C Cheriyan Kovoor

    2011-01-01

    Full Text Available Background : The treatment options of bone loss with infections include bone transport with external fixators, vascularized bone grafts, non-vascularized autogenous grafts and vascularized allografts. The research hypothesis was that the graft length and intact ipsilateral fibula influenced hypertrophy and stress fracture. We retrospectively studied the graft hypertrophy in 15 patients, in whom vascularized fibular graft was done for post-traumatic tibial defects with infection. Materials and Methods : 15 male patients with mean age 33.7 years (range 18 - 56 years of post traumatic tibial bone loss were analysed. The mean bony defect was 14.5 cm (range 6.5 - 20 cm. The mean length of the graft was 16.7 cm (range 11.5 - 21 cm. The osteoseptocutaneous flap (bone flap with attached overlying skin flap from the contralateral side was used in all patients except one. The graft was fixed to the recipient bone at both ends by one or two AO cortical screws, supplemented by a monolateral external fixator. A standard postoperative protocol was followed in all patients. The hypertrophy percentage of the vascularized fibular graft was calculated by a modification of the formula described by El-Gammal. The followup period averaged 46.5 months (range 24 - 164 months. The Pearson correlation coefficient (r was worked out, to find the relationship between graft length and hypertrophy. The t-test was performed to find out if there was any significant difference in the graft length of those who had a stress fracture and those who did not and to find out whether there was any significant difference in hypertrophy with and without ipsilateral fibula union. The Chi square test was performed to identify whether there was any association between the stress fracture and the fibula union. Given the small sample size we have not used any statistical analysis to determine the relation between the percentage of the graft hypertrophy and stress fracture. Results : Graft

  9. PRIMARY DERMIS FAT GRAFT IMPLANTATION IN ORBIT AFTER EVISCERATION

    Directory of Open Access Journals (Sweden)

    Sandeep K

    2015-04-01

    Full Text Available Background: Orbital implants allow for cosmesis and volume replacement of an eviscerated eye. Dermis fat graft is a viable alternative to alloplastic implants as a primary orbital implant following ocular evisceration. Aim/Objectives: To provide evidence for dermal fat graft as a safe and stable orbital volume replacement following ocular evisceration. Methodology: A prospective, interventional, non-comparative case series of patients who had an primary autologous dermis graft after evisceration.All the patients fulfilling the criteria were identified. At 6 weeks post-operatively, patients received an ocular prosthesis. The volume of the dermis-fat grafted globe was measured at 1 month and 9 months post-operatively by plain magnetic resonance imaging of the orbit. Results: Ten patients underwent ocular evisceration and dermis fat graft implant.Nine patients completed the study.Out of 10 patients 60% (6 were males and 40% (4 were females.Suture abscess was noted in 20% patients, hair growth in the dermis in 10%, sub conjunctival cysts in 10% patients.Cosmetic outcome showed very good result in 50% patients with good prosthetic motility in 60%. Conclusion: This case series shows that the use of a dermis graft is a safe and effective new technique to facilitate orbital rehabilitation. It is hypothesised that the extra surface area produced with a dermis graft preserves the fornices and allows a larger implant.

  10. Suction blister grafting for vitiligo: efficacy and clinical predictive factors.

    Science.gov (United States)

    Gou, Darlene; Currimbhoy, Sharif; Pandya, Amit G

    2015-05-01

    Suction blister epidermal grafting (SBEG) is a well-established treatment modality for vitiligo, but predictive factors for outcomes are not well characterized. To determine the efficacy and predictive variables for response to SBEG in patients with vitiligo. A retrospective single-center review of all cases treated with SBEG was performed. Repigmentation was assessed by 2 independent reviewers by assessing pigment spread of grafts during the postoperative period. Repigmentation rates were then compared with patient demographics and transplant location. A total of 28 patients were enrolled in this study. The total number of grafts was 129, of which 86.8% (112/129) survived. Highest rate of graft survival was seen in patients younger than 20 years (100%) and the lowest in patients older than 40 years (75%-78%). Repigmentation was seen in 68% of patients. The highest degree of pigment spread was on the neck (283%) and face (231%), whereas the hands and feet had the least response (119%). Blister grafting is successful in most patients with vitiligo, with a high graft survival rate; however, the degree of pigment spread is variable and depends on clinical characteristics of the patient and graft site.

  11. Percutaneous treatment of complications occurring during hemodialysis graft recanalization

    Energy Technology Data Exchange (ETDEWEB)

    Sofocleous, Constantinos T. E-mail: constant@pol.net; Schur, Israel; Koh, Elsie; Hinrichs, Clay; Cooper, Stanley G.; Welber, Adam; Brountzos, Elias; Kelekis, Dimitris

    2003-09-01

    Introduction/objective: To describe and evaluate percutaneous treatment methods of complications occurring during recanalization of thrombosed hemodialysis access grafts. Methods and materials: A retrospective review of 579 thrombosed hemodialysis access grafts revealed 48 complications occurring during urokinase thrombolysis (512) or mechanical thrombectomy (67). These include 12 venous or venous anastomotic ruptures not controlled by balloon tamponade, eight arterial emboli, 12 graft extravasations, seven small hematomas, four intragraft pseudointimal 'dissections', two incidents of pulmonary edema, one episode of intestinal angina, one procedural death, and one distant hematoma. Results: Twelve cases of post angioplasty ruptures were treated with uncovered stents of which 10 resulted in graft salvage allowing successful hemodialysis. All arterial emboli were retrieved by Fogarty or embolectomy balloons. The 10/12 graft extravasations were successfully treated by digital compression while the procedure was completed and the graft flow was restored. Dissections were treated with prolonged Percutaneous Trasluminal Angioplasty (PTA) balloon inflation. Overall technical success was 39/48 (81%). Kaplan-Meier Primary and secondary patency rates were 72 and 78% at 30, 62 and 73% at 90 and 36 and 67% at 180 days, respectively. Secondary patency rates remained over 50% at 1 year. There were no additional complications caused by these maneuvers. Discussions and conclusion: The majority of complications occurring during percutaneous thrombolysis/thrombectomy of thrombosed access grafts, can be treated at the same sitting allowing completion of the recanalization procedure and usage of the same access for hemodialysis.

  12. Grafted polymer chains suppress nanoparticle diffusion in athermal polymer melts

    Science.gov (United States)

    Lin, Chia-Chun; Griffin, Philip J.; Chao, Huikuan; Hore, Michael J. A.; Ohno, Kohji; Clarke, Nigel; Riggleman, Robert A.; Winey, Karen I.; Composto, Russell J.

    2017-05-01

    We measure the center-of-mass diffusion of poly(methyl methacrylate) (PMMA)-grafted nanoparticles (NPs) in unentangled to slightly entangled PMMA melts using Rutherford backscattering spectrometry. These grafted NPs diffuse ˜100 times slower than predicted by the Stokes-Einstein relation assuming a viscosity equal to bulk PMMA and a hydrodynamic NP size equal to the NP core diameter, 2Rcore = 4.3 nm. This slow NP diffusion is consistent with an increased effective NP size, 2Reff ≈ 20 nm, nominally independent of the range of grafting density and matrix molecular weights explored in this study. Comparing these experimental results to a modified Daoud-Cotton scaling estimate for the brush thickness as well as dynamic mean field simulations of polymer-grafted NPs in athermal polymer melts, we find that 2Reff is in quantitative agreement with the size of the NP core plus the extended grafted chains. Our results suggest that grafted polymer chains of moderate molecular weight and grafting density may alter the NP diffusion mechanism in polymer melts, primarily by increasing the NP effective size.

  13. Proximal tubular dysfunction as an indicator of chronic graft dysfunction

    Directory of Open Access Journals (Sweden)

    N.O.S. Câmara

    2009-03-01

    Full Text Available New strategies are being devised to limit the impact of renal sclerosis on graft function. Individualization of immunosuppression, specifically the interruption of calcineurin-inhibitors has been tried in order to promote better graft survival once chronic graft dysfunction has been established. However, the long-term impact of these approaches is still not totally clear. Nevertheless, patients at higher risk for tubular atrophy and interstitial fibrosis (TA/IF development should be carefully monitored for tubular function as well as glomerular performance. Since tubular-interstitial impairment is an early event in TA/IF pathogenesis and associated with graft function, it seems reasonable that strategies directed at assessing tubular structural integrity and function would yield important functional and prognostic data. The measurement of small proteins in urine such as α-1-microglobulin, N-acetyl-beta-D-glucosaminidase, alpha/pi S-glutathione transferases, β-2 microglobulin, and retinol binding protein is associated with proximal tubular cell dysfunction. Therefore, its straightforward assessment could provide a powerful tool in patient monitoring and ongoing clinical assessment of graft function, ultimately helping to facilitate longer patient and graft survival associated with good graft function.

  14. Computational Model of Aortic Valve Surgical Repair using Grafted Pericardium

    Science.gov (United States)

    Hammer, Peter E.; Chen, Peter C.; del Nido, Pedro J.; Howe, Robert D.

    2012-01-01

    Aortic valve reconstruction using leaflet grafts made from autologous pericardium is an effective surgical treatment for some forms of aortic regurgitation. Despite favorable outcomes in the hands of skilled surgeons, the procedure is underutilized because of the difficulty of sizing grafts to effectively seal with the native leaflets. Difficulty is largely due to the complex geometry and function of the valve and the lower distensibility of the graft material relative to native leaflet tissue. We used a structural finite element model to explore how a pericardial leaflet graft of various sizes interacts with two native leaflets when the valve is closed and loaded. Native leaflets and pericardium are described by anisotropic, hyperelastic constitutive laws, and we model all three leaflets explicitly and resolve leaflet contact in order to simulate repair strategies that are asymmetrical with respect to valve geometry and leaflet properties. We ran simulations with pericardial leaflet grafts of various widths (increase of 0%, 7%, 14%, 21% and 27%) and heights (increase of 0%, 13%, 27% and 40%) relative to the native leaflets. Effectiveness of valve closure was quantified based on the overlap between coapting leaflets. Results showed that graft width and height must both be increased to achieve proper valve closure, and that a graft 21% wider and 27% higher than the native leaflet creates a seal similar to a valve with three normal leaflets. Experimental validation in excised porcine aortas (n=9) corroborates the results of simulations. PMID:22341628

  15. Technical modification for composite grafts in myocardial revascularization surgery

    Directory of Open Access Journals (Sweden)

    Chaccur Paulo

    2002-01-01

    Full Text Available OBJECTIVE: In the last decade, the coronary artery bypass grafts (CABG with arterial grafting had been remarkable, mainly the combined ones in Y or T form, which start from the left internal thoracic artery (LITA. Elaborating this kind of grafting, we identified a certain worry related to the anastomoses of the radial artery in LITA, principally when realized in T, since any small traction, angulations or spasms of the radial artery might impaired the flow of the distal anastomoses of LITA to the anterior interventricular artery. METHOD: We modified the combined graft technique, by making anastomoses of the radial artery to the anterior interventricular artery, and, consequently the LITA is sewed above the anastomoses of the radial artery to the anterior interventricular artery, favoring therefore, the revascularization of the anterior interventricular artery with the LITA, transforming the radial artery into almost an extension of the LITA to the remaining branches of the left coronary artery. CONCLUSIONS: This technical modification for these composite grafts is simple, safer and effective, and it will enable a larger number of surgeons to routinelyuse composite grafts in coronary artery bypass grafting.

  16. Sulfonated Poly(styrene) Chains Grafted on Magnetic Nanoparticles

    Science.gov (United States)

    Jiao, Yang; Yevelev, Anton; Parra, Javier; Akcora, Pinar; Stevens Institute of Technology Team

    2014-03-01

    Iron oxide nanoparticles functionalized with poly(styrene) (PS) chains at various grafting densities and loadings present stable and ordered nanostructures for tuning the mechanical and conductive properties in polymer composites. Strings, spherical and anisotropic clusters and well-dispersed particles are achieved with PS-grafted Fe3O4 nanoparticles in PS matrices upon varying the system parameters. In this work, we report the effect of sulfonic group locations on the aggregation state of polymer-grafted nanoparticles. Structures formed by the random and diblock copolymers of PS-poly(styrene sulfonate) (PSS) grafted particles will be discussed with small-angle x-ray scattering (SAXS) measurements in solution and melts. The conformational changes in PS-grafted chains and ion-containing grafts will be also presented in small-angle neutron-scattering (SANS) results to understand the role of polymer on the assembly of particles at the low grafting density. We acknowledge support by NSF-CAREER-DMR (#1048865).

  17. Clinical Features of Primary Vein Grafts in Free Tissue Transfers

    Directory of Open Access Journals (Sweden)

    Mitsuru Nemoto

    2015-01-01

    Full Text Available The outcomes of free tissue transfers combined with vein grafts have been inconsistent, and discussions continue regarding their appropriate use. Of the 142 free tissue transfers that we performed from January 2004 to December 2011, we retrospectively analyzed 15 consecutive patients who underwent free tissue transfers in combination with vein grafts. Etiologies included trauma (8 patients, infection (4, and tumor (3. Types of free tissue transfers were fibula (4, anterolateral thigh (3, groin (3, jejunum (3, latissimus dorsi (1, and dorsal pedis (1. Vein grafts were used for the artery (6, vein (2, or both (7. The donor veins were the saphenous vein (12 and the external jugular vein (3. The mean length of the grafted veins was 10.8 cm (range: 4–18 cm. Even though complications of congestion occurred in 2 patients, these flaps survived by reexploration. The flap success rate was 15 of 15 (100% of vein grafted free flaps versus 124 of 127 (97.6% of free flaps not requiring vein grafts. To improve the success rate of free tissue transfers combined with vein grafts, securing healthy recipient vessels, meticulous surgical handling, a reliable vascular anastomosis technique, and strict postoperative monitoring are crucial.

  18. Second Unrelated Donor Hematopoietic Cell Transplantation for Primary Graft Failure

    Science.gov (United States)

    Schriber, Jeffrey; Agovi, Manza-A.; Ho, Vincent; Ballen, Karen K.; Bacigalupo, Andrea; Lazarus, Hillard M.; Bredeson, Christopher N.; Gupta, Vikas; Maziarz, Richard T.; Hale, Gregory A.; Litzow, Mark R.; Logan, Brent; Bornhauser, Martin; Giller, Roger H.; Isola, Luis; Marks, David I.; Rizzo, J. Douglas; Pasquini, Marcelo C.

    2010-01-01

    Failure to engraft donor cells is a devastating complication after allogeneic hematopoietic cell transplantation (HCT). We describe the results of 122 patients reported to the National Marrow Donor Program between 1990 and 2005, who received a second unrelated donor HCT after failing to achieve an absolute neutrophil count of ≥ 500/ μL without recurrent disease. Patients were transplanted for leukemia (n=83), myelodysplastic disorders (n=16), severe aplastic anemia (n=20) and other diseases (n=3). The median age was 29 years. Twenty-four patients received second grafts from a different unrelated donor. Among 98 patients who received a second graft from the same donor, 28 received products that were previously collected and cryopreserved for the first transplantation. One-year overall survival after second transplant was 11% with 10 patients alive at last follow up. We observed no differences between patients who received grafts from the same or different donors, or in those who received fresh or cryopreserved product. The outcomes after a second allogeneic HCT for primary graft failure are dismal. Identifying risk factors for primary graft failure can decrease the incidence of this complication. Further studies are needed to test whether early recognition and hastened procurement of alternative grafts can improve transplant outcomes for primary graft failure. PMID:20172038

  19. Adequacy of palmaris longus and plantaris tendons for tendon grafting.

    Science.gov (United States)

    Jakubietz, Michael G; Jakubietz, Danni F; Gruenert, Joerg G; Zahn, Robert; Meffert, Rainer H; Jakubietz, Rafael G

    2011-04-01

    The reconstruction of tendon defects is challenging. The palmaris longus and plantaris tendon are generally considered best for tendon grafting. Only a few studies have examined whether these tendons, when present, meet criteria for successful grafting. The purpose of this study was to evaluate these tendons in regard to adequacy as tendon grafts. To evaluate adequacy for grafting, the palmaris longus and plantaris tendons were harvested from 92 arms and legs of 46 cadavers. Macroscopic evaluation and measurements concerning presence, length, and diameter of the tendons were obtained. Criteria for adequacy were a minimum length of 15 cm with diameter of 3 mm or, alternatively, 30 cm with a diameter of 1.5 mm. The palmaris longus tendon was present bilaterally in 36 cases and was absent bilaterally in 4 cases. The plantaris tendon was present bilaterally in 38 cases and absent bilaterally in 4 cases. In 29 cadavers, the palmaris longus tendon did not meet the criteria to be used as a tendon graft. Only in 8 cases were the tendons satisfactory for grafting bilaterally. The plantaris tendon met criteria for grafting in 20 cases bilaterally. In 17 cases, the tendons were considered inadequate bilaterally. Despite their presence, the palmaris longus and plantaris tendons are adequate for grafting less often than previously thought. In less than 50%, the tendons, although present, would serve as useful grafts. Our findings underscore the importance of choosing a second donor site before surgery in case the primarily selected tendon is not found to be suitable. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  20. Immobilization of penicillin G acylase on paramagnetic aldehyde-functionalized mesostructured cellular foams.

    Science.gov (United States)

    Yang, Ling; Gao, Zhenyuan; Guo, Yanglong; Zhan, Wangcheng; Guo, Yun; Wang, Yunsong; Lu, Guanzhong

    2014-06-10

    Paramagnetic aldehyde-functionalized mesostructured cellular foams (PAMCFs), synthesized by grafting 3-aminopropyltriethoxysilane modified Fe3O4 (NH2-Fe3O4) nanoparticles with larger particle size than the window pore size of MCFs on the outer surface of aldehyde-functionalized mesostructured cellular foams (AMCFs), were investigated as efficient supports for immobilization of penicillin G acylase (PGA). The results show that NH2-Fe3O4 nanoparticles were successfully grafted on the outer surface of AMCFs and PGA molecules were mainly immobilized covalently on the inner surface of PAMCFs, which was because amino groups of NH2-Fe3O4 nanoparticles or PGA molecules reacted with aldehyde groups of AMCFs or PAMCFs to form imine bonds. PGA/PAMCFs-15 showed a rather high initial activity of 9563Ug(-1) and retained 89.1% of its initial activity after recycled for 10 times. PGA/PAMCFs are easily recycled by magnetic field in order to replace tedious separation of high-speed centrifugation for mesoporous materials.

  1. Sensing Phosphatidylserine in Cellular Membranes

    Directory of Open Access Journals (Sweden)

    Jason G. Kay

    2011-01-01

    Full Text Available Phosphatidylserine, a phospholipid with a negatively charged head-group, is an important constituent of eukaryotic cellular membranes. On the plasma membrane, rather than being evenly distributed, phosphatidylserine is found preferentially in the inner leaflet. Disruption of this asymmetry, leading to the appearance of phosphatidylserine on the surface of the cell, is known to play a central role in both apoptosis and blood clotting. Despite its importance, comparatively little is known about phosphatidylserine in cells: its precise subcellular localization, transmembrane topology and intracellular dynamics are poorly characterized. The recent development of new, genetically-encoded probes able to detect phosphatidylserine within live cells, however, is leading to a more in-depth understanding of the biology of this phospholipid. This review aims to give an overview of the current methods for phosphatidylserine detection within cells, and some of the recent realizations derived from their use.

  2. Discrete geodesics and cellular automata

    CERN Document Server

    Arrighi, Pablo

    2015-01-01

    This paper proposes a dynamical notion of discrete geodesics, understood as straightest trajectories in discretized curved spacetime. The notion is generic, as it is formulated in terms of a general deviation function, but readily specializes to metric spaces such as discretized pseudo-riemannian manifolds. It is effective: an algorithm for computing these geodesics naturally follows, which allows numerical validation---as shown by computing the perihelion shift of a Mercury-like planet. It is consistent, in the continuum limit, with the standard notion of timelike geodesics in a pseudo-riemannian manifold. Whether the algorithm fits within the framework of cellular automata is discussed at length. KEYWORDS: Discrete connection, parallel transport, general relativity, Regge calculus.

  3. Cellular compartmentalization of secondary metabolism

    Directory of Open Access Journals (Sweden)

    H. Corby eKistler

    2015-02-01

    Full Text Available Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors shared with the most essential processes of the cell (e.g. amino acids, acetyl CoA, NADPH, enzymes for secondary metabolite synthesis are compartmentalized at conserved subcellular sites that position pathway enzymes to use these common biochemical precursors. Co-compartmentalization of secondary metabolism pathway enzymes also may function to channel precursors, promote pathway efficiency and sequester pathway intermediates and products from the rest of the cell. In this review we discuss the compartmentalization of three well-studied fungal secondary metabolite biosynthetic pathways for penicillin G, aflatoxin and deoxynivalenol, and summarize evidence used to infer subcellular localization. We also discuss how these metabolites potentially are trafficked within the cell and may be exported.

  4. Molecular, cellular, and tissue engineering

    CERN Document Server

    Bronzino, Joseph D

    2015-01-01

    Known as the bible of biomedical engineering, The Biomedical Engineering Handbook, Fourth Edition, sets the standard against which all other references of this nature are measured. As such, it has served as a major resource for both skilled professionals and novices to biomedical engineering. Molecular, Cellular, and Tissue Engineering, the fourth volume of the handbook, presents material from respected scientists with diverse backgrounds in molecular biology, transport phenomena, physiological modeling, tissue engineering, stem cells, drug delivery systems, artificial organs, and personalized medicine. More than three dozen specific topics are examined, including DNA vaccines, biomimetic systems, cardiovascular dynamics, biomaterial scaffolds, cell mechanobiology, synthetic biomaterials, pluripotent stem cells, hematopoietic stem cells, mesenchymal stem cells, nanobiomaterials for tissue engineering, biomedical imaging of engineered tissues, gene therapy, noninvasive targeted protein and peptide drug deliver...

  5. Thermomechanical characterisation of cellular rubber

    Science.gov (United States)

    Seibert, H.; Scheffer, T.; Diebels, S.

    2016-09-01

    This contribution discusses an experimental possibility to characterise a cellular rubber in terms of the influence of multiaxiality, rate dependency under environmental temperature and its behaviour under hydrostatic pressure. In this context, a mixed open and closed cell rubber based on an ethylene propylene diene monomer is investigated exemplarily. The present article intends to give a general idea of the characterisation method and the considerable effects of this special type of material. The main focus lies on the experimental procedure and the used testing devices in combination with the analysis methods such as true three-dimensional digital image correlation. The structural compressibility is taken into account by an approach for a material model using the Theory of Porous Media with additional temperature dependence.

  6. REGULATORY MECHANISMS OF CELLULAR RESPIRATION

    Science.gov (United States)

    Barron, E. S. Guzman; Nelson, Leonard; Ardao, Maria Isabel

    1948-01-01

    Oxidizing agents of sulfhydryl groups such as iodosobenzoate, alkylating agents such as iodoacetamide, and mercaptide-forming agents such as cadmium chloride, mercuric chloride, p-chloromercuribenzoate, sodium arsenite, and p-carboxyphenylarsine oxide, added in small concentrations to a suspension of sea urchin sperm produced an increase in respiration. When the concentration was increased there was an inhibition. These effects are explained by postulating the presence in the cells of two kinds of sulfhydryl groups: soluble sulfhydryl groups, which regulate cellular respiration, and fixed sulfhydryl groups, present in the protein moiety of enzymes. Small concentrations of sulfhydryl reagents combine only with the first, thus producing an increase in respiration; when the concentration is increased, the fixed sulfhydryl groups are also attacked and inhibition of respiration is the consequence. Other inhibitors of cell respiration, such as cyanide and urethanes, which do not combine with —SH groups, did not stimulate respiration in small concentration. PMID:18891144

  7. Electrical Properties of n-Butylacrylate Grafted Polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang R. [CRIEPI Post-Doc. (Japan); Oh, Woo J.; Suh, Kwang S. [Korea University (Korea, Republic of); Kim, Ok [Taekwang Research Center (Korea, Republic of)

    1998-01-01

    Electrical properties such as space charge accumulation, conduction, dielectric breakdown and water treeing of n-butylacrylate-grafted polyethylene ( PE-g-nBA ) were investigated. Heterocharge accumulates in PE-g-nBA and their amount is larger than that in LDPE. Conduction currents and charge mobilities of PE-g-nBAs decreased with the increase of nBA graft ratio, while their conduction mechanisms remain unchanged. Dielectric breakdown strength increased and water treeing length decreased with the increase of graft ratio in PE-g-nBA. (author). 20 refs., 9 figs., 1 tab.

  8. Dermal grafts for correction of severe chordee associated with hypospadias.

    Science.gov (United States)

    Horton, C E; Gearhart, J P; Jeffs, R D

    1993-08-01

    We report on 24 patients with hypospadias and severe chordee that could not be straightened with conventional techniques. We used small dermal grafts to augment the ventral tunica albuginea, which resulted in a completely straight, normal appearing erection in all patients. Subsequent urethroplasty was not complicated by the presence of the dermal graft. This procedure is technically straightforward and consistently results in a completely straight penis. Although required only rarely in hypospadias surgery, we recommend the dermal graft technique of tunica albuginea augmentation for cases of refractory chordee.

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

    Science.gov (United States)

    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

  10. Guidelines for sizing pericardium for aortic valve leaflet grafts

    Science.gov (United States)

    Hammer, Peter E.; del Nido, Pedro J.

    2013-01-01

    Surgical repair of the aortic valve using leaflet grafts made from pericardium has been shown to be a viable option, particularly in children, in whom valve replacement has strong disadvantages. We present guidelines for sizing treated autologous pericardium to fabricate a leaflet graft for single leaflet replacement. Both our clinical experience and experimental evidence indicate that effective repairs are best achieved using a semicircular graft with diameter 10–15% greater than the sinotubular junction diameter in diastole. We also provide a simple formula to allow adjusting these guidelines to account for variation in valve geometry and tissue properties. PMID:23816114

  11. Liquid crystal of nanocellulose whiskers' grafted with acrylamide

    Institute of Scientific and Technical Information of China (English)

    Jie Yang; Dai Yong Ye

    2012-01-01

    12% acrylamide (AM) was grafted onto the surface of nanocellulose whiskers (NCW),which was self-assembled to be the chiral nematic suspension at 3% content.The acrylamide grafted NCW (AM-g-NCW) was characterized with Fourier Transform Infrared Spectroscopy (FTIR).The grafting ratio was measured by elemental analysis.The degrees of crystallinity of the AM-g-NCW were measured by X-ray diffraction (XRD).The liquid crystalline properties of the AM-g-NCW were investigated by the polarizing optical microscopy (POM).The AM-g-NCW was found to self-assembly to be a lyotropic state.

  12. Glanuloplasty with Oral Mucosa Graft following Total Glans Penis Amputation

    Directory of Open Access Journals (Sweden)

    Kwaku Appiah

    2014-01-01

    Full Text Available This is a report on the technique of neoglans reconstruction in a patient with amputated glans penis following guillotine neonatal circumcision. A 4 cm long and 2 cm wide lower lip oral mucosa graft was harvested and used to graft the distal 2 cm of the corporal bodies after 2 cm of the distal penile skin had been excised. One edge of the lower lip oral mucosa graft was anastomosed to the urethral margins distally and proximally to the skin. At six months of followup, patient had both satisfactory cosmetic and functional outcomes.

  13. Windthrow resistance of apple trees grafted in an orchard

    OpenAIRE

    Koizumi, Akio; Araki, Hajime; Hori, Hirotaka; Inagawa, Yutaka

    2008-01-01

    Pull-down tests were conducted for apple trees grafted in an orchard and for support posts in order to discuss the failure mode in windthrow damage, the effect of rootstock types on the uprooting strength, and the reinforcing effect of support posts on young trees. The test samples were 10 mature trees (20–23 years old) of 3 varieties grafted on two types of rootstocks, 3 young trees (7 years old) grafted on dwarf rootstocks, and 9 support posts of larch logs and steel pipes. The failure mode...

  14. Novel features of radiation-induced bystander signaling in Arabidopsis thaliana demonstrated using root micro-grafting

    Science.gov (United States)

    Wang, Ting; Li, Fanghua; Xu, Wei; Bian, Po; Wu, Yuejin; Wu, Lijun

    2012-01-01

    Radiation-induced bystander effects (RIBE) have been well demonstrated in whole organisms, as well as in single-cell culture models in vitro and multi-cellular tissues models in vitro, however, the underlying mechanisms remain unclear, including the temporal and spatial course of bystander signaling. The RIBE in vivo has been shown to exist in the model plant Arabidopsis thaliana (A. thaliana). Importantly, the unique plant grafting provides a delicate approach for studying the temporal and spatial course of bystander signaling in the context of whole plants. In our previous study, the time course of bystander signaling in plants has been well demonstrated using the root micro-grafting technique. In this study, we further investigated the temporal cooperation pattern of multiple bystander signals, the directionality of bystander signaling, and the effect of bystander tissues on the bystander signaling. The results showed that the bystander response could also be induced efficiently when the asynchronously generated bystander signals reached the bystander tissues in the same period, but not when they entered into the bystander tissues in an inversed sequence. The absence of bystander response in root-inversed grafting indicated that the bystander signaling along roots might be of directionality. The bystander signaling was shown to be independent of the bystander tissues. PMID:23072991

  15. 3-D Imaging Reveals Participation of Donor Islet Schwann Cells and Pericytes in Islet Transplantation and Graft Neurovascular Regeneration

    Directory of Open Access Journals (Sweden)

    Jyuhn-Huarng Juang

    2015-02-01

    Full Text Available The primary cells that participate in islet transplantation are the endocrine cells. However, in the islet microenvironment, the endocrine cells are closely associated with the neurovascular tissues consisting of the Schwann cells and pericytes, which form sheaths/barriers at the islet exterior and interior borders. The two cell types have shown their plasticity in islet injury, but their roles in transplantation remain unclear. In this research, we applied 3-dimensional neurovascular histology with cell tracing to reveal the participation of Schwann cells and pericytes in mouse islet transplantation. Longitudinal studies of the grafts under the kidney capsule identify that the donor Schwann cells and pericytes re-associate with the engrafted islets at the peri-graft and perivascular domains, respectively, indicating their adaptability in transplantation. Based on the morphological proximity and cellular reactivity, we propose that the new islet microenvironment should include the peri-graft Schwann cell sheath and perivascular pericytes as an integral part of the new tissue.

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

    Directory of Open Access Journals (Sweden)

    Naziri Qais

    2016-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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

  18. Fundamental Limits to Cellular Sensing

    Science.gov (United States)

    ten Wolde, Pieter Rein; Becker, Nils B.; Ouldridge, Thomas E.; Mugler, Andrew

    2016-03-01

    In recent years experiments have demonstrated that living cells can measure low chemical concentrations with high precision, and much progress has been made in understanding what sets the fundamental limit to the precision of chemical sensing. Chemical concentration measurements start with the binding of ligand molecules to receptor proteins, which is an inherently noisy process, especially at low concentrations. The signaling networks that transmit the information on the ligand concentration from the receptors into the cell have to filter this receptor input noise as much as possible. These networks, however, are also intrinsically stochastic in nature, which means that they will also add noise to the transmitted signal. In this review, we will first discuss how the diffusive transport and binding of ligand to the receptor sets the receptor correlation time, which is the timescale over which fluctuations in the state of the receptor, arising from the stochastic receptor-ligand binding, decay. We then describe how downstream signaling pathways integrate these receptor-state fluctuations, and how the number of receptors, the receptor correlation time, and the effective integration time set by the downstream network, together impose a fundamental limit on the precision of sensing. We then discuss how cells can remove the receptor input noise while simultaneously suppressing the intrinsic noise in the signaling network. We describe why this mechanism of time integration requires three classes (groups) of resources—receptors and their integration time, readout molecules, energy—and how each resource class sets a fundamental sensing limit. We also briefly discuss the scheme of maximum-likelihood estimation, the role of receptor cooperativity, and how cellular copy protocols differ from canonical copy protocols typically considered in the computational literature, explaining why cellular sensing systems can never reach the Landauer limit on the optimal trade

  19. Fluoropolymer-coated dacron versus PTFE grafts for femorofemoral crossover bypass: randomised trial

    DEFF Research Database (Denmark)

    Eiberg, J P; Røder, Ole Christian; Stahl-Madsen, Morten

    2006-01-01

    To investigate whether patency of a thin walled 8 mm fluoropassivated Dacron graft was similar to that of a standard 8mm PTFE graft for femorofemoral crossover bypass surgery.......To investigate whether patency of a thin walled 8 mm fluoropassivated Dacron graft was similar to that of a standard 8mm PTFE graft for femorofemoral crossover bypass surgery....

  20. Bone formation in cranial, mandibular, tibial and iliac bone grafts in rats

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Talsnes, O;

    1995-01-01

    Several studies have suggested that grafts from membranous derived bone (e.g., calvarial grafts) retain their volume better than those from endochondral derived bone (e.g., iliac bone grafts). Increased osteogenesis in grafts of the former type has been offered as the explanation. However, simple...